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The invention relates to the provision of mixtures of powders and to methods using them to produce highstrength, fine-grain sintered ceramic bodies, useful, for example, as cutting tools.
BACKGROUND OF THE INVENTION
Although many ceramic materials have been proposed as cutting tools for various applications, and some of these materials such as sintered or hot pressed silicon nitride are used quite successfully for some applications, aluminum oxide-titanium carbide is generally recognized as the best all around ceramic tool material. Commercial tools of this type are known to be produced by expensive and cumbersome hot pressing; see, by way of illustration, Ogawa et al, U.S. Pat. No. 3,580,708; Bergna et al, U.S. Pat. No. 3,542,529; and Ogawa et al, U.S. Pat. No. 4,063,908. In Brun, Lee and Szala, U.S. Pat. No. 4,515,746, a particulate mixture of powders of metal hydride, carbon and relatively inert ceramic powder, e.g., alumina are hot pressed to form useful composites comprising, for example, alumina-TiC when alumina, titanium hydride and carbon are hot pressed. Several recent disclosures, however, have shown that ceramic composites, e.g., alumina-TiC composites, can be sintered to a closed pore state, either by using specific oxides as sintering additives, e.g., Y 2 O 3 as in Kanemitsu et al, U.S. Pat. No. 4,356,272; Japanese Patent Publication 81,140,066 (Chem. Abs. 96:109112w) and Japanese Patent Publication No. 81,140,067 (Chem. Abs. 96:109111v); or by using titanium oxycarbide as in Japanese Patent Publication No. 79,103,407 (Chem. Abs. 92:63473b). Lee and Szala, U.S. Pat. Nos. 4,407,968 and 4,416,840 disclose sintering mixtures of aluminum oxide, carbon and elemental titanium or titanium hydride to composites having an Al 2 O 3 phase and a substoichiometric TiC phase. A very recent development is to use a significantly higher heating rate for the sintering process than is used in conventional practice; see Lee, Borom and Szala, U.S. Pat. No. 4,490,319.
If the heating rate of the sintering cycle is increased significantly over the current industrial practice, as disclosed in the above-mentioned U.S. Pat. No. 4,490,319, a dense, high quality ceramic article will be produced. Unfortunately, however, most commercial furnaces cannot produce high heating rates. Therefore, implementation of the new high-heating-rate process requires a sizable capital investment which decreases the economic incentives for adopting this new technology. On the other hand, addition of oxide additives in sufficient quantity to promote sintering of the ceramic powdered material to high density can alter the properties of the end products and diminish the usefulness of both the process and the product. Therefore, a method or methods which can produce materials without requiring major changes in facilities is still very much in need. The present invention solves such a need by providing new chemical compositions which can be sintered to a closed pore product with desirable properties using heating rates within the range of current industrial facilities. Moreover, if desired, the powdered ceramic mixtures provided by this invention can also be effectively densified using a rapid rate process, e g., that of the above-mentioned U.S. Pat. No. 4,490,319, to provide unexpected and desirable ultimate properties.
The following definitions are applicable to an understanding of this invention and/or the prior art:
SINTERING: development of strength and associated densification of a powder compact through the application of heat alone.
HOT PRESSING: the combined application of heat and of pressure applied through the action of a mechanical piston on the powder-filled cavity of a die. Under such conditions the pressure on the powder compact is non-uniformly applied due to die wall friction and the axial application of the piston force. Under proper conditions of temperature and pressure, densification of the compact can result.
HOT ISOSTATIC PRESSING (HIP): The simultaneous application of isostatic pressure and heat to a sample body whose porosity is to be reduced. Pressure is applied uniformly to the sample body by an inert gas. The sample body may be (a) a powder compact encapsulated in a gas impermeable, but deformable, envelope such as a tantalum foil can or a glass coating or (b) any solid substantially devoid of open porosity.
The sintered product of this invention is considered to be "substantially crystalline", because it is not atypical to encounter minor amounts of non-crystalline material (e.g. glasses) in the grain boundary phases.
This invention addresses a particularly troublesome problem encountered in the sintering of multiphase systems. Such systems frequently contain components, which will chemically interact at elevated temperatures and produce gases. If such chemical reaction proceeds fast enough to inhibit the desired densification or, if the nature of the reaction is such that it results in degradation of the system (i.e., undesirable solid, liquid or gaseous phases are produced), manufacture of the optimum product cannot be readily accomplished by sintering.
While not intending to be bound by any theory, it is believed that ceramic oxides, e.g., aluminum oxide, react with carbon or carbon-containing materials, e.g., titanium carbide, or the like, at temperatures exceeding about 1550° C., emitting gaseous materials which in turn hinder the consolidation of the mixture on further heating. Such problems seem to intensify if free carbon is introduced with the carbide or if the particle size of the powdered component in the mixture is reduced.
It has now been discovered that if an additional component is included, such problems will be minimized. Specifically, according to this invention there will be included in the ceramic powder an additive which will become an effective scavenger of the evolving gas phase from the reaction between alumina, for example, and carbon, or a source of carbon. Judiciously selected such additives will also provide enhanced properties in the sintered products.
Typical examples of the invention are the addition of small quantities of either zirconium hydride or hafnium hydride to a ceramic powder mixture, e.g., a mixture of alumina and titanium carbide, and the like. The hydrides stay relatively clean during the conventional powder processing stages, but decompose to highly reactive components at about 1000° C. This reactive metal forms oxides or carbides by reacting with the gaseous product evolving from the carbide-oxide or carbon-oxide reaction.
As a further advantage, small amounts of by-products, e.g., zirconium oxide or hafnium oxide, formed in the reaction, can also be retained in the high temperature phase to provide transformation toughening of the sintered product. In some cases, the resulting carbide from the process can dissolve into a carbide phase, for example, a titanium carbide phase, without detracting in any way from the desirable properties of the final product.
This invention is primarily described herein in respect to the Al 2 O 3 -TiC system, because this particular material system often presents the very problem in densification discussed herein above. However, the essential aspects of the sintering process disclosed herein are not dependent upon either the use of particular sintering additives, particular material proportions, or the nature of minor impurities. The process is expected to be broadly applicable to the sintering of powdered ceramic materials, that contain components which will chemically react at elevated temperatures to inhibit densification or degrade the system so that an undesirable sintered product results.
SUMMARY OF THE INVENTION
According to this invention, a mixture of powdered ceramic materials is consolidated under pressure to produce a cold pressed green compact of some preselected shape and volume, and the compact is heated to a maximum sintering temperature. The mixture contains non-inhibitory components, e.g., aluminum oxide, titanium carbide, and the like, and a source of inhibitory components, such as carbon or a carbon source, or an oxide or oxicarbide of a metal, such as titanium, magnesium, chromium, zirconium, hafnium, tungsten, or a mixture of any of the foregoing, the inhibitory components being capable of chemically interacting with the non-inhibitory components at elevated temperatures to generate gases which hinder densification or form phases undesirable for sintering. It is the essence of the invention to include in such mixtures an amount of a source of at least one component co-reactive with the inhibitory components at elevated temperatures to provide efficient densification and retention of properties in the sintered body.
In preferred aspects, the present invention contemplates the use of hot isostatic pressing after sintering; the use of ceramic mixtures comprising powdered aluminum oxide and powdered titanium carbide; and the use of additives comprising zirconium hydride, hafnium hydride or a mixture of such hydrides.
DETAILED DESCRIPTION OF THE INVENTION
The mixture of ceramic materials used in the present invention will vary widely in chemical type and proportions of ingredients used. In addition to the preferred combinations of aluminum oxide and titanium carbide, other components can be included or substituted, and the amounts varied. Merely by way of illustration, suitable starting powder mixtures, before addition of the additives of the invention can comprise:
aluminum oxide and titanium carbide, 50-50w/w, aluminum oxide and titanium carbide, 72-28w/w, aluminum oxide and zirconium oxide, 87.3-12.7w/w, aluminum oxide, titanium carbide and zirconium oxide, 63-30-7w/w,
aluminum oxide and titanium nitride, 70-30w/w, aluminum oxide and 500 ppm of magnesium oxide, commercial grade yttrium oxide powder, and many others,
ceramic oxides, like HfO 2 , BeO, Cr 2 O 3 , La 2 O 3 , ThO, UO 2 , ZrO 2 , BaZrO 3 , BeZr 2 O 7 , ThO 2 ·ZrO 2 , and mixtures and solid solutions thereof. Also ceramic carbides, such as the carbides of boron, hafnium, niobium, tantalum, vanadium, zirconium and mixtures and solid solutions thereof. Still other useful components in the ceramic powders are the borides of hafnium, niobium, tantalum, titanium, vanadium, zirconium, and mixtures and solid solutions thereof. More specifically, representatives of the borides are HfB 2 , NbB, NbB 2 , TaB, TaB 2 , TiB 2 , VB, VB 2 and ZrB 2 .
The proportions in the mixtures can vary within ranges well known to those skilled in this art. For example, the mixtures comprising alumina and titanium carbide most generally will be selected to provide products comprising 40 to 80% by weight of alumina and from about 20 to about 60% by weight of titanium carbide.
The amount of component effective to interact with the gas generating compound or gas used in the powdered mixture can vary rather widely, so long as at least enough is present to react with any inhibitory components present. Ordinarily this will range from about 0.5 to about 5 weight percent of the mixture, preferably from about 1 to about 2 weight percent. The components are introduced in conventional ways, e.g., by grinding or dry blending.
In addition to zirconium hydride and hafnium hydride, as additives there can be used the hydrides of niobium, tantalum, titanium, vanadium, mixtures thereof, and the like.
In carrying out the present process, a particulate homogeneous or at least a substantially homogeneous mixture or dispersion of ceramic powder and any sintering aid additive is formed. The components of the mixture or dispersion can be of commercial or technical grade. They can be admixed by a number of techniques such as, for example, ball milling, vibratory milling or jet milling, to produce a significantly or substantially uniform or homogeneous dispersion or mixture. The more uniform the dispersion, the more uniform is the microstructure, and therefore, the properties of the resulting sintered body.
Representative of these mixing techniques is ball milling, preferably with balls of material such as alpha-Al 2 O 3 which has low wear and which has no significant detrimental effect on the properties desired in the final product. If desired, such milling can also be used to break down any agglomerates and reduce all materials to comparable particle sizes. Milling may be carried out dry or with the charge suspended in a liquid medium inert to the ingredients. Typical liquids include ethyl alcohol and carbon tetrachloride. Milling time varies widely and depends largely on the amount and particle size reduction desired and type of milling equipment. In general, milling time ranges from about 1 hour to about 100 hours. Wet milled material can be dried by a number of conventional techniques to remove the liquid medium. Preferably, it is dried by spray drying.
In the present dispersion or mixture the average particle size ranges from about 0.1 micron to about 5 microns. An average particle size less than about 0.1 micron is not useful since it is generally difficult or impractical to compact such a powder to a density sufficient for handling purposes. On the other hand, an average particle size higher than about 5 microns will not produce the best ceramic body. Preferably the average particle size of the mixture ranges from about 0.3 micron to about 1 micron.
A number of techniques can be used to shape the powder mixture into a compact. For example, it can be extruded, injection molded, die-pressed, isostatically pressed or slip cast to produce the compact of desired shape. Any lubricants, binders or similar materials used in shaping the powder mixture should have no significant deteriorating effect on the resulting sintered body. Such materials are preferably of the type which evaporate on heating at relatively low temperatures, preferably below 500° C., leaving no significant residue. The compact should have a density at least sufficient for handling purposes, and preferably its density is as high as possible to promote densification during sintering.
The compact is placed within a furnace and provided with a partial vacuum wherein the residual vapor has no significantly deleterious effect thereon. Ordinarily, a carbon furnace is used, i.e., a furnace fabricated from elemental non-diamond carbon. This partial vacuum is provided throughout the present heating step producing the present sintered body. Preferably, upon completion of sintering, the sintered body is furnace cooled to room temperature in this partial vacuum. The partial vacuum should be at least sufficient to remove from the furnace chamber, i.e., the environment or atmosphere enveloping the compact, any excess gas generated during the heating step which would have a significantly deteriorating effect on the compact. On the other hand, the partial vacuum should not be so high as to vaporize the compact to any significant portion, i.e., higher than about 10% by volume, or the residual vapor in the environment or atmosphere enveloping the compact at sintering temperature is an inert gas such as nitrogen, helium or argon. Preferably, such gas is present during the entire heating period. A number of conventional techniques can be used to introduce and maintain the inert gas in the residual vapor. For example, the gas can be leaked in using a needle valve.
The present sintering temperature ranges from about 1650° C. to about 1950° C. Ordinarily, sintering temperatures outside this range will no produce the present sintered body. For best results the sintering temperature ranges from about 1850° C. to about 1920° C.
The particular sintering time period to produce a sintered body having a minimum Rockwell A hardness of 92 or 91 depends largely on the sintering temperature and is determinable empirically with increasing sintering temperature requiring less sintering time. Generally, however, to produce the present sintered body having a minimum Rockwell A hardness of about 92 at a sintering temperature of about 1800° C., a suitable sintering time period is about 2 hours, and to produce the sintered body with a minimum Rockwell A hardness of about 91, the sintering time period at 1800° C. would be somewhat less, i.e., about 1 hour.
Generally, the present sintered body having a minimum Rockwell A hardness of 91 has an outside surface portion which is impermeable to gas. Ordinarily, the outside surface portion of the sintered body with a minimum Rockwell A hardness of 92 is impermeable to gas. One way of determining if the outside surface portion of the sintered body is impermeable to gas can be carried out by suspending the sintered body and immersing it in water or other liquid and determining whether the thus-suspended-immersed body shows any observable weight gain. If no weight gain is observed, then the sintered body will have attained closed porosity in its entire outer surface. Alternatively, the closed porosity can be determined by careful metallographic examination of polished sections of the sintered body.
The Rockwell A hardness of the present sintered body having an outside surface portion which is impermeable to gas, can be increased by subjecting it to hot isostatic pressing. Such hot isostatic pressing can be carried out in a conventional manner. For example, the sintered body can be compressed in a pressurized gaseous atmosphere under a pressure of at least about 5000 psi, generally from about 5000 psi to about 15,000 psi, at a temperature ranging from about 1350° C. to about 1750° C. producing a sintered body having a Rockwell A hardness of about 93 or higher. The gaseous atmosphere should have no significant deleterious effect on the sintered body. Representative gases suitable for providing the pressurized gaseous atmosphere include argon, nitrogen and helium.
Ordinarily the volume fraction of pores in the present product is less than about 5% by volume and usually less than 3% by volume of the product. All, or substantially all, of the pores are closed or non-interconnecting, and generally, they are less than about 1 micron in diameter. The pores are well distributed in the product and have no significant deleterious effect thereon.
The present invention makes it possible to reproducibly and economically fabricate complex shaped ceramic articles directly. The sintered product of this invention can be produced in the form of a useful, simple, complex or hollow shaped article without machining. The dimensions of the sintered product would differ from those of the green compact by the extent of dimensional change occurring during shrinkage. The al 2 O 3 -TiC system as sintered in the practice of this invention has particular utility in the preparation of tool inserts for machining operations.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention is further illustrated by the following examples. In each example the powders were pre-pressed isostatically to about 50 kpsi. The compact plugs so produced were processed in the dilatometer-equipped furnace. The furnace was evacuated to 50 millimicrons vacuum, helium was introduced and was allowed to purge the furnace at one atmosphere pressure during the rest of the cycle. Natural furnace cooling was relied upon to reduce the temperature to room temperature. Where values are indicated, material density was determined by immersion density measurement. In all examples, the sintered bodies had essentially no open pores. Microstructural observations were made in most instances.
EXAMPLE 1
Seventy grams of -325 mesh titanium carbide powder was placed in a tungsten carbide/cobalt ball mill along with acetone as a vehicle. The powder was milled for 120 hrs. to reduce the particles to submicron size. One-hundred eighty grams of 0.3 micron alumina powder and 5 grams of -325 mesh zirconium hydride powder were added to the milled titanium carbide powder. The mixture was milled for 72 hours, air dried and sieved through a 50 mesh screen. For comparison purpose a control batch of powder containing no zirconium hydride was prepared following the same procedure as stated above.
Specimens of the powders were pressed to shape in a 3/4" square die at a pressure of approximately 1000 psi. The 3/8" thick specimens were further compacted by isostatic pressing at 52 kpsi (10 3 pounds per square inch) to a green density of 55% of theoretical.
The specimens were placed in a furnace and heated at a rate of 50° C./min. to 1950° C. in helium. Density of the fired specimens was determined by the immersion technique.
The sample according to this invention containing zirconium hydride achieved a density of 4.41 gm/cm 3 (98%) with no open porosity, while the sample without zirconium hydride, according to the prior art, only achieved a density of 3.71 (82%) with 15% open porosity. Both samples were then hot isostatically pressed at a temperature of 1525° C for 10 minutes at 15 kpsi gas pressure. The sample according to this invention, containing zirconium hydride, achieved essentially full density (4.50 gm/cm 3 ) with no porosity, while the sample without zirconium hydride, according to the prior art, experienced no change in density.
The hot isostatically pressed, composite made with zirconium hydride according to this invention, exhibits an extremely fine grained microstructure with essentially no residual porosity and a hardness of R a 94.5 (ASTM -18-74). X-Ray diffraction analysis indicates that the ZrH 2 additive was converted to tetragonal ZrO 2 .
EXAMPLE 2
The procedure of Example 1 was repeated, but using instead the rapid heating rate process disclosed in U.S. Pat. No. 4,490,319. The pressed powder body containing zirconium hydride was fired in helium at a heating rate of 50° C/min. up to 1500° C. followed by 400° C./min. to 1950° C. The rapid rate sintered sample after hot isostatic pressing had an extremely fine-grained highly desirable microstructure and a density of 4.48 which is 99% of theoretical.
EXAMPLE 3
Specimens of the hot isostatically pressed material made with zirconium hydride in accordance with Example 2 were ground into 1/2×1/2×3/16" cutting tools. These cutting tools were tested in cutting a nickel base superalloy at 600 surface feet per minute, at a 0.080 inch depth of cut and a 0.008 inch feed rate. The tool performance was highly acceptable and comparable to that of the best commercially available hot pressed Al 2 O 3 -TiC tools.
EXAMPLE 4
If the procedure of Example 1 is repeated, substituting hafnium hydride for the zirconium hydride, substantially the same results will be obtained.
The above-mentioned patents and publications are incorporated herein by reference.
The principles, preferred embodiments and mode of operation of the present invention have been described in the foregoing specification. The invention which is intended to be protected herein, however, is not to be construed as limited to the particular forms disclosed, since these are to be regarded as illustrative rather than restrictive. Variations and changes may be made by those skilled in the art without departing from the invention. | High-strength, fine-grain, multi-phase substantially crystalline sintered ceramic bodies are produced by a process comprising the steps of cold pressing, followed by sintering at a high temperature, of a mixture of different powdered ceramic materials containing non-inhibitory components and a source of inhibitory components that can chemically interact at elevated temperatures generate gases which hinder densification or form phases undesirable for sintering provided that there is also included in the mixture an amount of a source of a component co-reactive with the gases produced by the inhibitory components at elevated temperature to achieve efficient densification and retention of properties in the sintered body. | 23,510 |
This is a divisional of application Ser. No. 09/713,316 filed Nov. 16, 2000, which is a continuation-in-part of U.S. patent application Ser. No. 09/055,968 entitled HOUSEPLANT MAINTENANCE DEVICE AND METHOD filed Apr. 7, 1998, now U.S. Pat. No. 6,176,038 and is related to Provisional Utility Patent Application Serial No. 60/053,578, filed Jul. 17, 1997, entitled HOUSEPLANT MAINTENANCE DEVICE, both of which are incorporated by reference in each of their entireties herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to apparatus for maintaining and using houseplants grown in containers, specifically to increasing the utility of standard clay pot containers and to maintaining and regulating the moisture level of the potting mix within a clay pot planting as well as methods of conducting nutrient cations into the growing medium of a containerized plant from nutrient rocks and powders of low aqueous solubility.
2. Brief Description of the Related Art
Clay pots have been a perennial favorite container for potted plants around the home. The porous nature of these containers allows aeration for healthy root development of growing plants. In use for centuries, some drawbacks of clay pots, such as minimal drainage, have been overcome by age-old practices of layering broken clay pieces in the pot's bottom, followed by long fiber sphagnum moss filters beneath the soil layer. Moisture maintenance is a problem however, which has not been satisfactory solved. Mature plants in appropriately sized clay pots dry quickly, due to the porosity, and must be watered more often than is required for plastic containers. Conventional practices for growing plants in clay pots include repotting the plants in successively larger clay pots at various growth stages in an effort to avoid excessive wet soil. Since this moisture cannot be used by an underdeveloped root system, the excessive moisture can cause root rot.
Moisture applications with wick devices, which use capillary action to moisten the soil, have been around for at least 125 years, yet the use with clay pots is not widespread. Many traditional wicks exhibit such problems as leaving soil in the bottom of the pot very wet, while the soil in the upper regions is very dry. The soak spots in the lower portions at times are so severe as to promote microbial growth and “root rot.” With the upper portions of the soil being left so dry, roots can not be supported except through minimal depths of the soil.
Traditional wicks have been too thick for use with clay pots, and the interactive nature of wicking in response to the moisture level of the soil maybe lost if the wick is not in direct contact with dry soil. Further, the moisture addition rate is sometimes based on seepage through perforations in a cover of the wick, which may be difficult to control. Additionally, some traditional wicking materials are too large or complex to be easily incorporated into household use.
Introduction of moisture in the upper layers of soil, as happens in nature, is still the most common water addition technique to plants potted in clay. It allows for moisture distribution throughout the soil by allying two of the three forces, which move moisture in the soil: gravitational force and the capillary action of the soil itself. The third force is the energy used by the plant roots to draw in water. Nature's method of saturating the soil during a rain and letting the soil dry between rains is the mode of maintenance of most of the world's plants. Thus, we can assume that healthy plants readily tolerate, and in fact thrive, with at least some variance of moisture level within the soil. Water reservoirs associated with wicking elements have been large or cumbersome and have discouraged homeowners from using a reservoir wicking system.
Soil or plant growing medium is composed of colloids which carry a net negative charge. This is an important property because it allows the soil to hold positively charged nutrient ions or cations while negatively charged nutrients are left to leach through the soil. Calcium, magnesium, potassium, and ammonium are examples of important nutrients in cationic forms which influence the pH of the soil in a basic direction, while aluminum and hydrogen cations make the soil more acidic.
All plants need 16 to 19 elements for healthy growth, some in trace quantities, many of them are cations. Cations are also the form these nutrients enter the plant roots. Generally these cationic nutrients are added to the soil in one of two ways: as water soluble salts or as slow release materials, that is, materials that dissolve slowly in water. This latter group includes relatively aqueous insoluble rock powders and greensand. Addition of water soluble salts to containerized plantings has always been problematic because it is difficult to get a good nutrient mix at a level which both satisfies the plant's needs and does not burn the plant. Burn is caused by the salt ionized in the soil's moisture actually drawing water from the plant roots in an effort to equalize the ion levels.
Rock powders and greensand occur in nature with often excellent nutrient mixes. They are normally added directly to the soil. These relatively aqueous insoluble materials slowly dissolve and release their nutrients at rates which will not burn the plant. Often, however, it takes several years for the plant to show the benefits of the nutrients.
SUMMARY OF THE INVENTION
According to one embodiment of the present invention, a method of providing interactive delivery of liquid nutrients to the growing medium of a houseplant with the facility to set the capacity of the liquid nutrient delivery rate, comprising the steps of providing at least one wick element comprised of wicking material and casing around a central portion which holds said wicking material movably in place, wherein said casing is substantially impervious to moisture, with said wicking material exposed at either end of said casing; providing a reservoir of liquid nutrients with said reservoir having both a liquid surface level and an average liquid surface level over a fill and distribution cycle; providing a holder which secures said wick elements in position with respect to said liquid surface level with members which hold said outer casing, and allows movement of said wick elements to new secure positions with respect to the liquid surface level; positioning said wick elements in said holder; placing the wick elements, within the holder, along with a plant in growing medium inside a planting container, such that a portion of the wick elements, including both said casing and said wicking material protrude from the bottom of said planting container; and positioning said planting container with said protruding casing and wicking material above said reservoir of liquid nutrients such that the wick elements are immersed into the liquid to a position such that the bottom of said wick element casing is either above or below said liquid surface level; whereby the average liquid nutrient delivery rate capacity is set by the position of the wick elements within the holder, with respect to a given reservoir and average liquid surface level over a fill and delivery cycle, to the optimal range of liquid nutrient delivery rates for a specific plant, at its current growth stage, in its current environment, within the maintenance schedule of its current caregiver.
According to another embodiment of the present invention, a regulating wick device, usable with a liquid nutrient reservoir having a liquid surface level, said regulating wick device both for conducting nutrients, selected from a group consisting of water, plant fertilizers, antimicrobial agents, plant hormones, and mixtures thereof, and for setting and adjusting wicking rate to an elevated growing medium of a plant comprising at least one wick element comprised of a length of wicking material and a casing around a central portion thereof, said casing being substantially impervious to moisture, wherein said wicking material is exposed at either end of said casing; and a holder capable of positioning securely at least one of said wick elements so that said wick element is both immersed within said reservoir and extends upward into said elevated growing medium, thereby fixing the position of said wick element with respect to said liquid surface level with members which both hold said casing and allow movement of said wick element casing within said holder to new secure positions with respect to the liquid nutrient level.
According to yet another embodiment of the present invention, a water storage device usable with a wick device inserted into and extending from the bottom surface of a planting pot with means for orderly contiguous alignment of a plurality of said water storage devices and a means for elevation to prevent moisture damage to a setting surface such as fine furniture comprising a base having a housing and comprising an interior which forms a reservoir in said base for sealingly holding liquid nutrients; a top comprising an opening therein which communicates said reservoir with the exterior of said base; a compliant member or gasket for supporting the planting pot therein having an exterior shape similar to the said base top opening; an interior shelf for supporting the bottom of said compliant member; an alignment mechanism on the bottom of said water storage device for aligning a plurality of said water storage devices contiguously on a horizontal plane; a plurality of elevated support members on the bottom of said device of substantially equal length to support perpendicularly the bottom of said water storage device to space apart the moisture containing base from the setting surface; a drainage portal in the side of said base to allow said water storage device to be used outdoors during seasons of adequate rainfall to maintain only a predetermined water level and with an optional closure for indoor use which is substantially clear and functions as a fill level sight; and a liquid nutrient addition portal substantially above the water level for adding liquid nutrients directly into the reservoir.
According to still another embodiment of the present invention, a method of conducting nutrient cations sourced in relatively aqueous insoluble solids into the soil of a containerized houseplant comprising the steps of providing a wick element comprising wicking material which both conducts moisture and is chemically bonded as a cation exchanger, which provides negatively charged sites on said wicking material, said wick element further comprising a casing which surrounds the wicking material and exposes the wicking material at either end of said casing; placing the wick element in the soil along with a plant in a planting container such that both wicking material and casing protrude from the bottom of said planting container; providing an aqueous reservoir to which the relatively water insoluble nutrients have been added and to which water has been added creating a liquid surface level; and positioning said planting container with said protruding wick elements above said aqueous reservoir with said nutrients such that the wick elements are immersed below said liquid surface level in the reservoir; whereby dissociation of the nutrients in the reservoir produce cations which are attracted to the negative sites on the exposed wicking material and the wicking action of the moisture driving up the wick exchanges the cations upward into the soil encouraging more dissociation of the nutrient solid.
According to yet another embodiment of the present invention, a wick element for conducting nutrient cations from an aqueous reservoir to an elevated growing medium of a containerized houseplant comprising wicking material which both conducts moisture and is chemically bonded as a cation exchanger, adding sites with a negative charge in the wicking material, and a casing surrounding said wicking material with said wicking material exposed on both ends of said casement.
Still other objects, features, and attendant advantages of the present invention will become apparent to those skilled in the art from a reading of the following detailed description of embodiments constructed in accordance therewith, when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention of the present application will now be described in more detail with reference to preferred embodiments of the apparatus and method, given only by way of example, and with reference to the accompanying drawings, in which:
FIG. 1 illustrates an exploded perspective view of the water storage device assembly;
FIG. 2 illustrates an exploded and partially assembled view of the regulating wick device assembly according to the present invention;
FIG. 3 illustrates a cross-sectional composite view of the water storage device and regulating wick device in use according to the present invention;
FIG. 4 illustrates a cross sectional view of a regulating wick device in a drier soil configuration;
FIG. 5 illustrates a cross sectional view of the regulating wick devices of FIG. 4, in a wetter soil configuration;
FIG. 6 is a schematic view of the lower portions of two wick elements within a water storage device;
FIG. 7 is a view of part of the hanging mechanism, the interior pot support for hanging the modular potted plant which fits inside the water storage device;
FIG. 8 is a composite cross sectional view of the hanging mechanism including both the internal and external mounting assemblies and their relationship to the water storage device for hanging the modular potted plant according to the present invention;
FIG. 9 is an elevated perspective of the water storage device with the hanging mechanism attached showing particularly the external portions of the hanging mechanism;
FIG. 10 is an exploded view of the modular alignment mechanism of the present invention;
FIG. 11 is an exploded view of an alternate form of the modular alignment mechanism of the present invention;
FIG. 12 illustrates one of the flexible exemplary uses of the modular plantings using the water storage device;
FIG. 13 illustrates another of the flexible exemplary uses of the modular plantings using the water storage device;
FIG. 14 illustrates yet another of the flexible exemplary uses of the modular plantings using the water storage device;
FIG. 15 illustrates an application of the nutrient addition method of the present invention in physical terms with planting pot, reservoir, wick device and insoluble nutrients;
FIG. 16 illustrates an application of the nutrient addition method in chemical terms with nutrient dissociation, collection, ion exchange and release of cations to the soil; and
FIG. 17 illustrates a cross-sectional view of a portion of a regulating wick.
Reference Numerals In Drawings
02
growing plant
03
plant roots
04
growing medium (soil)
05
insoluble nutrients
06
planting pot (clay pot)
08
liquid nutrient level (water level)
09
release solution
10
Regulating Wick Device
12
Wick Element(s)
14
wicking material (fiber)
15
wedge-shaped filament
16
upper knot
17
core
18
bead
20
casing
21
membrane covering
22
Wick Element Holder (Wick Element Clamp)
24
upper member of wick element clamp
26
pressure fitting orifices
28
perforated or porous upper surface
30
ridged undersurface
32
threaded neck
34
pot stand (clamp nut)
36
planar upper portion on which pot sits
38
female opening to fit threaded neck of wick clamp
40
pot stand legs
42
The Water Storage Device (reservoir)
44
Base housing with top opening (reservoir with top opening)
46
raised lip around top opening
48
water addition orifice
50
snap lid for water addition orifice
52
opening(s) for connection device (grommet openings)
54
drainage port
55
drainage port gasket
56
optional closure for drainage port/water level sightings
58
retaining ridges for ballooned implants
60
drainage trough(s) (level sitting surface)
61
sloped bottom surface
62
reservoir well
64
compliant member for pot support (gasket)
66
interior shelf for gasket support (gasket retaining ring)
68
holes for connection device (grommet holes)
70
connection device (grommet connections)
72
ballooned leg implants for hollow legs
74
elevated support members (reservoir rising feet)
76
The Hanging Mechanism (optional use)
78
Interior Pot Support
80
pot seat
82
connecting leg(s)
84
leg expansions or grommet stop pin(s)
86
hanging fixtures (loop connector(s))
88
Exterior Hanger
90
C-hook(s)
92
loop retaining seat(s)
94
wire hanging leg(s)
96
hanging hook
98
Modular Alignment Mechanism (optional use)
100
Alignment Plank
102
Holes accommodating reservoir well
104
Nut securing reservoir well
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawing Figures, like reference numerals designate identical or corresponding elements throughout the several Figures.
The present invention provides a simple method of controlling moisture levels, moisture distribution throughout soil layers and adjustment of moisture delivery rate to the growing medium within a clay pot. The present invention is intended to enhance the utility of modular self contained plantings in clay pots by adding hanging utility, alignment utility, i.e., for window boxes, and elevation for use on fine furniture. Though these devices were developed for ordinary clay pots, they may also be used with other containers of appropriate size and shape. These devices may be especially appropriate for other porous containers like the currently popular coco-fiber or peat products. Likewise, though the present wick invention was primarily designed for the delivery of moisture to the growing medium of a houseplant, other liquid nutrients may also be conducted depending on the wicking material and nutrient.
The present wick invention is based on observations of working with covered wick devices and overcomes deficiencies of the prior art. The wick is based on moisture introduction in the upper soil just below the soil surface. Though moisture added to the bottom soil of a potted container may move upward to plant roots by the capillary action of the soil, moisture distribution is more even, and soak spots are overcome with introduction of moisture to the upper soil. Observations of upper soil moisture introduction made by moving moisture meters to various depths of soil show the maximum moisture levels still occur in the bottom soil, though the soil above is not saturated. Thus, controlling moisture in the upper soil controls the minimum level of soil saturation, with a gradual and increasing distribution to the lower soil. This mode of moisture distribution allows a cache of moisture storage in the upper soil and allows more root development through the available depth of soil. In theory, many factors influence the rate of moisture wicking by covered wicks, including: (1) height the wick extends from the water reservoir, (2) area of exposure of the wicking element outside its casement within the soil, and (3) number of wicks placed in the soil.
Observation of covered wicks and adjusting various factors, finds that the greatest determinant of wicking rate is the height of the bottom wick casing relative to the water surface in the reservoir, a somewhat surprising result. Therefore, one aspect of the wick of the present invention is based on wicking rate regulation by sliding the wick casement higher or lower relative to the water level. A special flow-through clamp, which maximizes drainage and facilitates the sliding action of the wick casement, is presented as part of the regulating wick device of this invention. Thus the regulating wick device of this invention is easily used with a clay pot, provides the optimum moisture distribution throughout the soil depth, and provides slow moisture delivery, up to 4 weeks or more under indoor conditions. The regulating wick device of this invention adds to the art a simple way to achieve moisture modulation according to the needs of the specific plant. Modulation ability is added to easily increase or decrease the rate of moisture delivery, even after the plant is potted, at various periods throughout its growth. The regulating wick device of the present invention is amenable to low cost manufacture and sale.
The present regulating wick device includes a number of wick elements, typically 3 for 21 cm (8″) pots, and a wick element clamp. The wick elements are preferably formed of rolled microfiber wicking material, and casing. Generally, an upper knot with a bead has been added to find wicks for adjustment in the upper soil. The wick element clamp is formed of an upper member positioned in the bottom interior of the pot, a hollow neck threaded on the outside, and a pot stand. The upper member of the wick element clamp features a flat square or other ergonomic shape for twisting with partial holes which pressure fit the wick elements in vertical position. The texture of the upper member is perforated or porous and the bottom surface of the upper member is ribbed or gridded to allow moisture drainage. The hollow threaded neck is connected to the upper member of the wick element clamp and fits through the bottom hole of the clay pot, holding the wick elements in its interior. The pot stand has a planar upper surface which also may be perforated featuring a female opening which fits the threaded neck of the wick element clamp. Finally the pot stand portion of the wick element clamp features legs which hold the pot approximately an inch and a half or so off the bottom of the floor of the water reservoir.
The objectives of the present water storage invention usable with the regulating wick device are similar to those presented in the aforementioned '968 application. The present water storage device works with the regulating wick device and clay pots, serves as water storage, and transforms the clay pot into a plant growing container of greater utility with arrangement for hanging, alignment of modular pots, and elevation for setting on fine furniture. The device fits variances within nominal standards (i.e. all 21 cm or 8″ pots). The device is designed for low cost manufacture and sale. Modifications to the water storage device presented in this application allow the device to be stronger and easier to manufacture, while retaining the full functionality of the original design.
Several aspects of the water storage invention may be summarized as follows. The complete device includes the water reservoir, and optionally, the hanging mechanism and the modular alignment mechanism. The water reservoir includes a cubic-like base with a top opening, a compliant beveled gasket, the metal retaining ring for a beveled gasket, grommets which connect the metal retaining ring to the top of the cubic reservoir, ballooned leg implants for the reservoir legs, and elevating feet for the reservoir. The cubic-shaped base features a raised lip around the top opening, a water addition orifice with closure, openings for the grommet connections, drainage port with optional closure, interior retaining ridges for the ballooned leg implants, and a reservoir well in the bottom of the device. The hanging mechanism includes an interior pot support and an exterior hanger. These pieces are attached when the unit is to be hung. The interior pot support features a square wire pot seat, which accepts the pot stand attached to the planting pot as described above, wire connecting leg(s), grommet stop pin(s) or expansions, and loop connectors. The exterior hanger features a C-hook with loop retaining seat(s), wire hanging leg(s), and a hanging hook. When modular units are to be aligned to affect window box arrangements, an alignment plank is used which features precision positioned holes accommodating the reservoir well.
The method of nutrient addition from relatively aqueous insoluble rocks or powders involves, instead of adding the insoluble rocks and powders into the soil, adding them to an aqueous reservoir below the soil. In this way more ionic dissociation is encouraged simply because there is more water surrounding the nutrient solids in which to dissociate into ions. A wick is provided having as wicking material a moisture conducting substance chemically treated as a cation exchanger, meaning the wicking material carries sites which have a negative charge. Nutrient cations are drawn to the wick and are collected and concentrated on the wick. The constant wicking action upward drives the exchange of cations upward. Thus the cations are taken out of the reservoir solution. By Le Chatelier's Principle this encourages more dissociation of the nutrient solids into ions for cation collection.
This phase of the method is called the collection step. It takes place over a relatively long period of time in the reservoir solution of relatively low ionic strength. Actually during this step some nutrient cations are driven into the soil with the constant wicking of moisture upward. Many nutrient cations remain on the wick however. After the long period of collection, a release phase is commenced in which the bottom of the wick is immersed into a solution of relatively high ionic strength for a short period of time. Numerous cations in the release solution exchange the collected cations on the wick and are driven upward and into the negatively charged soil for distribution by the cation exchange capacity of the soil to the plant roots. The accompanying drawings and specification detail further aspects of the method.
A preferred embodiment is illustrated in FIGS. 1-3 describing the low maintenance moisture delivery to a plant potted in clay. FIG. 1 illustrates an exploded view of the water storage device 42 . The assembly preferably includes a water reservoir 44 , ballooned leg implants 72 , a gasket retaining ring 66 which is the interior shelf for gasket support, a compliant gasket ring for pot support 64 , and elevated support members or rising feet for the reservoir 74 . The water reservoir preferably is a rotocasted piece and features a raised lip 46 around the top opening, and water addition orifice 48 with snap lid 50 , openings toward the top corners 52 for grommets 70 connections. The water reservoir 44 also preferably features a drainage port 54 to permit water above a predetermined level to flow out of the reservoir, the port including a gasket 55 and a clear optional closure for water level sightings 56 . The bottom of the reservoir 44 preferably features drainage troughs 60 and a sloped bottom surface 61 inclined toward the center. The drainage troughs 60 provide a level sitting surface and add strength to the reservoir bottom. FIG. 3 shows two other preferred features of the reservoir 44 , the retaining ridges 58 for the ballooned leg implants 72 , and the reservoir's bottom well 62 . Elevated support members 74 are preferably added to each of the four corners of the reservoir 44 . The ballooned leg implants 72 , which may be blow molded, are preferably snap placed in the hollow legs of the reservoir and held by the retaining ridges 58 . The gasket retaining ring 66 , preferably a sheet metal piece thick enough to add strength to the top of the reservoir, is preferably placed through the reservoir's top opening and acts as a mounting ring in some embodiments of the present invention. The ring may be one piece or several pieces connected together. It may have support tabs which fit the top of the reservoir. The retaining ring 66 preferably has openings 68 for grommets 70 , which connect the retaining ring to the top of the reservoir. The gasket ring for pot support 64 is preferably made of foamed rubber or soft plastic material. The compliant gasket ring 64 is preferably placed between the retaining ring 66 and the raised lip 46 of the water reservoir 44 . The gasket ring 64 may be scalloped for additional aeration around the inside ring, which preferably holds the clay pot. The inside of the gasket ring 64 is preferably beveled to accommodate both the shape and variances within the nominal clay pot standard sizes.
The water storage device 42 preferably sits below the clay pot 06 , which is held in the beveled gasket ring 64 as shown in FIG. 3 . The device may be used both indoors and outdoors. When in use outdoors, especially during periods of adequate rainfall, it is advisable to remove the drainage cover so that rain in excess of the designed recommended amount flows through the device without drowning the plant. Indoors or during drought periods the cover may be placed on the drain port for longer moisture delivery and for sighting the recommended water fill level 08 . The water fill level 08 is shown in FIGS. 4, 5 , 15 and 16 .
When potting a plant using an embodiment of the present invention one step is to assemble the regulating wick device 10 shown in FIG. 2 . Depending on the soil moisture preferences of the plant to be potted, preferably 1-4 wick elements 12 are pressed into the upper member 24 of the wick element clamp 22 through the partial openings 26 , which preferably pressure fit the wick elements 12 and hold them in vertical position. The higher the vertical position the wick element 12 is held, the slower the moisture delivery through the wick element.
The wick elements 12 include wicking material 14 , preferably formed of rolled microfiber, preferably a non-woven, star structure type as shown in FIG. 17 . The microfiber preferably has wedge-shaped polyester filaments 15 and a core 17 of nylon where the water-attracting polymers are woven into masses of tiny hooks and loops. An example of this type of microfiber is currently sold for use as cleaning clothes and is available from Blom Enterprises, 8425 West 3 rd Street, Suite 310, Los Angeles, Calif. 90048 (www.ecostarmicrofiber.com) or other sources.
A wick element 12 further includes a casing 20 . The casing 20 is preferably stainless or plastic tubing. The casing 20 forms a moisture impervious barrier that restricts the release of the moisture traveling upward through the wick to the upper end of the casing 20 at the point the wicking material 14 is exposed in the upper soil generally above the plant roots 03 . A knot 16 with a brightly colored bead 18 is preferably added at the upper end of the wicking material 14 at the top of each wick element 12 . These features allow the wick elements to be easily found in the upper soil for tactile monitoring and adjustment.
The wick elements 12 may be bent for more moisture introduction toward the outside of the pots shown in FIG. 3 or the wick elements may be straight as shown in FIG. 2 . The straight wick elements with straight casings are preferable for indoor/outdoor rotational use because the moisture delivery rate is more easily adjusted after potting the plant. For example, if it is desired to move a potted plant from indoors to outdoors where sunlight, heat, and moisture evaporation are expected to be higher, the interactive wicking will self adjust to some extent in response to the dryer conditions of the potted soil. The new conditions however may be such that the wicking capacity is at maximum and should be increased. Simply sliding the smooth wick casing downward does this. With the straight wick casings, no new volume of soil is displaced making the adjustment operation easier. Adjustments of this kind may be made in pots planted with seedlings. As the small plants grow requiring more water, the wicks can be adjusted downward rather than repotting the plant from smaller to larger pots.
Drainage in container gardening of any kind is very important. The bottom holes of clay pots are regarded as minimal drainage in most situations. To use the regulating wick device the age old practices of increasing drainage by layering broken clay, followed by long-fiber sphagnum moss, which acts as a soil filter, are encouraged. In a preferred embodiment of the invention, the regulating wick is designed to not impede drainage. The upper member of the wick element clamp 24 , which sits inside the clay pot, preferably features a perforated or porous upper surface 28 and a ridged undersurface 30 to affect a flow-through member.
The upper member of the wick element clamp 24 is preferably connected to the threaded neck 32 , which is hollow on the inside and acts as a passage for the wick elements 12 through the bottom hole of the clay pot 06 . The outside of the threaded neck 32 preferably contains screw threads, which form the male member for the pot stand 34 with the female opening 38 . The upper member of the wick element clamp 24 is preferably screwed into the pot stand 34 on the threaded neck 32 of the wick element clamp incorporating the bottom of the clay pot 06 . Other means of attachment will be readily apparent. The upper portion 36 of the pot stand 34 may be perforated for enhanced drainage. The clay pot 06 with protruding wick elements 12 may now stand upright on a horizontal surface sitting on the planar upper portion 36 of the pot stand 34 with the wick elements held in place through the bottom of the pot. The legs 40 of the pot stand 34 preferably hold the pot up off the surface. The upright pot may now be planted as usual with broken clay pieces, sphagnum moss, soil 04 , and plant 02 , then watered to start the system. The upper ends of the wick elements 12 are preferably spread evenly across the top of the soil, then pressed into the soil. Finally a mulch layer of plastic, moss or both preferably covers the upper wick elements. The potted plant with wick elements is set into the water storage device 42 as shown in FIG. 3 . Water is poured through the water addition orifice 48 to a level 08 viewed through the drainage port closure/sighting port 56 . Outside during periods of sufficient rainfall, closure 56 is preferably left off the drainage port 54 and water is preferably added until it is observed flowing out of the drainage port 54 .
Preferably, embodiments of the water storage device 42 are aesthetically sized for modular window box arrangements further discussed below. The water storage capacity beneath a 21 cm (8 inch) clay pot is approximately 1.3 liters (1.4 quarts) per 2.5 cm (inch). The legs of the pot stand are preferably sized slightly higher. Preferably, the drainage troughs 60 and sloped bottom surface 61 direct the water stored into the reservoir's bottom well 62 , making all stored water available for wicking. The vertical positioning of the wick elements 12 would determine the flow rate capacity sufficient to sustain the plant as long as possible. Two to four weeks are commonly observed with indoor plants. The flow rate capacity of moisture delivery declines slowly as the water level drops during the course of delivery and would increase immediately after filling, raising the water level. The actual rate of flow depends not only on flow capacity but also on the interactive wicking in the top of the soil. If environmental conditions or rate of plant growth induced greater moisture demand, the relatively drier soil 04 surrounding the exposed wicking fiber 14 would induce a faster rate of wicking up to the wicking capacity set by the wick element's vertical position. Thus water usage may not be the same water fill to water fill, but the wicking delivery has been optimized by the plant itself. It doesn't matter if the wicking capacity ebbs and flows with the height of the water level as happens in nature for example with the water table between rainfalls. The point is to provide adequate available moisture delivery for a sufficiently long enough time, so that manual filling and adjustments are necessary only at infrequent periods. Adjustments are made by observing the plant for evidence of stress and noting the amount of water required to bring the water level to the fill level. If either observation indicates the moisture delivery rate capacity is not sufficient, lowering the position of the wick casing and adding extra water to obtain the same adjustment period brings the plant back to optimum maintenance. Observations indicating that the plant is getting too much water include yellowing of leaves, wet soil 04 , yet sufficient water levels. Adjustment of the wicks upward decreases the moisture flow capacity and slows the rate of moisture delivery. These are quick, easy, relatively infrequent adjustments producing long-lived healthy plants.
A preferred embodiment of the invention uses smooth sliding wick elements within a wick element clamp as the regulating wick device 10 . Wicks positioned in water as they would be in a planting may take approximately 24 hours to fully hydrate. By lowering the wicks deeper into the water, hydration can be achieved many times faster. Once hydration is achieved, it can be maintained by returning the wick to its original position. In other words, there is not a difference in the hydration outcome based on the depth of the wick in water, only the rate at which it is achieved. There is also a dramatic difference in the rate of full hydration depending on whether the lower end of the wick casing 20 is below the water level or above it. Hydration rate is dramatically faster if the bottom of the wick casing 20 is below the water level 08 . The idea of wicking rate capacity helps solve a problem of maintaining plants which like a relatively dry pot. “Planting high”, which means positioning the wick elements relatively high in the wick element clamp with the bottom of the wick casing 20 above the water level, produces even but definitely drier moisture levels, preferred by these plants. Using the concept of wicking rate capacity as a regulating technique is one if the advantageous features of the present invention.
FIG. 4 contains growing medium 4 which is relatively drier than that of FIG. 5, which contains growing medium 4 which is relatively wetter. Each pot could presumably contain plants preferring maintenance of the conditions illustrated. Focusing on the wick casing bottom of each Figure for comparison, h is defined as the difference between the height of the water level 08 and the height of the bottom of the wick casing 20 . In FIG. 4 as illustrated the wick casing 20 sits above the current water level 08 . The h in this case is negative by approximately, 6 mm. In FIG. 5 as illustrated the bottom of the wick casing 20 is immersed below the surface of the water 08 . The h is positive by approximately 6 mm. All other factors such as number of wicks, wicking fiber 14 , surface area of exposed wick in the potting mix 04 , length of casing 20 , water level delta between low point and fill, are the same. There is a difference of about 12 mm in the height between the water surface and the height of the top of the wick casing in FIG. 4 which is greater than FIG. 5 . This difference of 12 mm, however, does not account for the dramatic difference in the wicking rates of the two pots.
One may assume that in FIG. 5 there is a “straw effect” of an open tube in water, a phenomenon commonly observed as children drinking sodas, called capillarity by physicist. This is the rise of water in the tube due to the surface tension between the water and the tube itself. Moreover in a column packed with fiber, this effect will be more pronounced. One may also assume that wicking within the tube is much more efficient than wicking outside it. In FIG. 4 as moisture is drawn from the water surface it is free to evaporate or move upward along the capillary fiber. Some moisture is lost before it reaches the mouth of the casing. Once inside the casing 20 moisture merely refluxes within the tube on or off the wicking fiber but capillary action continually driving the moisture upward. Thus the amount of moisture carried into the bottom of the casing is integral to the capacity to move moisture upward. Both capillarity and wicking efficiency are connected to the value of h. As h increases both capillarity and efficiency increases; the wicking capacity dramatically increases.
FIG. 6 illustrates how the maintenance habits of individual plant caregivers can be compensated by adjustment of the vertical position of the wick element. FIG. 6 shows the lower portions of two wick elements 12 showing both casings 20 and wicking fiber 14 . For purposes of this discussion assume the two wick elements are protruding from the bottom of a potted plant into a water storage device with well 62 . The water fill level is the same for both storage devices. Further assume a fastidious plant caregiver A who frequently checks the water level inside the water storage device and refills the water at point h ra , refill level height for caregiver A. In this case, over the course of the fill/distribution cycle, the water level varies equally above and below the bottom of the wick casing, h cb , height of the wick casing bottom. We can define the important quantity H based on the average height of the water level over the fill/distribution cycle. H equals the difference in the average height of the water level over the fill cycle minus the height of the bottom casing. H=h avg a −h cb . The quantity H would be zero in the case of caregiver A. Assume a second caregiver B who we shall describe as less than fastidious in the maintenance of the same plant, with the same reservoir and water fill level h f ; h fa =h fb . Caregiver B checks the water level much less frequently and refills the reservoir only when the water level reaches a much lower level, h rb , refill level height for caregiver B. In this case the water level varies unequally above and below the bottom of the wick casing, h cb . The average water level over the fill/distribution cycle is below the bottom of the wick casing and the important quantity H is negative by a height interval x. H=h avg b −h cb =−x.
Caregiver B could adjust the height of the bottom of the wick casing by simply sliding the wick element downward by an interval x. After the adjustment the important quantity H would be zero for caregiver B. H=h avg b −h cb =0. Thus after the adjustment the average wicking capacity over the course of the fill/distribution cycle would be the same for both caregivers A and B. It is true that in the case of caregiver B the amplitude of the wet cycle would be relatively wetter and the dry cycle relatively drier. However as previously mentioned, nature teaches the ultimate wet and dry cycles in the application of moisture to the roots of most of the world's plants.
Since the available water depths are the same in all water storage devices sized for a nominal standard, and fill frequencies are to be standardized for the caregiver's easy maintenance schedule, finding a good vertical position of the wicking elements 12 is all that is necessary for optimal moisture application. There is an optimum vertical position suitable to the needs of the plant in its current environment and growth stage. For most plants positioning the wick elements such that the casing is slightly below the water surface at fill level produces slowly developing moist and dry cycles between fillings as the water level drops and h decreases. These cycles are much gentler and more regular than is usually possible in nature.
FIG. 8 shows a hanging mechanism for a potted plant in clay, with regulating wick device and water storage device. The hanging mechanism 76 includes both an interior pot support 78 featured in FIG. 7 and the external hanger 88 illustrated in FIG. 9 with the pot and water storage device. The interior pot support 78 illustrated in FIG. 7 is preferably constructed of sturdy wire or twisted wire. The internal pot support 78 contains a pot seat 80 , square shaped in this case, and legs 82 attached at each corner of the pot seat 80 . The legs 82 are also feature leg expansions 84 (i.e. grommet stop pins or bent out portions of the legs 82 ), and ultimately connect to hanging fixtures 86 (i.e. loop connectors).
Referring to FIGS. 7, 8 , and 9 , when it is desired to hang the pot with wicks and water storage device, the potted plant with regulating wick device is removed from the water storage device 42 and set aside sitting on the wick element clamp's pot stand, 34 . The interior pot support 78 is placed through the top opening of the water storage device 42 . The legs 82 are turned upward toward the grommet openings 70 , best viewed in FIG. 9, and the loop connections 86 are pinched and threaded through the grommet connections 70 in the reservoir's corners as far as the leg expansions 84 will allow. The grommets 70 connect the gasket-retaining ring 66 to the top of the water storage device 42 . The loop connections 86 are held in place through the grommets by C-hooks 90 and retained on the C-hooks by loop retaining seats 92 . At this point it may be convenient to replace the clay pot, plant, and regulating wick device back into the water storage device 42 , carefully positioning the wick clamp pot stand 34 , over the pot seat 80 . The exterior wire hanging legs 94 are connected to the C-hooks 90 . The hanging legs 94 are also connected to the hanging hook 96 . The hanging hook 96 may now hang the device with potted plant.
With the hanging assembly illustrated in FIG. 8 the planting pot 6 , moist soil 4 , plant 2 which is not shown, and the regulating wick device 10 are supported by the wire hanging mechanism 76 . The water storage device 42 with water level 08 , not shown, hang on the leg expansions 84 beneath the gasket retaining ring outside the circumference of the raised lip 46 of the reservoir.
Note that the interior pot support 78 may be triangular or pentagonal or other shape, depending on how many attachment points are needed around the gasket retaining ring 66 .
Note also the exterior hanger 88 is preferably of a rigid nature so that the hanging water storage device 42 may be handled from the bottom with a pole device and platform. Referring to FIG. 10 and further discussed below, the pole device preferably has a platform shaped like a short version of the alignment plank 100 , and a perpendicular weight retaining ridge.
FIGS. 10 and 11 illustrate alternate forms for preferred methods of alignment. The alignment mechanisms include combining a plurality of potted plants in water storage devices for window box designs, patio borders and other alignment uses. Preferably, the water storage device exhibits a cubic nature and a smooth design, so that a plurality of devices aligned contiguously form the appearance of window boxes, patio borders, or decorative designs and borders. Use of different colored devices form decorative tile-like patterns. Referring to FIG. 10, the alignment is formed with the alignment mechanism 98 . An alignment plank 100 is easily constructed of treated wood, plastic, laminated particleboard or other material sufficiently strong to hold the plurality of devices. Strategically positioned in the alignment plank 100 are holes 102 accommodating the reservoir well 62 of the cubic reservoir 44 . Placing the reservoir 44 on the alignment plank 100 , taking care to fit the reservoir well 62 into the holes 102 , forms a smooth uninterrupted window box shape. In a like manner alignment mechanisms may be used for other types of decorative borders.
In FIG. 11 the alignment mechanism is basically the same as FIG. 10 with the exception of the reservoir well 62 which is threaded and held in place through a larger hole 102 in the alignment plank 100 by a female nut 104 beneath the plank. Other means of attachment will be readily apparent. With this alternate form of the alignment mechanism 98 the water storage device is secured below the plank. This feature may be useful if there is any occasion to slant the plank, for example for use with casement windows. The larger alignment holes 102 may also make it easier to slide overflowing pots into alignment.
FIGS. 12, 13 , and 14 summarize the expanded utility of the common inexpensive clay pot. The pot can now be placed on fine furniture, illustrated in FIG. 12 . It can be aligned as window boxes or other designs as illustrated in FIG. 13 . Finally the clay pot can be hung as illustrated in FIG. 14 . Moreover the plantings can be rotated to new modes of setting about the home without repotting the plant. For example, a window box planting may be brought indoors to use as a center piece in a table setting or vice versa. The porous clay pot has also been transformed into a low maintenance planting container with available water storage for use with a wick device.
FIG. 15 illustrates the two step collection and release process of cationic nutrients in physical terms. In both steps there is a planting pot 06 containing soil or growing medium 04 . Both steps illustrate the same wick device which includes a moisture conducting wicking material which has preferably been chemically treated as a cation exchanger 14 . Filter companies like Whatman manufacture chromatography papers such as cellulose bonded with phosphate groups, Whatman P81 Cellulose Phosphate Chromatography Paper, or cellulose loaded with silica gel which in turn are bonded with sulfonate groups. Alternately the wick could be a column of silica or resins bonded with negatively charged groups. Since moisture wicking is the only flow mechanism available as mobile phase, the chemical bonding should be adapted for this purpose. However collection, not separation, of cations is the only objective. Most current materials treated in this way are delicate. Therefore, the wick element also includes a casing 20 of stainless tubing or appropriate plastic which encloses the wick throughout the lower soil. A mesh or membrane 21 preferably surrounds the lower portion of the chemically treated wicking material which is immersed in the liquid nutrient reservoir. The mesh or membrane covering 21 excludes solids in the reservoir but allows the dissolved cations attracted to the wick's negatively charged sites there through. Note that an alternate way of keeping the wicks from fouling with solids is to package the insoluble rock powder in a mesh or membrane. This keeps the entire liquid in the reservoir free of small solids particles.
The potted plant with protruding special wick is positioned above a reservoir 42 , to which pure water at level 08 , and to which the relatively insoluble nutrient solids 05 have been added. This configuration, called the collection step, is in place for a relatively long period of time. These cationic nutrient conducting wicks can be used simultaneously with moisture conducting wicks, such as microfiber wicks, which provide pure moisture conductance. Moisture conductance has been discussed previously.
After a period of adding moisture and collecting cations on the wick, the release phase is commenced. Physically this is achieved by placing the bottom of the wick in a release solution 09 of relatively high ionic strength. A suitable solution may be one of potassium dihydrogen phosphate buffer at a suitable pH, perhaps between 6 and 7. This step is relatively short in duration and does not take a large volume of solution. The numerous potassium and hydrogen cations in the release solution quickly exchange the collected cations on the wick and drive the nutrients up to the negatively charged soil 04 . Gravity and the cation exchange capacity of the soil distribute the accessible nutrients to the plant roots.
FIG. 16 illustrates the method in chemical terms. As illustrated in FIG. 16, the wicks are in contact with the soil 04 and the liquid nutrient surface 08 . For ease of illustration only the wick construction and, nutrient conductance process is shown. During the collection phase the insoluble solids slowly dissolve and are dissociated into ions, specifically cations shown by way of example Mg +2 , Ca +2 , Mo +2 . The cations are attracted to the wick and adhere to its negatively charged sites. The positively charged cations are exchanged up the negatively charged wick as moisture is conducted upward. Removal of the cations out of solution decreases its ionic strength and encourages more dissociation according to Le Chatelier's Principle. Slowly the cations may move upward into the soil with the wicking action only, however a release phase may be commenced.
During the release phase the potassium dihydrogen phosphate solution has readily available numerous potassium and hydrogen cations which are also attracted to the negative sites in the wick. Immersion of the wick 14 in casing 20 deep into the solution increases the wicking capacity and these cations quickly exchange the collected cations on the wick and drive them upward into the soil 04 . Potassium and hydrogen are also essential plant nutrients and not harmful as long as the proper pH is maintained in the soil. Buffer solutions by their very nature control pH through the release process. Other releasing solutions can be formulated of citrate or sorbate which are organic and also can act as antimicrobials. Still others will be readily apparent to those skilled in the art.
The method of nutrient conductance described above is practical if wicks and reservoirs are already being used to maintain the moisture of a containerized houseplant. The wick holder preferably positions several “wicking elements” which conduct moisture. These elements are encased into the upper soil and are actually adjusted from the top of the soil. One can visualize a holder with three moisture conducting wicks and one nutrient conducting wick. The collection phase proceeds simultaneously with the addition of moisture to the plant. Between water fills to the reservoir, or before cleaning the reservoir, a release phase is begun by pulling the moisture wicks above the low liquid surface and installing a cup of release solution in which only the nutrient wick, perhaps too delicate to move, is immersed high up onto its casing for maximum flow upward. The cup of release solution is removed after this phase and the reservoir filled as usual with water.
In this way the plant is regularly bathed in low levels of nutrients which avoids the feast or famine addition procedures often used. The procedure is gentle enough not to burn the plant, yet more rapid than the decomposition of insoluble nutrients in the soil.
The regulating wick device presented has the advantage of introducing moisture in the top of the growing medium for distribution throughout more available rooting layers of potted soil. The simple sliding action of the wick elements within its holding device sets the moisture delivery capacity to rates conducive for maintaining a specific plant within the maintenance schedule of a specific caregiver. Finally, the regulating wick device using the straight wick elements provide for modulation of moisture delivery rates after the plant has been potted substantially without disturbing either potting soil or plant roots. The modulating adjustments can be conveniently made in the accessible upper soil by sliding the upper wick casing up or down to slow or increase the moisture delivery rate as desired.
Working together the regulating wick device and the water storage device offers modularity to plant a container and provide the soil and moisture conditions optimum for the specific plant. Working together they provide flexibility to use the planting in all the ways plantings can be set around the home. Finally working together they provide self containment with available water, and a slow delivery system designed for easy maintenance. With modularity, flexibility, and self containment the art of houseplant maintenance is greatly advanced to the point of facilitating indoor/outdoor rotation of houseplants. For the first time it may be practical to enjoy the occasional, proximate, indoor use of blooming, fragrant, sun loving plants. | Water storage device for use with potted plants is disclosed. This water storage device is a liquid nutrient reservoir usable with a wick regulating element inserted into and extending from the bottom of the planting pot to the storage device for control of liquid nutrient delivery rate. The water storage device accommodates some sizing variance in potted plants and securely holds the potted plant as a coupled modular unit. The water storage device is provided with structure for hanging the coupling. Additional structure is provided for contiguous alignment of a plurality of the water storage devices with secured potted plants as well as structure for elevation of the coupling to prevent moisture damage to a setting surface. | 61,468 |
This application relates to evacuation systems for offshore drilling platforms.
BACKGROUND OF THE INVENTION
The offshore drilling industry and the technology associated with it have developed rapidly in the last twenty years. The drilling rigs in use today have evolved into sophisticated structures, designed and built to withstand the severest of environmental conditions and to operate in very deep waters. Advanced computer technology has contributed substantially to bring platform development to its present position. Computers are integral, for example, to the collection and evaluation of geological and seismic date, to the operation of dynamically positioned platforms, and to methods of well control.
In spite of the advanced state of technology, accidents requiring evacuation from drilling platforms still occur. Such accidents may include, for example, fire on board. In addition to this type of accident, environmental conditions off certain coasts, such as off Eastern Canada, are especially severe with extremes of wind and wave, and a frequency of storms above that found in other areas. Both accidents and weather conditions may necessitate evacuation of the platform. Such occurences have in recent years lead to loss of life by virtue of the inadequacies of the evacuation systems.
Unfortunately, evacuation systems and the component parts of those systems have not kept pace with the rapid development of technology in the platform itself. There are currently, in particular, shortcomings in all three major components of evacuation. These components are the mustering and boarding procedure, the launch and the removal of the survival craft from the area of the platform. As a result, there is a critical need for a safe means of evacuation of a drilling platform in last resort situations.
PRIOR ART
A number of systems for evacuation of ocean-going vessels have been devised over a long period of years. These generally have been concerned with the specific manner of launch of lifeboats from ships.
Among early examples is that illustrated in U.S. Pat. No. 582,069, granted May 4, 1897, to Leslie, and illustrating a launch system in which a pair of davits of elongated configuration are attached to pivot downwardly from a ship's side to launch a lifeboat at some distance from the ship. The boat simply floats off the davits as they are lowered into the water.
A similar example is illustrated in U.S. Pat. No. 609,532, issued Aug. 23, 1898 to Cappellini. That patent illustrates a similar pair of pivoting davits which in this case are controlled in their descent by a hydraulic system. Of note in this early patent is the system allowing the ship's captain to launch the lifeboats from the bridge through a series of exploding blocks. The lifeboat will be deposited at some distance from the side of the ship.
U.S. Pat. No. 2,091,327, issued Aug. 31, 1937, to McPartland illustrates a further example of the rotating davit type of launch system which deposits the lifeboat some distance from the side of the ship. The boat simply floats off the davit as the davit is lowered toward water level.
Finally, U.S. Pat. No. 2,398,274, issued Apr. 9, 1946, to Albert, illustrates a launching and pick-up device for patrol boats, launches or the like. The launching and pick up platform is mounted on rotating davits and is lowered by a series of cables connected to the davits and the platform. The boat simply floats off the platform when the platform is lowered below water level. In this case the small boat is launched quite close to the mother ship. Of note, the direction of launch is such that the launched boat enters the water with a direction of travel aimed directly at, or, presumably, away from the mother ship.
In all these cases the systems include means for maintaining the trim of the survival craft during launch.
More recently, evacuation systems have been proposed for offshore drilling platforms which incorporate a number of the features of these early patents, including a rotating davit fixed to the side of the platform. Other proposals include free-fall type systems in which the escape craft is launched by free fall from tracks near the surface of the platform.
None of these systems deal adequately with the range of problems which must be addressed in order to establish a safe and reliable system.
Accordingly, the present system has been developed to overcome problems inherent in various of the prior art systems.
SUMMARY OF THE INVENTION
A system has now been developed which in its various embodiments is directed at improvements in the ability of personnel to board a survival craft, in the launch structures and procedures, in removal after launch from the area of the platform and in survival craft location by rescue ships when at sea.
Accordingly, in a first embodiment the invention provides an offshore evacuation system for drilling rigs or platforms comprising a launch structure for survival craft; the structure comprising at least one support strut adapted to be pivotally attached at one end thereof to the platform superstructure and carrying at the other end thereof a support cradle for survival craft, and rotatable between an upper position and a lower position; and means for effecting rotation of said launch structure from said upper to said lower position; and a closed passageway leading from the platform accommodation unit to the loading position of the survival craft and being in sealing relationship with the survival craft.
In a further embodiment, there is provided an offshore evacuation system for drilling rigs or platforms comprising a launch structure for a survival craft; the structure comprising at least one support strut pivotally attached at one end thereof to the platform superstructure and carrying at the other end thereof a support cradle for a survival craft; the structure rotatable between an upper load position and a lower launch position and means for effecting rotation of said launch structure from said upper to said lower position; and an onboard computer for said survival craft for monitoring environmental and platform conditions and for controlling the launch of said survival craft.
GENERAL DESCRIPTION OF THE INVENTION
A number of specific problems can readily be isolated which require solutions in the optimum system. A first problem lies in getting the crew to the boats in the most expeditious and safest manner. A second problem is in providing in the boat a "safe haven" prior to launch which enables the crew to delay launch to the last possible minute. A third problem is in reducing the complexities of launch and removing to as a great an extend as possible the human element. During launch it is essential that the boat be deposited at a safe distance from the platform to avoid collisions with the platform after launch. Finally, the problem of navigation following launch must be addressed, again to avoid collisions with the platform and to allow for quick location and retrieval of the boat from the sea. A complete system must deal with all of these problems, and the present invention in its various embodiments addresses these difficulities.
In broad form as noted above the invention includes a launch system for a totally enclosed motor propelled survival craft. Some such craft are known and others are under development. They must meet rigid regulatory requirements and they are not in themselves the subject matter of the present invention. The basic system may be enhanced by a closed companionway entry system to the craft and a computer controlled evacuation sequence.
The mechanical aspect of the launching system includes a rotating davit arrangement which is secured for rotation to the platform girders. Lowering of the davits is accomplished by means of a winch and cable arrangement. The preferred configuration for the davit system is an inverted V shape with a support member extending from the top thereof. While the preferred configuration is one in which the launch structure would accommodate a single survival craft only, it is also contemplated that the structure could if required accommodate a pair of survival craft. The single boat configuration is preferred because of a general feeling that larger craft are safer. However, particularly in a transition period where it might be economically attractive to utilize a platform's existing boats, the structure can be adapted to a two boat situation.
In the preferred case where a single survival craft is utilized, the support member at the top of the inverted V-shaped davit carries a U-shaped cradle support. Attached for rotation within the arms of the U-shaped cradle support is a survival craft support cradle. The cradle rotates to maintain the longitudinal axis of the craft in a horizontal position; i.e., to maintain trim, and, when the support structure pivots down to water level and below, the rescue craft simply floats off the cradle.
The permanent support structure in the loading area of the craft preferably includes a pair of stanchions with arms extending above the survival craft to secure the craft in the cradle prior to lowering.
The launch sequence is preferably computer controlled. When the survival craft is loaded and the latch manually closed, the computer begins to monitor and control the launch. Various control sequences can be proposed, and that discussed here is by way of example.
Upon sensing that the survival craft hatches are all sealed and closed, the computer provides suitable signals to the control person. When the first steps have been verified the computer will indicate that the craft is ready for launch.
As indicated, the survival craft satisfies the safe haven concept. That is to say, the craft provides an airtight enclosure which enables the platform crew to take refuge within the craft to avoid hazardous gases, fire and the like. Once the crew is in the craft with hatches closed, the actual launch of the craft can be delayed until it is determined that remaining with the platform will endanger the lives of the crew members. Since evacuation of the platform will only take place during time of maximum stress on crew members, it is highly desirable that the escape procedure be as automated as possible. It is for that reason that the present invention contemplates the availability of a launch sequence controlled entirely by computer. Obviously, the system is always subject to a manual override. The following descirbes generally the additional functions which can advantageously be carried out under microprocessor control.
When the survival craft is fully loaded or is otherwise ready for launch, as indicated by the sealing of the hatches on the craft, the launch sequence can shift to computer control. As a first step in this sequence, as indicated above, the microprocessor may ensure that weight distribution in the craft is acceptable for launch. This would be of particular importance in those situations where the craft was only partially filled.
The control system would then by visual and/or audible signal indicate that the craft is ready for launch. It is then necessary for the critical decision to be taken by the control person as to whether the crew is to remain in the survival craft as a safe haven at the platform or to continue with a full fledged evacuation. This decision is clearly based on a number of factors dealing with conditions exterior to the survival craft. For example, such data as time, wind speed and direction, wave height, general sea state, trim and list condition of the rig, condition of the well, presence of hazardous gases or fire are all factors which will influence a decision to abandon a rig. All such conditions are remotely monitored by the survival craft onboard computer.
Assuming a decision is made to evacuate the platform, a launch sequence initiator switch will be activated. Such a switch is preferably in the form of a large area push button. The reduced manual dexterity coincident with the wearing of an immersion suit requires that such switches be readily accessible with limited manipulation.
The second step in the automatic procedure contemplates a series of system activation steps. These include engine start up, sprinkler system activaton (may be delayed until craft is launched), onboard compressed air system activation (to create a positive pressure inside the survival craft to ensure that no hazardous gases are drawn in), and activation of the radio directional finder (RDF). The onboard computer through the RDF or the onboard compass automatically controls the course of the survival craft. A signal is received by the RDF from the platform standby vessel which will have positioned itself to effect rescue from the survival craft, following launch, and the survival craft will automatically set a course for the standby vessel.
In the preferred situation the survival craft is provided with a radar transponder to aid in location of the craft in the water by a rescue vessel.
Initiation of these systems completes preparation for launch, and a further visual and/or audible signal indicates this state of final readiness to the control person. Assuming the launch is to go forward, an actual launch initiation switch is activated. The effect of this action is to release the brake on the launch cable winch to thereby begin the lowering of the support frame. The frame is lowered at a controlled rate and, when it reaches water level, the survival craft simply floats off its cradle. The support frame continues to lower into the water to ensure that it is well clear of the survival craft. At this point the craft engine is at full throttle to ensure that the craft is not swept back into collision with the platform structure. The engaging of the transmission of the survival craft power train and application of full throttle is achieved automatically upon separation of the craft from the cradle. At this point a preprogrammed compass course followed after a preset time interval by an RDF signal from the standby vessel guides the survival craft away from the platform and toward the standby vessel.
A further preferred feature of the present invention is the presence of an enclosed airtight companionway connected through airtight seals at one end to the rear entry of the survival craft and at the other end to the accommodation area of the platform. This companionway provides protected and hazard-free access to the survival craft, thereby avoiding both the obstructions which arise from time to time on deck areas, and adverse environmental conditions, including fire and hazardous gases. The companionway is provided with emergency lighting and also acts as a heated storage area for immersion suits and lifejackets. Along with those stored in the accommodation area, the supply is sufficient to comply with regulatory requirements. Preferably the suits and jackets stored in the sealed companionway are in addition to the regular complement stored in the accommodation area.
It is much preferred that a single survival craft be utilized, since conditions prevailing at the time of an evacuation are such that difficulties in accounting for crew members are dramatically deceased by having a single assembly point. As well, the task of the standby vessel in dealing with the survival craft is simplified where only one such craft is present in the water.
A further distinct advantage to the use of a single larger craft is in its added space and seaworthiness. Both factors contribute to passenger morale and reduce the likelihood of seasickness.
Nonetheless, it is contemplated that a second and similar unit can be provided at the opposite end of the platform to be used as a backup unit should conditions prevent the crew from reaching the primary craft.
BRIEF DESCRIPTION OF THE DRAWINGS
In drawings which illustrate embodiments of the invention:
FIG. 1 is a top plan view of a semisubmersible drilling platform incorporating the system of the invention;
FIG. 2 is a side elevation of the platform of FIGURE 1;
FIG. 3 is a side elevation of a survival craft support structure in the raised position;
FIG. 4 is a top plane view of a survival craft support structure and cradle;
FIG. 5 is a plan view of a platform accommodation area including an evacuation companionway; and
FIG. 6 is a flow chart for one embodiment of the computer controlled launch sequence.
While the invention will be described in conjunction with illustrated embodiments, it will be understood that it is not intended to limit the invention to such embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following description, similar features in the drawings have been given similar reference numerals.
The drilling platform 10 is typical and is therefore useful in describing the invention. However, it will be readily apparent that the invention is applicable to a wide variety of drilling platforms having various specific configuraitons and layouts. The illustrated platform will therefore not be described in detail, the detail being apparent to those skilled in the art.
As illustrated, the evacuation structure 12 is installed at the bow 14 of the platform 10. In the preferred case a similar structure would be installed at the stern 16 of the platform 10. Each such structure would support a survival craft 18 capable of accommodating the entire crew of the platform 10. The usual required standard for evacuation capacity is two hundred per cent of the platform's complement. Accordingly, the installation of two of the systems of the invention, one at bow and one at stern, would fulfill this requirement.
The major components of the evacuation system of the present invention include the survival craft support structure 20, the onboard computer 22 (not illustrated), and the closed passageway 24. The totally enclosed motor propelled survival craft 18 is not in itself a part of the invention, inasmuch as conventional such craft could be modified to fit into the inventive system. It should be emphasized that it is not necessary that all of these components be present for all applications of the inventive system. For example, in some cases the closed passageway may not be present, although it is not to be implied that it is not highly preferable that the passageway be present in all cases. As well, in certain applications the onboard computer control functions may be modified or absent, although, again, it is highly preferable that the complete system be present in all cases.
With particular reference to FIGS. 3 and 4, the survival craft support structure 20 comprises the extended A-frame 28 and the cradle support structure 30. The A-frame 28 is rotatably connected at 32 and 34 on the main transverse girder 36. The main transverse girder 36 is at approximate pontoon level on a semisubmersible platform.
The rotation of the A-frame 28 is controlled by a winch and cable system comprising a winch 38 at deck level and a cable 40 secured to the A-frame 28 or the cradle support structure 30.
The cradle support structure 30 comprises an extension 42 to the A-frame 28, a transverse member 44 secured across the end of extension 42, and pair of upstanding arms 46. Structure 30 is in the plane of the A-frame 28.
Rotatably connected to the arms 46 is a survival craft support cradle 48. The cradle may take any of a large number of configurations but in one of its simpler forms as illustrated consists of a pair of elongated elements 50 and 52 from which are hung a pair of slings 58 and 60 each comprising a pair of vertical members 62 and 64 and transverse members 66 and 68. Vertical members 62 and 63 are of such length that elongated elements 50 and 52 are positioned immediately below the gunwales of the survival craft 18. The positioning of elements 50 and 52 with respect to the gunwales prevent the craft 18 from falling off of cradle 48 should the rig or platform sustain a significant list. Fixed to the transverse members 66, and 68 is a keel support member 70 which engage the keel or bottom of the hull of the survival craft 18. The survival craft 18 rests within this support cradle 48. As clearly illustrated in the drawings, no part of the launch structure extends above survival craft 18. As well, the cable 40 is attached to A-frame 28 or cradle support structure 30 below the level of support cradle 48.
The support cradle 48 is rotatably attached to the upstanding arms 46 by means of the pivot mechanisms 72 and 74 on the horizontal axis AA. Mechanisms 72 and 74 are such as to maintain the trim position of the support cradle 48 and thus of the survival craft 18 during the course of lowering the craft 18 into the sea. This is preferably achieved by a positive gear train which will not be susceptible to wind or water effects. A cable and reel system would also be very suitable.
It should be noted that the A-frame structure was chosen to provide adequate strength in the transverse direction. It is not of critical importance, however, that this particular configuration of structure be provided. It is only necessary that the structure have the pivoting capability and the strength required to withstand wind and wave effects.
As illustrated particularly in FIGS. 1 and 5, a decking structure 76 is provided at platform deck level to provide access to the survival craft 18 and to the support cradle 48 for maintenance purposes. As well, the decking structure 76 provides a support for the closed passageway to be discussed below.
In order to maintain the survival craft 18 securely in the support cradle 48 when in the storage position, at least one pair of stanchions 78 and 80 are provided extending upwardly from the decking structure 76. These stanchions include at the top thereof transversely extending members 82 and 84. These last contact the upper structure of the survival craft 18 and maintain its position. When a launch takes place, the support cradle 48 with the survival craft 18 simply drops away from members 82 and 84, leaving the craft 18 free to float off the cradle when the cradle is lowered into the water.
The survival craft 18 may take any one of a large number of configurations. All of these must meet applicable government regulations. As a minimum all will be totally enclosed and motor propelled. A positive pressure is maintained in the craft when in use to ensure that hazardous gases are not drawn inside. The craft is preferably equipped with individual high-backed seats with a four-point safety harness.
It is much preferred that the sequence of steps necessary to launch the survival craft be controlled by an onboard computer. The computer will have an onboard power supply but will be capable of interfacing with the drilling platform main computer. The following evacuation sequence is typical of those which might be utilized. The system is flow charted in FIG. 6. When an evacuation alarm sounds, all crew members will proceed to the survival craft 18, picking up immersion suits and lifejackets en route. When all crew members are accounted for the survival craft hatch will be closed and sealed. At this point the onboard computer becomes an integral part of the evacuation procedure. Following confirmation by the onboard computer that the entry hatch or hatches have been sealed, the computer will indicate that the survival craft is ready for launch.
It is then necessary for the control person to come to a final decision relative to evacuation. The onboard computer will provide information from various sources which will place the control person in a position to come to a decision. The computer, as indicated above, will monitor a substantial number of environmental factors and other indicators of the condition of the platform. For example, these will include wind speed and direction, wave height, general sea state, trim and list condition of the rig, information relative to the well and data relative to the presence or absence of hazardous gases.
All switches and controls, whether of the push button, lever or other type, are designed to enable easy operation by an operator enclosed in an immersion suit and lifejacket. The immersion suit substantially reduces manual dexerity, so that large and readily accessible controls are essential.
If a decision is made to proceed with evacuation, a switch is activiated to initiate the launch sequence. The computer will then activate a number of systems in preparation for survival craft launch. These functions preferably include the start up of the engine, activation of the onboard compressed air system and activation of the radio directional finder (RDF).
At this point the computer monitors internal air pressure and CO 2 levels and makes appropriate adjustments.
When this series of steps has been completed, completion is indicated to the control person via a visual and/or audible indicator. the control person then activates a launch switch. The computer then releases the cable winch brake and the cable 40 is fed out at a controlled rate to lower the support structure 20. That structure pivots about the connecting points 32 and 34 on girder 36 and the survival craft 18 arcs outwardly and downwardly in the support cradle 48 away from the platform 10.
As the support structure reaches and slips below the surface of the sea, the survival craft floats off the cradle 48. The structure 26 continues to pivot below the surface of the sea so that there is no possibility of further interference with the survival craft 18.
At the same time, the computer engages the survival craft transmission and applies maximum power to the survival craft engine. The survival craft then begins to move directly away from the platform. A preferred method of sensing launch is to have a contact pair between the cradle and the survival craft of which contact is broken when the craft begins to float off the cradle.
At this point also the system activates a sea water sprinkler to ensure a constant flow of water over the survival craft. This system is of particular significance in case of fire on the platform and possibly on the surrounding water.
Removal of the survival craft from the area of the platform is preferably conducted in two stages. In the first stage the craft is guided by the computer on a preset compass course, making use of an onboard compass to maintain the course. In the second stage, after a preset time has elapsed, the RDF takes over the course setting function, and the computer guides the craft according to signals received from the RDF. The theory here is that the craft will be guided on the preprogrammed compass course for a sufficient time to allow the craft to be well clear of the rig. The craft can then move on an RDF signal beam transmitted by the platform standby vessel.
The separation of the craft from the cradle also initiates in the computer the elapsed time counter which will determine the time during which the craft is controlled by the preprogrammed compass course.
The second survival craft, if also launched, is similarly computer controlled to move away from the platform to a prearranged area from which this craft also will be guided by the standby vessel RDF signal to effect a rendezvous. The initial computer controlled course will ensure that the survival craft is at all times well clear of the platform.
The survival craft is preferably provided with a radar transponder to enable the standby vessel to more easily locate the craft in the water. The transponder would also be activated automatically at launch.
With reference particularly to FIGS. 2 and 5, a closed passageway 24 is illustrated extending from the accommodation unit 92 to the rear of the survival craft 18. The passageway 24 is joined by air tight seals to the side wall 94 of the accommodation unit 92. As well, an airtight seal exists between the passageway 24 and the rear of the survival craft 18. The survival craft hatch 96 is within the sealed passageway.
A preferred location for the accommodation unit end of the passageway 24 is the mess area 98 in the accommodation unit 92. The hatchway 100 leading from mess area 98 to passageway 24 also has an airtight seal. Passageway 24 may also be provided with airtight hatches leading from the passageway to the deck 102 between the accommodation unit 92 and the end of platform 10.
The closed passageway provides a quick, obstruction-free means of moving from the accommodation area to the survival craft. At any time by far the majority of personnel on the platform will be located in the accommodation unit. Accordingly, the closed passageway provides direct access for those people from the accommodation unit for substantially horizontal or lateral entry into the survival craft. This factor can be of immense importance when keeping in mind that it will be only in extreme conditions that an evacution will take place. In these situations the deck area may be obscured by smoke, there may be fire aboard, high seas, wind and list may result in obstacles breaking loose and moving about the deck area, and there may be hazardous gases in the air. The use of the closed and sealed passageway will avoid all of these difficulties, and entry into the survival craft can be rapidly accomplished by a large crew.
It should be added that the location of the passageway can of course be varied to suit the particular configuration of the platform. As well, additional closed passageway can be located on other areas of the platform to avoid particular hazards.
The closed passageway also provides heated and protected storage for immersion suits and lifejackets. The primary source of these items would continue to be in the accommodation unit and as otherwise conventionally located. However, the additional supply of this evacuation equipment enables those not otherwise able to get to the equipment to obtain it immediately prior to boarding the survival craft. There has thus been described a complete system for fast and safe evacuation of a drilling platform. The system specifically avoids a substantial number of problems presented by earlier systems.
Thus it has been apparent that there has been provided in accordance with the invention an offshore evacuation system for drilling rigs or platforms that fully satisfies the objects, aims and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the spirit and broad scope of the invention. | There is provided a new and useful offshore evacuation system for drilling rigs or platforms comprising a launch structure for a survival craft; the structure comprising at least one support strut adapted to be pivotally attached at one end thereof to the platform superstructure and carrying at the other end thereof at least one support cradle for survival craft, and rotatable between an upper position and a lower position; and means for effecting rotation of said launch structure from said upper to said lower position; and a closed companionway leading from the platform accommodation unit to the loading position of the survival craft and being in sealing relationship with the survival craft. | 31,472 |
BACKGROUND OF THE INVENTION
This invention relates to face type shaft seals and more particularly to face type shaft seals for liquid metal pumps.
Typically primary coolant pumps used in large commercial nuclear power plants have controlled leakage face type seals to retain and confine the radioactive fluid within the pressure containment boundary of the pump. These seals are constructed to operate at moderately high system pressure. This system pressure is therefore utilized as the prime parameter to ensure operational reliability under normal conditions. However, these seals are also required to operate reliably for short periods of time at system pressure conditions far below the normal operating pressure. Prior controlled leakage face type seals are particularly sensitive in this region and are subject to rubbing at low pressure if thermal and/or pressure excursions are experienced.
The face type shaft seal must be capable of operating under normal operating conditions and also at start-up conditions. During normal operating conditions, a liquid film is generally developed between the two seal faces so as to prevent metal-to-metal contact of the two seal faces. However, during initial rotation of the pump shaft, there is generally an insufficient liquid film between the two faces so that a small amount of metal-to-metal rubbing may occur. This is generally not a serious problem because in most seals the metal is of a type that is capable of withstanding slight contact for a minimal amount of time.
In liquid metal pumps developed to date the pump has employed a shaft seal utilizing oil to maintain separation between the two seal faces. In the liquid metal pumps, since the alkali metal coolant being pumped is at a temperature of approximately 400° to 500° C., the pump shaft length must be increased so that the seal can be located a sufficient distance from the heat source so that the seal may be operated without deteriorating due to the extreme temperature of the alkali metal coolant. For example, a typical liquid metal pump shaft is generally more than twice the length of the pump shaft in a typical pressurized water reactor coolant pump. Of course, the increased pump shaft length results in a substantial increase in capital cost for the pump.
In analyzing the liquid metal fast breeder reactor, it becomes apparent that the gas-buffered, oil-lubricated seals of the coolant pump should be replaced by a pump shaft seal capable of operating near the liquid metal coolant. Such a pump shaft seal may be one in which the liquid metal coolant for the nuclear reactor is used as the liquid film between the two faces of the shaft seal. By using such a design, it is possible to greatly reduce the length of the pump shaft and thereby greatly reduce the capital cost of the liquid metal pump. A basic requirement of this type seal, however, is that it be a non-contacting type. This requirement is based on two facts. First, because of compatibility considerations with hot alkali metal, conventional said materials, such as carbon-graphite cannot be considered. As a result, both faces of the seal package must be manufactured from alkali metal compatible metals or ceramics, such as Stellite, carbides, or alumina. None of these materials have self-lubricating, properties, thus introducing a high degree of probability of severe scoring upon initiation of rotation of a contact-type face seal. Secondly, the fluid being sealed, such as sodium, has little if any lubricating ability and is an excellent reducing agent. By the removal of the beneficial boundary lubricant oxide layers, some of the proposed seal materials may quickly possess extremely clean metal surfaces with high self-welding tendencies.
Therefore, what is needed is a face type shaft seal that is capable of being operated in a liquid metal environment.
SUMMARY OF THE INVENTION
A face type shaft seal for liquid metal pumps comprises a non-contacting seal in which at least one seal face has spiral grooves therein. Both seal faces are gold plated which ensures complete wetting of the seal faces with the liquid metal coolant which thereby establishes a thin liquid metal film between the two seal faces thus preventing contact of the two seal faces. Upon shaft rotation, a pumping action of the spiral grooves is initiated, displacing the liquid metal toward the seal dam thus pressure-loading the seal. Therefore, no contact between the seal faces occurs before or during shaft rotation and the pumping action provides a driving force preventing fluid leakage.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter of the invention, it is believed the invention will be better understood from the following description, taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a partial cross-sectional view in elevation of a liquid metal pump;
FIG. 2 is a view along lines II--II of FIG. 1; and
FIG. 3 is a detail drawing of the seal faces in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In order to reduce the pump shaft length in a liquid metal pump, it is necessary to employ a liquid metal seal capable of operating in a liquid metal environment. The liquid metal seal must be non-contacting both when the pump shaft is not rotating and when the pump shaft is rotating. The invention described herein is a face type shaft seal for a liquid metal pump wherein the two faces of the seal are non-contacting when both the pump shaft is not rotating and when the pump shaft is rotating.
Referring to FIG. 1, the liquid metal pump is referred to generally as 20 and comprises a housing 22 which encloses a motor 24, pump shaft 26, and pump impeller 28. Motor 24 is connected to pump impeller 28 by means of pump shaft 26 as is commonly understood in the art. The action of motor 24 causes pump shaft 26 to rotate thereby rotating pump impeller 28. The rotation of pump impeller 28 causes liquid metal to be pumped through the nuclear reactor primary coolant system. A seal ring 30 is attached to housing 22 and surrounds pump shaft 26 thereby defining a first annulus 32 therebetween. First annulus 32 allows pump shaft 26 to rotate without contacting seal ring 30. Seal ring 30 has a first seal face 34 on the top thereof. A seal assembly 36 is attached to pump shaft 26 by means of a locking screw 38 and comprises a first member 40 that is a substantially cylindrical member disposed around pump shaft 26. A first contacting seal 42 which may be a metal O-ring is disposed in first member 40 and in contact with pump shaft 26 to prevent leakage therebetween. A second member 44 which may be substantially cylindrical is disposed around first member 40 in a sliding relationship. A second contacting seal 46 which may be a metal bellows type seal is disposed in first member 40 and in contact with second member 44 to seal the annulus between first member 40 and second member 44 while allowing second member 44 to slide vertically relative to first member 40. Second member 44 also has a slot near the top end thereof that allows second member 44 to slide relative to first member 40 without interfering with locking screw 38. A seal runner 48 is attached to the lower end of second member 44 so as to face seal ring 30. Seal runner 48 has a second seal face 50 that is arranged to confront first seal face 34. A biasing mechanism 52 which may be a single spring or a series of springs is disposed in first member 40 and extends into contact with second member 44 for urging first member 44 toward seal ring 30. The action of biasing mechanism 52 serves to urge second seal face 50 toward first seal face 34.
Referring now to FIGS. 2 and 3, seal ring 30 is bolted to housing 22 by means of bolts 54. A series of spriral grooves 56 are etched in first seal face 34. Of course, the spiral grooves in the alternative may be etched in second seal face 50. Spiral grooves 56 are etched to have a depth of approximately 0.0005 to 0.0015 inches. Both first seal face 34 and second seal face 50 are electroplated with a thin film of gold which may have a thickness of approximately 0.0001-0.0005 inches. Seal runner 48 is arranged as shown in FIG. 3 so that spiral grooves 56 extend beyond the inside diameter of seal runner 48 and terminate short of the outside diameter thereof. By having spiral grooves 56 extend beyond the inside diameter of seal runner 48, liquid metal is allowed to fill spiral grooves 56 and create a thin film of liquid metal between first seal face 34 and second seal face 50 thereby preventing metal-to-metal contact of first seal face 34 and second seal face 50. The liquid metal to be sealed may be chosen from those liquid metal coolants well known in the art such as sodium or a sodium-potassium mixture.
The key to achieving a successfully operating metal-to-metal seal combination operable in an alkali metal environment lies in ensuring that both seal surfaces are totally wetted by the sealed medium before operation is initiated. The surface phenomenon of a liquid, known as wetting, refers to the situation wherein the adhesive force between the molecules of the liquid metal of the seal and the molecules of the material of the seal faces is greater than the cohesive force between the molecules of liquid metal. In this case, wetting of the seal surfaces results in a thin film of liquid metal being established between first seal face 34 and second seal face 50 thereby preventing metal-to-metal contact of the seal faces. Wetting is accomplished in this manner by the thin film of gold that is electroplated to the seal faces. In this way, a thin film of alkali metal is tenaciously held to the seal surfaces and prevented from being totally forced from between the surfaces. In addition, liquid metal remains in the bottom of each spiral groove 56. During assembly the components are brought into abutting relationship and a closure force is exerted that is sufficient to contain a liquid metal at initial start-up pressure. The seal surfaces are then initially wetted with liquid metal. Once motor 24 has been activated, the rotation of pump shaft 26 and pump impeller 28 causes liquid metal to be forced through first annulus 32 and between first seal face 34 and second seal face 50. However, the rotation of seal runner 48 relative to seal ring 30 together with the action of spiral grooves 56 creates a pumping action which forces the liquid metal back toward first annulus 32 thus limiting the leakage between first seal face 34 and second seal face 50. The spiral groove-type seal combines hydrostatic and hydrodynamic features to provide a non-contacting, low-leakage face seal. Investigators have postulated that the hydrodynamic forces arise from a slider-bearing effect of the spiral grooves land area and from the pressure patterns developed by the spiral grooves. Thus, no contact between the seal faces occurs during shaft rotation, and the pumping action provides a driving force preventing fluid leakage. Furthermore, the initial establishment of the thin film of liquid metal between the seal faces caused by the wetting action of the gold-plated surfaces ensures that there is no metal-to-metal contact at initiation of rotation of the seal surfaces. Therefore, it can be seen that the invention provides a face type shaft seal for a liquid metal pump wherein the seal faces are non-contacting both at start-up and during operation of the pump. | A face type shaft seal for liquid metal pumps comprises a non-contacting seal in which at least one seal face has spiral grooves therein. The seal faces are gold plated and designed so that the liquid metal wets the seal faces and creates a thin layer of liquid metal between the two seal faces during both rotation of the pump shaft and non-rotation of the pump shaft. The thin layer of liquid metal prevents contact of the two seal faces during initial rotation of the pump shaft. | 11,653 |
FIELD OF THE INVENTION AND RELATED ART
[0001] The present invention primarily relates to an image forming apparatus which uses an electrophotographic process. In particular, it relates to a method for controlling an electrophotographic image forming apparatus so that when images, different in color, formed on the image bearing members of the apparatus are transferred onto the intermediary transferring member of the apparatus, or directly onto a sheet of final recording medium such as a sheet of recording paper, the images will precisely align among themselves.
[0002] A color image forming apparatus equipped with multiple photosensitive drums is designed so that images, different in color, formed on its photosensitive drums, one for one, do not fail to align among themselves as they are transferred onto the subsequent image bearing means. In reality, however, when the images, different in color, formed on the photosensitive drums are transferred onto the subsequent image bearing means, the images tend to fail to precisely align among themselves, because of mechanical errors, such as the one that occurs when the photosensitive drums are attached to the frame of the image forming apparatus, the error in the length of the path of the laser beam for writing each of the electrostatic latent images for forming the multiple monochromatic developer images, different in color, one for one, the changes which occur to the laser beam paths, etc. Thus, various methods for minimizing a color image forming apparatus in the amount by which misalignment occurs among the multiple monochromatic color images when the images are transferred onto the subsequent image bearing member.
[0003] One such method is disclosed in Japanese Laid-open Patent Application 2002-023445. According to this patent application, images for minimizing a color image forming apparatus in the amount by which multiple images, different in color, fail to align among themselves as they are transferred onto an intermediary transfer belt, is formed on the intermediary transfer belt. Then, the positioning of the images for minimizing the image forming apparatus in the amount of misalignment among the multiple images, different in color, on the intermediary transfer belt, is detected in order to minimizing the image forming apparatus in the amount of the misalignment, or making the image forming apparatus virtually free of the misalignment.
[0004] Japanese Laid-open Patent Application 2002-023445 discloses a method for detecting the amount of the positional deviation of each of the multiple monochromatic toner images different in color, from a referential positional deviation detection image, by detecting the light which is regularly reflected by the positional deviation detection image. In the case of this patent application, the means for detecting the positional deviation detection image is made up of a light emitting element such as an infrared light emitting diode, a light sensing element, such as a photo-transistor, for catching the light regularly reflected by the positional deviation detection image. The positional deviation detection image is such an image that is made of two sections having two referential sections of a specific color, and another section which is different in color from the referential sections and is sandwiched between the two referential sections. The amount of the positional deviation among the two referential sections and the other section is calculated based on the amount of positional deviation between the center of the two referential section and the center of the other section. Then, the image forming apparatus is adjusted in image formation settings such as the timing with which developer (toner) images, different in color, begin to be written, image formation clock, and/or the like, based on the calculated amount of the positional deviation among the two referential sections of the positional deviation detection image, and another section of the positional deviation detection image, in order to correct the apparatus in terms of the positional deviation among the multiple images, different in color, which the apparatus forms to yield a multicolor image.
[0005] Japanese Laid-open Patent Application 2009-93155 discloses another method for detecting the amount of the positional deviation among the multiple developer (toner) images, which an electrophotographic image forming apparatus forms to yield a multicolor image. According to this patent application, positional deviation detection images are formed on the intermediary transfer member of the apparatus, and the amount of the light which is diffusely reflected by the positional deviation detection images on the intermediary transfer belt is detected by the light sensing element of the sensor unit for detecting the positional deviation detection images, because the amount by which light is diffusely reflected by the intermediary transfer belt is not affected by the surface condition of the belt as much as the amount by which light is regularly reflected by the intermediary transfer belt. More specifically, in a case where the amount of the positional deviation among the positional deviation detection images is obtained by detecting the amount by which light is diffusely reflected by the positional deviation detection images, the amount by which light is diffusely reflected by a black developer image (image formed of black developer) formed on the intermediary transfer belt is as small as the amount by which light is diffusely reflected by the intermediary transfer belt itself. Therefore, the positional deviation detection images are formed as shown in FIG. 14 . That is, the positional deviation detection image of black color is formed on each of the three positional deviation detection images which are different in color from the black positional deviation detection images. More concretely, yellow, magenta and cyan developer images 1401 , 1402 and 1403 , respectively, are formed on the intermediary transfer belt, and three black developer images are formed on the yellow, magenta and cyan developer images 1401 , 1402 and 1403 , one for one. Thus, even the black developer image, which is very small in the amount by which it diffusely reflects light, can be detected.
[0006] Further, Japanese Laid-open Patent Applications 2007-272111 and 2005-234238 describe so-called “trailing edge piling”, which is a phenomenon that when an electrostatic image on the peripheral surface of a photosensitive member (drum) is developed during an electrophotographic image forming process, developer (toner) unintendedly piles along the trailing edge portion of an exposed area of the peripheral surface of a photosensitive member (drum). To describe how and why the “trailing edge piling” occurs with reference to FIG. 15 , when an electrostatic latent image on a photosensitive drum is developed by a development roller 1502 , the developer (toner) particles 1504 on the peripheral surface of the electrophotographic drum 1502 , which are facing the area of the peripheral surface of the photosensitive drum 1501 , which is between the exposed area 1503 and unexposed area 1505 , and the area adjacent thereto, jump onto the exposed area 1503 of the peripheral surface of the photosensitive drum 1501 , which is lower in electrical potential. That is, the upstream edge portion of the exposed area of the photosensitive drum 1501 in terms of the rotational direction of the photosensitive drum 1501 receives developer (toner) by an amount greater than the theoretically correct amount. In other words, the developer (toner) piles up across the trailing edge portion of the exposed area of the peripheral surface of the photosensitive drum 1501 as shown ( 1601 ) in FIG. 16 . Thus, in order to minimize an electrophotographic image forming apparatus in “trailing edge piling”, that is, in the amount by which developer (toner) piles up along the trailing edge of the exposed portion of the peripheral surface of the photosensitive drum 1501 , the fourth of the abovementioned four patent applications proposes the following method. That is, the method extracts the information about the contour of the image to be formed, from the information about the image to be formed. Then, it modifies (adjusts) the original image formation data in such a manner that the trailing edge portion of the image to be formed, will be theoretically less in image density.
[0007] Japanese Laid-open Patent Application H7-134479 describes the relationship between the ambient temperature of an image forming apparatus and the extent of the “trailing edge piling”. More specifically, when an electrophotographic image forming apparatus is operated in an environment which is low in temperature and humidity, the tribo-electric charge which the developer (toner) acquires is relatively narrow in terms of the range, and therefore, the “trailing edge piling” is small in the amount. However, there is such a tendency that as the environment in which an electrophotographic image forming apparatus is being operated increases in temperature and humidity, the level to which the developer (toner) becomes triboelectrically charged becomes wider in range in proportion to the amount by which temperature and humidity increase.
[0008] When an electrophotographic image forming apparatus is operated in an environment in which the “trailing edge piling” occurs, the “trailing edge piling” occurs to the positional deviation detection images while they are formed on the photosensitive drums to be transferred onto the intermediary transfer member. In a case where the position of the edge of the positional deviation detection images, along which developer (toner) has piled is detected by a sensor, it cannot be accurately detected, which is problematic in that the detected position of the trailing edge of the positional deviation detection image is incorrect.
[0009] For example, in a case where a sensor structured to detect the amount of the positional deviation of an image, by detecting the amount of the light diffusely reflected by the surface of the image, a positional deviation detection image is formed as shown in FIG. 17(A) . That is, first, a referential developer image 1701 , that is, a positional deviation detection image of yellow color (referential color) is formed, and a black developer image 1702 , that is, the image, the position of which is detected, formed on the referential (yellow) developer image 1701 . In this case, the trailing edge of the resultant positional deviation detection image is excessive in the amount of developer, being therefore higher in density than the theoretically correct amount, because of the effect of the “trail edge piling”, as shown in FIG. 17(B) . Thus, the analog signal outputted by the sensor, which shows the intensity (amount) of the light diffusely reflected by the positional deviation detection image, becomes as shown in FIG. 17(C) . More specifically, the analog signal related to the referential developer image, or the color (yellow) image, has the pattern represented by a solid line 1706 , being slightly higher in amplitude at the trailing edge. As for the analog signal related to the black developer image, the black developer image absorbs light, being therefore small in the amount (intensity) by which it diffusely reflect light. Therefore, the analog signal from the sensor, which shows the amount by which light is diffusely reflected by the black developer, is hardly effected by the “trail end piling”, even thought the “trailing edge piling” occurs to the black developer image.
[0010] The amount of positional deviation of the positional deviation detection image is calculated as follows. The analog signal outputted by the sensor is digitized with reference to a preset threshold value. Then, the amount of positional deviation of the positional deviation detection image is calculated based on a point in time at which the thus obtained digital signal steps up and a point in time at which the digital signal steps down. More concretely, referring to FIG. 17(D) , the position of the center of the background color developer image (pattern) 1701 is obtained (calculated) based on a point ty 11 in time at which the digital signal steps up in value and a point ty 12 in time at which the digital signal steps down in value. Similarly, the position of the center of the black developer image is obtained by calculation based on a point tk 11 in time at which the digital signal steps down, and a point tk 12 in time at which the digital signal steps up. Then, a distance Δdy between the position of the center of the background color image and the position of the center of the black developer image is calculated as the amount of positional deviation of the trailing edge of the background color image.
[0011] When the “trailing edge piling” does not occur, the analog signal outputted by the sensor, and the digital signal obtained from the analog signal with the use of a preset threshold value, become as indicated by a broken line 1705 in FIG. 17(C) and a broken line in 17 (D), respectively. Therefore, when there is no positional deviation between the background color image and black developer image, the amount Δdy of the positional deviation is zero (Δdy=0) as shown in FIG. 17(E) . However, when the “trailing edge piling” occurs, the tailing edge portion of the background developer image becomes higher in density. Therefore, the analog signal outputted by the sensor, and the digital signal obtained from the analog signal with the use of a preset threshold value, become as indicated by a solid line 1706 in FIG. 17(C) and a solid line in 17 (D), respectively. Therefore, even when there is no positional deviation between the background color image (pattern) and black developer pattern, the amount Δdy of the positional deviation is not zero (Δdy′≠0) as shown in FIG. 17(E) . That is, the position of the trailing edge of the background image is detected as if it has deviated in position.
[0012] As the “trailing edge piling” occurs, the amount of the positional deviation among the positional deviation detection images formed on the intermediary transfer belt cannot be accurately detected. Thus, it is impossible to precisely correct an electrophotographic image forming apparatus in the positional deviation among the positional deviation detection images, based on the results of the detection of the images by the sensor.
SUMMARY OF THE INVENTION
[0013] The present invention was made in consideration of the above-described issue. Thus, the primary object of the present invention is to provide a technology for precisely correcting an electrophotographic image forming apparatus which uses multiple developers, different in color, to form a multicolor image, in the positional deviation among the multiple monochromatic images formed on the multiple image bearing members of the apparatus, one for one.
[0014] These and other objects, features, and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is an example of a table which shows the relationship between the temperature/humidity range (having three sub-ranges), and the amounts PDe_ky, PDe_my and PDe_cy, by which the position of the trailing edge of the positional deviation detection images of black, magenta, and cyan colors, respectively, are to be corrected.
[0016] FIG. 2 is a schematic sectional view of the image forming apparatus in the first and second embodiments of the present invention, and shows the positioning of the various components of the apparatus, which are related to the present invention.
[0017] FIG. 3 is a schematic drawing of the sensor units in the first and second embodiments, and shows the structure of the units.
[0018] FIG. 4 is a drawing of the circuit for detecting the amount of light reflected by the positional deviation detection image, in the first and second embodiments.
[0019] FIG. 5 is a drawing of the positional deviation detection images, in the first and second embodiments.
[0020] FIG. 6 is a drawing which shows the pattern in which the positional deviation detection images are arranged in the first and second embodiments.
[0021] FIG. 7 is a drawing which shows the pattern in which the positional deviation detection images are arranged, and the signals outputted by the sensor for detecting the tailing edge of each of the positional deviation detection images, in the first and second embodiments.
[0022] FIG. 8 also is a drawing which shows the pattern in which the positional deviation detection images are arranged, and the signals outputted by the sensor for detecting the trailing edge of each of the positional deviation detection images, in the first and second embodiments.
[0023] FIG. 9 is a graph which shows how the ambient temperature and humidity ranges of the image forming apparatus are divided in the first embodiment.
[0024] FIG. 10 is a flowchart of the control sequence for correcting the image forming apparatus in the positional deviation among monochromatic images, in the first and second embodiments.
[0025] FIG. 11 is a graph which shows the division of the temperature range of the environment in which the image forming apparatus is operated, in the second embodiment.
[0026] FIG. 12 is an example of a table which shows the relationship between the temperature/humidity range (having three sub-ranges), and the amounts PDet_ky, PDet_my and PDet_cy, by which the position of the trailing edge of the positional deviation detection images of black, magenta, and cyan colors, respectively, are to be corrected.
[0027] FIG. 13 is a drawing which shows the division of the humidity range of the environment in which the image forming apparatus is operated, in the second embodiment.
[0028] FIG. 14 is a drawing which shows the positional deviation detection images in accordance with the background art, and the pattern in which the images are arranged.
[0029] FIG. 15 is a drawing for describing the principle based on which the “trailing edge piling” occur.
[0030] FIG. 16 is a drawing for showing the piling of developer (toner) along the trailing edge of the exposed area of the peripheral surface of the photosensitive drum.
[0031] FIG. 17 is a drawing of the positional deviation detection image in accordance with the prior art, and the waveform of the signal outputted by the sensor for detecting the amount by which light is reflected by the surface of the positional deviation detection image.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] Hereinafter, the embodiments of the present invention are described with reference to the appended drawings. The following embodiments of the present invention are examples of the embodiment of the present invention. They are not intended to limit the present invention in scope.
Embodiment 1
[0033] Next, the first embodiment of the present invention is described.
[0034] [Description of Image Forming Apparatus]
[0035] FIG. 2 is a schematic sectional view of the image forming apparatus 201 , more specifically, a color laser beam printer. It shows the structure of the apparatus. The image forming apparatus in this embodiment is capable of forming a multicolor image by layering two or more of yellow (Y), magenta (M), cyan (C) and black (Bk) images. Thus, it has four image forming stations, different in the color of the image they form.
[0036] The image forming operation of the color laser beam printer 201 is as follows. As the printer 201 receives image formation data 203 from a host computer 202 , it converts the image data 203 into video signal data with the use of its printable image generating section 204 , and generates video signals for forming the image to be formed. The control section 206 of the printer 201 has a computing means such as a CPU 209 . As the CPU 209 receives the video signal 205 generated by the printable image generating section 204 , it drives multiple laser diodes 211 , as laser light emitting elements, which are in the scanner units 210 , in response to the video signal 205 .
[0037] The beams 212 y , 212 m , 212 c and 212 k of laser light (which hereafter will be referred to as laser beam 212 ) emitted by the laser diodes 211 , one for one, are deflected by a polygonal mirror 207 , are transmitted through lenses 213 y , 213 m , 213 c and 213 k (which hereafter will be referred to as lens 213 ), are deflected by deflection mirrors 214 y , 214 m , 214 c and 214 k (which hereafter will be referred to as deflection mirror 214 ), so that they are projected upon the peripheral surface of the photosensitive drums 215 y , 215 m , 215 c and 215 k (which will be referred to as photosensitive drum 215 ), respectively. The photosensitive drums 215 y , 215 m , 215 c and 215 k , which are image bearing members, are charged by charging means 216 y , 216 m , 216 c and 216 k (which hereafter will be referred to as charging means 216 ), respectively.
[0038] As the laser beam 212 is projected upon the charged area of the peripheral surface of the photosensitive drum 215 , the points of the charged area of the peripheral surface of the photosensitive drum 215 , upon which the laser beam 212 were projected, reduce in surface potential level. Consequently, an electrostatic latent image is effected on the peripheral surface of the photosensitive drum 215 . This electrostatic latent image is developed by one of developing means 217 y , 217 m , 217 c and 217 k (which hereafter will be referred to as developing means 217 ) into visible image formed of toner (developer), which reflects the electrostatic latent image. That is, the image forming apparatus 201 has image forming means which form four toner images, different in color, on its four photosensitive drums 215 , one for one. The toner image formed on the photosensitive drum 215 is transferred (primary transfer) onto an intermediary transfer belt 219 , by a proper amount of bias voltage applied to primary transfer members 218 y , 218 m , 218 c and 218 k (which hereafter will be referred to as primary transfer member 218 ). The intermediary transfer belt 219 is an intermediary transfer member, and is in the form of an endless belt which is circularly movable.
[0039] To describe in more detail the primary transfer of a toner image, first, the yellow toner image is transferred onto the intermediary transfer belt 219 , and then, the magenta, cyan and black toner images are sequentially transferred in layers onto the yellow toner image on the intermediary transfer belt 219 . Consequently, a multicolor image is effected on the intermediary transfer belt 219 . As described above, the image forming apparatus 201 has also a transferring means which sequentially transfers the toner images formed on the photosensitive drums 215 , one for one, onto the intermediary transfer member.
[0040] The intermediary transfer belt 219 is circularly moved by an intermediary transfer belt driving roller 226 which is under the control of the control sections 206 . The sheets 221 of recording medium stored in layers in a cassette 220 are picked up one by one by a sheet feeding roller 222 , and are conveyed to a secondary transfer roller 223 in synchronism with the arrival of the images having transferred onto the intermediary transfer belt 219 at the second transfer roller 223 . Then, the images on the intermediary transfer belt 219 are transferred together (secondary transfer) onto the sheet 221 of recording medium by the secondary transfer roller 223 . During the secondary transfer, a proper bias voltage is applied to the secondary transfer roller 223 to increase the efficiency with which the images are transferred.
[0041] After the secondary transfer of the toner images onto the sheet 221 of recording medium, the toner images are thermally fixed to the sheet 221 by the heat and pressure in a fixing device 224 . Then, the sheet 221 is discharged into a delivery tray which is an integral part of the top wall of the external shell of the image forming apparatus. Designated by a referential code 225 in FIG. 1 is a sensor unit 225 for detecting the trailing edge of each of the positional deviation detection images, different in color, transferred onto the intermediary transfer belt 219 . The sensor unit 225 detects the amount of the beam of light projected upon each of the positional deviation detection images, different in color, formed on the intermediary transfer belt 219 , and reflected by each positional deviation detection image. Then, it sends the results of its detection to the control section 206 . The control section 206 determines the position of each of positional deviation detection images (formed of developer) on the intermediary transfer belt 219 , based on the results of detection of the positional deviation detection images by the sensor unit 225 , and corrects the image forming apparatus in terms of the positional deviation among the multiple images, different in color, formed to yield a multicolor image, based on the determined position of each image.
[0042] An environment detection sensor 227 has a temperature detection element and a humidity detection element, such as a thermistor. It is an environment detecting means which detects the temperature and humidity (which will be referred to as temperature/humidity, hereafter) of the environment in which the image forming apparatus 201 is being operated. It sends the detected temperature and humidity to the control section 206 . The environment detection sensor 227 is positioned in the image forming apparatus 201 , more specifically, in an area where it is unlikely to be affected by the heat generated within the image forming apparatus 201 and also, where it can accurately detect the temperature and humidity of the environment in which the image forming apparatus 201 is being operated.
[0043] The control section 206 adjusts the parameters for controlling pressure, fixation process, positional deviation correction process, etc., based on the temperature/humidity detected by the environment sensor 227 . In this embodiment, the environment sensor 227 is positioned in an internal area of the image forming apparatus 201 , in which the sensor 227 can accurately detect the temperature/humidity of the environment in which the apparatus 201 is being operated. However, the environment sensor 227 may be positioned in an internal area of the apparatus 201 so that it can accurately detect the temperature/humidity of a specific point in the apparatus 201 .
[0044] [Structure of Sensor Unit]
[0045] FIG. 3 shows the structure of the sensor unit 225 . The sensor unit 225 has a pair of optical sensors 301 and 302 , which are aligned in the direction perpendicular to the direction A in which the intermediary transfer belt 219 is moved, in order to detect the amount of image magnification in the primary scan direction, and the image angle relative to the secondary scan direction. The optical sensors 301 and 302 detect the amount by which a beam of light is diffusely reflected by the intermediary transfer belt 219 and each positional deviation detection image on the intermediary transfer belt 219 . Each of the optical sensors 301 and 302 has a light emitting element 303 and a light sensing element 304 . The light emitting element 303 is positioned so that the beam of infrared light emitted by the element 303 hits the surface of the intermediary transfer belt 219 at an angle of 15° relative to a line perpendicular to the surface of the intermediary transfer belt 219 .
[0046] The light sensing element 304 which is for detecting the portion of the beam of infrared light emitted by the light emitting element 303 and diffusely reflected by the surface of the intermediary transfer belt 219 and the positional deviation detection images 305 on the intermediary transfer belt 219 . It is positioned so that the angle between the line which connects the center of the light sensing element 304 and the point on the intermediary transfer belt 219 which the beam of infrared light emitted by the light emitting element 303 hits, and the line perpendicular to the surface of the intermediary transfer belt 219 becomes 45°. As the intermediary transfer belt 219 is circularly moved, the beam of infrared light emitted by the light emitting element 303 hits the surface of the intermediary transfer belt 219 and each of the positional deviation detection image 305 , different in color, on the intermediary transfer belt 219 , and the light sensing element 304 catches a portion of the beam of infrared light emitted by the light emitting element 303 and diffusely reflected by the surface of the intermediary transfer belt 219 and each of the positional deviation detection image 305 on the intermediary transfer belt 219 .
[0047] FIG. 4 shows the circuit for driving the sensor unit 225 . The light emitting element 303 is turned on and off by the light emitting element driving signal Vledon from the control section 206 . More specifically, a switching element 404 such as a transistor is driven by the light emitting element driving signal Vledon through a base resistor 405 , whereby the current which flows to the light emitting element 303 is controlled by a current regulator resistor 405 , turning on or off the light emitting element 303 . As the light sensing element 304 receives the portion of the beam of infrared light emitted by the light emitting element 303 and diffusely reflected by the surface of the intermediary transfer belt 219 and each positional deviation image on the intermediary transfer belt 219 , electric current flows through the resistor 401 by an amount proportional to the amount of light received by the light sensing element 304 . Thus, the amount of the diffusely reflected light received by the light sensing element 303 is outputted in the form of an analog signal.
[0048] The above-described analog signal which shows the amount of the diffusely reflected light is converted into a digital signal Vdout, by comparing the analog signal in voltage with a preset threshold voltage, the value of which is set by a pair of voltage dividing resistors 406 and 407 . The control section 206 detects the points in time at which the digital signal steps up in value (voltage) and the points in time at which the digital signal steps down in value (voltage) by sampling the digital signal Vout with preset intervals, and sequentially stores the points in time at which each edge was detected, in an unshown storage device.
[0049] [Positional Deviation Detection Images]
[0050] Described next are a set of positional deviation detection images in this embodiment, an example of the pattern in which the positional deviation detection images are arranged, and a method for correcting the image forming apparatus 201 in the positional deviation which occurs among multiple developer images (toner images) different in color as the images are transferred onto the intermediary transfer belt 219 .
[0051] FIG. 5 shows a set of positional deviation detection images, and the pattern in which the images are arranged. FIG. 5 does not show the trailing edge buildup of developer (toner). The positional deviation detection image set is made up of yellow developer images 501 y and 502 y , magenta developer images 501 m and 502 m , cyan developer images 501 c and 502 c , and black developer images 501 k and 502 k . As is evident from FIG. 5 , the positional deviation detection image set has a front half, which includes images 501 y , 501 m , 501 c and 501 k , and a rear half, which includes images 502 y , 502 m , 502 c and 502 k . The front and rear halves are symmetrical with reference to the line which coincides with the center of the set, in terms of the moving direction of the intermediary transfer belt 219 and is perpendicular to the moving direction of the intermediary transfer belt 219 .
[0052] The amount of positional deviation of this positional deviation detection set can be determined by detecting the amount of positional deviation of each developer image in the set, in terms of both the primary and secondary scan directions, by the sensor unit 225 . It should be noted here that the black developer image is layered upon the yellow developer image, because the light sensing element 304 of the sensor unit 225 used in this embodiment is such a light sensing element that senses the portion of the beam of light emitted from the light emitting element 303 and diffusely reflected by the positional deviation detection images.
[0053] The light which was diffusely reflected by the black developer image on the intermediary transfer belt 219 is as low in intensity as the light which was diffusely reflected by the intermediary transfer belt 219 itself. Thus, if the black developer image is formed directly on the intermediary transfer belt 219 , the difference in intensity between the light which was diffusely reflected by the black developer image and the light which was diffusely reflected by the intermediary transfer belt 219 itself is too small for the sensor unit 225 to detect the edge (pattern) of the black developer image. Therefore, the black developer image, which is small in the amount by which it diffusely reflect light, is formed on the color developer image which is larger in the amount by which it diffusely reflect light, so that the edge of the black developer image can be detected by the sensor unit 225 . It does not need to be the yellow developer image that the black developer image is to be formed. That is, it may be the cyan developer image or magenta developer images.
[0054] FIG. 6 is a drawing which shows the pattern in which the positional deviation detection images are formed on the intermediary transfer belt 219 . In FIG. 6 , the intermediary transfer belt 219 which is an endless belt is drawn as if it were an ordinary long belt. The positional deviation detection images PL 1 -PL 6 , and PR 1 -PR 6 , in FIG. 6 correspond to the positional deviation detection images of the positional deviation detection image set in FIG. 5 , respectively. In the case of FIG. 6 , a set of six positional deviation detection images (PL 1 -PL 6 ), which are to be detected by the optical sensor 301 , and another set of six positional deviation detection images (PR 1 -PR 6 ), which are to be detected by the optical sensor 302 , are formed on the intermediary transfer belt 219 , being evenly spaced across the entire circumference of the intermediary transfer belt 219 . That is, a total of 12 positional deviation detection images are formed on the intermediary transfer belt 219 . Thus, the fluctuation in the peripheral velocity, fluctuation in the moving speed of the intermediary transfer belt 219 , and the like, are cancelled. As the intermediary transfer belt 219 is moved in the direction indicated by an arrow mark in FIG. 6 , the positional deviation detection images on the intermediary transfer belt 219 are sequentially detected by the optical sensors 301 and 302 .
[0055] FIG. 7(C) shows an example of waveform of the analog signal outputted by the sensor unit 225 when the positional deviation detection images were detected by the sensor unit 225 . The analog signal outputted by the sensor unit 225 when the unit 225 detects the color development images in the positional deviation detection image set includes a large amount of light diffusely reflected by the color development images. Thus, its peak voltage is greater in value than the threshold voltage. On the other hand, the analog signals outputted by the sensor unit 225 when the unit 225 detects the black developer image and the intermediary transfer belt 219 itself do not include a large amount of components diffusely reflected by the black developer image and intermediary transfer belt 219 itself. Therefore, the portions of signals which correspond to the black developer image and intermediary transfer belt 219 itself, are lower in amplitude than the threshold voltage.
[0056] FIG. 7(D) shows an example of the waveform of the digital signal obtained by digitizing the analog signal outputted by the sensor unit 225 , based on the relationship between the peak and valley portions of the analog signal and the threshold voltage, with the use of a comparator or the like device. The position of the edge of each of the color developer images, and that of the black developer image, can be detected based on this digital signal.
[0057] [Description of Method for Detecting Positional Deviation]
[0058] Next, the method for calculating the amount of positional deviation among the images for detecting the positional deviation, based on the results of the detection of the position of the edge of each positional deviation detection image, is described. The computation for determining the amount of positional deviation with the use of the following mathematical equations is carried out by the control section 206 .
[0059] In this embodiment, the amount by which positional deviation will possibly occur among the images, different in color, for forming a multicolor image when the images are transferred onto the intermediary transfer belt 219 is obtained by computing the amount of positional deviation among the referential positional deviation detection image having the referential color, and each of the positional deviation detection images, which is different in color from the referential image. In the case of this embodiment, the amount of positional deviation of the magenta, cyan, and black images for positional deviation detection, relative to the yellow image for positional deviation detection, is calculated. FIG. 8(C) shows the points in time which correspond to the front edge, center, and trailing edge of each positional deviation detection images, computationally obtained by the control section 206 based on the digital signal obtained through the conversion of the analog signal outputted by the sensor unit 225 when the positional deviation detection images shown in FIGS. 8(A) and 8(B) were detected by the sensor unit 225 . What the referential codes in FIG. 8(C) stand for are as follows:
[0060] ty 11 , ty 12 and ty 1 : positions of front edge, trailing edge, and center of first yellow developer image, respectively,
[0061] tk 11 , tk 12 and tk 1 : positions of front edge, trailing edge, and center of first black developer image, respectively,
[0062] tm 11 , tm 12 and tm 1 : positions of front edge, trailing edge, and center of first magenta developer image, respectively,
[0063] tc 11 , tc 12 and tc 1 : positions of front edge, trailing edge, and center of first cyan developer image, respectively,
[0064] ty 21 , ty 22 and ty 2 : positions of front edge, trailing edge, and center of second yellow developer image, respectively,
[0065] tk 21 , tk 22 and tk 2 : positions of front edge, trailing edge, and center of second black developer image, respectively,
[0066] tm 21 , tm 22 and tm 2 : positions of front edge, trailing edge, and center of second magenta developer image, respectively,
[0067] tc 21 , tc 22 and tc 2 : positions of front edge, trailing edge, and center of second cyan developer image, respectively.
[0068] The position of the center of each positional deviation detection image can be obtained by following mathematical equations:
[0000] tk 1=( tk 11+ tk 12)/2
[0000] ty 1=( ty 11+ ty 12)/2
[0000] tm 1=( tm 11+ tm 12)/2
[0000] tc 1=( tc 11+ tc 12)/2
[0000] tk 2=( tk 21+ tk 22)/2
[0000] ty 2=( ty 21+ ty 22)/2
[0000] tm 2=( tm 21+ tm 22)/2
[0000] tc 2=( tc 21+ tc 22)/2
[0069] The difference in the length of time between the yellow developer image, or the referential developer image, and each of the rest of the developer images which are different in color, can be calculated with the use of the following mathematical equations, based on the calculated position of the center of each positional deviation detection image:
[0070] Amount of difference, in terms of length of time, of the black developer image: PDt_ky=((tk 1 −ty 1 )+(tk 2 −ty 2 ))/2,
[0071] Amount of difference, in terms of length of time, of the magenta developer image: PDt_my=((tm 1 −ty 1 )+(tm 2 −ty 2 ))/2, and
[0072] Amount of difference, in terms of length of time, of the cyan developer image: PDt_cy=((tc 1 −ty 1 )+(tc 2 −ty 2 ))/2.
[0073] The point in time which corresponds to the positions of the front edge, trailing edge, and center of each positional deviation detection image corresponds to the elapsed length of time from a preset referential point in time (for example, point in time at which timer is started). The control section 206 calculates the amount of positional deviation of each of the positional deviation detection images other than the yellow positional deviation detection image, or the referential image, relative to the yellow positional deviation detection image, with the use of the following equations, based on the speed PS of the intermediary transfer belt 219 and the calculated amount, in length in time, of the positional deviation:
[0074] Amount of positional deviation of black developer image in terms of the secondary scan direction: Photosensitive drum 1 _ky=PS×PDt_ky,
[0075] Amount of positional deviation of magenta developer image in terms of the secondary scan direction: Photosensitive drum 1 _my=PS×PDt_my, and
[0076] Amount of positional deviation of cyan developer image in terms of the secondary scan direction: Photosensitive drum 1 _my=PS×PDt_cy.
[0077] The control section 206 carries out the above described computation for each positional deviation detection image set, and obtains the average amount of positional deviation of all the sets, obtaining thereby the amount of positional difference between the point in time at which each of positional deviation detection images other than the yellow positional deviation detection image, that is, the referential positional deviation detection image, begins to be formed (written) and the point in time at which the yellow positional deviation detection image begins to be formed (written). Here, the calculated amounts PDd 1 _ky, PDd 1 _my and PDd 1 _cy will be referred to as the first amount of positional deviation. If the first positional deviation is positive in value, it means that the point in time at which the black, magenta, and/or cyan positional deviation detection image began to be written is later relative to the point in time at which the yellow positional deviation detection image, or the referential positional deviation detection image, began to be written. On the other hand, if the first position deviation is negative in value, it means that the point in time at which the black, magenta, and/or cyan positional deviation detection image began to be written is earlier than the point in time at which the yellow positional deviation detection image, or the referential positional deviation detection image, began to be written.
[0078] [Errors Attributable to Trail Edge Piling]
[0079] In a case where the “trailing edge piling”, that is, the phenomenon which results in increase in the image density of the downstream edge portion of a toner image, in terms of the secondary scan direction, formed on the intermediary transfer belt 219 , did not occur, the waveform of the analog signal outputted by the sensor unit 225 is as indicated by a broken line in FIG. 7(C) . In comparison, when the “trailing edge piling” occurred, the analog signal is as indicated by a solid line in FIG. 7(D) . That is, it is later in terms of the point in time at which its steps down in potential for the following reason. That is, as the “trailing edge piling” occurs to the positional deviation detection images, the positional deviation detection images become higher in density across their trailing edge portion, which in turn increase the amount by which the light emitted by the light emitting element 303 and diffusely reflected by the positional deviation detection image is detected by the sensor unit 225 .
[0080] In such a case, as shown in FIG. 7(D) , the position of the trailing edge of the positional deviation detection image, which is determined based on the signal outputted by the sensor unit 225 , is offset downstream compared to the detected position (actual position) of the trailing edge of the positional deviation detection image to which the “trail edge piling” did not occur. In FIG. 7(D) , the difference in length of time which occurs between the actual and calculated positions of the trailing edge of each positional deviation detection image is shown by a referential code Δty, Δtm or Δtc. Because of this error in the detection of the position of the trailing edge of a positional deviation detection image, the position of the center of each positional deviation detection image, which is calculated based on the output signal of the sensor unit 225 , is offset downstream by an amount proportional to the amount of increase, in density, of the trailing edge portion of the positional deviation detection image, which is attributable to the “trailing edge piling”.
[0081] As described above, the position of the trailing edge of each positional deviation detection image, which is determined by calculation based on the output signal from the sensor unit 225 includes the error attributable to the “trailing edge piling”. That is, the greater the amount of “trailing edge piling”, the greater the error in the calculated position of the trailing edge of the positional deviation detection image, which is determined by calculation based on the output signal from the sensor unit 225 , and therefore, the greater the error in the position of the center of the positional deviation detection image, which is calculated based on the calculated position of the trailing edge of the positional deviation detection image. Therefore, in order to accurately control the image forming apparatus 201 to correct the apparatus 201 in the positional deviation among multiple developer (toner) images which are different in color, it is necessary to take into consideration, the deviation of the calculated position of the center of each positional deviation detection image, from the actual center of each positional deviation detection image, which is attributable to the “trailing edge piling”.
[0082] One of the thinkable solutions to this problem is to use the value obtainable by subtracting the amount of error in the position of the trailing edge of the positional deviation detection image, which is attributable to the “trailing edge piling”, from the value which indicates the position of the trailing edge of the positional deviation detection image, which is determined by calculation based on the output signal from the sensor unit 225 . In this case, the position of the center of each of the positional deviation detection images is obtained based on the corrected position of the tail end edge of the positional deviation detection image. Then, the amount of positional deviation among the positional deviation detection images which are different in color are obtained by comparing the positional deviation detection images in terms of the position of their center. Then, the image forming apparatus 201 is corrected in the positional deviation which occurs as multiple color developer images are sequentially transferred onto its intermediary transfer belt 219 . Therefore, even if the “trailing edge piling” occurs, it is possible to accurately and precisely correct the image forming apparatus 201 in the positional deviation among multiple monochromatic developer images, different in color, which are formed to yield a multicolor image.
[0083] [Effect of Environment and Color upon Amount of “Trailing Edge Filing”]
[0084] The amount of “trailing edge piling” is affected by the changes in the temperature/humidity of the environment in which the image forming apparatus 201 is being used. Thus, the error in the detected amount of positional deviation among the positional deviation detection images reflects the changes in the temperature/humidity of the environment in which the image forming apparatus 201 is being used. More specifically, in an environment which is low in temperature/humidity, the triboelectric charge given to developer is narrow in its range of potential, and therefore, the amount of “trailing edge piling” is small. Therefore, the detected positional deviation among the positional deviation detection images is small in the amount of error. In comparison, as the environment in which the image forming apparatus 201 is being operated increases in temperature/humidity, the triboelectric charge which the developer acquires widens in the range of its potential, which in turn increases the amount of the “trailing edge piling”. Therefore, the calculated amount of the positional deviation among the positional deviation detection images is more erroneous than when the environment in which the image forming apparatus 201 is being operated is low in temperature/humidity.
[0085] In this embodiment, therefore, the amount of error in the calculated position of the center of each positional deviation detection image, which is attributable to the “trailing edge piling” is estimated based on the ambient temperature/humidity of the image forming apparatus 201 . Then, this estimated error is taken into consideration when the amount of positional deviation of each positional deviation detection image, relative to the referential positional deviation detection image, in terms of the direction of the secondary scan, which is calculated based on the output signal from the sensor unit 225 , is corrected. The thus obtained amount of positional deviation will be referred to as “second amount of positional deviation”, hereafter. Then, the image forming apparatus 201 is corrected in the positional deviation, based on the second amount of positional deviation. Thus, even if the “trailing edge piling” occurs to the positional deviation detection images, that is, even if developer piles along the trailing edge of the positional deviation detection image while the positional deviation detection image is formed, the error attributable to the “trailing edge piling” is minimized in its effect upon the calculation of the position of the trailing edge of the positional deviation detection image. Therefore, the image forming apparatus 201 can be accurately corrected in the positional deviation among the multiple color images, different in color, which are formed to yield a multicolor image.
[0086] Next, the method for estimating the amount of the error attributable to the effect of the ambient temperature/humidity of the image forming apparatus 201 upon the amount of the “trailing edge piling”, is described. Referring to FIG. 9 , in this embodiment, each of the temperature range and humidity range is divided into three sub-ranges (Sub-ranges A-C). The amount by which developer piles up along the trailing edge of the positional deviation detection image while the positional deviation detection image is formed is affected by the color of the positional deviation detection image. In this embodiment, therefore, the position of the trailing edge of each positional deviation detection image is calculated based on the output signal from the sensor unit 225 , under each sub-range of the temperature/humidity range, and the amount of the error in the calculated position of the positional deviation detection image, which is attributable to the “trailing edge piling” is found out in advance. Then, this information about the error is organized into a table which shows the relationship between the ambient temperature/humidity range (three sub-ranges) and developer color, and is stored in advance in a storage means 230 . This information about the error is such information that shows the correlation between the environment in which the image forming apparatus 201 is being operated, and the error, and is used as the amount by which the first amount of positional deviation is corrected (amount for compensating for “trailing edge piling”).
[0087] FIG. 1 is an example of a table which shows the relationship between the temperature/humidity range (having three sub-ranges), and the amounts PDe_ky, PDe_my and PDe_cy, by which the position of the trailing edge of the positional deviation detection image of black, magenta, and cyan colors, respectively, are to be corrected. In this embodiment, the temperature/humidity range is divided into three sub-ranges. However, it may be divided into four or more smaller sub-ranges. Further, instead of a table such as the one in FIG. 1 , a formula for calculating the amount by which compensation is to be made for the “trailing edge piling” based on the temperature/humidity detected by the environment sensor 227 may be provided. Further, FIG. 1 is for the case in which the calculated position of each of the positional deviation detection images of black, magenta, and cyan colors, relative to the calculated position of the positional deviation detection image of yellow color, that is, the referential positional deviation detection image, is corrected. However, it is not mandatory that the color of the referential positional deviation detection image is yellow. That is, in a case where color other than yellow is chosen as the color for the referential positional deviation detection image, the table in FIG. 1 is to be modified so that it shows the relationship between the temperature/humidity range (three sub-ranges) and the amount by which the calculated position of the trailing edge of each of the positional deviation detection images, which is different in color from the referential positional deviation detection image, in terms of the amount by which the calculated position of each positional deviation detection image is corrected.
[0088] The control section 206 uses the amount of the positional deviation among multiple (four) developer (toner) images, different in color, which is determined based on the output signal from the sensor unit 225 , and the amount of the “trailing edge piling”, which is affected by the ambient temperature/humidity detected by the environment sensor 227 . More specifically, the control section 206 adjusts the image forming apparatus 201 in the timing with which each developer (toner) image is formed by the image forming means.
[0089] [Control Sequence for Correcting Image Forming Apparatus in Positional Deviation among Multiple Developer Images]
[0090] FIG. 10 is a flowchart of the control sequence for correcting the image forming apparatus 201 in the positional deviation among multiple monochromatic developer images which the image forming apparatus 201 forms to yield a multicolor image. Hereafter, this control sequence will be referred to simply as “positional deviation control sequence”. In Step 1001 , the printable image data generation section 204 receives a calibration command, which is a command for making the image forming apparatus 201 carry out the positional deviation control sequence. As the section 204 receives the calibration command, the control section 206 obtains the values of the ambient temperature/humidity detected by the environment sensor 227 .
[0091] In Step 1002 , the control section 206 obtains, from the table for compensating for the “trailing edge piling”, the amount by which the calculated position of the trailing edge of each positional deviation detection image is to be corrected according to the temperature/humidity detected by the environment sensor 227 .
[0092] In Step 1003 , the control section 206 determines (calculates) the amount of the positional deviation. More specifically, it makes the image forming apparatus 201 form positional deviation detection images on the intermediary transfer belt 219 , obtains the output signal of the sensor unit 225 , and calculates the front edge position, trailing edge position, and center position of each positional deviation detection image, based on the output signal of the sensor unit 225 .
[0093] In Step 1004 , the control section 206 calculates the first amounts PDd 1 _ky, PDd 1 _my and PDd 1 _cy of positional deviation, from the position of the center of each positional deviation detection image, calculated based on the output signal of the sensor unit 225 .
[0094] In Step 1005 , the control section 206 calculates the amounts PDe_ky, PDe_my and PDe_cy, by which the position of the trailing edge of the positional deviation detection image of black, magenta, and cyan colors, respectively, are to be corrected according to the ambient temperature/humidity detected by the environment sensor 227 , with reference to the compensation table for the “trailing edge piling”. Then, the control section 206 calculates the second amounts PDd 2 _ky, PDd 2 _km and PDd 2 _kc of positional deviation, from the calculated amount of compensation for the “trailing edge piling”, and the first amounts of positional deviation, using the following mathematical equations:
[0000] PDd 2 — ky=PDd 1+ ky−PDe — ky,
[0000] PDd 2 — my=PDd 1+ my−PDe — my,
[0000] PDd 2 — cy=PDd 1+ cy−PDe — cy.
[0095] In Step 1006 , the control section 206 transmits the second amounts of positional deviation to the printable image generation section 204 , and makes the section 204 adjust, in proportion to the second amounts of the positional deviation, the position, in terms of the secondary scan direction, at which multiple images, different in color, begin to be written. Then, the control section 206 controls the image formation stations so that they begin to write multiple images, different in color, one for one, with the timings which correspond to the second amount of positional deviation. This correctional control sequence is only one of many correctional control sequences available for correcting the image forming apparatus 201 , more specifically, the image forming stations (image forming means), in the position of the developer images formed on the image bearing members, one for one, by the image forming means, based on the second amount of positional deviation, in order to ensure that the registration of the monochromatic color toner images, different in color, formed on the photosensitive drums 215 , one for one, will be such that the monochromatic color toner images properly align on the intermediary transfer belt 219 , or the medium, onto which the monochromatic toner images are transferred in layers. As for the other correctional control sequences, there are a method which electrically corrects image formation signals, a method which drives the mirror, which is positioned in the laser beam path, in order to compensate for the error in the length and/or angle of the laser beam path for each color, which is attributable to the mechanical error, such as the error in the distance among the photosensitive drums, which is attributable to the attachment of the photosensitive drums, and the like methods. In the case of such methods, the control section 206 corrects the image formation signal, based on the table stored in the ROM of the control section 206 , in order to correct the image forming apparatus 201 in terms of the error in the registration (positional deviation) of each monochromatic color image on the photosensitive drum.
[0096] In this embodiment, the position of the trailing edge of each positional deviation detection image, which is calculated based on the output signal from the sensor unit 225 , is corrected in consideration of the error attributable to the “trailing edge piling”. Then, the image forming apparatus 201 is corrected in the image formation operation, based on the corrected position of the trailing edge of the positional deviation detection image, so that the apparatus 201 is minimized in the amount of positional deviation among multiple monochromatic image, different in color, which are formed to yield a multicolor image. That is, the information related to the amount by which compensation is to be made for the error in the position of the trailing edge of the positional deviation detection image, which is determined based on the output signal of the sensor unit 225 , that is, the distance between the position of the trailing edge of the positional deviation detection image, which is determined based on the output signal of the sensor unit 225 and the actual position of the trailing edge of the positional deviation detection image, which is attributable to the unintended increase in image density which occurs to the downstream edge portion of the positional deviation detection image, in terms of the direction in which recording medium is conveyed or the intermediary transfer belt 219 is moved, when a monochromatic developer image is transferred onto a sheet of recording medium or the intermediary transfer belt 219 , is stored in advance for each color. Then, the image forming apparatus 201 is corrected in the position in which the developer image is formed by the image forming means, based on the information about the position of each of multiple positional deviation detection images, different in color, formed on a sheet of recording medium or the intermediary transfer belt 219 , and the information about the amount by which the position of the positional deviation detection image is to be corrected, in order to minimize the image forming apparatus 201 in terms of the positional deviation among the multiple monochromatic developer images, different in color, which are formed to yield a multicolor image. Further, the effect of the temperature/humidity (environmental factors) of the environment in which the image forming apparatus 201 is being operated, upon the amount of the “trailing edge piling” is taken into consideration. Therefore, even if the “trailing edge piling” occurs, that is, even if developer particles pile along the trailing edge of the exposed portion of the peripheral surface of the photosensitive drum 215 , the image forming apparatus 201 is highly precisely corrected in the positional deviation among the multiple monochromatic developer images formed to yield a multicolor image.
[0097] In this embodiment, first, the amount (first amount) of positional deviation of each positional deviation detection image, relative to the referential positional deviation detection image (positional deviation detection image of yellow color in this embodiment), in terms of the secondary scan direction, is calculated, and then, the first amount of positional deviation is adjusted based on the information about the error which is attributable to the “trailing edge piling” and may be in the calculated position of the trailing edge of the positional deviation detection image. However, the method for compensating for the error in the position of the trailing edge of the positional deviation detection image, which is attributable to the “trailing edge piling”, based on the information about the amount by which the first amount of positional deviation is to be corrected, is not limited to the above described one. For example, the amount of the positional deviation, which does not include the error attributable to the “trailing edge piling”, may be calculated by correcting the amount of the positional deviation of the trailing edge of the positional deviation detection image, which is calculated from the output signal from the sensor unit 225 , using the information about the amount by which the correction is to be made. Further, it may be calculated by correcting the position of the trailing edge of the positional deviation detection image calculated from the output signal from the sensor unit 225 , based on the information about the amount by which the correction is to be made, and then, calculating the amount of positional deviation, from the corrected position of the trailing edge of the positional deviation detection image. The values in FIG. 1 which are for the amount by which the trailing edge position of the positional deviation detection image calculated from the output signal from the sensor unit 225 is to be adjusted, have only to be set and stored in advance, according to what kind of factor is to be adjusted in value.
Embodiment 2
[0098] Next, the second embodiment of the present invention is described. The basic structure of the sensor unit, and the basic design and arrangement of the positional deviation detection images, in this embodiment are the same as those in the first embodiment. Therefore, they are not going to be described in detail here.
[0099] The environment sensor 227 positioned in the image forming apparatus 201 in this embodiment is a temperature detection element such as a thermistor. More specifically, the environment sensor 227 is placed with the image forming apparatus 201 , in the area which is unlikely to be affected by the heat generated within the image forming apparatus 201 , and yet, in which the environment sensor 227 can accurately detect the ambient temperature of the image forming apparatus 201 . The environment sensor 227 detects the ambient temperature of the image forming apparatus 201 . In this embodiment, the environment sensor 227 is positioned inside the image forming apparatus 201 , in the area in which the environment sensor 227 can accurately detect the ambient temperature of the image forming apparatus 201 . However, it is not mandatory that the environment sensor 227 is placed in the above described location. That is, the position in which the environment sensor 227 is to be placed may be any location as long as the location allows the environment sensor 227 to accurately detect the ambient temperature of the image forming apparatus 201 .
[0100] The amount by which the error attributable to the “trailing edge piling” is to be corrected is set based on the temperature level detected by the environment sensor 227 . Referring to FIG. 11 , the range into which the temperature detected by the environment sensor 227 is expected to fall is divided into three sub-ranges A-C, and the amount by which the error attributable to the “trailing edge piling” is set in advance for each sub-range. Further, since the amount of the “trailing edge piling”, that is, the amount by which developer piles along the trailing edge of an exposed area of the peripheral surface of the photosensitive drum 215 is affected by the color of the image to be formed on the photosensitive drum 215 . Therefore, the amount by which the error attributable to the “trailing edge piling” is to be corrected is set in advance for each color for the positional deviation detection image. FIG. 12 is an example of a table which shows the relationship in terms of the amounts PDet_ky, PDet_my and PDet_cy by which the error attributable to the “trailing edge piling” is to be corrected, with respect to the temperature (three sub-ranges) detected by the see 227 and the colors of the positional deviation detection images. In this embodiment, the temperature range is divided into three sub-ranges. However, the temperature range may be divided into four or more narrower sub-ranges. Further, instead of relying on a table such as the one in FIG. 12 , a formula for computing the amount by which compensation is made for the error attributable to the “trailing edge piling”, based on the ambient temperature of the image forming apparatus 201 may be created so that the error attributable to the “trailing edge piling” can be calculated based on the ambient temperature of the image forming apparatus 201 . That is, the information about the error attributable to the “trailing edge piling” to be stored in the storage means 230 may be a table like the one in FIG. 1 , or a formula usable to compute the amount of error attributable to the “trailing edge piling”, based on the ambient temperature of the image forming apparatus 201 and/or the color of the developer. The control section control section 206 obtains the amount by which the error attributable to the trailing edge piling to be corrected, with reference to the table or formula stored in the storage means 230 .
[0101] The operational sequence for correcting the image forming apparatus in the positional deviation among the multiple developer images, different in color, which are formed to yield a multicolor image is the same as the one in the first embodiment. That is, it is the same as Steps 1001 - 1006 . In this embodiment, the second amounts PDd 2 _ky, PDd 2 _my and PDd 2 _cy of the positional deviation are calculated with the use of the following equations:
[0000] PDd 2 — ky=PDd 1 — ky+PDet — ky,
[0000] PDd 2 — my=PDd 1 — my+PDet — my,
[0000] PDd 2 — cy=PDd 1 — cy+PDet — cy.
[0102] In this embodiment, the environment sensor 227 is a temperature detection element. However, it may be a humidity detection sensor. In a case where it is a humidity detection sensor, the humidity range is divided into three sub-ranges A-C, as shown in FIG. 13 , and a table such as the one in FIG. 12 which shows the relationship between the humidity range (having three sub-ranges), and the amounts by which the position of the trailing edge of the positional deviation detection image of black, magenta, and cyan colors, respectively, are to be adjusted, is stored in the storage means 230 . Then, the amount by which the position of the trailing edge of the positional deviation detection image, which is calculated based on the output signal from the sensor unit 225 , is to be corrected in terms of the error attributable to the “trailing edge piling” is calculated based on the detected humidity, with reference to the table in the storage means 230 . In other words, the second amount of positional deviation may be calculated from the first amount of positional deviation and the amount by which the position of the trailing edge of the positional deviation detection image calculated from the output signal of the sensor unit 225 is to be adjusted in terms of the error attributable to the “trailing edge piling”, as in the first embodiment.
[0103] The control section 206 makes the image formation stations start writing images, different in color, one for one, with the timings based on the second amount of positional deviation.
[0104] In this embodiment, the image forming apparatus 201 is more simply structured than the one in the first embodiment. That is, the condition of the environment in which the image forming apparatus 201 is being used is detected by using only the temperature sensor or humidity sensor, and the amount by which the trailing edge position of each positional deviation detection image detected by the sensor unit 225 is to be corrected in terms of the error attributable to the “trailing edge piling” is calculated based on the ambient humidity detected by the humidity sensor. Then, the point at which each of multiple developer images, different in color, is to begin to be written is adjusted by the calculated amount by which the trailing edge position of each positional deviation detection image detected by the sensor unit 225 is to be corrected in terms of the error attributable to the “trailing edge piling”. Therefore, even in a case where the “trailing edge piling” occurs, that is, developer piles along the trailing edge of an exposed portion of the peripheral surface of the photosensitive drum 215 , the image forming apparatus 201 is highly precise in the position at which each of multiple developer images, different in color, is to begin to be written.
[0105] In the preceding embodiments, the amount (first amount) by which the position of the trailing edge of each positional deviation detection image, which is detected by the sensor unit 225 and includes the error attributable to the “trailing edge piling”, is to be adjusted in consideration of the error attributable to the “trailing edge piling” to obtain the second amount by which the position at which each of the multiple images, different in color, is to begin to be written is adjusted. Then, based on the second amount of positional deviation, the image forming apparatus 201 is adjusted in the timing with which each of the multiple images, different in color, is to begin to be written (by laser). In the present invention, however, the timing with which the writing of the positional deviation detection image on the intermediary transfer belt 219 ends, that is, the timing with which the trailing edge of the positional deviation detection image is written on the intermediary transfer belt 219 , may be advanced by the amount equivalent to the amount of error attributable to the “trailing edge piling”. That is, the image forming apparatus 201 may be adjusted in the registration, in advance for the image forming means, by the amount equivalent to the error attributable to the “trailing edge piling”, in order to make the timing with which the writing of the trailing edge of the positional deviation detection image is to be ended, earlier than the original timing set by the information about the image to be formed, by modifying the control program and/or table to be used to control the operation of the image forming means based on the information about the image to be formed.
[0106] As the image forming means is controlled as described above, the portion of the intermediary transfer belt 219 , on which the trailing edge of the positional deviation detection image is to be formed, shifts frontward (upstream in terms of moving direction of intermediary transfer belt 219 ) of the original portion of the intermediary transfer belt 219 , on which the trailing edge of the positional deviation detection image is to be formed. On the other hand, as described above, due to the error attributable to the “trailing edge piling”, the position of the trailing edge of the positional deviation detection image calculated based on the output signal from the sensor unit 225 deviates rearward (downstream in terms of moving direction of intermediary transfer belt 219 ). Thus, if the timing with which the writing of each positional deviation detection image ends is advanced so that the frontward deviation and rearward deviation cancel each other, it is possible to make the trailing edge position of the positional deviation detection image calculated from the output signal from the sensor unit 225 precisely coincide with the point at which the trailing edge of the positional deviation detection image will be actually.
[0107] In this case, the amount (first amount) of positional deviation to be calculated based on the position of the trailing edge of the positional deviation detection image calculated based on the output signal from the sensor unit 225 will have been rid of the error attributable to the “trailing edge piling”. Therefore, the image forming apparatus 201 is more precisely corrected in the amount of positional deviation among the multiple developer images, different in color, than in a case where it is corrected based on the first amount of the positional deviation in the preceding embodiments.
[0108] Further, in the preceding embodiments, the image forming apparatus 201 was structured so that developer images were transferred (primary transfer) from the photosensitive drums 215 , as image bearing members, onto the intermediary transfer belt 219 , as intermediary transfer medium, and then, the developer images on the intermediary transfer belt 219 are transferred (secondary transfer) onto a sheet of recording paper. However, the present invention is also applicable to an image forming apparatus equipped with a transferring means which directly transfers developer images onto a sheet of recording paper, as final recording medium, from the photosensitive drums 215 . In a case where the present invention is applied to such an image forming apparatus, the sensor unit 225 detects the position of the trailing edge of positional deviation detection images formed on a sheet of recording paper.
[0109] Further, in each of the preceding embodiments, the photosensitive drums 215 were fixed in position, and the intermediary transfer belt 219 was circularly moved. Therefore, the developer images, different in color, are different in position at which they are transferred onto the intermediary transfer belt 219 . However, the present invention is also applicable to an image forming apparatus structured so that its multiple photosensitive drums are sequentially moved into a single location in which they are transferred onto the intermediary transferring member (primary transferring member) or a sheet of recording medium (paper) (secondary transfer member).
[0110] While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth, and this application is intended to cover such modifications or changes as may come within the purposes of the improvements or the scope of the following claims.
[0111] This application claims priority from Japanese Patent Application No. 270296/2011 filed Dec. 9, 2011 which is hereby incorporated by reference. | An image forming apparatus includes a plurality of image forming means; transferring means for superimposingly transferring the developed images; a detector for detecting light reflected by the developed image; a position detector for detecting a position of the developed image; memory for storing for each color of the developer, information relating to a correction amount for correcting an error between a position obtained by the position detector and an actual position, a corrector for correcting the position of the developed image formed on the image bearing member by the image forming means, on the basis of positions of the developed images of the respective color detected by the position detector and information relating to the correction amount stored in the memory. | 80,100 |
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation of application Ser. No. 849,555, filed Nov. 8, 1977, now abandoned, which was a division of application Ser. No. 574,446 filed May 5, 1975 and now U.S. Pat. No. 4,163,971.
BACKGROUND OF THE INVENTION
This invention relates to a panel for displaying analog limits and values, and particularly to a bar graph analog display panel for displaying a value which may vary between certain limits and must be continuously monitored.
In industrial processes, it is frequently necessary continuously to measure and monitor conditions such as temperatures, pressure, flow, etc., which are critical to the process. Frequently, transducers convert the parameter to be measured to an electrical value which is then displayed by a D'Arsonval meter movement. Ideally, in a D'Arsonval meter movement, the displacement of a pointer is proportional to the magnitude of an input current. This current is a known function of the input parameter to be measured so that the pointer displacement is a measure of the input parameter. Thus, the information is displayed in the form of a displacement which is continuously analogous to the input parameter.
Another electronic device which generates a displacement analog of an electrical value transduced from a parameter to be measured is a servo indicator. Here, a motor drives an indicator, and an electrical equivalent of the motor position is compared with the input value. When the motor reaches a null balance, the indicator displays a value corresponding to the parameter to be measured.
Process parameters may also be displayed digitally. A multi-digit number is displayed which indicates the value of the input parameter.
All of these displays have certain disadvantages. Both the D'Arsonval movement and the servo system involve the use of moving parts which are susceptible to destruction or failure as a result of shocks. Servo indicators are subject to hysteresis errors. An all-electronic digital indicator is rugged and has no moving parts. However, it requires mental calculation on the part of the observer to determine how far the value has strayed from an ideal value or from between desired limits.
Analog displays yield more information about a parameter than just its magnitude. By observing the pointer or scale, it can be noted that the variable is steady or drifting up and down and that it is, or is not, near some particular reference point. This type of information is generally called "rate information" or "trend information". Trend information is particularly useful when many instruments are grouped together, all of which are monitoring different parameters of a process. By viewing the magnitudes and trends of all measurements, a clearer picture of the process can be reached than by observing single measurements only. Furthermore, in many cases, it is desirable to know if a measured parameter is close to a danger point. By providing an index mark, it is possible to spot an approaching problem quickly using trend information.
Recently a new type of display device has been developed and marketed under the trademark SELF-SCAN. Basically, this is composed of a multi-element gas discharge device in which the area of illumination is moved around a display by selective excitation of the elements. In one version, a large number of cathode elements are printed on an insulating substrate. A transparent cover for this pattern carries a transparent anode surface on its underside. The interior between the cover and the pattern is filled with an ionizable gas. A glow discharge is generated between the anode plate and the cathode elements. A keep-alive anode forms a continuous discharge with a keep-alive cathode. The gap between them provides a continuous source of metastable ions. The system is energized so that the glow at any electrode can transfer only between adjacent gaps. A reset cathode near the keep-alive gap transfers the glow to a reset gap formed between the reset cathode and the transparent anode. The remaining cathodes are connected in three groups so that the glow can be constrained to travel along the display by opening the cathode which has the glow and grounding the next cathode in the desired phase sequence. The length of the illuminated area represents a quantized indication of an input parameter having trend information. Such devices have a number of disadvantages in the display of monitored analog information. They merely display a process parameter without displaying the range or limits within which this process parameter may vary. While the variable range may be painted behind the bar, it is desirable that the limits of this range be made variable so that they can be reset.
An object of the invention is to improve the display device itself so that it is capable of furnishing variable range or limit information.
SUMMARY OF THE INVENTION
According to a feature of the invention, the above object is attained in whole or in part, by forming a row of cathode display electrodes in an enclosure having an ionizable gas and spacing an anode electrode within the enclosure close enough to the cathode display electrodes to permit a visible discharge of a given intensity when a predetermined discharge voltage is applied between a cathode display electrode and the anode. Also, reset electrodes are provided at both ends of the row of cathode display electrodes so that successive scanning can start from either end of the bar. Circuit means energizes the anode electrode and scans the cathode display electrodes from one reset electrode at one end of the row until a band whose length corresponds to one set point value is illuminated, and then ceases scanning until the remaining portion of the scan cycle would produce an illuminated band from the second set point value to the upper limit.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a display panel embodying the invention and a schematic and logic diagram of a system for operating the panel;
FIG. 2 is an isometric drawing of a display panel used in FIG. 1 and embodying features of the invention; and
FIG. 3 is a schematic representation of the unit in FIG. 2 illustrating the manner in which the unit may be illuminated.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, a drive circuit C operates a bar graph display D. The bar graph display D is shown only partially in FIG. 1. Details of the display D appear in FIG. 2.
In FIGS. 1 and 2, the upper surface of a substrate 10 supports two rows of two hundred three aligned printed wiring cathodes 12 and 14 which form two bar graphs A and B of the display D. Every third cathode 12 is interconnected by three conductors to form phase 1A cathodes, phase 2A cathodes, and phase 3A cathodes as shown. Similarly, three separate conductors connect respective third ones of the cathodes 14 to form phase 1B cathodes, phase 2B cathodes, and phase 3B cathodes.
An insulating spacer 16 in the shape of a frame rests on the top peripheral edge of the substrate 10. The spacer separates the cathodes 12 and 14 from two transparent anodes 18 and 20 printed over the areas shown on the bottom face of a transparent cover plate 22. The anode 18 overlies the cathodes 12, and the anode 20 overlies the cathodes 14. The substrate 10, spacer 16 and plate 22 are sealed to form a gas-tight unit which contains an ionizable gas such as neon.
Two reset cathodes RA1 and RA2 are printed on the substrate 10 at the extreme ends of the cathodes 12 and connected to the substrate edge. Reset cathodes RB1 and RB2 are printed on the substrate 10 at the ends of the cathodes 14 and connected to opposite end edges of the substrate. The anodes 18 and 20 are sufficiently long to overlie the reset cathodes.
Extending between the reset cathode RA1 and the reset cathode RB1 but spaced therefrom by one intercathode step is a keep-alive cathode 24 printed on the substrate 10 and connected to a terminal. Extending from the reset cathode RA2 to the reset cathode RB2 is a second keep-alive cathode 26, also spaced from each of the reset cathodes by one intercathode step. Above the keep-alive cathodes 24 and 26 on the under surface of the plate 22 are keep-alive anodes 28 and 30 connected to otherwise unidentified terminals.
To drive the bar graph display D, the driver circuit C establishes a 250 volt potential between the keep-alive cathode 24 and the keep-alive anode 28, as well as between the keep-alive cathode 26 and the keep-alive anode 30, sufficient to ionize the gases between the elements 24 and 28 and between the elements 26 and 30 and to maintain the gas in its ionized state.
The keep-alive gaps between the keep-alive anodes and cathodes provide a continuous source of metastable ions in response to the power supplied. This provides the starting point for the entire operation.
In order to illuminate the portion of the bar A corresponding to an analog value, circuit C grounds the reset cathode RA1, and a positive potential is applied to the anode 18. This potential, together with the internal geometry of the display and the gas mixture, is selected so that the glow at any electrode can transfer between, but only between, adjacent anode-to-cathode gaps. The glow in the keep-alive gap at the cathode 24 now transfers to the anode-cathode reset gap. The driver circuit C then grounds the phase 1A cathodes and ungrounds or opens the reset cathode RA1. The glow now transfers from the reset cathode RA1 to the nearest phase 1A cathode. The circuit C then grounds the phase 2A cathodes and transfers the glow to the nearest phase 2A cathodes. Similarly, the driver circuit C then grounds the phase A3 cathodes and opens the phase A2 cathodes to transfer the glow to the nearest phase A3 cathode. By continuously grounding the phase 1, phase 2, and phase 3 cathodes in sequence and ungrounding the other cathodes, the driver C constrains the glow to travel along the display. Effectively, the driver circuit C opens the cathode which has the glow and grounds the next cathode in the desired phase sequence. The travel of the glow along the bar A continues until a point is reached that corresponds to the analog of the value to be displayed. The anode 18 is then de-energized, and the continuing scan along the cathodes fails to produce a glow.
After the circuit C has grounded the cathodes 12 a total number of two hundred three times so that the scan reaches the top, the driver circuit C waits to be recycled, at which time it again grounds the reset cathode RA1 and repeats the sequence. The basic parameters of the system establish the length of an entire display time within each cycle to be between ten and twenty-five milliseconds. In a preferred embodiment, the cycles are synchronized with a power line of 50 or 60 Hz. The cycles and the scanning speed, i.e., the inter-gap glow transfers, are sufficiently rapid and frequent so that a portion of the bar A corresponding to the analog value of the input voltage appears to be continuously illuminated. That is, the persistance of an observer's eye sees an illuminated bar portion extending from the reset cathode through the furthest cathode at which a glow has been introduced by grounding of the cathode and operation of the anode 18. This is shown in FIG. 3.
The system of FIG. 1 also displays a visual range or limits within which the input value shown in bar A is supposed to vary. The driver circuit C does this by illuminating the bottom portion of the bar B from the reset cathode RB1 to a lower set point established by a lower set point control LS and by illuminating the top of the bar B from the reset cathode RB2 down to an upper set point established by an upper set point control US in the driver circuit C. The unilluminated portion in the bar B represents the range. As shown in FIG. 3, the bar A is illuminated to a value V and the bar B between the bottom and a lower location LL and between the top and an upper location UL. If the system is to monitor a process variable that is permitted to vary between the ranges established between the upper set point and lower set point shown as UL and LL, an observer can note that the value V is between the set points. If the value V falls below the value LL or rises above the value UL, the observer is informed that the variable to be monitored has increased or decreased beyond the permitted range. In order to inform an observer more readily that the input value has increased or decreased beyond the permitted range, either the upper or the lower illuminated portion of the bar B is flashed when the input value causes the illuminated portion of the bar A to fall outside the permissible range.
In the driver circuit C, a flip-flop 40 synchronizes an oscillator 42 to a power line through a buffer amplifier 44. The resulting synchronization prevents stroboscopic interaction between ambient lighting and the display. When a positive zero crossing of the power line voltage occurs, buffer amplifier 44 enables the flip-flop 40, which in turn starts the oscillator 42. The latter produces clock pulses which drive an N stage counter 46. When the counter reaches the number 203, it triggers a 20 microsecond delay generator 48 which creates a reset pulse. At the end of this measurement cycle, the reset pulse disables flip-flop 40 which turns off the oscillator 42 until the next positive zero crossing of the power line at the buffer amplifier 44. The oscillator frequency is chosen to ensure that a measurement cycle is shorter than the interval between the power line voltage positive zero crossings. In this case, the measurement cycle is less than 16 ms, whereas the positive zero crossings occur every 162/3 ms for 60 Hz or 20 ms for 50 μs. The number 203 equals the number of electrodes 12 and also the number of electrodes 14 in the respective bars A and B. One of these cathodes represents zero on the scale. Therefore, to indicate an overscale condition, there are 203 states in the counter 46, and N must equal at least 203. Since the length of the measurement cycle is N pulses, the oscillator 42 produces N pulses in somewhat less time than one cycle of the power line. Therefore, the oscillator 42 operates at a frequency greater than N times the power line frequency.
The oscillator 42 drives two 3-phase cathode drivers 50 and 52, and an N-stage counter 46. The drivers 50 and 52 are illustrated as rotating selector switches which step one position for each pulse applied by the oscillator 42. In the successive positions of the driver 50, it successively and repeatedly grounds the phase 1A, phase 2A, and phase 3A cathodes. When the reset cathode has been grounded and the glow transferred from the keep-alive cathode, this repeatedly transfers the ionization glow from between the reset gap through the successive gaps along the bar A. While the driver 50 is shown as a rotating selector switch, it may be representative of any type of logic arrangement capable of performing this function. In a preferred embodiment, suitable buffer amplifiers exist between the driver 50 and the cathodes 12. The driver 52 performs the same function with the cathodes 14. However, intervening between the driver 52 and the cathodes, or any buffer amplifiers which may be used, is a phase reversing circuit shown as a double pole, double throw switch, which may represent any suitable logic circuit that performs this function. The driver 50 advances the input display, while the driver 52 advances the set point display.
The N stage counter 46 drives an N level digital-to-analog converter 54. The latter provides an output voltage proportional to the number in the counter. Thus, as the count increases from zero on each clock pulse from the N stage counter, the converter exhibits a voltage which increases linearly with the clock pulses or time, one level of increase for each clock pulse. Hence, each clock pulse advances the display one bar element and increases the converter output one unit of voltage.
The output of the digital-to-analog converter 54 is applied to a comparator 56 which compares this voltage to the input voltage. The input voltage is a preconditioned version of a parameter to be measured. A transducer, compressor, expander or other device conditions the input signal for operation in this environment. As long as the input voltage exceeds the converter 54 voltage, the comparator 56 produces a logic zero signal. During this time, a NOR gate 58 produces a logic 1 that permits an anode driver AD1 to apply the required glow-producing anode voltage at the anode 18. As long as this occurs, the anode 18 remains positive and the driver 50 advances the display of the discharge glow from cathode to cathode along the bar A. The NOR gate 58 forms part of an over and under range flashing circuit 60 through which the output of the comparator 56 passes.
When the output of converter 54 equals or exceeds the input voltage, the comparator 56 produces a logic 1 signal. An AND gate 62 combines this signal with a logic 1 signal from the Q terminal of a normally reset S-R flip-flop 64 to produce a logic 1 signal. The NOR gate 58 then produces a logic zero signal that causes the anode driver AD1 to ground the anode 18. The display of glow discharge along the bar A ceases advancing. The portion of the bar A along which the glow advanced is proportional to the input signal. The clock pulse 42 continues ineffectively to drive the driver 50 until the counter 46 advances to the number 203. After a 20 microsecond delay produced by the delay 48, the flip-flop 40 is reset and the oscillator 42 stops generating clock pulses.
Upon the next zero crossing of the voltage in the power line, the amplifier 44 again sets the flip-flop 40 and the process is repeated at the rate of the power line frequency. The continued glow advance over the section of the bar proportional to the value of the input produces what appears to be a persistent bar-shaped glow along the bar A corresponding to the value of the input.
An over-range and under-range comparison is made by examining the state of the comparator 56 at reset time and at full scale, as discussed more fully in parent application, Ser. No. 574,446 referred to above.
In summary, the bar B displays high and low set points, between which the indication in the bar A is supposed to lie for proper operation. To generate the set points, two potentiometers US and LS generate upper and lower set point command voltages. Comparators 76 and 78 compare these set point voltages with the output of the converter 54. From the start of each counting cycle after reset, the comparator 78 produces a logic zero until the lower set point is reached. Similarly, the comparator 76 produces a logic zero until the higher set point is reached. An OR gate 80 passes the logic zero value through an AND gate 82 and a NOR gate 84. An anode driver AD2 energizes the anode 20. This occurs as the driver 52 scans the bar B from bottom to top by advancing the glow from the reset cathode RB1 along the phase 1B cathodes, phase 2B cathodes, and phase 3B cathodes (14). When the lowest set point is reached, the comparator 78, which operates as a pulse width modulator, produces a logic 1 output. In the meantime, the comparator 76 is still producing a logic zero output. The logic 1 from the comparator 78 passes through OR gate 80 and the AND gate 82. The logic 1 at the input of the NOR gate 84 constrains the anode drive AD2 to inhibit the anode 20 voltage so that glow advance along the bar B stops. During this time, the logic zero output from the comparator 76 has disabled a NOR gate 88 which has enabled the AND gate 82. When the converter 54 potential reaches the upper set point at the potentiometer US, the comparator 76 produces a logic 1. The NOR gate 88 produces a logic zero that turns off gate 82 and prevents the NOR gate 84 from further inhibiting the anode driver 82. Thus, the anode 20 is energized. At the same time, a monostable multivibrator 92 produces a pulse that reverses the polarity on a switch 94 shown as a double pole, double throw switch but capable of being embodied as a logic circuit. This reverses the phase of the driver circuit 52. At the same time, the pulse from the monostable 92 actuates the reset cathode RB2 so that the various phases of cathodes 14 are scanned downwardly. As long as the anode 20 is energized, illumination of the ionizable gas between the gaps from the cathodes 14 to the anode 20 continues in sequence. When the N stage counter reaches the count 203, flip-flop 40 is reset which produces an anode inhibiting voltage at NOR gate 84 until the next zero crossing from the power line.
Because the bar B was illuminated by scanning from the top only from the time the converter 54 voltage reached the upper set voltage to the end of the count 203, only the portion of the bar from the top to the upper set voltage is illuminated beyond the earlier illumination of the portion below the lower set voltage.
Thus, when the lower set point is reached, signals from the comparator 78 hold the set point display cathodes in the reset mode without the anode energized. When the upper set point is reached, another signal from the comparator 76 reverses the counting sequence of the cathode drivers. At this time, the upper reset cathode is grounded, the anode energized and the driver 52 reversed. A discharge has now been formed at the top of the set point display bar B and counts down until full scale is reached and the measurement cycle ended. Therefore, the length of the bar illuminated to represent the upper set point is actually equal to the difference between the full scale and the upper set point.
Parent application Ser. No. 574,446 is incorporated herein by reference. Such parent application, as already noted, discloses an alarm circuit for operating when the input voltage falls below the low set point voltage or exceeds the high set voltage. | The display panel comprises a gas-filled envelope which contains a series of aligned cathode electrodes, an anode for the series, and a reset cathode at each end of the series of cathodes. The system includes a driving circuit which repeatedly scans along the series of aligned cathode electrodes by sequentially grounding the aligned electrodes and repeating the process cyclically. Within each cycle, a pulse width modulator energizes the anode, which is opposite the cathode electrodes, for a period of time corresponding to an input value. Sequential glow discharges thus occur between the cathodes and the anode over a portion of the anode length. The discharges occur with sufficient rapidity so that they are observed as an illuminated portion of a bar formed by the electrodes. The panel is particularly suited for producing two illuminated bands or bars separated from each other. Desired upper and lower set point limits for the input quantity determine the lengths of the bands and the separation between them. The separate bands are initiated from opposite ends of the series of cathode electrodes by first energizing the reset cathodes. The driver forms one band from one end of the aligned electrodes and the other band from the other end of the aligned electrodes. | 22,266 |
BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
The present invention relates to a swabbing device for molds of a bottle making machine, and more particularly, to a swabbing device for molds which are made of various kinds of materials to be used for a bottle making machine wherein a multiplicity of bottle forming sections are aligned.
2. Description of Related Art
A bottle making machine is generally provided, for instance, with a blank mold and neck-ring mold for forming a parison which shapes a neck-ring portion and a body portion of a bottle, and a blow mold and bottom mold for finishing the parison formed by the blank mold and neck-ring mold, wherein a gob which is a melted lump of glass is fed into a bottle forming section.
The temperature of the gob which is fed to the blank mold and neck-ring mold ranges as high as 1070° C.-1150° C. when the gob is supplied, and it causes the gob to adhere to metal and other materials easily. The mold releasing operation can not, therefore, be performed smoothly when a bottle is formed by the molds as described above. There is a problem especially when the gob is formed into a shape with the blank mold and neck-ring mold under high temperature.
In order to cope with such a difficulty, it has heretofore been practiced to manually swab the blank mold, neck-ring mold and a baffle with a swabbing agent periodically. In the case of a blank mold, for instance, it is desired to perform a swabbing operation at intervals of 10-20 minutes.
On the other hand, with a view to eliminate said manual swabbing operation or to prolong the intervals necessary for a swabbing operation, it has been practiced to spray a mold releasing agent automatically, or to adhere a mold releasing agent to the surface of a mold by baking, or to provide a dried precoated layer, or to adhere soot produced out of incomplete combustion of acetylene to a metal mold.
When a mold releasing agent is applied manually, oil adheres closely to the surface of a mold forming an oil film thereon to achieve satisfactory mold releasing. However, said manual application has to be conducted frequently under a noise and high temperature which eventually requires time and much labor. It is, therefore, desired to curtail the frequency of operation for application.
It is also dangerous when the manual application is conducted to a mold which is frequently opened and closed (for instance, at an interval of less than two seconds). For this reason, such a swabbing operation is closely observed by the Labor Standards Inspection Office and other competent institutions. Heretofore, a forming operation has been conducted at a speed of around six shots per minute. However, with the recent high-speed operation, the speed has increased more than 2.5 times. Under the circumstances, in the case when a forming operation exceeds 14 or 15 shots per minute, it is practiced to interrupt the forming operation during a swabbing operation in order to prevent the danger which adversely affect the productivity.
When a swabbing operation is performed by means of spray, only a particle of oil is put on the surface of a mold and it is likely to be removed by a particle of glass easily. The swabbing effect thus remains short, about half of the life as compared with the case of said manual swabbing operation. A swabbing operation should, therefore, be conducted at a short cycle, i.e. at intervals of 5-10 minutes. A supplementary operation by a manual swabbing is thus required to increase the duration of intervals.
There is another difficulty that an application can not be fully conducted all over the surface of a mold thus inviting partial checking and insufficient formation by stains. Further, on some occasion, a swabbing is done onto unnecessary portion of a mold to cause insufficient exhaustion thereat which adversely affect a forming effect. The surface of a product is thus made rough, and the product is easily stained compared with a product manufactured by the manual swabbing. For this reason, the appearance of a product can not be formed satisfactorily.
Moreover, a precoated layer is dissipated by itself, since it will evaporate as carbon dioxide when a hot gob fed to a mold comes in contact with the layer. The precoated layer is thus reduced every time when a forming operation is conducted, and the life of the layer expires in two-six hours. The life appears to be longer as compared with that of the case of the manual swabbing, however, said reduced precoated layer can not be replenished by a supplementary operation. It is, therefore, necessary to change a mold every time when the life of the precoated layer is expired by the reduction of the layer. The cycle for exchanging a mold is, therefore, short which causes a raise in manufacturing cost and lowers the productivity.
In the case of a treatment where an Alblack, which is a soot being sold on the market, is used, acetylene generates an intense heat with oxygen so that operation efficiency is lowered and an environment is worsen. Further, the bottom thickness of a product is excessively thickened, and it sometimes necessitates to change the design of a mold.
SUMMARY OF THE INVENTION
It is a primary object of the present invention to provide a swabbing device for molds of a bottle making machine which is capable of automatically performing a mold swabbing operation just like the case of a manual swabbing whereby the danger in the manual swabbing is prevented with elimination or reduction of labor, and fulfilling a rapid and precise swabbing operation in a high-speed forming operation thus improving the quality of a product and the productivity.
It is another object of the present invention to provide a swabbing device for molds of a bottle making machine which is capable of lowering manufacturing cost, and at the same time, accomplishing high efficiency wherein the whole body of a robot is moved to a location of a mold provided in each one of bottle forming sections to rapidly carry a swabbing member, and with a simple robotic action of swabbing onto a mold, the robot is able to swab all the molds provided in each section.
It is a further object of the present invention to provide a swabbing device for molds of a bottle making machine which is capable of fulfilling a precise swabbing operation at a low cost wherein a specified swabbing location of a robot corresponding to each one of the molds is adequately discriminated with a simple procedure to precisely perform an automatic swabbing operation by the robot at a proper location as predetermined.
It is a still further object of the present invention to provide a swabbing device for molds of bottle making machine which is capable of preventing a lowering of bottle manufacturing efficiency without adversely affecting a regular bottle manufacturing cycle, and eliminating or lessening a timing loss which is caused by a swabbing operation.
A further object of the present invention is to provide a swabbing device for molds of a bottle making machine which is capable of accomplishing a satisfactory swabbing operation which compares favorably with a manual swabbing operation wherein an impregnated material such as cloth and string are provided around a core member, and a swabbing agent is impregnated into the impregnated material for a swabbing operation.
These and other objects and features of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings which illustrate specific embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view roughly showing a part of bottle making machine to which the present invention is applied.
FIG. 2 is a plan view showing a part of the bottle making machine shown in FIG. 1.
FIG. 3 is a perspective view showing a robot provided with the bottle making machine shown in FIG. 1.
FIG. 4 is a plan view showing a condition how a blank mold is opened.
FIG. 5 is a sectional view showing a part of a kind of swabbing member.
FIG. 6 is a sectional view showing a part of another kind of swabbing member.
FIG. 7 is a block diagram showing a control circuit of the robot and bottle making machine.
FIG. 8 is a block diagram showing a control circuit of the robot and bottle making machine in another embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to accompanying drawings, description will now be made hereinafter on embodiments of a bottle making machine to which the present invention is applied.
In the bottle making machine of the present embodiment, there are provided bottle forming sections 3, for instance, 6-12 sections, laterally aligned as shown in FIGS. 1 and 2 wherein a blank mold 1 combined with an unillustrated neck-ring mold and a baffle, and a blow mold 2 combined with an unillustrated bottom mold are arranged. As shown in FIGS. 1, 2 and 4, the blank mold 1 is arranged to be automatically opened and closed right and left by an unillustrated air cylinder or the like in parallel movement. It may also be arranged to be rotatably opened and closed centering around a hinge.
The blank mold 1 is combined with a neck-ring mold at the lower portion and a baffle at the upper portion, and through a delivery mechanism, a gob which is a melted lump of glass prepared for bottle manufacturing is fed into each one of blank molds 1 in a predetermined order. The blank mold 1 then forms the neck-ring portion of a bottle, and the body and bottom portions of the bottle are shaped to form a parison.
The parison which is formed in the blank mold 1 is transferred to the blow mold 2 to be formed into a predetermined shape of bottle.
A timing for feeding the gob to each one of the blank molds 1 is set for subsequently repeating operations of rough formation of a bottle by the blank mold 1 at each one of bottle forming sections 3, and subsequent finishing formation of the bottle by the blow mold 2 at regular intervals.
At a side of the bottle making machine, a straight guide 5 is provided along a direction the bottle forming sections 3 are aligned, and both ends are held by a leg member 6. To the straight guide 5, the base 21 of a robot 7 is slidably held to be driven in reciprocating motion along the straight guide 5 by a linear motor 51 provided between the straight guide 5 and base 21.
The linear motor 51 consists of, for instance, a permanent magnet 51a on the base 21 and an electromagnet 51b on the side of the straight guide 5. However, in place of the linear motor 51, an AC servomotor may also be utilized.
On one of the leg members 6, there is provided an operation box 8 for giving instructions to control actions of the robot 7.
The robot 7 in the present embodiment is arranged to be easily and rapidly moved to a location opposite to a blank mold 1 provided in each one of the bottle forming sections 3 without resorting to any robotic action by the movement along the straight guide 5 so that any device which possesses a function to perform a swabbing action to a mold within a necessary range of action may be utilized when a swabbing operation is performed for the blank mold 1, and the neck-ring mold and the baffle combined therewith.
As illustrated in detail, the one shown in the FIG. 3 is a simple joint type provided with four joints of first to fourth joints 11-13 and 40 whereby a straight reciprocating movement of the robot 7 in a direction shown by an arrow 41 in FIGS. 1 and 2, a rotating action around the first, second and third joints 11-13, an action of the swing of the pendulum around the fourth joint 40 as shown by an arrow 42 in the FIGS. 3 and 4, and various actions in which said actions are combined can be performed. A swabbing member 26 can thus be rubbed over a necessary range of the surface of various metal molds.
Not limiting to such an arrangement as described above, six-joints type robot, seven-joints type robot or the like provided with a rotating shaft which rotates in various directions may selectively be utilized according to a requirement. The reciprocating movement or other arrangement may also be selectively adopted according to a requirement. Not only the action of the swing of the pendulum of the swabbing member 26, it may also be arranged to rotate it on its own axis, or to rotate it in an orbital motion, or to move it vertically.
The robot 7 is provided with motors 14-16, 43 for each one of the first-fourth joints 11-13, 40 for its rotating action around the joints (refer to FIG. 3), and through the base 21 which is slidably fitted and held to a straight guide 5, signals are delivered and received between a microcomputer 22 in the operation box 8 to control a reciprocating movement along the straight guide 5, and rotating actions around said first-third joints 11-13. An AC servomotor, stepping motor or the like may selectively be utilized for the motors 14-16 according to a method of control which is to be applied.
The microcomputer 22 controls the robot 7 to perform a swabbing operation correlatively with bottle making action of the bottle making machine in each one of the bottle forming sections 3. The microcomputer 22 is, therefore, arranged to deliver and receive signals between a microcomputer 32 which controls actions of the bottle making machine.
The position of movement of the robot 7 along the straight guide 5 may be measured from the amount of movement by setting a home position of the robot 7.
In the present embodiment, a position indication 23 is provided in each one of the bottle forming sections 3 corresponding to a central position in a longitudinal direction of the straight guide 5, and a position sensor 24 is provided at the lower front center of the base 21 of the robot 7. The position sensor 24 detects the position indication 23 when the sensor 24 is positioned opposite to the position indication 23 in a direction perpendicular to the longitudinal direction of the straight guide 5, and by a signal of the detection, the microcomputer 22 makes a judgment that the center of the blank mold 1 which is positioned opposite to the position sensor 24 and the center of the robot 7 are opposite to each other (refer to FIGS. 1-3).
An ultrasonic sensor, laser sensor or the like may be utilized in place of the position indication 23 and position sensor 24. A device which is arranged to mechanically detect a position may also be adopted.
A chuck 25 is provided at the tip of the robot 7 to removably attach the swabbing member 26 for performing a swabbing operation to the blank mold 1. Adjacent to the bottle making machine, there is provided a stacker 27 for storing various kinds of swabbing members 26. The robot 7 is thus able to selectively use one of the swabbing members stored in the stacker 27 corresponding to a required mold and swabbing condition.
For the selective use of the swabbing member 26, the stacker 27 is provided with a position indication 28 at a location where each kind of swabbing members 26 is stored as shown in FIG. 2. By detecting the position indication 28 with the position sensor 24, the microcomputer 22 makes a judgment that the robot 7 is positioned at a proper location opposite to a location where each swabbing member 26 is stored.
As shown in FIGS. 2 and 3, a swabbing agent supply pipe line 29 is connected with the chuck 25 for feeding a swabbing agent to a swabbing member 26 which is attached thereto. The swabbing member 26 is provided with an impregnated material 26b such as cloth and string around its core member 26a as shown in FIGS. 1, 4, 5 and 6. The swabbing member 26 may, therefore, be manufactured in any shape according to a requirement to be stored in the stacker 27.
In the core member 26a, there is provided a liquid passing path 26d which vertically runs through from the upper end to the lower end. The liquid passing path 26d is provided with openings 26c to the surface of the core member 26a where the impregnated material 26b is attached, and a swabbing agent fed through the swabbing agent supply pipe line 29 is forwarded to the liquid passing path 26d in the core member 26a through a check valve 31 provided with the chuck 25. Through the openings 26c, the swabbing agent spontaneously permeates into the impregnated material 26b around the core member 26a by the capillarity. Accordingly, when the swabbing member 26 is rubbed against the surface of blank mold 1, the swabbing agent impregnated in the impregnated material 26b is applied all over the surface of the metal mold like the case of the manual swabbing whereby elimination or reduction of labor may be accomplished.
There is no danger which might occur in a manual swabbing operation. Since a rapid and precise swabbing operation can be performed based on a condition preliminarily set, a swabbing may be conducted at a speed of around 16-20 shots per minute, and the quality of product and the productivity are improved.
The check valve 31 is arranged not to leak a swabbing agent which is fed to the chuck 25 when the swabbing member 26 is removed from the chuck 25. Since a swabbing agent is fed to the swabbing member 26 in spontaneous permeation from within the core member 26a to the impregnated material 26b, supply pressure of the swabbing agent through the swabbing agent supply pipe line 29 may be set, for instance, at a small pressure of 1-2 kg/cm 2 G. Even when a supply pressure is given by pump, a spontaneous flow of the swabbing agent is prevented without the check valve since the pump is stopped when a swabbing operation is not performed.
By making an arrangement to impregnate a swabbing agent into an impregnated material 26b from within the core member 26a, impregnation can be accomplished by forcibly feeding the swabbing agent through the core member 26a whenever and wherever the swabbing member 26 is positioned.
The chuck 25 is also provided with a click stopper 33 for elastically locking a swabbing member 26 in order to remove the attached swabbing member 26 with a proper amount of force. However, any type of locking means may be adopted. For instance, it may be arranged to lock and remove the swabbing member 26 by relative movement of the chuck 25 of robot 7 and the swabbing member 26 stored in the stacker 27.
FIG. 7 is a block diagram showing a control circuit for controlling actions of the bottle making machine and robot 7 by utilizing the microcomputers 22 and 32. In the present embodiment, the microcomputer 22 adopts a numerical control system for the robot 7, however, any type of control system such as a playback system or the like may be adopted according to a requirement.
The operation box 8 is connected with the microcomputer 22 for giving instructions of numerical control. It is also arranged to indicate confirmation of various operating conditions.
To an output side of the microcomputer 22, there are connected a linear motor driving circuit 65 in the straight guide section, first-fourth joints motor driving circuits 66-69 for driving each one of the motors 14-16, 43, and a swabbing agent supply pump driving circuit 70 for performing various operations. The position sensor 24 and other input are connected to an input side for properly performing said actions.
To an input side of the microcomputer 32, an operation panel 34 is connected for inputting various conditions in a bottle manufacturing process, and for indicating confirmation of various actions. Other input of various sensors is also connected for controlling various actions.
To an output side of the microcomputer 32, there are connected a blank mold opening/closing action driving circuit 61, blow mold opening/closing action driving circuit 62, bottle transfer driving circuit 63 from a blank mold 1 to a blow mold 2, finished bottle discharge action driving circuit 64, and other output.
With the arrangement as described above, the robot 7 is moved to and stopped at each position where the blank mold 1 provided in each one of the bottle forming sections 3 and the center of the robot 7 correspond with each other, and at each position where the swabbing member 26 stored in the stacker 27 and the center of the robot 7 correspond with each other.
With a necessary swabbing member 26 installed, the robot 7 is moved to a location where each one of the blank molds 1 is positioned, and rubs against each blank mold 1 as shown in the FIG. 4 to accomplish a swabbing operation in the same action as in a manual swabbing operation.
According to the experiments conducted by the inventor, it was found that the production of satisfactory bottles in the blank mold and neck-ring mold can only last for about an hour in the case of a swabbing by an automatic spray method. When a production time has exceeded one hour, there occurred such defects as wash board, wrinkles and laps, chilling, and insufficient feeding of gob into the blank mold. In the neck-ring mold, such defects as screw check, body seam check and the like were observed.
On the contrary, in the case of a swabbing performed by the robot 7 in the present embodiment, the production of satisfactory bottles in the blank mold continued for about eight hours, and about six hours in the neck-ring mold respectively.
When an automatic swabbing operation is conducted by the robot 7 in the present embodiment using a super hard alloyed material composed of Cu, Co, Ni and W (Item No. KRC-15 manufactured by Kobe Steel Co., Ltd.) which is treated by composite metal plating (Ni+P+SiC, Ni+P+W) for the neck-ring mold, the generation of defective checks and the like were restrained covering a shortage of swabbing agent. In sum, a forming capability is further improved when an alloyed material composed of Ni, Co, Cu and W which does not wet so easily is used in manufacturing metal molds.
A metal mold is applied to the present embodiment, however, any mold which is made of other materials other than metal may also be applied.
In the present invention, it may be arranged to provide a swabbing agent supply source such as a swabbing agent storage chamber for feeding a swabbing agent to the swabbing member, and by moving the swabbing member to the swabbing agent supply source by the robot, the swabbing agent is impregnated when they come in contact with each other. In this case, by making use of intervals between swabbing operations, or by making use of the time when the swabbing member is stored in the stacker, it may be arranged to impregnate the swabbing member by dipping it in the swabbing agent storage chamber.
FIG. 8 shows another embodiment of the present invention which differs from the previous embodiment on the points that an order of movement of the robot to each one of the molds in the bottle forming sections for a swabbing operation is predetermined, and that when there is a defective mold, the robot is voluntarily moved to such a mold. Further, the straight movement of the robot is made by a servomotor which utilizes a fluid such as air.
Description will now be made on the points of difference referring to the FIG. 8. Like parts and circuits are shown by corresponding reference characters throughout the views of drawings, and repeated descriptions will be omitted.
When the robot is controlled by the microcomputer 22, if there is not any defect in a product being manufactured such as wrinkles and laps, wash board, screw check and the like, the robot which is positioned at a home position is moved in consecutive order from one end to another in the sections aligned, i.e. from a small numbered section to a large numbered section assuming that each section is numbered starting from a home position of the robot. When a mold positioned opposite to the robot is opened and empty, the robot is stopped thereat for a swabbing operation, and each time a swabbing operation is completed, the robot is moved to the next section. When a swabbing operation is finished at the last section, the robot is returned to the home position to be ready for the next swabbing operation.
A servomotor driving circuit 165 is, therefore, connected to the microcomputer 22 for the straight movement of the robot. By adopting a servomotor, particularly an air servomotor, a straight movement mechanism may be provided at a low cost. Further, a position of the robot where it is moved can be found simply by an encoder, and a position control can be easily conducted. There may occur an error of 2 mm or so for the position control, however, it does not matter particularly.
An interval for moving the robot may be optionally set by an inputting means provided in the operation box 8. In the present embodiment, it can be set within a range of 0-60 minutes. At present, the setting is selectively made at intervals of 5, 10, 15, 20 minutes corresponding to a product forming condition. The timing when a mold in each section is opened and become empty is detected by a timing sensor 101 which is connected to the microcomputer 22, and based on a detection signal, a required time is obtained from the time a mold in each forming section is opened after a forming operation is completed until the mold is emptied.
When operator judges that there occurred such defects as wrinkles and laps, wash board, screw check and the like in a product being manufactured in one of the forming sections, the operator specify the section from a group of keys 102 provided on the operation box 8. The robot is thus moved to the specified section preferentially voluntarily by an interruption control. When the preferential swabbing operation is completed at the specified section, the operation is returned to an ordinary mode of control for movement.
When a plurality of specified sections are set, for instance, the preferential swabbing operation may be conducted in order of setting which has been set. Other order may also be selected.
Although the present invention has been fully described by way of examples with reference to the accompanying drawings, it is to be noted that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention, they should be construed as being included therein. | A robot carries a swabbing member to a position of each mold to rub the swabbing member against each one of the molds. The swabbing member feeds a swabbing agent to the surface of each mold where it comes in contact with, and rubs the agent thereinto. | 26,715 |
This is a continuation of application Ser. No. 557,333, filed Jul. 23, 1990, now abandoned, which, in turn, is a continuation-in-part of application U.S. Ser. No. 208,200, filed Jun. 17, 1988, now abandoned.
This invention relates to the separation of compounds having a molecular weight of less than 1000 daltons from bio-polymers. In particular, it relates to novel packing supports useful in liquid chromatography (LC) and solid phase extraction (SPE) techniques for separating drugs, metabolites, etc. from mixtures containing water soluble proteins.
BACKGROUND OF THE INVENTION
It is frequently necessary to confirm the presence of drug substances, their metabolites, etc., in serum or plasma and/or to measure the concentrations of these compounds. In other cases, it is necessary to separate bio-polymers from smaller substances as a step in purifying substances from biological or from biomass mixtures. Such analyses are carried out using liquid chromatographic systems as illustrated in FIG. 1 of the drawings. The invention is compatible with high performance liquid chromatographic systems but is not limited to them.
Most of the published data and methods in this area of research relate to the LC analysis of drugs, metabolites, etc., in serum or plasma. The ways the mixtures are sampled can be classified as indirect and direct sampling. Indirect sampling involves treatment of the sample to remove the proteins, e.g. by precipitation, followed by extraction of the compound(s) of interest into a protein-free solvent system. Although this method involves multi-step preparation before the sample can be analyzed by a particular LC method, it still attracts much of the practical attention. Direct sampling, or direct injection of the untreated sample on an LC analytical column, causes clogging of the column, resulting in increasing pressure drop, peak broadening, variation of retention times, etc., unless special precautions are taken. After each sample injection, or after a few injections, the column must be thoroughly washed to remove precipitated proteins, particularly when larger serum samples (≧10 μl) are needed to detect the analytes of interest at their therapeutic or biological levels.
A partial solution to the above problems was found in a combination of an analytical column and a precolumn and two delivery pumps in a column switching system. Usually, the serum sample is loaded onto a short precolumn under mobile phase conditions in which only the drug(s) elute onto the analytical column. When all the components of interest elute from the precolumn to the analytical column, a valve is switched so that one pump continues to deliver mobile phase for elution of the compounds of interest from the analytical column for separation, while the second pump delivers a washing solution to the precolumn for removal of the proteins. To avoid clogging, the precolumn is filled with relatively large particles, usually 20-40 μm, and is replaced frequently to avoid deterioration of the analytical column (W. Rothe, et al., J. Chromatog. 222 (1981) 13). Usually, both columns are filled with reversed phase packing, e.g. C 8 or C 18 bonded to a silica support.
To avoid protein accumulation in the precolumn and to speed up the washing step, a less hydrophobic packing has been used, butyl modified methacrylate, as manufactured by TosoH, Japan, and sold under the tradename TOYOPEARL™ BT-650M. In the loading cycle, 10-50% saturated ammonium sulfate (NH 4 ) 2 SO 4 aqueous mobile phase is used. Under such conditions, serum proteins are retained on the precolumn and the drugs elute to load the reversed phase analytical column. Then, by column switching, the analytical column is separately programmed, while the precolumn is cleaned of the retained proteins, using a buffer solution of lower ionic strength (G. Tamai, et al., Chromatographia 21 (1986) 519).
In another study, a polystyrene divinylbenzene resin, manufactured by Rohm and Haas, USA, and sold under the tradename Amberlite® XAD-2, was used as the packing in the precolumn to retain methaqualone (MTQ), while eluting the plasma proteins. After all the proteins are washed away (with a pH 9.3 buffer solution), the mobile phase is adjusted to elute MTQ (R. A. Hux, et al., Anal. Chem. 34 (1982) 113).
Another example of a two-modal HPLC system combines size exclusion chromatography (SEC) and reversed phase chromatography (RPLC) using two columns in a column switching system. Following exclusion of the biopolymers from the SEC column, the later eluting band of smaller molecular size compounds was backflushed to the RPLC analytical column (S. F. Chang, et al., J. Pharm. Sci. 72 (1983) 236).
All the above examples employ column switching which requires an elaborate chromatographic system, including a second solvent delivery system, a second column and a switching system. Moreover, the operation of the switching system itself requires labor or investment in additional control equipment.
A completely different approach was undertaken by Pinkerton, et al. (U.S. Pat. No. 4,544,485). They redesigned the packing of the analytical column in such a way that the proteins elute in the excluded volume (void volume) and the analytes are retained and separated on the same analytical column. This was accomplished by chemically modifying a hydrophilic diol phase with a hydrophobic oligopeptide, e.g. glycyl-(L-phenylalanine)n, where n=1,2, or 3. It is crucial to their invention that the diol phase is bonded to a porous silica gel having a pore diameter smaller than 80 angstroms. Following this modification, the phenylalanine moiety is enzymatically cleaved from the diol ligand with a protease. The cleavage is restricted to surface areas that are accessible to the protease, resulting in a support for which the diol ligands are only present on the external surface, while L-phenylalanine modified ligands are present in the internal surface, i.e., the pores of the packing material. The ligands that are not accessible to the enzyme are similarly not accessible to the serum proteins. Thus, these proteins are excluded from entering the pores and elute in the void volume, while the smaller molecules (e.g., drugs) can interact with the hydrophobic phenylalanine ligands (U.S. Pat. No. 4,544,485). This support, named internal surface reverse phase liquid chromatographic packing (IS-RP), can be used to analyze many serum sample without the damaging accumulation of proteinaceous precipitate seen on regular RPLC columns.
Conceptually, the study of Yoshida, et al., (Chromatographia 19 (1985) 466) is similar to that of Pinkerton. They adsorbed denatured plasma proteins on C 18 silica supports having small pore diameter. These supports no longer retained plasma proteins, but still showed reversed phase characteristics for smaller analytes. The phenomenon is depicted as similar to that of Pinkerton's model, or as having the proteinaceous precipitation limited to the externally exposed surface, thereby making the external surface hydrophilic, while keeping the non-exposed internal C 18 surface free of such precipitation and accessible for (hydrophobic) interaction with small compounds.
Thus an object of this invention is to provide a novel packing material for liquid chromatography which will allow the direct injection of biological fluids into the column.
Another object of this invention is to provide a packing material for chromatographic columns which has a hydrophilic exterior layer and a hydrophobic underlayer.
Still another object of this invention is to provide a chromatographic column which will shield and exclude large biopolymers but permit the partitioning of and hydrophobic interaction with small analytes.
Yet another object of this invention is to provide a novel shielded hydrophobic phase packing for chromatography adapted to bond to porous and non-porous silica supports.
Another object of this invention is to provide a chromatographic phase having a covalently bonded micellar surface.
Another object of this invention is to provide a packing material for chromatographic columns which has a hydrophilic exterior layer and an anionic underlayer.
Another object of this invention is to provide a packing material for chromatographic columns which has a hydrophilic exterior layer and a cationic underlayer.
Another object of this invention is to provide a packing material for chromatographic columns which has a hydrophilic exterior layer and a chelating underlayer.
These and other objects of this invention may be seen by reference to the present specifications, claims, and drawings.
THE INVENTION
We have discovered shielded stationary-phase packing materials useful for liquid chromatography analysis and/or solid-phase extraction of mixtures containing proteinaceous compounds and small analytes, comprising:
a support;
an internal leash bonded to the support and bearing functionality that interacts with the small analytes; and
an external hydrophilic moiety bonded to the internal leash to form a hydrophilic external layer;
whereby the external hydrophilic external layer forms a water solvated interface which allows the small analytes to diffuse and interact with the internal leash but prevents interaction between the internal leash and the proteinaceous compounds.
In an alternative embodiment, we have discovered a shielded stationary-phase packing material for liquid chromatography analysis and/or solid-phase extraction of mixtures containing proteinaceous compounds and small analytes, comprising:
a support;
a hydrophilic polymeric network covalently bonded to the support; and
regions embedded within the network which contain functionality which interacts with the small analytes;
whereby small analytes will diffuse through the network and interact with the embedded regions and proteinaceous compounds will be excluded from such interaction.
We have further discovered a method of making these shielded stationary-phase packing materials, chromatography columns packed with these shielded stationary-phase packing materials, a method of liquid chromatographic separation which uses these chromatography columns, and a method of solid-phase extraction which uses these shielded stationary-phase packing materials.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is a new concept providing novel LC or SPE packing materials which discriminate between water soluble proteins and smaller analytes on the bases of hydrophobic, ionic or other interactions. The novel LC or SPE packings of the present invention are (bonded) porous or non-porous supports in which an external, polar hydrophilic layer shields an underlayer which interacts with the small analytes, or in which pockets that interact with the small analytes are enclaved by a hydrophilic network. The underlayer or enclaved pockets may interact with the small analytes through hydrophobic, acidic, basic, ionic, chelating, or π--π bonding, or they may have other characteristics that cause them to interact and prevent or retard the elution of the small analytes. The present invention deals with supports having a bonded "micellar" layer, in which the micelles contain external polar and hydrophilic groups which are exposed to the mobile phase while shielding an underlayer that interacts with the small analytes. The present invention deals with a hydrophilic polymeric network that shields an underlayer that interacts with the small analytes, or such a network that contains enclaved regions that interact with the small analytes. Such hydrophilic shielding, when properly manipulated, can prevent water soluble proteins from interacting with the shielded part of the supports while allowing smaller substances to be retained or retarded by the interactive region, through hydrophobic, ionic, chelating or other interaction. These novel packings are termed shielded stationary phase (SSP).
The SSP packings of this invention are intended to eliminate the need for sample preparation procedures beyond the removal of particulate substances before the LC analysis. The packings are designed to elute the water soluble proteins, e.g. serum proteins, completely, or almost completely, in the void volume, and to retain drugs, metabolites, etc. Similarly, the packings of this invention can be used for separation of smaller analytes from water soluble proteins in the technique known as solid phase extraction, for small sample volumes to large scale industrial volumes. The SSP packing materials of the invention are conveniently produced from commercially available porous or non-porous silica supports, the surface of which is chemically modified with ligands or networks as described above. Similarly, the SSP packings can conveniently be produced from resins by modifying the surfaces of commercially available porous and nonporous materials, or by the direct preparation of such.
The use of micellar mobile phases in HPLC of proteins, e.g., nonionic surfactants, has been established in a number of studies, including use of direct plasma and serum injections (J. D. Dorsey, Chromatography 2 (1987) 13). Under these conditions, using for example a C 18 silica column, and a surfactant containing mobile phase, the surfactant saturates the stationary phase to form a double layer having a polar hydrophilic external interphase. The adsorption of many surfactants to such a reversed phase is strong enough to maintain the double layer even long after the additive has been removed from the mobile phase. Many water soluble proteins elute from such a column in the void volume, when the surfactant is selected from a groups of preferred detergents, e.g. the Tweens, bis-polyethyleneoxide derivatives of a fatty acid ester of sorbitol, as long as the double layer exists.
Albumins are known to associate with the Tweens and similar detergents below their critical micellar concentration (CMC) through hydrophobic patches located at the surface of these macromolecules, e.g. bovine serum albumin has four principal binding sites to adsorb deoxycholate, a biological "detergent" (A. Helenius, et al., Biochimica et Biophysica Acta 415 (1979) 29). A detergent-C 18 double layer can thus be drastically depleted of detergent molecules by injections of large serum samples due to the competitive adsorption of the serum albumin molecules to the surfactant.
Our invention attempts to mimic the chromatographic behavior of water soluble proteins on a "detergent modified" reversed phase by bonding appropriately designed ligands or polymeric phases to silica supports. Our invention is a new concept for chromatography in that it provides a covalently bonded micellar surface. The support consists of a non-polar spacer (R) which is interactive with small analytes and which is bonded to the support, and a hydrophilic end group (P). For a silica gel support (S) this can be represented by (S).tbd.Si--(R)--(P). The spacer R may be a hydrophobic moiety, in which case it will be a long chain aliphatic moiety, preferably containing 6-20 methylene groups, a crosslinked hydrocarbon, or a moiety that contains aryl groups. R may be a weak or strong anion-exchange group for ion pairing of acidic analytes, or a weak or strong cation-exchange group for ion pairing of basic analytes, or it may be a π--π donor to associate π--π acceptor analytes, or conversely a π--πacceptor to associate π--π donor analytes. It may bear chelating groups or other functional groups that will interact with the small analytes by complex formation. R may also be a combination of the groups and moieties described above. A preferred combination exists when R is a hydrophobic moiety which is substituted with weak or strong anion-exchange groups or weak or strong cation-exchange groups or π--π donor or acceptor groups or chelating groups, or combinations of these groups. P is the hydrophilic head containing one or more polar functional groups, and (S).tbd.Si is a siloxane bond (Si--O--Si) to the silica gel support. Alternatively, a hydrophilic polymeric network will shield an interactive, i.e. hydrophobic, cationic, anionic, chelating and the like, underlayer R or such a network containing interactive enclaved regions which provides a bonded phase with hydrophilic exterior, P, and interactive interior, R.
A particular advantage of the shielded stationary phase is the ability to select a phase from among the interactive underlayers or enclaved regions described above such that the retention times of particular analytes in chromatographic separations may be adjusted to resolve them from the large frontal peak of the proteins, or from other small analytes in a sample. One or more of the interactions described above may be employed to increase specific selectivity for particular analytes and make possible direct, quantitative analyses of complex mixtures such as biological matrix samples.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically illustrates a typical liquid chromatography system that consists of a solvent reservoir (10), sequentially connected to a pump (12), a mixer (14), an injector (16), a column (18), a detector (20), and a recorder or data collection unit (22). The column (18) is the device that contains the shielded stationary phase involved in the chromatographic separation.
FIG. 2 schematically shows the separation mechanism of a "micellar" shielded hydrophobic phase. The external polar heads form a hydrophilic layer (P) that is exposed to the protein and shields the hydrophobic underlayer (R). The proteins (G) come in contact with the noninteracting hydrophilic layer (P) while the small analytes (A) are partitioned and retained by the hydrophobic under layer (R).
FIG. 3 schematically shows the separation mechanism of a shielded hydrophobic phase consisting of hydrophobic pockets (R) enclaved by a hydrophilic network (P). Small analytes (A) can penetrate through the network and interact with the hydrophobic pockets, while larger proteins (G) are prevented from such an interaction.
FIG. 4 is a comparison of three chromatograms, A--human serum, B--propranolol (30), and C--propranolol (30) spiked human serum, as resolved upon Phase 1. N,N-bis(2'-methoxyethyl)-11-aminoundecylsilyl (see Example 1 and Table I).
Sample:
A) 20 μl injection of human serum
B) 1.0 μl injection containing 5 mg/ml propranolol in methanol
C) 2.0 μl injection containing 0.2 mg/ml of 30 in human serum
Column Dimensions: 15 cm×4.6 mm
Mobile Phase: 0.5M NH 4 OAc, adjusted to pH 6.0 with glacial acetic acid
Flow Rate: 2.0 ml/min.
Temperature: ambient
Detection: UV at 280 nm, 1.0 AUFS, ATTN 4
Chart Speed: 0.5 cm/min.
FIG. 5 is a comparison of two chromatograms, A--human serum spiked with trimethoprim (32), carbamazepine (34) and propranolol (30) and B--the same drugs in methanol, as resolved upon ω-(sulfonazide)alkylsilyl, Phase 3 (Example 3).
Sample:
A) 10 μl injection containing a 0.2 mg/ml or each drug in a 2:2:1:solution of human serum:mobile phase:methanol
B) 25 μl of 1 mg/ml of each drug in methanol
Column Dimensions: 5.0 cm×4.6 mm
Mobile Phase: 180 mM NH 4 OAc:ACN (90:10) (pH 7.0)
Flow Rate: 2.0 ml/min.
Chart Speed: 0.5 cm/min.
Temperature: ambient
Detection: UV at 280 nm, 0.5 AUFS, ATTN 2
FIG. 6 shows the resolution of trimethoprim (32) from spiked calf serum as resolved upon (10-carbomethoxydecyl)dimethylsilyl. Phase 4 (Example 4).
Sample: 10 μl injection of a 1:1 calf serum: 25 mg/ml trimethoprim (32) in 10% aqueous methanol. Chromatographic conditions as described in FIG. 5, except: 0.1 AUFS, ATTN 8.
FIG. 7 shows the resolution of trimethoprim (32) from spiked calf serum as resolved upon N,N'-bis(2-hydroxyethyl)ethylenediamino modified (10-carboxydecyl)dimethylsilyl, Phase 5. Chromatographic conditions as described in FIG. 6.
FIG. 8 shows the resolution of trimethoprim (32) from spiked calf serum as resolved upon 10 cyanodecylsilyl, Phase 6. Chromatographic conditions as described in FIG. 6.
FIG. 9 shows the resolution of trimethoprim (32) from spiked calf serum as resolved upon N-(3'-propylsulfonic acid)-11-undecylaminosilyl, Phase 7 (Example 7). Chromatographic conditions as described in FIG. 6.
FIG. 10 shows three chromatograms, A--theophylline (36), B--phenobarbital (38), and C--carbamazepine (34) of spiked calf serum at or below the therapeutic levels as resolved upon Phase 8 (Example 8).
Sample: 10 μl injection containing 10 μg/ml of each drug in calf serum
Column Dimensions: 15 cm×4.6 mm
Mobile Phase:
A--180 mM NH 4 OAc,
B and C--180 mM NH 4O Ac/ACN 95:5
Flow Rate: 2.0 cm/min.
Detection: UV at 254 nm, 0.001 AUFS, ATTN 8
Chart Speed: 5 mm/min.
FIG. 11 is a comparison of two chromatograms. A--ibuprofen (40) in human serum after Advil® ingestion and B--ibuprofen (40) standard, upon Phase 8 (Example 8).
Sample:
A--10 μl of human serum taken from a blood sample 90 minutes after ingestion of two Advil tablets
B--5 μl of ibuprofen standard (0.5 mg/ml in methanol)
Column Dimensions: 15 cm×4.6 mm
Mobile Phase: 180 mN NH 4 OAc/ACN/THF 95:5:1
Flow Rate: 2.0 ml/min.
Chart Speed: 5 mm/min.
Detection: UV at 273 nm, 0.001 AUFS, ATTN 4
FIG. 12 shows the purification of carbamazepine (34) form spiked calf serum upon Phase 8 (Example 8).
Sample:
250 μl injection of 5 μg/ml carbamazepine (34) in calf serum.
A--1.0 ml fraction was collected and 250 μl reinjected the protein containing fraction.
B--The carbamazepine (34) fraction was collected in a 2 ml fraction and 250 μl of the carbamazepine (34) fraction was reinjected (0.625 μg/ml)
Column Dimensions: 15 cm×4.6 mm
Mobile Phase:
A--180 mM NH 4 OAc
B--ACN
Gradient Profile:
______________________________________Time % A % B______________________________________0.0 100 05.0 100 05.1 85 1515.0 85 1515.1 100 020.0 100 0______________________________________
Flow rate: 2.0 ml/min.
Detection: UV at 285 nm, 0.032 AUFS
Chart Speed: 0.5 cm/min.
FIG. 13 represents, in schematic form, a cross-sectional view of a pore, 1, in the silica gel support, 2, with the hydrophilic shield, 3, and the shielded, interactive region, 4, which interacts with the small analytes.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, and in particular to FIG. 1, 10 represents a solvent reservoir connected to a mixer 12 which in turn is connected to a pump 14. Pump 14 is connected to a conventional injector 16, through which the sample to be analyzed is injected into the connected column 18 which contains the shielded hydrophobic phase, the subject of this invention. The column 18 is connected to a conventional chromatographic detector 20 which in turn is connected to a recorder 22. Recorder 22 graphs the chromatogram of the sample analysis. A continuous flow of solvent proceeds from the solvent reservoir 10 through the detector 20.
FIG. 2 schematically shows the interaction of a "micellar" shielded hydrophobic phase packed in the column 18. To the support (s) (usually silica gel) is bonded a hydrophobic spacer R.
The P groups form a hydrophilic and water solvated layer and the R groups a hydrophobic underlayer. The P layer prevents large bio-polymer molecules G from interacting with the underlayer R. Smaller analytes A may pass through and interact with the hydrophobic underlayer R.
FIG. 3 shows a hydrophilic network P bonding the silica support (s) to hydrophobic R group (such as alkyl, aryl, etc.).
Use of a properly designed polar hydrophilic head P excludes water soluble bio-polymers, by steric hindrance, from interacting with the underlying hydrophobic spacer R. On the other hand, small analytes are "solubilized" by the R-groups as they penetrate the hydrophilic polar layer. FIG. 2 schematically shows the chromatographic interactions of SSP with a sample consisting of bio-polymer and an analyte. The polar portion of the bonded phase will screen the bio-polymer from the hydrophobic regions of the bonded phase, resulting in its rapid elution. Under the same chromatographic conditions, the smaller analyte "solubilized" by the hydrophobic regions of the bonded phase is retained and thus separated from the larger macromolecules.
FIG. 3 describes a hydrophilic water solvated network containing enclaved hydrophobic moieties R. In a similar mechanism, the larger proteins G are screened by this network from interacting with the enclaved hydrophobic moieties R which are accessible to the smaller analytes A, resulting in fast elution of the former and retention of the latter compounds.
A large variety of high performance silica gel bonded phases have been synthesized and evaluated as SSP material for direct injection of serum, plasma, or body fluids containing drugs. These phases are set forth in the following listing as Phase 1 to Phase 8 and are illustrated by Examples and/or Figures in the drawings.
FIG. 13 represents a cross-sectional view of a pore, 1, in the silica gel support, 2, with an interactive phase, 4, bonded to the support, and a hydrophilic shield, 3, which shields the interactive phase from large, water-soluble biopolymers in the liquid being analyzed. This liquid fills the pores, 1, and carries the small, hydrophobic analytes, the large, water-soluble biopolymers, and other components. The large, water-soluble biopolymers are unable to penetrate the hydrophilic shield while the small analytes are small enough to penetrate it readily and interact with the interactive phase, producing the desired chromatographic separation.
In the drawings FIGS. 4-12 represent chromatograms. The following number designations represent peaks in the chromatogram indicating the presence of the following drugs:
(30) propranolol
(32) trimethoprim
(34) carbamazepine
(36) theophylline
(38) phenobarbital
(40) ibuprofen
SILICA GEL BONDED PHASES
Phase 1.tbd.Si(CH 2 ) 11 N(CH 2 CH 2 OCH 3 ) 2
Phase 2.tbd.Si(CH 2 ) 10 CON(CH 2 CH 2 OCH 3 ) 2
Phase 3.tbd.Si(CH 2 ) n SO 2 N 3 where n=7-10
Phase 4--Si(CH 3 ) 2 (CH 3 ) 10 CO 2 CH 3
Phase 5--Si(CH 3 ) 2 (CH 2 ) 10 CON(CH 2 CH 2 OH)(CH 2 CH 2 NRCH 2 CH 2 OH) where (R)=--H and/or --CO(CH 2 ) 10 Si(CH 3 ) 2 --
Phase 6.tbd.Si(CH 2 ) 10 CN
Phase 7.tbd.Si(CH 2 ) 11 NHCH 2 CH 2 CH 2 SO 3 H
Phase 8 ##STR1## where 0≦k, l, m, n≦50, R 1 =--CONH(CH 2 ) 3 Si.tbd.(S), (S)=silica gel, Si--(S)=Si--O--Si, and R 2 , R 3 =R 1 and/or another network of the same connected through a --CO-- bond and/or H, and or alkyl, and/or carboxylate, and/or alkanamide.
Phase 9 A mixed phase containing Phase 8 and (S).tbd.Si(CH 2 ) 3 N(CH 3 ) 2 in approximately equal surface concentration.
Phase 10 A mixed phase containing Phase 8 and (S).tbd.Si(CH 2 ) 3 N+(CH 3 ) 3 in approximately equal surface concentration.
Phase 11 A mixed phase containing Phase 8 in which R 1 is (S).tbd.Si(CH 2 ) 3 NH(CH 2 ) 2 NHCO--, and (S).tbd.Si(CH 2 ) 3 N+(C 4 H 9 ) 3 in approximately equal surface concentration.
Phase 12 A mixed phase containing Phase 8 and (S).tbd.Si(CH 2 ) 3 NHCO(CH 2 ) 2 CO 2 H in approximately equal surface concentration.
Phase 13 A mixed phase containing Phase 8 in which R 2 is ##STR2## in approximately equal surface concentration.
These phases demonstrate that the interactive region of the phase, R, may be selected from a wide variety of functionalities, including but not limited to, hydrophobic, weak-base anion exchange, strong-base anion exchange, weak-acid cation exchange and strong-acid cation exchange functionalities. Phases 1 through 8 have defined hydrophobic and hydrophilic regions and are covalently bonded to the chromatographic matrix. The bonded ligand of Phases 1-7 have a hydrophobic region R consisting of a hydrocarbon chain, --(CH 2 ) n -- where n=6 to 20, more preferably 7 to 11 and still more preferably 10 or 11, and a polar hydrophilic head P. The hydrophobic region, R, is also referred to herein as a "leash", as it both spaces the polar group from the support and tethers the polar group to the support. Phase 8 is a bonded hydrophilic polyether network enclaving hydrophobic phenyl groups bonded to the network through bis carbamate groups.
Phases 9 through 13 have regions R and P in which R is a hydrophobic group or a weak or strong cation-exchange group or a weak or strong anion-exchange group. The preferred phase contains as regions R both regions R a which are hydrophobic, and R b which are weak or strong cation-exchange groups or weak or strong anion-exchange groups or chelating groups or π--π accepting or donating groups. R a may be any of the hydrophobic groups described herein, and preferably one of the hydrophobic groups of Phases 1 through 8. The R b group may be attached to the R a group, as for example to the nitrogen in R 2 or R 3 of Phase 8, or to the silane silicon of Phase 8, in which case the R b group is shielded by the hydrophilic polymer network of the phase. Alternatively the R b group may be attached to the silica surface through an alkylsilyl, alkylaminosilyl or alkylamidosilyl group directly, and mixed-bonded with phases 1-7, in which case it will be shielded by the hydrophilic groups of neighboring hydrophobic leash-hydrophilic head micelles. The R b group in Phase 9 is --N(CH 3 ) 2 , a weakly basic anion exchanger; in Phase 10 it is --N + (CH 3 ) 3 , a strongly basic anion exchanger; in Phase 11 it is --N + (C 4 H 9 ) 3 , another strongly basic anion exchanger; in Phase 12 it is --CO 2 H, a weakly acidic cation exchanger; and in Phase 13 it is --SO 3 H, a strongly acidic cation exchanger.
These phases also demonstrate that the polar head P may be selected from a wide variety of functionalities including, but not limited to: amines, amides, esters, ethers, alcohols, azides, carboxylic acids, cyano groups, thiols, diols, amino acids, nitriles, sulfonic acids, ureas, and the like, or a combination of such. All of these phases have shown retention of small drug analytes while excluding serum proteins when tested with drug containing serum. FIGS. 4-12 illustrate various chromatographic separations as carried out with different SSP supports. In a typical chromatographic separation on an SSP, the bio-polymer will elute completely, or almost completely, in the void volume, while the analyte elutes later.
The SSP supports can be simply slurry packed into standard liquid chromatography columns and used with standard HPLC equipment. Such a combination allows for the direct, on-line resolution of small analytes from a complex bio-polymer matrix in a single and simple chromatographic step. The SSP supports solve, in a new and novel way, the problem of direct, on-line analysis of analytes in bio-matrices such as serum or plasma. An example for commercial applications of this invention is the direct analysis of drugs, metabolites, etc., from serum, plasma, saliva, urine, or other body fluids as is often performed in the pharmaceutical industry, clinical and drug testing laboratories, toxicology studies, etc.
The following examples are intended to illustrate the invention, and are not to limit it except as limited by the claims. All percentages herein are by weight unless otherwise indicated, and all reagents are of good commercial quality unless otherwise indicated.
EXAMPLE 1
N,N-bis(2'-methoxyethyl)-11-aminoundecylsilyl, Phase 1.tbd.Si(CH 2 ) 11 N(CH 2 CH 2 OCH 3 ) 2 N,N-bis(2'-Methoxyethyl)-11-(triethoxysilyl)undecylamine, (II)
To a solution of 16.8 g 10-undecenal in 25 ml methylene chloride, crystals of di-μ-chlorodichlorobis(ethylene)-diplatinum (II) were added and the solution heated to 40°-45° C. A solution of 16.4 g triethoxysilane in 25 ml methylene chloride was added dropwise over a period of 90 minutes. After reagent addition was completed, the rection mixture was heated for an additional 30 minutes. The mixture was fractionated and the product, 11-triethoxysilylundecanal (I) was obtained at 65° C. at 0.2 mm Hg at a 30% yield.
A solution of 6.0 g of I and 3.0 g of bis(2-methoxyethyl)amine in 100 ml absolute ethanol containing 0.25 g 10% Pd/C was hydrogenated in a Parr instrument for 90 minutes at room temperature. The mixture was filtered and the alcohol removed under reduced pressure. The residue was purified by column chromatography using 100 g dry silica gel, starting with toluene and increasing the polarity with ethyl acetate. The product, (II), eluted at 50% and 100% ethyl acetate fractions.
BONDING
A solution of (II) in 15 ml toluene was added to 4.0 g of silica gel (5-μm particle size, 100 m 2 /g surface area, 12.5 nm average pore diameter) placed in a 50 ml glass ampule. The mixture was slurried to homogeneity and the solvent was removed under vacuum while the slurry was continuously agitated. Ammonia (gaseous) was added to the evacuated mixture, then the ampule was sealed and heated at 100° C. overnight. The mixture was thoroughly washed with methylene chloride, then methanol, and then dried. From the elemental analysis: C--6.72% (silica blank C--0.41%), a ligand coverage of 3.13 μmol/m 2 was calculated for C 17 H 37 NO 3 Si, (═Si(OH)--(CH 2 ) 11 N(CH 2 CH 2 OCH 3 ) 2 ).
A 15 cm×4.6 mm column was slurry packed at pressure above 52 MegaPascals. Human serum spiked with the drugs listed in Table I was directly injected through injector 16 onto column 20 containing phase 1. The column resolved the drugs from the human serum components (see Table I). FIG. 4 shows the chromatographic resolution of propranolol and other drugs from spiked human serum using the procedures of Example 1.
TABLE I______________________________________RETENTION TIMES FOR DRUGS FROM SPIKEDHUMAN SERUM ON PHASE 1Drug Retention Time (min.) Mobile Phase______________________________________Theophylline 1.78 1Propranolol 5.00 1Propranolol 2.52 2Quinidine 1.97(a) 2Carbamazepine 33.58 1Carbamazepine 12.96 2Desipramine 4.25 2Column Dimensions: 15 cm × 4.6 mmFlow Rate: 2.0 ml/min.______________________________________ 1. 0.5M NH.sub.4 OAc aqueous solution adjusted to pH 6.0 with glacial acetic acid 2. 0.5M NH.sub.4 OAc pH 5.0 adjusted with H.sub.3 PO.sub.4 : 2propanol: THF 500:25:1 (a) Not completely resolved from minor serum components
EXAMPLE 2
N,N-bis(2'-methoxyethyl)-11-silylundecanamide, Phase 2 .tbd.Si(CH 2 ) 10 CON(CH 2 CH 2 OCH 3 ) 2
The material was prepared from N-hydroxysuccinimido 11-(triethoxysilyl)undecanoate which was treated with an equivalent of bis-(2-methoxyethyl)amine in methylene chloride in the presence of an equivalent of triethylamine. The product, N,N-bis-(2'-methoxyethyl)-11-(triethoxysilyl)undecanamide (III), was purified by column chromatography on a ten-fold w/w silica gel column, starting with toluene and increasing polarity with ethyl acetate. The product, an oil, eluted at 20% ethylene acetate with approximately 80% yield.
Bonding as for (II) Example 1 using 6.0 g of the same silica and impregnating with 1.65 g of (III) in 20 ml hexane yielded the N,N-bis-(2'-methoxyethyl)-11-undecanamide, Phase 2.
Elemental analysis: C--3.64, H--1.13, and N--0.40%. From the carbon percentage a coverage of 3.14 μmol/m 2 was calculated for C 17 H 35 --NO 4 Si (Si(OH)--(CH 2 ) 10 CON(CH 2 CH 2 OCH 3 ) 2 ) ligand. A 15 cm×4.6 mm column was slurry packed at pressures above 52 MegaPascals. Human serum spiked with the drugs listed in Table II was directly injected through injector 16 onto column 20 containing phase 2. The column retained the drugs as listed in Table II.
TABLE II______________________________________RETENTION TIMES FOR DRUGS ON PHASE 1Drug Retention Time (min.) Mobile Phase______________________________________Caffeine 1.11 1Acetaminophen 1.69 1Propranolol 18.01 1______________________________________ (1) 0.05M ammonium acetate, 0.1M potassium chloride (pH 3.0)/MeOH 80:20
EXAMPLE 3
ω-(sulfonazido)alkylsilyl, Phase 3 .tbd.Si(CH 2 ) n SO 2 N 3 n=7-10
To 10 g of SUPELCOSIL™ silica (5-μm particle size, 10-nm pore size) in a 100 ml round bottom flask were added 10 ml of AZ-CUP MC Azidosilane reagent (Hercules, Inc., Wilmington, Del.), 25 ml of methylene chloride and 25 ml of toluene. The mixture was refluxed for eight hours, cooled, filtered, washed with 3×100 ml of methylene chloride, followed by 3×100 ml of methanol, and oven dried at 80° C. Elemental analysis: C--8.92, H--1.82, N--1.07, and S--0.58%. The resultant bonded phase was slurring packed at pressures above 34 MegaPascals into a 5 cm×4.6 mm column. Human serum spiked with the drugs listed in Table III were directly injected through injector 16, onto column 20, containing phase 3. FIG. 5 shows the chromatographic resolution of trimethoprim (32), carbamazepine (34), and propranolol (30) from the spiked human serum sample.
Table III indicates the retention time for other drugs using the procedure of Example 3.
TABLE III______________________________________RETENTION TIME FOR DRUGS AND TEST PROBESFROM SPIKED HUMAN SERUM ON THE SULFAZIDEPHASE 3Test Compound Retention Time (min.)______________________________________Uracil 0.37Theophylline 0.54Caffeine 0.71Acetaminophen 0.54Trimethoprim (32) 3.34Carbamazepine (34) 4.50Codeine 2.92Hydrochlorothiazide 1.16Procainamide 2.04Propranolol (30) 13.52______________________________________
Column Dimensions: 5 cm×4.6 mm
Mobile Phase: 180 nM NH 4 OAc:ACN (90:10) (pH 7.0)
Flow Rate: 2.0 ml/min.
EXAMPLE 4
(10-carbomethoxydecyl)dimethylsilyl, Phase 4 --Si(CH 3 ) 2 (CH 2 ) 10 CO 2 CH 3
To 5.0 g of SUPELCOSIL™ silica (5-μm particle size, 10-nm pore size) in a round bottom flask was added 2.0 ml of (10-carboxymethoxydecyl)dimethylchlorosilane dissolved in 50 ml of dried toluene. The mixture was refluxed for 14 hours, cooled, filtered, washed with 3×100 ml of toluene followed by 3.×100 ml of methanol, and dried. Elemental analysis: C--5.66, and H--1.22%. A bonded phase coverage of 2.40 μmol/m 2 was calculated for C 14 H 29 O 2 Si ligand. A 5 cm×4.6 column was slurry packed with this material at pressures above 41 MegaPascals. The resultant column containing phase 4 was capable of baseline resolution of trimethoprim from calf serum (FIG. 6) directly injected through injector 16.
EXAMPLE 5
N,N'-bis(2-hydroxyethyl)ethylenediamino modified 11-dimethylsilylundecanoic acid (IV), Phase 5 --Si(CH 3 ) 2 (CH 2 ) 10 CON(CH 2 CH 2 OH(CH 2 CH 2 NRCH 2 OH) R=H and/or CO(CH 2 ) 10 Si(CH 3 ) 2 --
A 3.8 g sample of phase 4 was hydrolyzed with 50 ml 1:1 methanol:water mix adjusted to pH 2.85 using glacial acetic acid. The mixture was shaken overnight, filtered and washed with 3×50 ml of 1:1 methanol:water, followed by 3×50 ml of methanol, and dried to yield (IV). A 3.6 g of (IV) was placed in a flask with 1.0 g of N,N'-bis(2-hydroxyethyl)ethylene diamine and 1.1 g of EEDQ (1-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline) dissolved in 40 ml of dry THF. The mixture was shaken for six hours at room temperature. The mixture was filtered, washed with 3×100 ml of dry THF, followed by 3×100 ml of methanol, and dried. Elemental analysis:C--9.13, H--1.71, and N--1.57%. From the carbon percentage a coverage of 3.07 μmol/m 2 or 2.06 μmol/m 2 was calculated for (R=H) C 19 H 41 N 2 O 3 Si or for (R=CO(CH 2 ) 10 Si(CH 3 ) 2 --) C 32 N 66 N 2 O 4 Si 2 , respectively. A 5.0 cm×4.6 mm column was slurry packed at pressures above 41 MegaPascals. The resulting column containing Phase 5 gave a baseline resolution of trimethoprim from calf serum (FIG. 7) when injected directly through injector 16.
EXAMPLE 6
10-cyanodecylsilyl, Phase 6 .tbd.Si(CH 2 ) 10 CN
To 10 g of oven dried SULPELCOSIL™ silica (5-μm particle size, 10-nm pore size) in a 250 ml round bottom flask was added 2.5 ml of 10-cyanodecyltrichlorosilane and 75 ml of toluene. The mixture was refluxed for five hours and then 1.5 ml of trimethylchlorosilane was added and the mixture was refluxed an additional hour. The mixture was cooled, filtered, and washed with 3×100 ml of toluene followed by 3×100 ml of methanol, and dried.
Elemental Analysis: C--8.38, H--1.56, and N--0.98%. A bonded phase coverage of 4.03 μmol/m 2 was calculated for a C 11 H 22 NOSi ligand, (.tbd.Si(OH)(CH 2 )CN).
A 5.0 cm×4.6 mm column was slurry packed at pressures above 41 MegaPascals. The resultant column containing Phase 6 gave a baseline resolution of trimethoprim from calf serum (FIG. 8) when injected directly through injector 16.
EXAMPLE 7
N-(3'-propylsulfonic acid)-11-undecylaminosilyl, Phase 7 .tbd.Si--(CH 2 ) 11 NHCH 2 CH 2 CH 2 SO 3 H
Preparation of 11-(undecylamine)trimethoxysilane
According to Freifelder (J. Am. Chem. Soc. 82 (1960) 2386) by hydrogenating 10-(trimethoxysilyl)cyanodecane in the presence of 5% Rh/alumina in 12% methanolic ammonia solution instead of ethanolic solution. The product was fractionated b.p. 145°-147° C. at 0.25 mm Hg, 50% yield.
11-Aminoundecylsilyl Phase:
5.3 g of (11-undecylamine)trimethoxysilane was dissolved in 75 ml toluene and added to 20.4 g. of SUPELCOSIL™ silica (5-μm particle size, 10-nm pore size). The mixture was refluxed for seven hours, cooled, filtered, washed with 3.0×50 ml of toluene, followed by 3×50 ml of methanol, and dried.
Elemental analysis: C--6.68, H--1.38, N--0.54%. From the carbon percentage, a coverage of 3.38 μmol/m 2 was calculated for a C 12 H 27 NOSi ligand.
Phase 7 Preparation: to 5.0 g of the 11-aminoundecylsilyl phase dried at 65° C. under high vacuum was added 1.2 g of 1,3-propane sultone dissolved in 35 ml of methylene chloride, followed by 75 ml of methylene chloride containing 250 μl of pyridine. The mixture was shaken at room temperature for several minutes and then refluxed for three hours. The mixture was filtered, washed with 3×100 ml of methylene chloride, followed by 3×100 ml of methanol, and dried. Elemental analysis: C--8.58, H--1.60, N--1.40, and S--0.83%. From the carbon percentage, a coverage of 3.41 μmol/m 2 was calculated for a C 15 H 33 O 3 SSi ligand. A 5.0 cm×4.6 mm column was slurry packed at pressures above 41 MegaPascals. The resultant column containing Phase 7 gave a baseline resolution of trimethoprim from calf serum (FIG. 9) when injected directly through injector 16.
EXAMPLE 8
Urethane-modified 3-propylamine, Phase 8
.tbd.SiCH.sub.2 CH.sub.2 CH.sub.2 NHCONHR
where R=branched polyethylene oxide with terminal hydroxyl groups substituted with tolydiisocyanate: ##STR3## where 0≦k, l, m, n≦50, R 1 =.tbd.SiCH 2 CH 2 CH 2 NHCONHR, (S)=silica gel, Si--(S)=Si--O--Si, and R 2 , R 3 =R 1 and/or another network of the same connected through a --CO-- bond and/or H, and or alkyl, and/or carboxylate, and/or alkanamide.
To 30 g of dry SUPELCOSIL silica (5-μm particle size, 10-nm pore size) 20 g of 3-aminopropyltrimethoxysilane and 300 ml of toluene were added. The suspension was heated to reflux for 16 hours, and the reaction mixture was filtered and washed with 300 ml of toluene followed by 300 ml of methanol and dried at 60° C. under nitrogen for 10 hours.
To 600 ml of toluene in a 1000 ml round bottom flask was added 5.0 g of Hypol FHP 2000 polymer (W. R. Grace, Co., Lexington, Mass.). The polymer was completely dissolved by shaking and sonicating. To the solution 12.5 g of the 3-aminopropyltrimethoxysilane-bonded silica from the step above was added. The suspension was refluxed for three hours. To the mixture was added 0.2 g of 1,4-diazabicyclo-(2,2,2)octane dissolved in 10 ml of toluene, and the mixture was refluxed for an additional three hours. The "hot" mixture was filtered, washed with toluene, methylene chloride and methanol, and oven dried. Elemental analysis: C--10.41, H--1.66, and N--1.30%.
A 15 cm×4.6 mm column was slurry packed at pressures above 52 MegaPascals. The column resolved various drugs from calf and human sera. FIG. 10 shows carbamazepine-, phenobarbital- and theophylline-spiked human serum samples as resolved on a column containing Phase 8 by directly injecting the spiked samples through injector 16. FIG. 11 shows the resolution of ingested ibuprofen from human serum. FIG. 12 shows the trace enrichment/purification by a step-wise elution of a carbamazepine-spiked calf serum and the chromatographic results of the collected protein and drug containing fractions. This evaluation demonstrates the application of the packing material for trace enrichment, which could be applied in solid phase extraction of small volumes up to large scale industrial levels.
EXAMPLE 9
R=--N(CH 3 ) 2 , Phase 9
To 7.12 g of SUPELCOSIL™DB silica (5μm particle size, 10 nm pore size) previously conditioned at 85% humidity (allowing to equilibrate over a saturated aqueous solution of lithium chloride) were added 5.6 mmole (1.16 g) of N,N-dimethyl-3-aminopropyltrimethoxysilane, 5.6 mmole (1.0 g) 3-aminopropyltrimethoxysilane and 100 ml toluene. The mixture was suspended and refluxed for 4 hours. The mixture was filtered, and the solid material was washed with 200 ml toluene, then 200 ml methylene chloride, and finally 200 ml methanol. The solid product was dried at 60° C. under nitrogen for four hours followed by two hours at high vacuum. To the dried solid product a solution of 2.8 g Hypol FHP 2000 polymer (W. R. Grace Company, Lexington, Mass. in 100 ml of dry toluene was added. The mixture was suspended and refluxed for one hour; 1.0 ml of hexylamine was added and suspended, and the mixture was refluxed for one additional hour. The solid product was filtered hot and washed with 200 ml each of toluene, methylene chloride and methanol. The solid product was dried at 60° C. under nitrogen for four hours. To the solid product 50 ml of dry pyridine and 4.0 ml of acetic anhydride were added. The mixture was agitated for 10 hours, then filtered and washed with 100 ml toluene, 200 ml methylene chloride and 300 ml methanol. The solid product was dried at 60° C. under nitrogen for four hours.
Elemental analysis: C--14.95%; H--2.33%; N--1.99%.
A 4.6-mm×15-cm column was slurry packed at 59 MegaPascals with Phase 9. The operating conditions and results of chromatographic separations of serums spiked with chloramphenicol, salicylic acid and benzoic acid are shown in Table IV, below.
EXAMPLE 10
R=--N + (CH 3 ) 3 , Phase 10
Phase 10 was prepared according to the procedure of Example 9, above, except that 3 μmole per square meter of silica surface of a 50% methanolic solution of N-(3-trimethoxysilylpropyl)trimethylammonium chloride was used in place of the N,N-dimethyl-3-aminopropyltrimethoxysilane, and 3 μmol per square meter of silica surface of the 3-aminopropyltrimethoxysilane was used.
Elemental analysis: C--15.83% and N--1.92%.
A 4.6-mm×15-column was slurry packed at 59 MegaPascals with Phase 10. The operating conditions and results of chromatographic separations of serums spiked with chloramphenicol, salicylic acid and benzoic acid are shown in Table IV, below.
EXAMPLE 11
R=--N + (C 4 H 9 ) 3 , Phase 11
Phase 11 was prepared according to the procedure of Example 9, except that 3 μmole per square meter of silica surface of a 50% methanolic solution of N-(3-trimethoxysilylpropyl)tributylammonium bromide and 3 μmole per square meter of silica surface of N-(2-aminoethyl)-3-aminopropyltrimethylsilane were substituted for the N,N-dimethyl-3-aminopropyltrimethoxysilane and 3-aminopropyltrimethoxysilane of Example 9.
Elemental analysis: C--15.85% and N--2.40%
A 4.6-mm×15-cm column was slurry packed at 59 MegaPascals with Phase 11. The operating conditions and results of chromatographic separations of serums spiked with chloramphenicol, salicyclic acid and benzoic acid are shown in Table IV, below.
TABLE IV______________________________________CAPACITY FACTOR RESULTS FORCHROMATOGRAPHIC SEPARATION WITHBASIC MODIFIED PHASE 8SeparatedComponent Phase 8 Phase 9 Phase 10 Phase 11______________________________________Chloramphenicol 2.54 4.04 5.61 5.20Salicylic Acid 2.05 5.20 10.20 23.19Benzoic Acid 1.16 2.19 3.66 4.44Total Serum 11.5 10.8 11.6 12.0Protein Area,(million counts)______________________________________
Chromatographic Conditions
Mobile Phase: 95% 180 mM NH4OAc (aq) pH=7.0/5% AcN
Flow: 2.0 ml/min
Injection Volume: 10 μl
Concentration and Detection:
Chloramphenicol, 10 μg/ml, 278 nm, 0.016 AUFS
Salicylic Acid, 25 μg/ml, 280 nm, 0.008 AUFS
Benzoic Acid, 10 μg/ml, 254 nm, 0.016 AUFS or 0.032 AUFS
Serum, neat, 254 nm, 0.016 AUFS
Temperature: Ambient.
NOTE--The Capacity factor, C i , is defined as ##EQU1## where V i is the elution volume of compound i and V o is the elution volume of an unretained compound (V o is also termed the void volume).
EXAMPLE 12
R=--CO 2 H, Phase 12
Phase 12 was prepared according to the procedure of Example 9, except that only 20 μmole per square meter of silica surface of the 3-aminopropyltrimethoxysilane and no other aminosilane was used; subsequent to the addition of the pyridine but prior to the addition of the acetic anhydride, 0.15 g/g of silica of succinic anhydride was added and the mixture was agitated for 22 hours; and in the final washing of the solid product the first rinse was with water, followed by 50% aqueous methanol and finally methanol.
Elemental analysis: C--16.69%, H--2.48%, and N--2.23%.
A 4.6-mm×15-cm column was slurry packed at 59 MegaPascals with Phase 12. The operating conditions and results of chromatographic separations of serums spiked with chloramphenicol, salicylic acid and benzoic acid are shown in Table V, below.
EXAMPLE 13
R=--SO 3 H, Phase 13
Phase 13 was prepared according to the procedure of Example 12, except that the reaction mixture was cooled to room temperature and instead of the hexylamine, a solution of 1.5 g hexamethylenediamine in 50 ml of toluene for each 10 g of silica gel was added and the mixture was agitated for three hours. In addition, prior to adding the acetic anhydride the solid product is dried under high vacuum at 60° C. for two hours; 4 μmole per square meter of silica surface of 3-fluorosulfonylbenzenesulfonyl chloride was substituted for the succinic anhydride; and following the final washing step the solid product was dried under high vacuum at 60° C. for two hours. A calculated amount of 3 μmole per gram of silica, based on the pretreatment weight of silica used in this example, of tetrabutylammonium hydroxide in a 40% aqueous solution was evaporated to dryness under vacuum for three hours at ambient temperature, dissolved in 4 ml/g of silica of dry pyridine, and added to the silica. The mixture was agitated at room temperature for 20 hours, filtered and washed thoroughly with 1:9 acetonitrile:water containing 180 mmole ammonium acetate, followed by washing with water and then methanol. The solid product was dried at 60° C. under nitrogen for four hours.
Elemental analysis:
Prior to final treatment step- C--16.14%, H--2.48%, N--2.35%, S--0.75% and F--0.20%
Final product- C--16.19%, H--2.48%, N--1.83%, S--0.55% and F--0.050%.
Despite the presence of fluoride in the final product, the material that was almost completely inactive to ion exchange prior to the tetrabutylammonium hydroxide treatment became an active ion-exchange material following this treatment.
A 4.6-mm×15-cm column was slurry packed at 59 MegaPascals with Phase 13. The operating conditions and results of chromatographically separating a mixture of chloramphenicol, salicylic acid and benzoic acid are shown in Table V, below.
TABLE V______________________________________CAPACITY FACTOR RESULTS FORCHROMATOGRAPHIC SEPARATION WITHACID-MODIFIED PHASE 8Separated Phase 8 Phase 12 Phase 13Component pH 7 pH 4 pH 7 pH 4 pH 7 pH 4______________________________________Chloramiphenicol 2.54 2.25 3.79 3.16 4.06 3.53Trimethoprim 2.56 0.30 4.83 0.25 4.02 2.21Propranolol 2.94 0.85 8.40 0.76 9.80 6.00Total Serum 11.5 11.1 11.7 12.0 11.4 10.0Protein Area(million counts)______________________________________
Chromatographic Conditions
Mobile Phase:
for pH 7--95% 180 mM NH 4 OAc (aq) pH=7.0/5% AcN
for pH 4--95% 90 mM NH 4 OAc (aq) pH=4.0/5% AcN
Flow: 2.0 ml/min
Injection Volume: 10 μl
Concentration and Detection:
Chloramphenicol, 10 μg/ml, 278 nm, 0.016 AUFS
Trimethoprim, 25 μg/ml, 254 nm, 0.016 AUFS
Propranolol, 25 μg/ml, 254 nm, 0.016 AUFS
Serum, neat, 254 nm, 0.016 AUFS
Temperature: Ambient.
NOTE--Chloramphenicol, trimethoprim and propranolol values were determined in a serum matrix. | Novel packing materials are provided for liquid chromatography and/or solid phase extraction columns which will allow direct injection of biological fluids. These packing materials have a hydrophilic exterior layer and a hydrophobic, charged or otherwise selective portion that forms an underlayer or is embedded in the hydrophilic layer. During a chromatographic process large water soluble biopolymers will be in contact with the hydrophilic outer layer and be shielded from interacting with the underlayer or embedded portion and elute unretained. Small analytes, on the other hand, can be fully partitioned throughout the exterior and interior layers and are retained by hydrophobic or electrostatic interactions. Using such packings the direct analyses of plasma or serum for drug analysis is demonstrated. | 54,464 |
BACKGROUND OF THE INVENTION
1) Field of the Invention
The present invention relates to an image forming device of an electro-photographic system, electro-static recording system, or the like. Particularly, the present invention relates to an image forming device that forms an image on a sheet-like medium by transferring an image such as a developed image (toner image) formed on the surface of a latent image carrier such as a photosensitive body on a sheet-like medium conveyed by a conveying belt.
2) Description of the Related Art
Electro-photographic printers as image forming devices, for example, have generally the structure as shown in FIG. 8. The electro-photographic printer 1 shown in FIG. 8 consists of a color printing engine 2, paper cassettes 3 and 4, a sheet feeding unit 5, a sheet ejecting unit 6, a sheet stacker 7, a power supply/control unit 8, and others.
In the electro-photographic printer 1, the transfer paper (sheet-like medium, sheet) 18 to be printed are stored in the sheet cassettes 3 and 4. At the time of printing, the transfer paper 18 is sent out of the sheet feeding unit 5 and then guided by means of the conveying roller 23 along the conveying guide (transfer path) 24 to the color printing engine 2. The transfer paper 18 which is color-printed by the color printing engine 2 (to be described later) is guided via the conveying guide (conveying path) 24 and the sheet ejecting unit 6 and then ejected into the sheet stacker 7.
The power supply/control unit 8 has the function of supplying electric power for the operation of the printer 1 to various portions and controlling the whole operation of the printer 1 including the printing operation of the color printing engine 2.
The printer 1 shown in FIG. 8 includes a double-sided surface mechanism (not shown) that reverses the transfer paper 18 with one surface printed to the side of the sheet ejecting unit 6 to perform a double-sided surface printing on the transfer paper 18 and a conveying guide (conveying path) 24A that again sends the transfer paper 18 reversed by the double-sided mechanism to the color printing engine 2.
Generally speaking, the color printing engine 2 which performs a color image printing operation includes four printing units 10Y, 10M, 10C, and 10K, a fixing unit 16, an endless electrostatic adsorption belt (conveying belt, transfer belt) 17 of a resin which conveys the transfer paper 18.
The printing unit 10Y is formed of a photosensitive body (transfer drum, latent image carrier) 11, a front charger 12, an optical unit 13, a developing unit 14, and a transfer roller 15 in order to transfer a toner image of yellow (Y) on the transfer paper 18. The printing unit 10M is formed of a photosensitive body (transfer drum, latent image carrier) 11, a front charger 12, an optical unit 13, a developing unit 14, and a transfer roller 15 in order to transfer a toner image of magenta (M) on the transfer paper 18. The printing unit 10C is formed of a photosensitive body (transfer drum, latent image carrier) 11, a front charger 12, an optical unit 13, a developing unit 14, and a transfer roller 15 in order to transfer a toner image of cyan (C) on the transfer paper 18. The printing unit 10K is formed of a photosensitive body (transfer drum, latent image carrier) 11, a front charger 12, an optical unit 13, a developing unit 14, and a transfer roller 15 in order to transfer a toner image of black (B) on the transfer paper 18. The printing units 10Y, 10M, 10C and 10K are arranged nearly in parallel along the electrostatic adsorption belt 17.
The photosensitive body 11 is rotatably driven by means of a drive motor (not shown). The front charger 12 charges evenly the surface of the photosensitive body 11. The optical unit 13 projects an image light corresponding to recording information (information regarding print data) on the surface of the photosensitive body 11. The optical unit 13 exposes a pattern corresponding to print data on the surface of the photosensitive body 11 to form an electrostatic latent image.
The developing unit 14 develops the electrostatic latent image formed on the surface of the photosensitive body 11. In fact, the developing process is performed by supplying toner on the surface of the photosensitive body 11 and then forming a toner image (latent image, developing image) which is visible. The transfer rollers 15 are arranged so as to confront the photosensitive bodies 11, thus sandwiching the electrostatic adsorption belt (or the transfer paper 18) 17. The toner image on the photosensitive body 11 is transferred onto the transfer paper 18 by sandwiching the transfer paper 18 conveyed by the electrostatic adsorption belt 17 between the transfer roller 15 and the photosensitive body 11.
Further, when the transfer paper 18 on which a toner image of each color is transferred by means of the printing units 10Y, 10M, 10C and 10K is conveyed, the fixing unit 16 fixes the toner image formed on the transfer paper 18 onto the transfer paper 18 thermally, or under pressure, lighting, or the like.
The electrostatic adsorption belt 17 is endlessly wound around the drive roller 19, the following roller 20, and tensioning rollers (tensioners) 21 and 22, and is driven by transmitting the rotational drive force of the drive motor (refer to numeral 25 in FIG. 9) by means of the drive roller 19. The transfer paper 18 which is electrically charged by means of the corona charger (refer to numeral 26 in FIG. 9) is electrostatistically adsorbed on the outer surface (the surface confronting the photosensitive body 11) and then is conveyed sequentially to the printing units 10Y, 10M, 10C and 10K.
In order to arrange in order the front ends of plural sheets of transfer paper 18, the resist roller (not shown) is arranged just in front of the image transfer point (the image transfer point made by the photosensitive body 11 and the transfer roller 15) of the transfer paper 18 in each of the printing units 10Y, 10M, 10C and 10K.
In the electro-photographic printer 1 with the above-mentioned structure shown in FIG. 8, the transfer paper 18 is transmitted from the sheet cassette 3 or 4 onto the transfer belt 17 of the color printing engine 2 via the sheet feeding unit 5. Then the transfer belt 17 transmits the transfer paper 18 to the fixing unit 16 by passing through the printing units 10Y, 10M, 10C and 10K.
While the transfer paper 18 passes through the printing units 10Y, 10M, 10C and 10K, a toner image of each color (Y, M, C, K) is transferred on the transfer paper 18. While the transfer paper 18 passes through the fixing unit 16, the toner image is fixed on the transfer paper 18.
When a printing operation is performed by overlaying sequentially different colors on the transfer paper 18 in the printing units 10Y, 10M, 10C and 10K, a color image is formed on the transfer paper 18.
The sheet conveying velocity of the electrostatic adsorption belt 17 is set to the same as that of the conveying roller 23 arranged upstream to the electrostatic adsorption belt 17. However, it is very difficult to match completely two sheet conveying velocities to each other because of the accuracy in dimension of the constituent member of the eletrostatic adsorption belt 17, the accuracy in dimension of the pair of the conveying rollers 23, the accuracy in revolution of the drive motor (refer to numerals 25 and 30 in FIG. 9) for the drive roller 19 or the conveying roller 23, wear of the conveying roller 23, and others.
When two sheet conveying velocities do not match to each other, bending and fluttering occur in the transfer paper 18 at the portion where the transfer paper 18 is transmitted from the conveying system including the conveying roller 23 to the conveying system including the electrostatic adsorption belt 17. The fluttering causes the unstable state of the transfer paper 18 at the image transfer point of each of the printing units 10Y, 10M, 10C and 10K, thus occurring the shear and variation in printing due to the printing units 10Y, 10M, 10C and 10K. As a result, the printing accuracy is deteriorated.
Further, it has been proposed that the conveying system 32, for example, shown in FIG. 9 is prepared in the front stage of the color printing engine 2 to convey the transfer paper 18 at high speed. That is, the conveying system 32 includes conveying rollers 28 and 29 which are driven at high speed by means of the drive motor 30. The conveying rollers 28 and 29 convey the transfer paper 18 immediately before the color printing unit 2 (the conveying system including the electrostatic adsorption belt 17).
The clutch 31 is arranged between the conveying roller 28 arranged just before the color printing unit 2 and the drive motor 30. The problem of the difference in velocity between the conveying system including the electrostatic adsorption belt 17 and the conveying system 32 can be eliminated by coupling on or off the clutch 31 while the transfer paper 18 is conveyed at a high speed. The drive motor 25 which drives the electrostatic adsorption belt 17 belongs to a different system from the conveying system 32 including the drive motor 30. The drive motors 25 and 30 drive respectively the conveying systems at completely different speed.
That is, with the clutch 31 coupled, the conveying rollers 28 and 29 feed the transfer paper 18 into the color printing unit 2. When the rear end of the transfer paper 18 passes through the position of the conveying roller 29, the clutch 31 is coupled off so that the conveying roller 28 is changed in its idle mode. At this time, the front end of the transfer paper 18 reaches the upper surface of the electrostatic adsorption belt 17. Thereafter, the transfer paper 18 is fed at the conveying speed of the conveying system including the electrostatic adsorption belt 17. The conveying roller 28 also co-rotates at the conveying speed.
Referring to FIG. 9, numeral 26 represents a corona charger. In the color printing engine 2, the corona charger 26 is arranged near to the portion where the sheet-like medium 18 is fed from the conveying system 32 and charges the transfer paper 18 fed onto the electrostatic adsorption belt 17 to be adsorbed on the electrostatic adsorption belt 17. The corona charger 26 is not illustrated in FIG. 8.
However, compared with the example described with FIG. 8, it is more difficult to eliminate completely the problem of the difference in velocity between the conveying system including the electrostatic adsorption belt 17 and the conveying system 32 even if the clutch 31 is coupled on or off.
For example, when the conveying speed of the pair of the conveying rollers 23 or 28 is smaller than that of the electrostatic adsorption belt 17, the pair of the conveying rollers 23 or 28 pulls relatively the rear portion of the transfer paper 18. This phenomenon causes the positional displacement of the transfer paper 18 to the electrostatic adsorption belt 17. The phenomenon also may cause the transfer failure due to the deformation of the electrostatic adsorption belt 17 shown in FIG. 10(a) as well as the displacement in transfer position between the toner image of the first color and the toner image of the second color. Moreover, at the moment when the end of the transfer paper 18 has passed through the pair of the conveying rollers 23 or 28, the electrostatic adsorption belt 17 can be quickly recovered. Hence, the shocking operation may cause transfer variations.
When the conveying speed of the pair of the conveying rollers 23 or 28 is larger than that of the electrostatic adsorption belt 17, the pair of the conveying rollers 23 or 28 pushes out the rear portion of the transfer paper 18 relatively. Therefore, since the electrostatic adsorption belt 17 may deform or the transfer paper 18 is lifted from the electrostatic adsorption belt 17 as shown in FIG. 10(b), the before-mentioned troubles occur.
This problem becomes more remarkable in the case of a large-sized transfer paper 18. Further, the problem become a significant demerit in the copier market demanding high-quality images, particularly in the color copier market demanding the improved color reproducibility. The positional shear of the transfer paper 18 on the electrostatic adsorption belt 17 may cause jamming when an adsorption failure or adsorption jam induces or the transfer paper is peeled from the electrostatic adsorption belt 17 in the post process.
SUMMARY OF THE INVENTION
The present invention is made to overcome the above mentioned problems. An object of the present invention is to provide an image forming device that can surely prevent a flutter of the sheet-like medium in the feeding portion even when there is a small difference in velocity between the conveying belt and the pre-conveying system at the time of feeding a sheet-like medium acting as a transfer paper onto the conveying belt, whereby a high-quality image can be obtained without causing any transfer failure, jam, or the like.
In order to achieve the above objects, according to the present invention, the image forming device is characterized by a printing unit for performing a printing operation on a sheet-like medium by transferring a developed image on the sheet-like medium at an image transfer point; a conveying belt for conveying the sheet-like medium along a conveying path formed so as to pass over the image transfer point by means of the printing unit; a conveying system for conveying the sheet-like medium on the conveying belt; a driving system for respectively driving the conveying belt and the sheet-like medium by means of different drive systems; and a pressure roller mounted in an idle mode on the conveying belt and near to the portion where the sheet-like medium is fed from the conveying system, the sheet-like medium being transferred from the conveying system onto the conveying belt while being sandwiched between the pressure roller and the conveying belt.
Each of plural printing units is arranged for each of plural colors to form a color image by overlaying the plural colors; and the conveying belt conveys the sheet-like medium along a conveying path to perform continuously a printing operation on the sheet-like medium by means of each of the printing units, the conveying path being formed so as to pass over the image transfer point by means of each of the printing units.
Further, the image forming device includes a power supply for supplying electric power to said pressure roller; and the pressure roller acts as a charger that electrically charges the sheet-like medium.
As described above, even when there is somewhat a difference in velocity between the conveying belt and the pre-conveying system, the fluttering of a sheet-like medium can be certainly prevented in the feeding portion by feeding a sheet-like medium from the conveying system onto the conveying belt while being sandwiched between the pressure roller and the conveying belt.
As described above, the image forming device according to the present invention has the advantage of forming high-quality images without producing any transfer failure or jamming since the fluttering of a sheet-like medium can be certainly prevented in the feeding portion by feeding a sheet-like medium from the conveying system onto the conveying belt while being sandwiched between the pressure roller and the conveying belt.
Particularly, when a color image is formed by overlaying plural colors with a printing unit for each color, high-quality images can be formed without any color shift.
Since the pressure roller acts as a charger that electrically charges the sheet-like medium, it is not needed to arrange another charger that makes the conveying belt to adsorb the sheet-like medium. This feature contributes to the device configuration simplified and slimmed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side sectional view schematically showing the main portion of an image forming device according to an embodiment of the present invention;
FIG. 2 is a side sectional view schematically showing the main portion of an image forming device to explain the operation of a present embodiment;
FIG. 3 is a side sectional view schematically showing the main portion of an image forming device to explain the operation of present embodiment;
FIG. 4 is a side sectional view schematically showing the main portion of an image forming device to explain the operation of a present embodiment;
FIG. 5 is a side sectional view schematically showing the main portion of an image forming device to explain the operation of a present embodiment;
FIG. 6 is a side sectional view schematically showing the main portion of an image forming device according to a modified embodiment of the present invention;
FIG. 7 is a side sectional view schematically showing the main portion of an image forming device according to another modified embodiment of the present invention;
FIG. 8 is a side sectional view schematically showing the internal structure of a general image forming device;
FIG. 9 is a side sectional view schematically showing the main portion of a general image forming device having a high-speed sheet conveying system;
FIG. 10(a) is a diagram used for explaining that an operation status occurs due to the difference in velocity between a conveying system using an electro-static adsorption belt and another conveying system; and
FIG. 10(b) is a diagram used for explaining that an operation status occurs due to the difference in velocity between a conveying system using an electrostatic adsorption belt and another conveying system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Let us explain an embodiment of the present invention with reference to the attached drawings.
FIG. 1 is a side-sectional view schematically illustrating the major portion of an image forming device as an embodiment of the present invention. The image forming device according to the present embodiment relates to the electro-photographic printer 1 before-mentioned with FIG. 8. The main portion (the feature of the present invention) shown in FIG. 1 has nearly the same configuration as the example including the conveying system 32 shown in FIG. 9. Hence, in FIGS. 1 to 7, like elements represented with like numerals shown in FIGS. 8 and 9. The detailed explanation of the same elements will be omitted here.
As depicted in FIG. 1, the color printing engine 2 includes four printing units 10Y, 10M, 10C and 10K (refer to FIG. 8). Each of the printing units 10Y, 10M, 10C and 10K transfers a toner image onto the transfer paper (sheet-like medium) 18 at the image transfer point 42 formed between the photosensitive body 11 and the transfer roller 15. In FIG. 1, the photosensitive body 11 and the transfer roller 15 in each of the printing units 10Y and 10M are illustrated, but other corresponding portions are omitted.
In order to perform the continuous printing operation of the printing units 10Y, 10M, 10C and 10K to the transfer paper 18, the electrostatic adsorption belt 17 acting as a conveying belt feeds the transfer paper 18 along the endless conveying path passing through the image transfer points 42 of the printing units 10Y, 10M, 10C and 10K.
The electrostatic adsorption belt 17, as described before, is wound endlessly around the drive roller 19, the following roller 20 and the tension rollers (tensioners) 21 and 22. The electrostatic adsorption belt 17 is driven by the revolution drive force of the drive motor (drive system) 25 transmitted via the drive roller 19 to feed sequentially the transfer paper 18 onto its outer surface (the surface confronting the photosensitive body 11) to the printing units 10Y, 10M, 10C and 10K.
Further, in the color printing engine 2, the corona charger 26 is arranged adjacent to the portion where the sheet-like medium 18 is transmitted from the conveying system 32. The corona charger 26 electrically charges the transfer paper 18 to adsorb the transfer paper 18 sent onto the electrostatic adsorption belt 17.
A conveying system 32 is arranged in the front stage of the color printing engine 2 to feed the transfer paper 18 to the electrostatic adsorption belt 17 at a high speed. Like the system shown in FIG. 9, the conveying system 32 includes conveying rollers 28 and 29 which are rotatably driven at a high speed by means of the drive motor (drive system) 30. The transfer paper 18 is conveyed immediately before the color printing unit 2 (the conveying system including the electrostatic adsorption belt 17) by means of the conveying rollers 28 and 29.
A clutch 31 is arranged between the conveying roller 28 arranged just before the color printing engine 2 and the drive motor 30. The clutch 31 is coupled on or off according to the procedure explained with FIGS. 2 to 5 when the transfer paper 18 is fed from the conveying system 32 to the system including the electrostatic adsorption belt 17. The drive motor 25 to drive the electrostatic adsorption belt 17 belongs to a system completely different from the conveying system 32 including the drive motor 30. The drive motor 35 drives respectively the conveying systems at completely different speeds.
In the present embodiment, a pressure roller (a following roller) 40 is mounted in a freely movable state on the electrostatic adsorption belt 17 and near to the portion where the transfer paper 18 is fed from the conveying system 32 and at the position which it confronts the following roller 20 on the upper side to the corona charger 26. The system is constructed such that the transfer paper 18 is fed from the conveying system 32 onto the electrostatic adsorption belt 17 while it is sandwiched between the pressure roller 40 and the electrostatic adsorption belt (following roller 20) 17.
The pressure roller 40 is supported on one end of the lever member 43 (member shown with chain double-dashed lines in FIG. 1), with its both sides being in rotatable state. The other end of the lever member 43 is rotatably supported to the side plate (not shown) which supports rotatably on both ends of the drive roller 19 and the following roller 20. The lever member 43 can rock. The pressure roller 40 is always pressed against the electrostatic adsorption belt (following roller 20) 17 by its weight and rocks somewhat with the lever member 43 according to the thickness of the transfer paper 18 fed from the conveying system 32.
The operation of the present embodiment with above-mentioned structure will be explained below by referring to FIGS. 2 to 5, together with the on/off procedure of the clutch 31.
As shown in FIG. 2, before reaching the conveying roller 28, the transfer paper 18 is conveyed by driving the conveying roller 29 by means of the motor 30, with the clutch 31 coupled off.
As shown in FIG. 3, when the transfer paper 18 reaches the conveying roller 28, the clutch 31 is changed to its on state so that the motor 30 drives the conveying rollers 28 and 29 to feed the transfer paper 18. In such a state, the transfer paper 18 is fed out from the conveying system 32 to the electrostatic adsorption belt 17 while the end portion for the transfer paper 18 is sandwiched between the pressure roller 40 and the electrostatic adsorption roller (following roller 20) 17. At this time, the transfer paper 18 is electrically charged by means of the corona charger 26 and then adsorbed on the electrostatic adsorption belt 17.
As shown in FIG. 4, the conveying roller 28 becomes an idle mode by switching the clutch 31 and the drive motor 30 to off state at the time when the rear end of the transfer paper 18 passes through the position of the transfer roller 29. Thereafter, the transfer paper 18 is conveyed at the conveying velocity of the conveying system including the electrostatic adsorption belt 17. While the conveying roller 28 is co-rotated at its conveying speed, the transfer paper 18 is fed onto the electrostatic adsorption belt 17, as shown in FIG. 5.
Since the transfer paper 18 is sandwiched between the pressure roller 40 and the electrostatic adsorption roller 17 (the following roller 20), the deformation of the electrostatic adsorption belt 17 and the positional shift and fluttering of the transfer paper 18, as shown in FIGS. 10(a) and 10(b), can be surely prevented. Consequently, since the motion of the transfer paper 18 can be stable, it is eliminated that the component of the difference in velocity between the conveying system including the electrostatic belt 17 and the conveying system 32 is transferred at the image transfer point 42.
As a result, a high-quality image can be formed without bringing about the transfer failure or jamming. Particularly, in the case of the formation of a color image, the positional shift of a toner image of each color can be surely suppressed by overlaying toner images of colors used in the printing units 10Y, 10M, 10C and 10K. Thus a high-quality color image with no color shift can be formed.
In the above-mentioned embodiment, the example in which the transfer roller 15 is used in each of the printing units 10Y, 10M, 10C and 10K to transfer the toner image formed on the photosensitive body 11 onto the transfer paper 18 has been explained. However, instead of the transfer roller 15, the corona charger 15A may be used as shown in FIG. 6. The corona charger 15A produces the potential difference between the transfer paper 18 and the photosensitive body 11 at the image transfer point of each of the printing units 10Y, 10M, 10C and 10K by charging the transfer paper 18. Then the potential difference allows the toner image on the photosensitive body 11 to be transferred onto the transfer paper 18. In this case, the same function and effect as those in the above-mentioned embodiment can be achieved by mounting the pressure roller 40.
As shown in FIG. 7, a power supply 41 that supplies the pressure roller 40 shown in FIGS. 1 to 6 can be connected and the pressure roller 40 can work as a charger that electrically charges the transfer roller 40. In this case, it is unnecessary to arrange differently the corona charger 26 (see FIGS. 1 to 6 and 9) that adsorbs the transfer paper 18 to the electrostatic adsorption belt 17. The system configuration can be simplified and slimmed.
Further, in the present embodiment, the case where the conveying system 32 is arranged upper side of the color printing engine 2 for the purpose of its high-speed operation has been explained. However, the present invention is applicable to the case where a different conveying system (such as the conveying roller 23 and the conveying guide 24) is arranged as shown in FIG. 8. Thus the same function and effect as those in the above-mentioned embodiment can be obtained. | An image forming device that can surely prevent a flutter of a sheet-like medium in the feeding portion even when there is a difference in velocity between the conveying belt and the front conveying system at the time of feeding a sheet-like medium onto the conveying belt, thereby obtaining a high-quality image. The image forming device includes a pressure roller mounted in an idle mode on the conveying belt and near to the portion where the transfer paper is fed from the conveying system, the transfer paper being transferred from the conveying system onto the conveying belt while being sandwiched between the pressure roller and the conveying belt. The image forming device is applicable to printers of electro-photographic system, electro-static recording system, or the like. | 27,153 |
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application is a division of U.S. patent application Ser. No. 09/371,717, filed on Aug. 9, 1999, the specification of which is incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The present invention relates generally to radio frequency identification, and more specifically to a tracking system, method, and components for use with radio frequency identification.
BACKGROUND OF THE INVENTION
[0003] Numerous systems exist for the physical tracking of inventory, raw materials, materials in manufacture, or other items in a variety of locations, such as manufacturing facilities, libraries, offices, and the like. Accurate and inexpensive locating, tracking, and inventorying of the physical location of items such as parts, goods, and materials is a necessity for many operations, such as manufacturing and warehousing, for a number of reasons. Such reasons include the desire or need to quickly determine the physical location of a part in the manufacturing process, or to determine whether a part is present in inventory or storage, to determine the quantity of an item on hand, to track the progress of an item in manufacture, and many other such functions.
[0004] Apparatuses and methods for the performance of the tracking of material and the performance of inventory-like processes have evolved over time. For example, inventory strategies have been modified from the hand tallying of stock and location in a notebook or the like, to sophisticated computer driven hardware and software for tracking inventory. Traditionally, a full inventory operation could close an entire facility, such as a retail store, warehouse, or manufacturing plant, for a day or more every time a detailed inventory was required. The large costs associated with physically shutting down an operation to do inventory were and are a known cost of the operation of many businesses.
[0005] An accurate record of the items available in a store or warehouse, as well as their location, is a key component of successfully operating a business. Knowing what is on hand allows the skilled manager or supply personnel to make informed ordering decisions. Knowledge of the availability and location of items or parts in a facility decreases the amount of time necessary for retrieval of such items, thereby increasing overall efficiency.
[0006] The advent of computers, and their rapid entrenchment into mainstream businesses and personal life, has also led to an advent in tracking items and performing and maintaining an inventory. For example, when physical inventory was still routinely performed by hand, a database could be created and maintained to track inventory in a more dynamic fashion. The potential errors of misplacing the physical inventory sheet, and the potential corruption of the physical inventory record were replaced with the increasingly lower incidence of potential errors of lost data and data corruption. Data entry error still also posed potential human error problems. Still, the computerized storage and retrieval of inventory information allowed for various sorting and categorization of data not previously easily available. The database functions of hand entered computer inventories were readily extended to other material tracking endeavors such as warehousing, stocking, ordering, and the like.
[0007] As technology continued to advance, various apparatuses and methods for tracking the inventory of a retail store, manufacturing plant, warehouse, and the like, in real-time or near real-time, were placed into use. Production lot tracking technology systems had and have widely varied capability, success, ease of use, and cost. Currently proposed and available lot tracking technologies include manual keyboard entry, bar coding, and proprietary systems such as those provided by JENOPTIK, Fluoroware, Micron Communications, Inc., and Omron.
[0008] Manual keyboard entry of lot numbers of parts in a lot tracking or inventory situation is already in use in many facilities. Such systems are not automated, but instead are manually performed. The physical inventory process is still undertaken, and generally the information gathered is entered into a computerized database. Data entry errors due to human error are in large part an unavoidable part of the manual inventory process. Such errors are difficult if not impossible to track and correct. Any information which is desired or required to be obtained and stored or entered into a computer or other system beyond a simple inventory creates additional work for the inventory taker. The time it takes to perform an inventory using manual keyboard entry of lot numbers and the like is not significantly less than traditional pencil and paper inventories which often require the full or at least partial shutdown of an entire facility. Such an inventory process is subject to high costs reflected not necessarily in terms of equipment, but in terms of employee-hours and lost revenues from a shutdown.
[0009] Because of its advantages over manual inventory, whether using a computer for further organization or not, bar coding has become commonplace in many if not most retail outlets and warehouses, grocery stores, chains, and large retail outlets. hI a bar coding scheme, an identifying label containing encoded information is placed on the goods, parts, part bin, or other item to be identified by a bar code reader. The encoded information is read by the reader with no user data entry generally required. This is referred to as keyless data entry. The information encoded on the bar code is then typically passed to a computer or other processing medium for decoding and data entry. Such data entry is largely error free due to the decreased reliance on error-prone human activities. Bar code data entry is also typically faster than manual data entry.
[0010] Bar coding is a common and easy to implement technology. However, bar coding requires a scanner or reader for every terminal, or a portable scanner which is moved around from location to location. Further, bar coding requires a separate label for implementation. Without further data entry, which has additional associated costs and potential error factors, other desired or required information such as an exact location of the scanned item is unknown.
[0011] Another type of lot tracking system uses an infrared lot box micro terminal with a pager-like display for lot tracking. A micro terminal is physically attached to each lot box. Each micro terminal communicates via infrared communication with an infrared (IR) transceiver grid, which must be in sight of the micro terminal in order for the system to function properly. Typically, the IR transceiver grid is positioned or installed along the ceiling of a facility. Stacked pallets, lots, or wafer boats will be unreadable using an IR system. The micro terminals and IR transceiver grid of the IR system are expensive. A micro terminal system requires an elaborate software platform, but does allow for reduced data entry error, faster data entry, and simple user entries. The IR system requires a major procedural change in the standards for performing lot tracking. The micro terminals must also be positioned in a specific orientation with respect to the transceiver grid for proper functioning. The terminal must be physically attached to a lot box to be tracked. Lot location can only be identified to an area as small as the IR field of view.
[0012] Another lot tracking system is available from Fluoroware. This system uses passive tags in a cassette. The passive tags are scanned by a scanning station over which an item, wafer boat, or lot which has been tagged passes. The item, lot, or boat is identified when it passes over the scanning station. Often, wafer boats are specific to the particular station, but parts may be moved to a number of different locations. Tracking a cassette may require a large amount of reassociation of the tag information to accurately track the part or item. The scanning stations of the Fluoroware system are expensive, on the order of $2,000-$3,000 per station. Additionally, a main computer to centralize, organize, and coordinate operation of the tracking system is required. The Fluoroware system, like other more automated systems, reduces data entry error and data entry time. The tags used in the system are relatively low in cost, and can be embedded into boats. However, many controllers are needed for the system, and the scanning stations have a high cost. Further, the reassociation of tags with different locations requires extra data entry or tag reprogramming, which introduces further potential errors.
[0013] When an inventory or lot tracking system works with a large number of parts or locations, which may number into the thousands of locations and many thousands if not millions of parts, the systems described above become unwieldy to effectively operate, become cost prohibitive, or both. Further, with a large number of parts and locations, an exact location match is difficult if not impossible to provide with the above systems. Such a lack of ability to pinpoint the location of a part further hinders the operation and effectiveness of the above systems.
[0014] Additionally, items or lots in a manufacturing facility may sit in a certain location without being used or moved for weeks or more. In addition, the pallets of wafer boats in such a facility or storage area may be stacked in stacks five or more layers deep. Personnel are often assigned to physically search all lots to find a lot which may be missing. Lots in large manufacturing facilities have been known to be lost for 6 months to a year. A more accurate tracking system for lots would be desirable.
[0015] In manufacturing situations, other tracking of inventory and parts is often desirable or necessary. Such other tracking may include tracking the amount of time a part spends between stations, the amount of time it takes for a part to complete a certain operation, a history of the travel of a part from start to finish of a manufacturing or fabrication operation, and the like.
SUMMARY OF THE INVENTION
[0016] The present invention solves the above-mentioned problems in the art and other problems which will be understood by those skilled in the art upon reading and understanding the present specification. The present invention provides a method and apparatus for tracking items automatically. An apparatus embodiment of the present invention is a passive RFID (Radio Frequency IDentification) tag material tracking system capable of real-time pinpoint location and identification of thousands of items in production and storage areas. Passive RFID tags are attached to the item to be tracked, remote sensing antennas are placed at each remote location to be monitored, scanning interrogators with several multiplexed antenna inputs are connected to the sensing antennas, and a host computer communicates with the interrogators to determine item locations to an exacting antenna position.
[0017] Another embodiment of the present invention is a method for tracking the location of an object having an identification tag attached to or near the object, using an interrogator connected to a sensing antenna and to a computer, comprising activating the sensing antenna, determining if there is a voltage at the sensing antenna, obtaining data from a passive identification tag attached to the object, and communicating between the host computer and the interrogator to log tag location data.
[0018] Still another embodiment of the present invention is an RFID material tracking system, comprising a plurality of RFID tags, each tag attachable to a container or an item to be tracked, a plurality of sensing antennas, each antenna placeable at a location to be monitored, a plurality of interrogators, each interrogator having a plurality of antenna inputs, each of the plurality of sensing antennas connected to an interrogator, and a computer operatively connected to each of the interrogators and receiving tag location information therefrom to log tag location data.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In the drawings, where like numerals refer to like components throughout the several views,
[0020] [0020]FIGS. 1A and 1B are perspective drawings of a dual nesting station with a container having an RFID tag embedded therein;
[0021] [0021]FIG. 2 is a perspective view of a storage shelf having a plurality of nesting stations with some tracked container placed thereon;
[0022] [0022]FIG. 3 is a block diagram view of a system embodiment of the present invention;
[0023] [0023]FIG. 4 is a schematic diagram of an embodiment of a circuit layout for a 2×2 pad embodying the invention;
[0024] [0024]FIG. 5 is diagram of an embodiment of an antenna suitable for use in the embodiment of claim 1;
[0025] [0025]FIG. 5 a is a top view of another embodiment of an antenna suitable for use in the embodiment of claim 1;
[0026] [0026]FIG. 5 b is a section view of the embodiment of FIG. 5 a taken along lines 5 b - 5 b thereof;
[0027] [0027]FIG. 6 is a circuit diagram of an embodiment of a tuned circuit according to the invention;
[0028] [0028]FIG. 7 is a block schematic diagram of an embodiment of an interrogator of the present invention;
[0029] [0029]FIG. 7 a is a schematic diagram of an RF harmonic reduction embodiment of the driver system;
[0030] [0030]FIG. 8 is a block diagram of another embodiment of an interrogator system of the present invention;
[0031] [0031]FIG. 9 is a block diagram of another system embodiment of the present invention;
[0032] [0032]FIG. 10 is a side elevation view of an another antenna embodiment of the present invention;
[0033] [0033]FIG. 11 is a flow chart diagram of a method embodiment of the present invention;
[0034] [0034]FIG. 12 is a flow chart diagram of another method embodiment of the present invention;
[0035] [0035]FIG. 13 is a flow chart diagram of a lot association method of the present invention;
[0036] [0036]FIG. 13 a is a flow chart diagram of another method of the present invention;
[0037] [0037]FIG. 14 is a flow chart diagram of an embodiment of a tag attachment method of the present invention;
[0038] [0038]FIG. 15 is a perspective diagram of a computer system on which various embodiments of the present invention may be implemented; and
[0039] [0039]FIG. 16 is a schematic diagram of annunciator embodiments of the present invention.
[0040] [0040]FIG. 17 is a block diagram of another embodiment of an application for the present invention.
DESCRIPTION OF EMBODIMENTS
[0041] In the following detailed description of the embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention.
[0042] The physical similarities between inventory operations and other similar operations such as warehousing, quantity and position tracking, and the like allow the discussion of one such operation to generalize for a number of similar operations. As such, this description will discuss generally a variety of inventory strategies, with the understanding that generalization to other operations may easily be accomplished by one of ordinary skill in the art. Such modification and specification are therefore within the scope of the present invention.
PHYSICAL OVERVIEW
[0043] An implementation of a portion of a container tracking and identification system according to the present invention is shown in FIGS. 1A, 1B and 2 . Referring to FIG. 1, a dual nesting station 10 is shown upon which an item or container 12 may be placed. Hereafter, reference to container will mean any item which may be tracked by the present invention. The dual nesting station contains two locations 14 , 16 where containers may be placed and tracked according to the present invention. A dual nesting station 10 is shown as an exemplary embodiment, however, those skilled in the art will readily recognize that a single nesting station 14 may be implemented, or any plurality of nesting stations may be implemented in accordance with the teachings of the present invention. The nesting stations 14 , 16 may be implemented as a generally flat component which may be placed wherever there is a need to track a container, or it may be formed as an integral part of a shelf, pallet, bench, table, or any other location where items or containers are located.
[0044] Each nesting station includes an antenna 18 imbedded within of upon each nesting stations 14 , 16 . Other circuitry, not shown in FIGS. 1A and 1B but described below, is used to send and receive signals to and from an RFID tag 19 imbedded within or placed upon container 12 . As shown in FIG. 12, when container 12 is placed in proximity to nesting station 14 , communication of signals between container RFID tag 19 and antenna 18 is possible. These communication signals will be more fully described below.
[0045] [0045]FIG. 2 shows an exemplary implementation of a shelf arrangement 20 with which the present invention may be used. A plurality of nesting stations 16 are part of the shelf arrangement with each nesting station 16 having an integral antenna 18 for each shelf location. Containers 12 or other items to be tracked, can be placed at various shelf locations and the contains can be located, identified, tracked, etc., with the teaching of the present invention. An optional feature of the present invention are the use of annunciators or indicators 22 which may be used to indicate the location of a desired container. Nesting stations 16 may be placed upon the shelves or they may be integrated with the shelf itself.
SYSTEM OVERVIEW
[0046] Referring now to FIG. 3, an embodiment 100 of a system of the present invention is shown in block diagram. Lot tracking system 100 comprises a host or control module 102 operatively connected to a plurality of interrogators 104 , 106 , and 108 . The interrogators 104 , 106 , and 108 are each have a plurality of sensing antennas and circuitry 110 operatively connected to the main interrogator body by connection lines. The interrogators 104 , 106 , 108 , are preferably local to the sensing antenna circuits 110 . The sensing antenna circuits 110 are positioned so that they are in sensing proximity to a location at or over which a plurality of containers may be located or pass. Each container (shown in FIGS. 1A, 1B and 2 ) is capable of holding items such as lots of wafers used to manufacture integrated circuits. In such an application of the present invention, the container is termed a “boat” and would hold lots of partially fabricated or fully fabricated wafers which may be routed through the plurality steps required in the IC fabrication at an IC foundry.
[0047] Each container has an attached Radio Frequency IDentification (RFID) tag 19 (shown in FIGS. 1A, 1B and 2 ) capable of being excited by the sensing antenna circuits 110 , capable of relaying, conveying, or communicating identification information to the sensing antenna circuits, and on to the control module 102 .
[0048] The tags are preferably low frequency passive RFID tags 19 which carry a serial number or identification number which can be cross-referenced within a database or other data structure maintained by the control module 102 or one of its components. Each interrogator 104 , 106 , and 108 contains drive electronics and detection circuitry to excite and read back identification information contained on a tag. Driving information is communicated to the tag through the antenna coil or primary of an electromagnetically coupled circuit. The data out on the communication line 114 , 126 , 140 is linkable to the host or control module system for other action. Tags are polled by exciting the sensing antenna circuits 110 , which induces a current in the tag 19 , causing it to communicate its stored information, which will be described in more detail below.
[0049] The RFID tags 19 contain generally simple information, but the tag information may be as widely varied as the uses for the system 100 itself. For example, tags can contain simple presence/no presence bit, or detailed information regarding an entire build process, or specifications about lot number, serial number, and the like. The radio frequency of the interrogator powers up the tag, and the carrier frequency (usually 125 KHZ for passive tags in one embodiment) becomes the clocking frequency to generate a clock to clock the data out. Passive tags can be made and used very inexpensively, making them more economical for use with multiple read locations.
[0050] In one arrangement shown in FIG. 3, interrogator 104 is operatively connected to a plurality of sensing antenna circuits 110 on a nesting station 112 via connection lines 114 . In this arrangement, two quad-nesting stations are shown. In another arrangement, interrogator 106 is operatively connected to a plurality of sensing antenna circuits 116 on quad nesting station 118 via connection line 120 , and to antennas 122 of dual nesting station 124 via connection line 126 . In yet another arrangement, interrogator 108 is operatively connected to a plurality of antenna circuits 128 on a dual nesting station 130 via connection line 132 , and to antenna circuits 134 on another dual nesting station 136 via connection line 138 . Further interrogators may be added to the embodiment 100 to accommodate more nesting stations.
[0051] Control module 102 may include such components as a computer with a database of information pertaining to lot numbers, lot locations, and other lot information for the items in container 12 . Control module 102 controls the interrogators 104 , 106 , 108 to poll appropriate locations to gather and maintain information about containers 12 .
[0052] The connection lines of embodiment 100 may comprise a plurality types of connections such as standard flat phone cables with a phone jack connector to attached to multiple sensing antennas. Depending upon the configuration of the nesting station to which the connection lines are connected, the telephone cables used in embodiment 100 may be four conductor flat phone cables, eight conductor flat phone cables, or a combination of such cables. The connector phone jack may be an RJ-11 type four conductor jack, or an RJ-45 type eight conductor jack, depending upon the type of cable connection. Flat telephone cable is used so that the drive signals for the antenna circuits (described below) are physically separated from the sense line and are readily available at low cost.
[0053] Alternatively, twisted pair cabling may be used in a network environment. In such a configuration, the detection and ground wires (described below) would be twisted together, and the drive signal lines would be twisted together. Only one drive wire is active at any one time. One antenna circuit 110 is driven at a time, and a common detection circuit is used for all of the antennas. The drive signal is switched from one antenna circuit to the next using a multiplexor (MUX). The switching may be sequential, ordered, or random, but only one antenna circuit 110 is driven at any one given time. This allows the use of a common detection processor detection circuit which is used for each antenna circuit of the plurality of antenna circuits that are wired into each interrogator. The multiplexor selects which antenna circuit is being driven by the drive signal.
[0054] The jacks for the connection can be standard telephone connection jacks, selected for their availability and low cost. Those skilled the art will readily recognize that a wide variety if wire types, wiring configurations and electrical connectors may be used in the implementation of the present invention without departing from the spirit and scope of the present invention.
[0055] Nesting stations have been described above as single-, dual- or quad-, but many other arrangements of nesting stations is possible with the present invention. For the example of tracking boxes of semiconductor wafers, each nesting station would be typically implemented as a dual nesting station sized to be approximately one foot by 2 feet to form a suitably sized location for two typical 200 millimeter wafer boxes which have a footprint of approximately one square foot. This is referred to as a 1×2 pad. A 2×2 pad would be implemented with as a quad nesting station described above and would be approximately two feet by two feet in size. Thus, a 2×2 would be a quad nesting station for four semiconductor wafer boxes.
[0056] For a 1×2 pad nesting station such as nesting station 124 , 130 , or 136 , an RJ-11 four conductor jack may be used to connect the four conductor telephone cables 126 , 132 , and 138 , respectively, to the antenna circuits 122 , 128 , and 134 respectively. For a 2×2 pad nesting station such as nesting station 112 or 118 , an RJ-45 eight conductor jack may be used to connect the eight conductor telephone cable 114 or 120 respectively to the antenna circuits 110 or 116 .
[0057] Alternatively, instead of an eight conductor cable such as cable 114 or cable 120 , two four conductor cables can be used side by side in an RJ-45 jack. In this case, the opposite ends of the four conductor cables may be fitted with RJ-11 phone jacks for ease of connection. This configuration is useful for connection of two 1×2 pads such as pads 130 and 136 to a single interrogator such as interrogator 108 . For example, in FIG. 3, cables 132 and 138 may be four conductor telephone cables, each having an RJ-11 jack for connection of the cables to the nesting stations 130 and 136 . The two cables 132 and 138 plug into a single RJ-45 eight position jack to connect the cables to interrogator 108 . When two four connector cables are used in a single RJ-45 eight conductor jack, they are mirrored so as to place the detector circuit, that is the signal that has been rectified and has the greatest noise sensitivity, on the outside of the cable where it is furthest from the drive electronics.
NESTING PAD DESCRIPTION
[0058] [0058]FIG. 4 shows an exemplary embodiment of a 2×2 pad 152 implemented with two 1×2 pads 154 and 156 , along with the antenna circuitry, arranged in a mirrored configuration (discussed below) in schematic diagram form. A connection 158 for cabling to the interrogator has eight contact positions 160 which may comprise two four conductor RJ-11 jacks, or a single eight conductor RJ-45 jack as described above. Each 1×2 pad 154 and 156 has a four conductor RJ-11 jack connecting its four contact positions, 162 and 164 respectively, to an appropriate four conductor cable to the interrogator. As shown, the physical layout of contact positions 162 mirrors that of the physical layout of contact 164 , with position 162 - 4 and position 164 - 4 being adjacent within the 2×2 pad 152 . This mirrored configuration places the detection circuit, that is the rectified signal with the greatest noise sensitivity, on the outside of the cable. The detector conductors (position 1 ) are therefore placed away from the drive signal conductors (positions 3 , 4 ) by the ground conductors (position 2 ) to help eliminate noise.
[0059] The antennas used in embodiment 100 preferably each comprise a flat coil, a flat radial single layer antennas comprising a length of copper wire which is coiled to form an antenna. The flat coil construction allows some degree of side to side movement of the antenna without significant degradation of performance. Further, the flat coil antenna construction also provides relatively good height detection of the antenna without drastically affecting the performance of the system. A flat coil is less sensitive to surrounding metal surfaces in the same plane as the coil. Other antennas could also be used. Representative embodiments of antennas will be discussed further below.
ANTENNA CIRCUIT DESCRIPTION
[0060] [0060]FIG. 5 shows a top view of a representative embodiment of a flat antenna coil 200 is shown in FIG. 5. Antenna coil 200 comprises a length of coiled wire 202 , such as copper wire. Although copper wire is preferred, other conductive wires and embodiments are well within the scope of the invention, as will be known by one of skill in the art.
[0061] [0061]FIG. 5 a shows a top view of another embodiment 250 of an antenna. Antenna 250 comprises a substantially circular magnetic core 252 having an annular ring 254 extending from the core 252 to form a magnetic cup. A magnetic center post 256 extends from the core 252 approximately at the center of core 252 , in the same direction as the annular ring 254 . Coil windings 158 are wrapped around the center post 156 . FIG. 5 b shows a section view of antenna 250 taken along lines 5 b - 5 b of FIG. 5 a . FIG. 5 b shows focused flux lines 260 from the focused antenna 250 .
[0062] As shown in FIG. 6, each antenna circuit 300 form a tuned tank circuit which is connected to interrogators 104 , 106 , and 108 . The interrogators contain circuitry for excitation of the tuned tank circuits and for detection of the information transmitted by an excited RFID tag. Since the nesting stations are somewhat remote from the interrogators, the tuned circuit embodiment 300 of the present invention places a capacitor 302 in close proximity to the antenna coil 304 , so that the entire tank circuit 300 is remote. Therefore the cable length and type can vary or be changed without affecting the operation of the antenna 304 and drive electronics.
[0063] One skilled in the art will recognize that if the capacitive element and the antenna coil were separated, with the capacitive element located at an interrogator would require that the interrogator be part of the tuned circuit. Cabling between the antenna (nesting station) and the capacitive element (interrogator) would be a factor in deciphering information from any excited tag. In such a configuration, when the location of the antenna changed, the tuning of the circuit changed. This latter configuration would be problematic since tuning the tank circuit for proper operation would be time consuming. By placing the entire tank circuit in the nesting station, the components of the system are readily interchangeable and cabling lengths are not a factor in the proper operation.
[0064] In operation, the interrogator drives the tuned tank circuit comprised of series connected elements 302 and 304 with a square wave power signal. In an exemplary embodiment, the drive signal operates at 125 kHz, capacitor 302 is 3000 picoFarads and antenna coil 18 , 202 , or 304 is 800 microHenrys. The square wave drive signal is smoothed to a nearly a sine wave signal which is emitted from the antenna coil 304 to excite RFID tag 19 . The excited tag emits a signal containing information unique to the tag (such as a serial number). This signal from the tag is detected by antenna coil 304 , rectified by diode 306 and sent to the interrogator for demodulation. The diode 306 generates a rectified peak voltage of the tank circuit 300 and the detected signal appears as a pulse stream in the form of a series of dips in the 125 kHz rectified carrier signal. This pulse stream is then decoded by the interrogator for the data it carries.
INTERROGATOR DESCRIPTION
[0065] An embodiment 400 of an interrogator is shown in FIG. 7 which includes a processor 405 and an antenna reader circuit 404 . Antennas are connectable to the interrogator 400 at connection point 406 , and connection to the power supply and host or control module is effected at point 408 . Power for operating the interrogator 400 may be obtained locally or it may be received through the host communication cable. Communication of processor 405 with host or control module 102 is accomplished through port 410 . Host protocol interface port 410 may be a serial communication RS-232 port, or a differential port such as a multi-drop IEEE 485 or non multi-drop IEEE 422. The host or control module processes instructions according to a predefined operational structure, issuing commands to the interrogator for control of multiplexor 412 which selects the antenna which is to be driven at any given time.
[0066] In the exemplary embodiment shown in FIG. 7, each antenna connected to the interrogator 400 has a dedicated power driver 411 circuit to generate the square wave excitation signal. The preferred power driver for the antennas is a low cost CMOS power driver to drive the square wave which is converted to a sine wave by the tuned circuit. In this example, each antenna has its own power driver within the interrogator because an electronic multiplexor switch with a low on resistance would be more expensive than the CMOS drivers. It is desirable to use power drivers with fast rise times, such as MOSFET and CMOS power drivers.
[0067] Details of the power driver circuitry are shown in FIG. 7 a . Drivers 411 have a fast rise time and radiate a high frequency harmonic because of that. To slow the rise time, drivers 411 are each connected to the antenna drive voltage through an inductor 413 . Further, an inductor 415 is electrically interposed between each driver 411 and ground. The inductors 413 and 415 are used to slow the rises and fall times of the driver 411 to reduce harmonic radiated RF.
[0068] Once the sensing antennas have excited a tag, the information received from tank circuit such as circuit 300 is sent to interrogator 400 and detected by detector 414 along a sense line 419 . Since only one antenna is excited at a time, all detector sense lines 419 from all nesting stations may be wired to the same detector. Processor or microchip controller 405 decodes data from the detector circuit 414 and can provide for sequential, ordered, or random scanning of the ports of the system through antenna selector 412 .
[0069] Detector circuit 414 is preferably implemented with analog amplification/detection of the DC rectified signal of the diode of the tuned circuit. The detected signal can be provided to processor 405 where each detection circuit 414 also has decoding capabilities, such as digital signal processing (DSP) type decoding built in. Each multiplexor board could have its own detector and processor, allowing for the driving of multiple antennas at once.
[0070] The processor 405 of interrogator 400 can be essentially a microcomputer, that is an all in one chip with on board RAM, EPROM, I/O points, a microprocessor, and analog input. The processor 405 could have hard-coded (burned into PROM) control software, or it could download the control software from a separate processor or computer system.
[0071] The interrogator 400 is preferably positioned in close proximity to the sensing antenna, which reduces the bundle of wires that must be run from the interrogator to the host computer or control module. From the interrogator, a low cost serial port may be used to run power into the interrogator along a communication line from the host. This allows for a wide operating voltage, which is preferably maintained low (24V for example) for safety purposes, but high enough that there is a low current draw. In this exemplary implementation, there is only one cable which needs to be disconnected in the event that the interrogator must be moved. In some environments, this a fairly common event. Referring back to FIG. 2, a single interrogator may be located on the shelving units and serving all nesting stations of this shelf unit. If the shelf is to be moved, only one cable need be disconnected from the host. That cable my be a wall jack with in-the-wall network wires running to the host.
[0072] To keep the efficiency of the system up and power current down, voltage regulation circuitry 416 is used to perform regulation of unregulated 24V power to regulated 12V and 5V power. In one embodiment, DC to DC voltage regulators are used to perform main power reduction from an unregulated 24V power supply to a regulated 12V and 5V power supply to drive the interrogator components.
[0073] Alternatively, communications coming through host protocol interface 410 could be jumpered to an auxiliary processor board 418 that may contain an auxiliary processor 402 and wide variety of optional communication or I/O protocols 421 , such as ETHERNET, wireless modem, another processor with a large amount of memory, or the like. In such a configuration, the entire interrogator system 400 runs without interaction between the interrogator and the host. Gathered information may be downloaded to the host or control module at a later time. If no auxiliary processor 402 is present, then the connections which would go to the COM and COM 1 ports of the auxiliary processor 402 are jumpered together.
[0074] A wide variety of auxiliary functions could also be performed by such an auxiliary control I/O 421 piggybacked to the circuit 404 . A daughterboard 418 with auxiliary input/output capability could be used to unlock doors, generate alarm signals, including local alarm signals for an object removed from a nesting station or boat, or the location from which an object has been removed, or drive an operator interface display terminal.
[0075] An interrogator system embodiment 500 of the present invention as shown in FIG. 8 comprises tags 502 and an interrogator 504 . Each tag 502 is associated with a specific lot, and contains identification information specific to the lot or item to which the tag is attached. Each tag 502 may be attached to a lot box or the like. Each tag, when excited, will communicate a signal indicative of its identification information. The tag can carry such information as a serial number and the like, which may be cross-referenced in a database maintained at the system host (computer). Antennas 506 are positioned in close proximity to the lot location which they will be polling. Interrogator 504 is connected to antennas 506 by a communication line 508 , which in the example shown will be a four line conductor. Connection jacks 510 and 512 connect the communication line 508 to the interrogator 504 and the nesting station 506 respectively. As discussed above, a four line conductor will typically be terminated with an RJ-11 four conductor jack.
[0076] Tags 502 , as has been mentioned above, are typically passive tags. This reduces the overall tag cost, which is important since a large number of tags may be required in application. The passive tags 502 , which allow for low cost, generally have a short effective operating range. The range may be on the order of 0 to 15-20 inches, depending upon antenna size. The larger the antenna, the greater the operating range. In one embodiment, the present invention limits the tag range further, preferably on the order of two (2) inches. Taking advantage of this short range allows this embodiment of the present invention to excite a tag and obtain its information, while also determining its exact location. Further, with simple timing and recordation schemes, it is possible given the precise nature of multiple antenna locations and close discrimination between lots to know which part is at which exact location at any given time.
[0077] Each interrogator has an address stored in interrogator address module 417 , which may be a volatile or a non-volatile memory. Each antenna connection has a sub-address.
[0078] Each antenna array location has its own unique identification information or address. In this way, the unique address can be programmed into the system, so that the physical location is not determined by where the antenna array is plugged in, but by what the address of the array has been programmed to. Then, under that address each antenna point will have its own address, allowing resolution down to each specific individual shelf and position. The system resolves exactly where each item is. This allows the mapping of a shelf and/or a location for a graphics display or the like, to locate an item with specificity. The reduced range of the antennas of this embodiment of the present invention allow for such a close up representation of exact item position. The range of on the order of two inches allows the reading of each tag to a precise location.
[0079] For example, in a wafer production fabrication, there may be 1000 lot boxes running production wafers, and 1000 lots of test wafers, plus 500 lots of reference type wafers, all at a general location. This results in 2500 lot boxes in a physical space. This can represent upwards of 5000 locations, because of the open queue space which is needed to move lots through such an operation. A system which works must be low cost and distributed to allow for multiple read locations, and inexpensive read points.
[0080] With a large number of locations to be polled, multiple interrogators will be required. Each interrogator concentrates multiple antenna locations into one interrogator. Typically in a wafer production line, production shelves are 2×4, or eight lots per shelf. Racks of shelves may be stacked six shelves high, and may have 32-56 boats per rack. Typically, the maximum number of boats per rack is 60. With two telephone cable per shelf, a single location may have 12 eight conductor flat cables running from the location to the interrogator. The benefits of local interrogators multiply with increased numbers of read locations.
[0081] With an interrogator having 60 antennas, 60 sets of data are collected and stored internally. At the next polling, only absolute differences are considered. That is, the delta data is polled. If only one of the sets of data has changed, it is the only set of data transmitted. This reduces the amount of data required to be transmitted. A complete polling may be taken at a specified interval or number of scans, in one embodiment every 100 scans. Further, tag information transmitted may be limited in one embodiment. Some tags contain an amount of user specific information that is the same for every tag associated with that user. If all tags polled are for a certain customer or user, then certain identification information need not be transmitted. Also, tags out of range of a certain specified parameter can be flagged, or an alarm can be given.
[0082] With 180 interrogators in a room, multiple options are available. First, all interrogators could be local, taking gathered information from its read locations or bays and sending the information into a switched multidrop configuration. This configuration would result in some data throughput difficulties (long time between individual location interrogation), but in a slow changing environment this may not be critical. Problems with such a multidrop configuration is that it places more equipment in the field, creating more service locations and an increased number of locations for things to break down. In one embodiment, communication drops to each interrogator are all sent back to a communications room in a star configuration which is in turn connected to the host. However, the scale could be dropped down to individual or a small number of components together on a power supply depending on the facility requirements.
[0083] Alternatively, an infrared link may be positioned on an interrogator, or located remote to an interrogator, and an infrared transceiver pod could be positioned on the ceiling of a room, for obtaining by infrared the location information gathered by each interrogator. Power would still need to be provided to each interrogator, most likely on a cable, but full data communication links to the host would not be required. Other technologies could also be supported, such as cellular phone, pager, wireless modem, solar power, and the like.
[0084] [0084]FIG. 9 shows an embodiment 600 of another system embodying the present invention. Multiplexor 606 has a plurality of connections to single antennas 608 a , 608 b, . . . 608 n, which are driven by drivers 610 a , 610 b , . . . 610 n . A common detector circuit 602 is connected in parallel to each of the drivers 610 a , 610 b , . . . 610 n and to controller 604 . Controller 604 controls selection of which antenna 608 is to be active at any given time.
[0085] In embodiments of the invention as described above, the use of a flat coil antenna has been shown to allow some lateral movement of the boxes to allow for positioning tolerances without significant degradation of performance. Further, the flat coil antenna construction also provides relatively good height detection of the antenna without drastically affecting the performance of the system. A flat coil is more sensitive to ferrous materials in the vicinity of the coil. However, if the shelf or nesting station upon which tags are placed is composed of a material such as wood, plastic, and the like instead of metal, then a balance between separation of the antenna from the shelf and the performance of the antenna is not an issue.
[0086] If the height or distance of the antenna from the tag increases, the communication or readability degrades. As the height or distance decreases, the tuned circuit becomes detuned. Further, if a ferrous material object such as a wrench, clipboard, or pad is placed on or in close proximity to the nesting station or antenna, a voltage anomaly due to the object may show up in the output from the diode of the tuned circuit, and tag communication may degrade. At that point, it will be evident that the antenna is not sensing a tag, but instead is sensing something abnormal. For example, if no voltage is indicated in the tuned circuit, that could indicate that the antenna is not present, or that there is a fault in the circuit.
[0087] Changes in antenna performance or surrounding load will change the peak rectified voltage from the diode. This changed peak rectified voltage can be compared to historical data or absolute values to detect system faults or performance degradation.
[0088] An embodiment 700 of an antenna which decreases sensitivity to anomalies is shown in FIG. 10. A ferrous cover plate or metal sheet 702 is positioned a predetermined distance 706 from the back of the antenna 704 . The metal sheet or cover 702 serves to magnetically preload the coil 704 . This ferric loading of the coil serves to reduce the sensitivity of the antenna 704 to further surrounding metal. The tuned circuit, such as tuned circuit 300 , is then tuned with the cover or metal sheet 702 in place. It has been determined that a preferable separation 706 between the antenna 704 and the plate or sheet 702 is approximately ⅜ of an inch. However, other distances will also serve to preload the tuned circuit.
PROCESS FLOW
[0089] A method embodiment 800 of tracking the location of identification tags as shown in FIG. 11 comprises activating a sensing antenna, which is part of a tuned circuit, to excite a passive identification tag in block 802 , determining if a voltage is induced in the sensing antenna in block 804 , and storing or communicating to the host any induced voltage in the sensing antenna in block 806 if a voltage is induced in the sensing antenna.
[0090] An interrogator such as interrogator 400 described in detail above with included multiplexing capability controls multiple antennas all attached to the interrogator, with one antenna being driven at any given time. A detector circuit in the interrogator serves to detect the signals returned from the sensing antenna. The method 800 may further comprise activating a plurality of further sensing antennas in a predetermined or random sequence in block 808 , followed by the re-execution of blocks 804 and 806 as needed.
[0091] The sensing antennas and interrogators described in detail above may be used in a tag identification method such as method 800 . One or more processors in the interrogator may be used to not only decode data coming back from the detector circuit but also to provide sequential scanning of the ports. Process flow in method 800 allows for either scanning all antenna locations or ports regardless of whether anything is plugged into them. In other words, the sensing antenna, tuned circuit, and detector circuit determine whether an antenna is plugged into a location or not by measuring the voltage generated by the rectification of the tank circuit. This voltage is typically a nominal voltage stable across all antennas.
[0092] If no voltage is present in decision block 804 , several options for further process flow are available, and will be described in detail below. If no voltage is present, that may indicate that no antenna is present. Alternatively, a lookup table or representation of the configuration of the antenna system may indicate that there should be an antenna at a given location. Further, when a tag powers up, it may not correctly initialize or communicate information. A reinitialization may be necessary. If no voltage is present in block 804 , an alarm for an antenna failure or other alarm condition, such as antenna degradation or the like, can be generated. The host system can track antenna voltage and compare historical data to detect problems as discussed above.
[0093] A self-testing embodiment of a material tracking system is a part of the present invention. A self-testing embodiment 1000 is shown in detail in FIG. 12. Self-testing embodiment 1000 incorporates some of the basic process flow of embodiment 800 . Embodiment 1000 comprises selecting a scan method from a number of possible scanning methods in block 1002 , checking an antenna map or the like to allow skipping of inactive antennas in block 1004 , and activating the selected antenna in block 802 . If no antenna is supposed to be present, process flow can continue with the next antenna position. If the antenna voltage for the selected antenna does not exceed a predetermined lower limit as determined by decision block 804 , the host is alerted or a local alarm is activated in block 1020 . If the antenna voltage for the selected antenna is above the predetermined lower limit as determined by decision block 804 , process flow continues with block 1006 .
[0094] In block 1006 , a timeout timer is reset. The timeout timer counts a predetermined time during which the embodiment 1000 waits for tag data to be read. The embodiment waits for tag data or the timeout limit of the timeout timer in block 1008 . A determination is made as to whether tag data has been detected in decision block 1010 . If tag data has been detected in block 1010 , the data is stored or sent to the host in block 806 , and the next antenna is selected in block 808 . Following that, process flow continues with block 1004 .
[0095] For each instance in which tag data is not detected, an iteration count is compared against an iteration limit in block 1012 . A predetermined limit of the number of iterations allowed for detecting tag data is set in the embodiment 1000 . This number may be set to depend on a number of factors, including the response time of the tags, the required or desired response time of the circuit, and the like. Each unsuccessful detection of tag data results in an incrementing of the iteration count. If no tag data has been detected in block 1010 , the iteration count is checked against a predetermined iteration limit in decision block 1012 . If the iteration count is not above the predetermined limit, the iteration counter is incremented in block 1016 , and the antenna driver is cycled off and back on in block 1018 . Process flow continues with decision block 804 . If the iteration count is above the predetermined iteration limit, then “no tag” data is generated in block 1014 , and process flow continues with block 806 . At the selection of the next antenna, the iteration count is reset.
[0096] Typically, a time period of approximately 50 milliseconds is enough to determine whether a signal will be present. This amounts to approximately two power cycles. If no tag is sensed, the typical scan time is approximately 0.1 seconds for each scan. In a worst case scenario, an entire shelf of 60 antennas with no tags can be scanned in approximately six (6) seconds. The fastest read conditions occur when all active antennas have tags present, and all tags properly power up.
[0097] Depending upon required response time, the ratio of read points to interrogators could be increased. At 60 to 1, scan time for a shelf is approximately 6 seconds. Increasing the read point to interrogator ratio to 500 to 1 or higher would push scan time to around a minute, which is still acceptable for numerous inventory functions.
[0098] Given the availability of polling a shelf of up to 60 positions in approximately six seconds, any number of possibilities of tracking procedures and other inventory control functions may be implemented in computer software. Currently, bar codes on lots are scanned with the information therefrom being stored in a database. The identification tags are generally molded into a wafer boat or box. Typically, the wafer box remains with the lot for most of the lot life except for a few times, for example, when the boxes are washed, or if the box gets contaminated.
[0099] Another embodiment 1100 of the present invention for tracking the carrier box association to a lot is shown in FIG. 13. A lot is placed with a box in block 1102 , and a bar code label is placed on the box in block 1104 . The box is associated with the tag in block 1106 . A database entry is made regarding the association in block 1108 . This same database is used to record the sampling information generated at various polling locations around the plant or location in which a system embodiment of the present invention is in place.
[0100] Yet another embodiment 1110 of the present invention for associating a tag with material and manufacturer information is shown in FIG. 13 a . Method 1110 comprises scanning, collecting, or entering manufacturer data into a database in block 1112 , attaching a tag to the raw material in block 1114 , and associating the tag with the manufacturer data in block 1116 . The material is moved to storage in block 1118 , transported in block 1120 , and is moved through a production line in block 1122 . While in any phase of the process 1110 , apparatus embodiments of the present invention may be used to track the location of the material. The material is transported again in block 1124 , and again stored in block 1126 . At the completion of the production cycle, the tag is removed in block 1128 , and is disposed of or returned for reprogramming in block 1130 .
[0101] An identification tag may be attached to an object to be tracked by method embodiment 1150 shown in FIG. 14. Method 1150 comprises forming a shallow polypropylene cup in block 1152 , placing the identification tag in the polypropylene cup in block 1154 , welding the identification tag to the polypropylene cup ultrasonically in block 1156 , and welding the polypropylene cup to the object ultrasonically in block 1158 .
[0102] The database generated from all of the association information of the tags and boxes in a particular database can be sampled to generate history information. It is envisioned that such a database will be accessible at multiple locations around a plant or inventory location. The database can be queried to generate the appropriate information. The possibilities are numerous given the present invention embodiments' ability to update information of a box approximately every 6 seconds. Information that could be tracked includes by way of example only, and not by way of limitation, timing a process, timing a transfer time form one location to another, tracking missing lots, tracking movement of lots, detecting when a tag is missing, and the like.
[0103] Further, the information in the database may be queried, and software written for managing product flow in a production area, scheduling, tracking, notification of arrival and departure, history, spare equipment inventory, and the like. The nearly real-time gathering of information allows vast flexibility limited only by the capabilities of the systems on which the software may be implemented.
[0104] The methods shown in FIGS. 11, 12, and 13 may be implemented in various embodiments in a machine readable medium comprising machine readable instructions for causing a computer 1200 such as is shown in FIG. 15 to perform the methods. The computer programs run on the central processing unit 1202 out of main memory, and may be transferred to main memory from permanent storage via disk drive 1204 when stored on removable media or via a network connection or modem connection when stored outside of the personal computer, or via other types of computer or machine readable medium from which it can be read and utilized.
[0105] Such machine readable medium may include software modules and computer programs. The computer programs comprise multiple modules or objects to perform the methods in FIGS. 11, 12, and 13 , or the functions of various modules in the apparatuses of FIGS. 3, 7, 8 , and 9 . The type of computer programming languages used to write the code may vary between procedural code type languages to object oriented languages. The files or objects need not have a one to one correspondence to the modules or method steps described depending on the desires of the programmer. Further, the method and apparatus may comprise combinations of software, hardware and firmware.
[0106] The software implementing the various embodiments of the present invention may be implemented by computer programs of machine-executable instructions written in any number of suitable languages and stored on machine or computer readable media such as disk, diskette, RAM, ROM, EPROM, EEPROM, or other device commonly included in a personal computer. Firmware can be downloaded by the host into the microcontroller or the auxiliary processor for implementing the embodiments of the invention.
ANNUNCIATOR DESIGN
[0107] Given a typical scan time for a shelf of approximately six seconds, a feedback mechanism such as an annunciator, bell, whistle, light, or the like could be used in a circuit such as circuit 150 shown in FIG. 4, that could be used to locate a lot or a specific part in a lot location. A representation such as a graphical representation of a shelf, could be employed at a visual display terminal, with the exact location of a certain identified part to be shown on the display, Such representation, due to the close detail allowed by the present invention, would facilitate pinpointing the location of an item or lot for easy retrieval of the part or item.
[0108] A coordinate mapping system could be used with graphics on a computer screen, including a number for elevation of a particular shelf in a stack, and a standard position for the shelf, for example an XY scheme with shelf number and position.
[0109] An annunciator embodiment 1300 of the present invention is shown in FIG. 16. A variety of different annunciator type configurations are shown in FIG. 16. For example, one annunciator embodiment 1302 comprises a resistor 1303 and a light emitting diode 1304 connected in series across the incoming square wave signal. The annunciator embodiment 1302 will light the LED 1304 when the shelf or lot location to which the annunciator embodiment 1302 is connected is polled.
[0110] Another annunciator embodiment 1308 comprises a tuned circuit connected across an incoming square wave, the tuned circuit having a different resonance frequency than the resonance frequency of the tuned circuit used as a sensing antenna. Annunciator embodiment 1308 comprises a tuned LC circuit 1310 and an indicator 1312 . Indicator 1312 will become activated when the shelf or lot location to which the annunciator embodiment 1308 is connected is polled with the alternate frequency.
[0111] In another annunciator embodiment 1316 , a signaling LED 1318 is shown in reverse polarity. In normal operation, suppose that ground is connected to positive, and a bipolar driver sends a drive signal to an antenna. Switching the drive circuit or the ground polarity allows a pulsing reverse bias causing LED 1318 to light. In normal connections, with a positive bias on LED 1318 , it is not lit. Placing a reverse bias on the annunciator embodiment 1316 causes LED 1318 to light.
[0112] In another embodiment, an alphanumeric display 1320 is operatively connected across an incoming square wave. The display 1320 can derive power from the line, or power can be externally provided. When the line is not used for driving an antenna, the display 1320 is recognized by the system, and the display may be used to display tag information such as the tag number, lot number, and the like. Once the tag information is decoded, the path to the host of to the microcontroller could shut off the antenna, and an ASCII signal could be sent on a non-LC frequency. The display recognizes valid data and displays the data.
[0113] Primary application of the embodiments of the present invention are seen in wafer applications. However, multiplexing antennas offers a wide variety of other potential applications such as in large parking lots where RFID tags are placed at front or rear bumpers of vehicles, for example, and antennas are placed at the end of the parking space for identification of location and identity of vehicles. Other uses for the present invention include inventory control systems with large numbers of points to be inventoried but not requiring immediate scanning. Another example is material on a conveyer belt for objects that are momentarily stationary or stationary within approximately a ten second or longer period. Such modifications, variations, and other uses will be apparent to one of skill in the art, and are within the scope of the present invention.
[0114] For example, another embodiment of an application 1700 for the present invention is shown in FIG. 17. Tracking of raw material such as gas bottles, chemical bottles such as gas container 1702 is accomplished using an omnidirectional tag 1704 situated around the neck of a canister 1702 contained in a cabinet or other enclosure 1706 . An antenna 1708 connected to a system such as those discussed above receives information from collar or tag 1704 upon polling of the tag location. An auxiliary I/O control such as control 421 is used to actuate a valve 1710 to dispense gas from the container 1702 . The auxiliary control controls the gas flow, rate of dispensation, and the like.
MANUFACTURE OF THE NESTING STATIONS
[0115] Physical implementation of the nesting stations may vary. One implementation is to use a clamshell-type plastic molding with molded ridges, stiffeners and anchor points molded directly into the plastic. The circuit board for the tuned tank includes the capacitors with the connection jacks mounted directly on the circuit board. The circuit board lays in a notch in the top half of the assembly. The metal ground plane plate is placed in the bottom half of the assembly. The antenna coil leads are attached to the circuit board while the antenna coil would be attached to the top half of the molding. A foam filler fills then fills the void and the molding is closed. The assembly of this type is key to keeping the cost low. The configurations allowed by this type of assembly cover very diverse arrangements.
CONCLUSION
[0116] The embodiments of the present invention have added multiplexing circuitry to an interrogator, allowing a single detection circuit and processor to be common to a plurality of antennas. A control module or host is used to control the driving of the antennas.
[0117] The embodiments of the present invention take advantage of a short range of a sensing antenna to distinguish multiple lots which may be placed very close together in a small area. One interrogator can distinguish many items. The invention has a low cost per read station, which is beneficial due to the large number of read locations. | A method and apparatus for tracking items automatically is described. A passive RFID (Radio Frequency IDentification) tag is used with a material tracking system capable of real-time pinpoint location and identification of thousands of items in production and storage areas. Passive RFID tags are attached to the item to be tracked, remote sensing antennas are placed at each remote location to be monitored, interrogators with several antenna inputs are connected to the sensing antennas to multiplex the antenna signals, and a host computer communicates with the interrogators to determine item locations to an exacting measure. | 66,646 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to an auxiliary method for setting vehicle satellite navigating destinations to assist users to set destinations in a vehicle navigation host.
[0003] 2. Description of the Prior Art
[0004] In the past driving a car to a destination relies on maps by following the roads shown thereon. Due to fast business and community developments, the road system becomes very complicated. Nowadays it is not uncommon that even a destination a few blocks away could be difficult to reach directly due to the restrictions of one-way streets, no-left turn roads, overpasses, rivers, and the like. Hence a desired driving route often has to be planned ahead. The navigation system now equipped in many vehicles is a helpful tool for drivers to select the optimum route. However at present setting a destination on the vehicle navigation host mostly has to use a remote controller to do selection or search on the map. The remote controller has a limited number of keys. Hence users have to move slowing through the direction keys to the destination to do setting, or move to a landmark close to the destination (such as a government building, park, or the like), then move the direction keys from the landmark to the desired destination for setting. It is inconvenient, and also does not conform to the using habit of most users. As users generally know the street or road and city of the destination before searching, to find out the destination through the direction keys on a display screen about seven inches or smaller is not practical or helpful.
[0005] Moreover, nowadays many people planning their travel and trip by accessing the Internet and downloading the geographic location of the visiting areas or hotels. Users generally have to print the maps appeared on the Web pages and use the maps as the guide during actual driving. It also is not convenient.
SUMMARY OF THE INVENTION
[0006] Therefore the object of the present invention is to resolve the disadvantages of the conventional vehicle navigation host such as difficult to set destinations and not practical. The present invention provides an auxiliary method for setting vehicle satellite navigating destinations. The method includes a procedure as follow:
[0007] (1) selecting a destination file from Web pages on a Web site;
[0008] (2) downloading the destination file into a navigation host;
[0009] (3) setting up an interim file in the memory unit of the navigation host;
[0010] (4) starting the navigation host to check and update the interim file; and
[0011] (5) planning the navigation route.
[0012] In the auxiliary method set forth above, the data source of the destination file is outside the navigation host, such as selecting from Web pages of a Web site, and is downloaded into the memory unit of the navigation host through radio transmission or a memory card.
[0013] In one aspect, the Web pages have electronic maps corresponding to the navigation system of the navigation host. Users or other people can select a destination on the maps to set up a destination file.
[0014] In another aspect, the destination file includes at least longitude and latitude data of the destination.
[0015] In yet another aspect, the destination file includes one or more picture related to the destination to be displayed on the navigation host to show the exact appearance of the destination.
[0016] In still another aspect, the destination file includes address data.
[0017] In another aspect, the destination file may be expanded to become a destination file folder which contains one or more destination file.
[0018] In another aspect, the destination file has a sub-file name consisting of common and selected characters for identification.
[0019] In another aspect, the navigation host includes one or more memory unit which contains a data file of a preset destination, and one or more interim file which may be updated anytime desired.
[0020] In another aspect, the navigation host includes one or more memory unit which may be a removable memory card device.
[0021] In another aspect, the navigation host includes a software for reading the interim file to set a navigation route to the destination, and to search as desired files stored in the memory card that have been added or modified, and treat the file data as the destination file for user selection to serve the destination of the navigation route.
[0022] In another aspect, the navigation host includes a software which has a directory for destination selection. The directory has a menu named by the destination file name or destination file folder so that when user selects the menu item the navigation host opens the destination file or folder.
[0023] In another aspect, the source of the destination file is obtained by E-mail.
[0024] In another aspect, the destination file data include visiting site introductions appeared on the Web pages that have location information on the electronic map for setting up a destination file.
[0025] In another aspect, the destination file includes interesting spots such as restaurants, hotels, shopping stores, service centers, entertainment sites, amusement parks, gas stations, and the like.
[0026] By means of the invention, the electronic maps on the Web pages of a Web site may be selected to build a destination file. Interesting spots may be selected and planned and added to the destination file. The destination file data may be obtained by E-mail, and may also be downloaded to the navigation host for planning the navigation route. Thus it can overcome the problems occurred to the conventional routing data that are not adequate or practical.
[0027] The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a block diagram of the structure of the navigation host of the invention.
[0029] FIG. 2 is the main flow chart of the method of the invention.
[0030] FIG. 3 is the secondary flow chart- 1 of the invention.
[0031] FIG. 4 is the secondary flow chart- 2 of the invention.
[0032] FIG. 5 is a flow chart for entering the destination in the navigation host of the invention.
[0033] FIG. 6 is another flow chart for entering the destination in the navigation host of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] Referring to FIG. 1 , the navigation host 1 according to the invention includes:
[0035] a satellite positioning device 11 to receive satellite signals;
[0036] a positioning calculator 12 to receive the signals of the satellite positioning device 11 for downstream processing;
[0037] a memory unit 13 to store data of the navigation host 1 , such as maps, destination data, and the like. It contains one or more destination data file and one or more interim file which may be updated anytime;
[0038] a longitude and latitude comparing and processing unit 14 to receive the signals of the satellite positioning device 11 and mate the electronic maps of the memory unit 13 to mark the location of the navigation host 1 ;
[0039] a display unit 15 to display the navigation maps, current position and other related data; and
[0040] an access interface 16 to receive external data, such as read/write interfaces including infrared transceivers, radio transceivers (FM, AM, wireless LAN), Bluetooth transceivers, card readers (CF, MD, SM, SD, MMC, MS), optical disk drives, and the like.
[0041] By means of the construction set forth above, a user can use a network device to link and access Web sites to search destinations, and select the ones desired on the map of the Web pages, and order the Web page program to generate a destination file to be used by the vehicle navigation host 1 . The procedure (referring to FIG. 2 ) is as follow: p 1 (1) select a destination file on the Web pages of a Web site (step 200 ): link the network to the Web site which has electronic maps compatible to the navigation host 1 . Search a destination desired through the electronic map program of the Web site by maps or keywords. Once the destination is chosen, user can add related text descriptions or pictures, and set up a destination file with a sub-file name. The file includes the longitude and latitude coordinates of the destination, and the text and pictures entered by the user;
(2) download the destination file into the navigation host (step 300 ): after the destination is set up (referring to FIG. 5 ), the file may be output and stored in a memory card (step 311 and 312 ). Insert the memory card into the navigation host (step 313 ). The navigation host reads or downloads the destination file into the memory unit 13 (step 315 ). Or transfer the destination file by radio transmission to the navigation host 1 (step 314 and 315 ) through a wireless communication system 7 such as a GSM or CDMA module (also referring to FIG. 1 ). The wireless communication system 7 can transmit the destination file to the navigation host 1 ; (3) build an interim file in the memory unit of the navigation host (step 400 ): the memory unit 13 of the navigation host 1 has a preset destination data file and an interim file which may be updated anytime desired. When the destination file is transmitted to the memory unit 13 , it is stored in the interim file; (4) start the navigation host to check and update the interim file (step 500 ): when the navigation host 1 starts operation, it checks whether there are updating data for the content of the interim file. If yes, update the file; and (5) plan the navigation route (step 600 ): the navigation host 1 configures a route to the destination according to the longitude and latitude data in the interim file, and stores the route in the destination data file to be used in the navigation process.
[0046] The navigation host 1 includes a software for reading the interim file to set the destination of the navigation route.
[0047] The destination file may be expanded to become a destination file folder with a common sub-file name. The navigation host 1 can selectively read the sub-file name like inquiring a directory to search the destination file or destination file folder. It also serves as a basis to differentiate the external destination files.
[0048] In the step 200 of select a destination file on the Web pages of a Web site as shown in FIG. 3 , first, search the electronic maps on the Web site that correspond to the navigation host 1 (step 211 ); next, find out the destination on the electronic maps (step 212 ); then finish setup of the destination file (step 213 ).
[0049] Moreover, in the step 200 of select a destination file on the Web pages of a Web site, the destination file data include site introductions from the Web pages. As shown in FIG. 4 , first, search the electronic maps corresponding to the navigation host 1 on the Web site (step 221 ); select the interesting spot location on the electronic maps (step 222 ); store data (step 223 ); continue selection and searching (step 224 ); finish setup of the destination file (step 225 ). The destination file further includes introduction text, pictures, special scenic sites, folklore and special features. The interesting spots may include landmarks such as restaurants, hotels, shopping stores, service centers, entertainment sites, amusement parks, gas stations, and the like.
[0050] In the step 300 of download the destination file into the navigation host, the destination file may be sent by E-mail to a computer or handset of the user of the navigation host 1 . Then the file is transmitted to the navigation host 1 according to the procedure shown in FIG. 6 . Namely, output the destination file (step 321 ); transmit the file by E-mail (step 322 ); store the file in a memory card (step 323 ); insert the memory card into the navigation host 1 (step 324 ); load the destination file into the memory unit 13 of the navigation host 1 (step 326 ); or output the destination file directly by wireless transmission to the memory unit of the navigation host 1 (step 325 and 326 ).
[0051] In summary, the invention provides a method for setting destination that better suits the habits of people and computer users. It overcomes the restrictions occurred to the conventional navigation system. It also breaks the limitation of the conventional technique that displays only maps or address text. Instead, a destination file is directly delivered to the navigation host in the vehicle so that users can find out the geographical location easily. | An auxiliary method for setting vehicle satellite navigating destinations aims to build a destination file from electronic map data of Web pages of a Web site. The data source of the destination file may be retrieved by E-mail. The destination file data are downloaded by radio transmission or through a memory card into a memory unit of a navigation host to enable the navigation host to perform navigation route planning thereby to overcome the problem of inadequate data or poor usability occurred to the conventional route planning. | 13,554 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority from U.S. Provisional Patent Application No. 60/810,995, filed Jun. 5, 2006, which is incorporated herein by reference.
STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH AND DEVELOPMENT
This invention was made, in part, with government support under Grant Number F49620-02-0359 awarded by AFOSR MURI and Grant Number 200-2002-00528 awarded by NIOSH/CDCP. The United States government may have certain rights in this invention.
FIELD OF THE INVENTION
The present invention is directed generally to apparatuses, systems, and methods utilizing capillary action and, more specifically, to methods and apparatuses to control the movement or placement of liquids or other materials in micro-devices and nano-devices.
BACKGROUND OF THE INVENTION
Single-chip electronic noses, enabled by full on-chip integration of gas chemical microsensors with signal-conditioning electronics have tremendous medical, environmental and safety applications. Gravimetric detection is an important sensing modality for these microsystems.
Commercially available mass-sensitive devices for volatile organic compound detection use piezoelectric quartz substrates. Thickness shear mode resonators (TSMR), also known as quartz micro-balances (QMB) (Patel, R., Zhou, R. Zinszer, K., and F. Josse, “Real-time detection of organic compounds in liquid environments using polymer-coated thickness shear mode quartz resonators”, Analytical Chemistry, vol. 72, no. 20, p. 4888-4898, 2000) (Schierbaum, K. D., Gerlach, A., Haug, M., and W. Gopel, “Selective detection of organic molecules with polymers and supramolecular compounds: application of capacitance, quartz microbalance, and calorimetric transducers”, Sensors and Actuators A, 31, p. 130-137, 1992), and Rayleigh surface acoustic wave (SAW) devices (Ricco, A. J., Kepley, L. J., Thomas, R. C., Sun, L., and R. M. Crooks, “Self-assembling monolayers on SAW devices for selective chemical detection”, IEEE Solid-State Sensor & Actuator Workshop, Hilton Head, S.C. June 22-25, p. 114-117, 1992) are examples of such devices. However, these piezoelectric devices have not been fully integrated with on chip electronics. In contrast, resonant cantilever chemical microsensors integrated with CMOS have been demonstrated (A. Hierlemann and H. Baltes, “CMOS-based chemical microsensors”, Analyst, 128, p. 15-28, 2003). Prior work on cantilever mass sensors includes detection of humidity, mercury vapor, and volatile organic compounds (Lange, D., Hagleitner, C., Hierlemann, A., Brand, O., and H. Baltes, “Complementary Metal Oxide Semiconductor Cantilever Arrays on a Single Chip: Mass-Sensitive Detection of Volatile Organic Compounds”, Analytical Chemistry, vol. 74., no. 13, p. 3084-3095, 2002) as well as biomolecular recognition in a liquid media (Fritz, J., Bailer, M. K., Lang, H. P., Rothuizen, H., Vettiger, P., Meyer, E., Guntherodt, H. J., Gerber, Ch., and J. K. Gimzewski, “Translating biomolecular recognition into nanomechanics”, Science, 288, p. 316-318, 2000.). Post-CMOS micromachining has been used to make fully integrated mass sensitive oscillators with pico-gram resolution (H. Baltes, D. Lange, A. Koll, “The electronic nose in Lilliput,” IEEE Spectrum, 9, 35, (1998)). These devices were formed through deposition of precise amounts of a chemically sensitive layer onto relatively wide cantilevers.
Another example of a CMOS-MEMS resonant gas sensor used electrostatic actuation and detection to form a free-running oscillator (S. S. Bedair and G. K. Fedder, “CMOS MEMS Oscillator for Gas Chemical Detection,” Proceedings of IEEE Sensors, Vienna, Austria, Oct. 24-27, 2004). A cantilever beam suspended a plate made large enough to accommodate drops of chemically sensitive polymer placed directly onto the plate using drop-on-demand ink jet deposition. Ink jet deposition can functionalize each cantilever in an arrayed structure with a separate polymer. This non-contact technology is scalable for large arrays, easy to use, versatile, and faster than other means of coating such as from micro-capillaries and drop casting from pipettes (A. Bietsch, J. Zhang, M. Hegner, H. P. Lang, and C. Gerber, “Rapid functionalization of cantilever array sensors by inkjet printing”, 2004 Nanotechnology 15 873-880). Other thin film application methods include dip pen and shadow mask processing which are both time consuming processes.
Another prior microfluidic system is described in U.S. patent application, 20050064581 and in a corresponding paper (T. P. Burg, A. R. Mirza, N. Milovic, C. H. Tsau, G. A. Popescu, J. S. Foster and S. R. Manalis, “Vacuum-packaged suspended microchannel resonant maass sensor for biomolecular detection,” J. Microelectromechanical Systems, December 2006). These prior art documents describe an enclosed microchannel. Material is flowed into the channel to functionalize sidewalls of the channel to capture biomolecules on the sidewalls. However, the channel in these works is not used or taught as a wicking structure for deposition of a non-liquid material, such as polymers, that fills or partly fills the channel. Specifically, the patent application describes a microfluidic channel to detect analyte that may have a liquid or gel in the channel. The analyte is flowed into the microchannel. The gel may be delivered by pressure flow or electrophoresis, but no description or teaching of gel deposition through wicking is provided. The invention requires an enclosed microchannel for analyte delivery through flow, and in order to package in vacuum.
It is beneficial to further scale down the size of the resonant microstructure to achieve an increased mass sensitivity and reduced cost. Scaling cantilevers down to micro- and nano-scale dimensions is achievable with optical or piezoresistive resonant detection. However, microstructures with low-noise electrostatic actuation and detection require narrow air gaps that are generally incompatible with existing polymer deposition techniques.
Accordingly, there is a need for improved apparatuses and methods to control polymer addition to micro-cantilevers and nano-cantilevers for biological and chemical sensing. Those and other advantages of the present invention will be described in more detail hereinbelow.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed generally to apparatuses, systems, and methods utilizing capillary action. The present invention has many applications and many variations. For example, the present invention may be used in the operation of sensors. The present invention may be used to fill a space between two or more parts. In some embodiments, the present invention may be used to carry an adhesive to a desired location to fix two or more parts together. In other embodiments the present invention may be used to provide a dielectric between two or more electrodes or contacts. In another embodiment, the present invention may be used in a chemo resistor device in which electrically resistive material is positioned between two or more electrodes or contacts. The present invention may also be used with a mass sensor for gas chemical sensing applications. The present invention may also be used with many different fluids and materials, and in many specific applications such as to control material addition to micro-cantilevers and nano-cantilevers for biological sensing, chemical sensing, and other sensing.
In one specific embodiment, the present invention will be described in terms of apparatuses and methods to mass load a microstructure with polymer without affecting nearby gaps. Precise amounts of polymer or other materials, which may be suspended in solution, are wicked onto the microstructure through capillary action of micro-grooves formed along the length of the beam. The polymer or other material is left on the microstructure after drying of the solvent. Scaling down the mass of the mass sensitive cantilever leads to a higher mass sensitivity which leads to highly sensitive gas chemical sensing applications. The technique enables design of low-mass polymer-loaded cantilevers with electrostatic actuation and capacitive sensing for integrated gas chemical detector arrays.
The present invention may also include two or more devices formed in a single apparatus or on a single substrate. The single apparatus or substrate may contain several devices of the same type, such as to perform same test or operation many times. Alternatively, the single apparatus or substrate may contain several devices of different types, such as to perform a variety of different tests. In some embodiments, the devices receive different materials in their respective target areas, and in some embodiments they receive the same materials. As a result, redundant or different testing, sensing, or other functions may be performed on a single structure.
Although the present invention will generally be described in terms of specific embodiments, many variations, modifications, and other applications are possible with the present invention. These and other teachings, variations, and advantages of the present invention will become apparent from the following detailed description of the invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings for the purpose of illustrating the embodiments, and not for purposes of limiting the invention, wherein:
FIG. 1 illustrates one embodiment of an apparatus according to the present invention.
FIGS. 2 a - 2 h illustrate embodiments of wicking devices according to the present invention.
FIG. 3 a illustrates one embodiment of a gravimetric micro-cantilever resonant sensor according to the present invention.
FIGS. 3 b and 3 c illustrate cross-sectional views along lines IIIb-IIIb and IIIc-IIIc, respectively, in FIG. 3 a.
FIGS. 4 a and 4 b illustrate an embodiment of an electrostatically actuated resonator with differential comb drive and sensing electrodes.
FIG. 5 illustrates one embodiment of a solution delivery to the resonator.
FIG. 6 illustrates one embodiment of an oscillator gas sensor schematic. The electrostatically actuated resonator is placed in a feedback loop with off-chip electronics for oscillation.
FIG. 7 illustrates one embodiment of post CMOS processing steps: (a) CMOS chip from foundry, (b) Reactive-ion etch of dielectric layers, (c) DRIE of silicon substrate, (d) isotropic etch of silicon substrate, (e) Ink jet deposition of polymer solution.
FIG. 8 illustrates an example of a beam pinned under stator electrodes after direct ink jet deposition onto cantilever.
FIG. 9 a - 9 d illustrate one embodiment of a device before and after solution deposition in the well:(a) entrance from well to micro-channel which extends along the length of the resonator, (b) resonator at the base with polystyrene, (c) tip of resonator without polystyrene, (d) tip of resonator with polystyrene.
FIG. 9 e illustrates frequency response of one embodiment of a device before and after polystyrene deposition into a 2 μm channel in the device.
FIGS. 10 a - 10 g are scanning electron micrographs of several embodiments of the present invention.
FIG. 11 illustrates one embodiment of a gas test setup according to the present invention.
FIG. 12 illustrates spectrum analyzer output of resonant frequency shifts due to ethanol, IPA, and acetone gas flows according to one embodiment of the present invention.
FIGS. 13 a and 13 b illustrate another embodiment of the present invention in which one or more channels are used to provide an adhesive to secure two objects together.
FIGS. 13 c and 13 d illustrate another embodiment of the present invention in which a suspended beam is used for form a space or gap.
FIGS. 14 and 15 illustrate another embodiment of the present invention in which parts of an object or layer are joined with a material according to the present invention.
FIG. 16 illustrates one embodiment of a system according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be generally described in terms of specific examples and embodiments, although many variations and modifications are possible. For example, although the present invention is sometimes described in connection with the use of polystyrene, many other materials may be used with the present invention. For example, the present invention may be used with materials that can be delivered with solvents, and other materials in solution and fluids. For example, these materials can be active polymers, nano particles, polymer composites, biomolecules, solgel, electro- and magneto-active polymers, adhesives, and sealants. Furthermore, the present invention may be constructed in scales other than those specifically defined herein. For example, specific dimensions are provided in some examples, although smaller devices may be desirable to provide additional sensitivity in some applications, and larger devices may be desirable in other applications. Similarly, the use of the term “micro”, such as in “micro-cantilever”, “microstructure”, “micro-capillary”, and others, is illustrative and is not a limitation of the present invention. For example, the present invention may also be used at nano-scales or at smaller or larger scales.
FIG. 1 illustrates one embodiment of an apparatus according to the present invention. In this embodiment the apparatus 10 is a sensor, although the apparatus of the present invention may take other forms, such as in assembling parts for microelectromechanical systems, providing adhesive, sealant, or other material between two or more parts, and in other applications.
In FIG. 1 the sensor 10 includes wicking device 12 , a fluid well 14 , motion sensors 16 , actuators 18 , and a fluid dispenser 19 .
The wicking device 12 carries a fluid along a channel (not shown) in the wicking device 12 via capillary action. The wicking device 12 may be an elongated structure, such as a straight beam, or it may be a curved structure, or it may have other shapes. In some embodiments the wicking device is cantilevered, although it is not required to be cantilevered. The channel will be described in more detail hereinbelow and may take different forms, such as a gap between two surfaces, a groove or recess formed in a surface, or a passage through an object. In some embodiments, the material is deposited in the fluid well 14 and is wicked into the wicking device 12 , so that the deposited material does not interfere or contact any other parts of the devices, such as the motion sensors 16 or the actuators 18 .
In some embodiments the wicking device 12 will be suspended. As used herein, a “suspended” wicking device 12 means a significant portion of the wicking device 12 is surrounded by air, or void, or ambient conditions other than structural elements used to support the wicking device 12 . For example, in some embodiments the wicking device 12 is in the form of a cantilevered beam supported at one end and suspended in air (or in other conditions) for most of its length. In other embodiments, the wicking device 12 is in the form of an object or layer formed over a recess, in which at least a portion of the object or layer is suspended over the recess. In some embodiments, the wicking device 12 can be formed from two or more parts or pieces, and in some cases all parts or pieces are suspended, and in other cases some parts or pieces are suspended and other parts or pieces are not suspended. Although several embodiments of the present invention will be described in terms of a suspended wicking device, advantages of the present invention may also be realized with wicking devices 12 that are not suspended in any way.
The fluid well 14 is the source of the fluid that is carried along the channel in the wicking device 12 via capillary action. The fluid well 14 is significantly larger than the channel in the wicking device 12 and directly receives the fluid, such as through an ink jet deposition or through other means such as micro capillaries and pipettes, dip pen, and shadow mask processing. The fluid well 14 will sometimes be referred to as a “target area”, “target well area”, and other names. These terms are interchangeable.
The motion sensors 16 detect motion of the wicking device 12 . The motion sensors 16 are not required in the present invention, and some embodiments illustrated herein do not use the motion sensors 16 .
The actuators 18 cause the wicking device 12 to move. The actuators 18 may, for example, cause motion through the application of electrostatic forces, or through other means. The actuators 18 are not required in the present invention, and some embodiments illustrated herein do not use the actuators 18 .
The fluid dispenser 19 is oriented to dispense fluid into the fluid well. The fluid dispenser 19 may be, for example, drop-on-demand ink jet device, or a micro-pipette device, or a dip pen device, or it may be other forms of fluid dispensers 19 . Unlike the prior art, the present invention dispenses or deposits the fluid into a fluid well 14 , from which it is wicked onto the channel 20 or channels of the wicking device 12 . Many variations are possible with the fluid dispenser 19 . For example; there may be a dedicated fluid dispenser 19 for each fluid well, or one fluid dispenser 19 may be used with more than one fluid well 14 , such as by moving the fluid well 14 , moving the fluid dispenser 19 , or otherwise changing the orientation of the fluid well 14 and the fluid dispenser 19 . In some embodiments of the present invention, the fluid dispenser 19 is integrated into the device including the fluid well 14 , and in other embodiments the fluid dispenser 19 is separate from the rest of the device and is engaged with the apparatus 10 when it is needed.
The sensor 10 illustrated in FIG. 1 is a gravimetric sensor in which the actuators 18 cause the wicking device to move, and the motion sensors 16 measure the movement. The frequency response of the wicking device is indicative of the mass, and the distribution of mass, of the wicking device 12 and any material deposited or absorbed on the wicking device 12 . The frequency response of an empty wicking device 12 can be established, so that any change in the response is indicate of the additional material added to the wicking device 12 . In this way, the mass of material deposited on the wicking device can be determined. A mass sensitive material can be deposited onto the wicking device. In this way, the mass of an additional material absorbed into the mass sensitive material on the wicking device can be determined. For example, the additional material to be determined can be a gas chemical analyte absorbed into a mass sensitive polymer. The present invention is not limited to use in gravimetric sensors, and may be used in other types of sensors 10 , such as chemo-resist sensors, capacitive sensors, or other types of sensors. The present invention can also be used in apparatuses other than sensors, as will be described in more detail hereinbelow.
Many variations are possible with the present invention. For example, the sensor 10 may or may not include motion sensors 16 and actuators 18 , or may contain a more or fewer motion sensors 16 and actuators 18 than shown herein. For example, a sensor 10 may include only one motion sensor 16 or actuator 18 , or it may include more than two motion sensors 16 and actuators 18 . Similarly, more than one fluid well 14 may be used, and more than one wicking device 12 may be used in the sensor 10 . More than one wicking device 12 may be used for each fluid well 14 . The sensor 10 may also include devices not shown in this figure, such as devices for applying and measuring electrical current and voltage, and other devices. In some embodiments, the sensor 10 includes sources of controlled electrical voltage or current, and devices for measuring one or more electrical characteristics, such as voltage, resistance, current, capacitance, and electro-magnetic fields. These embodiments may also include motion sensors 16 and actuators 18 , or the embodiments may exclude one or both of motion sensors 16 and actuators 18 .
FIG. 2 a illustrates one embodiment of a wicking device 12 according to the present invention. The wicking device 12 includes a channel 20 formed in the wicking device 12 . The channel is in the form of a groove 20 and is defined by three surfaces of the wicking device 12 .
FIG. 2 b illustrates another embodiment of the wicking device 12 in which the wicking device 12 is formed from two parallel plates and the channel 20 is defined by the space between the two plates. Although the plates are illustrated as being parallel, they may also be non-parallel.
FIG. 2 c illustrates another embodiment of the wicking device 12 in which two plates are oriented vertically and the channel 20 is formed between the vertical plates. In other embodiments the plates may have other orientations, such as 45 degrees and others.
FIG. 2 d illustrates another embodiment of the wicking device 12 in which one or more supports 22 are provided between the plates of the wicking device 12 . The supports 22 resist the forces applied to the plates from the capillary action of fluids between the plates. As a result, the supports prevent the plates of the wicking device 12 from bending inward and touching each other.
Supports may also be included in other orientations of channels, such as in FIG. 2 c . Supports 22 are shown in FIG. 2 d as cylindrical and in the center of the channel, but supports can also be rectangular or other shapes and can be located at other locations in the channel.
FIG. 2 e illustrates another embodiment of the wicking device in which at least one plate includes an opening 24 . One or more plates or other parts of the wicking device 12 may include one or more openings. The openings may be of any shape, spacing, and orientation. The opening 24 reduces the mass of the wicking device and, in some applications, allows for increased sensitivity.
FIG. 2 f illustrates another embodiment of the wicking device 12 in which more than two plates are used. In that embodiment, two of the plates 26 are electrical conductors, and the other two plates 28 are electrical insulators. This embodiment may be used, for example, when the sensor is measuring capacitance with the fluid in the channel 20 of the wicking device 12 .
FIG. 2 g illustrates another embodiment of the wicking device 12 in which the structure of the electrical conductor 26 and insulator 28 vary from the previous embodiment. In this embodiment, one of the electrical conductors 26 is embedded with one of the electrical insulators 28 . These and other variations are possible.
FIG. 2 h illustrates another embodiment of the wicking device. In this embodiment, the channel 20 is formed in a more complex cross-sectional shape than in the previous embodiments. Also, there are several electrical conductors 26 and electrical insulators 28 on the walls of the channel 12 . This embodiment may be used, for example, to measure electrical resistance of the material in the channel 20 . Many combinations of measurements may be taken from the various electrical conductors 26 . In other embodiments, for example, different numbers of electrical conductors 26 , in different orientations, may be used. The electrical conductors 26 may be exposed to the channel 20 along the entire length of the channel, or the electrical conductors 26 may be exposed only in selected portions of the channel 20 , such as at the end or at other locations.
Many other variations of the wicking device 12 are also possible. For example, although the wicking devices 12 are shown as being open at their ends, they may also be capped or closed at the ends, and the wicking devices 12 may include different numbers, orientations, and structures of plates and other components forming the wicking device 12 and defining the channel 20 . In some embodiments, the channel 20 is tapered at the free end so as to wick more liquid to that end and, thereby, deposit addition material there. This results in non-uniform distribution of material, with more material at the free end where the device is more sensitive to mass. This embodiment, for example, may allow for the use of less liquid and less material while achieving greater sensitivity.
In another embodiment, a wider channel is used, thereby resulting in a larger volume that can be carried on wicking device 12 . However, if the same volume of liquid is used, the liquid and the material carried in the liquid will be driven to the free end of the wicking device 12 , resulting in all or most of the liquid and material at or near the free end of the wicking device 12 . As a result, there will be a non-uniform distribution of liquid and material along the wicking device 12 .
In another embodiment, the channel 20 may be non-linear. For example, the channel 20 may branch into several side channels, the channel 20 may include one or more “t” junctions, the channel 20 may include circular path components, the channel 20 may include a square spiral path component, and the channel 20 may include other path features and combinations of features. Similarly, the wicking device 12 may also have a shape other than a uniform, linear shape along its length.
Several embodiments of the present invention will now be described to illustrate the present invention. Those embodiments are illustrative, and not limiting. Other variations and embodiments of the present invention are also possible.
Micro-Cantilever Design
FIG. 3 a is an image of an actual gravimetric micro-cantilever sensor 10 constructed according to one embodiment of the present invention. FIGS. 3 b and 3 c illustrate cross-sectional views along lines and respectively, in FIG. 3 a . FIGS. 4 a and 4 b illustrate close up views of the beam microstructures forming the wicking device 12 , the motion sensors 16 , and the actuators 18 . The reservoir or target well area 14 for solution delivery is placed at the base of the cantilevered beam 12 , which is a movable structure in this embodiment.
FIG. 3 b illustrates a cross-sectional view along line IIIb-IIIb of the invention illustrated in FIG. 3 a . FIG. 3 b shows the wicking device 12 suspended above a substrate 36 . The substrate may be silicon, such as when semiconductor fabrication techniques are used to make the present invention. However, other materials and other fabrication techniques may also be used.
FIG. 3 c illustrates a cross-sectional view along line IIIc-IIIc of the invention illustrated in FIG. 3 a . FIG. 3 c shows the fluid well 14 built on a substrate 36 and with walls made from conductive 26 and insulating 28 materials such as those used to make the wicking device 12 and described hereinabove. In other embodiments, different materials and structures may be used to form the well 14 and its associated parts.
FIGS. 4 a and 4 b illustrate the structure of the device including the cantilevered beam, a differential comb drive 18 , and motion sensing electrodes 16 . The wicking device 12 is anchored 46 at one end (see FIG. 4 b ), such as to a substrate, and is free to move or resonate at the other end. Ink jetting technology is used to deposit solution into the fluid well 14 which is sized to accommodate the volume of the drop emitted from the ink jet. In the illustrated embodiment the target area 14 includes grooves or ridges 40 to facilitate capillary motion of the fluid towards the groove 20 of the wicking device 12 . The ridges 40 are omitted from the cross-section in FIG. 3C for simplicity.
This non-contact technology is scalable for large arrays, easy to use, faster than other means of coating such as micro capillaries and pipettes, and versatile. Other thin film application methods include dip pen and shadow mask processing which are both time consuming processes. Ink jetting is an excellent technology for functionalizing each individual cantilever separately in an arrayed structure. Although the present invention will be discussed in terms of using ink jetting, other application technologies may also be used.
In one embodiment of the present invention, the solution is deposited into the reservoir 14 and the solution is wicked into the 2 μm wide groove 20 running the length of the micro-cantilever 12 , which is 4 μm wide. Once the solvent from the solution evaporates and dries, the polymer which was cast in solution is left in the 2 μm groove 20 . This process of depositing polymer onto a micro-cantilever 12 is done without destruction of the device. Such a delivery system using ink-jet printing technology is significant because the approximate volume of the drop, 3×10 −14 m 3 , is greater than the volume of the micro-cantilever 12, 1.4×10 −15 m 3 , by more than an order of magnitude. The present invention teaches a method for depositing polymer onto a micro-cantilever 12 without destruction of the device. Polymer delivery to the cantilever 12 leads to gas chemical sensing and other applications by using a mass sensitive polymer. The combination of a sensitive layer with an electrostatically actuated cantilever 12 yields a mass sensitive detector. On chip electronics can be integrated with this mass sensor for motion detection using capacitive detection. Applications of this fabrication method may include mass sensing and chemo-resistive sensing for gas chemical detection.
In the illustrated embodiments the resonant structure 12 is a simple 120 μm-long, 4 μm-wide beam with a 2 μm-wide micro-groove 20 running along the length of the beam, although other dimensions are possible with the present invention. Motion is parallel to the surface of the silicon substrate. Differential comb drives 18 with seven rotor fingers are located near the end of the beam 12 for lateral electrostatic actuation. The stator fingers are suspended by three cantilever beams connected in parallel and sized identically to the resonator cantilever beam 12 . Any curl from vertical stress gradient is matched to ensure the stator 18 and movable comb fingers are aligned in the same plane. Motion sensing of the plate is implemented using capacitive comb electrodes 16 placed on both sides of the main beam 12 and located further toward the base from the actuation combs. A limit stop 42 is located between the actuator 18 and sense combs of the motion sensor 16 . The beam 12 , sensors 16 , actuators 18 , limit stops 42 , and their associated structures are suspended over a silicon etch pit 44 .
A target well 14 area is located at the base of the cantilever 12 to collect the jetted drops. The well 14 has an approximate depth of 9 μm and a maximum width of 165 μm. The well 14 narrows in width toward the base of the cantilever 12 at a 45° angle on each side. Other sizes and shapes are also possible for the target well 14 area.
Although FIGS. 3 a , 3 b , 3 c , 4 a , and 4 b illustrate a single apparatus 10 , the present invention may include multiple apparatuses 10 in a single device or on a single substrate. For example, multiple apparatuses 10 may be used to perform redundant tests to ensure accuracy. Alternatively, different apparatuses 10 may perform different tests to provide a wide variety of information. As a result, a single device may contain a single apparatus 10 , or it may contain multiple apparatuses in which there are several versions of the same apparatus 10 , or in which there are several different apparatuses 10 . The apparatuses 10 may, for example, receive the same material in their respective target wells 14 , or they may receive different materials. For example, these different materials can be different polymers each with different mass sensitivity to various gas chemical analytes.
FIG. 5 illustrates a schematic of the transition region between the well 14 and the groove 20 . A pressure difference exists between the two surfaces of the liquid/gas interface (R. Aoyama, M. Seki, J. W. Hong, T. Fujii, and I. Endo, “Novel Liquid Injection Method with Wedge-Shaped Microchannel on a PDMS Microchip System for Diagnostic Analyses,” Journal of MEMS, p. 1232, (2001)). This differential pressure is:
Δ P XC = 2 γ cos θ C ( 1 W X - 1 W C ) ( 1 )
where γ is the surface tension, θ C is the contact angle, W X is the width of the well and W C is the width of the micro-groove 20 running along the length of the cantilever 12 . This causes a flow of the solution by capillary action from the well 14 to the resonator 12 . Once the solvent dries polymer is left in the micro-channel in the resonator 12 .
Oscillator Design
FIG. 6 illustrates a block diagram of the closed-loop feedback system 50 to sustain the resonant oscillation. A dc polarizing voltage, V dc 52 , is applied to the movable beam 12 . The resonator velocity is detected by measuring the motional displacement current, V dc dC/dt, through the comb finger capacitors. An on-chip preamplifier 54 produces a voltage, V s , that is proportional to the difference of the current through the differential capacitors formed by the sense comb electrodes.
An external amplifier 56 placed in series with the on-chip pre-amplifier 54 provides 40 dB of gain and −90° of phase shift at the mechanical resonance. This phase compensation is needed for free running oscillation. In this implementation, only one side of the differential actuator is used. During free oscillation, the actuator voltage amplitude is 0.2 V with a dc polarizing voltage of 23.0 V. A spectrum analyzer 58 is used to monitor the output of the amplifier 56 and determine differences in the resonance frequency of the device movable beam 12 .
The calculated resonant frequency from layout dimensions and prior to polymer deposition is 250 kHz. With analyte addition, a change in the mass of the cantilever 12 changes the resonance frequency. The mass sensitivity (gm/Hz) is:
Δ m Δ f = - 4 π ( m b + m poly ) 3 2 k = - 2 ( m b + m poly ) f o ( 2 )
where m b is the mass of the beam, m poly is the mass of the polystyrene or other material being measured, k is the spring constant of the cantilever, and f o is the resonance frequency of the cantilever 12 . The calculated mass sensitivity for this device is 76 fg/Hz. The sensitivity (Hz/ppm) of the micro-balance due to analyte concentration is calculated as follows (see, S. S. Bedair and G. K. Fedder, “CMOS MEMS Oscillator for Gas Chemical Detection,” Proceedings of IEEE Sensors, Vienna, Austria, Oct. 24-27, 2004):
Δ f Δ C air = Δ f Δ m Δ m Δ C air = - f o 2 ( m b + m poly ) K PG V poly ( 3 )
where C air is the concentration of the analyte in air, K PG is the partition coefficient associated with the particular polymer/analyte combination, and V poly is the volume of the polymer on the beam 12 . The volume of polymer to fill the micro-groove 20 is 7.2×10-16 m 3 . Assuming that the micro-groove 20 is filled with polystyrene the concentration sensitivity to ethanol, 2-propanol, and acetone is calculated to be 0.006 Hz/ppm, 0.005 Hz/ppm, and 0.01 Hz/ppm, respectively. Other materials will result in a different sensitivity of the device 10 .
Fabrication
FIG. 7 illustrates one method of fabricating a sensor 10 according to the present invention. The sensor 10 was fabricated in the SiGe 0.35 μm BiCMOS technology from Jazz Semiconductor (Newport Beach, CA) followed by post-CMOS micromachining (G. K. Fedder, S. Santhanum, M. L. Reed, S. C. Eagle, D. F. Guillou, M. S. C. Lu, and L. R. Carley, “Laminated high-aspect-ratio microstructures in a conventional CMOS process,” Proceedings of the 9 th IEEE International Workshop on Micro Electro Mechanical Systems (MEMS '96), San Diego, Calif., Feb. 15-17, 1996, pp. 13-18). As illustrated in FIG. 7( a ), the structures 60 that will form the sensor are embedded in silicon oxide-based layers 62 or other material used in the fabrication process. Metal interconnect layers 64 are also present.
After foundry CMOS fabrication, three dry etch steps are used for definition and release of the structures 60 , as illustrated in FIG. 7( b ). The intermetal dielectric layers are etched using an anisotropic CHF 3 /O 2 reactive-ion etch (RIE) ( FIG. 7( b )) where the top metal layer 66 acts as a mask defining the pattern of the structure. A subsequent undercutting of the structures 60 by a Si etch is performed using an anisotropic deep reactive-ion etch (DRIE) to form a recess 70 in the bulk silicon 72 ( FIG.7( c )) followed by an SF 6 /O 2 isotropic etch ( FIG. 7( d )) of the bulk silicon 72 to form the undercut 74 of the structures 60 for structural release of the metal and dielectric stack 60 . In the illustrated embodiment, the sidewalls and bottom of the micro-grooves are defined by the metal- 3 and metal- 1 layer, respectively, in the CMOS technology.
In FIG. 7( e ) the chemically sensitive polymer dissolved in solvent 76 is deposited using a piezoelectric drop-on-demand ink jet purchased from MicroFab Technologies (Plano, Tex.). The orifice of the ink jet is 30 μm in diameter and the average drop size is 31 μm in diameter. An x-y stage (Aerotech Inc.) that moves the device under the ink jet provides positional accuracy of 0.2 μm.
Although the present invention has been described in terms of one embodiment with regard to FIGS. 7( a )- 7 ( e ), other variations and modifications are also possible with the present invention. For example, different devices, such as different types of sensors as well as devices other than sensors, may be used with the present invention. Similarly, other structures and other materials may be used with the present invention. In addition, other processes and technologies, such as other micromachining and nanomachining processes and technologies may also be used to manufacture apparatuses according to the present invention.
Polymer Delivery Results
FIG. 8 illustrates an attempt to directly deposit material onto a cantilever wicking device 12 . Polymer deposition tests used two mg/mL polystyrene mixed in a 1:1 mixture of HPLC grade toluene and xylene at room temperature. The solution was then sonicated for ten minutes.
As expected, attempts to directly deposit onto the cantilever 12 result in the destruction of the device 10 . This occurs because the ink-jetted drop volume (˜33 pL) greatly exceeds the target cantilever 12 size. The wicking device 12 is pinned under the actuating electrodes 18 due to surface tension effects rendering it inoperable. In addition, the deposited material covers both the cantilevered wicking device 12 and surrounding structures, such as actuators 18 and motion sensors 16 . As a result, even if the wicking device 12 were to remain in, or be returned to, a functioning state, the apparatus 10 would not function because other parts of the apparatus 10 are covered in the material that was supposed to be deposited only on the wicking device 12 .
FIGS. 9 a - 9 d illustrate loading material onto the cantilever 12 according to the present invention. In that example, six drops of solution (two mg/mL polystyrene in 1 toluene:1 xylene) were deposited onto the target area at the base of the cantilever beam 12 . The polymer wicks onto the cantilever beam 12 and the solvent then evaporates. A view at the base of the cantilever micro-channel 20 is shown in FIG. 9( a ) and FIG. 9( b ) before and after polystyrene deposition, respectively. The tip of the micro-channel resonator 12 with and without polystyrene is shown in FIG. 9( c ) and FIG. 9( d ), respectively. The device was successfully operated with electrostatic actuation.
FIG. 9 e illustrates the frequency response of the cantilever 12 before and after polystyrene loading. The resonance frequency shifted down by 5400 Hz. This corresponds to an added polymer mass of 410pg. The calculated mass of polystyrene in six drops of solution is 396 pg.
FIG. 10 a - 10 g are scanning electron micrographs (“SEM”) illustrating several embodiments of the present invention after material deposition. In these embodiments, the material deposited is a polymer, although other materials may also be used with the present invention.
FIG. 10 a is a top view SEM after polymer deposition. FIG. 10 b is a cross-sectional view along line Xb-Xb in FIG. 10 a . FIG. 10 b shows material at the tip of the wicking device 12 after polymer deposition. FIGS. 10 a and 10 b illustrate an embodiment of the present invention in which the channel 20 is a vertical slot type channel, having a channel width and height of 1.5 μm and 3.2 μm, respectively.
FIG. 10 c is a top view SEM after polymer deposition of another embodiment of the present invention. FIG. 10 d is a cross-sectional view along line Xd-Xd in FIG. 10 c . FIG. 10 d shows material at the tip of the wicking device 12 after polymer deposition. FIGS. 10 c and 10 d illustrate an embodiment of the present invention in which the channel 20 is a vertical slot type channel, having a channel width and height of 2.4 μm and 4.8 μm, respectively.
FIG. 10 e is a top view SEM after polymer deposition of another embodiment of the present invention. FIG. 10 f is a cross-sectional view along line Xf-Xf in FIG. 10 e . FIG. 10 f shows material at the tip of the wicking device 12 after polymer deposition. FIGS. 10 e and 10 f illustrate an embodiment of the present invention in which the channel 20 is a vertical slot type channel, having a channel width and height of 2.8 μm and 4.8 μm, respectively.
FIG. 10 g is a cross-section view of the tip of a wicking device 12 after polymer deposition. The channel 20 in the wicking device 12 is a vertical groove type. The channel width and height are 1.5 μm and 3.5 μm, respectively.
Gas Test Measurements
FIG. 11 illustrates a gas test system 80 according to one embodiment of the present invention. Gas analytes are introduced with nitrogen as the carrier gas. The nitrogen supply 82 is connected through an adjustable flow-meter 84 and a 2-way ball valve 86 . The flow-meter 84 has a minimum flow rate of 0.21 liters per minute (Lpm) and a maximum rate of 1.21 Lpm. One outlet of the ball valve 86 connects to a T-connector 88 for direct connection of the carrier gas and analyte vapor to the test chamber 90 . The other outlet of the ball valve 86 is connected to the inlet of a bubbler 92 which is submersed in the liquid form of the analyte of interest. The outlet of the bubbler 92 is connected to the through a valve 94 and the T-connector 88 to the test chamber 90 .
Tests were performed with ethanol, 2-propanol, and acetone. N 2 was flowed at 1 Lpm through the chamber using an external bubbler until an equilibrium concentration is reached. In these initial tests, the equilibrium concentration was not measured but is assumed to be at or close to the saturation concentration of the corresponding vapor at a temperature of 300 K and a pressure of 1 atm.
FIG. 12 illustrates the free-running oscillator responses to ethanol, 2-propanol, and acetone flows. The mechanical resonance frequency with no exposure to analyte is 204.499 kHz. The oscillator signal has a 65 dB SNR and a 3 dB width of 3 Hz limited by the 3 Hz resolution bandwidth of the spectrum analyzer. From the frequency shifts in FIG. 12 , the amount in grams of ethanol, 2-propanol, and acetone loaded into the polystyrene is calculated to be approximately 1.5 pg, 2.6 pg, and 9.9 pg, respectively.
Conclusions
The gas tests successfully demonstrate an organic vapor detector using the CMOS-MEMS self-excited resonator oscillator. The polymer loading method that exploits capillary action in the micro-groove enables design of narrow-gap electrostatic combs alongside the micro-cantilever. Compatibility with ink jet polymer delivery enables loading of different polymers to individual cantilever sensors. The precise amount of polymer loading with this method should lead to repeatable results from device to device.
Scaling down the cantilever size led to a high mass sensitivity of 76 fg/Hz for the 4 μm-wide cantilever design. With further design maturation, further device scaling and incorporation of further materials onto the wicking devices on the cantlivers, the technology should lead to highly sensitive gas chemical gravimetric sensor arrays on chip.
Other Embodiments
FIGS. 13 a and 13 b illustrate another application of the present invention in which one or more channels 20 are used to provide an adhesive to secure a first object 100 to a second object 102 . In FIG. 13 a , the first 100 and second 102 objects are apart and a force 104 presses them together. In FIG. 13 b , the first 100 and second 102 objects are together, and one or more channels 20 in the second object 102 are used to carry adhesive to an interface between the first 100 and second 102 objects. After the adhesive dries the first 100 and second 102 objects are bonded together.
This application of the present invention may be used, for example, to assemble parts, such as parts used to create microelectromechanical systems, or other parts. In the illustrated embodiment, the first object 100 includes offsets or stops 106 which engage the second object 102 and provide for a predetermined spacing or gap 108 between the first 100 and second 102 objects. This may allow, for example for very small and/or very precise gaps or spaces to be formed.
Narrow gaps, for example, smaller than possible with conventional photolithographic techniques, with electrodes at either side of the gap are of interest for providing high electrostatic forces and high capacitance sensitivity. In other embodiments, stops 106 may be omitted, and two or more parts may be assembled in different orientations. Many other variations and modification are possible with this application of the present invention.
FIGS. 13 c and 13 d illustrate another embodiment of the present invention in which material, such as an adhesive, is deposited in the well 14 and wicked through the channel 20 . Part of the channel is defined by a moveable beam 109 . When the material flows through the portion of the channel 20 formed by the moveable beam 109 , the surface tension of the material causes the beam 109 to bend inward. If the material is an adhesive, it will dry and fix the beam 109 in that position. In the illustrated embodiment, the bent beam 109 engages stops 106 limiting the motion of the beam and forming a space or gap 108 .
FIG. 14 illustrates another application of the present invention in which the channel 12 is an opening or void in an object or layer 110 . In the illustrated embodiment, the channel 20 . defines a circular portion 112 within the larger object 110 . In this embodiment, an adhesive or other material is provided in the fluid well 14 , from which the material flows into the channel 20 and fills the channel 20 . The material filling the channel 20 may be flexible and allow for relative movement between the circular portion 112 and the larger object, or it may have some other function. Many different shapes 114 and other variations of this embodiment may be practiced with the present invention.
FIG. 15 illustrates a cross-section view along line XV-XV of the apparatus illustrated in FIG. 14 . The two portions 110 , 112 of the top layer are joined by the material in the channel 20 .
In this embodiment, an opening 114 exists below the two portions 110 , 112 of the top layer and a lower layer 116 , although it is not required for an opening 114 to exist below the two portions 110 , 112 of the top layer. The material filling the channel can be used to seal the opening 114 from the outside ambient. For example, this sealing can be used to keep liquids from entering area 114 , or can be used to seal liquids inside area 114 .
FIG. 16 illustrates a system 120 according to the present invention. In that embodiment, several apparatuses 10 , such as that illustrated in FIG. 1 , are on a single substrate 122 or material. FIG. 16 illustrates the apparatuses 10 as being “sensors”, although any apparatus 10 , or any combination of different types of apparatuses, may be formed in this manner. Accordingly, the present invention allows for a large number of apparatuses to be made or used as part of a single system 120 or unit. In some embodiments, the apparatuses 10 may all be the same, such as to perform the same test multiple times on the same or different samples. In other embodiments, the apparatuses may be different, such as to provide for a variety of functions from a single system 120 .
Many variations and modifications are possible with the present invention. For example, the present invention may be used in the operation of sensors. The present invention may be used to fill a space between, or to connect, two or more parts. In some embodiments, the present invention may be used to carry an adhesive to a desired location to fix two or more parts together. In other embodiments the present invention may be used to provide a dielectric between two or more electrodes or contacts. In another embodiment, the present invention may be used in a chemo resistor device in which electrically resistive material is positioned between two or more electrodes or contacts. In another embodiment, the present invention may be used as an electrostatic actuator. The present invention may also be used with a mass sensor for gas chemical sensing applications. The present invention may also be used with other fluids and materials and in other applications, such as chemo-resistive fabrication and devices, chemo-capacitive fabrication and devices, applying adhesives for capping or otherwise connecting devices, and other applications. In addition, different materials and structures may be used with the present invention. For example, some embodiments are described in terms of particular materials, although different materials may also be used. Similarly, some of the embodiments herein show a particular number and orientation of material layers used to create the various parts of the present invention. Those examples are illustrative and not limiting, and different numbers and orientations of layers may be used with the present invention. Those and other variations of the present invention are possible.
The present invention may also include two or more devices formed in a single apparatus or on a single substrate. The single apparatus or substrate may contain several devices of the same type, or it may contain different types of devices. In some embodiments, the devices receive different materials in their respective target areas, and in some embodiments they receive the same materials. As a result, different testing, sensing, or other functions may be performed on a single structure.
These and other variations and modifications of the present invention are possible and contemplated, and it is intended that the foregoing specification and the following claims cover such modifications and variations. | Apparatuses, systems, and methods utilizing capillary action and to control the movement or placement of liquids or other materials in micro-devices and nano-devices. In some embodiments, the present invention may be used to control polymer addition to micro-cantilevers and nano-cantilevers for biological sensing, chemical sensing, and other sensing. In other embodiments, the present invention may be used to deliver adhesives, dielectrics, chemo resistor materials, and other materials to micro-devices and nano-devices. | 53,560 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the benefit of under 35 U.S.C. §109(e) of U.S. Provisional Patent Application No. 60/947,267 filed on Jun. 29, 2007, the disclosure of which is incorporated herein by reference.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
[0002] NOT APPLICABLE
REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISK
[0003] NOT APPLICABLE
BACKGROUND OF THE INVENTION
[0004] Since the mid-seventies, the prevalence of obesity has increased sharply for both adults and children. Data from two National Health And Nutrition Examination Surveys (NHANES) show that among adults aged 20-74 years the prevalence of obesity increased from 15.0% (in the 1976-1980 survey) to 32.9% (in the 2003-2004 survey). The two surveys also show increases in overweight among children and teens. For children aged 2-5 years, the prevalence of overweight increased from 5.0% to 13.9%; for those aged 6-11 years, prevalence increased from 6.5% to 18.8%; and for those aged 12-19 years, prevalence increased from 5.0% to 17.4%.
[0005] These increasing rates raise concern because of their implications for Americans' health. Being overweight or obese increases the risk of many diseases and health conditions, including the following: hypertension, dyslipidemia (for example, high total cholesterol or high levels of triglycerides), type 2 diabetes, coronary heart disease, stroke, gallbladder disease, osteoarthritis, sleep apnea and respiratory problems, and some cancers (endometrial, breast, and colon).
[0006] Obesity and its associated health problems have a significant economic impact on the U.S. health care system. Medical costs associated with overweight and obesity may involve direct and indirect costs. Direct medical costs may include preventive, diagnostic, and treatment services related to obesity. Indirect costs relate to morbidity and mortality costs. Morbidity costs are defined as the value of income lost from decreased productivity, restricted activity, absenteeism, and bed days. Mortality costs are the value of future income lost by premature death.
[0007] Electrical stimulation has been investigated as a treatment of obesity. Typically, such stimulation systems attempt to induce a desired outcome of reduced food intake and weight loss. However, many patients continue eating regardless of the electrical stimulation. Likewise, the human body is adept at becoming desensitized to continuous stimulation thereby reducing stimulation effectiveness over time.
[0008] Therefore, it would be desirable to provide an electrical stimulation system that is tailored to the needs of an individual patient, reduces the likelihood of desensitization, modifies behavior, and successfully leads to weight reduction. At least some of these objectives will be met with the present invention.
BRIEF SUMMARY OF THE INVENTION
[0009] A gastric stimulation system is provided for treating a patient, particularly by modifying behavior of the patient leading to excess weight loss. In some embodiments, such weight loss is achieved with a combination approach which includes two or more of the following: acute screening of the potential patients, gastric stimulation, induction of symptoms or specific behaviors and integration of patient management data into the treatment plan. Acute screening removes non-responders to gastric stimulation from the patient population. Such patients are more suitably treated with other methodologies. Gastric stimulation is provided to portions of the gastrointestinal tract, particularly the stomach, with the use of at least one electrode. A variety of gastric stimulation systems may be used, including stimulators that are endoscopically placed, laparoscopically placed or placed by modified or combination methods.
[0010] Symptoms or specific behaviors are induced by gastric stimulation in response to sensed parameters in the body. A primary example of such a sensed parameter is ingestion. If the stimulation system senses that ingestion has occurred, it is then determined whether ingestion is desirable. Desirability of ingestion is based on one or more factors which will also be discussed in detail in later sections. If the ingestion is determined to be undesirable, stimulation is provided at a level at or above a “stop eating threshold” SET for the patient that typically causes the patient to feel a displeasurable sensation or symptom, such as gastric discomfort such as to the extent of nausea, pain or vomiting. Such a displeasurable sensation is one which causes the patient to stop the undesired ingestion, thus a specific behavior has been induced. Since each patient may react differently to the same level of stimulation, the SET will be customized for each patient by prior testing of the patient's response to gastric stimulation. If the patient does not stop the undesired ingestion, the level of stimulation may be increased until cessation is reached.
[0011] In some embodiments, patient management data is integrated into the treatment plan. Patient management data may be collected and recorded by the gastric stimulator, either alone or in combination with gastric stimulation treatment. Such patient management data includes data related to activity levels, sleep patterns, eating patterns, caloric intake, etc. Since such data is recorded by the stimulation system, false reporting by the patient in a diary or log is avoided. Patient management data may be recorded prior to treatment with gastric stimulation so that such data may be used in formulation of an initial treatment plan. Or patient management data may be recorded during treatment to monitor the patient and track improvement.
[0012] In a first aspect of the present invention, a system is provided for use in providing gastric stimulation to a patient, wherein the system includes an ingestion sensor, a stimulator, and a processor coupled to the sensor and the stimulator. The processor is configured to determine an ingestion of material by the patient, a desirability of the ingestion by the patient, and a level of stimulation based on the determination of ingestion and the determination of desirability of ingestion. The processor then induces the stimulator to transmit the level of stimulation. In many embodiments, the ingestion sensor comprises a temperature sensor, however a variety of sensors may be used.
[0013] In some embodiments, the processor comprises a module for determining the level of stimulation, wherein the module for determining the level of stimulation selects a level of no stimulation in response to a determination that material has been ingested by the patient and a determination that ingestion by the patient is desirable. Optionally, the module for determining the level of stimulation selects a level of stimulation below a personal threshold for the patient in response to a determination that material has been ingested by the patient and a determination that ingestion by the patient is desirable. Or, in some instances, the module for determining the level of stimulation selects a level of stimulation at or above a personal threshold for the patient in response to a determination that material has been ingested by the patient and a determination that ingestion by the patient is undesirable. In such instances, the module for determining the level of stimulation may include code for increasing the level of stimulation until a desired response is given by the patient.
[0014] In some embodiments, the processor comprises a module for determining the desirability of ingestion by the patient that includes a module for determining if ingestion occurs during a meal window. Optionally, the system may further comprise a real time clock and such a real time clock may be adjustable by a global positioning system.
[0015] In some embodiments, the processor comprises a module for determining the desirability of ingestion by the patient that includes a module for determining whether the material has a desirable compositional property. In some instances, the sensor comprises a compositional sensor configured to sense the compositional property of the ingested material.
[0016] In some embodiments, the processor comprises a module for determining the desirability of ingestion by the patient that includes a module for determining if the patient has a desirable activity level. In such instances the system may further comprise a motion sensor configured to sense motion of the patient or sense position of the patient.
[0017] In some embodiments, the processor comprises a module for determining the desirability of ingestion by the patient that includes a module for determining if the duration of the meal is acceptable. In other embodiments, the processor comprises a module for determining the desirability of ingestion by the patient that includes a module for determining if the patient is sufficiently hungry. In such embodiments, the system may further include a pH sensor, pressure sensor, mechanical sensor, or a biochemical sensor.
[0018] In a second aspect of the present invention, a system is provided for use in providing gastric stimulation to a patient, the system comprising a stimulator, and a processor coupled to the stimulator. The processor is configured to determine if current time is within a meal window, and a level of stimulation based on the determination of whether the current time is within the meal window, the level of stimulation being below a stop eating threshold for the patient in response to a determination that the current time is within the meal window. The processor then induces the stimulator to transmit the level of stimulation.
[0019] In some embodiments, the system further comprises a real time clock configured to provide current time and the real-time clock may be adjustable by a global positioning system. Optionally, the processor may comprise a module for determining if current time is within a meal window, wherein this module compares the current time to a predetermined meal time schedule.
[0020] In some embodiments, the processor comprises a module for determining the level of stimulation, wherein the module for determining the level of stimulation selects a level of stimulation below the stop eating threshold for the patient in response to a determination that ingested material has a desirable compositional property and that the current time is within the meal window.
[0021] In another aspect of the present invention, a system is provided for use in providing gastric stimulation to a patient, the system comprising a compositional sensor configured to sense a compositional property of ingested material, a stimulator, and a processor coupled to the stimulator. The processor is configured to determine desirability of the compositional property of the ingested material, and a level of stimulation based on the determination of the desirability of the compositional property. The processor then induces the stimulator to transmit the level of stimulation.
[0022] In some embodiments, the processor comprises a module for determining the level of stimulation, wherein the module selects a level of stimulation at or above a stop eating threshold for the patient in response to a determination that the ingested material has an undesirable compositional property.
[0023] In yet another aspect of the present invention, a system is provided for use in providing gastric stimulation to a patient, the system comprising a processor and a memory coupled to the processor, the memory configured to store a plurality of code modules for execution by the processor. The plurality of code modules comprises a module for determining if material has been ingested by the patient, a module for determining desirability of ingestion by the patient, and a module for determining a level of stimulation based on the determination of ingestion and the determination of desirability of ingestion.
[0024] In still another aspect of the present invention, a method is provided for gastric stimulation of a patient, the method comprising determining if material has been ingested by the patient, determining desirability of the ingestion by the patient, determining a level of stimulation based on the determined ingestion and the determined desirability of ingestion, and applying the determined level of stimulation to the patient from a stimulator implanted in the patient.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 illustrates an embodiment of a stimulation system of the present invention.
[0026] FIG. 2 illustrates another embodiment of a stimulation system of the present invention.
[0027] FIG. 3 illustrates a flowchart depicting an example stimulation protocol.
[0028] FIGS. 4-5 illustrate example sensor information obtained from a temperature sensor within a stomach of a patient.
[0029] FIG. 6 provides an example flowchart illustrating steps involved in determining if material has been ingested.
[0030] FIG. 7 illustrates example temperature measurements stored in a buffer split into time periods.
[0031] FIG. 8 illustrates examples of additional determinations in the determination f whether ingestion is desirable.
[0032] FIG. 9 illustrates an example wherein the determination of whether ingestion is desirable comprises the determination of whether ingestion occurs within a meal window.
[0033] FIG. 10 illustrates an example stimulation protocol based on the flowchart of FIG. 3 using the determination of desirability of ingestion of FIG. 9 .
[0034] FIG. 11 illustrates an example wherein the determination of whether ingestion is desirable comprises the determination of whether the ingested material has a desirable compositional property.
[0035] FIG. 12 illustrates an example wherein the determination of whether ingestion is desirable comprises the determination of whether the patient has a desirable activity level.
[0036] FIG. 13 illustrates an example wherein the determination of whether ingestion is desirable comprises the determination of whether the duration of the meal is acceptable.
[0037] FIG. 14 illustrates an example wherein the determination of whether ingestion is desirable comprises the determination of whether the patient is sufficiently hungry.
[0038] FIG. 15 illustrates an example wherein the determination of whether ingestion is desirable comprises the determination of whether ingestion occurs within a meal window and optionally the combination of the determination of whether the ingested material has a desirable compositional property.
[0039] FIG. 16 illustrates an example wherein the determination of whether ingestion is desirable comprises the determination of whether the duration of the meal is acceptable and optionally the combination of determination of whether the ingested material has a desirable compositional property.
[0040] FIG. 17 illustrates an example wherein the determination of whether ingestion is desirable comprises the determination of whether the patient has a desirable activity level and optionally the combination of determination of whether ingestion occurred within a meal window.
[0041] FIG. 18 illustrates an example wherein the determination of whether ingestion is desirable comprises a determination of whether ingestion occurs within a meal window and optionally the combination of determination of whether the patient is sufficiently hungry.
[0042] FIG. 19 illustrates an example wherein the determination of whether ingestion is desirable comprises the determination of whether the patient is sufficiently hungry and the optional combination of the determination of whether the material has a desirable compositional property and further the optional combination of the determination of whether the patient has a desirable activity level.
[0043] FIG. 20 illustrates another example of a complex combination of determinations to determine desirability of ingestion.
[0044] FIG. 21 illustrates an embodiment wherein the determination of the level of stimulation is based on the determination of whether the current time is within a meal window.
[0045] FIG. 22 illustrates an embodiment wherein the determination of the level of stimulation is based on the determination of whether the current time is within a meal window and optionally on the determination of whether the material consumed has a desirable compositional property.
[0046] FIG. 23 illustrates an embodiment wherein the determination of the level of stimulation is based on the compositional desirability of ingested material.
DETAILED DESCRIPTION OF THE INVENTION
[0047] In most instances, patients suffering from obesity have diminished ability to self-manage their daily food intake. Patients often overeat, snack between meals and generally make poor food choices. Methods, systems and devices are provided for using gastric stimulation to assist management of food intake. Such assistance may eventually cause learning of behavioral patterns by the patient, leading to corrected self-management.
[0048] Patient management for obesity treatment may be established according to the following goals and objectives:
Reducing total quantity of food consumed during meals Reducing ingestion of food between meals Reducing binging of food Reducing intake of unhealthy foods Reducing eating when not hungry Increasing physical activity Improving sleeping patterns, such as duration and restfulness (deep sleep)
Each of these goals and objectives may be achieved with the use of gastric stimulation of the present invention in combination with various sensors.
[0056] Gastric stimulation may be achieved with the use of a variety of gastric stimulators, such as described in U.S. patent application Ser. Nos. 09/847,884 (U.S. Pat. No. 6,535,764), Ser. Nos. 10/109,296, 10/116,481, 10/691,880 (U.S. Pat. No. 7,020,531), Ser. Nos. 10/295,128, 10/290,788 (U.S. Pat. No. 7,016,735), Ser. Nos. 10/291,449, 10/295,115, 10/950,345, 10/888,218, 10/888,622, 10/992,382, 10/991,648, 11/256,264, 11/249,661, 11/249,290, 11/249,291, 11/281,234, 11/281,049, 60/815,640, each of which are incorporated herein by reference for all purposes. In some embodiments, the stimulator comprises electronic circuitry, optionally enclosed in a housing which may be implanted subcutaneously or attached to the stomach wall, and electronic leads that are coupled to the electronics circuitry. The leads include stimulating electrodes that are electrically couplable to the stomach wall. In some embodiments, the electronic circuitry includes a processor and a memory device having one or more code modules. The processor executes the one or more code modules to determine the level, duration and pattern of the stimulation. Typically, the electronic circuitry of the stimulator also includes a telemetry circuit for communication with separate devices, of which one may be for programming the stimulator's various operational parameters. It may be appreciated that memory may alternatively or additionally be located on the separate device.
[0057] An example stimulation system 1000 is illustrated in FIG. 1 . In this embodiment, the system 1000 comprises a stimulator 1100 which is implantable within an organ such as a stomach 12 , small intestine or colon. The stimulator 1100 comprises implantable electronic circuitry 1200 contained within an implantable pulse generator (IPG) 10 which typically has a protective housing 1300 . The housing 1300 is constructed of a corrosion resistant material, such as a material able to withstand implantation within a gastric environment. An IPG anchor 2000 is coupled to the IPG 10 and is configured to anchor the IPG 10 to a wall of the stomach. The stimulator 1100 also includes an electrode lead anchor 3000 comprising a first electrode 3200 and a return electrode 3250 . The electrodes 3200 , 3250 are coupled to the electronic circuitry 1200 through a flexible lead portion 3100 to a connector 1800 within header 1400 of housing 1300 . The electrode lead anchor 3000 is configured to anchor the electrode 3200 so that it is in electrical contact with, or in proximity to the stomach wall 12 . The electronic circuitry 1200 is configured to provide an electrically stimulating signal to a stomach wall via the electrodes 3200 , 3250 . While the electrodes 3200 , 3250 are shown in particular configurations and locations, numerous electrode configurations and positions are contemplated. An external computer or programmer 1500 may be used to program various stimulation parameters or other instructions into a memory device included with the electronic circuitry 1200 . The external programmer 1500 may be coupled to a telemetry device 1600 that communicates with the electronic circuitry via radio frequency signals.
[0058] FIG. 2 illustrates another example of a stimulation system. This embodiment includes a stimulator 20 having an implantable pulse generator (IPG) 21 implanted subcutaneously within a patient. The stimulator further comprises leads 22 a , 23 a extending from the IPG 21 through the abdomen and to the stomach S where electrodes 22 , 23 are implanted into the stomach muscle layer from the outside of the stomach S. The IPG 21 further comprises a sensor 24 a located on the IPG 21 and/or a sensor 24 b may be separate from the IPG and located elsewhere in the patient and coupled to the electronic circuitry 29 in the IPG by lead 24 c . The stimulator also includes sensors 25 , 26 , that are implanted on or in the stomach S, respectively, with leads 25 a , 26 a extending from the sensors 25 , 26 to the IPG 21 . Sensor 26 is exposed to the inside of the stomach S while sensor 25 is attached to the outside of the stomach. Leads 22 a , 23 a , 24 c , 25 a , 26 a are electrically coupled to the electronic circuitry 29 located in the IPG 21 .
[0059] The gastric stimulators include or are used with at least one sensor for sensing information. The sensors may be located on or extend from the IPG and/or the sensors may be located on or extend from a lead or other device. Alternatively or additionally, a sensor may be located separately on the stomach wall and/or a sensor may be otherwise positioned elsewhere within, coupled to or in communication with the patient. The sensors and other responsive elements may include but are not limited to a number of types of sensors and responsive elements and any combination thereof. When the sensors are implanted in the stomach, they may sense ingestion of material, presence of material in the stomach, composition of such material, temperature, pH or pressure within the stomach, and/or patient motion corresponding to respiration or gross movement. Sensors positioned on the stomach may also sense various parameters that indicate the actions of the stomach, e.g. movement, contractions. The sensors may also utilize various imaging techniques (e.g. ultrasound or spectroscopy (absorption of various wavelengths of light) to identify ingestion composition of material in the stomach.
[0060] Example sensors include a temperature sensor, a pH sensor, an optical sensor, a pressure sensor, a mechanical/contraction sensor, a biochemical sensor, an alcohol sensor, a motion sensor/accelerometer, and an impedance sensor, to name a few. The stimulation device may be programmed to deliver stimulation in response to sensed parameters and/or the sensors may sense a plurality of parameters in order to determine whether or not to stimulate or otherwise respond. Alternatively or in addition, the stimulation device may be programmed to record sensor data without delivering stimulation. Thus, the device may be used to monitor the activities of the patient, such as eating patterns, activity levels, sleep duration and sleep quality, food quality, etc. In some embodiments, such monitoring is used for a period of time prior to treatment so that the patient's normal habits are accurately recorded for proper analysis and creation of an appropriate treatment protocol. The device may then be reprogrammed to delivery stimulation according to the treatment protocol and/or sensed parameters. In other embodiments, the stimulation device monitors certain activities of the patient and records such sensor data while simultaneously responding to certain sensed parameters. For example, the stimulation device may record continuous sensor data reflecting activity levels to provide an “exercise diary” while stimulating in response to sensed ingestion of food as such ingestion occurs. In such an example, the exercise diary may be retrieved at a later date for review while the ingestion patterns are temporal and not retrievable. It may be appreciated that any sensor data may be recorded and stored in combination with any other sensor data that is not recorded and stored. Overall, sensing may be used or over time to identify patterns, diagnose diseases and evaluate effectiveness of various treatment protocols.
[0061] In the embodiment of FIG. 1 , circuitry 1200 , telemetry device 1600 , and external programmer 1500 are included in a data processing system of stimulation system 1000 . Similarly, in the embodiment of FIG. 2 , circuitry 29 may comprise a stand alone data processing system or may be configured to interface with one or more additional electronic components external of (and/or implanted at different locations within) the patient. Generally, the data processing systems included in embodiments of the invention may include at least one processor, which will typically include circuitry implanted in the patient, circuitry external of the patient, or both. When external processor circuitry is included in the data processing system, it may include one or more proprietary processor boards, and/or may make use of a general purpose desktop computer, notebook computer, handheld computer, or the like. The external processor may communicate with a number of peripheral devices (and/or other processors) via a bus subsystem, and these peripheral devices may include a data and/or programming storage subsystem or memory. The peripheral devices may also include one or more user interface input devices, user interface output devices, and a network interface subsystem to provide an interface with other processing systems and networks such as the Internet, an intranet, an Ethernet™, and/or the like. Implanted circuitry of the processor system may have some or all of the constituent components described above for external circuitry, with peripheral devices that provide user input, user output, and networking generally employing wireless communication capabilities, although hard-wired embodiments or other transcutaneous telemetry techniques could also be employed.
[0062] An external or implanted memory of the processor system will often be used to store, in a tangible storage media, machine readable instructions or programming in the form of a computer executable code embodying one or more of the methods described herein. The memory may also similarly store data for implementing one or more of these methods. The memory may, for example, include a random access memory (RAM) for storage of instructions and data during program execution, and/or a read only memory (ROM) in which fixed instructions are stored. Persistent (non-volatile) storage may be provided, and/or the memory may include a hard disk drive, a compact digital read only memory (CD-ROM) drive, an optical drive, DVD, CD-R, CD-RW, solid-state removable memory, and/or other fixed or removable media cartridges or disks. Some or all of the stored programming code may be altered after implantation and/or initial use of the device to alter functionality of the stimulator system.
[0063] The functions and methods described herein may be implemented with a wide variety of hardware, software, firmware, and/or the like. In many embodiments, the various functions will be implemented by modules, with each module comprising data processing hardware and/or software configured to perform the associated function. The modules may all be integrated together so that a single processor board runs a single integrated code, but will often be separated so that, for example, more than one processor board or chip or a series subroutines or codes are used. Similarly, a single functional module may be separated into separate subroutines or be run in part on separate processor chip that is integrated with another module. Hence, a wide variety of centralized or distributed data processing architectures and/or program code architectures may be employed within different embodiments.
[0064] The electronic circuitry comprises and/or is included within a controller or processor for controlling the operations of the device, including sensing, stimulating, signal transmission, charging and/or using energy from a battery device for powering the various components of the circuit, and the like. As such, the processor and battery device are coupled to each of the major components of the implanted circuit. In some embodiments, the electronic circuitry includes an internal clock. The internal clock may also include a real time clock component. The internal clock and/or real time clock may be used to control stimulation, e.g. by stimulating or allowing stimulation at a particular time of the day. The real time clock component may also provide a date/time stamp for detected events that are stored as information in a memory device. Optionally, the memory may be preserved by saving information corresponding to an event of interest which is saved along with the time/date when the event occurred.
[0065] The memory device is configured to store a plurality of code modules for execution by the processor. The code modules provide a variety of determinations based on sensor information and various other inputs, such as information from the internal clock, which are used to actuate a stimulation driver. The stimulation driver is coupled to the stimulating electrodes that are used to provide electrical stimulation.
[0066] Referring to FIG. 3 , a flowchart depicting a stimulation protocol of the present invention is provided. Here, the stimulation protocol begins with the determination of whether material has been ingested by the patient (step 100 ). Such a determination may be based on signals from one or more sensors, input from the patient, or other mechanisms as will be discussed in later sections. The memory device of the stimulator also includes a module for making such determination. If no ingestion has been determined, no stimulation will be provided (step 102 ). Thus, the stimulator remains quiet when the patient is not eating. This conserves energy and ultimately battery life. If it is determined that ingestion has occurred, it is then determined whether such ingestion is desirable (step 104 ). Desirability of ingestion is based on one or more factors which will also be discussed in detail in later sections. The memory device also includes a module for making this determination of desirability. If the ingestion is determined to be undesirable, stimulation is provided at a level at or above a “stop eating threshold” SET (step 106 ) for the patient that typically causes the patient to feel a displeasurable sensation, such as gastric discomfort such as to the extent of nausea, pain or vomiting. Such a displeasurable sensation is one which causes the patient to stop the undesired ingestion. Since each patient may react differently to the same level of stimulation, the SET will be customized for each patient by prior testing of the patient's response to gastric stimulation. If the patient does not stop the undesired ingestion, the level of stimulation may be increased until cessation is reached.
[0067] In some embodiments, if the ingestion is determined to be desirable, no stimulation is provided (step 108 ). Thus, the patient is able to eat without stimulation with the assumption that such ingestion is allowed. In other embodiments, if ingestion is determined to be desirable, stimulation is provided at a level below the SET (step 108 ) for the patient. Stimulation below the SET may include a variety of gastric sensations, including bloating, salivation, fullness, dyspepsia and early satiety. The intent of stimulating below the SET while the patient is consuming is to decrease the overall quantity of ingested material. Patients feel full sooner, curtail eating time and typically eat less when stimulated below the SET during consumption. This will also be described in detail in a later section.
[0068] It may be appreciated that the actual physical sensations associated with different levels of stimulation may vary from patient to patient and from incident to incident for the same patient. Also, a particular sensation, such as nausea, may be felt at a SET by one patient and not by another. Therefore, the SET is determined by patient behavior, rather than elicited sensations, and is established for an individual patient during a preliminary testing period. During use, stimulation is provided at, above or below the SET depending on the sensed behavior of the patient. If the desired resultant behavior is not attained, such as immediate cessation of eating, the stimulation can then be increased at that time to achieve the desired result.
[0069] Thus, in some embodiments, the memory device includes a module for determining a level of stimulation based on the determination of ingestion and the determination of desirability of ingestion.
[0000] Determining if Material has been Ingested
[0070] The determination of whether material has been ingested is based on sensor information from one or more ingestion sensors. In some embodiments, such sensor information is provided from a temperature sensor disposed at least partially within the stomach lumen so that temperature changes within the stomach can be sensed. For example, the ingestion of a hot beverage or meal item will immediately register an increase in temperature by the sensor as the sensor senses the presence of the hot ingested material. Likewise, ingestion of ice water or a cold meal item will register a decrease in temperature by the sensor. FIGS. 4-5 illustrate example sensor information obtained from a temperature sensor within a stomach of a patient during consumption of various foods. FIG. 4 illustrates temperatures detected while a patient consumes a meal. As shown, the patient begins by consuming a warm soup wherein a responsive temperature rise is shown. Throughout the meal, the patient eats food of various temperatures and drinks water of various temperatures with responsive changes in sensed temperature. Similarly, FIG. 5 illustrates temperatures detected while a patient consumes brunch. As shown, the patient eats food of various temperatures and drinks water of various temperatures with responsive changes in sensed temperature.
[0071] FIG. 6 provides an example flowchart illustrating steps involved in determining if material has been ingested (step 100 ). To begin, temperature is sampled at a predetermined rate (step 200 ). The sampling rate is high enough to capture fast transients yet conserves memory, processor time and power. In some embodiments, temperature is sampled at 6 second intervals. The temperature measurements are recorded to a buffer (step 202 ). The size of the buffer maximizes the accurate determination of ingestion of material yet conserves memory, computation requirements and resultant delay. In some embodiments, the buffer includes 32 samples, spanning the previous 3 minutes and 6 seconds. While temperature measurements are made every sampling period, determinations of ingestion are made less frequently. Thus, at each sampling time, a decision is made (step 204 ) as to whether it is time to determine if material has been ingested. If it is not time, then no action is taken until the next sample is acquired (step 206 ). If it is time, calculations are made to determine if an ingestion event ( 100 a ) has occurred.
[0072] In some embodiments, the calculations include splitting the temperature measurements in the buffer into three time periods ranging from oldest to newest. FIG. 7 illustrates example temperature measurements stored in the buffer split into a first time period 210 , a second time period 212 and a third time period 214 . In this embodiment, the average of the temperature measurements of the oldest or first time period 210 are calculated and compared to the temperature measurements of the second time period 212 . If the difference exceeds a predetermined threshold, it is determined that ingestion has occurred. Thus, referring to FIG. 6 , the processor would then proceed to the next code module which determines if the ingestion is desirable (step 104 ). If the difference does not exceed a predetermined threshold, it is determined that ingestion has not occurred. In such an instance, no stimulation would occur (step 102 ).
[0073] In some embodiments, the buffer of temperature measurements is used to differentiate between eating and drinking. In such embodiments, if it has been determined that ingestion has occurred, the processor then executes a code module which determines if eating has occurred or if drinking has occurred. In some embodiments, stimulation response is based on whether the patient is eating or drinking. For example, the response may be more aggressive in relation to eating than drinking. Thus, patients may be encouraged to consume beverages, such as water.
[0074] In some embodiments, temperature changes due to the sensing of ingested material are differentiated from common body temperature changes with the use of a plurality of temperature sensors. In such embodiments, at least one sensor is disposed within the stomach to measure temperature within, and at least one sensor is disposed outside of the stomach. For example, when the stimulator has a housing implanted subcutaneously within a patient, the sensor may be disposed on or within the housing. Any common body temperature changes would occur in both sensors while temperature changes due to ingestion would only affect the sensor within the stomach. Thus, temperature changes due to ingestion may be differentiated from general body temperature fluctuations.
[0075] It may be appreciated that other ingestion sensors may be used. Example ingestion sensors include pH sensors, mechanical sensors, strain gauges, contraction sensors, electrical sensors, impedance sensors, pressure sensors, biochemical sensors, optical emitters and sensors, and the like. The ingestion sensors may be used alone, in plurality or in any combination.
Determining if Ingestion is Desirable
[0076] The determination of whether ingestion is desirable is based on one or more additional determinations. Examples of such additional determinations are illustrated in FIG. 8 and include:
Determining whether ingestion occurs within a meal window (step 300 ) Determining whether ingested material has a desirable compositional characteristic (step 302 ) Determining whether the patient has a desirable activity level (step 304 ) Determining whether the duration of the meal is acceptable (step 306 ) Determining whether the patient is sufficiently hungry (step 308 )
These determinations 300 , 302 , 304 , 306 , 308 can each be used to determine if ingestion by the patient is desirable at any given time. Likewise, any combination of these determinations, or any combination of any subset of these determinations, can also be used to ultimately determine if ingestion is desirable. Example combinations of these determinations will be illustrated in a later section. Each type of determination will be described in more detail herein:
Meal Windows
[0082] FIG. 9 illustrates an example wherein the determination of whether ingestion is desirable (step 104 ) comprises the determination of whether ingestion occurs within a meal window (step 300 ). Meal windows may be predetermined for an individual patient to encourage eating during specific time periods and discourage eating outside of these time periods. For example, desired meal windows may include 8:00-8:30 am (breakfast), 12:00 pm-12:30 pm (lunch) and 6:00-6:30 pm (dinner). This may establish regular healthy eating patterns and diminish undesired habits, such as snacking between meals and late night eating. The predetermined meal time windows may also reduce binging or extending eating by providing a designated length of time within which the meal is to be consumed.
[0083] In these embodiments, the gastric stimulator includes a timer or internal clock, such as a real time clock. The clock may include time of day, day of week, date, year, or any combination, to name a few. The clock may have the capability of being set by the patient. However, to improve patient compliance, the clock may have a feature which restricts setting or resetting to specific individuals, such as with a code or key. Alternatively or in addition, the clock may be adjusted or calibrated to a specific time with the use of GPS or similar system. Such calibration may be useful during travel, such as crossing various time zones. The clock may also be used in creating a timestamp, e.g. recording the time in which an event occurred. Such an event may be a signal provided by a sensor, such as sensed ingestion. The timestamps may be stored in the memory device and used to record behavior of the patient. Thus, the gastric stimulator may used as a recorder to record the eating patterns of the patient prior to treatment. Such recording can be used to tailor the treatment protocol to the individual needs of the patient. The timestamps may also be used in the determinations by the processor, such as to determine the level of stimulation to provide at a given moment.
[0084] FIG. 10 illustrates an example stimulation protocol based on the flowchart of FIG. 3 using the determination of desirability of ingestion of FIG. 9 . A meal window 312 is illustrated within a time frame 314 . And, a stimulation strength or stimulation level curve 316 is illustrated in relation to the time frame 314 showing the changing levels of stimulation. The stimulation level may vary between baseline or no stimulation 320 and a maximum symptom threshold 322 . Various threshold levels may be established for an individual patient during a preliminary testing period. Example thresholds include a first symptom threshold 324 , which is determined based on the lowest stimulation which evokes a symptom such as gastric discomfort, and a SET 326 , which is determined based on the stimulation which causes the patient to immediately stop eating. Between the first symptom threshold 324 and the SET 326 resides a level of stimulation which reduces intake 328 by the patient.
[0085] In the example of FIG. 10 , the patient begins eating at the start of the meal window 312 . The processor executes the module for determining the level of stimulation based on the positive determination of ingestion, the real time clock, and the consequent positive determination of desirability of ingestion. The stimulation strength increases to the reduced food intake level 328 as illustrated by the stimulation level curve 316 a . This is maintained throughout the meal window 312 , and in this example, is raised slightly 316 b in anticipation of the end of the meal window 312 to further curtail eating. After the patient stops eating, the stimulation drops down to baseline. This can be sensor based or time based. If the ingestion is detected outside of the meal window 312 , the stimulation strength increases to the SET 326 as illustrated by the stimulation level curve 316 c . This causes the patient to immediately discontinue eating. It may be appreciated that immediateness may vary and is considered to be significantly shorter than a typical meal. Also, stimulation may be increased above the SET 326 to assist in the discontinuance of eating. Once ingestion is no longer sensed, the stimulation returns to baseline.
Compositional Properties
[0086] FIG. 11 illustrates an example wherein the determination of whether ingestion is desirable (step 104 ) comprises the determination of whether the ingested material has a desirable compositional property (step 302 ). A desirable compositional property is a property which is considered healthful or dietarily acceptable for a given patient. Most foods are compositionally complex materials made up of a variety of different chemical constituents. Their composition can be specified according to a variety of properties, such as specific atoms (e.g. carbon, hydrogen, oxygen, nitrogen, sodium, etc.), specific molecules (e.g. water, sucrose, tristearin, etc.), types of molecules, (e.g. fats, proteins, carbohydrates, fiber, minerals, etc.) or specific substances (e.g. peas, flour, milk, butter, peanuts, etc). In some embodiments, the present invention includes mechanisms and devices which identify one or more such properties of the ingested material. The mechanisms can be tailored to identify any of the above described properties depending on how the treatment protocol is designed. For example, a patient may be restricted from eating foods having a fat content over a predetermined amount. Or, a patient may be restricted from eating particular foods, such as butter, which are considered unhealthy. Or the patient may be allowed to consume beverages, such as water, which are considered to be healthy. In some instances, the patient may be allowed to consume low calorie artificial sweeteners but not sugar. Each of these properties of the ingested material may be determined and utilized in the determination of whether the ingestion is desirable. The consequent stimulation is then provided to the patient.
[0087] A variety of mechanisms and devices may be used for identifying such compositional properties and may be considered compositional sensors. In many embodiments, such mechanisms utilize spectroscopy, e.g. UV-visible, fluorescence, atomic, infrared, near-infrared (NIR) and nuclear magnetic resonance spectroscopes. Such mechanisms utilize interactions between electromagnetic radiation and matter. The type of mechanism based on spectroscopy depends on the nature of the energetic transitions involved, (e.g. electronic, vibration, rotation, translation, nuclear), the nature of the radiative process involved (e.g. absorption, emission, fluorescence) and the nature of the food matrix (e.g. absorbing, non-absorbing). These factors determine the wavelength or frequency of electromagnetic radiation used, the way that the electromagnetic radiation is generated and the way that the electromagnetic radiation is detected.
[0088] Thus, a variety of spectroscopic analyses and other mechanisms may be utilized in the present invention. Such mechanisms include known analytical procedures for characterizing food samples. Example procedures are used in major sectors of the food industry, including food manufacturers, ingredient suppliers, analytical service laboratories, government agencies (FDA, USDA, etc), and University research laboratories. For example, NIR spectroscopy is used routinely for the compositional, functional and sensory analysis of food ingredients, process intermediates and final products (“Near-infrared Spectroscopy in Food Analysis”, Encyclopedia of Analytical Chemistry , ed. Robert A. Meyers, John Wiley & Sons Ltd. ISBN 0471976709, incorporated herein by reference for all purposes).
[0089] In some embodiments, the determination of whether the ingested material has a desirable compositional property is based on the presence of one or more markers. Markers may be incorporated into prepackaged or prepared food that is designated for the patient to consume according to the treatment protocol. For example, a variety of current dietary programs include prepared meals, such as Jenny Craig®, Weight Watchers®, etc. The patient is instructed to consume the meals provided by the program according to a schedule in order to control the food quality and quantity that the patient eats. However, such programs do not prevent the patient from eating foods outside of the program and therefore rely on the discipline of the patient alone for success. The present invention provides markers within the food of the prepared meals and the markers are detected by sensors or other devices in communication with the gastric stimulator. If the ingested material does not include a detectable marker, the material is determined to not have a desirable compositional property and stimulation is delivered at or above the SET. If the ingested material does include a detectable marker, the material is determined to have a desirable compositional property and no stimulation is delivered or stimulation below the SET is delivered.
[0090] A variety of markers may be used. Example markers include any biocompatible markers, such as fluorescent markers, that are food-safe. Other types of markers include food-safe quantum dots, such as related to a Type 2 EviTag™ luminescent label (Evident Technologies; Troy, N.Y.).
Activity Level
[0091] FIG. 12 illustrates an example wherein the determination of whether ingestion is desirable (step 104 ) comprises the determination of whether the patient has a desirable activity level (step 304 ). In some embodiments, the patient is encouraged to increase activity levels to burn calories, build muscle tone, improve overall health, etc. During such activity, the patient may desire to consume liquids, such as water or a sports drink, or solid food, such as an energy bar. To assist in such encouragement and to ensure adequate hydration and sustenance for the patient during such exercise, the stimulation level may be determined based on the activity level of the patient. The activity level of the patient may be determined with the use of one or more of a variety of sensors, including an accelerometer.
[0092] In some embodiments, a 3-axis MEMS-type accelerometer is used. This accelerometer provides a voltage offset on each of the 3 axes, which can be used to determine position of the accelerometer, and, after calibration, position of the patient (e.g. lying down or standing upright). This accelerometer also provides an increased voltage from the offset based on motion. The level of this voltage can be used as an indication of the activity level of the patient (i.e. the voltage will be greater as the activity level increases).
[0093] In other embodiments, the activity level of the patient is determined using a 1- or 2-axis accelerometer, or a piezo sensor. Examples of such are those currently used in conventional pacemakers and defibrillators.
[0094] The activity sensor can also be used to monitor sleeping patterns, such as duration and restfulness. It has been found that some patients overeat to compensate for lack of sleep. Thus, sleep duration can be recorded with the use of the stimulation device and such information can be used in treatment of the patient. Alternatively, the stimulation device may be automatically shut off during periods of sensed sleep so as to conserve battery life.
Duration of Meal
[0095] FIG. 13 illustrates an example wherein the determination of whether ingestion is desirable (step 104 ) comprises the determination of whether the duration of the meal is acceptable (step 306 ). Limiting the duration of the meal may assist in reducing episodes of binging by the patient. Thus, a limit on the meal time may be set at, for example, 20 minutes after the commencement of the meal. Such limitations differ from meal windows in that the limit or “end time” for the meal is not based on the time of day or a predetermined sequence of meal times, but rather on duration of time since the commencement of the meal. Therefore, such binge control may be applied to patients who do not desire the restriction of eating at specific times of day but may benefit from meal time limitations. Such a feature essentially creates “moving meal windows”—a meal window created when the patient decides to ingest food.
[0096] Once ingestion has been detected, the event is time-stamped and stored by the memory device. This event begins the meal which is allowed a predetermined duration time. When ingestion of material is detected thereafter, the time elapsed since the commencement of the meal is compared to the predetermined duration time. If the time elapsed is less than the predetermined duration time, the duration of the meal is considered acceptable, and therefore the ingestion is considered desirable. No stimulation or stimulation below the SET ensues, per the sequence outlined in FIG. 3 . Once the time elapsed exceeds the predetermined duration time, the duration of the meal is considered unacceptable, and therefore ingestion is considered undesirable. Stimulation at or above the SET ensues, per the sequence outlined in FIG. 3 .
[0097] To ensure that the patient is not consuming meals back to back, each ingestion event may be time-stamped and stored by the memory device. The pattern of ingestion events is then used to determine which ingestion event marks the commencement of a meal.
[0098] In some embodiments, the commencement of a meal is indicated by the patient. The patient is given an activator that is positionable near or against the body. The patient presses a button on the activator, or similarly activates a switch, that triggers by telemetry the stimulation device to time stamp the event. In these embodiments, the patient may be instructed that, for example, four meals are allowed in a 24 hour period. They can use their meals at any time, however additional meals will not be allowed. Each of the meals are limited by the predetermined duration time and eating between meals is considered undesirable. Therefore, patients will be motivated to register the commencement of a meal to allow themselves a meal time. They will also be unmotivated to register too many meals back to back since, in this example, they know they are only allowed four meals per day. Such a system would be ideal for patients who have gained some level of self-regulation, such as through use of the gastric stimulator of the present invention, and can handle increased control over meal times but would still like assistance from the device.
Hunger Level
[0099] FIG. 14 illustrates an example wherein the determination of whether ingestion is desirable (step 104 ) comprises the determination of whether the patient is sufficiently hungry (step 308 ). Many patients eat for various reasons other than hunger, such habit, boredom, stress, anxiety, etc. Thus, patients tend to eat more often than they are hungry which can lead to weight gain. In addition, associations between these emotions and eating are formed which continues the pattern leading to continual weight gain. To break this cycle and retrain the patient to reduce eating when not sufficiently hungry, gastric stimulation may be governed at least in part by the level of patient hunger.
[0100] The level of patient hunger may be sensed by one or more sensors such as by a pH sensor, pressure sensor, mechanical/contraction sensor, or a biochemical sensor such as a leptin or ghrelin sensor, to name a few. In some embodiments, a blood glucose sensor is used. In other embodiments, acid secretion levels are sensed. In yet other embodiments, the start of slow waves that correlate with hunger are sensed.
[0101] In this embodiment, desirability of ingestion is dependent upon whether the patient is sufficiently hungry. When ingestion is detected, the processor executes the module for determining if the patient is sufficiently hungry which in turn determines if the ingestion is desirable. The processor then executes the module for determining the level of stimulation based on the positive determination of ingestion and the determination of desirability of ingestion, as illustrated in FIG. 3 .
Combinations
[0102] As mentioned previously, the above described determinations 300 , 302 , 304 , 306 , 308 , or any subset of these determinations, can be combined in any arrangement to ultimately determine if ingestion is desirable. FIGS. 15-20 illustrate some example combinations of these determinations. Such examples are illustrative and not considered to be limiting in scope of the present invention.
[0103] FIG. 15 illustrates an example wherein the determination of whether ingestion is desirable (step 104 ) comprises the determination of whether ingestion occurs within a meal window (step 300 ) and optionally the combination of the determination of whether the ingested material has a desirable compositional property (step 302 ). After it has been positively determined that material has been ingested (step 100 ), the processor then executes the module to determine whether the ingestion occurs within a meal window (step 300 ). If this is a negative determination (i.e. the patient is consuming outside of a meal window), the ingestion is considered undesirable and the patient is provided stimulation at or above the SET (step 106 ), per FIG. 3 . Thus, any eating outside of the meal window, regardless of the composition of the food, is restricted.
[0104] If there is a positive determination (i.e. the patient is consuming within the meal window (step 300 )), the processor then executes the module to determine if the material has a desirable compositional property (step 302 ). If so, the ingestion is considered desirable and the patient is provided with no stimulation or stimulation below the SET (step 108 ) per FIG. 3 . If not, the ingestion is considered undesirable and the patient is provided stimulation at or above the SET (step 106 ), per FIG. 3 . Thus, the patient must eat during a meal window and must eat food that is acceptable (e.g. healthy, prescribed, allowable, etc) to avoid stimulation at or above the SET.
[0105] FIG. 16 illustrates an example wherein the determination of whether ingestion is desirable (step 104 ) comprises the determination of whether the duration of the meal is acceptable (step 306 ) and optionally the combination of determination of whether the ingested material has a desirable compositional property (step 302 ). After it has been positively determined that material has been ingested (step 100 ), the processor then executes the module to determine whether the duration of the meal is acceptable (step 306 ). If this is a negative determination (i.e. the patient is binging or consuming beyond the predetermined duration of time), the ingestion is considered undesirable and the patient is provided stimulation at or above the SET (step 106 ), per FIG. 3 . Thus, any extended eating, regardless of the composition of the ingested material, is deterred.
[0106] If there is a positive determination (i.e. the patient is consuming within the acceptable duration of time ( 306 )), the processor then executes the module to determine if the material has a desirable compositional property (step 302 ). If so, the ingestion is considered desirable and the patient is provided with no stimulation or stimulation below the set (step 108 ) per FIG. 3 . If not, the ingestion is considered undesirable and the patient is provided stimulation at or above the SET (step 106 ), per FIG. 3 . Thus, the patient must eat within the acceptable duration of time and must eat food that is acceptable (e.g. healthy, prescribed, allowable, etc) to avoid stimulation at or above the SET.
[0107] FIG. 17 illustrates an example wherein the determination of whether ingestion is desirable (step 104 ) comprises the determination of whether the patient has a desirable activity level (step 304 ) and optionally the combination of determination of whether ingestion occurred within a meal window (step 300 ). After it has been positively determined that material has been ingested (step 100 ), the processor then executes the module to determine whether the patient activity level is desirable (step 304 ). If this is a positive determination (e.g. the patient is exercising), the ingestion is considered desirable and the patient is provided with no stimulation or stimulation below the SET (step 108 ) per FIG. 3 . Thus, any consumption during exercise is allowed.
[0108] If there is a negative determination (e.g. the patient is not exercising or sustaining a high enough level of activity), the processor then executes the module to determine if the ingestion is occurring within a meal window (step 300 ). If so, the ingestion is considered desirable and the patient is provided with no stimulation or stimulation below the set (step 108 ) per FIG. 3 . If not, the ingestion is considered undesirable and the patient is provided stimulation at or above the SET (step 106 ), per FIG. 3 . Thus, the patient may ingest at any time while maintaining a desirable activity level but is otherwise restricted to ingestion during meal windows. This allows the patient to readily consume water, sports drinks or other sustenance while exercising. This may also motivate the patient to exercise more.
[0109] FIG. 18 illustrates an example wherein the determination of whether ingestion is desirable (step 104 ) comprises a determination of whether ingestion occurs within a meal window (step 300 ) and optionally the combination of determination of whether the patient is sufficiently hungry ( 308 ). After it has been positively determined that material has been ingested (step 100 ), the processor then executes the module to determine whether the ingestion occurs within a meal window (step 300 ). If this is a positive determination, (i.e. the patient is consuming within a meal window), the ingestion is considered desirable regardless of actual hunger levels. If this is a negative determination (i.e. the patient is consuming outside of a meal window), it is then determined whether the patient is sufficiently hungry (step 308 ). If so, the ingestion is considered desirable and the patient is provided with no stimulation or stimulation below the SET (step 108 ) per FIG. 3 . If not, the ingestion is considered undesirable and the patient is provided stimulation at or above the SET (step 106 ), per FIG. 3 . Thus, the patient is not deterred from eating outside of meal windows if sufficiently hungry. However, emotional eating or other non-hunger related eating is deterred.
[0110] FIG. 19 illustrates an example wherein the determination of whether ingestion is desirable (step 104 ) comprises the determination of whether the patient is sufficiently hungry (step 308 ), and the optional combination of the determination of whether the material has a desirable compositional property (step 302 ), and further the optional combination of the determination of whether the patient has a desirable activity level (step 304 ). After it has been positively determined that material has been ingested (step 100 ), the processor then executes the module to determine whether the patient is sufficiently hungry (step 308 ). If this is a negative determination, the ingestion is considered undesirable and the patient is provided stimulation at or above the SET (step 106 ), per FIG. 3 . Thus, eating while not sufficiently hungry is undesired regardless of other conditions.
[0111] If this is a positive determination (i.e. the patient is sufficiently hungry), the processor then executes the module to determine if the ingested material has a desirable compositional property (step 302 ). If so, the ingestion is considered desirable and the patient is provided with no stimulation or stimulation below the SET (step 108 ) per FIG. 3 . If not, the processor then executes the module to determine whether the patient has a desirable level of activity (step 304 ). If so, the ingestion is considered desirable and the patient is provided with no stimulation or stimulation below the SET (step 108 ) per FIG. 3 . If not, the ingestion is considered undesirable and the patient is provided stimulation at or above the SET (step 106 ), per FIG. 3 . Thus, if the patient has a desirable activity level, the material may be consumed regardless of the desirability of a compositional property. However, desirable activity level does not override lack of hunger. It may be appreciated that combinations of any complexity may be used to determine desirability of ingestion.
[0112] For example, FIG. 20 illustrates another example of a complex combination of determinations to determine desirability of ingestion (step 104 ). Here the determination of whether ingestion is desirable (step 104 ) comprises the determination of whether the ingestion occurs within a meal window (step 300 ), the optional combination of determining if the duration of the meal is acceptable (step 306 ), and further the optional combination of whether the material has a desirable compositional property (step 302 ) and whether the patient has a desirable activity level (step 304 ).
[0113] After it has been positively determined that material has been ingested (step 100 ), the processor then executes the module to determine whether the ingestion occurs within a meal window (step 300 ). If so, the processor then executes the module to determine if the duration of the meal is acceptable (step 306 ). Such combination may be useful in situations wherein the meal window is quite large. For example, the patient may be allowed a 2 hour meal window but may only be allowed 20 minutes to eat the meal. This allows the patient flexibility in planning time for a meal yet provides for binge control once the meal has commenced. If the duration of the meal is determined to be acceptable, the processor then executes the module to determine whether the material has a desirable compositional property (step 302 ). If this also has a positive determination, the ingestion is considered desirable and the patient is provided with no stimulation or stimulation below the SET (step 108 ) per FIG. 3 .
[0114] If the determination was negative for any of steps 300 , 306 , 302 , the processor then executes the module to determine if the patient has a desirable activity level (step 304 ). If so, the ingestion is considered desirable and the patient is provided with no stimulation or stimulation below the set (step 108 ) per FIG. 3 . Thus, regardless of meal windows, meal duration and material composition, a patient can override these decisions, in this example, with a desirable activity level, such as exercise. However, if the activity level is determined to be undesirable, the patient is provided stimulation at or above the SET (step 106 ), per FIG. 3 .
Other Sequences
[0115] The above described embodiments involve determining a level of stimulation based on the determination of ingestion and the determination of desirability of ingestion. Other embodiments are provided wherein determining the level of stimulation is based on other determinations.
[0116] For example, FIG. 21 illustrates an embodiment wherein the determination of the level of stimulation is based on the determination of whether the current time is within a meal window (step 400 ). Thus, stimulation does not rely on determining if material has been ingested. Instead, the processor executes a module in the memory device which determines if the current time is within a meal window (e.g. with the use of a real time clock). At any time outside of a meal window, no stimulation is provided to the patient (step 402 ). Once the meal window has begun, the patient is stimulated at a level below the SET (step 404 ). Thus, while the patient is eating, the patient's total eating is curtailed due to the stimulation. Such an embodiment may be useful for patients in controlled eating environments wherein meals are provided at designated times. Such an embodiment may also be useful for patients who have gained a level of self-regulation and simply desire assistance during meals.
[0117] Another example, illustrated in FIG. 22 , is also based on the determination of whether the current time is within a meal window (step 400 ). Here, again at any time outside of a meal window, no stimulation is provided to the patient (step 402 ). Once the meal window has begun, the processor executes a module to determine if material consumed has a desirable compositional property (step 302 ). If so, the patient is stimulated at a level below the SET (step 404 ). If not, the patient is stimulated at a level at or above the SET (step 406 ). Thus, the patient is deterred from eating unhealthy or undesired food during the meal window but can continue eating compositionally desirable food with stimulation control.
[0118] FIG. 23 illustrates an embodiment which does not rely on meal windows or determinations of whether material has been ingested. Here, the patient is monitored for compositional desirability of ingested material. Such monitoring may be achieved with the use of any of the sensors or devices described above to determine compositional desirability. Monitoring may be continuous or in intervals. When material having an undesirable compositional property is detected, stimulation is provided at a level at or above the SET (step 406 ). At all other times, no stimulation (step 402 ) is provided. Such an embodiment may be useful for patients wishing to improve their dietary food choices, rather than regulating quantity and timing of intake.
Levels of Stimulation
[0119] As described above, a “stop eating threshold” or SET is established for each patient. The SET is the level of stimulation that typically causes the patient to stop ingesting. This is typically due to a displeasurable sensation, such as gastric discomfort. The actual symptoms may vary but may include nausea, pain or vomiting. In some instances, lesser symptoms may cause a cessation of eating, including but not limited to dyspepsia, fullness, bloating, etc. In some embodiments, the stimulation is varied by pulse width and amplitude until the patient becomes symptomatic. In patients that are initially responsive to a given pulse width, the patient typically becomes more symptomatic as amplitude is increased while the pulse width remains constant. In such instances, the amplitude is increased until the patient stops ingesting, therefore establishing the SET. The following data set shows two examples wherein pulse amplitude and pulse duration are paired appropriately to establish a SET:
[0000]
Stimulation Scenario #1
Stimulation Scenario #2
Pulse width
0.3
msec
1.0
msec
Amplitude
9
mA
14
mA
[0120] A SET may be attained with many combinations of pulse amplitude and pulse duration. In general, shorter pulse widths may require a higher pulse amplitude to establish a SET and longer duration pulse widths may require a lower pulse amplitude to establish a similar SET. In some embodiments, the amplitude is in the range of approximately 1-16 mA or approximately 1-20 mA. And in some embodiments, the pulse width is in the range of approximately 50-1000 μseconds. It may be appreciated that the SET may be alternatively or additionally established by other aspects of the stimulation signal. For example, pulse frequency, burst length, burst cycle (i.e. time on vs. time off), waveform composition (e.g. ramping up or ramping down a variable such as amplitude), etc.
[0121] Once the SET is established for each patient, the SET is stored in the memory device and utilized by the processor to provide stimulation to the patient. If by chance the patient does not respond appropriately to the SET once the gastric stimulator is in use, the stimulation level may be increased until the desired result is achieved (e.g. cessation of eating). Such increase may be gradual so as to reach the minimum stimulation level that causes the desired result. In some embodiments, the increased SET may be stored in the memory to replace the previous SET. This may overcome any adaptation or changes in patient response over time. A history of SET thresholds may be stored in the device to track the potential changes in this parameter. Historical tracking of the SET may be valuable in understanding a patient's potential adaptation to long-term gastric stimulation. Further, analysis of SET thresholds over time may reveal an association between certain patient conditions such as diabetes or other co-morbidities and the change in SET thresholds over time. This information may further fine-tune the patient selection process to identify those patients best suited for long-term gastric stimulation therapy.
[0122] As described above, the patient may be stimulated at a level below the SET to curtail consumption, such as during a meal. In some embodiments, this stimulation level has a signal with the same pulse width as the SET and an amplitude reduced by a percentage, such as approximately 10-50%, particularly approximately 25%. This level of stimulation may reduce the food consumed by weight at a meal by a percentage, such as 5-50%. Stimulation at this level typically causes the patient to feel full sooner, curtail eating time and therefore typically eat less. In some instances, such stimulation may also suppress eating at other times of day when no stimulation is provided. Thus, the effects of such stimulation may be more global and far reaching for some patients leading to successful weight loss and more healthy eating habits.
[0123] Although the foregoing invention has been described in some detail by way of illustration and example, for purposes of clarity of understanding, it will be obvious that various alternatives, modifications and equivalents may be used and the above description should not be taken as limiting in scope of the invention which is defined by the appended claims. | Gastric stimulation systems and methods are provided for treating a patient, particularly by modifying behavior of the patient leading to excess weight loss. In some embodiments, such weight loss is achieved with a combination approach which includes two or more of the following: acute screening of the potential patients, gastric stimulation, induction of symptoms or specific behaviors and integration of patient management data into the treatment plan. Gastric stimulation is provided to portions of the gastrointestinal tract, particularly the stomach, with the use of at least one electrode. A variety of gastric stimulation systems may be used, including stimulators that are endoscopically placed, laparoscopically placed or placed by modified or combination methods. | 76,937 |
Background of the Invention
[0001] 1. Field of the Invention
[0002] The present invention relates to conformationally constrained parathyroid hormone (PTH) analogs, and methods of preparing and using the PTH analogs.
[0003] 2. Background Art
[0004] Parathyroid Hormone
[0005] Parathyroid hormone (PTH), an 84 amino acid peptide, is the principal regulator of ionized blood calcium in the human body (Kronenberg, H. M., et al., In Handbook of Experimental Pharmacology, Mundy, G. R., and Martin, T. J., (eds), pp. 185-201, Springer-Verlag, Heidelberg (1993)). Regulation of calcium concentration is necessary for the normal function of the gastrointestinal, skeletal, neurologic, neuromuscular, and cardiovascular systems. PTH synthesis and release are controlled principally by the serum calcium level; a low level stimulates and a high level suppresses both hormone synthesis and release. PTH, in turn, maintains the serum calcium level by directly or indirectly promoting calcium entry into the blood at three sites of calcium exchange: gut, bone, and kidney. PTH contributes to net gastrointestinal absorption of calcium by favoring the renal synthesis of the active form of vitamin D. PTH promotes calcium resorption from bone indirectly by stimulating differentiation of the bone-resorbing cells, osteoclasts. It also mediates at least three main effects on the kidney: stimulation of tubular calcium reabsorption, enhancement of phosphate clearance, and promotion of an increase in the enzyme that completes synthesis of the active form of vitamin D. PTH is thought to exert these effects primarily through receptor-mediated activation of adenylate cyclase and/or phospholipase C.
[0006] Disruption of calcium homeostasis may produce many clinical disorders (e.g., severe bone disease, anemia, renal impairment, ulcers, myopathy, and neuropathy) and usually results from conditions that produce an alteration in the level of parathyroid hormone. Hypercalcemia is a condition that is characterized by an elevation in the serum calcium level. It is often associated with primary hyperparathyroidism in which an excess of PTH production occurs as a result of a parathyroid gland lesion (e.g., adenoma, hyperplasia, or carcinoma). Another type of hypercalcemia, humoral hypercalcemia of malignancy (HHM) is the most common paraneoplastic syndrome. It appears to result in most instances from the production by tumors (e.g., squamous, renal, ovarian, or bladder carcinomas) of a class of protein hormone which shares amino acid homology with PTH. These PTH-related proteins (PTHrP) appear to mimic certain of the renal and skeletal actions of PTH and are believed to interact with the PTH receptor in these tissues.
[0007] Osteoporosis
[0008] Osteoporosis is a potentially crippling skeletal disease observed in a substantial portion of the senior adult population, in pregnant women and even in juveniles. The term osteoporosis refers to a heterogeneous group of disorders. Clinically, osteoporosis is separated into type I and type II. Type I osteoporosis occurs predominantly in middle aged women and is associated with estrogen loss at menopause, while osteoporosis type II is associated with advancing age. Patients with osteoporosis would benefit from new therapies designed to promote fracture repair, or from therapies designed t6 prevent or lessen the fractures associated with the disease.
[0009] The disease is marked by diminished bone mass, decreased bone mineral density (BMD), decreased bone strength and an increased risk of bone fracture. At present, there is no effective cure for osteoporosis, though estrogen, calcitonin and the bisphosphonates, etidronate and alendronate are used to treat the disease with varying levels of success. These agents act to decrease bone resorption. Since parathyroid hormone regulates blood calcium and the phosphate levels, and has potent anabolic (bone-forming) effects on the skeleton, in animals (Shen, V., et al., Calcif Tissue Int. 50:214-220 (1992); Whitefild, J. F., et al., Calcif Tissue Int. 56:227-231 (1995) and Whitfield, J. F., et al., Calcif Tissue Int. 60:26-29 (1997)) and humans (Slovik, D. M., et al., J. Bone Miner. Res. 1:377-381 (1986); Dempster, D. W., et al., Endocr. Rev. 14:690-709 (1993) and Dempster, D. W., et al., Endocr. Rev. 15:261 (1994)) when administered intermittently, PTH, or PTH derivatives, are prime candidates for new and effective therapies for osteoporosis.
[0010] PTH Derivatives
[0011] PTH derivatives include polypeptides that have amino acid substitutions or are truncated relative to the full length molecule. Both a 14 and a 34 amino acid amino-terminal truncated form of PTH, as well as a C-terminal truncated form have been studied. Additionally, amino acid substitutions within the truncated polypeptides have also been investigated.
[0012] Synthetic PTH(1-34) exhibits full bioactivity in most cell-based assay systems, has potent anabolic effects on bone mass in animals and has recently been shown to reduce the risk of bone fracture in postmenopausal osteoporotic women (Neer, R. M., et al., N.E.J.M. 344:1434-1441 (2001); Dempster, D. W., et al., Endocr Rev 14:690-709 (1993)). PTH acts on the PTH/PTHrP receptor (P1R), a class II G protein-coupled heptahelical receptor that couples to the adenylyl cyclase/CAMP and phospolipase C/inositol phosphate (IP) signaling pathway (Rippner, H., et al., Science 254:1024-1026 (1991)). Deletion analysis studies have shown that the amino-terminal residues of PTH play a crucial role in stimulating the P1 R to activate the cAMP and IP signaling pathways (Tregear, G. W., et al., Endocrinology 93:1349-1353 (1973); Takasu, H., et al., Biochemistry 38:13453-13460(1999)). Crosslinking and receptor mutagenesis studies have indicated that residues in the amino-terminal portion of PTH interact with the extracellular loops and extracellular ends of the seven transmembrane helices, which reside within the juxtamembrane region of the receptor (Bergwitz, C., et al., J. Biol. Chem. 271:26469-26472 (1996); Hoare, S. R. J., et al., J. Biol. Chem 276:7741-7753 (2001); Behar, V., et al., J. Biol. Chem. 275:9-17 (1999); Shimizu, M., et al., J. Biol. Chem. 275:19456-19460(2000); Luck, M. D., et al., Molecular Endocrinology 13:670-680 (1999)).
BRIEF SUMMARY OF THE INVENTION
[0013] The invention provides novel PTH polypeptide derivatives containing amino acid substitutions at selected positions in the polypeptides. The derivatives function as full, or nearly full, agonists of the PTH-1 receptor. Because of their unique properties, these polypeptides have a utility as drugs for treating human diseases of the skeleton, such as osteoporosis.
[0014] The invention provides derivatives of PTH(1-21), PTH(1-20), PTH(1-19), PTH(1-18),PTH(1-17), PTH(1-16), PTH(1-15), PTH(1-14), PH(1-13), PTH(1-12), PTH(1-11) and PTH(1-10) polypeptides, wherein at least one residue in each polypeptide is a helix, preferably an α-helix, stabilizing residue. The invention also provides methods of making such peptides. Further, the invention encompasses compositions and methods for use in limiting undesired bone loss in a vertebrate at risk of such bone loss, in treating conditions that are characterized by undesired bone loss or by the need for bone growth, e.g. in treating fractures or cartilage disorders and for raising cAMP levels in cells where deemed necessary.
[0015] In one aspect, the invention is directed to a biologically active peptide consisting essentially of X 01 ValX 02 GluIleGlnLeuMetHisX 03 X 04 X 05 X 06 X 07 (SEQ ID NO: 1), wherein X 01 is an α-helix-stabilizing residue, desaminoGly, desaminoSer or desaminoAla; X 02 is an α-helix-stabilizing residue, Ala, or Ser; X 03 is Ala, Gln or Asn; X 04 is Arg, Har or Leu; X 05 is an α-helix-stabilizing residue, Ala or Gly; X 06 is an α-helix-stabilizing residue or Lys; and X 07 is an α-helix-stabilizing residue, Trp or His: and wherein at least one of X 01 , X 02 , X 03 , X 04 , X 05 , X 06 or X 07 is an α-helix-stabilizing residue.
[0016] In another aspect, the invention relates to SEQ ID NO: 1, wherein the α-helix-stabilizing amino acid is selected from the group consisting of Aib, ACPC (1-aminocyclopropylcarboxylic acid), DEG (diethylglycine) and 1-aminocyclopentanecarboxylic acid. In another aspect, the invention relates to SEQ ID NO: 1, wherein the α-helix-stabilizing amino acid is Aib.
[0017] The invention is further drawn to fragments ofthe peptide of SEQ ID NO: 1, in particular X 01 ValX 02 GluIleGlnLeuMetHisX 03 X 04 X 05 X 06 (SEQ ID NO: 12), X 01 ValX 02 GluIleGlnLeuMetHisX 03 X 04 X 05 (SEQ ID NO: 13), X 01 ValX 02 GluIleGlnLeuMetHisX 03 X 04 (SEQ ID NO: 14) and X 01 ValX 02 GluIleGlnLeuMetHisX 03 (SEQ ID NO: 15). The invention further encompasses pharmaceutically acceptable salts of the above-described peptides, and N- or C-derivatives of the peptides. A preferable embodiment of the invention is drawn to any of the above recited polypeptides, wherein the polypeptide contains a C-terminal amnide.
[0018] In addition, the invention is drawn to a biologically active polypeptide consisting essentially of AibValAibGluIleGlnLeuNleHisGlnHarAlaLysTrpLeu-AlaSerValArgArtTyr (SEQ ID NO. 8); fragments thereof, containing amino acids 1-20, 1-19, 1-18, 1-17, 1-16 or 1-15; pharmaceutically acceptable salts thereof; or N- or C-derivatives thereof.
[0019] The invention is further drawn to any of the above polypeptides labeled with a label selected from the group consisting of: a radiolabel, a flourescent label, a bioluminescent label, or a chemiluminescent label. In a preferable embodiment the radiolabel is 125 I or 99m Tc.
[0020] Preferred embodiments of the biologically active peptide include: AibValSerGluIleGlnLeuMetHisAsnLeuGlyLysHis (SEQ ID NO. 2); desamino-AlaValAibGluIleGlnLeuMetHisAsnLeuGlyLysHis (SEQ ID NO. 3); desamino-SerValAibGluIleGlnLeuMetHisAsnLeuGlyLysHis (SEQ ID NO. 4); desamino-GlyValAibGluIleGlnLeuMetHisAsnLeuGlyLysHis (SEQ ID NO. 5); AibValAibGluIleGlnLeuMetHisGlnHarAlaLysTrp (SEQ ID NO. 6); AibValAibGluIleGlnLeuMetHisAsnLeuGlyLysHis (SEQ ID NO. 7); AibValAlaGluIleGlnLeuMetHisGlnHarAlaLysTrp (SEQ ID NO. 9); AlaValAibGluIleGlnLeuMetHisGlnHarAlaLysTrp (SEQ ID NO. 10); SerValAibGluIleGffi uMetHisGlnHarAlaLysTrp (SEQ ID NO. 11); and AibValAibGluIleGlnLeuMetHisGlnHar (SEQ ID NO. 16). It is contemplated that fragments of the above mentioned peptides, containing amino acids 1-10, 1-11, 1-12 or 1-13, are also embodiments of the present invention. The invention further encompasses pharmaceutically acceptable salts of the above-described peptides, and N- or C-derivatives of the peptides.
[0021] Other constrained amino acids that are substituted for Aib are ACPC (1-aminocyclopropylcarboxylic acid), DEG (diethylglycine) and 1-aminocyclopentanecarboxylic acid.
[0022] In accordance with yet a further aspect of the invention, this invention also provides pharmaceutical compositions comprising a PTH derivative and a pharmaceutically acceptable excipient and/or a pharmaceutically acceptable solution such as saline or a physiologically buffered solution.
[0023] This invention also provides a method for treating mammalian conditions characterized by decreases in bone mass, which method comprises administering to a subject in need thereof an effective bone mass-increasing amount of a biologically active PTH polypeptide. A preferable embodiment of the invention is drawn to conditions such as osteoporosis. The types of osteoporosis include, but are not limited to old age osteoporosis and postmenopausal osteoporosis. Additional preferable embodiments include using an effective amounts of the polypeptide of about 0.01 μg/kg/day to about 1.0 μg/kg/day wherein the polypeptide is administered parenterally, subcutaneously or by nasal insufflation.
[0024] In accordance with yet a further aspect of the invention, this invention also provides a method for determining rates of bone reformation, bone resorption and/or bone remodeling comprising administering to a patient an effective amount of a labeled PTH polypeptide, such as for example, SEQ ID NO: 1 or a derivatives thereof and determining the uptake of the peptide into the bone of the patient. The peptide is labeled with a label selected from the group consisting of: radiolabel, flourescent label, bioluminescent label, or chemiluminescent label. An example of a suitable radiolabel is 99m Tc.
[0025] The invention is further related to a method of increasing cAMP in a mammalian cell having PTH-1 receptors, the method comprising contacting the cell with a sufficient amount of the polypeptide of the invention to increase cAMP.
[0026] The invention also provides derivatives of rat PTH(1-34) (rPTH(1-34)) given by AlaValSerGluIleGlnLeuMetHisAsnLeuGlyLysHisLeuAlaSerValGluArg MetGlnTrpLeuArgLysLysLeuGlnAspValHisAsnPhe (SEQ ID NO: 30), and of human PTH(1-34) (hPTH(1-34)) given by SerValSerGluIleGlnLeuMetHisAsn LeuGlyLysHisLeuAsnSerMetGluArgValGluTrpLeuArgLysLysLeuGlnAspVal HisAsnPhe (SEQ ID NO: 31).
[0027] In another aspect, the invention relates to a biologically active peptide consisting essentially ofthe formula X 01 ValX 02 GluIleGlnLeuX 03 HisX 04 X 05 X 06 X 07 X 08 LeuX 09 SerX 10 X 11 ArgX 12 X 13 TrpLeuArgLysLysLeuGlnAspValHisAsnX 14 (SEQ ID NO: 19) wherein X 01 is an α-helix-stabilizing residue, desaminoGly, desaminoSer or desaminoAla; X 02 is an α-helix-stabilizing residue, Ala, or Ser; X 03 is Met or Nle; X 04 is Ala, Gln or Asn; X 05 is Arg, Har or Leu; X 06 is an α-helix-stabilizing residue, Ala or Gly; X 07 is an α-helix-stabilizing residue or Lys; X 08 is an α-helix-stabilizing residue, Trp or His; X 09 is Ala or Asn; X 10 is Met or Val; X 11 is Arg or Glu; X 12 is Met or Val; X 13 is Gln or Glu; X 14 is Tyr or Phe; and wherein at least one of X 01 , X 02 , X 06 , X 7 , or X 08 is an α-helix-stabilizing residue. The invention also relates to fragments thereof, containing amino acids 1-33, 1-32, 1-31, 1-30, 1-29, 1-28, 1-27, 1-26, 1-25, 1-24, 1-23, 1-22, 1-21, 1-20, 1-19, 1-18, 1-17, 1-16, 1-15, 1-14, 1-13, 1-12, or 1-11. The invention also relates to pharmaceutically acceptable salts and N- or C-derivatives of SEQ ID NO: 19 or the above described fragments.
[0028] In another aspect, the invention relates to SEQ ID NO: 19, wherein the α-helix-stabilizing amino acid is selected from the group consisting of Aib, ACPC (1-aminocyclopropylcarboxylic acid), DEG (diethylglycine) and 1-aminocyclopropylcarboxylic acid. In another aspect, the invention relates to SEQ ID NO: 19, wherein the α-helix-stabilizing amino acid is Aib.
[0029] In another aspect, the invention relates specifically to the following peptides: AibValSerGluIleGlnLeuMetHisAsnLeuGlyLysHisLeuX 09 Ser 10 X 11 Arg X 12 X 13 TrpLeuArgLysLysLeuGlnAspValHisAsnX 14 (SEQ ID NO. 20); desaminoAlaValAibGluIleGlnLeuMetHisAsnLeuGlyLysHis LeuX 09 SerX 10 X 11 ArgX 12 X 13 Trp LeuArgLysLysLeuGlnAspValHisAsnX 14 (SEQ ID NO. 21); desaminoSerValAibGluIleGlnLeuMetHisAsnLeuGlyLysHis LeuX 09 SerX 10 X 11 ArgX 12 X 13 Trp LeuArgLysLysLeuGlnAspValHisAsnX 14 (SEQ ID NO. 22); desaminoGlyValAibGluIleGlnLeuMetHisAsnLeuGlyLysHisLeu X 09 SerX 10 X 11 ArgX 12 X 13 Trp LeuArgLysLysLeuGlnAspValHisAsnX 14 (SEQ ID NO. 23); AibValAibGluIleGlnLeuMetHisGlnHarGlyLysTrpLeuX 09 Ser X 10 X 11 ArgX 12 X 13 Trp LeuArgLysLysLeuGlnAspValHisAsnX 14 (SEQ ID NO. 24); AibValAibGluIleGlnLeuMetHisAsnLeuGlyLysHisLeuX 09 Ser X 10 X 11 ArgX 12 X 13 Trp LeuArgLysLysLeuGlnAspValHisAsnX 14 (SEQ ID NO. 25); AibValAlaGluIleGlnLeuMetHisGlnHarAlaLysTrpLeuX 09 SerX 10 X 11 ArgX 12 X 13 Trp LeuArgLysLysLeuGlnAspValHisAsnX 14 (SEQ ID NO. 26); AlaValAibGluIleGlnLeuMetHisGlnHarAlaLysTrpLeuX 09 SerX 10 X 11 ArgX 12 X 13 TrpLeuArgLysLysLeuGlnAspValHisAsn X 14 (SEQ ID NO. 27); and SerValAibGluIleGlnLeuMetHisGlnHarAlaLysTrpLeu X 09 Ser X 10 X 11 ArgX 12 X 13 Trp LeuArgLysLysLeuGlnAspValHisAsnX 14 (SEQ ID NO. 28). X 09 , X 10 , X 11 , X 12 , X 13 and X 14 have the same meaning as defined for SEQ ID NO: 19. The invention also relates to pharmaceutically acceptable salts or N- or C-derivatives of the above peptides.
[0030] The invention also relates to a biologically active peptide consisting essentially of the formula AibValAibGluIleGlnLeuNleHisGlnHarAlaLysTrpLeu AlaSerValArgArgX 12 X 13 TrpLeuArgLysLysLeuGlnAspValHisAsnX 14 (SEQ ID NO: 29) wherein X 12 is Met or Val; X 13 is Gln or Glu; and X 14 is Tyr or Phe. The invention also relates to pharmaceutically acceptable salts or N- or C-derivatives of SEQ ID NO: 29. The invention also relates to fragments thereof, containing amino acids 1-33, 1-32, 1-31, 1-30, 1-29, 1-28, 1-27, 1-26, 1-25, 1-24, 1-23, 1-22, 1-21, 1-20, 1-19, 1-18, 1-17, 1-16, 1-15, 1-14, 1-13, 1-12, or 1-11.
[0031] In another aspect of the invention, SEQ ID NO: 19, SEQ ID NO: 29 or any of the above peptides are labeled. In another aspect of the invention,SEQ ID NO: 19, SEQ ID NO: 29 or any of the above peptides are labeled with a fluorescent label, a chemiluminescent label; a bioluminescent label; a radioactive label; 125 I; or 99m Tc.
[0032] In another aspect, the invention is directed to a pharmaceutical composition comprising the biologically active peptide SEQ ID NO: 19, SEQ ID NO: 29 or any of the above peptides, and a pharmaceutically acceptable carrier.
[0033] In another aspcet, the invention is directed to a method for treating mammalian conditions characterized by decreases in bone mass, the method comprising administering to a subject in need thereof an effective bone mass-increasing amount of a biologically active peptide of SEQ ID NO: 19, SEQ ID NO: 29 or any of the above peptides.
[0034] In another aspcet, the invention is directed to a method for treating mammalian conditions characterized by decreases in bone mass, the method comprising administering to a subject in need thereof an effective bone mass-increasing amount of a composition comprising a biologically active peptide of SEQ ID NO: 19, SEQ ID NO: 29 or any of the above peptides and a pharmaceutically acceptable carrier.
[0035] In another aspect of the invention, the condition to be treated is osteoporosis, old age osteoporosis, or post-menopausal osteoporosis. In another aspect of the invention, the effective amount of SEQ ID NO: 19, SEQ ID NO: 29 or any of the above peptides for increasing bone mass is from about 0.01 μg/kg/day to about 1.0 μg/kg/day. In another aspect of the invention, the method of administration is parenteral, subcutaneous or nasal insufflation.
[0036] In another aspcet, the invention is directed to a method for determining rates of bone reformation, bone resorption and/or bone remodeling comprising administering to a patient an effective amount of SEQ ID NO: 19, SEQ ID NO: 29 or any of the above peptides and determining the uptake of the peptide into the bone of the patient.
[0037] In another aspcet, the invention is directed to a method of making SEQ ID NO: 19, SEQ ID NO: 29 or any of the above peptides, wherein the peptide is synthesized by solid phase synthesis. in another aspcet, the invention is directed to a method of making SEQ ID NO: 19, SEQ ID NO: 29 or any of the above peptides, wherein the peptide is protected by FMOC.
BRIEF DESCRIPTION OF THE FIGURES
[0038] FIG. 1 . Aib-scan of a modified PTH(1-14) analog in HKRK-B28 cells. The peptide [Ala 3,12 ,Gln 10 ,Har 11 ,Trp 14 ]PTH(1-14) amide {[M]PTH(1-14)}, and derivatives of that peptide containing a single Aib substitution at one of each residue position, were evaluated for the capacity to stimulate intracellular cAMP accumulation in HKRK-B28 cells. The peptides with substitutions at position 1-7 are shown in panel A, and those with substitutions at position 8-9 are shown in B. Shown are combined data (mean±S.E.M.) from 3 to 10 experiments, each performed in duplicate. Symbols are defined in the key.
[0039] FIG. 2 . cAMP-signaling and binding properties of PTH analogs in HKRK-B28 cells. Peptides were evaluated in HKRK-B28 cells for the capacity to stimulate intracellular cAMP accumulation (A) and the capacity to inhibit binding of 125 I-[M]PTH(1-21) (B). Shown are combined data (mean±S.E.M.) from 3 or 4 experiments, each performed in duplicate. Peptides and corresponding symbols are identified in the key.
[0040] FIG. 3 . Signaling and binding properties of PTH analogs in COS-7 cells expressing an N-terminally truncated P1R. COS-7 cells were transiently transfectd with P1R-delNt, a truncated P1R which is deleted for most of the amino-terminal extracellular domain, and subsequently used to evaluate the capacities of the indicated PTH analogs to stimulate intracellular cAMP accumulation (A); stimulate formation of 3 H-inositol phosphates (IP 1 +IP 2 +IP 3 ) (B); and inhibit the binding of 125 I-[Aib 1,3 ,M]PTH(1-21) (C). Each curve shows data combined (mean±S.E.M.) from 3 to 6 experiments, each performed in duplicate. The mean basal level of 3 H-inositol phosphates (2,929±877 cpm/well) is indicated by the dashed iine. Peptides and corresponding symbols are identified in the key.
[0041] FIG. 4 . cAMP-signaling properties of PTH analogs in SaOS-2 cells. The peptides, PTH(1-34), native PTH(1-14), [M]PTH(1-14) and [Aib 1,3 ,M]PTH(1-14) were evaluated in the human osteosarcoma-derived cell line SaOS-2 for the capacity to stimulate intracellular cAMP accumulation. Shown are combined data (mean±S.E.M.) from 3 or 4 experiments, each performed in duplicate. Symbols are defined in the Key.
[0042] FIG. 5 . Effect of PTH analogs on bone mineralization in embryonic mouse metatarsals. Cartilaginous metatarsal bone rudiments were excised from E15.5 mouse embryos and transferred to tissue culture plates containing serum-free media. Added to the samples for 48 h were vehicle: (A); PTH(1-34) (0.1 μM) (B); [Aib 1,3 ,M]PTH(1-14) (1 μM) (C) or native PTH(1-14) (2 μM) (D). Samples were explanted and incubated at 37° C. for a total of 64 h; peptide or vehicle were added at 16 h and again at 24 h. At the end of the incubation, the samples were fixed, sectioned and directly visualized under white light using a dissecting scope. In the vehicle- and native PTH(1-14)-treated samples mineralization can be detected as dark material at the center of the bone rudiment. Both PTH(1-34) and [Aib 1,3 ,M]PTH(1-14) inhibited mineralization. Shown are data from a single experiment, comparable results were obtained in three other replicate experiments.
[0043] FIG. 6 . Circular Dichroism Spectroscopy. Spectra were recorded for the indicated N-terminal PTH oligopeptides, each at 20 μM, in 50 nM sodium phosphate buffer, pH 7.4 containing 20% 2,2,2,-trifluoroethanol. The negative extrema in the spectra at ˜209 nM and ˜222 nM, and the positive extrema at ˜192 nM, which are more apparent in the Aib-containing PTH analogs, as compared to the non-Aib-containing peptides, are indicative of helical content.
[0044] FIG. 7 . Signaling and binding properties of hPTH(1-34) analogs in COS-7 cells expressing wildtype P1R (hP1R-WT, FIG. 7A ) and N-terminally truncated P1R (hP1R-delNT, FIG. 7B ). The COS-7 cells were used to evaluate the capacities of the indicated PTH analogs to stimulate intracellular cAMP accumulation. Cells expressing hP1R-delNT were prepared as described above. Peptides and corresponding symbols are identified in the key.
DETAILED DESCRIPTION OF THE INVENTION
[heading-0045] Definitions
[0046] Amino Acid Sequences: The amino acid sequences in this application use either the single letter or three letter designations for the amino acids. These designations are well known to one of skill in the art and can be found in numerous readily available references, such as for example in Cooper, G. M., The Cell 1997, ASM Press, Washington, D.C. or Ausubel et al., Current Protocols in Molecular Biology, 1994. Where substitutions in a sequence are referred to, for example, as Ser-3→Ala or [Ala 3 ]peptide, this means that the serine in the third position from the N-terminal end of the polypeptide is replaced with another amino acid, Alanine in this instance.
[0047] In the present application [M]PTH(1-14) is defined as [Ala 3,12 ,Gln 10 ,Har 11 ,Trp 14 ]PTH(1-14)amide. [M]PTH(1-21)is defined as [Ala 3,12 ,Nle 8 ,Gln 10 ,Har 11 ,Trp 14 ,Arg 19 ,Tyr 21 ]PTH(1-21)amide. [M]PTH(1-11) is defined as [Ala 3 ,Gln 10 ,Har 11 ]PTH(1-11)amide.
[0048] In the present application, “Aib” refers to α-aminoisobutyric acid; “Har” refers to homoarginine; “Nle” refers to norleucine; and other amino acids are in either the conventional one- or three-letter codes.
[0049] Biological Activity of the Protein: This expression refers to any biological activity of the polypeptide. Examples of these activities include, but are not limited to metabolic or physiologic function of compounds of SEQ ID NO: 1 or SEQ ID NO: 8 or derivatives thereof, including similar activities or improved activities, or those activities with decreased undesirable side-effects. Also included are antigenic and immunogenic activities of the above-described compounds.
[0050] Derivative or Functional Derivative: The term “derivative” or “functional derivative” is intended to include “variants,” the “derivatives,” or “chemical derivatives” of the PTH molecule. A “variant” of a molecule such as for example, a compound of SEQ ID NO: 1 or derivative thereof is meant to refer to a molecule substantially similar to either the entire molecule, or a fragment thereof. An “analog” of a molecule such as for example, a compound of SEQ ID NO: 1or derivative thereof is meant to refer to a non-natural molecule substantially similar to either the SEQ ID NO: 1 molecules or fragments thereof.
[0051] PTH derivatives contain changes in the polypeptide relative to the native PTH polypeptide of the same size. The sequence of the native PTH(1-14) polypeptide is the first fourteen amino acids of SEQ. ID NO: 17 (human PTH (1-21))or SEQ. ID NO: 18(rat PTH(1-21)). A molecule is said to be “substantially similar” to another molecule if the sequence of amino acids in both molecules is substantially the same, and if both molecules possess a similar biological activity. Thus, two molecules that possess a similar activity, may be considered variants, derivatives, or analogs as that term is used herein even if one of the molecules contains additional amino acid residues not found in the other, or if the sequence of amino acid residues is not identical. PTH derivatives, however, need not have substantially similar biological activity to the native molecule. In some instances PTH derivatives have substantially different activity than the native PTH. For example, a derivative may be either an antagonist or an agonist of the PTH receptor.
[0052] As used herein, a molecule is said to be a “chemical derivative” of another molecule when it contains additional chemical moieties not normally a part of the molecule. Such moieties may improve the molecule's solubility, absorption, biological half-life, etc. The moieties may alternatively decrease the toxicity of the molecule, eliminate or attenuate any undesirable side effect of the molecule, etc. Examples of moieties capable of mediating such effects are disclosed in Remington's Pharmaceutical Sciences (1980) and will be apparent to those of ordinary skill in the art.
[0053] Fragment: A “fragment” of a molecule such as for example, SEQ ID NO: 1 or derivative thereof is meant to refer to any polypeptide subset of these molecules.
[0054] Fusion protein: By the term “fusion protein” is intended a fused protein comprising compounds such as for example, SEQ ID NO: 1 or derivatives thereof, either with or without a “selective cleavage site” linked at its N-terminus, which is in turn linked to an additional amino acid leader polypeptide sequence.
[0055] Polypeptide: Polypeptide and peptide are used interchangeably. The term polypeptide refers to any peptide or protein comprising two or more amino acids joined to each other by peptide bonds or modified peptide bonds, i.e., peptide isosteres. “Polypeptide” refers to both short chains, commonly referred to as peptides, oligopeptides or oligomers, and to longer chains, generally referred to as proteins. Polypeptides may contain amino acids other than the 20 gene-encoded amino acids and include amino acid sequences modified either by natural processes, such as post-translational processing, or by chemical modification techniques which are well known in the art. Such modifications are well described in basic texts and in more detailed monographs, as well as in the research literature. Modifications can occur anywhere in a polypeptide, including the peptide backbone, the amino acid side-chains and the amino or carboxyl termini. It will be appreciated that the same type of modification may be present in the same or varying degrees at several sites in a given polypeptide. Also, a given polypeptide may contain many types of modifications.
[0056] Polypeptides may be branched and they may be cyclic, with or without branching. Cyclic, branched and branched cyclic polypeptides may result from post-translational modifications or may be made by synthetic methods. Modifications include acetylation, acylation, ADP-ribosylation, amidation, covalent attachment of flavin, covalent attachment of a heme moiety, covalent attachment of a nucleotide or nucleotide derivative, covalent attachment of a lipid or lipid derivative, covalent attachment of phosphotidylinositol, cross-linking, cyclization, disulfide bond formation, demethylation, formation of covalent cross-links, formation of cystine, formation of pyroglutamate, formylation, gamma-carboxylation, glycosylation, GPI anchor formation, hydroxylation, iodination, methylation, myristoylation, oxidation, proteolytic processing, phosphorylation, prenylation, racemization, selenoylation, sulfation, transfer-RNA mediated addition of amino acids to proteins such as arginylation, and ubiquitination. See, for instance, Proteins - Structure and Molecular Properties, 2nd Ed., T. E. Creighton, W. H. Freeman and Company, New York, 1993 and Wold, F., Posttranslational Protein Modifications: Perspectives and Prospects, pgs. 1-12 in Posttranslational Covalent Modification of Proteins, B. C. Johnson, Ed., Academic Press. New York, 1983; Seifter et al., “Analysis for protein modifications and nonprotein cofactors”, Methods in Enzymol. 182:626-646 (1990) and Rattan et al., “Protein Synthesis: Posttranslational Modifications and Aging”, Ann NY Acad Sci 663:48-62 (1992).
[heading-0057] PTH Analogs—Structural and Functional Properties
[0058] α-aminoisobutyric acid (Aib) was introduced into short N-terminal PTH peptide analogs. The numerous NMR studies of PTH(1-34) analogs, performed in a variety of polar or non-polar solvents, have generally indicated two domains of secondary structure: a stable C-terminal helix extending approximately from Ser-17 to Val-31, and a shorter and less stable amino-terminal helix, extending variably from Ser-3 to Lys-13, the two domain being connected by a bend or turn region (Marx, U. C., et al., Biochem. Biophys. Res. Commun. 267:213-220 (2000); Chen, Z., et al., Biochemistry 39:12766-12777 (2000); Marx, U. C., et al., J. Biol Chem. 270:15194-15202 (1995); Marx, U. C., et al., J. Biol. Chem. 273:4308-4316 (1998); Pellegrini, M., et al., Biochemistry 37:12737-12743 (1998); Gronwald, W., et al., Biol. Chem. Hoppe Seyler 377:175-186 (1996); Barden, J. A., and Kemp, B. E., Biochemistry 32:7126-7132 (1993)). The recent crystallographic study of PTH(1-34) indicated a continuous α-helix extending from Ser-3 to His-32 and containing only a slight 15° bend at the midsection. However, NMR data indicates that the N-terminal α-helix is relatively weak. Helix-stabilizing modifications, such as the introduction of Aib residues, offer significant benefits in terms of peptide potency, and result in short peptides (≦14 amino acids) with activity comparable to PTH(1-34).
[0059] Described herein are novel “minimized” variants of PTH that are small enough to be deliverable by simple non-injection methods. The variants of the present invention contain substitutions in the first 14 amino acids of the polypeptide. The new polypeptides correspond to the 1-21, 1-20, 1-19, 1-18, 1-17, 1-16, 1-15, 1-14, 1-13, 1-12, 1-11, and 1-10 amino acid sequence of the mature PTH polypeptide. The shorter variants (≦PTH1-14) have a molecular weight of less than 2,000 daltons.
[0060] The primary amino acid sequence of the native human PTH(1-21) peptide (N-terminus to C-terminus) is SerValSerGluIleGlnLeuMetHisAsnLeuGlyLysHisLeuAsnSerMetGluArgVal (SEQ ID NO: 17), whereas the primary sequence of the native rat PTH (1-21) is AlaValSerGluIleGlnLeuMetHisAsnLeuGlyLysHisLeuAlaSerValGluArgMet (SEQ ID NO. 18).
[0061] As protein products, compounds described herein are amenable to production by the techniques of solution- or solid-phase peptide synthesis. The solid phase peptide synthesis technique, in particular, has been successfully applied in the production of human PTH and can be used for the production of these compounds (for guidance, see Kimura et al., supra, and see Fairwell et al., Biochem. 22:2691 (1983)). Success with producing human PTH on a relatively large scale has been reported by Goud et al., in J. Bone Min. Res. 6(8):781 (1991). The synthetic peptide synthesis approach generally entails the use of automated synthesizers and appropriate resin as solid phase, to which is attached the C-terminal amino acid of the desired compounds of SEQ ID NO: 1 or derivatives thereof. Extension of the peptide in the N-terminal direction is then achieved by successively coupling a suitably protected form of the next desired amino acid, using either FMOC- or BOC-based chemical protocols typically, until synthesis is complete. Protecting groups are then cleaved from the peptide, usually simultaneously with cleavage of peptide from the resin, and the peptide is then isolated and purified using conventional techniques, such as by reversed phase HPLC using acetonitrile as solvent and tri-fluoroacetic acid as ion-pairing agent. Such procedures are generally described in numerous publications and reference may be made, for example, to Stewart and Young, “Solid Phase Peptide Synthesis,” 2nd Edition, Pierce Chemical Company, Rockford, Ill. (1984). It will be appreciated that the peptide synthesis approach is required for production of such as for example, SEQ ID NO: 1 and derivatives thereof which incorporate amino acids that are not genetically encoded, such as Aib.
[0062] In accordance with another aspect of the present invention, substituents are attached to the free amine of the N-terminal amino acid of compounds of the present invention standard methods known in the art. For example, alkyl groups, e.g., C 1-12 alkyl, are attached using reductive alkylation. Hydroxyalkyl groups, e.g. C 1-12 hydroxyalkyl, are also attached using reductive alkylation wherein the free hydroxy group is protected with a t-butyl ester. Acyl groups, e.g., COE 1 , are attached by coupling the free acid, e.g., E 1 COOH, to the free amino of the N-terminal amino acid. Additionally, possible chemical modifications of the C-terminal end of the polypeptide are encompassed within the scope of the invention. These modifications may modify binding affinity to the receptor.
[0063] Also contemplated within the scope of this invention are those compounds such as for example, SEQ ID NO: 1 and derivatives thereof with altered secondary or tertiary structure, and/or altered stability, which still retain biological activity. Such derivatives might be achieved through lactam cyclization, disulfide bonds, or other means known to a person of ordinary skill in the art.
[heading-0064] Utility and Administration of Compounds of the Invention
[0065] Compounds of the invention or derivatives thereof have multiple uses. These include, inter alia, agonists or antagonists ofthe PTH receptor, prevention and treatment of a variety of mammalian conditions manifested by loss of bone mass, diagnostic probes, antigens to prepare antibodies for use as diagnostic probes and even as molecular weight markers. Being able to specifically substitute one or more amino acids in the PTH polypeptide permits construction of specific molecular weight polypeptides.
[0066] In particular, the compounds of this invention are indicated for the prophylaxis and therapeutic treatment of osteoporosis and osteopenia in humans. Furthermore, the compounds of this invention are indicated for the prophylaxis and therapeutic treatment of other bone diseases. The compounds of this invention are also indicated for the prophylaxis and therapeutic treatment of hypoparathyroidism. Finally, the compounds of this invention are indicated for use as agonists for fracture repair and as antagonists for hypercalcemia.
[0067] In general, compounds of the present invention, or salts thereof, are administered in amounts between about 0.01 and 1 μg/kg body weight per day, preferably from about 0.07 to about 0.2 μg/kg body weight per day. For a 50 kg human female subject, the daily dose of biologically active compound is from about 0.5 to about 50 μgs, preferably from about 3.5 to about 10 μgs. In other mammals, such as horses, dogs, and cattle, higher doses may be required. This dosage may be delivered in a conventional pharmaceutical composition by a single administration, by multiple applications, or via controlled release, as needed to achieve the most effective results, preferably one or more times daily by injection. For example, this dosage may be delivered in a conventional pharmaceutical composition by nasal insufflation.
[0068] The selection ofthe exact dose and composition and the most appropriate delivery regimen will be influenced by, inter alia, the pharmacological properties of the selected compounds of the invention, the nature and severity of the condition being treated, and the physical condition and mental acuity of the recipient.
[0069] Representative preferred delivery regimens include, without limitation, oral, parenteral, subcutaneous, transcutaneous, intramuscular and intravenous, rectal, buccal (including sublingual), transdermal, and intranasal insufflation.
[0070] Pharmaceutically acceptable salts retain the desired biological activity of the compounds of the invention without toxic side effects. Examples of such salts are (a) acid addition salts formed with inorganic acids, for example hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid, nitric acid and the like; and salts formed with organic acids such as, for example, acetic acid, oxalic acid, tartaric acid, succinic acid, maleic acid, fumaric acid, gluconic acid, citric acid, malic acid, ascorbic acid, benzoic acid, tannic acid, pamoic acid, alginic acid, polyglutamic acid, naphthalenesulfonic acids, naphthalene disulfonic acids, polygalacturonic acid and the like; (b) base addition salts formed with polyvalent metal cations such as zinc, calcium, bismuth, barium, magnesium, aluminum, copper, cobalt, nickel, cadmium, and the like; or with an organic cation formed from N,N′-dibenzylethylenediamine or ethylenediamine; or (c) combinations of (a) and (b), e.g., a zinc tannate salt and the like. Pharmaceutically acceptable buffers include but are not limited to saline or phosphate buffered saline. Also included in these solutions may be acceptable preservative known to those of skill in the art.
[0071] A further aspect of the present invention relates to pharmaceutical compositions comprising as an active ingredient compounds of the invention or derivatives thereof of the present invention, or pharmaceutically acceptable salt thereof, in admixture with a pharmaceutically acceptable, non-toxic carrier. As mentioned above, such compositions may be prepared for parenteral (subcutaneous, transcutaneous, intramuscular or intravenous) administration, particularly in the form of liquid solutions or suspensions; for oral or buccal administration, particularly in the form of tablets or capsules; for rectal, transdermal administration; and for intranasal administration, particularly in the form of powders, nasal drops or aerosols.
[0072] The compositions may conveniently be administered in unit dosage form and may be prepared by any of the methods well-known in the pharmaceutical art, for example as described in Remington's Pharmaceutical Sciences, 17th ed., Mack Publishing Company, Easton, Pa., (1985), incorporated herein by reference. Formulations for parenteral administration may contain as excipients sterile water or saline, alkylene glycols such as propylene glycol, polyalkylene glycols such as polyethylene glycol, oils of vegetable origin, hydrogenated naphthalenes and the like. For oral administration, the formulation can be enhanced by the addition of bile salts or acylcarnitines. Formulations for nasal administration may be solid and may contain excipients for example, lactose or dextran, or may be aqueous or oily solutions for use in the form of nasal drops or metered spray. For buccal administration typical excipients include sugars, calcium stearate, magnesium stearate, pregelatinated starch, and the like.
[0073] When formulated for the most preferred route of administration, nasal administration, the absorption across the nasal mucous membrane may be enhanced by surfactant acids, such as for example, glycocholic acid, cholic acid, taurocholic acid, ethocholic acid, deoxycholic acid, chenodeoxycholic acid, dehydrocholic acid, glycodeoxycholic acid, cyclodextrins and the like in an amount in the range between about 0.2 and 15 weight percent, preferably between about 0.5 and 4 weight percent, most preferably about 2 weight percent.
[0074] Delivery of the compounds of the present invention to the subject over prolonged periods of time, for example, for periods of one week to one year, may be accomplished by a single administration of a controlled release system containing sufficient active ingredient for the desired release period. Various controlled release systems, such as monolithic or reservoir-type microcapsules, depot implants, osmotic pumps, vesicles, micelles, liposomes, transdermal patches, iontophoretic devices and alternative injectable dosage forms may be utilized for this purpose. Localization at the site to which delivery of the active ingredient is desired is an additional feature of some controlled release devices, which may prove beneficial in the treatment of certain disorders.
[0075] One form of controlled release formulation contains the polypeptide or its salt dispersed or encapsulated in a slowly degrading, non-toxic, non-antigenic polymer such as copoly(lactic/glycolic) acid, as described in the pioneering work of Kent, Lewis, Sanders, and Tice, U.S. Pat. No. 4,675,189. The compounds or, preferably, their relatively insoluble salts, may also be formulated in cholesterol or other lipid matrix pellets, or silastomer matrix implants. Additional slow release, depot implant or injectable formulations will be apparent to the skilled artisan. See, for example, Sustained and Controlled Release Drug Delivery Systems, J. R. Robinson ed., Marcel Dekker, Inc., New York, 1978, and R. W. Baker, Controlled Release of Biologically Active Agents, John Wiley & Sons, New York, 1987.
[0076] Like PTH, the PTH variants may be administered in combination with other agents usefull in treating a given clinical condition. When treating osteoporosis and other bone-related disorders for example, the PTH variants may be administered in conjunction with a dietary calcium supplement or with a vitamin D analog (see U.S. Pat. No. 4,698,328). Alternatively, the PTH variant may be administered, preferably using a cyclic therapeutic regimen, in combination with bisphosphonates, as described for example in U.S. Pat. No. 4,761,406, or in combination with one or more bone therapeutic agents such as, without limitation, calcitonin and estrogen.
[heading-0077] PTH Analog Receptor-Signaling Activities
[0078] A crucial step in the expression of hormonal action is the interaction of hormones with receptors on the plasma membrane surface of target cells. The formation of hormone-receptor complexes allows the transduction of extracellular signals into the cell to elicit a variety of biological responses.
[0079] Polypeptides described herein can be screened for their agonistic or antagonistic properties using the cAMP accumulation assay. Cells expressing PTH-1 receptor on the cell surface are incubated with native PTH(1-84) for 5-60 minutes at 37° C., in the presence of 2 mM IBMX (3-isobutyl-1-methyl-xanthine, Sigma, St. Louis, Mo.). Cyclic AMP accumulation is measured by specific radio-immunoassay. A compound that competes with native PTH(1-84) or PTH(1-34) for binding to the PTH-1 receptor, and that inhibits the effect of native PTH(1-84) or PTH(1-34) on cAMP accumulation, is considered a competitive antagonist. Such a compound would be useful for treating hypercalcemia.
[0080] Conversely, a PTH analog described herein or a derivative thereof that does not compete with native PTH(1-84) or PTH(1-34) for binding to the PTH-1receptor, but which still prevents native PTH(1-84) or PTH(1-34) activation of cAMP accumulation (presumably by blocking the receptor activation site) is considered a non-competitive antagonist. Such a compound would be useful for treating hypercalcemia.
[0081] The compounds described herein that compete with native PTH(1-84) or PTH(1-34)) for binding to the PTH-1 receptor, and which stimulates cAMP accumulation in the presence or absence of native PTH(1-84) or PTH(1-34) are competitive agonists. A compound that does not compete with native PTH(1-84) or PTH(1-34) for binding to the PTH-1 receptor but which is still capable of stimulating cAMP accumulation in the presence or absence of native PTH(1-84) or PTH(1-34), or which stimulates a higher cAMP accumulation than that observed by a compound of the invention or a derivative thereof alone, would be considered a non-competitive agonist.
[heading-0082] Therapeutic Uses of PTH Analogs
[0083] Some forms of hypercalcemia and hypocalcemia are related to the interaction between PTH and PTHrP and the PTH-1 and receptors. Hypercalcemia is a condition in which there is an abnormal elevation in serum calcium level; it is often associated with other diseases, including hyperparathyroidism, osteoporosis, carcinomas of the breast, lung and prostate, epidermoid cancers of the head and neck and of the esophagus, multiple myeloma, and hypernephroma. Hypocalcemia, a condition in which the serum calcium level is abnormally low, may result from a deficiency of effective PTH, e.g., following thyroid surgery.
[0084] By “agonist” is intended a ligand capable of enhancing or potentiating a cellular response mediated by the PTH-1 receptor. By “antagonist” is intended a ligand capable of inhibiting a cellular response mediated by the PTH-1 receptor. Whether any candidate “agonist” or “antagonist” of the present invention can enhance or inhibit such a cellular response can be determined using art-known protein ligand/receptor cellular response or binding assays, including those described elsewhere in this application.
[0085] In accordance with yet a further aspect of the invention, there is provided a method for treating a medical disorder that results from altered or excessive action of the PTH-1 receptor, comprising administering to a patient therapeutically effective amount of a compound of the invention or a derivative thereof sufficient to inhibit activation of the PTH-1 receptor of said patient.
[0086] In this embodiment, a patient who is suspected of having a disorder resulting from altered action of the PTH-1 receptor can be treated using compounds of the invention or derivatives thereof of the invention which are a selective antagonists of the PTH-1 receptor. Such antagonists include compounds of the invention or derivatives thereof of the invention which have been determined (by the assays described herein) to interfere with PTH-1 receptor-mediated cell activation or other derivatives having similar properties.
[0087] To administer the antagonist, the appropriate compound of the invention or a derivative thereof is used in the manufacture of a medicament, generally by being formulated in an appropriate carrier or excipient such as, e.g., physiological saline, and preferably administered intravenously, intramuscularly, subcutaneously, orally, or intranasally, at a dosage that provides adequate inhibition of a compound of the invention or a derivative thereof binding to the PTH-1 receptor. Typical dosage would be 1 ng to 10 mg of the peptide per kg body weight per day.
[0088] In accordance with yet a further aspect of the invention, there is provided a method for treating osteoporosis, comprising administering to a patient a therapeutically effective amount of a compound of the invention or a derivative thereof, sufficient to activate the PTH-1 receptor of said patient. Similar dosages and administration as described above for the PTI/PTHrP antagonist, can be used for administration of a PTH/PTHrP agonist, e.g., for treatment of conditions such as osteoporosis, other metabolic bone disorders, and hypoparathyroidism and related disorders.
[0089] It will be appreciated to those skilled in the art that the invention can be performed within a wide range of equivalent parameters of composition, concentration, modes of administration, and conditions without departing from the spirit or scope of the invention or any embodiment thereof.
[0090] Having now fully described the invention, the same will be more readily understood by reference to specific examples which are provided by way of illustration, and are not intended to be limiting of the invention, unless herein specified.
EXAMPLES
[0091] The following protocols and experimental details are referenced in the examples that follow.
[0092] Peptides. Each peptide utilized in this study contained a free amino acid terminus and a carboxamide at the C-terminus. Peptides were prepared on automated peptide synthesizers (model 430A PE, Applied Biosystems, Foster City, Calif., or Model 396 MBS Advanced Chem Tect, Louisville, Ky.) using Fmoc main-chain protecting group chemistry, HBTU/HOBt/DIEA (1:1:2 molar ratio) for coupling reactions, and TFA-mediated cleavage/sidechain-deprotection (MGH Biopolymer Synthesis Facility, Boston, Mass.). All peptides were desalted by adsorption on a C18-containing cartridge, and purified further by HPLC. The dry peptide powders were reconstituted in 10 mM acetic acid and stored at −80° C. The purity, identity, and stock concentration for each peptide was secured by analytical HPLC, Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry and amino acid analysis. Radiolabeling of [M]PTH(1-21) and [Aib 1,3 ,M]PTH(1-21) was performed using 125 I-Na (2,200 Ci/mmol, NEN) and chloramine-T; the resultant radioligands were purified by HPLC.
[0093] Cell Culture. The cell line HKRK-B28 (Takasu, H., et al., J. Bone Miner. Res. 14:11-20 (1999)) was derived from the porcine kidney cell line, LLC-PK 1 by stable transfection with plasmid DNA encoding the human P1R and expresses ˜280,000 receptors per cell. These cells, as well as COS-7 cells and SaOS-2-B10 cells, were cultured at 27° C. in T-75 flasks (75 mm 2 ) in Dulbecco's modified Eagle's medium (DMEM) supplemented with fetal bovine serum (10%), penicillin G (20 units/ml), streptomycin sulfate (20 μg/ml) and amphotericin B (0.05 μg/ml) in a humidified atmosphere containing 5% CO 2 . Stock solutions of EGTA/trypsin and antibiotics were from GIBCO; fetal bovine serum was from Hyclone Laboratories (Logan, Utah). COS-7 cells sub-cultured in 24-well plates were transfected with plasmid DNA (200 ng per well) encoding the wild-type human P1R or truncated human P1R deleted for residues (24-181) (Shimizu, M., et al., J. Biol. Chem. 275:21836-21843 (2000)) that was purified by cesium chloride/ethidium bromide density gradient centrifugation, and FuGENE 6 transfection reagent (Roche Indianapolis Ind.) according to the manufacturer's recommended procedure. All cells, in 24-well plates, were treated with fresh media and shifted to 33° C. for 12 to 24 h prior to assay.
[0094] cAMP Stimulation. Stimulation of cells with peptide analogs was performed in 24-well plates. Cells were rinsed with 0.5 mL of binding buffer (50 mM Tris-HCI, 100 nM NaCI, 5 mM KCl, 2 mM CaCl 2 , 5% heat-inactivated horse serum, 0.5% fetal bovine serum, adjusted to pH 7.5 with HCl) and treated with 200 μL of cAMP assay buffer (Delbecco's modified Eagle's medium containing 2 mM 3-isobutyl-1-methylxanthine, 1 mg/mL bovine serum albumin, 35 mM Hepes-NaOH, pH 7.4) and 100 μL of binding buffer containing varying amounts of peptide analog (final volume=300 μL). The medium was removed after incubation for 30 to 60 minutes at room temperature, and the cells were frozen on dry ice, lysed with 0.5 mL 50 mM HCl, and refrozen (˜80° C). The cAMP content of the diluted lysate was determined by radioimmunoassay. The EC 50 response values were calculated using nonlinear regression (see below).
[0095] Competition Binding. Binding reactions were performed with HKRK-B28 cells or in COS-7 cells in 24-well plates. The cells were rinsed with 0.5 mL of binding buffer, and then treated successively with 100 μL binding buffer, 100 μL of binding buffer containing various amounts of unlabeled competitor ligand, and 100 μL of binding buffer containing ca. 100,000 cpm of 125 I-[M]PTH(1-21) or 125 I-[Aib 1,3 ,M]PTH(1-21)} (ca. 26 fmol; final volume=300 μL). Incubations were 4 to 6 h at 4° C., at which time near equilibrium conditions were attained. Cells were then placed on ice, the binding medium was removed, and the monolayer was rinsed three times with 0.5 mL of cold binding buffer. The cells were subsequently lysed with 0.5 mL 5N NaOH and counted for radioactivity. For each tracer and in each experiment, the non-specific binding was determined as the radioactivity that bound in the presence of the same unlabeled peptide at a concentration of 1 μM, and was ˜1% of total radioactivity added for each tracer. The maximum specific binding (B 0 ) was the total radioactivity bound in the absence of competing ligand, corrected for nonspecific binding, and for each tracer, ranged from 8% to 20% of the total radioactivity added. Nonlinear regression was used to calculate binding IC 50 values (see below). Scatchard transformations of homologous competition binding data derived from studies with 26 fmol of 125 I-[Aib 1,3 ,M]PTH(1-21) were employed for estimations of apparent equilibrium dissociation constant (k Dapp s) and total number of ligand binding sites (B max ), assuming a single class of binding sites and equal affinities of the iodinated and non iodinated ligand.
[0096] Stimulation of Inositol Phosphate Production. COS-7 cells transfected as above with P1R-WT were treated with serum-free, inositol-free DMEM containing 0.1% bovine serum albumin and [ 3 H]myo-inositol (NEN, Boston, Mass.) (2 μCi/mL) for 16 h prior to assay. At the time of the assay, the cells were rinsed with binding buffer containing LiCl (30 mM) and treated with the same buffer with or without a PTH analog. The cells were then incubated at 37° C. for 40 min, after which the buffer was removed and replaced by 0.5 mL of ice cold 5% trichloroacetic acid solution. After 3 h on ice, the lysate was collected and extracted twice with ethyl ether. The lysate was then applied to an ion exchange column (0.5 mL resin bed) and the total inositol phosphates were eluted as described previously (Berridge, M. J., et al., Biochem. J. 212:473-482 (1983)), and counted in liquid scintillation cocktail.
[0097] Inhibition of Chondrocyte Differentiation in Embryonic Mouse Metatarsals. Metatarsals from embryonic day (E) 15.5 mouse embryos were excised and cultured in a 37° C. humidified incubator (5% CO 2 ) in serum-free αXMEM media in 24 well plates. Sixteen hours later, a PTH analog or vehicle was added, and the samples were incubated for an additional 48 h in 37° C. with peptide or vehicle added again at the 24 h time point. At the end of the 64 h incubation period, the samples were fixed with 10% formalin/phosphate-buffered saline, then directly visualized on a dissecting microscope using white light. Sections were processed for in-situ hybridization analysis using 35 S-labeled riboprobes specific for collagen type X mRNA, a developmental marker gene expressed only in hypertrophic chrondrocytes of the growth plate.
[0098] Circular Dichroism. Circular Dichroism spectra were recorded on a Jasco model 710 spectropolarimeter; peptides were analyzed at a concentration of20 μM in 50 mM sodium phosphate buffer pH 7.4, or the same buffer containing 2,2,2-trifluoroethanol at 20% (v/v). Spectroscopic scans were preformed at 20° C. and at wavelengths between 185 and 255 nM, with data recored at each 1 nM interval. The spectral bandwidth was 1.5 nM and 8 scans were accumulated and averaged for each sample. At each wavelength, the mean residue elipticity [θ×100/l×C×n); where θ is the raw elipticity value (in dimensions of millidegree), l is the sample path length, C=is the molar peptide concentration, and n is the number of residues in the peptide (Bowen, W. P., and Jerman, J. C., Trends in Pharmacol. Sci. 16: 413-417 (1995)). The helical content of each peptide was estimated by dividing [θ] observed at 222 nM for that peptide by −28,100, which is the reported [θ] 222 obs for a model helical decapeptide (Bowen, W. P., and Jerman, J. C., Trends in Pharmacol. Sci. 16: 413-417 (1995)).
[0099] Data Calculation. Calculations were performed using Microsoft® Excel. Nonlinear regression analyses of binding and cAMP dose-response data were performed using the four-parameter equation: y p =Min+[(Max−Min)/(1+(IC 50 /x) slope )]. The Excel Solver function was utilized for parameter optimization, as described previously (Carter, P. H., et al., Endocrinology 140: 4972-4981 (1999); Bowen, W. P., and Jerman, J. C., Trends in Pharmacol. Sci. 16: 413-417 (1995)). Differences between paired data sets were statistically evaluated using a one-tailed Student's t-test, assuming unequal variances for the two sets.
Example 1
Aib-scan in [M]PTH(1-14)
[0100] The effect of introducing individual Aib substitutions at each position in the scaffold peptide [M]PTH(1-14) (Shimizu, M., et al., Endocrinology (2001) (In Press))) were analyzed. In cAMP stimulation assays in HKRK-B28 cells, the parent peptide [M]PTH(1-14) stimulated approximately the same (˜70-fold) maximun (Emax) increase in intracellular cAMP that was induced by PTH(1-34), but the potency (EC 50 ) of the shorter peptide was 40-fold less than that of PTH(1-34) (EC 50 s=100±20 and 2.5±0.4. nM, respectively) ( FIG. 1 and Table 1). Most of the Aib substitutions diminished potency. Severe reductions occured with Aib substitutions at positions 6, 8 and 9 (all>2,300-fold), moderate reductions occurred with substitution at positions 2, 4, 5 and 11 (all 170 to 670-fold) and minor reductions occurred with substitutions at positions 7, 10, 12, 13 and 14 (all<3-fold; Table 1). Substitution of Aib at positions 1 and 3 resulted in peptides with 10- and 8-fold improvements in potency, relative to [M]PTH(1-14), respectively (P≦0.01). These Aib-scan data extend previous alanine-scan and substitution analyses of PTH(1-14) analogs, in which residues in the (1-9) region, excluding residue 3, were found to be intolerant to substitution, and residues 3 and 10-14. were found to be relatively tolerant (Luck, M. D., et al., Molecular Endocrinology 13:670-680 (1999); Shimizu, M., et al., J. Biol. Chem. 275:19456-19460 (2000); Pellegrini, M., et al., J. Biol. Chem. 273:10420-10427 (1998)).
[0101] The P1R-binding properties of these analogs were assayed in competition studies performed in HKRK-B8 cells. In previous studies, PTH(1-14) binding could not be detected using 125 I-PTH(1-34) and related N-terminally intact and relatively unmodified radioligands (Luck, M. D., et al., Molecular Endocrinology 13:670-680 (1999)). However, measurable PTH(1-14) binding was observed with 125 I-PTH(3-34) used as a tracer radioligand (Hoare, S. R. J., et al., J. Biol. Chem 276:7741-7753 (2001); Shimizu, M., et al., Endocrinology ( 2001) (In Press)). Receptor binding affinity was assessed using a tracer radioligand that was structurally more homologous to the [M]PTH(1-14) analogs being investigated. The radiolabeled peptide 125 I-[Ala 3,12 Nle 8 Gln 10 ,Har 11 ,Trp 14 ,Tyr 15 ]PTH(1-15)amide was evaluated, but did not bind detectably to HKRK-B28 cells. A similar analog, which was extended to position 21 and contained the affinity-enhancing substitution of Glu 19 →Arg (Takasu, H., et al., Biochemistry 38:13453-13460 (1999); Kronenberg, H. M., et al., Recent Prog. Horm. Res. 53:283-301 (1998)), was prepared. The resulting radioligand 125 I-[M]PTH(1-21) bound adequately to the P1R expressed intact HKRK-B28 cells, as the amount of specifically bound radioactivity (e.g. that which could be inhibited by excess unlabeled [M]PTH(1-2) peptide), was ˜15% to 20% of total radioactivity added, and that which bound to untransfected LLC-PK1 cells was<2% of total added. Thus, this tracer ligand was suitable for competition analyses.
[0102] The binding of 125 I-[M]PTH(1-21) to HKRK-B28 cells was fully inhibited by PTH(1-34) (IC 50 =18±3 nM) and more weakly but to near completion by [M]PTH(1-14) (IC 50 =13,000±3,000 nM, Table 1). Relative to the apparent binding affinity of [M]PTH(1-14), most of the Aib substitutions reduced affinity, in accordance with the corresponding effects on cAMP-signaling potency (Table 1). The only Aib substitutions that improved affinity significantly were those at positions 1 and 3 (13- and 8-fold, respectively, Aib at position 10 showed a trend towards causing a 1.4-fold improvement in affinity, P=0.16). Strong (>10-fold) reductions in affinity occurred with Aib substitutions at positions 4, 7, 8 and 9, while mild (<10-fold) reductions occurred with the Aib at positions 2, 5, 12, 13 and 14. While most of the Aib substitutions had effects on receptor-binding affinity that were approximately proportional to their effects on cAMP-stimulating potency, those at positions 2 and 6 had less of an effect on binding than on potency. Thus, these two substitutions reduced affinity ˜3-fold, relative to [M]PTH(1-14), while they reduced potency ˜470- and ˜2,300-fold, respectively (Table 1).
[0103] Combining the Aib substitutions at positions 1 and 3 revealed an additive effects, as [Aib 1,3 ,M]PTH(1-14) was 90-fold more potent in stimulating cAMP formation than was [M]PTH(1-14) (EC 50 s=1.1±0.1 nM, 100±20 nM, respectively), and at least as potent as PTH(1-34) (EC 50 =2.5±0.4 nM, P=0.01, FIG. 2A and Tale 1). The effects of the single Aib substitutions at position 1 and 3 on receptor-binding affinity were also additive, as [Aib 1,3 ,M]PTH(1-14) bound with 100-fold higher apparent affinity than did [M]PTH(1-14) ( FIG. 2B and Table 1). Aib substitutions were subsequently introduced at positions 1 and 3 in [M]PTH(1-11) analog to determine if the paired substitution could enhance activity of the shorter peptide sequence. Previously, it was shown that while native PTH peptides shorter than (1-14) were devoid of cAMP-stimulating activity (Luck, M. D., et al., Molecular Endocrinology 13:670-680 (1999)), modified PTH(1-11) analogs, such as [M]PTH(1-11) could induce a full cAMP response in HKRK-B28 cells, albeit with a potency (EC 50 =3 μM) nearly 1,000-fold weaker than that of PTH(1-34)(Shimizu, M., et al., Endocrinology (2001) (In Press)). In cAMP stimulation assays in HKRK-B28 cells, [Aib 1,3 ,M]PTH(1-11) was fully efficacious and its potency (EC 50 4.0±0.8 nM) was 1,000-fold greater than that of [M]PTH(1-11) (Shimizu, M., et al., Endocrinology (2001) (In Press)) and nearly equal to that of PTH(1-34) ( FIG. 2A , Table 1). The Aib-1,3 modification also enhanced potency of PTH(1-10) analog, as [Aib 1,3 ,Gln 10 ]PTH(1-10) was 50-fold more potent than our previously most potent PTH(1-10) analog, [Ala 3 ,Gln 10 ]PTH(1-10) (EC 50 s=16±2 μM and ˜800 μM, respectively) (Shimizu, M., et al., Endocrinology (2001) (In Press)) ( FIG. 2A , Table 1). The 4000-fold weaker potency that [Aib 1,3 ,Gln 10 ]PTH(1-10) exhibited, relative to that of [Aib 1,3 ,M]PTH(1-1 1), indicated the importance of the position 11 residue (homoarginine) in the activities of the Aib-containing pep tides. Little or no stimulation of cAMP accumulation was observed with [Aib 1,3 ]PTH(1-9) ( FIG. 2A and Table 1). In competition binding assays, [Aib 1,3 ,M]PTH(1-11) effectively inhibited 125 I-[Aib 1,3 ,M[PTH(1-21) binding to HKRK-B8 cells (IC 50 =970±300 nM), but [Aib 1,3 ,Gln 10 ]PTH(1-10) and [Aib 1,3 ]PTH(1-9) did not bind detachably ( FIG. 2B and Table 1).
TABLE 1 cAMP Stimulation and hP1R-Binding Properties in HKRK-B28 cells cAMP EMax (obs.,) Binding EC 50 pmole/ IC 50 # Peptide nM well (n) nM (n) 92 PTH(1-34) 2.5 ± 0.4 280 ± 11 10 18 ± 3 7 621 [M]PTH(1-14) 100 ± 20 270 ± 8 10 13,000 ± 3,000 4 Aib scan in [M]PTH(1-14) 622 Aib-1 10 ± 3 273 ± 6 6 980 ± 160 3 623 Aib-2 47,000 ± 13,000 168 ± 6 3 50,000 ± 11,000 3 624 Aib-3 13 ± 3 269 ± 7 6 1,700 ± 200 3 625 Aib-4 17,000 ± 3,400 221 ± 10 3 148,000 ± 40,000 3 626 Aib-5 66,000 ± 38,000 169 ± 18 3 N.B. 3 627 Aib-6 230,000 ± 78,000 116 ± 12 3 31,000 ± 7,000 3 628 Aib-7 2,600 ± 980 275 ± 8 3 490,000 ± 170,000 3 629 Aib-8 1,500,000 ± 970,000 34 ± 7 3 N.B. 3 630 Aib-9 710,000 ± 330,000 51 ± 8 4 N.B. 3 631 Aib-10 3,000 ± 2,100 214 ± 22 3 9,100 ± 1,500 3 632 Aib-11 67,000 ± 51,000 96 ± 18 4 N.B. 3 633 Aib-12 440 ± 300 263 ± 9 3 15,000 ± 3,000 3 634 Aib-13 480 ± 250 259 ± 10 4 44,000 ± 8,000 3 635 Aib-14 350 ± 100 273 ± 6 3 79,000 ± 27,000 3 Aib-1,3 in [M]PTH(1-X) 608 [M]PTH(1-21) N.D. 53 ± 4 3 674 [Aib 1,3 , M]PTH (1-21) 4.3 ± 1.6 284 ± 76 3 31 ± 7 3 671 [Aib 1,3 , M]PTH (1-14) 1.1 ± 0.1 278 ± 20 5 130 ± 20 5 682 [Aib 1,3 , M]PTH (1-11) 4.0 ± 0.8 243 ± 15 4 970 ± 300 3 684 [Aib 1,3 , M]PTH (1-10) 16,000 ± 2,000 111 ± 8 4 N.B. 3 696 [Aib 1,3 ]PTH (1-9) >10,000 10 ± 1 3 N.B. 3 Peptides PTH(1-34) ([Nle 8,21 , Tyr 34 ]PTH(1-34)amide), [M]PTH(1-14) (M = Ala 3,12 , Gln 10 , Har 11 , Trp 14 ), and [M]PTH(1-14 analogs, or C-terminally truncated derivatives thereof, containing α-aminoisobutyric acid (Aib) substitutions at the indicated positions were functionally evaluated in HKRK-B28 cells. “M” in [Aib 1,3 , M]PTH(1-21) = Nle 8 , Gln 10 , Har 11 , Ala 12 , Trp 14 , Arg 19 and Tyr 21 . The basal cAMP values (not subtracted) were 4.0 ± 0.1 pmole/well (n = 10). Peptides were based on the rat PTH sequence and were carboxy-amidated. Competition binding analyses were performed with 125 I-[M]PTH(1-21 )amide (Ala 1,3 ) as tracer for 4 h at 4° C. Data are means (±S.E.M.) Of the number of experiments indiated (n). N.B., no binding was detected at a peptide concentration of 10 μm; N.D.; the experiment was not done. The sequence of MPTH(1-14) is: Ala-Val-Ala*-Glu-Ile-Gln-Leu-Met-His-Gln*-Har*-Ala*-Lys-Trp* where the asterisk denotes substituted amino acids are not found at that position in native rat PTH(1-14).
Example 2
Analog Activity in COS-7 Cells
[0104] The possibility that the activity-enhancing effects of the Aib substitutions at positions 1 and 3 were mediated through the juxtamembrane (J) region of the receptor was investigated in COS-7 cells transiently transfected with P1R-delNt. P1R-delNt was a truncated P1R that lacked most of the amino-terminal extracellular domain. With this receptor construct, PTH(1-34) was a much weaker agonist than it was with P1R-WT, while other PTH(1-14) analogs exhibited approximately the same potency with P1R-delNt as with P1R-WT (Kaul, R., and Balaram, P., Bioorganic & Medicinal Chemistry 7:105-117 (1999)). Consistent with this, the cAMP-stimulating potency of [Aib 1,3 ,M]PTH(1-14) on P1R-delNt (EC 50 =0.73±0.16 nM) was comparable to its potency on COS-7 cells expressing P1R-WT (1.2±0.6 nM) (Table 2). On P1R-delNt, [Aib 1,3 ,M]PTH(1-14) was 55-fold more potent than was [M]PTH(1-14) (EC 50 =40±2 nM, FIG. 3A and Table 2). This result indicated that the potency-enhancing effects of the Aib-1,3 substitutions were exerted through the J domain of the receptor. Remarkably, [Aib 1,3 ,M]PTH(1-14) was as potent on P1R-delNt as PTH(1-34) was on P1R-WT (EC 50 s=0.73±0.16 nM and 1.4±0.7 nM, respectively, P=0.4, Table 2) and the EMax induced by [Aib 1,3 ,M]PTH(1-14) on P1R-delNt was equal to that induced by PTH(1-34) on P1R-WT (250±20 picomole/well and 240±50 picomole/well, respectively, P=0.7, Table 2). As expected, PTH(1-34), was ˜500-fold weaker on P1R-delNt than P1R-WT (EC 50 s=680±110 nM and 1.4±0.7 nM, respectively; FIG. 3A and Table 2).
[0105] Heretofore, it was not possible to demonstrate a PLC response for any PTH analog in cells expressing P1R-delNt, including [M]PTH(1-14). The analog [Aib 1,33 ,M]PTH(1-14), however, induced an approximate 3-fold increase in inositol phosphate (IP) production, relative to the basal level of IPs, in COS-7 cells expressing P1R-delNt, while, as expected, PTH(1-34) and [M]PTH(1-14) were inactive ( FIG. 3B ). Thus, the truncated receptor can couple to the PCL signaling pathway when stimulated with the Aib-containing PTH peptide. With P1R-WT, both [Aib 1,3 ,M]PTH(1-14) and [M]PTH(1-14) stimulated the same 4-fold increase in IP formation that was observed for PTH(1-34) acting on this receptor, and with this receptor, [Aib 1,3 ,M]PTH(1-14) was 66-fold more potent than [M]PTH(1-14) (EC 50 =71±9 nM, and 4,700±2,000 nM, respectively, Table 2). Thus, the Aib-1,3 substitutions enhance the ligand's capacity to stimulate PLC activity with P1R-WT, as well as with P1R-delNt.
[0106] The radioligand used in the above binding studies HKRK-B8 cells, 125 I-[M]PTH(1-21), did not bind detectably to P1R-delNt. To potentially improve affinity of this peptide, the paired Aib-1,3 modifications were introduced to produce [Aib 1,3 ,M]PTH(1-21). The corresponding radioiodinated peptide, 125 I-[Aib 1,3 ,M]PTH(1-21), bound to COS-7 cells expressing P1R-WT; thus, the specific binding of this tracer (e.g. that which could be inhibited by excess unlabeled [Aib 1,3 ,M]PTH(1-21) peptide) was ˜10% and ˜15% of the total radioactivity added, for each receptor, respectively. The total specific binding observed in COS-7 cells tranfected with vector DNA alone was<2% of total radioactivity added. This radioligand, therefore, enabled competition binding experiments to be performed with both the wild-type and truncated PTH-1 receptors. Scatchard transformation of homologous competition binding data obtained with 125 I-[Aib 1,3 , M]PTH(1-21) as tracer radioligand and varying amounts of unlabeled [Aib 1,3 ,M]PTH(1-21) indicated that the ligand's affinity at P1R-delNt was slightly (<2-fold) weaker than it was at P1R-WT (K Dapp s=29±3 and 17±2 nM, respectively, P=0.01), while the corresponding B max values for the two receptors were not significantly different (1.3±0.1×10 6 receptors/cell and 1.9±0.8×10 6 receptors/cell respectively, P=0.3).
[0107] At the truncated receptor, [Aib 1,3 ,M]PTH(1-14), in addition to [Aib 1,3 ,M]PTH(1-21), effectively inhibited the binding of 125 I-[Aib 1,3 ,M]PTH(1-21), whereas, PTH(1-34) did not ( FIG. 3C ). Like [Aib 1,3 ,M]PTH(1-21), the apparent binding affinities that [Aib 1,3 ,M]PTH(1-14) and [M]PTH(1-14) exhibited at P1R-delNt were comparable to the corresponding affinities observed at the wild-type P1R (Table 2). At both P1R-delNt and P1R-WT, the binding affinities of [Aib 1,3 ,M]PTH(1-14)were ˜10-fold stronger than the corresponding affinities observed for [M]PTH(1-14). The Aib substitutions therefore enhanced the ligand's binding affinity for the J domain of the P1R.
TABLE 2 Functional properties of PTH analogs in COS-7 cells cAMP PLC Binding EC 50 EMAX (obs.) EC 50 EMAX (obs.) IC 50 Peptide a nM pmole/well (n) nM foldxbasal (n) nM (n) hP1R-WT 92.5 PTH(1-34) 1.4 ± 0.7 240 ± 50 3 17 ± 2 4.2 ± 0.6 3 12 ± 3 4 521 PTH(1-14) 90,000 ± 34,000 140 ± 30* 3 — N.B. 3 621 [M]PTH(1-14) 49 ± 21 240 ± 50 3 4,700 ± 2,000 3.9 ± 0.5 3 20,000 ± 3,000 3 674 [Aib 1,3 M]PTH(1-21) 0.8 ± 0.1 300 ± 30 3 N.D. 28 ± 5 6 671 [Aib 1,3 M]PTH(1-14) 1.2 ± 0.6 240 ± 40 3 71 ± 9 4.3 ± 0.6 3 2,250 ± 1,100 4 682 [Aib 1,3 M]PTH(1-11) 2.1 ± 0.7 190 ± 40 3 N.D. 16,000 ± 1,000 3 684 [Aib 1,3 M]PTH(1-10) 100,000 ± 40,000 120 ± 10* 3 N.D. N.B. 3 hP1R-delNT 92.5 PTH(1-34) 680 ± 110 220 ± 30 3 — 3 N.B. 4 521 PTH(1-14) 140,000 ± 30,000 110 ± 10* 3 — N.B. 3 621 [M]PTH(1-14) 40 ± 2.0 220 ± 20 3 — 3 17,400 ± 1,400 3 674 [Aib 1,3 M]PTH(1-21) 0.38 ± 0.10 240 ± 20 3 N.D. 27 ± 1 6 671 [Aib 1,3 M]PTH(1-14) 0.73 ± 0.16 250 ± 20 3 130 ± 30 3.1 ± 0.2 3 1,600 ± 200 4 682 [Aib 1,3 M]PTH(1-11) 2.00 ± 0.40 220 ± 20 3 N.D. 13,000 ± 1,000 3 684 [Aib 1,3 M]PTH(1-10) 53,000 ± 10,000 84 ± 4* 3 N.D. N.B. 3 The peptides were derivatives of rat PTH with C-terminal carboxamides; in PTH(1-14) and shorter analogs, “M” refers to the amino acid modifications: Ala 3,12. Gln 10 , Har 11 , Trp 14 , unless the residue position was absent due to truncation or replaced by Aib (α-aminoisobutyric acid); in the PTH(1-21) analog, “M” refers to the same modifications and the modifications # of Nle 8 , Arg 19 and Tyr 21 . Peptides were evaluated in COS-7 cells transiently transected with either the wild-type hP1R (hP1R-WT), or a truncated hP1R lacking most of the amino-terminal extracellular domain (hP1R-delNt). The basal levels of cAMP were 10.3 ± 1.1 and 9.5 ± 1.3 picomole per well for hP1R-WT and hP1R-delNt, respectively. The basal levels of 3 H-inositol phosphates were 1,103 ± 143 and 2,929 ± 877 cpm per well for hP1R-WT and hP1R-delNt, respectively. The Emax (obs.) (maximum response observed) values in the cAMP and PLC assays were determined at ligand doses of 0.1 to 100 μM; an asterisk indicated that a plateau in the response curve was not attained and the curve-fitting equation used to determine the EC 50 was constrained to within one standard deviation of the maximum response observed with the same receptor in the same assay. Competition binding assays were performed # with 125 1-[Aib 1,3 , M]PTH(1-21) radioligand as tracer. Values are means (±S.E.M.) of data from the number of independent experiments indicated (n), each of which was performed in duplicate. A dashed line indicates that no cAMP or PLC response was observed. N.B. indicates that no inhibition of tracer binding was observed. N.D. indicates that the experiment was not done.
Example 3
Activity in Bone Cells
[0108] The number of PTH-1 receptors expressed on the surface of the PTH target cells in bone or kidney is uncertain, but it is likely to be considerably lower than that found in HKRK-B28 cells. Therefore, several of the Aib-mounted PTH analogs were evaluated using SaOS-2 cells. These cells were derived from a human osteosarcoma, exhibited osteoblast-like properties and endogenously expressed relatively low levels of the PTH-1 receptor (˜20,000 receptors/cell (Marx, U. C., et al., J. Biol. Chem. 273:4308-4316 (1998)). In these cells, [Aib 1 ,M]PTH(1-14) and [Aib 3 ,M]PTH(1-14) were 15- and 8-fold more potent in stimulating cAMP formation than was [M]PTH(1-14), and [Aib 1,3 ,M]PTH(1-14) was 130-fold more potent than [M]PTH(1-14) ( FIG. 4 and Table 3). Thus, in SaOS-2 cells, [Aib 1,3 ,M]PTH(1-14) was only 13-fold less potent than PTH(1-34) and at least five-orders of magnitude more potent than native PTH(1-14), for which no activity could be detected, even at a dose of 10 μM ( FIG. 4 ).
[0109] Whether or not [Aib 1,3 ,M]PTH(1-14) activity could be detected in a more intact bone system was studied in an explant assay. An explant assay utilized cartilaginous metatarsal rudiments isolated from E15.5mouse embryos and subsequently cultured in multi-well plates containing serum-free media. A PTH peptide analog or vehicle control, was added to the culture 16 h after explantion, then again at 24 h. The incubation was terminated 24 h later for a total of 48 h of treatment over a 64 h period. In the absence of PTH, chondrocyte differentation occurred, such that by the end of the experiment, dense mineralization was apparent at the bone's mid-section ( FIG. 5A ). Differentiation was inhibited by the presence of PTH(1-34) (0.1 μM) or [Aib 1,3 ,M]PTH(1-14) (1μM), as no mineralization was observed ( FIGS. 5 , B and C). Mineralization was also inhibited in these assays by [Aib 1,3 ,M]PTH(1-14), whereas no effect could be detected for native PTH(1-14) (2 μM) ( FIG. 5D ). Comparable results were obtained in each of three replicate experiments. In addition, mRNA in situ hybridization analysis performed on the explanted metatarsals demonstrated that both PTH(1-34) and [Aib 1,3 ,M]PTH(1-14) inhibited expression of the collagen X gene, a bone developmental marker gene (data not shown). These inhibitory effects were consistent with the known capacity of PTHRP to retard chondrocyte differentiation in the growth plate cartilage of developing long bones (Pellegrini, M., et al., Biochemistry 37:12737-12743 (1998)).
TABLE 3 cAMP Stimulation in SaOS-2 cells Peptide EC 50 nM EMAX (obs.) pmole/well n 93 PTH (1-34) 0.2 ± 0.02 350 ± 30 4 621 [M]PTH(1-14) 340 ± 120 340 ± 30 4 521 PTH(1-14) N.R. 2 622 [Aib 1 , M]PTH(1-14) 22 ± 4 340 ± 30 4 624 [Aib 3 , M]PTH(1-14) 42 ± 8 330 ± 30 4 671 [Aib 1,3 , M]PTH(1-14) 2.6 ± 0.5 320 ± 30 3 The peptides PTH(1-34) ([Nle 8,21 , Tyr 34 ]PTH(1-34)amide), [M]PTH(1-14) (m = Ala 3,12 , Gln 10 , Har 11 , Trp 14 ), native PTH(1-14), and analogs of[M]PTH(1-14) containing α-aminoisobutyric acid (Aib) at positions 1 and/or 3, were evaluated for the capacity to stimulate cAMP production in the human osteoblastic cell line SaOS-2. The calculated EC50 values and observed maximum response values are means (±S.E.M.) of data from the number of experiments indicated (n). The basal cAMP level was 6.4 ± 0.8 (n = 4). N.R. indicates that no cAMP response was detected.
Example 4
Circular Dichroism
[0110] Circular dichroism (CD) spectroscopy was used to analyze the potential effects that the Aib substitutions had on peptide secondary structure when the peptides were free in solution. Samples were analyzed in both aqueous phosphate buffer and in phosphate buffer containing 2,2,2-trifloroethanol, an organic solvent which promotes helical structure in oligopeptides, including PTH peptide fragments (Pellegrini, M., et al., J. Biol. Chem. 273:10420-10427 (1998); Gronwald, W., et al., Biol. Chem. Hoppe Seyler 377:175-186 (1996); Barden, J. A., and Kemp, B. E., Biochemistry 32:7126-7132 (1993)). In phosphate buffer, the helical content of each peptide, estimated from the elipticity observed at 222 nM, was small (≦16%); however, [Aib 1,3 ,M]PTH(1-14) contained nearly twice as much helix as did [M]PTH(1-14) (16% and 8.1% respectively), as did [Aib 1,3 ,M]PTH(1-1l), as compared to [M]PTH(1-1) (13% and 7.5% respectively, Table 4). In 2,2,2-trifluoroethanol, the helical content of each peptide increased; [Aib 1,3 ,M]PTH(1-14) and [Aib 1,3 ,M]PTH(1-11) exhibited the two highest levels of helical content (56% and 57%, respectively) and were each more helical than their Ala-1,-3-containing counterpart peptides ( FIG. 6 and Table 4). The higher helical contents of these two peptides were evident not only from the negative elipticities at 192 nM and 222 nM, but also from the positive elipticities at 192 nM ( FIG. 6 ). Unmodified PTH(1-11) exhibited the least amount of helical structure (30%), whereas [Aib 1,3 ,M]PTH(1-10) was approximately 47% helical ( FIG. 6 and Table 4). These results suggest that the Aib-1,3 modifications increase the helical structure of the N-terminal PTH oligo peptides in the free solution phase.
TABLE 4 Helicity in N-terminal PTH peptides [0] 222 obs × 10 −3 helical residues (%) peptide Phos. Phos + TFE Phos. Phos + TFE PTH(1-14) −2.6 −10.6 9.1 38 [M]PTH(1-14) −2.3 −11.9 8.1 42 Aib 1,3 , M]PTH(1-14) −4.6 −15.7 16 56 PTH(1-11) −1.8 −8.4 6.5 30 [M]PTH(-11) −2.1 −9.9 7.5 35 [Aib 1,3 , M]PTH(1-11) −3.7 −16.1 13 57 [Aib 1,3 , M]PTH(1-10) −3.2 −13.1 11 47 Circular dichroism spectra were recorded in either 50 mM phosphate buffer or 50 mM phosphate buffer containing trifluoroethanol (20%) as described in Material and Methods and shown in FIG. 6 . The mean residue elipticity ([0] 222 obs/ [0] 222 max ) × 100; where [0] 222 obs is the mean residue elipticity at 222 nM observed for that peptide and [0] 222 max is the mean residue elipticity # reported for a model helical peptide of 10 amino acids (−28.1 × 10 −3 ; Yang et al. 1986 Methods in Enzymol. 130, 208-269).
Example 5
PTH Analogs
[0111] As the first step, Aib was introduced at each position in [M]PTH(1-14). The Aib-scanning data indicated that substitutions at most positions diminished activity. However, the Aib scan data revealed considerable (8- to 10-fold) improvements in cAMP signaling potency with substitutions at position one and three, and these effects were additive, as [Aib 1,3 ,M]PTH(1-14), with an EC 50 of ˜1 nM in HKRK-B28 cells, was 100-fold more potent than [M]PTH(1-14), and at least as potent as PTH(1-34).
[0112] Competition binding studies performed with 125 I-[M]PTH(1-21) indicated that most of the Aib substitutions exerted their effects on potency (positive or negative), at least in part, by changing PTH-1 receptor-binding affinity. Thus, the Aib-1 and Aib-3 substitutions each improved the apparent affinity of [M]PTH(1-14) for HKRK-B28 cells by approximately 10-fold, and the combined Aib-1,3 substitution increased affinity by approximately 100-fold. Likewise, the decreases in cAMP signaling potency caused by most of the other Aib substitutions could be explained by decreases in apparent binding affinity, even though, overall, binding affinities were generally 10- to 100-fold weaker than the corresponding cAMP signaling potencies. Two exceptions to this were the peptides substituted at positions 2 and 6, at which signaling potency was comparable with (position 2) or ˜10-fold weaker than the corresponding apparent binding affinity. That the substitution of Aib for valine-2 or glutamine-6 impaired signaling activity more than receptor-binding affinity, is consistent with the disproportionate reductions in signaling potency, relative to binding affinity, that occur with substitutions at these positions in PTH(1-34) analogs, and, in fact, result in PTH-1R antagonists (Cohen, F. E., et al., J. Biol. Chem. 266:1997-2004 (1991); Gardella, T. J., et al., J. Biol. Chem. 266:13141-13146(1991), Carter 1999 #1180).
[0113] The 100-fold increase in cAMP-stimulating potency effect that occurred with the paired Aib-1,3 modification to [M]PTH(1-14) seems consistent with the hypothesis that an α-helix in the N-terminal portion of PTH is required for activation of the PTH-1 receptor. The capacity of Aib to stabilize α-helical structure in oligopeptides arises from the steric restrictions on the rotations about the N-C° (φ) and C°-CO (ψ) bonds of the Aib residue that are imposed by the two methyl groups symmetrically bonded to its C° atom (Kaul, R., and Balaram, P., Bioorganic & Medicinal Chemistry 7:105-117 (1999); Burgess, A. W., and Leach, S. J., Biopolymers 12:2599-2605 (1973)). The φ and ψ torsion angles about this C° atom are tightly restricted to those that occur in α-helices but the symmetry of the di-allyl-substituted C° atom of Aib allows for either right-handed or left-handed α-helices. If the latter “reversed” configuration occurs in an otherwise right-handed helix, then the Aib residue will, in all probability, induce a turn, and thus terminate the helix (Kaul, R., and Balaram, P., Bioorganic & Medicinal Chemistry 7:105-117 (1999); Venkataram Prasad, B. V., et al., Biopolymers 18:1635-1646 (1979)). This reversed configuration is rare in peptide structures, relative to the right-handed configuration (Kaul, R., and Balaram, P., Bioorganic & Medicinal Chemistry 7:105-117 (1999)), but it nevertheless leaves open the possibility that Aib at the amino-terminus of PTH(1-14) enhances potency through some mechanism other than stabilization of an α-helix.
[0114] It is also of interest that the most beneficial effects on peptide potency/affinity occurred with Aib substitutions at positions 1 and 3, since none of the structural studies on PTH(1-34) analogs have detected structure N-terminal of residue 3. It may be that Aib at position 1 nucleates helix formation of “down-stream” residues within itself participating in the helix. Alternatively, the modification may induce or stabilize helical structure at the very N-terminus of the peptide which is simply too unstable in the native sequence to be detected by NMR spectroscopy or x-ray crystallography. In any case, the 1000-fold higher cAMP signaling potency exhibited by [Aib 1,3 ,Gln 10 ,Har 11 ]PTH(1-11) as compared to [Ala 3 ,Gln 10 ,Har 11 ]PTH(1-11) (EC 50 s˜6 nM Vs. 3 μM, respectively, Table 1 and (Shimizu, M., et al., Endocrinology (2001) (In Press)) demonstrates that the effects of the Aib substitutions are exerted locally, e.g. within the first 11 amino acids of the peptide.
[0115] Direct structural analyses of these analogs, as free peptides, or potentially in complex with the PTH-1 receptor, could provide valuable insights into the ligand structures that allow a ligand to act as an agonist on the PTH-1 receptor. In this regard, the information derived from the data set described herein could be of use in the design of peptide mimetics for the PTH-1 receptor. Approaching this problem from the standpoint of the native PTH peptide sequence is made difficult by the conformational diversity that is possible at each position in the peptide backbone chain. The incorporation of stereochemically constrained amino acids, such as Aib, into the peptide chain, lessens this problem, as it serves to nucleate predictable peptide structures. Thus, the approach can facilitate the de novo design of peptide or nonpeptide agonists for the PTH-1 receptor. Given the recently proven utility of PTH(1-34) in treating osteoporosis (Neer, R. M., et al., N.E.J.M. 344:1434-1441 (2001)), such agonists should have important medical impact.
[0116] At the molecular level, it is presently unclear how the [Aib 1,3 ,M]PTH analogs interact with the receptor; nor is this known for any PTH ligand, although fairly specific computer models of the interaction with native PTH are now being developed (Jin, L., et al., J. Biol. Chem. 275:27238-27244 (2000); Rölz, C., and Mierke, D. F., Biophysical Chemistry (2000) (In Press)). The above described experiments with the truncated PTH-1 receptor, P1R-delNt, provide some insights, as they demonstrate that the enhancing effects of the Aib substitutions at positions 1 and 3 are mediated through the juxtamembrane region (J domain) of the receptor containing the extracellular loops and transmembrane domains. This finding is consistent with the cumulative crosslinking and mutational data on the PTH/PTH-1 receptor interaction, which indicate that residues in the (1-14) domain of PTH interact primarily, if not exclusively, with the receptor's J domain, as opposed to its amino-terminal extracellular domain (N domain) (Bergwitz, C., et al., J. Biol. Chem. 271:26469-26472 (1996); Hoare, S. R. J., et al., J. Biol. Chem 276:7741-7753 (2001); Behar, V., et al., J. Biol. Chem. 275:9-17 (1999); Shimizu, M., et al., J. Biol. Chem. 275:19456-19460 (2000); Luck, M. D., et al., Molecular Endocrinology 13:670-680 (1999); Shimizu, M., et al., J. Biol. Chem. 275:21836-21843 (2000); Carter, P. H., and Gardella, T. J., Biochim. Biophys. Acta 1538:290-304 (2001); Gardella, T. J., et al., Endocrinology 132:2024-2030 (1993); Bisello, A., et al., J. Biol. Chem. 273:22498-22505 (1998)).
[0117] Another important conclusion to derive from our study with P1R-delNt, in which [Aib 1,3 ,M]PTH(1-14) exhibited low nanomolar potency and full efficacy in cAMP assays and nearly fill efficacy in PLC assays, is that the truncated receptor, which lacks nearly all of the N domain, is capable of mounting a sensitive and robust response to a small agonist ligand. The availability of a radioligand that binds to the P1R-delNt, 125 I-[Aib 1,3 ,M]PTH(1-21), enabled, for the first time, binding studies to be performed on this truncated receptor. Scatchard analysis of our homologous competition binding data yielded Bmax values for P1R-delNt that were not significantly different from those observed for P1R-WT (1.3±0.1 receptors/cell Vs. 1.9±0.8 receptors/cell, respectively, P=0.3). Thus, the truncated receptor is well expressed on the surface of COS-7 cells. Not surprisingly, PTH(1-34) failed to inhibit the binding of 125 I-[Aib 1,3 ,M]PTH(1-21) to P1R-delNt, a result which highlights the importance of the interaction between the N domain of the receptor and the C-terminal (15-34) domain of the native peptide in stabilizing the overall hormone-receptor complex. This result also supports the view that the interaction between the amino-terminal portion of PTH and the J domain of the receptor is of very weak affinity (Hoare, S. R. J., et al., J. Biol. Chem 276:7741-7753 (2001)). Clearly, the affinity of the interaction can be improved considerably, as the apparent affinity with which [Aib 1,3 ,M]PTH(1-14) bound to P1R-delNt (IC 50 ˜1,500 nM) was much greater than that of native PTH(1-14), which failed to inhibit tracer binding. The 50-fold difference that we observed in the affinities with which [Aib 1,3 ,M]PTH(1-14) and [Aib 1,3 ,M]PTH(1-21) bound to P1R-delNt shows that residues C-terminal of residue 14 (e.g., residues 15-21) contribute binding interactions to the J domain of the receptor. Studies on related analogs suggest that at least some of this effect involves residue 19.
[0118] In summary, highly potent PTH(1-14) analogs are obtained by introducing the conformationally constrained amino acid, Aib, at the N-terminus of the peptide. The propensity of Aib to stabilize α-helical structure, and the high potency with which the modified analogs activated P1R-delNt, show that the N-terminal portion of PTH is α-helical when it is bound to the activation domain of the receptor. The results also establish that the activation domain of the PTH-1R, as defined by P1R-delNt, is fully capable of mediating high affinity and productive interactions with an agonist ligand.
Example 6
PTH(1-34) Derivatives
[0119] We have found that Aib substitutions at positions 1 and 3 in PTH(1-34) ([Tyr34]hPTH(1-34)amide) improve cAMP-stimulating potency on P1R-delNT expressed in COS-7 cells by ˜100-fold, relative to unmodified PTH(1-34) (see Table 5 and FIG. 7B ). The Aib substitutions do not detectably improve potency of PTH(1-34) on the intact wild-type PTH-1 receptor in COS-7 cells (Table 5, and FIG. 7A ); a result which may be due to the already maximal response mediated by native PTH(1-34) in these cells which express very high levels of the intact receptor. In a less sensitive cell system, such as with the delNT receptor, in which nearly the entire amino-terminal extracellular domain of the receptor is deleted, or perhaps in bone cells in animals expressing low levels of endogenous PTH receptors, the effect of Aib-1,3 substitutions on PTH(1-34) potency are significant. Peptides with other, above described modifications (e.g. Gln10, homoArg11, Ala12, Trp14, Arg19) are much more potent than PTH(1-34) in COS-7 cells expressing hP1R-delNT as well. For example, [Aib 1,3 ,Gln 10 ,Har 11 , Ala 12 ,Trp 14 ,Arg 19 ,Tyr 34 ]hPTH(1-34) has an EC50 value of 1.9±0.6 nM on P1R-delNT. It is expected that the above described modifications will also be much more potent than PTH(1-34) in other native bone cell systems of low sensitivity.
TABLE 5 cAMP Responses of hPTH(1-34) Analogs in COS-7 Cells EC50(nM) EC50(nM) peptide hP1R-WT hP1R-delNt [Tyr 34 ]-hPTH(1-34) 0.44 ± 0.02 2,800 ± 300 [Aib 1,3 , Tyr 34 ]-hPTH(1-34) 0.67 ± 0.18 43 ± 24
[0120] Having now fully described the present invention in some detail by way of illustration and example for purposes of clarity of understanding, it will be obvious to one of ordinary skill in the art that same can be performed by modifying or changing the invention with a wide and equivalent range of conditions, formulations and other parameters thereof, and that such modifications or changes are intended to be encompassed within the scope of the appended claims.
[0121] All publications, patents and patent applications mentioned hereinabove are herein incorporated in their entirety and by reference to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated by reference. | The present invention relates to conformationally constrained parathyroid hormone (PTH) analogs, and methods of preparing and using the PTH analogs. The invention provides novel PTH polypeptide derivatives containing amino acid substitutions at selected positions in the polypeptides. The invention provides derivatives of PTH (1-34), PTH(1-21), PTH(1-20), PTH(1-19), PTH(1-18), PTH(1-17), PTH(1-16), PTH(1-15), PTH(1-14), PTH(1-13), PTH(1-12), PTH(1-11) and PTH(1-1 0) polypeptides, wherein at least one residue in each polypeptide is a helix, preferably an a-helix, stabilizing residue. The invention also provides methods of making such peptides. Further, the invention encompasses compositions and methods for use in limiting undesired bone loss in a vertebrate at risk of such bone loss, in treating conditions that are characterized by undesired bone loss or by the need for bone growth, e.g. in treating fractures or cartilage disorders and for raising cAMP levels in cells where deemed necessary. | 97,419 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International Application No. PCT/EP2006/069104, filed Nov. 30, 2006 and claims the benefit thereof. The International Application claims the benefits of European application No. 05026378.9 filed Dec. 2, 2005, both of the applications are incorporated by reference herein in their entirety.
FIELD OF INVENTION
[0002] The invention relates to an alloy as described in the claims, a protective layer for protecting a component against corrosion and/or oxidation at high temperatures and a component as described in the claims.
[0003] The invention relates in particular to a protective layer for a component that consists of a nickel-base or cobalt-base superalloy.
BACKGROUND OF THE INVENTION
[0004] Numerous protective layers for metallic components that are supposed to increase the corrosion resistance and/or oxidation resistance of said components are known from the prior art. Most of these protective layers are known under the collective name MCrAlX, where M stands for at least one of the elements selected from the group consisting of iron, cobalt and nickel and further essential constituents are chromium, aluminum and X=Yttrium, wherein the latter may also be partially or completely replaced by an equivalent element selected from the group consisting of scandium and the rare earth elements.
[0005] Typical coatings of this type are known from U.S. Pat. Nos. 4,005,989 and 4,034,142.
[0006] U.S. Pat. No. 6,280,857 B1 discloses a protective layer which contains the elements cobalt, chromium and aluminum, based on nickel, with the optional addition of rhenium and obligatory admixtures of yttrium and silicon.
[0007] EP 1 439 245 A1 discloses a cobalt-based rhenium-containing layer.
[0008] The objective of increasing the inlet temperatures of both stationery gas turbines and aircraft engines is of considerable significance in the specialist field of gas turbines, since the inlet temperatures are important variables determining the thermodynamic efficiencies which can be achieved by gas turbines. The use of specially developed alloys as base materials for components which are to be exposed to high thermal stresses, such as guide vanes and rotor blades, and in particular the use of single-crystal superalloys, allows the use of inlet temperatures of well over 1000° C. Nowadays, the prior art permits inlet temperatures of 950° C. and above in the case of stationary gas turbines and 1100° C. and above in the case of gas turbines for aircraft engines.
[0009] Examples of the structure of a turbine blade or vane having a single-crystal substrate, which for its part may be of complex structure, are revealed by WO 91/01433 A1.
[0010] Whereas the physical load-bearing capacity of the base materials which have by now been developed for the highly stressed components does not present any major problems with a view to possible further increases in the inlet temperatures, protective layers have to be employed to achieve sufficient resistance to oxidation and corrosion. In addition to the sufficient chemical stability of a protective layer under the attacks expected from flue gases at temperatures of the order of magnitude of 1000° C., a protective layer also has to have sufficiently good mechanical properties, not least with a view to the mechanical interaction between the protective layer and the base material. In particular, the protective layer must be sufficiently ductile to enable any deformation of the base material to be followed and not to crack, since points of attack for oxidation and corrosion would be created in this way. This typically gives rise to the problem that an increase in the levels of elements such as aluminum and chromium, which can increase the resistance of a protective layer to oxidation and corrosion, leads to a deterioration in the ductility of the protective layer, which means that mechanical failure, in particular the formation of cracks, is likely under mechanical loading which usually occurs in a gas turbine.
SUMMARY OF INVENTION
[0011] Accordingly, the invention is based on the object of providing an alloy and a protective layer which has a good high-temperature stability with regard to corrosion and oxidation, good long-term stability and, moreover, is particularly well matched to mechanical stresses which are expected at a high temperature in particular in a gas turbine.
[0012] The object is achieved by the alloy as claimed in the claims and the protective layer as claimed in the claims.
[0013] A further object of the invention is to provide a component which offers increased protection against corrosion and oxidation.
[0014] This object is achieved by the component as claimed in the claims, in particular a component of a gas turbine or steam turbine, which for protection against corrosion and oxidation at high temperatures, has a protective layer of the type described above.
[0015] The subclaims list further advantageous measures.
[0016] The measures listed in the subclaims can be combined with one another as desired in advantageous ways.
[0017] The invention is based on the discovery, inter alia, that the desired protective layer has brittle precipitates in the layer and also in the transition region between the protective layer and the base material. These brittle phases, the formation of which increases over time and with use temperature, in operation lead to highly pronounced longitudinal cracks in the layer and in the layer/base material interface, with subsequent layer detachment. The interaction with carbon, which can diffuse out of the base material into the layer or diffuses into the layer through the surface during a heat treatment in the furnace, additionally increases the brittleness of the precipitates. The susceptibility to cracking is boosted still further by oxidation of the brittle precipitates.
[0018] In this context, the influence of nickel, which determines thermal and mechanical properties, is also important.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The invention is explained in more detail below. In the drawing:
[0020] FIG. 1 shows a layer system having a protective layer,
[0021] FIG. 2 shows compositions of superalloys,
[0022] FIG. 3 shows a gas turbine,
[0023] FIG. 5 shows a perspective view of a turbine blade or vane, and
[0024] FIG. 4 shows a perspective view of a combustion chamber.
DETAILED DESCRIPTION OF INVENTION
[0025] According to the invention, a protective layer 7 ( FIG. 1 ) for protecting a component against corrosion and oxidation at high temperature comprises the following elements (details of amounts in wt %):
[0026] 27% to 31% nickel
[0027] 23% to 29% chromium
[0028] 7% to 11% aluminum
[0029] 0.5% to 0.7% yttrium and/or at least one metal selected from the group consisting of scandium and the rare earth elements, optionally 0.6% to 0.8% silicon, and/or optionally 0.5% to 0.7% zirconium, remainder cobalt (CoNiCrAlY).
[0030] It is preferable for either only silicon or zirconium to be added.
[0031] Particular exemplary embodiments are:
[0032] 1) Co-30Ni-28Cr-8Al-0.6Y
[0033] 2) Co-30Ni-28Cr-8Al-0.6Y-0.7Si
[0034] 3) Co-28Ni-24Cr-10Al-0.6Y-0.6Zr.
[0035] It should be noted that the levels of the individual elements are specifically adapted with a view to their actions. Surprisingly, the selection of 27 wt % to 31 wt % nickel significantly and disproportionately improves the thermal and mechanical properties of the protective layer 7 .
[0036] In conjunction with the reduction in brittle phases, which have negative effects in particular with relatively elevated mechanical properties, the reduction in the mechanical stresses resulting from the selected nickel content improves the mechanical properties.
[0037] The protective layer, with a good resistance to corrosion, has a particularly good resistance to oxidation and is furthermore distinguished by especially good ductility properties, making it particularly well qualified for use in a gas turbine with a further increase in the inlet temperature. Scarcely any embrittlement occurs during operation.
[0038] The trace elements in the powder to be sprayed, which form precipitates and therefore constitute sources of embrittlement, also play an important role.
[0039] The powders are applied, for example, by plasma spraying (APS, LPPS, VPS, . . . ). Other processes are also conceivable (PVP, CVD, cold spraying).
[0040] The protective layer 7 described also acts as a bonding layer to a superalloy.
[0041] Further layers, in particular ceramic thermal barrier coatings 10 , can be applied to this protective layer 7 .
[0042] In this component, the protective layer 7 is advantageously applied to a substrate 4 made from a nickel-base or cobalt-base superalloy.
[0043] A suitable substrate has in particular the following composition (details in wt %):
[0000]
0.1% to 0.15%
Carbon
18% to 22%
Chromium
18% to 19%
Cobalt
0% to 2%
Tungsten
0% to 4%
Molybdenum
0% to 1.5%
Tantalum
0% to 1%
Niobium
1% to 3%
Aluminum
2% to 4%
Titanium
0% to 0.75%
Hafnium
[0044] optionally small quantities of boron and/or zirconium, remainder nickel.
[0045] Compositions of this type are known as casting alloys under the names GTD222, IN939, IN6203 and Udimet 500.
[0046] Further alternatives for the substrate of the component are listed in FIG. 2 .
[0047] The thickness of the protective layer 7 on the component 1 is preferably between approximately 100 μm and 300 μm.
[0048] The protective layer 7 is particularly suitable for protecting a component against corrosion and oxidation when the component is exposed to a flue gas at a material temperature of around 950° C., and in the case of aircraft turbines even around 1100° C.
[0049] The protective layer 7 according to the invention is therefore particularly well qualified for protecting a component of a gas turbine 100 , in particular a guide vane 120 , rotor blade 130 or other component, which is exposed to hot gas upstream of or in the turbine of the gas turbine.
[0050] The protective layer 7 can be used as an overlay (the protective layer is the outer layer) or as a bond coat (the protective layer is an interlayer).
[0051] FIG. 1 shows a layer system 1 as a component.
[0052] The layer system 1 comprises a substrate 4 .
[0053] The substrate 4 may be metallic and/or ceramic. In particular in the case of turbine components, such as for example turbine rotor blades 120 ( FIG. 5 ) or turbine guide vanes 130 ( FIGS. 3 , 5 ), combustion chamber linings 155 ( FIG. 4 ) and other housing parts of a steam or gas turbine 100 ( FIG. 3 ), the substrate 4 consists of a nickel-base, cobalt-base or iron-base superalloy.
[0054] It is preferable to use cobalt-base or nickel-base superalloys.
[0055] The protective layer 7 according to the invention is present on the substrate 4 .
[0056] It is preferable for this protective layer 7 to be applied by LPPS (low pressure plasma spraying).
[0057] It can be used as the outer layer (not shown) or as the interlayer ( FIG. 1 ).
[0058] In the latter case, a ceramic thermal barrier coating 10 is present on the protective layer 7 .
[0059] The protective layer 7 can be applied to newly produced components and refurbished components.
[0060] Refurbishment means that after they have been used, layers (thermal barrier coating) may have to be detached from components 1 and corrosion and oxidation products removed, for example by an acid treatment (acid stripping). If appropriate, cracks also have to be repaired. This can be followed by recoating of a component of this type, since the substrate 4 is very expensive.
[0061] FIG. 3 shows by way of example a partial longitudinal section through a gas turbine 100 .
[0062] In its interior, the gas turbine 100 has a rotor 103 which is mounted such that it can rotate about an axis of rotation 102 , has a shaft 102 , and is also referred to as the turbine rotor.
[0063] An intake casing 104 , a compressor 105 , a for example toric combustion chamber 110 , in particular an annular combustion chamber, with a plurality of coaxially arranged burners 107 , a turbine 108 and the exhaust gas casing 109 follow one another along the rotor 103 .
[0064] The annular combustion chamber 110 is in communication with a for example annular hot gas duct 111 . There, by way of example, four successive turbine stages 112 form the turbine 108 .
[0065] Each turbine stage 112 is formed for example from two blade rings. As seen in the direction of flow of a working medium 113 , a guide vane row 115 is followed in the hot gas duct 111 by a row 125 formed from rotor blades 120 .
[0066] The guide vanes 130 are secured to an inner casing 138 of a stator 143 , whereas the rotor blades 120 belonging to a row 125 are arranged on the rotor 103 , for example by means of a turbine disk 133 .
[0067] A generator (not shown) is coupled to the rotor 103 .
[0068] While the gas turbine 100 is operating, air 135 is drawn in through the intake casing 104 and compressed by the compressor 105 . The compressed air provided at the turbine end of the compressor 105 is passed to the burners 107 , where it is mixed with a fuel. The mixture is then burnt in the combustion chamber 110 , forming the working medium 113 . From there, the working medium 113 flows along the hot gas duct 111 past the guide vanes 130 and the rotor blades 120 . The working medium 113 is expanded at the rotor blades 120 , transferring its momentum, so that the rotor blades 120 drive the rotor 103 and the latter in turn drives the generator coupled to it.
[0069] While the gas turbine 100 is operating, the components which are exposed to the hot working medium 113 are subject to thermal stresses. The guide vanes 130 and rotor blades 120 of the first turbine stage 112 , as seen in the direction of flow of the working medium 113 , together with the heat shield elements which line the annular combustion chamber 110 , are subject to the highest thermal stresses.
[0070] To be able to withstand the temperatures which prevail there, they can be cooled by means of a coolant.
[0071] Substrates of the components may likewise have a directional structure, i.e. they are in single-crystal form (SX structure) or have only longitudinally oriented grains (DS structure).
[0072] By way of example, iron-base, nickel-base or cobalt-base superalloys are used as material for the components, in particular for the turbine blade or vane 120 , 130 and components of the combustion chamber 110 .
[0073] Superalloys of this type are known for example from EP 1 204 776 B1, EP 1 306 454, EP 1 319 729 A1, WO 99/67435 or WO60/44949; these documents form part of the disclosure with regard to the chemical composition of the alloys.
[0074] The guide vane 130 has a guide vane root (not shown here) facing the inner casing 138 of the turbine 108 and a guide vane head at the opposite end from the guide vane root. The guide vane head faces the rotor 103 and is fixed to a securing ring 140 of the stator 143 .
[0075] FIG. 5 shows a perspective view of a rotor blade 120 or guide vane 130 of a turbomachine, which extends along a longitudinal axis 121 .
[0076] The turbomachine may be a gas turbine of an aircraft or of a power plant for generating electricity, a steam turbine or a compressor.
[0077] The blade or vane 120 , 130 has, in succession along the longitudinal axis 121 , a securing region 400 , an adjoining blade or vane platform 403 , a main blade or vane part 406 and a blade or vane tip 415 .
[0078] As a guide vane 130 , the vane 130 may have a further platform (not shown) at its vane tip 415 .
[0079] A blade or vane root 183 , which is used to secure the rotor blades 120 , 130 to a shaft or a disk (not shown), is formed in the securing region 400 .
[0080] The blade or vane root 183 is designed, for example, in hammerhead form. Other configurations, such as a fir-tree or dovetail root, are possible.
[0081] The blade or vane 120 , 130 has a leading edge 409 and a trailing edge 412 for a medium which flows past the main blade or vane part 406 .
[0082] In the case of conventional blades or vanes 120 , 130 , by way of example solid metallic materials, in particular superalloys, are used in all regions 400 , 403 , 406 of the blade or vane 120 , 130 .
[0083] Superalloys of this type are known, for example, from EP 1 204 776 B1, EP 1 306 454, EP 1 319 729 A1, WO 99/67435 or WO 00/44949; these documents form part of the disclosure with regard to the chemical composition of the alloy.
[0084] The blade or vane 120 , 130 may in this case be produced by a casting process, also by means of directional solidification, by a forging process, by a milling process or combinations thereof.
[0085] Workpieces with a single-crystal structure or structures are used as components for machines which, in operation, are exposed to high mechanical, thermal and/or chemical stresses.
[0086] Single-crystal workpieces of this type are produced, for example, by directional solidification from the melt. This involves casting processes in which the liquid metallic alloy solidifies to form the single-crystal structure, i.e. the single-crystal workpiece, or solidifies directionally.
[0087] In this case, dendritic crystals are oriented along the direction of heat flow and form either a columnar crystalline grain structure (i.e. grains which run over the entire length of the workpiece and are referred to here, in accordance with the language customarily used, as directionally solidified) or a single-crystal structure, i.e. the entire workpiece consists of one single crystal. In these processes, a transition to globular (polycrystalline) solidification needs to be avoided, since non-directional growth inevitably forms transverse and longitudinal grain boundaries, which negate the favorable properties of the directionally solidified or single-crystal component.
[0088] Where the text refers in general terms to directionally solidified microstructures, this is to be understood as meaning both single crystals, which do not have any grain boundaries or at most have small-angle grain boundaries, and columnar crystal structures, which do have grain boundaries running in the longitudinal direction but do not have any transverse grain boundaries. This second form of crystalline structures is also described as directionally solidified microstructures. (directionally solidified structures).
[0089] Processes of this type are known from U.S. Pat. No. 6,024,792 and EP 0 892 090 A1; these documents form part of the disclosure with regard to the solidification process.
[0090] The blades or vanes 120 , 130 may likewise have protective layers 7 according to the invention protecting against corrosion or oxidation. The density is preferably 95% of the theoretical density. A protective aluminum oxide layer (TGO=thermally grown oxide layer) is formed on the MCrAlX layer (as an interlayer or as the outermost layer).
[0091] It is also possible for a thermal barrier coating, which is preferably the outermost layer and consists for example of ZrO 2 , Y 2 O 3 —ZrO 2 , i.e. unstabilized, partially stabilized or fully stabilized by yttrium oxide and/or calcium oxide and/or magnesium oxide, to be present on the MCrAlX.
[0092] The thermal barrier coating covers the entire MCrAlX layer.
[0093] Columnar grains are produced in the thermal barrier coating by means of suitable coating processes, such as for example electron beam physical vapor deposition (EB-PVD).
[0094] Other coating processes are conceivable, for example atmospheric plasma spraying (APS), LPPS, VPS or CVD. The thermal barrier coating may have grains that are porous and/or include micro-cracks or macro-cracks in order to improve the resistance to thermal shocks. Therefore, the thermal barrier coating is preferably more porous than the MCrAlX layer.
[0095] The blade or vane 120 , 130 may be hollow or solid in form. If the blade or vane 120 , 130 is to be cooled, it is hollow and may also have film-cooling holes 418 (indicated by dashed lines).
[0096] FIG. 4 shows a combustion chamber 110 of the gas turbine 100 . The combustion chamber 110 is configured, for example, as what is known as an annular combustion chamber, in which a multiplicity of burners 107 , which generate flames 156 and are arranged circumferentially around an axis of rotation 102 , open out into a common combustion chamber space 154 . For this purpose, the combustion chamber 110 overall is of annular configuration positioned around the axis of rotation 102 .
[0097] To achieve a relatively high efficiency, the combustion chamber 110 is designed for a relatively high temperature of the working medium M of approximately 1000° C. to 1600° C. To allow a relatively long service life even with these operating parameters, which are unfavorable for the materials, the combustion chamber wall 153 is provided, on its side which faces the working medium M, with an inner lining formed from heat shield elements 155 .
[0098] A cooling system may also be provided for the heat shield elements 155 and/or their holding elements, on account of the high temperatures in the interior of the combustion chamber 110 . The heat shield elements 155 are then for example hollow and may also have cooling holes (not shown) which open out into the combustion chamber space 154 .
[0099] On the working medium side, each heat shield element 155 made from an alloy is equipped with a particularly heat-resistant protective layer (MCrAlX layer and/or ceramic coating) or is made from material that is able to withstand high temperatures (solid ceramic bricks).
[0100] These protective layers 7 may be similar to those used for the turbine blades or vanes 120 , 130 , i.e. for example MCrAlX: M is at least one element selected from the group consisting of iron (Fe), cobalt (Co), nickel (Ni), X is an active element and stands for yttrium (Y) and/or silicon and/or at least one of the rare earth elements, or hafnium (Hf). Alloys of this type are known from EP 0 486 489 B1, EP 0 786 017 B1, EP 0 412 397 B1 or EP 1 306 454 A1.
[0101] A for example ceramic thermal barrier coating, consisting for example of ZrO 2 , Y 2 O 3 —ZrO 2 , i.e. unstabilized, partially stabilized or fully stabilized by yttrium oxide and/or calcium oxide and/or magnesium oxide, may also be present on the MCrAlX.
[0102] Columnar grains are produced in the thermal barrier coating by suitable coating processes, such as for example electron beam physical vapor deposition (EB-PVD).
[0103] Other coating processes are conceivable, for example atmospheric plasma spraying (APS), LPPS, VPS or CVD. The thermal barrier coating may have grains that are porous and/or include micro-cracks or macro-cracks in order to improve the resistance to thermal shocks.
[0104] Refurbishment means that after they have been used, protective layers may have to be removed from turbine blades or vanes 120 , 130 , heat shield elements 155 (e.g. by sand-blasting). Then, the corrosion and/or oxidation layers and products are removed.
[0105] If appropriate, cracks in the turbine blade or vane 120 , 130 or the heat shield element 155 are also repaired. This is followed by recoating of the turbine blades or vanes 120 , 130 , heat shield elements 155 , after which the turbine blades or vanes 120 , 130 or the heat shield elements 155 can be reused. | Known protective layers with a high Cr content and additionally a silicon form brittle phases, which become even more brittle under the influence of carbon during use. The protective layer according to the invention has the composition 27% to 31% nickel, 23% to 29% chromium, 7% to 11% aluminum, 0.5% to 0.7% yttrium and/or at least one equivalent metal from the group comprising scandium and rare earth elements, optionally 0.6% to 0.8% silicon, optionally 0.5% to 0.7% zirconium and the remainder cobalt. | 26,046 |
FIELD OF THE INVENTION
[0001] The present invention relates to a highly efficient process for producing isoxazoline derivatives.
BACKGROUND OF THE INVENTION
[0002] Isoxazoline derivatives represented by the general formula (1)
[0000]
[0000] wherein Ar 1 represents an aryl group which may be substituted; Ar 2 represents another aryl group, which may be substituted as well, and may or may not be the same as Ar 1 ; R represents electron withdrawing group including but not limited to alkoxycarbonyl, aryloxycarbonyl, aminocarbonyl, cyano, alkylcarbonyl, arylcarbonyl, formyl, alkylsulfinyl, arylsulfinyl, alkylsulfonyl or arylsulfonyl are compounds that are widely used in the field of agriculture. One particular example of the isoxazoline derivatives is ethyl 5,5-diphenyl-3-isoxazolinecarboxylate (commercially known as isoxadifen-ethyl) which is used as a safener in a herbicide for corn production (WO 01/54501/A2 by Syngenta participations AG) and as an insecticide (WO 2006/8110 A1 by Bayer cropscience AG). The estimated worldwide annual consumption of isoxadifen-ethyl is 800 to 1000 tons.
[0003] Heretofore, the isoxazoline derivatives represented by the formula (1) are generally prepared through dipolar [2+3] cycloaddition of the corresponding alkenes represented by the general formula (2)
[0000]
[0000] and 1-chloro-oxime represented by the general formula (3) (DE 4331448 A1 19950323)
[0000]
[0000] wherein R 1 , R 2 and R are as defined as above.
[0004] Another prior art process for preparing the isoxazoline derivatives represented by the formula (1) is the [2+3] dipolar cycloaddition of alkenes represented by the formula (2) with nitro compounds represented by the general formula (4) (Tetra. Asymmetry, 2008, 19, 2850-2855)
[0000]
[0000] wherein R is as defined above.
[0005] These two processes to prepare the isoxazoline derivatives are generally well-known in the prior art. However, the disadvantages of the processes are also generally recognized in the field, particularly for preparing ethyl 5,5-diphenyl-3-isooxazolinecarboxylate:
[0006] A) Both of these two processes are low efficiency: through these processes the isoxazoline derivative is produced in modest yield (86% yield using one equivalent of ethyl 2-chloro-2-hydroxyiminoacetate and 1.5 equivalents of 1,1-diphenylethene (DE 4331448 A1 19950323), and 75% yield when the nitro compound used (Tetra. Asymmetry, 2008, 19, 2850-2855));
[0007] B) The materials used in these processes are expensive because they have to be made in two or three steps from more common materials; for example, the alkene, 1,1-diphenylethene represented by the general formula (2), wherein R 1 , R 2 are Phenyls, is commonly made by the reaction of the corresponding diphenyl ketone and the Grignard reagent in an anhydrous pyrophoric ethereal solvent, followed by dehydrogenation with strong acid; and the ethyl 2-chloro-2-hydroxyiminoacetate represented by the general formula (3), wherein R is ethoxycarbonyl, is generally prepared from glycine via esterification with large excess of thionyl chloride, a process through which a large quality of hydrogen chloride and sulphur dioxide are released; followed by oxidation with nitrite under acidic conditions, and the ethyl 2-chloro-2-hydroxyiminoacetate was obtained in only 55-76% overall yield (Bulletin of the Chemical Society of Japan, 1971, 44, 219); and the synthesis of the nitro compounds (4) is achieved in 60-78% yield through nitration of ethyl acetoacetate with fumic nitric acid in acetic anhydride (U.S. Pat. No. 5,162,572 A1 1992). Overall, the existing processes for producing the isoxazoline derivatives represented by the general formula (1) are of low efficiency, highly expensive, and environmentally costly. As a result, there is real need for a novel cost-effective process to improve the production yield and ease the environmental concern.
[0008] Cyclopropane derivatives with vicinal electron donor and acceptor substituents are able to be subjected to heterolytic ring cleavage to form 1,3 zwitterionic intermediates (Reissig, H.-U. Topics of Current Chemistry, 144, 73, 1988). In particular, when treated with unsaturated electrophiles they undergo [2+3] type reactions to form five membered carbon or heterocyclic compounds (Shimada, S.; Hashimoto, Y.; Sudo, A.; Hasegawa, M.; Saigo, K. Journal of Organic Chemistry, 57, 7126, 1992; Graziano, M. L.; Isece, M. R.; Cermola, F. Journal of Chemical Research, (S) 82, (M) 0622, 1996). Among these unsaturated electrophiles, nitrosylation reagents including NOCI, NOBr, NOBF 4 , NaNO 2 —CF 3 CO 2 H have been reported to react with cyclopropane derivatives to form isoxazoline derivatives or/and isoxazodine derivatives: cyclopropane derivatives that have been reported to react with NOCI include ethyl 2,2-dimethoxycyclopropanyl carboxylate, ethyl 2,2-dimethoxy-3,3-dimethylcyclopropanyl carboxylate, ethyl 2-ethoxy-cyclopropanyl carboxylate, ethyl 2,2-dimethoxy-3-methylcyclopropanyl carboxylate (Cermola, F.; Gioia, L. D.; Graziano, M. L.; Isece, M. R.; Journal of Chemical Research 677-681, 2005); cyclopropane derivatives that have been reported to react with NOBF 4 include ethyl 2-ethoxy-cyclopropanyl carboxylate (Cermola, F.; Gioia, L. D.; Graziano, M. L.; Isece, M. R.; Journal of Chemical Research 677-681, 2005), 1,1-dichloro-2-arylcyclopropane (Lin, S.-T.; Kuo, S.-H.; Yang, F.-M. Journal of Organic Chemistry, 62, 5229, 1997), 1-aryl-2-arylcyclopropane (Mizuno, K.; Ichinose, N.; Tamai, T.; Otsuji, Y. Journal of Organic Chemistry, 57, 4669-4675, 1992), phenylcyclopropane (Kim, E. K.; Kochi, J. K. Journal of American Chemical Society, 113, 4962, 1991); cyclopropane derivatives that have been reported to react with NaNO 2 —CF 3 CO 2 H include ethyl 2-arylcyclopropanyl carboxylate (Kadzhaeva, A. Z.; Trofimova, E. V.; Fedotov, A. N.; Potekhin, K. A.; Gazzaeva, R. A.; Mochalov, S. S.; Zefirov, N. S. Journal of Heterocyclic Compounds 45, 595, 2009). However, examples presented in these publications listed above clearly demonstrate that the reaction of nitrosylation reagents and cyclopropanes is not feasible as a method for preparing isoxazoline derivatives, as the reaction generally delivers a mixture composed of the desired isoxazoline derivatives, isoxazlidine derivatives and other non-cyclic compounds. And the desired isoxazoline derivatives were generated only in low yields.
[0009] This invention discloses a novel process to prepare isoxazoline derivatives represented by the general formula (1) in high efficiency from easy accessible materials. Therefore, it addresses the need for a more cost-effective and more environmentally friendly technology for the synthesis process. This need is solved by the subject matter disclosed herein.
SUMMARY OF THE INVENTION
[0010] This invention provides an efficient process to produce the isoxazolidine derivatives represented by the general formula (1)
[0000]
[0000] wherein Ar 1 , Ar 2 represent aryl groups that may contain one to five substituents that include but not limited to halide, alkyloxy, alkyl, aryl, carbonyl, nitro, cyano; and Ar 2 may or may not be the same as Ar 1 ; R represents an electron withdrawing group including but not limited to alkoxylcarbonyl, aryloxylcarbonyl, aminocarbonyl, cyano, alkylcarbonyl, arylcarbonyl, formyl, alkylsulfinyl, arylsulfinyl, alkylsulfonyl, arylsulfonyl from the corresponding cyclopropane derivatives represented by the general formula (5)
[0000]
[0000] wherein Ar 1 , Ar 2 and R are as defined above, with electrophilic nitrosylation reagents including but not limited to nitrosylchloride, nitrosylbromide, nitrosylsulfuric acid or a combination of sodium nitrite or potassium nitrite with strong acid including but not limited to sulphuric acid, trifluoroacetic acid, hydrogen chloride or nitric acid, or with Lewis acid including but not limited to BF 3 , AlCl 3 in the solvent including but not limited to acetic acid, trifluoroacetic acid, sulphuric acid, halogenated solvent such as dicloromethane, 1,2-dichloroethane etc., aromatic solvent such as benzene, toluene, chlorobenzene etc.; aliphatic ether, aliphatic ester, acetonitrile, at the temperature ranging from −20° C. to 100° C.
DETAILED DESCRIPTION OF THE INVENTION
[0011] The applicant has discovered an efficient process to prepare the isoxazoline derivatives represented in the general formula (1)
[0000]
[0000] by reacting the cyclopropane derivatives represented in the general formula (5)
[0000]
[0000] with an electrophilic nitrosylation reagent; wherein Ar 1 , Ar 2 in both formula (1) and (5) represent aryl groups that may be substituted, and Ar 2 may or may not be the same as Ar 1 ; R represents electron withdrawing group including but not limited to alkoxylcarbonyl, aryloxylcarbonyl, aminocarbonyl, cyano, alkylcarbonyl, arylcarbonyl, formyl, alkylsulfinyl, arylsulfinyl, alkylsulfonyl, arylsulfonyl, nitro; and the electrophilic nitrosylation reagents include but not limited to nitrosylchloride, nitrosylbromide, nitrosylsulfuric acid and electrophilic nitrosylation reagents composed of at least one member of nitrites including but not limited to lithium nitrite, sodium nitrite or potassium nitrite and one member of strong acids including but not limited to sulphuric acid, trifluoroacetic acid, hydrogen chloride nitric acid, or with Lewis acid including but not limited to BF 3 , AlCl 3 in the solvent including but not limited to acetic acid, trifluoroacetic acid, sulphuric acid, halogenated solvent such as dicloromethane, 1,2-dichloroethane etc.; aromatic solvent such as benzene, toluene, chlorobenzene etc.; aliphatic ether, aliphatic ester, acetonitrile at the temperature ranging from −20° C. to 100° C.
[0012] The invention is described in details via preparation of ethyl 5,5-diphenyl-3-isoxazolinecarboxylate. The corresponding cyclopropane derivative, ethyl 2,2-diphenylcyclopropanylcarboxylate, is prepared via an amended known one step process: diphenyl diazomethane solution was efficient, economic and environmentally benign produced by oxidizing diphenylketone hydrazine with either yellow mercury oxide (Synlett, 11, 1623-1626, 2010; Yu, J.; Lian, G.; Zhang, D. Synthetic communications, 37, 37-46, 2007), manganese dioxide (Tetrahedron, 54, 6867-6896, 1998) or sodium hypochlorite (Tokushima, I.-K.; Naruto, I.-W.; Tokushima, M.-S. PCT/JP94/02124); and decomposition of diphenyl diazomethane in the presence of ethyl acrylate at 50° C. produces ethyl 2,2-diphenylcyclopropylcarboxylate in greater than 94% overall yield. The ethyl 2,2-diphenylcyclopropanylcarboxylate thus prepared is normally contaminated with less than five percent of various impurities depending on the exact method used. The presence of impurities in the cyclopropane derivatives obtained does not have significant impact on the production of the isoxazoline derivatives.
[0013] Non-limiting examples of electrophilic nitrosylation reagent used in the reaction of this invention include nitrosylchloride, nitrosylbromide, nitrosylsulfuric acid or a combination of nitrite salt including but not limited to sodium nitrite or potassium nitrite with strong acid including but not limited to sulphuric acid, trifluoroacetic acid, hydrogen chloride, nitric acid, or with strong Lewis acid including but not limited to boron trifluoride, aluminium trichloride.
[0014] Non-limiting examples of solvent used in the reaction of this invention include acetic acid, trifluoroacetic acid, sulphuric acid, nitric acid, halogenated solvent such as dichloromethane, 1,2-dichloroethane; aromatic solvent such as benzene, toluene, chlorobenzene; aliphatic ether, aliphatic ester, acetonitrile.
[0015] The mole ratio of nitrosylation reagent to the cyclopropane derivatives represented by the general formula (5) varies from 1:1 to 10:1. And the most preferred ratio is approximately 1.1:1.
[0016] The concentration of the cyclopropane derivatives represented by the general formula (5) used in the reaction can range from 0.01 mole per litre to 10.0 mole per litre, the preferable concentration is within the range of 0.1 mole per litre to 5.0 mole per litre.
[0017] In this invention, the reaction is a strong exothermic process. It is preferable to maintain the reactants at the temperature as low as possible while slowly mixing the nitrosylation reagent mentioned above with the cyclopropane derivatives represented by the general formula (5). Generally the reaction temperature needs to be maintained below 100° C., and more preferred below 40° C.
[0018] The Examples listed below illustrate methods for preparing the isoxazoline derivatives according to the invention.
EXAMPLES
Example 1
Synthesis of 2,2-diphenylcyclopropanyl carboxylate ethyl ester
[0019] Diphenylketone hydrazone (3.92 g, 20 mmol) was mixed with yellow mercury oxide (4.33 g, 20 mmol) in 40 mL petroleum. The mixture was stirred at the temperature less than 20° C. for 16 hours. The deep red solution of diphenyl diazomethane in petroleum was added into ethyl acrylate (6.0 g, 60 mmol) at 50° C. in ten minutes. When the red colour fade off the solvent and excess of ethyl acrylate were removed under reduced pressure and the crude product obtained was further purified over silica chromatography to furnish 2,2-diphenylcyclopropanyl carboxylate ethyl ester 5.11 g (96% yield) as a pale yellow oil. 1 H NMR (400 MHz, CDCl 3 ): 7.36-7.17 (10H, m), 4.00-3.83 (2H, m), 2.54 (1H, dd, J=8.3, 6.0 Hz), 2.17 (1H, dd, J=1H, dd, 6.0, 4.8 Hz), 1.59 (1H, dd, J=8.3, 4.8 Hz), 1.01 (3H, t, J=7.1 Hz).
Example 2
Synthesis of 2,2-diphenylcyclopropanyl carboxylate ethyl ester
[0020] Diphenylketone hydrazone (8.9 g, 45.4 mmol) in DCM (19 mL) was mixed with KI (0.45 g) in water (0.6 mL) and benzyldimethyloctylammonium chloride (10 mg). To the mixture was added the aqueous solution composing of 25% NaOH (27 mL), water (18 mL), and sodium chlorite (12-14%, 28 mL) at 5° C. with vigorous stirring. Twenty minutes later after addition, the stirring was turned off to let the reaction mixture separate. The red DCM solution was separated and dried over anhydrous Na 2 SO 4 . After removing the desiccant, the solvent was removed under reduced pressure; the residue was re-dissolved in hexane, and the unreacted hydrazone and side product was insoluble in hexane and removed by filtration. The red hexane diphenyl diazomethane solution was added to ethyl acrylate (13.6 g, 136 mmol) at 50° C. within 30 mints. When the red colour fade off the solvent and excess of ethyl acrylate was removed under reduced pressure to give crude product with 94% purity in 56-94% yield.
Experiment 3
Synthesis of 2,2-diphenylcyclopropanyl carboxylate ethyl ester
[0021] To the solution of diphenylketone hydrazone (45 g, 0.227 mol) in 220 mL chloroform was added activated MnO 2 (Aldrich, 85%, 49.4 g, 0.567 mol). The mixture was vigorously stirred at the temperature less than 20° C. until all starting material had been consumed. The solid was removed by filtration over celite. And the deep red solution was added to 68 g ethyl acrylate at 50° C. in 40 mints. When the red colour fade off, the chloroform (more than 200 mL) and excess ethyl acrylate (37 g) were collected by distillation; and the crude product obtained containing great than 96% of 2,2-diphenylcyclopropanyl carboxylate ethyl ester.
Experiment 4
Synthesis of 5,5-diphenylisoxazoline carboxylate ethyl ester
[0022] The cyclopropane derivative, 2,2-diphenylcyclopropanyl carboxylate ethyl ester (0.97 g, 3.7 mmol) was dissolved in 3.7 mL CF 3 CO 2 H. Into the solution was added NaNO 2 (0.28 g, 4.0 mmol, 1.1 eq.) in several ports so that the reaction temperature did not excess 40° C. After addition, the reactants were stirred at room temperature (about 18° C.) for half an hour. And the reactants were poured into an iced water and extracted with diethyl ether (2×20 mL); the ethereal solutions were combined and subsequently washed with sat. NaHCO 3 (2×20 mL), then water (20 mL) and brine (20 mL). The washed ethereal solution was then dried over anhydrous Na 2 SO 4 . After removing the desiccant, the ethereal solution was concentrated to obtain a light brown oil. The crude product 1 H NMR of the crude product showed that the reaction was clean and a virtual 100% yield. The crude product was further purified over silica chromatography (Rf: 0.45, eluent: 20% ethyl acetate in petrol) to obtain 5,5-diphenylisoxazoline carboxylate ethyl ester 0.958 g (89% yield) as a white solide. 1 H NMR (400 MHz, CDCl 3 ): 7.41-7.26 (10H, m), 4.34 (2H, q, J=7.1 Hz), 3.86 (2H, s), 1.36 (3H, t, J=7.1 Hz). 13 C NMR (400 MHz, CDCl 3 ): 160.54, 151.09, 142.99, 128.54, 128.02, 125.95, 94.79, 62.15, 46.78, 14.12.
Example 5
Synthesis of 5,5-diphenylisoxazoline carboxylate ethyl ester
[0023] The cyclopropane derivative, 2,2-diphenylcyclopropanyl carboxylate ethyl ester (1.0 g, 3.8 mmol) was dissolved in 4.0 mL AcOH at room temperature (18° C.). Into the solution was carefully added 2.0 mL concentrated H 2 SO 4 , followed by adding NaNO 2 (0.29 g, 4.1 mmol, 1.1 eq) in several portions so that the reaction temperature did not excess 40° C. After addition, the reactants were stirred at room temperature (about 18° C.) for half an hour before the reactants were poured into iced water and extracted with diethyl ether (2×20 mL), the ethereal solutions were combined and washed with sat. NaHCO 3 (2×20 mL), then water (20 mL) and brine (20 mL). The washed ethereal solution was then dried over Na 2 SO 4 . After removing the desiccant, the ethereal solution was concentrated to furnish a thick oily product. The 1 H NMR of the crude product showed that the reaction was clean and the yield was virtually 100%. The thick oily crude product was stirred with 10 mL petrol to give a pale yellow solid 1.07 g, 97% yield.
Example 6
Synthesis of 5,5-diphenylisoxazoline carboxylate ethyl ester
[0024] The crude cyclopropane derivative, 2,2-diphenylcyclopropanyl carboxylate ethyl ester (generated through the reported one step procedure as a crude product in 107% yield) (1.14 g, 4.3 mmol) was dissolved in 4.0 mL AcOH at room temperature (18° C.). Into the solution was carefully added 2.0 mL concentrated H 2 SO 4 , followed by adding NaNO 2 (0.33 g, 4.7 mmol, 1.1 eq) in several portions so that the reaction temperature did not excess 40° C. After addition, the reactants were stirred at room temperature (about 18° C.) for half an hour. And the reactants were poured into an iced water and extracted with diethyl ether (2×20 mL), the ethereal solutions were combined and washed with sat. NaHCO 3 (2×20 mL), then water (20 mL) and brine (20 mL) in sequence. The washed ethereal solution was then dried over Na 2 SO 4 . After removing the desiccant, the ethereal solution was concentrated to furnish a thick oily crude product. The 1 H NMR of the crude product showed that the reaction was clean and a virtual 100% yield. The thick oily crude product was stirred with 10 mL petrol to give a pale yellow solid 1.15 g, 91% yield (97% over yield in two steps based on diphenyl ketone hydrazine).
Example 7
Synthesis of 5,5-diphenylisoxazoline carboxylate ethyl ester
[0025] The crude cyclopropane derivative, 2,2-diphenylcyclopropanyl carboxylate ethyl ester (generated through the reported one step procedure as a crude product in 107% yield) (21.3 g, 80 mmol) was dissolved in 80.0 mL AcOH at room temperature (18° C.). Into the solution was carefully added 40.0 mL concentrated H 2 SO 4 , followed by adding NaNO 2 (6.1 g, 88 mmol, 1.1 eq) in several portions so that the reaction temperature did not excess 40° C. After addition, the reactants were stirred at room temperature (about 18° C.) for half an hour. And the reactants were poured into an iced water and extracted with diethyl ether (2×200 mL), the ethereal solutions were combined and washed with sat. NaHCO 3 (2×100 mL), then water (100 mL) and brine (50 mL) in sequence. The washed ethereal solution was then dried over Na 2 SO 4 . After removing the desiccant, the ethereal solution was concentrated to furnish a thick oily crude product. The 1 H NMR of the crude product showed that the reaction was clean and a virtual 100% yield. The thick oily crude product was stirred with 10 mL petrol to give a pale yellow solid 21.7 g, 92% yield (98% over yield in two steps based on diphenyl ketone hydrazine). | A process for producing isoxazoline derivatives by ring-opening and cyclization of the corresponding cyclopropane derivatives with electrophilic nitrosylation reagents. | 21,730 |
BACKGROUND OF THE INVENTION
As the connections between healthy teeth and gums, and general overall health, have become increasingly evident in the past 100 years, oral care has become an important part of people's daily health maintenance regimens. In the process, a healthy looking smile has become representative of one's level of personal grooming, and even social status, with straight, white and well shaped teeth being promoted in advertising and by cosmetic dentists as an integral part of one's self-image. Over the past 20 years, the availability of tooth whitening products and services has exploded in the marketplace, ranging from low priced over-the-counter (OTC) self-applied trays, strips, pens, mouthwashes and toothpastes, to expensive professionally applied or monitored products and procedures capable of effectively whitening teeth in as little as 45 minutes. In general, professionally applied products and services administered to a patient in a dental office or other clinical setting are seen to achieve the best teeth whitening results in the shortest amount of time. This is primarily due to the concentration of active ingredient, usually hydrogen peroxide or a hydrogen peroxide precursor, found in professionally applied whitening compositions. Such high concentrations, typically above 15% hydrogen peroxide by weight and often as high as 50% hydrogen peroxide by weight, can only be safely administered in a controlled setting where a professionally trained individual can isolate soft tissues from contact with these highly oxidative compositions. Frequent monitoring, of a patient's progress over, for instance, a one-hour period is also critical in maintaining a high degree of safety when working with such high hydrogen peroxide concentrations. Optionally, light or heat energy may be applied in conjunction with these strong oxidizing compositions, in order to accelerate the process beyond that which is possible using just the compositions on then own. In general, these professionally-monitored products and services applied in a dental office or clinic will be referred to collectively as in-office or chairside whitening procedures.
Chairside whitening procedures are generally performed during a dental appointment scheduled specifically for the purpose of whitening the patient's teeth, or as an adjunct following a professional teeth cleaning, formally known as a dental prophylaxis or “prophy”. When tooth whitening is conducted immediately following a prophy, the total amount of time that the patient must remain in a dental chair can often exceed two hours.
A professional tooth cleaning is recommended by the American Dental Association as a means to prevent gum disease. Gum disease, of periodontitis, is the primary cause of tooth loss in adults over the age of 40. Gum disease has also been linked to other health problems, such as heart disease, osteoporosis, respiratory diseases, and other more serious systemic diseases. According to the Center for Disease Control and Prevention, approximately 68% of adults in the United States have at least one professional tooth cleaning annually (2008). There is speculation as to the reasons why so many adults neglect the benefits obtainable from regular tooth cleanings, ranging from lack of health insurance to the fear of dental procedures. Lack of patient knowledge is a problem that can be managed, however studies have shown that better education of patients only leads to modest changes in behavior and attitudes towards preventative dentistry.
In general, a typical teeth cleaning dental appointment comprises the following, procedural steps:
(1) A dental hygienist or dental assistant may or may not take x-rays of a patient's teeth. (2) The dental hygienist or dental assistant will generally take between 15 and 60 minutes to work on the teeth and gums (the exact time depending upon both the amount of accumulation present, as well as the teeth cleaning method chosen), using a variety of tools, including manual or ultrasonic scalers to remove the tartar and plaque from the patient's teeth. (3) The hygienist will then floss between the teeth and generally complete the cleaning procedure by polishing the front (buccal) and had (lingual) surfaces of the teeth with an abrasive composition known as a prophylaxis (“prophy”) paste. Tooth polishing leaves a smooth tooth surface that is more resistant to the adhesion and buildup of dental plaque between dental cleaning appointments.
Despite the apparent benefits of preventative teeth cleaning as described above, nearly 80% of the population has some form of gum disease ranging from early stage gingivitis to advanced periodontitis. Symptoms of guru disease may include one or more of the following: bleeding gums, halitosis bad breath), bad taste in the mouth, tooth sensitivity, sore gums, loose adult teeth, abscessed teeth or gums pulling away from the teeth, changes in the way the teeth fit together or dentures fitting poorly, exudates between the gums and teeth, sores in the mouth, and actual tooth loss. Such a high rate of chronic or acute gum disease indicates a low level of compliance when it comes to scheduling of a regular dental cleaning, and any means of increasing such compliance would clearly be beneficial to the patient's general oral health.
BRIEF DESCRIPTION OF THE INVENTION
The inventive tooth cleaning and whitening method comprises novel compositions and procedural steps that allow for the simultaneous performance of a dental prophylaxis and tooth whitening procedure. The procedure involves steps performed at least partially in parallel or contemporaneously with a typical dental prophylaxi procedure during which a significant amount of plaque, tartar and acquired pellicle are removed, in general, these steps may include, but are not limited to, chemical, mechanical and/or chemomechanical tooth surface conditioning, contact or impregnation of one or more teeth with a catalyst, contact or impregnation of one or more teeth with an oxidiz ing agent, exposure of one or more teeth to actinic energy comprising heat, light, sound, ultrasound, air or mechanical pressure (and combinations thereof), and contact or impregnation of one or more teeth with a tooth remineralizing, opacifying or pigmenting composition. Combinations of the above procedural steps have been developed that accomplish significant whitening of stained teeth in less than about 90 minutes when performed in conjunction with or during a dental prophylaxis procedure.
The ability of the inventive compositions and methods to simultaneously whiten teeth in parallel with a dental cleaning procedure is highly dependent upon the ability of the oxidizing agent to penetrate into tooth enamel and dentin. Both tooth enamel and dentin are composite structures comprising both organic and inorganic phases as well as interstitial spaces that are occupied by fluid. These interstitial spaces can accommodate fluid movement, which is generally in an outward direction, in other words from the interior of the tooth towards the enamel surface. However, fluids and other materials in contact with the enamel surface can influence fluid movement through tooth enamel and dentin with concentration gradients and/or capillary action, as well as in conjunction with pressure, heat, light and other external physical forces that can change the dynamic relationship between the tooth and the fluid in contact with the tooth.
Mathematical models have been constructed to predict the ability of fluids to penetrate into porous substrates. The Lucas-Washburn equation is one such method of developing a comparative “Penetration Coefficient” for various fluids, based on their viscosity, surface tension (with air) and contact angle (with a porous substrate). The model assumes that the porous solid is a bundle of open capillaries, so in other words the Penetration Coefficient is a comparative predictor of capillary flow rate. The Lucas-Washburn equation
d 2 = ( γ cos θ 2 η ) rt
predicts the distance (d) traveled by a liquid in a porous substrate, where the liquid has a surface tension (γ) with air, a contact angle (θ) with the porous substrate surface and a dynamic viscosity (η) and where (r) is the capillary pore radius and (t) is the penetration time. The bracketed component of the Lucas-Washburn equation is the Penetration Coefficient, expressed as centimeters per second
PC
=
γ
cos
θ
2
η
The Lucas-Washburn equation predicts that the higher the PC, the faster a liquid will penetrate into a given porous capillary substrate. This means that, at least in theory, a high PC can be achieved for liquids with low viscosities, particularly for compositions also having a low contact angle (which is often, but not always, associated with a liquid having a low surface tension that will lead to efficient wetting of the porous substrate.
Penetration coefficients have been used recently to design improved dental materials, specifically sealants and low-viscosity composites intended to arrest the progression of carious lesions (Paris, et al, Penetration Coefficients of Commercially Available and Experimental Composites Intended to Infiltrate Enamel Carions Lesions , Dental Materials 23 (2007) 742-748). The authors show that low viscosity materials with high Penetration Coefficients (>50 cm/s) are capable of penetrating enamel carious lesions better than materials with low PCs (see corresponding patent application US 2006/0264532).
Prior art tooth whitening compositions have generally been formulated to have high viscosities for better retention in dental trays during the bleaching process, which prevents migration of the whitening composition from the tray due to salivary dilution. Moderate to high viscosities have also been the norm for chairside whitening procedures, in order to prevent the whitening composition from migrating away from the tooth enamel surface. According to the Lucas-Washburn equation, moderate to high viscosity tooth whitening compositions (greater than about 100 centipoise at 25 deg C.) will have low Penetration Coefficients and thus be predicted to have restricted movement into the whitening target, that is, the porous enamel substrate. It would thus be advantageous to design a tooth whitening carrier composition comprising an oxidizing agent with a low viscosity (<100 cps) and a high Penetration Coefficient ( 50 cm/s) in order to achieve rapid penetration into tooth enamel and dentin.
Other factors affecting, the ability of a liquid penetrant to infiltrate enamel and dentin are (1) surface charge effects (which is related to pH of the micro environment within the tooth, as well as the PH and counter ion content of the liquid penetrant), (2) adhesion of the liquid penetrant to the tooth surface (which is related to the surface tension and wetting, ability of the liquid penetrant), and (3) osmotic effects (which are related to the direction of diffusion of the interstitial fluid in the tooth structure in relation to the liquid penetrant in contact with the tooth). Under certain circumstances, tooth whitening composition having viscosities in excess of 100 cps are contemplated, for instance when auxiliary means of increasing the penetration rate are available. For example, a tooth whitening composition with a viscosity between 5,000 and 100,000 cps can be utilized if heat and/or light and/or vibrational energy is used to increase the penetration rate of the composition into the tooth enamel structure.
In general, one aspect of the inventive simultaneous tooth cleaning and whitening method comprises the following steps, preferably performed in a sequence of steps comprising:
applying an oxidizing composition to the surfaces of the teeth to be whitened; and performing a dental cleaning or hygiene procedure while the oxidizing composition is in contact with the teeth to be whitened.
In another aspect of the invention a method for simultaneously cleaning and whitening teeth comprises the steps of:
applying a conditioning composition to the teeth surface; applying an oxidizing composition to the teeth surface; applying a sealant composition to the teeth surface; cleaning the teeth surface; polishing the teeth surface; and removing the condition compositions from the teeth.
In yet another aspect of the invention, a method for simultaneously cleaning and whitening teeth comprises the steps of:
applying a composition to the teeth surface, wherein said composition is comprised of at least a fluid carrier, a tooth conditioner, an oxidizing agent and a water-resistant polymer, cleaning said teeth surface; polishing said teeth surface; and removing said composition,
There is typically an extensive amount of scraping, scaling, and other modes of plaque and tartar removal performed during a dental cleaning or prophylaxis. During the cleaning procedure, the patient's mouth is usually open for an extended period of time during which excess saliva may accumulate in the oral cavity and come in contact with the tooth surfaces. Also, the patient is typically asked to rinse with water or a mouthwash at various times during the cleaning procedure in order to clear debris (plaque, tartar, blood, saliva, etc) from the oral cavity that accumulates from the cleaning process. It has been found that in order to achieve a desirable (that is, a noticeable) level of tooth whitening during said dental cleaning, or prophylaxis, it is advantageous to prevent moisture from saliva or external sources (such as the rinsing solutions referred to above) from directly contacting the tooth surfaces that have been previously contacted with the oxidizing composition. By creating a barrier between extraneous moisture and the oxidizing composition, said moisture is prevented or limited in its ability to remove, dilute, neutralize or otherwise decrease the effectiveness of the oxidizing composition during the cleaning procedure.
One means of limiting the contact of external moisture with the oxidizing composition is to utilize an oxidizing composition having hydrophobic (“water-repelling”) properties when in contact with the tooth surface.
An alternative means of preventing moisture contamination of the oxidizing composition on the tooth surface is to cover the oxidizing composition with a film of water-insoluble or water-resistance material. Such materials may include, but are not limited to polymer films and water-resistant or water-insoluble fluids, gels, creams, waxes and solids.
Yet another alternative means of preventing moisture contamination of the oxidizing composition on the tooth surface is to cover the oxidizing composition with a curable composition that can be converted from a liquid or gel into a higher viscosity liquid, gel or solid upon exposure to an external source of energy. Said external energy source may be electromagnetic or light energy, sound or ultrasound energy, mechanical or vibrational energy, electrical energy, or combinations thereof.
A preferred tooth cleaning and whitening method comprises the following steps
1) Placing a cheek and lip retraction means into the oral cavity of a subject. Said means may include a cheek retractor and/or cotton rolls placed in such a way as to prevent the soft tissue of the inside of the lips and cheeks from coming into contact with the tooth surfaces, 2) Conditioning of the teeth surfaces to be whitened with a conditioning agent or conditioning composition, using chemical, mechanical, or chemo-mechanical means, 3) Contacting the conditioned tooth surfaces with one or more compositions comprising an oxidizing agent, 4) Contacting the tooth surfaces with a water-resistant coating or film-forming composition to protect the oxidizing agent from direct contact with external moisture during the tooth cleaning process, 5) Cleaning and scaling of subject's teeth in proximity to the gum line, gingival margins and crevicular spaces while the compositions of steps (3) and (4) above are in contact with the tooth surfaces, 6) Polishing, the teeth with prophylaxis or polishing paste following completion of step (5), 7) Optionally repeating steps (3) and (4), and 8) Cleaning and rinsing all residual materials from tooth and gum surfaces that were applied or produced during the performance of steps (1) through (7).
Modifications to the above procedure are possible and are some cases preferable. For instance, the conditioning agent or conditioning composition may be combined with the oxidizing composition of step (3) in order to reduce the amount of time required to perform the combined cleaning and whitening procedure. Also, water-resistant properties may be imparted to the oxidizing composition of step (3) in order to obviate the need for a separate step (4). Therefore, it is contemplated, but not required, that the compositions and/or agents of steps (2), (3) and (4) may be combined into a single composition (a) prior to packaging, (b) just prior to use, or (c) on the tooth surface during use. Optionally, a tooth-desensitizing agent, such as potassium nitrate, may be applied before, during, or after any of the steps outlined above. Such tooth-desensitizing, agent may be applied as a stand-alone formulation or combined with the conditioning agent, oxidizing agent, water-resistant or film-forming composition, or any combination of these.
It is also contemplated within the scope of this invention to employ light energy and/or heat energy to accelerate the tooth whitening process through various means such as increasing the rate of oxidizing composition penetration into enamel and dentin, increasing the susceptibility of tooth stain chromogens to oxidation, and accelerating the oxidation process through advanced oxidation processes such as the photo-Fenton reaction. An added benefit of employing light energy, particularly that in the blue region of the light spectrum (approximately 400-500 nanometers), during the inventive simultaneous tooth cleaning and whitening process, is observed by the attenuation and/or killing of periodontal pathogens within the light energy exposure field. A particularly useful benefit to reducing the viability of periodontal pathogens prior to, during and/or after a tooth cleaning is the reduction in risk associated with a lower bacterial burden during a moderately invasive procedure (tooth cleaning) that can sometimes involve bleeding. Reduction of the available numbers and types of oral pathogens during a tooth cleaning, process may be of significant benefit to the subject's overall oral and whole body health, since the association between the presence of periodontal pathogens, such as the black pigmented bacteria species Fusobacterium nucleatum and Porphyromonas gingivalis , and the incidence of systemic diseases (such as heart disease) has been shown in recent years to be quite strong. Light energy employed in the initial steps of the present inventive method is seen to be most beneficial, since pathogen reduction prior to the invasive cleaning process would occur. However, light energy applied at any point in time during the cleaning and whitening process can be of significant benefit to the patient's gingival and periodontal health.
Particularly useful is light energy having the following characteristics: wavelengths of between 380 and 700 nanometers (nm), between 400 and 500 nm, and between 410 and 460 nm; and light intensity (measured at the target surface, for example the tooth or gum surfaces, in terms of power density) of between 100 and 5,000 milliwatts per centimeter squared (mW/cm 2 ), between 100 and 2,000 mW/cm 2 , between 500 and 1,500 mW/cm 2 , and between 100 and 300 mW/cm 2 . Light sources such as light emitting diodes (LEDs), quartz halogen bulbs, tungsten halogen bulbs, plasma arc bulbs, and xenon flash lamps, to name a few, are contemplated to have utility in the present invention. Preferred light sources are LEDs with emission peaks between 400 and 500 nanometers.
BRIEF DESCRIPTION OF THE DRAWING
The objects of the invention will be better understood from the detailed description of its preferred embodiments which follows below, when taken in conjunction with the accompanying drawings, in which like numerals and letters refer to like features throughout. The following is a brief identification of the drawing figures used in the accompanying detailed description.
FIG. 1 is a schematic depiction of an over molded lens that can be attached to a hand-held dental curing lamp for enhancing whitening, in accordance with one aspect of the present invention.
FIG. 2 is an isometric view of the over molded lens shown in FIG. 1 .
Those skilled in the art will readily understand that the drawings in some instances may not be strictly to scale and that they may further be schematic in nature, but nevertheless will find them sufficient, when taken with the detailed descriptions of preferred embodiments that follow, to make and use the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The compositions of the present invention are designed to provide a fast and effective means of whitening the teeth during the performance of a dental cleaning or prophylaxis. Various combinations of tooth conditioning compositions, oxidizing compositions and sealant compositions are envisaged to have utility in the practice of the inventive method, and the properties of these individual compositions may be combined into a single composition for ease of use and application. Alternatively, a tooth conditioning function may be combined with an oxidizing function into a single composition. Another alternative is to combine a tooth sealing function with an oxidizing function to reduce the number of application steps.
The tooth conditioning composition may comprise a fluid carrier and one or more tooth conditioning ingredients. Fluid carriers include water, ethanol, diethyl ether, methoxypropane(methyl propyl ether), dimethyl isosorbide and combinations thereof. The tooth conditioning function, that is the ingredient or ingredients that remove the acquired pellicle and subsequently open the enamel porosities for better penetration of the oxidizing composition, may be provided by ingredients having an acidic and/or calcium chelating capabilities. Useful acidic compounds include both inorganic and organic acids such as phosphoric acid, hydrochloric acid, acetic acid, lactic acid, citric acid, and their salts. Useful calcium chelating compounds include both inorganic and organic chelating agents such as ethylenediaminetetraacetic acid (EDTA), phytic acid, 1-hydroxyethylidene-1,1′-diphosphonic acid, citric acid, and their salts. The tooth conditioning composition may also comprise a colorants and/or pigments to assist in the placement and application of the tooth conditioning composition onto the teeth during the combination whitening and cleaning procedure.
The oxidizing composition comprises a fluid carrier and an oxidizing, agent. Fluid carriers include water, ethanol, diethyl ether, methoxypropane(methyl propyl ether), dimethyl isosorbide and combinations thereof. Oxidizing agents include peroxides, metal chlorites, percarbonates, perborates, peroxyacids, hypochlorites and combinations thereof. Preferred oxidizing agents are hydrogen peroxide, carbamide peroxide, poly(vinyl pyrrolidone)-hydrogen peroxide complex (Peroxydone®, ISP Corp, Wayne, N.J.), peroxyacetic acid, and sodium chlorite. The oxidizing composition preferably has a viscosity of less than about 100 centipoise and most preferably less than about 10 centipoise. The oxidizing composition may also comprise active components further related to the tooth whitening function (such as stabilizers, a secondary oxidizing agent, an oxidation catalyst, a pH-adjusting agent, and a calcium cheating agent), or to a non-tooth whitening function (such as remineralization of the tooth surface, prevention of tooth decay, tooth-desensitization, prevention of gingivitis and/or periodontal disease, and other diseases or conditions of the oral cavity). In addition, the oxidizing composition may comprise one or more colorants and/or pigments to assist in the placement and application of the sealant onto the teeth during the combination whitening and cleaning procedure. Such colorants and/or pigments may also be present to provide a stain masking effect that changes the appearance of the tooth while the oxidizing composition is in contact with the tooth surface during the procedure.
Preferred oxidation catalysts are chelated metal complexes, in particular complexes of iron and manganese. Particularly preferred chelated metal complexes are the family of tetraamido-N-macrocyclic ligand (TAML) iron catalysts described in U.S. Pat. Nos. 7,060,818, 6,241,779, 6,136,223, 6,100,394, 6,054,580, 6,099,586, 6,051,704, 6,011,152, 5,876,625, 5,853,428, and 5,847,120.
The oxidizing compositions of the present invention ay also contain a surface active agent in order to lower the surface tension of the composition to provide for better wetting and adhesion of the liquid to the surface of the tooth. Anionic, cationic, non-ionic and zwitterionic surfactants are contemplated to have utility in providing the oxidizing compositions with a low surface tension. Preferred surfactants are sulfobetaines (such as amidosulfobetaine 3-16 and Lonzaine CS) and fluorosurfactants (such as Capstone 50 and Capstone FS-10).
Sealant compositions of the present invention may comprise a water-resistant polymer, copolymer or crosspolymer, and a fluid carrier. Hereinafter the term “polymer” and “polymers” shall he used to denote polymer(s), copolymer(s) or crosspolymer(s). Suitable water-resistant polymers include acrylate polymers, methacrylate polymers, modified cellulosic polymers, silicone polymers, urethane polymers, polyamide polymers, vinyl polymers, vinyl pyrrolidone polymers, maleic acid or itaconic acid polymers, and others. The water-resistant polymer should be soluble or dispersible in the fluid carrier. Particularly preferred polymers are poly(butyl methacrylate-co-(2-dimethylaminoethyl)methacrylate-co-methyl methacrylate), poly(ethyl acrylate-co-methyl methacrylate-co-trimethylammonioethyl methacrylate chloride), ethylcellulose, and esterified or crosslinked poly(methyl vinyl ether-co-maleic anhydride). The fluid carrier may be a volatile solvent which will evaporate after contacting the sealant composition with the tooth surface, leaving behind a liquid or solid coating or film. Said solvent should have an evaporation rate equal to or greater than that of water, and preferably equal to or greater than that of butyl acetate. Suitable solvents include, but are not limited to, water, ethanol, diethyl ether, methoxypropane(methyl propyl ether), acetone, ethyl acetate, and other highly volatile solvents.
Alternatively, the sealant compositions may be curable liquids or gels, which are placed or the tooth surface and subsequently exposed to sonic form of activating energy which converts the liquid or gel sealant composition to a solid coating or film. Curable sealant compositions may also be chemically cured, whereby two or more components are combined just prior to use and placed on the tooth surface to cure, in other words, to change from a liquid or gel into a solid coating or film.
The sealant composition may also comprise active components related to a tooth whitening function (such as an oxidizing agent, an oxidation catalyst, a pH-adjusting agent, and a calcium chelating agent), or to a non-tooth whitening function (such as remineralization of the tooth surface, tooth-desensitization, prevention of tooth decay, prevention of gingivitis and/or periodontal disease, and other diseases or conditions of the oral cavity). In addition, the sealant composition may comprise one or more colorants and/or pigments to assist in the placement and application of the sealant onto the teeth during the combination whitening and cleaning procedure. Such colorants and/or pigments may also be present to provide a stain masking effect that changes the appearance of the tooth while the sealant composition is attached to the tooth surface in the form of a coating or film.
The combination whitening and cleaning method described herein may also be practiced by employing an additional source of energy to accelerate the oxidation process and further reduce the time needed to complete the procedure. External energy sources such as electromagnetic or light energy, sound or ultrasound energy, mechanical or vibrational energy, electrical energy, or combinations thereof may be advantageously employed at any point in time during the combination whitening and cleaning procedure to accelerate the process.
EXAMPLES
In order to achieve a significant degree of tooth whitening in an abbreviated time frame suitable for integration into the tooth cleaning (dental prophylaxis) process, ideal conditions for (1) oxidizer penetration into the tooth and (2) conversion of initial oxidizer form into active whitening species must be facilitated.
Time limitations are imposed on the additional steps required to achieve whitening during the tooth cleaning process by the realities of patient scheduling in the typical dental office, and such additional steps should not exceed 30 minutes beyond or in addition to the time required to perform a typical dental prophylaxis. Optimal conditions for penetration of an active whitening composition into tooth enamel must he present in order to reduce the amount of time and oxidizer concentration required to reach intrinsic stain depth. Important factors related to oxidizer penetration into the tooth are (1) the viscosity of the oxidizing composition, (2) the surface tension of the oxidizing composition and (3) the surface free energy (also called the critical surface tension) of the tooth surface.
The surface free energy of exposed tooth enamel is generally in the range of about 50-55 dynes/cm, however the acquired pellicle can lower this number significantly. In fact, one of the important functions of the acquired pellicle is to reduce the critical surface tension of the tooth surface in order to reduce the adhesion of bacteria. Liquid and gel compositions contacting the tooth surface penetrate into the tooth structure in relation to four primary factors: time, viscosity of the liquid or gel, surface tension of the liquid or gel, and surface free energy of the tooth at the point of contact.
The relationship of liquid surface tension to solid surface free energy, low contact angle (the tangential angle formed by a droplet deposited on a solid surface) and low viscosity are all directly related to the Penetration Coefficient (as derived from the Lucas-Washburn equation) and must be optimized for the whitening composition to (1) rapidly wet the surface of tooth enamel and (2) penetrate the available porosities and channels through enamel as quickly as physically possible.
Example 1
The ability of various oxidizing compositions to penetrate intact enamel and dentin was determined as follows. Extracted molar and pre-molar teeth were obtained from orthodontists with patient consent and stored refrigerated in phosphate buffered saline (PBS) solution at 6.8 until use. In order to assess the ability of various liquid carrier fluids to penetrate tooth enamel, teeth were sectioned to remove their roots and a 3 mm diameter chamber was created in the center of the sectioned crown that was filled with PBS solution. The crowns were partially immersed (chamber with PBS solution facing up) in various liquid carrier fluids and a small (1 microliter) sample of the PBS solution was drawn every 60 seconds and place on a peroxide test strip (EM Quant Strips 10337, EMD Chemicals, a division of Merck SA, Darmstadt, Germany) to determine the amount of time required for hydrogen peroxide to penetrate the tooth enamel and dentin from the outer surface of the crown to the interior chamber containing PBS.
Oxidizing compositions in Table 1 below were prepared and stored in 20 ml glass vials until use.
TABLE 1
Percent (w/w)
Ingredient
1A
1B
1C
1D
1E
1F
1G
1H
1I
1J
1K
1L
Water
75.0
65.0
75.0
65.0
85.0
75.0
65.0
75.0
65.0
75.0
65.0
100.0
Ethanol 200
10.0
20.0
5.0
15.0
5.0
15.0
Diethyl ether
5.0
5.0
Methoxypropane
5.0
5.0
Acetone
10.0
20.0
Dimethyl isosorbide
10.0
20.0
Hydrogen peroxide
15.0
15.0
15.0
15.0
15.0
15.0
15.0
15.0
15.0
15.0
15.0
0.0
Adjusted to pH 4.0 with potassium hydroxide 0.1M
Viscosity (cps @ 25 C.)
<1
<1
<1
<1
1.3
<1
<1
<1
<1
1.5
1.5
1
Surface tension
<40
<40
<40
<40
>50
<40
<40
<40
<40
<40
<40
>50
dynes/cm
Contact angle (deg)
<10
<10
<10
<10
30+
<10
<10
<10
<10
15
15
50+
PC (calculated)
>100
>100
>100
>100
<50
>100
>100
>100
>100
>100
>100
<30
H 2 O 2 detection (min)
13
12
12
10
20
14
12
14
14
15
15
ND*
*ND = Not detected
Oxidizing compositions in Table I trended towards faster penetration of the tooth when both contact angle and viscosity of the composition was low (Examples 1A, 1B, 1C, 1D, 1F, 1G, 1H, 1I, 1J, and 1K). Oxidizing with high contact angles (greater than 30 degrees) did not seem to penetrate as well as those with contact angles less than about 10 degrees.
Example 2
The following multi-step process was developed to provide for rapid and effective whitening of the teeth during a dental cleaning procedure.
Step 1—Acquired Pellicle Removal
Facilitating oxidizer penetration into the tooth requires a thorough removal or modification of the acquired pellicle prior to contact with the oxidizer formulation. Therefore, whether integrated into a dental prophylaxis procedure or performed as a stand-alone process, the first step in the abbreviated whitening process (after determining a starting tooth shade) must be the removal of the acquired pellicle using chemical, mechanical or (preferably) chemo-mechanical means. Once the acquired pellicle has been removed, it is important that the “cleaned” tooth enamel surface has limited contact with the patient's saliva prior to application of the oxidizer composition (see Step 2) in order to prevent reformation of the pellicle film on the exposed enamel surface. Removal or modification of the acquired pellicle and optional micro-roughening of the exposed enamel surface will elevate the enamel surface free energy (preferably above about 60 dyne/cm) which promotes better wetting of the enamel surface by the oxidizing composition. Surface wetting is a key factor related to the speed at which a composition penetrates enamel, analogous to the effects of viscosity and surface tension on the penetration of bonding adhesives into conditioned enamel and sealants into caries lesions.
Step 1a Placement of Cheek Retractor or Other Means of Preventing Contact of the Lips and Interior Mini Surfaces with the Teeth.
Step 1b Application of Conditioner for 30-60 Seconds
Tooth Conditioner Composition
Ingredient Percent (w/w) Water 90.0 Poly (methyl vinyl ether-co-maleic anhydride)* 10.0 *Gantrez S-95 (ISP Corp, Wayne, NJ) (hydrolyzed, pH 2.0)
Step 2—Oxidizer Contact and Penetration
Once the acquired pellicle has been removed, the teeth surfaces are contacted with a low viscosity oxidizer composition with a surface tension significantly lower than that of the surface free energy of the exposed enamel surface. A low viscosity oxidizing composition that has a low surface tension will have a very low contact angle when placed on the enamel surface and thus be better suited to penetrate into the enamel porosities. The oxidizer composition should comprise hydrogen peroxide in an aqueous form (or mixed with viscosity-reducing solvents) and at a concentration between about 1% and 30% by weight (higher amounts being contemplated in situations where precise control and placement of the oxidizing composition is possible). The oxidizing composition should also have a within a range similar to that reported for the isoelectric point of tooth enamel, which is between about 3.8 and 4.7, although higher pH levels are possible with oxidizing compositions comprising ionized species capable of counteracting the influence of charged components in tooth enamel. The oxidizing composition is brushed repeatedly onto the tooth surfaces to be whitened over the period of about 7-10 minutes to provide as much full strength hydrogen peroxide at the interface over the initial treatment phase.
Step 2a Application of Oxidizing Composition to Buccal and (Optionally) Lingual Surfaces of Teeth
Oxidizer Composition
Example 1D
Step 3—Sealing Enamel Surface Prior to Dental Prophylaxis Procedure
In order to prevent dilution or removal of the oxidizing composition in or from the tooth enamel treated in accordance with Step 2 above, a water-resistant protective sealant is applied (and if solvent-based, allowed sufficient time for the carrier solvent to evaporate). The sealant composition may also comprise an additional oxidizine, agent to provide an additional reservoir of whitening active, and/or an advanced oxidation catalyst in order to promote active oxidizing species such as hydroxyl radicals (.OH) and perhydroxyl anions (—OOH) and/or a desensitizing agent to reduce or eliminate any tooth sensitivity associated with the procedure.
Step 3a Application of Sealant to Buccal and (Optionally) Lingual Surfaces of Teeth
Sealant Composition
Ingredient
Percent (w/w)
Ethanol 200 proof
90.0
Poly (butyl methacrylate-co-(2-dimethylaminoethyl)
10.0
methacrylate-co-methyl methacrylate)*
*Eudragit E100 or EPO (Evonik Rohm GmbH, Darmstadt, (Germany)
The sealant composition is applied onto the surfaces of the teeth previously contacted with the oxidizing composition and allowed to fully dry before proceeding to Step 4.
Step 4—Performance of the Dental Prophylaxis Procedure
Following the sealing process, a dental prophylaxis is performed using, standard protocols and materials. Care should be taken to avoid excessive disruption of the sealant on the buccal and lingual (if coated) surfaces of the teeth during the cleaning procedure. The dental prophylaxis is otherwise performed in a standard fashion, including polishing of the teeth with a standard prophy paste (which will remove the Sealant applied in Step 3). A final tooth shade may be taken at this time.
Step 5—Final Treatment
If time permits, Steps 2 and 3 are repeated after prophy cleanup. No further intervention is required to remove the Sealant if applied after completion of the dental prophylaxis and dismissal of the patient. The Sealant may remain in place after the patient leaves the office and will slowly erode over time. The patient may also be supplied with a home-use version of the oxidizing composition and the sealant as an option for continued improvement in tooth color.
The above steps were performed on extracted molars and premolars (n=25) obtained through orthodontists with patient consent and stored refrigerated in phosphate buffered saline (PBS) solution at pH 6.8 until use. Individual teeth were removed from the PBS solution, allowed to air dry for 60 seconds and the roots inserted, up to the cementoenamel junction into a high viscosity aqueous gel to keep the roots hydrated during the procedure. An initial tooth shade was taken using a Minolta CM504i chromameter (Konica-Minolta) and recorded. Steps 2 (total treatment time of 10 minutes) and 3 (total treatment time of 120 seconds) were performed on the extracted teeth, and a 32 minute period was allowed to elapse during, which the teeth were rinse with water every 8 minutes to simulate the rinsing process that typically occurs during the cleaning process. After the simulated cleaning process time had elapsed, the teeth were polished with a medium grit prophy paste using, a slow speed handpiece and prophy cup. Teeth were rinse with water and a final tooth shade was taken using the method described above and recorded in Table 2 below (L, a, b=Initial color readings. L*, a*, b*=final color readings).
TABLE 2
Tooth
L
a
b
L*
a*
b*
Delta L
Delta a
Delta b
Delta E
1
76.10
3.14
15.98
78.11
1.61
13.13
2.01
−1.53
−2.85
3.81
2
76.90
3.44
12.45
80.98
2.40
13.01
4.08
−1.04
0.56
4.25
3
74.23
3.32
16.05
78.33
1.98
12.77
4.10
−1.34
−3.28
5.42
4
74 25
2.00
16.21
77.21
1.74
12.12
2.96
−0.26
−4.09
5.06
5
78.21
3.24
14.76
80.43
1.99
11.26
2.22
−1.25
−3.50
4.33
6
75.21
3.01
15.90
77.77
2.45
14.01
2.56
−0.56
−1.89
3.23
7
74.79
1.82
13.88
78.23
1.43
13.20
3.44
−0.39
−0.68
3.53
8
72.24
3.32
16.43
75.20
2.99
13.95
2.96
−0.33
−2.48
3.88
9
73.19
3.87
15.81
78.81
2.33
10.32
5.62
−1.54
−5.49
8.01
10
77.31
3.66
14.73
77.60
1.84
9.99
0.29
−1.82
−4.74
5.09
11
71.89
3.97
17.68
76.39
2.77
14.02
4.50
−1.20
−3.66
5.92
12
74.54
3.58
14.32
78.40
2.87
13.13
3.86
−0.71
−1.19
4.10
13
73.29
3.82
14.65
78.41
2.02
13.03
5.12
−1.80
−1.62
5.66
14
74.03
3.92
16.33
76.75
2.36
14.56
2.72
−1.56
−1.77
3.60
15
71.99
2.98
15.03
77.90
1.75
11.82
5.91
−1.23
−3.21
6.84
16
73.98
3.92
15.57
78.02
1.99
11.08
4.04
−1.93
−4.49
6.34
17
73.12
3.22
16.23
76.19
1.56
13.84
3.07
−1.66
−2.39
4.23
18
76.00
3.42
15.48
78.88
1.98
10.63
2.88
−1.44
−4.85
5.82
19
73.94
3.73
14.14
78.58
2.02
10.73
4.64
−1.71
−3.41
6.01
20
74.74
3.46
15.02
77.33
2.38
13.05
2.59
−1.08
−1.97
3.43
21
70.95
3.98
17.43
75.02
2.97
12.83
4.07
−1.01
−4.60
6.22
22
73.49
4.03
16.55
77.91
3.13
13.43
4.42
−0.90
−3.12
5.48
23
76.03
3.10
18.30
78.73
1.57
13.22
2.70
−1.53
−5.08
5.95
24
73.83
3.28
17.43
77.00
1.22
10.15
3.17
−2.06
−7.28
8.20
25
74.17
2.98
15.12
78.36
2.09
11.03
4.19
−0.89
−4.09
5.92
Average
73.94
3.46
16.03
77.63
2.06
11.98
3.79
−1.40
−4.04
5.72
Example 3
The following whitening method was used to demonstrate the ability of a high viscosity tooth whitening composition to remove an artificial stain from the surface of a bovine enamel substrate in vitro when light energy is use to enhance penetration.
Staining of Bovine Enamel Slabs
1. Substrates
a. 10 mm×10 mm bovine incisor (enamel) fragments mounted in clear resin
b. 600 grit finished surface
c. Unsealed
2. Storage of Substrates
a. Always store substrates at 100% relative humidity, or at 4° C. in Double Distilled H 2 O or Phosphate Buffered Saline solution
b. Never allow substrates to fully dry out as surface will change, dry only as part of staining procedure and never for extended periods.
3. Staining Solution
a. 3 g of fine ground leaf Tea
b. 3 g of fine ground Coffee
e. 300 ml of boiling ddH 2 O
d. Infuse fix 10 min with stirring (use magnetic stirrer)
e. Filter solution through tea strainer with additional filter paper
f. Cool to 37° C.
4. Preparation of tooth samples
a. Labelling: Label the bovine samples on one side of the resin with permanent marker (to track the samples if using more than one)
b. Rub the surface of the enamel with wet wipe and then grit finish is on the wet surface with orbital motion covering the whole surface for nearly 10 sec
c. Wash the surface with water and make it dry with Kimwipe
d. Sealing: Seal all the surfaces of the resin, excluding the enamel surface of bovine fragment (i.e., all four sides and bottom) with clear nail varnish
e. Leave it on bench top for air drying with the enamel surface touching the bottom for 30-45 min
f. Etching: sequential immersion in 0.2 m HCl saturated Na 2 CO 3 , 1% Phytic Acid (30 seconds each) and finally rinse with double distilled H 2 O
g. Make it dry with Kimwipe and then they are ready for staining
5. L*a*b Measurement
Measurement before and after staining,
6. Staining Procedure
a. Prepare the staining broth (Section 3) and fill a glass bottle with 200 ml of the broth
b. Keep the samples to be stained in the broth continuously for four days
c. Tighten the cap of the bottle to ensure that the broth is not evaporating from the bottle
d. Gently mix the broth every day to make sure that the particles are not settling at the bottom of the bottle
e. After staining the samples, rinse substrate with Millipore water (wipe it) and measure LAB values
Samples of the stained bovine enamel slabs were contacted with a tooth whitening composition shown in Table 3.
TABLE 3
Ingredient
Percent
Deionized water
35.40
Glycerin
20.00
Etidronic acid
0.30
Potassium stannate
0.10
Hydrogen peroxide
12.00
Carbopol 974P-NF
2.00
Sucralose
0.30
PEG-60 hydrogenated castor oil
3.00
Flavor
1.00
Ammonium Hydroxide 29% (to pH 5.0)
1.10
Total
100.00
The above composition is a transparent gel having a viscosity of approximately 10,000 cps @25 deg C. and a pH of 5.0.
The tooth whitening composition of Table 3 was brushed on to the surfaces of stained bovine enamel slabs prepared as described above. Immediately after contacting the slabs with the tooth whitening composition, light energy was applied, using a hand-held dental curing, light with a high-powered LED emitting approximately 500 mW/cm 2 of blue light with a peak wavelength of approximately 450 nm. The hand-held curing light used a lens cup 10 depicted schematically in FIGS. 1 and 2 as having a lens 12 over which a thermoplastic elastomer cup 14 was molded to provide a mechanism for spacing the curing light energy L (represented notionally in FIG. 1 ) at the same distance from the surface of the bovine slab for each sample. The over molded cup forms a small chamber that controls the positioning and movement of the gel on the tooth surface, while simultaneously emitting light energy through the lens onto the tooth surface to accelerate the penetration of the tooth whitening composition into the tooth structure.
The resulting changes in L, a and b values, together with the composite delta E change in tooth color, is shown in Table 4 below.
TABLE 4
dL
da
db
dE * ab
tooth 1
8.15
−4.17
−6.17
11.04
tooth 2
6.91
−3.56
−5.71
9.65
tooth 3
2.69
−1.76
−5.18
6.09
tooth 4
5.53
−2.89
−2.45
6.71
As can be seen by the changes in L, a and b values, as well as the composite delta E value changes, significant tooth color changes may be effected by utilizing a high viscosity tooth whitening composition when combined with a high intensity light source adapted with a lens comprising an over molded thermoplastic elastomer spacer cup. It is anticipated that the inclusion of a light exposure step, as demonstrated in the Example, would be of significant advantage in improving the tooth whitening effect observed in Examples 1 and 2, Exposing the tooth surfaces and their surrounding soft tissue will also lead to an improvement in periodontal health through the reduction of periodontal pathogens such as black pigmented bacteria.
SUMMARY
It will be understood that the embodiments of the invention described above can be modified in myriad ways other than those specifically discussed without departing from the scope of the invention. General variations to these embodiments may include different tooth whitening compositions, light sources, methods of applying compositions and/or light, and contact and/or exposure time of tooth whitening compositions and/or light on the tooth surface.
Those skilled in the art will readily recognize that only selected preferred embodiments of the invention have been depicted and described, and it will be understood that various changes and modifications can be made other than those specifically mentioned above without departing from the spirit and scope of the invention, which is defined solely by the claims that follow. | A tooth whitening method applies a light transmitting oxidizing composition to teeth in an oral cavity, after which a hand-held LED light source with a light transmitting lens and a cup forming a chamber having an open end is moved over the teeth so that the cup distributes the oxidizing composition while the teeth are exposed to light transmitted through the lens. This not only ensures intimate contact of the teeth with the oxidizing composition, but also maintains a more or less constant spacing between the light source and the tooth surfaces for optimum results. A sealant is then applied to the teeth to resist moisture contamination of the oxidizing composition. | 65,012 |
BACKGROUND OF THE INVENTION
The invention relates to a semiconductor diode laser--often referred to as laser for short hereinafter--with a semiconductor body comprising a substrate of a first conductivity type and situated thereon a semiconductor layer structure with at least a first cladding layer of the first conductivity type, a second cladding layer of a second conductivity type opposed to the first, and between the first and second cladding layers an active layer and a pn junction which, given a sufficient current strength in the forward direction, is capable of generating monochromatic coherent electromagnetic radiation in a strip-shaped active region situated within a resonance cavity formed between two end faces, the active layer comprising one or several quantum well layers of a first semiconductor material which are mutually separated or surrounded by barrier layers of a second semiconductor material, while the second cladding layer and the substrate are electrically connected to connection conductors and a first portion of the quantum well and barrier layers forming part of the active layer has a compression stress because the semiconductor material in the first portion has a lattice constant which is greater than that of the substrate, and a second portion of said layers has a tensile stress because the semiconductor material in the second portion has a lattice constant which is smaller than that of the substrate. It is noted that the term "barrier layers" also refers to so-called separate confinement layers. The invention also relates to a method of manufacturing such a laser.
Such a laser is known from the U.S. Pat. published under No. 5,373,166 on Dec. 13th, 1994. The laser disclosed therein is manufactured in the InP/InGaAsP material system which corresponds to the wavelength region from 1 to 1.5 μm, and utilizes a Multi Quantum Well (MQW) active layer in which the quantum well and barrier layers comprise a material with a lattice constant which is alternately greater than and smaller than that of the substrate. A greater lattice constant results in a compression stress of the relevant layer, a smaller in a tensile stress. Such a laser has a starting current which is much lower than that of a laser in which all layers exactly match the substrate owing to the influence of the stresses on the shape and position of the valency and conduction band. The known laser is stress-compensated, i.e. the total compression stress is approximately equal to the total tensile stress. In other words, the product of the absolute value of the relative difference in lattice constant and the thickness is the same for both types of layers. Defects in the active layer of the laser will occur less readily thanks to this stress compensation, which benefits useful product life. In addition, such a laser also has a strongly reduced starting current.
A disadvantage of the known laser is that it has too short a life, especially if the laser is manufactured in the GaAs/AlGaAs or the InGaP/InAlGaP material system. This is sometimes a disadvantage in the application in an optical disc system, laser printer, or bar code reader, especially if a high power level is desired there.
SUMMARY OF THE INVENTION
The present invention has for its object inter alia to provide a laser which has not only a low starting current but also a very long life, especially with a comparatively low laser emission wavelength and a high (optical) power emission.
A semiconductor diode laser of the kind mentioned in the opening paragraph is for this purpose characterized in that the relative deviation of the lattice constant compared with that of the substrate and the thicknesses of the two portions of the active layer are so chosen that the total tensile stress in the active layer is greater than the total compression stress, so that part of the stress is compensated and the resulting stress in the active layer is a tensile stress. The invention is based first of all on the surprising recognition that stresses in layers forming part of the active layer are relaxed adjacent the end face. A layer with a compression stress has an increase in its bandgap as a result of this stress, which increase, however, disappears wholly or partly near the end face owing to stress relaxation, so that the bandgap is smaller close to the end face than it is farther away from it. A tensile stress results in a reduction in the bandgap, which again disappears close to the end face owing to relaxation, so that the active layer has a greater bandgap close to an end face in this case. The invention is further based on the recognition that the first case is unfavourable because the absorption of the generated radiation increases near the end face then. The heat generated thereby leads to degradation of the laser. The second case on the other hand is favourable. In fact, an increased bandgap leads to a decreased absorption and thus to a lower degradation, especially a lower so-called end face or mirror degradation of the laser. In the known laser, where both kinds of stress are compensated, the effects thereof and those of any occurring relaxation on the bandgap are compensated. As a result, the known laser has an active layer which has a (substantially) constant bandgap over the entire length of the resonance cavity. In a laser according to the invention, however, which is as it were overcompensated, the bandgap near the end face is greater than elsewhere owing to the net tensile stress. The end face degradation of such a laser is accordingly small and laser life is long, also in the case of a high optical power. In addition, the laser according to the invention profits from the partial compensation of the stresses. This indeed causes the laser to have a particularly low starting current. Furthermore, the active layer of the laser may comprise a comparatively great number of layers or comparatively thick layers each having a stress. This brings with it further advantages, such as a better confinement and a comparatively great wavelength of the generated radiation. The risk of defects arising has already been considerably reduced by the partial compensation. The resulting laser has a particularly long useful life.
It is noted that said effects of a compression or tensile stress on shape and position of valency and conduction bands, and thus on the value of the bandgap, relate exclusively to the influence of mechanical stresses. In practice, the choice of a different lattice constant also implies the choice of a different material--including the choice of a different material composition--which has a much stronger influence on the bandgap. In the case of a compression stress, this means that the bandgap of the active layer is considerably smaller than if there were no stress. In the case of a tensile stress, the bandgap is much greater. The influence of a change in composition, however, is the same over the entire length of the resonance cavity and is unchangeable. Although very important for the direction in which and the degree to which the wavelength of the generated radiation is shifted, the latter effect (which is superimposed on the effects described further above) does not detract from the validity of the discussion in the preceding paragraph.
A method according to the invention whereby on a substrate of a first conductivity type a semiconductor layer structure is provided with at least a first cladding layer of a first conductivity type, an active layer, and a second cladding layer of a second conductivity type opposed to the first, and the active layer is formed by one or several quantum well layers of a first semiconductor material mutually separated or surrounded by barrier layers of a second semiconductor material, the second cladding layer and the substrate being provided with electrical connection conductors, while the first and the second semiconductor material or the compositions thereof are so chosen that a first portion of the layers forming part of the active layer has a lattice constant smaller than that of the substrate, and a second portion has a lattice constant greater than that of the substrate, is characterized in that the values of the differences in lattice constant and the thicknesses of the two portions are so chosen that the opposed stresses in the active layer do not fully compensate one another and the resulting stress is a tensile stress. Lasers according to the invention are obtained by such a method in a simple manner.
In a first embodiment of a laser according to the invention, the first portion of the active layer comprises at least one quantum well layer with a greater tensile stress and the second portion of the active layer comprises at least one barrier layer with a smaller compression stress. The words greater and smaller here mean greater or smaller than the stress in the other portion. The resulting stress depends, as stated above, not only on the degree to which the lattice constant of the relevant layer differs from that of the substrate, but also on the thickness of the relevant layer. This embodiment of the laser has a comparatively low emission wavelength owing to the material effect discussed in the preceding paragraph. The emission wavelength lies, for example, between 630 and 650 nm when this embodiment of the laser is formed in the GaAs/InGaP/InAlGaP material system.
A preferred embodiment of a laser according to the invention is characterized in that the first portion comprises at least one quantum well layer with a smaller compression stress and the second portion comprises at least one barrier layer with a greater tensile stress such that the resulting stress in the active layer is a tensile stress. Such a laser has a comparatively high emission wavelength. It lies, for example, between 650 and 700 nm for a laser in the GaAs/InGaP/InAlGaP material system comprising a quantum well layer of InGaP. Such a laser has a particularly low starting current thanks to the comparatively high emission wavelength. The use of cladding layers having the greatest possible bandgap here in fact implies that the confinement is better than if the emission wavelength were lower.
Preferably, the resulting tensile stress in the active layer of a laser according to the invention is smaller than or equal to approximately 30 nm. %. This means, for example, that the relative deviation of the lattice constant for a layer of 30 nm thickness compared with the substrate is less than -1%. It is avoided thereby that the resulting (tensile) stress leads to defects in the active layer with subsequent degradation of the luminescence.
In a favourable modification, the barrier layers comprise first barrier layers with a small thickness and a great stress and second barrier layers with a great thickness and a small stress. Such a distribution of the stress in the barrier layers over two kinds of barrier layers has the advantage that a great stress is possible while maintaining symmetry around the quantum well layers. This is particularly favourable for the preferred embodiment mentioned above in which the stress, i.e. tensile stress, in the barrier layers must be comparatively great.
A further favourable modification arises when the active layer comprises at least one quantum well layer with a thickness between 4 and 16 nm and at least two barrier layers with a thickness between 2 and 30 nm, the semiconductor material of one of the two portions of the active layer has a relative deviation of the lattice constant compared with the substrate of which the absolute value lies between 0.3 and 2%, and the semiconductor material of the other portion of the active layer has a relative deviation of the lattice constant compared with the substrate of which the absolute value lies between 0.15 and 1%. A symmetrical arrangement is thus possible, and thinner layers may have a comparatively great stress while thicker layers have a somewhat smaller stress. The stresses and thicknesses are so chosen, as noted above, that the product of layer thickness (d) and relative deviation of the lattice constant (Δa/a) is the same for the portions which compensate one another's stresses. Said product (d*Δa/a) is summed for each kind of stress if the kind of stress is distributed over several layers. The excess tensile stress, i.e. the result of the summation is preferably smaller than or equal to 30 nm. %.
In the preferred embodiment mentioned above, a very favourable result is obtained when the at least one quantum well layer has a thickness of approximately 8 nm, the at least two barrier layers have thicknesses between 8 and 30 nm, and the first semiconductor material has a relative deviation in its lattice constant compared with the substrate of approximately +1%, while the second semiconductor material has a relative deviation in its lattice constant compared with the substrate of between -1.0 and -0.5%.
A laser according to the invention may advantageously be manufactured in material systems such as the InP/InGaAsP material system and the GaAs/AlGaAs material system. In the latter case, a compression stress and a tensile stress may be realised through the addition of indium and phosphorus atoms, respectively. Preferably, the laser is realised in the GaAs/InGaP/InAlGaP material system. The substrate may comprise GaAs in that case, the quantum well layers InGaP, the barrier layers InAlGaP, and the cladding layers InAlGaP or InAlP. Lasers are created thereby with emission wavelengths below approximately 700 nm and with excellent properties.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be explained in more detail with reference to two embodiments and the accompanying drawing, in which
FIG. 1 shows a semiconductor diode laser according to the invention diagrammatically and in a cross-section taken perpendicularly to the longitudinal direction of the resonance cavity,
FIGS. 2 and 3 diagrammatically show a first and a second embodiment, respectively, of the active layer of the laser of FIG. 1, and
FIGS. 4 and 5 show the influence of the invention on the bandgap (E g ) as a function of the distance (S) to an end face for the first and the second embodiment, respectively.
The Figures are diagrammatic and not drawn to scale, the dimensions in the thickness direction being particularly exaggerated for greater clarity. Corresponding parts are generally given the same reference numerals in the various Figures.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a first and a second embodiment of a laser according to the invention diagrammatically and in a cross-section taken perpendicularly to the longitudinal direction of the resonance cavity. The laser comprises a semiconductor body 10 with a substrate 11 of a first, here the n-conductivity type, in this example consisting of monocrystalline gallium arsenide, provided with a connection conductor 9. On this body, a semiconductor layer structure is provided, in this example comprising a buffer layer 12 of n-AlGaAs, a first cladding layer 1 of n-InAlGaP, an active layer 2 of InGaP and InAlGaP, a second cladding layer 3 of p-InAlGaP, a third cladding layer 5 also of p-InAlGaP, a transition layer 6 of InGaP, and a contact layer 7 of p-GaAs. Between the second cladding layer 3 and the third cladding layer 5 there is a pn junction and in this case an intermediate layer 4 which acts inter alia as an etching stopper layer in the formation of the strip-shaped mesa 20 which comprises the third cladding layer 5 and the transition layer 6. A current blocking layer 15 is present here on either side of the mesa 20 and between the intermediate layer 4 and the contact layer 7. During operation, a strip-shaped active region arises within a resonance cavity below the mesa 20 in the active layer 2. Two end faces 30 of the semiconductor body 10, here acting as mirror surfaces and limiting the resonance cavity in longitudinal direction, are parallel to the plane of drawing. The laser in this example is of the so-called index-guided type. The electrical connection of the pn junction situated between the first and the second cladding layer 1, 3 is effected by means of connection conductors 8, 9 on the contact layer 7 and the substrate 1, respectively.
FIG. 2 shows the construction of the active layer 2 of a first example of the laser of FIG. 1. The active layer 2 comprises a single quantum well layer 2A which is surrounded by two barrier layers 2B. According to the invention, a portion of the active layer 2, here the quantum well layer 2A, has a compression stress while another portion of the active layer 2, here two barrier layers 2B, has a tensile stress which is effectively greater than the compression stress, so that the resultant net stress in the active layer 2 is a tensile stress. The stress situation in the active layer 2 necessary for the invention is achieved in this example as listed in the Table below. Δa/a therein is the relative difference in lattice constant compared with the substrate 11 and d is the thickness of the layer in question. The resultant tensile stress in the active layer 2 is: 2*(16)*(-0.5)+1*(8) *(+1)=-8 nm* %, the absolute value of which is smaller, in this case much smaller than 30 nm. %. This means that there is practically no risk of stress-induced defects occurring in the active layer 2. The stress relaxation in quantum well layer 2A and barrier layers 2B which occurs in the laser near the end faces 3 and the overcompensation of the compression stress cause a greater bandgap (E g ) near the end faces 30 in the active layer, so that the absorption of radiation generated in the active region decreases (strongly) near the end face 30. End face or mirror degradation in the laser according to the invention is substantially lower as a result of this than in the known laser, and the former has a considerably improved useful life. Thicknesses and compositions chosen for the two portions of the active layer 2 preferably lie in the domains mentioned in the introductory description. Lasers whose layers have properties lying within these domains yield the favourable results. The Table also contains relevant data on the other layers of the two embodiments of the laser, showing that in this example the active layer 2 also comprises two further barrier layers 2C which act as so-called separate cladding layers 2C and which in this example have the same lattice constant as the substrate 11.
______________________________________ Conc. d Δa/aLayer Semiconductor Type (at/cm.sup.3) (μm) (%)______________________________________11 GaAs N 2 × 10.sup.18 350 012 Al.sub.0.20 Ga.sub.0.80 As N 2 × 10.sup.18 0.1 0 1 In.sub.0.50 Al.sub.0.35 Ga.sub.0.15 P N 5 × 10.sup.17 1.4 0 2A In.sub.0.62 Ga.sub.0.38 P -- -- 0.008 +1.0 2B In.sub.0.42 Al.sub.0.23 Ga.sub.0.35 P -- -- 0.016 -0.5 2C In.sub.0.50 Al.sub.0.20 Ga.sub.0.30 P -- -- 0.030 0 3 In.sub.0.50 Al.sub.0.35 Ga.sub.0.15 P P 3 × 10.sup.17 0.3 0 4 In.sub.0.49 Ga.sub.0.51 P P 1 × 10.sup.18 0.05 0 5 In.sub.0.50 Al.sub.0.35 Ga.sub.0.15 P P 3 × 10.sup.17 1.1 0 6 In.sub.0.49 Ga.sub.0.51 P P 1 × 10.sup.18 0.01 0 7 GaAs P 2 × 10.sup.18 0.8 015 GaAs N 1 × 10.sup.18 0.8 0______________________________________
In FIG. 4, curve 42 represents the bandgap (E g ) of the active layer 2 as a function of the distance (S) to the end face 30 of the laser of this example. Curve 42 shows that the bandgap of the active layer 2 is greater, here by approximately 15 meV, between approximately 10 and 80 nm from the end face 30 than at a greater distance from the end face 30. This means that absorption of radiation generated in the laser in the region adjoining the end face 30 is considerably smaller than in a laser where the compression stress and tensile stress are mutually compensated. In that case, in fact, the bandgap gradient is as shown in curve 41. It should also be borne in mind here that absorption of the generated radiation depends exponentially on the bandgap (E g ). For comparison, finally, curve 40 shows the case where the active layer 2 has a compression stress, exclusively or as a net result, which yields an even worse situation than in the stress-compensated case of curve 41.
The width of the mesa 20 is 5 μm. The length and width of the semiconductor body 10 and the length of the mesa 20 are approximately 500 μm. The conductive layers 8, 9 are of usual thickness and composition. The emission wavelength of this embodiment of the laser realized in the InGaP/InAlGaP material system is approximately 680 nm. The laser is manufactured in a usual manner for the major part. Briefly, manufacture proceeds as follows. The layers 12 and 1 to 6 are provided on substrate 11 in a first growing process. The material compositions and thicknesses in accordance with the invention, here as listed in the Tables, are chosen for the active layer 2 in this case. Then the mesa 20 is formed by etching on both sides of a strip-shaped mask of SiO 2 down to the etching stopper layer 4. In a second epitaxy process, the current blocking layer 15 is provided on either side of the mesa 20, resulting in a substantially planar structure. Finally, after the SiO 2 mask has been removed, the contact layer 7 is provided over the structure in a third growing process. After two-sided metallization 8, 9 and cleaving in two directions, the lasers are ready for use.
FIG. 3 shows the construction of the active layer 2 of a second embodiment of a laser according to the invention having the structure of FIG. 1. The active layer 2 in this example comprises two quantum well layers 2A mutually separated and surrounded by three barrier layers 2B, of which the outermost layers are surrounded by two further barrier layers 2C which act as separate cladding layers. The other layers 12, 1, 3 to 7, 15 and the substrate 11 of the laser are the same as in the first embodiment of the laser. According to the invention, a portion of the active layer 2, here the quantum well layers 2A, has a compression stress while another portion of the active layer 2, here three barrier layers 2B and two further barrier layers 2C, has a tensile stress which is effectively greater than the compression stress, so that the resulting net stress in the active layer 2 is a tensile stress. In this example, the desired stress situation in the active layer 2 has been achieved as indicated in the Table below. The resulting tensile stress is: 3*(8)*(-1)+2*(24) *(-0.5)+2*(8)*(+1)=-32 nm* %, the absolute value of which is approximately 30 nm. %. In this example, the total tensile stress present is distributed over two kinds of barrier layers 2C, 2D. This has the advantage that a great tensile stress is possible while the symmetry around the quantum well layers 2A is maintained. Relaxation of the stress in quantum well layers 2A and barrier layers 2C, 2D occurs close to the end faces 30 also in this embodiment of the laser. Owing to the overcompensation of the compression stress, an increase in the bandgap occurs again near the end faces 30 in the active layer 2, so that the absorption of radiation generated in the active region is (strongly) reduced near the end face 30. The end face or mirror degradation in the laser according to the invention is thus much lower than in the known laser, and the former has a much improved useful life. The wavelength of the generated radiation in this embodiment of the laser is again approximately 680 nm. The stress in the barrier layers 2B, 2C is advantageously distributed in this embodiment. That is to say that the barrier layers 2B are thin and have a high tensile stress, while the barrier layers 2C are thick and have a lower compression stress, which renders it easier to obtain a symmetrical construction.
______________________________________ Conc. d Δa/aLayer Semiconductor Type (at/cm.sup.3) (μm) (%)______________________________________2A In.sub.0.62 Ga.sub.0.38 P -- -- 0.008 +1.02B In.sub.0.35 Al.sub.0.26 Ga.sub.0.39 P -- -- 0.008 -1.02C In.sub.0.42 Al.sub.0.23 Ga.sub.0.35 P -- -- 0.024 -0.5______________________________________
In FIG. 5, curve 53 represents the bandgap (E g ) of the active layer 2 as a function of the distance (S) to the end face 30 for this embodiment of the laser. Curve 53 shows that the bandgap of the active layer 2 is greater by a few tens of meV, here by approximately 25 meV, between approximately 10 and 80 nm from the end face 30 than at a greater distance from the end face 30. This means that the absorption of radiation generated in the laser is much lower in this region than in a laser in which the compression stress and tensile stress are mutually compensated. In the latter case, the bandgap has a gradient as shown with curve 51. Curve 50 shows the case in which the active layer 2 has a compression stress only, which leads to an even worse situation than in the stress-compensated case of curve 51. The influence of the outer barrier layers 2C is illustrated with curve 52. Curve 52 refers to the situation corresponding to the above Table, but with the two outermost barrier layers 2C omitted. In that case, too, the favourable effect according to the invention is present, but to approximately the same degree as in the first embodiment of the laser. Thanks to a net tensile stress which has approximately the maximum admissible value of 30 nm. %, the advantage of the invention in the present example is a maximum in the situation corresponding to curve 53.
The invention is not limited to the embodiments given, many modifications and variations being possible to those skilled in the art within the scope of the invention. Thus different semiconductor materials or different compositions of the chosen semiconductor materials may be used compared with those mentioned in the examples. This relates in particular to the use of the material systems InP/InGaAsP and GaAs/AlGaAs mentioned earlier. Furthermore, the invention is not limited to situations in which the quantum well layers and/or the barrier layers each have only one type of stress. Thus it is possible for quantum well layers with a compression stress and with a tensile stress to be present simultaneously. In that case the emission wavelength of both may sometimes be rendered equal through the use of the quantum effect, i.e. through adaptation of the thickness (ratio) of the quantum well layers.
It is also possible to replace the conductivity types all (simultaneously) with their opposites. Various techniques, such as MOVPE (=Metal Organic Vapour Phase Epitaxy), etc. may be used for providing the semiconductor layers.
The invention is furthermore not limited to the laser embodiment described here which is of the BR (=Buried Ridge) type. The invention may also be used for other types such as the BH (=Buried Hetero) type or the RW (=Ridge Waveguide) type, etc. | The invention relates to a laser with a multi quantum well active layer in which a portion of the quantum well and barrier layers is provided with a compression stress, while another portion is provided with an oppositely directed tensile stress. Said stresses are overcompensated such that the net stress is a tensile stress. Preferably, the laser comprises one or several quantum well layers with a compression stress and a number of barrier layers with an excess tensile stress. | 28,000 |
This application is a continuation-in-part of Ser. No. 883,769, filed Jul. 9, 1986, .Iadd.U.S. Pat. No. 4,797,087, .Iaddend.which is a continuation-in-part of application Ser. No. 755,831, filed Jul. 15, 1985, .Iadd.U.S. Pat. No. 4,642,047, .Iaddend.which is a continuation-in-part of application Ser. No. 642,141, filed Aug. 17, 1984, issued as U.S. Pat. No. 4,622,007; all of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to hazardous waste disposal systems, and more particularly to an improved incineration system and method which results in the efficient destruction of liquid and solid wastes in an apparatus including a primary incineration combustion means, at least one afterburner and a flue gas treatment system.
A typical waste incineration system for the destruction and removal of hazardous wastes consists of a primary incineration combustion apparatus, an afterburner and a flue gas treatment system. Additionally, the incineration system may include:
a solid and/or liquid waste feed system;
a system for feeding an auxiliary fuel, usually in gaseous or liquid form;
a system for feeding oxidizer, usually air and sometimes oxygen or an oxygen enriched air;
a system for the evacuation of incombustible solid products of incineration, such as bottom ash;
a system of heat recovery from the hot exhaust combustion flue gases with generation of preheated combustion air of waste incineration units, hot water, steam and/or electricity;
a system for preparing, feeding, recycling and treating any water solutions produced for removal of gaseous and/or particulates in the flue gas treatment system;
a stack for the discharge of treated flue gases to the atmosphere;
a control system including flow, pressure and temperature transducers and controllers for controlling the flow of fuel and oxidizers, process temperatures and pressures at strategic locations in the system; and
a flue gas sampling system.
The primary incineration combustion apparatus for solid and liquid wastes and sludges may be embodied as rotary kilns, multiple hearth furnaces, fluidized bed furnaces, grate furnaces and other combustion apparatus. Liquid and semiliquid pumpable wastes can also be combusted in cyclonic reactors as well as in various burners during the initial thermal destruction step of incineration process.
The rotary kiln is the preferable embodiment of the primary incineration process due to its versatility. It is arranged as a cylindrical refractory lined vessel rotating about a slightly inclined axis. The residence time in the kiln varies from a fraction of a second to several seconds for gaseous materials and from several minutes to several hours for solid materials. Solid wastes can be charged in a kiln either continuously as in the case of shredded material or as a batch charge as in the case of containerized materials such as drums or bundles. Special loading devices are used for charging solid wastes while pumpable liquid wastes and sludges are typically introduced directly into the kiln. The combustible fraction of wastes is partially pyrolysed and oxidized in the kiln. An auxiliary fuel such as combustible liquid waste, oil, natural gas or propane is commonly used for preheating the kiln lining, for providing supplemental heating while combusting low caloric value wastes, and for insuring the combustion stability.
Although the design of other primary incineration combustion units differs from that of a rotary kiln, they typically accomplish the same functions and contain many of the same functional elements as the rotary kilns and exhibit much the same disadvantages as those discussed below for the kilns.
Afterburners are typically cylindrical refractory lined vessels equipped with an auxiliary burner which is fed with a liquid and/or gaseous fuel and an oxidizer. Combustible liquid wastes can be used instead of, or in addition to, the auxiliary fuel. Afterburners are used to insure combustion of organic vapors, soot and other combustible components remaining after the primary incineration process. The afterburners provide a high temperature, highly oxidizing atmosphere with sufficient residence time and mixing of combustible vapors with oxygen to insure the required degree of organics destruction.
The most typical unit for treatment of flue gases leaving the afterburner is a wet scrubber wherein the combustion gases are washed by water or water solutions. Soot and halogens are largely absorbed and sulfur dioxide and nitrogen oxides are partially removed in the scrubber. Some polar organics and organics which are adsorbed in the soot are also partially removed. An alkali is often added to the scrubbing water to increase the efficiency of scrubbing of halogens and sulfur dioxide. Electrostatic precipitators or dust baghouses for often used for removal of the particulates from flue gases.
Heat recovery units are often installed between thermal destruction and flue gas treatment units. Heat of hot combustion flue gases may be used to preheat the combustion air for the primary incinerator and/or afterburner.
Solid and liquid wastes typically contain organic and inorganic combustible constituents. A fraction of organics may be highly toxic, mutanogenic and teratogenic. This fraction of organics is usually called principle organic hydrocarbons (POHC). Many POHCs are very stable and require oxidation at elevated temperatures for their destruction. When wastes are charged into a kiln, a rapid volatilization and partial pyrolysis of organics, including POHCs and water, if any, occurs. The volatilized components of organics require an adequate quantity of oxygen for their oxidation. Fuel and oxygen are also needed to supply heat for vaporization of water and organics and for raising the temperature to required levels.
The appropriate firing rate and combustion air feed rate are selected to provide adequate temperatures and excess oxygen level for the incineration system to achieve the required destruction efficiency of the POHCs for a given type and quantity of wastes. This temperature and excess oxygen level will be maintained by the control system. Other nonhazardous organics present as well as the fuel as usually essentially oxidized when POHCs are oxidized in the primary incineration combustion apparatus; however, new intermediate products may be formed during the combustion process. These products include carbon microparticles, carbon monoxide and an array of organic compounds. Many of these organic compounds are a higher molecular weight polycyclic or polyaromatic organics such as dioxins, benz(a) pyrene, dibenz(a,c)anthracene, picene, dibenz(a,h)anthracene, 7, 12-dimethyl(a)anthracene, benz(b)fluortane, 9,10-dimethylanthracene. These higher molecular weight organics are often called products of incomplete combustion (PICs). PICs are often as hazardous as POHCs. A fraction of PICs becomes absorbed on carbon microparticles. The combined PICs and carbon particles represent soot. Accordingly, soot is also a hazardous product. Carbon monoxide is also a toxic constituent and only a limited quantity of it may be permitted for discharge into the atmosphere. Therefore, the waste incineration steps must insure the thermal destruction of carbon monoxide, soot and PICs in the gaseous phase. Such destruction should be provided prior to the discharge of the combustion gases from the afterburner.
Both the feed rate and the properties of wastes which are fed into the combustion system may vary. Extreme variations in the feed rate occur during the so called batch charge when a substantial quantity of wastes is rammed or otherwise introduced into the apparatus in a short period of time. Gradual variations in the feed rate are also possible for continuously charged waste streams. The operational objective of an incineration system is to maximize the amount of waste passing through the system while minimizing the amounts of discharged flue gases, POHCs, and PICs. Generally, the maximum allowable concentrations of pollutants in the flue gases are specified in the operating permit which is based on the current environmental requirements and regulations.
In order to achieve this operational objective high temperatures, sufficient retention time and high turbulence should be provided in both the primary incineration combustion apparatus and the afterburner. Typically, the kiln temperature ranges from 750° C. (1400° F.) to above 1100° C. (2500° F.). The residence time for gases in both the kiln and the afterburner ranges from a fraction of a second to several seconds. Turbulence in either the kiln or the afterburner is not defined quantitatively, however. It is usually assumed that mixing is sufficient to heat adequately all elementary streams of gases and to provide a sufficient contact between organics and oxygen molecules in the furnace. In order to insure the sufficient contact between organics and oxygen, an excess of combustion air in the range of 5% to 200% of stoichiometric is commonly used.
Temperature, retention time, level of excess air and turbulence in the primary incineration combustion apparatus and afterburner effect the destruction efficiency which may be maintained during the operation of a conventional incineration system. An increase in any of these parameters will enhance the destruction efficiency. Attempts to improve destruction efficiency by increasing one or more of the above parameters, however, has not proven to be effective utilizing currently available incineration systems because of a corresponding drop in one of the parameters as one of the others is increased. For example, a higher level of excess oxygen provided by an increase in the air feed results in a lower temperature and lower retention time of gases in the furnace. An increase of the temperature by raising the amount of auxiliary fuel results in increase of combustion product volume which reduces retention time.
The incompatible nature of these parameters in existing incineration systems has limited the capability of existing incineration systems to dynamically intensify the incineration process to overcome transient process malfunctions leading to process failures. Typical transient malfunctions resulting in incineration process failure modes are described below using the kiln as an example for the primary incineration apparatus.
When wastes are charged in large batches or when loading rates of liquids and sludges are rapidly increased, the quantity of oxygen present in the kiln and the amount of oxygen being fed into the kiln during the rapid vaporization stage typically is not sufficient for complete combustion to occur, resulting in an overcharging failure. Only a fraction of combustible constituents of wastes, including POHC, is completely oxidized, forming CO 2 and H 2 O. The remaining organics are partially pyrolyzed and oxidized, thus forming carbon microparticles, CO and PICs. Vaporized fractions of POHCs and of wastes together with carbon microparticles, CO and PICs formed are transferred in an increased amount into the afterburner, so that afterburner is also overloaded. Meeting the oxygen requirements during the overload period in the kiln by substantially increasing the level of continuous combustion air feed rate would result in a shortening of the retention time for volatilized and partially pyrolyzed products in the kiln and may degrade the flame stability. This problem is aggravated by the fact that the substantially excessive air feed brings along extra nitrogen which absorbs a portion of the heat generated in the kiln, thus reducing the heat available for the process and, correspondingly, the temperature level resulting in reduced destruction efficiency of organics.
When a portion of the waste charged into the kiln during a certain time period has lower caloric value than the expected design value, the kiln temperature can decline due to reduced heat release. This may lead to the formation of cold spots in the furnace when local temperatures decrease below the ignition point for some organics. The result is a low temperature failure mode with a substantial breakthrough of the original organics which cannot be destroyed at lower temperatures. A drastic increase in PIC formation may also occur due to quenching of pyrolytic products forming from the original wastes and fuel.
Other failure modes may occur as a result of poor atomization of liquid wastes and poor mixing of wastes with available oxidizers. Poor atomization of liquid wastes leads to increased size of droplets resulting in incomplete combustion while poor mixing may provide an opportunity for the volatilized wastes to short circuit the combustion process, avoiding adequate contact with an oxidizer. Both of these failure modes result in products of incomplete combustion being transferred to the afterburner.
Flameout failure modes predominantly occur at unfavorable aerodynamic conditions in the combustion zone. High velocities of gaseous products near the burner during low fire conditions, a deficiency of oxidizer, and excessive infiltration of cold ambient air in the combustion apparatus are typically events which cause flameout. Excessive increase in the ambient air moisture content and the high moisture of the wastes being charged may be other sources of low temperature or flameout failure.
Failure modes similar to those described above for the kiln may also occur in the afterburner. In addition, overcharging, low residence time, low temperature, poor mixing, the cold wall effect, flameout and poor atomization in the kiln will always result in an increased PICs loading rate on the afterburner, and subsequently, in a lower thermal destruction efficiency overall for existing incineration systems.
Conventional incineration systems are hindered in their ability to address failure modes because the kiln, the afterburner, if used, and the air pollution control system are designed to operate in steady state conditions ignoring the existence of transient process disturbances which result in failure modes. Existing incineration systems are also unable to anticipate transient operational changes of the several individual elements of the incineration system. For example, they are not capable of rapidly boosting temperatures and oxygen content in the afterburner to overcome failure modes in the primary combustion apparatus.
Several attempts have been made to improve thermal destruction efficiency by enriching combustion air in the primary incineration means with oxygen (see, for example, U.S. Pat. Nos. 4,520,746; 4,462,318 and 4,279,208). The advantage of oxygen use in incineration processes is based on the reduction in the volume of nitrogen introduced into the incineration process. This reduction in the volume of nitrogen decreases the amount of heat stored in the nitrogen molecules making additional heat available for waste destruction and for increasing the temperature in the kiln. In addition, the use of oxygen reduces the quantity of gases flowing through the kiln, thereby increasing the residence time and the efficiency of destruction of persistent organics.
The use of oxygen in the waste incineration processes helps to stabilize combustion and to eliminate the possibility of failures related to low temperature, insufficient residence time and the negative impacts of low caloric wastes. However, the steady flow of additional oxygen may be only marginally effective in cases of transient overcharging, poor atomization and poor mixing, which are the failure modes most prone to the breakthrough of POHCs and formation of PICs. Permanently maintaining an elevated oxygen feed rate can result in overheating of primary incineration combustion apparatus and in damage to the metal parts and refractories. Moreover, an increased oxygen feed results in added operational costs. Although the additional use of a permanent oxygen flow may improve the destruction efficiency of kilns and afterburners, it cannot solve the problems related to the transient changes such as those caused by batch charging, poor atomization and poor mixing. This also cannot help to optimize the destruction efficiency at a given capacity or to maximize the capacity of the facility at a given or required efficiency. Existing methods cannot reconcile the conflict among the desired factors of high temperature, retention time, turbulence, and oxygen level in furnaces.
There exists, therefore, a need for an incineration system and method which results in the efficient destruction of liquid and solid wastes.
Further, there exists a need for a system and method which solves the problems related to the transient changes such as those caused by batch charging, poor atomization and poor mixing.
Also, there exists a need for a system and method capable of identifying critical prefailure conditions of the process and providing optimum levels of fuel, oxygen and air to be fed into the system.
SUMMARY OF THE INVENTION
The present invention relates to a waste incineration system comprised of a primary incineration combustion means which preferably includes a kiln, an afterburner means, and a flue gas treatment means. Both the incineration means and the afterburner means may utilize at least two oxidizing gases having different oxygen concentrations, for example, oxygen and air or oxygen and oxygen enriched air. By varying the ratio of these oxidizers the amount of total oxygen and nitrogen delivered in either the primary incineration combustion means, the afterburner means, or both can be adjusted. In the course of this adjustment the required temperature, retention time, turbulence and oxygen supply level can all be provided simultaneously and without negative side effects.
Additional oxidizing agents can be optionally used. For example, water or steam may be introduced to reduce soot and NO x formation. Additionally, water can be used for the temperature control in either the primary incineration apparatus or in the afterburner. Ozonated oxygen or air may also be used as an initiator of chain reactions.
Dynamic variations in the rates of feed of these different oxidizing gases insures the optimization of the combustion process so that the quantity of oxygen and nitrogen and water supplied conforms with that required for complete combustion whenever fluctuations in the demand for oxygen for combustion of waste occurs. In particular, such fluctuations are related to charging of large batches or other transient events that may potentially reduce the efficiency of thermal waste destruction.
Improvements in incineration processes by the use of oxygen may be achieved with the use of traditional combustion apparatus such as oxy-fuel burners, oxygen enriched burners and oxygen lances. Further improvements can be accomplished by the separate introduction of two different oxidizing gases such as air and oxygen into the combustion tunnel of the burner, as previously described in U.S. Pat. No. 4,622,077 and U.S. Pat. .[.[number currently corresponding to allowed application Ser. No. 755,831].]. .Iadd.No. 4,642,047.Iaddend.. In accordance with these patents, the oxygen stream is introduced primarily as a high pressure, high velocity jet or jets directed through the hot core of the flame. The excess oxygen directed throughout the flame core has a substantially elevated temperature as compared with excess oxygen being introduced around flame pattern in a mixture with combustion air into a primary incineration combustion apparatus. Such hot oxygen has an increased ability to oxidize organics. Additionally, the axial introduction of a high velocity oxygen stream enveloped by fuel and/or fluid waste stream which in turn is enveloped by air or oxygen enriched air, insures a more effective mixing of combustible components of the fuel and/or of the waste stream inside the flame pattern, thus reducing NO x and PICs formations. The transport of oxidizer toward the fuel or liquid waste particles in the flame pattern is also intensified due to better conditions for mixing of oxygen with combustibles from both outside and inside the flame pattern.
Stable combustion under dynamically changing operational conditions may be provided by the use of a burner described in U.S. Pat. .[.application No. 883,769.]. .Iadd.No. 4,797,087.Iaddend.. This burner design provides a high temperature oxidizing gas being delivered for incineration purposes through a controllable flame pattern capable of uniform heating of the primary incineration combustion means and the afterburner means. This increased controllability reduces the possibility of cold spot formation or local overheating of the incineration system. Additionally, the high flame velocity of this burner is used to improve mixing and to reduce short circuiting.
The present invention also includes a dynamic control system containing transducers for measuring process variables such as temperature, pressure and flows of fuel, fluid waste, oxidizing gases and hot combustion products in order to identify critical prefailure conditions of the process based on signals received from the transducers and on such signals received by the process controller. The system prescribes the new "emergency" levels of fuel, oxygen and air to be fed into the primary incineration combustion means and the afterburner means to bring the process back to the desired mode of operation and to prevent process failure. Fuel, oxygen and air are supplied to the primary incineration combustion means by a gas train system containing the necessary valves and actuators communicating with the computerized control system to control fuel, oxygen and air flows according with the prescription of the process controller.
The present invention also relates to a method of waste incineration including the steps of identifying transient prefailure events and responding to such events by properly raising the ratio between the "emergency" amounts of oxygen and nitrogen being delivered into the afterburner means. An increase in the oxygen/nitrogen ratio immediately increases the temperature of the gaseous atmosphere of the afterburner vessel due to reduction of the ballast nitrogen flow. Also, a reduction in the nitrogen feed into the process results in an increase of the residence time for waste destruction and, therefore, in an improved destruction efficiency of the afterburner.
A further step in response to prefailure modes may be a rapid decrease of the flow of fuel being introduced in primary incineration means, without creating a problem with flame stability, to slow down the rate of volatilization in the primary incineration combustion means, to increase the quantity of oxygen available for the oxidation of the wastes and to further increase the retention time, simultaneously.
When two oxidizing gases are also utilized in the primary combustion incineration means, similar "emergency" changes in flow rates of these oxidizing gases may be implemented. If during an "emergency" operation, the kiln or afterburner temperatures rise for a prolonged period of time to a level above that allowable for the refractories, water or steam injection may be used for cooling purposes.
Mixing in the gaseous atmosphere and heat transfer in the afterburner means may be improved by tangentially feeding flue gases exhausted from the primary incineration combustion means into a vortex chamber of the afterburner vessel, thus eliminating short circuiting. Introduction of a high velocity flame in the afterburner may be arranged to create a venturi effect to move the entering stream of combustion products into the combustion chamber with less of a pressure drop. Alternatively, the flue gases may be fed into the vortex chamber axially, while a burner is fired into this chamber tangentially so that the hot exhaust gases from the primary combustion means are enveloped by and mixed with the hot oxidizing gases discharged from the burner.
The present method and apparatus are also capable of minimizing unplanned shutdowns of the incineration system and inappropriate transient releases of the POHCs and PICs to the atmosphere during shutdowns and transient surge conditions such as those caused by batch charging or unexpected changes in the caloric value of the waste as well as by other system malfunctions.
Other advantages of the invention will in part be obvious and in part appear hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a process flow diagram of an incineration system.
FIG. 2 is a longitudinal cross-sectional view of a burner mixer chamber used in the afterburner means.
FIG. 3 is a side cross-sectional view of a vortex chamber taken along lines 3--3 in FIG. 2.
FIG. 4 is a longitudinal cross-sectional view of an alternative burner mixer chamber used in the afterburner means.
FIG. 5 is a side cross-sectional view of a vortex chamber taken along line 5--5 in FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the invention, comprising a primary incineration combustion means, an afterburner means and flue gas treatment system means, is now described with reference to the drawings in which like numbers indicate like parts throughout the views.
Apparatus
FIG. 1 shows a flow diagram including a primary incineration combustion vessel, or kiln 1, which is a part of the primary incineration combustion means 70, and a means for providing containment for combustion and destruction 2 connected to the kiln by a connecting duct 5. A fluid waste burner 3 is attached to kiln 1, preferably a watercooled burner as described in detail in U.S. Pat. .[.application Ser. No. 833,769.]. .Iadd.No. 4,797,087.Iaddend.. A means for feeding solid wastes 29 is attached to kiln 1. The burner 3 has a waste port 9 for the introduction of pumpable fluid wastes, a first gas port 6 for the introduction of a first oxidizing gas (for example, air), a second gas port 7 for the introduction of a second oxidizing gas having a different oxygen concentration from the first oxidizing gas (for example, oxygen), a fuel port 8 for the introduction of an auxiliary fuel, a water port 30 for the introduction of cooling water, and a cooling water discharge outlet 31. A collecting container 4 for ash residue is connected to kiln 1. A first flame supervising means 18 which determines the existence of a flame, such as an ultraviolet sensor, is built into the burner 3.
FIGS. 2 and 3 show a vortex mixing chamber 10 attached to the containment means 2 which receives hot flue gases from the kiln 1 by flue gas inlet 11. A first oxidizing gas, for example oxygen, is supplied through a first oxidizing gas inlet 13 to the fluid waste burner 26, and then into vortex mixing chamber 10. A second oxidizing gas having a different oxygen concentration from the first oxidizing gas, for example air, is supplied to the burner 26 through a second oxidizing gas inlet 12. Auxiliary fuel is supplied through an auxiliary fuel inlet 14. Pumpable fluid waste may be supplied in some cases through a liquid waste inlet 15. Cooling water for the liquid waste burner 26 is supplied through a cooling water inlet 16 and evacuated through a cooling water discharge outlet 17. A second flame supervising means 19 is used to identify the existence of the flame. The burner 26 is preferably designed as described in U.S. Pat. .[.application No. 883,769.]. .Iadd.No. 4,797,087 .Iaddend.to maintain a hot stable flame core during continuous incineration operation, to prevent flame failure and to minimize NO x formation.
FIGS. 4 and 5 show an alternative afterburner means which includes a vortex mixing chamber 101 with inlet 102 for flue gases fed from the primary combustion means 1 and a burner 103 which is similar in design to burner 26. Burner 103 is equipped with lines 104 and 105 for feeding primary and secondary oxidizing gases such as oxygen, oxygen enriched air or air, 106 for an auxiliary gaseous fuel and 107 for an auxiliary liquid fuel, and 108 and 109 for cooling water.
Referring again to FIG. 1, temperatures of combustion products exhausting from the kiln 1 are registered by a first thermocouple 20. Temperatures in the afterburner vessel 55 of containment means 2 are registered by a second thermocouple 21. The absolute pressure and the effluent flue gas flow rate from the kiln 1 are determined by first and second transducer 22 and 23, respectively, and the absolute pressure and the effluent flue gas flow rate from containment means 2 are monitored by third and fourth transducers 24 and 25, respectively.
A control system for detecting and adjusting to operational conditions in the apparatus is provided. The system includes a feed indicating means 33 for indication to a control means 34 of a batch charge approaching the feeding means 29. The feed indicating means 33 may be arranged, for example, as a limit switch which is energized when the batch charge passes its location. The control means 34 communicates with the feed indicating means 33. The control means 34 receives signals from thermocouples 20 and 21, electrical flow transducers 23 and 25, and pressure transducers 22 and 24. An optional smoke detection means 35 may be used to detect smoke in combustion products entering the flue duct 5. Such detection means 35 may include an ultraviolet flame detector or an electrical opacity sensor communicating with the control means 34. The control means 34 is also connected to operate a first air flow modulating means 47 on the first air line 80, a second air flow modulating means 51 on the second air line 81, a first oxygen flow modulating means 48 on the first oxygen line 82, a second oxygen flow modulating means 50 on the second oxygen line 83, a first auxiliary fuel flow modulating means 52 on the first auxiliary fuel line 84, a second fuel flow modulating means 49 on the second auxiliary fuel line 85, a first waste flow modulating means 36 on the first pumpable fluid waste line 86, and a second waste flow modulating means 37 on the second pumpable liquid waste line 87. The instant input flows to burner 3 are sensed for feedback control of the inputs by control means 34 as follows: air is measured by the first air flow metering means 38; oxygen is measured by the first oxygen flow metering means 39; auxiliary fuel is measured by the first auxiliary fuel flow metering means 41; and, pumpable wastes are measured by the first waste flow metering means 40. Similarly, for the second burner means 26, instant flow of air is measured by the second air flow metering means 45; oxygen is measured by the second oxygen flow metering means 44; auxiliary fuel is measured by the second auxiliary fuel flow metering means 43; and, pumpable wastes are measured by the second waste flow metering means 42.
The burner means 26 is fired into the interior of the vortex mixing chamber 10, shown in FIGS. 2 and 3, which is filled with hot flue gases being delivered from the kiln 1. The flue gases preferably enter tangentially to the interior 27 of the vortex mixing chamber 10, shown in FIGS. 2 and 3, thereby causing a rotating mixing movement. The flame of the fluid waste burner means 26, along with a controlled amount of excess oxygen, is directed through the burner combustion chamber 28 at high velocity, thereby creating a venturi effect for inspirating the kiln flue gases into the flame directed toward the afterburner vessel 55. This creates intensive mixing of the gaseous stream prior to entering a refractory lined afterburner vessel 55 of the containment means 2.
Referring now to FIGS. 1, 4 and 5, there is shown an alternative embodiment of the afterburner. This afterburner consists of a vortex mixing chamber 101 with inlet 102 for the flue gas transferred from the primary incineration means 1 and outlet 110 for transferring the hot gases in the afterburner vessel 55. The burner means 103 is tangentially attached to the vortex chamber 101. The burner means 26 has inlets 107, 104, 106 and 105 for feeding a combustible fluid (waste or fuel), a first oxidizer such as oxygen, an auxiliary fuel (when needed) and a second oxidizer, such as air, respectively.
Means for feeding additional amounts of oxygen 120 may also be provided. This means 120 allows oxygen to be fed directly into the vortex mixing chamber 101, if desired, rather than through input port 104. The vortex chamber 101 is attached to the afterburner vessel 55 by outlet 110 and is connected to the flue gas duct 5 by inlet 102. Alternatively, means 120 may be attached to the contracted section of the outlet 110. Additionally, a secondary burner similar to burner means 120 may be installed downstream of means 26. A further modification of afterburner shown in FIGS. 4 and 5 may include two or more consecutive rapid mix chambers similar to vortex chamber 101, having preferably burner means similar to means 103. These rapid mix chambers are communicating with each other by apertures allowing the flow of gases from the first rapid mix chamber into the second and following rapid mix chambers. Optionally, water or steam feeding means may be provided in either first, or second or all rapid mix chambers. Said rapid mix chambers may include afterburner vessels communicating with each mixing chamber to provide additional retention time.
Operation
Referring now to all of the figures, the operation of the system will be described. Solid waste may be continuously or batch charged into kiln 1 through feeder 29. At the same time pumpable fluid waste may be introduced for incineration through the waste port 9 into the fluid waste burner 3 and further with a flame into the kiln 1 interior.
For lower caloric value waste streams, auxiliary fuel may be introduced through auxiliary fuel port 8 into the burner 3 and further directed through the burner combustion chamber 28 towards the kiln 1 interior. A first oxidizing gas with low oxygen concentration (for example, air) enters the burner through first gas port 6 and is further directed through the burner combustion chamber 28 toward the kiln 1 interior. A second oxidizing gas with higher oxygen concentration (for example, oxygen) may be supplied from a liquid oxygen tank or from an on-site oxygen generation unit through second gas port 7 to fluid waste burner 3 and further through burner combustion chamber 28 toward kiln 1 interior.
To satisfy the required temperature in kiln 1 measured by thermocouple 20, the waste feeding rate, the auxiliary fuel flow and the first and second oxidizing gas flows to burner 3 and kiln 1 are maintained essentially constant during steady state operation. The kiln 1 temperature has to exceed sufficiently the temperature of volatilization of all organic components of the waste to a gaseous state during the solids retention time in the kiln 1. Additionally, the temperature should be above the ignition point of volatilized components originating from solid waste as well as combustible components formed during pyrolysis of pumpable waste and auxiliary fuel so that said volatilized combustion components undergo thermal destruction.
At the same time, the total amount of oxygen being delivered with oxidizing gases into the kiln 1 has to be kept high enough to insure its availability to completely combust auxiliary fuel and fluid waste, and to provide extra oxygen flow to destroy the bulk of combustible components being formed in the interior of the kiln 1.
Flue gases exhausted from the kiln 1 are directed into the first vortex mixing chamber 10 through flue gas inlet 11 and further throughout the interior 27 of the vortex mixing chamber 10 toward the interior of the afterburner vessel 55. At the same time, pumpable fluid wastes may be incinerated by introduction through liquid waste inlet 15 into combustion chamber 28 of the fluid waste burner 26 and further through the interior 27 of the vortex mixing chamber 10 toward the refractory lined vessel 55 of the containment means 2. Auxiliary fuel may be introduced when needed to insure flame stability and/or additional heat input to maintain the required afterburner temperature (for instance, as required by regulations), through auxiliary fuel inlet 14 into burner 26 then throughout burner combustion chamber 28 and further through the interior 27 of the mixing chamber 10 toward afterburner vessel 55. The first oxidizing gas with a higher oxygen content (for example, oxygen) than second oxidizing gas is directed into the burner 26 through the first oxidizing gas inlet 13, and further throughout combustion chamber 28, thus discharging hot oxidizing agent originated as auxiliary combustion products from the flame envelope of burner means 26 toward the interior 27 of vortex mixing chamber 10 and further toward afterburner vessel 55. A second oxidizing gas with low oxygen content (for example, air or oxygen enriched air) is directed into burner 26 through the second oxidizing gas inlet 12 and further throughout combustion chamber 28 thus discharging said hot oxidizing gas agent toward the interior 27 of the mixing chamber 10 and further toward afterburner vessel 55. At least 2% to 3% of residual oxygen content in the combustion gases leaving afterburner preferrably should be provided during steady-state operating conditions.
Referring now to FIGS. 4 and 5, an alternative embodiment of the vortex chamber will be operated as follows: The flue gases from the primary combustion means will be fed axially into the vortex mixing chamber 101 through inlet 102. The burner means 103 will be fed with a combustible fluid (waste or fuel), a first oxidizer such as oxygen, and a second oxidizer, such as air, or oxygen enriched air, through ports 107, 104 and 105, respectively. Auxiliary fuel may also be fed through port 106 when needed. The burner means 103 fires tangentially into mixing chamber 101 so that the hot auxiliary combustion product which may be, depending on operational mode, a hot oxidizing or reducing agent, originating as hot auxiliary combustion product from the flame envelope of burner means 103 mix with the flue gases fed from the primary combustion means 1 in the vortex chamber. Several operational modes of afterburner may be used. The selection of the operation mode depends on the composition of flue gases fed in the afterburner and environmental regulations.
When substantial quantities of POHCs, PICs, soot and CO are expected in the flue gases fed in the afterburner and NO x is of no concern, the burner means 26 is fired to produce a hot oxidizing auxiliary combustion product. Under this operational conditions, heat and oxygen are added to the flue gases in the afterburner, thus providing the required destruction of POHCs, PIC, soot and CO. In order to reduce NO x formation in the burner means 26, a fraction of oxidizing gas can be fed downstream of the hot flame zone at the burner means 26 by the use of the oxidizer injecting means 120.
When in addition to POHCs, PICs, soot and CO the concentration of NO x must also be controlled, the operation of the afterburner may be further improved as follows. The burner means 26 will be fired using fuel rich conditions to produce hot reducing auxiliary combustion products rich with CO and H 2 . Since CO and H 2 are selective reducing species for NO x , NO x will be reduced while oxygen in the flue gases will be consumed to a lesser extent. Simultaneously POHCs and PICs will undergo a further thermal destruction due to the additional heat provided with the hot reducing auxiliary combustion products generated in the burning means 26. By feeding additional oxidizing gas through the injecting means 120 downstream of the flame zone of the burner means 26, additional oxidative destruction of POHCs, PICs, soot and CO will be achieved to satisfy environmental regulations. A further improvement of this operating mode may be accomplished by the injection of a hot oxidizing auxiliary combustion product by the use of burner means similar to means 26 instead of or together with injecting a plain oxidizer by means 120. In this improvement additional heat is provided simultaneously with oxygen. A further improvement of this operating mode may include injection of water or steam into the burner means 26 thus increasing the CO and H 2 content in the hot reducing auxiliary combustion products.
When multiple consecutive rapid mix chambers are used, the chambers at the head of the afterburner can be fed with hot reducing auxiliary combustion products while the final stages will be fed with hot oxidizing auxiliary combustion product thus insuring NO x reduction and POHCs, PICs, soot and CO destruction.
Said hot auxiliary oxidizing combustion products have high temperatures and high momentum and provide high turbulence, extra heat to raise mix temperature and excess oxygen. As a result, rapid and uniform mixing occurs in chamber 101 and a final hot combustion product with at least 2% to 3% of residual oxygen is transferred through outlet 110 into afterburner vessel 55, wherein the required retention time is provided Such operation of afterburner insures accelerated burning of residual POHCs, CO, soot and gaseous PICs and provides higher destruction efficiency than that achievable with air above.
A negative pressure will be maintained in the kiln and in the afterburner in order to prevent gas leakage outside the system. An exhaust fan is used for creating the required negative pressure.
In the preferred embodiment and its operation, the ratio of air to oxygen or oxygen enriched air, the fuel feed rate and the oxygen excess level are selected for a particular composition and a particular feed rate of waste so that the required temperature, retention time, partial pressure of oxygen and turbulence in the afterburner and in the kiln are provided and the required destruction efficiency of POHCs is insured to comply with environmental standards.
The desired settings for temperature in the kiln and the afterburner, the maximum flow rates of combustion products from the kiln and the afterburner, and the safe level of negative pressure in the kiln and the afterburner vessel will be entered by the operator into the controller means 34.
Control means 34 will maintain the temperature of combustion product exhausted from the kiln according to a set point chosen by the operator. When temperature measured by thermocouple 20 drops below the desired set point, control means 34 will increase the amount of auxiliary fuel being delivered to the burner by raising the instant for setting for the auxiliary fuel supply line and accordingly on oxygen supply line so that the chosen oxygen excess level is provided until the temperature measured by thermocouple 20 has reached the desired set points chosen by the operator. Similar temperature control is provided for burner 10 of containment means 2.
At the same time, the control means 34 continuously compares the pressure measured by pressure transducer 22, with the pressure set point chosen by the operator as required to maintain a safe negative pressure condition within the kiln, insuring that any looseness in the kiln will result in a leakage of ambient air into the kiln rather than a leakage of combustion products from the kiln. Anytime the negative pressure measured by the pressure transducer 22 exceeds the safe set point chosen by the operator, the control means 34 will reduce the air flow set point and raise the oxygen flow set point in such fashion that each 4.76 volumes of air will be substituted by approximately 1 volume of oxygen fed in kiln 1 maintaining the total amount of the oxygen feed approximately constant until the negative pressure reaches the safe set point. Similar pressure regulation involving pressure transducer 24 is utilized in the afterburner.
To insure a maintenance of the desired retention time and to avoid additional air pollution volumes being produced in the kiln, the control means 34 continuously compares the allowed combustion product flow setting for the kiln discharge with the actual flow being measured by the flow transducer 23. When the actual flow exceeds the allowed set point chosen by the operator, the control means 34 reduces the air flow and increases the oxygen flow supplied to burner 1 in such a manner that the reduction in every 4.76 volumes of air flow will result in approximately a 1 volume increase in oxygen flow maintaining the total amount of the oxygen feed approximately constant until the combustion product flow reaches the allowed flow rate.
The control system 34, by means of thermocouples 20 and 21, will recognize an excessive increase in combustion product temperatures which result from the adjustments in pressures and flows and will reduce auxiliary fuel flow to bring the temperatures down to the desired levels. Simultaneously with the reduction of the auxiliary fuel flow, the oxygen flow will be reduced according to the approximately stoichiometric fuel/oxygen ratio.
Additionally, feed forward controls may be preferrably used for both the primary incineration combustion means and containment means 2 when solid wastes are batch charged. Prior to the feeding of a batch charge, the feed indicating means 33 located upstream of the loading chute of feeding means 29 transmits a signal to the controlling means 34 identifying that a charge is approaching loading chute 29. In response, the control means 34 changes air, oxygen and auxiliary fuel set points to a special "emergency" set of values, insuring the supply of additional excess oxygen during such transient loading conditions, and activates modulating means 47-52 so that the feeding of air is reduced and the feeding of oxygen is increased in both the kiln and the afterburner prior to loading of the incineration system, resulting in a rapid rise in oxygen concentration in the kiln and afterburner as well as the temperature in the afterburner. The emergency set of values should provide for maximum prestored oxygen mass in the primary combustion incineration means and afterburner while maintaining the flame stability, as well as the required temperatures and retention time of gases during the transient event. The excess mass of oxygen accumulated in the kiln 1 in anticipation of the approaching batch charge is utilized to provide sufficient oxidizer during the first stage of waste charge volatilization. Optionally, the auxiliary fuel feed and/or the liquid waste feed delivered to primary incineration combustion means may also be reduced while maintaining the temperature in the kiln under venting conditions substantially above the temperature of ignition of organics in the waste to be charged, thus leaving more oxygen in the kiln volume available for incineration of a batch of wastes, and increasing the retention time for gaseous products in the kiln.
When the batch charge enters the kiln 1, there exists a substantial prestored oxygen mass in the primary incineration combustion means as well as the afterburner and the temperature conditions necessary for the combustion of organics in said batch in the primary incineration combustion means and afterburner. The levels of oxygen, air and fuel feed will be returned to those corresponding to the nominal feeding rates when the destruction of volatilized organics created during the transient overload condition is complete. The duration of such "emergency" cycle can be predicted by experience and the timer of control means 34 will maintain the initial duration setting of such "emergency" transient air, auxiliary fuel and oxygen flows based upon this prediction maintaining maximum partial pressure of oxygen and temperature in afterburner. During such an "emergency" cycle, thermocouples 20 and 21 may indicate temperature levels beyond steady state opening conditions. However, the control means 34 will overrule these signals during an "emergency" cycle so that overheating for a short time period is allowed
After the "emergency" cycle ends, the control means 34 begins an "approaching cycle" which is designed to change gradually the auxiliary fuel flow and the oxygen flow towards a steady state ratio first in primary incineration combustion means and then in the afterburner. If during such cycle the smoke indicating means indicates smoke formation, the increase in the fuel flow will be discontinued but the oxygen flow will be raised again for a preset short time interval. After this time interval elapses, the "approaching cycle" will be initiated again. The control system will repeat the approaching cycle until the smoke is eliminated and the temperature and the level of excess oxygen in the kiln reach a normal level for steady operation. After such event the additional flow of oxygen being supplied to the afterburner to insure the complete combustion of any excess PICs during transient loading in the kiln will be discontinued and the afterburner will reach steady operational conditions. Proper temperature will be further maintained by thermocouples 20 and 21 and by control means 34.
Sensor means 20, 22, 23 and 35 located after the exit from kiln 1 and prior to containment means 2 will provide feedback control of the primary incineration combustion means and feed forward control of the afterburner means during the incineration process. These means supply electrical signals to control means 34 indicating the temperature, pressure or flow rate of gas leaving kiln 1 or the presence of excess smoke or flame. These signals are received and interpreted by control means 34, which in turn changes the oxygen, air and fuel flow into the kiln 1 and/or containment means 2.
Signals from thermocouples 20 and 21 are continuously compared with desired set points by the control means 34. A decrease or increase of the kiln 1 temperature beyond a desired set point triggers an increase or decrease, respectively, in the flow of auxiliary fuel by the use of the first fuel flow modulating means 52. The afterburner temperature is measured with thermocouple 21 and is compared by the control means 34 with a desired set point. A decrease or increase of the afterburner temperature beyond the desired set point triggers an increase or decrease, respectively, in the flow of auxiliary fuel by the use of the second fuel flow modulating means 49. An increase or decrease in the auxiliary fuel flow into the primary incineration combustion means 70 or the containment means 2 will be identified by control means 34 through communication with flow metering means 41 and 43. The control means 34 will also respond by adjusting the flow of oxygen to control the proper ratio between auxiliary fuel and oxidizer.
In order to prevent excess flue gas discharge from the incineration system, the control system will raise the flow of oxygen and reduce the flow of air based upon signals from the transducers 22, 23, 24, and 25 indicating that an excess amount of flue gases are being generated.
When the sensor means 35 detects excessive smoke or flame existing in the flue exhaust duct 5, indicating to the control means 34 a deficiency of oxygen in kiln 1, the control means 34 will activate first oxygen flow modulating means 48 to increase the oxygen supply and modulating means 52 and 36 to reduce auxiliary fuel flow and/or pumpable waste. When the second sensor means 65 detects excessive smoke or flame existing in the flue exhaust duct 32 indicating to the control means 34 a deficiency of oxygen in the containment means 2, the control means 34 will activate second oxygen flow modulating means 50 to increase the oxygen supply and modulating means 49 and 37 to reduce auxiliary fuel flow and/or pumpable waste.
Within the allowed magnitude of the batch charge and gradual fluctuations in the flow rate and composition of wastes, the process insures the required destruction efficiency of POHCs, prevents formation of PICs and minimizes formation of NO x due to the following features:
(a) The controlled oxygen to air ratio permits the change in the oxidizer flow in order to meet the oxygen demand and simultaneously to maintain the required temperature, retention time and turbulence. This eliminates such failure modes as overcharging or burning of wastes with low caloric value at temperatures below the required level. Additionally, the destruction and efficiency of POHCs, PICs and soot are increased, the negative effect of poor atomization of liquid wastes is minimized, and the possibility of a flame out failure is virtually eliminated;
(b) Uniform heating and intensive mixing due to the use of the burner means as described and due to rapid mixing of the hot oxidizing auxiliary combustion products with the flue gases, as presently described, eliminates cold spots and breakthrough of POHCs;
(c) The use of hot oxidizing and reducing auxiliary combustion products in combination with the hot oxidizing auxiliary combustion products in the afterburner further improves removal of NO x and destruction of POHCs, PICs and soot in the afterburner;
(d) The use of water or steam and ozone permits further optimization of either the oxidizing or reducing hot auxiliary combustion products which are used for NO x reduction and POHCs, PICs, sot and CO elimination;
(e) The use of rapid mix of the hot auxiliary combustion products with the flue gases in the afterburner provides uniform temperature and gaseous constituents distribution in the rapid mix chamber; and
(f) Rapid control of oxygen, air and fuel feed into the primary combustion means and after burner provide fast response to changes in the waste feed and composition. The feed-forward control of batch combustion in both the primary and the secondary combustion means allows the maximization of the size of the batch charge for a given system, while feedback control of the primary and feed-forward control of the secondary combustion means allows the maximization of the magnitude of the gradual changes in the waste feed. In either case the temperature, retention time and turbulence are maintained at required levels
A possible modification to the system is the conversion of a portion of the oxygen stream to ozone prior to its use as an exclusive oxidizer or in combination with air, oxygen or oxygen enriched air. Ozone can be most beneficially used as an oxidizer in situations where the need for additional heat input into the afterburner is insignificant. Ozone initiates chain reactions in the flame, thus resulting in faster and more complete destruction of POHC and reduction in the PIC formation.
A further modification is the use of water in line 90 as an additional oxidizing-reducing agent by its introduction into the combustion process in the primary incineration combination means and afterburner. Water will disassociate at high temperatures into hydrogen, oxygen and hydroxide, which are beneficial to the combustion process. These species prevent formation of soot and cyclic and aromatic hydrocarbons including halogenated and oxygenated compounds which are frequently PICs. The use of water is most advantageous when the caloric value of the wastes being incinerated in the primary incineration combustion means is high and/or the ratio of H:C is low. The hydrogen formed from water reacts with halogens which are often found in the POHCs forming HCl, HF, etc., thus making halogens mobilized and not available for the formation of halogenated PICs.
A further modification of the vortex mixing chamber is the use of co-current or counter-current feed of flue gases from the primary incineration chamber and the hot auxiliary combustion product generated in the afterburner burner.
In cases where further improvements of the destruction level of hazardous waste is needed, a second afterburner means may be utilized with an embodiment similar to those described above to provide an additional step of afterburning the hot gaseous products leaving the first afterburner means. A partial recycling of the gaseous products between the primary incineration combustion means and the afterburner, or between a first and second afterburner, may be utilized for further reduction of PICs and POHCs. Partial recycling of flue gases provides mixing of high and low concentrated portions of flue gases and equalization of fluctuations of POHC an PIC in the gaseous effluent from the system. Optionally, a reducing atmosphere may be maintained in the first afterburner and/or in recycled gases thus providing NO x reduction in the flue gases entering the final afterburner. An oxidizing atmosphere may be provided in the second afterburner.
Alternative probes, such as thermal pyrometers, combustible gas analyzers, oxygen analyzers and UV scanners, may be used to indicate to the control system the existence of prefailure conditions.
While the above description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as an amplification of one preferred embodiment thereof. | The invention relates to an afterburner apparatus and an incineration system and methods of waste destruction in primary incineration combustion means and afterburner means which both preferably utilize at least two different oxidizing gases. By varying the ratio of said oxidizing gases, the amount of total oxygen and nitrogen delivered in either means can be dynamically adjusted in accordance with the process requirements. Varying the flows of at least two oxydizing gases and auxiliary fuel in both the primary incinerator and afterburner makes it possible to operate the system under fluctuating waste loading conditions, by controlling temperature, partial pressure of oxygen and heat available for the process as a function of said ratio. | 57,839 |
BACKGROUND OF THE INVENTION
The present invention relates to optical reader-scanner systems and, in particular, for improved means for processing data detected by a reader-scanner system.
Optical reader-scanner systems have achieved applications at automated supermarket check-out counters. A reader-scanner system operates as a data input system for electronic cash register systems and is used to read UPC (universal product code) symbols on the items.
The UPC symbol system was developed by the Universal Grocery Product Code Council, Inc., and is a bar code system which provides for binary coding of ten product identification decimal digits. The first five of these digits identify the producer of the item, and the last five identify the particular item of his product line. The actual symbol is comprised of about sixty parallel light and dark bars. Each of the ten digits used to identify the item is represented by a specific group of these bars and the actual encoding of the digit is obtained by variation in widths of bars making up this group.
In some cases, lesser numbers of digits are used and provisions have been made for utilizing greater numbers of digits for future codification. A complete description of the UPC symbol system may be found in a publication entitled "UPC Symbol Specification" dated May 1973 and published by Distribution Number Bank, 1725 K Street, N.W., Washington, D.C.
The reader-scan system contributes to the efficiency and convenience of the operation of automated check-out counters by allowing the UPC symbols to be read automatically as a package is manually transferred from the counter, across a scan pattern area or window.
In automatic electronic cash register systems, the data covering such things as pricing, quantity or coupon discounting and taxable or non-taxable nature of the item are stored in a memory bank of a controller console. The controller is programmed so that the address of this memory bank location corresponds to digital information encoded in the UPC symbol printed on the package of the item.
Typically, the scan pattern system uses a very low-powered laser, such as a helium-neon laser, to provide a coherent beam of monochromatic light. This type of light source provides the high level signal-to-noise ratio necessary for processing that is unavailable from other sources. The laser beam is then directed to a scanner mechanism which generates an optical scan pattern at a window in the check-out counter. An example of such an optical scan system is disclosed in copending patent application Ser. No. 568,633, filed Apr. 16, 1975, entitled "Optical Scan Pattern Generator" of James L. Hobart and Wayne S. Mefferd, and assigned to the assignee of the present application.
The actual identification of the symbol is made by electronically analyzing the signals generated by the laser light beam that is reflected back from the package surface to an optical detector. The output of the detector then goes to electronic circuitry and is continuously analyzed for the UPC symbol coded content.
When the high speed movement of the light beam crosses the light and dark bars of a UPC symbol, a specific pulse train waveform is generated. The characteristics of this waveform are established by the width of the individual light and dark bars and by the speed of the sweep. If the electronic circuitry determines that the symbol is valid and positive identification of the symbol is made, the signal is passed onto the controller of the cash register system. This output signal provides the address for the memory bank location where the instructions, for billing and cash register-receipt recording of that symbol, are stored.
If the symbol is not valid, i.e. has been tampered with, altered or damaged, the positive identification cannot be made, a no-reading visual or audio alarm is sounded. This notifies the clerk that a visual identification and a manual cash register entry must be made.
In scanner-reader systems presently available, the validation and identification of the stream of light and dark bars does not take place in real time. By this it is meant that the electronic processing circuitry does not analyze the data on a one-for-one basis as it is received. Rather, data which is believed to be valid data is routed to off-line registers or other storage devices, where the data is analyzed by the processor. Simultaneously, on-coming data which may be valid is routed to other registers. Data remains in a register until the processor determines that it is either valid or invalid.
Depending upon the optical scanner system used and the position of a label as it passes the scanner window, it is possible that only one or a few scans will intercept the label. When this happens, it is important that the data stream be correctly processed to determine the label information or else the label will not be read.
In the prior art system previously described, the storage registers frequently fill up with information which, although originally thought to be good information, turns out to be invalid. For example, the register may be filled with signals reflected from print on the container surface. If the processor takes a longer time to determine the contents of each register than it takes to fill up the registers, and if all the registers fill up with invalid data, then a for a given scan, good data which is subsequently provided as the beam sweeps the label is lost. In the case described above, where only one or a few scans intersect the label, this results in the label not being read at all.
The foregoing data processing system has other disadvantages. Processing time is relatively slow since the processing time does not take place in real time. Also, data is frequently stored long after sufficient information is available to determine that it is invalid. Also, this approach involves relatively expensive and complex electronic circuitry for its implementation.
SUMMARY OF THE INVENTION
In accordance with the present invention a system is provided for decoding coded character information where each encoded character comprises a plurality of bars of alternating light reflective characteristics of one or more widths which includes means responsive to bar width and character information to determine in real time valid sequences of the information.
More specifically, means are provided for establishing a multiple level decision-making sequence which includes means for comparing incoming bar width and characteristic information with bar width and characteristic values allowable at that level of the decision-making sequence for the bar and characteristic information sequence developed to that point, means for failing any information sequence which is not allowable, and means for moving to the next and subsequent levels of the decision-making sequence so long as the information sequence is an allowable one, until the completion of the multi-level sequence at which time an individual character is uniquely defined.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of the improved decoder of the subject invention utilizing a decision tree technique.
FIG. 2A is the UPC standard symbol; and FIG. 2B is the UPC character structure for the characters shown in FIG. 2A.
FIGS. 3A and 3B are a detailed graphical illustration of the digit tree starting with white shown in FIG. 1.
FIGS. 4A and 4B are graphical illustrations of the digit tree starting with black shown in FIG. 1.
FIG. 5 is a detailed graphical illustration of the edge guard bar tree and center pattern bar tree shown in FIG. 1.
FIG. 6 is a detailed graphical illustration of the funny tree shown in FIG. 1.
FIG. 7 is a block schematic diagram of one implementation of a decoder utilizing the decision tree technique of the subject invention for UPC applications; and
FIGS. 8A, 8B, 8C and 8D are detailed schematics of the block schematic diagram of FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a block diagram of a decoder 10 for identifying information encoded in the form of a plurality of bars of alternating light reflective characteristics of one or more widths. For purposes of illustrating and describing the invention, the UPC code is hereafter used and described. However, the invention is equally applicable to other coding schemes and the invention is not limited to decoding UPC information.
Before explaining the operation of the decoder 10, a further description of the UPC is necessary. As explained above, for a complete description of this code, reference is made to the "UPC Symbol Specification."
FIG. 2A shows the UPC standard symbol. Among its characteristics are:
1. Overall rectangular shape, consisting of light and dark parallel bars (30 dark and 29 light for any 10-character code) with a light margin on each side. There are ten numeric characters.
2. Each character or digit of a code is represented by two dark bars and two light bars.
3. Each character is made up of seven data elements; a data element hereinafter is called a "module". A module may be dark or light.
4. A bar may be made up of 1, 2, 3 or 4 dark modules, as shown in FIG. 2B.
5. The symbol also includes two characters beyond the ten needed to encode the UPC;
i. One character, a modulo check character, is embedded in the right-most position of the symbol to ensure a high level of reading reliability.
ii. Another character, embedded in the left-most position of the symbol, shows which number system a particular symbol encodes.
6. Starting at the left side of the regular symbol following the light margin are edge or guard bars, followed by the number system character, followed by five UPC characters on the left side of the "center bar pattern", and then with the remaining five UPC characters on the right side of the center bar pattern, followed by the modulo-10 check character. Finally, the same guard bars are provided at the right side.
7. Dark modules represent 1's while light modules represent 0's. The number of dark modules per character on the left side is always 3 or 5 (i.e. odd) and the number is always 2 or 4 (i.e. even) for right-hand characters. This provides an "odd" and "even" parity encodation for each character.
8. Encoding is identical for all characters on a given side of the symbol, whether the character is part of the UPC number or is the number system character in the modulo check character.
9. The left and right guard bars are each encoded 101.
10. The center bar pattern is encoded 01010.
11. Encodation for the regular UPC characters (Version A) is given in the following table:
TABLE NO. 1______________________________________Decimal Left RightValue Characters Characters______________________________________ (Odd Parity - O) (Even Parity - E)0 0001101 11100101 0011001 11001102 0010011 11011003 0111101 10000104 0100011 10111005 0110001 10011106 0101111 10100007 0111011 10001008 0110111 10010009 0001011 1110100______________________________________
For purposes of describing the invention, only the Regular Version, or Version A, and the Zero Suppression, or Version E, of the UPC are considered. Once again, however, the subject invention is applicable to all versions of the UPC.
The zero suppression version of the symbol is included to facilitate source symbol marking on packages that would otherwise be too small to include a symbol. This is achieved by encoding the symbol in a special way that leaves out some zeros that can occur in the UPC code. For example, code 56700-00089 can be encoded as 56789, effectively eliminating half of the area that would otherwise be required for the symbol. There is no explicit number system character for this version of the symbol.
The zero suppression label is similar to the portion of the regular UPC symbol, Version A, to the left of the center except for several items, including the following:
1. It has a right guard pattern which is coded 010101.
2. Three of the characters are coded in odd parity and three are in even. Character encodation for this version (E) only is given in the following table:
TABLE NO. 2______________________________________Character Odd EvenValue Parity Parity______________________________________0 0001101 01001111 0011001 01100112 0010011 00110113 0111101 01000014 0100011 00111015 0110001 01110016 0101111 00001017 0111011 00100018 0110111 00010019 0001011 0010111______________________________________
Note that the even parity encodation is different for Version E than that shown in Table I for the regular version.
3. As was pointed out above, the coding of the zero suppression version is compressed into six characters of varying parity. The determination of whether a character's parity is odd or even is per the following table:
TABLE NO. 3______________________________________ZERO SUPPRESSION - PARITY PATTERN______________________________________Number Modulo Check Character Location NumberSystem Character Value 1 2 3 4 5 6______________________________________0 0 E E E O O O0 1 E E O E O O0 2 E E E O E O0 3 E E O O O E0 4 E O E E O O0 5 E O O E E O0 6 E O O O E E0 7 E O E O E O0 8 E O E O O E0 9 E O O E O E1 0 O O O E E E1 1 O O E O E E1 2 O O E E O E1 3 O O E E E O1 4 O E O O E E1 5 O E E O O E1 6 O E E E O O1 7 O E O E O E1 8 O E O E E O1 9 O E E O E O______________________________________
There is, therefore, no explicit character encodation of the category or modulo check characters, their values are derived from the parity permutation of the six encoded characters. For further explanation, reference is made to page 17 of "UPC Symbol Specification" referred to above.
As set forth above, co-pending patent application entitled "Optical Scan Generator" by James L. Hobart et al, Ser. No. 568,633, as assigned to the same assignee as the subject invention, describes a system for optically scanning an item containing a UPC label with a laser beam as it passes over the scanning window. The subject matter of that patent application is incorporated herein by reference.
Referring to patent application Ser. No. 568,633, for any given laser beam scan of an item containing a UPC code, the reflected light beam and resulting electrical equivalent signal from the detector 58 may not provide useful information to decoder 10. This happens when the beam scans print on the product label, only a portion of the UPC symbol, etc. It is thus the job of decoder 10 to separate the valid UPC information from the useless information and to properly decode the valid data.
For operation of the decoder 10 of FIG. 1, it is first necessary to provide it with bar width (1, 2, 3 or 4 modules) or light and color characteristics (black or white) information which could be valid data. Whether it is or not is determined by the decoder 10 and subsequent processing circuitry.
A bar width measurer (BWM) 11 provides this information. It is the function of the BWM to examine the stream of video data from detector 58 representing the relative widths of the bars printed on the bar code label as it is scanned by the optical system. The length of time the digital video input signal remains in one logic state represents the width of one bar of one reflectivity. The absolute length of time the video signal remains in a given logic state is unimportant as long as it is within some rather crude limits. The information of interest is contained in the relative width of a bar with respect to the other bars in the label and, in particular, with respect to the basic unit of width, the module, upon which the bars are based.
There are a number of ways of accomplishing this function and presently in use in scanning equipment, all within the state of the art of those skilled in the art. See, for example, U.S. Pat. No. 3,723,710. Since the BWM 11 does not form a part of the subject invention, it will not be described in great detail, although the following brief description is given of one approach to the design of a BWM.
The BWM accepts the digital video from the optical scanning system and compares each bar to the basic unit of width upon which all the bars are based and determines how many of these basic units are contained in the bar being examined. It does so by pursuing a certain set of assumptions about which bars are contained by the boundary pattern and proceeding until it sees a bar that is either too big or too small to exist in the label if the basic assumption was correct. When it sees a bar such as this, i.e. out of range, it begins again with new assumptions. These assumptions are:
1. Too Large: If a bar that is too large is encountered, assume (a) it was a margin, and (b) the next bar is the beginning of a boundary pattern.
2. Too Small: If a bar that is too small is encountered, assume (a) it must be the first bar of a boundary pattern.
Thus, decoder 10 is fed a stream of signals from the BWM indicating bar sizes and color, which in relationship to each other may be valid. The decoder 10 must determine if the sequence of those bars constitutes a valid one or not. This includes distinguishing when only a part of a label has been scanned, but not enough to get a complete reading. The validation of one-half of a regular UPC symbol is considered a complete identification since the other half of the label can be read and validated by earlier or subsequent scans.
In order to determine the start of a valid half label, decoder 10 must identify either a left guard bar pattern, a right guard bar pattern, or a center bar pattern. The edge guard bar pattern tree 12 and the center pattern bar tree 14 accomplish this in a manner which will be described subsequently.
Assuming that a guard bar or center bar pattern has been identified, then the BWM information goes to either decision (or digit) tree 16 or 18. The former is applicable if the next bar is one which is white and the latter if it is dark.
FIGS. 3A and 3B are graphical representations of decision tree 16 and FIGS. 4A and 4B of decision tree 18. Each tree 16 and 18 provides a four level decision making sequence. It has four levels because each character comprises four bars of from one to four modules in size. At each level a determination is made whether for the bar width sequence information provided, the sequence is a valid one, i.e. does it represent a valid sequence of 1's and 0's as set forth in Tables 1 and 2?. If it turns out to be valid, then the next BWM signal is looked at at the subsequent level of the decision tree. As long as the sequence is valid, the process continues through all the decision tree levels, i.e. four levels, and a valid character is decoded.
If at any time an invalid sequence is determined, decoder 10 is initialized and the search for a center bar pattern or an edge pattern begins again. If a valid character is decoded, the next BWM information is sent to the beginning of the same decision tree 16 or 18 and the decision tree procedure is followed again until it either culminates into the identification of another valid character or else it fails and the decoder 10 is initialized, and the search begins for another guard edge bar or center bar pattern.
There is one exception where the identification of an invalid sequence does not result in initialization of decoder 10. This occurs where the scan beam is sweeping past only a part of one side of the label and, without having scanned the entire side, passes over the center bar pattern. In that case, since the subsequent scan could result in a valid scan of the other half of the label, once decoder 10 realizes the number is invalid, but that this situation has occurred, it drops out of the decision tree 16 or 18 and into the appropriate level of the center pattern bar tree 14. Further explanation of this procedure will be given subsequently.
Each validated digit is loaded into a buffer 120, which is shown in FIG. 7 and which will be described in greater detail subsequently. Once six digits representing one-half of a label are read and stored in the buffer, then the decoder 10 looks for either an edge pattern and white margin or a center bar pattern, depending upon the direction of the scan. If it finds either, it signals a valid one-half label complete. In the case of an edge pattern, since the scan can no longer be on the UPC symbol, the decoder is initialized, and it looks for the next edge guard pattern or center bar pattern. In the case of a center pattern, since there is the possibility of a scan of the remaining half label, the decoder goes back to decision tree 18, since the center bar pattern always ends with a white bar.
The operation of the digit trees 16 and 18 are best understood by providing several examples of their operation. Suppose that the first signal from the BWM 11 indicates a bar which is white and is one module wide. This is indicated by "1W" in FIG. 3A, at the first level of the decision tree, at reference #71. Since, of course, this is a valid first bar for quite a few digits, see Tables 1 and 2, the decoder progresses up to the second level of the tree. At this level of the tree, every size black bar, i.e. from 1B to 4B, is still a possible valid bar for the digits shown in Tables 1 and 2.
Let us suppose that the next bar is a black bar three modules wide, i.e. 3B. This corresponds to position #713 in FIG. 3A. At this next level, level 3, only a 1W or 2W bar constitutes a valid sequence. Thus, if the next input is either 3W or 4W, there is an invalid sequence and the decoder is initialized.
Assuming the next bar is 1W, then for there to be a valid digit, the next bar at the 4th level must be 2B, which gives the sequence 1W, 3B, 1W, 2B or 0111011. This corresponds to the digit 7, on the left side of the label, having odd parity, with the scanning beam going east. This can be confirmed by reference to Tables 1 and 2.
Should the last bar have been 1B, and hence invalid, the decoder 10 would not have initialized. This is because the scan could have been passing through a part of one side of the label and then, without scanning a complete half, have started into a center bar pattern or edge pattern. In the case of the former, it is thus possible that the remainder of the scan, across the other half of the label, will result in a valid half label scan. Accordingly, in the case of a 1B in this case, the decoder 10 automatically switches to the center bar tree at the first level.
Under the circumstances set forth in the previous paragraph, the decoder 10 switches to the center bar pattern tree. More specifically these circumstances are: whenever decoder 10 fails to progress further in tree 14 or 16 because the current BWM is invalid, and it is either a 1W or 1B, it shifts to the center bar pattern and, using the information previously acquired, it shifts into the appropriate place in the center bar pattern tree. The latter will be explained in greater detail in connection with the following explanation of the guard bar and center bar pattern trees 12 and 14 which are shown in greater detail in FIG. 5.
At the first, second or third levels of the edge tree 12, if a 1B-1W-1B sequence doesn't occur, then the tree is initialized, i.e. it starts back at the beginning of trees 12 and 14 looking for the start of an edge or center pattern. At the fourth level of edge tree 12, if the BWM is 2W, 3W or 4W, then the decoder switches to the first level of digit tree 16, indicated by the numbers 71-74 in FIGS. 3A and 3B, since the previous combination of bars indicates an edge guard pattern.
Should the bar at the fourth level be 1W, then the tree progresses to the fifth level since the scan may be either the start of a digit having 1W as its first bar or else the second bar of an edge pattern.
At level 5 of tree 12, if the BWM provides either a 2B, 3B or 4B, the decoder 10 switches again to the digit tree 16, but this time at its second level since it already has a 1W as the first level. This level is indicated as numbers 711-714. If the bar is 1B, it still could be the beginning of a character (having 1W, 1B as the first two bars) or it could be the fifth bar of a zero suppress label.
If the next bar is 1W, at the sixth level, then it knows, in fact, that it is a right edge of a zero suppress label since it has picked up a 1B-1W-1B-1W-1B-1W. A 2W, 3W or 4W puts it into digit tree 16 at the third level.
At the first and third levels of center pattern tree 14, if a 1W isn't present, it cannot be a center tree pattern and hence the tree initializes back to the edge tree 12 in anticipation of an edge bar. At the second and fourth levels of center tree 14, if no 1B is provided, then there cannot be a center tree and hence the decoder initializes, but back to the same tree in anticipation of a center pattern.
At the fifth level of center tree 14, if a 1W appears, a possible center pattern is determined and decoder 10 shifts over to funny tree 20, starting with black. Funny tree 20, shown in greater detail in FIG. 6, will be explained subsequently. If a 2W, 3W or 4W appears, then the decoder switches to digit tree 16, at the first level, since the three preceding bars, e.g. 1B, 1W, 1B, define an edge pattern.
Funny Tree 20
Whenever decoder 10 picks up what appears to be a center pattern, there is a potential ambiguity that the first two bars of the alleged center pattern actually are the last two bars of the character adjacent the center pattern. This can only happen in the case of the left hand digits 0 and 4 and right hand digits 4 and 6 since these are the only digits which end in bar 1W, 1B going toward the center pattern. See Table 1.
Recognizing this potential ambiguity, decoder 10, if it gets a single black or single white bar after a center pattern, goes to the funny decision tree 20. Funny tree 20 is the same as the regular digit trees 16 and 18 except that decoder 10 only stays in it so long as the first two bars of the characters are single black and single white, i.e. right 3's and 6's and left 0's and 4's. With this general rule stated, the following specific action is taken by the funny tree 20, referring additionally to FIG. 6.
1. If following 1B, 1W, either 2B, 3B or 4B follows, then decoder 10 knows that right 3's and 6's and left 0's and 4's are not being scanned and decoder 10 switches to the second level of digit tree 18 (FIG. 4A), numbers 812-814.
2. If decoder 10 keeps decoding any sequences of right 3's and 6's or left 0's and 4's, then decoder 10 stays in the funny tree throughout the six digit sequence and afterwards looks for the standard terminating edge pattern and large white space. In this situation, decoder 10 has seen a "real" center pattern.
3. If at any time, a 1B is not followed by 1W, and it is the beginning of a legitimate character sequence, a transfer is made to digit tree 18 at an appropriate level, i.e. the second level numbers 812-813. This is an indication that the center pattern was "real" and decoder 10 switches back into the regular tree.
4. If, following 1B, 1W, any of the following sequences occur, the decoder 10 goes to the third level of digit tree 18 as indicated in FIG. 6 and a funny convert takes place:
1B -- 1W
1b -- 2w
1b -- 3w
2b -- 1w
2b -- 2w
2b -- 3w
3b -- 1w
3b -- 3w
3b -- 4w
4b -- 2w
4b -- 3w
4b -- 4w
a funny convert indicates that the center pattern was not "real" and a conversion must take place to "shift" over two places. This is what takes place by shifting to the third level of digit tree 18. Further details of funny convert will be explained subsequently in connection with FIGS. 7 and 8A-8B.
5. If, following 1B, 1W, any of the following sequences occur, then the decoder 10 remains in the decision tree:
1B -- 4W
2b -- 3w
3b -- 2w
4b -- 1w
one example of the implementation of the decision tree technique of decoder 10 which has been described above is now given. Reference is made to FIG. 7 which is a block schematic diagram of decoder 10 and to FIGS. 8A-8D which are detailed schematics of the block diagram of FIG. 7.
The heart of the decoder 10 is the program ROM 100 which contains 256, 16-bit instructions that direct the functioning of decoder 10. Included in these instructions are Front End and Back End instructions. The Back End instructions process the information acquired by the Front End operation to perform the "checksum check" (see "UPC Symbol Specification" referred to above) and outputting of decoded data. The Back End instructions are not pertinent to an understanding of the subject invention and will not be described in detail.
The Front End instructions constitute the various decision trees which have been described above. Henceforth these trees will be referred to collectively as "tree". These instructions derive their information from current data relating to bar size and color and past history consisting of 5 bits from the previous 16 bit instruction. Thus, program action consists of examining each piece of information as it comes in and making decisions for action immediately, rather than storing a large volume of data and then looking at all of the individual pieces of information to decide if any group of data is valid. This function of processing data from UPC labels in real time, i.e. examining data as it appears, is a major and unique feature of decoder 10.
Each new piece of data is used by the Front End instructions to update the program position in the tree. The program position in the tree determines whether the instruction output causes the program to continue looking at incoming data or causes the program to jump back to the beginning of the tree. The jump back to the beginning of the tree will be caused by a new piece of data trying to force the program to an illegal branch of the tree or by having acquired enough valid data to constitute a complete set of data, i.e. a valid half label.
Since the program ROM, block 100, contains both Front End and Back End instruction as explained and they will never both be used simultaneously, ROM output requirements can be cut in half by making duplicate use of the output bits. In the Front End, the bits have one meaning and in the Back End, another. The logic distinguishes between these two states by referencing all interpretation of the output bits to QBACK, block 136. If flag (flip-flop) QBACK is reset, Front End operation is indicated. IF QBACK is set, Back End operation is indicated. The meaning of the bits in Back End operation is not discussed, as it is not necessary for an understanding of the subject invention.
The breakdown of the 16-bit instruction word is given below for `Front End` operation only:
______________________________________ROM OUTPUT DESIGNATIONBITS FOR THE BITS FUNCTION______________________________________11-15 XA0-XA4 Address bits (`A` bits) 7-10 XV0-XV3 Value bits (`V` bits)3-6 XE0-XE3 Expected bar size data (`E` bits)2 XP Parity bit1 XM Funny convert enableφXNS Inhibit Update______________________________________
The `A` bits help to determine the next program address for the program ROM, block 100. Three bits of UPC label video, XBLK, XBS0, and XBS1 combine with the five `A` bits to specify the next 8-bit address as will be explained in greater detail subsequently.
The `V` bits specify Front End instructions as shown in the table below:
*TABLE NO. 4__________________________________________________________________________VALUE OFV BITSXV3 XV2 XV1 XV0 FRONT END INSTRUCTION__________________________________________________________________________0 0 0 0 Load a `0` into the digit buffer block 1200 0 0 1 Load a `1` into the digit buffer block 1200 0 1 0 Load a `2` into the digit buffer block 1200 0 1 1 Load a `3` into the digit buffer block 1200 1 0 0 Load a `4` into the digit buffer block 1200 1 0 1 Load a `5` into the digit buffer block 1200 1 1 0 Load a `6` into the digit buffer block 1200 1 1 1 Load a `7` into the digit buffer block 1201 0 0 0 Load a `8` into the digit buffer block 1201 0 0 1 Load a `9` into the digit buffer block 1201 0 1 0 Load a `A` into the digit buffer block 1201 0 1 1 Load a `B` into the digit buffer block 1201 1 0 0 XHC - Half Complete1 1 0 1 XHC - Half Complete1 1 1 0 Not Used1 1 1 1 NOP Instruction (No Operation)__________________________________________________________________________ *Notes 1. The command XSTD is generated for the first twelve `V`commands. This i what actually causes the appropriate number to be loaded into the digit buffer, block 120. 2. All data is represented in hexadecimal. 3. The `A` or `B` hexadecimal are loaded for the Funny Convert situation only.
The `E` bits are used by the program to specify the next allowable bar size. The program knows, from where it is currently in the tree, what the allowable bar sizes are for the next data coming in, as will be explained by way of example subsequently. This data is fed into the illegal bar size detector 128, with the current bar size, to indicate good or bad bar size data from bar width measure. See the table below for `E` data coding:
TABLE NO. 5______________________________________E DATAXE3 XE2 XE1 XE0 ALLOWABLE BAR SIZES______________________________________0 0 0 0 Not Defined0 0 0 1 10 0 1 0 20 0 1 1 1,20 1 0 0 30 1 0 1 1,30 1 1 0 2,30 1 1 1 1,2,31 0 0 0 41 0 0 1 1,41 0 1 0 2,41 0 1 1 1,2,41 1 0 0 3,41 1 0 1 1,3,41 1 1 0 2,3,41 1 1 1 1,2,3,4______________________________________
the parity bit, XP, specifies the parity of the black modules in the UPC label digit being loaded into the digit buffer 120. The parity for each digit in the digit buffer 120 is stored in the parity buffer 124. The parity is stored only for one label half at a time. See "UPC Symbol Specification" referred to above for more information concerning parity of the black modules.
The funny convert enable bit, XM, enables the funny convert flags 132, QRHFC and QLHFC, so they are set if conditions indicate they should. The inhibit update bit, XNS, inhibits the updating function of the Bar Width Measurer if XNS is true.
Each branch in the tree actually consists of a particular 8-bit address at the input of the program ROM 100. The program counter 102 applies this 8-bit address. The program counter operates in two modes: the "load" and the "count" modes. In the load mode, the data at the input to the counter 102 appears at the counter outputs following the rising edge of the counter clock signal.
In the count mode, the counter output increments by 1 following the rising edge of the counter clock signal. The counter is in the load mode during the Front End and is in the count mode during the Back End. This is because during the Front End, the program ROM 100 must be free to instruct a jump in address, corresponding to a branch in the tree. This means that not all addresses are consecutive and therefore the program counter 102 does not have a sequential output. Thus, it must be in the load mode, where its output follows the input and not a sequential counting scheme.
The program counter 102 is in the load mode when QBACK or XA4 is true. The term QBACK is a flag (flip-flop output) designating Back End operation when set, Front End operation when reset. XA4 has no effect on the load input to the program counter 102 during the Front End because QBACK is reset. XA4 affects the load function of the program counter 102 only during Back End operation.
The count enable input of the program counter 102 is true if the load term is false and QCE 104 is set. The flag QCE is set when a valid set of data has been acquired (XVLD is true) and is set only for Back End operation, so its function is not pertinent.
The clear input of the program counter 102 is activated only if QIDLE, block 106, is set. The flag QIDLE is controlled by Back End and Entry/Exit logic, so its function does not relate to the subject invention except that it starts the program counter, block 102, always at 00 (hexadecimal). This assures that the program ROM 100 always has a fixed starting address (tree location) for the program.
The program counter 102 clock input comes from the clock select logic 108. During Front End operation, the clock output is XCCC, the color change clock that is part of the UPC label video information from the Bar Width Measurer 11. Thus, the program counter 102 does nothing and the program ROM 100 instruction output bits do not change, until a new piece of video data is sent from the Bar Width Measurer. In Back End operation, data acquisition has halted and the data that is currently stored needs to be processed for a "checksum check". Therefore, an internal Back End clock, CPB, is selected to clock the program counter 102 so the appropriate processing can take place by sequencing the program ROM 100 address inputs.
The program counter 102 load inputs come from the 8-bit address multiplexor, Mux 110. Normally, the `B` inputs of the Mux are selected, meaning that the 8-bit program counter 102 inputs consist of the `A` bit outputs from the program ROM 100, and three bits of video data from the Bar Width Measurer, XBS0, XBS1, XBLK.
If the disable input on the address Mux 110 is high, all outputs of the Mux become a logic 0. This causes the program counter, block 102, to load a 00H (00hexadecimal), forcing the program back to address 00H. The disable is high if XHFFL is true, XSMALL is false, and QBACK is false. In the Front End operation QBACK is always false. The XSMALL term is an error signal from the Bar Width Measurer, indicating that it has discovered some bad data and this term is normally false. Later explanation covers the case where it is true. The term XHFFL is the output of fail detect logic, block 130. Any of four types of failure or a masterclear signal causes XHFFL to become true.
If XSIXTH, XSMALL or QBACK is true, address Mux 110 `A` inputs are selected. The flat QBACK true indicates Back End operation. The signal XSMALL is an error signal sent to the decoder 10 by the Bar Width Measurer and indicates bad video data. The signal XSIXTH is an output of the digit buffer address counter 122 and indicates that six valid digits from a UPC label have been stored. This indicates either a partial or complete UPC label has been acquired, depending upon the status of the program flag 132 outputs.
Any of the three signals described in the preceding paragraph require special action on the part of the program. Therefore, the `A` inputs of the address Mux 110 are selected for the program counter 102 load inputs. This connects the output of the Front End special address logic 114 to the program counter 102 load inputs.
This means that the load inputs for the program counter 102 and consequently the next address for the program ROM 100 are determined by the front end special address logic 114. The inputs to the front end special address logic are XBLK, XSMALL, and QBACK. For Front End operation, QBACK is false all the time, so the variable inputs to the front end special address logic 114 are only XBLK and XSMALL, both signals from the Bar Width Measurer.
Summarizing operation of the address logic for the program in the Front End (QBACK is always false), the following simple operation becomes apparent:
TABLE NO. 6______________________________________ NEXTXHFFL XSIXTH XSMALL PROGRAM ADDRESS______________________________________0 0 0 5 bits of ROM instruction out- put (XA0-XA4) and 3 bits of video data, XBS0, XBS1, XBLKX 0 1 one of two 8-bit addresses depending on what XBLK (color) is0 1 0 one of two 8-bit addresses depending on what XBLK (color) isX 1 1 Not possible1 X 0 00H (hexadecimal)______________________________________ Notes: 1. A `0` denotes A logic false condition. A `1` denotes A logic true condition. 2. An `X` denotes either a `0` or a `1` and will cause the same address action in either case.
The front end instruction decode logic 118 looks at the `V` data and if appropriate, generates a `store digit` (XSTD) signal or a `half complete` (XHC) signal. As was shown in Table No. 4, XSTD occurs for `V` data of 0H-9H (0-9 hexadecimal).
The `V` data is also the data input for the digit buffer 120. The write enable for the digit buffer is XSTD, XCCC, and XBFL. The signal XBFL indicates that the digit buffer is full. If the buffer is full, no more data can be written into it. When a store digit command (XSTD) is given, the color change clock (XCCC) will write the `V` data into the buffer if the buffer is not full (XBFL). Note that since `V` data 0H-BH (0-B hex) causes the front end instruction decode 118 to generate a store digit command (XSTD), and that the same `V` data 0H-BH is present at the digit buffer 120 data inputs, `V` data 0H-BH is equivalent to `Load digit 0H-BH specified by `V` data into the digit buffer`. That is, `V` data of 3H means "Load 3H into the digit buffer".
If `V` data were AH, a AH digit would be loaded in to the digit buffer 120. Thus, when the program is at a point in the tree where it knows that the last piece of UPC video data it saw was the last bar of a valid character, the program puts the hexadecimal value of that character of the `V` data outputs of the program ROM 100, causing the value of that character to be loaded into the digit buffer 120. The data output from the digit buffer goes to the Back End logic.
For Front End operation, the digit buffer address consists of the digit buffer address counter 122, and a signal XRH. This specifies where in the buffer the digits are stored. It is necessary to store data in fixed locations in the digit buffer so during Back End operation, the Back End logic always calls out data from the digit buffer in the correct order that it appears on the UPC label code. The signal XRH specifies which half of the digit buffer the data is stored in and the 3-bit digit buffer address counter 122 specifies the particular location within the half.
The digit buffer address counter 122 is incremented with each store digit command, XSTD. The next location in the half of the digit buffer being loaded is selected each time a digit is loaded into the digit buffer. The clock for the buffer address counter is the same as for the program counter 102, CPC.
During Front End operation, CPC is the color change clock XCCC. The digit buffer address counter is cleared by XHFFL 130, or XSPA, block 110. The signal XSPA is XSIXTH, or XSMALL, or QBACK. During the operation of the tree, the digit buffer address counter is cleared by the error signal XSMALL from the Bar Width Measurer Unit, or XSIXTH, one of the digit buffer address counter, block 122, outputs indicating a complete label half (6 digits) has been loaded in the digit buffer, or by XHFFL, indicating some error in label data being acquired.
In each of these cases, the data in the digit buffer 120 is not cleared, but the buffer address is moved back to its starting location so that new data is written over the data that was written in error. In the case where a complete label half of data was completed, the digit buffer address counter being cleared does not cause new data to be written over the old because the XRH signal that is one of the digit buffer address inputs changes state so that new data is written into the beginning location of the other half of the digit buffer.
The digit buffer address counter 122 also provides the address input for the parity buffer 124. This buffer provides the same function as the digit buffer, except it stores the black module parity of the digit being stored in the digit buffer.
The data input for this buffer is the program ROM 100, output of XP. The condition for writing into the parity buffer is that if no valid zero suppress label has been read (XZSVLD) and a store digit command has been given, write the parity, XP, on the color change clock, XCCC.
The parity check ROM 126 performs this check of the parity pattern. For a regular (Version A) UPC label (12 digits) the black module parity of all six digits in a half is the same, but the parity of left half digits is opposite the parity of right half digits. In the UPC zero suppress label, there are only six digits in the label and it is not possible to read only half the label successfully. Therefore, there are no left and right label halves as with the expanded UPC label. In the zero suppress label, the parity of all six digits is not the same. See Table 3.
This parity pattern of odd-even-even-odd, etc. can be only one of twenty different combinations. If all combinations were allowed, there would be sixty-four combinations. The parity check ROM 126 has as inputs XPZS, which indicates a zero suppress label, and QLP, which indicates, for a Regular Version, which half of the label is currently being tested for parity. The parity check ROM is normally disabled, so its output has no effect. When the program generates the XHC (half complete) command 118, the parity check ROM 126 is enabled during the command, so its output is active. If any parity discrepancy exists, the output XPE, for a parity error, comes up.
Another error detecting circuit is the illegal bar size detector 128. As was mentioned above, the `E` data out of the ROM 100 gives the allowable bar sizes for the next bar seen by the video and measured by the bar size measurer. The expected bar size (`E` data) is matched against the bar size (XBS0,XBS1) and if a discrepancy exists, the XBADBAR signal goes up.
The fail detect logic 130 indicates a failure to acquire a label half (XHFFL) if XPE or XBADBAR occur, or if the Bar Size Measurer detects a bar size discrepancy with a bar suddenly far too large or small compared to the bars it had been measuring (XLARGE, XSMALL), or if a master clear occurs (usually only on powering up).
The program flags, block 132, are flip-flops that indicate the status of the decoder 10 as it is attempting to read a UPC label. The flags are used by the rest of the decoder 10 logic to indicate action that has been taken and the action that still needs to be taken in order to acquire a complete valid UPC label.
All the flags are clocked by CPC, the same clock that clocks the program counter 102, so that during Front End operation, they are clocked by XCCC, the color change clock. They are set and reset by the signal inputs depending on the state of these, but they are all cleared by XOVER, a signal generated by the Back End and Entry/Exit Logic 138. This signal occurs as the operator, who is moving a UPC label through the scan target or window area, causes the label to leave the scan target area. As the decoder 10 senses that the label has left the scanning area, it resets all the program flags to be ready to start from scratch on the next label that enters the scan target area.
The flags QRP and QLP are the "right partial" and "left partial" flags, respectively. These are set as soon as the first valid UPC label digit is read and stored by a store digit (XSTD) command. One or the other is set, depending upon the parity (XP) of the first digit. As was mentioned earlier, in the explanation of the parity ROM 126, for an expanded label, the parity of all the digits are the same and the parity of the right half digits is opposite the left half.
The program starts off assuming a Regular Version UPC label is being read and sets either QRP or QLP, as XP indicates. At the same time, the flag QEVEN is set or not and then its inputs are locked out until a complete label half has been acquired or the flags have been reset by a fail condition.
The flag QEVEN stores the parity of the first digit in the half label currently being acquired for use as reference later on, as will soon be explained. For a Regular Version label, the flags stay in the state they are in during the remainder of the acquisition of the half if no fail condition occurs, as designated by XHFFL, block 130, or by XOVER which indicates the Back End functions are complete and the label is out of the acquisition area. During the half acquisition, XRH tells the digit buffer 120 which half of the label is currently being acquired and thus, which half of the digit buffer to store the digits in. When the sixth digit is stored, XSIXTH occurs and is detected by the program.
The program generates the half complete command, XHC, block 118, and the parity check ROM 126 is enabled. The parity ROM 126 checks the status of QLP to check parity. If QLP is not set, QRP is assumed to be set. The half complete command, XHC, also enables either QRHC or QLHC (right or left half complete) flags to be set, and the one set will depend on whether QRP or QLP respectively are set when XHC occurs. If at this time a parity error (XPE is true) occurs, then the flags are all reset and the program starts looking for another half label from scratch. If no parity error occurs, QRHC or QLHC are set and the program accepts only label halves of the missing variety (i.e. left halves if QRHC is set, or right halves, if QLHC is set). This is true until XOVER happens, at which point all flags are reset.
For zero suppress labels, the flag operation is similar, but additional flags are required. The flags QRP, QLP and QEVEN are set as described above, depending on the parity of the first digit stored. As was stated above, the program makes the assumption that one half of the UPC Regular Version label is being acquired at this point. If, however, the parity of one of the six digits being acquired changes from what the parity of the first digit was (QEVEN), it is realized that a zero suppress label is being acquired. Therefore, QRZS or QLZS (right or left zero suppress) is set, depending on whether QRP or QLP, respectively, are set. The terminology "right" or "left" zero suppress does not imply that there are two zero suppress label halves. It just indicates what the parity of the first digit was and, therefore, which half of the digit buffer 120 the zero suppress label is being stored in.
As soon as QRZS or QLZS is set, the indicator XPZS comes up, indicating a "partial zero suppress" label has been acquired and the rest of it is still to be acquired. This flag output, XPZS, is one of the inputs to the parity ROM 126, and indicates that when the command "half complete", XHC, is given, the parity ROM must check the parity pattern of the six digits to see that it agrees with one of the accepted patterns. The half complete command, XHC, also sets QRHC or QLHC as was described above. At this point, the flag output XZSVLD (zero suppress valid) comes up if QRHC and QRZS or QLHC and QLZS are true.
The two remaining flags, QRHFC and QLHFC (right or left half funny convert) are set from the input XBADBAR and XM. Under conditions described above, the program gets out of step with the incoming data so that it is looking at part of one UPC character and part of another, yet it thinks it is looking at all of one character. As explained previously, there are some digits that are encoded in such a manner that by taking part of one digit's code and placing it with part of another digit's code, a valid digit code, being neither of the two digits involved, is seen by the program. As was explained earlier (see UPC label and funny convert explanation), there are only four digits that can be involved in a funny convert situation. These digits are `0`, `4`, `3`, and `6`. At times a `0` can look like a `4` and vice versa. Similarly, a `3` can look like a `6` and vice versa. When this condition exists, the program realizes it, but at this point does not have enough information to tell what it is actually seeing, so it writes either an `A` or `B` hexadecimal into the digit buffer. The `A` will be converted (funny convert) to a `0` or `4` by the Back End logic and the `B` will be converted to a `3` or `6`. This conversion will be explained shortly.
As soon as the program comes to two digits that do not yield a valid code, the signal XBADBAR occurs, because the program was expecting a certain bar size and did not see it. At this point, the logic normally generates a fail condition indication, XHFFL, block 130. The program can recognize that it was in this type of situation usually, so when the XBADBAR signal occurs, it gives the XM command that inhibits XHFFL and sets one of the funny convert flags, QRHFC or QLHFC, if conditions warrant it.
The funny convert flags are used by the Back End logic 138 to convert the `A` or `B` stored in the digit buffer 120 to the proper number.
Funny Convert Explanation
This is done by a ROM in the Back End logic which will convert an `A` hexadecimal number stored in the digit buffer 120 to a `0` or `4`, as the digits are being moved out of the digit buffer in the Back End operation. A `B` hexadecimal number will be converted to a `3` or `6`. Digits `0` through `9`, including `0`, `4`, `3`, and `6` are uneffected by the funny convert operation of the ROM. They are moved out of the digit buffer 120 in the same form as they are stored. The conversion that takes place depends upon the state of the funny convert flags, QRHFC and QLHFC, and the half of the UPC label that the digit `A` or `B` was from. A digit is said to be stored in the "left half" of the digit buffer if the digit was part of the left half of a UPC label or in the "right half" of the buffer if the digit was from the right half portion of a UPC label. Digits are always stored in fixed locations depending on which half of the label they are in (see digit buffer 120 explanation) so the Back End logic always knows which half of a UPC label a digit was from by its location in the digit buffer. The following table will define these relationships as they apply to the funny convert operation:
TABLE NO. 7______________________________________Digit Being Buffer Half ConvertedConverted Digit Stored In QLHFC ORHFC Digit______________________________________A Left 0 0 `0`A Left 0 1 `0`A Left 1 0 `4`A Left 1 1 `4`A Right 0 0 `4`A Right 0 1 `0`A Right 1 0 `4`A Right 1 1 `0`B Left 0 0 `3`B Left 0 1 `3`B Left 1 0 `6`B Left 1 1 `6`B Right 0 0 `6`B Right 0 1 `3`B Right 1 0 `6`B Right 1 1 `3`______________________________________ Note: A `0` or `1` value in the QLHFC and QRHFC columns denotes a logic state, false or true, respectively.
The valid label detect logic 134 generates the signal XVLD (valid label acquired) that sets QBACK and puts the processor unit in the Back End mode. The flags QRHC and QLHC or XZSVLD cause the XVLD signal to go high.
The flag QBACK, block 136, determines whether the decoder 10 is in the Front End or Back End mode. That is, whether the decoder 10 is acquiring (reading) a UPC label (Front End operation) or it is processing stored UPC label digits (Back End operation). If QBACK is true, it indicates Back End operation. The flag QBACK is set by XVLD and reset by one of several Back End logic 138 signals.
The Back End function is to check the checksum according to the modulo 10 algorithm defined by the UPC specifications. The Back End is entered after the Front End has fully decoded a label known to be valid in every way except for the checksum. The Back End then performs the modulo 10 calculations and checks for the correct check character. If the checksum is incorrect, the decoder 10 is completely reinitialized and returns to Front End operation. If the checksum is valid, the decoder 10 becomes idle until the entry/exit logic 130 signals that the operator has removed the label from the scanning target area. At this time, the data in the digit buffer 120 is taken by an interface unit external to the decoder and the decoder is placed in an idle state as indicated by a logic true condition of the flag QIDLE.
The Back End and entry/exit logic 138 is not shown in FIG. 8 since it is not pertinent to the description of the subject invention.
Detailed Functional Examples
To further aid in explaining the operation of decoder 10, the step by step operation of the action of the decision "tree" is given by way of two different examples. The first illustrates the fail condition response and the second illustrates the successful acquisition of a complete label half of a UPC label.
A review of how the program makes the decision on allowable bar sizes would be helpful. The widths of all the bars in the UPC label that encode the numeric information are required to be an even multiple of the unit module width (i.e. 1, 2, 3 or 4 module widths). By definition, there are a total of seven unit module widths required per encoded digit. This total is the sum of the black modules and white modules.
Also, there are four bars required for each encoded digit, two white bars and two black bars, alternating within the character. Each character must have seven modules and four bars. It follows that the largest allowable bar is four modules. This is because if one bar is four modules, there are only three modules left and there are still three bars required. Since each bar has to be at least one module wide, there are just enough modules left for three-one module bars.
This is the scheme used by the program to deduce which bar sizes are allowable for the next bar. Some examples follow:
______________________________________ Bar Bar Size Total Mo- Bar Sizes Being (Mo- Modules dules Bars Allowed forEx Considered dules) Used Left Left Next bar______________________________________1. First 3 3 4 3 1,2 Second 2 5 2 2 1 Third 1 6 1 1 1 Fourth 1 7 0 0 --2. First 1 1 6 3 1,2,3,4 Second 1 2 5 2 1,2,3,4 Third 1 3 4 1 4 Fourth 4 7 0 0 --3. First 2 2 5 3 1,2,3 Second 2 4 3 2 1,2 Third 1 5 2 1 2 Fourth 2 7 0 0 --______________________________________
Example I:
This example assumes the following bars seen by the Bar Width Measurer Unit: Color Bar Size
______________________________________B 1W 1 Guard Bar PatternB 1W 3 First four bars shouldB 2 constitute a valid UPCW 1 character. In this case,B 3 the black 3 is an illegalW 2 bar size.______________________________________
Each of the following examples represents the change due to a single color change clock, XCCC. The program ROM 100 outputs are derived directly from the ROM program listing, Table No. 8, which follows:
TABLE NO. 8__________________________________________________________________________ROM ROM ROM ROMADDR CONTENTS ADDR CONTENTS ADDR CONTENTS ADDR CONTENTS__________________________________________________________________________00-----A788 7F-----6798 BF-----F7F801-----17F8 40-----A788 80-----9788 CO-----A78802-----27F8 41-----17F8 81-----37F8 C1-----37F803-----6F88 42-----27F8 82-----C788 C2-----4FB804-----17F8 43-----3FB8 83-----ED8A C3-----452205-----6F88 44-----3FB8 84-----C788 C4-----4FB806-----8F88 45-----3FB8 85-----1188 C5-----102007-----098C 46-----EFB8 86-----9F88 C6-----57B808-----0780 47-----0824 87-----0000 07-----109009-----0000 48-----5798 88-----0000 C8-----11140A-----0000 49-----5798 89-----0000 C9-----87F80B-----0780 4A-----0894 8A-----0000 CA-----108C0C-----C788 4B-----17FC 8B-----0000 CB-----14080D-----0002 4C-----0910 8C-----D788 CC-----AF880E-----4280 4D-----7F88 8D-----0002 CD-----0010OF-----0110 4E-----0A8C 8E-----4280 CE-----011510-----011C 4F-----0888 8F-----0110 CF-----011811-----0120 50-----0C0C 90-----011C D0-----012412-----012C 51-----0000 91-----0120 D1-----012813-----0130 52-----0000 92-----0128 D2-----013414-----013C 53-----0000 93-----0134 D3-----013815-----0200 54-----0000 94-----4138 D4-----017C16-----0080 55-----0000 95-----0200 D5-----017017-----0000 56-----0000 96-----0080 D6-----016C18-----0000 57-----0000 97-----0000 D7-----016019-----0000 58-----0000 98-----0000 D8-----015C1A-----0000 59-----0000 99-----0000 D9-----01501B-----0000 5A-----0000 9A-----0000 DA-----00801C-----0000 5B-----0000 9B-----0000 DB-----03801D-----0780 5C-----0000 9C-----0000 DC-----00001E-----098C 5D-----0780 9D-----0000 DD-----7F981F-----8F88 5E-----0824 9E-----0000 DE-----128820-----A788 5F-----EFB8 9F-----9F88 DF-----57B821-----17F8 60-----A788 A0-----A788 E0-----A78822-----27F8 61-----17F8 A1-----37F8 E1-----37F823-----1FF8 62-----27F8 A2-----1FF8 E2-----6F9824-----2FF8 63-----F798 A3-----25C6 E3-----5D1625-----2FF8 64-----F798 A4-----2FF8 E4-----6F9826-----37F8 65-----F798 A5-----1344 E5-----121427-----0F48 66-----6798 A6-----3FF8 E6-----779828-----47B8 67-----0A10 A7-----1424 E7-----128C29-----47B8 68-----17F8 A8-----14A0 E8-----13882A-----0C20 69-----7788 A9-----0000 E9-----00002B-----5F98 6A-----0A88 AA-----1110 EA-----00002C-----0CA4 6B-----0780 AB-----1494 EB-----00002D-----5F98 6C-----0B8C AC-----8798 EC-----00002E-----0B90 6D-----0002 AD-----118C ED-----00022F-----0914 6E-----4280 AE-----1208 EE-----428030-----0C90 6F-----0110 AF-----100C EF-----011031-----0688 70-----011C B0-----1308 F0-----011C32-----9788 71-----0120 B1-----B788 F1-----012433-----0988 72-----012C B2-----CF88 F2-----012834-----9F88 73-----9134 B3-----FFF8 F3-----013435-----0808 74-----4138 B4-----A788 F4-----013836-----0B0C 75-----0200 B5-----0F88 F5-----020037-----0A0C 76-----0080 B6-----DF88 F6-----008038-----8788 77-----0000 B7-----1688 F7-----000039-----AF88 78-----0000 B8-----8F88 F8-----00003A-----B788 79-----0000 B9-----0000 F9-----00003B-----BF88 7A-----0000 BA-----0000 FA-----00003C-----0000 7B-----0000 BB-----0000 FB-----00003D-----17F8 7C-----0000 BC-----0000 FC-----00003E-----17F8 7D-----0780 BD-----67B8 FD-----BF883F-----FFF8 7E-----0A10 BE-----1394 FE-----0000 FF-----7798__________________________________________________________________________
For example, at ROM address 2BH (hexadecimal), the ROM 100 output is 5F98H. The output breaks down as follows:
______________________________________ XA4 0 XA3 1`A` DATA XA2 0 5 XA1 1 XA0 1 XV3 1 XV2 1 F`V` DATA XV1 1 XV0 1 XE3 0 XE2 0 9`E` DATA XE1 1 XE0 1 XP 0 XM 0 8 XNS 0______________________________________
This output implies that the `A` data is 0BH (hexadecimal), the `V` data is FH (NOP instruction), the `E` data is 3H (the next bar must be a 1 or 2 to be valid), the parity, XP, is 0 (odd partiy), XM is 0 (no funny convert), and XNS, which is not pertinent to the subject invention.
EXAMPLE I.__________________________________________________________________________Video Data ROM ROM `A` `V` `E`XLargeXSmall XBlk XBSI XBS0 Address Output XHFFL Data Data Data XP XN XNS Comments__________________________________________________________________________1 0 0 0 1 00 A788 1 10100 1111 0001 0 0 0 White 1 - ROM Addr = 00 because XHFFF is high Xlarge causes XHFFL & occurs at the start of every label.0 0 1 0 1 B4 A788 0 10100 1111 0001 0 0 0 Black 1 - NOP allowable bar size (BS)=10 0 0 0 1 34 9F88 0 10011 1111 0001 0 0 0 White 1 - NOP BS=10 0 1 0 1 B3 FFF8 0 11111 1111 1111 0 0 0 Black 1 - NOP. BS=1,2,3, or 4. Guard bar pattern has been recognized, so next bar will be first bar of a digit.0 0 0 1 1 7F 6798 0 01100 1111 0011 0 0 0 White 3 - NOP. BS=1,20 0 1 1 0 CC AF88 0 10101 1111 0001 0 0 0 Black 2 - NOP. BS=10 0 0 0 1 35 0808 0 00001 0000 0001 0 0 0 White 1 - next clock will store a zero (V data=0) if no fail occurs BS=10 0 1 1 1 E1 37F8 1 00110 1111 1111 0 0 0 Black 3 - A `0` is stored as a result of the previous `V` data, but half fail (XHFFL) goes up because of bad bar size.0 0 0 1 0 00 A788 1 10100 1111 0001 0 0 0 White 2 - ROM Addr. forced to 00 and all logic is reset by__________________________________________________________________________ XHFFL.
Example II: will follow the program through acquisition of a complete label half as shown below:
______________________________________Color Bar Size______________________________________B 1W 1 Guard Bar PatternB 1W 3B 2W 1 0B 1W 2B 2W 2 1B 1W 2B 1W 2 2B 2W 1B 4W 1 3B 1W 1B 1W 3 4B 2W 1B 2W 3 5B 1W 1B 1W 1 Center PatternB 1W 1______________________________________
EXAMPLE II.__________________________________________________________________________Video Data ROM ROM `A` `V` `E`XLargeXSmall XBlk XBSI XBS0 Address Output XHFFL Data Data Data XP XN XNS Comments__________________________________________________________________________1 0 0 0 1 φφ A788 1 10100 1111 0001 0 0 0 White 1 - Label start-up0 0 1 0 1 B4 A788 0 10100 1111 0001 0 0 0 Black 1 - NOP. BS=10 0 0 0 1 34 9F88 0 10011 1111 0001 0 0 0 White 1 - NOP. BS=10 0 1 0 1 B3 FFF8 0 11111 1111 1111 0 0 0 Black 1 - NOP. BS=1,2,3,4. Next bar will be first bar of first digit.0 0 0 1 1 7F 6798 0 01100 1111 0011 0 0 0 White 3 - NOP. BS=1,20 0 1 1 0 CC AF88 0 10101 1111 0001 0 0 0 Black 2 - NOP. BS=10 0 0 0 35 0808 0 00001 0000 0001 0 0 0White 1 - next clock will load a zero. BS=10 0 1 0 1 A1 37F8 0 00110 1111 1111 0 0 0 Black 1 - `φ` loaded into digit buffer. QLP set (first store digit XSTD. odd parity, XP=0).0 0 0 1 0 46 EFB8 0 11101 1111 0111 0 0 0 White 2 - NOP. BS=1,2,30 0 1 1 0 DD 7F98 0 01111 1111 0011 0 0 0 Black 2 - NOP. BS=1,20 0 0 1 0 4F 0888 0 00001 0001 0001 0 0 0 White 2 - next clock will load `1`. BS=10 0 1 0 1 A1 37F8 0 00110 1111 1111 0 0 0 Black 1 - `1` loaded. BS=1,2,3,40 0 0 1 0 46 EFB8 0 11101 1111 0111 0 0 0 White 2 - NOP. BS=1,2,30 0 1 0 1 BD 67B8 0 01100 1111 0111 0 0 0 Black 1 - NOP. BS=1,2,30 0 0 1 0 4C 0910 0 00001 0010 0010 0 0 0 White 2 - two will be loaded on next clock. BS=20 0 1 1 0 C1 37F8 0 00110 1111 1111 0 0 0 Black 2 - `2` loaded. BS=1,2,3,40 0 0 0 1 26 37F8 0 00110 1111 1111 0 0 0 White 1 - NOP. BS=1,2,3,40 0 1 0 0 86 9F88 0 10011 1111 0001 0 0 0 Black 4 - NOP. BS=10 0 0 0 1 33 0988 0 00001 0011 0001 0 0 0 White 1 - three will be loaded on next clock. BS=10 0 1 0 1 A1 37F8 0 00110 1111 1111 0 0 0 Black 1 - `3` loaded. BS=1,2,3,40 0 0 0 1 26 37F8 0 00110 1111 1111 0 0 0 White 1 - NOP. BS=1,2,3,40 0 1 0 1 A6 3FF8 0 00111 1111 1111 0 0 0 Black 1 - NOP. BS=1,2,3,40 0 0 1 1 67 0A10 0 00001 0100 0010 0 0 0 White 3 - four will be loaded on next clock. BS=20 0 1 1 0 C1 37F8 0 00110 1111 1111 0 0 0 Black 2 - `4` loaded. BS=1,2,3,40 0 0 0 1 26 37F8 0 00110 1111 1111 0 0 0 White 1 - NOP. BS=1,2,3,40 0 1 1 0 C6 57B8 0 01010 1111 0111 0 0 0 Black 2 - NOP. BS=1,2,30 0 0 1 1 6A 0A88 0 00001 0101 0001 0 0 0 White 3 - five will be loaded on next clock. BS=10 0 1 0 1 A1 37F8 0 00110 1111 1111 0 0 0 Black 1 - `5` loaded. BS=1,2,3,4. Xsixth occurs because this is the 6th digit loaded.0 0 0 0 1 0C C788 0 11000 1111 0001 0 0 0 White 1 - ROM address forced because Xsixth switched in special address mux. Xsixth goes away on this clock.0 0 1 0 1 B8 8F88 0 10001 1111 0001 0 0 0 Black 1 - NOP. BS=1. This is the second bar of the center pattern.0 0 0 0 1 31 0688 0 00000 1101 0001 0 0 0 White 1 - half complete command. It will be clocked into the flags on the next clock. BS=10 0 1 0 1 Aφ A788 0 10100 1111 0001 0 0 0 Black 1 - QLHC Set. (QLP . XHC sets QLHC). QLP was set when the first digit was stored.0 0 0 0 1 34 9F88 0 10011 1111 0001 0 0 0 White 1 - last bar of center pattern. NOP.,__________________________________________________________________________ BS=1 | A system for decoding encoded character information characterized by a plurality of bars of alternating light reflective characteristics of one or more widths in applications such as reader/scanner systems utilizing a decision tree technique that enables decoding to take place on line in real time. | 87,078 |
TECHNICAL FIELD
[0001] The present disclosure relates to parking assist systems for vehicles.
BACKGROUND
[0002] When a vehicle is parked on a hill, a driver may angle the wheels in a certain direction to prevent the vehicle from rolling. For example, the front wheels of the vehicle may be angled away from the curb if the vehicle is facing uphill, toward the curb if the vehicle is facing downhill, or to the right if no curb is present.
SUMMARY
[0003] A parking assist system for a vehicle includes a controller configured to, in response to activation of the vehicle and data indicating that an inclination of the vehicle exceeds a first threshold and a steering angle of the vehicle exceeds a second threshold, adjust the steering angle to center wheels of the vehicle.
[0004] A vehicle includes a parking assist system configured to identify an inclination of the vehicle and an angle of wheels relative to a centerline of the vehicle, and a controller configured to, in response activation of the vehicle, the inclination exceeding a first threshold, and the angle exceeding a second threshold, adjust the angle to center the wheels relative to the centerline.
[0005] A control method for a parking assist system of a vehicle includes, in response to activation of the vehicle and data indicating a vehicle incline exceeding a first threshold and a steering angle exceeding a second threshold, adjusting by a controller the steering angle to center a set of wheels of the vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a schematic view of a vehicle parked on an inclined roadway; and
[0007] FIG. 2 is a control logic flow diagram for centering the wheels of the vehicle after vehicle activation.
DETAILED DESCRIPTION
[0008] Embodiments of the present disclosure are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments may take various and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures may be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations.
[0009] FIG. 1 depicts a schematic view of a vehicle 10 parked on an inclined roadway 12 . The vehicle 10 includes a steering system 14 having a steering wheel 16 , an accelerometer 17 , an EPAS motor 18 , and a steering angle sensor 20 in communication with a controller 22 . The steering angle sensor 20 may include a pinion angle sensor, a steering wheel angle sensor, or any other sensor that may be configured to determine an angle of vehicle wheels 32 . Further, the vehicle 10 includes a parking assist system 21 to communicate, using near field communication, between the controller 22 and an activation transceiver 24 . While preferred, any other communication system may allow communication between the controller 22 and the activation transceiver 24 , such as but not limited to, Bluetooth, WiFi, dedicated short range communication, or in-vehicle networks. The activation transceiver 24 may start, or ignite a vehicle engine to allow the vehicle 10 to propel forward or deactivate the vehicle and turn off a vehicle engine in order to park the vehicle 10 . The controller 22 may also be in communication with a vehicle vision system 26 including a camera 27 or an ultrasonic sensor 29 , as well as a navigation system 25 and a map 23 to detect the presence of a curb 28 . Any other vehicle vision sensors may be used to communicate the presence of the curb 28 to the controller 22 .
[0010] The inclined roadway 12 has an incline β. Incline β corresponds with a steering angle α. The steering angle α may be defined as an angle between the wheels 32 and a center 34 of the vehicle 10 . As incline β reaches a first threshold, the accelerometer 17 communicates that the incline β is above the first threshold to the controller 22 . The controller 22 uses the steering system 14 to account for the incline β of the roadway 12 . As by way of example, the steering system 14 uses the incline data from the controller 22 to activate the EPAS motor 18 to adjust the steering wheel 16 such that the steering angle α exceeds a second threshold. The steering system 14 may also be configured to adjust the steering angle α by angling the wheels 32 in vehicles without a steering wheel. The controller 22 may also use the accelerometer 17 to determine which direction the steering system 14 should adjust the wheels 32 . For example, FIG. 1 depicts a scenario in which a front 30 of the vehicle 10 faces downhill and the incline β exceeds the first threshold. When a front 30 of the vehicle 10 faces downhill, the controller 22 instructs the steering system 14 to adjust the vehicle wheels 32 toward the curb 28 to achieve the steering angle α. Angling the wheels 32 toward the curb 28 when the front 30 of the vehicle 10 faces downhill allows the curb 28 to act as a stop, preventing the vehicle 10 from rolling downhill. Downhill may be defined when the front 30 of the vehicle 10 faces toward a decline 23 of a slope 25 of the inclined roadway 12 .
[0011] While depicted in FIG. 1 , the controller 22 may use the accelerometer 17 to account for similar scenarios. For example, if the controller 22 , using the accelerometer 17 , determines a front 30 of the vehicle faces uphill while the incline β of the roadway 12 still exceeds the first threshold, the controller 22 instructs the steering system 14 to adjust the vehicle wheels 32 away from the curb 28 to achieve the steering angle α. Angling the wheels 32 away from the curb 28 when the front 30 of the vehicle 10 faces uphill allows the curb 28 to prevent the vehicle 10 from rolling down the roadway 12 . Uphill may be defined when the front 30 of the vehicle faces toward an incline (not shown) of the slope 25 of the inclined roadway 12 .
[0012] The controller 22 may angle the wheels 32 , using the steering system 14 as described above, when the activation transceiver 24 indicates the vehicle 10 is off and the steering angle sensor 20 indicates the wheels 32 are aligned with a center 34 of the vehicle 10 . This allows the steering system 14 to automatically adjust the wheels 32 to further park the vehicle 10 on the inclined roadway 12 .
[0013] The controller 22 is also configured to use the steering system 14 to align the wheels 32 with the center 34 of the vehicle 10 when the activation transceiver 24 indicates vehicle activation. For example, when the parking assist system 21 indicates to the controller 22 that the distance between the activation transceiver 24 and the parking assist system falls below a third threshold, the controller will instruct the steering system 14 to align the wheels 32 with the center 34 of the vehicle. The third threshold may preferably be when the activation transceiver 24 is within a cabin (not shown) of the vehicle 10 . However, the parking assist system 21 may also indicate that the activation transceiver 24 is within the third threshold at a predetermined distance from the parking assist system 21 . The predetermined distance may be based on the range of near field communication systems.
[0014] For example upon actuation of the activation transceiver 24 , the controller 22 receives input from the steering angle sensor 20 indicating that the wheels 32 have been angled at the steering angle α exceeding the second threshold and from the accelerometer 17 that the vehicle 10 is on the incline β exceeding the first threshold. The controller instructs the steering system 14 to actuate the EPAS motor 18 to turn the wheels 32 , based on the input from the steering angle sensor 20 , to align the wheels 32 with the center 34 of the vehicle 10 . Aligning the wheels 32 with the center 34 of the vehicle 10 prepares the vehicle 10 for road use. Further, the controller 22 may also instruct the steering system 14 to further adjust the steering angle α such that the wheels 32 are angled away from the curb 28 and toward the roadway 12 to prepare the vehicle 10 for road use. The parking assist system 21 may also be configured to send an input signal to the controller 22 indicating cancellation of the steering system 14 centering maneuver described above.
[0015] For example, if the incline β exceeds the first threshold and the steering angle α exceeds the second threshold and the activation transceiver 24 is within the third threshold of the parking assist system 21 and indicates vehicle activation, but an operator (not shown) indicates that aligning the wheels 32 with the center 34 of the vehicle 10 may not be ideal, the operator may apply a brake 36 for the vehicle 10 . Applying the brake 36 alerts the controller 22 that centering the wheels 32 may not be necessary and the controller 22 may likewise instruct the steering system 14 to maintain the wheels 32 at the steering angle α. Likewise, the operator may grab the steering wheel 16 to alert the controller 22 that centering the wheels may not be necessary.
[0016] Further, the steering system 14 may adjust the steering angle α to center the steering wheel 16 between vehicle activation and displacement of the brake 36 . This allows the parking assist system 21 to account for varying circumstances that may arise during operation of the vehicle 10 . Further, the controller 22 may also be configured to apply the brake 36 while the steering system 14 is aligning the wheels 32 with the center 34 of the vehicle. If the accelerometer 17 indicates that the incline β of the roadway 12 requires the brakes 36 be applied while the wheels 32 are centered, the controller 22 may likewise be configured to automatically apply the brakes 36 while the steering system 14 centers the wheels 32 .
[0017] The controller 22 may also be configured to activate an alert 38 of the pending centering of the wheels 32 by the steering system 14 . In at least one embodiment, the alert 38 may be an audible tone or dialect indicating that the steering system 14 is aligning the wheels 32 with the center 34 of the vehicle 10 . The alert 38 may also include a visual indication of the maneuver, or by providing haptic feedback indicating the maneuver. The alert 38 allows the operator the opportunity to abort aligning the wheels 32 with the center 34 of the vehicle 10 as described above. The alert 38 ensures that the operator is aware of the maneuver by the steering system 14 and may be able to control the vehicle 10 if needed.
[0018] FIG. 2 depicts control logic for the controller 22 to center the wheels 32 of the vehicle 10 . At 40 , the controller 22 determines if the activation transceiver is within range of the vehicle 10 or is sending data indicating vehicle activation. If at 40 the controller 22 does not receive data indicating vehicle activation from the activation transceiver, the control logic ends. If however at 40 the controller 22 does receive data indicating vehicle activation, the controller 22 uses the accelerometer to calculate the inclination of the roadway at 42 . The controller 22 uses the inclination data at 42 to determine if the vehicle inclination is greater than a first threshold at 44 . If the vehicle inclination is not greater than a first threshold at 44 , the control logic ends. If the controller 22 determines that the vehicle inclination is greater than the first threshold at 44 , the controller 22 may use the vision system, such as an ultrasonic sensor or camera to detect the presence of a curb 46 .
[0019] The controller 22 then receives input, using the steering angle sensor 20 , of the wheel angle at 48 . The controller 22 uses the input of the steering angle at 48 as well as the presence of the curb at 46 to determine if the steering angle is greater than the second threshold at 50 . If the curb is present at 46 and the steering angle has been adjusted at 48 to account for the curb, the controller 22 may then determine at 50 if the wheels 32 have been sufficiently angled toward the curb, exceeding the second threshold. If at 50 the controller determines that the steering angle does not exceed the second threshold and the wheels 32 do not need to be centered, the control logic ends. If however the controller 22 determines at 50 that the steering angle exceeds second threshold, the controller 22 determines at 52 whether centering the wheels 32 using the steering system 14 should be canceled. For example, at 52 the controller 22 will determine if a brake pedal has been depressed, as described above.
[0020] If at 52 the controller 22 determines that a brake pedal has been depressed, the controller 22 will activate the braking system at 54 . After activating the braking system at 54 the control logic ends. If, at 52 , the controller determines that a brake pedal has not been depressed, the controller 22 will adjust the steering angle, using the steering system 14 , to align the wheels 32 with the center of the vehicle 10 at 56 . While the controller 22 centers the wheels 32 with respect to the vehicle 10 , the controller 22 also will issue an alert of the centering at 58 . As stated above, issuing the alert of the centering at 58 further provides control and communication such that an occupant is aware of the adjustment at 56 . After the wheels 32 have been centered at 56 and the alert has been issued at 58 the control logic ends and the vehicle 10 is ready for travel.
[0021] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments may be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics may be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes may include, but are not limited to cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, embodiments described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and may be desirable for particular applications. | A vehicle includes a parking assist system that identifies an inclination of the vehicle and an angle of wheels relative to a centerline of the vehicle. The vehicle also includes a controller that, in response activation of the vehicle, the inclination exceeding a first threshold, and the angle exceeding a second threshold, adjusts the angle to center the wheels relative to the centerline. | 16,302 |
FIELD OF THE INVENTION
[0001] This application is a Continuation-In-Part of application Ser. No. 09/807,214, filed Apr. 11, 2001 and hereby claims priority to said application and incorporates the entire application by reference. The present invention relates to an electrode structure using an ion-conducting polymer, and to an electrical component such as a primary cell, a secondary cell, and an electric double layer capacitor.
BACKGROUND OF THE INVENTION
[0002] In the prior art, in a lithium ion battery, a positive electrode h is manufactured by mixing a mixture e of a powdered electrode active substance a comprising LiCoO 2 , powdered electrically-conducting carbon b, a binder polymer c and a solvent d into a slurry, and applying it to a current-collecting member f to form a compound film g, as shown in FIG. 13 . The compound film g of FIG. 13 is a partial enlargement of the mixture e on the current-collecting member f.
[0003] A negative electrode i is manufactured by mixing the mixture e of the powdered electrode active substance a comprising powdered graphite, the binder polymer c and the solvent d into a slurry, applying it to the current-collecting member f, and drying to form the compound film g, as shown in FIG. 14 .
[0004] A lithium secondary cell contains an electrolyte j between the positive electrode h and negative electrode i, a separator k being disposed in the electrolyte j, as shown in FIG. 15 .
[0005] The lithium secondary cell is generally formed by applying a dispersion of the electrode active substance a or the binder c in an organic solvent to a current-collecting member f comprising metal foil or the like, drying, winding a sheet electrode comprising the compound film g into a spiral shape together with the separator k, inserting this spiral-shaped electrode into a battery case, filling with the organic solvent electrolyte j, and sealing. This battery is characterized by having a high energy density per unit capacity and high energy density per unit weight.
[0006] However, concerning the electrode active substance a contained in the compound film g, doping/undoping of lithium ions is performed during charging and discharging through the electrolyte j which permeated the voids in the compound film j, and if the particles of the electrode active substance a are covered by the binder polymer c, lithium ions are prevented from penetrating the electrode active substance a, so battery performance declines.
[0007] Specifically, this is because the binder polymer c which is generally used does not have ion-conducting properties. The binder polymer c may be vinylidene polyfluoride, a fluoride resin such as polytetrafluoroethylene-hexafluoropropylene copolymer, styrene-butadiene rubber latex or carboxyl-modified styrene-butadiene rubber latex.
[0008] Even if there are minute interstices on the surfaces of the electrode active substance particles a covered by the binder polymer c, the electrolyte j cannot penetrate them, so passage of lithium ions is blocked and the battery characteristics decline.
[0009] If the amount of the added binder polymer c is reduced in an attempt to increase the interstices on the particle surfaces of the electrode active substance a, the strength of the compound film g decreases, so cohesion between the electrode active substance a or electron-conducting assistant and the current-collecting member f gradually declines during repeated charges and discharges of the battery, and battery performance declines due to decrease of electron-conducting properties.
[0010] As a means of resolving this problem, Japanese Patent Laid-Open Hei 10-106540 discloses a method of forming the binder polymer c as a mesh. However, even if the electrode active substance a is made to adhere in a mesh-like fashion by the binder polymer c, the binder polymer c which is used is a non-ion conducting polymer, so ions cannot penetrate or move through the binder polymer c. Therefore, in this case also, penetration of lithium ions into the electrode active substance a is blocked as in the case of a prior art electrode. As a result, the battery performance declines.
[0011] In U.S. Pat. No. 5,641,590 (Japanese Patent Laid-Open Hei 9-50824), the inventors disclose a method for manufacturing electrodes wherein an ion-conducting polymer is added to the electrode instead of the prior art binder polymer c which does not have ion-conducting properties. However, in this case, the ion-conducting polymer itself has a weak adhesive force, and as it is merely added to the electrode active substance a when the compound film g is manufactured, it does not permit manufacture of a battery having satisfactory performance.
[0012] Batteries are used for various types of electrical components, and they have to satisfy stringent safety criteria with regard to fire, etc. In the case of a lithium-ion battery, oxygen is generated if the LiCoO 2 is heated to high temperature and as there is a risk of explosion or fire if a large current flows due to a short-circuit, safety is a prime consideration.
SUMMARY OF THE INVENTION
[0013] It is an object of this invention to provide a highly efficient electrode. It is a further object of this invention to provide an electrode with a high level of safety. It is a further object of this invention to provide a secondary cell with a high level of safety. It is a further object of this invention to provide an extremely safe electric double layer capacitor. It is a further object of this invention to provide a secondary cell which does not use an electrolyte. It is a further object of this invention to provide an electric double layer capacitor which does not require the use of electrolyte.
[0014] This invention specifically relates to: an electrode structure for electrical components wherein ions migrate between electrodes, wherein a powdered electrode active substance coated with an ion-conducting polymer or a powdered large surface material is made to adhere to a current-collecting member, a secondary cell comprising a positive electrode structure and negative electrode structure comprising a current-collecting member to which a powdered electrode active substance coated with an ion-conducting polymer is made to adhere, and an ion-conducting substance disposed between the positive electrode structure and negative electrode structure, a method of manufacturing an electrode structure for electrical components wherein ions migrate between electrodes, wherein the electrode structure is formed by press-sliding a mixture of at least an ion-conducting polymer or ion-conducting polymer raw material with a powdered electrode active substance or a powdered large surface material so as to coat the powdered electrode active substance or a powdered large surface material with the ion-conducting polymer, and applying the product to a current-collecting member, a method of manufacturing a secondary cell wherein ions migrate between electrodes, wherein an ion-conducting substance is disposed between a positive electrode structure and a negative electrode structure formed by press-sliding at least an ion-conducting polymer and a powdered electrode active substance so as to coat the powdered electrode active substance with the ion-conducting polymer, and applying the product to a current-collecting member, and an electric double layer capacitor having an electrode structure comprising a current-collecting member to which a powdered large surface material coated with an ion-conducting polymer is made to adhere and an ion-conducting substance disposed between the electrode structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The above and other objects of the present invention will become readily apparent by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:
[0016] FIG. 1 is a diagram showing the manufacture of an electrode structure comprising an electrode active substance which supplies ions;
[0017] FIG. 2 is a diagram of an electrode structure comprising an electrically conducting substance wherein electricity moves between ions;
[0018] FIG. 3 is a schematic view of a secondary cell;
[0019] FIG. 4 is a descriptive diagram of a pressure-sliding mixer;
[0020] FIG. 5 is a schematic view of the press-sliding mixer wherein the bottom surface of a container is flat;
[0021] FIG. 6 is another schematic view of the press-sliding mixer;
[0022] FIG. 7 is a front view of the press-sliding mixer;
[0023] FIG. 8 is a lateral view of the press-sliding mixer;
[0024] FIG. 9 is a descriptive diagram of a cohesion device;
[0025] FIG. 10 is an electron micrograph of LiCoO 2 which has not received any processing;
[0026] FIG. 11 is an electron micrograph of a positive electrode structure obtained in a third embodiment;
[0027] FIG. 12 is a photograph of a secondary electronic image of the positive electrode structure obtained in the third embodiment;
[0028] FIG. 13 is a diagram showing the manufacture of a positive electrode structure of a secondary cell according to the prior art;
[0029] FIG. 14 is a diagram showing the manufacture of a negative electrode structure of a secondary cell according to the prior art; and
[0030] FIG. 15 is a schematic view of a secondary cell according to the prior art.
DETAILED EXPLANATION OF THE INVENTION
[0031] This invention will now be described in more detail referring to the drawings.
[0032] (a) Electrical Components
[0033] Electrical components wherein ions migrate between electrodes are those in which an ion-conducting substance is disposed between electrode structures functioning as electrodes, and ions migrate within the ion-conducting substance so that a current flows between the electrodes, e.g., primary cells, secondary cells, and an electric double layer capacitor.
[0034] Batteries are characterized in that an ion-conducting substance disposed between the positive electrode structure and negative electrode structure and that an ion, including a proton or a positive hydrogen ion, migrates between electrodes and is accumulated. An electric double layer capacitor is characterized in that an ion-conducting substance is disposed between a pair of electrode structures and an electric double layer is formed between a large surface material within the electrode structures and an electrolyte of the ion-conducting substance.
[0035] (b) Electrode Structures
[0036] Electrode structures are used as electrodes in these electrical components, and exchange electrical charges with ions or draw ions. For this purpose, they have a construction in which a powdered electrode substance coated with an ion-conducting polymer, is made to adhere to a current-collecting member. For instance, they have a construction in which the powdered electrode active substance used for batteries or a powdered large surface material with a large surface area used for an electric double layer capacitor is made to adhere to a current-collecting member.
[0037] FIG. 1 shows a process for manufacturing an electrode structure 1 wherein a powdered electrode substance, i.e., a powdered electrode active substance 11 , comprising particles of a compound such as LiCoO 2 is coated with an ion-conducting polymer 12 , and is made to adhere to a current-collecting member 13 . Likewise, FIG. 2 shows a process for manufacturing the electrode structure 1 wherein a powdered electrode substance, i.e., the powdered electrode active substance 11 having a form such as that of graphite or hard carbon is coated with the ion-conducting polymer 12 , and is made to adhere to the current-collecting member 13 . A powdered large surface material such as an activated carbon as the powdered electrode substance may be coated with the ion-conducting polymer and is adhered to the current-collecting member to form an electrode structure of the electric double layer capacitor.
[0038] FIG. 1 shows the case where the electrical conductivity of the powdered electrode active substance 11 is low. The electrical conductivity in the powdered electrode active substance and between the powdered electrode active substance 11 and current-collecting member 13 , is increased and the current-collecting efficiency improved by mixing with a powdered electrically-conducting substance 14 . The powdered electrically-conducting substance 14 may or may not be coated with the ion-conducting polymer.
[0039] “Coating” refers to a state of contact wherein ions can easily migrate between the ion-conducting polymer 12 and the powdered electrode substance, i.e., the powdered electrode active substance 11 over their entire surfaces or the powdered large surface material over their entire surfaces. The ion-conducting polymer 12 is coated on the surface of the powdered electrode active substance 11 or the powdered large surface material so that the latter is covered by the ion-conducting polymer 12 . The powdered electrode active substance 11 becomes more active the finer the particles of which it is comprised, but its activity can be suppressed to give greater stability by coating with the ion-conducting polymer 12 .
[0040] If the layer of the coated ion-conducting polymer 12 is thick, conductivity decreases and current-collecting efficiency is poorer, so it is preferably thin.
[0041] The term “powdered” as used in the powdered electrode active substance 11 , the powdered electrically-conducting substance 14 , or the powdered large surface material refers to a substance having a fine particle state. In some cases, it may refer to a state wherein a large number of substances having a fine particle state are agglomerated.
[0042] (c) Powdered Electrode Active Substance
[0043] The powdered electrode active substance may be a material which permits insertion and separation of ions, or a π-conjugated electrically-conducting polymer material.
[0044] There is no particular limitation on the electrode active material used as the positive electrode in a non-aqueous electrolytic battery, but in the case of a rechargeable secondary cell, a chalcogen compound permitting insertion and separation of lithium ions or a complex chalcogen compound containing lithium may for example be used.
[0045] Examples of chalcogen compounds are FeS 2 , TiS 2 , MoS 2 , V 2 O 5 , V 6 O 13 and MnO 2 . Examples of chalcogen compounds containing lithium are LiCoO 2 , lithium complexes represented by LixNiyM 1 -yO 2 (where M is at least one metal element chosen from transition metals or Al, but preferably at least one metal element chosen from Co, Mn, Ti, Cr, V and Al, and 0.05≦x≦1.10, 0.5≦y≦1.0), LiNiO 2 , LiMnO 2 and LiMn 2 O 4 . These compounds may be obtained from the oxides, salts or hydroxides of lithium, cobalt, nickel or manganese as starting materials, mixing the starting materials depending on the composition, and firing in an oxygen atmosphere at a temperature in the range of 600° C.-1000° C.
[0046] There is no particular limitation on the electrode active substance used as the negative electrode in a non-aqueous electrolyte battery, but a material permitting insertion and separation of lithium ions may be used such as lithium metal, lithium alloy (alloys of lithium and aluminum, lead and indium, etc.), and carbon materials.
[0047] Examples of π-conjugated conducting polymer materials are polyacetylenes, polyanilines, polypyrroles, polythiophenes, poly-ρ(para)-phenylenes, polycarbazoles, polyacenes and sulfur polymers.
[0048] In particular, in non-aqueous electrolyte primary cells, a large battery capacity can be obtained by using lithium metal for the negative electrode.
[0049] In non-aqueous electrolyte secondary cells, an excellent cycle life can be obtained by using carbon materials which permit insertion and separation of lithium as the negative electrode. There is no particular limitation on the carbon material, examples being pyrolytic carbon, cokes (pitch coke, needle coke or petroleum coke), graphites, glass carbons, organic polymer compound firing products (products obtained by firing and carbonizing phenolic resins and furan resins at a suitable temperature), carbon fiber and active carbon.
[0050] (d) Powdered Electrode Substance With a Large Surface Area
[0051] A powdered electrode substance with a large surface area is a powdered large surface material that may draw many ions on that surface. A preferable powdered large surface material has its specific surface area of 500 m 2 /g or larger, more preferably 1000 m 2 /g or larger, further more preferably 1500 m 2 /g-3000 m 2 /g, and its average particle diameter of 30 μm or lower, more preferably 5-30 μm carbon material. If the specific surface area and the average particle diameter are out of the above-specified range, and it may be difficult to secure a high electrostatic capacity and a low resistance electric double layer capacitor.
[0052] A preferable powdered large surface material especially is an activated carbon resulting from activating the carbon material such as by a steam activating treatment and a fused KOH activating treatment. The activated carbon for example may be palm shell activated carbon, a phenol activated carbon, a petroleum coke type activated carbon, and polyacenes. One of the above activated carbon types or combination of two ore more activated carbon types may be employed. Phenol activated carbon, a petroleum coke type activated carbon, and a polyacenes are preferable since they provide a larger electrostatic capacity.
[0053] (e) Powdered Electrically-Conducting Substance
[0054] The powdered electrically-conducting substance increases the electrical conductivity of the electrode structure, there being no particular limitation thereon, but metal powders and carbon powder may be used. As carbon powder, pyrolytic carbon such as carbon black and its graphitization products, artificial and natural scaly graphite powder, and carbon fiber and its graphitization products, are suitable. Mixtures of these carbon powders may also be used.
[0055] (f) Ion-Conducting Polymer
[0056] The ion-conducting polymer material means suggest substances that cause polymerization reaction by supplying external energy and cross-linking reaction, and generate the ion-conducting polymer. The external energy suggests but not limited to heat, ultraviolet, visible ray, and electron ray, and among them heat is preferably used.
[0057] The ion-conducting polymer according to this invention has the following characteristics:
(1) weight-average molecular weight of the polymer is 1000 or more; (2) ion-conducting polymer can dissolve lithium salt at a concentration of at 0.1 (mol-salt/g-polymer) or more without involving organic solvent and water, (without involving organic solvent and water means constant weight where the polymer is continuously dried under reduced pressure at 100° C. and no weight reduction can be observed; and (3) ion-conducting polymer is neutral polymer without dissociated substitutional group (the dissociated substitutional group means sulfonic group, acidic group such as carboxylic acid, or primary-quarternary amino groups but does not have substitutional group within alkaline molecule.
[0061] The polymer herein has all above-three characteristics, and the polymer disclosed in the embodiments can preferably be used. For example, the polymer with cyanoethyl group having neutral and large dipole moment is preferably used within the molecule.
[0062] Regarding the above second characteristic (2), polymer, lithium salt, and ancillary solvent as necessary are mixed. The resulted mixed material is coated/filmed on a glass plate with a thickness of about 500 micrometer. This film is left still standing in a reduced pressure dryer arranged at 100° C., thereby removing evaporating materials. When the ancillary solvent is used, it can be evaporated though this process. Water involved in the polymer and lithium salt can be evaporated to. Weight is measured periodically to determine a final point when the weight reduction ended. This final point is a condition when the polymer does not contain solvent and water. There are some cases that a small percentage of solvent and/or water remain but the remaining amount is preferably 2 percent or lower. A complex of the polymer and lithium salt obtained thereafter is arranged between two deflection plates orthogonal thereto so as to perform observation using a polarization microscope. The condition that no birefringence is seen in the polymer film is considered the condition that the lithium salt is being dissolved in the polymer. The concentration is 0.1 (mol-salt/g-polymer) or more. The lithium salt is one ore more lithium salt of anion of either ClO 4 − , CF 3 SO 3 − , BF 4 − , PF 6 − , AsF 6 , SbF 6 − , CF 3 CO 2 − , or (CF 3 SO 2 ) 2 N − . Polymer, which has dissolved lithium salt at the concentration of 0.1M or more shows electric conductivity of 10 − 8 S (siemens)/cm at room temperature, is preferable. Here, most preferably, the ion conducting polymer is such that the lithium salt is dissolved to the concentration of 0.8M-1.5M and shows 10 − 8 S/cm-10 − 8 S/cm at room temperature.
[0063] Migration of hydrogen ion (proton; H+) requires water. According to the technology in this invention, ion other than hydrogen ion (proton; H+) can be migrated, and practically water requirement for hydrogen ion migration is eliminated.
[0064] (g) Current-Collecting Member
[0065] The current-collecting member should be a substance which easily passes electricity. Its shape and material are selected according to the electrical components involved, and as an example, it can be formed by fashioning an electrically-conducting substance such as aluminum or copper into a plate, foil or mesh.
[0066] In the case of a plate or foil current-collecting member, one surface or both surfaces are used according to the structure of the electrical components, and the powdered electrode active substance is made to adhere to one surface or both surfaces.
[0067] (h) Secondary Cell
[0068] The secondary cell comprises the ion-conducting substance disposed between two types of the electrode structures 1 . The secondary cell is formed by introducing a liquid such as the electrolyte 14 between an electrode structure 101 of the positive electrode and an electrode structure 102 of the negative electrode, and disposing a separator 15 between them as shown for example in FIG. 3 (A). Alternatively, it is formed by disposing a solid electrolyte substance such as an ion-conducting polymer 16 between the electrode structure 101 of the positive electrode and the electrode structure 102 of the negative electrode as shown in FIG. 3 (B).
[0069] (i) Electric Double Layer Capacitor
[0070] For electric double layer capacitor, lithium salt or ammonium salt may be used for electrolyte. For the electric double layer capacitor, quarternary ammonium salt, such as for example tetramethylammonium/6-phosphate fluoride, tetrapropylammonium/6-phosphate fluoride, methyltriethylammonium/6-phosphate fluoride, tetraethylamonium/4-borate fluoride, or tetraethylammonium/perchlorate, more specifically, chain amidine, cyclic amidine (such as imidazole, imidazoline, pyrimidine, 1, and 5-diazabicyclo[4.3.0]nonene-5 (DBN), 1, 8-diazabicyclo[5.4.0]undecyne (DBU)), pyrrole, pyrazole, oxazole, thiazole, oxadiazole, thiadiazole, triazole, pyridine, pyridine and triazine, pyrrolidine, morpholine, piperidine, and piperazine, can be used.
[0071] Especially, it is preferable to have the quarternary oniumcation, which can be explained by such as a general chemical formula, R 21 R 22 R 23 R 24 N + or R 21 R 22 R 23 R 24 P + (however, R 21 -R 24 are the same or allyl of carbon numbers 1-10 allowing to have the difference), and salt in combination of anion, BF 4 , N(CF 3 SO 2 ) 2 , PF 6 , ClO 4 . In the concrete, there are such as (C 2 H 5 ) 4 PBF 4 , (C 3 H 7 ) 4 PBF 4 , (C 4 H 9 ) 4 PBF 4 , (C 6 H 13 ) 4 PBF 4 , (C 4 H 9 ) 3 CH 3 PBF 4 , (C 2 H 5 ) 3 (Ph-CH 2 )PBF 4 (Ph is phenyl), (C 2 H 5 ) 4 PPF 6 , (C 2 H 5 )PCF 3 SO 2 , (C 2 H 6 ) 4 NBF 4 , (C 4 H 9 ) 4 NBF 4 , (C 6 H 13 ) 4 NBF 4 , (C 2 H 5 ) 6 NPF 6 , LiBF 4 , LiCF 3 SO 3 , and any one of these or two or more of these in combination can be used. At this time, the concentration of the electrolyte salt in electrolyte generally is 0.05-3 mol/L and preferably 0.1-2 mol/L. If the concentration of the electrolyte salt is too low, sufficient ion conductivity may not be obtained.
[0072] The method of manufacturing these electrode structures will now be described.
[0073] (a) Manufacture of Electrode Structure
[0074] If the powdered electrode active substance is used as the powdered electrode substance, to manufacture the electrode structure, an extremely thin ion-conducting polymer or ion-conducting polymer raw material is coated on the surface of the powdered electrode active substance 11 . Next, a solvent is added to liquefy the mixture into a paste which is applied to the current-collecting member, and dried to evaporate the solvent. Alternatively, the solvent can be added from the beginning to make a paste when the ion-conducting polymer or ion-conducting polymer raw material is coated. If the powdered large surface material is used as the powdered electrode substance, the same process applied with the powdered electrode active substance may be employed to manufacture the electrode structure.
[0075] In this process, a minute amount of the ion-conducting polymer or ion-conducting polymer raw material is used, the particle surfaces of the powdered electrode active substance are coated with the ion-conducting polymer, no voids are formed, and gaps in the powdered substance are reduced.
[0076] To coat the ion-conducting polymer or ion-conducting polymer raw material on the powdered electrode active substance, the ion-conducting polymer or ion-conducting polymer raw material and the powdered electrode active substance are press-slid together to obtain a press-slid product.
[0077] (b) Press-Sliding
[0078] Press-sliding is the action of sliding while pressing mixtures 10 of the ion-conducting polymer 12 or the raw material of the ion-conducting polymer 12 and the powdered substance 11 together. An external force is applied to the mixtures so that they cohere to each other and the particles rotate, and this process is performed repeatedly to obtain a press-sliding product.
[0079] (c) Press-Sliding Mixer
[0080] The press-sliding mixer is shown, for example, in FIG. 4 . The mixture 10 of the ion-conducting polymer 12 or its raw material with the powdered substance 11 , or the mixture 10 comprising this mixture and a solvent or the like, is introduced into a container 21 , and the main blade 22 is rotated. There is a gap between a base 211 of the container 21 and a bottom surface of the main blade 22 . When the main blade 22 is rotated, part of the mixture 10 enters the space between the base 211 of the container and the main blade 22 , is subjected to press-sliding, and is kneaded. This process is repeated so that the ion-conducting polymer 12 or its raw material coats the powdered substance 11 .
[0081] A press-sliding mixer 2 may if necessary be provided with a dispersion blade 23 in the container 21 . The dispersion blade 23 is rotated at high speed to disperse the press-slid mixture 10 .
[0082] (d) Container
[0083] The container 21 is provided for holding the mixture 10 which is press-slid and stirred. The bottom surface of the container 21 may be such as to permit press-sliding of the mixture 10 , and may be slanting as in FIG. 4 or flat as in FIG. 5 . For example, if it is slanting, it has a bottom part 2111 , and slants upwards from the bottom part 2111 towards the circumference. The center part may be situated in a low position, and have a slope rising towards the circumference. The bottom 211 may be formed in the shape of, for example, a grinding mortar, and the angle of the bottom part 2111 may for example be 120 degrees. The bottom 211 of the container is wear-resistant, and is formed by thermal spraying with tungsten or carbide using SUS. Plural bottom parts 2111 of this type may also be formed on the bottom surface.
[0084] (e) Main Blade
[0085] The main blade 22 functions together with the bottom surface of the container 21 , serving to press-slide and stir the mixture. The main blade may have a number of different shapes. For example, in FIG. 5 or FIG. 6 (B), it is disk-shaped or plate-shaped and in FIG. 6 (A), it is fashioned into a wide blade so as to provide a large surface area between the bottom surface of the container and the blade adjacent to it, thereby increasing the efficiency of press-sliding. If the main blade is disk-shaped, for example, it has some through holes 224 as is shown in FIG. 5 (B) and notched grooves 225 as is shown in FIG. 6 (B). The mixture is transported to a gap between the bottom surface of the main blade 22 and the container via the through holes 224 or the notched grooves 225 .
[0086] If the mixture adhering to the lateral surfaces of the container is removed, stirring efficiency can be increased. For this purpose, members adjacent to the lateral surfaces of the container, for example scrapers 223 , may be attached to the tip of the main blade as shown in FIG. 5 or FIG. 6 . The scrapers 223 rotate together with the main blade so that mixture in the vicinity of the lateral surfaces of the container is scraped off, and is transported to the gap between the bottom surface of the container and the blade surface. Hence, press-sliding is performed with high efficiency. At least, the tip of the main blade is to remove the mixture adhered to the lateral surface of the container and may be positioned away from the main blade for the independent operation.
[0087] In the main blade 22 , a shaft is attached in a position corresponding to the bottom part 2111 of the container 21 as shown for example in FIG. 4 (B), and if the bottom surface of the container is slanting, it curves upwards along the bottom of the container from the bottom part 2111 . The main blade 22 may comprise two blades attached from the center part as shown in FIG. 4 (B), or it may comprise a larger number of blades, e.g. 10 or more, depending on the amount and type of mixture. Instead of a large number of blades, a wide blade having a wide base may also be used. This allows larger surface for the press-sliding action, thereby providing more efficient press-sliding.
[0088] The main blade is rotated by a main motor 222 . By permitting the blade to rotate freely in the reverse direction, more complex press-sliding control can be performed. A sympathetic flow may also be set up in the mixture due to the rotation of the main blade, so sympathetic flow is prevented by reversing the main blade during the rotation. For example, forward rotation is performed for 10 seconds, the blade is stopped, and reverse rotation is then performed for 10 seconds. By repeating this action, press-sliding control is performed. Practically identical results for press-sliding were obtained when this back and forth reverse control was performed for approximately 30 minutes, and when rotation in the same direction was performed for approximately 3 hours. There are also many other rotation methods, for example the rotation angle can continuously be suitably varied like a sine curve, etc. The rotation speed of the main blade, i.e., the number of rotations, is set low, for example to 120 rpm or less, when press-sliding is performed.
[0089] The gap between the bottom surface of the container 21 and the base surface of the main blade 22 is set as narrow as is necessary for press-sliding the mixture, for example 15 mm or less. This distance depends on the capacity of the press-sliding mixer 2 and on the shape of the main blade, etc.
[0090] For the main blade 22 having the particular shape described in FIG. 4 , the surface in the motion direction (press-sliding direction) of the main blade 22 is formed so that a pressing angle θ relative to the bottom surface of the container 21 is an acute angle. For example, if the cross-section of the main blade 22 is a reverse trapezoid as shown in FIG. 4 (C), the pressing angle is from 3 degrees to 70 degrees. The cross-section of the main blade 22 may also be circular or have a rounded corner as shown in FIG. 4 (D). The material of the main blade has wear-resistant properties, and is formed for example by thermal spraying with tungsten or carbide using SUS.
[0091] If a surface in a direction opposite to the motion direction (press-sliding direction) of the main blade 22 is formed for example effectively perpendicular to or at an obtuse angle to the bottom surface, the mixture 10 can be collected around the main shaft 221 by rotating the main shaft 221 in the reverse direction.
[0092] If there are plural bottom parts 2111 on the bottom surface, the center parts of the main blade 22 are also disposed in positions of the bottom part corresponding to their number.
[0093] (f) Dispersing Blade
[0094] The dispersion blade 23 is intended to disperse the mixture 10 which has been press-slid by the main blade 22 . The dispersion blade 23 is disposed in a position at which the mixture 10 can be dispersed, and it rotates at a high speed such as 1000-4000 rpm. Due to this high speed rotation, the ion-conducting polymer 12 or its raw material coated on the particle surfaces of the powdered substance 11 uniformly disperses through the whole of the powdered substance. The mixture adheres on the area surrounding the main shaft 221 of the main blade 22 when in firm mixing or low clay dispersion and tends to be ununiformed mixing. The dispersion blade 23 is positioned on the main shaft 221 of the main blade 22 , rotating the same from the dry mixing stage to prevent the adhesion on the area surrounding the main shaft 221 .
[0095] (g) Action of Press-Sliding Mixer
[0096] A description of the operation using the press-sliding mixer of FIG. 7 and FIG. 8 will now be given. The press-sliding mixer is supported on a supporting platform 24 , the container 21 being raised by a handle 241 , and is controlled by a control panel 25 .
[0097] First, the powdered substance 11 (containing an additive) is measured out, and introduced from a powdered substance input port 34 . In an automated system, a measuring hopper or the like is installed above the powdered substance input port 34 for storage and measurement, and a valve 341 of the powdered substance input port is automatically opened by an input command. Simultaneously, to eliminate measurement errors from pressure rise in the container due to introduction of the powder, a discharge port 32 fitted with an aspiration filter 322 is opened alone so that only air is discharged.
[0098] Next, a valve 331 of an input port 33 for the ion-conducting polymer or its raw material is opened, and the polymer or its raw material is measured out manually or automatically and introduced into the container in the same way as the powdered substance. After introduction of the powdered substance and ion-conducting polymer or its raw material is complete, the input valves 331 , 341 are closed. Further, if warm water at 30° C. is recirculated through a jacket 213 of the container to promote wetting of the powdered substance and the ion-conducting polymer or its raw material, the wetting efficiency can be improved. However, when a penetration-assisting solvent is used, processing is performed at ordinary temperature.
[0099] Next, the main motor 222 is rotated at a low speed of about 10 rpm, the mixture 10 of the ion-conducting polymer or its raw material and the powdered substance is press-slid between the bottom surface of the container 21 and the main blade 22 , and the ion-conducting polymer or its raw material gradually begins to penetrate the powdered substance. At this time, the press-slid mixture 10 rises up the container at the tip of the main blade 22 , the mixture 10 falls down from above the center part of the container, and a turning over action takes place in the container over its entire circumference. This is repeated regularly so that the whole mixture is uniformly press-slid. After repeating the action for approximately 1 hour, the rotation speed of the main shaft 221 is automatically or manually increased to 60 rpm, and when wetting of the mixture 10 has reached effectively half of the surface area, a vacuum pump 353 of a degassing port 35 is operated, a degassing valve 351 is opened, and degassing is performed via a filter 352 for about 1 hour. In other words, the main blade 22 press-slides the mixture 10 while degassing is performed, so wetting and penetration dispersion of the ion-conducting polymer or its raw material in the powdered substance is promoted. Here, care should be taken when a low boiling-point solvent is added to the ion-conducting polymer or its raw material to promote dispersion in the powdered substance, as the concentration or viscosity of the ion-conducting polymer or its raw material increases and dispersion becomes difficult if suction degassing is continuously performed by a high vacuum blower.
[0100] When penetration degassing has reached about 70% after degassing for approximately 1 hour, the dispersion blade is rotated at 2800 rpm to promote dispersion.
[0101] (h) Application to Current-Collecting Member
[0102] The press-slid substance which has been made into a paste is thinly applied to the surface of the current-collecting member. After application, the solvent evaporates and dries to obtain the electrode structure. The device which applies the press-slid substance to the current-collecting member may be a doctor knife applicator.
[0103] The applied press-slid substance may be pressed against the current-collecting member to make it adhere to it more strongly. To achieve this, the bonding device 4 shown in FIG. 9 may for example be used. The press-slid substance can be made to adhere to the current-collecting member by gripping the electrode structure 1 comprising the current-collecting member coated with the press-slid substance between pressure rollers 41 , applying a pressure to backup rollers 42 by a pressure device 43 , and rotating the rollers.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0104] Hereafter, an embodiment of a lithium ion secondary cell will be described.
[0105] (a) Example of Manufacture of Positive Electrode Structure (Example 1)
[0106] 9.1 weight parts of LiCoO 2 of average particle size 5 μm which is a powdered electrode active substance, and 0.6 weight parts of graphite powder of average particle size 4 μm which is a powdered electrically-conducting substance, were introduced into a press-sliding mixer, and press-slid for 20 minutes. Next, 0.546 weight parts of an ion-conducting polymer raw material (A 1 ) and 3.5 weight parts of acetonitrile were added. The ion-conducting polymer raw material (A 1 ) was a mixture, and its composition and mixing ratio are shown in TABLE 1.
TABLE 1 Ion-conducting polymer raw material (A1) Mixing ratio (weight Substance parts) Trifunctional (propylene glycol/ethylene 8.36 glycol) random copolymer, SANNIX FA-103 (PO/EO = 2/8, Mw = 3,282, Sanyo Chemical Industries, Ltd.) Trifunctional polyol, 1,4-butadiol 0.34 Ethylene cyanohydrin 1.27 Reaction catalyst NC-IM (Sankyo Air 0.03 Products K.K.) Total 10
[0107] The press-slid substance to which the ion-conducting polymer raw material (A 1 ) was added, was press-slid in the press-sliding mixer for 5 hours. The press-slid substance was paste-like. 0.254 weight parts of polymeric MDI, MR-200 (NPU Co.) was added to the press-slid substance, and the mixture stirred for 5 minutes in the press-sliding mixer. The press-slid substance was removed, transferred to aluminum foil of thickness 20 μm, and spread by a doctor knife applicator of 100 μm gap. The resulting product was left at room temperature for 15 minutes, and then heated at 80° C. for 1 hour. The thickness of the positive electrode structure obtained was 80 μm. The same effectiveness is seen when spreading by a doctor knife applicator of 200 μm gap.
[0108] (b) Example of Manufacture of Positive Electrode Structure (Example 2)
[0109] 9.0 weight parts of LiCoO 2 of average particle size 5 μm which is a powdered electrode active substance, and 0.6 weight parts of ketjenblack and 0.2 weight parts of graphite powder of average particle size 4 μm which are powdered electrically-conducting substances, were introduced into a press-sliding mixer (capacity 300 cc), and press-slid for 20 minutes. Next, 1.172 weight parts of an ion-conducting polymer raw material (A 1 ) and 3.5 weight parts of acetonitrile were added. These mixtures were press-slid for 5 hours in the press-sliding mixer. The press-slid substance was paste-like. 0.548 weight parts of polymeric MDI, MR-200 (NPU Co.), was added to the press-slid substance, and the mixture press-slid for 5 minutes. The press-slid substance was removed, transferred to aluminum foil of thickness 20 μm, and spread by a doctor knife applicator of 100 μm gap. The resulting product was left at room temperature for 15 minutes, and heated at 80° C. for 1 hour. The thickness of the electrode obtained was 80 μm. The same effectiveness is seen by the use of 10.0 weight parts of acetonitrile and spreading a doctor knife applicator of 250 μm gap.
[0110] (c) Example of Manufacture of Positive Electrode Structure (Example 3)
[0111] 9.1 weight parts of LiCoO 2 of average particle size 5 μm which is a powdered electrode active substance, 0.341 weight parts of an ion-conducting polymer raw material (A 1 ) and 3.0 weight parts of acetonitrile were introduced into a press-sliding mixer (capacity 300 cc), and the mixture press-slid for 7 hours. The press-slid substance was paste-like. Next, 0.159 weight parts of polymeric MDI, MR-200 (NPU Co.) was added, and the mixture press-slid for 5 minutes. The press-slid substance was removed, transferred to aluminum foil of thickness 20 μm, and spread by a doctor knife applicator of 100 μm gap. The resulting product was left at room temperature for 15 minutes, and heated at 80° C. for 1 hour. The thickness of the electrode obtained was 80 μm. The same effectiveness is seen when spreading by a doctor knife applicator of 200 μm gap.
[0112] (d) Example of Manufacture of Positive Electrode Structure (Example 4)
[0113] 9.1 weight parts of LiCoO 2 of average particle size 5 μm which is a powdered electrode active substance, and 0.6 weight parts of graphite powder of average particle size 4 μm which is a powdered electrically-conducting substance, were introduced into a press-sliding mixer device (capacity 300 cc), and press-slid for 20 minutes. Next, 2.0 weight parts of an ion-conducting polymer raw material (A 2 ) and 3.0 weight parts of acetonitrile were added. The ion-conducting polymer raw material (A 2 ) was a mixture, and its composition and mixing ratio are shown in TABLE 2. In the TABLE 2, the same result may be obtained by the use of polyethyleneglycoldimethacrylate (536 molecular weight) instead of trimethylolpropanetrimethacrylate.
TABLE 2 Ion-conducting polymer raw material (A2) Mixing ratio (weight Substance parts) Cyanoethylated/dihydroxypropylated polyvinyl alcohol 0.625 Methoxypolyethyleneglycol methacrylate (mol. wt. 468) 3.125 Trimethylolpropanetri methacrylate 6.25 Total 10
[0114] The press-slid substance to which the ion-conducting polymer raw material (A 2 ) was added, was press-slid in the press-sliding mixer (capacity 300 cc) for 5 hours. The press-slid substance was paste-like. A solution of 0.01 weight parts of 2,2′-azobis (2,4-dimethylvaleronitrile) and 0.5 weight parts of a (1/1) vol liquid electrolyte of ethylene carbonate (EC)/diethylene carbonate (DEC) was added to the press-slid substance, and the mixture further press-slid for 5 minutes. The press-slid substance was removed, transferred to aluminum foil of thickness 20 μm, and spread by a doctor knife applicator of 100 μm gap. The resulting product was left at room temperature for 15 minutes, and heated at 80° C. for 3 hours. The thickness of the electrode obtained was 80 μm. The same effectiveness may be expected by the use of 0.5 weight parts of the ion-conducting polymer raw material (A 2 ), 0.003 weight parts of 2,2′-azobis (2,4-dimethylvaleronitrile), and by spreading a doctor knife applicator of 200 μm gap.
[0115] (e) Example of Manufacture of Negative Electrode Structure (Example 5)
[0116] 9.1 weight parts of graphite powder of average particle size 5 μm which is a powdered electrode active substance, 0.341 weight parts of an ion-conducting polymer raw material (A 1 ) and 3.0 weight parts of acetonitrile were introduced into a press-sliding mixer (capacity 300 cc), and the mixture press-slid for 7 hours. The press-slid substance was paste-like. Next, 0.159 weight parts of polymeric MDI, MR-200 (NPU Co.) was added, and the mixture press-slid for 5 minutes. The press-slid substance was removed, transferred to copper foil of thickness 20 μm, and spread by a doctor knife applicator of 100 μm gap. The resulting product was left at room temperature for 15 minutes, and heated at 80° C. for 1 hour. The thickness of the electrode obtained was 80 μm. The same effectiveness may be expected by the use of 10.0 weight parts of the acetonitrile and spreading a doctor knife applicator of 250 μm gap.
[0117] (f) Example of Manufacture of Positive Electrode Structure (Example 6)
[0118] 9.1 weight parts of graphite powder of average particle size 5 μm which is a powdered electrode active substance, 0.2 weight parts of an ion-conducting polymer raw material (A 2 ) and 3.0 weight parts of acetonitrile were introduced into a press-sliding mixer (capacity 300 cc), and press-slid for 5 hours. The press-slid substance was paste-like. A solution of 0.01 weight parts of 2,2′-azobis (2,4-dimethylvaleronitrile) and 0.5 weight parts of a liquid electrolyte of ethylene carbonate (EC)/diethylene carbonate (DEC) in a volume ratio of 1:1 was added to the press-slid substance, and the mixture further press-slid for 5 minutes. The press-slid substance was removed, transferred to copper foil of thickness 20 μm, and spread by a doctor knife applicator of 100 μm gap. The resulting product was left at room temperature for 15 minutes, and heated at 80° C. for 3 hours. The thickness of the electrode obtained was 80 μm. The same effectiveness may be expected by the use of 0.8 weight parts of the ion-conducting polymer raw material (A 2 ), 10.0 weight parts of acetonitrile, 0.004 weight parts of 2,2′-azobis (2,4-dimethylvaleronitrile), and by spreading a doctor knife applicator of 250 μm gap.
[0119] (g) Analysis of Electrode Structure
[0120] FIG. 10 shows 5000 times magnified electron micrograph of LiCoO 2 of average particle size 5 μm which had not received any processing. In FIG. 10 , the corners of the compound particles of LiCoO 2 are square and clearly visible. The electron micrograph of FIG. 11 is an electron micrograph of the positive electrode structure obtained in Example 3. In FIG. 11 , the corners of the compound particles of LiCoO 2 are smooth, and appear to be covered by a film. Hence, comparing with the LiCoO 2 in FIG. 10 , it is evident that the LiCoO 2 particles in FIG. 11 are uniformly covered with a film of ion-conducting polymer.
[0121] FIG. 12 shows 5000 times magnified a two-dimensional electronic image of the surface of the positive electrode structure obtained in Example 3 measured by a Shimadzu EPMA-8705 Electron Probe Micro-Analyzer. The particles of FIG. 12 have smooth corners and appear to be covered by a coating.
[0122] (h) Comparative Example of Positive Electrode Structure (Comparative Example 1)
[0123] 11.5 weight parts of n-methylpyrrolidine containing, in solution, 0.5 weight parts of polyvinylidene fluoride (PVDF) which has no ion-conducting property as a polymer binder, was mixed with 9.0 weight parts of LiCoO 2 of average particle size 5 μm which is a powdered electrode active substance, and 0.8 weight parts of ketjenblack and 0.2 weight parts of graphite powder of average particle size 4 μm which are powdered electrically-conducting substances, in an ordinary blade mixer. After mixing for 8 hours, the mixture was removed, transferred to copper foil of thickness 20 μm, and spread by a doctor knife applicator of 100 μm gap. The resulting product was then heated to evaporate n-methylpyrrolidine. The thickness of the electrode obtained was 80 μm. The same result is expected by the use of 5.0 weight parts of n-methylpyrrolidine and spreading a doctor knife applicator of 200 μm gap.
[0124] (i) Comparative Example of Positive Electrode Structure (Comparative Example 2)
[0125] 25.5 weight parts of n-methylpyrrolidine containing, in solution, 0.5 weight parts of polyvinylidene fluoride (PVDF) which has no ion-conducting property as a polymer binder, was mixed with 9.5 weight parts of graphite powder of average particle size 4 μm which is a powdered electrically-conducting substance, in an ordinary blade mixer. After mixing for 8 hours, the mixture was removed, transferred to copper foil of thickness 20 μm, and spread by a doctor knife applicator of 100 μm gap. The resulting product was then heated to evaporate n-methylpyrrolidine. The thickness of the electrode obtained was 80 μm. The same result is expected by the use of 10.0 weight parts of n-methylpyrrolidine containing, in solution, 1.0 weight parts of polyvinylidene fluoride (PVDF) and spreading a doctor knife applicator of 250 μm gap.
[0126] (j) Charging/discharging tests
[0127] A test lithium ion secondary cell was manufactured using the positive electrode structures manufactured in the examples and comparative examples. The positive electrode and negative electrode were both cut out to have an electrode surface area of 4 cm 2 . Completely solid polymer (all polymer), polymer gel electrolyte (polymer gel), liquid electrolyte (liquid) and a separator were sandwiched between the positive electrode and negative electrode to manufacture the test cell. The concentration of lithium salt (supporting electrolyte salt) in the respective electrolytes was arranged to be 1M. This cell was charged at 0.3 mA per 1 cm 2 of electrolyte surface area to 4.1V, and after allowing to stand for 15 minutes, it was discharged at 0.3 mA/cm 2 to 2.7V. Combinations for which two of these charging/discharging cycles were successfully performed, were considered to be combinations for which charging/discharging is possible, and are shown in TABLE 3. TABLE 4 shows the contents of the electrolytes listed in TABLE 3. The same effectiveness is expected if the thickness of the electrolyte is 20 μm at P1-AP4 and 30 μm at PG1-PG2.
TABLE 3 Charging/discharging test results Positive Negative Charging/discharging No electrode electrode Electrolyte test result 1 Example 1 Example 5 AP1 Possible 2 Example 1 Example 5 AP2 Possible 3 Example 1 Example 5 APS Possible 4 Example 1 Example 5 AP4 Possible 5 Example 1 Example 5 PG1 Possible 6 Example 1 Example 5 PG2 Possible 7 Example 1 Example 5 L1 Possible 8 Example 2 Example 5 AP3 Possible 9 Example 2 Example 6 PG2 Possible 10 Example 4 Example 5 AP3 Possible 11 Example 4 Example 6 PG2 Possible 12 Comparative Comparative AP1 Charging/discharging example 1 example 2 impossible 13 Comparative Comparative AP2 Charging/discharging example 1 example 2 impossible 14 Comparative Comparative AP3 Charging/discharging example 1 example 2 impossible 15 Comparative Comparative AP4 Charging/discharging example 1 example 2 impossible 16 Comparative Comparative PG1 Charging/discharging example 1 example 2 impossible 17 Comparative Comparative PG2 Charging/discharging example 1 example 2 impossible 18 Comparative Comparative L1 Possible example 1 example 2
[0128]
TABLE 4
Electrolyte used in test
Sym-
Thick-
bol
Type
Composition
ness
AP1
All
Cyanoethylated/dihydroxypropylated
100 μm
polymer
cellulose
(e.g. Japanese Patent Application
Laid-Open No. 8-225626)
AP2
All
Cyanoethylated/dihydroxypropylated
100 μm
polymer
cellulose and methacryl polymer 3D
cross-linked structure
(e.g. Japanese Patent Application
Laid-Open No. 8-225626)
AP3
All
High viscosity polyurethane electrolyte
100 μm
polymer
(e.g. Japanese Patent Application No.
11-78085)
AP4
All
Cyanoethylated/dihydroxypropylated
100 μm
polymer
polyvinyl alcohol
(e.g. Japanese Patent Application No.
11-78086)
PG1
Polymer
Cyanoethylated/dihydroxypropylated
100 μm
gel
polyvinyl alcohol and methacryl polymer
3D cross-linked structure containing 50%
ethylene carbonate (EC)/diethylene
carbonate (DEC) = (1/1) vol liquid
electrolyte (e.g. Japanese Patent
Application No. 11-78087)
PG2
Polymer
High viscosity polyurethane electrolyte
100 μm
gel
containing 50% ethylene carbonate
(EC)/diethylene carbonate (DEC) =
(1/1) vol liquid electrolyte
(e.g. Japanese Patent Application No.
11-78085)
L1
Liquid
Impregnation of ethylene carbonate
23 μm
(EC)/diethylene carbonate (DEC) =
(1/1) vol solution in polyethylene
separator
[0129] In the charging/discharging tests of the examples and comparative examples, test cells using the positive electrode and negative electrode of this invention could be successfully charged and discharged. However, test cells using the electrodes of the comparative examples and a solid or gel electrolyte could not be charged/discharged, although test cells using liquid electrolytes could be charged/discharged.
[0130] An embodiment of the electric double layer capacitor is explained next.
[0131] Embodiment of Electrode Structure of Capacitor
[0132] An electrode structure for capacitor is manufactured by adding the carbon black as the powdered conducting substance in a phenol activated carbon (manufactured by Kansai Kagaku Corporation) as the powdered electrode substance; dry-mixing with a mixing container; adding the polymer A 1 as the binder to be mixed; adding NMP (N methylpyrolidone) as the solvent to be mixed; applying on the current-collecting member by the doctor knife applicator; and drying. The thickness of the electrode is 75μ.
INDUSTRIAL FIELD OF APPLICATION
[0133] This invention makes it possible to obtain an electrode having a satisfactory electromotive effect with ions. This invention makes it possible to obtain an electrode which is very safe. This invention further makes it possible to obtain a secondary cell which is very safe. This invention further makes it possible to obtain an extremely safe electric double layer capacitor. This invention further makes it possible to obtain a secondary cell or capacitor which does not use an electrolyte. This invention further makes it possible to obtain an electric double layer capacitor which does not require an electrolyte.
[0134] It is readily apparent that the above-described embodiments have the advantage of wide commercial utility. It should be understood that the specific form of the invention hereinabove described is intended to be representative only, as certain modifications within the scope of these teachings will be apparent to those skilled in the art. Accordingly, reference should be made to the following claims in determining the full scope of the invention. | An electrode structure 1 comprising a powdered active electrode substance 11 coated by an ion-conducting polymer 12 which is made to adhere to a current-collecting member 13 , a secondary cell employing this structure and a method of manufacturing this structure are proposed to provide an electrode, secondary cell, or electric double layer capacitor with a high degree of safety, or a secondary cell or electric double layer capacitor which does not use an electrolyte. | 62,419 |
FIELD AND BACKGROUND OF THE INVENTION
[0001] 1.1 Arterial and Venous Oxygen Saturation
[0002] Transfer of oxygen from the lungs to the tissue cells is done mainly via the hemoglobin molecules in the red blood cells and only small part of it is dissolved in arterial plasma. Oxygen saturation (SO 2 ) is the ratio of oxygenated hemoglobin to total hemoglobin (SO 2 ═HbO 2 /(HbO 2 +Hb)), and its value in the arterial blood, SaO 2 , is 94-99%. The assessment of SaO 2 is mainly important for clinical evaluation of proper respiratory function, since SaO 2 depends on the adequacy of the ventilation and respiratory function.
[0003] Most of the hemoglobin in venous blood is still oxygenated: normal values of the oxygen saturation in the peripheral venous blood are 70-80%. The value of the oxygen saturation in the venous blood also has physiological and clinical significance, as lower blood flow to the tissue results in higher utilization of the oxygen in the blood and lower value of venous oxygen saturation. The measurement of oxygen saturation in the venous blood of an organ provides therefore information on the adequacy of its blood supply.
[0004] The blood from the veins of the whole body is drained into the pulmonary artery after being mixed by the right ventricle. The pulmonary artery blood is named mixed venous blood. The value of the mixed venous oxygen saturation, SmvO 2 , represents the mean oxygen saturation in the veins of the whole body and is of particular interest. Low values of SmvO 2 indicate inadequate oxygen supply to the body, either because of low blood flow or because of improper respiration. If the latter failure is eliminated by using SaO 2 measurement, low values of SmvO 2 indicate low total blood flow, which is equivalent to low cardiac output. In fact the mixed venous oxygen saturation, SmvO 2 , is used for the quantitative assessment of the cardiac output by means of the Fick method: the cardiac output is determined from the values of total oxygen consumption, arterial oxygen content and venous oxygen content. The total oxygen consumption can be obtained from oxygen consumption measurements in the inhaled and exhaled air and the values of the arterial and venous oxygen content can be derived from the values of SaO 2 and SmvO 2 respectively.
[0005] The measurement of SaO 2 , the oxygen saturation in the arterial blood, can be performed noninvasively by pulse oximetry, which is based on the different light absorption spectrum for oxygenated and de-oxygenated hemoglobin, as shown in FIG. 1 . Oximetry is a technique in which the attenuation in a substance of light in two wavelengths is measured and the difference in the attenuation of the light between the wavelengths is attributed to the difference in their absorption in the substance. However, in order to quantitatively assess SaO 2 the contribution of the arterial blood to the light absorption must be isolated from the contribution of the venous blood. In pulse oximetry the technique for the isolation of the arterial contribution is based on photoplethysmography (PPG)—the measurement of light absorption changes due to the cardiac induced blood volume changes. During systole the blood volume in tissue arteries increases and the transmission through the tissue decreases. FIG. 2 shows the inverted PPG signal: during systole there is fast increase in arterial blood volume. Pulse oximetry uses the PPG signal in two wavelengths for the assessment of the oxygen saturation in the arterial blood, SaO 2 (Yoshiya, 1980), as will be described later.
[0006] In order to assess SaO 2 by pulse oximetry there is also a need to consider the effect of scattering on the attenuation of the light. The light traversing a given tissue is not only subject to absorption by the hemoglobin but also to scattering by the various organelles in the tissue cells and in the red blood cells, which diverts the light from its original direct path and also increases its path-length. In order to assess SaO 2 or SvO 2 by optical means the contribution of the absorption to the attenuation has to be isolated.
[0007] While the measurement of SaO 2 can be performed noninvasively by pulse oximetry, the available techniques for the measurement of SmvO 2 , the mixed venous oxygen saturation, are invasive and require the insertion of a catheter into the pulmonary artery (Swan-Ganz catheter). After inserting the catheter SmvO 2 can be measured either in vitro by extracting mixed venous blood from the pulmonary artery or by in vivo measurements, using an optical probe attached to the tip of the catheter. The invasive measurement of SmvO 2 is the reason for the invasiveness of the Fick method for the measurement of cardiac output.
[0008] 1.2 The PPG Signal and its Origin
[0009] The PPG probe consists of a light source emitting light into the tissue and a photodetector measuring the light transmitted through the tissue. Two kinds of PPG probes are used for clinical diagnosis and research: transmission and reflection. In transmission PPG, the light source and the detector are attached to two sides of a small organ, such as a finger or an ear lobe, and the detector measures the light transmitted through the organ. In reflection PPG, the light source and the detector are attached to the same side of the organ and the detector measures the scattered light from the tissue under the probe. In both kinds of PPG probe, the detector output oscillates at the heart rate: during systole, blood is ejected from the left ventricle into the peripheral vascular system, thereby increasing the arterial blood content, and consequently decreasing the light intensity transmitted through the tissue. FIG. 3 shows the direct PPG signal. The maximal and minimal values of the PPG signal, I D and I S , respectively, are proportional to the light irradiance transmitted through the tissue when the tissue blood volume is minimal or maximal, respectively. The amplitude of the PPG signal, (I D −I S ), is related to the maximal change in arterial blood volume during systole, ΔV a . if I D −I S is much smaller than I S , then the relative change in of the PPG signal (I D −I S )/I S is proportional to ΔV a :
[0000] ( I D −I S ) /I S =α a ΔV a (1)
[0000] where α a is the effective absorption coefficient of the arterial blood, which is a function of the absorption and scattering attenuation constants. ΔV a , the maximal change in arterial blood volume during systole, is equal to the product of the pulse pressure and the arterial compliance. Hence the amplitude of the PPG signal provides information on the arterial compliance of the systemic circulation (Babchenko et al. 2001, Shelley 2007).
[0010] Equation (1) can be applied only for relatively homogenous tissue geometry, as occurs in pure microcirculatory bed. The presence of large blood vessels, where significant light absorption occurs in a single vessel, can limit the validity of Equation (1). Nitzan et al (1998) also showed that the linear relationship between blood volume changes and the PPG pulses holds only for small vessels, in which the absorbed light is small relative to the, incident light.
[0011] 1.3. Theory of Pulse Oximetry
[0012] FIG. 1 presents the extinction coefficient of oxygenated and de-oxygenated hemoglobin as a function of the light wavelength, where the extinction coefficient of a hemoglobin solution is defined as the absorption constant of the hemoglobin solution divided by the concentration of the hemoglobin in the solution.
[0013] The theory of deriving arterial oxygen saturation, SaO 2 , from the PPG signals at two wavelengths is described in several articles (see Wieben, 1997, Mannheimer et al, 1997, Nitzan et al, 2000). The transmitted light intensity, through a tissue sample which includes vessels with whole blood is based on Beer-Lambert law and is given by:
[0000] I t =I 0 exp( −αl−εcl ) (2)
[0000] where l is the effective optical path-length (which is higher than the width of the tissue sample because of scattering in the tissue) α is the absorption constant of the tissue, c is the concentration of the blood in the tissue, and s is the extinction coefficient of the blood, defined as the absorption constant of the blood divided by the concentration of the blood in the tissue. I 0 is the incident light intensity.
[0014] During systole the tissue blood volume increases and consequently the light transmission through the tissue decreases, creating the PPG signal. If I S is the light transmission through the tissue at the maximal increase in tissue blood volume and I D is the light transmitted through the tissue at end diastole (when the tissue blood volume has its minimal value), then
[0000] I S =I D exp(−ε a Δc a l )
[0000] In ( I D /I S )=ε a Δc a l (3)
[0000] where ε a is the extinction coefficient for the arterial blood, and Δc a is the increase of blood concentration (in the tissue) due to the maximal systolic increase of blood volume. For small blood volume changes ΔI a =I D −I S <<I S , and ln(I D /I S ) can be approximated by ΔI a /I S . If the light transmission is measured for two wavelengths λ 1 and λ 2 , then
[0000] (Δ I a /I S ) 1 =ε a1 Δc a1 l I ; (Δ I a /I S ) 2 =ε a2 Δc a2 l 2 (4)
[0000] and the ratio R, defined by
[0000]
R
=
(
Δ
I
a
/
I
S
)
1
(
Δ
I
a
/
I
S
)
2
(
5
)
[0000] satisfies the equation
[0000]
R
≈
ɛ
a
1
l
1
ɛ
a
2
l
2
(
6
a
)
[0000] assuming that the difference in the blood concentration change, Δc a , between the two wavelengths can be neglected (Δc a1 ≈Δc a2 ). Note that the last assumption is not always satisfied in reflection PPG, if the penetration depth for the two wavelengths is different. If the two wavelengths are close to each other then the difference of the effective optical path-length is small and
[0000]
R
≈
ɛ
a
1
ɛ
a
2
(
6
b
)
[0015] The relationship between the ratio R—the measured parameter—and the oxygen saturation SaO 2 can be derived from the decomposition of the extinction coefficient ε into its two components, the extinction coefficients for oxygenated blood ε 0 and for deoxygenated blood ε d :
[0000] ε=ε o SaO 2 +ε d (1−Sa) 2 )=ε d +SaO 2 (α o −ε d ) (7)
Then
[0016]
R
=
ɛ
d
1
+
Sa
O
2
(
ɛ
o
1
-
ɛ
d
1
)
ɛ
d
2
+
Sa
O
2
(
ɛ
o
2
-
ɛ
d
2
)
and
(
8
)
Sa
O
2
=
ɛ
d
1
-
R
ɛ
d
2
R
(
ɛ
02
-
ɛ
d
2
)
+
(
ɛ
d
1
-
ɛ
0
1
)
(
9
)
[0017] The physiological parameter SaO 2 can be derived from the measured parameter
[0018] R by using Equation 9 and the various values of the extinction coefficient (which are known from the literature) provided that the difference between the pathlengths for the two wavelengths can be neglected. However, commercial pulse oximeters choose one of the wavelengths in the infrared region and the other in the red region (where the difference in the extinction coefficient between oxygenated and deoxygenated blood is maximal) in order to have a higher difference in light transmittance between the two wavelengths. For this choice, the red light scattering constant significantly differs from that of the infrared light resulting in non-negligible difference in optical path-lengths for the two wavelengths.
[0019] Due to the difference in scattering between the red and infrared wavelengths, the clinical parameter oxygen saturation SaO 2 cannot be derived from the measured parameter R and Equation 9. The actual relationship between the measured parameter R and oxygen saturation SaO 2 is achieved for each type of pulse oximeter sensor by calibration (Schowalter, 1997): R is measured in several persons simultaneously with in vitro SaO 2 measurement in extracted arterial blood by means of co-oximeter which is the gold-standard for SaO 2 measurements. For each person R and SaO 2 measurements are taken for several values of SaO 2 , achieved by changing the partial pressure of oxygen in the inspired air. The table of the simultaneous measurements of R and SaO 2 provides the required calibration for the derivation of the clinical parameter oxygen saturation SaO 2 from the measured parameter R. The relationship between R and SaO 2 can be determined by proposing an analytical formula, such as
[0000]
Sa
O
2
=
a
-
b
R
c
-
d
R
(
10
)
[0000] and obtaining the values of the constants a,b,c, and d in the calibration process described above.
[0020] The reliability of the calibration is based on the assumption that l 2 /l 1 does not change between different persons and different physiological and clinical situations. The validity of this assumption is limited and deviations from this assumption are the likely origin of the inherent inaccuracy of the pulse oximetry technique for the assessment of the oxygen saturation, SaO 2 , in the arterial blood.
[0021] If the two wavelengths are close to each other, l 2 /l 1 is expected to be about 1 and SaO 2 can be derived from Equation 9 without calibration. This was shown in our study (Nitzan et al 2000), in which we measured SpO 2 , using pulse oximetry based on two infrared light emitting diodes (LEDs) (of peak wavelengths 767 and 811 nm) and Equation 9, without calibration. The SpO 2 values were somewhat lower than that obtained by commercial calibrated pulse oximeters using red and infrared light, probably because small deviations from the assumption of l 2 /l 1 =1 and because the emission spectrum of the LED is broad, and the extinction coefficient of its light is not accurately definite. The accuracy of the technique increased by using Equation (12) and assessing (l 2 /l 1 ) value from published data (like that of Duncan et al., 1995 for the forearm, (l 2 /l 1 )=0.97). The accuracy of the technique is also increased by using two infrared laser diodes of narrow emission spectrum instead of LEDs.
[0022] At the end of Section 1.2 it was claimed that the linear relationship between blood volume changes and the PPG pulses holds only for the small blood vessels of the microcirculation, where the absorbed light in a single vessel is small relative to the incident light. Since pulse oximetry is based on PPG measurements and on the linear relationship between blood volume changes and the PPG signal amplitude, it can be inferred that measurement of oxygen saturation in arterial blood by pulse oximetry can be properly performed only on the microcirculation in tissue. In their articles Mannheimer et al. (2004) and Reuss and Siker (2004) claimed that pulse oximetry is affected by large subcutaneous blood vessels, so that reflectance pulse oximetry should be avoided in sites with palpable arterial pulsatility. While the pulse oximetry is performed on the microcirculatory bed, the calibration, which is required in the conventional pulse oximetry, is done by extracting blood from the big, conduit arteries. The calibration procedure is valid, because the value of oxygen saturation is the same in all arteries, from the big ones to the arterioles, since oxygen dissipation occurs only in the capillaries.
[0023] In contrast to the well-established non-invasive measurement of SaO 2 by pulse oximetry in the systemic microcirculation, the available techniques for the measurement of SvO 2 , the mixed venous oxygen saturation, are invasive and require the insertion of a Swan-Ganz catheter into the pulmonary artery. Accordingly, there is a need for an innovative method for the less invasive measurement of the oxygen saturation in mixed venous blood, SvO 2 .
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein:
[0025] FIG. 1 a is a plot of the extinction coefficients of the oxi- and deoxi-hemoglobin as a function of the wavelength, in the visible and near-infrared regions. The figure was published by Scott Prahl, Oregon Medical Laser Center, 1999, as a best estimate of the spectrum of Hb and HbO 2 from a variety of sources. (Appears in M. Nitzan and H. Taitelbaum, 2008. IEEE Instrumentation and Measurement Magazine, 11:9-15.)
[0026] FIG. 1 b is a plot of the extinction coefficients of the oxi- and deoxi-hemoglobin as a function of the wavelength, in the near-infrared region, published by Kim and Liu, 2007, Phys. Med. Biol. 52:6295-6322.
[0027] FIG. 2 is a plot of an inverted PPG signal in the systemic circulation, which presents the light absorption in the tissue against time, showing variations at the heart rate, wherein minimal light absorption occurs at end-diastole when the tissue blood volume is at minimum.
[0028] FIG. 3 is a plot of a direct PPG signal in the systemic circulation, which presents the light transmission through the tissue against time, showing variations at the heart rate, wherein maximal intensity of transmitted light occurs at end-diastole when the tissue blood volume is at minimum.
[0029] FIG. 4 presents a cross-section of the thorax, with an element for emitting infrared light into the thorax and an element for detecting the light transmitted through the thorax wall and through a portion of the pulmonary tissue.
[0030] FIG. 5 presents a cross-section of transmitter and receiver elements, which include optic fiber and reflection prism, for emitting infrared light from a laser diode into the skin and for detecting the light transmitted through the tissue.
[0031] FIG. 6 a presents a cross-section of the esophagus and a catheter with a PPG probe, which includes a LED and a detector. The PPG probe is applied on a site in the inner esophageal wall, where the lung tissue is in close proximity to the outer esophageal wall. The balloon pressure causes the PPG probe to be in close contact with the inner esophageal wall.
[0032] FIG. 6 b presents a cross-section of the esophagus and a catheter with a PPG probe, which includes two optic fibers leading from a laser diode and to a detector. The PPG probe is applied on a site in the inner esophageal wall, where the lung tissue is in close proximity to the outer esophageal wall. The balloon pressure causes the PPG probe to be in close contact with the inner esophageal wall.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] In the current invention, a method is presented for the measurement of the pulmonary PPG signal, presenting the oscillations at the heart rate of the transmission of light through a region in the microcirculation of the pulmonary system. The pulmonary PPG signal can be utilized for the assessment of the cardiopulmonary circulatory system. It can also be used for the determination of the oxygen saturation in the pulmonary arteries, which is actually the oxygen saturation in mixed venous blood. The latter parameter enables the noninvasive (or minimally invasive) determination of cardiac output by the Fick method. The conventional PPG technique is based on measurements in the arterial system of the systemic circulation conducting blood from the left ventricle to the different organs of the body, except the lungs. The blood volume in the systemic arteries increases by the blood which is ejected from the left ventricle during systole and decreases by the relatively constant blood flow through the capillaries to the veins. The lungs are supplied with venous blood from the right ventricle through the pulmonary artery and, similarly to the systemic circulation, the pulmonary arterial blood volume increases during systole and decreases during diastole. Pulmonary blood volume increase during systole has been demonstrated in several prior studies, using several techniques, including N 2 O body plethysmography (Karatzas 1969), analysis of pulmonary arterial pressure curves (Her 1987), ECG-gated radionuclide scintigraphy (Nitzan 1992, 1994), and cardiovascular magnetic resonance (Ugander 2009). One of these techniques (Her 1987) is invasive; the other techniques require either special training of the examinees (Karatzas 1969), or a sophisticated imaging device (Nitzan 1992, 1994, Ugander 2009).
[0034] The present invention provides a pulmonary PPG method, in which the pulmonary blood volume increase during systole is detected by the resultant decrease in light transmission through the lungs — The method requires that light emitted from a light-source reaches the lungs and that the light transmitted through the lung tissue is detected. The light transmitted through the lung tissue oscillates at the heart rate, like the systemic PPG, and like the latter the pulmonary PPG is related to the blood volume change in the pulmonary arteries through Equation 1. Like the systemic circulation the systolic blood volume change in the pulmonary arteries is related to the stroke volume and to the arterial compliance and small arteries resistance in the pulmonary system. Hence the pulmonary PPG signal can provide information on these cardiovascular parameters in the cardio-pulmonary system.
[0035] The present invention relates generically to any and all techniques in which a pulmonary PPG signal is derived from measurements of light transmission through microcirculatory tissue of the lungs, whether by non-invasive, minimally invasive or fully invasive procedures. While it is simple to achieve the PPG signal in the systemic circulation, because of the proximity of the tissue under examination to the skin, the achievement of the pulmonary PPG is significantly more difficult, since the lungs lay inside the thoracic wall. By way of exemplary but non-limiting preferred examples, the present invention will be exemplified herein with reference to four non-invasive or minimally invasive techniques that enable the measurement of the light transmitted through the pulmonary tissue, each of which is believed to be of value in its own right:
1. A light source and a detector are applied to the thoracic wall of a patient and the detector measures the light which was emitted from the light source and transmitted through the thorax. See FIGS. 4 and 5 . The light source and the detector are separated by at least 20 mm so that the region of illumination overlaps a portion of the pulmonary microcirculation beneath the PPG probe. The technique is especially suitable for infants, whose thoracic wall is relatively thin. 2. A light source and a detector are inserted into the esophagus and brought into close contact with its wall, in a site where the pulmonary tissue is in tight proximity to the esophageal wall, and the detector measures the light which was emitted from the light source and transmitted through the esophageal wall and part of the lungs. See FIG. 6 . The light source and the detector are separated by at least 10 mm so that the region of illumination overlaps a portion of the pulmonary microcirculation in the neighborhood of the PPG probe. 3. A light source is applied to the thoracic wall of a patient and a detector is inserted into the esophagus and brought into close contact with its wall in a site where the pulmonary tissue is in tight proximity to the esophageal wall. The detector measures the light which was emitted from the light source and transmitted through the thoracic wall and the esophageal wall and through part of the lungs. By suitable choice of the locations of the light-source and the detector the detected light is mainly affected by absorption in the pulmonary microcirculation and the contribution of the attenuation by other organs can be neglected. 4. A catheter with two optic fibers is inserted through the thoracic wall and brought into adjacent relation (i.e., with minimal intervening tissue) with the pulmonary pleura, which covers the lung tissue. The light delivering element and light receiving element in the probe (catheter) are typically brought into contact with the pulmonary pleura or preferably into close proximity to the pulmonary pleura, without contacting it, in order to avoid harm to the vulnerable organ. One of the optic fibers conveys light from a light source into the lung tissue and the other one conveys light which was scattered by the tissue to a detector. Both the light source and the detector are located out of the body.
[0040] In the first three above-mentioned pulmonary PPG techniques, referred to herein as “remote PPG techniques”, the light, in its way to the pulmonary tissue, also passes through the thoracic wall or the esophageal wall, which are supplied by the systemic circulation. Nevertheless, the main contribution to the PPG signal is by the pulmonary circulation, because the stroke volumes from the right and left ventricles are equal while the former is distributed in the relatively small pulmonary tissue volume and the latter is distributed in the relatively high systemic tissue volume. The relationship between the increase in pulmonary blood volume during systole and the right stroke volume (which is the blood volume ejected from the right ventricle during systole) was determined in several studies: it is 50-67% of the total stroke volume (Karatzas 1969, Nitzan 1992, 1994, Ugander 2009, Her 1987). Hence the systolic blood volume increase in a volume element in the pulmonary circulation is much higher than in a typical volume element in the systemic circulation, enabling the pulmonary PPG measurement
[0041] Because of the depth of pulmonary tissue relative to the measurement surface in the remote PPG techniques, the light source and the detector are preferably separated by at least 10 mm in the esophageal probe and by at least 15 mm in the thoracic probe. In order to assess the contribution of the esophageal wall or the thoracic wall circulation to the PPG signal, a second detector can be attached to the esophageal wall or the thoracic wall, where the second detector and the light source are separated by less than 8 mm. In another technique for the assessment of the contribution of the esophageal wall circulation or the thoracic wall circulation to the PPG signal, a second light source is attached to the thoracic wall, where the second light source and the first detector are separated by less than 8 mm. Light transmission measurement by a light-source and a detector of relatively short separation provides information of the tissue of short depth relative to the measurement surface. For a probe adjacent to the pulmonary pleura (option 4, above), smaller spacing between the two optic fibers is preferably used in order to use a single penetrating catheter.
[0042] In each of the remote pulmonary PPG techniques, the pathlength of the light is long, and in order to have significant amount of transmitted light intensity for the measurement, infrared light which is less absorbed than visible light, is preferred. FIG. 1 a presents the extinction coefficients of oxi- and deoxi-hemoglobin. Red light, in the wavelength region of 600-700 nm, is more absorbed by deoxi-hemoglobin, than infrared light, of 700-1000 nm wavelength. For a probe adjacent to the pulmonary pleura (option 4, above), other wavelengths, such as visible wavelengths, may be used.
[0043] Parenthetically, it should be noted that the term “light source” is used herein to refer to the light delivering element from which light is released into the tissue. The “light source” thus defined may be a light generating element, such as a laser diode or LED, brought directly to the required location for delivering light, or may be the end of an optic fiber, an applicator connected to such a fiber, or any other waveguide or the like that conveys light to the required site from one or more remotely located light generating device.
[0044] Similarly the term “detector” is used herein to refer to the light detecting element which detects the light scattered from the tissue. The “detector” thus defined may be an electro-optic light detecting element, such as a PIN diode or avalanche photodiode, brought directly to the required site of measurement for detecting light, or may be the end of an optic fiber, an applicator connected to such a fiber, or any other waveguide or the like that conveys light to the more remotely electro-optic detecting element from the required site of measurement.
[0045] Similar to conventional pulse oximetry technique, which provides information on SaO 2 via the measurement of systemic PPG in two wavelengths, the measurement of pulmonary PPG in two wavelengths provides information on the oxygen saturation of the arterial blood in the pulmonary tissue, SvO 2 , which in fact is equal to the mixed venous blood saturation, SmvO 2 . SmvO 2 provides information on the adequacy of the systemic blood supply and is an essential component in the quantitative determination of cardiac output by the Fick method, as mentioned in Section 1.1.
[0046] The current method for SmvO 2 measurement in the pulmonary artery is invasive in the sense that it includes insertion of a Swan-Ganz balloon catheter in the pulmonary artery. SmvO 2 is then measured, either intermittently, by extracting blood from the pulmonary artery or continuously, by means of oximetric measurements through optic fibers in the pulmonary artery blood. In another invasive technique, the oxygen saturation in the upper vena cava (central venous oxygen saturation) is measured. The invasive insertion of a catheter in the vena cava is of lower hazard than that through the right ventricle into the pulmonary artery, but the values of oxygen saturation in the two vessels may be different.
[0047] Several optical methods have been proposed for the non-invasive or minimally invasive measurement of oxygen saturation of blood within the pulmonary artery or in a central vein. These methods derive the required parameter from spectroscopic absorption measurements utilizing scattered light from the pulmonary artery or the central vein. The proposed various methods try to isolate the contribution of the scattered light from the pulmonary artery (or the other vessel) from that of the surrounding tissue.
[0048] Cheng et al in US patent No. US 2006/0253007 presented a method for the assessment of the oxygen saturation in a blood vessel such as the interior jugular vein by illuminating it from the skin. They suggest transmitting of the radiation into two regions, containing different portions of the target structure, for the isolation of the scattered radiation from the target vessel. They also suggest using ultrasound imaging for optimal placement of the optical transmitters and the receivers above the target structure.
[0049] Dixon in US Patent No. US2010/0198027 proposed a non-invasive method for the determination of oxygen saturation of blood within a deep vascular structure. Deep vascular structure are major blood vessels which are not superficially located, and include the inferior and superior vena cava, the right atrium, the right ventricle and central and peripheral parts of the pulmonary arteries. The method includes placing emitter and receiver elements of light oximeter device on the skin in the vicinity of the deep vascular structure of interest, wherein placement of the elements is achieved through matching of the plethysmography trace obtained from the oximeter device to known plethysrnography characteristics of the deep vascular structure. Kohl et al in U.S. Pat. No. 6,961,600B2 presented a minimally-invasive technique for the determination of mixed venous oxygen saturation by introducing catheter with an optical fiber in the bronchia, in the vicinity of the pulmonary artery.
[0050] These inventions suggest measuring SmvO 2 in the blood within the big arteries or veins, using non-invasive or minimally-invasive techniques, similar to the conventional invasive technique, which measures SmvO 2 in the pulmonary artery. However, the measurement of SmvO 2 by pulse oximetry, based on light scattering from big vessels is not accurate, as was found in the systemic circulation, that pulse oximetry cannot be used in the vicinity of big blood vessels (Mannheimer 2004, Reuss 2004). Pulse oximetry in the systemic circulation has to be performed on the microcirculatory bed, and the same must be done in the pulmonary system. In preferred implementations of the present invention, the pulmonary pulse oximetry is preferably performed by illuminating the pulmonary tissue, while avoiding scattering of light from the major blood vessels in the thorax, which include the inferior and superior vena cava, the right atrium, the right ventricle and central and peripheral parts of the pulmonary arteries.
[0051] Certain embodiments of the present invention perform pulmonary pulse oximetry using pulmonary PPG signals in two wavelengths obtained by a PPG probe applied either on the thoracic wall or on the esophageal wall. As was explained above, two wavelengths in the infrared are preferably used for the measurement of the pulmonary PPG signals and SvO 2 due to the long path of the light from the light-source to the detector. This is in contrast to the pulse oximetry in the systemic circulation, which is generally done by red and infrared light, taking the advantage of the relatively high difference between the values of the extinction coefficients of oxi- and deoxi-hemoglobin for red light (see FIG. 1 ). In the pulse oximetry in the systemic circulation the use of red light is possible because the pathlength required for measurements in skin is small, in the order of a few millimeters. Similarly, in the fourth above-mentioned embodiment of the pulmonary pulse oximetry, which uses optic fibers to convey the light to and from the lung, the use of red light is possible. As was explained in Section 1.3, the pathlengths of the red and infrared light are significantly different, so that calibration by extracted arterial blood is required for the determination of the relationship between SaO 2 and the measured parameter R derived from the two PPG signals. Similarly, in the pulmonary pulse oximetry technique, if the difference between the pathlengths of the two wavelengths in the infrared is significant, calibration by extracted blood from the pulmonary artery is required. This calibration is typically not required in pulse oximeter which uses two wavelengths in the infrared region, if they are close enough so that the difference between their pathlengths can be neglected. It is therefore preferable to use two adjacent wavelengths in the infrared, of small difference between their pathlength, and use Equation 9, after neglecting the small difference in their pathlength or correcting it by a suitable correction factor (see Section 1.3).
[0052] In the description of the pulse oximetry method presented above, SvO 2 is obtained from R, which was defined as the ratio of the ratios ΔI a /I S for the two wavelengths. SvO 2 can also be obtained from the ratio of two values of a parameter related to the change in the PPG signal for the two wavelengths, which can be different than ΔI a /I S . It can be chosen as ln(I D /I S ) (as in U.S. Pat. Nos. 4,773,422 and 4,167,331) or the derivative of I divided by I (as in U.S. Pat. No. 6,505,060).
[0053] The esophageal pulmonary pulse oximetry presented in the current patent application differs from the esophageal pulse oximeters presented by Atlee (U.S. Pat. No. 5,329,922) and Kyriacou et al (Kyriacou 2006), for the measurement of SaO 2 in the systemic microcirculation of the esophagus. Accordingly, the distance between the light source and the detector was less than 8 mm enabling the measurement of the PPG signal in the esophageal wall, where the light source and the detector were applied. The two light sources in each wavelength in the esophageal systemic pulse oximeters are required for the increase the PPG signal, while the two detectors in each wavelength in the esophageal pulmonary pulse oximeters are required for the differentiation between the contributions of the systemic and the pulmonary circulations to the PPG signal.
[0054] An esophageal systemic pulse oximetry, based on fiber-optic reflectance sensor was presented by Phillips et al (Phillips 2011) and an apparatus for measuring the oxygen saturation level of blood at an internal measurement site, based also on fiber-optic reflectance pulse oximetry was presented by Phillips et al in US patent 2008/0045822. In the former device, the distance between the ends of the detector and the light-sources optic fibers was 4 mm. In the latter apparatus the optical centers of the first and second optical fibers are separated by at least 1 mm at their distal ends. A short distance, of few mms, between the detector and the light-sources or between the ends of the optic fibers of the detector and the light-sources is required for measuring the light absorption in the tissue in contact to the pulse oximeter. In both articles and in the patent application the light-sources included a red emitter, which is highly absorbed in the tissue and can therefore be used only for measurements in tissue of short distance to the pulse oximeter, like the esophageal wail. In the pulmonary pulse oximeter the light-sources emit infrared light and the light sources-detector separation is higher than 10-20 mm, to allow penetration of light to depth of 10-20 mm relative to the measurement surface, which contains pulmonary tissue. It should be noted that the pulse oximeter presented by Phillips et al in their US patent 2008/0045822 was also suggested for the measurement of oxygen saturation in internal tissue like brain, but the probe must be inserted through the skull and applied adjacent to the brain surface in order to measure the oxygen saturation in the brain blood.
[0055] The preferred pulse oximeter is a device, which includes two laser diodes of two peak wavelengths in the infrared region and of narrow spectrum and a detector which can detect, for each wavelength, the transmitted light through a portion of the thorax. The light from the laser diodes is conveyed to the thoracic wall by an optic fiber and the light transmitted through the thorax is conveyed to the detector by another optic fiber.
[0056] For each laser diode a PPG curve is obtained and from each of the two PPG curves the ratio between the PPG pulse amplitude and its baseline is derived. The ratio R of the two values of this amplitude-to-baseline ratio for the two wavelengths is calculated and SvO 2 is determined from the equation
[0000]
Sv
O
2
=
ɛ
d
1
-
R
ɛ
d
2
R
(
ɛ
02
-
ɛ
d
2
)
+
(
ɛ
d
1
-
ɛ
0
1
)
[0057] The value of the extinction coefficients for oxygenated blood c o and for deoxygenated blood ε d can be retrieved from the literature data-bases, for each peak wavelength.
[0058] Another preferred pulse oximeter is an esophageal probe which includes the tips of two optic fibers, one of them conveying infrared light from two laser diodes of two peak wavelengths in the infrared region and of narrow spectrum and the second optic fiber conveying light to a detector. The probe is applied to the esophageal wall, in close proximity to the lung tissue. The two optic fiber tips are separated by more than 10 mm, so that a significant quantity of the light reaching the detector have been scattered by the lung tissue and the PPG pulse will mainly represent the blood volume changes in the pulmonary circulation. For each laser diode a PPG curve is obtained and from each of the two PPG curves the ratio between the PPG pulse amplitude and its baseline is derived. The ratio R of the two values of this amplitude-to-baseline ratio for the two wavelengths is calculated and SvO 2 is determined from the equation
[0000]
Sv
O
2
=
ɛ
d
1
-
R
ɛ
d
2
R
(
ɛ
02
-
ɛ
d
2
)
+
(
ɛ
d
1
-
ɛ
0
1
)
[0059] The value of the extinction coefficients for oxygenated blood ε o and for deoxygenated blood ε d can be retrieved from the literature data-bases, for each peak wavelength. In another preferred embodiment SvO 2 is obtained from the ratio of two values of a parameter related to the change in light transmission for the two wavelengths, and this parameter can be different than amplitude-to-baseline ratio. It can be chosen as ln(I D /I S ) or the derivative of I divided by I.
[0060] In another preferred embodiment light emitting diodes (LEDs) are used instead of laser diodes and inserted directly into the esophagus with no need for optic fibers. The emission spectrum of LED is broad, so that the calculation of the mean extinction coefficients over the spectrum band of the emitted light is required.
[0061] In another preferred embodiment the LEDs with narrow-band filter are used, so that the calculation of the mean extinction coefficients over the spectrum band of the emitted light is simpler and more accurate.
[0062] In another preferred embodiment the pulmonary PPG signal is obtained from several pulmonary PPG pulses, summed together, where the start of each PPG pulse is determined by the corresponding PPG pulse of the systemic circulation.
[0063] In another preferred embodiment the pulmonary PPG signal is obtained during specific phase of the respiration.
[0064] In another preferred embodiment the pulmonary PPG signal is obtained during the time of minimal movement of the lungs, such as at end expiration or at end inspiration.
BIBLIOGRAPHY
Articles
[0000]
1. L Yoshiya, Y. Shimady and K. Tanake, 1980. Spectrophotometric monitoring of arterial oxygen saturation on the fingertip. Med. Biol. Eng. Comput. 18:27-32.
2. A. Babchenko, E. Davidson, Y. Ginosar, V. Kurtz, I. Feib, D. Adler and M. Nitzan, 2001. Photoplethysmo graphic measurement of changes in total and pulsatile tissue blood volume following sympathetic blockade. Physiol. Meas. 22:389-396.
3. K. H. Shelley, 2007. Photoplethysmography: beyond the calculation of arterial oxygen saturation and heart rate. Anesth Analg, 105:S31-6.
4. M. N. Nitzan, A. Babchenko, B. Khanokh and D. Landau, 1998. The variability of the photoplethysmographic signal—a potential method for the evaluation of the autonomic nervous system. Physiol. Meas. 19:93-102.
5. O. Wieben. Light absorbance in pulse oximetry. In: Design of Pulse Oximeters. J. G. Webster, editor, 1997. Institute of Physics Publishing, Bristol, pp. 40-55.
6. P. D. Mannheimer, J. R. Casciani, M. E. Fein, S. L. Nierlich, 1997. Wavelength selection for low-saturation pulse oximetry. IEEE Trans. Biomed. Eng. 44(3): 148-158.
7. M. Nitzan, A. Babchenko, B. Khanokh, and H. Taitelbaum, 2000. The measurement of oxygen saturation in venous blood by dynamic near IR spectroscopy. J. Blamed. Optics. 5:155-162.
8. Schowalter J S, Calibration. In: Design of Pulse Oximeters. J. G. Webster, editor, 1997. Institute of Physics Publishing, Bristol, pp. 159-175.
9. A. Duncan , J. H. Meek , M. Clemence , C. E. Elwell . L. Tyszczuk , M. Cope and D. T. Delpy, 1995. Optical pathlength measurements on adult head, calf and forearm and the head of the newborn infant using phase resolved spectroscopy. Phys. Med. Biol. 40:295-304.
10. J. L. Reuss and D. Siker, 2004. The pulse in reflectance pulse oximetry:
[0075] modeling and experimental studies. J Clin Monit Comput. 18:289-99.
11. P. D. Mannheimer , O' N M, E. Konecny, 2004. The influence of larger subcutaneous blood vessels on pulse oximetry. J Clin Monit Comput. 18:179-88. 12. N. B. Karatzas and G. J. Lee, 1969. Propagation of blood flow pulse in the normal human pulmonary arterial system. Circ. Res. 15:11-21. 13. C. Her, D. Hays and D. E. Lees, 1987. Elevated pulmonary artery systolic storage volume associated with redistribution of pulmonary perfusion. Crit. Care Med. 15:1023-9. 14. M. Nitzan, Y. Mahler, S. Yaffe, R. Marziano, M. Boeber and R. Chishin, 1992. ECG-gated radionuclide plethysmography—a method for the assessment of pulmonary systolic blood volume increase. Clin. Phys. Physiol Meas. 13:21-8. 15. M. Nitzan, Y. Mahler, D. Schechter, S. Yaffe, M. Bocher and R. Chishin, 1994. A measurement of pulmonary blood volume increase during systole in humans. Physiol Meas. 15:489-498 16. M. Ugander, E. Jense and H. Arheden, 2009. Pulmonary intravascular blood volume changes through the cardiac cycle in healthy volunteers studied by cardivascular magnetic resonance measurements of arterial and venous flow. J. Cardiovasc. magnetic resonance, 11:42 17. P. A. Kyriacou, 2006. Pulse oximetry in the esophagus. Physiol Meas. 27:R1-35 18. J. P. Phillips, R. M. Langford, S. H. Chang, P. A. Kyriacou, D. P. Jones, 2011. Photoplethysmographic measurements from the esophagus using a new fiber-optic reflectance sensor. J. Biomed Opt. 16(7):077005.
Patents
[0000]
1. B. Dixon. Non-invasive measurement of blood oxygen saturation. US Patent Application Publication No. US 2010/0198027, 2010.
2. X. Cheng et al., Apparatus and method for non-invasive and minimally-invasive sensing of parameters relating to blood. US Patent Application Publication No. US 2006/0253007.
3. B. A. Kohl et al., Transbronchial reflectance oximetric measurement of mixed venous saturation and device therefore.n U.S. Pat. No. 6,961,600B2, 2005.
4. P. O. Isaacson et al., Single channel pulse oximeter, U.S. Pat. No. 4,773,422, 1988
5. L. L. Nielsen, Multi-wavelength incremental absorbence oximeter U.S. Pat. No. 4,167,331 1979.
6. M. A. Norris, Method and apparatus for determining pulse oximetry differential values U.S. Pat. No. 6,505,060, 2003.
7. J. L. Atlee, Oximetric esophageal probe. U.S. Pat. No. 5,329,922 1994.
8. J. P. Phillips, R. M. Langford, D. P. Jones, and P. A. Kyriacou, 2008. Optical fiber catheter pulse oximeter. US Patent Application Publication No. US 2008/0045822. | A method for obtaining diagnostic information relating to the lungs of a subject includes directing into tissue of the lungs of the subject light of a first wavelength and detecting part of the light that has passed primarily through microcirculatory tissue of the lungs and generating a signal which is a function of intensity of the detected light. The signal is then processed to derive a PPG curve for pulmonary microcirculatory arteries. The method is implemented using various locations for a light source and a detector, including various combinations of positioning on the thoracic wall, insertion into the esophagus, and in some cases, insertion of a probe through the thoracic wall to a position adjacent to the pulmonary pleura. Use of two different wavelengths allows derivation of mixed venous blood oxygen saturation. | 65,498 |
TECHNICAL FIELD
[0001] This invention is pertinent to the thermodynamic modeling of multicomponent mixtures and the calculation of a mixture's phase state at different pressures and temperatures and may utilize a two-phase flash algorithm that employs cubic equation of state (EOS) models. Specifically, this invention addresses the problem of two-phase cubic EOS models falsely identifying vapor/liquid multiphase splits at relatively low temperatures where no such vapor phase may physically exist.
BACKGROUND
[0002] Thermodynamic equation of state (EOS) models relates known state variables, such as pressure and temperature, to unknown state variables, such as volume, density, fugacity, etc. In addition they may be used to determine the phase state of a given pure substance or multicomponent mixture. Cubic EOS models are a subclass of thermodynamic EOS models that relate pressure, temperature, and molar volume through a cubic polynomial function. Cubic EOS models are used to predict phase behavior and fluid properties in a broad range of applications, including the petrophysical, geophysical, refrigeration, aerospace, and chemical process design industries. Their broad adoption and application is due to the relative simplicity of the model form, ease of computational implementation, limited number of fluid property inputs required for operation, and overall computational robustness.
[0003] The cubic EOS model subclass was first developed by van der Waals (1873) as an extension to the ideal gas law, where both attractive and repulsive molecular forces are included. In the van der Wall model, pressure, temperature, and volume are related as
[0000]
P
=
RT
V
-
b
-
a
V
2
,
(
1.1
)
[0000] where R is the universal gas constant, and a and b are attractive and repulsive parameters specific to each pure substance or mixture. Since the initial formulation of a cubic EOS model by van der Waals, numerous modifications to the model form have been made in an effort to increase predictive accuracy and general applicability. Of note are the Redlich-Kwong (RK) modification to the attractive term creating the RK cubic EOS model, the Soave modification to the Redlich-Kwong attractive term creating the SRK cubic EOS, and the Peng-Robinson (PR) modification creating the PR cubic EOS. Widespread adoption and application of cubic EOS models came about with the advent of the SRK and PR cubic EOS models, which may be expressed in a universal form:
[0000]
P
=
RT
V
-
b
-
a
α
V
2
+
u
1
bV
+
u
2
b
2
,
(
1.2
)
[0000] where the values and model forms for a, α, b, u 1 , and u 2 are listed in Table 1. Expressed in its cubic polynomial form, all four models may be written as:
[0000]
Z
3
-
(
1
+
B
-
u
1
B
)
Z
2
+
(
A
+
u
2
B
2
-
u
1
B
-
u
1
B
2
)
Z
-
(
AB
+
u
2
B
2
+
u
2
B
3
)
=
0
,
(
1.3
)
where
A
=
(
a
α
)
mix
P
R
2
T
2
and
B
=
b
mix
P
RT
.
(
1.4
)
[0004] Attractive and repulsive terms for mixtures are calculated using the mixing rules:
[0000]
(
a
α
)
mix
=
∑
i
N
∑
j
N
[
x
i
x
j
a
i
a
j
α
i
α
j
(
1
-
k
ij
)
]
,
(
1.5
)
b
mix
=
∑
i
N
x
i
b
i
,
(
1.6
)
[0005] where x i is the mole fraction of each component in the phase of interest (liquid or gas) and k ij are binary interaction coefficients.
[0000]
TABLE 1
Cubic EOS parameters.
Model
a
α
b
Ω a
Ω b
u 1
u 2
Van der Waals
27
26
R
2
T
c
2
P
c
1
RT
c
8
P
c
n/a
n/a
0
0
RK
Ω
a
R
2
T
c
2
P
c
T r −0.5
Ω
b
RT
c
P
c
0.42748
0.08664
1
0
SRK
Ω
a
R
2
T
c
2
P
c
[1 + f ω (1 − T r 0.5 )] 2 f ω = 0.48 + 1.574ω − 0.176ω 2
Ω
b
RT
c
P
c
0.42748
0.08664
1
0
PR
Ω
a
R
2
T
c
2
P
c
[1 + f ω (1 − T r 0.5 )] 2 f ω = 0.37464 + 1.54226ω − 0.2699ω 2
Ω
b
RT
c
P
c
0.45724
0.07780
2
−1
[0006] Provided physical properties for each mixture component, a cubic EOS may be used to calculate the compressibility factor Z for each potential phase (liquid and vapor phases). However, the determination of the phase state (liquid, vapor, or some combination of each) is a function of the fugacity of each component. Vapor-liquid equilibrium is achieved when the fugacity of the vapor phase (real or potential vapor phase) and the fugacity of the liquid phase (real or potential liquid phase) are equal for each component in the mixture
[0000] f i liq =f i vap (1.7)
[0007] This may also be expressed in the form of the equilibrium ratio:
[0000]
K
i
=
y
i
x
i
f
i
liq
f
i
vap
=
ϕ
i
liq
ϕ
i
vap
(
1.8
)
[0000] where φ i liq =f i liq /x i P is the liquid-phase fugacity coefficient and φ i vap =f i vap /y i P is the vapor-phase fugacity coefficient. The fugacity coefficient of each component may be calculated by
[0000]
ln
(
ϕ
i
liq
)
=
b
i
(
Z
liq
-
1
)
b
mix
-
ln
(
Z
liq
-
B
liq
)
-
A
liq
B
liq
(
δ
2
-
δ
1
)
(
2
Ψ
i
liq
(
a
α
)
mix
-
b
i
b
mix
)
ln
(
Z
liq
+
δ
1
B
liq
Z
liq
+
δ
2
B
liq
)
,
ln
(
ϕ
i
vap
)
=
b
i
(
Z
vap
-
1
)
b
mix
-
ln
(
Z
vap
-
B
vap
)
-
A
vap
B
vap
(
δ
2
-
δ
1
)
(
2
Ψ
i
vap
(
a
α
)
mix
-
b
i
b
mix
)
ln
(
Z
vap
+
δ
1
B
vap
Z
vap
+
δ
2
B
vap
)
,
Ψ
i
liq
=
∑
j
N
[
x
j
a
i
a
j
α
i
α
j
(
1
-
k
ij
)
]
,
and
Ψ
i
vap
=
∑
j
N
[
y
j
a
i
a
j
α
i
α
j
(
1
-
k
ij
)
]
.
(
5.9
)
[0008] For RK and SRK models, δ 1 =1 and δ 2 =0. For the PR model, δ 1 =1+√{square root over (2)} and δ 2 =1−√{square root over (2)}.
[0009] In order to determine the liquid/vapor quality of a mixture, the Rachford-Rice equations must be solved, which depend upon the composition of the mixture and the equilibrium ratio. The solution to the Rachford-Rice equation contains a physical solution, i.e., the mole fraction of vapor existing on the interval 0<n vap <1, if both g(0)≧1.0 and g(1)≧1.0 where
[0000]
g
(
0
)
=
∑
1
N
z
i
K
i
and
g
(
1
)
=
∑
1
N
z
i
K
i
(
1.10
)
[0000] If g(0)<1.0, then the substance or mixture is expected to exist entirely as a liquid-phase fluid. Conversely, if g(1)<1.0, then the substance or mixture is expected to exist entirely as a vapor-phase fluid. Thus, given values for the equilibrium ratio K i , this check allows for the EOS to determine the phase state of a substance or mixture. Since a priori knowledge of the K i is generally not available for any arbitrary mixture at any pressure-temperature state condition, the solution to a cubic EOS, property mixture rules, and fugacity formulation is performed in an iterative manner with an initial guess for K i provided. Typically, that initial seeding guess is provided by Wilson's K i :
[0000]
K
i
=
P
c
,
i
P
exp
[
5.373
(
1
+
ω
i
)
(
1
-
T
c
,
i
T
)
]
(
1.11
)
SUMMARY
[0010] According to one embodiment, an apparatus for estimating saturation conditions of reservoir brines in an underground reservoir that includes a sensor for measuring a temperature of the brine a processor is disclosed. The processor is configured to: receive data representing the temperature; determine if the temperature is greater than a preset value; select either a first method or second method, different than the first method, of calculating the saturation conditions based on the determination; wherein the first method is selected when the temperature is greater than the preset value and the second method is selected when the temperature is less than the preset value; and based on results of the first or second method, form the saturation condition estimates utilizing an equation of state (EOS) model.
[0011] According to another embodiment, a computer based method of estimating saturation conditions of reservoir brines in an underground reservoir is disclosed. The method includes receiving at the computing device data representing a temperature of the brine; determining with the computing device if the temperature is greater than a preset value; selecting either a first method or second method, different than the first method, of calculating the saturation conditions based on the determination, wherein the first method is selected when the temperature is greater than the preset value and the second method is selected when the temperature is less than the preset value; and based on results of the first or second method, forming the saturation condition estimates utilizing an equation of state (EOS) model.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein like elements are numbered alike, in which:
[0013] FIG. 1 shows an example drilling system according to one embodiment;
[0014] FIG. 2 is a diagram of the new hybrid model workflow;
[0015] FIG. 3 is a more detailed version of portions the flow diagram shown in FIG. 2 ; and
[0016] FIG. 4 is a more detailed version of portions the flow diagram shown in FIG. 2 .
DETAILED DESCRIPTION
[0017] In one embodiment, this invention addresses the problem of two-phase cubic EOS models falsely identifying vapor/liquid multiphase splits at relatively low temperatures where no such vapor phase may physically exist.
[0018] Referring to FIG. 1 , an exemplary embodiment of a downhole drilling, monitoring, evaluation, exploration and/or production system 10 disposed in a wellbore 12 is shown. A borehole string 14 is disposed in the wellbore 12 , which penetrates at least one earth formation 16 for performing functions such as extracting matter from the formation and/or making measurements of properties of the formation 16 and/or the wellbore 12 downhole. The borehole string 14 is made from, for example, a pipe, multiple pipe sections or flexible tubing. The system 10 and/or the borehole string 14 include any number of downhole tools 18 for various processes including drilling, hydrocarbon production, and measuring one or more physical quantities in or around a borehole. Various measurement tools 18 may be incorporated into the system 10 to affect measurement regimes such as wireline measurement applications or logging-while-drilling (LWD) applications.
[0019] In one embodiment, a parameter measurement system is included as part of the system 10 and is configured to measure or estimate various downhole parameters of the formation 16 , the borehole 14 , the tool 18 and/or other downhole components. The illustrated measurement system includes an optical interrogator or measurement unit 20 connected in operable communication with at least one optical fiber sensing assembly 22 . The measurement unit 20 may be located, for example, at a surface location, a subsea location and/or a surface location on a marine well platform or a marine craft. The measurement unit 20 may also be incorporated with the borehole string 12 or tool 18 , or otherwise disposed downhole as desired.
[0020] In the illustrated embodiment, an optical fiber assembly 22 is operably connected to the measurement unit 20 and is configured to be disposed downhole. The optical fiber assembly 22 includes at least one optical fiber core 24 (referred to as a “sensor core” 24 ) configured to take a distributed measurement of a downhole parameter (e.g., temperature, pressure, stress, strain and others). In one embodiment, the system may optionally include at least one optical fiber core 26 (referred to as a “system reference core” 26 ) configured to generate a reference signal. The sensor core 24 includes one or more sensing locations 28 disposed along a length of the sensor core, which are configured to reflect and/or scatter optical interrogation signals transmitted by the measurement unit 20 . Examples of sensing locations 28 include fibre Bragg gratings, Fabry-Perot cavities, partially reflecting mirrors, and locations of intrinsic scattering such as Rayleigh scattering, Brillouin scattering and Raman scattering locations. If included, the system reference core 26 may be disposed in a fixed relationship to the sensor core 24 and provides a reference optical path having an effective cavity length that is stable relative to the optical path cavity length of the sensor core 24 .
[0021] In one embodiment, a length of the optical fiber assembly 22 defines a measurement region 30 along which distributed parameter measurements may be taken. For example, the measurement region 30 extends along a length of the assembly that includes sensor core sensing locations 28 .
[0022] The measurement unit 20 includes, for example, one or more electromagnetic signal sources 34 such as a tunable light source, a LED and/or a laser, and one or more signal detectors 36 (e.g., photodiodes). Signal processing electronics may also be included in the measurement unit 20 , for combining reflected signals and/or processing the signals. In one embodiment, a processing unit 38 is in operable communication with the signal source 34 and the detector 36 and is configured to control the source 34 , receive reflected signal data from the detector 36 and/or process reflected signal data.
[0023] In one embodiment, the measurement system is configured as a coherent optical frequency-domain reflectometry (OFDR) system. In this embodiment, the source 34 includes a continuously tunable laser that is used to spectrally interrogate the optical fiber sensing assembly 22 .
[0024] The optical fiber assembly 22 and/or the measurement system are not limited to the embodiments described herein, and may be disposed with any suitable carrier. That is, while an optical fiber assembly 22 is shown, any type of now known or later developed manners of obtaining information relative a reservoir may be utilized to measure various information (e.g., temperature, pressure, salinity and the like) about fluids in a reservoir. Thus, in one embodiment, the measurement system may not employ any fibers at all and may communicate data electrically.
[0025] A “carrier” as described herein means any device, device component, combination of devices, media and/or member that may be used to convey, house, support or otherwise facilitate the use of another device, device component, combination of devices, media and/or member. Exemplary non-limiting carriers include drill strings of the coiled tube type, of the jointed pipe type and any combination or portion thereof. Other carrier examples include casing pipes, wirelines, wireline sondes, slickline sondes, drop shots, downhole subs, bottom-hole assemblies, and drill strings.
[0026] In support of the teachings herein, various analysis components may be used, including a digital and/or an analog system. Components of the system, such as the measurement unit 20 , the processor 38 , the processing assembly 50 and other components of the system 10 , may have components such as a processor, storage media, memory, input, output, communications link, user interfaces, software programs, signal processors (digital or analog) and other such components (such as resistors, capacitors, inductors and others) to provide for operation and analyses of the apparatus and methods disclosed herein in any of several manners well appreciated in the art. It is considered that these teachings may be, but need not be, implemented in conjunction with a set of computer executable instructions stored on a computer readable medium, including memory (ROMs, RAMs), optical (CD-ROMs), or magnetic (disks, hard drives), or any other type that when executed causes a computer to implement the method of the present invention. These instructions may provide for equipment operation, control, data collection and analysis and other functions deemed relevant by a system designer, owner, user or other such personnel, in addition to the functions described in this disclosure.
[0027] Further, various other components may be included and called upon for providing for aspects of the teachings herein. For example, a power supply (e.g., at least one of a generator, a remote supply and a battery), cooling unit, heating unit, motive force (such as a translational force, propulsional force or a rotational force), magnet, electromagnet, sensor, electrode, transmitter, receiver, transceiver, antenna, controller, optical unit, electrical unit or electromechanical unit may be included in support of the various aspects discussed herein or in support of other functions beyond this disclosure.
[0028] Disclosed is new hybrid PR EOS model for calculating brine saturation conditions. The hybrid model is formulated by the combination of two independent models. One model is the Søreide and Whitson (SW) modified PR EOS and the second is a new modified version of the PR EOS using the Haas correlation. Each of the original models will be described in greater detail below. However, as a general statement the purpose of combining the two models is to provide an accurate prediction of brine saturation conditions over the entire saturation boundary.
[0029] With reference to FIG. 2 , at block 202 the temperature of the brine is determined. This may include any now known or later developed method of determining the temperature of a brine in a reservoir. For instance, the above described optical measurement system may be employed or another type of measurement system may be utilized.
[0030] In the event that the temperature is greater than 573, the PR EOS parameters are calculated according Hass as indicated by blocks 204 and 208 , respectively. In the event that the temperature is less than 573, the PR EOS parameters are calculated according SW as indicated by blocks 204 and 206 , respectively. Regardless of how the PR EOS parameters are calculated, at block 210 the PR EOS equations are solved to provide properties of reservoir water and brines.
[0031] In more detail, the correlation of Haas is a common and widely accepted model in the reservoir engineering community to calculate the saturation pressure and temperature conditions of reservoir brine. It provides a simple method to calculate the pressure and temperature of saturated brine with a high degree of accuracy compared to experimental data. Haas establishes that the temperature of pure water, T 0 , and temperature of a brine solution of sodium chloride, T x , at the same vapor pressure can be correlated by the following relation:
[0000]
ln
T
0
=
ln
T
x
a
+
b
T
x
+
c
(
1
)
[0000] where temperature is Kelvin and a, b and c are model variables. Haas used this model form to empirically generate the values of a and b, assuming c=0, with least-squares regression. These coefficients were described by the following formulas:
[0000] a= 1.0+5.93582×10 −6 x− 5.19386×10 −5 x 2 +1.23156×10 −5 x 3 (2)
[0000] b= 1.0+1.15420×10 −6 x+ 1.41254×10 −7 x 2 −1.92476×10 4 x 3 −1.70717×10 −9 x 4 +1.05390×10 −10 x 5 (3)
[0000] where x is the molality of the brine solution. Once the saturation temperature of the brine, T x , is obtained, the value of vapor pressure, P v (in bar), can be calculated by applying the following equation:
[0000]
ln
P
v
=
e
0
+
e
1
z
+
e
2
w
z
+
[
10
(
e
3
w
2
)
-
1.0
]
+
e
4
[
10
(
e
5
(
y
)
1.25
)
]
(
4
)
where
w
=
z
2
-
e
6
y
=
647.27
-
T
0
z
=
T
0
+
0.01
e
0
=
12.50849
e
1
=
-
4.616913
×
10
3
e
2
=
3.193455
×
10
-
4
e
3
=
1.1965
×
10
-
11
e
4
=
-
1.013137
×
10
-
2
e
5
=
-
5.7148
×
10
-
3
e
6
=
2.9370
×
10
5
.
(
5
)
[0032] Equations (1)-(5) result in a standard error for the prediction of the vapor pressure of sodium chloride solutions of 0.32% in reference to the experimentally observed pressure. These equations were developed for the range of sodium chloride concentration of 0 weight percent sodium chloride to halite saturation. Beyond the experimentally validated temperature range (262.15 to 573.15 K), the equations provide predictions which vary smoothly and continuously to higher temperatures. No error estimate outside the experimental temperature range is provided by Haas.
[0033] These equations have proven very useful in determining the saturation curves for brine solutions. However, one aspect to remember is that it is strictly a correlation for saturation temperature and pressure. This limits the correlation's ability to provide much detail about other fluid properties that may be of interest in the larger scheme of fluid analysis. An approach that can calculate the saturation boundary and be more generalized and flexible for a broader range of analyses would be very desirable.
[0034] According to one embodiment, and as illustrated at block 108 , the critical temperature of brine can be estimated as a function of salt concentration through the use of the Haas correlation. Thus, at block 208 , the PR EOS calculated parameter include the critical temperature.
[0035] Turning now to block 210 , cubic EOS models are frequently used in reservoir engineering applications and processes due to their ability to provide reliable calculations, be generalized to many components, and be used in a predictive manner for many different applications. A commonly used cubic EOS model form is the Peng-Robinson (PR) EOS model which may be utilized in block 210 and was developed from the modified van der Waals equation of state. The generic form can be expressed as:
[0000]
P
=
RT
V
-
b
EOS
-
a
EOS
α
V
(
V
+
b
EOS
)
+
b
EOS
(
V
-
b
EOS
)
(
6
)
[0036] where R is the universal gas constant and V is volume. This can be rewritten as:
[0000] Z 3 −(1+ B−u 1 B ) Z 2 +( A+u 2 B 2 −u 1 B−u 1 B 2 ) Z −( AB−u 2 B 2 −u 2 B 3 )=0. (7)
[0037] The coefficients A, B, and Z are defined as:
[0000]
A
=
(
a
EOS
,
i
α
)
m
P
(
RT
)
2
(
8
)
B
=
b
EOS
,
i
P
RT
(
9
)
Z
=
PV
RT
.
(
10
)
[0038] The cubic EOS parameters a EOS , b EOS , and a are defined as:
[0000]
a
EOS
,
i
=
Ω
a
R
2
T
ci
2
P
ci
(
11
)
b
EOS
,
i
=
Ω
b
RT
ci
P
ci
(
12
)
α
i
=
[
1
+
m
i
(
1
-
T
ri
)
]
2
(
13
)
[0000] where T c is the critical temperature, P c is the critical pressure, and T r is the reduced temperature (T/T c ). The subscripts i and m refer to individual components and mixture values, respectively. The values of Ω a , Ω b , u 1 , u 2 , and m are model form dependent and are defined for the PR EOS as:
[0000]
m
i
(
ω
i
)
=
{
0.379642
+
1.48503
ω
i
-
0.1644
ω
i
2
+
0.16667
ω
i
3
ω
i
>
0.49
0.379642
+
1.54226
ω
i
-
0.2699
ω
i
2
ω
i
≤
0.49
Ω
a
=
0.45724
Ω
b
=
0.00780
u
1
=
2
u
2
=
-
1
(
14
)
[0039] With equations (6)-(14) as outlined above, the properties of a fluid including volumetric properties and vapor-liquid equilibrium can be calculated by using a number of well-documented solution methodologies. Herein, in the case where the measured temperature of the brine is greater than 573K, the critical temperature T c is calculated per Hass as indicated at blocks 204 and 208 . In one embodiment, the method used in the calculations of block 210 is the successive substitution iterative solution of the Rachford-Rice equation. This method is well-documented in the open literature and thus is not repeated in detail here.
[0040] In the alternative case (e.g., where T<573K) the Søreide and Whitson modified EOS parameters are used. In particular, as opposed to as is described above, calculations as implemented in block 206 utilize an a that is expressed as:
[0000] α 1/2 =1+0.4530[1− T r (1−0.0103 x 1.1 )]+0.0034( T r −3 −1) (15)
[0000] where x is again the molality of the solution and T r is the reduced temperature. The critical temperature of pure water is used in this embodiment.
[0041] FIG. 3 shows a more detailed version of the calculations performed in blocks 208 and 210 . At block 302 the critical temperature is calculated according to Hass. In one embodiment, the critical temperature (T c,Hass ) is calculated from:
[0000]
ln
T
0
=
ln
T
c
,
Hass
a
+
bT
c
,
Hass
+
c
(
16
)
[0000] Where c is 0, and a and b are as expressed in equations 3 and 4 above.
[0042] At block 304 new cubic EOS parameters a EOS , b EOS , and a are calculated. This can be performed by defined as:
[0000]
a
EOS
=
Ω
a
R
2
T
c
,
Hass
2
P
c
(
17
)
b
EOS
=
Ω
b
RT
c
,
Hass
P
c
(
18
)
α
=
[
1
+
m
i
(
1
-
T
T
c
,
Hass
)
]
2
(
19
)
[0000] The values of Ω a , Ω b , u 1 , u 2 , and m are model form dependent and are defined above.
[0043] At block 306 a flash solver can be used to solve for saturation at different pressures and temperatures based on equation 6 above.
[0044] FIG. 4 shows a more detailed version of the calculations performed in blocks 204 and 210 . At block 402 , a is calculated per SW as:
[0000] α 1/2 =1+0.4530[1− T r (1−0.0103 x 11 )]+0.0034( T r −3 −1) (15)
[0000] where T r =T/T c,Purewater .
[0045] At block 404 a flash solver can be used to solve for saturation at different pressures and temperatures based on equation 6 above.
[0046] While the invention has been described with reference to exemplary embodiments, it will be understood that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications will be appreciated to adapt a particular instrument, situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. | A method of estimating saturation conditions of reservoir brines in an underground reservoir includes: receiving data representing a temperature of the brine; determining if the temperature is greater than a preset value; and selecting either a first method or second method, different than the first method, of calculating the saturation conditions based on the determination. The first method is selected when the temperature is greater than the preset value and the second method is selected when the temperature is less than the preset value. | 98,913 |
TECHNICAL FIELD
[0001] The present application relates to hearing devices, in particular to sound source separation in a multi-source environment. The disclosure relates specifically to a hearing device comprising an input unit for providing one or more electric input signals representing sound from a sound environment generated by a number of sound sources.
[0002] The application furthermore relates to a method of separating sound sources in a multi-sound-source environment.
[0003] The application further relates to a data processing system comprising a processor and program code means for causing the processor to perform at least some of the steps of the method.
[0004] Embodiments of the disclosure may e.g. be useful in applications such as hearing devices, e.g. hearing aids, headsets, ear phones, active ear protection systems, handsfree telephone systems, mobile telephones, teleconferencing systems, public address systems, karaoke systems, classroom amplification systems, etc.
BACKGROUND
[0005] Audio sound source separation comprises the task of separation of different constituent sources within an audio mixture (the audio mixture comprising sound from a number of sources mixed in a sound field). Currently, most approaches to this problem have been performed ‘offline’, meaning that the entire audio mixture is present at the time of separation (generally in the form of a digital recording), rather than in ‘realtime’, where sources are separated as new audio data are entered into the system. In the cocktail party situation, the presence of multiple competing talkers can make listening to the information transmitted by a single source difficult, but successful sound source separation is able to present the listener with the information present from only a single talker at a time.
[0006] In order for sound source separation to be useful in real communication situations, it should be performed in real-time, or at very low latency. If a significant processing delay occurs between audio being spoken, and audio being separated, the listener may be perturbed by the asynchrony between talker mouth movement and corresponding audio, as well as receiving less benefit from possible lip-reading. Therefore, a sound source separation approach which operates at low latency (e.g. less than 20 ms between an audio sample entering and leaving the system) is advantageous. Current (additive mixture model based) sound-source separation approaches rely on the use of fairly long analysis frames (typically of the order of >50 ms), which, if implemented directly, would violate requirements for low latency.
[0007] In this context, we consider only what we refer to as ‘data latency’, in that it is assumed that the actual processing algorithms can be executed in time, given the correct implementation and computational power.
[0008] A number of solutions to the problem a two-talker mixture exists.
[0009] Some studies into real-time Nonnegative Matrix Factorization (NMF) have provided good results, but don't address window sizes small enough to produce the desired latency performance for hearing aid applications (<20 ms). Likewise, the Probabilistic Latent Component Analysis (PLCA) approach in also claims real-time performance, but operates on frames of length 64 ms, which doesn't satisfy the latency requirements of hearing-aid-users.
[0010] Until now, most NMF-based algorithms have been designed to run ‘offline’, however, i.e. the whole mixture signal to be separated/enhanced is available to the processing algorithm at once.
[0011] Although some attempts to provide real-time solutions have been reported, there is a need for a solution that give satisfactory results in a hearing device during normal operation.
SUMMARY
[0012] The present disclosure proposes to solve the problem of real-time source separation using a dictionary specific to each source to be separated, and dedicated frame-handling approaches to provide enhanced separation, even for short processing frames (which produce lowest latency). By storing a cache of previous input frames in a circular buffer, filter coefficients for the current frame to be output based on greater temporal context can be derived. Further, better source separation performance for low latency can be produced compared to the use of short input frames alone.
[0013] Objects of the application are achieved by the invention described in the accompanying claims and as described in the following.
A Hearing Device:
[0014] In an aspect of the present application, an object of the application is achieved by a hearing device comprising
an input unit for delivering a time varying electric input signal representing an audio signal comprising at least two sound sources, a cyclic analysis buffer unit of length A adapted for storing the last A audio samples, and a cyclic synthesis buffer unit of length L, where L is smaller than A, adapted for storing the last L audio samples, which are intended to be separated in individual sound sources, a database having stored recorded sound examples from said at least two sound sources, each entry (recorded sound example) in the database being termed an atom, the atoms originating from audio samples from first and second buffers corresponding in size to said synthesis and analysis buffer units, where for each atom, the audio samples from the first buffer overlaps with the audio samples from the second buffer, and where atoms originating from the first buffer constitute a reconstruction dictionary, and where atoms originating from the second buffer constitute an analysis dictionary.
[0019] The hearing device further comprises, a sound source separation unit for separating said electric input signal to provide at least two separated signals representing said at least two sound sources, the sound source separation unit being configured to determine the most optimal representation (W) of the last A audio samples given the atoms in the analysis dictionary of the database, and to generate said at least two separated signals by combining atoms in the synthesis (reconstruction) dictionary of the database using the optimal representation (W).
[0020] The present disclosure is based on the method's ability to enhance the separation of the last L samples from the last A samples, where L<A, and at the same time separate the individual sources (e.g. voices) that were present in the L audio samples. The method calculates a representation of the last A audio samples from the database consisting of (or originating from) recorded examples of length A, the definition of the representation W, e.g., weights for a weighted sum, e.g. as defined by a compositional (e.g. additive) model, is then applied to the recorded examples from the database of length L to provide the current separated signals of the current contents of the synthesis buffer.
[0021] In an embodiment, the at least two sound sources comprises at least one target sound source. In an embodiment, the at least two sound sources comprises a noise sound source. In an embodiment, the at least two sound sources comprises a target sound source and a noise sound source. In an embodiment, only a target sound source and a noise sound source is present at a given point in time or time span. In an embodiment, the at least two sound sources comprises two or more different target sound sources. In an embodiment, the at least two sound sources comprises three or more different target sound sources. In the present context, the term ‘target sound source’ is intended to mean a sound source that the user has an intention to take notice of. In the present context, the term ‘target sound source’ is intended to mean a sound source for which a learned database exists (comprising analysis and reconstruction dictionaries for use in source separation according to the present disclosure).
[0022] In an embodiment, the hearing device comprises a time frequency (TF) conversion unit for providing the contents of said analysis and/or synthesis buffer(s) in a time-frequency representation (k,m). In an embodiment, the time frequency conversion unit provides a time segment of the electric input signal (e.g. on a time frame by time frame basis, e.g. corresponding to the analysis and/or synthesis time frames/buffers) in a number of frequency bands at a number of time instances, k being a frequency band index and m being a time index, and wherein (k, m) defines a specific time-frequency bin or unit comprising a signal component in the form of a complex or real value of the electric input signal corresponding to frequency index k and time instance m. In an embodiment, only the magnitude of the signal is considered. In an embodiment, the TF conversion unit comprises a filter bank for filtering a (time varying) input signal and providing a number of (time varying) output signals each comprising a distinct frequency range of the input signal. In an embodiment, the TF conversion unit comprises a Fourier transformation unit for converting a time variant input signal to a (time variant) signal in the frequency domain, e.g. a Discrete Fourier Transform (DFT). In an embodiment, the frequency range considered by the hearing device from a minimum frequency f min to a maximum frequency f max comprises a part of the typical human audible frequency range from 20 Hz to 20 kHz, e.g. a part of the range from 20 Hz to 12 kHz. In an embodiment, a signal of the forward and/or analysis path of the hearing device is split into a number NI of frequency bands, where NI is e.g. larger than 5, such as larger than 10, such as larger than 50, such as larger than 100, such as larger than 500, at least some of which are processed individually. In an embodiment, the hearing device is/are adapted to process a signal of the forward and/or analysis path in a number NP of different frequency channels (NP≦NI). The frequency channels may be uniform or non-uniform in width (e.g. increasing in width with frequency), overlapping or non-overlapping.
[0023] In an embodiment, the atoms of the database are represented in the time domain or in the (time-)frequency domain.
[0024] In an embodiment, the hearing device comprises a time-frequency to time conversion unit for providing the time domain representation of the separated sources.
[0025] In an embodiment, the sound source separation unit comprises the cyclic analysis and synthesis buffers and/or the time to time-frequency conversion unit and/or the time-frequency to time conversion unit.
[0026] In an embodiment, the hearing device comprises a feature extraction unit for extracting characteristic features of the contents of said analysis buffer and/or said synthesis buffer.
[0027] In an embodiment, the feature extraction unit is configured to provide said characteristic features in a time-frequency representation. Examples of characteristics could be short examples (say shorter than 100 ms) of sound of the particular sources in the time-frequency domain (as in FIG. 3B, 3C ).
[0028] In an embodiment, the sound separation unit is configured to base said sound source separation on Non Negative Matrix Factorization (NMF), Hidden Markov Model (HMM), or Deep Neural Networks (DNN).
[0029] In an embodiment, each of the recorded sound examples in the database consist of an atom pair originating from audio samples from first and second buffers, respectively, the first and second buffers corresponding in size to the synthesis and analysis buffer units.
[0030] In an embodiment, each of the corresponding atom pairs of the database comprises an identifier of the sound source from which it originates, e.g. a name of a person whose voice is represented by a given set of atom pairs, or a type of sound source, or a number of a sound source, e.g. source#1, source#2, etc.
[0031] In an embodiment, the database comprises an analysis and a reconstruction dictionary for each sound source. Each atom in the analysis and reconstruction dictionary is associated with a corresponding atom in the other dictionary (originating from, or being characteristic of, the same sound element). In an embodiment, each dictionary or each atom of a dictionary is associated with a specific sound source, e.g. source 1, source 2, source 3.
[0032] In an embodiment, the size of the individual dictionaries is reduced by standard data reduction techniques, such as K-means clustering, or by introducing sparsity constraints in the learning of the dictionaries.
[0033] In an embodiment, the sound source separation unit is configured to use the identifier of the sound source to generate said at least two sound sources. In an embodiment, the sound source separation unit is configured to use a compositional model to generate said at least two sound sources. In an embodiment, the compositional model comprises an optimization procedure, e.g. a minimization procedure. In an embodiment, the sound source separation unit is configured to minimize a divergence function (e.g. the Kullback-Liebler (KL) divergence) between an observation vector, x, and its approximation, {circumflex over (x)}.
[0034] In an embodiment, the hearing device comprises a control unit for controlling the update of the analysis and synthesis buffers with a predefined update frequency, and configured—at each update—to store in the analysis and synthesis buffers the last H audio samples received from the input unit and discarding the oldest H audio samples stored in the analysis and synthesis buffers. In an embodiment, the number H of audio samples between each update of the analysis and synthesis buffers is less than 16, such as less than 8, such as less than 4, such as less than 2. In an embodiment, the control unit is configured to update the separated signals according to a predefined scheme, e.g. regularly, e.g. with a predefined update frequency f upd , e.g. every H audio samples (f upd =1/(H*f s ), where f s is the sampling frequency).
[0035] In an embodiment, the hearing device comprises a signal processing unit for processing one or more of said separated signals representing said at least two sound sources (or a signal derived therefrom). In an embodiment, the signal processing unit is configured to present the user with one or more of the separated signals, e.g. one after the other, so that information from only a single source s i is presented at a given time.
[0036] In an embodiment, the hearing device is configured to provide a sound source separation with a latency less than or equal to 20 ms between an audio sample entering and leaving the source separation system, e.g. by optimizing the sizes of the synthesis and analysis frame lengths. In an embodiment, the hearing device is configured to dynamically adapt the synthesis and analysis frame lengths, e.g. in dependence of the current acoustic environment (e.g. of the number of sound sources, the ambient noise level, etc.).
[0037] In an embodiment, the hearing device (the input unit) comprises an input transducer for converting an input sound to an electric input signal. In an embodiment, the hearing device comprises a directional microphone system adapted to enhance a target acoustic source among a multitude of acoustic sources in the local environment of the user wearing the hearing device. In an embodiment, the hearing device comprises a multitude of input transducers and/or receives one or more direct input signals representing audio. In an embodiment, the hearing device is configured to create a directional signal based on electric input signals from said multitude of input transducers and/or on said one or more direct input signals. In an embodiment, the hearing device is configured to create a directional signal based on at least one of said separated signals. In an embodiment, the hearing device is adapted to receive a microphone signal from another device, e.g. a remote control or a SmartPhone and/or a separate (e.g. partner) microphone. In an embodiment, the other device is a contra-lateral hearing device of a binaural hearing system. In an embodiment, the hearing device is configured to create a directional signal based on at least one of said separated signals and at least one microphone signal received from another device. In an embodiment, the directional system is adapted to detect (such as adaptively detect) from which direction a particular part of the microphone signal originates. This can be achieved in various different ways as e.g. described in the prior art.
[0038] In an embodiment, the hearing device is adapted to provide a frequency dependent gain and/or a level dependent compression and/or a transposition (with or without frequency compression) of one or more frequency ranges to one or more other frequency ranges, e.g. to compensate for a hearing impairment of a user. In an embodiment, the hearing device comprises a signal processing unit for enhancing the input signals and providing a processed output signal.
[0039] In an embodiment, the hearing device comprises an output unit for providing a stimulus perceived by the user as an acoustic signal based on a processed electric signal. In an embodiment, the output unit comprises a number of electrodes of a cochlear implant or a vibrator of a bone conducting hearing device. In an embodiment, the output unit comprises an output transducer. In an embodiment, the output transducer comprises a receiver (loudspeaker) for providing the stimulus as an acoustic signal to the user. In an embodiment, the output transducer comprises a vibrator for providing the stimulus as mechanical vibration of a skull bone to the user (e.g. in a bone-attached or bone-anchored hearing device).
[0040] In an embodiment, the hearing device comprises an antenna and transceiver circuitry for wirelessly receiving a direct electric input signal from another device, e.g. a communication device or another hearing device. In an embodiment, the hearing device comprises a (possibly standardized) electric interface (e.g. in the form of a connector) for receiving a wired direct electric input signal from another device, e.g. a communication device or another hearing device. In an embodiment, the direct electric input signal represents or comprises an audio signal and/or a control signal and/or an information signal.
[0041] In an embodiment, the hearing device has a maximum outer dimension of the order of 0.08 m (e.g. a head set). In an embodiment, the hearing device has a maximum outer dimension of the order of 0.04 m (e.g. a hearing instrument).
[0042] In an embodiment, the hearing device is portable device, e.g. a device comprising a local energy source, e.g. a battery, e.g. a rechargeable battery. In an embodiment, the hearing device is a low power device.
[0043] In an embodiment, the hearing device comprises a forward or signal path between an input transducer (microphone system and/or direct electric input (e.g. a wireless receiver)) and an output transducer. In an embodiment, the signal processing unit is located in the forward path. In an embodiment, the signal processing unit is adapted to provide a frequency dependent gain according to a user's particular needs. In an embodiment, the hearing device comprises an analysis path comprising functional components for analyzing the input signal (e.g. determining a level, a modulation, a type of signal, an acoustic feedback estimate, etc.). In an embodiment, some or all signal processing of the analysis path and/or the signal path is conducted in the frequency domain. In an embodiment, some or all signal processing of the analysis path and/or the signal path is conducted in the time domain.
[0044] In an embodiment, the hearing devices comprise an analogue-to-digital (AD) converter to digitize an analogue input with a predefined sampling rate, e.g. 20 kHz. In an embodiment, the hearing devices comprise a digital-to-analogue (DA) converter to convert a digital signal to an analogue output signal, e.g. for being presented to a user via an output transducer.
[0045] In an embodiment, an analogue electric signal representing an acoustic signal is converted to a digital audio signal in an analogue-to-digital (AD) conversion process, where the analogue signal is sampled with a predefined sampling frequency or rate f s , f s being e.g. in the range from 8 kHz to 40 kHz (adapted to the particular needs of the application) to provide digital samples x n (or x[n]) at discrete points in time t n (or n), each audio sample representing the value of the acoustic signal at t n by a predefined number N s of bits, N s being e.g. in the range from 1 to 16 bits. A digital sample x has a length in time of 1/f s , e.g. 50 μs, for f s =20 kHz. In an embodiment, a number of audio samples are arranged in a time frame. In an embodiment, a time frame comprises 64 audio data samples (corresponding to 3.2 ms for f s =20 kHz). Other frame lengths may be used depending on the practical application.
[0046] In an embodiment, the hearing device comprises a classification unit for classifying a current acoustic environment around the hearing device. In an embodiment, the hearing device comprises a number of detectors providing inputs to the classification unit and on which the classification is based.
[0047] In an embodiment, the hearing device comprises a level detector (LD) for determining the level of an input signal (e.g. on a band level and/or of the full (wide band) signal). The input level of the electric microphone signal picked up from the user's acoustic environment is e.g. a classifier of the environment. In an embodiment, the level detector is adapted to classify a current acoustic environment of the user according to a number of different (e.g. average) signal levels, e.g. as a HIGH-LEVEL or LOW-LEVEL environment.
[0048] In a particular embodiment, the hearing device comprises a voice detector (VD) for determining whether or not an input signal comprises a voice signal (at a given point in time). A voice signal is in the present context taken to include a speech signal from a human being. It may also include other forms of utterances generated by the human speech system (e.g. singing). In an embodiment, the voice detector unit is adapted to classify a current acoustic environment of the user as a VOICE or NO-VOICE environment. This has the advantage that time segments of the electric microphone signal comprising human utterances (e.g. speech) in the user's environment can be identified, and thus separated from time segments only comprising other sound sources (e.g. artificially generated noise). In an embodiment, the voice detector is adapted to detect as a VOICE also the user's own voice. Alternatively, the voice detector is adapted to exclude a user's own voice from the detection of a VOICE. In an embodiment, the hearing device comprises a noise level detector.
[0049] In an embodiment, the hearing device comprises an own voice detector for detecting whether a given input sound (e.g. a voice) originates from the voice of the user of the system. In an embodiment, the microphone system of the hearing device is adapted to be able to differentiate between a user's own voice and another person's voice and possibly from NON-voice sounds.
[0050] In an embodiment, the hearing device comprises an acoustic (and/or mechanical) feedback suppression system, e.g. an adaptive feedback cancellation system having has the ability to track feedback path changes over time.
[0051] In an embodiment, the hearing device further comprises other relevant functionality for the application in question, e.g. level compression, noise reduction, etc.
[0052] In an embodiment, the hearing device comprises a listening device, e.g. a hearing aid, e.g. a hearing instrument, e.g. a hearing instrument adapted for being located at the ear or fully or partially in the ear canal of or to be fully or partially implanted in the head of a user, a headset, an earphone, an ear protection device or a combination thereof.
[0053] In an embodiment, the functional components of the hearing device according to the present disclosure are enclosed in a single device e.g. a hearing instrument. In an embodiment, functional components of the hearing device according to the present disclosure are enclosed in a several separate devices (e.g. two or more). In an embodiment, the several (preferably portable) separate devices are adapted to be in wired or wireless communication with each other. In an embodiment, at least a part of the processing related to sound separation is performed in a separate (auxiliary) device, e.g. a portable device, e.g. a remote control device, e.g. a cellular telephone, e.g. a SmartPhone.
Use:
[0054] In an aspect, use of a hearing device as described above, in the ‘detailed description of embodiments’ and in the claims, is moreover provided. In an embodiment, use is provided in a system comprising one or more hearing instruments, headsets, ear phones, active ear protection systems, etc., e.g. in handsfree telephone systems, teleconferencing systems, public address systems, karaoke systems, classroom amplification systems, etc.
A Method:
[0055] In an aspect, a method of separating sound sources in a multi-sound-source environment is furthermore provided by the present application. The method comprises
providing a time varying electric input signal representing an audio signal comprising at least two sound sources, providing a cyclic analysis buffer unit of length A adapted for storing the last A audio samples, and providing a cyclic synthesis buffer unit of length L, where L is smaller than A, adapted for storing the last L audio samples, which are intended to be separated in individual sound sources, providing a database having stored recorded sound examples from said at least two sound sources, each entry (recorded sound example) in the database being termed an atom, the atoms originating from audio samples from first and second buffers corresponding in size to said synthesis and analysis buffer units, where for each atom, the audio samples from the first buffer overlaps with the audio samples from the second buffer, and where atoms originating from the first buffer constitute a reconstruction dictionary, and where atoms originating from the second buffer constitute an analysis dictionary, and separating said electric input signal to provide separated signals representing said at least two sound sources by determining the most optimal representation (W) of the last A audio samples given the atoms in the analysis dictionary of the database, and to generate said separated signals by combining atoms in the synthesis (reconstruction) dictionary of the database using the optimal representation (W).
[0061] It is intended that some or all of the structural features of the device described above, in the ‘detailed description of embodiments’ or in the claims can be combined with embodiments of the method, when appropriately substituted by a corresponding process and vice versa. Embodiments of the method have the same advantages as the corresponding devices.
[0062] In order to obtain low algorithmic latency, the method (algorithm) is applied on relatively short incoming data frames (synthesis frames), whilst the filter weights are established by examining relatively longer previous temporal context (analysis frames). Since two different frame sizes are used to gather time-domain data for processing, two different atom lengths exist across the coupled dictionaries used in the additive (compositional) model. For each source, a separate dictionary for the purposes of analysis and reconstruction, respectively, is therefore created.
[0063] An incoming audio mixture signal is analyzed and processed in a frame-based manner, e.g. with feature vectors derived from each time domain frame. Separation is performed by representing feature vectors with a compositional model, where the atoms in each dictionary sum non-negatively to approximate the spectral features of the sources within the mixture. Individual dictionary atoms therefore have the same dimensions as the feature vectors formed from the mixture signal, which are either analyzed or filtered in terms of the dictionary contents.
[0064] The present disclosure further relates to a method of creating a database comprising separate coupled analysis and reconstruction dictionaries for each of the sound sources to be separated.
A Computer Readable Medium:
[0065] In an aspect, a tangible computer-readable medium storing a computer program comprising program code means for causing a data processing system to perform at least some (such as a majority or all) of the steps of the method described above, in the ‘detailed description of embodiments’ and in the claims, when said computer program is executed on the data processing system, is furthermore provided by the present application.
[0066] By way of example, and not limitation, such tangible computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. In addition to being stored on a tangible medium, the computer program can also be transmitted via a transmission medium such as a wired or wireless link or a network, e.g. the Internet, and loaded into a data processing system for being executed at a location different from that of the tangible medium. Such activity is also intended to be covered by the present disclosure and claims.
A Data Processing System:
[0067] In an aspect, a data processing system comprising a processor and program code means for causing the processor to perform at least some (such as a majority or all) of the steps of the method described above, in the ‘detailed description of embodiments’ and in the claims is furthermore provided by the present application.
A Hearing System:
[0068] In a further aspect, a hearing system comprising a hearing device as described above, in the ‘detailed description of embodiments’, and in the claims, AND an auxiliary device is moreover provided.
[0069] In an embodiment, the system is adapted to establish a communication link between the hearing device and the auxiliary device to provide that information (e.g. data, such as control and/or status signals, intermediate results, and/or audio signals) can be exchanged between them or forwarded from one to the other.
[0070] In an embodiment, the communication link is a link based on near-field communication, e.g. an inductive link based on an inductive coupling between antenna coils of transmitter and receiver parts. In another embodiment, the wireless link is based on far-field, electromagnetic radiation. In an embodiment, the communication via the wireless link is arranged according to a specific modulation scheme, e.g. an analogue modulation scheme, such as FM (frequency modulation) or AM (amplitude modulation) or PM (phase modulation), or a digital modulation scheme, such as ASK (amplitude shift keying), e.g. On-Off keying, FSK (frequency shift keying), PSK (phase shift keying) or QAM (quadrature amplitude modulation). Preferably, frequencies used to establish a communication link between the hearing device and the other device is below 70 GHz, e.g. located in a range from 50 MHz to 50 GHz, e.g. above 300 MHz, e.g. in an ISM range above 300 MHz, e.g. in the 900 MHz range or in the 2.4 GHz range or in the 5.8 GHz range or in the 60 GHz range (ISM=Industrial, Scientific and Medical, such standardized ranges being e.g. defined by the International Telecommunication Union, ITU). In an embodiment, the wireless link is based on a standardized or proprietary technology. In an embodiment, the wireless link is based on Bluetooth technology (e.g. Bluetooth Low-Energy technology).
[0071] In an embodiment, the auxiliary device is or comprises an audio gateway device adapted for receiving a multitude of audio signals and adapted for allowing the selection of an appropriate one of the received audio signals (or a combination of selected signals) for transmission to the hearing device. In an embodiment, the auxiliary device is or comprises a remote control for controlling functionality and operation of the hearing device(s). In an embodiment, the function of a remote control is implemented in a SmartPhone, the SmartPhone possibly running an APP allowing to control the functionality of the audio processing device via the SmartPhone (the hearing device(s) comprising an appropriate wireless interface to the SmartPhone, e.g. based on Bluetooth or some other standardized or proprietary scheme).
[0072] In an embodiment, the auxiliary device is or comprises another hearing device. In an embodiment, the auxiliary device is or comprises a hearing device as described above, in the detailed description of embodiments and in the claims. In an embodiment, the hearing system comprises two hearing devices adapted to implement a binaural hearing system, e.g. a binaural hearing aid system.
DEFINITIONS
[0073] In the present context, a ‘hearing device’ refers to a device, such as e.g. a hearing instrument or an active ear-protection device or other audio processing device, which is adapted to improve, augment and/or protect the hearing capability of a user by receiving acoustic signals from the user's surroundings, generating corresponding audio signals, possibly modifying the audio signals and providing the possibly modified audio signals as audible signals to at least one of the user's ears. A ‘hearing device’ further refers to a device such as an earphone or a headset adapted to receive audio signals electronically, possibly modifying the audio signals and providing the possibly modified audio signals as audible signals to at least one of the user's ears. Such audible signals may e.g. be provided in the form of acoustic signals radiated into the user's outer ears, acoustic signals transferred as mechanical vibrations to the user's inner ears through the bone structure of the user's head and/or through parts of the middle ear as well as electric signals transferred directly or indirectly to the cochlear nerve of the user.
[0074] The hearing device may be configured to be worn in any known way, e.g. as a unit arranged behind the ear with a tube leading radiated acoustic signals into the ear canal or with a loudspeaker arranged close to or in the ear canal, as a unit entirely or partly arranged in the pinna and/or in the ear canal, as a unit attached to a fixture implanted into the skull bone, as an entirely or partly implanted unit, etc. The hearing device may comprise a single unit or several units communicating electronically with each other.
[0075] More generally, a hearing device comprises an input transducer for receiving an acoustic signal from a user's surroundings and providing a corresponding input audio signal and/or a receiver for electronically (i.e. wired or wirelessly) receiving an input audio signal, a signal processing circuit for processing the input audio signal and an output means for providing an audible signal to the user in dependence on the processed audio signal. In some hearing devices, an amplifier may constitute the signal processing circuit. In some hearing devices, the output means may comprise an output transducer, such as e.g. a loudspeaker for providing an air-borne acoustic signal or a vibrator for providing a structure-borne or liquid-borne acoustic signal. In some hearing devices, the output means may comprise one or more output electrodes for providing electric signals.
[0076] In some hearing devices, the vibrator may be adapted to provide a structure-borne acoustic signal transcutaneously or percutaneously to the skull bone. In some hearing devices, the vibrator may be implanted in the middle ear and/or in the inner ear. In some hearing devices, the vibrator may be adapted to provide a structure-borne acoustic signal to a middle-ear bone and/or to the cochlea. In some hearing devices, the vibrator may be adapted to provide a liquid-borne acoustic signal to the cochlear liquid, e.g. through the oval window. In some hearing devices, the output electrodes may be implanted in the cochlea or on the inside of the skull bone and may be adapted to provide the electric signals to the hair cells of the cochlea, to one or more hearing nerves, to the auditory cortex and/or to other parts of the cerebral cortex.
[0077] A ‘hearing system’ refers to a system comprising one or two hearing devices, and a ‘binaural hearing system’ refers to a system comprising one or two hearing devices and being adapted to cooperatively provide audible signals to both of the user's ears. Hearing systems or binaural hearing systems may further comprise ‘auxiliary devices’, which communicate with the hearing devices and affect and/or benefit from the function of the hearing devices. Auxiliary devices may be e.g. remote controls, audio gateway devices, mobile phones, public-address systems, car audio systems or music players. Hearing devices, hearing systems or binaural hearing systems may e.g. be used for compensating for a hearing-impaired person's loss of hearing capability, augmenting or protecting a normal-hearing person's hearing capability and/or conveying electronic audio signals to a person.
BRIEF DESCRIPTION OF DRAWINGS
[0078] The aspects of the disclosure may be best understood from the following detailed description taken in conjunction with the accompanying figures. The figures are schematic and simplified for clarity, and they just show details to improve the understanding of the claims, while other details are left out. Throughout, the same reference numerals are used for identical or corresponding parts. The individual features of each aspect may each be combined with any or all features of the other aspects. These and other aspects, features and/or technical effect will be apparent from and elucidated with reference to the illustrations described hereinafter in which:
[0079] FIGS. 1A-1B schematically show the mixing of two audio sources to a common sound field that is picked up by a microphone and converted to an electrical, digitized signal and stored in two buffers (a t , s t ), where the a t buffer is at least as long as the s t buffer ( FIG. 1A ), and the principle of acoustic source separation with two sources (e.g. voices) based on pre-learned analysis and synthesis (reconstruction) dictionaries according to the present disclosure for each source. ( FIG. 1B ),
[0080] FIG. 2 schematically shows an embodiment of the learning process part of a source separation scheme according to the present disclosure,
[0081] FIGS. 3A-3C schematically illustrate three embodiments of coupled dictionaries (or database) according to the present disclosure, FIG. 3A showing an embodiment where the atoms are in the time domain, FIG. 3B showing an embodiment where the atoms are in the time-frequency domain, and FIG. 3C showing an embodiment, where the atoms of the coupled dictionaries are partly in the time domain and partly in the time-frequency domain,
[0082] FIG. 4 shows the analysis part of the source separation procedure according to an embodiment of the present disclosure,
[0083] FIGS. 5A-5D schematically illustrate four embodiments ( FIG. 5A , FIG. 5B , FIG. 5C and FIG. 5D ) of a hearing device (or a hearing system) according to the present disclosure,
[0084] FIG. 6 shows an embodiment of a binaural hearing system according to the present disclosure, where two hearing devices exchange input, intermediate, and outputs signals as part of a binaural separation algorithm, and
[0085] FIG. 7 shows an embodiment of hearing system according to the present disclosure comprising two hearing devices and an auxiliary device, wherein the auxiliary device comprises a user interface.
[0086] The figures are schematic and simplified for clarity, and they just show details which are essential to the understanding of the disclosure, while other details are left out. Throughout, the same reference signs are used for identical or corresponding parts.
[0087] Further scope of applicability of the present disclosure will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the disclosure, are given by way of illustration only. Other embodiments may become apparent to those skilled in the art from the following detailed description.
DETAILED DESCRIPTION OF EMBODIMENTS
[0088] The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. Several aspects of the apparatus and methods are described by various blocks, functional units, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as “elements”). Depending upon particular application, design constraints or other reasons, these elements may be implemented using electronic hardware, computer program, or any combination thereof.
[0089] The electronic hardware may include microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. The term ‘computer program’ shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.
[0090] Sound source separation through approximation using linear models has been shown to be effective, see e.g. references [1]-[5]. The spectral magnitude of a mixture is approximated through weighted summation of components, which are stored within pre-trained dictionaries, each modeling a specific sound source, with the contributions from each dictionary being used to produce a Wiener filter which is applied to the mixture spectrogram to isolate that source.
[0091] Assume a collection of N dictionaries, were each individual dictionary models the characteristics of a given sound source, e.g. dictionaries for a number of known voices. The dictionary for source n consist of K n atoms d k n , with k as the atom number within the dictionary. Each atom d k n can be a consecutive number of sound (audio) samples, the frequency domain representation of the same consecutive number of sound samples, or the time frequency domain representation of the same consecutive number of sound samples. The values can be real for sound samples and time frequency representations as well as complex values for time frequency representations. The atoms d k n are termed a ndi and s ndi in connection with the description of FIG. 2, 3 below (where n is the source index, as above, and i is the atom number (corresponding to k in d k n )).
[0092] Consider the case where an observation of consecutive audio samples x contains sounds originating from one or more sources for which the individual dictionaries have been trained. The observation is modelled as a weighted summation of the atoms in the database.
[0093] The frame is modelled as a sum of dictionary ‘atoms’ d k n the frequency representations of known examples of that sound source d k n , such that the non-negative weights w k n of the atoms d k n are estimated in the below equation (1) defining an exemplary compositional model:
[0000]
x
^
=
∑
n
=
1
N
x
^
n
=
∑
n
=
1
N
∑
k
=
1
K
n
w
n
k
d
n
k
Eq
.
(
1
)
[0094] The separation is achieved by finding the optimal weights w n k , for all atoms of the database followed and reconstructing each source as the weighted sum of atoms corresponding to that source. The weights estimation is performed by minimizing a cost function, this could be the Kullback-Leibler (KL) divergence between the observation x and the estimation {circumflex over (x)}, and furthermore the cost function could include sparsity constraints within source dictionaries and between source dictionaries.
[0095] Finally, Switching to matrix notation Equation (1) can be rewritten as:
[0000] ĉ=Dw Eq. (2)
[0000] where the dictionaries matrix D is partitioned
[0000] D=[D 1 D 2 . . . D N ] Eq. (3)
[0000] with D n containing atoms trained on source n. The weights pertaining to each source are notated w n , and the model can be described as:
[0000]
x
^
=
[
D
1
D
2
…
D
N
]
[
w
1
w
2
…
w
N
]
Eq
.
(
4
)
[0096] Sources are separated using the above compositional model (e.g. Eq. (1)) in the following way. If the complex-valued observation vector to be separated is y, then the separated contribution of the source n, s n is extracted directly from atoms or by filtering
[0000]
s
n
=
D
n
w
n
or
s
n
=
y
⊗
D
n
w
n
∑
n
=
1
N
D
n
w
n
Eq
.
(
5
)
[0000] using the appropriate dictionary and weights in the numerator of Equation 5 (the symbol ‘{circle around (×)}’ denoting convolution). The later, operation can be considered a Wiener filter in the frequency domain, and the optional normalization ensures that reconstructed source estimates sum to the original mixture.
[0097] For low-latency systems, the time-delay between audio samples being available for processing and being output as audio should be as low as possible. In frame-based processing schemes, a whole frame of data must be collected and stored before it can be processed for output. We refer to the theoretical minimal delay between a sample incoming into the algorithm and being processed and available for output as ‘algorithmic latency’, T a , whereas the actual processing time can be called ‘computational latency’, T c . The overall achievable latency T is the sum of these values:
[0000] T=T a +T c Eq. (6)
[0098] We consider only the constraints of realizing low algorithmic latency, since depending on the parameters of a particular processing scheme, hardware etc., time latency is non-deterministic.
[0099] Since synthesis frames are processed in a block-based manner, a whole frame of input must be captured before the first sample can be output. From a purely algorithmic perspective, sample output can occur as soon as a frame has been processed, regardless of frame overlap. The algorithmic latency of such an approach is therefore the synthesis frame length. Practically, any processing overhead adds to the actual minimal latency.
[0100] Computational complexity is reduced for non-overlapping frames, but this can result in discontinuities between the last sample of one output frame and the first sample of the next. Greater overlap provides more information which should provide better separation quality than non-overlapping frames.
[0101] In an embodiment, a windowing function, e.g. Hanning window, has preferably been applied prior to any Fourier transform, e.g. Discrete Fourier Transform (DFT), on all vectors (a and s) to provide temporal smoothing and adjust the amount of frequency overlap. This is omitted from the rest of the description for clarity.
[0102] In order to obtain low algorithmic latency, the algorithm is applied on short incoming data frames, whilst the filter weights are established by examining longer previous temporal context. Since two different frame sizes are used to gather time-domain data for processing, two different atom lengths exist (see e.g. s di and a di , respectively, in FIG. 3 ) across the coupled dictionaries used in the additive model. For each source, a separate dictionary for the purposes of analysis and reconstruction is therefore created.
[0103] An incoming audio mixture signal is analyzed and processed in a frame-based manner, with feature vectors derived from each time domain frame. Separation is performed by representing feature vectors with a compositional model, where the atoms in each dictionary sum non-negatively to approximate the spectral features of the sources within the mixture. Individual dictionary atoms therefore have the same dimensions as the feature vectors formed from the mixture signal, which are either analyzed or filtered in terms of the dictionary contents.
[0104] For clarity, time domain frame lengths and feature vectors derived from them are defined in the following (in general, variables are summarized in the Symbols table at the end of the description). We refer to the frame data, which are processed for the purposes of separated source reconstruction as the synthesis frame s t of length L. An analysis buffer a t of previous incoming audio samples, length A, is maintained (where A>L) and referred to as the ‘analysis frame’. The temporal context from which the filters to be applied to the processing frame can be derived from the analysis buffer. Furthermore, either or both analysis and synthesis buffers can be further subdivided.
[0105] In an embodiment, the analysis feature vector, y, is formed from a t by taking the absolute value of the DFT (see |DFT| in FIG. 2 ) of analysis sub-frames of length L with 50% overlap, and concatenating the resulting (2(A/L)−1) sub-frame outputs into a single feature vector. The vector effectively describes the magnitude of frequencies present during the past A audio samples (see FIG. 2 ). The same size of s t and sub-frames in a t is assumed for clarity. The sub-frames in a t do indeed not need to have same length as s t . The complex-valued frequency-domain synthesis vector s is formed by taking only the positive frequencies of the DFT result of real-valued data in s t , and so has length (L/2)+1. s is filtered at each frame output to produce the separated source estimates (see s 1 and s 2 in FIG. 1B ).
[0106] For additive model based separation, a dictionary of atoms is typically learned for each speaker in the mixture (see DIC-S 1 and DIC-S 2 in FIG. 1B ). The use of coupled dictionaries for each talker is proposed in the present disclosure (see FIG. 3 ), whereby a dictionary of longer analysis atoms (a di , i=1, 2, . . . , N D , in FIG. 3 ) is produced alongside a dictionary of shorter synthesis atoms (s di , i=1, 2, . . . , N D , in FIG. 3 ) for source reconstruction.
[0107] Explicitly, in a 2 -talker mixture model, one dictionary A for analysis and one dictionary R for reconstruction may advantageously be used. Each dictionary comprises talker-specific regions as indicated in Equation 3. The portion of a dictionary trained on source n is notated by the subscript n, e.g. A n , and thus:
[0000] A=[A 1 A 2 ] Eq. (7)
[0000] and
[0000] R=[R 1 R 2 ] Eq. (8)
[0108] The k th atom in each dictionary is coupled to the atom at the same index in the alternate dictionary (cf. e.g. dotted lines from s di to a di in FIG. 3 ), as indicated by the following expression,
[0000] R :,k A :,k Eq. (9)
[0000] by the fact that each was obtained from similar portions of training data (where the analysis atoms a di are taken from a longer previous context than synthesis atoms s di ). The notation R :,k (A :,k ) is intended to refer to the k th column of dictionary R (A).
[0109] The actual dictionary atom creation process is similar to that of feature vector creation depicted in FIG. 2 . Analysis dictionary atoms are obtained by the same processing as to produce feature vector y. Reconstruction dictionary atoms are created similarly to s, except that the real-valued absolute value of the DFT result is stored, as opposed to the complex-valued result present in each s.
[0110] Atoms in A are formed from time domain data of length A whilst L audio samples are used to form atoms in reconstruction dictionary R. The atoms in A are used to estimate the weights applied to atoms in R, in order to form the frequency-domain Wiener filters applied to the complex-valued synthesis frame s (see filter unit S-FIL in FIG. 1B ).
[0111] Analysis is performed by learning the weights w which minimize KL-divergence between analysis vector y and a weighted sum of atoms from dictionary A (Equation 10).
[0000]
min
d
f
(
d
)
=
KL
(
Y
Aw
)
Eq
.
(
10
)
[0112] In an embodiment, the Active-Set Newton Algorithm (ASNA) algorithm is employed (cf. e.g. [6, 7]) to find the optimal solution due to its rapid computation time and guaranteed convergence, although NMF-based approaches could equally well be used, and may offer speed advantages on GPU-based processor architectures.
[0113] The learned weights w are applied to the corresponding coupled dictionary atoms in dictionary R to form the reconstruction Wiener filters. Filters are applied to the synthesis vector s at each frame processing step so that for each synthesis frame the n th separated source is reconstructed:
[0000]
s
n
=
s
⊗
R
n
w
n
Σ
n
R
n
w
n
Eq
.
(
11
)
[0114] The separated time-domain sources are reconstructed by generating complex conjugates of Sn and performing the inverse DFT for each frame to be overlap-add and reconstructed into a continuous time output.
[0115] FIGS. 1A-1B illustrates the environmental mixing (mix) in FIG. 1A of two audio sources S 1 , S 2 to a common sound field that is picked up by a microphone (or a microphone system, e.g. a microphone array) and converted to an electrical, digitized signal and stored in two buffers where the analysis buffer (a t ) is at least as long as the synthesis buffer (s t ) ( FIG. 1A ). In FIG. 1B the principle of acoustic source separation with two sound sources (e.g. two voices) S 1 , S 2 based on pre-learned analysis and synthesis (reconstruction) dictionaries DIC-S 1 , and DIC-S 2 according to the present disclosure for each source S 1 , and S 2 , respectively.
[0116] In FIG. 1A , the mixture of sound sources S 1 , S 2 is represented by sound signal IN, which is picked up by input transducer (here microphone) MIC. The analogue electric input signal is sampled with a predefined sampling frequency f s , e.g. 20 kHz, in analogue to digital converter AD providing digital audio samples to cyclic analysis and synthesis buffers BUF as relatively longer analysis frame a t (comprising A audio samples) and relatively shorter synthesis buffer s t (comprising L<A audio samples). The resulting digitized electric input signal x at time instance t n is denoted x(t n ) in— FIGS. 1A-1B .
[0117] In FIG. 1B , the digitized electric output signals of analysis and synthesis buffers a t and s t , signals a(t n ) and s(t n ), respectively, are fed to a sound source separation unit (SSU) for separating the electric input signal s(t n ) to provide separated signals (s 1 , s 2 ) representing the two sound sources (S 1 , S 2 ). The sound source separation unit (SSU) is configured to determine the most optimal representation (W) of the last A audio samples given the atoms in the analysis dictionaries (A 1 , A 2 ) of the database (DATABASE), and to generate the at least two sound source signals (s 1 , s 2 ) by combining atoms in the respective synthesis (reconstruction) dictionaries (R 1 , R 2 ) of the database (DATABASE) using the optimal representation (W) determined from the analysis dictionaries (A 1 , A 2 ). The sound source separation unit (SSU) comprises synthesis filter (S-FIL) for generating the two separated sound source signals (s 1 , s 2 ) from the electric inputs signal s(t n ) using filter weights (w i ) provided by filter update unit (FIL-UPD). The forwarding of the last L input audio samples to S-FIL is optional, but enables the S-FIL unit to compare the separated output with the current input.
[0118] The arrows from DIC-S 1 , DIC-S 2 to the filter update unit (FIL-UPD) is intended to indicate the transfer of the analysis and synthesis atoms from source dictionaries DIC-S 1 , DIC-S 2 to the filter update unit. The analysis atoms are used (in the filter update unit) for finding the weights. The weights are used with the corresponding synthesis atoms and delivered to filter unit (S-FIL) to generate source separated signals (s 1 , s 2 ).
[0119] FIG. 2 shows an embodiment of the learning process part of a source separation scheme according to the present disclosure. The source separation scheme is based on a compositional model (cf. e.g. eq. (1)) and coupled dictionaries (R 1 , A 1 ) comprising basic elements of each sound source to be separated (e.g. speech from different persons), e.g. in the form of spectral feature vectors for the sound sources in question. In FIG. 2 , the generation of analysis and synthesis (reconstruction) dictionaries (A 1 , R 1 ) for sound source S 1 is illustrated. The contents of a specific synthesis frame s 1D (t n ) (here taken at time t n , but it is the contents of the time frame that matters, not its tome index) is transformed into the frequency domain by DFT-unit (DFT) providing frequency domain atom s 1D (f,t n ), e.g. s 1di in the synthesis (reconstruction) dictionary R 1 (see e.g. FIG. 3B ). Likewise, the contents of a specific analysis frame a 1D (t n ) (here represented by overlapping sub-frames a 11D (t n ), a 12D (t n ), a 13D (t n )) is transformed into the frequency domain by respective DFT-units (|DFT|) and combined by combination unit COMB to frequency domain atom a 1D (f,t n ), e.g. a 1di in the analysis dictionary A 1 (see e.g. FIG. 3B ).
[0120] FIG. 2 illustrates an embodiment of the learning process of the analysis and synthesis buffers according to the present disclosure. No source separation takes place in FIG. 2 . The learning procedure is preferably performed prior to normal use of the hearing device. The element number (across the dictionary atoms (s 1d1 , s 1d2 , . . . , s 1dnD1 ) and (a 1d1 , a 2d2 , . . . , a 1dnD1 ) in each database, over ‘atom-index’ i=1, 2, . . . , ND 1 , where ND 1 is the number of (coupled) atoms in dictionaries A 1 , R 1 for sound source S 1 ) do not imply a time dependency. In a further step (not shown) ‘K-means’ or other data reduction methods (cluster analysis) are applied to elements in the database.
[0121] The length L of the synthesis buffer s t is shown to be, but does not need to be identical to the length of the overlapping sub-frames a 11D , a 12D , a 13D of the analysis buffer. It is preferable with a certain overlap between the sub-frames to minimize artifacts from one frame to the next (when spectral analysis form part of the source separation). In the example shown in FIG. 2 , three individual frames of length L audio samples have a 50% overlap with each of its neighbouring frames in the analysis buffer.
[0122] Without loss of generality it is also possible to subdivide the synthesis buffer into overlapping frames in a similar manner to the analysis buffer.
[0123] When the synthesis frame is shorter than, say 20 ms, it is further expected that an improvement in performance of the source separation is achieved through use of an analysis frame which is longer than the synthesis frame. In general, using larger dictionaries produces better separation performance than shorter frames, as does using longer reconstruction windows. Where an advantage is gained by use of a longer analysis frame than synthesis frame, the level of improvement reduces as the analysis frame becomes significantly longer than the synthesis frame. For a particular synthesis window length, greatest performance increases are generally achieved when the analysis window is 2-4 times longer.
[0124] It is the insight of the present inventors that the use of two dictionaries (A, R) pr. source reduces the delay of the separation procedure. Previous methods (e.g. Virtanen et al., references [6]+[7]) only used one dictionary pr. source and thus could not achieve the same quality with same short delay below, say 20 ms.
[0125] FIGS. 3A-3C illustrates three embodiments of coupled dictionaries (DATABASE) according to the present disclosure. The coupling between analysis atoms a di and synthesis atoms s di having the same index i is indicated by the dotted vertical lines (indicated between analysis atoms a di and synthesis atoms s di , for i=1, 2, and N Dt /N Df /N Dft ).
[0126] FIG. 3A shows an embodiment where the atoms of the two dictionaries (A, R) are all in the time domain. The synthesis (reconstruction) dictionary R consists of N Dt synthesis atoms s di , consisting of time domain frames of length L audio samples. Three examples of synthesis atoms s di , (i=1, 2, N Dt ) are shown in the top part of the drawing. The analysis dictionary A consists of N Dt synthesis atoms a di , consisting of time domain frames of length A audio samples. Three examples of analysis atoms a di , (i=1, 2, N Dt ) are shown in the bottom part of the drawing.
[0127] FIG. 3B shows an embodiment where the atoms of the two dictionaries (A, R) are all in the time-frequency domain. The synthesis (reconstruction) dictionary R consists of N Df synthesis atoms s di , each consisting of a frequency domain spectrum of length N s (N s frequency bands). The analysis dictionary A consists of N Df analysis atoms a di , each consisting of a frequency domain spectrum of length N a (N a frequency bands, e.g. corresponding to the spectra of a number of consecutive time frames, e.g. A/L).
[0128] FIG. 3C shows an embodiment, where the atoms of the coupled dictionaries are partly in the time domain (synthesis (reconstruction) dictionary R) and partly in the time-frequency domain (analysis dictionary A). The synthesis (reconstruction) dictionary R consists of N Dft synthesis atoms s di , consisting of time domain frames of length L audio samples. Three examples of synthesis atoms s di , (i=1, 2, N Dt ) are shown in the top part of the drawing. The analysis dictionary A consists of N Df analysis atoms a di , each consisting of a frequency domain spectrum of length N a (N a frequency bands, e.g. corresponding to the spectra of a number of consecutive time frames, e.g. A/L).
[0129] In a further embodiment (not illustrated), the atoms of the coupled dictionaries are again partly in the time-frequency domain (synthesis (reconstruction) dictionary R) and partly in the time domain (analysis dictionary A).
[0130] FIG. 4 schematically illustrates the analysis part of the source separation procedure according to an embodiment of the present disclosure.
[0131] FIG. 4 illustrates time varying digitized incoming audio (Input audio signal) and the corresponding contents of analysis and synthesis frames a t and s t , respectively, at times t and t+H audio samples.
[0132] The method separates the audio contained in the synthesis frame s t each time step in different sound sources (see FIG. 1B ), based on the data stored in analysis frame a t . At each update, the latest H audio samples are loaded into the cyclic analysis buffer (a t+H ), and the oldest H audio samples discarded. In an embodiment, the buffer contents is then transformed into the frequency domain for separation (as illustrated in FIG. 2 for the generation of dictionaries).
[0133] Separation is performed by modelling the contents of the buffer at each update (e.g. every H audio samples) as an additive sum of components (the absolute magnitude of frequencies present in the analysis frame), which are stored in pre-computed dictionaries, such as in the well established DNN, FHMM, NMF and ASNA approaches (cf. FIG. 2, 3 ).
[0134] FIGS. 5A-5D schematically illustrates four embodiments of a hearing device (or a hearing system) according to the present disclosure.
[0135] FIG. 5A shows an embodiment of a hearing device (HD) comprising an input unit (IU) for receiving an input sound signal comprising a multitude N of sound sources S 1 , S 2 , . . . , S N and providing a digitized electric input signal x representing a mixed sound signal. The hearing device (HD) comprises a sound source separation unit (SSU) for separating input signal x in a multitude of separated signals (s 1 , s 2 , . . . , s N ) as described in connection with FIG. 1-4 . The hearing device (HD) also comprises a signal processing unit (SPU) for processing one or more of the separated signals (s 1 , s 2 , . . . , s N ), e.g. for generating further improved versions thereof, e.g. by applying noise reduction or other processing algorithms to the separated signals, or mixing two or more of them in an appropriate ratio. In an embodiment, the signal processing unit (SPU) is configured to present the user with one or more of the separated signals (s 1 , s 2 , . . . , s N ) consecutively, so that information from only a single source s i (e.g. a talker) is presented at a time. The processed output signal u is fed to output unit OU for generating output stimuli perceivable by a user as sound (symbolized by bold arrow and signal OUT). In an alternative embodiment, one or more, such as a majority or all, of the separated signals (s 1 , s 2 , . . . , s N ) are presented to a user (or to separate users in parallel, e.g. one user for each source) via separate output transducers.
[0136] FIG. 5B shows an embodiment of a hearing device (HD) as in FIG. 5A but where the input unit (IU) provides to electric input signals x 1 and x 2 (e.g. from two input transducers), each comprising a mixture of a multitude of audio sources S 1 , S 2 , . . . , S N . The embodiment of FIG. 5B comprises first and second sound source separation units (SSU 1 , SSU 2 ) sharing a common DATABASE, the first and second sound separation units being configured to separate input signals x 1 and x 2 in separated signals (s 11 , s 12 , . . . , s 1N ) and (s 21 , s 22 , . . . , s 2N ), respectively. The separated signals are fed to a beamformer unit providing a directional signal DIR from at least some of the separated signals. The directional signal DIR is connected to the signal processing unit (SPU) for further processing, e.g. for applying a level and/or frequency dependent gain according to the needs of a user, or as described in connection with FIG. 5A . The embodiment of FIG. 5B comprises further comprises antenna and transceiver circuitry Rx/Tx for communicating with an auxiliary device AD via wireless link WL-RF (see also FIG. 7 ). The hearing device HD is configured to transfer one or more of the separated signals (s 11 , s 12 , . . . , s 1N ) and (s 21 , s 22 , . . . , s 2N ) and one or more directional signal(s)(symbolized by signals src and dir, respectively, and accompanying grey arrows) to the auxiliary device AD via the wireless link WL-RF. The auxiliary device is configured to receive the signals e.g. for further processing and/or display. In an embodiment, the auxiliary device is or form part of a cellular telephone, e.g. a SmartPhone (cf. e.g. FIG. 7 ).
[0137] FIG. 5C shows another embodiment of a hearing device (HD), wherein the input unit IU provides a multitude M of electric input signals x 1 , x 2 , . . . , x M (e.g. from M input transducers). The input signals are coupled to a beamformer unit BF that provides a directional signal DIR, which is fed to sound source separation unit (SSU) for separating directional signal DIR in a multitude of separated signals (s 1 , s 2 , . . . , s N ) as described in connection with FIG. 1-4 . The separated signals are fed to signal processing unit (SPU) for further processing and output, e.g. as described in connection with FIG. 5A or 5C . The hearing device (HD) of FIG. 5C further comprises a combined control and transceiver unit CONT-Rx/Tx for controlling and establishing a wireless link WL-RF to auxiliary device AD. As indicated by shaded arrows and signals mic, dir, src, and out, one or more of the electric input signals (x 1 , x 2 , . . . , x M ), the directional signal(s) DIR, the separated signals (s 1 , s 2 , . . . , s N ) and the output signal u may be transmitted to the auxiliary device via the wireless link. Likewise control signals bf and pc for controlling or influencing the beamformer unit BF and the signal processing unit SPU may be generated in the control unit CONT-Rx/Tx or received from the auxiliary device, e.g. via a user interface provided by the auxiliary device AD (cf. FIG. 7 ).
[0138] FIG. 5D shows another embodiment of hearing device comprising a hearing instrument (HI) and an auxiliary device (AD). The auxiliary device (AD) comprises the sound separation functionality. The auxiliary device (AD) comprises input unit (IU) for receiving an input sound signal comprising a multitude N of sound sources (S 1 , S 2 , . . . , S N ) and providing a digitized electric input signal x representing a mixed sound signal. The Auxiliary Device (AD) also comprises sound source separation unit (SSU) for separating input signal x in a multitude of separated signals (s 1 , s 2 , . . . , s N ) as described in connection with FIG. 1-4 . The Auxiliary Device (AD) further comprises a signal processing unit (SPU) for processing one or more of the separated signals (s 1 , s 2 , . . . , s N ), e.g. for generating further improved versions thereof, e.g. by applying noise reduction or other processing algorithms to the separated signals, or mixing two or more of them in an appropriate ratio. The processed output u is transferred to the hearing instrument (HI) over wireless connection WL implemented by corresponding antenna and transceiver circuitry (ANT, Rx/Tx) in the auxiliary device and the hearing instrument. The hearing instrument (HI) is configured to receive the processed output signal u and to present the signal to a user via output unit OU (here loudspeaker SP) as a sound signal OUT. The hearing instrument (HI) is further shown to comprise an optional microphone unit MIC (for picking up an acoustic sound from the environment) and a selection unit SEL for selecting (or mixing) the wirelessly received signal INw from the auxiliary device or the microphone signal INm (in the embodiment of FIG. 5D , the transceiver, microphone, and selection units together form input unit IU-HI). The resulting signal IN from the selection unit is presented to an optional signal processing unit (SPU-HI), and the optionally processed signal u-HI is presented to the user via speaker SP as sound signal OUT. This partition of the functional tasks of sound separation and presentation to a user has the advantage that the tasks requiring a lot of processing (sound separation) is separated from the ear worn hearing instrument (of small size, low energy capacity). The processing demanding tasks are performed in a special device (AD, e.g. a remote control of other hand held device (e.g. a SmartPhone)) having more electric power and processing capacity than the ear worn hearing instrument (HI).
[0139] In a further alternative embodiment (not shown) comprising the same functional parts as the embodiment of FIG. 5D , and having a similar but slightly different partition of tasks, the auxiliary device AD again comprises input unit (IU) for receiving an input sound signal comprising a multitude N of sound sources S 1 , S 2 , . . . , S N , and a (part of the) sound source separation unit (SSU-AD) including the analysis part of the database (A-BUF, and FIL-UPD in the embodiments of FIG. 5A-5D ) for separating the input signal x into a multitude weights (w 1 , w 2 , . . . w N ) defining the separated signals as described in connection with FIG. 1-4 . The hearing instrument, on the other hand comprises another (part of the) source separation unit (SSU-HI) with the synthesis part of the database (unit S-FIL in the embodiments of FIG. 5A-5D ) for reconstructing the multitude of separated signals, and the output unit OU. The weights (w 1 , w 2 , . . . w N ) are transmitted to the hearing instrument HI via wireless link WL and applied to filter unit S-FIL to provide separated signal in the (s 1 , s 2 , . . . , s N ). The corresponding contents of the synthesis buffer may be transmitted from the auxiliary device to the hearing instrument together with the filter weights. Alternatively, the synthesis buffer may be crated in the hearing instrument from a signal picked up by a microphone (MIC) of the input unit (IU-HI in FIG. 5D ). The separated signals may e.g. be further processed in a signal processing unit (SPU-HI in FIG. 5D ) of the hearing instrument as described in connection with other embodiments before presentation to the user via output unit OU of the hearing instrument.
[0140] FIG. 6 shows an embodiment of a binaural hearing system comprising first and second hearing devices (HD- 1 , HD- 2 ) to the present disclosure, where the two hearing devices may exchange input signals, intermediate signals, and output signals as part of a binaural separation algorithm. The first and second hearing devices (HD- 1 , HD- 2 ) may e.g. comprise elements and embodiments as discussed in connection with FIG. 1-5 . The input unit IU of the first and second hearing devices (HD- 1 , HD- 2 ) comprises a microphone MIC for picking up acoustic input aIN comprising a mixture of sound sources S 1 , S 2 , . . . , S N , and providing electric input signal INm, which is fed to a first input of selection or mixing unit SEL. The input unit IU further comprises antenna and wireless transceiver (ANT, Rx/Tx) (at least) for receiving a direct electric signal wIN comprising control and/or audio signals form another device (e.g. a remote control device and/or a cellular telephone), and providing electric input signal INw, which is fed to a second input of selection or mixing unit SEL. Input unit IU provides (as an output from selection or mixing unit SEL) a resulting electric input signal x (x 1 and x 2 in HD- 1 and HD- 2 , respectively). Each of the first and second hearing devices (HD- 1 , HD- 2 ) comprises respective sound separation units (SSU), signal processing units (SPU) and output units (OU), e.g. as discussed in connection with FIG. 5 . Each of the first and second hearing devices (HD- 1 , HD- 2 ) further comprises antenna and transceiver circuitry IA-Rx/Tx for establishing an interaural wireless link IA-WLS between the two devices. As indicated in connection with embodiments of FIGS. 5B and 5C , the first and second hearing devices are configured to exchange input signals, intermediate signals (e.g. sound separated signals, control signals), and output signals (symbolized by signals IAx and double arrowed line between the sound separation units (SSU) and the transceiver units (IA-Rx/Tx) in each of the first and second hearing devices) as part of a binaural separation algorithm to thereby improve binaural processing of audio signals.
[0141] FIG. 7 shows an embodiment of hearing system according to the present disclosure comprising two hearing devices (HD 1 , HD 2 ) and an auxiliary device (AD), wherein the auxiliary device comprises a user interface (UI) for displaying the currently present sources and—if available—the position relative to a user (U) of the currently present sound sources (S 1 , S 2 , S 3 ). In an embodiment, the sound source separation occurs in the auxiliary device. In an embodiment, the sound source localization takes place in the hearing devices. In an embodiment, the two hearing devices and the auxiliary device each comprises one or more microphones. In an embodiment, the two hearing devices and the auxiliary device each comprises antenna and transceiver circuitry allowing the devices to communicate with each other, e.g. to exchange audio and/or control signals. In an embodiment, the auxiliary device is a remote control device for controlling the functionality of the hearing devices. In an embodiment, the auxiliary device AD is a cellular telephone, e.g. a SmartPhone.
[0142] The user interface (UI) is e.g. adapted for viewing and (possibly) influencing the directionality (e.g. the separated source to listen to) of current sound sources (S s ) in the environment of the binaural hearing system.
[0143] The right and left hearing devices (HD 1 , HD 2 ) are e.g. implemented as described in connection with FIG. 1-6 . The first and second hearing devices (HD 1 , HD 2 ) and the auxiliary device (AD) each comprise relevant antenna and transceiver circuitry for establishing wireless communication links between the hearing devices (link IA-WL) as well as between at least one of or each of the assistance devices and the auxiliary device (link WL-RF). The antenna and transceiver circuitry in each of the first and second hearing devices necessary for establishing the two links is denoted RF-IA-RX/Tx- 1 , and RF-IA-RX/Tx- 2 , respectively, in FIG. 7 . Each of the first and second hearing devices (HD 1 , HD 2 ) comprises respective source separation units according to the present disclosure. In an embodiment, the interaural link IA-WL is based on near-field communication (e.g. on inductive coupling), but may alternatively be based on radiated fields (e.g. according to the Bluetooth standard, and/or be based on audio transmission utilizing the Bluetooth Low Energy standard). In an embodiment, the link WL-RF between the auxiliary device and the hearing devices is based on radiated fields (e.g. according to the Bluetooth standard, and/or based on audio transmission utilizing the Bluetooth Low Energy standard), but may alternatively be based on near-field communication (e.g. on inductive coupling). The bandwidth of the links (IA-WL, WL-RF) is preferably adapted to allow sound source signals (or at least parts thereof, e.g. selected frequency bands and/or time segments) and/or localization parameters identifying a current location of a sound source to be transferred between the devices. In an embodiment, processing of the system (e.g. sound source separation) and/or the function of a remote control is fully or partially implemented in the auxiliary device AD. In an embodiment, the user interface UI is implemented by the auxiliary device AD possibly running an APP allowing to control the functionality of the hearing system, e.g. utilizing a display of the auxiliary device AD (e.g. a SmartPhone) to implement a graphical interface (e.g. combined with text entry options).
[0144] In an embodiment, the binaural hearing system is configured to allow a user to select a current sound source which has been determined by the source separation unit for being focused on (e.g. played to the user via the output unit OU of the hearing device or the auxiliary device). As illustrated in the exemplary screen of the auxiliary device in FIG. 7 , a Localization and separation of the sound sources APP is active and the currently identified sound sources (S 1 , S 2 , S 3 ) as defined by sound source separation and beamforming units of the first and second hearing devices are displayed by the user interface (UI) of the auxiliary device (which is convenient for viewing and interaction via a touch sensitive display, when the auxiliary device is held in a hand (Hand) of the user (U)). In the illustrated example in FIG. 7 , the location of the 3 identified sound sources S 1 , S 2 and S 3 (as represented by respective vectors d 1 , d 2 , and d 3 in the indicated orthogonal coordinate system (x, y, z) having its center between the respective first and second hearing devices (HD 1 , HD 2 ) are displayed relative to the user (U).
[0145] It is intended that the structural features of the devices described above, either in the detailed description and/or in the claims, may be combined with steps of the method, when appropriately substituted by a corresponding process.
[0146] As used, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well (i.e. to have the meaning “at least one”), unless expressly stated otherwise. It will be further understood that the terms “includes,” “comprises,” “including,” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will also be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element but an intervening elements may also be present, unless expressly stated otherwise. Furthermore, “connected” or “coupled” as used herein may include wirelessly connected or coupled. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. The steps of any disclosed method is not limited to the exact order stated herein, unless expressly stated otherwise.
[0147] It should be appreciated that reference throughout this specification to “one embodiment” or “an embodiment” or “an aspect” or features included as “may” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. Furthermore, the particular features, structures or characteristics may be combined as suitable in one or more embodiments of the disclosure. The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects.
[0148] The claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Unless specifically stated otherwise, the term “some” refers to one or more.
[0149] Accordingly, the scope should be judged in terms of the claims that follow.
SYMBOLS
[0000]
a t Time-domain analysis frame
s t Time-domain synthesis frame
A Length in samples of a t
L Length in samples of s t
y Real-valued feature vector formed from a t
s Complex-valued synthesis vector formed from s t
A Analysis dictionary
R Reconstruction dictionary
R :;k The k th column of dictionary R.
w Weights vector for a single output frame
s n The reconstructed frame for the n th source in a mixture
n Subscript referring to the n th source in dictionaries, weights, or reconstructed frames.
REFERENCES
[0000]
[1] C. Joder, F. Weninger, F. Eyben, D. Virette and B. Schuller, “Real-Time Speech Separation by Semi-supervised Nonnegative Matrix Factorization,” in Latent Variable Analysis and Signal Separation, Lecture Notes in Computer Science Volume 7191, Springer, 2012, pp. 322-329.
[2] Z. Duan, G. Mysore and P. Smaragdis, “Online PCLA for Real-Time Semi-supervised Source Separation,” in Latent Variable Analysis and Signal Separation, Lecture Notes in Computer Science Volume 7191, Springer, 2012, pp. 34-41.
[3] J. H. Gomez, “Low Latency Audio Source Separation for Speech Enhancement in Cochlear Implants (Master's Thesis),” Universitat Pompeu Fabra, Barcelona, 2012.
[4] R. Marxer, J. Janer and J. Bonada, “Low-Latency Instrument Separation in Polyphonic Music Using Timbre Models,” in Latent Variable Analysis and Signal Separation, Tel Aviv, 2012.
[5] T. Barker, G. Campos, P. Dias, J. Viera, C. Mendonca and J. Santos, “Real-time Auralisation System for Virtual Microphone Positioning,” in Int. Conference on Digital Audio Effects (DAFx-12), York, 2012.
[6] T. Virtanen, J. F. Gemmeke, and B. Raj, “Active-Set Newton Algorithm for Overcomplete Non-Negative Representations of Audio,” IEEE Transactions on Audio, Speech and Language Processing, 2013.
[7] T. Virtanen, B. Raj, J. F. Gemmeke, and H. Van Hamme, “Active-set newton algorithm for non-negative sparse coding of audio,” in In Proc. International Conference on Acoustics, Speech, and Signal Processing, 2014. | The application relates to a hearing device comprising a) an input unit for delivering a time varying electric input signal representing an audio signal comprising at least two sound sources, b) a cyclic analysis buffer unit of length A adapted for storing the last A audio samples, c) a cyclic synthesis buffer unit of length, where L is smaller than A, adapted for storing the last L audio samples, which are intended to be separated in individual sound sources, d) a database having stored recorded sound examples from said at least two sound sources, each entry in the database being termed an atom, the atoms originating from audio samples from first and second buffers corresponding in size to said synthesis and analysis buffer units, where for each atom, the audio samples from the first buffer overlaps with the audio samples from the second buffer, and where atoms originating from the first buffer constitute a reconstruction dictionary, and where atoms originating from the second buffer constitute an analysis dictionary. The application further relates to a method of separating audio sources, and e) a sound source separation unit for separating said electric input signal to provide separated signals representing said at least two sound sources, the sound source separation unit being configured to determine the most optimal representation (W) of the last A samples given the atoms in the analysis dictionary of the database, and to generate said at least two sound sources by combining atoms in the reconstruction dictionary of the database using the optimal representation (W). The invention may e.g. be used for hearing devices, e.g. hearing aids, headsets, ear phones, active ear protection systems, handsfree telephone systems, mobile telephones, teleconferencing systems, public address systems, classroom amplification systems, etc. | 97,629 |
STATEMENT OF THE PRIOR ART
In underwater operations, particularly those involving a diving bell or any similar apparatus, it is necessary to provide by means of cables and hoses (often termed "elements" or "Conduits") all means necessary to support and operate the bell. Furthermore, as a matter of safety it is necessary to provide a backup load bearing line capable of supporting the bell should the primary "down line" break. A conventional way of meeting the aforementioned requirements has been to wrap helically a load bearing member with any necessary elements and then joining same by hand taping them together. This procedure is ineffective because the cables as well as the load bearing member share the load of the bell upon breaking of the down line, thereby stretching and breaking the elements themselves. Moreover, frequent retaping has been required in order to secure the combination of the load bearing member and elements, thereby requiring unnecessary expenditure of time and money.
Another approach has been an attempt to unitize the elements within a protective jacket. Such attempts have been ineffective because once again all the elements are helically wound within the jacket and are subject to supporting the load of the bell upon fracture of the down line. Because these helically arranged elements are cabled under tension, upon release of that tension many of these elements are subject to axial contraction thereby causing "Z kinking," a phenomenon of metal wire wherein the load per unit caused by unloading the wire causes a point displacement resulting in a figure similar to a "Z." Past attempts at unitized marine umbilicals have not allowed for repair of the interior thereof.
Applicant is aware of U.S. Pat. No. 1,880,060 of Sept. 27, 1932 to Wanamaker disclosing a deep sea telephone, life line and diving cable having a centrally disposed wire rope stress member, a cushioning member entirely unlike that of the present invention, a yielding wrapping thereround, the presence of yielding spacer elements as well as the requirement for cables relatively smaller in size to that of the centered life line.
Applicant is also aware of U.S. Pat. Nos. 1,305,247 of June 3, 1919 to Beaver, 3,517,110 of June 23, 1970 to Morgan, 2,910,524 of Oct. 27, 1959 to Schaffhauser which disclose neither apparatus similar to that of the present invention nor propose to solve the problems resolved by the present invention.
SUMMARY OF INVENTION
The present invention relates to a unitized marine umbilical cable able to withstand the tensional impact resulting from a sudden tensional load placed upon the umbilical cable such as that caused by the break of the primary down line while at the same time supplying all necessary elements to, for example, a diving bell, for purposes of life support, television operation, electrical supply and the like. Moreover, the present invention relates to a unitized marine umbilical cable possessing the aforementioned capabilities while retaining sufficient flexibility for disposition around a reel, over a conveyor or sheave, as well as permitting easy repair or replacement of the internal elements thereof.
It is therefore a primary object of the present invention to provide a marine umbilical cable sufficient to withstand the tensional impact of a sinking diving bell and of continued support of the diving bell while reeling it to the surface.
Another object of the present invention is to have a unitized marine umbilical cable carrying not only a stress member but all necessary elements for operation and life support of the diving bell therein.
Yet another object of the present invention is the disposition of a high strength, highly resilient, low durometer elastomer material around the stress member thereby acting as a radial shock absorber against objects radially impacting the umbilical and tensional impact in the vertical part of the marine umbilical which is partially converted into radial impact at those points where the umbilical is substantially horizontal, to-wit, where the umbilical is disposed horizontally over a conveyor or sheave and circularly around a reel.
Still another object of the present invention is helically to dispose a combination of elements around the stress member whereby the stress member carries the entire impact and load of the diving bell thereby preventing the helically cabled elements from unwinding or breaking.
An even further object of the present invention is the extrusion of an exterior polyurethane jacket around the umbilical thereby facilitating easy and economic removal of the jacket for purposes of repair or replacement as necessary of one or more elements therein.
Still further objects of the invention will become apparent in the following specification, drawings, descriptions, and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an environmental view depicting a surface support ship, an underwater diving bell, a primary down line supporting the bell from the surface ship, a marine umbilical cable tethering the diving bell to the surface ship and being slackened relative to the primary down line, a conveyor or sheave for guidingly facilitating the raising or lowering of the marine umbilical cable, a reel means for raising or lowering the umbilical cable, and a separate sheave and reel means for guiding and driving the primary down line not shown in the drawing.
FIG. 2 is an isometric view of the helical exterior embodiment of the invention irrespective of the particular type core.
FIG. 3 is a cross sectional view of FIG. 2 disclosing a diagrammatical representation of a wire rope center stress member, a surrounding low melt temperature high strength plastic jacket compression extruded onto the wire rope, an internal polyurethane jacket extruded onto the plastic jacket, a high strength, highly resilient, low durometer elastomer material compression extruded onto the internal polyurethane jacket, any number of conventional elements helically disposed around the core, a resilient fill material disposed within the internal interstices between the elements and the core, a polyurethane jacket tube extruded onto the exterior of the helically disposed elements and unfilled external interstices between the helically disposed elements and external polyurethane jacket which have been enlarged in the drawing for purposes of description only.
FIG. 4 is a diagrammatical representation of any flexible, high load bearing wire rope, this particular diagram showing by example a 6×36 Warrington Seale with independent wire rope center.
FIG. 5 represents an alternate stress member shown as an aramid fiber.
FIG. 6 is a cross sectional view of a marine umbilical cable having a stress member as shown in FIG. 5, an interior polyurethane jacket extruded onto the stress member, a high strength, highly resilient, low durometer elastomer material compression extruded onto the internal polyurethane jacket, helically disposed elements thereround, a resilient fill material in the internal interstices between the helical elements and the core, a substantially cylindrical exterior polyurethane jacket extruded onto the helically disposed elements and a conforming fill material disposed within the external interstices between the elements and the exterior polyurethane jacket.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
While the embodiments of the marine umbilical cable illustrated in the drawings and described in detail herein are directed for use primarily in maintaining while capable of supporting an underwater device such as but not limited to a diving bell, it is understood that the present device is equally suitable for any environment having a calling for a unitized umbilical cable supporting and maintaining any object or device requiring same.
Referring now to the drawings, reference character 4 represents a diving bell or any similar device requiring both physical support by tether means as well as life support. Reference character 2 depicts a surface ship floating on water level 3. Reference character 6 represents a primary down line supporting the bell 4 by tether means to surface ship 2 by passing the primary down line 6 over a conveyor or sheave 10 and thence onto and around reel means 12, the conveyor or sheave 10 and reel means 12 both being affixed to the ship 2, and being separate from the conveyor or sheave and reel means of the umbilical cable.
It should be noted that during normal operation the primary down line 6 supports the load of the bell 4 while the marine unbilical cable 8 connects the bell 4 to the ship 2 but remains unloaded. Upon breaking of the primary down line 6, the bell 4 will drop a certain distance necessary to take up the slack of the umbilical cable 8. Because of the dropping effect of the bell 4, umbilical cable 8 is first subjected to tensional impact along the vertical segment of the umbilical cable lying between the bell 4 and the sheave 10. Those skilled in the art will realize that a swelling sea raising the ship 2 relative to bell 4 will likewise cause tensional impact upon the umbilical 8 if the primary down line is broken. That part of the marine umbilical cable 8 disposed on and between the sheave 10 and the reel means 12 is substantially horizontal; therefore some of the impact and load produced by the falling bell 4 or the rising ship 2 on the umbilical cable 8 is radial as well as tensional on the upper portion of the sheave 10 as well as around the reel means 12. Consequently, any radial resiliency within the marine umbilical cable 8 and disposed upon the sheave 10 and the reel 12 tends to act as a radial shock absorber against the tensional impact of umbilical cable 8.
Similarly, a direct radial impact or load upon the umbilical 8 is cushioned by the resilient material 28, preferably a high strength, highly resilient, low durometer material, tending to prevent damage to the stress member 22 and elements 16.
FIG. 2 shows a particular mode of the marine umbilcal cable 8 having an exterior conforming to the helically cabled elements 16. FIG. 2 illustrates a core 14, one form of which is shown in FIG. 3 as comprising a wire rope stress member 22, a low melt temperature high strength plastic jacket 24 compression extruded onto wire rope stress member 22, an inner polyurethane jacket 26 extruded onto the jacketed stress member 22, 24 and a high strength, highly resilient, low durometer elastomer material 28 compression extruded onto the inner polyurethane jacket 26.
Another embodiment of the core 14 is shown in FIG. 6 as having an aramid fiber stress member 32, a polyurethane inner jacket 26 extruded onto stress member 32 and a high strength, highly reslient, low durometer elastomer material 28 compression extruded onto the inner jacket 26. It will be recognized by those skilled in the art that either embodiment of the core 14 is appropriate for a marine umbilical cable having a helical exterior 8' or cylindrical exterior 8.
Referring again to FIG. 6, the stress member 32 is laid axially to the cylindrical surface 8 of the marine umbilical. Because conventional elements 16 are helically cabled around the core 14, the stress member 32 is the shortest member per unit length of the marine umbilical 8 or 8' thereby being the first to assume any tensional load applied thereto; hence, the stress member 32, having sufficient load bearing characteristics for the particular tensional load to be applied, will not elongate sufficiently to cause elongation of the conventional elements 16, which are non-load bearing elements, or unwinding of the elements 16 and breakage thereof.
As previously noted, the inner polyurethane jacket 26 is extruded onto the stress member 32. The inner jacket 26 produces a transitional effect between stress member 32 which is substantially incompressible and the highly resilient, high strength, low durometer material 28. The inner jacket 26, tending to project the area of the stress member 22 or 32 bearing upon the high strength, highly resilient, low durometer elastomer 28, has reasonably high strength characteristics while at the same time possessing a noticeable degree of resiliency. The elastomer material 28, however, is a non-load bearing material which is highly resilient. Consequently, when radial loads are applied to the marine umbilical cable 8 or 8', the high strength elastomer 28 tends evenly to distribute that radial load. Resilient fill material 18 is injected as a high viscosity liquid during the cabling process into the internal interstices between the core 14 and conventional elements 16 and assists the elastomer material 28 in distributing a radial load applied to the marine umbilical 8 or 8'.
Turning now to FIG. 3, a preferred embodiment of the core 14 is shown as having a wire rope stress member 24. The particular wire rope used will vary according to the amount of load and impact expected to be applied to the umbilical 8 by the bell 4. A wire rope comprises an excellent stress member 22 in that it is both load bearing and flexible. One configuration of the wire rope 22 which is shown for purposes of illustration only, is a 6×36 Warrington Seale with independent wire rope center shown in FIG. 4. Interstices 33 as well as the individual wires comprising the wire rope stress member 22 generally come from the manufacturer with a lubricant thereupon which reduces galling of the wire rope 22 during repeated flexion thereof.
A low melt temperature high strength plastic jacket 24 of 0.005 inches minimum thickness is compression extruded onto the wire rope stress member 22, thereby inhibiting corrosion by salt water of the wire rope 22 and preventing bubbling of the inner jacket 26 by contact with a lubricant on wire rope 22.
Because the wire rope embodiment of stress member 22 is substantially less compressible than the stress member 32, the inner polyurethane jacket 26 even more importantly provides a transitional effect between the imcompressible stress member 22 and the highly resilient, high strength, low durometer elastomer 28. Because a wire rope stress member 22 has elongation characteristics of approximately one third of that of aramid fiber stress member 32, the cross sectional area of stress member 22 need be only approximately one third that of stress member 32. Consequently, because the inner polyurethane jacket is of approximate equal thickness for either embodiment of the core 14, preferably being at least 0.050 inches thick, the elastomer material 28 will vary according to the particular stress member utilized, thereby occupying a greater area of the core 14 when the wire rope stress member 22 is utilized and less of the core 14 when the aramid fiber stress member 32 is employed.
The external polyurethane jacket 20 is tube extruded as shown in FIGS. 2 and 3 onto the exterior of elements 16, and may be either tube or compression extruded as shown in FIG. 6. The embodiment shown in FIGS. 2 and 3 shows minute unfilled areas 30 in the external interstices between the surfaces of elements 16 and the external polyurethane jacket 20. It is understood that for purposes of representation only, the unfilled areas 30 are greatly enlarged in the drawings. These unfilled areas 30 must necessarily remain small in order to avoid undue stress on the jacket 20 caused by underwater pressures.
The jacket 20 may be economically removed for purposes of repair or replacement of the elements 16 and then a new jacket 20 extruded thereupon. An advantage of the helical configuration shown in FIGS. 2 and 3 of surface 8' is a reduction in the overall weight of the umbilical 8' resulting from the conforming of the jacket 20 approximately to the helices produced by the elements 16 as well as the unfilled external interstices 30. Furthermore, because all underwater lines are preferably black or of a substantially dark color in order to avoid attraction of sharks thereby prohibiting color coding, the rope configuration 8' is easily identifiable both onboard ship 2 where many lines may be in proximity to each other as well as underwater. Moreover, it is easier to grip the umbilical cable 8' than it is to grip the umbilical cable 8.
In some applications high radial loading upon the umbilical cable 8' disposed around the reel 12 or the sheave 10 may cause distortion of the helical configuration 8'. Consequently, it is more desirable to use a cylindrical embodiment 8 as shown in FIG. 6. Accordingly, a conforming fill material is disposed within the external interstices 36 between the elements 16 and the cylindrical polyurethane external jacket 34 thereby tending to support the elements 16 and to distribute radial loads applied to the umbilical 8. In any event, it will be recognized that the maximum effective diameter of the helical configuration 8' is equal to that of the cylindrical configuration 8. The cylindrical umbilical 8 remains easily and economically repairable in the manner described for configuration 8'.
Referring again to the core 14, those skilled in the art will easily recognize that the aramid fiber stress member 32 is non-corrosive and somewhat more elastic than the wire rope stress member 22, thereby necessitating less elastomer material 28 and thereby causing the diameter of the core 14 carrying the stress member 32 to be identical in diameter to the core 14 carrying stress member 22.
A preferred embodiment of the marine umbilical cable 8' comprises a wire rope center 22, a polyethylene jacket 24 of 0.005 inches or more in thickness compression extruded onto the wire rope stress member 22, a lubricant on and within wire rope 22, an inner-polyurethane jacket 26 compression extruded onto the polyethylene jacket, a high strength, highly resilient, low durometer elastomer 28 in the range of 2800-6000 P.S.I. tensile strength, 300-800% elongation and 50-80 durometer respectively an example of which is marketed under the trademark ROYALAR E-80 owned by Uniroyal, compression extruded onto the inner-polyurethane jacket 26, elements 16 helically cabled thereround, a resilient fill material located within internal interstices 18, and a polyurethane jacket 20 tube extruded around elements 16 without completely filling external interstices 30 and which is easily removable for economic repair of cable 8'.
An additional preferred embodiment is shown in FIG. 6. An aramid fiber stress member 32 marketed under the registered trademark of Kevlar owned by Du Pont is surrounded by a polyurethane jacket extruded thereupon. A high strength, highly resilient, low durometer elastomer 28 described above acts as a shock absorber against radial loading and is compression extruded onto the internal polyurethane jacket. The helically cabled elements 16 define internal interstices 18 carrying a resilient fill material. An external polyurethane jacket 34, being substantially cylindrical in shape, tangentially encircles the helically cabled elements 16 and the conforming fill material in the external interstices 36 tends to support the elements 16 and to distribute uniformly radial loading.
While the presently preferred embodiments of the invention have been given for the purposes of disclosure, changes may be made therein which are within the spirit of the invention as defined by the scope of the appended claims. | A unitized marine umbilical cable carrying any number or combination of conventional elements such as hoses and electrical cables. A center stress member disposed along the axis of the marine umbilical cable is capable of supporting an underwater device such as a diving bell should the primary down line break. Cylindrically surrounding the stress member is a compression extrusion of a high strength highly resilient elastomer around which are helically cabled various conventional elements. Within the interstices between the high strength elastomer and the helically cabled elements is a resilient fill material. The resilient fill material and high strength highly resilient, low durometer elastomer serve as a radial shock absorber against tensional impact upon the umbilical or radial forces thereupon. | 19,686 |
RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application Ser. No. 10/215,249, filed Aug. 9, 2002, which claims priority from U.S. Provisional Application No. 60/401,340, filed Aug. 7, 2002, both of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention generally relates to methods, systems and medium for automatically dispensing and/or packaging of prescriptions and/or prescription orders wherein disparate pharmaceutical packages, e.g., bottles with automatically and/or manually dispensed pills, packages with pharmaceutical products, literature packs that are optionally patient specific, etc., are automatically dispensed and/or combined into packages. The present invention may be used for mail order pharmacies, wholesalers and/or central fill dealers for subsequent distribution or sale including a retailer.
BACKGROUND OF THE INVENTION
[0003] In mail service pharmacies and large retail pharmacies, prescription drugs are dispensed in a high volume. For such services, it is known to use an automatic pill dispensing system to carry out the dispensing of the prescription drugs automatically at a rapid rate and to label pill containers which can then be provided to the patient for whom the prescriptions were written.
[0004] A known automatic pill dispensing system is described in U.S. Pat. No. 5,771,657 issued to Lasher et al., which is incorporated herein by reference. In the patent, as shown in the schematic illustration of FIG. 1A, orders (e.g., orders to fill prescriptions) are received by a host computer 9 which forwards the orders to a distributed computer system including a central computer called Pharmacy Automation Controller 10 (PAC). PAC maintains an order file of the information about each prescription to be filled in an order including all of the information needed to fill each prescription, prepare a prescription label for each prescription and the information to print literature to go in a shipping container with the prescription or prescriptions. PAC updates the order file to maintain a record of the current status of each prescription being filled as it progresses through the automated system.
[0005] PAC 10 controls a set of PAL stations 14 which print prescription bottle labels, apply the prescriptions to prescription bottles, and load the labeled bottles onto bottle carriers, a carrier conveyer system 21 which carries the bottle carriers to different parts of the system, automatic drug dispensing machines 23 which dispense tablets or capsules into the prescription bottles in the bottle carriers as they are carried by the conveyer system 21 , bottle cappers 25 which apply caps to the bottles, and OCP stations 29 at which the bottles are unloaded from the carriers and placed in the shipping containers corresponding to the patient orders. The conveyer system 21 carries the bottles in the carriers from the PAL stations through the automatic drug dispensing machines 23 to the bottle cappers 25 and then from the bottle cappers to the OCP stations 29 . The conveyer system 21 also carries the empty carriers back to the PAL stations 14 . The OCP stations each also have a literature dispensing mechanism, which inserts printed literature into each shipping container with the filled and capped prescription bottles. PAC 10 controls literature printers 31 which print literature for each prescription order and enclose the literature for each prescription order in an envelope, print a bar code that shows through a window in the envelope identifying the prescription order, and then place each envelope on a literature conveyer 34 which carries the envelope from the literature printers 31 to the OCP stations 29 .
[0006] As shown in FIG. 1B, bottles to be automatically filled with the prescription drugs are introduced to the automated system by hoppers 37 which receive the bottles in bulk form and automatically feed the bottles to unscramblers 39 . One of the hoppers 37 and one of the unscramblers 39 will be for large bottles of 160 cc. and the remaining hoppers and unscramblers will be for small bottles of 110 cc. The small bottle size can accommodate a majority of the automatically filled prescriptions. The large bottles are large enough for 91 percent of the prescriptions and are used to fill the prescriptions in that 91 percent which are too large for the small bottles. The remaining 9 percent of the prescriptions which are too large for the large bottles are filled by using multiple bottles. A large bottle and a small bottle will contain a volume required for 97.5 percent of the automatically filled prescriptions. In the unscramblers, the bottles are singulated and oriented so that the bottle opening first faces downward. The bottles are then righted and directed to PAL stations 14 on bottle conveyers 41 and 43 , one for large bottles and one for small bottles.
[0007] In the above described conventional system, bottles from one order and corresponding literature are combined into one package. However, many orders include prescriptions for non-pill pharmaceutical products. For example, prescriptions may include liquid pharmaceutical packages, boxes and/or pre-packaged bulk bottles. In addition, as noted above, when prescriptions are filled and mailed to patients, the mail package may include literatures relating to the drugs in the package. The conventional systems are not configured to dispense and combine automatically the above-listed disparate pharmaceutical products into packages.
SUMMARY OF THE INVENTION
[0008] Computer-assisted methods, systems and mediums of the present invention overcome, among others, the shortcomings of the above-described conventional systems.
[0009] The present invention includes a system for filling at least one order that includes one or more prescriptions. The system includes at least one order consolidation station configured to receive at least one bottle containing pills individually counted and/or the at least one package containing pharmaceutical products without having been pre-designated for the at least one order when the at least one package was created. The at least one bottle is specifically designated for the at least one order, and the at least one order includes at least one prescription for the at least one package. The order consolidation station is further configured to combine automatically the received at least one bottle and/or the at least one package to send the combined the at least one bottle and/or the at least one package to a patient for whom the at least one order was written, thereby filling the at least one prescription.
[0010] The at least one order consolidation station can be further configured to receive at least one literature pack containing printed literature relating to the at least one order and configured to combine the at least one literature pack with the combined at least one bottle and/or the at least one package.
[0011] The system may also include a package storage device having an array of locations and configured to store the at least one package into one of the array of locations. The system can also include a package dispenser configured to identify the one of the array of locations, pick the at least one package from the one of the array of locations and send the at least one package to the order consolidation station.
[0012] The system may also include a package storage device having an array of locations and configured to store a plurality of packages into the array of locations and store the at least one package into one of the array of locations. The system can include a package dispenser configured to identify the one of the array of locations, pick the at least one package from the one of the array of locations and send the at least one package to the order consolidation station.
[0013] The package dispenser can include a package label printer to print at least one label for the at least one package. The label is printed with patient specific information including instructions by a prescribing doctor to the patient. The package dispenser may further include a label folder and/or manipulator configured to fold and/or manipulate the at least one label into a wrapped label having a sufficiently small footprint to be affixed on the at least one package. The package dispenser can also include an error detection system configured to detect and read the label affixed on the at least one package and configured to reject the at least one package and the label if an incorrect label is affixed thereto.
[0014] The system can also include a bottle storage device having an array of locations and configured to store a plurality of bottles into one of the array of locations, and a bottle dispenser configured to identify the one of the array of locations and send the at least one bottle from the one of the array of the locations to the order consolidation station.
[0015] The bottle dispenser can also comprise a metal detector configured to detect a present of a metallic substance in the at least one bottle. The bottle dispenser can be further configured to reject the at least one bottle if a metallic substance is detected therein. The bottle dispenser can also include a bottle magazine to receive the at least one bottle belonging to the one of at least one order. The bottle magazine is disposed and configured to release the received at least one bottle into the bag.
[0016] In addition, the system can also include a bagger configured to open a bag to receive the at least one bottle and/or the at least one package into the bag. The bagger can also include an address label or internal control label printer configured to print an address of the patient. The bagger can be further configured to affix the address label or internal control label on the bag before the bag is opened.
[0017] The present invention also includes a system for filling at least one order. The system may include a bottle handling station configured to store and dispense at least one bottle containing pills individually counted. The at least one bottle is specifically designated for the at least one order. The system can also include a package handling station configured to store and dispense at least one package containing pharmaceutical products without having been pre-designated for the at least one order when the at least one package was created. The at least one order includes at least one prescription for the at least one package. The system can further include an order consolidation station configured to combine the received at least one bottle and/or the at least one package to send the received at least one bottle and the at least one package to a patient for whom the at least one order was written, to thereby fill the one of at least one order and/or prescription.
[0018] The system may also include a literature handling station configured to store and dispense at least one literature pack containing printed literature relating to the at least one order. The order consolidation station can be further configured to receive the at least one literature pack and combine the at least one literature pack with the received at least one bottle and/or the at least one package.
[0019] The present invention also provides a system for filling a plurality of orders. The system comprises a bottle handling station configured to store a plurality of bottles each containing pills individually counted. Each bottle is specifically designated for one of the plurality of orders. The system can also include a literature handling station configured to store a plurality of literature packs each containing printed literature relating to one of the plurality of orders and configured to determine a sequence in which the literature packs are stored with respect to corresponding orders. The system may also include a computer system configured to monitor the bottle handling and literature handling stations and configured to cause the bottle handling station to dispense the bottles in the sequence in which the literature packs are stored with respect to corresponding orders and/or prescriptions. The system may further include an order consolidation station configured to receive the bottles and the literature packs in the sequence in which the literature packs are stored with respect to corresponding orders and/or prescriptions and configured to combine the bottles and the literature packs belonging to one of the plurality of orders.
[0020] The system may also include a package handling station configured to store a plurality of packages containing pharmaceutical products without having been designated for any of the plurality of orders when the plurality of packages is created. The computer system is further configured to monitor the package handling station and cause the package handling station to dispense the packages in the sequence in which the literature packs are stored with respect to corresponding orders. The order consolidation station can be further configured to receive the packages in the sequence in which the literature packs are stored with respect to corresponding orders and/or prescriptions and configured to combine the packages belonging to the one of the plurality of orders with the combined bottles and literature packs.
[0021] The computer system can also be configured to detect an error when the bottles are not received by the order consolidation station in the sequence in which the literature packs are stored. The computer system can also be configured to detect an error when the packages are not received by the order consolidation station in the sequence in which the literature packs are stored.
[0022] The present invention also provides a method for filling at least one order. The method can include the step of receiving at least one bottle containing pills individually counted and/or the at least one package containing pharmaceutical products without having been pre-designated for the at least one order when the at least one package was created. The at least one bottle is specifically designated for the at least one order, and the at least one order includes at least one prescription for the at least one package. The method may also include the step of automatically combining the received at least one bottle and/or the at least one package to send the at least one bottle and/or the at least one package to a patient for whom the at least one order was written, to thereby fill the one of at least one order.
[0023] The method may also include the step of receiving at least one literature pack containing printed literature relating to the at least one order and configured to combine the at least one literature pack with the received at least one bottle and/or the at least one package.
[0024] The method can also include the steps of storing the at least one package into one of an array of locations of a package storage device, identifying the one of the array of locations, and picking the at least one package from the one of the array of locations. The method may further include the step of printing at least one label for the at least one package. The label is printed with patient specific information including instructions by a prescribing doctor to the patient. The method can also include the step of folding, configuring or manipulating the at least one label into a sufficiently small footprint to be affixed on the at least one package.
[0025] The method may also include the steps of detecting and reading the label affixed on the at least one package, and rejecting the at least one package and the label if an incorrect label is affixed thereto. The method can also include the steps of storing the at least one bottle into one of an array of locations in a bottle storage device, and identifying the one of the array of locations. The method may further comprise the steps of detecting the presence of a metallic substance in the at least one bottle and rejecting the at least one bottle if a metallic substance is detected therein.
[0026] The method may also include the step of opening a bag to receive the at least one bottle and/or the at least one package into the bag. The method may also include the steps of printing an address of the patient and affixing the address label on the bag before the bag is opened.
[0027] The present invention also provides a method for filling at least one order. The method comprises the step of storing and dispensing at least one bottle containing pills individually counted. The at least one bottle is specifically designated for the at least one order. The method may also include the step of storing and dispensing at least one package containing pharmaceutical products without having been designated for any of the at least one order when the at least one package was created. The at least one order includes at least one prescription for the at least one package. The method can also include the step of combining the received at least one bottle and/or the at least one package to send directly or indirectly using a variety of means, for example, through a retailer, wholesaler, and/or central fill, the at least one bottle and/or the at least one package to a patient for whom the at least one order was written, to thereby fill the one of at least one order.
[0028] The method may also include the steps of storing and dispensing at least one literature pack containing printed literature relating to the at least one order and receiving the at least one literature pack and combining the at least one literature pack with the received at least one bottle and/or the at least one package.
[0029] The present invention also provides a system for filling at least one order. The system includes at least one order consolidation means for receiving at least one bottle containing pills individually counted and/or the at least one package containing pharmaceutical products without having been pre-designated for the at least one order when the at least one package was created. The at least one bottle is specifically designated for the at least one order, and the at least one order includes at least one prescription for the at least one package. The order consolidation means can be further configured for automatically combining the received at least one bottle and/or the at least one package into a bag to be sent to a patient for whom the at least one order was written, to thereby fill the one of at least one order.
[0030] The order consolidation means can be further configured for receiving at least one literature pack containing printed literature relating to the at least one order and combining the at least one literature pack with the received at least one bottle and at least one package.
[0031] The system may also include a package storage means, having an array of locations, for storing the at least one package into one of the array of locations and a package dispense means for identifying the one of the array of locations, picking the at least one package from the one of the array of locations and sending the at least one package to the order consolidation means. The package dispense means can also include a package label printer to print at least one label for the at least one package. The label is printed with patient specific information including instructions by a prescribing doctor to the patient. The package dispense means can further include a label folder configured to fold the at least one configured or manipulated label having a sufficiently small footprint to be affixed on the at least one package.
[0032] The package dispense means can further include an error detection system configured to detect and read the label affixed on the at least one package and discard the at least one package and the label if an incorrect label is affixed thereto.
[0033] The system can also include a bottle storage means, having an array of locations, for storing the at least one bottle into one of the array of locations and a bottle dispense means for identifying the one of the array of locations and sending the at least one bottle from the one of the array of the locations to the order consolidation means.
[0034] The bottle dispense means can include a metal detector means for detecting the presence of a metallic substance in the at least one bottle. The bottle dispense means may be further configured for rejecting the at least one bottle if a metallic substance is detected therein.
[0035] The bottle dispense means can include a bottle magazine means for receiving the at least one bottle belonging to the one of at least one order. The bottle magazine means is disposed and configured to release all received at least one bottle into the bag.
[0036] The system may also include a bagger means for opening the bag to receive the at least one bottle and at least one package into the bag. The bagger means may include an address label printer means for printing an address of the patient. The bagger means can be further configured for affixing the address label on the bag before the bag is opened.
[0037] The present invention may also provide a system for filling at least one order. The system may include a bottle handling means for storing and dispensing at least one bottle containing pills individually counted. The at least one bottle is specifically designated for the at least one order. The system may also include a package handling means for storing and dispensing at least one package containing pharmaceutical products without having been designated for any of the at least one order when the at least one package was created. The at least one order may include at least one prescription for the at least one package. The system may also include an order consolidation means for combining the received at least one bottle and at least one package into a bag to be sent to a patient for whom the at least one order was written, to thereby fill the one of at least one order.
[0038] The system may also include a literature handling means for storing and dispensing at least one literature pack containing printed literature relating to the at least one order. The order consolidation means can be further configured to receive the at least one literature pack and combining the at least one literature pack with the received at least one bottle and/or the at least one package.
[0039] The system can also provide a system for filling a plurality of orders. The system can include a bottle handling means for storing a plurality of bottles each containing pills individually counted. Each bottle and/or bottles is/are specifically designated for one of the plurality of orders. The system may also include a literature handling means for storing a plurality of literature packs each containing printed literature relating to one of the plurality of orders and for determining a sequence in which the literature packs are stored with respect to corresponding orders. The system may also include a computer system configured to monitor the bottle handling and literature handling means and configured to cause the bottle handling means to dispense the bottles in the sequence in which the literature packs are stored with respect to corresponding orders. The system may also include an order consolidation means for receiving the bottles and the literature packs in the sequence in which the literature packs are stored with respect to corresponding orders and for combining the bottles and the literature packs belonging to one of the plurality of orders.
[0040] The system may further include a package handling means for storing a plurality of packages containing pharmaceutical products without having been designated for any of the plurality of orders when the plurality of packages is created. The computer system can be further configured to monitor the package handling means and cause the package handling means to dispense the packages in the sequence in which the literature packs are stored with respect to corresponding orders. The order consolidation means can be further configured for receiving the packages in the sequence in which the literature packs are stored with respect to corresponding orders and configured for combining the packages belonging to the one of the plurality of orders with the received bottles and literature packs.
[0041] The present invention may also include a bottle storage apparatus. The device comprising a plurality of storage locations, each storage location, for example, having a top side and a bottom side, and a pin disposed on the bottom side of each of the plurality of storage locations, the pin having an open position and a closed position. Other storage location configurations may alternatively be used. The device also comprises a first gantry crane having a means for picking up a bottle and feeding the bottle to one of the plurality of storage locations via the top side thereof. The bottle is held by the one of the plurality of storage locations, for example, when the pin is in the closed position. The system may also include a second gantry crane having a means for moving, for example, one of the pins from the closed position to the open position. The system may also include a computer system coupled to the first and second loading devices (e.g., gantry cranes) and capable of identifying a location of each storage location. The computer system can be configured to instruct the first loading device to pick up one or more bottles belonging to a order and to feed the one or more bottles to one or more of the plurality of storage locations. The computer system can be further configured to instruct the second gantry crane to, for example, move the pins of the one or more of the plurality of storage locations from the close position to the open position when all of the one or more bottles belonging to the order has been fed to the one or more of the plurality of storage locations.
[0042] The plurality of storage locations forms a table. The first gantry crane is disposed on a top side of the table and the second gantry crane, robot arm and/or other standard mechanism is disposed on a bottom side of the table.
[0043] The invention of present application provides a system of filling a plurality of orders. A pinch belt including a plurality of locations each of which is capable of carrying a pack of printed material belong to a order. A bottle storage table includes a plurality of storage locations to store at least one bottle belonging to the order. A first conveyor line is located to receive the at least one bottle from the bottle storage table and having a moving surface to move the at least one bottle received from the bottle storage table. The system may also include a means for receiving and holding the at least one bottle and a plurality of shelf locations, each shelf location containing at least one package belonging to the order. The system may also include a robot having an end effector to pick the at least one package and a means to release the at least one package and a second conveyor line having a moving surface to move the at least one package received from the robot. The system can also include a robot arm or other standard mechanism having an end effector to pick up the at least one package and a bagger having a set of arms to open and hold a bag. The system can further include a computer system configured to instruct the pinch belt to convey at least one pack of printed material and discharge the at least one pack into the bag, instruct the bottle storage table to release the at least one bottle, instruct the first conveyor line to move the at least one bottle and dispose the at least one bottle into the bag, instruct the robot to pick up the at least one package and release the at least one package onto the second conveyor line, instruct the second conveyor line to move the at least one package, and instruct the robot arm to pick up and dispose the at least one package into the bag.
[0044] There has thus been outlined, rather broadly, the features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.
[0045] In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
[0046] As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
[0047] These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated preferred embodiments of the invention.
[0048] Other features of the present invention will be evident to those of ordinary skill, particularly upon consideration of the following detailed description of the preferred embodiments.
[0049] Notations and Nomenclature
[0050] The detailed descriptions which follow may be presented in terms of program procedures executed on computing or processing systems such as, for example, a stand-alone computing machine, a computer or network of computers. These procedural descriptions and representations are the means used by those skilled in the art to most effectively convey the substance of their work to others skilled in the art.
[0051] A procedure is here, and generally, conceived to be a sequence of steps leading to a desired result. These steps are those that may require physical manipulations of physical quantities (e.g., combining various pharmaceutical products into packages). Usually, though not necessarily, these quantities take the form of electrical, optical or magnetic signals capable of being stored, transferred, combined, compared and otherwise manipulated. It proves convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. It should be noted, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities.
[0052] Further, the manipulations performed are often referred to in terms, such as adding or comparing, which are commonly associated with mental operations performed by a human operator. No such capability of a human operator is necessary, or desirable in most cases, in any of the operations described herein which form part of the present invention; the operations are machine operations. Useful machines for performing the operation of the present invention include general purpose digital computers or similar devices, including, but not limited to, microprocessors.
BRIEF DESCRIPTION OF THE DRAWINGS
[0053] The detailed description of the present application showing various distinctive features may be best understood when the detailed description is read in reference to the appended drawing in which:
[0054] FIGS. 1 A- 1 B are diagrams illustrating a conventional automated pill dispenser;
[0055] [0055]FIG. 2 is a diagram illustrating various components of embodiments of the present invention;
[0056] [0056]FIG. 3 is a diagram illustrating an initial set of determinations that a host computer is configured to make for embodiments of the present invention;
[0057] [0057]FIG. 4 is a diagram illustrating various steps performed by embodiments of the present invention;
[0058] [0058]FIG. 5 is a diagram illustrating various steps performed by embodiments of the present invention;
[0059] [0059]FIG. 6 is a diagram illustrating various steps performed by embodiments of the present invention;
[0060] [0060]FIG. 7 is a diagram illustrating various steps performed by embodiments of the present invention;
[0061] [0061]FIG. 8 is a diagram illustrating various example components of embodiments of the present invention;
[0062] FIGS. 9 A- 9 C are diagrams illustrating an example bottle storage table of embodiments of the present invention;
[0063] [0063]FIG. 10 is a diagram illustrating a tube structure of the example bottle storage table of embodiments of the present invention;
[0064] [0064]FIG. 11 is a diagram illustrating an example storage device and dispenser for packages of embodiments of the present invention;
[0065] [0065]FIG. 12 is a diagram illustrating an example consolidation station and its associated components of embodiments of the present invention;
[0066] [0066]FIG. 13 is a diagram illustrating the steps performed by the consolidation station and its associated components of embodiments of the present invention;
[0067] [0067]FIG. 14 is a diagram illustrating an example package scanning and labeling station of embodiments of the present invention;
[0068] [0068]FIG. 15A- 15 E are diagrams of an example consolidation station and its associated components of embodiments of the present invention;
[0069] [0069]FIG. 16 is a schematic diagram of example bagger and dispenser for packages of embodiments of the present invention;
[0070] [0070]FIG. 17 is a schematic diagram of an example bagger and dispenser for bottles of embodiments of the present invention;
[0071] [0071]FIG. 18 is a diagram illustrating a label for a package of embodiments of the present invention;
[0072] [0072]FIG. 19 is a diagram illustrating the steps performed and dispenser for packages and its local computer of embodiments of the present invention;
[0073] [0073]FIG. 20 is diagram illustrating an example bagger of embodiments of the present invention;
[0074] [0074]FIG. 21 is a diagram illustrating example control processes for embodiments of the present invention;
[0075] FIGS. 22 - 26 are diagrams illustrating example control schemes for literature packs of embodiments of the present invention;
[0076] [0076]FIG. 27 is a diagram illustrating an example computer network scheme for embodiments of the present invention;
[0077] [0077]FIG. 28 is a block diagram representation of an example embodiment of computer network(s) implementing embodiments of the present invention;
[0078] [0078]FIG. 29 illustrates a computer that can be used in implementing embodiments of the present invention;
[0079] [0079]FIG. 30 is a block diagram of internal hardware of the example computer shown in FIG. 29; and
[0080] [0080]FIG. 31 illustrates one example of a memory medium which may be used for storing computer programs of embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0081] Reference now will be made in detail to the presently preferred embodiments of the invention. Such embodiments are provided by way of explanation of the invention, which is not intended to be limited thereto. In fact, those of ordinary skill in the art may appreciate upon reading the present specification and viewing the present drawings that various modifications and variations can be made.
[0082] For example, features illustrated or described as part of one embodiment can be used on other embodiments to yield a still further embodiment. Additionally, certain features may be interchanged with similar devices or features not mentioned yet which perform the same or similar functions. It is therefore intended that such modifications and variations are included within the totality of the present invention.
[0083] Embodiments of the present invention are directed to dispensing orders that include various pharmaceutical products (e.g., bottles that contain counted pills, packages that include liquid or pre-packaged pharmaceutical products and/or patient specific literatures). In embodiments of the present invention pills also refer to tablets, capsules and other similar terms known in the art. FIG. 2 is a schematic diagram illustrating various components that can be used in embodiments of the present invention. In particular, the components include a storage device for packages 203 , dispenser for the packages 205 , storage device for bottles filled with counted pills 209 , dispenser for the bottled with counted pills 207 , storage device for patient specific literatures 211 , dispenser for the patient specific literatures 213 , consolidation station 215 and host computer 201 . Embodiments of the present invention can also include one or more local computers (Not shown in FIG. 2). For instance, each of the components listed above (e.g., the storage device for packages 203 , dispenser for the packages 205 , storage device for bottles 209 , dispenser for bottles 207 , storage device for literature packs 211 and dispenser for literature packs 213 ) can be connected to one or more local computers. The local computers in turn are connected to the host computer 201 . In this way, the host computer 201 and local computers are configured to control the various components of the present invention as described below.
[0084] A local computer can also function with a standard Programmable Logic Controller (PLC). A PLC typically includes an I/O card to turn on/off a device. Accordingly, when a component is to be controlled by turning it on/off, a PLC can be used. When a large quantity of data is to be exchanged, a local computer can be used. The storage device for packages 203 stores packages that contain pharmaceutical products. For example, one set of packages may contain a predetermined number of tablets (e.g., 500 tablets) of a certain drug (e.g., Allegra). Another set of example packages may include liquid pharmaceutical products. The packages can be made by original producers of drugs (e.g., Hoechst Marion Roussel). The packages can also be bulk bottles that are filled by any one of many automated (e.g., the ADDS) or manual methods known in the art. These packages can then be shelved so that their locations can be automatically identified. In turn, the dispenser for the packages 205 is configured to automatically identify the location of any package with a certain type of drug, dosage and/or quantity and configured to pick one or more packages from the identified location. In other words, a package contains a pharmaceutical product without having been pre-designated for any specific order when the package was created.
[0085] In operation, the command to locate and pick one or more packages is received from the host computer 201 . The dispenser for packages can also be connected to its own local computer to perform the necessary functions to locate and pick one or more packages in accordance with the command from the host computer 201 . It should be noted that the packages stored in the storage device for packages 203 are not designated for any specific patient. In other words, any package can be picked to fill a order of a patient as long as the type of drug, dosage and/or quantity are matched with the order.
[0086] Embodiments of the present invention can also include a standard sensor or a standard counter to indicate when a specific type of package is out of stock in the storage device for packages 203 . These sensors or counters can be present at each location (or a substantial number of them). The signals from the sensors or counters can be communicated to, for example, the host computer 201 via the local computer. In turn, the host computer 201 can notify an operator or system to replenish the specific packages and/or stop the process of filling orders that require the specific type of package that are out of stock in the storage device for packages 203 . In addition, or optionally, the host computer 201 can send a query to the storage device for packages 203 regarding whether a certain number of certain packages are available to be dispensed. In response, the storage device for packages 203 , or in combination with its local computer, can send a response based on information from the sensors and/or counters. Alternatively, sensors may be placed on the robot arm or picking device to provide the similar functionality. In yet another alternative, sensors are not utilized and the system keeps logical control by knowing how many packages have been placed in a channel and how many packages have been removed from the channel.
[0087] The dispenser for bottles 207 is configured to receive bottles that contain specific number (e.g., 1-500 or more) of pills for a specific order. For example, one bottle may include 350 tablets of one type of drug for patient A, while another bottle may include 600 tablets of another type of drug for patient B. The bottles can be filled by any automatic dispensing mechanisms known in the art (e.g., the system shown in U.S. Pat. No. 5,771,657). The bottles can also be filled by a person (e.g., a pharmacist) manually counting pills.
[0088] If an automatic dispensing system is used, the host computer 201 sends commands to fill bottles with certain number of pills for a certain type of drug. Once they are filled, the bottles are stored in the storage device for bottles 209 . In a similar fashion, in a manual system, the dispensing person would receive an instruction to count certain number of tablets for a certain type of drug. The person fills bottles according to the instructions and forwards the bottles to the storage device for bottles 209 .
[0089] Once the storage device for bottles 209 receives all the bottles necessary to fill an order, the storage device for bottles 209 or in connection with its local computer sends a message to the host computer 201 indicating that the bottle portion of the order has been filled. For example, an order to fill an order may require 1450 pills of a certain type of drug. In this example, the storage device for packages 203 may already have two packages each with 500 pills of the drug. If so, one bottle with 450 pills of the drug is necessary to fill the bottle portion of the order. (If one bottle cannot receive all 450 pills then more than one bottle would become necessary to provide the 450 pills).
[0090] Now turning to describe the storage device for literature packs 211 , contains literatures to be packaged with specific orders. For example, a set of literature packs for one order may include information relating to each of the prescribed drugs, how often each drug must be taken, billing information, special instructions from the prescribing doctor, insurance information, refilling information and/or general information, for example health or notification of other services. The set of literature packs is then packaged per order and collected in the storage device for literature packs 211 . Once the necessary literature packs are created, the storage device for literature packs 211 , or in combination with its local computer, can notify the host computer 201 that the literature pack has been printed.
[0091] Upon receiving various information from the storage device for packages 203 , storage device for bottles 209 and storage device for literature packs 211 , the host computer 201 then sends instructions to the dispenser for the packages 205 , dispenser for bottles 207 and dispenser for literature packs 213 , or to their local computers, to dispense necessary bottle(s), package(s) and literature pack(s) to fill one or more orders. The dispensed bottle(s), package(s) and literature pack(s) are then consolidated by the consolidation station 215 and then sent, distributed or mailed out directly or indirectly to patients associated with the orders. The interactions between the consolidation station 215 and the various components illustrated in FIG. 2 are further described in detail below.
[0092] More specifically, FIG. 3 illustrates example steps taken by the host computer 201 in combination with the local computers and/or the various components. The host computer 201 first receives a request to fill a order. In response, the host computer 201 creates an order number and determines whether the order contains an order that requires bottles to be filled by counting individual tablets and whether the order contains an order that requires packages from the storage device for bottles 209 . Depending upon the answers to the above two questions the host computer 201 conducts a number of different sets of steps.
[0093] If the order requires both one or more bottles from the storage device for bottles 209 and one or more packages from the storage device for packages 203 , then the steps shown in FIG. 4 are executed. If the order requires one or more bottles from the storage device for bottles 209 but does not require any packages from the storage device for packages 203 , then the steps shown in FIG. 5 are executed. If the order requires no bottles from the storage device for bottles 209 but requires one or more packages from storage device for packages 203 , then the steps shown in FIG. 6 are executed. If the order requires no bottles from the storage device for bottles 209 and no packages from the storage device for packages 203 , then the steps shown in FIG. 7 are executed.
[0094] Referring to FIG. 4, there is shown a set of steps that can be performed by the host computer 201 , in combination with various other components illustrated in FIG. 2 and their local computers when both bottle(s) from the storage device for bottles 209 and package(s) from the storage device for packages 203 are required to be filled for a order. In the manual counting system, an instruction can be printed or shown on an operator's computer monitor to count and fill a specific drug. In the automated system, the host computer 201 can send a set of commands to cause a drug dispenser to count and fill a specific drug, thereby performing the step of automatically dispensing tablets into bottles (step 401 ).
[0095] Whether the manual system and/or the automated system is used, label(s) are prepared and printed to be affixed on the surface of the bottles, thereby performing the step of associating order specific information with the bottles (step 403 ). The label can be affixed on the caps, sides and/or bottom sides of the bottles as long as they can be located in the later processing steps. The printed labels can contain various information. At minimum, it can contain machine readable (e.g., barcodes) and/or human readable codes/texts so the bottles can be matched to the order numbers in the later processing steps. In addition, the labels can contain information relating to the patient, the drug or any other pertinent information or any combination thereof. One label or a set of labels can be printed and affixed on each bottle. The labels can be printed before, after and/or while the bottles are filled. If the labels are printed before or after the bottles are filled, then printed labels or the bottles need to be queued to be matched with correct bottles or labels, respectively. It should be noted that the information can be printed on the bottles directly and that the information can be alternatively contained in a unique identifier (e.g., radio tags).
[0096] As noted above, in filling some orders, more than one bottle may be required. Accordingly, the host computer 201 and/or the local computer determines how many bottles are required. If more than one bottle is required, a notification that the bottles are filled is sent after all the bottles have been filled (steps 405 , 407 , and 409 ). If only one bottle is required, a notification is sent as soon as the one bottle is filled (steps 405 and 409 ). The bottles with the labels affixed thereon are then sent and stored in the storage device for bottles 209 . Upon receiving the notification, the host computer 201 and/or a local computer causes corresponding literature pack(s) to be printed (step 411 ). In some embodiments before, after and/or while the bottles are filled, the host computer 201 can cause literature pack(s) relating to the order to be printed. Once the literature pack(s) is printed, they can be sent and stored in the storage device for literature packs 211 .
[0097] When the printing literature packs step is completed, a notification is sent to the host computer 201 and/or local computer (step 415 ). Upon receiving the notification that the literature packs have been printed, the host computer 201 and/or local computers cause packages required to fill the order to be automatically dispensed from dispenser for the packages 205 (steps 415 ).
[0098] With respect to the packages in the storage device for packages 203 , as noted above, the host computer 201 can determine if the necessary packages are stocked in the storage device for packages 203 . If not, then the host computer 201 can cause the necessary packages to be stocked in the storage device for packages 203 (either manually or automatically).
[0099] Although the steps illustrated in FIG. 4 can be performed in a sequence, such a sequence is not required in the present invention. For instance, the step of printing literature packs (step 411 ) can be performed before other steps. In another example, the step of filling bottles (steps 405 , 407 , 409 ) can be performed before other steps. It should be noted that determining which of the steps are performed before other steps can be an engineering design choice. In one instance, if the step of printing literature packs takes the longest time compared with other steps, then the printing step may be started the first. In another instance, if the step of filling bottle(s) takes the longest time compared with other steps, then the filling bottle(s) step may be started the first before other steps.
[0100] Now turning back to FIG. 4, once the host computer 201 receives notifications from the storage device for literature packs 211 , storage device for bottles 209 and storage device for packages 203 that the respective literature(s), bottle(s) and package(s) for a order have been received and stored, then the host computer 201 causes the dispenser for literature packs 213 , dispenser for bottles 207 and dispenser for the packages 205 to dispense and send the items to the consolidation station 215 . The consolidation station 215 , upon receiving the literature(s), bottle(s) and package(s), combines them into one or more bags (step 417 ). If the received packages completely fill a order, then the one or more bags can be sealed and a mailing label or internal control label can be affixed on each bag. If the received packages do not completely fill a order and require more packages to be put into the one or more bags, then those bags are sent over to a station where the remaining packages can be put into the bags or joined to the order.
[0101] In some embodiments of the present invention, the dispenser for literature packs 213 , dispenser for bottles 207 and dispenser for the packages 205 can be configured to dispense literature(s), bottle(s) and package(s) to fill one order at a time. In particular, the dispenser for literature packs 213 dispenses one set of literature(s) to fill one order for one patient, the dispenser for bottles 207 dispenses one set of bottles to fill the one order, the dispenser for the packages 205 dispenses one set of packages to fill the one order. In such embodiments, the consolidation station 215 is configured to receive the packages and put them into bags to be mailed or sent over to the next process stations.
[0102] In other embodiments of the present invention more than one (e.g., many tens of thousands) of orders can be filled continuously. In such embodiments, a batch of literature packs for a number of orders can be printed and queued in the storage device for literature packs 211 . In this embodiment, the sequence in which the literature packs are queued can be used in determining which order's bottle(s) and package(s) are filled first. For instance, assume the literature packs queued in the dispenser for literature packs 213 are in the following sequence: Order A, Order B, Order C and so on. If so, the host computer 201 causes the bottle(s) for Order A be filled first. As soon as the bottle(s) are filled, the host computer 201 then can cause the dispenser for bottles 207 to dispense the bottle(s) for Order A to be dispensed and sent over to consolidation station 215 , while causing the dispenser for literature packs 213 to dispense and send the literature pack for Order A be dispensed and sent over to the consolidation station 215 . The host computer 201 also causes the same for the packages to dispensed by the dispenser for the packages 205 . The consolidation station 215 then combines the received packages.
[0103] In yet other embodiments of the present invention, a batch of bottles for a number of orders can be queued in the dispenser for bottles 207 . In such embodiments, the sequence in which the bottles are queued can be used in determining which order's literature(s) and package(s) are filled first in a similar manner as described above. Embodiments in which a batch of packages in the dispenser for the packages 205 that determines the sequence of dispensing are also contemplated within this invention.
[0104] Referring to FIG. 5, there is shown a set of steps that can be performed by the host computer 201 , in combination with various other devices/components illustrated in FIG. 2 and their local computers when bottles from the storage device for bottles 209 but no package(s) from the storage device for packages 203 are required to fill orders. As shown in FIG. 5, most of the steps are similar to the steps shown in FIG. 4 but no steps to dispense packages are included.
[0105] In FIG. 6, there is shown a set of steps that can be performed by the host computer 201 , in combination with various other devices/components illustrated in FIG. 2 and their local computers when package(s) from the storage device for packages 203 but no bottle from the storage device for bottles 209 are required to be filled. As shown in FIG. 6, most of the steps are similar to the steps shown in FIG. 4 but no steps to dispense bottles are included.
[0106] Referring to FIG. 7, there is shown a set of steps that can be performed by the host computer 201 , in combination with various other devices/components illustrated in FIG. 2 and their local computers when only manually picked packages are required to fill orders. Examples of manually picked packages are oddly shaped boxes, large boxes, products packaged in plastic bags, manual assistance, etc. These packages cannot be stocked in the storage device for packages 203 because of their odd shapes or because of possible failures. As shown in FIG. 7, literature packs for the orders are printed (step 701 ). After one or a batch of the literature packs have been printed, the host computer 201 is notified that all packs have been printed (steps 703 and 705 ). Upon receiving the notification, the host computer 201 sends a set of instructions to an operator to fill the orders by manually counting the required packages. It should be noted that the steps of manually picking packages can also be included in the steps illustrated in FIGS. 4 - 6 .
[0107] Now turning to describe details of the various components shown in FIG. 2, FIG. 8 illustrates an overall plant layout of an example embodiment of the present invention. In the example embodiment, the storage device for literature packs 211 is a dispatch unit 801 , the dispenser for literature packs 213 is a conveyor belt 803 (e.g., a pinch belt), the storage device for bottles 209 is a bottle storage table 805 , the dispenser for bottles 207 is a mechanism that releases bottles queued in the bottle storage table 805 , the storage device for packages 203 is a bank of shelves 807 , the dispenser for the packages 205 is a standard picking robot 809 , and the consolidation station 215 is an order consolidation station 811 including a bagger 813 .
[0108] These various components can be provided in an assembly line configuration. As shown in FIG. 8, three sets of each component/system can be provided. For instance, the order consolidation station 813 receives literature packs from the dispatch unit 801 via the conveyor belt 803 , receives bottles from the bottle storage table 805 and receives the packages from the picking robot 809 . The dispatch unit 801 includes a scanner to read the barcodes on the literature packs. The dispatch unit 801 then mounts the literature packs on the belt 803 . It should be noted that, although FIG. 8 illustrates only three sets of components, the present invention is not limited to the described number of sets of components. It follows that the present invention may include one to as many sets of the components required to fill orders as they may be received. In one alternative embodiment, a bottle storage table is not used. In another alternative embodiment, more than one AOC and/or bottle storage table may be used. In other alternative embodiments of the invention, manual intervention and/or manual processes may be substituted for one or more components.
[0109] [0109]FIG. 9A illustrates a top view of an example of the bottle storage table 805 and its assembly that includes a bottle conveyor belt 901 , an array of bottle storage locations 903 , a standard gantry crane 905 , a reject conveyor belt 907 and a bottle conveyor belt 909 to feed bottles from the bottle storage table 805 to the order consolidation station. In this example, the bottle storage table 805 receives bottles filled by an automated/manual process as described above in connection with FIG. 2. The labels on the bottles can be scanned to identify its order number. The order number can be barcodes that the host computer 201 , or in combination with a local computer, can match to a specific order number. If no match can be made or if any other inconsistencies are detected, the bottle is rejected and sent to a quality assurance station via the bottle reject conveyor belt 907 .
[0110] Once bottles arrive at the bottle storage table 805 , the standard gantry crane 905 picks up the bottles and places them into one of an array of bottle storage locations 903 . The gantry crane 905 is known in the art. Examples of such devices include 5126-620 Load to Storage H-BOT, ATS Standard Products, 305290-1370-1350-BV, H-BOT, and 5126-640 Unload from storage H-BOT, ATS Standard Products, 305290-1370-1350-BV, H-BOT, for example, as described in Canadian Patent Application No. 2,226,379, incorporated herein by reference. The local computer can determine which location to put each bottle and instruct the crane 905 . The location information is then matched and stored into the local computer along with a corresponding order number. In some embodiments, each location may hold only one bottle. In other embodiments, each location may hold more than one bottle (e.g., four) belonging to the same order. Whether the locations can hold one bottle only or more than one bottle, the local computer is configured to store their corresponding order numbers. Accordingly, when the local computer is instructed to release all the bottles belonging to one order, they can all be located. When one or more locations are identified as having bottles to be released, the bottles in those locations can be then picked up by the crane 905 . FIGs. B-C show different perspective view of the bottle storage table.
[0111] In some embodiments, each storage location is in the form of a tube structure 1001 with a pin switch 1003 near its bottom opening (as shown in FIG. 10). In these embodiments, the tube 1001 structure is configured to receive the bottles via its top opening and hold them therein supported by the pin switch 1003 . When the bottles in the tube structure are to be sent over to the order consolidation station 811 , the pin 1003 is opened by another gantry crane (part of which is shown in FIGS. 9 B-C). When the pin 1003 is opened, the bottles stored in the tube structure 1001 (belong to the same order) slide down through the bottom opening of the tube structure 1001 . The bottles are then collected and sent over to the order consolidation station 811 via the bottle conveyor 909 .
[0112] In the example shown in FIG. 9A, the bottle storage table 805 has a two-dimensional array of storage locations. It should be noted that the bottle storage table 805 can have a one-dimensional array of locations or any other shape of array of locations as long as each location can be identified by the local computer.
[0113] Now referring to FIG. 11, there is shown a more detailed example of the storage device for packages 203 . In this example, the storage device for packages 203 includes a number of shelves 807 to store various packages to be dispensed, a picking robot maintenance area 1101 , a picking robot track and the picking robot 809 , such as the MDS picker MODEL—MDS01 manufactured by KNAPP Logistics & Automation, 659 Henderson Drive, Suite I, Catersville, Ga. 30120 U.S.A. and/or Knapp Logistik Automation Ges. m. b. H., Gunter-Knapp Str. 5-7 A-8075 Hart bei Graz, Osterrich/Austria. In this example embodiment, the shelves are divided into an array of identifiable locations. Each shelving location has a replenishing side 1103 and picking side 1105 . One type of package is fed into each shelving location from its replenishing side 1103 and picked up by the picking robot 809 from the picking side 1105 . The shelves are optionally arranged so that the replenishing side 1103 is vertically higher than the picking side 1105 . This allows the packages to slide 211 down to the picking side 1105 from the replenishing side 1103 .
[0114] The locations are stored in a local computer of the storage device for packages 203 . The shelf locations can be in a two-dimensional array. In such an embodiment, the picking robot grabbing mechanism 1109 is mounted on an elevator to move up/down/forward/backward. It should be noted that the shelves 807 can also be in one-dimensional array or any other shaped arrays as long as its local computer can identify each individual shelf location. Furthermore, the shelves 807 can be located on two sides of the picking robot 809 . Accordingly, the picking robot 809 is configured to pick up packages from both sides thereof. It should also be noted that three-sided, oval shaped, semi-circular shaped shelf formations and/or corresponding picking robots are also contemplated within embodiments of the present invention.
[0115] When in operation, the local computer receives instructions from the host computer 201 that include information relating to the quantity and type of drugs to be dispensed from the storage device for packages 203 . The local computer then commands the picking robot 809 to traverse on the track 1107 to the location where the package for one type of drug requested is located. The picking robot 809 then picks up the requested quantity of the packages (using its grabbing mechanism or end effector 1109 , for example, a pair of fingers) and so on until the request is filled. The request can be filled in a certain sequence parallel, and/or in a random fashion. The picking robot 809 can also have sufficient space to temporarily store all the requested packages to fill the request. In some embodiments, the picking robot 809 is configured to have only limited space to temporarily store the packages. In such embodiments, the local computer is configured to calculate the maximum number of packages (based on information of the foot print sizes of each packages) that can be fit on the limited space. The local computer then commands the picking robot 809 to pick up only the maximum number of packages per load. In an alternative embodiment, the picking robot can be replaced with an A-frame or other picking methods, including manual methods. Alternative control structures or architectures may be used with respect to the local and host computers. For example, in an alternative embodiment, the host computer or other central computer may perform one or more of the functions of the local computer.
[0116] Once the packages are picked up, the picking robot 809 traverses to the package disposing location to unload the picked packages. The picking robot 809 can be placed into the picking robot maintenance area 1101 for regularly scheduled maintenance.
[0117] [0117]FIGS. 12 and 13 show certain components of the example embodiment shown in FIGS. 9 - 11 and operations thereof. More specifically, FIG. 12 illustrates the bottle storage table 805 for the bottles, the picking robot 809 and the conveyor belt 803 for the literature packs. The bottles, packages and literature packs are combined in the order consolidation station 811 and put into one or more bags at the bagger 813 . In operation, bottles filled with counted pills are stored into the bottle storage table 805 (step 1301 ). When a complete set of bottles is received by the bottle storage table 805 , its local computer notifies the host computer 201 that all the bottles for a particular order have been received (step 1303 ). In response, the host computer 201 causes literature packs for the order to be printed (step 1305 ) and sent to the dispatch unit (either in a batch or individually) (step 1307 ). When the literature packs are received, they are organized such that literature packs for one order are next to each other. The dispatch unit 801 also determines the sequence of orders that the literature packs are received by reading identification codes affixed (or printed) on the literature packs. The dispatch unit 801 then sends the literature packs, as they are received and sequenced, to the order consolidation station 811 via the conveyor belt 803 . The dispatch unit 801 also notifies the host computer 201 the sequence of literature packs.
[0118] Upon receiving the information from the dispatch unit 801 , the host computer 201 then instructs the bottle storage table 805 to release corresponding bottles and the picking robot 809 to pick corresponding packages of the order (steps to 1309 and 1311 ). The example embodiment is further configured such that the bottles, packages and literature packs all arrive at the bagger 803 simultaneously for each order, although the bagger 803 can optionally receive them at different times in storage locations for later bagging. This configuration allows the bagger 803 to put the bottles, packages, and literature packs into one or more bags automatically.
[0119] Now referring to FIG. 14, there is shown mechanical/schematic illustration of an example embodiment of the dispenser for the packages 205 and consolidation station 215 . In particular, FIG. 14 shows an example package scanning and labeling station 1401 . The station 1401 includes an induct belt 1403 configured to receive packages picked and unloaded by the picking robot 809 . The received packages are then transported to a separation and accumulation belt 1405 configured to put gaps between the packages. The separation and accumulation belt 1405 then moves the packages into a set of barcode scanners 1407 configured to detect and read barcodes from any of five exposed sides of the packages. (Since the packages are boxes, when the packages are placed on the belt 1405 , five sides are exposed other than the side that touches the belt.) In such embodiments, when the packages are replenished into the shelves, their barcodes should not be on the bottom. In some other embodiments, only a top side can be scanned as long as the packages are placed into the shelves so that their barcodes are on the top. Accordingly, any combination of barcode readers can be used as long as barcodes on the packages can be detected and read. It should be noted that in some embodiments of the present invention, the belt 1405 can be transparent so that barcodes from the bottom side of the packages can also be detected and read by a barcode reader located below the belt 1405 .
[0120] When barcodes are read, they are verified by a local computer. The local computer ensures that the scanned package actually belongs to the order that is about to be filled by the consolidation station 215 . After the barcode scanners 1407 are used, the images of the packages are captured by a camera 1409 . The images are then sent to the local computer to determine the shape and orientation of the packages as they lay on the belt 1405 . Based on the determined shape, height and orientation, the local computer commands a robot arm to pick up the package from the belt 1405 . An example of conventional computer vision software includes Adept AIM System, Motionware, Robot & Vision, Version 3.3B-Jun. 9, 1999, U.S. Pat. No. 4,835,730.
[0121] [0121]FIGS. 15A, 16 and 17 schematically show example components of the storage device for packages 203 , dispenser for the packages 205 and consolidation station 215 . FIGS. 15 B-E show mechanical drawings of parts of these example components in different perspective views. As part of the dispenser for the packages 205 , the example embodiment includes the induct conveyor belt 1403 for the packages, the conveyor belt 1405 for the packages, the barcode tunnel 1407 , a order labeler 1501 , a label barcode reader 1503 and a robot 1505 . An example of conventional label printers includes Zebra Technologies Corp., Model: 90XiIII, Address: 333. Corporate Woods Parkway, Vernon Hills, Ill. 60061. And, and example of conventional robots includes Staubi Corp., Model: RX60, Address: 201 Parkway West, P.O Box 189; Hillside Park, Duncan, S.C. 29334.
[0122] Similar to the example embodiment shown in FIG. 14, the packages are transported through the barcode tunnel 1407 that detects and reads barcodes on the packages. The packages are then picked up by the robot 1505 (using its end effector 1601 as shown in FIG. 16). The local computer causes a patient label to be printed by the patient labeler 1501 for each package. The information printed on the labels and the form of the labels are discussed below in connection with FIG. 18. While a package is picked up by the robot 1505 and being transported, its label is affixed to the package. Then the robot 1505 swings the package next to the barcode reader 1503 . The presence of a correct label is determined by the label barcode reader 1503 . In addition, the robot 1501 , label barcode reader 1503 , and their local computer can also be configured to cooperate with each other to detect the labels and reject any packages without a label or with an incorrect label. Once, the package is determined to have a correct label affixed thereto, the robot 1505 can drop the package into the bag opened in the bagger 813 as will be discussed below in connection with FIGS. 19 - 20 .
[0123] With respect to the bottles, they are transported via a metal detect conveyor 1509 which has a metal detector 1511 rejected thereon. In such example embodiments, the bottles are passed through the metal detector 1511 which determines any presence of metallic substances in the bottles. Bottles with metallic substances are rejected. The bottles belonging to one order are then placed into a bottle magazine 1513 by a pick-and-place device 1507 . An example of pick-and-place devices includes Stelron, Model: SVIP-A-M-P-6.00, X-2.00 Y-spec, U.S. Pat. No. 3,703,834, Mahwah, N.J. In this example embodiment, a bottle barcode reader is provided to ensure that correct bottles have been delivered to the bottle magazine. Once all the bottles have been loaded to the bottle magazine, they can be released into the bag opened by the bagger 813 all will be discussed below in connection with FIGS. 19 - 20 .
[0124] With respect to the literature packs, they are transported to the bagger 813 via the literature conveyor 803 . As the packs arrive at the bagger 813 , their barcodes are detected and checked by a literature barcode reader 1517 . The literature barcode reader 1517 and it local computer ensures that correct literature packs are to be included in the bag. As the literature packs arrive, they are discharged into the bag as will be discussed below in connection with FIGS. 19 - 20 .
[0125] [0125]FIG. 18 illustrates an example label 1801 to be affixed on a package. The label has patient information printed thereon. For instance, the patient information may include one or any combination of the following information: the name of the doctor; how often the package is to be taken by the patient; the name of the drug; the manufacturer of the drug; the number or strength of the drug; any warnings; any refills; and/or the number of or quantity of the packages being dispensed, directly or indirectly, to the patient, if it is standard patient label information. Other information as required may alternatively be printed or placed on the label as well.
[0126] The label, after being printed, is folded up so that one surface has adhesive placed thereon and the other surface has an identification mark (e.g., barcodes) printed thereon. An example of a folded label is shown as 1803 . The side with the adhesive is placed on its corresponding package and pressed thereon in order to securely attach the label to its package. When the label is folded up, its size is approximately, a one and one-half inch long by one and one-half inch wide. When the label is not folded, the label is about eleven inches long in its width is one and one-half inches. A wrapping tool is provided to fold up the labels.
[0127] In contrast to the prior art Outserts which do not contain information specific to any patient, the present invention advantageously includes patient specific information on the label.
[0128] [0128]FIG. 19 illustrates the steps taken by the various components, their local computers, and the host computer 201 in the order consolidation station 215 . In particular, bottles belonging to one order number are received from the bottle storage table 805 (step 1901 ). The received bottles are run through the metal detector 1511 (step 1903 ). The bottles are then mounted on the bottle magazine 1513 by the pick-and-place device 1507 (step 1905 ). Simultaneously, packages belonging to the same order number are received from the storage device for packages 203 (step 1907 ). A label is affixed to each of the received packages (step 1909 ). Again simultaneously, the conveyor belt 803 moves literature packs belonging to the same order number to the bagger. When all the items arrive, they are disposed into one or more bags at the bagger 813 .
[0129] If any error is detected, the items belonging to the same order number are all sent to a quality assurance station. If the error cannot be resolved, the order is cancelled and re-ordered. The host computer 201 reinitiates the process from the beginning to fill the order again. The example errors can be a rejected bottle because a metallic substance was detected, a patient label not being affixed to a package, incorrect literature packs being delivered, etc.
[0130] Now referring to FIG. 20, there is shown an example embodiment of the bagger 813 in detail. The example bagger 813 includes a supply of bags 2001 , a printer 2003 , tamp 2004 , a scanner 2005 , a mechanism 2006 to open a bag and hold it open and a mechanism 2007 to seal the bag. In operation, bags are fed from the bag supply 2001 one at a time. As the bags move up through the bagger 815 , a label or information about the order that is about to be filled is placed on the bag. For example, The label may be printed and then pressed against the bag by the tamp 2004 . The label or information is then detected and read by the scanner 2005 . The scanner determines whether the correct label is printed and/or the label is properly affixed to the bag. The bag is then opened to receive the items in the manner as described above in connection with FIG. 19. If the bag contains all the items necessary to fill the order, then the bag is sealed. Optionally, the bag is not sealed, if an error is detected. If one or more manually picked packages are required as described above in connection with FIG. 7, then the bag is left unsealed. Although the present invention includes a bagger as described above, any container that can receive various pharmaceutical products and literature packs are also contemplated within this invention.
[0131] Now referring back to FIG. 15A, since the sealed bags are ready to be distributed or mailed, they are put on, for example, a conveyor belt 1519 . For the unsealed bags, they are put on a tote conveyor 1521 in a tote. The tote is then transferred to an operator who can then completely fill the order by manually adding the required package(s).
[0132] In order to fill order in the manner described above in connection with FIG. 19 in a continuous basis, flow logic, error detection and/or correction may be required. FIG. 21 illustrates an example process called consolidation logic 2101 and its interface with other example control logic processes for various components. The logic processes can run on the host computer 201 and/or in combination with the local computers.
[0133] For example, a literature handling process 2103 can interact with the consolidation logic process 2101 to ensure correct literature packs are included when a order is filled. As shown in FIG. 17, the conveyor belt has three positions. Position 1 designates the position on the belt 803 in which its literature pack is ready to be disposed into the bag at the bagger 813 . Position 2 designates the position on the belt 803 in which its literature pack can be discarded if some error is detected. Position 3 designates the position on the belt in which the barcode reader 1517 shown in FIG. 15A detects and reads the barcode of the literature pack. The literature handling logic 2103 can report on the status of the literature packs in the three positions. In turn, the consolidation logic process 2101 can instruct the literature handling logic process 2103 to perform one or more tasks (e.g., accept or reject certain literature packs and/or advance the conveyor belt 803 ).
[0134] For example, in FIG. 22, the consolidation logic 2101 starts by querying whether the literature packs are in a steady state (step 2201 ). In other words, the process 2101 is attempting to determine if the literature packs are being supplied by the conveyor belt 803 . It is also attempting to determine if any literature packs have been consolidated. It then determines if there are literature packs in positions 1 and 2 (steps 2201 and 2203 ). If the answer is affirmative, then it further determines if the literature pack in the position 2 is in the same order as the literature packs were picked by the dispatch unit 801 and fed to the conveyor belt 803 (step 2209 ). If not, the literature pack in the position 2 is discarded (step 2209 ). If affirmative, then the consolidation logic 2101 further determines if the literature pack in the position 2 is consolidated (step 2211 ). If affirmative, then the literature pack in position 2 is discarded (step 2209 ). Subsequently, the belt 803 is moved one position to repeat the processes. In this way, multiple literature packs can be put into one bag.
[0135] In some occasions, a bag at the bagger 813 cannot receive all the items. A second bag may be required to put literature packs only. This is called a literature pack only order. For such an order, the bagger 813 is not required to print a mailing label. As shown in FIG. 23, the logic process 2101 first determines if the literatures pack in the position 2 is for literature only order (step 2301 ). If so, the literature pack is discharged (step 2303 ). If not, the process confirms the barcode is detected and read the barcode on the literature pack (step 2305 ). If so, the process further determines if the literature pack in the position 1 is for the bottles in the bottle magazine (step 2307 ). If so, the process also determines if the print queue in the bagger is in a literature only mode (i.e., not required to print any label) (step 2309 ). If so, then the literature pack is discharged (step 2303 ). FIGS. 24 - 26 show various other decisions to be made by the literature handling logic process 2103 and consolidation logic process 2101 .
[0136] Now referring back to FIG. 21, besides the literature handling logic 2103 , the consolidation logic process 2101 also interacts with other processes (e.g., a robot process 2105 , patient label printer process 2107 , bagger process 2109 , etc.). It should be noted that FIGS. 21 - 26 are provided herein only as a part of an example embodiment in which orders are continuously filled in a high speed. Furthermore, these logic processes are specifically engineered only in the case with specific implementations. For example, if there are four or more positions for the literature packs rather than three as described above, then the logic processes would be required to be correspondingly changed. Hence, one of ordinary skill in the art can appreciate possible permutations and combination of logic processes for various control flow logic implementations.
[0137] In addition, instead of relying solely on logic processes, in other example embodiments, manual processes can also be implemented. For instance, if an error is detected, the bag and its contents can be sent to quality assurance stations where one or more operators can check and correct the errors.
[0138] [0138]FIG. 27 is a computer networking diagram illustrating an example embodiment in which the host computer 201 , local computers and their various processes are connected to each other. In this example embodiment, the host computer 201 includes two main processes: an ADS-PAC process 2701 and a CADS-PAC process 2703 . The ADS-PAC process 2701 controls the way in which pills are dispensed into bottles in an automated pill dispensing device (e.g., the ADDS shown in FIG. 1). A bottle table 1 (one of many tables) includes a PLC 2705 . The PLC 2705 is in turn connected to a bottle table communication node 2707 via a dedicated link 2709 (e.g., Ethernet). The node 2707 is then connected to the ADS-PAC 2701 via another dedicated link. Alternatively, the ADS-PAC and the CADS-PAC process may be combined or separated using a variety of standard methods or programming techniques.
[0139] Once bottles are filled for one or more orders, the information relating to those orders is transferred over to the CAD-PAC process 2703 . This process then carries out the consolidation process. For example, the CAD-PAC process 2703 is connected to an AOC cell communication node 2709 via a dedicated line. The controller for the patient label printer 2711 is controlled directly by the AOC node 2709 over an RS-232 line 2713 because relatively large data need to be transferred to the printer to print the patient labels (similarly, the controller for the bagger printer 2715 also has a direct connection to the AOC node 2709 ). Other devices, for example, the controller for literature dispatch unit 2717 , are indirectly connected to the AOC node 2709 via an AOC cell PLC 2719 .
[0140] [0140]FIG. 28 is an illustration of the architecture of the combined Internet, POTS (plain, old, telephone service), and ADSL (asymmetric, digital, subscriber line) for use in accordance with the principles of the present invention. In other words, instead of using dedicated lines and such communication schemes as shown in FIG. 27, this example embodiment envisions a remotely controllable system. Furthermore, it is to be understood that the use of the Internet, ADSL, and POTS are for exemplary reasons only and that any suitable communications network may be substituted without departing from the principles of the present invention. This particular example is briefly discussed below.
[0141] In FIG. 28, to preserve POTS and to prevent a fault in the ADSL equipment 2854 , 2856 from compromising analog voice traffic 2826 the voice part of the spectrum (the lowest 4 kHz) is separated from the rest by a passive filter, called a POTS splitter 2858 , 2860 . The rest of the available bandwidth—from about 10 kHz to 1 MHz—carries data at rates up to 6 bits per second for every hertz of bandwidth from data equipment 2862 , 2864 , and 2894 . The ADSL equipment 2856 then has access to a number of destinations including significantly the Internet 2820 or other data communications networks, and other destinations 2870 , 2872 .
[0142] To exploit the higher frequencies, ADSL makes use of advanced modulation techniques, of which the best known is the discrete multitone (DMT) technology. As its name implies, ADSL transmits data asymmetrically—at different rates upstream toward the central office 2852 and downstream toward the subscriber 2850 .
[0143] Cable television services are providing analogous Internet service to PC users over their TV cable systems by means of special cable modems. Such modems are capable of transmitting up to 30 Mb/s over hybrid fiber/coax system, which use fiber to bring signals to a neighborhood and coax to distribute it to individual subscribers.
[0144] Cable modems come in many forms. Most create a downstream data stream out of one of the 6-MHz TV channels that occupy spectrum above 50 MHz (and more likely 550 MHz) and carve an upstream channel out of the 5-50-MHz band, which is currently unused. Using 64-state quadrature amplitude modulation (64 QAM), a downstream channel can realistically transmit about 30 Mb/s (the oft-quoted lower speed of 10 Mb/s refers to PC rates associated with Ethernet connections). Upstream rates differ considerably from vendor to vendor, but good hybrid fiber/coax systems can deliver upstream speeds of a few megabits per second. Thus, like ADSL, cable modems transmit much more information downstream than upstream. Then Internet architecture 2820 and ADSL architecture 2854 , 2856 may also be combined with, for example, user networks 2822 , 2824 , and 2028 .
[0145] In accordance with the principles of the present invention, in one example, a main computing server (e.g., the host computer 201 ) implementing the process of the invention may be located on one or more computing nodes or terminals (e.g., on user networks 2822 , 2824 , and 2828 or system 2840 ). Then, various users (e.g., one or more of the local computers described above) may interface with the main server via, for instance, the ADSL equipment discussed above, and access the information and processes of the present invention from remotely located PCs. As illustrated in this embodiment, users may access, use or interact with the computer assisted program in computer system 2840 via various access methods. Databases 2885 , 2886 , 2887 , 2888 , and 2840 are accessible via, for example computer system 2840 and may be used in conjunction with client manager module 2891 , tracking module 2892 , for the various functions described above.
[0146] Viewed externally in FIG. 29, a computer system (e.g., the host computer 201 or the local computers) designated by reference numeral 2940 has a computer 2942 having disk drives 2944 and 2946 . Disk drive indications 2944 and 2946 are merely symbolic of a number of disk drives which might be accommodated by the computer system. Typically, these would include a floppy disk drive 2944 , a hard disk drive (not shown externally) and a CD ROM indicated by slot 2946 . The number and type of drives vary, typically with different computer configurations. Disk drives 2944 and 2946 are in fact optional, and for space considerations, are easily omitted from the computer system used in conjunction with the production process/apparatus described herein.
[0147] The computer system also has an optional display upon which information screens may be displayed. In some situations, a keyboard 2950 and a mouse 2952 are provided as input devices through which a user's actions may be inputted, thus allowing input to interface with the central processing unit 2942 . Then again, for enhanced portability, the keyboard 2950 is either a limited function keyboard or omitted in its entirety. In addition, mouse 2952 optionally is a touch pad control device, or a track ball device, or even omitted in its entirety as well, and similarly may be used to input a user's selections. In addition, the computer system also optionally includes at least one infrared transmitter and/or infrared received for either transmitting and/or receiving infrared signals, as described below.
[0148] [0148]FIG. 30 illustrates a block diagram of one example of the internal hardware 3040 configured to perform various example steps as described above. A bus 3056 serves as the main information highway interconnecting various components therein. CPU 3058 is the central processing unit of the internal hardware 3040 , performing calculations and logic operations required to execute the control/operation processes of the present invention as well as other programs. Read only memory (ROM) 3060 and random access memory (RAM) 3062 constitute the main memory of the internal hardware 2140 . Disk controller 3064 interfaces one or more disk drives to the system bus 3056 . These disk drives are, for example, floppy disk drives 3070 , or CD ROM or DVD (digital video disks) drives 3066 , or internal or external hard drives 3068 . These various disk drives and disk controllers are optional devices.
[0149] A display interface 3072 interfaces display 3048 and permits information from the bus 3056 to be displayed on display 3048 . Communications with external devices such as the other components (e.g., a PLC) of the system described above, occur utilizing, for example, communication port 3074 . Optical fibers and/or electrical cables and/or conductors and/or optical communication (e.g., infrared, and the like) and/or wireless communication (e.g., radio frequency (RF), and the like) can be used as the transport medium between the external devices and communication port 3074 . Peripheral interface 3054 interfaces the keyboard 3050 and mouse 3052 , permitting input data to be transmitted to bus 3056 . In addition to these components, the internal hardware 3040 also optionally include an infrared transmitter and/or infrared receiver. Infrared transmitters are optionally utilized when the computer system is used in conjunction with one or more of the processing components/stations/modules that transmits/receives data via infrared signal transmission. Instead of utilizing an infrared transmitter or infrared receiver, the computer system may also optionally use a low power radio transmitter 3080 and/or a low power radio receiver 3082 . The low power radio transmitter transmits the signal for reception by components of the production process, and receives signals from the components via the low power radio receiver. The low power radio transmitter and/or receiver are standard devices in industry.
[0150] Although the server in FIG. 31 is illustrated having a single processor, a single hard disk drive and a single local memory, the analyzer is optionally suitably equipped with any multitude or combination of processors or storage devices. For example, the computer may be replaced by, or combined with, any suitable processing system operative in accordance with the principles of embodiments of the present invention, including sophisticated calculators, and hand-held, laptop/notebook, mini, mainframe and super computers, as well as processing system network combinations of the same.
[0151] [0151]FIG. 31 is an illustration of an example computer readable memory medium 3184 utilizable for storing computer readable code or instructions. As one example, medium 3184 may be used with disk drives illustrated in FIG. 30. Typically, memory media such as floppy disks, or a CD ROM, or a digital video disk will contain, for example, a multi-byte locale for a single byte language and the program information for controlling the modeler to enable the computer to perform the functions described herein. Alternatively, ROM 3060 and/or RAM 3062 illustrated in FIG. 30 can also be used to store the program information that is used to instruct the central processing unit 3058 to perform the operations associated with various automated processes of the present invention. Other examples of suitable computer readable media for storing information include magnetic, electronic, or optical (including holographic) storage, some combination thereof, etc.
[0152] In general, it should be emphasized that the various components of embodiments of the present invention can be implemented in hardware, software or a combination thereof. In such embodiments, the various components and steps would be implemented in hardware and/or software to perform the functions of embodiments of the present invention. Any presently available or future developed computer software language and/or hardware components can be employed in such embodiments of the present invention. For example, at least some of the functionality mentioned above could be implemented using Visual Basic, C, C++, or any assembly language appropriate in view of the processor(s) being used. It could also be written in an interpretive environment such as Java and transported to multiple destinations to various users.
[0153] The many features and advantages of embodiments of the present invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | Computer assisted systems, methods and mediums for filling one or more orders. One embodiment of the present invention is a system that includes an order consolidation station configured to receive at least one bottle containing pills individually counted and/or at least one package containing pharmaceutical products without having been designated for any of the orders when the package was created and/or at least one literature pack optionally including patient specific information. The order consolidation station is further configured to combine automatically the received bottle and/or package and/or literature pack into a container to be sent to a recipient including, for example, mail order pharmacies, wholesalers and/or central fill dealers for subsequent distribution or sale including retailer distribution or sale. The bottle is specifically designated for the order, and the order generally includes at least one prescription for the package. | 98,200 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of application Ser. No. 09/921,615, filed Aug. 3, 2001, pending, which is a continuation of application Ser. No. 09/495,534, filed Jan. 31, 2000, now U.S. Pat. No. 6,291,340, issued Sep. 18, 2001, which is a continuation of application Ser. No. 09/012,685, filed Jan. 23, 1998, now U.S. Pat. No. 6,081,034, issued Jun. 27, 2000, which is a continuation of application Ser. No. 08/509,708, filed Jul. 31, 1995, now U.S. Pat. No. 5,723,382, issued Mar. 3, 1998, which is a continuation-in-part of U.S. application Ser. 08/228,795, filed Apr. 15, 1994, now abandoned, which is a continuation of now abandoned U.S. application Ser. 07/898,059, filed Jun. 12, 1992.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to integrated circuit manufacturing technology and, more specifically, to structures for making low resistance contact through a dielectric layer to a diffusion region in an underlying silicon layer. The structures include an amorphous titanium nitride barrier layer that is deposited via chemical vapor deposition.
[0004] 2. State of the Art
[0005] The compound titanium nitride (TiN) has numerous potential applications because it is extremely hard, chemically inert (although it readily dissolves in hydrofluoric acid), an excellent conductor, possesses optical characteristics similar to those of gold, and has a melting point around 3000° C. This durable material has long been used to gild inexpensive jewelry and other art objects. However, during the last ten to twelve years, important uses have been found for TiN in the field of integrated circuit manufacturing. Not only is TiN unaffected by integrated circuit processing temperatures and most reagents, it also functions as an excellent barrier against diffusion of dopants between semiconductor layers. In addition, TiN also makes excellent ohmic contact with other conductive layers.
[0006] In a common application for integrated circuit manufacture, a contact opening is etched through an insulative layer down to a diffusion region to which electrical contact is to be made. Titanium metal is then sputtered over the wafer so that the exposed surface of the diffusion region is coated. The titanium metal is eventually converted to titanium silicide, thus providing an excellent conductive interface at the surface of the diffusion region. A titanium nitride barrier layer is then deposited, coating the walls and floor of the contact opening. Chemical vapor deposition of tungsten or polysilicon follows. In the case of tungsten, the titanium nitride layer provides greatly improved adhesion between the walls of the opening and the tungsten metal. In the case of the polysilicon, the titanium nitride layer acts as a barrier against dopant diffusion from the polysilicon layer into the diffusion region.
[0007] Titanium nitride films may be created using a variety of processes. Some of those processes are reactive sputtering of a titanium nitride target; annealing of an already deposited titanium layer in a nitrogen ambient; chemical vapor deposition at high temperature and at atmospheric pressure, using titanium tetrachloride, nitrogen and hydrogen as reactants; and chemical vapor deposition at low-temperature and at atmospheric pressure, using ammonia and Ti(NR 2 ) 4 compounds as precursors. Each of these processes has its associated problems.
[0008] Both reactive sputtering and nitrogen ambient annealing of deposited titanium result in films having poor step coverage, which are not useable in submicron processes. Chemical vapor deposition (CVD) processes have an important advantage in that conformal layers of any thickness may be deposited. This is especially advantageous in ultra-large-scale-integration circuits, where minimum feature widths may be smaller than 0.5 μm. Layers as thin as 10 Å may be readily produced using CVD. However, TiN coatings prepared using the high-temperature atmospheric pressure CVD (APCVD) process must be prepared at temperatures between 900-1000° C. The high temperatures involved in this process are incompatible with conventional integrated circuit manufacturing processes. Hence, depositions using the APCVD process are restricted to refractory substrates such as tungsten carbide. The low-temperature APCVD, on the other hand, though performed within a temperature range of 100-400° C. that is compatible with conventional integrated circuit manufacturing processes, is problematic because the precursor compounds (ammonia and Ti(NR 2 ) 4 ) react spontaneously in the gas phase. Consequently, special precursor delivery systems are required to keep the gases separated during delivery to the reaction chamber. In spite of special delivery systems, the highly spontaneous reaction makes full wafer coverage difficult to achieve. Even when achieved, the deposited films tend to lack uniform conformality, are generally characterized by poor step coverage, and tend to deposit on every surface within the reaction chamber, leading to particle problems.
[0009] U.S. Pat. No. 3,807,008, which issued in 1974, suggested that tetrakis dimethylamino titanium, tetrakis diethylamino titanium, or tetrakis diphenylamino titanium might be decomposed within a temperature range of 400-1,200° C. to form a coating on titanium-containing substrates. It appears that no experiments were performed to demonstrate the efficacy of the suggestion, nor were any process parameters specifically given. However, it appears that the suggested reaction was to be performed at atmospheric pressure.
[0010] In U.S. Pat. No. 5,178,911, issued to R. G. Gordon, et al., a chemical vapor deposition process is disclosed for creating thin, crystalline titanium nitride films using tetrakis-dimethylamido-titanium and ammonia as precursors.
[0011] In the J. Appl. Phys. 70(7) October 1991, pp 3,666-3,677, A. Katz and colleagues describe a rapid-thermal, low-pressure, chemical vapor deposition (RTLPCVD) process for depositing titanium nitride films, which, like those deposited by the process of Gordon, et al., are crystalline in structure.
BRIEF SUMMARY OF THE INVENTION
[0012] This invention constitutes a contact structure incorporating an amorphous titanium nitride barrier layer formed via low-pressure chemical vapor deposition (LPCVD) utilizing tetrakis-dialkylamido-titanium, Ti(NMe 2 ) 4 , as the precursor. Although the barrier layer compound is primarily amorphous titanium nitride, its stoichiometry is variable, and it may contain carbon impurities in amounts which are dependent on deposition and post-deposition conditions. The barrier layers so deposited demonstrate excellent step coverage, a high degree of conformality, and an acceptable level of resistivity. Because of their amorphous structure (i.e., having no definite crystalline structure), the titanium nitride layer acts as an exceptional barrier to the migration of ions or atoms from a metal layer on one side of the titanium carbonitride barrier layer to a semiconductor layer on the other side thereof, or as a barrier to the migration of dopants between two different semiconductor layers which are physically separated by the barrier layer.
[0013] The contact structure is fabricated by etching a contact opening through a dielectric layer down to a diffusion region to which electrical contact is to be made. Titanium metal is deposited over the surface of the wafer so that the exposed surface of the diffusion region is completely covered by a layer of the metal. Sputtering is the most commonly utilized method of titanium deposition. At least a portion of the titanium metal layer is eventually converted to titanium silicide, thus providing an excellent conductive interface at the surface of the diffusion region. A titanium nitride barrier layer is then deposited using a low-pressure chemical vapor deposition (LPCVD) process, coating the walls and floor of the contact opening. Chemical vapor deposition (CVD) of polycrystalline silicon, or of a metal, such as tungsten, follows, and proceeds until the contact opening is completely filled with either polycrystalline silicon or the metal. In the case of the polysilicon, which must be doped with N-type or P-type impurities to render it conductive, the titanium nitride layer acts as a barrier against dopant diffusion from the polysilicon layer into the diffusion region. In the case of CVD tungsten, the titanium nitride layer protects the junction from reactions with precursor gases during the CVD deposition process, provides greatly improved adhesion between the walls of the opening and the tungsten metal, and prevents the diffusion of tungsten atoms into the diffusion region.
[0014] Deposition of the titanium nitride barrier layer takes place in a low-pressure chamber (i.e. a chamber in which pressure has been reduced to less than 100 torr prior to deposition), and utilizes a metal-organic tetrakis-dialkylamido-titanium compound as the sole precursor. Any noble gas, as well as nitrogen or hydrogen, or a mixture of two or more of the foregoing may be used as a carrier for the precursor. The wafer is heated to a temperature within a range of 200-600° C. Precursor molecules which contact the heated wafer are pyrolyzed to form titanium nitride containing variable amounts of carbon impurities, which deposits as a highly conformal film on the wafer.
[0015] The carbon content of the barrier film may be minimized by utilizing tetrakis-dimethylamido-titanium, Ti(NMe 2 ) 4 , as the precursor, rather than compounds such as tetrakis-diethylamido-titanium or tetrakis-dibutylamido-titanium, which contain a higher percentage of carbon by weight. The carbon content of the barrier film may be further minimized by performing a rapid thermal anneal step in the presence of ammonia.
[0016] The basic deposition process may be enhanced to further reduce the carbon content of the deposited titanium nitride film by introducing one or more halogen gases, or one or more activated species (which may include halogen, NH 3 , or hydrogen radicals) into the deposition chamber. Halogen gases and activated species attack the alkyl-nitrogen bonds of the primary precursor and convert displaced alkyl groups into volatile compounds.
[0017] As heretofore stated, the titanium carbonitride films formed by the instant chemical vapor deposition process are principally amorphous compounds. Other processes currently in use for depositing titanium nitride-containing compounds as barrier layers within integrated circuits result in titanium nitride having crystalline structures. As atomic and ionic migration tends to occur at crystal grain boundaries, an amorphous film is a superior barrier to such migration.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0018] [0018]FIG. 1 is a block schematic diagram of a low-pressure chemical vapor deposition reactor system;
[0019] [0019]FIG. 2 is an X-ray spectrum (i.e., a plot of counts per second as a function of 2-theta);
[0020] [0020]FIG. 3 is a cross-sectional view of a contact opening having a narrow aspect ratio that has been etched through an insulative layer to an underlying silicon substrate, the insulative layer and the contact opening having been subjected to a blanket deposition of titanium metal;
[0021] [0021]FIG. 4 is a cross-sectional view of the contact opening of FIG. 3 following the deposition of an amorphous titanium nitride film;
[0022] [0022]FIG. 5 is a cross-sectional view of the contact opening of FIG. 4 following an anneal step; and
[0023] [0023]FIG. 6 is a cross-sectional view of the contact opening of FIG. 5 following the deposition of a conductive material layer.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The integrated circuit contact structure that is the focus of this disclosure is unique because of the use of a predominantly amorphous titanium or titanium carbonitride barrier layer therein. The layer is deposited using a low-pressure chemical vapor deposition (LPCVD) process that is the subject of previously filed U.S. patent applications as heretofore noted.
[0025] The LPCVD process for depositing highly conformal titanium nitride and titanium carbonitride barrier films will now be briefly described in reference to the low-pressure chemical vapor deposition reactor system depicted in FIG. 1. The deposition process takes place in a cold wall chamber 11 . A wafer 12 , on which the deposition will be performed, is mounted on a susceptor plate 13 , which is heated to a temperature within a range of 200-600° C. by a heat lamp array 14 . For the instant process, a carrier gas selected from a group consisting of the noble gases and nitrogen and hydrogen is bubbled through liquid tetrakis-dialkylamido-titanium 15 (the sole metal-organic precursor compound) in a bubbler apparatus 16 .
[0026] It should be noted that tetrakis-dialkylamido-titanium is a family of compounds, of which tetrakis-dimethylamido-titanium, tetrakis-diethylamido-titanium and tetrakis-dibutylamido-titanium have been synthesized. Because of its lower carbon content per unit of molecular weight, tetrakis-dimethylamido-titanium is the preferred precursor because it results in barrier films having lower carbon content. However, any of the three compounds or any combination of the three compounds will result in highly conformal barrier layers when pyrolyzed (decomposition by heating) in a CVD deposition chamber. These barrier layers are characterized by an amorphous structure, and by step coverage on vertical wall portions near the base of submicron contact openings having depth-to-width aspect ratios of 3:1 that range from 80-90 percent of the horizontal film thickness at the top of the opening.
[0027] Still referring to FIG. 1, the carrier gas, at least partially saturated with a vaporized precursor compound, is transported via a primary intake manifold 17 to a premix chamber 18 . Additional carrier gas may be optionally supplied to premix chamber 18 via supply tube 19 . Carrier gas, mixed with the precursor compound, is then ducted through a secondary intake manifold 20 to a shower head 21 , from which they enter the chamber 11 . The precursor compound, upon coming into contact with the heated wafer, pyrolyzes and deposits as a highly conformal titanium carbonitride film on the surface of the wafer 12 . The reaction products from the pyrolysis of the precursor compound are withdrawn from the chamber 11 via an exhaust manifold 22 . Incorporated in the exhaust manifold 22 are a pressure sensor 23 , a pressure switch 24 , a vacuum valve 25 , a pressure control valve 26 , a blower 27 , and a particulate filter 28 , which filters out solid reactants before the exhaust is vented to the atmosphere. During the deposition process, the pressure within chamber 11 is maintained at a pressure of less than 100 torr and at a pressure of less than 1 torr by pressure control components 23 , 24 , 25 , 26 , and 27 . The process parameters that are presently deemed to be optimum, or nearly so, are a carrier gas flow through secondary intake manifold 20 of 400 standard cubic centimeters per minute (scc/m), a deposition chamber temperature of 425° C., and a flow of carrier gas through bubbler apparatus 16 of 100 scc/m, with the liquid precursor material 15 being maintained at a constant temperature of approximately 40° C.
[0028] Thus, the carrier gas (or gases) and the vaporized precursor compound are then gradually admitted into the chamber until the desired pressure and gas composition is achieved. The reaction, therefore, takes place at a constant temperature, but with varying gas partial pressures during the initial phase of the process. This combination of process parameters is apparently responsible for the deposition of titanium carbonitride having a predominantly amorphous structure as the precursor compound undergoes thermal decomposition. The X-ray spectrum of FIG. 2 is indicative of such an amorphous structure. Both the peak at a 2-theta value of 36, which is characteristic of titanium nitride having a ( 111 ) crystal orientation, and the peak at a 2-theta value of 41, which is characteristic of titanium nitride having a ( 200 ) crystal orientation, are conspicuously absent from the spectrum. Such a spectrum indicates that there is virtually no crystalline titanium nitride in the analyzed film. Incidentally, the peak at a 2-theta value of 69 is representative of silicon.
[0029] Although the compound deposited on the wafer with this process may be referred to as titanium carbonitride (represented by the chemical formula TiC x N y ), the stoichiometry of the compound is variable, depending on the conditions under which it is deposited. The primary constituents of films deposited using the new process and tetrakis-dimethylamido-titanium as the precursor are titanium and nitrogen, with the ratio of nitrogen atoms to carbon atoms in the film falling within a range of 5:1 to 10:1. In addition, upon exposure to the atmosphere, the deposited films absorb oxygen. Thus the final film may be represented by the chemical formula TiC x N y O z . The carbon and oxygen impurities affect the characteristics of the film in at least two ways. Firstly, the barrier function of the film is enhanced. Secondly, the carbon and oxygen impurities dramatically raise the resistivity of the film. Sputtered titanium nitride has a bulk sheet resistivity of approximately 75 μohm-cm, while the titanium carbonitride films deposited through the CVD process disclosed herein have bulk sheet resistivities of 2,000 to 50,000 μohm-cm. In spite of this dramatic increase in bulk resistivity, the utility of such films as barrier layers is largely unaffected, due to the characteristic thinness of barrier layers used in integrated circuit manufacture. A simple analysis of the contact geometry for calculating various contributions to the overall resistance suggests that metal (e.g., tungsten) plug resistance and metal-to-silicon interface resistance play a much more significant role in overall contact resistance than does the barrier layer.
[0030] There are a number of ways by which the basic LPCVD process may be enhanced to minimize the carbon content of the deposited barrier film.
[0031] The simplest way is to perform a rapid thermal anneal step in the presence of ammonia. During such a step, much of the carbon in the deposited film is displaced by nitrogen atoms.
[0032] The basic deposition process may be enhanced to further reduce the carbon content of the deposited titanium nitride film by introducing an activated species into the deposition chamber. The activated species attacks the alkyl-nitrogen bonds of the primary precursor, and converts displaced alkyl groups into volatile compounds. The activated species, which may include halogen, NH 3 , or hydrogen radicals, or a combination thereof, are generated in the absence of the primary precursor at a location remote from the deposition chamber. Remote generation of the activated species is required because it is not desirable to employ a plasma CVD process, as Ti(NR 2 ) 4 is known to break down in plasma, resulting in large amounts of carbon in the deposited film. A high carbon content will elevate the bulk resistivity of the film to levels that are unacceptable for most integrated circuit applications. The primary precursor molecules and the activated species are mixed, preferably, just prior to being ducted into the deposition chamber. It is hypothesized that as soon as the mixing has occurred, the activated species begin to tear away the alkyl groups from the primary precursor molecules. Relatively uncontaminated titanium nitride deposits on the heated wafer surface.
[0033] Alternatively, the basic deposition process may be enhanced to lower the carbon content of the deposited titanium nitride films by introducing a halogen gas, such as F 2 , Cl 2 or Br 2 , into the deposition chamber. The halogen gas molecule attacks the alkyl-nitrogen bonds of the primary precursor compound molecule and converts the displaced alkyl groups into a volatile compound. The halogen gas is admitted to the deposition chamber in one of three ways. The first way is to admit halogen gas into the deposition chamber before the primary precursor compound is admitted. During this “pre-conditioning” step, the halogen gas becomes adsorbed on the chamber and wafer surfaces. The LPCVD deposition process is then performed without admitting additional halogen gas into the deposition chamber. As a first alternative, the halogen gas and vaporized primary precursor compound are admitted into the deposition chamber simultaneously. Ideally, the halogen gas and vaporized primary precursor compound are introduced into the chamber via a single shower head having separate ducts for both the halogen gas and the vaporized primary precursor compound. Maintaining the halogen gas separate from the primary precursor compound until it has entered the deposition chamber prevents the deposition of titanium nitride on the shower head. It is hypothesized that as soon as the mixing has occurred, the halogen molecules attack the primary precursor molecules and begin to tear away the alkyl groups therefrom. Relatively uncontaminated titanium nitride deposits on the heated wafer surface. As a second alternative, halogen gas is admitted into the chamber both before and during the introduction of the primary precursor compound.
[0034] As heretofore stated, the titanium nitride or titanium carbonitride films deposited by the described LPCVD process are predominantly amorphous compounds. Other processes currently in use for depositing titanium nitride-containing compounds as barrier layers within integrated circuits result in titanium nitride having crystalline structures. As atomic and ionic migration tends to occur at crystal grain boundaries, an amorphous film is a superior barrier to such migration.
[0035] Referring now to FIG. 3, which is but a tiny cross-sectional area of a silicon wafer undergoing an integrated circuit fabrication process, a contact opening 31 having a narrow aspect ratio has been etched through a borophosphosilicate glass (BPSG) layer 32 to a diffusion region 33 in an underlying silicon substrate 34 . A titanium metal layer 35 is then deposited over the surface of the wafer. Because titanium metal is normally deposited by sputtering, it deposits primarily on horizontal surfaces. Thus, the portions of the titanium metal layer 35 on the walls and at the bottom of the contact opening 31 are much thinner than the portion that is outside of the opening on horizontal surfaces. The portion of titanium metal layer 35 that covers diffusion region 33 at the bottom of contact opening 31 will be denoted 35 A. At least a portion of the titanium metal layer 35 A will be converted to titanium silicide in order to provide a low-resistance interface at the surface of the diffusion region.
[0036] Referring now to FIG. 4, a titanium nitride barrier layer 41 is then deposited utilizing the LPCVD process, coating the walls and floor of the contact opening 31 .
[0037] Referring now to FIG. 5, a high-temperature anneal step in an ambient gas such as nitrogen, argon, ammonia, or hydrogen is performed either after the deposition of the titanium metal layer 35 or after the deposition of the titanium nitride barrier layer 41 . Rapid thermal processing (RTP) and furnace annealing are two viable options for this step. During the anneal step, the titanium metal layer 35 A at the bottom of contact opening 31 is either partially or completely consumed by reaction with a portion of the upper surface of the diffusion region 33 to form a titanium silicide layer 51 . The titanium silicide layer 51 , which forms at the interface between the diffusion region 33 and titanium metal layer 35 A, greatly lowers contact resistance in the contact region.
[0038] Referring now to FIG. 6, a low-resistance conductive layer 62 of metal or heavily-doped polysilicon may be deposited on top of the titanium nitride barrier layer 41 . Tungsten or aluminum metal is commonly used for such applications. Copper or nickel, though more difficult to etch than aluminum or tungsten, may also be used.
[0039] Although only several embodiments of the inventive process have been disclosed herein, it will be obvious to those having ordinary skill in the art that modifications and changes may be made thereto without affecting the scope and spirit of the invention as claimed. | A contact structure incorporating an amorphous titanium nitride barrier layer formed via low-pressure chemical vapor deposition (LPCVD) utilizing tetrakis-dialkylamido-titanium, Ti(NMe 2 ) 4 , as the precursor. The contact structure is fabricated by etching a contact opening through an dielectric layer down to a diffusion region to which electrical contact is to be made. Titanium metal is deposited over the surface of the wafer so that the exposed surface of the diffusion region is completely covered by a layer of the metal. At least a portion of the titanium metal layer is eventually converted to titanium silicide, thus providing an excellent conductive interface at the surface of the diffusion region. A titanium nitride barrier layer is then deposited using the LPCVD process, coating the walls and floor of the contact opening. Chemical vapor deposition of polycrystalline silicon or of a metal follows. | 25,286 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application #60/905,120
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] This invention was made under grants from the National Institutes of Health (R33CA959944; and R01CA97360)
BACKGROUND OF THE INVENTION
[0003] The invention relates generally to methods of identification of cell types on the basis of identification of specific targets, and more specifically to methods of identifying pancreatic cancer cells on the basis of the expression of a particular combination of specific targets.
[0004] The targeting of imaging agents or therapeutic agents to molecular targets on the surface of particular cell types holds considerable promise as a research, diagnostic and therapeutic strategy. Cell surface molecules are often favored because their structural diversity and because agents that target cell surface molecules do not need to cross the plasma membrane to reach their targets. Many targeting agents contain one or more moieties capable of specifically binding a single cell surface protein. Such agents include small molecules and monoclonal antibodies. There have been successes using this approach. In one example, a series of RGD-peptide based ligands coupled with a variety of proteins, small molecules, nucleic acids and radiotracers were developed to deliver therapeutics to tumor vasculature (see reference 18). The 18F-Galacto-RGD ligand was tested in humans and showed desirable pharmacokinetics and good visualization of αvβ3-integrin expression under PET scan (see references 19 and 20). Additionally, radiolabeled monoclonal antibodies that target cell surface antigens were approved as a treatment of B-cell non-Hodgkin's lymphoma (see reference 21). However, while such monospecific (also termed monomeric or monovalent) agents have demonstrated some utility in targeting and identifying some tumors, their use is limited the rare instance in which a target is expressed at a high level on tumor relative to normal tissue. Moreover, agents capable of binding only a single cell surface target might not be specific enough to differentiate one cell type from another (in one nonlimiting example, differentiation of a tumor cell from a noncancerous cell). As a result, some monospecific agents used as therapeutics often cause substantial side effects. Similarly, only a small proportion of cell surface targets are overexpressed in solid tumors relative to normal tissues. Therefore, monospecific ligands are useful in only a small proportion of the potential cell surface targets on solid tumors.
[0005] A multispecific (also termed multimeric or multivalent) ligand, on the other hand, has multiple binding specificities per ligand. Because a multispecific ligand can bind multiple surface targets on a cell, it has a greater overall affinity and avidity to cells expressing a particular combination of targets with minimal binding to cells that express only some or none of the targets. Such a ligand would also be able to select between very similar cell types, indicating new subpopulations of cells. This would have important implications in the fields of research, diagnostics and therapeutics. See references 11, 22-24. Multispecific ligands, then, have great potential. However, the development of such ligands is has been slowed by the difficulty of identifying combinations of targets that, when concurrently expressed, identify a particular cell type. If multispecific ligands are to become a viable treatment option, methods that identify particular cell types using combinations of targets are necessary.
[0006] So as to reduce the complexity and length of the Detailed Specification, and to fully establish the state of the art in certain areas of technology, Applicants herein expressly incorporate by reference all of the following materials identified in each numbered paragraph below. The incorporated materials are not necessarily “prior art” and Applicants expressly reserve the right to swear behind any of the incorporated materials.
1. Jemal A et al, Cancer Statistics, CA Cancer J Clin 56, 106-130 (March/April, 2006). 2. Hale G, Therapeutic antibodies—Delivering the promise?, Adv Drug Deliv Rev, 58 633-639 (May, 2006). 3. Pegram M D et al, Targeted therapy: wave of the future. J Clin Oncol 23 1776-1781 (2005). 4. Reichert J M et al, Monoclonal antibody successes in the clinic. Nat Biotechnol 23 1073-1078 (2005) 5. Richter M and H Zhang, Receptor-targeted cancer therapy. DNA Cell Biol 24 271-282 (2005) 6. Sawyers C, Targeted cancer therapy, Nature, 432 294-297 (2004). 7. Vasir J K and Labhasetwar V, Targeted drug delivery in cancer therapy, Technol Cancer Res Treat, 4 363-374 (2005) 8. Tang P A, M S Tsao and M J Moore, A review of erlotinib and its clinical use, Expert Opin Pharmacother 7 177-193 (Feb, 2006). 9. Moore M J, Brief communication: a new combination in the treatment of advanced pancreatic cancer, Semin Oncol 32 5-6 (2005). 10. Handl H L et al, Hitting multiple targets with multimeric ligands, Expert Opin Ther Targets, 8 565-586 (2004). 11. Vagner J et al, Novel targeting strategy based on multimeric ligands for drug delivery and molecular imaging: homooligomers of alpha-MSH, Bioorg Med Chem Let 14 211-215 (2004). 12. Son C G et al, Database of mRNA gene expression profiles of multiple human organs, Genome Res 15 443-450 (2005). 13. Shyamsundar R et al, A DNA microarray survey of gene expression in normal human tissues, Genome Biol 6 R22.1-R22.7 (2005). 14. Kallioniemi O P et al, Tissue microarray technology for high-throughput molecular profiling of cancer, Hum Mol Genet 10657-662 (2001). 15. Nocito A et al, Tissue microarrays (TMAs) for high-throughput molecular pathology research, Int J Cancer, 94 1-5 (2001). 16. Torhorst J et al, Tissue microarrays for rapid linking of molecular changes to clinical endpoints, Am JPathol 159 2249-2256 (2001). 17. Kononen J et al, Tissue microarrays for high throughput molecular profiling of tumor specimens, Nat Med 4 844-847 (1998). 18. Temming K et al, RGD-based strategies for selective delivery of therapeutics and imaging agents to the tumour vasculature, Drug Resist Update 8 381-402 (2005). 19. Haubner R et al, Noninvasive visualization of the activated alphavbeta3 integrin in cancer patients by positron emission tomography and [18F] Galacto-RGD, PLoS Med, 2, 0244-0252 (2005). 20. Beer A J et al, PET-based human dosimetry of 18F-galacto-RGD, a new radiotracer for imaging alpha v beta3 expression, J Nucl Med 47, 763-769 (May, 2006). 21. Goldenberg D M and Sharkey R M. Novel radiolabeled antibody conjugates, Oncogene 26 3734-3744 (May, 2007). 22. Jhanwar Y S and Divgi C, Current status of therapy of solid tumors, J Nucl Med 46 141S-150S (2005) 23. Goldenberg D M and Sharkey R M, Advances in cancer therapy with radiolabeled antibodies, Q J Nucl Med Mol Imaging 50 248-264 (Dec, 2006). 24. Boturyn D et al, Template assembled cyclopeptides as multimeric system for integrin targeting and endocytosis, J Am Chem Soc, 126 5730-5739 (2004). 25. Handl H L et al, Hitting multiple targets with multimeric ligands, Expert Opin Ther Targets, 8 565-586 (2004). 26. Laugel B et al, Design of soluble recombinant T cell receptors for antigen targeting and T cell inhibition, J Biol Chem 280 1882-1892 (2005). 27. Garanger E et al, Multivalent RGD synthetic peptides as potent alphaVbeta3 integrin ligands, Org Biomol Chem, 4 1958-1965 (April, 2006). 28. Mammen M et al, Polyvalent Interactions in Biological Systems: Implications for Design and Use of Multivalent Ligands and Inhibitors, Angewandte Chemie 37 2754-2796 (1998). 29. Boyd R S et al, Proteomic analysis of the cell-surface membrane in chronic lymphocytic leukemia: identification of two novel proteins, BCNP1 and MIG2B, Leukemia 17 1605-1612 (2003). 30. Zhao Y et al, Proteomic analysis of integral plasma membrane proteins. Anal Chem, 76 1817-1823 (2004). 31. Loyet K M et al, Proteomic profiling of surface proteins on Th1 and Th2 cells. J Proteome Res, 4 400-409 (2005). 32. Tangrea M A et al, Novel proteomic approaches for tissue analysis, Expert Rev Proteomics 1 185-92 (2004). 33. Dougherty E R et al, Inference from clustering with application to gene-expression microarrays, J Comput Biol, 9 105-126 (2002). 34. Andersen C L et al, Improved procedure for fluorescence in situ hybridization on tissue microarrays, Cytometry 45 83-86 (2001). 35. Mousses S et al. Clinical validation of candidate genes associated with prostate cancer progression in the CWR22 model system using tissue microarrays, Cancer Res 62 1256-1260 (2002). 36. Watanabe A et al, Tissue microarrays: applications in genomic research, Expert Rev Mol Diagn, 5 171-181 (2005). 37. Morse D L et al, Determining suitable internal standards for mRNA quantification of increasing cancer progression in human breast cells by real-time reverse transcriptase polymerase chain reaction, Anal Biochem 342 69-77 (2005). 38. Lynch R M et al, Modulation of hexokinase association with mitochondria analyzed with quantitative three-dimensional confocal microscopy, J Cell Biol 112 385-395 (1991). 39. Rose A, The sensitivity performance of the human eye on an absolute scale, J Opt Soc Am 38 196-208 (1948). 40. Barrett H H and Swindell W, Noise in Images. In: Barrett H H, Swindell W, eds Radiological Imaging: Academic Press 494-560 (198 1).
[0047] Applicants believe that the material incorporated above is “non-essential” in accordance with 37 CFR 1.57, because it is referred to for purposes of indicating the background of the invention or illustrating the state of the art. However, if the Examiner believes that any of the above-incorporated material constitutes “essential material” within the meaning of 37 CFR 1.57(c)(1)-(3), applicants will amend the specification to expressly recite the essential material that is incorporated by reference as allowed by the applicable rules.
BRIEF SUMMARY OF THE INVENTION
[0048] The present invention provides among other things a method of identifying a cell as a pancreatic cancer cell based on assessing the expression of combinations of targets.
[0049] It is an object of the invention to identify a cell as a pancreatic cancer cell by analyzing the expression of a particular combination of at least three targets.
[0050] It is an object of the invention to identify a cell as a pancreatic cancer cell by assessing the expression of a particular combination of at least four targets.
[0051] It is an object of the invention to identify a cell as a pancreatic cancer cell through microarray analysis of the expression a particular combination of targets.
[0052] It is an object of the invention to identify a cell as a pancreatic cancer cell using labeled antibodies to analyze the expression of a particular combination of targets
[0053] It is an object of the invention to identify a cell as a pancreatic cancer cell through immunohistochemistry analysis of the expression of a particular combination of targets.
[0054] It is an object of the invention to identify a cell as a pancreatic cancer cell through immunohistochemistry analysis of the expression of a particular combination of targets expressed on a tissue microarray.
[0055] It is an object of the invention to identify a cell as a pancreatic cancer cell using immunocytochemistry analysis of the expression of a particular combination of targets.
[0056] It is an object of the invention to identify a cell as a pancreatic cancer cell using a flow cytometer to analyze the expression of a particular combination of targets.
[0057] It is an object of the invention to identify a cell as a pancreatic cancer cell by reverse transcriptase polymerase chain reaction (RTPCR).
[0058] It is an object of the invention to identify a cell as a pancreatic cancer cell by quantitative real time reverse transcriptase polymerase chain reaction (qRT-RTPCR).
[0059] It is an object of the invention to identify a cell as a pancreatic cancer cell using a multispecific targeting agent to analyze the expression of a particular combination of targets.
[0060] It is an object of the invention to detect a pancreatic cancer cell using a labeled multispecific targeting agent capable of specifically binding a combination of a set of cell surface proteins that, when expressed in combination, identify a cell as a pancreatic cancer cell.
[0061] It is an object of the invention to identify a cell as a pancreatic cancer cell using a multispecific targeting agent that is conjugated with an agent toxic to the cell and is capable of specifically binding a combination of cell surface proteins that identify a cell as a pancreatic cancer cell.
[0062] The above and other objects may be achieved using methods involving assessing the expression of PCDHB10, IL1RAP, and SLC01B3 in combination.
[0063] The above and other objects may be achieved using methods involving assessing the expression of PCDHB10, IL1RAP, and PTPRR isoform 1 in combination.
[0064] The above and other objects may be achieved using methods involving assessing the expression of PCDHB10, IL1RAP, and PTPRR isoform 2 in combination.
[0065] The above and other objects may be achieved using methods involving assessing the expression of PCDHB10, IL1RAP, and SLCA2A13 in combination.
[0066] The above and other objects may be achieved using methods involving assessing the expression of PCDHB10, SLC01B3, and FCGR1A in combination.
[0067] The above and other objects may be achieved using methods involving assessing the expression of PCDHB10, SLC01B3, and CLEC4A isoform 1 in combination.
[0068] The above and other objects may be achieved using methods involving assessing the expression of PCDHB10, SLC01B3, and CLEC4A isoform 2 in combination.
[0069] The above and other objects may be achieved using methods involving assessing the expression of PCDHB10, SLC01B3, and CLEC4A isoform 3 in combination.
[0070] The above and other objects may be achieved using methods involving assessing the expression of PCDHB10, SLC01B3, and CLEC4A isoform 4 in combination.
[0071] The above and other objects may be achieved using methods involving assessing the expression of PCDHB10, TM4SF4, and SLC21A3 in combination.
[0072] The above and other objects may be achieved using methods involving assessing the expression of PCDHB10, TM4SF4, and FCGR1A in combination. The above and other objects may be achieved using methods involving assessing the expression of TM4S4, IL1RAP, FCGR1A, and ASGR1 in combination.
[0073] The above and other objects may be achieved using methods involving assessing the expression of TM4S4, IL1RAP, PCDHB10, and PCDHB9 in combination.
[0074] The above and other objects may be achieved using methods involving assessing the expression of PTPRR isoform 1, SLC01B3, ASGR1, and PTPRC isoform 1 in combination.
[0075] The above and other objects may be achieved using methods involving assessing the expression of PTPRR isoform 1, SLC01B3, ASGR1, and PTPRC isoform 2 in combination.
[0076] The above and other objects may be achieved using methods involving assessing the expression of PTPRR isoform 1, SLC01B3, ASGR1, and PTPRC isoform 3 in combination.
[0077] The above and other objects may be achieved using methods involving assessing the expression of PTPRR isoform 1, SLC01B3, ASGR1, and PTPRC isoform 4 in combination.
[0078] The above and other objects may be achieved using methods involving assessing the expression of PTPRR isoform 2, SLC01B3, ASGR1, and PTPRC isoform 1 in combination.
[0079] The above and other objects may be achieved using methods involving assessing the expression of PTPRR isoform 2, SLC01B3, ASGR1, and PTPRC isoform 2 in combination.
[0080] The above and other objects may be achieved using methods involving assessing the expression of PTPRR isoform 2, SLC01B3, ASGR1, and PTPRC isoform 3 in combination.
[0081] The above and other objects may be achieved using methods involving assessing the expression of PTPRR isoform 2, SLC01B3, ASGR1, and PTPRC isoform 4 in combination.
[0082] The above and other objects may be achieved using methods involving assessing the expression of PTPRR isoform 1, SLC01B3, ASGR1, and MS4A4A in combination.
[0083] The above and other objects may be achieved using methods involving assessing the expression of PTPRR isoform 2, SLC01B3, ASGR1, and MS4A4A in combination.
[0084] The above and other objects may be achieved using methods involving assessing the expression of TM4S4, TNFSF4, MGC34293, and TGFBR1 in combination.
[0085] The above and other objects may be achieved using methods involving assessing the expression of PCDHB8, HLA-DQA1, PCDHB10, and SLC01B3 in combination.
[0086] The above and other objects may be achieved using methods involving assessing the expression of PTPRR isoform 1, CEACAM6, MS4A4A, and SLC01B3 in combination.
[0087] The above and other objects may be achieved using methods involving assessing the expression of PTPRR isoform 2, CEACAM6, MS4A4A, and SLC01B3 in combination.
[0088] Aspects and applications of the invention presented here are described below in the drawings and detailed description of the invention. Unless specifically noted, it is intended that the words and phrases in the specification and the claims be given their plain, ordinary, and accustomed meaning to those of ordinary skill in the applicable arts. The inventors are fully aware that they can be their own lexicographers if desired. The inventors expressly elect, as their own lexicographers, to use only the plain and ordinary meaning of terms in the specification and claims unless they clearly state otherwise and then further, expressly set forth the “special” definition of that term and explain how it differs from the plain and ordinary meaning. Absent such clear statements of intent to apply a “special” definition, it is the inventors' intent and desire that the simple, plain and ordinary meaning to the terms be applied to the interpretation of the specification and claims.
[0089] The inventors are also aware of the normal precepts of English grammar. Thus, if a noun, term, or phrase is intended to be further characterized, specified, or narrowed in some way, then such noun, term, or phrase will expressly include additional adjectives, descriptive terms, or other modifiers in accordance with the normal precepts of English grammar. Absent the use of such adjectives, descriptive terms, or modifiers, it is the intent that such nouns, terms, or phrases be given their plain, and ordinary English meaning to those skilled in the applicable arts as set forth above.
[0090] Further, the inventors are fully informed of the standards and application of the special provisions of 35 U.S.C. § 112, ¶6. Thus, the use of the words “function,” “means” or “step” in the Detailed Description or Description of the Drawings or claims is not intended to somehow indicate a desire to invoke the special provisions of 35 U.S.C. § 112, ¶6, to define the invention. To the contrary, if the provisions of 35 U.S.C. § 112, ¶6 are sought to be invoked to define the inventions, the claims will specifically and expressly state the exact phrases “means for” or “step for, and will also recite the word “function” (i.e., will state “means for performing the function of [insert function]”), without also reciting in such phrases any structure, material or act in support of the function. Thus, even when the claims recite a “means for performing the function of . . . ” or “step for performing the function of . . . ,” if the claims also recite any structure, material or acts in support of that means or step, or that perform the recited function, then it is the clear intention of the inventors not to invoke the provisions of 35 U.S.C. § 112, ¶6. Moreover, even if the provisions of 35 U.S.C. § 112, ¶6 are invoked to define the claimed inventions, it is intended that the inventions not be limited only to the specific structure, material or acts that are described in the preferred embodiments, but in addition, include any and all structures, materials or acts that perform the claimed function as described in alternative embodiments or forms of the invention, or that are well known present or later-developed, equivalent structures, material or acts for performing the claimed function.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0091] A more complete understanding of the present invention may be derived by referring to the detailed description when considered in connection with the following illustrative figures. In the figures, like reference numbers refer to like elements or acts throughout the figures.
[0092] FIG. 1 depicts multidimensional scaling plots of the pancreatic tumor tissues (black dots) and normal tissues (gray dots) based on microarray expression data.
[0093] FIG. 2 depicts microarray intensity distribution plots of pancreatic tumor samples (dashed line) and normal tissue samples (solid line). Vertical lines show cutoff values demarcate a target as either “positively expressed” in a given tumor sample (dashed line with a circle) or “not expressed” in a given normal sample (dashed line with a cross).
[0094] FIG. 3 depicts a dendrogram of pancreatic tumor tissue groupings with normal tissues based on expression of cell-surface targets. NMel: normal melanocytes; Nhea: Normal heart; NCol: Normal colon; NBre: Normal breast; NOva: Normal ovary; NOst: Normal osteoblasts; NSal: Normal salivary gland; NSke: Normal skeletal muscle; NAdi: Normal adipose tissue; NAdr: Normal Adrenal gland; NSto: Normal stomach; NCar: Normal cartilage tissue; NPan: Normal pancreas; TPan: Pancreatic tumor samples.
[0095] FIG. 4 depicts validation of target combinations by tissue microarray (TMA) based immunohistochemistry. The pancreatic tumor TMA (left) was constructed by Applicants and the normal tissue microarray (right) was obtained from NCI's cooperative tissue network.
[0096] Elements and acts in the figures are illustrated for simplicity and have not necessarily been rendered according to any particular sequence or embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0097] In the following description, and for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the various aspects of the invention. It will be understood, however, by those skilled in the relevant arts, that the present invention may be practiced without these specific details. In other instances, known structures and devices are shown or discussed more generally in order to avoid obscuring the invention. In many cases, a description of the operation is sufficient to enable one to implement the various forms of the invention, particularly when the operation is to be implemented in software. It should be noted that there are many different and alternative configurations, devices and technologies to which the disclosed inventions may be applied. The full scope of the inventions is not limited to the examples that are described below.
[0098] Herein, Applicants describe methods of using combinations of targets expressed by pancreatic cancer cells in order to identify a cell as a pancreatic cancer cell. Targets include any molecular structure produced by a cell and expressed inside the cell, on the cell surface, or secreted by the cell. Targets include proteins, lipids, carbohydrates, nucleic acids, and combinations thereof including subcellular structures, glycoproteins, and viruses. Preferably, the targets include proteins or glycoproteins associated with the cell membrane. A target associated with the cell membrane may achieve said association with the cell membrane by some hydrophobic or other membrane-directing domain such as a membrane-spanning domain. Alternatively, a target may be associated with the cell membrane by as part of a complex of two or more proteins, one of which is directly associated with the cell membrane.
[0099] Expression encompasses all processes through which specific molecules may be derived from a nucleic acid template. Expression thus includes RNA transcription, mRNA splicing, protein translation, protein folding, post-translational modification, membrane transport, associations with other molecules, addition of carbohydrate moeties to proteins, phosphorylation, protein complex formation and any other process through which specific biological material may be made from a nucleic acid template. Expression also encompasses all processes through which the production of material derived from a nucleic acid template may be actively or passively suppressed. Such processes include all aspects of transcriptional and translational regulation. Examples include heterochromatic silencing, transcription factor inhibition, any form of RNAi silencing, alternative splicing, protease digestion, post-translational modification, and alternative protein folding. Expression is an integral process of a target in that without expression of the target, there would be no target.
[0100] Expression may be assessed by any of a number of methods used to detect material derived from a nucleic acid template used currently in the art and yet to be developed. Examples of such methods include any nucleic acid detection method including the following nonlimiting examples, microarray analysis, RNA in situ hybridization, RNAse protection assay, Northern blot, RTPCR, and QRTPCR. Other examples include any process of detecting expression that uses an antibody including the following nonlimiting examples, flow cytometry, immunohistochemistry, ELISA, Western blot, and immunoaffinity chromatograpy. Antibodies may be monoclonal, polyclonal, or any antibody fragment including an Fab, F(ab) 2 , Fv, scFv, phage display antibody, peptibody, multispecific ligand, or any other reagent with specific binding to a target. Such methods also include direct methods used to assess protein expression including the following nonlimiting examples: HPLC, mass spectrometry, protein microarray analysis, PAGE analysis, isoelectric focusing, 2-D gel electrophoresis, and enzymatic assays. Samples from which expression may be detected include single cells, whole organs or any fraction of a whole organ, whether in vitro, ex vivo, in vivo, or post-mortem. Preferably the sample includes cells derived from human pancreas.
[0101] Methods to detect targets may include the use of a ligand with specificity for the target. Ligands may be monospecific (also termed monomeric or monovalent) as well as multispecific (also termed multimeric or multivalent). Monospecific ligands have at least one target binding site, but only one specificity per ligand while multispecific ligands have at least two target binding sites per ligand. While all binding sites on monospecific ligands are equivalent, multispecific ligands include at least two different types of binding site per ligand. Such binding sites on a multispecific ligand may have specificity for different targets or for different epitopes on the same target. Ligands (whether monospecific or multispecific) include antibodies, antibody complexes, conjugates, natural ligands, small molecules, nanoparticles, any combination of molecules that includes one or more of the above, or any other molecular entity capable of specific binding to a target existing now or developed in the future. Monospecific and multispecific ligands may be associated with a label such as a radioactive isotope or chelate thereof, dye (fluorescent or nonfluorescent,) stain, enzyme, nonradioactive metal, or any other substance capable of aiding a machine or a human eye from differentiating a cell expressing a target from a cell not expressing a target whether in existence now or developed in the future. Additionally, expression may be assessed by monospecific or multispecific ligands associated with substances capable of killing the cell. Such substances include protein or small molecule toxins, cytokines, pro-apoptotic substances, pore forming substances, radioactive isotopes, or any other substance toxic to a cell that may be delivered to a cell by a ligand.
[0102] Positive expression includes any difference between a cell expressing a specific target and a cell that does not express a specific target. The exact nature of positive expression varies by the method, but is well known to those skilled in the art of practicing a particular method. Positive expression may be assessed by a detector, an instrument containing a detector, or by aided or unaided human eye. Examples include but are not limited to specific staining of cells expressing a target in an IHC slide, binding of RNA from a sample to a microarray and detection by said microarray, a high rate of dye incorporation in real-time RTPCR, detection of fluorescence on a cell expressing a target by a flow cytometer, the presence of radiolabeled bands on film in a Northern blot, detection of labeled blocked RNA by RNAse protection assay, cell death measured by apoptotic markers, cell death measured by shrinkage of a tumor, or any other signal for the expression of a target in existence now or yet to be developed.
[0103] A specific target may be identified by the sequence of a nucleic acid from which it can be derived (see Table 8). Examples of such nucleic acids include mRNA, cDNA, or genomic sequences. Alternatively, a specific target may be identified by a protein sequence. However, the specific target is not limited to the products of the exact nucleic acid sequence or protein sequence by which it may be identified. Rather, a specific target encompasses all sequences that yield positive expression when the expression of the specific target is assessed. Examples of sequences encompassed by a specific target identified by a nucleic acid molecule include point mutations, silent mutations, deletions, frameshift mutations, translocations, alternative splicing derivatives, differentially methylated sequences, differentially modified protein sequences, and any other variation that results in a product that may be identified as the specific target. The following nonlimiting example is included for the purposes of illustrating the concept of what is encompassed by a target: if expression of a specific target in a sample is assessed by immunohistochemistry, and if the sample expresses a sequence different from the sequence used to identify the specific target (e.g. a variation of one or more nucleic acid molecules,) but positive expression is still determined, then the target encompasses the sequence expressed by the sample.
[0104] In one aspect of the invention, target expression may be assessed by microarray. The following protocol is included solely to illustrate one example of this aspect of the invention. This aspect also encompasses any variation the following protocol including any method that assesses the expression of a target through the binding of a complimentary nucleic acid probe. In addition, the following protocol describes the methodology used in identifying combinations of targets that identify cells as prostate cancer cells. Total RNA is isolated from tissues using the NucleoSpin RNA II isolation kit (BD Biosciences, Palo Alto, Calif.) following manufacturer's instructions hereby incorporated by reference. The microarray analysis including target labeling and chip hybridization and processing are carried out by following the protocols recommended by the manufacturer, (Agilent Technologies, Palo Alto, Calif.), hereby incorporated by reference. Briefly, 1 μg of total RNA is used to generate CY5 cRNA targets using the Agilent low input RNA fluorescent linear amplification kit, using manufacturer's protocol, hereby incorporated by reference. A total RNA sample isolated from normal pancreas is labeled with CY3 to serve as a reference. The concentration and integrity of fluorescent cRNA as well as the incorporation efficiency of cyanine dyes are analyzed using the Agilent 2100 Bioanalyzer RNA microfluidics chip following manufacturer's protocols, hereby incorporated by reference. Equal amounts of labeled cRNA targets from the tissue sample and the universal reference are hybridized onto Agilent Human 1A and Agilent Human 1A(V2) oligonucleotide arrays. The hybridization signals are acquired and normalized using Agilent's Feature Extraction Image Analysis software (v.7.1).
[0105] To obtain targets useful in detecting cells as pancreatic cancer cells, DNA microarray expression data was assessed in three pancreatic cell lines, all of which were obtained from the American Type Tissue Collection (ATCC), were generated using the same procedure using total RNA isolated from cells grown to 80% confluent. The arrays include 18,778 and 22,073 individual 160-mer probes, respectively. Microarray data was obtained from the 105 normal tissue/cell samples representing 28 different organ sites/cell types. In addition, microarray data was obtained from 28 pancreatic adenocarcinoma tissue samples. The feature intensities derived from each sample were first normalized by the median intensity value of the array in order to cross compare different samples run on different chips. Multidimensional scaling (MDS) analysis was used to test the internal consistency of the data set by checking the clustering of the individual samples. As shown in FIG. 1 , despite the fact that the tissues were obtained from different sources and represent diverse ethnic, age and sex groups, normal tissue samples belonging to the same organ type tend to cluster together. In contrast to this observation, the pancreatic tumor samples were not always clustered, indicating more heterogeneous expression patterns in the pancreatic tumors.
[0106] Applicants focused upon targets expressing putative cell surface molecules included in the Agilent Human 1A and 1A V2 oligonucleotide array, with cell surface or transmembrane regions. A total of 2133 targets met their criteria. Applicants then manually examined the cellular localization of each target by browsing through information in databases (Genecard, Harvester, Entrez, Protein Database, UniProt and PubMed) and literature (PubMed). Targets encoding proteins with putative cell-surface or transmembrane regions were also included. The final list consists of 2,133 targets, including GPCRs, integral membrane proteins and other cell surface proteins. Each category was followed through the hierarchy to the lowest possible level in order to select lists containing targets with cell-surface epitopes, while excluding lists that were sure to not include cell-surface proteins. A list was compiled from all of the selected lists containing 6,389 targets. Since Applicants intended to use this list to assess expression using the Agilent Human 1A (V2) oligonucleotide array chips, Applicants removed targets from our cell-surface list that were not represented on the Agilent array. The resulting new list contained 4,407 targets. Each target on the master list was then checked using information from existing databases (Genecard, Harvester, Entrez, Protein Database, UniProt and PubMed) to determine if it encodes a cell surface protein, if it is predicted to encode one by similarity or homology, if it is a non cell-surface target, or if the sub-cellular localization is not determinable. Non cell-surface targets were removed from the list. The resulting list was thus enriched with targets expected to encode proteins that have epitopes exposed on the cell surface. Our final list contains a total of 2177 targets covered by the Agilent Human 1A V2 and 1928 targets covered by the 1A(V1).
[0107] Hierarchical clustering (agglomerative procedure) was used to form clusters using the median normalized microarray expression data of the cell surface targets of the tissue samples. The object of this clustering analysis is to compute a dendrogram that assembles all tissue samples into a single tree based on their similarities in cell surface target expression (see FIG. 3 ). The clustering algorithm used is based on the average-linkage method as described in reference 17. Since our tissue samples had 29 distinct types (28 different normal tissue/cell types plus the pancreatic tumor tissue group), the repetitive clustering process was stopped when it formed 29 groups.
[0108] Referring now to FIG. 2 , the frequency histogram of mRNA abundance follows a pseudo-power law. Thus, an important component of the effort includes assessing RNA expression from non-expression when using microarray analysis. Because the level of mRNA expression is not always linearly related to the level of protein translation and subsequent localization to the cell surface, Applicants determined the relationship between assessing the expression of targets through microarray and assessing the expression of targets through methods that measure protein at the cell surface. The normal and tumor threshold values (indicated in the vertical lines in FIG. 2 ) were adjusted in order to provide the target combinations with the maximum stringency of the coverage analyses. DNA array intensities below the value of normalized normal tissue threshold values are considered not to have positive expression. Intensities above tumor tissue threshold values displayed positive expression. Setting a normal tissue based threshold value of 0.35, provided no combinations while using any higher tumor cutoff setting. Setting a tumor area based threshold value of 0.75, provided no combinations while using any lower normal cutoff setting. Area based cutoffs that provided target combinations ranged from 0.35 to 0.55 in normal tissues, and 0.55 to 0.75 in tumor tissues. Combinations that provided the highest coverage amongst tumor tissues with the most stringent cutoff values were selected.
[0109] To further demarcate positive expression from non-expression, Applicants quantified the expression of common CD (Cluster of Differentiation) targets using Europium -labeled antibodies binding to three different cell lines (Mia PaCa-2, BxPC-3 and Capan-2) with varying RNA expression as determined by microarray of the CD targets. Results are summarized in Table 7. Binding was quantified on whole cells using time resolved fluorescence and indicated that median normalized intensities of 0.55 as measured in microarray analysis corresponded to the minimum detectable protein level above the background signal. However, CD antibody binding data also showed that higher microarray intensity does not necessarily indicate a high binding signal. Applicants used a median microarray intensity ratio of 0.45 non-expression cutoff in normal tissue samples. Applicants used microarray intensity levels from 0.55 to 0.85 as a positive expression cutoff in pancreatic tumor tissue samples. Microarray data were parsed with these varying levels of upper cutoff to generate binarized data with a value of 1 to signify positive expression and 0 to signify non-expression.
[0110] Microarray data were generated using eleven pancreatic adenocarcinoma cell lines. From these data, five lines (AsPC-1, Capan-1, HPAFII, PSN-1 and SU86.86) were selected that may express all three targets in at least one of the validated three-target combinations. Expression of the four validated targets (IL1RAP, PCDHB10, PTPRR and SLC1A13) was determined quantitatively at the level of mRNA by qRT-PCR, and qualitatively at the level of protein by immunocytochemistry (ICC) (results summarized in Table 7). Cell lines were identified that express all three targets in both validated combinations, e.g. AsPC-1 and Capan-1 cells express targets in both combinations at relatively high levels. When expression of the IL1RAP-PCDHB10-PTPRR combination was assessed, Capan-1 cells expressed mRNA ranging from 0.006-0.05 the level of β-actin (ACTB) mRNA and demonstrated relatively high staining of all three targets by ICC.
[0111] When assessing the expression of cells with a multispecific targeting agent, the binding avidity to a cell is determined by the binding affinities of the individual ligands that make up the agent to the respective target receptors as well as by the presence and concentration of each target receptor on the cell surface. The cellular specificity of a multispecific targeting agent is largely determined by differences in the expression of each target protein between normal and tumor tissues. In the following nonlimiting example: a multispecific ligand that binds to 3 different target proteins in a tumor and only 1 protein in a normal tissue (difference of 2 in the number of proteins it binds) will have a higher specificity than a ligand that binds to 3 proteins in a tumor and 2 proteins in a normal tissue (difference of 1 in the number of proteins).
[0112] Based on the results of empirical studies, Rose and others have determined that detection of an image detail by the human eye requires a signal intensity to background noise ratio (SNR) of at least 2 to 3 (see references 39 and 40). Thus, in the case of imaging, a 3-fold signal enhancement in a target tissue relative to background enhancement is generally required. Further, it is estimated that in the case of targeted therapies, a 100-fold increase in binding to target tissue relative to normal tissues is required (see reference 25). Vagner and others have reported that ligands exhibiting heterobivalent binding interactions demonstrate an ˜50-fold increase in binding relative to monovalent interactions (see reference 11). An ˜100-fold increase in homotrivalent binding interactions relative to monovalent interactions was also demonstrated (see references 11 and 28).
[0113] From these observations of cooperative affinity, Applicants selected combinations of targets with a difference of 2 in the number of targets in tumor tissue relative to normal tissue. That is, if a combination contains N targets and the tumor expresses all N targets, no more than N-2 targets may be expressed in any given normal tissue by microarray. In the case of two-target combinations, neither target may be expressed in normal tissue. To identify target combinations that meet this rule, the expression of the cell surface targets was binarized to non-expression or positive expression in each tissue sample using area-based cutoff values with the highest possible stringency
[0114] To rank the target combinations by their coverage of tumor samples, a coverage flag ‘1’ was assigned to a tumor sample if positive expression of a given target combination was at least N-2 greater than in all normal samples. Otherwise, the tumor sample was assigned ‘0’. This process is repeated with each individual tumor sample and the combination was ordered based on the coverage (‘average coverage flag’) obtained from all the tumor samples. Thus, the highest ranked combinations covered the most tumors with low to no avidity to most, if not all, normal tissues. Because higher dimensional combinations might be computed, it is possible that the same tumor samples could be covered by lower dimensional combinations. In order to only select combinations that cover more tumor samples than any lower dimension combinations Applicants introduced the Coverage Measurement (Ψ) to quantify each combination. If Ψ q is the Coverage Measurement of the qth dimension, then a combination with q+1 dimensions is said to have an improvement in coverage over a combination with q dimensions only if: Ψ q+1 >Ψ q . Only combinations with a higher Coverage Measurement than all combinations with lower dimensions (Ψ q+1 >v{Ψ 1 , Ψ 2 , . . . , Ψ q }) were selected as valid target combinations.
[0115] To identify single targets, Applicants assessed the expression of each of the targets in the final list (above) in both pancreatic tumors and normal pancreas. Using a median normalized ratio of 0.45 as the non-expression cutoff in normal pancreas and 0.85 as the positive expression cutoff in pancreatic tumor tissues, Applicants produced a list of targets non-expressed in normal pancreas but expressed in at least 20% of the pancreatic cancer patient samples. Targets with positive expression in normal liver, heart, kidney, lung and pancreas, or in two or more other normal tissue types were eliminated from further consideration.
[0116] The analysis resulted in a set of three-target and four-target combinations that each cover at least 3 out of 28 (11%) of pancreatic tumor samples assessed. The three-target combinations are listed in Table 2 and the four-target combinations are listed in Table 3. Combinations containing more than four targets may be assembled using the three- and four-target combinations, and other aspects of the invention encompass these combinations as well. FIG. 3 is a dendrogram that reveals a clustering of pancreatic tumor tissues into four groupings by expression of cell-surface targets, with 96% of the tumor tissues being divided between three major groupings (I, II and IV). Group II contains two very close clusters (the Nsto2/TPan18 cluster and the TPan16/TPan19-TPan25/TPan27-TPan28 cluster). Group IV tumors clustered with the normal pancreas tissue, indicating that these tumors may be difficult to distinguish from normal pancreatic tissue by cell-surface expression, or that the tumor biopsy samples in group IV contain a high percentage of normal tissue. Groups I and II each contain 39% of the tumor samples. The three- and four- target combinations that were identified as having the broadest tumor coverage, predominantly covers tumors in group II, with three of the seven 3-target combinations also covering the single tumor in group III, one of the seven 4-target combinations covered the single tumor in group III and three of the seven covered one tumor in group I. Together, the combinations identified cover 100% of the group II tumors.
[0117] In one aspect of the invention, expression of a target may be assessed within the context of a tissue. The following protocol is included solely to illustrate one example of this aspect of the invention. This aspect of the invention encompasses all variations on the protocol and any other protocol that results in a set of one or more tissues that facilitates assessing the expression of a target. Such tissues include whole, excised, post mortem, frozen or paraffin embedded sections, or tissues presented in the context of a tissue microarray (TMA.) To construct a tissue microarray, morphologically representative areas of tumors were selected from formalin fixed tissue samples embedded in paraffin blocks. Two 1.5 mm diameter cores per case were re-embedded in a tissue microarray using a tissue arrayer according to Kononen's method (see reference Number 17). An average of 200 sections can be cut from one tissue microarray block. Using this procedure, Applicants examined two pancreatic tissue microarrays (shown in FIG. 4 ). To construct a TMA, formalin-fixed paraffin embedded tissues were examined with H&E staining of whole sections to identify pathological distinct areas of interest. With each tissue block, areas representative of tumor, borderline and normal were selected to punch 1.0 mm-diameter discs (two discs per tumor, one disc per border line normal and one disc per normal) used in TMA construction. The discs were re-embedded into a new paraffin block using a tissue arrayer (See references 17 and 34-36). A total of 52 pancreatic ductal adenocarcinoma cases, 38 of which also included a disc from adjacent normal region, 2 cases of pancreatitis and 2 cases of normal pancreas samples were included in the array. After the completion of the block, 5-μm sections were cut with a microtome. The TMA slides were dipped in paraffin in order to achieve uniform epitope preservation. The entire TMA block was sectioned with H & E staining every 50 sections to assess retention of desired tissue targets. TMA slides containing normal tissues were obtained from the Corporative Human Tissue Network of the National Cancer Institute, National Institutes of Health, Bethesda MD (Version CHTN2002N1). This normal tissue TMA series contains 66 human tissue types in 0.6 mm spot sizes (chtn.nci.nih.gov).
[0118] In one aspect of the invention, target expression may be assessed by immunohistochemistry. The following protocol is included solely to illustrate one example of this aspect of the invention. This aspect of the invention encompasses all variations on the protocol and any other protocols that may assess the expression of a target using an agent capable of specifically binding the target in the context of a section of tissue. Antibodies capable of specifically binding to one of the targets are titrated against regular tissue sections and ‘tester’ TMA slides that contain a variety of tumor and normal counterpart tissues in order to optimize the binding conditions. TMA slides are subjected to antigen retrieval by heating at 100° C. in citrate buffer (0.1 M, pH 6.0) for 5-30 min, depending on the antibody used. The slides are incubated with the primary antibodies at the optimized dilutions for 30 minutes at room temperature. Biotinylated secondary antibodies are applied to the tissues, as is streptavidin-peroxidase complex. Binding is resolved with diaminobenzidine (DAB). Slides are evaluated using light microscopy and scored (0=negative, to 3+=intensely positive). Examples of primary antibodies, their sources, and the dilutions used in TMA staining include: rabbit anti-PTPRR (Orbigen Inc, San Diego, Calif.), 1:100; rabbit anti-SLC2A13 (Unites States Biological, Swampscott, Mass.), 1:300; mouse anti-PCDHB10 (Abnova corporation, Teipei, ROC), 1:75; and rabbit anti-IL1RAP (Abcam Inc., Cambridge, Mass.), 1:150. These antibodies cover of two of the three-target combinations listed in Table 2 in their entirety and contain at least one target in the remaining three target combinations listed in Table 2. In addition, these antibodies cover two targets in one of the four-target combinations listed in Table 3 and at least one target in five of the four-target combinations listed in Table 3.
[0119] Scoring results are summarized in Table 4. In brief, defining positive expression as a score of 2+ or above, all four targets displayed positive expression in most tumor tissues and non-expression in the normal, non-diseased tissues. The target PTPRR was positively expressed in 75% of the tumor cases assessed, the target PCDHB 10 was positively expressed in 37% of the tumor cases assessed, the target IL1RAP was positively expressed in 48% of the tumor cases assessed, and the target SLC2A13 was positively expressed in 47% of the tumor cases assessed. Non-expression was seen in all normal pancreas assessed.
[0120] In addition, expression of two target combinations on normal non-pancreatic tissue was assessed. The results obtained from the combination of PTPRR, IL1RAP and PCDHB10 are summarized in Table 5, while the results obtained from the combination of IL1RAP, PCDHB10, and SLC2A13 are summarized in Table 6. Positive expression (score of greater than 2+) of PTPRR was seen in the gastric mucosa, fallopian tube, adrenal gland and kidney. Positive expression of IL1RAP was seen in small intestine, fallopian tube, and bladder epithelium, positive expression of PCDHB10 was seen in the adrenal gland and kidney, and positive expression of ELC2A13 was not seen in any of the tissues assessed in Table 6. So the PTPRR, IL1RAP, and PCDHB10 combination displays positive expression of two of the targets in fallopian tube, adrenal gland, and kidney. The IL1RAP, PCDHB10, and SLC2A13 combination displays positive expression in fallopian tube only.
[0121] In another aspect of the invention, expression may be assessed by quantitative real-time reverse-transcriptase PCR (qRT-RTPCR.) The following protocol is included solely to illustrate one example of this aspect of the invention. This aspect of the invention encompasses all variations of the following protocol including any protocol through which target RNA expression may be assessed through a PCR or other nucleic acid amplification. Additionally, this aspect of the invention encompasses assessing target RNA in any sample including whole tissue, biopsy samples, necropsy samples, punches, cells removed by laser-capture microdissection, or any other samples that may contain one or more mRNA molecule in a condition that allows amplification by any method. The protocol is based upon the qRT-RTPCR protocol in reference 22, but with the following alterations. Primer sets are designed to amplify fragments derived from ACTB (β-actin), IL1RAP, PCDHB10, PTPRR, and SLC2A13 mRNA, and PCR conditions are determined (summarized in Table 1). Real-time RT-PCR is conducted using a Smart Cyclers (Cephid, Sunnyvale, Calif.)—the operations manual of which is herein incorporated by reference—and the QuantiTect SYBR Green RT-PCR Kit (Qiagen, Valencia, Calif.)—manufacturers protocol hereby incorporated by reference. Reverse transcriptase (RT) conversion of RNA into cDNA may be performed during a 20 min (HotStarTaq) incubation at 50° C., followed by a 15 min incubation at 95° C. followed by 35 of the following cycles (15 seconds at 94° C., 30 seconds at a primer-set specific annealing temperature, and 20 seconds at 72° C.).
[0122] Melt curves ranging from 60 to 90° C. yielded a single melt-peak in all template reactions and a minimal melt peaks in the no-template control reaction. Raw mRNA expression values were determined as being 2 −C T , where C T is the second derivative of the fluorescence curve. Target expression was normalized to ACTB expression. Target expression was assessed in the AsPC-1, Capan-1, HPAFII, PSN-1 and SU86.86 cell lines, summarized in Table 7 using three extracts per cell line (to determine mean and standard error.) Reproducibility of measurements by this method is high (Cronbach's alpha of 0.93 (see reference 37)) so only one run per primer set per extract was performed. Results are reported in Table 7 as the mean and error is reported as standard error of the mean (sem).
[0123] In another aspect of the invention, expression may be assessed by immunocytochemistry (ICC.) The following protocol is included solely to illustrate one example of this aspect of the invention. This aspect includes all variations on the protocol as well as any protocol that may be used to assess expression of a target using fluorescently labeled ligands capable of specifically binding to one or more targets, including assessment of expression in a flow cytometer. The protocol is based upon that reported by Lynch, et al (see reference 38) and uses the same primary antibodies capable of specifically binding IL1RAP, PTPRR, and SLC2A13 used in the immunohistochemistry example above. The secondary antibody used to stain IL1RAP, PTPRR and SLC2A13 antibodies in this example is Molecular Probes® AlexaFluor488 Goat Anti Rabbit (Invitrogen, San Diego, Calif.), and the secondary antibody used to stain PCDHB10 antibody is Molecular Probes® AlexaFluor488 Goat Anti-mouse (Invitrogen, San Diego, Calif.). Primary antibodies are diluted 1:50 and secondary antibodies are diluted 1:200. Cells are grown to 80% confluence on glass coverslips in 6-well plates. ICC was performed in duplicate on each cell-line and primary antibody combination. Control experiments are performed on each cell line by not including eliminating the primary antibody incubation. Following incubation, coverslips are mounted on slides using Vectashield fluorescence mounting medium (Vector Laboratories, Burlingame, Calif.) and slides stored in the dark at −20° C. until scoring. Scoring is performed using an A.G. Heinze™ Precision MicroOptics TS100 inverted microscope with fluorescence and mounted digital camera (A.G. Heinze, Inc., Lake Forest, Calif.). Positive expression was assessed as ++ or above and non-expression as +or below. Results are summarized in Table 7.
[0124] In one aspect of the invention, expression is assessed using a multispecific (also known in the art as multimeric) targeting agent. Multispecific targeting agents may be comprised of more than one binding domain tethered together via a linker or scaffold. Other examples of multispecific targeting agents include bispecific antibodies, complexes that include binding sites capable of binding to multiple targets or multiple epitopes on the same target or any other agent capable of more than one binding specificity whether in existence now or yet to be developed. The specificity of a multispecific targeting agent with regard to a cell may be determined by the difference in the number of targets expressed by the cell the multispecific targeting agent is designed to identify and the number of targets expressed by other cells. In the following nonlimiting example: one multispecific targeting agent capable of binding with three or more different targets in a tumor cell, but only a single target in a normal cell in the same tissue will have a higher specificity than a multispecific targeting agent that is capable of binding with three or more targets in a tumor cell and two or more different targets in a normal cell in the same tissue. A multispecific targeting agent should be capable of specifically binding at least two more targets expressed on the cell type it is designed to target than the number expressed on other similar tissue. While this two-or-more target excess is optimal, this aspect of the invention also encompasses an excess of one target.
[0000]
TABLE 1
Target
Product
Annealing T
Sequence
Accession No.
Primer
Sequence (5′-3′)
Length (bp)
(° C.)
IL1RAP
NM_002182
forward
gct gtg cat ctt tga ccg a
86
53
mRNA/cDNA
reverse
gag gcg tct gct ttt ctg aa
PCDHB10
NM_018930
forward
cag ggt ttc cta ctg ctg ttc
121
53
mRNA/cDNA
reverse
aca gga ctt gcc ttt gtc ttg
PTPRR
NM_002849
forward
agg agt tgt gga tgc act aag
127
53
mRNA/cDNA
reverse
ctg ctg aaa gtc tgc tct cat a
SLC2A13
NM_052885
forward
tgg gag tct ggc ttg ttg ag
82
53
mRNA/cDNA
reverse
ata atg agt gct acg gtg gta cc
[0000]
TABLE 2
Tumor Coverage by Cluster Analysis
Combination
Target Symbols
Grouping (See FIG. 3)
1
TM4SF4
PCDHB10
FCGR1A
Group II: TPan21, TPan22, TPan24,
and TPan 25
2
IL1RAP
PCDHB10
SLC01B3
Group II: TPan21, TPan22, TPan24,
and TPan25
3
PTPRR
IL1RAP
PCDHB10
Group II: TPan22 and TPan25.
Group III: TPan26.
4
IL1RAP
PCDHB10
SLC2A13
Group II: TPan22 and TPan25.
Group III: TPan26
5
TM4SF4
PCDHB10
SLC2A13
Group II: TPan22 and TPan25.
Group III: TPan26
6
PCDHB10
FCGR1A
SLC01B3
Group II: TPan21, TPan22, TPan24
and TPan25
7
CLEC4A
PCDHB10
SLC01B3
Group II: TPan21, TPan22, TPan24
and TPan25
[0000]
TABLE 3
Tumor Coverage by Cluster Analysis Group
Combination
Target Symbols
See FIG. 3
1
TM4SF4
FCGR1A
ASGR1
IL1RAP
Group II: TPan19, TPan21, TPan22, TPan24,
TPan25 and TPan27.
2
TM4SF4
PCDHB10
PCDHB9
IL1RAP
Group II: TPan21, TPan22, TPan24 and
TPan25
Group III: TPan26.
3
TNFSF4
TM4SF4
MGC34923
TGFBR1
Group II: TPan15, TPan19, TPan22, TPan25
and TPan27
4
PCDHB8
HLA-DQA1
PCDHB10
SLC01B3
Group II: TPan18, TPan21, TPan22, TPan24
and TPan25
5
PTPRR
PTPRC
SLC01B3
ASGR1
Group I: TPan10.
Group II: TPan20, TPan22, TPan23, TPan25
and TPan28
6
PTPRR
MS4A4A
SLC01B3
ASGR1
Group I: TPan10.
Group II: TPan20, TPan22, TPan23, TPan25
and TPan28
7
PTPRR
CEACAM6
MS4A4A
SLC01B3
Group I: TPan10.
Group II: TPan20, TPan22, TPan23, TPan25
and TPan28
[0000]
TABLE 4
Sample
Score
% of cases
Target
classification
0
1+
2+
3+
N/E
with ≧2+
PTPRR
Normal
2
2
0
0
0
0
Tumor
0
12
28
8
4
75
PCDHB10
Normal
3
1
0
0
0
0
Tumor
1
21
22
4
4
37
IL1RAP
Normal
4
0
0
0
0
0
Tumor
6
19
18
5
4
48
SLC2A13
Normal
2
0
0
0
2
0
Tumor
7
18
18
4
5
47
[0000]
TABLE 5
Tissue
Target
PTPRR
IL1RAP
PCDHB10
Gastric Mucosa
3+
1+
1+
Small Intestine
0
2+
1+
Epididymis
1+
1+
1+
Seminiferous tubules
1+
0
2+
Gallbladder
1+
1+
0
Salivary gland
1+
0
1+
Hair follicle
0
1+
1+
Fallopian tube
2+
2+
1+
Adrenal gland
2+
0
3+
Bronchial cartilage
1+
0
1+
Uterus, smooth
1+
0
1+
muscle
Ovary, corpus luteum
1+
1+
1+
Placenta
1+
1+
1+
Appendix
0
1+
1+
Bronchial epithelium
1+
0
1+
Kidney
2+
0
2+
Bladder epithelium
1+
2+
1+
[0000]
TABLE 6
Target
Tissue
IL1RAP
PCDHB10
SLC2A13
Gastric mucosa
1+
1+
1+
Epididymis
1+
1+
0
Small Intestine
2+
1+
0
Hair follicles
1+
1+
0
Fallopian Tube
2+
1+
0
Adrenal gland
0
3+
1+
Ovary, corpus luteum
1+
1+
0
Placenta
1+
1+
0
Appendix
1+
1+
1+
Kidney
0
2+
1+
Bladder epithelium
2+
1+
1+
[0000]
TABLE 7
Target
IL1RAP
PCDHB10
PTPRR
SLC2A13
Cell
mRNA
IL1RAP
mRNA
PCDHB10
mRNA
PTPRR
mRNA
SLC2A13
Line
(sem) #
Protein †
(sem) #
Protein †
(sem) #
Protein †
(sem) #
Protein †
AsPC-1
1.9 (0.1)
+++
13 (3)
+++
57 (10)
+++
90 (10)
+++
Capan-1
12 (2)
+++
5.5 (0.8)
+++
46 (8)
+++
1.5 (0.8)
+++
HPAFII
0.63 (0.1)
+++
2.0 (0.3)
++
26 (5)
+++
5.9 (4)
+++
PSN-1
0.70 (0.1)
+++
0.044 (0.004)
++
0.1 (0.09)
++
11 (0.6)
++
SU86.86
0.62 (0.1)
+
0.009 (0.005)
++
2.3 (0.1)
++
0.39 (0.1)
++
# Normalized to β-actin (ACTB) expression [(target 2 −CT /ACTB 2 −CT ) * 1000]. Data are the mean of 3 samples and error values are the standard error of the mean (sem).
† Relative staining intensity as compared to no 1° Ab control: +++ = high, ++ = moderate, + = low. Controls had no staining.
[0000]
TABLE 8
Target
Designation
PCDHB10
SEQ ID NO 01
PCDHB10 protein
SEQ ID NO 02
IL1RAP
SEQ ID NO 03
IL1RAP protein
SEQ ID NO 04
SLC01B3
SEQ ID NO 05
SLC01B3 protein
SEQ ID NO 06
PTPRR isoform 1
SEQ ID NO 07
PTPRR isoform 1 protein
SEQ ID NO 08
PTPRR isoform 2
SEQ ID NO 09
PTPRR isoform 2 protein
SEQ ID NO 10
SLC2A13
SEQ ID NO 11
SLC2A13 protein
SEQ ID NO 12
FCGR1A
SEQ ID NO 13
FCGR1A protein
SEQ ID NO 14
CLEC4A isoform 1
SEQ ID NO 15
CLEC4A isoform 1 protein
SEQ ID NO 16
CLEC4A isoform 2
SEQ ID NO 17
CLEC4A isoform 2 protein
SEQ ID NO 18
CLEC4A isoform 3
SEQ ID NO 19
CLEC4A isoform 3 protein
SEQ ID NO 20
CLEC4A isoform 4
SEQ ID NO 21
CLEC4A isoform 4 protein
SEQ ID NO 22
TM4SF4
SEQ ID NO 23
TM4SF4 protein
SEQ ID NO 24
ASGR1
SEQ ID NO 25
ASGR1 protein
SEQ ID NO 26
PTPRC isoform 1
SEQ ID NO 27
PTPRC isoform 1 protein
SEQ ID NO 28
PTPRC isoform 2
SEQ ID NO 29
PTPRC isoform 2 protein
SEQ ID NO 30
PTPRC isoform 3
SEQ ID NO 31
PTPRC isoform 3 protein
SEQ ID NO 32
PTPRC isoform 4
SEQ ID NO 33
PTPRC isoform 4 protein
SEQ ID NO 34
MS4A4A
SEQ ID NO 35
MS4A4A protein
SEQ ID NO 36
TNFSF4
SEQ ID NO 37
TNFSF4 protein
SEQ ID NO 38
MGC34293
SEQ ID NO 39
MGC34293 protein
SEQ ID NO 40
TGFBR1
SEQ ID NO 41
TGFBR1 protein
SEQ ID NO 42
HLADQA1
SEQ ID NO 43
HLADQA1 protein
SEQ ID NO 44
CEACAM6
SEQ ID NO 45
CEACAM6 protein
SEQ ID NO 46
PCDHB8
SEQ ID NO 47
PCDHB8 protein
SEQ ID NO 48
PCDHB9
SEQ ID NO 49
PCDHB9 protein
SEQ ID NO 50 | Methods that identify cells as pancreatic cancer cells based on assessing the expression of combinations of target molecules expressed preferentially on pancreatic cancer cells are disclosed. Combinations were initially discovered by microarray analysis and selected based upon tumor specificity, relative lack of cross-reactivity with normal tissues, and applicability as targets of multispecific ligands. The claimed methods encompass measuring the expression of three or more specific target molecules in combination and correlating positive expression of the combination with an identification of the cell as a pancreatic cancer cell. | 86,716 |
CROSS-REFERENCES TO RELATED APPLICATIONS
This is a continuation of application Ser. No. 309,698, filed Nov. 27, 1972, abandoned, which is a continuation-in-part application of application Ser. No. 871,656, filed Nov. 14, 1969, abandoned, continuing application of Ser. No. 725,336 filed Apr. 30, 1968, abandoned, a continuation-in-part application of Ser. No. 504,949 filed Oct. 24, 1965, now Patent No. 3,380,779.
BACKGROUND OF THE INVENTION
A need exists for practicable means to counteract the tendency of a vehicle making a curve on a flat surface to lean outward and, if its speed is excessive, to slide or roll over or both due to centrifugal forces acting on the vehicle.
SUMMARY OF THE INVENTION
This invention relates to an improved wheel with a periphery adapted to expand or contract in response to forces acting parallel to its axle so that the tendency of a vehicle having such wheels on both sides to lean outward in making a curve is counteracted by expansion of the wheels farther from the center of the curve and by contraction of the wheel nearest the center. In addition, a means for absorbing lateral force on a vehicle within limits is provided in the wheel whereby the tendency of the vehicle to slide under such conditions is diminished.
Other objects, adaptabilities and capabilities will be appreciated as the description progresses, reference being had to the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary side view of one embodiment of the invention;
FIG. 2 is a sectional view, partly in elevation, taken on line II -- II of FIG. 1;
FIG. 3 is a schematic plan view of the embodiment shown in FIG. 1;
FIG. 4 is a schematic plan view similar to FIG. 3 showing a modification of the embodiment;
FIG. 5A and 5B are diagrams illustrating the effects of lateral forces on the wheel of the invention;
FIG. 6 is a representation in elevation of a further embodiment of the invention;
FIG. 7 is a diagram illustrating the application of lateral force on the embodiment shown in FIG. 6;
FIG. 8 is a fragmentary side view of a still further embodiment of the invention;
FIG. 9 is a sectional view, partly in elevation, taken on lines IX -- IX of FIG. 8;
FIG. 10 is a detail bottom view of a surface contacting member of the embodiment shown in FIGS. 8 and 9;
FIG. 10a, shows another embodiment of the surface contacting member;
FIG. 11 is a detail perspective view of a resilient bracket member of the embodiment shown in FIGS. 8 and 9;
FIG. 12 is a detail bottom view of a spoke guidance member in the embodiment shown in FIGS. 8 and 9;
FIG. 13 illustrates a removable resilient lug for tractors and the like;
FIG. 14 depicts the relationship between adjacent lugs as shown in FIG. 13 when attached to the wheel of a tractor; and
FIG. 15 shows a further embodiment of a lug similar to FIG. 13.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the embodiment shown in FIGS. 1 - 3, a wheel designated generally 10 is secured to an axle member 11 by means of bolts 12 extending through holes in the central portion 14 of wheel 10. A ring member 15 integral with central portion 14 extends around same and includes a limiting flange 16 on the inboard side and an outwardly biased flange 17 on the outboard side of wheel 10.
Secured on the outer periphery of the ring member 15 between flanges 16 and 17 is a securing portion 20 which is secured thereto by bolts, rivets or other suitable fastening means. Extending upwardly from the securing portion 20 is an inboard spoke portion 21 which joins, opposite the securing portion 20, a ground engaging portion 24. An outboard spoke portion 22 extends inwardly from ground engaging portion 24 and connects with a further securing portion 20 which connects with a still further inboard spoke portion 21 and so on until an endless member designated generally 25 comprised of successive portions 21--21--24--22 surrounds ring member 15.
The endless member 25 is composed of a resilient material such as, for example, spring steel which is sufficiently strong to support the vehicle involved. As will be noted from the drawings, the ground engaging members are disposed diagonally so as to overlap as seen from the side and present a smooth, uninterrupted ground contact. The spoke portions 21 and 22 include curves at 26 and 27 which tend to bend when the weight of the vehicle is borne by the associated spoke, and thus cushion and distribute the weight onto the adjacent spoke portions.
If desired, adjacent ground engaging portions 24 may be connected by resilient connecting members 30, as shown in FIG. 4, which are secured thereto by any suitable fastening means (not shown).
The spokes 21 all lie in the surface of an imaginary cone having an apex angle of about 150°, more or less, whereas, to increase stability of the wheels, the spokes 22 all lie in the surface of an imaginary cone having a slightly less apex angle -- say 145°, more or less.
FIG. 5A illustrates a vehicle having wheels 10a and 10b without the application of lateral forces. The axle member 11 is horizontal and angles a and b (one-half the aforesaid apex angles) are equal. Application of lateral force (such as centrifugal force) in the direction of arrow 31, as shown in FIG. 5B, increases the angle a to almost 90° and angle b is similarly decreased to about 60°. The periphery of wheel 10a is thus effectively increased and the periphery of wheel 10b is effectively decreased whereby the axle 11 is caused to slant downwardly into the force applied. From this, it will be understood that the disclosed structure tends to lean into, rather than away from, a curve. Any tendency of wheels 10 to "walk" away from lateral forces is compensated in part by the relatively increased wheel periphery which occurs in the outboard wheels and is minimized by provision of connecting members 30.
FIG. 6 shows an expansible wheel 40 which has a helical form and surrounds an axle 42. The spokes 41 are inclined increasingly outwardly from the center towards the sides as illustrated; the spokes 41 connecting the wheel 40 and the axle 42. The wheel 40 and spokes 41 are composed of a resilient material. Preferably, the wheel 40 is sinuous within the surface of an imaginary cylinder surrounding axle 42 so as to be capable of direct expansion or contraction. A vehicle 44, shown in dotdash lines, is carried on the axle 42 through supports 43.
When force is applied in direction 46, as shown in the diagram of FIG. 7, the angles c, away from the application of force, tend to increase whereas the angles d toward the application of force decrease and axle 42 is thus caused to lean in a direction to meet the application of force as illustrated.
Referring to FIGS. 8 and 9, a wheel designated generally 50 comprises an axle means 51 which includes openings 52 spaced about the wheel's axis of rotation to receive bolts extending therefrom for interconnection to the axle of a vehicle, in a well-known manner. A plurality of bolts 54 extend from axle means 51 about its axis of rotation to secure a hub cap or cover means 53. A plurality of spoke guidance means 55 are secured about the periphery of axle means 51 by bolts 56 or other suitable means. As seen in FIG. 9, each guidance means 55 is trapezoidal in configuration and includes elongated aperatures 57 on the bottom and circular aperatures 58 at top. A pair of parallel spoke members 60 are each received through a top and bottom aperture 58 and 57. The upper end of each spoke member 60 is threaded to receive nuts 61 and a resilient washer 62 may be received on each spoke member 60 between nut 61 and the top of guidance means 55. Within each guidance means 55, each spoke member 60 has a stop 64 rigidly attached thereto, the stop 64 having a configuration whereby it may pass through aperature 57. Between each stop 64 and the under side of the top of guidance means 55 is compression spring 65 surrounding each spoke member 60 in this area and, being in compression, urging each spoke member 60 outwardly relative to the axis of rotation of axle means 51. The strength of each spring 65 is such that it is only partly compressed when conveying its share of the weight of the vehicle involved in both loaded and unloaded condition and is almost fully compressed when it is subjected to a substantially greater force such as when the segment of wheel 50 involved encounters a rock or bump in the road.
Each spoke member 60 terminates in its outermost end with a ball 66 of a ball and socket joint 67 in a steel shoe plate 70. Secured to plate 70 by bolts 71 in recesses 72 is a rubber surface contacting member 74. The upper portion of plate 70 has secured thereto a resilient bracket member 75 by bolts 71. Bracket member 75 includes a pair of U-shaped parts 76 each having an opening 77 to receive snugly the lower end of a spoke member 60. The bracket member 75 is provided with resilience such that under unloaded conditions with the normal downward force due to the weight of the vehicle carried by wheels 50 a lateral force applied parallel to the axis of rotation of the vehicle 80 which is slightly or somewhat less than that required to cause member 74 to slide laterally on a wet flat concrete or asphalt surface changes the angle of spoke members 60 to that indicated by dot-dash lines 81 and an opposite like force changes the angle of spoke members 60 to that indicated by dot-dash lines 82, with the spoke members 60 being guided and limited in their movement by elongated aperatures 57. Rubber bumpers 84 secured in guidance means 55 adjacent to and slightly overlapping aperatures 57 protect the ends of aperatures 57 from undue wear and increase the resilient resistance against spoke members 60 to lateral forces as indicated above.
The plates 70 and surface contacting members 74 may be of an overlapping parallelogram configuration as shown in FIG. 10 or overlapping on both sides as shown in FIG. 10a which causes following action in successive spoke members 60 and avoids any tendency of the wheel to "walk" sidewise when the vehicle is subject to lateral force.
In operation, the springs 65 provide vertical cushioning of the vehicle to some extent and permits surface contacting members 74 to adjust to the inclination of the underlying surface within limits. In the event of lateral force vectors acting on the vehicle, such as occur when the vehicle turns, is on an incline, has a collision involving impact on one side, or the like, there is a certain lateral movement of the vehicle which takes place prior to lateral sliding by the surface contacting members 74 whereby the lateral force may, in effect, be absorbed and the sliding averted. Also, for reasons heretofore explained there is a tendency for a vehicle provided with wheels 50 50 to "lean" into a curve.
Referring to FIGS. 13 and 14, a lug 90 is bolted or otherwise secured to a steel tractor wheel 91 by a plurality of bolts 92, the lug 90 is curved so as to have a U-shaped configuration and has a rubber strip 94 bolted or otherwise secured to its opposite outward arm for contacting the ground. Strip 94 includes recesses 95 to receive the bolts 96. It will be noted from FIG. 14 that the lugs 90 are bolted to the wheel 91 so as to be biased relative to its normal directions of travel and with the strips 94 overlapping so there always will be at least one strip 94 contacting the ground. If desired, lug 90 and strip 94 can be divided as indicated by dot-dash lines 93 whereby it constitutes a plurality of lugs which act independently. FIG. 15 shows a lug 90a which is S-shaped, but otherwise similar to lug 90. The lugs 90 and 90a may be used with or in lieu of the lugs otherwise provided on a lugged steel tractor wheel or the like. If used with such lugs, then lugs 90 and 90a should extend beyond the existing lugs on the wheel. Preferably, lugs 90 and 90a are made of resilient steel. With such lugs, it is possible to travel on surfaced roads and highways which would be otherwise damaged. At the same time, the lugs 90 and 90a provide superior traction to pneumatic tractor tires under most conditions.
Although I have described preferred embodiments of my invention, it is to be understood that it is capable of other adaptions and modifications within the scope of the appended claims. | A wheel wherein the periphery comprises overlapping resilient members so that viewed from the side such members form a continuous circle about the wheel's axle; the spokes connecting such members with the axle extending within the surface of an imaginary cone having the same axis of the axis of rotation of the wheel; the individual peripheral members either not being connected or being connected in a manner that the periphery is, in effect, expansible and resiliently expands when force is applied parallel to the axle whereby the apex angle of the imaginary cone is enlarged. | 12,610 |
BACKGROUND OF INVENTION
This invention relates generally to methods for beneficiation of minerals, and more specifically, relates to a method for improving the brightness of kaolin clays through the use of synergistically related flotation and magnetic separation.
Naturally occurring kaolin clays frequently include discoloring contaminants in the forms of iron-based ("ferruginous") and titanium-based ("titaniferous") impurities. The quantities of the titaniferous discolorants are particularly significant in the case of the sedimentary kaolins of Georgia, where such impurities are commonly present as iron-stained anatase and rutile. In the case of various crude kaolin clays, it is accordingly often desired and indeed, frequently imperative, to refine the natural product in order to bring the brightness characteristics thereof to a level acceptable for paper coating and other applications. Various techniques have been used in the past to effect the removal of the aforementioned discolorants. Thus, for example, hydrosulfites have been widely used for converting at least part of the ferruginous discolorants to soluble forms, which may then be removed from the clays.
Among the most effective methods for removing titaniferous impurities, including, e.g., iron-stained anatase, are the well-known froth flotation techniques. According to such methods, an aqueous suspension or slurry of the clay is formed, the pH of the slurry is raised to an alkaline value, for example by the addition of ammonium hydroxide, and a collecting agent is added, as for example, oleic acid. The slurry is then conditioned by agitating same for a relatively sustained period. A frothing agent, such as pine oil, is then added to the conditioned slurry, after which air is passed through the slurry in a froth flotation cell to effect separation of the impurities.
The aforementioned flotation technology, however, becomes of decreasing effectiveness as one attempts to utilize same to remove smaller and smaller discolorant particles. The difficulty in this regard is that the flotation forces are insufficient with respect to such small particles to overcome drag forces; and hence, the particles cannot adequately respond to the flotation treatment.
Within recent years it has further been demonstrated that high intensity magnetic separation techniques may be utilized for removing certain of the aforementioned impurities, including titaniferous impurities, and certain ferruginous matter. Anatase, for example, and certain other paramagnetic minerals, have been found to respond to high intensity magnetic fields. Thus, for example, U.S. Pat. No. 3,471,011 to Joseph Iannicelli et al., discloses that clay slurries may be beneficiated by retention for a period of from about 30 seconds to 8 minutes in a magnetic field of 8,500 gauss or higher. Reference may also be made to U.S. Pat. No. 3,676,337, to Henry H. Kolm, disclosing a process for treating mineral slurries by passing same through a steel wool matrix in the presence of a background field of at least 12,000 gauss. Various apparatus, such as that disclosed in Marston, U.S. Pat. No. 3,627,678, may be utilized in carrying out the kolm processes. In this latter instance the slurry is thus passed through a canister, which contains a stainless steel or similar filamentary ferromagnetic matrix, while a high intensity magnetic field is impressed on the matrix by enveloping coils.
In certain further instances, as for example, in the teaching of U.S. Pat. No. 3,826,365, to V. Mercade, titaniferous impurities which are sought to be separated by a high-intensity magnetic field, are in advance of such separation, selectively flocculated. Somewhat similar phenomena are considered in Soviet Pat. No. 235,591 to Tikhanov, where several agents are used to selectively flocculate impurities in a slip of clay, which impurities are thereafter separated in a ferromagnetic filter including steel balls which have been previously rendered hydrophobic by treatment with a silicone compound.
All of the above magnetic separation methods, including those which employ differential flocculation, suffer from the limitation that particles with low magnetic susceptibility are not readily separated, despite the various technologies mentioned.
It may further be noted that in U.S. Pat. No. 3,974,067, to Alan J. Nott, which patent is assigned to the assignee of the present application, a method is disclosed for brightening a kaolin clay, wherein the clay as an aqueous dispersed slurry is subjected to a froth flotation treatment to remove titaniferous impurities, and the purified product from the froth flotation is thereupon subjected to magnetic separation by passing such product through a slurry-pervious ferromagnetic matrix positioned in a high intensity magnetic field. This method, while very effective compared to many prior art techniques, still retains certain of the limitations discussed in connection with flotation and conventional magnetic separation, i.e., small particle sized discolorants are floated only with difficulty, and particles of very low magnetic susceptibility cannot ultimately be removed by the magnetic separator stage of the process.
In a series of recent United States patents assigned to the assignee of the present application, a method has been disclosed for vastly increasing the effectiveness of magnetic separation methodology as same is applied to various minerals, including kaolin clays. In the techniques set forth in these patents, which include Nott et al U.S. Pat. Nos. 4,087,004, and 4,125,460, a dispersed aqueous slurry of the clay to be treated, is mixed with a finely divided magnetic particulate based upon magnetic ferrite particles. The slurry is thereupon passed through the aforementioned porous ferromagnetic matrix in the presence of an applied magnetic field, whereby contaminants seeded by the particulate are separated by the slurry. The said techniques are so effective that it is possible to obtain a high degree of brightening even with very low intensity applied fields. U.S. Pat. No. 4,125,460 indeed discloses achieving of fully acceptable brightening at field intensities as low as 0.5 kilogauss.
Further pertinent art is disclosed in Shubert, U.S. Pat. No. 3,926,789, which teaches the selective separation of minerals by use of ferrofluids. In particular the ferrofluid is used to selectively wet a mineral component sought to be separated from a mineral mixture. In consequence the selected component is rendered of increased magnetic susceptibility, and is able to respond and be captured in the magnetic separator through which the mineral mixture is then passed.
Despite the fact that very minute discolorant particles can often not be recovered by the method, for aforementioned magnetic seeding methodology as disclosed in the Nott et al U.S. Pat. Nos. 4,087,004 and 4,125,460 above mentioned, has been among the most effective techniques thus far found to remove titaniferous and feruginous discolorants. Certain practical difficulties, however, are presented by commercial scale use of the said seeding technology. A principal one of these is that use of the magnetic seeding materials tends to produce relatively rapid fouling and blinding of the porous ferromagnetic matrix.
In particular, the magnetic separating apparatus which are most commonly utilized in the kaolin and other minerals processing industries, and which are generally of the type disclosed in the aforementioned U.S. Pat. No. 3,676,337, employ, as already mentioned, a matrix comprising fine steel wool. The magnetic ferrites (such as ferroso-ferric oxide) which are used as the magnetic seed, are of course, removed at the steel wool matrix during passage of the seeded slurry through the said matrix. In the usual procedures for utilizing these magnetic separators, the matrix is periodically flushed with the magnetic field extinguished, i.e., in order to remove and flush the discolorant materials and magnetic seed which have become accumulated in the matrix. In conventional magnetic separation technology, these flushing operations are highly effective, and the said apparatus can operate for months without any requirement for completely disassembling the apparatus for removal for thorough cleaning or replacement of the steel wool.
Magnetic ferrite particles, as for example the aforementioned ferroso-ferric oxide, have, however, a degree of residual magnetism. In consequence they are not easily flushed from the steel wool matrix, i.e., flushed during the normal flushing operations which occur in situ. In consequence, fouling and blinding of the steel wool matrices can occur with rapidity, necessitating relatively frequent disassembling of the separator apparatus and replacement or separate cleaning of the fouled matrix.
It may further be pointed out that certain of the magnetic seeding compositions include liquid organics. These materials can similarly accumulate in the matrix and cause contamination and fouling of same. In addition, certain of the organics, as for example, fatty acids which can be present with various ferrofluids, even if such compounds do not excessively foul the matrix, remain in the beneficiated output from the separator. Where such output is a coating clay, the said compounds can add highly undesirable properties. Oleic acid, for example, will introduce an undesirable frothiness into the coating clay, which will render same relatively unsuitable for most coating applications.
In accordance with the foregoing, it may be regarded as an object of the present invention, to provide a method for magnetically beneficiating clays by utilizing as one aspect thereof, magnetic seeding, which method removes discoloring titaniferous and ferruginous discolorants, to enable brightness improvements previously unattainable through prior art techniques based upon flotation, magnetic separation, or prior known combinations of same.
It is a further object of the present invention, to provide a method for magnetically beneficiating kaolin clays, which is so highly effective in removing titaniferous and iron-containing discolorants, as to enable production of coating quality clays from crudes previously deemed too contaminated for such ultimate use.
It is a still further object of the present invention, to provide a method as aforementioned, which is based upon use of magnetic seeding materials, and which method may be practiced utilizing conventional porous matrix magnetic separators, without rapidly fouling or blinding the said matrices.
It is a yet further object of the invention, to provide a method for magnetically beneficiating kaolin clays, which method employs magnetic seeding materials which are produceable at low cost, which are highly stable and storeable, and which therefore, are admirably suitable for commercial scale operations.
SUMMARY OF INVENTION
Now in accordance with the present invention, the foregoing objects, and others as will become apparent in the course of the ensuing specification, are achieved in a method which synergistically integrates the processes of magnetic separation of seeded discolorants and froth flotation of clays, which processes were previously deemed distinct, so as to enable results previously unachievable by the individual processes, or by prior known combinations of same.
In accordance with the present invention, titaniferous and ferruginous discolorants are separated from a crude kaolin clay, by forming a dispersed aqueous slurry of the clay containing a deflocculant, and a fatty acid collecting agent. The slurry is thereupon conditioned in the presence of at least 0.25 lb/ton dry of the collecting agent (which more typically can be present as from about 1 to 4 lbs/ton of dry clay) to coat the discolorants with the collecting agent, and thereby render the discolorants hydrophobic. The slurry is thereupon seeded with a system of sub-micron sized magnetic ferrite seeding particles, the surfaces of which have been rendered hydrophobic, after which the seeded slurry is mixed to coalesce the hydrophobic-surfaced discolorants with the hydrophobic-surfaced seeding particles. The seeded slurry is thereupon subjected to a froth flotation to remove substantial quantities of the discolorants and seeding particles coalesced with same, and to remove excess seeding particles and excess collecting agent. Thereupon, the flotationbeneficiated slurry is subjected to a magnetic separation to remove further quantities of the discolorants and seeding particles associated therewith, and to remove seeding particles unassociated with the discolorants. The magnetic separation may be effected by passing the slurry through a porous ferromagnetic matrix whereat a field intensity of at least 0.5 kilogauss is maintained.
In a presently preferred embodiment of the invention, the magnetic seeding system may comprise magnetic ferrite particles in an aqueous phase, together with a fatty acid containing from 10 to 15 carbon atoms, the acid rendering the ferrite particles hydrophobic and serving to size-stabilize same.
The fatty acid should be present in the seeding system in concentrations of at least 6.7×10 -3 g-moles per lb. of magnetic ferrite expressed as Fe 3 O 4 , with a typical concentration of the said fatty acid being of the order of 3.8×10 -2 g-moles per lb. of the said ferrite. Because of its ready availability and low cost, dodecanoic acid is an especially attractive fatty acid for use in the foregoing seeding system.
In a further aspect of the invention, the seeding system may comprise magnetic ferrite particles in an organic liquid phase containing a fatty acid which will render the ferrite particle surfaces organophilac. The organic liquid in such a system may, for example, be kerosene or a similar hydrocarbon or hydrocarbon mixture and should be present in sufficient quantity to produce a fluid mixture of the ferrite particles and liquid. The fatty acid can be oleic acid, although numerous other fatty acids as are known in the art, can be utilized to render the ferrite surfaces organophilac--with sufficient of the acid being present to produce the desired surface characteristics. The above organic liquid phase can be present as a single phase, or as a component of an emulsion with water which is stable at ambient temperature. Where the latter, sufficient of the organic liquid should be present to produce the said stable emulsion.
The magnetic ferrite utilized in the seeding systems preferably comprises ferroso-ferric oxide particles, which may be prepared as described in the aforementioned U.S. Pat. Nos. 4,087,004, and 4,125,460. In the procedure set forth in said patents, a particulate of the said ferroso-ferric oxide is prepared as a product of aqueous coprecipitation of iron (III) with iron (II) salts, by an excess of a relatively strong base. For present purposes, the resulting precipitate may be extracted into the organic liquid/fatty acid phase or left in aqueous phase with addition of a stabilizing fatty acid such as the dodecanoic acid mentioned above. The precipitate can be washed or unwashed in either event.
In addition to the mentioned ferroso-ferric oxide, other finely divided ferrimagnetic materials may be used in the invention, including cubic ferrites such as NiFe 2 O 4 and CoFe 2 O 4 ; gamma-ferric oxide; and more generally, the magnetic ferrites represented by the general formula MO.Fe 2 O 3 , where M is a divalent metal ion such as Mn, Mi, Fe, Co, Mg, etc.
The magnetic seeding system is added to the clay slurry in quantities of at least 0.2 lbs. expressed as Fe 3 O 4 , per ton of dry clay, with from 1 to 2 lbs/ton dry clay being preferred. As excess ferrite seed is removed by flotation, as well as by magnetic separation, overdosing does not detrimentally affect the clay brightness. Thus although there is in principle no objection to higher dosage rates for the seed, economics dictate use of the smallest dose as will produce a desired product brightness.
The magnetic field to which the slurry is subjected during the magnetic separation step, may in practice of the invention be reduced to as low as 0.5 kilogauss--and yet provide brightening of the treated mineral to acceptacle levels. In general, retention times in the field are adjusted to the field intensities utilized and to the brightening required. Utilizing field intensities in a typical operational range of from about 5 to 10 kilogauss, typical retention times in practice of the present invention are of the order of 15 to 80 seconds. Within the limits of the technology (and of economics) higher fields may also be used with the invention, e.g., up to 60 kilogauss or higher.
While not all aspects of the mechanism of the present invention are fully understood, and while applicants are not bound by any particular hypothesis, it is presently believed that as a result of the conditioning of the clay slurry with the fatty acid collecting agent, and of the subsequent seeding with a system of sub-micron sized magnetic ferrite particles the surfaces of which have been rendered hydrophobic, the subsequent mixing effects a high degree of coalescence between hydrophic-surfaced discolorants and the hydrophobic-surfaced seeding particles. Futher, the common hydrophobicity of seed particles tends to coalesce excess seed particles with other excess seed particles. To be noted is that the phenomenom of this invention is fundamentally different from the spontaneous seed-discolorant association which occurs in the processes of the Nott et al patents. In the latter instances, the surfaces of the discolorants in the clay slurry are much more active, having not been coated with oleic or other fatty acids.
Thus, when the conditioned and seeded slurry is thereupon subjected to a froth flotation, not only are discolorants removed which would "normally" be removed by flotation, but in addition, some discolorant particles are removed which have become associated with seeding particles by coalescence, and futher, some seeding particles (which are floatable by virtue of their hydrophobic surface) are removed. A final element being removed is the excess fatty acid collecting agent, which would otherwise add highly undesirable properties to the clay slurry.
Hence, it will be evident that as a result of the steps thus far described, a hydrophobic coalescence has occurred, which coalescence has also produced discolorant-seed and seed-seed bodies, which are susceptible to removal by flotation and which have a high magnetic susceptability.
The flotation has removed particles which are ultimately sought to be separated, and which would otherwise create serious problems at the magnetic separator stage. In particular, the flotation has removed large quantities of discolorants, i.e., the larger discolorant particles and associated seed; and the flotation has removed excess seeding particles. All of these elements would otherwise be removed at the separator stage, whereat (especially the seed) would contribute to rapid fouling of the matrix.
The flotation has also removed the excess fatty acid collector, together with other floatable organics as may be present, thereby eliminating the fouling which such organics would otherwise cause at the separator stage.
Thereupon, in the final step of the instant process, the purified underflow from the flotation cell is provided to the magnetic separator, but the underflow as mentioned, is now free of many of those elements which would generate serious problems at the separator and otherwise impair the effective operation of same. Indeed, substantially what remains for removal at the magnetic field, are small discolorant particles, which have been coalesced with seed particles and perhaps with other discolorant particles to create entities of higher magnetic susceptibility than would otherwise be present. Accordingly, the magnetic separator can act with a new degree of efficiency, not only in that it is relieved of the burden of removing larger discolorant particles, the seed associated with such particles, and excess seed (all of which have already come out at the flotation and which would otherwise rapidly foul the magnetic matrix), but moreover, because of the enhanced magnetic susceptibility of the remaining discolorant particles.
Thus, it will be clear that the blunging and conditioning and flotation steps of the present method directly interact with and affect the subsequent magnetic separation step, to enable in totality, a synergistically integrated result which is not otherwise possible.
BRIEF DESCRIPTION OF DRAWINGS
In the drawings appended hereto:
FIG. 1 is a graph plotting titania content as a function of cumulative volumes of clay beneficiated in a magnetic separator, for clay samples processed by the present invention, and by the identical process excluding only the flotation step;
FIG. 2 is a graph plotting bleached clay product brightness for the samples processed as described for FIG. 1;
FIG. 3 is a graph plotting bleached clay product brightness as a function of applied magnetic field intensity, for clay samples beneficiated by the process of the present invention;
FIG. 4 is a graph plotting titania content for samples processed as described for FIG. 3;
FIG. 5 is a graph plotting bleached clay product brightness as a function of the magnetic ferrite seed dose rate; and
FIG. 6 is a graph plotting titania content for the samples processed as described for FIG. 5.
DESCRIPTION OF PREFERRED EMBODIMENTS
The manner in which the present invention is practiced is best understood by consideration of the Examples now to be set forth, which further, will render clear to those familiar with the present art, the striking improvements achieved by the practice of the present methodology.
In Examples I through IX, three soft, cream Georgia kaolin clay samples were subjected to various beneficiation procedures, including the procedures of the present invention. In particular, each of the clays A, B, and C, were initially blunged. In each instance, an aqueous alkaline dispersion of the crude clay was formed, (pH adjusted to about 7 to 10 with ammonium hydroxide). The blunging was effected in the presence of a small amount of a dispersant, such as sodium silicate--and in the case of clay C, in the presence of a polyacrylate available under the tradename "Dispex N-40" from Allied Colloids of Great Britain.
In all instances in this specification it will be understood that brightness values were obtained according to the specification established by TAPPI procedure T646 os-75. Bleached brightness values were obtained by subjecting the samples to a conventional reductive bleaching treatment with sodium hydrosulfite at an addition level of 5.6 lbs/ton. Finally the TiO 2 content was determined by means of X-ray flourescence. The resulting data for all of Examples I through IX are set forth in Table I hereinbelow.
EXAMPLE I
The present Example was intended to provide one of a series of control Examples to demonstrate (by comparison) the efficacy of the present invention. The blunged slurries were thus diluted to 18% solids (by weight), and were screened, and then bleached. The indicated brightness and TiO 2 values thus represent controls for crude clay samples of the clays A, B, and C, which have been blunged, diluted, and screened, but not in other respects beneficiated.
EXAMPLE II
In this Example, intended to provide further control data, the procedures described in connection with Example I were again followed, except at the conclusion of screening the slurry was classified in a Bird centrifuge to recover a fraction wherein 92% by weight of the particulate material had an E.S.D. (equivalent spherical diameter) less than 2 microns. The size characteristics just indicated, and particle size characteristics as same may hereinafter be discussed in this specification, are as determined by Sedigraph analysis ("Sedigraph" is a trademark for size analysis instruments manufactured by Micromeritics Instrument Corp. of Norcross, Ga.). Resulting brightness and TiO 2 content data (for the said fraction), is set forth in Table I.
EXAMPLE III
In this Example, the same procedure was used as described in Example II, except that following blunging, dilution to 18% solids, and screening, the slurry was subjected to a magnetic separation by being passed through a canister containing a steel wool matrix (7.5% packing) in an apparatus of the general type described in the aforementioned Marston U.S. Pat. No. 3,627,678. The average field intensity during such treatment was about 12 kilogauss, and the retention time in the field was approximately 51 seconds. The data yielded is again tabulated in Table I hereinbelow, and may be regarded as representative of beneficiation of a clay slurry by conventional (non-seeded) high intensity magnetic separation.
EXAMPLE IV
In this instance, samples were processed as in Example II, except that the samples were seeded using a magnetic particulate of the type described in the prior art, more specifically of the type described in the aforementioned Alan J. Nott et al patents, including U.S. Pat. No. 4,087,004. This particulate thus comprised a synthesized ferroso-ferric oxide prepared by coprecipitating iron (III) and iron (II) ions from an aqueous solution in a desired molar ratio by contacting with an excess of a relatively strong base, i.e., ammonium hydroxide. The mode of preparation of such particulate is described in Example II of the aforementioned U.S. Pat. No. 4,087,004. This prior art aqueous particulate was utilized with the clay samples as taught in said U.S. Pat. No. 4,087,004. Ferroso-ferric oxide was added at the rate of 1.2 lbs/ton of dry clay. Thereupon the slurry was mixed to facilitate seeding, the seeded slurry was diluted to 18% solids and then passed through the magnetic separator under conditions identical to Example III. It was then classified to provide a 92% by weight less than 2 micron ESD fraction, which was subjected to the aforementioned testing procedures to determine bleached clay product brightness, and TiO 2 content. The data set forth in Table I, shows that quite excellent improvements in brightness, and reduction in titania content can be achieved by the procedure of this Example.
EXAMPLE V
It will be appreciated that thus far, all of the Examples set forth, specifically Examples I through IV, have utilized prior art techniques, and hence may all be regarded as control Examples, i.e., for providing comparative data for evaluating the present invention. In the instant Example, a procedure was utilized which is similar to that described in connection with Example IV, except in this instance the system of magnetic ferrite seeding particles was prepared by first utilizing the preparative procedures described in Example IV, i.e., by the same procedures as are referenced in the Nott et al U.S. Pat. No. 4,087,004 (see Example II of that patent). The aqueous magnetic particulate which results from the Nott et al procedure was, however (in correspondence to one aspect of the present invention), subjected to the further important step of particle size stabilization, by mixing the said magnetic particulate with approximately 0.017 lbs. of dodecanoic acid per lb. of ferroso-ferric oxide.
It may be pointed out in this connection that the use of dodecanoic acid, as well as of other fatty acids having carbon chain length of from about 10 to 15 carbon atoms, in connection with aqueous magnetic fluids, is not in its broadest sense first taught herein. Rather, reference may be made to the article, "Preparation of Dilution-Stable Aqueous Magnetic Fluids", by S. E. Khalafalla and George W. Reimers, appearing in IEEE TRANSACTIONS ON MAGNETICS VOL. MAG-16, No. 2, March, 1980. This article describes the use of dodecanoic acid and other fatty acids as mentioned, to produce an aqueous magnetic fluid which is stable toward dilution with water. It is, however, pointedly observed herein, that the said article considers exclusively "ferrofluids", i.e., homogeneous, completely stable magnetic fluids. In the present Example, i.e., in the magnetic ferrite particulate system used in this Example, the system is not a ferrofluid, as the system is actually not dispersed or peptized; indeed, the system above described is non-homogeneous, and upon standing, settles out into two components, one a relatively dark-colored phase including the ferroso-ferric oxide, and the other a clear aqueous phase. However, the dodecanoic acid, in any event, size stabilizes the magnetic ferrite particles, which is a most important aspect of the present process. In the process of the invention, the said dodecanoic acid or other fatty acid in the indicated carbon chain length, should be present in concentration of at least 6.7×10- 3 g-moles/lb of magnetic ferrite expressed as Fe 3 O 4 , with a typical concentration of the fatty acid being of the order of 3.8×10- 2 g-moles/lb. of the said ferrite (expressed as Fe 3 O 4 ). The 6.7×10- 3 figure translates to about 0.003 lbs. of dodecanoic acid. It may be noted that much greater quantities of the fatty acid can be utilized in the seeding system as same will be removed during flotation; but in consideration of economics it is desirable to use the minimum quantity of fatty acid as is effective. It is also of interest to note that the quantities of fatty acid used in the present seeding system are far below the range which is recommended for use in the compositions taught in the aforementiond Reimers and Khalafalla article. Of further interest for purposes of the present invention, is that the described aqueous seeding systems are found to be stable for use over sustained periods; e.g., after a month's storage, they are found to perform just as well in the process of the invention (such as in Example IX below).
In the instant Example, and following the addition of the said seeding system, the resultant slurry was diluted once again to 18% solids by weight, screened, subjected to magnetic separation as aforementioned, and thereupon classified to produce for testing a fraction of clay, including 92% by weight of particles which are less than 2 microns ESD. The resulting data is again set forth in Table I hereinbelow. The data is of interest, in part in showing that this type of seeding system, when used in the prior art Nott et al process (of Example IV) is actually less effective than the seeding materials described in Nott et al (which are used in the above Example IV). Part of the explanation for this is thought to be that the dodecanoic acid has passivitated the surfaces of the magnetic ferrite particles, and thereby reduced the tendency to spontaneous seeding which occurs with the prior art particulates.
EXAMPLE VI
In the present Example (a further control), the procedure utilized differed from that described in Example V, in that persuant to a key aspect of the invention, the crude clay was blunged and then conditioned in the presence of a conventional fatty acid collecting agent i.e., oleic acid. The subsequent processing was identical to that described in connection with Example V. In studying the results set forth in Table I, it is seen that the bleached clay product brightness has been increased considerably by the present procedure, and of considerable further interest is the lowering of titania content. While it will be appreciated that a flotation step has not been utilized in the present Example, the cited improvements in brightness and titania levels tends to support the hypothesized mechanism of the present invention, i.e., as being one wherein hydrophobic coalescence occurs, facilitating removal of the coalesced materials by subsequent separation processes, which in this instance, includes only magnetic separation.
EXAMPLE VII
In this Example, the groups of clays A, B, and C, were subjected to a further control procedure, in this instance to conventional benefication by froth flotation. Such procedure is described as one aspect of Nott U.S. Pat. No. 3,974,067. In particular, in such sequence, the crude clay samples were blunged and conditioned in the presence of oleic acid as a collecting agent. The blunged and conditioned slurry, after addition of a frothing agent, was then subjected to a conventional treatment in a froth flotation cell, after which the beneficiated underflow was classified in a centrifuge to yield a 92% by weight less than 2 micron ESD fraction, which was subjected to the tests for brightness and titania content, as previously discussed. The resulting data is set forth in Table I, from which it will be seen that bleached clay product brightness and titania levels are not as good as those achieved with the seeding and magnetic separation processes called for in Examples IV, V, and VI.
EXAMPLE VIII
In this Example, which again constitutes a further control, for comparing and evaluating the results yielded by the present invention, the same series of clay specimens, i.e., of groups A, B, and C, were subjected to the combined flotation and magnetic separation procedure of the prior art, as same is disclosed in the Alan J. Nott U.S. Pat. No. 3,974,067, which has previously been referenced. The flotation procedure was as disclosed in Example VII; and following flotation the beneficiated output from the flotation cells were subjected to subsequent treatment in a high intensity magnetic field. The flotation-beneficiated slurry samples, after being diluted, as appropriate to include about 30% solids content, were passed through the magnetic separator of the aforementioned Marston type, wherein an approximate field intensity of about 15.5 kilogauss was maintained at the steel wool matrix. The flow rate of the slurry during the magnetic treatment was such that retention time in the magnetic field was approximately 1.2 minutes. The samples emerging from the magnetic separator were flocculated, bleached, and dewatered to yield test samples. The result of the said processes are once again set forth in Table I, from which it will be seen that very excellent brightness improvements were achieved, and titania levels were reduced well below those yielded by the flotation alone procedure of Example VII.
EXAMPLE IX
In the present Example, the process of the present invention was utilized to beneficiate the clay samples of groups A, B, and C. Thus, in the procedure utilized in this Example, the samples were first blunged together with oleic acid, as in Examples VI, VII, and VIII. A seeding system of the type described in Examples V and VI, which comprised ferroso-ferric oxide particles in an aqueous phase, together with 0.017 lbs. dodecanoic acid per lb. of ferroso-ferric oxide, was thereupon added to the blunged and conditioned clay slurry samples. The said seeding system was added to the slurries in quantities to yield 1.2 lb. expressed as Fe 3 O 4 per ton of dry clay. Following this, the resulting seeded slurry was further mixed to coalesce the hydrophobic-surfaced discolorants with the hydrophobic-surfaced seeding particles. The resulting seeded slurries were then subjected to froth flotation as described in connection with Examples VII and VIII; and thereupon the beneficiated underflow was subjected to a magnetic separation by passing same through the aforementioned Marston-type separator utilizing a field intensity of about 12 kG and retention time of 51 seconds.
Thereupon, 92% less than 2 micron fractions of the beneficiated slurry samples were evaluated for bleached product brightness and titania content. The results are set forth in Table I, from whence it will be seen that brightnesses have been achieved well exceeding those obtained in any of the procedures described in the preceding Examples. Further, it will be seen that a remarkable reduction in titania content has been achieved. Clearly the results exceed all expectations yielded by the prior art procedures.
TABLE I__________________________________________________________________________CLAY A CLAY B CLAY CBleached Clay Bleached Clay Bleached ClayExampleProduct Brightness %TiO.sub.2 Example Product Brightness %TiO.sub.2 Example Product Brightness %TiO.sub.2__________________________________________________________________________I 83.5 3.24 I 84.7 1.4 I 85.7 1.47II 83.5 3.24 II 84.8 1.4 II 86.8 1.28III 85.7 2.67 III 88.7 1.28 III 89.8 .90IV 88.0 1.47 IV 91.0 .52 IV 91.9 .33V 86.8 2.16 V 90.6 .71 V 91.7 .43VI 87.1 1.78 VI 91.2 .52 VI 92.3 .33VII 85.6 2.41 VII 88.7 .75 VII 88.3 .90VIII 87.4 2.03 VIII 90.4 .58 VIII 90.2 .58IX 90.7 .84 IX 91.7 .39 IX 92.4 .20__________________________________________________________________________
EXAMPLE X
A most important and significant aspect of the present invention as previously discussed herein, is the fact that where the present process is utilized, the matrix material of the magnetic separator (which material commonly comprises steel wool as aforementioned) is not rapidly fouled and blinded, as occurs in prior art beneficiation of clays utilizing magnetic seeding techniques.
In the present Example, this aspect of the invention was illustrated by subjecting clay samples which consisted of approximately 50% by weight of the aforementioned clay A, and 50% by weight of the aforementioned clay C, to two types of beneficiation, namely to beneficiation sequences corresponding to those set forth in Example VI and in Example IX. Example IX, of course, is in accordance with the present invention, and constitutes a preferred mode of operation persuant to same. The procedure in Example VI is similar to that of Example IX, with the important distinction that no flotation step is utilized. In each instance, the beneficiated clay slurries were passed through a magnetic separator of the Marston type at flow rates of approximately 800 ml/min, and at a field intensity of 12 kilogauss. The initial crude samples had a titania content of 2.35% by weight. The canister volumes in each instance were such that retention time in the field was approximately 51 seconds.
Utilizing the two procedures, specimens of the output from the magnetic separator were examined for titania content after a specified number of canister volumes had been successively processed. Thus, it was possible by this procedure to determine how the efficiency of the magnetic separator was being effected by the cumulative processing of samples. The results yielded are set forth in the graph of FIG. 1, from whence it will be apparent that by use of the process of the present invention, the titania content is not only reduced to far lower levels than by following a similar sequence but without the use of the synergistically related flotation step; but further, it will be evident that in the sequence of seeding and magnetic separation without the intermediate flotation, the magnetic separator rapidly loses its ability to remove the titania, this being a consequence of fouling of the matrix. On the contrary, however, and using the process of the present invention, it will be clear that the efficiency of removal remains at its extremely high level for a very extended period. Indeed, the efficiency remains fairly close to a constant value to the end of the graph, where 60 canister volumes have been cumulatively processed.
EXAMPLE XI
In the present Example, the same procedure as was described in connection with Example X was utilized, except in this instance, bleached brightnesses were determined as a function of cumulative flow through the canister of the magnetic separating apparatus. The results yielded by this procedure are set forth in the graph of FIG. 2, which is similar in nature to FIG. 1, except that bleached clay product brightnesses are plotted as ordinates against number of canister volumes which have been processed up to the abscissa at which the ordinate is plotted. Examination of the comparative curve (at lower left) for the data yielded by a procedure using a sequence which is substantially identical to the present invention, but which does not employ the intermediate flotation step following the blunging and conditioning with oleic acid and seeding, shows a rapid fouling of the matrix, whereby there is a rapid drop off in the brightness level of the processed clay samples. In marked contrast, the process of the present invention, which yields the results shown in the uppermost curve, shows but a very slow drop-off in brightness as the canister volumes are processed. The curve is indeed seen to be close to flat.
EXAMPLE XII
In order to demonstrate the effect of magnetic field intensity levels upon the process of the present invention, a group of samples of clay C were first beneficiated by prior art flotation, as in Example VII, and by the combined flotation and magnetic separation (at 12 kG) technique of Example VIII. These respectively yielded bleached product brightnesses of 88.3 and 90.2, which served as control values. Further such samples, were then subjected to the seeded flotation and magnetic separation process of the present invention, using the procedure set forth in Example IX. The quantity of the aqueous seeding system was such as to provide ferrite concentration of 1 lb. Fe 3 O 4 equivalent per ton of dry clay, and the seeding system was otherwise identical to that utilized in Example IX. Flow rate through the magnetic separator during the magnetic separation step was 800 ml/min. corresponding to a residence time of 0.85 minutes (51 seconds) in the magnetic field. The said procedure was carried out utilizing a a sequence of clay samples which were processed at different field intensities at the magnetic separator. The beneficiated samples were then processed to determine bleached clay product brightness, and the resulting data is plotted in the graph of FIG. 3, which specifically plots bleached clay product brightnesses as a function of magnetic field intensity. From this it will be seen that even at the lowest intensity utilized, i.e., approximately 0.64 kilogauss, the process of the invention has yielded a bleached clay product brightness of approximately 91.8, which is very remarkable, especially considering that conventional flotation (normally regarded as a very efficient process) has yielded a brightness of 88.3 and even combined conventional flotation and magnetic separation, a brightness of 90.2. Further to be noted, is that there is remarkably little variation in the bleached brightness over the range of magnetic intensity studied.
EXAMPLE XIII
In this Example, samples of clay C were subjected to the process of the invention as described in Example XII, and were then analyzed to determine the titania content thereof as a function of the applied magnetic field at the separator. The conventional flotation process in this instance, i.e., the conventional procedure of Example VII, had yielded an average titania content of 0.90% by weight for the samples. The results yielded by practice of the present invention are set forth in the graph of FIG. 4, which plots percentage titania (by weight) as a function of the intensity of the said field. It will be evident that the titania content has been remarkably reduced, especially in comparison to what is normally considered a very effective process in its own right, i.e., conventional flotation. It will also be seen that even at very low field values of approximately 0.6 kilogauss, the the process of the invention is still remarkably effective.
EXAMPLE XIV
In this Example, the process of the present invention as exemplified by the procedure of Example IX, was carried out with a series of clay B samples, utilizing, however, various dosage levels for the aqueous magnetic seeding system. In order to again provide a control, the samples were subjected to a conventional flotation procedure as exemplified by the process described in Example VII. This yielded a bleached clay product brightness of 85.7. The samples were then subjected to the process of the invention utilizing a field intensity at the magnetic separator of 12 kG, and a 0.85 minutes residence time in the magnetic field. Bleached clay product brightnesses were determined as a function of concentration of the ferrite seed in the clay slurry. The results are set forth in the graph of FIG. 5, which represents bleached clay product brightness as a function of lbs/ton of dry clay of the ferrite expressed as Fe 3 O 4 . The depicted range for the curve is seen to run from about 0.27 lb/ton to 1.35 lb/ton-- the curve is seen to be virtually flat over this range. The flattening out of the curve illustrates that there is little advantage in operating with seed concentrations exceeding the 1 to 2 lbs/ton previously mentioned.
EXAMPLE XV
In this Example the same procedures as were described in connection with Example XIII were followed, for the purposes, however, of determining the effect of concentration of the magnetic ferrite added by the seeding system upon titania content in the beneficiated samples. Again, for control purposes, evaluation of titania content was made of similar clay B samples which had been subjected to a conventional flotation treatment as described in connection with Example VII. This yielded a titania content of 0.75% by weight.
FIG. 6 plots the percentage of titania in the beneficiated samples for various dosage levels yielded in the slurry from addition of the seeding system. The abscissa values are identical to those in FIG. 4. To be noted again, is that the process of the invention is highly efficient over the entire range of data plotted, although the curve is not as flat as that of FIG. 5, suggesting that greater quantities of titania are removed at the somewhat higher seed concentrations.
EXAMPLE XVI
In this Example, the seeding system utilized was of the type set forth in Example IX, i.e., it constituted a system of magnetic ferrite particles in an aqueous phase together with a fatty acid containing from 10 to 15 carbon atoms. The objective of the Example was to demonstrate the effect of the fatty acid concentration on the bleached clay product brightnesses. In order to provide controls, a sample of clay A, was initially subjected to a conventional beneficiation by flotation as in the procedure of Example VII. This yielded a bleached clay product brightness of 85.6. Similar clay A samples were then subjected to the combined conventional flotation and magnetic separation treatment as in Example VIII. This yielded a bleached clay product brightness of 87.4. Thereupon, further samples of clay A were subjected to the process of the invention as in Example IX, with the fatty acid utilized in the seeding system being dodecanoic acid. The bleached brightnesses yielded in consequence of this procedure are set forth in Table II below.
TABLE II______________________________________Dodecanoic Acid Concentration Bleached Clayin lbs/lb of Magnetic Ferrite Product Brightness______________________________________.0025 87.9.005 88.1.01 88.5.0125 89.3.046 89.4.072 89.5.144 89.5______________________________________
It is seen from the above Table that good results are yielded even with the fatty acid at the minimum tabularized concentration. In many representative applications of the process, the dodecanoic acid will be present in the seeding system at about 0.017 lbs/lb of the ferrite. It can be seen from the Table II, that at such level approximately the maximum brightness has been reached; i.e., as the quantity of dodecanoic acid is raised beyond this level, there is little further advantage to be gained in brightness improvements.
EXAMPLE XVII
In this Example, the procedure of the invention, i.e., as in Example IX utilizing a sequence of blunging and conditioning with a fatty acid collecting agent, followed by seeding, flotation, and magnetic separation, was again followed; except in this instance the seeding system utilized was not the aqueous system described in connection with Example IX. Rather, the seeding system of the present Example was prepared by first forming a ferroso-ferric oxide precipitate as in Example II of the Nott et al. U.S. Pat. No. 4,087,004, which material was admixed with a mixture of kerosene and oleic acid. This yielded a thick, creamy emulsion. The emulsion was added to clay slurry samples formed from a further soft cream Georia kaolin at an identical processing point as in the procedure of Example IX, and the seeding system was added in sufficient quantity to give the same concentration of magnetic ferrite with relationship to the dry clay in the slurry. Following flotation and classification, the samples were evaluated for brightness. This yielded a value of 91.3. Corresponding control brightnesses were determined for the same samples of clay when beneficiated by flotation alone, as in Example VII, and for the combined flotation and magnetic separation treatment as in Example VIII. This provided respective control brightnesses of 88.7 and 89.7.
EXAMPLE XVIII
The same procedure as described in connection with Example XVII was repeated, except in this instance, the seeding system, while initially prepared as in Example XVII, was admixed with more water and with sulfuric acid, in order to break the emulsion, and was thereupon heated to facilitate such breaking. This led to a separation into two layers, with the resulting system being used by first mixing the system so as to intermix the layers, and then adding the intermixed product to yield the desired concentrations of magnetic ferrite as aforesaid. It was found that bleached clay product brightnesses yielded were substantially identical to those found in Example XIX.
While the present invention has been particularly set forth in terms of specific embodiments thereof, it will be understood in view of the instant disclosure, that numerous variations upon the invention yet reside within the scope of the present teaching. Accordingly the invention is to be broadly construed, and limited only by the scope and spirit of the claims now appended hereto. | A method is disclosed for separating titaniferous and ferruginous discolorants from a crude kaolin clay. A dispersed aqueous slurry of the clay is formed containing a deflocculant and a fatty acid collecting agent, and the slurry is conditioned to coat the discolorants with the collecting agent to thereby render the discolorants hydrophobic. A system of sub-micron sized magnetic ferrite seeding particles, the surfaces of which have been rendered hydrophobic, is thereupon added to the slurry. The seeded slurry is mixed to coalesce the hydrophobic-surfaced discolorants with the hydrophobic-surfaced seeding particles, and the slurry is then subjected to a froth flotation, which removes substantial quantities of the discolorants and seeding particles coalesced therewith, and also removes excess seeding particles and excess collecting agent. The flotation-beneficiated slurry is then subjected to a magnetic separation by passing the slurry through a porous ferromagnetic matrix positioned in a magnetic field, having an intensity of at least 0.5 kilogauss, to remove further quantities of the discolorants and seeding particles associated therewith, and to remove seeding particles unassociated with said discolorants. | 51,582 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application No. 62/163,724, filed on May 19, 2015, entitled “ILLUMINATOR”, which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The subject invention relates to an optical device for generating illumination that appears to emanate from a location different from the actual light source. Such an optical device is useful for a variety of photographic or video capture situations where it is impractical or impossible to place an actual physical light source where needed.
BACKGROUND OF THE INVENTION
[0003] Most photographic or video capture situations require some form of illumination. The desired illumination could be supplied, for example, by a flash connected to a camera. However, in many situations, providing the needed illumination can be a challenge.
[0004] One such situation relates to a display system developed by the assignee herein for the creation of an augmented reality for a user. In such a system, the user would be provided with a head mounted device that includes a window for viewing the outside world. The window would have the capability to generate image information and project that image information into the eyes of the user. In such a system, images of simulated objects could be generated and added to the real world scene. A more detailed description of this type of window is provided below.
[0005] There is interest in adding certain functionality to such head mounted displays. For example, there is interest in including a camera for monitoring the gaze direction of the user. Knowing where the user is looking at any moment has many benefits. For example, knowledge of a person's gaze can be used to control the display system. Knowledge of gaze direction can be used as a selection tool to control a mouse pointer, or its analog. Knowledge of gaze direction can be used to select objects in the field of view. Capturing gaze information with a camera can be improved by providing a source to illuminate the eye.
[0006] Another feature of interest in head mounted displays is the possibility of identifying the user through biometric measurements, such as iris recognition. An iris recognition system will include a camera for capturing an image of the iris. The process of capturing iris information can be improved if a source of illumination is provided.
[0007] The illumination device of the subject invention has some similarities to the structure of the window used by the assignee herein to create augmented reality. Although the embodiment of the subject invention will be discussed in this context, it should be understood that the invention is not limited to augmented reality systems but, in fact, could be used in any situation that requires illumination, particularly where it is desired to create a virtual illumination source.
[0008] The subject device includes a planar waveguide having a structure similar to that proposed for use in augmented reality. A description of a device for creating an augmented reality can be found in U.S. Patent Publication No. 2015/001677, published Jan. 15, 2015, the disclosure of which is incorporated herein by reference.
[0009] As described in the latter publication and illustrated in FIG. 1 herein, the optical system 100 can include a primary waveguide apparatus 102 that includes a planar waveguide 1 . The planar waveguide is provided with one or more diffractive optical elements (DOEs) 2 for controlling the total internal reflection of the light within the planar waveguide. The optical system further includes an optical coupler system 104 and a control system 106 .
[0010] As best illustrated in FIG. 2 , the primary planar waveguide 1 has a first end 108 a and a second end 108 b , the second end 108 b opposed to the first end 108 a along a length 110 of the primary planar waveguide 1 . The primary planar waveguide 1 has a first face 112 a and a second face 112 b , at least the first and the second faces 112 a , 112 b (collectively, 112 ) forming a partially internally reflective optical path (illustrated by arrow 114 a and broken line arrow 114 b , collectively, 114 ) along at least a portion of the length 110 of the primary planar waveguide 1 . The primary planar waveguide 1 may take a variety of forms which provide for substantially total internal reflection (TIR) for light striking the faces 112 at less than a defined critical angle. The planar waveguides 1 may, for example, take the form of a pane or plane of glass, fused silica, acrylic, or polycarbonate.
[0011] The DOE 2 (illustrated in FIGS. 1 and 2 by dash-dot double line) may take a large variety of forms which interrupt the TIR optical path 114 , providing a plurality of optical paths (illustrated by arrows 116 a and broken line arrows 116 b , collectively, 116 ) between an interior 118 and an exterior 120 of the planar waveguide 1 extending along at least a portion of the length 110 of the planar waveguide 1 . The DOE 2 may advantageously combine the phase functions of a linear diffraction grating with that of a circular or radial symmetric zone plate, allowing positioning of apparent objects and a focus plane for apparent objects. The DOE may be formed on the surface of the waveguide or in the interior thereof.
[0012] With reference to FIG. 1 , the optical coupler subsystem 104 optically couples light to the waveguide apparatus 102 . Alternatively, the light may be coupled directly into the edge of the waveguide 108 b if the coupler is not used. As illustrated in FIG. 1 , the optical coupler subsystem may include an optical element 5 , for instance a reflective surface, mirror, dichroic mirror or prism to optically couple light into an edge 122 of the primary planar waveguide 1 . The light can also be coupled into the waveguide apparatus through either the front or back faces 112 . The optical coupler subsystem 104 may additionally or alternatively include a collimation element 6 that collimates light.
[0013] The control subsystem 106 includes one or more light sources and drive electronics that generate image data which may be encoded in the form of light that is spatially and/or temporally varying. As noted above, a collimation element 6 may collimate the light, and the collimated light is optically coupled into one or more primary planar waveguides 1 (only one primary waveguide is illustrated in FIGS. 1 and 2 ).
[0014] As illustrated in FIG. 2 , the light propagates along the primary planar waveguide with at least some reflections or “bounces” resulting from the TIR propagation. It is noted that some implementations may employ one or more reflectors in the internal optical path, for instance thin-films, dielectric coatings, metalized coatings, etc., which may facilitate reflection. Light that propagates along the length 110 of the waveguide 1 intersects with the DOE 2 at various positions along the length 110 . The DOE 2 may be incorporated within the primary planar waveguide 1 or abutting or adjacent one or more of the faces 112 of the primary planar waveguide 1 . The DOE 2 accomplishes at least two functions. The DOE 2 shifts an angle of the light, causing a portion of the light to escape TIR, and emerge from the interior 118 to the exterior 120 via one or more faces 112 of the primary planar waveguide 1 . The DOE 2 can also be configured to direct the out-coupled light rays to control the virtual location of an object at the desired apparent viewing distance. Thus, someone looking through a face 112 a of the primary planar waveguide 1 can see the virtual light source as if from a specific viewing distance.
[0015] As will be discussed below, the subject illuminator can be configured using the DOE and waveguide technology discussed above.
BRIEF SUMMARY OF THE INVENTION
[0016] An optical device is disclosed for generating illumination that appears to emanate from a location different from the actual light source. The device includes a waveguide having opposed first and second planar faces. A light source is positioned to direct light into the waveguide. A diffractive optical element (DOE) is formed across the waveguide. The DOE distributes the light entering the waveguide via total internal reflection and couples the light out of the surface of said first face.
[0017] In one embodiment, the DOE is configured to collimate the outgoing light, so as to emulate the light field of a source positioned at an infinite distance from the waveguide. In another embodiment, the DOE is configured to diverge the outgoing light, so as to emulate a light field of a source that is a predetermined distance from the waveguide. In a preferred embodiment, the light source generates a narrow bandwidth of radiation in the infrared region of the spectrum.
[0018] For instance, the DOE may be configured such that light rays exit said first face perpendicular thereto, or such that light rays exit said first face in a manner to create a virtual source in space opposite the second face; or such that light rays exit said first face in a manner to create at least two virtual sources in space opposite the second face.
[0019] Additionally, the light source may generate infrared radiation. The second face may be provided with a coating reflective for infrared radiation.
[0020] The light from the light source may be directed into the waveguide via the first face thereof and/or via the second face thereof. In another embodiment, the light source from the light source may be directed into the waveguide via an edge of the waveguide. In such an embodiment, the illuminator may include a second waveguide extending along the edge of the first waveguide. The second waveguide may receive the radiation from the light source and distribute the light along an axis of the first waveguide parallel to the edge.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a schematic diagram showing an optical system including a waveguide apparatus, a subsystem to couple light to or from the waveguide apparatus, and a control subsystem, according to one illustrated embodiment.
[0022] FIG. 2 is an elevational view showing a waveguide apparatus including a planar waveguide and at least one diffractive optical element positioned within the planar waveguide, illustrating a number of optical paths including totally internally reflective optical paths and optical paths between an exterior and an interior of the planar waveguide, according to one illustrated embodiment.
[0023] FIG. 3 is a schematic diagram showing an illuminator formed in accordance with a first embodiment of the subject invention where the virtual light source is at infinity.
[0024] FIG. 4 is a schematic diagram showing an illuminator formed in accordance with a second embodiment of the subject invention where the virtual light source is a point in space some finite distance from the waveguide.
[0025] FIG. 5 is a schematic diagram showing an illuminator formed in accordance with a third embodiment of the subject invention which includes a distribution waveguide.
DETAILED DESCRIPTION OF THE INVENTION
[0026] FIG. 3 illustrates a first embodiment of an illumination device 10 made in accordance with the subject invention. The device may be used in a wide variety of applications that require illumination. The device may be particularly useful with head mounted displays for implementing features such as gaze tracking or iris identification.
[0027] Device 10 includes a planar waveguide 20 . One or more diffractive optical elements (DOEs) 22 are formed in the waveguide. The DOE can be formed on a surface of the waveguide or be embedded within the waveguide.
[0028] A light source 24 is provided for generating optical radiation for illumination. A wide variety of light sources could be used. In the preferred embodiment, the light source generates a single wavelength or a narrow band of wavelengths. In one example, the light source 24 is a light emitting diode (LED). The light output of the LED is directed into the waveguide. The light can be directed into either side of the waveguide or along the edge thereof. The light then propagates throughout the waveguide by total internal reflections.
[0029] The DOE is arranged to out couple the light at various points along the surface of the waveguide. In the embodiment of FIG. 3 , the light rays coupled out are substantially perpendicular to the surface of the waveguide. This approach emulates the situation where the light source would be located at an infinite distance from the waveguide and the light is substantially collimated.
[0030] FIG. 4 illustrates a device 10 b in accordance with a second embodiment of the invention. In the FIG. 4 embodiment, the DOE 22 a of waveguide 20 a is arranged to create diverging rays to emulate the effect of a point source 30 located a particular distance from the opposite side of the waveguide. The particular location of the virtual light source is controlled by configuring the DOE.
[0031] The DOE can be arranged to place the virtual light source in any location, from quite close to the waveguide to quite far away. The choice will depend on providing the best illumination for the particular application. For example, if the illumination of the eye is used to capture images of the iris, it may be better to move the virtual source farther away from the waveguide to create a more uniform illumination.
[0032] For augmented reality applications, it is preferable that the light source emits illumination in the infrared spectrum so that the radiation is not visible to the user. In this way, the illuminator would not interfere with the real world or computer generated images reaching the user. Using infrared illumination is particular useful for iris recognition as a much higher level of detail of the iris is available in this wavelength range.
[0033] In a system using an infrared source, it may be preferable to provide a coating that reflects infrared radiation on the side 32 ( 32 a ) of the waveguide (opposite the transmission side). An infrared coating would minimize any losses due to light leakage on that side. The infrared coating would not interfere with the transmission of visible light from the real world, through the waveguide and into the eyes of the user.
[0034] The embodiment of FIG. 4 shows how the DOE can be configured to emulate light coming from a single point source. It is within the scope of the subject invention to configure the DOE to create diverging light rays that emulate light emanating from two or more virtual light sources. This could be achieved by allocating some fraction of the pixels of the DOE to one virtual source and another fraction of the DOE pixels to another virtual source. Of course, one could achieve a similar result by using two waveguides 30 a . The two waveguides would be aligned parallel to each other. Each waveguide 30 a would be configured to emulate a point light source at a different location.
[0035] Various pupil tracking systems are configured to require multiple light sources to generate multiple reflections from the eye. It is envisioned that an embodiment of the subject invention which can generate multiple virtual point source could be used to implement these type of pupil tracking systems.
[0036] FIG. 5 is a diagram of a system 10 c that includes a planar waveguide 50 having a DOE 52 . System 10 c further includes a second waveguide 56 aligned with an edge of waveguide 50 . Second waveguide 56 includes a DOE 58 . Light source 54 directs light into the second waveguide. The light spreads across the second waveguide 56 via total internal reflection. The light exits second waveguide 56 and enters waveguide 50 . In this embodiment, waveguide 56 acts to distribute light along the axis thereof (vertical axis of FIG. 5 ). Waveguide 50 then distributes the light along the horizontal axis of FIG. 5 . The use of the second waveguide may improve coupling efficiency.
[0037] While the subject invention has been described with reference to some preferred embodiments, various changes and modifications could be made therein by one skilled in the art, without varying from the scope and spirit of the subject invention as defined by the appended claims. | An optical device is disclosed for generating illumination that appears to emanate from a location different from the actual light source. The device includes a waveguide having opposed first and second planar faces. A light source is positioned to direct light into the waveguide. A diffractive optical element (DOE) is formed across the waveguide. The DOE distributes the light entering the waveguide via total internal reflection and couples the light out of the surface of said first face. | 17,110 |
RELATED APPLICATIONS
This application is a continuation-in-part of commonly owned, application Ser. No. 09/448,523 of Edward C. Sisler, filed Nov. 23, 1999, now U.S. Pat. No. 6,194,350 the disclosure of which is incorporated by reference herein in its entirety. This application also claims priority from Edward C. Sisler, U.S. Provisional Application No. 60/193,202, filed Mar. 30, 2000, the disclosure of which is incorporated by reference herein in its entirety.
GOVERNMENT SUPPORT
This invention was made with government support under Grant No. US-2786-96R awarded by the U.S. Department of Agriculture. The government has certain rights in the invention.
FIELD OF THE INVENTION
The present invention generally relates to methods of blocking ethylene responses in plants and plant materials, and particularly relates to methods of inhibiting various ethylene responses including plant maturation and degradation by applying cyclopropene derivatives and compositions thereof to plants.
BACKGROUND OF THE INVENTION
Ethylene is known to mediate a variety of growth phenomena in plants. See generally Fritz et al. U.S. Pat. No. 3,879,188. This activity is understood to be achieved through a specific ethylene receptor in plants. Many compounds other than ethylene interact with this receptor: some mimic the action of ethylene; others prevent ethylene from binding and thereby counteract its action.
Many compounds that block the action of ethylene do so by binding to the ethylene binding site. Unfortunately, they often diffuse from the binding site over a period of several hours. See E. Sisler and C. Wood, Plant Growth Reg. 7, 181-191 (1988). These compounds may be used to counteract ethylene action. A problem with such compounds, however, is that exposure must be continuous if the effect is to last for more than a few hours.
Photoaffinity labeling has been used in biological studies to label binding sites in a permanent manner: usually by generating a carbene or nitrene intermediate. Such intermediates are very reactive and react rapidly and indiscriminately with many things. A compound already bound, however, would react mostly with the binding site. In a preliminary study, it was shown that transcyclooctene was an effective blocking agent for ethylene binding. See E. Sisler et al., Plant Growth Reg. 9, 157-164 (1990). Methods of combating the ethylene response in plants with diazocyclopentadiene and derivatives thereof are disclosed in U.S. Pat. No. 5,100,462 to Sisler et al. U.S. Pat. No. 5,518,988 to Sisler et al. describes the use of cyclopropenes having a C 1 to C 4 alkyl group to block the action of ethylene.
Notwithstanding these efforts, there remains a need in the art for improved plant maturation and degradation regulation.
SUMMARY OF THE INVENTION
Methods of inhibiting an ethylene response in a plant are disclosed herein. According to the present invention, one such method comprises applying to the plant an effective ethylene response-inhibiting amount of a cyclopropene derivative or a composition thereof described further in detail herein. Long-chain cyclopropene derivatives are particularly preferred as described below.
Another aspect of the present invention is a method of blocking ethylene receptors in plants by applying to the plants an effective ethylene receptor-blocking amount of a cyclopropene derivative or a composition thereof.
Also disclosed is a method of inhibiting abscission in a plant, comprising applying to the plant an effective abscission-inhibiting amount of a cyclopropene derivative or a composition thereof.
Also disclosed is a method of prolonging the life of a cut flower, comprising applying to the cut flower an effective life-prolonging amount of a cyclopropene derivative or a composition thereof.
Also disclosed is a method of inhibiting the ripening of a harvested fruit, comprising applying to the harvested fruit an effective inhibiting amount of a cyclopropene derivative or a composition thereof.
Also disclosed is a method of inhibiting the ripening of a harvested vegetable, comprising applying to the harvested vegetable an effective inhibiting amount of a cyclopropene derivative or a composition thereof.
The methods described herein may be carried out in a number of suitable manners, such as by contacting the plant with a cyclopropene derivative or a composition thereof, whether in solid, liquid, or gaseous form, or by introducing the plant, cut flower, picked fruit or picked vegetable into an atmosphere infused with the cyclopropene derivative or a composition thereof. These and other suitable methods of application are discussed in detail below.
Also disclosed is the use of a cyclopropene derivative as described herein for the preparation of an agricultural composition for carrying out any of the methods described above.
DETAILED DESCRIPTION OF THE INVENTION
Cyclopropene derivatives which may be used to carry out the present invention are defined by Formula I:
wherein:
n is a number from 1 to 4. Preferably n is 1 or 2, and most preferably n is 1.
R is a saturated or unsaturated, linear or branched-chain, unsubstituted or substituted, C 5 to C 20 alkyl, alkenyl, or alkynyl.
The terms “alkyl”, “alkenyl”, and “alkynyl”, as used herein, refer to linear or branched alkyl, alkenyl or alkynyl substituents. The terms should be interpreted broadly and may include compounds in which one or more of the carbons in one or more of the R groups is replaced by a group such as ester groups, nitriles, amines, amine salts, acids, acid salts, esters of acids, hydroxyl groups, halogen groups, and heteroatoms selected from the group consisting of oxygen and nitrogen or where such chains include halogen, amino, alkoxy, carboxy, alkoxycarbonyl, oxycarbonylalkyl, or hydroxy substituents. Thus, the resulting R groups can contain, for example, hydroxyl, ether, ketone, aldehyde, ester, acid, acid salt, amine, amine salt, amide, oxime, nitrile, and halogen groups.
Cyclopropene derivatives which may be used to carry out the present invention may be prepared by various methods known to those skilled in the art. For example, the reaction of a bromo-olefin with dibromocarbene gives a tribromocyclopropane, which can be converted to the cyclopropene with methyllithium or other organolithium compounds as shown. (see Baird, M. S.;
Hussain, H. H.; Nethercott, W; J. Chem. Soc. Perkin Trans. 1, 1986, 1845-1854 and Baird, M. S.; Fitton, H. L.; Clegg, W; McCamley, A.; J. Chem. Soc. Perkin Trans. 1, 1993, 321-326).
The bromo-olefins can be prepared by standard methods.
Additionally, 3,3-disubstituted cyclopropenes can be prepared using methods described by N. I. Yakushkina and I. G. Bolesov in Dehydrohalogenation of Monohalogenocyclopropanes as a Method for the Synthesis of Sterically Screened Cyclopropenes, R USSIAN J. OF O RGANIC C HEM . 15:853-59 (1979). Furthermore, a 1,1-disubstituted olefin can also react with dibromocarbene to give a dibrominated intermediate. This can be reduced with zinc to the mono-brominated cyclopropane. Elimination of the bromide with base gives the cyclopropene (see Binger, P.; Synthesis 1974, 190).
Cyclopropene can be deprotonated with a strong base such as sodium amide in liquid ammonia and alkylated with an alkyl halide or other alkylating agent to give a substituted cyclopropene (reference: Schipperijn, A. J.; Smael, P.; Recl. Trav. Chim. Pays - Bas, 1973, 92, 1159). The lithium salt of substituted cyclopropenes, generated from the cyclopropene or by reaction of the tribromocyclopropane with an alkyllithium, can be alkylated to give new cyclopropene derivatives.
Compounds according to the present invention can also be obtained from a malonate derivative as shown.
Methyl sterculate was formed by the procedure of Gensler et. al. (Gensler, W. J.; Floyd, M. B.; Yanase, R.; Pober, K. W. J. Am. Chem. Soc., 1970, 92, 2472).
The addition of a diazo compound to an acetylene is another method that can be used for the synthesis of cyclopropenes (Mueller, P.; Cranisher, C; Helv. Chim. Acta 1993, 76, 521). Alternatively, the commercially available ethyl diazo acetate can be added to the acetylene to give the compound:
with R′″ being ethyl. This compound can be hydrolyzed to the carboxylic acid, and reacted with oxalyl chloride to give the acid chloride. The acid chloride can then be reacted with an alcohol to give the ester. In the foregoing synthesis routes, R 1 -R 4 are as described above for R.
Agricultural compositions comprising the compounds defined by Formula (I) described above are also encompassed by the invention. Preferably the compositions comprise between a lower limit of 0.005, 5, 10, 20 or 30% and an upper limit of 70, 80, 90, 95 or 99% by weight of the active compounds of the present invention. These compositions may optionally include various additives typically found in agricultural compositions including, but not limited to, carriers, adjuvants, wetting agents and the like.
Numerous organic solvents may be used as carriers for the active compounds of the present invention, e.g., hydrocarbons such as hexane, benzene, toluene, xylene, kerosene, diesel oil, fuel oil and petroleum naphtha, ketones such as acetone, methyl ethyl ketone and cyclohexanone, chlorinated hydrocarbons such as carbon tetrachloride, esters such as ethyl acetate, amyl acetate and butyl acetate, ethers, e.g., ethylene glycol monomethyl ether and diethylene glycol monomethyl ether, alcohols, e.g., ethanol, methanol, isopropanol, amyl alcohol, ethylene glycol, propylene glycol, butyl carbitol acetate and glycerine.
Mixtures of water and organic solvents, either as solutions or emulsions, can also be employed as inert carriers for the active compounds.
The active compounds of the present invention may also include adjuvants or carriers such as talc, pyrophyllite, synthetic fine silica, attapulgus clay (attaclay), kieselguhr, chalk, diatomaceous earth, lime, calcium carbonate, bentonite, fuller's earth, cottonseed hulls, wheat flour, soybean flour pumice, tripoli, wood flour, walnut shell flour, redwood flour and lignin.
It may be desirable to incorporate a wetting agent in the compositions of the present invention. Such wetting agents may be employed in both the solid and liquid compositions. The wetting agent can be anionic, cationic or nonionic in character.
Typical classes of wetting agents include alkyl sulfonate salts, alkylaryl sulfonate salts, alkyl sulfate salts, alkylamide sulfonate salts, alkylaryl polyether alcohols, fatty acid esters of polyhydric alcohols and the alkylene oxide addition products of such esters, and addition products of long chain mercaptans and alkylene oxides. Typical examples of such wetting agents include the sodium alkylbenzene sulfonates having 10 to 18 carbon atoms in the alkyl group, alkylphenol ethylene oxide condensation products, e.g., p-isooctylphenol condensed with 10 ethylene oxide units, soaps, e.g., sodium stearate and potassium oleate, sodium salt of propylnaphthalene sulfonic acid (di-2-ethylhexyl), ester of sodium sulfosuccinic acid, sodium lauryl sulfate, sodium stearate and potassium oleate, sodium salt of the sulfonated monoglyceride of coconut fatty acids, sorbitan, sesquioleate, lauryl trimethyl ammonium chloride, octadecyl trimethyl ammonium chloride, polyethylene glycol lauryl ether, polyethylene esters of fatty acids and rosin acids (e.g., Ethofat® 7 and 13, commercially available from Akzo Nobel Chemicals, Inc. of Chicago, Ill.), sodium N-methyl-N-oleyltaurate, Turkey Red oil, sodium dibutylnaphthalene sulfonate, sodium lignin sulfonate (Marasperse® N, commercially available from Ligno Tech USA of Rothschild, Wis.), polyethylene glycol stearate, sodium dodecylbenzene sulfonate, tertiary dodecyl polyethylene glycol thioether, long chain ethylene oxide-propylene oxide condensation products (e.g., Pluronic® 61 (molecular weight 1,000) commercially available from BASF of Mount Olive, N.J.), sorbitan sesquioleate, polyethylene glycol ester of tall oil acids, sodium octyl phenoxyethoxyethyl sulfate, polyoxyethylene (20) sorbitan monolaurate (Tween® 20, commercially available from ICI Americas Inc. of Wilmington, Del.) tris(polyoxyethylene) sorbitan monostearate (Tween® 60, commercially available from ICI Americas Inc. of Wilmington, Del.), and sodium dihexyl sulfosuccinate.
The solid, liquid, and gaseous formulations can be prepared by various conventional procedures. Thus, the active ingredient, in finely divided form if a solid, may be tumbled together with finely divided solid carrier. Alternatively, the active ingredient in liquid form, including mixtures, solutions, dispersions, emulsions and suspensions thereof, may be admixed with the solid carrier in finely divided form. Furthermore, the active ingredient in solid form may be admixed with a liquid carrier to form a mixture, solution, dispersion, emulsion, suspension or the like.
The active compounds of the present invention can be applied to plants by various suitable means. For example, an active compound may be applied alone in gaseous, liquid, or solid form by contacting the compound with the plant to be treated. Additionally the active compound may be converted to the salt form, and then applied to the plants. Alternatively, compositions containing one or more active compounds of the present invention may be formed. The compositions may be applied in gaseous, liquid, or solid form by contacting the composition with the plant to be treated. Such compositions may include an inert carrier. Suitable solid carriers include dusts. Similarly, when in gaseous form, the compound may be dispersed in an inert gaseous carrier to provide a gaseous solution. The active compound may also be suspended in a liquid solution such as an organic solvent or an aqueous solution that may serve as the inert carrier. Solutions containing the active compound may be heterogeneous or homogeneous and may be of various forms including mixtures, dispersions, emulsions, suspensions and the like.
The active compounds and compositions thereof can also be applied as aerosols, e.g., by dispersing them in air using a compressed gas such as dichlorodifluoromethane, trichlorofluoromethane, and other Freons, for example.
The term “plant” is used in a generic sense herein, and includes woody-stemmed plants such as trees and shrubs. Plants to be treated by the methods described herein include whole plants and any portions thereof, such as field crops, potted plants, cut flowers (stems and flowers), and harvested fruits and vegetables.
Plants treated with the compounds and by the methods of the present invention are preferably treated with a non-phytotoxic amount of the active compound.
The present invention can be employed to modify a variety of different ethylene responses. Ethylene responses may be initiated by either exogenous or endogenous sources of ethylene. Ethylene responses include, for example, the ripening and/or senescence of flowers, fruits and vegetables, abscission of foliage, flowers and fruit, the shortening of life of ornamentals such as potted plants, cut flowers, shrubbery, seeds, and dormant seedlings, in some plants (e.g., pea) the inhibition of growth, and in other plants (e.g., rice) the stimulation of growth. Additional ethylene responses or ethylene-type responses that may be inhibited by active compounds of the present invention include, but are not limited to, auxin activity, inhibition of terminal growth, control of apical dominance, increase in branching, increase in tillering, changing bio-chemical compositions of plants (such as increasing leaf area relative to stem area), abortion or inhibition of flowering and seed development, lodging effects, stimulation of seed germination and breaking of dormancy, and hormone or epinasty effects.
Methods according to embodiments of the present invention inhibit the ripening and/or senescence of vegetables. As used herein, “vegetable ripening” includes the ripening of the vegetable while still on the vegetable-bearing plant and the ripening of the vegetable after having been harvested from the vegetable-bearing plant. Vegetables which may be treated by the method of the present invention to inhibit ripening and/or senescence include leafy green vegetables such as lettuce (e.g., Lactuea sativa ), spinach ( Spinaca oleracea ), and cabbage ( Brassica oleracea ), various roots, such as potatoes ( Solanum tuberosum ) and carrots (Daucus), bulbs, such as onions (Allium sp.), herbs, such as basil ( Ocimum basilicum ), oregano ( Origanum vulgare ), dill ( Anethum graveolens ), as well as soybean ( Glycine max ), lima beans ( Phaseolus limensis ), peas (Lathyrus spp.), corn ( Zea mays ), broccoli ( Brassica oleracea italica ), cauliflower ( Brassica oleracea botrytis ), and asparagus ( Asparagus officinalis ).
Methods according to embodiments of the present invention inhibit the ripening of fruits. As used herein, “fruit ripening” includes the ripening of fruit while still on the fruit-bearing plant as well as the ripening of fruit after having been harvested from the fruit-bearing plant. Fruits which may be treated by the method of the present invention to inhibit ripening include tomatoes ( Lycopersicon esculentum ), apples ( Malus domestica ), bananas ( Musa sapientum ), pears ( Pyrus communis ), papaya ( Carica papaya ), mangoes ( Mangifera indica ), peaches ( Prunus persica ), apricots ( Prunus armeniaca ), nectarines ( Prunus persica nectarina ), oranges (Citrus sp.), lemons ( Citrus limonia ), limes ( Citrus aurantifolia ), grapefruit ( Citrus paradisi ), tangerines ( Citrus nobilis deliciosa ), kiwi ( Actinidia chinenus ), melons such as cantaloupe ( C. cantalupensis ) and musk melon ( C. melo ), pineapple ( Aranas comosus ), persimmon (Diospyros sp.), various small fruits including berries such as strawberries (Fragaria), blueberries (Vaccinium sp.) and raspberries (e.g., Rubus ursinus ), green beans ( Phaseolus vulgaris ), members of the genus Cucumis such as cucumber ( C. sativus ), and avocados ( Persea americana ).
Ornamental plants which may be treated by the method of the present invention to inhibit senescence and/or to prolong flower life and appearance (e.g., delay wilting), include potted ornamentals, and cut flowers. Potted ornamentals and cut flowers which may be treated with the present invention include azalea (Rhododendron spp.), hydrangea ( Macrophylla hydrangea ), hybiscus ( Hibiscus rosasanensis ), snapdragons (Antirrhinum sp.), poinsettia ( Euphorbia pulcherima ), cactus (e.g. Cactaceae schlumbergera truncata ), begonias (Begonia sp.), roses (Rosa spp.), tulips (Tulipa sp.), daffodils (Narcissus spp.), petunias ( Petunia hybrida ), carnation ( Dianthus caryophyllus ), lily (e.g., Lilium sp.), gladiolus (Gladiolus sp.), alstroemeria ( Alstoemeria brasiliensis ), anemone (e.g., Anemone blanda ), columbine (Aquilegia sp.), aralia (e.g., Aralia chinensis ), aster (e.g., Aster carolinianus ), bougainvillea (Bougainvillea sp), camellia (Camellia sp.), bellflower (Campanula sp.), cockscomb (celosia sp.), falsecypress (Chamaecyparis sp.), chrysanthemum (Chrysanthemum sp.), clematis (Clematis sp.), cyclamen (Cyclamen sp.), freesia (e.g., Freesia refracta ), and orchids of the family Orchidaceae.
Plants which may be treated by the method of the present invention to inhibit abscission of foliage, flowers and fruit include cotton (Gossypium spp.), apples, pears, cherries ( Prunus avium ), pecans ( Carva illinoensis ), grapes ( Vitis vinifera ), olives (e.g. Vitis vinifera and Olea europaea ), coffee ( Coffea arabica ), snapbeans ( Phaseolus vulgaris ), and weeping fig ( ficus benjamina ), as well as dormant seedlings such as various fruit trees including apple, ornamental plants, shrubbery, and tree seedlings. In addition, shrubbery which may be treated according to the present invention to inhibit abscission of foliage include privet (Ligustrum sp.), photinea (Photinia sp.), holly (Ilex sp.), ferns of the family Polypodiaceae, schefflera (Schefflera sp.), aglaonema (Aglaonema sp.), cotoneaster (Cotoneaster sp.), barberry (Berberis sp.), waxmyrtle (Myrica sp.), abelia (Abelia sp.), acacia (Acacia sp.) and bromeliades of the family Bromeliaceae.
Active compounds of the present invention have proven to be unexpectedly potent inhibitors of ethylene action on plants, fruits and vegetables, even when applied at low concentrations. Among other things, compounds of the present invention may result in a longer period of insensitivity to ethylene than compounds found in the prior art. This longer period of insensitivity may occur even when compounds of the present invention are applied at a lower concentration than previous compounds.
The present invention is explained in greater detail in the following non-limiting Examples. In these examples, μl means microliters; ml means milliliters; nl means nanoliters; l means liters; cm means centimeters; and temperatures are given in degrees Celsius.
Comparative Example A
Activity of Short-Chain Cyclopropene Derivatives
To obtain the minimum concentration that protected bananas from 333 μl/l of ethylene, compounds described in U.S. Pat. No. 5,518,988 to Sisler et al. were applied to bananas according to the methods setforth herein. A known amount of an active compound was injected as a gas into a 3-liter jar containing a banana. The jar was sealed and the banana was removed after 24 hours. At the end of exposure, the banana was treated with 333 pill of ethylene in a 3-liter jar for 12-15 hours. It was then observed for ripening. The minimum concentration is the minimum concentration that protected the banana from 333 μl/l of ethylene. Ten microliters/liter of ethylene is usually considered to be a saturating amount.
To obtain the time of protection, bananas were exposed to a saturating amount of the compound for 24 hours (this was done as above and at least 10 times the minimum protection amount was used). After exposure, bananas were removed from the jars and each day individual bananas were exposed to 333 pill of ethylene for 12-15 hours. The day the bananas responded to ethylene was recorded as the protection time. The results are shown in Table A.
TABLE A
Minimum Concentration and Time of Insensitivity for 1-Cyclopropenes
Described in U.S. Pat. No. 5,518,988 to Sisler et al.
Concen-
tration
Time
Compound
Structure
(nl/l)
(days)
cyclopropene (CP)
0.7
12
1-methylcyclopropene (1-MCP)
0.7
12
1-ethylcyclopropene (1-ECP)
4
12
1-propylcyclopropene (1-PCP)
6
12
1-butylcyclopropene (1-BCP)
3
12
EXAMPLE 1
Compounds of the Present Invention: Minimum Concentration for Protection
To obtain the minimum concentration that protected bananas from 333 μl/l of ethylene, compounds according to the present invention were applied to bananas according to the method described herein. A known amount of the active compound was placed on filter paper in a 3-liter jar to facilitate evaporation into the vapor state. The compounds were applied in an ethyl ether solution because the amount used was potentially too small to apply unless they were in solution. The amount of ether (about 10 μl in 3 l) was without effect when applied alone on a banana contained in a 3-liter jar. The jar was sealed and the banana was removed after 4 hours of exposure. At the end of exposure, the banana was treated with 333 μl/l of ethylene in a 3-liter jar for 12-15 hours. It was then observed for ripening. The minimum concentration is the concentration that protected the bananas from 333 μl/l of ethylene. Ten microliters/liter of ethylene is usually considered to be a saturating amount. This procedure was repeated for 8-, 24- and 48-hour treatment times to determine the minimum concentration of active compounds of the present invention needed to provide protection from 333 μl/l of ethylene for a given treatment time. The results are shown in Table 1.
TABLE 1
Treatment Time and Minimum Concentration of
1-Cyclopropenes of the Present Invention on Banana Fruit
Treatment
Minimum
Time
Concentration
Active Compound
(hours)
(nl/l)
1-hexylcyclopropene
4
12.0
8
0.8
24
0.4
48
0.3
1-octylcyclopropene
4
0.8
8
0.45
24
0.3
48
0.25
EXAMPLE 2
Compounds of the Present Invention: Time of Protection
To obtain the time of protection, bananas were exposed to a saturating amount of the compound for 24 hours (this was done as described in Example 1 above and at least 10 times the minimum protection amount was used). After exposure, bananas were removed from the jars and each day individual bananas were exposed to 333 μl/l of ethylene for 12-15 hours. The day the bananas responded to ethylene was recorded as the protection time. The results are shown in Table 2.
TABLE 2
Minimum Concentration and Time of Insensitivity for 1-Cyclopropenes
Provided by the Present Invention
Concen-
tration
Time
Compound
Structure
(nl/l)
(days)
1-hexylcyclopropene (1-HCP)
0.4
20
1-octylcyclopropene (1-OCP)
0.3
25
EXAMPLES 3 THROUGH 29
In general, all cyclopropenes are stored at −80° C. All reactions were carried out under an atmosphere of nitrogen. Flash chromatography of cyclopropenes was carried out under an atmosphere of nitrogen. All target compounds were 80% or greater purity unless otherwise noted.
EXAMPLE 3
Preparation of N,N′-dibenzyl-N,N,N′,N′-tetramethylethylenediammonium Dibromide and N,N′-dibenzyl-N,N,N′,N′-tetraethylethylenediammonium Dibromide
To a stirred solution of 16.5 g (142 mmol) of N,N,N′,N′-tetramethylethylenediamine in 60 g of acetonitrile was added 50.1 g (292 mmol) of benzyl bromide. The mixture self warmed and was allowed to stir for 2.5 hours whereon a heavy precipitate was observed. The slurry was diluted with diethyl ether, filtered, washed with diethyl ether and dried yielding 61.8 g of the desired N,N′-dibenzyl-N,N,N′,N′-tetramethylethylenediammonium dibromide, a white solid mp 230-232° C.
In an analogous way, using N,N,N′,N′-tetraethylethylenediamine one obtains N,N′-dibenzyl-N,N,N′,N′-tetraethylethylenediammonium dibromide, a white solid mp 190-193° C., decomposes.
EXAMPLE 4
Preparation of 1-Hexyl-cyclopropene (Compound 1)
a. 2-Bromo-oct-1-ene
A solution of 9.42 ml (0.0728 mol) of 2,3-dibromopropene in 70 ml diethylether was placed under a nitrogen atmosphere by use of a Firestone valve. While cooling in an ice water bath, a solution of 0.091 mol of pentylmagnesium bromide in 70 ml diethyl ether was added slowly via addition funnel. After stirring for 2 hours while warming to room temperature, there was then added via syringe 50 ml of 1 N hydrochloric acid to the reaction cooling in an ice water bath. The resulting mixture was transferred to a separatory funnel and the phases were separated. The organic layer was dried over MgSO 4 and filtered. The solvent was removed from the filtrate in vacuo to yield 15.0 g (85.7% of theory) of 81% pure 2-bromo-oct-1-ene as an oil.
b. 1,1,2-Tribromo-2-hexyl-cyclopropane
To 5.42 g (0.0284 mol) of 2-bromo-oct-1-ene in 7.42 ml (0.0851 mol) of bromoform and 48.8 ml of methylene chloride, were added 1.30 g ( 0.00284 mol) of N,N′-dibenzyl-N,N,N′,N′-tetramethylethylenediammonium dibromide and 12.1 ml (0.142 mol) of 45% aqueous potassium hydroxide. The mixture was left at room temperature for 5 days. There was then added hexanes and water. This mixture was gravity filtered through qualitative fluted filter paper. The resulting mixture was transferred to a separatory funnel and the phases were separated. The organic layer was dried over MgSO 4 and filtered. The solvent was removed from the filtrate in vacuo to yield 5.25 g (51.0% of theoretical) of 1,1,2-tribromo-2-hexyl-cyclopropane as an oil.
c. 1-Hexyl-cyclopropene
A solution of 1.01 g (0.00278 mol) of 1,1,2-tribromo-2-hexyl-cyclopropane in 4 ml of diethyl ether was placed under a nitrogen atmosphere via use of a Firestone valve. While cooling in an ice water bath, 6.3 ml (0.00835 mol) of 1.4M methyl lithium in diethyl ether was added slowly by syringe. After 15 minutes, 2 ml of water was added via syringe. The resulting mixture was transferred to a separatory funnel and the phases were separated. The organic layer was dried over MgSO 4 and filtered. The solvent was removed from the filtrate in vacuo with a bath temperature under 20° C. to yield 0.300 g (87% of theoretical) of 1-hexyl-cyclopropene pure as an oil.
EXAMPLE 5
Preparation of 3-Octylcyclopropene (Compound 2)
1-Bromo-dec-1-ene was prepared by the method of Millar et al (Millar, J. G.; Underhill, E. W.; J. Org. Chem. 1986, 51, 4726). This olefin was converted to 3-octylcyclopropene in a similar manner to the preparation of 70% pure 1-hexylcyclopropene.
EXAMPLE 6
Preparation of 1-(7-Methoxyheptyl)-cyclopropene (Compound 3)
6-Bromohexyl methyl ether was prepared from 1,6-dibromohexane. To 48.8 g (200 mmol) of 1,6-dibromohexane at 60° C. was added 44 g (200 mmol) of a 25% solution of sodium methoxide in methanol. The reaction mixture was held 0.5 hours, then an additional 4 g of sodium methoxide solution was added, and the reaction mixture was held an additional hour. Hexane and water were added, the organic phase was washed with brine and dried with magnesium sulfate, filtered and stripped. Fractional distillation under vacuum gave 93% pure 6-bromohexyl methyl ether. This bromide was converted to the Grignard reagent, which was converted to 1-(7-methoxyheptyl)-cyclopropene in the same manner that pentylmagnesium bromide was converted to 1-hexylcyclopropene.
EXAMPLE 7
Preparation of 1-(Undec-5-ynl)-cyclopropene (Compound 4)
1-Bromodec-4-yne was prepared from 1-chlorodec-4-yne. The 1-chlorodec-4-yne (10.6 g, 61 mmol) and 25 g of lithium bromide were refluxed in 80 ml of THF for 21 hours. The conversion was 74%. Ether was added, the reaction mixture was washed with water (2×) and brine, dried over magnesium sulfate and stripped. The product was dissolved in 70 ml of THF and refluxed for 8 hours with an additional 25 g of lithium bromide. This gave 95% conversion of the chloride to the bromide. The same workup provided 11.36 g of 1-bromodec-4-yne.
The 1-bromodec4-yne was converted to the Grignard reagent in THF. The Grignard reagent was converted to 1-(undec-5-ynl)-cyclopropene in the same manner that pentylmagnesium bromide was converted to 1-hexylcyclopropene.
EXAMPLE 8
Preparation of 1-(7-Hydroxyheptyl)-cyclopropene (Compound 5)
a. 1-(1-Ethoxyethoxy)-6-bromohexane
To a cooled solution of 80 mg of toluenesulfonic acid in 40 ml of ether was fed 20 g (110 mmol) of 6-bromohexanol and 40 ml of ethyl vinyl ether simultaneously by separate additional funnels. The temperature of the reaction mixture was kept at 7° C. or lower during the feeds, which took 1 hour. The reaction mixture was stirred 20 minutes longer, then roughly 1 ml of triethylamine was added. The reaction mixture was washed with water and brine, dried over potassium carbonate, filtered and stripped to give 25.7 g of a pale yellow liquid, which was used without further purification.
b. 9-(1-Ethoxyethoxy)-2-bromonon-1-ene
A slurry of 5.6 g of magnesium turnings (230 mmol) in 100 ml of THF was treated with a small amount of 1,2-dibromoethane. 1-(1-Ethoxyethoxy)-6-bromohexane (38.5 g, 152 mmol) was fed slowly to the reaction mixture, maintaining the temperature at 40-50° C. At the end of the addition the reaction mixture was held 20 minutes, then transferred by cannula to solution of 33.4 9 (167 mmol) of 1,2-dibromoprop-2-ene in 25 ml of THF at 0C. The reaction mixture was stirred at 0° C. for 15 minutes, then stirred at room temperature for 15 minutes, then quenched with water. The reaction mixture was transferred into a separatory funnel. A small amount of 1 N HCl was added, the phases were separated, the ether phase was washed with water and brine, then dried over magnesium sulfate, filtered, and stripped to give 33.63 g of a yellow liquid which was used without further purification.
c. 1,1,2-Tribromo-2-(7-hydroxyheptyl)cyclopropane
A mixture of 9-(1-ethoxyethoxy)-2-bromonon-1-ene (33.63 g, 115 mmol), 4.1 g of N,N′-dibenzyl-N,N,N′,N′-tetraethylethylenediammonium dibromide, 42 g of 45% potassium hydroxide (337 mmol), 93 g of bromoform (368 mmol) and 280 g of methylene chloride were rapidly stirred at room temperature for two days. When the reaction stalled, the reaction mixture was transferred to a separatory funnel and washed with water. The methylene chloride phase was transferred to a flask and treated with the same amount of the phase transfer catalyst and 45% potassium hydroxide, then stirred at room temperature for an additional 3 days. The reaction mixture was washed with water, the methylene chloride phase was dried with magnesium sulfate, and then stripped. The product was treated with 320 ml of methanol and 40 ml of 1 N HCl for 1 hour at room temperature. The methanol was stripped, ethyl acetate was added. The organic phase was washed with water and brine, then treated with 200 ml of silica gel. Filtration followed by a strip gave 38 g of black product. This was chromatographed on silica gel to give 19.0 g of 1,1,2-tribromo-2-(7-hydroxyheptyl)cyclopropane as a pale yellow liquid.
d. 1-(7-Hydroxyheptyl)-cyclopropene
A solution of 1.0 g 1,1,2-tribromo-2-(7-hydroxyheptyl)cyclopropane (2.5 mmol) in 25 ml of ether was treated at −78° C. with 7.2 ml of methyllithium (1.4 M, 10 mmol). After 5 minutes, the reaction mixture was warmed to 0° C. and held at this temperature. The reaction was quenched with saturated ammonium chloride. The reaction mixture was washed with water and brine, dried over magnesium sulfate, filtered and stripped to give 240 mg of 1-(7-hydroxyheptyl)-cyclopropene (90% purity).
EXAMPLE 9
Preparation of 1-(7-Acetoxyheptyl)-cyclopropene (Compound 6)
A solution of 2.5 mmol of 1-(7-hydroxyheptyl)-cyclopropene in 5 ml of ether was cooled in an ice bath. Triethylamine (0.44 ml) and 0.21 g (2.7 mmol) of acetyl chloride were added, and the reaction mixture was stirred 1 hour at 5° C. Additional acetyl chloride (0.11 g), ether and triethylamine were added, and the reaction was stirred at 5° C. until GC analysis indicated 95% conversion. The reaction was worked up by adding more ether and washing the organic phase with water, dilute HCl solution (diluted 1M aqueous HCl), potassium carbonate solution (2×), water and brine. The ether phase was dried over magnesium sulfate and stripped. Hexane was added and the reaction was stripped again to give 1-(7-acetoxyheptyl)-cyclopropene.
EXAMPLE 10
Preparation of 7-Cycloprop-1-enyl-heptanoic Acid (Compound 7)
a. 7-(1,1,2-Tribromo-cyclopropyl)-heptanoic acid
1,1,2-Tribromo-2-(7-hydroxyheptyl)cyclopropane (0.90 g, 2.3 mmol) was dissolved in 60 ml of glacial acetic acid. A solution of 1.0 g (10 mmol) of chromium trioxide dissolved in 14 ml of 90% aqueous acetic acid was added and the reaction mixture was stirred at room temperature for 24 hours. Water (300 ml) was added. The solution was extracted with ether. The ether phase was extracted three times with 1N NaOH solution. A little sodium bisulfite was added. The aqueous extracts were acidified with 6N HCl, and extracted with ether twice. The ether extracts were washed with brine, dried over magnesium sulfate and stripped to give 0.56 g 7-(1,1,2-tribromo-cyclopropyl)-heptanoic acid.
b. 7-Cycloprop-1-enyl-heptanoic acid
1,1,2-Tribromo-2-(7-carboxyheptyl)-cyclopropane (1.28 g, 3.1 mmol) was dissolved in 60 ml of ether and cooled to −78° C. Methyllithium (9.0 ml, 12.6 mmol) was added and the reaction was stirred at −78° C. for two hours. The reaction mixture was put in an ice bath for 5 minutes, then recooled to −78° C. until workup. Water was added to the reaction mixture, which was warmed to room temperature. The aqueous phase was separated, and the ether phase was extracted with three times with 1N NaOH solution. The combined aqueous extracts were acidified with aqueous HCl, and extracted with ether three times. The ether extracts were washed with brine, dried over magnesium sulfate and stripped to give 300 mg of 7-cycloprop-1-enyl-heptanoic acid.
EXAMPLE 11
Preparation of 7-Cycloprop-1-enyl-heptanoic Acid Isopropylamine Salt (Compound 8)
A solution of 7-cycloprop-1-enyl-heptanoic acid ethyl ester in 5 ml of ether was treated with 0.1 g of isopropyl amine at room temperature. The solvent was stripped to give 40 mg of 7-cycloprop-1-enyl-heptanoic acid isopropylamine salt.
EXAMPLE 12
Preparation of 7-Cycloprop-1-enyl-heptanoic Acid Ethyl Ester (Compound 9)
A solution of 220 mg (1.3 mmol) of 1-(7-carboxyheptyl)-cyclopropene in ether was cooled to 0° C. Triethylamine (0.20 g, 2 mmol) was added, then 0.12 g (1.3 mmol) of methylchloroformate was added. After 2 hours at 0° C., the reaction mixture was transferred to a separatory funnel. The ether phase was washed with water (2×) and brine, dried over magnesium sulfate, filtered and stripped. The product was dissolved in ethanol, cooled in an ice bath and treated with 1 ml of a 21% sodium ethoxide in ethanol solution. The reaction mixture was stirred ½ hour, then water and ether were added. The ether phase was washed with 1N sodium hydroxide solution, water, and brine, dried over magnesium sulfate, filtered and stripped to give 10 mg of 75% pure 7-cycloprop-1-enyl-heptanoic acid ethyl ester.
EXAMPLE 13
Preparation of 1-(7-Cyanoheptyl)-cyclopropene (Compound 10)
a. 1-(7-Methanesulfonyloxyheptyl)-cyclopropene
A solution of 3.8 mmol of 1-(7-hydroxyheptyl)-cyclopropene in 50 ml of ether was cooled in an ice bath. Triethylamine (1 ml) and 0.48 g of methanesulfonyl chloride (4.2 mmol) were added and the reaction mixture was stirred for 2½ hours at 0° C. The reaction mixture was washed with water and brine, dried over magnesium sulfate, filtered and stripped to give 1-(7-methanesulfonyloxyheptyl)-cyclopropene which was used without further purification.
b. 1-(7-Cyanoheptyl)-cyclopropene
The crude product from the above reaction was dissolved in 5 ml of DMSO, and treated with 0.99 g (15 mmol) of potassium cyanide. After 6.5 hours at room temperature, the reaction was 72% complete. Ether and water were added. The aqueous phase was washed with more ether. The combined organic phases were washed with water (2×) and brine, dried over magnesium sulfate, filtered and stripped. The product was rapidly chromatographed on silica gel to give 190 mg of 1-(7-cyanoheptyl)-cyclopropene as a colorless liquid, >95% purity.
EXAMPLE 14
Preparation of 1-(7-N,N-Diethylaminoheptyl)-cyclopropene (Compound 11)
a. 1,1,2-Tribromo-2-(7- N,N-diethylaminoheptyl)-cyclopropane
A solution of 1.5 g of 1,1,2-Tribromo-2-(7-hydroxyheptyl)cyclopropane (3.8 mmol) in 10 ml of ether was cooled in an ice bath and treated with 0.77 g (6 mmol) of diisopropylethyl amine. Triflic anhydride (1.18 g, 4.2 mmol) was added dropwise, and the reaction was stirred at 0° C. for ½ hour. Excess diethylamine (roughly 4 ml) was added and the reaction was stirred overnight. The reaction mixture was quenched with water and transferred to a separatory funnel. A small amount of 1N NaOH was added. The aqueous phase was separated, the organic phase was washed twice more with water, then extracted three times with 1N HCl. The acidic washes were treated made basic with aqueous sodium hydroxide solution and extracted three times with ether. The ether was washed with brine, dried over potassium carbonate and stripped. The product was chromatographed through Florisil to give 1,1,2-tribromo-2-(7-N,N-diethylaminoheptyl)-cyclopropane.
b. 1-(7-N,N-Diethylaminoheptyl)-cyclopropene
To a solution of 1.0 g (2.4 mmol) of 1,1,2-tribromo-2-(7-N,N-diethylaminoheptyl)-cyclopropane in 25 ml of THF at −78° C. was added 4.55 ml (1.6 M, 7.3 mmol) of n-BuLi. The reaction mixture was stirred ½ hour, then quenched with methanol. The reaction mixture was warmed to room temperature. Ether was added, the organic phase was washed with water (3×) and brine, dried over magnesium sulfate, and filtered. The solution was stripped on a rotary evaporator with no heat added. A few pipetfuls of toluene were added, and the sample was stripped again to give 1-(7-N,N-diethylaminoheptyl)-cyclopropene.
EXAMPLE 15
Preparation of 1-(7-N,N,-Diethylammoniumheptyl)-cyclopropene Acetate (Compound 12)
A solution of 1-(7-N,N,-diethylamminoheptyl)-cyclopropene in ether was treated with acetic acid. The solvent was removed to give the salt.
EXAMPLE 16
Preparation of 1-(7-N,N,N-Diethylmethylammoniumheptyl)-cyclopropene Iodide (Compound 13)
A mixture of roughly 1.6 mmol of 1-(7-N,N-diethylaminoheptyl)-cyclopropene and excess iodomethane (roughly ½ ml in 5 ml of acetonitrile were stirred at room temperature for two hours. The reaction mixture was stripped to give 300 mg of 1-(7-N,N,N-diethylmethylammoniumheptyl)-cyclopropene iodide.
EXAMPLE 17
Preparation of 1-Hexyloxymethyl-cyclopropene (Compound 14)
a. Preparation of 2-Bromo-3-hexyloxypropene
To a three neck round bottom flask equipped with an addition funnel and an overhead stirrer was added 35 ml of hexane, 42 g of 50% sodium hydroxide and 0.50 g of tetra-n-butylammonium bromide. A mixture of 6.74 g of hexanol (66 mmol) and 20 g (100 mmol) of 2,3-dibromopropene were fed to the well-stirred reaction mixture over a 20 minute period. The reaction was stirred an additional 1 hour, then water was added, and the phases were separated. The organic phase was washed with water and brine, dried over magnesium sulfate, filtered and stripped. The product was fractionally distilled under reduced pressure to give 6.1 g of 95% pure 2-bromo-3-hexyloxypropene.
b. 1,1,2-Tribromo-2-(hexyloxymethyl)cyclopropane
A mixture of 5.9 g of 2-bromo-3-hexyloxypropene(26.7 mmol), 2.05 g of N,N′-dibenzyl-ethane-1,2-bis-(diethylammonium bromide), 10.5 g of 45% potassium hydroxide (84 mmol), 23.3 g of bromoform (92 mmol) and 70 g of methylene chloride were rapidly stirred at room temperature for two days. When the reaction stalled, the reaction mixture was transferred to a separatory funnel and washed with water. The methylene chloride phase was transferred to a flask and treated with the same amount of the phase transfer catalyst and 45% potassium hydroxide, then stirred at room temperature for an additional 3 days. The workup-recharge sequence was repeated once more, and the reaction was stirred one more day at room temperature. The reaction mixture was washed with water, the methylene chloride phase was dried with magnesium sulfate, and then stripped. The product was chromatographed on silica gel with 20% ethyl acetate 80% hexane to give 1.35 g of 87% pure 1,1,2-tribromo-2-(hexyloxymethyl)cyclopropane.
c. 1-Hexyloxymethyl-cyclopropene
A solution of 1.15 g of 1,1,2-tribromo-2-(hexyloxymethyl)cyclopropane (2.9 mmol) in 6 ml of ether was treated at −78° C. with 1.4 ml of methyllithium (1.4 M, 8.8 mmol). After 5 minutes, the reaction mixture was warmed to 0° C. and held at this temperature. The reaction was quenched with saturated ammonium chloride. The reaction mixture was washed with water and brine, dried over magnesium sulfate, filtered and stripped to give 320 mg of 1-hexyloxymethyl-cyclopropene, as a dark yellow liquid.
EXAMPLE 18
Preparation of 1-Pentyloxyethyl-cyclopropene (Compound 15)
a. Preparation of 2-Bromo-4-pentyloxybutene
To a three neck round bottom flask equipped with an addition funnel and an overhead stirrer was added 35 ml of hexane, 42 g of 50% sodium hydroxide and 0.50 g of tetra-n-butylammonium bromide. A mixture of 10 g of 2-bromobuten-4-ol (66 mmol) and 15 g (100 mmol) of 2,3-dibromopropene were fed to the well-stirred reaction mixture. When the addition was complete, the reaction mixture was warmed to for 1 hour, then water was added, and the phases were separated. The organic phase was washed with water and brine, dried over magnesium sulfate, filtered and stripped. A column was run (silica gel, 20% ethyl acetate/80% hexane) to give product that was 70% pure. The more volatile material was removed by distillation under reduced pressure; the material left in the pot was 1.63 g of 99% pure 2-bromo-4-pentyloxybutene.
This olefin was converted to 1-pentyloxyethyl-cyclopropene in the same manner that 2-bromo-3-hexyloxypropene was converted to 1-hexyloxymethyl-cyclopropene.
EXAMPLE 19
Preparation of 3,3-Dipentyl-cyclopropene (Compound 16)
a. 2-Pentyl-hept-1-ene
To a 500 ml, 3 necked, round bottom flask, which was previously placed under a nitrogen atmosphere via use of a Firestone valve, was added 8.50 g (0.0759 mol) of potassium t-butoxide and 27.2 g (0.0762 mol) of methyl triphenylphosphonium bromide and 200 ml tetrahydrofuran. After stirring at room temperature for 4 hours, 12.0 ml (0.0849 mol) of 6-undecanone was added. After 3 days, the reaction mixture was poured onto 200 ml 10% w/v aqueous ammonium chloride. The resulting mixture was transferred to a separatory funnel, extracted twice with hexanes and the phases were separated. The combined organic layers were dried over MgSO 4 and filtered. The solvent was removed from the filtrate in vacuo to yield 18.5 g orange solid. This was slurried in 125 ml diethyl ether and gravity filtered through qualitative fluted filter paper rinsing with an additional 125 ml diethyl ether. The solvent was removed from the filtrate in vacuo to yield 12.7 g orange oil. This residue was purified by column chromatography with hexanes to give 6.79 g (47.5% of theoretical) of 2-pentyl-hept-1-ene as an oil.
b. 2,2-Dibromo-1,1-dipentyl-cyclopropane
To a solution of 4.16 g (0.0247 mol) of 2-pentyl-hept-1-ene in 31 ml of pentanes, was added 4.95 g (0.0441 mol) of potassium t-butoxide. While cooling the resulting mixture to an internal temperature of 5° C., 4.01 ml ( 0.0459 mol) of bromoform was added slowly via addition funnel. The reaction mixture was allowed to warm naturally to room temperature and left overnight. To the reaction mixture was added 25 ml of water then 36 ml of 1 N hydrochloric acid. The resulting mixture was transferred to a separatory funnel and the phases were separated. The organic layer was dried over MgSO 4 and filtered. The solvent was removed from the filtrate in vacuo to yield 7.00 g (83.4% of theory) of 2,2-dibromo-1,1-dipentyl-cyclopropane as an oil.
c. 2-Bromo-1, 1-dipentyl-cyclopropane
To a solution of 4.00 g (0.0118 mol) of 2,2-dibromo-1,1-dipentyl-cyclopropane in 11 ml of methanol was added 0.744 ml ( 0.0129 mol) of glacial acetic acid and 0.766 g (0.0118 mol) of zinc dust. After 2 hours 0.744 ml of glacial acetic acid and 0.766 g of zinc dust were added to the mixture. After 2 further hours, the solvent was removed from the reaction mixture in vacuo. The resulting residue was extracted with hexanes and then diethyl ether from water. The combined organic layers were dried over MgSO 4 and filtered. The solvent was removed from the filtrate in vacuo to yield 2.1 g (68.2% of theory) of an equal mixture of 2-bromo-1,1-dipentyl-cyclopropane and 1,1-dipentyl-cyclopropane as an oil.
d. 3,3-Dipentyl-cyclopropene
To a solution of 1.90 g of an equal mixture of 2-bromo-1,1-dipentyl-cyclopropane and 1,1-dipentyl-cyclopropane in 10 ml dimethylsulfoxide was added 0.818 g (0.00308 mol) of potassium t-butoxide. The resulting mixture was heated to 85° C. for 5 hours and then stirred at room temperature for 16 hours. To this was added 0.100 g of potassium t-butoxide. The resulting mixture was heated to 85° C. for 2 hours then cooled to room temperature. The reaction mixture was poured onto water and then extracted with diethyl ether. The resulting mixture was transferred to a separatory funnel and the phases were separated. The organic layer was dried over MgSO 4 and filtered. The solvent was removed from the filtrate in vacuo to yield 1.90 g of 3,3-dipentyl-cyclopropene mixed in equal parts with 1,1-dipentyl-cyclopropane as an oil.
EXAMPLE 20
Preparation of 1-Pent-2-enyl-2-pentyl-cyclopropene (Compound 17)
A solution of 1.00 g (0.00287 mol) of 1,1,2-tribromo-2-pentyl-cyclopropane in 4 ml of tetrahydrofuran was placed under an inert atmosphere of nitrogen via a Firestone valve. To this mixture, cooling in an ice water bath, was added via syringe 3.58 ml (0.00861 mol) of 1.6M n-butyllithium in hexanes. After 30 minutes, 0.432 ml (0.00287 mol) of tetramethylethylene diamine and 0.339 ml (0.00287 mol) of 1-bromo-2-pentene were added by syringe. The reaction stirred for one hour while warming to room temperature, then for three hours at room temperature. To the resulting mixture was added 2 ml of water. This residue was extracted with diethyl ether. The resulting mixture was transferred to a separatory funnel and the phases were separated. The organic layer was dried over MgSO 4 and filtered. The solvent was removed from the filtrate in vacuo to yield 0.200 g (39.1% of theory) of 1-pent-2-enyl-2-pentyl-cyclopropene as an oil.
EXAMPLE 21
Preparation of 1-Pent-2-enyl-3,3-dipentyl-cyclopropene (Compound 18)
A solution of 0.450 g of a 1:1 mixture of 3,3-dipentyl-cyclopropene and 1,1-dipentyl-cyclopropane in 2 ml of tetrahydrofuran with 0.070 (0.000500 mol) ml of diisopropylamine was placed under an inert atmosphere of nitrogen via a Firestone valve. To this mixture, cooling in an ice water bath, was added via syringe 1.72 ml (0.00275 mol) of 1.6M N-butyllithium in hexanes. After 1 hour, 0.478 ml hexamethylphosphoramide and 0.325 ml of 1-bromo-2-pentene were added separately via syringe. The reaction mixture was allowed to warm to room temperature and stirred for 2 days. The reaction was quenched by the addition of 2 ml of water by syringe. This residue was extracted with diethyl ether. The resulting mixture was transferred to a separatory funnel and the phases were separated. The organic layer was dried over MgSO 4 and filtered. The solvent was removed from the filtrate in vacuo to yield 0.280 g of 1:1 mixture of 1-pent-2-enyl-3,3-dipentyl-cyclopropene and 1,1-dipentyl-cyclopropane as an oil.
EXAMPLE 22
Preparation of 1-(Oct-7-enyl)-cyclopropene (Compound 19)
Cyclopropene was prepared according to the following reference: Binger, P.; Wedemann, P.; Goddard, R.; Brinker, U.; J. Org. Chem., 1996, 61, 6462.
8-Iodooct-1-ene was prepared by refluxing 5 g of 8-bromooct-1-ene (26 mmol) and 10 g of sodium iodide in 50 ml of acetone for 1 hour. The acetone was stripped and the residue was partitioned between water and ether. The aqueous phase was washed with brine, dried over magnesium sulfate and stripped to give 5.66 g of 8-iodooct-1-ene.
A mixture of 0.43 g (11 mmol) of sodium amide in roughly 15 ml of ammonia was cooled to −78° C. A chilled solution of cyclopropene in ammonia (1:1, 0.85 g, 10 mmol) was poured into the reaction mixture. The reaction mixture was stirred at −78° C. for ½ hour, warmed briefly to the ammonia boiling point, then recooled to −78° C. 8-Iodooct-1-ene (1.2 g, 5 mmol) was added by syringe, and the reaction mixture was warmed to reflux for ½ hour. A few ml of ethanol were added. Ether (25 ml) was slowly added while the ammonia was allowed to distill out of the reaction mixture. The reaction mixture was washed with water, 0.5M HCl (2×), water and brine. It was dried over MgSO 4 , filtered and stripped. The product was purified by chromatography on silica gel using hexane as the eluent. A 10 mg sample of 67% pure 1-(oct-7-enyl)-cyclopropene was obtained.
EXAMPLE 23
Preparation of 4-(1-Cyclopropenyl)-2-methylbutan-2-ol (Compound 20)
a. 4-Bromo-pent-4-enoic acid ethyl ester
This ester was prepared by the method of Mori, JOC, 1983 48, 4062
b. 3-(1,2,2-Tribromo-cyclopropyl)-propionic acid ethyl ester
To a solution made of 12.12 g (58 mmol) of 4-bromo-pent4-enoic acid ethyl ester and 51 g (202 mmol) of bromoform and 100 g of methylene chloride was added 2.0 g of N,N′-dibenzyl-N,N,N′,N′-tetramethylethylenediammonium dibromide and 27.1 g (218 mmol) of 45% aqueous potassium hydroxide. The reaction mixture was stirred rapidly for 4 days. The resulting mixture was transferred to a separatory funnel and the phases were separated. The solvent was removed from the isolated organic layer in vacuo. This residue was extracted with hexanes from water. The resulting mixture was transferred to a separatory funnel and the phases were separated. The organic layer was dried over MgSO 4 and filtered. The solvent was removed from the filtrate in vacuo. This residue was purified by column chromatography with 10% diethyl ether/hexanes to yield 14.6 g (66.3% of theory) of 3-(1,2,2-tribromo-cyclopropyl)-propionic acid ethyl ester.
c. 4-(1-Cyclopropenyl)-2-methylbutan-2-ol
A solution of 1.08 g (0.00285 mol) of 3-(1,2,2-tribromo-cyclopropyl)-propionic acid ethyl ester in 4 ml of diethyl ether was placed under a nitrogen atmosphere by use of a Firestone valve. While cooling in an ice water bath, 10.2 ml (0.0142 mol) of 1.4 M methyl lithium in diethyl ether was added slowly via syringe. After 15 minutes, 2 ml of water was added via syringe. The resulting mixture was transferred to a separatory funnel and the phases were separated. The organic layer was dried over MgSO 4 and filtered. The solvent was removed from the filtrate in vacuo with a bath temperature under 20° C. to yield 0.380 g of 75% pure with remainder being diethyl ether (79% of theoretical yield corrected for ether) of 4-cycloprop-1-enyl-2-methyl-butan-2-ol as an oil. Product is stored at −80° C.
EXAMPLE 24
Preparation of Methyl Sterculate (Compound 21)
Methyl sterculate (40% purity) was formed by the procedure of Gensler et. al. (Gensler, W. J.; Floyd, M. B.; Yanase, R.; Pober, K. W. J. Am. Chem. Soc., 1970, 92, 2472).
EXAMPLE 25
Preparation of Hex-5-yne 2-octylcycloprop-2-ene-1-carboxylate (Compound 22)
a. Ethyl 2-octylcycloprop-2-ene-1-carboxylate
Ethyl 2-octylcycloprop-2-ene-1-carboxylate was prepared from 1-decyne and ethyl diazoacetate by the method of Mueller, P.; Pautex, N.; Helv. Chim Acta 1990, 73,1233.
b. 2-Octylcycloprop-2-ene-1-carboxylic acid
Ethyl 2-octylcycloprop-2-ene-1-carboxylate (1.12 g, 5 mmol) and 100 ml of 0.2 N potassium hydroxide were stirred at room temperature for one week. Ether was added and the phases were separated. The aqueous phase was acidified and extracted with methylene chloride. The organic phase was dried over magnesium sulfate and stripped to give 0.8 g of 2-octylcycloprop-2-ene-1-carboxylic acid.
c. 2-Octylcycloprop-2-ene-1-carbonyl chloride
A solution of 2-octylcycloprop-2-ene-1-carboxylic acid (350 mg, 1.8 mmol) in ether was treated with 0.45 g (3.5 mmol) of oxalyl chloride at room temperature. The reaction mixture was stirred for one hour then stripped to give 330 mg of 2-octylcycloprop-2-ene-1-carbonyl chloride.
d. Hex-5-yne 2-octylcycloprop-2-ene-1-carboxylate
To a solution of 2-octylcycloprop-2-ene-1-carbonyl chloride (330 mg, 1.5 mmol) in 5 ml of ether is added 1.5 ml of triethylamine. 5-Hexyn-1-ol (0.18 g, 1.8 mmol) was added to the reaction mixture, which was stirred at room temperature over the weekend. Water and additional ether were added, and the resulting mixture was transferred to a separatory funnel and the phases were separated. The organic layer was washed with water and brine, dried over MgSO 4 , filtered and stripped. The product was chromatographed on silica gel to give 40 mg of 60% pure hex-5-yne 2-octylcycloprop-2-ene-1-carboxylate containing roughly 40% 2-octylcycloprop-2-ene-1-carboxylic acid.
EXAMPLE 26
Preparation of 7-Cycloprop-1-enyl-heptanoic Acid (Compound 7) and 8-Cycloprop-1-enyl-octan-2-one (Compound 46)
a. 7-(1,1,2-Tribromo-cyclopropyl)-heptanoic acid
1,1,2-Tribromo-2-(7-hydroxyheptyl)cyclopropane (0.90 g, 2.3 mmol) was dissolved in 60 ml of glacial acetic acid. A solution of 1.0 g (10 mmol) of chromium trioxide dissolved in 14 ml of 90% aqueous acetic acid was added and the reaction mixture was stirred at room temperature for 24 hours. Water (300 ml) was added. The solution was extracted with ether. The ether phase was extracted three times with 1N NaOH solution. A little sodium bisulfite was added. The aqueous extracts were acidified with 6N HCl, and extracted with ether twice. The ether extracts were washed with brine, dried over magnesium sulfate and stripped to give 0.56 g 7-(1,1,2-tribromo-cyclopropyl)-heptanoic acid.
b. 7-Cycloprop-1-enyl-heptanoic acid and 8-Cycloprop-1-enyl-octan-2-one
1,1,2-Tribromo-2-(7-carboxyheptyl)-cyclopropane (1.28 g, 3.1 mmol) was dissolved in 60 ml of ether and cooled to −78° C. Methyllithium (9.0 ml, 12.6 mmol) was added and the reaction was stirred at −78° C. for two hours. The reaction mixture was put in an ice bath for 5 minutes, then recooled to −78° C. until workup. Water was added to the reaction mixture, which was warmed to room temperature. The aqueous phase was separated, and the ether phase was extracted with three times with 1N NaOH solution. The ether phase contained 8-cycloprop-1-enyl-octan-2-one and the combined aqueous extracts contained 7-cycloprop-1-enyl-heptanoic acid.
The ether phase from above was washed with brine, dried over magnesium sulfate and stripped to give 200 mg of 8-cycloprop-1-enyl-octan-2-one, Compound 46.
The combined aqueous extracts containing 7-cycloprop-1-enyl-heptanoic acid were acidified with aqueous HCl, and extracted with ether three times. The ether extracts were washed with brine, dried over magnesium sulfate and stripped to give 300 mg of 7-cycloprop-1-enyl-heptanoic acid, Compound 7.
EXAMPLE 27
Preparation of 8-Cycloprop-1-enyl-octan-2-one O-methyl Oxime (Compound 47)
To a solution of 0.15 g (0.9 mmol) of 8-cycloprop-1-enyl-octan-2-one in 10 mL of methanol cooled in an ice bath was added 0.30 g (3 mmol1) of triethylamine and 0.83 g of a 30-35% aqueous solution of methoxylamine hydrochloride (3 mmol). The ice bath was removed, and the reaction mixture was stirred at room temperature for 1.5 hours. Water and ether were added. The phases were separated and the aqueous phase was washed with ether. The combined ether phases were washed with dilute aqueous hydrochloride acid, water (2×), and brine, then dried over magnesium sulfate, filtered and stripped. Column chromatography gave 50 mg of 8-cycloprop-1-enyl-octan-2-one O-methyl oxime (Compound 47) as a 30% solution in ether. The ratio of oxime isomers was 3:1.
EXAMPLE 28
Preparation of 7-Cycloprop-1-enyl-heptanoic Acid Diethylamide (Compound 48)
A solution of 7-cycloprop-1-enyl-heptanoic acid (0.25 g, 1.5 mmol) in 10 ml of ether was cooled in an ice bath and treated with 0.3 mL of triethyl amine. Methyl chloroformate (0.16 g, 17 mmol) was added, and the reaction was stirred for 1.5 hours. Excess diethylamine was added while the reaction was still cooled in an ice bath, and the reaction was stirred for one half hour. Additional ether and water were added, and the aqueous phase was acidified to pH 1 with aqueous HCl. The phases were separated, and the organic phase was washed with water, 1N sodium hydroxide, water and brine. The organic phase was dried over magnesium sulfate, filtered and stripped. Column chromatography gave 70 mg of colorless liquid 7-cycloprop-1-enyl-heptanoic acid diethylamide (Compound 48) in 74% purity.
EXAMPLE 29
In a manner similar to those described above, the following compounds were made:
TABLE 3
Additional compounds
Com-
pound
R 1
R 2
R 3
R 4
Comments
23
Octyl
H
H
H
24
n-Nonyl
H
H
H
1:1 mixture with
1-bromo-2-
nonylcyclopropene
25
n-Decyl
H
H
H
26
n-Heptyl
H
H
H
27
Undecyl
H
H
H
70% purity
28
3-Ethylheptyl
H
H
H
29
Tridecyl
H
H
H
30
2-(2-methoxy-
H
H
H
ethoxy)-
ethoxymethyl
31
n-Amyl
H
H
H
32
2-Methylheptyl
H
H
H
33
2-propionyl-
H
H
H
75% purity
oxyethane
34
6-Methylheptyl
H
H
H
35
3,5,5-Tri-
H
H
H
methylhexyl
36
7-Octenyl
H
H
H
37
5,5,5-Tri-
H
H
H
Tested as a 51%
fluoropentyl
solution in ether
35
Pentadecyl
H
H
H
39
4,8-Nonyl
H
H
H
40
Dodecyl
H
H
H
41
Di-n-butyl-
H
H
H
1:4 mixture with
aminomethyl
2-bromo-3-(di-N-
butylamino)
prop-1-ene
42
Tetradecyl
H
H
H
43
3,3-Dimethyl-
H
H
H
butyl
44
Hexyl
H
Hexyl
H
70% purity
45
Pentyl
Pentyl
H
H
EXAMPLE 30
The compounds described above were characterized using a variety of spectroscopic techniques. The NMR data for compounds 1-45 is given in Table 4. For compounds containing impurities, the chemical shifts of the impurities are not reported, and the integrals are adjusted to reflect only the contribution of the target compound.
TABLE 4
NMR Data
Compound
NMR data
1
(CDCl3) 0.9(m, 5H), 1.3(m, 6H), 1.5(m, 2H), 2.5(t, 2H),
6.4(t, 1H).
2
(CDCl3): 0.88(t, 3H), 1.15-1.35(m, 14H), 1.5(m, 1H),
7.3(s, 2H).
3
(CDCl3): 0.88(d, 2H), 1.2-1.45(m, 6H), 1.5-1.7(m, 4H),
2.45(dt, 2H), 3.33(s, 3H), 3.37(t, 2H), 6.45(t, 1H).
4
(CDCl3): 0.89(t and d, 5H), 1.2-1.45(m, 4H),
1.45-1.6(m, 4H), 1.6-1.75(m, 2H), 2.05-2.2(m, 4H),
2.48(dt, 2H), 6.45(s, 1H).
5
(CDCl3): 0.88(d, 2H), 1.2-1.45(m, 6H), 1.5-1.7(m, 4H),
1.8(bs, 1H), 2.47(dt, 2H), 3.63(t, 2H), 6.4(s, 1H).
6
(CDCl3): 0.88(d, 2H), 1.25-1.45(m, 6H), 1.5-1.75
(m, 4H), 2.05(s, 3H), 2.5(dt, 2H), 4.05 (t, 2H), 6.45(s, 1H).
7
(CDCl3): 0.88(d, 2H), 1.25-1.45(m, 4H), 1.5-1.8(m, 4H),
2.36(t, 2H), 2.48(dt, 2H), 6.44(t, 1H).
8
(CDCl3): 0.88(d, 2H), 1.22(d, 6H), 1.3-1.45(m, 4H),
1.5-1.7(m, 4H), 2.24(t, 2H), 2.47(dt, 2H), 3.2(m, 1H),
3.4-3.9(bs, 2H and water), 6.45(t, 1H).
9
(CDCl3): 0.88(d, 2H), 1.2(t, 3H), 1.25-1.45(m, 4H),
1.5-1.8(m, 4H), 2.28(t, 2H), 2.45(dt, 2H), 4.13(q, 2H),
6.45(s, 1H).
10
(CDCl3): 0.88(d, 2H), 1.4-1.55(m, 6H),
1.55-1.75(m, 4H), 2.34(t, 2H), 2.48(dt, 2H), 6.44(t, 1H).
11
(CDCl3): 0.88(d, 2H), 1.04(t, 6H), 1.2-1.4(m, 6H),
1.4-1.55(m, 2H), 1.55-1.65(m, 2H), 2.4-2.5(m, 4H),
2.55(q, 4H), 6.44(s, 1H).
12
(CDCl3): 0.88(d, 2H), 1.25(t, 6H), 1.3-1.4(m, 6H),
1.5-1.7(m, 4H), 2.02(s, 3H), 2.45(t, 2H),
2.85-2.95(m, 2H), 3.05(q, 4H), 6.45(s, 1H).
13
(CDCl3): 0.88(d, 2H), 1.3-1.45(t and m, 12H),
1.6(quintet, 2H), 1.75(m, 2H), 2.45(dt, 2H), 3.27(s, 3H),
3.35-3.5(m, 2H), 3.61(q, 4H), 6.45(s, 1H).
14
(CDCl3): 0.89(t, 3H), 1.06(d, 2H), 1.2-1.45(m, 6H),
1.5-1.7(m, 2H), 3.5(t, 2H), 4.51(d, 2H), 6.74(t, 1H).
15
(CDCl3): 0.90(m, 5H), 1.2-1.45(m, 4H), 1.5-1.7(m, 2H),
2.76 (dt, 2H), 3.45(t, 2H), 3.65(t, 2H), 6.55(t, 1H).
16
(Acetone-d6): 0.7(m, 6H), 1.05-1.3(m, 12H), 1.85(m, 4H),
7.25(s, 2H).
17
(CDCl3): 0.85-1.05(m, 8H), 1.15-1.35(m, 4H),
1.45-1.65(m, 2H), 2-2.1(m, 2H), 2.4(m, 2H), 3.15(m, 2H),
5.4-5.6(m, 2H).
18
(Acetone-d6): 0.9(m, 6H), 1.0(m, 3H), 1.05-1.55(m, 18H),
2.86(d, 2H), 5.4-5.75(m, 2H), 6.85(s, 1H).
19
(CDCl3): 0.88 (d, 2H), 1.25-1.5(m, 6H), 1.5-1.7(m, 2H),
1.95-2.15(m, 2H), 2.47(dt, 2H), 4.92(dd, 1H),
4.98(dd, 1H), 5.8(m, 1H), 6.44(t, 1H).
20
(CDCl3): 0.9(d, 2H), 1.25(s, 6H), 1.35(m, 2H),
1.65(s, 1H), 1.8(t, 2H), 6.45(t, 1H).
21
(CDCl3): 0.76(s, 2H), 0.88(t, 3H), 1.15-1.4(m, 18H),
1.45-1.7(m, 4H), 2.1(m, 2H), 2.3(t, 2H), 2.4(t, 3H),
3.67(s, 3H)
22
(CDCl3): 0.88(t, 3H), 1.2-1.45(m, 10H), 1.5-1.7(m, 4H),
1.75(m, 2H), 1.95 (t, 1H), 2.18(s, 1H), 2.23(dt, 2H),
2.4-2.55(m, 2H), 4.05-4.15(m, 2H), 6.32(s, 1H).
23
(CDCl3): 0.9(t and s, 5H), 1.2-1.5(m, 10H), 1.6(m, 2H),
2.5(t, 2H), 6.42(s, 1H).
24
(CDCl3): 0.9(t and s, 5H), 1.2-1.5(m, 12H), 1.7(m, 2H),
2.4(t, 2H), 6.45(s, 1H).
25
(CDCl3): 0.88(t and s, 5H), 1.2-1.5(m, 14H), 1.7(m, 2H),
2.5(t, 2H), 6.45(s, 1H).
26
(CDCl3): 0.88(t and d, 5H), 1.2-1.5(m, 8H), 1.7(m, 2H),
2.5(t, 2H), 6.42(s, 1H).
27
(CDCl3): 0.88(t and d, 5H), 1.2-1.5(m, 16H), 1.7(m, 2H),
2.4(t, 2H), 6.4(s, 1H).
28
(CDCl3): 0.8(m, 8H), 1.1-1.4(m, 10H), 1.7(m, 2H),
2.4(t, 2H), 6.42(s, 1H).
29
(CDCl3): 0.9(m, 5H), 1.2-1.5(m, 20H), 1.6(m, 2H),
2.4(t, 2H), 6.4(s, 1H).
30
(CDCl3): 1.06(d, 2H), 3.39(s, 3H), 3.5-3.8(m, 8H),
4.59(d, 2H), 6.75(t, 1H).
31
(CDCl3): 0.9(m, 5H), 1.3(m, 4H), 1.6(m, 2H), 2.5(t, 2H),
6.4(s, 1H).
32
(CDCl3): 0.85-0.95(m, 8H), 1.1-1.4(m, 8H), 1.8(m, 1H),
2.25-2.6(2dd, 2H), 6.45(s, 1H).
33
(CDCl3): 0.93(d, 2H), 1.12(t, 3H), 2.32(q, 2H),
2.82(dt, 2H), 4.32(t, 2H), 6.60(s, 1H).
34
(CDCl3): 0.88(m, 8H), 1.1-1.4(m, 5H), 1.45-1.17(m, 4H),
2.45(t, 2H), 6.45(s, 1H).
35
(CDCl3): 0.88(m, 14H), 1-1.6(m, 7H), 2.4(t, 2H),
6.45(s, 1H).
36
(CDCl3): 0.9(m, 8H), 1-1.8(m, 7H), 2.5(m, 2H),
6.4(t, 1H).
37
(CDCl3): 0.90(d, 2H), 1.5-1.75(m, 4H), 2.0-2.2 (m, 2H),
2.55(dt, 2H), 4.92(dd, 1H), 4.98(dd, 1H), 5.8(m, 1H),
6.5(t, 1H).
38
(CDCl3): 0.88(m, 5H), 1.15-1.3(m, 24H), 1.55(m, 2H),
2.45(t, 2H), 6.45(s, 1H).
39
(CDCl3): 0.9(d, 11H), 1.05-1.7(m, 12H), 2.45(t, 2H),
6.45(s, 1H).
40
(CDCl3): 0.88(m, 5H), 1.15-1.45(m, 16H), 1.6(m, 4H),
2.45(t, 2H), 6.45(s, 1H).
41
(CDCl3): 0.88(d, 2H), 1.05(t, 6H), 1.3-1.55(m, 8H),
2.4-2.65(m, 4H), 3.65(s, 2H), 6.6(t, 1H).
42
(CDCl3): 0.88(m, 5H), 1.25(s, 24H), 2.45(t, 2H),
6.45(s, 1H).
43
(CDCl3): 0.9(m, 11H), 1.45-1.55(m, 2H),
2.4-2.55(m, 2H), 6.4(s, 1H).
44
(CDCl3): 0.9(m, 6H), 1.25-1.45(m, 17H), 1.5(m, 2H),
2.45(t, 2H), 6.65(s, 1H).
45
(CDCl3): 0.77(s, 2H), 0.9(t, 6H), 1.3(m, 4H), 1.5(m, 8H),
2.4(m, 4H).
46
(CDCl3): 0.88(d, 2H), 1.2-1.4(m, 4H), 1.5-1.7(m, 4H),
2.14(s, 3H), 2.43(t, 2H), 2.47(dt, 2H), 6.45(t, 1H).
47
(CDCl3): 0.88(d, 2H), 1.2-1.45(m, 4H), 1.5-1.7(m, 4H),
1.82(major isomer), 1.85(minor isomer) (2s, 3H),
2.15(major isomer) 2.30(minor isomer) (2t, 2H),
2.47(dt, 2H), 3.80(minor isomer), 3.83(major isomer)
(2s, 3H), 6.45(t, 1H).
48
(CDCl3): 0.87(d, 2H), 1.1, 1.15(2tx, 6H),
1.3-1.45(m, 4H), 1.5-1.75(m, 4H), 2.29(t, 2H),
2.47(dt, 2H), 3.30(q, 2H), 3.37(q, 2H), 6.43(t, 1H).
EXAMPLE 31
Biological Activity
Tomato Epinasty Test Protocols
The test procedure is designed to determine the ability of an compound according to the present invention to block the epinastic growth response induced by ethylene in tomato plants when the compound is administered either as a volatile gas or as a component of a spray solution.
Treatment chambers are of an appropriate size for the test plants and are airtight. Each is fitted with a reusable septum to be used for injection of ethylene.
Test plants are Patio variety tomato seedlings planted two plants per three inch square plastic pot.
Volatile gas treatment entails placing two pots of Patio var. tomatoes into a polystyrene 4.8 L volume treatment chamber along with one-half (upper or lower section) of a 50×9 mm plastic Petri dish containing a Gelman filter pad. The appropriate amount of experimental compound, dissolved in 1.0 ml acetone, is pipetted onto the filter pad and the chamber immediately sealed. Four hours later ethylene gas equal to 10 ppm v/v final concentration is injected into the sealed chamber. Sixteen hours later the chambers are opened in an exhaust hood, allowed to air and the plants scored visually for the degree of protection against ethylene-induced epinasty conferred by the experimental compound when compared to ethylene treated and untreated controls on a scale of 0 to 10. A rating of 10 means complete protection. A rating of 0 means no protection from the effects of ethylene.
Spray application treatment entails using a DeVilbiss atomizer to completely cover all foliage and stems of two pots of Patio var. tomato plants with the appropriate amount of experimental compound dissolved in 10% acetone/90% water with 0.05% Silwett L-77 surfactant. Plants are air-dried in a drying hood for four hours then transferred to a 4.8 L polystyrene chamber which is sealed.
Ethylene gas equal to 10 ppm v/v final concentration is injected into the sealed chamber. Sixteen hours later the chambers are opened in an exhaust hood, allowed to air and the plants scored visually for the degree of protection against ethylene-induced epinasty conferred by the experimental compound when compared to ethylene treated and untreated controls on a scale of 0 to 10. A rating of 10 means complete protection. A rating of 0 means no protection from the effects of ethylene.
When applied as a spray in the tomato epinasty test, 1-pentylcyclobutene was superior to 1-butylcyclobutene. The pentyl analog was rated 10 (complete protection), while the butyl analog was rated 5.
The activity of the compounds of this invention in the tomato epinasty test when applied as a gas is given in the table.
TABLE 5
Activity of compounds according to the
present invention in the tomato epinasty test
Gas
Gas
Gas
Gas
Compound
1000 ppm
750 ppm
500 ppm
10 ppm
1
10
2
10
0
3
9.5
4
10
5
10
0
6
10
0
7
8
3
8
8
0
9
4
10
10
2
11
10
3
12
10
2
13
6
14
10
15
10
16
10
0
17
10
0
18
10
0
19
10
20
8
0
21
9
5
22
9
0
23
10
24
9.5
25
9
26
10
27
10
28
9
29
10
3.5
30
10
3
31
10
32
9.5
33
10
0
34
10
35
10
36
10
37
10
38
10
4.5
39
10
40
10
4
41
10
3
42
10
2
43
10
44
10
0
45
10
0
46
9
3
47
9.5
48
7
0
The foregoing embodiments and examples are illustrative of the present invention and are not to be construed as limiting thereof. The invention is defined by the following claims, with equivalents of the claims to be included therein. | Methods of applying C 5-20 cyclopropene derivatives and compositions thereof to block ethylene receptors in plants are disclosed. One such method comprises applying to the plant an effective ethylene response-inhibiting amount of cyclopropene derivatives or compositions thereof. Also disclosed are methods of inhibiting abscission in plants, methods of prolonging the life of cut flowers, methods of inhibiting ripening of picked fruits, and methods of inhibiting ripening of picked vegetables. | 97,040 |
This application is based on and claims priority under 35 U.S.C. §119 with respect to Japanese Application No. 11(1999)-186746 filed on Jun. 30, 1999, the entire content of which is incorporated herein by reference.
FIELD OF THE INVENTION
This invention generally relates to a vehicle motion control system. More particularly, the present invention pertains to a vehicle motion control system which supplies hydraulic pressure generated by an automatic hydraulic pressure generator, capable of generating hydraulic pressure irrespective of a brake pedal operation, to a wheel brake cylinder via a control valve. This vehicle motion control system is applicable to a brake steering controller (a controller for preventing vehicle lateral skidding) and to a traction controller.
BACKGROUND OF THE INVENTION
A known type of vehicle motion control system is described in Japanese Patent No. 2790288 issued in 1998, and U.S. Pat. No. 4,966,248. In this vehicle motion control system, a switching solenoid valve is connected to a vacuum servo unit or vacuum booster. The switching solenoid valve is capable of being selectively switched between either a non-operative position in which a servo unit does not operates when a brake pedal is not depressed or an operative position in which a vacuum servo unit operates independently when the brake pedal is not depressed. During an acceleration slip of the driving wheels (i.e., during a traction control), the switching solenoid valve is switched to the operative position, the vacuum servo unit is operated, and a master cylinder generates a hydraulic pressure without any brake pedal operation. The master cylinder hydraulic pressure is controlled by a modulation unit (a hydraulic pressure control valve) and is supplied to a wheel brake cylinder of a driving wheel which is experiencing acceleration slipping.
The known system described above suffers from several drawbacks. Because the switching solenoid valve is maintained at the operative position during traction control, the hydraulic pressure generated in the master cylinder could exceed the hydraulic pressure that the traction control requires when a negative pressure supplied to a constant pressure chamber of the servo unit changes. An undesired switching noise is generated when a hydraulic brake pressure of a wheel brake cylinder is adjusted by the modulation unit in the above situation.
The switching noise is generated when the fluid communication between the master cylinder and the wheel brake cylinder is switched from the open to closed condition by the modulation unit while excessively high master cylinder hydraulic pressure exists. Also, when the fluid communication between the master cylinder and the wheel brake cylinder is switched from the closed to the open condition, a switching noise is generated by the differential pressure between the master cylinder and the wheel brake cylinder. Likewise, a switching noise is generated when the connection between the wheel cylinder and the reservoir is opened or closed by the modulation unit.
The phenomenon mentioned above occurs remarkably when the known vehicle motion control system is applied to a control for preventing vehicle lateral skidding because the hydraulic pressure necessary for the vehicle lateral skidding control is high.
In light of the foregoing, a need exists for a vehicle motion control system which generates less switching noise when the hydraulic pressure valve is switched while the motion control is under operation.
SUMMARY OF THE INVENTION
The present invention provides a vehicle motion control system that includes a wheel brake cylinder disposed on a wheel to supply a braking force to the wheel, an automatic hydraulic pressure generator which generates hydraulic pressure irrespective of brake pedal operation, a hydraulic pressure control valve disposed between the automatic hydraulic pressure generator and the wheel brake cylinder to adjust the hydraulic brake pressure of the wheel brake cylinder by controlling fluid communication between the automatic hydraulic pressure generator and the wheel brake cylinder, and a braking controller for performing the motion control by actuating the hydraulic pressure control valve in accordance with the motion condition of the vehicle. A hydraulic pressure detecting device detects the generated hydraulic pressure of the automatic hydraulic pressure generator, and a braking control mechanism includes a necessary hydraulic pressure setting device for setting a hydraulic pressure required for the motion control in accordance with the vehicle motion condition during the motion control, and a hydraulic pressure adjusting device for controlling the automatic hydraulic pressure generator and adjusting the generated hydraulic pressure thereof in accordance with the compared result of the actually generated hydraulic pressure of the automatic hydraulic pressure and the required pressure for the motion control.
The motion control system can also include a brake steering control, or control for preventing a vehicle lateral skidding, a traction control and an automatic brake control (a control of the distance between moving vehicles).
The system of the present invention is capable of reducing the switching noise generated when the hydraulic pressure control valve is switched. This is because the generated hydraulic pressure of the automatic hydraulic pressure generator is regulated to the level of the necessary hydraulic pressure for the motion control by adjusting the generated hydraulic pressure of the automatic hydraulic pressure generator in accordance with the comparison between the necessary hydraulic pressure for the motion control and the actually generated hydraulic pressure of the automatic hydraulic pressure generator.
Because the automatic hydraulic pressure generator is controlled in accordance with the result of the comparison between the necessary hydraulic pressure for control and the generated hydraulic pressure of the automatic hydraulic pressure generator, the operation frequency of the hydraulic pressure controller can be reduced. Thus the generation frequency of the switching noise can be reduced.
The necessary hydraulic pressure setting device sets the necessary hydraulic pressure of each wheel in accordance with the vehicle motion attitude during the motion control. Preferably, the hydraulic pressure adjusting device controls the automatic hydraulic pressure generator to adjust the generated hydraulic pressure in accordance with the comparison between the generated hydraulic pressure of the automatic hydraulic pressure generator and the maximum value of the necessary hydraulic pressure of a plurality of controlled wheels. The necessary hydraulic pressure is supplied to all of the controlled wheels securely because the generated hydraulic pressure of the automatic hydraulic pressure generator is adjusted in accordance with the result of the comparison between the generated hydraulic pressure of the automatic hydraulic pressure generator and the maximum value of the necessary hydraulic pressure of a plurality of the controlled wheels.
It is preferable that the hydraulic pressure adjusting mechanism is adapted to control the automatic hydraulic pressure generator to make the generated hydraulic pressure of the automatic hydraulic pressure generator correspond to the necessary hydraulic pressure of the controlled wheels. The switching noise generated when the hydraulic pressure control valve is switched and the frequency of generation of the switching noise can thus be reduced. Further, the necessary hydraulic pressure for the motion control can thus be supplied to the controlled wheels.
It is also preferable that the necessary hydraulic pressure setting device is adapted to set the necessary hydraulic pressure for the motion control for every motion control action, and to calculate the maximum value of a plurality of the necessary hydraulic pressures when a plurality of the motion controls are performed to the vehicle. Also, the hydraulic pressure adjusting device is adapted to adjust the generated hydraulic pressure of the automatic hydraulic pressure generator in accordance with the result of the comparison between the generated hydraulic pressure of the automatic hydraulic pressure generator and the maximum value of a plurality of the necessary hydraulic pressures. When the plurality of the motion controls are performed with respect to the vehicle, a plurality of motion controls are appropriately performed because the generated hydraulic pressure of the automatic hydraulic pressure generator is adjusted in accordance with the result of the comparison between the automatic hydraulic pressure generator and the maximum value of the plurality of necessary hydraulic pressures.
The brake controller includes a traction control device and a brake steering control device. The traction control device applies braking torque to a driving wheel by controlling the hydraulic pressure control valve in accordance with the acceleration slip condition of the driving wheel of the vehicle during the vehicle acceleration. The brake steering control device applies at least one wheel of the vehicle a braking force by controlling the hydraulic pressure control valve in accordance with the tendency of an oversteering or understeering condition of the vehicle. The necessary hydraulic pressure setting device sets the necessary hydraulic pressure for the traction control in accordance with the acceleration slip condition during the traction control and sets the necessary hydraulic pressure for each controlled wheel in accordance with the tendency of the oversteering or understeering condition of the vehicle during the brake steering control. In addition, the necessary hydraulic pressure setting device calculates the maximum value of the necessary hydraulic pressures of the brake steering control wheels set for each wheel and the necessary hydraulic pressure of the traction control. The hydraulic pressure adjusting device is adapted to adjust the generated hydraulic pressure by controlling the automatic hydraulic pressure generator in accordance with the result of the comparison between the generated hydraulic pressure of the automatic hydraulic pressure generator and the maximum value of the necessary hydraulic pressure.
When both traction control and the brake steering control to the vehicle are performed, the generated hydraulic pressure of the automatic hydraulic pressure generator is compared to the maximum value of the necessary hydraulic pressure of the brake steering control wheel, and the generated hydraulic pressure of the automatic hydraulic pressure generator is adjusted in accordance with the result. As a result, the traction control and the brake steering control are performed appropriately.
The automatic hydraulic generating device includes a master cylinder, a vacuum booster, and a switching solenoid valve. The master cylinder generates the hydraulic pressure corresponding to the depression force of the brake pedal. The switching solenoid valve is capable of selectively being switched to either a non-operative position in which the vacuum booster is not actuated or an operative position in which the master cylinder is operated by the actuation of the vacuum booster at least partially irrespective of the operation of the brake pedal. The hydraulic pressure adjusting device is adapted to adjust the master cylinder hydraulic pressure by controlling the switching solenoid valve in accordance with the result of the comparison between the master cylinder hydraulic pressure and the controlled wheels. A brake control actuator of the motion control device can thus be produced at a low cost.
The vacuum booster is comprised of a movable partition, a constant pressure chamber, a variable pressure chamber, a valve mechanism, an auxiliary movable partition, and an auxiliary variable pressure chamber. The constant pressure chamber is formed in front of the movable partition, and negative pressure is introduced into the constant pressure chamber. The variable pressure chamber is formed in back of the movable partition, and is set to select either the condition in which it is connected to the constant pressure chamber for introduction of negative pressure or the condition blocked from the constant pressure chamber and exposed to the atmosphere. The valve mechanism opens and closes the communication between the constant pressure chamber and the variable pressure chamber, and the connection between the variable pressure chamber and the atmosphere. The auxiliary movable partition is disposed in the constant pressure chamber, actuates the master cylinder in accordance with the depression of the brake pedal, and drives the master cylinder when the brake pedal is not operated. The auxiliary variable pressure chamber is formed between the auxiliary movable partition and the movable partition. Preferably, the switching solenoid valve is adapted to switch between an operative position that exposes the auxiliary variable pressure chamber to the atmosphere and a non-operative position that introduces negative pressure to the auxiliary variable pressure chamber.
According to another aspect of the invention, a vehicle motion control system includes a wheel brake cylinder for applying a braking force to a wheel, an automatic hydraulic pressure generator which generates a hydraulic pressure including during non-operation of a brake pedal, a hydraulic pressure control valve disposed between the automatic hydraulic pressure generator and the wheel brake cylinder to adjust hydraulic brake pressure supplied to the wheel brake cylinder by alternatively connecting and disconnecting at least the automatic hydraulic pressure generator and the wheel brake cylinder, a hydraulic pressure detector for detecting a generated hydraulic pressure of the automatic hydraulic pressure generator, and a brake controller for performing vehicle motion control by controlling at least the hydraulic pressure control valve in accordance with a motion condition of the vehicle. The brake controller includes a necessary hydraulic pressure setting mechanism for setting a necessary hydraulic pressure that is necessary for effecting the motion control in accordance with the motion condition of the vehicle and a comparing mechanism for comparing the necessary hydraulic pressure set by the necessary hydraulic pressure setting mechanism with the generated hydraulic pressure detected by the hydraulic pressure detecting mechanism. A hydraulic pressure adjusting device adjusts the generated hydraulic pressure of the automatic hydraulic pressure generator based on the results of the comparison between the necessary hydraulic pressure and the generated hydraulic pressure.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
The foregoing and additional features of the present invention will become more apparent from the following detailed description considered with reference to the accompanying drawing figures in which like elements are designated by like reference numerals and wherein:
FIG. 1 is a schematic view of the vehicle motion control system according to an embodiment of the present invention;
FIG. 2 is a schematic illustration of the hydraulic pressure system of the motion control system shown in FIG. 1;
FIG. 3 is a flow chart explaining the process and operation of the motion control system according to the present invention;
FIG. 4 is a flow chart showing the details of the actual slip ratio calculation carried out in step 105 of FIG. 3;
FIG. 5 is a flow chart showing the details of the brake steering control calculation carried out in step 109 of FIG. 3;
FIG. 6 is a flow chart showing the details of traction control calculation carried out in step 110 of FIG. 3;
FIG. 7 is a flow chart showing the details of the hydraulic pressure control carried out in step 111 of FIG. 3;
FIG. 8 is a flow chart showing the details of the calculation of the maximum value of the necessary hydraulic pressure carried out in step 507 of FIG. 7;
FIG. 9 is a flow chart showing the details of a booster switch valve actuating transaction carried out in step 508 of FIG. 7;
FIG. 10 is a graph showing a controlled area of oversteering control according to the present invention;
FIG. 11 is a graph showing a controlled area of understeering control according to the present invention; and
FIG. 12 is a graph showing the relationship of a parameter for hydraulic brake pressure control and hydraulic pressure mode (for a hydraulic brake pressure control) according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a vehicle motion control system according to the present invention is described and explained below with reference to FIGS. 1-12. Referring initially to FIG. 1, in the vehicle braking control system, an internal combustion engine EG is provided with a throttle control device TH and a fuel injection device FI. The throttle control device TH controls the main throttle opening of a main throttle valve MT in accordance with the operation of an acceleration pedal AP. In accordance with the output of an electronic controller ECU, a sub-throttle valve ST of the throttle control device TH is operated to control a sub-throttle opening and the fuel injection device FI is operated to control the amount of fuel injection. The engine EG is connected to a pair of front wheels FL, FR through a transmission GS and a differential gear DF. The illustrated vehicle is a front wheel drive type vehicle.
The braking system includes wheel brake cylinders Wfl, Wfr, Wrl, Wrr mounted on respective wheels FL, FR, RL, RR. A hydraulic brake pressure control device is connected with these wheel brake cylinders FL, FR, RL, RR. The wheel FL represents the front left driving wheel, the wheel FR represents the front right driving wheel, the wheel RL represents the rear left driven wheel, and the wheel RR represents the rear right driven wheel. The hydraulic brake pressure control device described below is constructed in the manner shown in FIG. 2 .
Wheel speed sensors WS 1 , WS 2 , WS 3 , WS 4 are disposed on the respective wheels FL, FR, RL, RR. These wheel speed sensors WS 1 -WS 4 are connected to the electronic controller ECU so that the rotational speed of each wheel, which is indicated as a pulse whose number is proportional to the respective wheel speed, is inputted to the electronic controller ECU. A plurality of elements are connected to the electronic controller ECU. These parts include: a brake switch BS turned on when a brake pedal BP is depressed; the front left wheel FL, a front wheel steering angle sensor SSf detecting the steering angle of the front wheels FL, FR; a lateral acceleration sensor YG detecting the lateral acceleration Gy of the vehicle; a yaw rate sensor YS detecting the yaw rate γ of the vehicle; and a throttle sensor SS detecting the openings of the main throttle valve MT and the sub-throttle valve ST. The yaw rate sensor YS detects the rate of change of the vehicle rotation angle (yaw angle) at a vertical axis located at the center of gravity of the vehicle, which is called yaw rate. The yaw rate is outputted to the electronic controller ECU as an actual yaw rate γ.
A steering angle controller (not shown) can be attached between the rear wheels RL, RR. Using this device, the steering angle of the wheel RL, RR can be controlled by a motor (not shown) in accordance with the output of the electronic controller ECU.
The electronic controller ECU is provided with a microcomputer CMP which includes a central processing unit CPU, a read-only memory ROM, a random access memory RAM, an input port IPT, those of which are reciprocally connected through a bus. Output signals from the wheel speed sensors WS 1 -WS 4 , the brake switch BS, the front wheel steering angle sensor SSf, the yaw rate sensor YS, the lateral acceleration sensor YG, the throttle sensor SS, etc., are inputted via an amplifier circuit AMP and respective input port IPT into the central processing unit CPU. The control signal is outputted from the output port OPT to the throttle controller TH and the brake hydraulic controller PC respectively via driving circuits ACT. The read-only memory ROM memorizes a program dealing with various processes including the steps shown in the flowchart of FIG. 3 . The central processing unit CPU runs the program while an ignition switch (not shown) is closed. The random access memory RAM tentatively memorizes variable data necessary for running the program. It should be noted that a plurality of microcomputers may be used for each control device such as the throttle control or may be used for several controls which relate to one another.
FIG. 2 shows the brake hydraulic controller PC. A master cylinder MC is boosted via a vacuum booster VB in accordance with the operation of the brake pedal BP. The brake fluid in a master reservoir LRS is pressurized to output master cylinder hydraulic pressure to a hydraulic brake pressure system of the wheels FR, RL and another hydraulic brake pressure system of the wheels FL, RR, respectively. Thus, the illustrated braking system is a diagonal system. The master cylinder MC, which may be a tandem style master cylinder, consists of two pressure chambers MCa, MCb, each connected to one of the two brake hydraulic systems. The first pressure chamber MCa communicates with the hydraulic brake pressure system for the wheels FR, RL on the one side and the second pressure chamber MCb is connected to the hydraulic brake pressure system for the wheels FL, RR on the other side. A pressure sensor PS detecting the output hydraulic pressure of the master cylinder hydraulic pressure Pmc is disposed on the output side of the master cylinder, and the detected signal is inputted to the electronic controller ECU.
The vacuum booster VB is of a conventional structure and includes a constant pressure chamber B 2 and a variable pressure chamber B 3 separately formed by a movable partition B 1 . The movable partition B 1 is connected to the brake pedal BP. A valve mechanism B 4 is provided and includes a vacuum valve (not shown) interrupting communication between the constant pressure chamber B 2 and the variable pressure chamber B 3 and an air valve (not shown) interrupting communication between the variable pressure chamber B 3 and the atmosphere. The constant pressure chamber B 2 is in constant communication with an intake manifold (not shown) of the engine EG, and the negative pressure is introduced into the constant pressure chamber. The variable pressure chamber B 3 can be selectively under one of two operating conditions, one in which the variable pressure chamber B 3 is under a negative pressure by virtue of being in communication with the constant pressure chamber B 2 or the other in which the variable pressure chamber B 3 is disconnected from the constant pressure chamber B 2 and is exposed to the atmosphere using the valve mechanism B 4 . The vacuum valve and the air valve of the valve mechanism B 4 open and close in accordance with the operation of the brake pedal BP. The differential pressure derived from the operation of the brake pedal BP is generated between the constant pressure chamber B 2 and the variable pressure chamber B 3 . As a result, the output boosted in accordance with the operation of the brake pedal BP is transmitted to the master cylinder.
The vacuum booster according to this embodiment includes an auxiliary movable partition B 5 in the constant pressure chamber B 2 and an auxiliary variable pressure chamber B 6 formed between the movable partition B 1 and the auxiliary movable partition B 5 . The auxiliary movable partition B 5 can move in the direction of the master cylinder accompanying movement of the brake pedal BP and can move in the direction of the master cylinder irrespective of the operation of the brake pedal BP to actuate the master cylinder. The auxiliary variable pressure chamber B 6 is structured to selectively be in the condition in which negative pressure is introduced by virtue of communication with the intake manifold of the engine EG and the condition in which it is exposed to the atmosphere in accordance with the operation of a booster switch valve (switching solenoid valve) SB. The booster switch valve SB is a three port two-position switching solenoid valve which includes a solenoid SL to effect a connection of the auxiliary variable pressure chamber B 6 with the intake manifold at the non-operative position of the solenoid SL when the solenoid SL is de-energized (i.e., the normal condition), and to effect exposure of the auxiliary variable pressure chamber B 6 to the atmosphere AR at the operative position when the solenoid SL is energized.
When negative pressure is introduced into the auxiliary variable pressure chamber B 6 via the booster switch valve SB, the predetermined distance between the auxiliary movable partition B 5 and the movable partition B 1 is maintained and the auxiliary movable partition B 5 moves in the direction of the master cylinder along with the movement of the brake pedal BP. When the auxiliary variable pressure chamber B 6 is exposed to the atmosphere, a differential pressure between the constant pressure chamber B 2 filled with negative pressure and the auxiliary variable pressure chamber B 6 is generated. As a consequence, the master cylinder is operated irrespective of the operation of the brake pedal BP (that is, even when the brake pedal is not depressed) in accordance with the movement of the auxiliary movable partition B 5 , whereupon the master cylinder hydraulic pressure is generated. The vacuum booster VB, the booster switch valve SB and the master cylinder MC form an automatic hydraulic pressure generator.
With respect to the hydraulic brake pressure system on the FR and RL wheel side, the first pressure chamber MCa is connected to the wheel brake cylinders Wfr, Wrl respectively via a main hydraulic pressure conduit MFl and respective branch hydraulic pressure conduits MFr, MFl.
The branch hydraulic pressure conduits or circuits MFr, MFl include normal open style two-port, two-position solenoid switching valves PC 1 , PC 2 (switching valves), respectively. In addition, a check valve CV 1 , CV 2 is disposed parallel to each of the switching valves. The check valves CV 1 , CV 2 only allow brake fluid flow in the direction of the master cylinder. The brake fluid in the wheel brake cylinder Wfr, Wrl is returned to the master cylinder MC and the master cylinder reservoir LRS via these check valves CV 1 , CV 2 and the switching valves PC 1 , PC 2 . Accordingly, the hydraulic pressure in the wheel brake cylinders Wfr, Wrl promptly follows the decrease of the hydraulic pressure of the master cylinder. Normally closed two-port, two-position solenoid switching valves PC 5 , PC 6 (switching valves) are disposed on the respective branch hydraulic pressure conduits RFr, RFl on the discharge circuit connected to the wheel brake cylinders Wfr, Wrl. The discharge hydraulic pressure conduit RF merged by the branch hydraulic pressure conduits RFr and RFl is connected to an auxiliary reservoir RSI.
The auxiliary reservoir RS 1 is connected to the suction side of a hydraulic pressure pump HP 1 via a check valve CV 6 and the emission or discharge side of the hydraulic pressure pump HP 1 is connected at a point upstream of the switching valves PC 1 , PC 2 via the check valve CV 7 . The hydraulic pressure pump HP 1 is driven by an electric motor M, and the hydraulic pressure pump HP 1 pumps brake fluid from the auxiliary reservoir RS 1 to return it to the emission side. The auxiliary reservoir RS 1 is disposed independently from the master reservoir LRS of the master cylinder MC. The auxiliary reservoir RS 1 is provided with a piston and a spring, and is adapted to reserve a predetermined amount of brake fluid. The auxiliary reservoir can be referred to as an accumulator. The check valves CV 6 , CV 7 function as a suction valve and an emission valve respectively and regulate the flow of brake fluid emitted through the hydraulic pressure pump HP 1 in one direction. The check valves CV 6 , CV 7 are preferably structured in one piece with the hydraulic pressure pump HP 1 .
A damper DP 1 is disposed on the emission or discharge side of the hydraulic pressure pump HP 1 . In addition, a proportioning valve PV 1 is disposed in the fluid pressure conduit that is connected to the wheel brake cylinder Wrl on the rear wheel side.
The hydraulic brake pressure system on the FL and RR wheel side is similar to the hydraulic brake pressure system on the FR and RL wheel side, and includes normally open type solenoid switching valves PC 3 , PC 4 , normally closed solenoid switching valves PC 7 , PC 8 , check valves CV 3 , CV 4 , CV 9 , CV 10 , an auxiliary reservoir RS 2 , a damper DP 2 , and a proportioning valve PV 2 disposed in the manner shown in FIG. 2 and in a manner similar to that described above with respect to the hydraulic brake pressure system on the FR and RL wheel side. A hydraulic pressure pump HP 2 is driven by the same electric motor M that drives the hydraulic pressure pump HP 1 .
The switch valves PC 1 -PC 8 are the parts of the hydraulic pressure control valve that adjust the hydraulic brake pressure of the wheel brake cylinders of each wheel.
The aforementioned booster switch valve SB, switch valves PC 1 -PC 8 and electric motor M are controlled by the electronic controller ECU as shown in FIG. 1 . Various vehicle motion controls such as a brake steering control (oversteering control or understeering control) or traction control are performed by the parts mentioned above. When the ignition switch is on, a motion control program according to the flowchart in FIG. 3 is performed at a 6 ms calculation cycle.
According to the flowchart in FIG. 3, the microcomputer CMP is first initialized in step 101 . Then, in step 102 the microcomputer CMP reads in wheel speeds from the wheel speed sensors WS 1 -WS 4 , a detected signal of the front wheel steering angle (i.e., the steering angle θf), a detected signal of the yaw rate sensor YS (i.e., the actual yaw rate γ), a detected signal of a lateral acceleration sensor YG (i.e., the actual lateral acceleration indicated as Gya), the detected signal of the hydraulic pressure sensor PS (i.e., the master cylinder hydraulic pressure Pmc), etc.
In step 103 , the wheel speed Vw** of each wheel is calculated, the wheel acceleration DVw** of each wheel is calculated by applying differential calculus to the wheel speed Vw**, and the actual wheel acceleration speed FDVW** is determined by eliminating the noise with a filter (not shown). Next, in step 104 the estimated vehicle speed (the center of gravity position vehicle speed) Vso which is derived from the wheel speed Vw** of each wheel at the center of gravity position is calculated. The center of gravity position vehicle speed Vso is calculated as Vso=MIN (Vw**) when the vehicle is under acceleration driving or constant speed driving and as Vso=MAX (Vw**) when the veicle is under braking. Next, the estimated vehicle speed (vehicle speed at each wheel position) Vso** at the position of each wheel is calculated. If necessary, normalization to the vehicle speed at each wheel position is conducted to reduce the error derived from the difference between the minimum turning outer radius and the minimum turning inner radius when the vehicle is turning. A normalized vehicle speed Nvso** is calculated as Nvso**=Vso**(n)−ΔVr**(n). ΔVr**(n) indicates a correction coefficient for correcting the turning. For example, the correction coefficient mentioned above is set as follows. The correction coefficient ΔVr** (**indicates each wheel, with FW standing for the front wheels and RW standing for the rear wheels) is set following a map (not shown) of each wheel except the standardized wheel based on the turning radius R of the vehicle and γ·VsoFW (=lateral acceleration Gya). When ΔVrFL is set as a standardized wheel, ΔVrFL is equivalent to 0, ΔVrFR is set following the difference between the turning outer radius and the turning inner radius gap map, ΔVrRL is set following the difference between the minimum turning inner radius and the minimum turning inner radius gap map, ΔVrRR is set following a difference between the minimum turning outer radius and the minimum turning outer radius gap map and a difference between the minimum turning outer radius and the minimum turning inner radius gap map. A vehicle acceleration (vehicle acceleration at the center of gravity position) DVso in the longitudinal direction at the center of gravity position of the vehicle is calculated by applying differential calculus to the vehicle speed Vso at the center of gravity position.
The program then proceeds to step 105 where the actual slip ratio Sa** of each wheel is calculated using the wheel speed Vw** of each wheel and the vehicle speed Vso** at each wheel position obtained from steps 103 and 104 . The actual slip rate calculation in step 105 of the flowchart shown in FIG. 3 is carried out using the subroutine shown in FIG. 4 . In step 201 of FIG. 4, it is determined whether the brake switch BS is on or off. When the brake switch BS is off (that is when the vehicle is under acceleration driving or constant speeding driving), the actual slip ratio is calculated in step 202 applying the equation Sa**=(Vw**−Vso**)/Vw**. When the brake switch Bs is on (that is when the vehicle is under braking), the actual slip ratio is calculated as Sa**=(Vso**−Vw**)/Vso**.
The operation then returns to the flow chart in FIG. 3 and at step 106 , a friction coefficient μ of the road surface is estimated or approximated as μ=(DVso 2 +Gya 2 )½ based on the vehicle acceleration DVso at the center of gravity position and the actual acceleration Gya from the detected signal of the lateral acceleration sensor. The friction coefficient μ** at each wheel position according to the estimated value of the friction coefficient μ of the road surface and the wheel brake cylinder hydraulic pressure Pw** of each wheel can be calculated. Next, in step 107 a side slip angular velocity Dβ is calculated as Dβ=Gya/Vso−γ according to the detected signal from the yaw rate sensor YS (actual yaw rate γ), the detected signal from the lateral acceleration sensor YG (actual lateral acceleration Gya), and the vehicle speed Vso at the center of gravity position.
Then, in step 108 , a vehicle side slip angle β is calculated as β=∫Dβdt. The vehicle side slip angle β is the angle of the vehicle direction to the forward direction of the vehicle. The angular velocity of the vehicle skidding Dβ is calculated as dβ/dt which is a differential derivation value of the vehicle side slip angle β. The vehicle side slip angle β can be calculated as β=tan−1 (Vy/Vx) using a vehicle speed Vx relative to the forward direction and a vehicle speed Vy in the lateral direction which at a right angle to Vx direction.
In step 109 , a brake steering control calculation is performed and a target slip ratio for controlling is set up. Then, in step 110 traction control calculation is performed and the target slip ratio for controlling is set up. The details associated with the brake steering control calculation and the traction control calculation will be explained below. Finally, in step 111 , a hydraulic pressure servo control is performed, with the hydraulic brake pressure controller PC being controlled in accordance with the vehicle motion. The details of the hydraulic pressure servo control is also described below. The program then returns to step 102 .
The brake steering control calculation in step 109 of FIG. 3 is explained with reference to the subroutine shown in FIG. 5 . The brake steering control calculation includes oversteering control (OS) and understeering control (US). With respect to the controlled wheels, a target slip ratio in accordance with the oversteering control or understeering control is set up. Initially, in steps 301 and 302 , a start or termination of the oversteering control or understeering control is judged.
A start and termination judgment of the oversteering control in step 301 is performed based on the condition if the steering control is in a controlled area indicated with hatching in FIG. 10 . When the value of the vehicle side slip angle β and the side slip angular velocity Dβ is in the controlled area, the oversteering control starts and when the steering control is out of the controlled area, the oversteering control is terminated. The oversteering is controlled as shown in FIG. 10 as a curve with an arrow. The braking force of each wheel is maximized at the point where the curve has the farthest distance from the borders between the controlled areas and the non-controlled area which are identified with the two dotted chain lines in FIG. 10 .
A start and termination judgment of the understeering control is judged by the condition whether the steering control is in the controlled area indicated with hatching in FIG. 11 . The understeering control starts when the steering control is off the orbit of an ideal condition shown by the one-dotted chain line and enters the controlled area in accordance with the change of the actual lateral acceleration Gya relative to the target lateral acceleration Gyt during the judgment. The understeering control is terminated when the steering control is out of the controlled area. The control is described as the arrowed curve in FIG. 11 .
Next, in step 303 , it is judged whether or not the oversteering control is under operation. If the oversteering control is not under operation, it is judged whether or not the understeering control is under operation. If the understeering control is not under operation, the process returns to the beginning of the main routine. In step 304 , if it is judged that the understeering is under operation (controlling), the process proceeds to step 305 , and the turning of the inner rear wheel and both front wheels are selected, with the target slip ratio of these wheels being set as Sturi, Stufo, and Stufi respectively at understeering control. In these designations, “S” stands for a slip ratio, “t” stands for a target which is compared with “a” mentioned later representing actual measure, “u” stands for understeering control, “f” stands for a front wheel, “r” stands for a rear wheel, “o” stands for outer, and “i” stands for inner.
A differential value between the target lateral acceleration Gyt and actual lateral acceleration Gya is used. The target lateral acceleration Gyt is determined based on the equation of Gyt=γ(θf)·Vso. γ(θf) is determined as γ(θf)={(θf/N)·L}·Vso/(1+Kh·Vso 2 ). Kh stands for a stability factor, N stands for a steering gear ratio, and L stands for a wheel base. The target slip ratio for understeering control is set as follows based on the deviation ΔGy of the target lateral acceleration Gyt and the actual lateral acceleration. That is, Stufo is set as KS·ΔGy and a constant K 5 is set as the value for control in the pressurizing direction (or pressure decreasing direction). Stufi and Sturi are set as K 6 ·ΔGy and K 7 ·ΔGy respectively, with the constants K 6 and K 7 being set as the value for control in the pressing direction.
In step 306 , a load value Fz** of the controlled wheels (i.e., the front wheels and the turning inner rear wheel) is calculated. The turning outer front wheel load is calculated as Fzfo=Wf−W·DVso·Kx+W·Gya·Ky. The turning inner front wheel load is calculated as Fzfi=Wf−W·DVso·Kx−W·Gya·Ky. The turning inner rear wheel load is calculated as Fzfi=Wf+W·DVso·Kx−W·Gya·Ky. Wf stands for a front wheel static load, Wr stands for a rear wheel static load, W stands for a total load, Kx stands for a load moving coefficients in the longitudinal direction, Ky stands for a load moving coefficient in the lateral direction, W·DVso·Kx stands for a total load moving in the longitudinal direction, and W·Gya·Ky stands for a total load moving in the lateral direction.
In step 303 , if it is judged that the oversteering control is under operation, the program proceeds to step 307 and it is judged whether or not the understeering control is under operation. If the understeering control is not under operation, the process goes to step 308 . In step 308 , a turning outer front wheel and a turning inner rear wheel are selected. The target slip ratios for these wheels are set as Stefo and Steri (=0) respectively, wherein “e” stands for the oversteering control.
To determine the target slip ratio, the vehicle side slip angle β and the side slip angular velocity Dβ are utilized. The following equations are set based on those values: Stefo=K 1 ·β+K 2 ·Dβ and Steri=K 3 ·β+K 4 ·Dβ. K 1 through K 4 are constants. The target slip ratio Stefo of the turning outer front wheel is set at the value for the control in the pressurizing direction (i.e., the direction to increase the braking force). The target slip ratio Steri of the turning inner wheels is set at the value for the control in the pressure decrease direction (i.e., the direction to reduce the braking force). Accordingly, the equation Steri=0 is determined when the brake pedal is not under operation. K 3 ≦K 1 /5 and K 4 ≦K 2 /5 are also determined.
If it is judged at step 307 that the understeering control is under operation, the process proceeds to step 310 . In step 310 , the target slip ratio of the turning outer front wheel is set as Stefo for oversteering control. The target slip ratio of the turning inner front and rear wheels is set as Stufi and Sturi for understeering control. When the oversteering control and understeering control are performed simultaneously, the target slip ratio of the turning outer front wheel is set in the manner with the target slip ratio of the oversteering control. The target slip ratio of the turning inner front and rear wheels is set in the same manner with that of the understeering control.
In step 311 , the load value Fz** of the controlled wheels (that is both front wheels and the turning inner rear wheel) is calculated in the same manner as in step 306 .
In any case, the turning outer rear wheel (that is the driven wheel of the front wheel driving vehicle) is not controlled to calculate the vehicle speed Vso at the center of gravity position. The target slip ratio is not set for the turning outer rear wheel.
The operational details associated with the traction control calculation of step 110 in FIG. 3 will be explained with reference to FIG. 6 . In step 401 of FIG. 6, a judgment is made for permission to judge if each wheel is ready for traction control. If it is judged that the acceleration pedal AP is under operation using a detected signal of the throttle sensor SS, it is then determined whether the brake pedal BP is under operation using the detected signal from the brake switch BS. When the acceleration pedal AP is under operation and the brake pedal BP is not under operation, the judgment to permit control is determined. When the acceleration pedal AP is not operated or when both the acceleration pedal AP and the brake pedal BP are operated, the judgment to prohibit the control is determined.
In step 402 , it is determined whether or not the traction control is required regarding each wheel. In step 401 , when a traction controller receives controlling permission and the actual slip ratio Sa** exceeds the predetermined slip ratio Ss, it is judged that initiation of traction control is required. When the traction controller receives a determination of controlling prohibition in step 401 or in case the traction controller receives controlling permission but the actual slip ratio Sa** of the wheel is less than the predetermined slip ratio Ss, it is judged that the traction control is not required to be initiated.
In step 403 , it is determined whether termination of the traction control is required. The traction control is judged to be terminated when the judgment is switched from the control permitting condition to the control prohibiting condition in step 401 or when the actual slip ratio Sa** of the wheel is reduced to be less than the predetermined slip ratio Se even though the control permission is given in step 401 . Continuation of the traction control is determined when the control permission is given in step 401 and the actual slip ratio Sa** of the wheel exceeds the predetermined slip ratio Se.
In step 404 , it is determined whether or not traction control is under operation. When traction control is under operation, the process proceeds to step 405 and when the traction control is not under operation, the process returns to the beginning of the main routine. In step 405 , the target slip ratio Stt is determined in accordance with the a friction coefficient μ of the road surface estimated in step 106 of FIG. 3 . In step 406 , the driving torque TD of the controlled wheel is calculated. Based on the throttle opening θt and the rotation number NE of the engine and using a predetermined map, an engine torque Et is calculated. The driving torque TD is calculated as TD=Et/2 using the obtained engine torque Et. When the two front wheels are the controlled wheels, the driving torque of these wheels is equal.
The operational details associated with the hydraulic pressure servo control in step 111 of FIG. 3 will be explained with reference to FIG. 7. A slip ratio servo control of the wheel brake cylinder for each controlled wheel is performed.
In step 501 , the target slip ratio (Stv**) of the wheels where brake steering control should be performed as determined in steps 305 , 308 and 310 in FIG. 5 and the target slip ratio Stt of the wheels where traction control should be performed as determined in step 405 of FIG. 6 are read out. When both brake steering control and traction control are performed at a wheel, the target slip ratio St** is determined and renewed by adding the target slip ratio Stt for traction control to the target slip ratio Stv** for brake steering control.
In step 502 , a slip ratio deviation ΔSt** of each controlled wheel is calculated. In step 503 , the vehicle acceleration deviation ΔDVso** is calculated. In step 502 , the difference between the target slip ratio St** of the controlled wheel and the actual slip ratio Sa** is calculated, then the slip ratio deviation ΔSt** is obtained (ΔSt**=St**−Sa**). In step 503 , the difference between the vehicle acceleration DV at the center of gravity position and the wheel acceleration DVw is calculated, and the vehicle acceleration deviation ΔDVso** is obtained. The calculation of the vehicle acceleration deviation ΔDVso** varies depending on whether the controlling mode is the traction control or brake steering control. Based on knowledge in the art, a detailed explanation for these variations is not described here.
In step 504 , one parameter Y** for hydraulic brake pressure control at each controlling mode is calculated as Gs**·ΔSt** (Gs is a constant). In step 505 , another parameter X** for hydraulic brake pressure control is calculated as Gd**·ΔDVso** (Gd** is a constant).
In step 506 , for each controlled wheel, the hydraulic pressure mode based on the aforementioned parameters X** and Y** is set following a control map shown in FIG. 12 . In FIG. 12, a steep reduced pressure area, a pulse reduced pressure area, a hydraulic pressure maintaining area, a pulse increased pressure area, and a steep increased pressure area are set in advance. In step 506 , in accordance with values of the parameters X** and Y**, the corresponding area is chosen. The hydraulic pressure control mode is no set at the non-controlling condition (solenoid off).
In step 507 , a maximum value of the necessary hydraulic pressure of the controlled wheel is calculated. In step 508 , a driving transaction of the booster switch valve SB is conducted. An explanation of this will be set forth below. In step 509 , the switching valve PC*, which functions as a hydraulic pressure control valve working in accordance with the hydraulic pressure mode determined in step 506 , is controlled. The hydraulic brake pressure in the wheel brake cylinder increases is maintained or decreases. In step 510 , the driving transaction of the motor M is conducted. The motor M continues to be energized while the traction control and brake steering control are performed.
The details of the maximum value of the necessary hydraulic pressure in step 507 of FIG. 7 will be explained with reference to FIG. 8 . In step 601 of FIG. 8, a necessary hydraulic pressure Ptt for the traction control is calculated uniformly to all controlled wheels based on the driving torque TD of the controlled wheel obtained from the calculation in step 406 of FIG. 6 . When the driving torque TD is less than a first predetermined value, the necessary hydraulic pressure Ptt of all controlled wheels is set at a first predetermined pressure (e.g., 2 Mpa). When the driving torque TD is greater than or equal to a second predetermined value which is larger than the first predetermined value, the necessary hydraulic pressure Ptt is set at a second predetermined pressure (e.g., 6 Mpa). When the driving torque TD is greater than or equal to the first predetermined value and less than the second predetermined value (the second value is larger than the first), the necessary hydraulic pressure Ptt is set to the value which is greater than or equal to the first predetermined pressure and less than the second predetermined pressure and which is directly proportional to the driving torque TD. The larger the driving torque TD, the higher the necessary hydraulic pressure Ptt because the level of acceleration slip is larger at larger driving torque.
In step 602 , in accordance with the friction coefficient μ of the road surface estimated in step 106 of FIG. 3, a correction quantity ΔPtt of the aforementioned necessary hydraulic pressure Ptt is calculated. When the friction coefficient μ of the road surface (of a wheel) is less than a first predetermined value (e.g., 0.1 G), the correction quantity or value ΔPtt is set at a first predetermined quantity (e.g., 1 Mpa). When the friction coefficient μ of the road surface is greater than a second predetermined value (e.g., 0.8 G) which is larger than the first predetermined value, the correction quantity ΔPtt is set at the second predetermined quantity or value (e.g., 3 Mpa) which is larger than the first predetermined quantity. When the friction coefficient μ of the road surface is more than the first predetermined value and less than the second predetermined value, the correction quantity or value ΔPtt is set at a value or quantity which is more than the first predetermined value and less than the second predetermined value and which is directly proportional to the friction coefficient μ of the road surface. The higher the friction coefficient μ of the road surface, the larger the correction quantity ΔPtt. In step 603 , the necessary hydraulic pressure Ptt is corrected as Ptt'=Ptt−ΔPtt. In steps 602 and 603 , the correction quantity ΔPtt is set to a large volume when the first friction coefficient μ of the road surface is high compared to the case when it is low. As a result, the necessary hydraulic pressure Ptt' is set to be small after the correction. This is because the degree of the acceleration slip is smaller when the friction coefficient μ of the road surface is higher.
In step 604 , based on the slip ratio deviation ΔSt** calculated in step 502 of FIG. 7, a hydraulic pressure Ptv** necessary for brake steering control is calculated for each controlled wheel. When the slip ratio deviation ΔSt** is less than a predetermined value (e.g., less than 30%), the necessary hydraulic pressure Ptv** of each controlled wheel is fixed at a value which is directly proportional to the slip ratio deviation ΔSt** of the wheels. The larger the slip ratio deviation ΔSt**, the higher the necessary hydraulic pressure Ptv**. When the slip ratio deviation ΔSt** of each controlled wheel is more than a predetermined value (e.g., more than 30%), the necessary hydraulic pressure Ptv** is fixed at a predetermined pressure (e.g., 12 Mpa).
In step 605 , a correction coefficient Kv** of the aforementioned necessary hydraulic pressure Ptv** is calculated in accordance with the product of the friction coefficient μ of the road surface estimated in step 106 of FIG. 3 and the wheel load Fz** calculated in steps 306 , 309 , and 311 of FIG. 5 . When the product of the friction coefficient μ of the road surface and the wheel load ratio Fz**/W** (W** is a static load) is less than a first predetermined value (e.g., 0.1 G), the correction coefficient Kv** is set to the positive value (e.g., 0.3) which is less than 1. When the product of the friction coefficient μ and the ratio Fz**/W** is more than a second predetermined value (e.g., 0.8 G) which is larger than the first predetermined value, the correction coefficient Kv** is set to 1. When μ·Fz** is more than the first predetermined value and less than the second predetermined value, the correction coefficient Kv** is set to 0.3≦Kv**≦1 and set to the value which is directly proportional to μ·Fz**. The higher the value of μ·Fz**, the larger the correction coefficient Kv**. In step 606 , the necessary hydraulic pressure Ptv** is corrected according to Ptv**′=Kv**·Ptv**.
When the friction coefficient μ of the road surface is low, the value of the correction coefficient Kv** has a small value and the necessary hydraulic pressure Ptv** after correction is small. The necessary hydraulic pressure Ptv** after correction of a wheel with a smaller load value Fz** has a smaller value than a wheel with a larger load value Fz**. This is because the wheel is apt to be locked at the low friction coefficient μ and with the wheel having a small load value Fz**.
In step 607 , it is determined whether or not the brake steering control is under operation. When the brake steering control is under operation, the process proceeds to step 608 , and it is determined whether or not the traction control is under operation. When the traction control is not under operation, the process proceeds to step 609 . In step 609 , a maximum value of the necessary hydraulic pressure PMAX of all controlled wheels is calculated as PMAX=MAX (Ptv**′). That is, when the brake steering control is under operation, the maximum hydraulic pressure of the necessary hydraulic pressure Ptv**′ after correction of all controlled wheels is determined as the necessary hydraulic pressure maximum value PMAX.
In step 608 , when it is judged that the traction control is under operation, the process proceeds to step 610 . The maximum value of the necessary hydraulic pressure PMAX is calculated as PMAX=MAX (Ptt, Ptv**′). When both the brake steering control and the traction control are performed, the maximum hydraulic pressure of the necessary hydraulic pressure Ptt after the correction of the traction control and the necessary hydraulic pressure Ptv**′ after the correction of all controlled wheels of the brake steering control is determined as the maximum value of the necessary hydraulic pressure PMAX.
When it is determined that the brake steering control is not under operation in step 607 , the process advances to step 611 where it is determined whether the traction control is under operation. When the traction control is under operation, the process proceeds to step 612 , and the maximum value PMAX of the necessary hydraulic pressure is set as Ptt′. When it is judged that the traction control is not under operation, the process returns to the beginning of the main routine without setting the maximum value PMAX of the necessary hydraulic pressure.
Finally, the details of the booster switch valve drive operation in step 508 of FIG. 7 will be explained with reference to FIG. 9 . In step 700 , it is judged whether the traction control or the brake steering control is under control. When the traction control or the brake steering control is under operation, the process advances to step 701 , and a master cylinder hydraulic pressure Pmc is compared with the maximum value PMAX of the necessary hydraulic pressure calculated in FIG. 8 . When the master cylinder hydraulic pressure Pmc is less than the maximum value PMAX of the necessary hydraulic pressure, the booster switch valve SB is turned on, and the auxiliary variable pressure chamber B 6 is exposed to the atmosphere. The booster switch valve is turned on when the master cylinder hydraulic pressure Pmc is lower than the maximum value PMAX of the necessary hydraulic pressure or when the master cylinder hydraulic pressure Pmc is equal to the maximum value PMAX of the necessary hydraulic pressure. When the master cylinder hydraulic pressure Pmc is higher than the maximum value PMAX of the necessary hydraulic pressure, the booster switch valve SB is turned off, and the auxiliary variable pressure chamber B 6 is in communication with the negative pressure (non-operative position).
At the beginning of the traction control and the brake steering control, the master cylinder hydraulic pressure Pmc is lower than the maximum value of the necessary hydraulic pressure (for example, in the case of traction control Pmc=0), and so the booster switch valve is turned on.
When the master cylinder hydraulic pressure Pmc exceeds the maximum value PMAX of the necessary hydraulic pressure, the booster switch valve SB is turned off, and the hydraulic pressure Pmc decreases because of the introduction of the negative pressure in the auxiliary variable pressure chamber B 6 . On the other hand, when the master cylinder hydraulic pressure Pmc is less than the maximum value of the necessary hydraulic pressure, the booster switch valve SB turns on, and atmospheric air is introduced into the auxiliary variable pressure chamber B 6 . The booster switch valve SB is switched so that the master cylinder hydraulic pressure Pmc corresponds to the maximum value of the necessary hydraulic pressure under control.
In step 700 , when it is judged that neither the traction control nor the brake steering control is being performed, the process advances to step 703 and the booster switch valve is turned off.
The maximum value PMAX of the necessary hydraulic pressure can be set at a higher value than the actual maximum value of the necessary hydraulic pressure.
In this embodiment of the present invention, because the booster switch valve SB is turned off when the master cylinder hydraulic pressure Pmc exceeds the maximum value of the necessary hydraulic pressure PMAX, which avoids an unnecessary rise of the master cylinder hydraulic pressure Pmc, switching noise generated when the hydraulic pressure control valve is switched is reduced.
The reduction of the frequency of operation of the hydraulic pressure control valve leads to the reduction of the frequency of the generation of the switching noise.
It is to be understood that instead of using a vacuum booster and a booster switch valve SB, a hydraulic pressure pump may be used to supply brake pressure to the wheel brake cylinders from the master cylinder MC and the master cylinder reservoir LRS via the hydraulic pressure control valve. Comparing the maximum value PMAX of the necessary hydraulic pressure with the output pressure of the hydraulic pressure pump, a motor for driving the pump may be duty-driven to adjust the pressure of the pump.
Although in this embodiment the traction control and the brake steering control are explained, this invention is also applicable to an automatic brake control (control of the distance between moving vehicles) and the control for automatic pressurization of wheel brake cylinder at the brake assistant control.
The principles, preferred embodiment and mode of operation of the present invention have been described in the foregoing specification. However, the invention which is intended to be protected is not to be construed as limited to the particular embodiment described. Further, the embodiment described herein is to be regarded as illustrative rather than restrictive. Variations and changes may be made by others, and equivalents employed, without departing from the spirit of the present invention. Accordingly, it is expressly intended that all such variations, changes and equivalents which fall within the spirit and scope of the invention be embraced thereby. | A vehicle motion control system which generates a minimized switching noise when a hydraulic pressure control valve is switched. The vehicle motion control system includes an automatic hydraulic pressure generator generating a hydraulic pressure irrespective of a brake pedal operation and a hydraulic pressure control valve adjusting the hydraulic brake pressure by opening or blocking a connection between the automatic hydraulic pressure generator and a wheel brake cylinder, and performs a motion control by controlling at least the hydraulic pressure control valve in accordance with the motion of a vehicle. The vehicle motion control system has a hydraulic pressure sensor detecting a generated hydraulic pressure of the automatic hydraulic pressure generator, setting a necessary hydraulic pressure for control, and adjusting the generated hydraulic pressure of the automatic hydraulic pressure generator by controlling the automatic hydraulic pressure generator in accordance with the result of a comparison between the actually generated hydraulic pressure of the automatic hydraulic pressure generator and the necessary hydraulic pressure for the motion control. | 61,508 |
FIELD OF THE INVENTION
The present invention relates generally to computer networks, and particularly to methods and systems for prioritizing the setting up of Virtual Private Network (VPN) connections over communication networks.
BACKGROUND OF THE INVENTION
Many organizations use Virtual Private Networks (VPNs) to connect users and remote sites securely to their corporate network. VPNs over Internet Protocol (IP) networks often use the IP security (IPsec) protocol suite, which provides a set of cryptographically-based security services. The IPsec architecture is described by Kent and Atkinson in “Security Architecture for the Internet Protocol,” published as Request for Comments 2401 by the Internet Engineering Task Force (IETF RFC 2401), November 1998, which is incorporated herein by reference.
Internet key exchange (IKE) is a sub-protocol of IPsec that authenticates each peer in an IPsec transaction, negotiates security policy and handles the exchange of encryption keys. IKE is described by Harkins and Carrel in “The Internet Key Exchange,” IETF RFC 2409, November 1998, which is incorporated herein by reference.
The Internet Security Association and Key Management Protocol (ISAKMP) is a protocol that is part of IKE. ISAKMP defines procedures and packet formats for establishing, negotiating, modifying and deleting security associations (SA) between peers. ISAKMP is defined by Maughan, et al., in “Internet Security Association and Key Management Protocol (ISAKMP),” IETF RFC 2408, November 1998, which is incorporated herein by reference.
The present invention will be more fully understood from the following detailed description of the embodiments thereof, taken together with the drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram that schematically illustrates a computer network, in accordance with an embodiment of the present invention; and
FIG. 2 is a flow chart that schematically illustrates a method for prioritizing VPN tunnel setup requests, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
System Description
FIG. 1 is a block diagram that schematically illustrates a computer network 20 , in accordance with an embodiment of the present invention. Network 20 comprises multiple remote clients 24 and remote sites 28 that connect to a corporate network 32 via a wide-area network (WAN) 36 , such as the Internet. Corporate network 32 typically belongs to an organization having employees and/or customers that need to remotely connect to the organizational network. Remote clients 24 may comprise, for example, employees working from home and traveling users connecting to the network from hotel rooms or via wireless hotspots. Remote sites 28 may comprise, for example, branch offices located away from the corporate headquarters and customers or suppliers that are granted access to certain services of the corporate network. In some embodiments typical of remote branch offices, remote site 28 comprises a number of personal computers or work-stations 37 connected by a local area network (LAN) 38 . LAN 38 is connected to WAN 36 using a router 39 . (In the description that follows, remote clients and remote sites are collectively referred to as “clients” for the sake of simplicity.)
In many applications it is desirable to maintain a high level of information security when communicating over WAN 36 . For this purpose, clients 24 and sites 28 are connected to network 32 using Virtual Private Network (VPN) connections, also referred to as VPN tunnels. Each client establishes a secure VPN tunnel to corporate network 32 via a VPN aggregator 40 . In particular, aggregator 40 prioritizes the setting up of VPN tunnels for different client types based on predefined client profiles, as will be explained in detail below. In some embodiments, aggregator 40 may prioritize and set up VPN tunnels for any or all of the clients of network 32 .
Some exemplary VPN aggregators that can use the prioritization methods described herein are the VPN 3000 series concentrators produced by Cisco Systems, Inc. (San Jose, Calif.).
Each VPN tunnel generally uses a secure communication protocol between the client and the VPN aggregator. The protocol typically uses mutually-agreed encryption keys to encrypt and decrypt the information being transferred. In some embodiments, networks 32 and comprise Internet Protocol (IP) networks that communicate by exchanging IP packets. In these embodiments, the exchange of packets within and between these networks is performed in accordance with the IPsec and IKE protocols, as defined and described in the IETF RFCs cited above.
The network configuration shown in FIG. 1 is an exemplary configuration chosen purely for the sake of conceptual clarity. In general, network 20 may comprise any number of remote clients and/or remote sites. Remote clients and sites may be connected to WAN 36 using any suitable wired or wireless links. Aggregator 40 may comprise any network element, which may serve as the gateway connecting corporate network 32 to WAN 36 , or may be part of any other suitable configuration that connects the two networks. Corporate network 32 may comprise a private network or be implemented as part of a shared public network whose services are provided by a service provider.
Although the embodiments described herein mainly relate to a “responder mode” in which the clients initiate the setting up of VPN tunnels with network 32 , the methods and systems described herein can be used, mutatis mutandis , in an “initiator mode” in which aggregator 40 initiates the setting up of the VPN tunnels.
Aggregator 40 comprises an aggregation processor 44 , which performs the various functions associated with setting up and managing the VPN tunnels, and a network interface 48 , for communicating with WAN 36 and with the different components of corporate network 32 . Typically, processor 44 of aggregator 40 comprises a general-purpose computer, which is programmed in software to carry out the functions described herein. The software may be downloaded to the computer in electronic form, over a network, for example, or it may alternatively be supplied to the computer on tangible media, such as CD-ROM. Further alternatively, processor 44 may be implemented using a combination of hardware and software elements. The processor may be a standalone unit, or it may alternatively be integrated with other computing platforms of corporate network 32 .
Typically, a newly-joining client sends an IKE request packet to the VPN aggregator, requesting to set up a VPN connection (tunnel) to network 32 . The VPN aggregator receives the request packet and performs a tunnel setup process that authenticates the client and exchanges encryption keys. In many cases, the IKE process of setting up a VPN tunnel for a newly-joining client is a long and computation-intensive process that consumes a significant amount of time and computation resources in aggregator 40 . The length and complexity of this process are partly due to the algebraic calculations associated with generating the encryption keys. In some cases, aggregator 40 may need to communicate with other nodes in network 32 in order to authenticate a particular client, which further lengthens the tunnel setup process.
In some applications, aggregator 40 supports many thousands of clients simultaneously. In peak periods (such as at the beginning of a working day), several hundred clients may request to set up VPN tunnels every second. Due to the finite resources of the aggregator, some of these clients may experience a noticeable delay in setting up their VPN tunnels. An extreme scenario occurs when parts of the network, or aggregator 40 itself, recover from a communication failure that affects a large number of clients. When the network recovers, thousands of clients may request to set up VPN tunnels simultaneously. In such a scenario, some of these clients may suffer significant delays of up to several minutes in establishing their VPN connections. Clearly, such delays may be considered a prohibitive and intolerable quality of service (QoS) flaw by some clients and applications.
Some VPN applications use a Call Admission Control (CAC) mechanism, which limits the rate of tunnel setup request packets being processed in order to protect the resources of the aggregator. Typically, when the aggregator resource utilization exceeds a predetermined threshold, the CAC process prevents subsequent request packets from being processed. For example, in some embodiments the CAC process measures the aggregator processor utilization (i.e., the percentage of CPU resources used). If the processor utilization crosses a predetermined threshold, the CAC process rejects subsequent request packets. Because of the computational complexity of the tunnel setup process, the CAC process often gives higher priority to requests whose processing has already begun and may reject new requests.
In view of the long setup delays that may be experienced by clients, it is sometimes desirable to assign priorities to the setup request packets based on a classification of the clients. For example, in some networks it is desirable to give remote sites (e.g., branch offices) priority over individual remote clients. As another example, some remote clients may be classified as senior employees or as premium customers that are offered higher service quality. In other cases, it is desirable to give higher priority to VPN tunnels that use voice services or to tunnels used for network control. Request packets from clients having higher priority should be handled first by the aggregator, thereby shortening the connection delay for these clients.
Existing QoS mechanisms, such as the Modular QoS Command line interface (MQC) provided by Cisco Systems, Inc. (San Jose, Calif.), are generally unsuitable for prioritizing IKE request packets. Since the majority of IKE-related information is encrypted, such QoS mechanisms are generally unable to process and prioritize IKE packets.
Prioritization Method Description
In order to provide a faster connection time and an overall better QoS to selected client types, embodiments of the present invention provide methods and systems for prioritizing the setting-up of VPN tunnels based on client profiles.
FIG. 2 is a flow chart that schematically illustrates a method for prioritizing VPN tunnel setup requests, carried out by VPN aggregator 40 in accordance with an embodiment of the present invention. The method begins with an operator, such as a system administrator, defining a configuration of two or more client profiles, at a profile definition step 60 . Each client profile defines the client's association with certain predetermined client categories. A client category may comprise, for example, branch offices or other remote sites. Other client categories may comprise, for example, senior employees or premium customers. In general, the configuration of client profiles is arranged so that every client is associated with no more than a single profile.
As part of the profile definition, each client category is assigned a priority level. Typically, the priority level is represented as a number selected from a predetermined range.
In some VPN applications, the VPN aggregator maintains a set of ISAKMP profiles as part of the ISAKMP process. The ISAKMP profiles are used, for example, for identity matching, certificate filtering, authentication, authorization and virtual routing and forwarding (VRF). In some embodiments of the present invention, the ISAKMP profiles are adapted to serve as client profiles for prioritizing the VPN tunnel setup requests. For this purpose, an additional “priority” command is added to the ISAKMP profile. The following code shows an exemplary configuration comprising three adapted ISAKMP profiles:
crypto isakmp profile cisco
vrf cisco match identity group cisco-vpncluster match identity user JohnChambers
priority 1
match identity group cisco-engineers
priority 2
match identity group cisco-sales
priority 3
match certificate group cisco-ca keying cisco-keyring client authentication list cisco-client isakmp authorization list global-aaa priority 1
crypto isakmp profile company-A
vrf cmp-A match identity group cmp-A-vpncluster match certificate group cmp-A-ca keying cmp-A-keyring client authentication list cmp-A-client isakmp authorization list global-aaa priority 2
crypto isakmp profile company-B
vrf cmp-B match identity group cmp-B-vpncluster match certificate group cmp-B-ca keying cmp-B-keyring client authentication list amp-B-client isakmp authorization list global-aaa priority 2
Each ISAKMP profile comprises one or more “match identity” commands, identifying client categories such as client groups or individual clients. In some embodiments, when a “priority” command is added below a certain “match identity” command, the aggregator assigns the priority level specified in this command to this category. When a single “priority” command is added to the entire ISAKMP profile, this priority level applies to all “match identity” commands in this profile. (See, for example, the “company-A” and “company-B” profiles above.)
Having defined the client profiles, the profiles are provided to aggregator 40 . In some embodiments, the configuration of client profiles can be modified and updated whenever necessary during operation.
Aggregator 40 receives IKE VPN tunnel setup request packets (referred to as request packets for brevity) from clients of corporate network 32 , at a request reception step 62 . According to the IKE protocol, each request packet comprises an identification (ID) payload, which identifies the client sending the packet.
Aggregator 40 matches each VPN request packet with one of the client profiles, at a matching step 64 . In some embodiments, the aggregator extracts the ID payload from the request packet and attempts to match it against the different “match identity” commands in the ISAKMP profiles. If a matching “match identity” command is found, the aggregator reads the priority level assigned to this category from the client profile and assigns the priority level to the request packet. In some embodiments, if a match is not found, the request packet is assigned a default priority level, such as the lowest priority level. Alternatively, the request packet may be dropped.
Aggregator 40 prioritizes the request packets, at a prioritization step 66 . In some embodiments, aggregator uses the priority levels assigned to each request packet at step 64 above to prioritize the handling of the packets. Typically, request packets having the same priority level are handled on a “first come, first served” basis, although any other criterion can be used for this purpose.
In some embodiments, aggregator 40 operates a prioritized Call Admission Control (CAC) mechanism responsively to the assigned priorities, at a CAC operation step 68 . For example, the CAC mechanism may operate several queues, each queue associated with a particular priority level. After assigning priorities to the request packets, the aggregator adds each request packet to the queue associated with the priority of this packet. The queues are then served, typically giving more weight to queues associated with higher priority levels. Any suitable scheduling method known in the art, such as Modified Deficit Round Robin (MDRR), can be used for this purpose. As noted above, the CAC mechanism is used to protect the aggregator resources, typically by rejecting pending request packets when the aggregator utilization exceeds a predetermined threshold. However, when using the CAC mechanism described above, high priority requests are served first and are unlikely to be rejected.
Aggregator 40 sets up VPN tunnels according to the prioritized order of the request packets, at a tunnel setup step 70 . The method then returns to request reception step 62 above for receiving subsequent request packets.
In some embodiments, aggregator 40 may assign priorities to clients responsively to measured traffic characteristics of the clients. For example, the aggregator may measure the volume of traffic (e.g. the average packet rate) originating from each client and assign a higher priority to high traffic clients. As another example, the aggregator may identify service types used by clients, and give a higher priority to clients who frequently use a certain service type (e.g. voice). Any other suitable traffic characteristic or combination of characteristics can be used for this purpose. The measurement of the traffic characteristics and the assignment of priorities based on these characteristics may be performed during a learning period and/or during normal operation of the network. The process may be fully-automated or may involve a human operator, for example for verifying the automated assignments, for reviewing measured characteristics or for manually assigning priorities to automatically measured traffic characteristics.
Although the embodiments described herein relate mainly to prioritizing IKE VPN tunnel setup requests, the principles of the present invention can also be used in other tunnel-based protocols that use aggregators, such as PPP, L2TP, SSH and SSL.
It will thus be appreciated that the embodiments described above are cited by way of example, and that the present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and sub-combinations of the various features described hereinabove, as well as variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description and which are not disclosed in the prior art. | A method for communication includes predefining two or more client profiles applicable to clients of a communication network. Virtual Private Network (VPN) connections are initiated between at least two of the clients and the network. At least two of the clients are matched with respective profiles selected from the two or more predefined client profiles. Priorities are assigned to packets exchanged between the at least two of the clients and the network responsively to the profiles. The VPN connections are set up for the at least two of the clients responsively to the priorities. | 18,416 |
This application claims priority to International Patent Application PCT/AU98/00882 filed Oct. 23, 1998, and Australian Patent Application No. PP0120 filed Oct. 30, 1997.
This invention relates to methods and nucleic acid probes for assessing characteristics of lipid metabolism in animals, and in particular to methods of predicting fat levels in meat, milk, or other fat depots of animals. The invention is particularly applicable to predicting deposition of fat in muscular tissue, which produces the characteristic “marbling” of meat, and to assessment of milk fat content. The methods of the invention are useful in selection of animals, particularly cattle, for ability to produce or high levels of marbling in meat, and to produce high or low levels of milk fat content.
BACKGROUND OF THE INVENTION
The manner in which animals metabolise fat is of considerable economic significance in agriculture and animal husbandry. In some markets the high content of fat in meat, in the form of small fat deposits or “marbling”, is regarded as highly desirable, and to induce heavy marbling of meat in cattle in particular the animals are grain fed for at least a short period prior to marketing and slaughter. In other markets a very lean meat is preferred. Similarly, a high fat content of milk is usually regarded as desirable. This can be particularly important if the milk is to be used for cheese production, and so these factors are important not only in cattle but also in sheep and goats. Recently generation of transgenic animals which secrete valuable proteins into their milk has been achieved, and in order to reduce the costs of purification of the desired protein a low content of fat in the milk is desirable.
Thus there is a need for methods by which the propensity of animals, particularly bovids and other ungulates, to deposit fat in muscle or to secrete fat into milk can be assessed.
Intramuscular or marbling fat is deposited in cattle between the fascicules of muscles, and usually develops when animals are fed a high calorie diet for a long time. The quantity of marbling fat is expressed either as a lipid concentration or as a standardised marbling score (eg. the Australian AUSMEAT standard). Unlike fat deposited in subcutaneous and renal depots, marbling fat is deposited continuously until relatively late in the development of the animal (Hood and Allen, 1973; Cianzio et al, 1985), and the amount of this fat is strongly correlated with the number of fat cells or adipocytes found in the muscle fascicules. Although some of the factors that are important in the differentiation of adipocytes are known (Ailhaud et al, 1992; Smas and Sul, 1995), the genetic factors that are involved in the difference between individuals in differentiation and development of the interfascicular adipocytes and deposition of fat were unknown, as were the genetic variants leading to a high or low marbling score.
To address this lack of information, we have obtained cattle samples from several breeds, the Angus, the Shorthorn and the Wagyu. These samples were readily differentiated due to their marbling score, with approximately half of the sample having a high marbling score and the other half of the sample having a low marbling score. We tested DNA markers from several regions of the bovine genome on the samples and the distribution of alleles was compared in the two groups.
Surprisingly, a significant association to marbling score was found with the anonymous DNA marker CSSM66. This marker had been assigned to bovine chromosome 14 (chr. 14) on the International Bovine Reference Family Panel (described in Barendse et al, 1997), with a location near the centromere. The gene for thyroglobulin (TG) is known to be located near this DNA marker (Barendse et al, 1997). TG is the molecular store for the thyroid hormones triiodothyronine and tetraiodothyronine, which have been implicated in the development of fat cells (Ailhaud et al, 1992; Darimont et al, 1993; Smas and Sul, 1995). TG has been sequenced in cattle (De Martynoff et al, 1987; Parma et al, 1987), and several DNA polymorphisms have been described previously (Georges et al, 1987). However, none of these polymorphisms is associated with fat or marbling.
We sought a polymorphism in the 5′ untranslated region (5′UTR) of TG in cattle, since the transcriptional and translational regulation of genes is mediated by the 5′UTR (Ptashne, 1988; Beato, 1989; Kozak, 1991).
A novel polymorphism in the 5′UTR of TG was identified, and shown to be correlated with marbling. This polymorphism can be used as a test to select animals for marbling performance, either as breeding stock or as animals to be fed for particular markets. Other characteristics of fat, such as fat thickness in other fat depots as well as fat percentage of tissues, including milk, are expected to be predicted by this marker, since the iodothyronines affect the general differentiation of adipocytes and since the influence of the level of the thyroid hormones on milk fat percentage is well known (Folley and Malpress, 1948). It is also expected that fat percentage of other mammalian species will be predicted by variation in the 5′UTR of the TG of those species.
In addition, we have surprisingly found significant associations between marbling score and the hitherto anonymous DNA markers CSSM34 and ETH10 on chromosome 5. CSSM34 is associated with retinoic acid receptor gamma (RARG), which is a known factor in the growth and differentiation of adipocytes. ETH10 is associated with retinol dehydrogenase 5 (RDH5), which catalyzes the interconversion of retinol and retinoic acid, and the level of retinol in the serum is directly related to intramuscular fat levels. The thyroid and steroid hormones such as thyroxine, retinol, and estrogen bind to a family of nuclear receptors with a similar set of hormone response elements. These nuclear receptors, such as RARG, initiate the transcription of genes, and are important elements in the growth, differentiation and specification of tissues. These elements are linked together structurally by similarities at the DNA sequence level.
SUMMARY OF THE INVENTION
In its general aspect the invention provides a method of assessing the fat metabolism characteristics of an animal, comprising the step of testing the animal for the presence or absence of one or more markers selected from the group consisting of:
a) an allele of the 5′ untranslated region of the gene encoding thyroglobulin;
b) an allele of the DNA polymorphism CSSM34, associated with the gene encoding retinoic acid receptor gamma (RARG); and
c) an allele of the DNA polymorphism ETH10, associated with 11-cis, 9-cis retinol dehydrogenase (RDH5).
According to a first embodiment the invention provides a method of assessing the fat metabolism characteristics of an animal, comprising the step of testing the animal for the presence or absence of an allele of the 5′ untranslated region of the gene encoding thyroglobulin.
Preferably the allele is allele 3, which indicates a high marbling score and/or high fat content of milk, or is allele 2, which indicates a low marbling score and/or low fat content in milk.
In a second embodiment the invention provides a method of identifying an animal with a high propensity for fat deposition in muscle (high marbling score), comprising the step of testing said animal for the presence or absence of allele 3 of the 5′ untranslated region of the gene encoding thyroglobulin, and selecting those animals possessing the allele. Preferably the animal is also tested for the presence or absence of allele 2 of the 5′ untranslated region of the gene encoding thyroglobulin, and those animals possessing allele 3 and not possessing allele 2 are selected. Most preferably the animal is homozygous for allele 3.
In a third embodiment, the invention provides a method of identifying an animal with a low propensity for fat deposition in muscle, comprising the step of testing the animal for the presence or absence of allele 2 of the 5′ untranslated region of the gene encoding thyroglobulin, and selecting those animals having allele 2. Preferably the animal is also tested for allele 3, and those animals having allele 2 but not allele 3 are selected. Most preferably the animal is homozygous for allele 2.
According to a fourth embodiment the invention provides a method of identifying an animal with a high propensity for fat deposition in muscle (high marbling score), comprising the step of testing the animal for the presence or absence of an allele of the DNA polymorphism CSSM34 associated with the gene encoding retinoic acid receptor gamma (RARG).
Preferably the allele is allele 2, which indicates a high marbling score. Preferably the animal is also tested for other alleles at the CSSM34 DNA polymorphism. For high marbling scores the animal is most preferably homozygous for allele 2. Allele 2 is 102 base pairs (bp) of DNA long.
According to a fifth embodiment the invention provides a method of identifying an animal with a low propensity for fat deposition in muscle, comprising the step of testing the animal for the presence or absence of an allele of the DNA polymorphism CSSM34 associated with the gene encoding retinoic acid receptor gamma.
Preferably the allele is allele 6, which indicates a low marbling score. Preferably the animal is also tested for other alleles at the CSSM34 DNA polymorphism. For low marbling scores the animal is most preferably homozygous for allele 6. Allele 6 is 112 bp of DNA long.
According to a sixth embodiment the invention provides a method of identifying an animal with intermediate propensity for fat deposition in muscle (low marbling score), comprising the step of testing the animal for the presence or absence of an allele of the DNA polymorphism CSSM34 associated with the gene retinoic acid receptor gamma.
Preferably the allele is one or more of alleles 1, 3, 4, and 5 which indicates an intermediate marbling score. Preferably the animal is also tested for other alleles at the CSSM34 DNA polymorphism. The sizes of the alleles are given in Table 11. There is no special preference for genotype with these alleles. Other alleles may occur at CSSM34 with different lengths of DNA.
In a seventh embodiment, the invention provides a method of identifying an animal of, or derived from, the Wagyu cattle breed with a high propensity for fat deposition in muscle, comprising the step of testing the animal for the presence or absence of an allele of the ETH10 DNA marker. Preferably the allele is allele 5. Allele 5 is 223 bp long.
In an eighth embodiment, the invention provides a method of identifying an animal of, or derived from, the Wagyu cattle breed with a low propensity for fat deposition in muscle, comprising the step of testing the animal for the presence or absence of an allele of the ETH10 DNA marker. Preferably the allele is allele 2. Allele 2 is 217 bp long.
These embodiments of the invention are also applicable to the selection of animals for high or low fat content of milk respectively. The method is also useful for testing for fat levels in carcases.
According to a second aspect the invention provides a method of detecting one or more of the alleles of the invention in an animal, comprising the steps of:
a) obtaining a biological sample from the animal,
b) extracting DNA from the sample,
c) amplifying DNA from the relevant gene, and
d) identifying alleles in the amplified DNA.
Preferably the DNA is either of the 5′ untranslated region of thyroglobulin or of DNA segments near the retinoic acid receptor gamma; if the animal is of the Wagyu breed of cattle, the DNA segments are near the retinol dehydrogenase 5 gene.
Preferably the biological sample is blood, but other biological samples from which DNA can be amplified may be used. For example hair root samples, cheek scrapings, skin samples and the like may be used. Preferably for alleles of the 5′ untranslated region of the thyroglobulin gene the region of DNA amplified includes a homopurine sequence and a copy of the monomeric dispersed repeat sequence. Preferably amplification is performed using polymerase chain reaction, but other DNA amplification methods such as ligase chain reaction are well known in the art, and may alternatively be used. Preferably the alleles are identified by polyacrylamide gel electrophoresis.
In a third aspect the invention provides oligonucleotide probes for amplification of the markers of the invention, selected from the group consisting of:
a) oligonucleotide probes for the 5′ untranslated region of the thyroglobulin gene, having the sequences
TG5U2
5′ ggg gat gac tac gag tat gac tg 3′
(SEQ ID NO: 1)
TG5D1
5′ gtg aaa atc ttg tgg agg ctg ta 3′
(SEQ ID NO: 2)
b) oligonucleotide probes for amplication of the CSSM34 DNA marker, with the sequences
CSSM34U
5′ cca taa ctc tgg gac ttt tcc tca 3′
(SEQ ID NO. 6)
CSSM34D
5′ atg ttc agc cat ctc tcc ttg tcc 3′
(SEQ ID NO. 7)
c) oligonucleotide probes for amplication of fragments from the RARG gene in cattle, with sequences
RARGSJ1U
5′ cca agg atg cta atg aag atc ac 3′
(SEQ ID NO: 9)
RARGSJ1D
5′ gac taa cat tca tca aac acc gc 3′
(SEQ ID NO 10)
RARGE3U1
5′ ccg cga caa aaa ctg tat ca 3′
(SEQ ID NO: 11)
RARGE3D1
5′ ttg ctg acc ttg gtg atg ag 3′
(SEQ ID NO: 12)
RARGE8U2
5′ aat ccg aga gat gct gga ga 3′
(SEQ ID NO: 13)
RARGE8D1
5′ cac ccc tag aaa ctt tgg ca 3′
(SEQ ID NO: 14)
d) oligonucleotide probes for amplification of fragments from the RDH5 gene in cattle, with sequences
RDH5U
5′ atg cca agc tgc tct ggt t 3′
(SEQ ID NO: 15)
RDH5D
5′ tga agt gac tgt ttt atg cca cac 3′
(SEQ ID NO: 16)
e) oligonucleotide probes for amplification of the ETH10 marker in Wagyu cattle, with sequences:
ETH10U
5′ gtt cag gac tgg ccc tgc taa ca 3′
(SEQ ID NO: 17)
ETH10D
5′ cc tcc agc cca ctt tct ctt ctc 3′
(SEQ ID NO: 18)
In a fourth aspect the invention identifies Yeast Artificial Chromosomes, which are positive by hybridization to the oligonucleotide primers for CSSM34U and CSSM34D as well as for RARGE8U2 and RARGE8D1. These are 77D3, 77E3, 71G8, 94B4 and 71E4.
In a sixth aspect the invention provides an isolated nucleic acid molecule encoding part of the bovine retinoic acid receptor gamma, having the sequence set out in SEQ ID NO: 8 as defined herein.
The methods of the invention may be used both for the selection of breeding animals and for the selection of unpedigreed animals for entry into feed lots. In the latter case, the methods of the invention are applicable to deciding the length of time which animals spend in feedlots, since a high marbling score is unlikely to be attained with animals which are homozygous for allele 2 of the 5′ untranslated region of thyroglobulin or allele 6 of CSSM34, or a Wagyu animal with allele 2 of ETH10, even after long feedlot holding.
The methods of the invention are applicable to animals including but not limited to cattle and other bovids, including water buffalo and bison, to other ungulates, including sheep, goats and deer, and to pigs.
For the purposes of this specification it will be clearly understood that the word “comprising” means “including but not limited to”, and that the word “comprises” has a corresponding meaning.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a photograph of a single strand conformational polymorphism (SSCP) gel illustrating the polymorphism of the 5′ untranslated region of the thyroglobulin gene.
FIG. 2 shows the results of tests of associations between DNA markers or chromosome 5 and the marbling score.
DETAILED DESCRIPTION OF THE INVENTION
The invention will now be described in detail by way of reference only to the figure and to the following non-limiting examples.
EXAMPLE 1
CSSM66 is Associated with Marbling in Offspring of a Wagyu Sire
In the first experiment, DNA markers were selected from the bovine genetic linkage maps (Barendse et al, 1994, 1997; Bishop et al, 1994) so that a highly polymorphic DNA marker was present on each chromosome. These markers were evaluated for polymorphism on the Wagyu sire and if he was a homozygote an alternative marker was found. The resultant group of DNA markers were evaluated sequentially on the Wagyu offspring for linkage to marbling.
Since the sires and offspring were genotyped but no dams were genotyped, only those offspring that shared one allele with the sire provide direct information on linkage. The offspring that share none consistently were removed from the analysis as they indicate mispaternity. The offspring that share two alleles with the father can provide some information on linkage only if allele frequencies of the marker are known for this population. For these offspring the parental origin of each allele is uncertain, but probabilities of origin can be assigned for different genotypes of the dam, and the occurrence of the genotypes for the dams can be derived from the population frequencies of the alleles. These data are inferential, require a likelihood ratio approach for analysis, and were not used. Clearly, the more alleles to the marker the more information on linkage is available for analysis, since the offspring is more likely to share only one allele with the sire.
The results were analysed by segregating the individuals by marbling score and by paternal allele after parentage testing had been completed. These 2×2 tables were analysed via contingency chi-square analyses to test associations that are not dependent upon a genetic model. They were also analysed by setting expected proportions equal, as if there was a single Mendelian locus on that particular chromosome with an additive effect on marbling.
The fingerprinting of the offspring of the Wagyu sire showed 5 offspring that regularly failed to share a band with the sire, and so they were excluded from further analyses, although the samples were retained since they provided clear landmarks on the autoradiograms. These results are summarized in Table 1.
TABLE 1
Association Between the DNA Marker CSSM66
and the Marbling Score Among Offspring of the Wagyu Sire
M2
M4
Allele
49
7
2
37
26
4
χ 2 1 = 12.24 p < 0.001
M2 and M4 are marbling scores of 2 and 4 respectively. Allele is the allele of the sire inherited by the steer. Alleles are ranked in mobility, with the fastest migrating allele=1
The polymorphic DNA marker CSSM66 showed an association to marbling score in the offspring of the Wagyu sire, with a probability of less than 0.001 of this occurring by chance. This marker was the 12th in a series of loci chosen at random. The locus RM180 was tested, and found to show a non-significant deviation from the expected values. RM180 is 18 cM distal to CSSM66, indicating that a gene affecting marbling would be in the close vicinity of CSSM66.
EXAMPLE 2
CSSM66 and Marbling in Angus and Shorthorn Offspring
The DNA markers that showed a positive association in the first experiment were tested in the second experiment. They have an a priori expectation of being positively associated, and a lower threshold for significance is acceptable. Two approaches were taken to these data. In the first, the two groups of extreme marbling scores were compared irrespective of ancestry. This rough analysis would show an association if there were linkage disequilibrium between the DNA markers and a locus that affects the marbling score. Irrespective of the prior linkage demonstrated for these regions, however, these results could be biased if they are dominated by a single sire that contributed many individuals of one particular marbling score, where this sire was a homozygote for the DNA marker. In the second approach, only those animals that were drawn at random and were essentially unrelated to others in the study were analysed by marbling groups and by genotype for a population association. For the animals in sire groups, only those from sires that had offspring of low and of high marbling score were retained and the rest excluded. The gene frequencies of the two groups were compared via the chi-square analysis. The relative risk was calculated via the method of Woolf (1955).
CSSM66 was tested over the Angus and Shorthorn offspring irrespective of ancestry, and the results are shown in Table 2.
TABLE 2
Association Between the DNA Marker CSSM66
and Marbling Score Among Angus and Shorthorn Steers
M1
M4
Allele
22
20
1
11
11
2
25
28
3
14
39
4
5
5
5
57
52
6
2
2
7
χ 2 6 = 5.82 p < 0.45 n.s.
M1 and M4 are marbling scores of 1 and 4 respectively. Allele is the allele of the steer. Alleles are ranked in mobility with the fastest migrating allele=1, and are comparable to Table 1.
No significant association was found between CSSM66 and marbling score. The allele ‘4’, which had been found linked to high marbling scores in the Wagyu experiment, was twice as common in animals of high marbling but there is no corresponding allele that showed an excess among animals with low marbling.
RM180 showed no association.
EXAMPLE 3
Identification of Thyroglobulin Polymorphism Associated with Marbling
Primers were designed so as to be complementary to the 5′ untranslated region (5′UTR) of the thyroglobulin gene (TG: Genbank accession X05380). This sequence contains a homopurine sequence and a copy of the bovine monomeric dispersed repeat (de Martynoff et al, 1987), and the primers were located to include both of these features. The primer sequences are:
TG5U2
5′ggg gat gac tac gag tat gac tg 3′
(SEQ ID NO: 1)
TG5D1
5′gtg aaa atc ttg tgg agg ctg ta 3′
(SEQ ID NO: 2)
and the expected size of the fragment is 545 base pairs. The fragment was amplified by the polymerase chain reaction (PCR), and tested for polymorphism by single strand conformational analysis (SSCA) using previously described methods (Mullis et al, 1986; Orita et al, 1989; Barendse et al, 1993). The fragments were amplified with an annealing temperature of 55° C. at 2 mM magnesium chloride for at least 30 cycles of the PCR. The fragments were then separated for 22 hours on 0.4 mm gels composed of 8% acrylamide (89:1::acrylamide:bis-acrylamide), 0% glycerol, 0.5×TBE (1×TBE is 0.089 M TrisHCl, 0.089 M boric acid, 0.002 M disodium ethylenediaminetetraacetic acid) in 38 cm wide×50 cm long gels at 3 Watts at room temperature. These conditions provide the best means of separating all three alleles, particularly the rare 1 allele, at this locus, although several different conditions of glycerol (5 and 10 percent) and power (5 and 7 W) provide separation of the alleles 2 and 3. The fragments were detected by autoradiography.
The primers for the 5′UTR of thyroglobulin produce a single fragment, which shows three alleles when run on single strand conformational polymorphism (SSCP) gels, as illustrated in FIG. 1 . There are 11 complete genotypes on the gel. The top series of bands is one conformation of the DNA fragment and is uninformative. The bottom series of bands is the alternative conformation which shows three alleles. The genotypes are in the order:
33 22 23 23 22 22 23 22 22 23 13
Five associations were calculated. The first was for all individuals that were sampled at random, as summarized in Table 3. The probability of the association occurring by chance is less than 0.05, with allele 3 being associated with high marbling levels. The relative risk of possessing allele 3 is 3.81.
TABLE 3
Association Between Thyroglobulin and
Marbling Score Among the Angus and
Shorthorn Steers Drawn from the Cattle Population
Genotypes
Marbling
22
23
33
M1/2
10
7
0
M4/5
6
15
1
χ 2 1 = 3.94 p < 0.05
M1/2 are low marbling scores and M4/5 are high marbling scores. Genotype is the genotype of the steer. Allele 1 is extremely rare, and only 2 copies of this allele have been seen in 264 individuals.
The one genotype of ‘33’ was merged with the ‘23’ genotypes for the M4/5 class to calculate the chi-square. The relative risk for the ‘3’ allele and increased marbling is 3.81.
In the second association, the steers compared were derived from sires who produced steers of high and of low marbling, and again there is a small sample size. The results are summarized in Table 4. This association shows the same direction, where allele three is associated with high marbling scores, and has a probability less than 0.05 of occurring by chance.
TABLE 4
The Association Between Thyroglobulin and Marbling
Score Among the Angus and Shorthorn Steers Drawn from
Families Where the Sire and Offspring of High
and of Low Marbling Score
M1/2
M4/5
Allele
60
45
2
22
33
3
χ 2 1 = 4.25 p < 0.04
M1/2 are low marbling scores and M4/5 are high marbling scores. Allele ‘1’ is extremely rare and only 2 copies of this allele have been seen in 264 individuals.
EXAMPLE 4
DNA Sequence of the Thyroglobulin Alleles TG5U2 and TG5D1 Described in Example 3
The DNA sequence of the thyroglobulin gene, amplified by the primers TG5U2 and TG5D1 described in Example 3, shows three alleles in the study population. These alleles were isolated, and the DNA sequence of each was determined using the standard dideoxy sequencing method (Sanger et al, 1977). The numbering of the alleles corresponds to that in FIG. 1 . The DNA sequence of each allele is given in Table 5, and the DNA sequence differences responsible for the variation are highlighted.
TABLE 5
The Sequences of Three of the Alleles Amplified by the TG5U2
and TG5D1 Primers.
The sequence differences that define the alleles are in
bold capital letters
Allele 1 (SEQ ID NO: 3)
ggggatgactacgagtatgactgtgcgtgtgtttggcttatctcatcaaaatctctaca
ttctgtgttaatggatctgcctgttttgttccctgccatatcctcatggcctagaatag
tgtctgcttctctatcagactctaaagaaacattgctaggagggaaggaaggagcatgg
atgaggagggagggagcattgtgtttctctcacggtgggcctgaacgtgtggcccacca
agttgttaactttggcctttacccctgaagatgaattatgaagccacacccccagttct
tccttggtggctcagatggtcaagaatccacctgcaatgcgggagacctgggtttgatc
cctgggttgggaagat C ccctggagaagggaatggctacccactccagtattctggcct
ggagaatcccatggacagaggagcctggcgggatgcagtccatggggtctcagagagtc
agatgtgactgagcgactttcacacaca C tcgtccctggttctgctcccctacagcctc
cacaagattttcac
Allele 2 (SEQ ID NO: 4)
ggggatgactacgagtatgactgtgcgtgtgtttggcttatctcatcaaaatctctaca
ttctgtgttaatggatctgcctgttttgttccctgccatatcctcatggcctagaatag
tgtctgcttctctatcagactctaaagaaacattgctaggagggaaggaaggagcatgg
atgaggagggagggagcattgtgtttctctcacggtgggcctgaacgtgtggcccacca
agttgttaactttggcctttacccctgaagatgaattatgaagccacacccccagttct
tccttggtggctcagatggtcaagaatccacctgcaatgcgggagacctgggtttgatc
cctgggttgggaagatcccctggagaagggaatggctacccactccagtattctggcct
ggagaatcccatggacagaggagcctggcgggatgcagtccatggggtctcagagagtc
agatgtgactgagcgactttcacacaca T tcgtccctggttctgctcccctacagcctc
cacaagattttcac
Allele 3 (SEQ ID NO: 5)
ggggatgactacgagtatgactgtgcgtgtgtttggcttatctcatcaaaatctctaca
ttctgtgttaatggatctgcctgttttgttccctgccatatcctcatggcctagaatag
tgtctgcttctctatcagactctaaagaaacattgctaggagggaaggaaggagcatgg
atgaggagggagggagcattgtgtttctctcacggtgggcctgaacgtgtggcccacca
agttgttaactttggcctttacccctgaagatgaattatgaagccacacccccagttct
tccttggtggctcagatggtcaagaatccacctgcaatgcgggagacctgggtttgatc
cctgggttgggaagat T ccctggagaagggaatggctacccactccagtattctggcct
ggagaatcccatggacagaggagcctggcgggatgcagtccatggggtctcagagagtc
agatgtgactgagcgactttcacacaca T tcgtccctggttctgctcccctacagcctc
cacaagattttcac
EXAMPLE 5
Thyroglobulin Polymorphism in Wagyu Offspring
For the thyroglobulin polymorphism, the offspring of the Wagyu sire were analysed retrospectively to determine whether there was an association to marbling score and whether this association was in the same general direction as that found in the Angus and Shorthorn steers. Since the Wagyu samples were collected from three different feedlots at three different times, these samples were analysed separately. Furthermore, since there are only effectively two alleles at the thyroglobulin polymorphism (see below), this locus was analysed for population association rather than genetic linkage, using goodness of fit contingency chi-squares, since the allelic contribution of the sire cannot be ascertained in the heterozygotes as the maternal genotypes are not available. In two of the three Wagyu subsamples there were insufficient individuals with extreme marbling scores, so all the marbling scores were analysed.
The probabilities (P) of the independent chi-squares were transformed using natural logarithms and summed (Sokal and Rohlf, 1981) to form a combined probability estimate for the association between thyroglobulin and marbling. The value of −2ΣlnP is distributed as a chi-square with the number of degrees of freedom equal to twice the number of component probabilities.
The third, fourth and fifth associations were tested among the Wagyu offspring. Two of these three associations have probability values less than 0.05 of occurring by chance when the genetic model is assumed to be dominant inheritance; having one copy of the ‘3’ allele gives the same effect as having two copies of the ‘3’ allele. None of the associations has a probability level below 0.05 when a codominant model is assumed. Of these three associations, one uses the extremes of marbling, as shown in Table 6.
TABLE 6
The First Sample of Wagyu Steers that are Extreme
for Marbling Genotyped for the Thyroglobulin Polymorphism.
Marbling
Genotype
M2
M4
22
44
5
23
33
12
33
6
2
χ 2 1 = 4.41 p < 0.04 (A: Dominant mode)
χ 2 2 = 4.43 p < 0.11 (B: Co-dominant mode)
Two genetic models are used. Model 1 assumes a dominant mode of inheritance, and model 2 assumes a co-dominant mode of inheritance.
Note: The 33 genotypes were added to the 23 genotypes to get the dominant mode.
The thyroglobulin genotypes were compared to the marbling scores, and an association between higher marbling score and the possession of one or more copies of the ‘3’ allele was formed, with a probability less than 0.05 of occurring by chance. For the two other associations the thyroglobulin genotypes were compared to all the marbling scores, since these subsamples had insufficient numbers of animals with extreme marbling scores for statistical significance to be demonstrated. These results are summarized in Tables 7 and 8.
TABLE 7
The Second Sample of the Wagyu Steers:
Analysis of the Trend to Higher Marbling Score
Among Individuals of the 23 Genotype
Marbling Score
Genotype
M2
M3
M4
M5
M6
22
10
16
6
3
0
23
14
23
23
7
2
33
3
4
5
2
0
χ 2 1 = 4.20 p < 0.05 (A: 22 vs 23/33)
χ 2 2 = 4.68 p < 0.10 (B: Co-dominant)
There were insufficient animals of extreme marbling score to analyse only the extremes.
Instead of extremes being compared, M2 plus M3 is compared to M4, M5 plus M6.
TABLE 8
The Third Sample of the Wagyu Steers:
Analysis of the Trend to Higher Marbling Score
Among Individuals of the 23 Genotype
Marbling Score
Genotype
M2
M3
M4
M5
M6
22
4
28
5
1
0
23
11
48
7
1
0
33
0
5
1
1
0
χ 2 1 = 0.11 p < 0.75 (A: 22 vs 23/33)
χ 2 2 = 1.54 p < 0.47 (B: Co-dominant)
There were insufficient animals of extreme marbling score to analyse only the extremes.
Instead of extremes being compared, M2 plus M3 is compared to M4, M5 plus M6.
The numbers of individuals with marbling scores M2 and M3 were combined and compared to the combined number for marbling scores of M4, M5 and M6. One of the two samples showed an association between possession of one or more copies of the ‘3’ allele and higher marbling scores (Table 7), with a probability less than 0.05 of occurring by chance. The other sample (Table 8) showed no association of thyroglobulin with marbling score. In no case was there an association between possession of the ‘22’ genotype and high marbling score.
The probabilities for the five thyroglobulin tests were summed in two ways as three of the five tests having two models—dominant and co-dominant. The results are shown in Table 9.
TABLE 9
The Combination of Chi-Square Probabilities for all
the Associations Between Thyroglobulin and Marbling
Chi-Square
P
1 nP
1.
χ 2 1 = 3.94
p = 0.047
−3.058
2.
χ 2 1 = 4.25
p = 0.039
−3.244
3.
χ 2 1 = 4.41
A
p = 0.036
−3.324
χ 2 2 = 4.43
B
p = 0.109
−2.216
4.
χ 2 1 = 4.20
A
p = 0.040
−3.219
χ 2 2 = 4.68
B
p = 0.096
−2.216
5.
χ 2 1 = 0.11
A
p = 0.745
−0.294
χ 2 2 = 1.54
B
p = 0.464
−0.768
χ 2 5 = 26.278 p < 0.005 (A)
χ 2 5 = 23.258 p < 0.005 (B)
All associations bar one show an association between the 3 allele and high marbling score, one test showing no association. The A series represents the dominant mode of inheritance, while the B series represents the co-dominant mode.
The two combinations are thus all the dominant models and all the co-dominant models. Both of these summations have probabilities less than 0.005 of occurring by chance, and are extremely significant.
The Wagyu sire is a heterozygote for this polymorphism, with the genotype ‘23’. Among the 335 offspring of the Wagyu sire tested none showed the ‘1’ allele.
EXAMPLE 6
Chromosome 5 is Associated with Marbling in Offspring of a Wagyu Sire
Surprisingly also, significant associations to marbling score were found with the anonymous DNA markers CSSM34 and ETH10 and these will be described in the next several examples. These markers had been assigned to bovine chromosome 5 on the International Bovine Reference Family Panel (described in Barendse et al, 1997), with a location about one third of the way down the chromosome. Using the Wagyu family material described in Example 1 above, DNA markers from chromosome 5 were genotyped on the Wagyu sire and his offspring. The DNA marker from chromosome 5 with the best association in the 2×2 contingency chi-square is ETH10 (Toldo et al, 1993), as shown in Table 10.
TABLE 10
Association Between the DNA Marker ETH10 and the
Marbling Score Among Offspring of the Wagyu Sire
M2
M4
Allele
60
12
2
24
17
5
χ 2 1 = 8.42 P < 0.005
χ 2 1 = 16.28 P < 0.0001 (Dominant model)
M2 and M4 are marbling scores of 2 and 4 respectively. Allele is the allele of the sire and that the steer inherited. Alleles are ranked in mobility, with the fastest migrating allele=1. Allele 2 is 217 bp long and allele 5 is 223 bp long. Other lengths of alleles are expected at the ETH10 DNA marker.
The polymorphic DNA marker ETH10 showed an association to marbling score in the offspring of the Wagyu sire, with a probability of less than 0.005 of this occurring by chance, and with a probability of less than 0.0001 of this occurring by chance if a dominant mode of inheritance is assumed. This marker was the tenth in a series of loci chosen at random. This association indicated that a gene affecting marbling would be in the close vicinity of ETH10. Allele 5 of ETH10 was associated with higher marbling scores, while allele 2 was associated with lower marbling scores. The marker CSSM34 showed no association with marbling in this family: the sire provided informative meioses, but there was no evidence for segregation of marbling near CSSM34.
EXAMPLE 7
Chromosome 5 Markers and Marbling in Angus and Shorthorn Steers
A series of DNA markers from chromosome 5 which are located on either side of ETH10 were tested on a sample of Angus and Shorthorn steers of known ancestry. These are the same steers as those used in Example 2. The analysis was performed so that at most two steers from each grandsire were used. Only steers of extreme marbling score were used, so that a comparison of extreme marbling scores was made across a cross-section of the beef industry. The DNA marker CSSM34 (Moore et al, 1994) had the most significant association with marbling, as shown in Table 11, and the pattern of association of marbling to the DNA markers shows that a marbling gene on chromosome 5 is located in close proximity to CSSM34, as shown in FIG. 2 . ETH10 showed no association to marbling in these Angus and Shorthorn steers.
TABLE 11
Association Between the DNA Marker CSSM34
and the Marbling Score Among Offspring
of Known Angus and Shorthorn Sires
ALLELE
MARBLING
1
2
3
4
5
6
M1
3
31
14
5
18
9
M4+
1
49
24
5
7
2
χ 2 5 = 16.63 P < 0.0053
M1 and M4+ are marbling scores of 1 and greater than or equal to 4 respectively. Allele is the allele that the steer possesses. Alleles are ranked in mobility, with the fastest migrating allele=1. The alleles differ in size, hence the differences in mobility, and allele 1=100 bp (base pairs), allele 2=102 bp, allele 3=106 bp, allele 4=108 bp, allele 5=110 bp and allele 6=112 bp. Other alleles with different sizes are expected to exist.
The association between marbling and CSSM34 is strong, and has a probability of less than 0.0053 of occurring by chance. Since a marbling gene had already been demonstrated through the association with ETH10 in Example 6, this association provides strong evidence of the existence of a gene affecting marbling score on chromosome 5. No other DNA marker tested for chromosome 5 had as strong an association with marbling. The next best association was to the gene LALBA, but that had a probability only slightly less than 0.05 of occurring by chance. Since LALBA has a genetic distance of approximately 2 cM from CSSM34 (Barendse et al, 1997), this indicates that CSSM34 is in close allelic association with a marbling gene.
Several of the alleles of CSSM34 show allelic association with marbling. Notably alleles 2 and 3 are associated more with higher marbling scores, while 5 and 6 are associated with lower marbling scores.
EXAMPLE 8
CSSM34 Evaluated on Randomly Drawn Angus and Shorthorn Steers of Unknown Ancestry
CSSM34 was then tested on randomly-collected Angus and Shorthorn steers of unknown ancestry. Firstly, a positive association would confirm the results found in steers of known ancestry. If the results showed the same pattern of allelic disequilibrium this would indicate that the marker CSSM34 was not only a robust predictor of marbling capacity, but that it was extremely closely associated with the causal mutation for marbling. Secondly, a positive association would indicate that the marker CSSM34 could be used as a tool in feedlots to draft animals into particular feeding regimes on the basis of their genotype, and in that way alter the probability of achieving desired marbling scores.
The sample of cattle for this experiment was obtained by bleeding 50 to 100 cattle each week of the Angus or Shorthorn breed of unknown parentage from the same abbatoir. In addition to the breed identification, the identity of the vendor was recorded as well as the standard chiller room and feedlot data such as marbling score, subcutaneous fat thickness, age, feeding regime and carcass weight. By sampling each week and by maximizing the number of vendors that were present in a sample, a wide cross section of the beef industry was obtained. There are an average of five steers per vendor in the sample with a total of 162 vendors. DNA was extracted from all available blood samples. The data form a contingency table with marbling scores as the rows and the allele possessed by the individual as the columns. The contingency data were analysed using the G statistic (Sokal and Rohlf, 1981), since some of the cells had small expected numbers and the G statistic provides a superior approximation to the chi-square distribution.
The association between CSSM34 and marbling in the randomly-collected Angus and Shorthorn steers is shown in Table 12.
TABLE 12
Association Between CSSM34 and Marbling Scores
for Randomly Collected Angus and Shorthorn
Steers of Unknown Ancestry
ALLELE
MARBLING
1
2
3
4
5
6
M1
4
35
35
11
8
9
M2
8
257
261
47
89
66
M3
4
213
158
24
41
33
M4
2
80
58
11
16
7
M5
0
13
8
1
2
0
G adj = 32.17 df 20 P < 0.05
M1 to M5 are marbling scores of 1 through to 5. Allele is the allele that the steer possesses. Alleles are ranked in mobility, with the fastest migrating allele=1, and are the same designations as in Table 11. G adj is the G statistic adjusted using the Williams correction (Sokal and Rohlf, 1981).
This comparison shows that there is clearly an allelic association between marbling score and allele at the DNA marker CSSM34, and is consistent with the previous analyses. Since the animals are sampled at random from the population and their ancestry is unknown, our result confirms that this marker can predict average marbling score without knowing the ancestry of a steer. When allele 2 is compared to allele 6 from Table 12 the G adj =15.21, df 4, P<0.005, indicating that there is a highly significant difference in marbling score for those with allele 2 compared to those with allele 6. This association between alleles 2 and 6 and marbling is consistent with the previous sample, shown in Table 11, which indicates that the allelic association is not only consistent but is also stable. Such associations occur when the polymorphism is responsible, or where the marker is closely associated with the responsible gene.
EXAMPLE 9
CSSM34 is Closely Associated with the Retinoic Acid Receptor Gamma (RARG) Gene While ETH10 is Closely Associated with the Retinol Dehydrogenase 5 (RDH5) Gene
No immediate candidate genes for marbling were evident, although several adipocyte differentiating factors were expected to be on chromosome 5 on the basis of their genomic locations in humans and mice. CSSM34 is located very close to collagen 2 alpha 1 (COL2A1), but that gene is not a candidate gene for marbling. Based on the human map near COL2A1, two candidate genes suggested themselves. These are the genes for retinoic acid receptor gamma (RARG) and 11-cis and 9-cis retinol dehydrogenase (RDH5). RARG is a nuclear receptor for all-trans retinoic acid, which is derived from retinol, and RDH5 catalyses the interconversion of 11-cis and 9-cis retinol to 11-cis and 9-cis retinoic acid (Mertz et al, 1997). The level of retinol (vitamin A) in the blood is linearly related to marbling score (Torii et al, 1996), and the retinoic acid receptors are known factors in the differentiation of pre-adipocytes (Ailhaud et al, 1992; Darimont et al, 1993; Smas and Sul, 1995). Importantly, the concentration of retinol has an impact on marbling score but no impact on the thickness of subcutaneous fat, suggesting that DNA tests for this region could identify a propensity for increase marbling without necessarily also increased fat levels in other fat depots of cattle. A standard treatment in Japan to enhance marbling score is to reduce the level of vitamin A precursors such as β-carotene in the diet of the steer. RDH5 has been sequenced in cattle, but RARG had not previously been sequenced and a DNA clone had not been isolated.
We sought to identify the genes with which the DNA markers CSSM34 and ETH10 were associated. The first stage was to identify fragments from the bovine RARG and RDH5 genes and locate these on the bovine chromosomes at high resolution relative to the CSSM34 and ETH10 polymorphisms. A whole-genome radiation hybrid panel (Womack et al, 1997) was used to locate CSSM34 and ETH10 relative to several genes and DNA markers from chromosome 5. RDH5 proved to be close to ETH10, at a distance of 1.01 centi-Rads (cR). RARG proved to be close to CSSM34, at a distance of 3.25 cR. These distances represent extremely close physical distances, and these DNA markers are clearly closely associated with the respective genes. The primers for CSSM34 and for RARG were then used to probe a Yeast Artificial Chromosome (YAC) library, and every DNA clone that was positive for CSSM34 was also positive for RARG. We have thus identified cloned DNA fragments for the cattle RARG gene, and all of these contain the CSSM34 DNA marker. A RARG-associated polymorphism, CSSM34, can be used to predict marbling score in, but not limited to, the Angus and Shorthorn breeds of cattle. Further, a RDH5 associated polymorphism, ETH10, is linked to marbling in the Wagyu breed of cattle.
The bovine sequence for RDH5 (Genbank accession X82262, Simon et al, 1995) was used to design primers for RDH5. The primers RDH5U and RDH5D generate a 282 bp fragment from bovine DNA. This fragment is polymorphic in cattle, with two alleles.
No bovine sequence for RARG has been described, so the human and mouse sequences were used to generate fragments from bovine DNA. The human sequence for RARG (Genbank accession M38258, Lehmann et al, 1991) and the mouse sequence for RARG (Genbank accession M34476, Giguere et al, 1990) were obtained to design heterologous primers for RARG. Primers were used to amplify the intron between exon 6 and exon 7, and the amplified fragment was cloned and sequenced using standard dideoxy sequencing methods (Sanger et al, 1977). The fragment was analysed using fluorescent labelling via the ABI cycle sequencing protocol (Perkin Elmer, Foster City, Calif., USA) to confirm that RARG was cloned in cattle. The sequence is shown in Table 13. Primers (RARGSJ1U, RARGSJ1D) derived from this sequence amplify bovine DNA. Other primers were also designed to amplify RARG from bovine DNA (RARGE3U1, RARGE3D1 and RARGE8U2, RARGE8D1). The sequences of these primers are shown in Table 14, together with the sequences for primers RDH5U and RDH5D for RDH5, and primers ETH10U and ETH10D for ETH10.
TABLE 13
The DNA Sequence for the Cloned Fragment of Cattle RARG
(SEQ ID NO: 8)
tatgatacnaattcgagctcggtacctacatgttcccaaggatgctaatgaagatcact
gacctccggggcatcagcaccaagggttagtcgggagcaagcctcccctctgtcttctc
ggagctgccggtctcccaggtcaggcagagacaagagcanagtggggtataatcaggca
gcctgcactcgcatcctcgctccgctgcatgctagtgggaacacttggtgcaaaatacc
tttcctttttgtaccttgtttttctgtttgtgaggatgaaacaagttaacacacaacag
gcctacagctgtgctgagttataaagttcagtgcctcctgccctggatggagcagatgt
ttccancatcacaggaangttgattggacgcctggcacgcggtgtttgatgaatgtta
gtcntagtgataaatgttattaagaacagccatgggcttacggaggggtccanngtgtg
tggctggaagtggqcgctgtgtgatcttggaggagacagcctgaaagaaagtgggcagt
ggacttggcagagaagacaggcagagttccaggcagaggagtgggccccaggagcttta
cagtagaaagagggagagaaagaagcagacagagataacaggcctgtgatgggagcccc
agagggcagtcaagcagagttagggaggccgccgtaggtgctgtacntcagccccctga
actcttgttcntccactgcaggagcagaaagggccattaccctgaagatggagattcca
ggcccgatgcctcccctgatccgagaaatgctggagaaccccgaaatgtttgaggacga
ctcctcgcagcctggccctcaccccaaggcctctagcgaggatgaggttcctggggatc
ctctagagtcgacctgcaggcatgcaagctaggcactggccgtcgttttacaacaa
TABLE 14
Oligonucleotide Primers for Amplification of
DNA Encoding RARG
RARGSJ1U
5′ cca agg atg cta atg aag atc ac 3′
(SEQ ID NO: 9)
RARGSJ1D
5′ gac taa cat tca tca aac acc gc 3′
(SEQ ID NO: 10)
RARGE3U1
5′ ccg cga caa aaa ctg tat ca 3′
(SEQ ID NO: 11)
RARGE3D1
5′ ttg ctg acc ttg gtg atg ag 3′
(SEQ ID NO: 12)
RARGE8U2
5′ aat ccg aga gat gct gga ga 3′
(SEQ ID NO: 13)
RARGE8D1
5′ cac ccc tag aaa ctt tgg ca 3′
(SEQ ID NO: 14)
RDH5U
5′ atg cca agc tgc tct ggt t 3′
(SEQ ID NO: 15)
RDH5D
5′ tga agt gac tgt ttt atg cca cac 3′
(SEQ ID NO: 16)
ETH10U
5′ gtt cag gac tgg ccc tgc taa ca 3′
(SEQ ID NO: 17)
ETH10D
5′ cc tcc agc cca ctt tct ctt ctc 3′
(SEQ ID NO: 18)
The loci CSSM34, RARG (primers RARGSJ1U and RARGSJ1D) and RDH5 as well as LALBA, ETH10 and CSSM22 (Moore et al, 1994) were genotyped on the whole genome radiation panel of Womack and associates (1997). The results of these genotypes are shown in Table 15.
TABLE 15
The Genotypes for the 6 loci LALBA, CSSM34, RARGSJ1, ETH10, CSSN22 and RDH5
from the Whole Genome Radiation Hybrid Panel of Cattle
Locus
Radiation Panel Clones
LALBA
000000000000000000001101001000000100010000001110000000000100010000010000011000101000000001
CSSM34
000000000000000000001001001100000100010000001110000000000100010000010000011000111000000001
RARGSJ1
000000000000000000001001001100000100010100001110001000000100010000010000011000111010000001
ETH10
000000000100000000001000001000010000000000010010101000001000000000010001011000101000000011
RDH5
000000010100000000001000001000010000000000010010101000001000000000010001011000101000000011
CSSM22
000000010100000000000100001010010000000000000010001000000000000000010001011000101000000011
The 0 and 1 symbols represent presence or absence of the locus in a particular radiation hybrid clone. The closer two loci are, the more hybrid clones they have in common, and the fewer the differences between them.
The hybrid clone data place RARGSJ1 between LALBA and CSSM34, with a 3.25 cR distance between RARGSJ1 and CSSM34. This is equivalent to a few hundred kilobase pairs between the amplified DNA fragments. These data also place RDH5 1.01 cR from ETH10. Alternatively, CSSM34 is 54 cR from RDH5, a substantial physical distance.
The small relative distance between CSSM34 and RARGSJ1 indicates that both DNA fragments may be contained on a single DNA clone. To test this proposition, a YAC (Yeast Artificial Chromosome) library was screened by hybridization with both of the primers for CSSM34 after these primers were end-labelled with 32 P γ ATP using Polynucleotide Kinase (Richardson, 1981). The yeast library is contained in the yeast strain AB1380 with the bovine DNA contained in the vector pYAC4. This library was constructed using the methods of Libert and coworkers (1993), and has been deposted in the Resource Centre of the German Human Genome Project http://web.rzpd.de/index.html). Positive clones were identified by autoradiography. The library was also screened with both primers for RARGE8 after the primers were end-labelled with 32 P γ ATP. Positive clones were identified by autoradiography, and all positive clones were the same as the positives for CSSM34. The clone names are 77D3, 77E3, 71G8, 94B4 and 71E4. This demonstrates that CSSM34 is closely associated with the genomic sequence of RARG.
DISCUSSION
The linkage between CSSM66 and marbling strongly suggests that a locus affecting marbling is located on bovine chromosome 14. The lack of association to RM180 indicates that candidate genes for the effect will be located close to CSSM66, which is located to the proximal third of the chromosome (Barendse et al, 1997). The lack of a gross association between alleles of CSSM66 and marbling indicates that the causative gene is not very close to CSSM66. The gene for thyroglobulin is located some 7 cM from CSSM66, and this gene shows an extremely significant association with marbling score, consistent with a marbling gene on chromosome 14.
Thyroglobulin is encoded by a massive 300 kilobase stretch of genomic DNA. This protein acts as the molecular store for triiodothyronine and tetraiodothyronine (Parma et al, 1987), hormones that are known to have an effect on adipocyte differentiation. It has been known for a half a century (Salter, 1950) that the thyroid hormones are associated with the deposition of fat cells in muscle. Recent experiments in cell culture have shown the role of these hormones in the growth and differentiation of adipocytes (Levacher et al, 1984; Darimont et al, 1993). Furthermore, structural mutational variation in the thyroglobulin gene has been shown to be causally implicated in congenital goitre in Afrikander cattle (Ricketts et al, 1985), so it is unlikely that structural mutations at this gene would be responsible for variation in fat cell differentiation. In addition, the thyroglobulin genomic DNA sequence is unusually low in variation both in humans and cattle (Baas et al, 1984; Georges et al, 1987), suggesting tight control through natural selection. Alterations in the processing of iodine are likely to have catastrophic results, as can be seen when the diet of humans is deficient in iodine, an element critical to the production of thyroid hormones. The consequences of this deficiency are cretinism, failure of proper development and growth of the bones resulting in a high body weight to length ratio, and myxoedema. The level of the thyroid hormones is implicated in adipocyte differentiation and has an effect on metabolic rate, which in turn has an impact upon the amount of energy available for storage.
Since the 5′ untranslated regions (5′UTR) of genes are critical in transcription and translation (Ptashne, 1988, Kozak, 1991), and hence affect the level and availability of a protein, a DNA polymorphism was sought in the 5′UTR of thyroglobulin. The novel polymorphism identified in this specification shows an association to marbling which has a consistent direction, in which allele ‘3’ is associated with higher marbling scores in four of five subdivisions of the data. For a small sample of unrelated animals the relative risk of allele ‘3’ compared to allele ‘2’ was 3.81; thus animals with high marbling score are almost 4 times more likely to have at least one copy of allele ‘3’ than to be a ‘22’ homozygote. Consistent with this model, the Wagyu sire is a ‘23’ heterozygote and segregates marbling score on chr. 14. It would have been a powerful test of this fragment had he been a homozygote. The overall probability level for the association between marbling score and this thyroglobulin polymorphism is very strong, being less than 0.005, and the evidence for marbling gene on chromosome 14 is convincing, being probability level for the association less than 0.0001 irrespective of the mode of inheritance.
Due to linkage disequilibrium, polymorphisms located near to thyroglobulin on chromosome 14 will also have some predictive value for marbling. However, CSSM66 is not one of them, consistent with the 7 cM distance between CSSM66 and thyroglobulin; linkage disequilibrium is usually expected when the genetic distance is low, generally when it is less than 3 cM. Nevertheless, unless it is proved that there are other likely genes affecting marbling in this region of chromosome 14 it must be assumed that these other polymorphisms are predicting the same test described in this report. Polymorphisms in the 5′UTR of the thyroglobulin molecule of other mammalian species may predict levels of fat in those species, since the action of the iodothyronines is conserved across species, and the structure of thyroglobulin is relatively strongly conserved. There is 84% homology of sequence between humans and cattle, and 75% homology between mice and cattle.
Obviously, marbling is affected by the products of several genes as well as being subjected to environmental influences, so one genetic test will not cover all the variation. Thus, some ‘33’ homozygotes are expected to have low marbling scores due to the influence of variation at other genes or of suboptimal management. Nevertheless, selection of animals on the basis of the thyroglobulin polymorphism described here will shift the proportions of animals that show high and low levels of marbling, either in feedlots or when selecting parents to generate steers.
CSSM66 has been shown to be linked to milk fat percentage in USA Holstein dairy cattle (Ron et al, 1996), so it is expected that the polymorphism in the thyroglobulin gene described here will be predictive in the selection of cattle for high levels of milk fat, since the thyroid hormones are known to have an impact on the fat percentage of milk (Folley and Malpress, 1948).
The linkage between both ETH10 and CSSM34 and marbling indicates that one or more loci affecting marbling occurs on bovine chromosome 5. The replicated, strong population association with CSSM34, and the weak association to the nearby gene LALBA indicate that a locus affecting marbling is closely associated with CSSM34. The gene for RARG is closely associated with CSSM34, and occurs in the same DNA clone with it. On the basis of biochemical evidence, RARG is a strong candidate gene for the effect, as it is a ligand for all-trans retinoic acid (Mertz et al, 1997), and the concentration of retinol in the serum is directly related to the marbling score of a steer (Torii et al, 1996), but unrelated to subcutaneous fat thickness. This indicates that RARG is the likely locus affecting marbling. Nevertheless, CSSM34 is not the only predictor of marbling score in this genomic region, and markers on either side of CSSM34 will also act to predict marbling, just as LALBA is a weak predictor of marbling capacity due to its close proximity. The gene encoding the Roan factor (Charlier et al, 1996) is in the same genomic region as CSSM34, and so, in breeds that segregate the Roan factor, the colour of a steer will be associated with marbling score in some families. These polymorphisms must be assumed to be predicting a locus affecting marbling in and around the RARG gene in cattle.
The fact that the Wagyu data (Example 6) show a peak at ETH10, some 20 cM or 54 cR from CSSM34 (Barendse et al, 1997), may indicate that there is more than one gene for marbling on chromosome 5. The ETH10 polymorphism shows no association to marbling in the Angus and Shorthorn, while the CSSM34 polymorphism shows no association to marbling in the Wagyu offspring. The gene RDH5, catalysing the conversion of 11-cis and 9-cis retinol to 11-cis and 9-cis retinoic acid, is extremely closely associated with ETH10. Indeed, the association of ETH10 with RDH5 is closer than that of CSSM34 with RARG. Again, the level of retinol in the serum is directly related to marbling score in cattle, and an enzyme catalyzing the conversion of retinol to retinoic acid would affect the availability of retinoic acid for binding to the retinoic acid receptors. RDH5 is thus a strong candidate for a locus affecting marbling in Wagyu-derived cattle. Other polymorphisms near ETH10 and RDH5 would also show linkage to marbling, and those polymorphisms must be assumed to be predicting the same locus affecting marbling score in and around the RDH5 gene in cattle. The total evidence for a marbling gene on chromosome 5 is convincing, with a combined probability of less than 0.00015 of being due to chance.
RDH5 and RARG should act in concert, and since they are approximately 20 cM apart, it is likely that some animals will have chromosomes that have a favourable allele for marbling at one locus and an unfavourable allele for marbling at the other locus, cancelling each other out. Progress to improve marbling would be slow if those animals were used in breeding schemes using conventional methods. However, with the DNA marker tests specified here, it will be a simple matter to breed cattle that have alleles favourable for marbling at both genes. Naturally, the breeding would also use the TG marker on chromosome 14, which is expected to be associated with fatness in general in addition to marbling, to generate steers of consistent and optimal marbling score.
It will be apparent to the person skilled in the art that while the invention has been described in some detail for the purposes of clarity and understanding, various modifications and alterations to the embodiments and methods described herein may be made without departing from the scope of the inventive concept disclosed in this specification.
References cited herein are listed on the following pages, and are incorporated herein by this reference.
REFERENCES
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Barendse, W., Armitage, S. M., Kossarek, L. M., Shalom, A., Kirkpatrick, B. W., Ryan, A. M., Clayton, D., Li, L., Neibergs, H. L., Zhang, N., Grosse, W. M., Weiss, J., Creighton, P., McCarthy, F., Ron, M., Teale, A. J., Fries, R., McGraw, R. A., Moore, S. S., Georges, M., Soller, M., Womack, J. E. and Hetzel, D. J. S. Nature Genetics, 1994 6 227-235
Barendse, W., Armitage, S. M., Ryan, A. M., Moore, S. S., Clayton, D., Georges, M., Womack, J. E. and Hetzel, J. Genomics, 1993 18 602-608
Barendse, W., Vaiman, D., Kemp, S. J., Sugimoto, Y., Armitage, S. M., Williams, J. L., Sun, H. S., Eggen, A., Agaba, M., Aleyasin, S. A., Band, M., Bishop, M. D., Buitkamp, J., Byrne, K., Collins, F., Cooper, L., Coppettiers, W., Denys, B., Drinkwater, R. D., Easterday, K., Elduque, C., Ennis, S., Erhardt, G., Ferretti, L., Flavin, N., Gao, Q., Georges, M., Gurung, R., Harlizius, B., Hawkins, G., Hetzel, J., Hirano, T., Hulme, D., Jorgensen, C., Kessler, M., Kirkpatrick, B. W., Konfortov, B., Kostia, S., Kuhn, C., Lenstra, J. A., Leveziel, H., Lewin, H. A., Leyhe, B., Li, L., Martin Burriel, I., McGraw, R. A., Miller, J. R., Moody, D. E., Moore, S. S., Nakane, S., Nijman, I. J., Olsaker, I., Pomp, D., Rando, A., Ron, M., Shalom, A., Teale, A. J., Thieven, U., Urquhart, B. G. D., Vage, D-I., Van de Weghe, A., Varvio, S., Velmala, R., Vilkki, J., Weikard, R., Woodside, C., Womack, J. E., Zanotti, M. and Zaragoza, P. Mammalian Genome, 1997 8 21-28
Beato, M. Cell, 1989 56 335-344
Bishop, M. D., Kappes, S. M., Keele, J. W., Stone, R. T., Sunden, S. L. F., Hawkins, G. A., Solinas Toldo, S., Fries, R., Grosz, M. D., Yoo, J. and Beattie, C. W. Genetics, 1994 136 619-639
Charlier, C, Denys, B., Belanche, J. L., Coppieters, W., Grobet, L., Mni, M., Womack, J., Hanset, R. and Georges, M. Mammalian Genome, 1996 7 138-142
Cianzio, D. S., Topel, D. G., Whitehurst, G. B., Beitz, D. C. and Self, H. L. Journal of Animal Science, 1985 60 970-976
Darimont, C., Gaillard, D., Ailhaud, G. and Negrel, R. Molecular and Cellular Endocrinology, 1993 98 67-73
De Martynoff, G., Pohl, V., Mercken, L., van Ommen, G.-J. and Vassart, G. European Journal of Biochemistry, 1987 164 591-599
Folley, S. J. and Malpress, F. H. The Hormones, Physiology, Chemistry and Applications, 1948 1 745-805. eds Pincus, G. and Thimann, K. V. Academic Press Inc., New York.
Georges, M., Lequarre, S., Hanset, R., and Vassart, G. Animal Genetics, 1987 18 41-50
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Levacher, C., Sztalryd, C., Kinebanyan, M. F. and Picon, L. American Journal of Physiology, 1984 246 C50-C56
Libert, F., Lefort, A., Okimoto, R., Womack, J., and Georges, M. Genomics, 1993 18 270-276.
Mertz, J. R., Shang, E., Piantedosi, R., Wei, S., Wolgemuth, D. J. and Blaner, W. S. Journal of Biological Chemistry, 1997 272 11744-11749
Moore, S. S., Byrne, K, Berger, K. T., Barendse, W., McCarthy, F., Womack, J. E. and Hetzel, D. J. S. Mammalian Genome, 1994 5 84-90
Mullis, K., Faloona, F., Scharf, S., Saiki, R., Horn, G. and Erlich, H. Cold Spring Harbor Symposia on Quantitative Biology, 1986 51 263-273
Orita, M., Iwahana, H., Kanazawa, H., Hayashi, K. and Sekiya, T. Procedings of the National Academy of Sciences USA, 1989 86 2766-2770
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Richardson, C. C. Bacteriophage T4 polynucleotide kinase in ‘The Enzymes’ Vol 14 ed Academic Press Inc., 1981
Ricketts, M. H., Pohl, V., de Martynoff, G., Boyd, C. D., Bester, A. J., van Jaarsveld, P. P. and Vassart, G. EMBO Journal, 1985 4 731-737
Ron, M., Heyen, D. W., Band, M., Feldmesser, E., Ochramento, H., Da, Y., Wiggans, G. R., Vanraden, P. M., Weller, J. I. and Lewin, H. A. Animal Genetics, 1996 27 105 E017.
Salter, W. T. The Hormones, Physiology, Chemistry and Applications, 1950 2 181-299, eds Pincus, G., and Thimann, K. V. Academic Press Inc., New York.
Sanger, F., Nicklen, S. and Coulsen, A. R. Proceedings of the National Academy of Sciences (USA), 1977 74 5463-5467
Simon, A., Hellman, U., Wernstedt, C. and Eriksson, U. Journal of Biological Chemistry, 1995 270 1107-1112.
Smas, C. M. and Sul, H. S. Biochemical Journal, 1995 309 697-710
Sokal, R. R. and Rohlf, F. J. Biometry. Second Edition. W.H. Freeman and Co., San Francisco. 1981
Toldo, S. S., Fries, R., Steffen, P., Neibergs, H. L., Barendse, W., Womack, J. E., Hetzel, D. J. S. and Stranzinger, G. Mammalian Genome, 1993 4 720-727
Torii, S., Matsui, T. and Yano, H. Animal Science, 1996 63 73-78
Womack, J. E., Johnson, J. S., Owens, E. K., Rexroad, C. E. III., Schlapfer, J. and Yang, Y.-P. Mammalian Genome, 1997 8 854-856.
Woolf, B. Annals of Human Genetics, 1955 19 251-253
AUSMEAT Standard Chiller Assessment, a Pictorial Guide (Australian Meat and Livestock Corporation, Sydney) 14-15
18
1
23
DNA
Bos taurus
1
ggggatgact acgagtatga ctg 23
2
23
DNA
Bos taurus
2
gtgaaaatct tgtggaggct gta 23
3
545
DNA
Bos taurus
3
ggggatgact acgagtatga ctgtgcgtgt gtttggctta tctcatcaaa atctctacat 60
tctgtgttaa tggatctgcc tgttttgttc cctgccatat cctcatggcc tagaatagtg 120
tctgcttctc tatcagactc taaagaaaca ttgctaggag ggaaggaagg agcatggatg 180
aggagggagg gagcattgtg tttctctcac ggtgggcctg aacgtgtggc ccaccaagtt 240
gttaactttg gcctttaccc ctgaagatga attatgaagc cacaccccca gttcttcctt 300
ggtggctcag atggtcaaga atccacctgc aatgcgggag acctgggttt gatccctggg 360
ttgggaagat cccctggaga agggaatggc tacccactcc agtattctgg cctggagaat 420
cccatggaca gaggagcctg gcgggatgca gtccatgggg tctcagagag tcagatgtga 480
ctgagcgact ttcacacaca ctcgtccctg gttctgctcc cctacagcct ccacaagatt 540
ttcac 545
4
545
DNA
Bos taurus
4
ggggatgact acgagtatga ctgtgcgtgt gtttggctta tctcatcaaa atctctacat 60
tctgtgttaa tggatctgcc tgttttgttc cctgccatat cctcatggcc tagaatagtg 120
tctgcttctc tatcagactc taaagaaaca ttgctaggag ggaaggaagg agcatggatg 180
aggagggagg gagcattgtg tttctctcac ggtgggcctg aacgtgtggc ccaccaagtt 240
gttaactttg gcctttaccc ctgaagatga attatgaagc cacaccccca gttcttcctt 300
ggtggctcag atggtcaaga atccacctgc aatgcgggag acctgggttt gatccctggg 360
ttgggaagat cccctggaga agggaatggc tacccactcc agtattctgg cctggagaat 420
cccatggaca gaggagcctg gcgggatgca gtccatgggg tctcagagag tcagatgtga 480
ctgagcgact ttcacacaca ttcgtccctg gttctgctcc cctacagcct ccacaagatt 540
ttcac 545
5
545
DNA
Bos taurus
5
ggggatgact acgagtatga ctgtgcgtgt gtttggctta tctcatcaaa atctctacat 60
tctgtgttaa tggatctgcc tgttttgttc cctgccatat cctcatggcc tagaatagtg 120
tctgcttctc tatcagactc taaagaaaca ttgctaggag ggaaggaagg agcatggatg 180
aggagggagg gagcattgtg tttctctcac ggtgggcctg aacgtgtggc ccaccaagtt 240
gttaactttg gcctttaccc ctgaagatga attatgaagc cacaccccca gttcttcctt 300
ggtggctcag atggtcaaga atccacctgc aatgcgggag acctgggttt gatccctggg 360
ttgggaagat tccctggaga agggaatggc tacccactcc agtattctgg cctggagaat 420
cccatggaca gaggagcctg gcgggatgca gtccatgggg tctcagagag tcagatgtga 480
ctgagcgact ttcacacaca ttcgtccctg gttctgctcc cctacagcct ccacaagatt 540
ttcac 545
6
24
DNA
Bos taurus
6
ccataactct gggacttttc ctca 24
7
24
DNA
Bos taurus
7
atgttcagcc atctctcctt gtcc 24
8
931
DNA
Bos taurus
8
tatgatacaa ttcgagctcg gtacctacat gttcccaagg atgctaatga agatcactga 60
cctccggggc atcagcacca agggttagtc gggagcaagc ctcccctctg tcttctcgga 120
gctgccggtc tcccaggtca ggcagagaca agagcaagtg gggtataatc aggcagcctg 180
cactcgcatc ctcgctccgc tgcatgctag tgggaacact tggtgcaaaa tacctttcct 240
ttttgtacct tgtttttctg tttgtgagga tgaaacaagt taacacacaa caggcctaca 300
gctgtgctga gttataaagt tcagtgcctc ctgccctgga tggagcagat gtttccacat 360
cacaggaagt tgattggacg cctggcacgc ggtgtttgat gaatgttagt ctagtgataa 420
atgttattaa gaacagccat gggcttacgg aggggtccag tgtgtggctg gaagtgggcg 480
ctgtgtgatc ttggaggaga cagcctgaaa gaaagtgggc agtggacttg gcagagaaga 540
caggcagagt tccaggcaga ggagtgggcc ccaggagctt tacagtagaa agagggagag 600
aaagaagcag acagagataa caggcctgtg atgggagccc cagagggcag tcaagcagag 660
ttagggaggc cgccgtaggt gctgtactca gccccctgaa ctcttgttct ccactgcagg 720
agcagaaagg gccattaccc tgaagatgga gattccaggc ccgatgcctc ccctgatccg 780
agaaatgctg gagaaccccg aaatgtttga ggacgactcc tcgcagcctg gccctcaccc 840
caaggcctct agcgaggatg aggttcctgg ggatcctcta gagtcgacct gcaggcatgc 900
aagctaggca ctggccgtcg ttttacaaca a 931
9
23
DNA
Bos taurus
9
ccaaggatgc taatgaagat cac 23
10
23
DNA
Bos taurus
10
gactaacatt catcaaacac cgc 23
11
20
DNA
Bos taurus
11
ccgcgacaaa aactgtatca 20
12
20
DNA
Bos taurus
12
ttgctgacct tggtgatgag 20
13
20
DNA
Bos taurus
13
aatccgagag atgctggaga 20
14
20
DNA
Bos taurus
14
cacccctaga aactttggca 20
15
19
DNA
Bos taurus
15
atgccaagct gctctggtt 19
16
24
DNA
Bos taurus
16
tgaagtgact gttttatgcc acac 24
17
22
DNA
Bos taurus
17
ttcaggactg gccctgctaa ca 22
18
23
DNA
Bos taurus
18
cctccagccc actttctctt ctc 23 | This invention relates to methods and nucleic acid probes for assessing characteristics of lipid metabolism in animals, and in particular to methods of predicting fat levels in meat, milk, or other fat depots of animals. Thus the invention provides a method of assessing the fat metabolism characteristics of an animal, comprising the step of testing the animal for the presence or absence of one or more markers selected from the group consisting of: a) an allele of the 5′ untranslated region of thyroglobulin; b) an allele of the DNA polymorphism CSSM34, associated with the gene encoding retinoic acid receptor gamma (RARG); and c) an allele of the DNA polymorphism ETH10, associated with 11-cis, 9-cis retinol dehydrogenase (RDH5). The invention is particularly applicable to predicting disposition of fat in muscle tissue, which produces the characteristic “marbling” of meat, and to assessment of milk fat content. The methods of the invention are useful in selection of animals, particularly cattle, for ability to produce high or low levels of milk fat content. | 98,604 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. patent application Ser. No. 62/025,910, which was filed on Jul. 17, 2014, and is incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] This disclosure relates to implementations of a method to use eugenol to treat blisters.
BACKGROUND
[0003] U.S. Pat. No. 8,273,719 disclose that it is known that the eugenol is generally used as an analgesic agent for toothache and others, and further has a blood flow promotion effect or demelanizing effect when applied to a surface topical site. The '719 patent discloses an antiwrinkle agent comprising an eugenyl glycoside.
[0004] U.S. Pat. No. 6,313,329 discloses that clove bud oil has long been used as a herbal remedy. The '329 patent discloses that the oil is distilled from the dried-flower buds. The '329 patent discloses that the oil is used in many natural-based toothpastes. The '329 patent discloses that the oil is also a strong insect repellent and useful as a moth repellent. The '329 patent discloses that clove bud oil is a strong antiseptic, anti-spasmodic. The '329 patent discloses that clove bud is also anti viral, anti fungal and healing. The '329 patent discloses that the oil comes from the buds of cloves. The '329 patent discloses that the oil has been used traditionally to remedy skin infections and to reduce digestive upsets. The '329 patent discloses that the oil is also used to kill intestinal parasites and to aid in childbirth. The '329 patent discloses that a tea that is made from cloves is often used to relieve nausea. The '329 patent discloses that the bud oil also has been used for the symptoms above for diarrhea, hernias, bad breath and bronchitis. The '329 patent discloses that the oil can be used to reduce acne, athlete's foot, and pain from burns. The '329 patent discloses that the oil is a very effective insect repellent and will relieve the pain of most toothaches, ulcers and wounds. The '329 patent discloses that the vapors of the oil have beneficial effects on arthritis, rheumatism and most sprains.
DETAILED DESCRIPTION
[0005] A method to use eugenol to treat blisters is provided. In some implementations, the composition may be comprised of 85% or about 85% of eugenol by weight. In some implementations, the composition may be comprised of less than 85% or more than 85% eugenol by weight. In some implementations, the composition may be comprised of 85% or about 85% of eugenol by volume. In some implementations, the composition may be comprised of less than 85% or more than 85% eugenol by volume.
[0006] In some implementations, the composition may be comprised of 85% or about 85% of clove oil by weight. In some implementations, the composition may be comprised of less than 85% or more than 85% clove oil by weight. In some implementations, the composition may be comprised of 85% or about 85% of clove oil by volume. In some implementations, the composition may be comprised of less than 85% or more than 85% clove oil by volume.
[0007] In some implementations, the composition may be comprised of 15% or about 15% of sesame oil by weight. In some implementations, the composition may be comprised of less than 15% or more than 15% sesame oil by weight. In some implementations, the composition may be comprised of 15% or about 15% of sesame oil by volume. In some implementations, the composition may be comprised of less than 15% or more than 15% sesame oil by volume.
[0008] In some implementations, eugenol is a phenylpropene. In some implementations, eugenol is a member of the phenylpropanoids class of chemical compounds. In some implementations, eugenol may be extracted from essential oils. In some implementations, eugenol may be extracted from clove oil, nutmeg, cinnamon, basil, and/or bay leaf.
[0009] In some implementations, the composition containing eugenol, and in some implementation sesame oil, may be a paste. In some implementations, the composition containing eugenol, and in some implementation sesame oil, may be a liquid. In some implementations, the composition containing eugenol, and in some implementation sesame oil, may be a gel.
[0010] In some implementations, a composition comprising eugenol, and in some implementation sesame oil, may be applied topically to the epidermis of a patient. In some implementations, a composition comprising eugenol, and in some implementation sesame oil, may be applied to a blister which has formed on the epidermis of a patient. In this way, the eugenol, and in some implementation sesame oil, may cause the blister to heal faster than a blister that has not had eugenol applied thereto. In some implementations, the composition comprising eugenol, and in some implementation sesame oil, may be applied topically to the epidermis of a patient to help treat shingles, psoriasis, acne, eczema, irritations from bug bits, bee stings, poison oak, and other skin irritations, rashes, and blisters.
[0011] Table 1 shows an example implementation of the composition comprised of eugenol and sesame oil according to the present disclosure. The composition may be comprised of the following ingredients:
[0000]
TABLE 1
Components
Quantity
Clove Oil
4.92 ml
Sesame Oil
1.08 ml
[0012] The above composition was used on various skin condition including shingles, acne, eczema, irritations from bug bits, bee stings, poison oak, and other skin irritations, rashes, and blisters. Subjects found the composition eased pain and dried up blisters. The sesame oil helped moisturize the skin and dilute the eugenol.
[0013] Reference throughout this specification to “an embodiment” or “implementation” or words of similar import means that a particular described feature, structure, or characteristic is included in at least one embodiment of the present invention. Thus, the phrase “in some implementations” or a phrase of similar import in various places throughout this specification does not necessarily refer to the same embodiment.
[0014] Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings.
[0015] The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the above description, numerous specific details are provided for a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that embodiments of the invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations may not be shown or described in detail.
[0016] While operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. | Implementations of a method for treating an affected area of an epidermis having a blister or rash caused by shingles, psoriasis, acne, eczema, bug bits, bee stings, and poison oak comprising applying topically to the affected area of an epidermis a composition comprises eugenol and sesame oil. | 8,160 |
RELATED APPLICATIONS
This application claims priority under 35 USC 119(e) to U.S. Provisional Application No. 60/423,377, filed Nov. 4, 2002, U.S. Provisional Application No. 60/424,001, filed Nov. 6, 2002, U.S. Provisional Application No. 60/430,089, filed Dec. 2, 2002, U.S. Provisional Application No. 60/449,554, filed Feb. 24, 2003 and U.S. Provisional Application No. 60/450,285, filed Feb. 27, 2003, all of which are incorporated herein by reference in their entireties.
TECHNICAL FIELD OF THE INVENTION
The invention relates to methods and apparatuses for manipulating small amounts of solids. Specific embodiments of the invention are particularly suited for the automated transfer of small amounts of solids.
BACKGROUND OF THE INVENTION
A variety of methods and devices exist for obtaining and dispensing small amounts of liquids that have found use in a variety of applications. However, few methods and devices exist for manipulating small amounts (e.g., less than about 25, 10, 5, or 1 mg) of solids (e.g., powders). In the laboratory, such small amounts of solids are often dispensed by hand using a highly accurate scale. Unfortunately, such methods are not amenable to the rapid or automated manipulation of compounds, as they are tedious, time consuming, and prone to error.
Recently, methods and systems have been disclosed for the preparation and analysis of arrays of samples, each of which can contain very small amounts of one or more compounds. See e.g., International Publication WO01/51919, published on Jul. 19, 2001. In such applications, it is often desirable to rapidly and accurately measure and dispense small amounts of solids. In some circumstances, this can be done by dissolving a compound in a solvent to provide a solution of known concentration, dispensing controlled amounts of that solution using micropipettors, and then evaporating the solvent. In certain applications, however, it is necessary that a solid compound be manipulated in a manner that does not substantially affect its physical form. For example, if the crystallinity of a solid is important, it is desirable to measure and dispense the solid in a manner that does not affect its crystalline form (e.g., its crystal structure and habit). Similarly, if the amorphous nature (e.g., average particle size and distribution of particle sizes) of a solid is important, it is preferred that the methods and devices used to manipulate the solid do not substantially affect that quality. Physical characteristics such as these cannot be controlled using solution-based dispensing techniques.
A need therefore exists for methods and devices that can be used to rapidly and accurately dispense small amounts of solids. A need also exists for methods and devices that can be used to manipulate solids without substantially affecting their form.
SUMMARY OF THE INVENTION
This invention encompasses methods of manipulating (e.g., obtaining, transferring, dispensing, mixing and/or weighing) small amounts of solids (e.g., powders), and apparatuses that can be used in such methods. Particular embodiments of the invention are particularly useful in the high throughput preparation and screening of arrays of compounds and compositions. Specific embodiments of the invention do not substantially affect the form of the solid being manipulated.
One embodiment of the invention encompasses methods and apparatuses for dispensing solids by producing plugs with a controlled amount of a solid material of interest. Specific plugs are formed in a way that does not substantially affect the form of the solid.
Another embodiment of the invention encompasses methods and apparatuses for dispensing solids using slurries. Specific methods of this embodiment do not substantially affect the form of the solid.
Another embodiment of the invention encompasses methods and apparatuses for manipulating solids, wherein particles of the solid are adhered non-electrostatically to an adhesive surface. Specific methods of this embodiment do not substantially affect the form of the solid.
Another embodiment of the invention encompasses methods and apparatuses for transferring the solid content inside one container into another container. Specific methods of this embodiment do not substantially affect the form of the solid.
Another embodiment of the invention encompasses methods and apparatuses for mixing small amounts of solid in a container. Specific methods of this embodiment do not substantially affect the form of the solid.
Another embodiment of the invention encompasses methods and apparatuses for transferring and measuring the mass of small amounts of solid. Specific methods of this embodiment do not substantially affect the form of the solid.
BRIEF DESCRIPTION OF THE FIGURES
Specific embodiments of the invention can be understood with reference to the attached figures, described below:
FIG. 1 illustrates a method of forming a uniform powder bed that involves lifting a rotating pin from a packed powder bed.
FIG. 2 illustrates a top view of a grille that is placed on top of the uniform powder bed that is produced via the method shown in FIG. 1 .
FIG. 3 illustrates a method of forming a uniform powder bed that involves sliding a plate off of a packed powder bed.
FIG. 4 illustrates a top view of a grille that is placed on top of the uniform powder bed that is produced via the method shown in FIG. 3 .
FIG. 5 illustrates a method of creating and dispensing a plug of powder that involves inserting a tube completely through a powder bed, lifting, and then ejecting.
FIG. 6 illustrates a method of creating and dispensing a plug of powder that involves inserting a tube completely through a powder bed, compressing the plug, lifting, and then ejecting.
FIG. 7 illustrates a method of creating and dispensing a plug of powder that involves inserting a tube part way through a powder bed, lifting, and then ejecting.
FIG. 8 illustrates a method of creating and dispensing a plug of powder that involves inserting a tube part way through a powder bed with the ejector piston held stationary at a predetermined height relative to the tube, lifting, and then ejecting.
FIG. 9 illustrates a specific apparatus to punch and dispense plugs of solids which includes a punching assembly, x and y linear servos, a receiving plate, a source receptacle assembly, a wash station, a weigh station and a supporting base and frame.
FIG. 10 illustrates a method of extruding powder from a source chamber into a dose chamber to create a plug of powder.
FIG. 11 illustrates examples of trajectories for moving and filling the dose chamber above the powder surface.
FIG. 12 illustrates a method of ejecting a plug of powder from the dose chamber into a receiving plate.
FIG. 13 illustrates the front and side view of a specific apparatus to extrude plugs of powder which includes a dispensing assembly, x and y linear servos, a receiving plate, a weigh station and a supporting base and frame.
FIG. 14 illustrates a method of preparing solids for extrusion.
FIG. 15 illustrates the grid cutter utilized in the method shown in FIG. 14 .
FIG. 16 illustrates a method of extruding multiple plugs of powder and ejecting the plugs into a receiving plate.
FIG. 17 illustrates a method of installing a slide plate to vary the thickness of the plugs of powder produced.
FIG. 18 illustrates a method of extruding multiple plugs of powder of different thicknesses using more than one ejector pin.
FIG. 19 illustrates the front and side view of a specific apparatus to extrude multiple plugs of powder which includes a dispensing assembly, x and y linear servos, a receiving plate, a weigh station and a supporting base and frame.
FIG. 20 illustrates various arrangements of adhesive areas on a surface to manipulate solids.
FIG. 21 illustrates a method of applying solids to the adhesive areas on a surface.
FIG. 22 illustrates a method of mixing solids adhered to an adhesive area with a solvent, reagent or excipient suspended on a separate surface such that the resultant agglomeration can be easily dispensed into a container.
FIG. 23 illustrates a method of transferring solids from one container into another container by turning the original container upside-down.
FIG. 24 illustrates a method of increasing the throughput of the transfer process by incorporating a carousel with two or more stations.
FIG. 25 illustrates a method of enhancing the release of solids from a container by applying external vibration to the swing arm or the container.
FIG. 26 illustrates a method of preventing the premature release of solids from a container by incorporating a retractable seal on the container.
FIG. 27 illustrates a method of transferring solids from one container into another by utilizing a container with a retractable bottom plate.
FIG. 28 illustrates a method of transferring solids from one container into another by utilizing a container with a filter plate.
FIG. 29 illustrates a method of transferring solids from one container into another by utilizing a container with an internal piston.
FIG. 30 illustrates a method of placing a container holding solids into another container to achieve a two-dimensional array of containers.
FIG. 31 illustrates a method of increasing the throughput of pick-and-placing containers by incorporating a carousel with two or more stations.
FIG. 32 illustrates a method of mixing solids in a sealed container using turbulent gas jets.
FIG. 33 illustrates a method of mixing solids in a sealed container using rotating wire.
FIG. 34 illustrates a method of mixing solids in a sealed container using rotating blades.
FIG. 35 illustrates a method of mixing solids in a sealed container by compressing the walls of the container.
FIG. 36 illustrates a method of mixing solids by dispensing alternate layers of different solids into a container.
FIG. 37 illustrates a method of weighing individual samples as part of a two-dimensional array of samples.
FIG. 38 illustrates a method of dispensing and weighing a plug of powder using a coring device and an integrated mass sensor.
FIG. 39 illustrates a typical frequency spectrum of the mechanical response of a coring tube that is used to identify its resonant frequency.
FIG. 40 illustrates a typical shift in the frequency response of the coring tube when a mass is ejected from the tube.
FIG. 41 illustrates a correlation between the measured frequency ratio and the amount of mass dispensed from a coring tube.
FIG. 42 illustrates a method of dispensing and weighing a plug of powder using an electrode assembly and an integrated mass sensor.
FIG. 43 illustrates a typical frequency spectrum of the mechanical response of an electrode assembly that is used to identify its resonant frequency.
FIG. 44 illustrates a correlation between the measured frequency ratio and the amount of mass dispensed from an electrode assembly.
DEFINITIONS
As used herein and unless otherwise indicated, the term “controlled amount” refers to an amount of a compound that is weighed, aliquotted, or otherwise dispensed in a manner that attempts to control the amount of the compound. Preferably, a controlled amount of a compound differs from a target amount by less than about 30, 20, 10, 5, or 1 percent of the target amount. For example, if a target amount of 100 micrograms is specified for a particular application, a controlled amount for that application would be a mass that is between about 70 micrograms to about 130 micrograms, or about 80 micrograms to about 120 micrograms, or about 90 micrograms to about 110 micrograms, or about 95 micrograms to about 105 micrograms, or about 99 micrograms to about 101 micrograms.
As used herein and unless otherwise indicated, the term “plug” is used to refer to an agglomeration of a solid or solids. Preferred plugs are not compressed, or are compressed under conditions that do not substantially affect the form of the solid or solids.
As used herein and unless otherwise indicated, the terms “form” and “physical form,” when used to refer to a solid, mean the physical characteristics of the solid. Such characteristics include, but are not limited to, crystallinity or lack of crystallinity, appearance, texture, and color. For example, a solid may be in the form of a powder comprised of particles having a particular average size or size distribution, shape, or color. A solid may be amorphous, crystalline, or may comprise both amorphous and crystalline components. Further, the form of a crystalline solid includes, but is not limited to, its crystal structure and habit.
As used herein and unless otherwise indicated, the phrase “without substantially affecting the form,” when used to refer to the effect of a method, process, or device on a compound, means that the method, process, or device does not materially change the physical form of a majority of the compound. For example, the phrase encompasses methods, processes, and devices that do not affect the form of about 70, 80, 90, 95, or 99 weight percent of a compound. The phrase also encompasses methods, processes, and devices that affect the average particle size or particle size distribution of a powder of a crystalline compound but that do not affect the crystal structure or habit of the crystalline compound.
As used herein and unless otherwise indicated, the term “slurry” refers to a mixture of solid and liquid wherein a substantial portion of the solid (e.g., greater than about 70, 80, 90, 95, or 99 weight percent) is not dissolved in the liquid.
As used herein and unless otherwise indicated, the term “tube” refers to a hollow instrument (e.g., a hollow needle) with an outer wall and a definable cross-sectional area (e.g, a cylinder, a square, or a hexagon) that can be inserted into a bed of powder.
As used herein and unless otherwise indicated, the term “controlled distance” refers to a distance that does not differ substantially from a predetermined distance. Preferably, a controlled distance differs from a predetermined distance by less than about 10, 5, or 1 percent of the predetermined distance. For example, if one were to insert a tube 2 mm into a bed of powder, a controlled distance of insertion would preferably be from about 1.9 mm to about 2.1 mm, from 1.95 mm to about 2.05 mm, or from about 1.99 mm to about 2.01 mm.
DETAILED DESCRIPTION OF THE INVENTION
This invention encompasses methods and apparatuses that can be used to accurately manipulate small amounts (e.g., less than about 25 mg, 10 mg, 5 mg, 1 mg, 750 micrograms, 500 micrograms, 350 micrograms, 250 micrograms, 175 micrograms, 100 micrograms, 75 micrograms, 50 micrograms, 25 micrograms, 15 micrograms, 10 micrograms, 7.5 micrograms, 5 micrograms, 3 micrograms, 1 micrograms, 900 ng, 750 ng, 500 ng, 350 ng, 250 ng, or 100 ng) of solids. Examples of solids include, but are not limited to pharmaceuticals, excipients, dietary substances, alternative medicines, nutraceuticals, agrochemicals, sensory compounds, the active components of industrial formulations, and the active components of consumer formulations. Solids can be amorphous, crystalline, or mixtures thereof.
A first embodiment of the invention encompasses a method and apparatus for manipulating a solid in the form of a powder by compressing a controlled amount of powder into a plug. Preferably, the amount of compression is sufficient to provide a plug that can be manipulated to a desired degree but which is insufficient to substantially affect the physical form of the solid (e.g., by inducing a loss of crystallinity or polymorphism).
A specific method of this embodiment comprises the steps of: (a) forming a bed of powder of predetermined mass and uniform height; (b) inserting a tube a controlled distance into the bed or completely through the bed to obtain a plug of powder, wherein the tube has an interior that accommodates a means of ejecting materials from within the tube; (c) optionally, compressing the powder within the tube; (d) removing the tube with the plug of powder from the bed; (e) moving the tube over a target location; and (f) ejecting the plug of powder.
Another method of the first embodiment comprises the steps of: (a) forming a bed of powder of predetermined mass and uniform height; (b) inserting a grid with multiple hollow partitions with side walls of sufficient width, length (or diameter) and height to create a desired volume of space (e.g., a grid made of thin blades) a controlled distance into the bed or completely through the bed to obtain multiple plugs of powder; (c) optionally, compressing the powder within each partition of the grid; (d) moving the grid with the powder plugs over a target location; and (e) selectively ejecting a plug of powder into the target.
Another method of the first embodiment comprises the steps of: (a) dispensing a predetermined mass of powder into a source chamber; (b) sealing the source chamber with a plate which holds a smaller chamber of variable depth; (c) applying pressure to the powder in the source chamber; (d) sliding the plate against the powder surface in a patterned motion that exposes the smaller chamber to the powder and fills it with powder; (e) releasing the pressure on the source powder; (f) moving the slide plate with its plug of powder away from the source chamber to a target location; and (g) ejecting the plug of powder from the cavity
Another method of the first embodiment comprises the steps of: (a) dispensing a predetermined mass of powder into a source chamber; (b) sealing the chamber with a plate which contains a grid with multiple hollow partitions, with side walls of sufficient width, length (or diameter) and height to create a desired volume of space (e.g., a grid made of thin blades), centered above the source chamber and covered by another solid plate; (c) applying pressure to the powder in the source chamber such that the powder flows into the partitions of the grid; (d) releasing the pressure on the source powder; (e) moving the plate with its plugs of powder away from the source chamber to a target location; and (f) selectively ejecting a plug of powder from the cavity
Another embodiment of the invention encompasses a method for manipulating a solid by producing a slurry, which comprises the steps of: (a) blending a controlled amount of the solid with a liquid to provide a slurry; (b) dispensing a controlled amount of the slurry; and (c) removing the liquid to provide an amount of the solid, wherein the amount of the solid is less than about 1 mg. In specific embodiments, the amount of the solid is less than about 25 mg, 10 mg, 5 mg, 1 mg, 750 micrograms, 500 micrograms, 350 micrograms, 250 micrograms, 175 micrograms, 100 micrograms, 75 micrograms, 50 micrograms, 25 micrograms, 15 micrograms, 10 micrograms, 7.5 micrograms, 5 micrograms, 3 micrograms, 1 micrograms, 900 ng, 750 ng, 500 ng, 350 ng, 250 ng, or 100 ng. The liquid vehicle can be selected such that it does not dissolve a substantial portion (e.g., which can be specified as less than 10 percent, 5 percent, 2.5 percent, 1 percent, 0.5 percent, 0.25 percent, 0.1 percent, 0.01 percent or 0.001 percent) of the solid to avoid affecting the solid form.
Another embodiment of the invention encompasses a method and apparatus for manipulating a solid by using adhesive surfaces, which comprises contacting particles of the solid with a surface comprising a plurality of discrete adhesive areas separated by non-adhesive areas. In specific embodiments, the size of the adhesive areas are less than about 1 cm 2 , 50 mm 2 , 10 mm 2 , 1 mm 2 , or 0.5 mm 2 . As used herein and unless otherwise indicated, the terms “adhesive surface” and “adhesive area” encompass any surface or area on a surface to which a particular solid can adhere by, for example, chemisorption, chemical bonding interactions (e.g., hydrogen bonding and van der Waals interactions), or adsorption (e.g., as a result of vapor deposition). Adhesive surfaces may be a liquid, semi-solid, or solid. Specific adhesive surfaces may utilize conventional adhesives (e.g., glues or gummy or sticky materials). Suitable adhesives are well known to those of ordinary skill in the art. Examples of specific adhesive materials include, but are not limited to, pressure-sensitive adhesives (PSA's), silicones, and hydrogels. Certain pharmaceutically acceptable excipients may also be used as adhesives. In preferred methods of this embodiment, the form of the solid(s) being manipulated does not substantially change during manipulation.
Another embodiment of the invention encompasses a method and apparatus for transferring the solids content inside one container (e.g., a tube or vial) into another container (e.g., a multi-well plate). A specific method of this embodiment comprises the steps of: (a) accelerating a container that holds a controlled amount of solids through an arc trajectory and (b) halting the motion of the container suddenly when it is located above the receiving container in a downward-facing position, thereby causing the solids to be expelled from the initial container and into the receiving container. Another embodiment comprises the steps of: (a) utilizing a container that holds a controlled amount of solids and that has bottom plate which is removable and (b) removing the bottom plate in order to release the solids into a receiving container positioned below the initial container. Another embodiment comprises the steps of: (a) utilizing a container that holds a controlled amount of solids and that has a gas-permeable bottom plate, (b) inverting the container while applying suction through the bottom plate to retain the solids, and (c) reversing the direction of the gas through the bottom plate to expel the solids into a receiving container positioned below the initial container. Another embodiment comprises the steps of: (a) utilizing a container that holds a controlled amount of solids and that has an internal piston, (b) inverting the container, and (c) actuating the piston through the container to eject the solids into a receiving container positioned below the initial container. Another embodiment comprises the steps of: (a) utilizing a container that holds a controlled amount of solids and (b) placing the container inside a well in a receiving plate that has a two-dimensional array of wells.
Another embodiment of the invention encompasses a method and apparatus for mixing small amounts of solid inside a container (e.g., a tube, vial or a well in a multi-well plate). Mixing achieves intimate particulate contact between the solids such that resulting chemical or physical interactions can be analyzed. A specific method of this embodiment comprises applying gas jets through gas-permeable container walls to mix the contents inside the container. Another embodiment comprises vibrating or rotating the container in various directions, orientations, and speeds to mix its contents. Another embodiment comprises placing a mixing tool such as a bar, ball, blade, or wire inside the container and manipulating the mixing tool by means of an oscillating magnet or rotating drive shaft connected to the tool. Another embodiment comprises compressing the walls of the container to mix the contents of the container. Another embodiment comprises dispensing alternate layers of different solids into a container to achieve interparticle contact between different solids.
Another embodiment of the invention encompasses a method and apparatus to manipulate and weigh small amounts of solids. Measuring the mass of a controlled amount of solids is a necessary step for various chemical assays including crystallization, dissolution, and stability analysis. A specific method of this embodiment comprises an apparatus that rapidly dispenses and weighs controlled amounts of solids in a two-dimensional array format with a conventional microbalance. Another method of this embodiment manipulates and measures the mass of a controlled amount of solids without using a conventional microbalance. The method comprises the steps of: (a) measuring a first mechanical resonant frequency of a transfer device, (b) adhering particles to the transfer device, (c) measuring a second mechanical resonant frequency of the transfer device, (d) determining the mass of the attached particles by comparing the first and second resonant frequencies, and (e) removing the particles from the transfer device. Another method of this embodiment comprises the steps of: (a) adhering particles to a transfer device, (b) measuring a first mechanical resonant frequency of the transfer device, (c) removing the particles from the transfer device, (d) measuring a second mechanical resonant frequency of the transfer device, and (e) determining the mass of the removed particles by comparing the first and second resonant frequencies. In addition, the ability to weigh the transferred solids, can be used to provide real-time feedback to the transfer device. Thus, the parameters that control the transfer device can be adjusted to transfer a desired amount of solids.
Specific methods and apparatuses of the invention do not substantially affect the form of the solid being manipulated. Futhermore, specific methods and apparatuses can be readily adapted for use in the high-throughput preparation of arrays of samples. For example, embodiments of the invention can be incorporated into the methods and systems referred to as FAST® and CRYSTALMAX™. The methods and systems referred to as FAST® are described in U.S. patent application Ser. No. 09/628,667, filed Jul. 28, 2000, the entirety of which is incorporated herein by reference. The methods and systems referred to as CRYSTALMAX™ are described in U.S. patent application Ser. No. 09/756,092, filed Jan. 8, 2001, and International Publication WO01/51919, published on Jul. 19, 2001, both of which are incorporated herein by reference in their entireties.
EXAMPLES
Certain embodiments of the invention, as well as certain novel and unexpected advantages of the invention, are illustrated by the following non-limiting examples.
Example 1
Manipulating Solids by Coring a Plug of Powder From a Powder Bed
Solids, such as those in the form of a powder, can be manipulated using systems and methods described for the present invention. For example, solids in the form of fine powders comprising particles having an average size of less than about 200, 150, 100, 50, 10, 5, 1, 0.1, or 0.01 micrometers can be compressed and dispensed in controlled amounts as plugs without the use of solvents, high pressures, or temperatures that may affect the form of the solids. As will be apparent to those of skill in the art, the particular amount of pressure that can be used to provide such plugs will depend on the particular compound and its form. However, that amount is readily determined using little, if any, routine experimentation. Examples of such pressures include, but are not limited to, less than about 30, 20, 10, 5, or 2 psi. The use of such low pressures typically avoids physical form changes such as loss of crystallinity or conversion to a polymorphic form, which can occur under compression conditions used to make conventional tablets.
In a specific embodiment of this method, a known mass of powder (e.g., less than about 1 gram, 500 mg, 100 mg, 25 mg, 1 mg, 500 micrograms, 250 micrograms, or 100 micrograms) is dispensed into a cylindrical cavity of predetermined diameter and depth. The powder is packed evenly across the base of the cavity using a rotating cylinder that applies a predetermined average pressure to the bed that is less than 30, 20, 10, 5, or 1 psi. Next, a hollow tube (e.g. a cylindrical needle with an inner diameter less than 0.01 mm, 0.1 mm, 0.5 mm, 1 mm, 2 mm, 3 mm, 5 mm or 10 mm) with a predetermined cross sectional area is used to core a plug of the powder. The tube, which can be of any shape so long as the volume of the resulting plug can be determined, is inserted a controlled distance into the powder bed to obtain a plug of predictable size. Preferably, the tube is inserted all the way through the powder bed. Reproducible packing inside the tube can result from specific ratios of height to diameter of the coring cavity, for example, a 1:1 height to diameter ratio is effective. The plug is then optionally compressed, as discussed below, and the tube, which still contains the plug, is removed from the powder bed and positioned over a receptacle (e.g., a tube, vial or a well in a multi-well plate). To prevent the bed from breaking apart during punching, a grill (i.e. a thin plate with an array of holes) that the tube can pass through may be placed over the bed prior to punching. The plug is then ejected from the tube using, for example, compressed gas, a liquid in which the solid is soluble, sparingly soluble, or insoluble, vibration of the tube, or mechanical means, such as a piston located within the tube.
FIGS. 1A through 1D illustrate a method and apparatus for uniform powder bed preparation. A predetermined weight of powder 200 is placed in a cavity (e.g., hollow cylinder) 204 in source receptacle assembly 205 , as shown in FIG. 1A . Source receptacle assembly 205 comprises top block 208 with cavity 204 in its interior, strike plate 207 , and base 206 . Then, as shown in FIG. 1B , rod 210 (preferably cylindrical) is inserted through cavity 204 and pressed into powder 200 with a predetermined force, which results in a powder bed pressure typically in the range of about 0.5 psi to about 30 psi. Cylindrical rod 210 is then rotated through an angle of typically 90 degrees in either direction with pressure applied. Cylindrical rod 210 is then rotated and pulled out (normally rotated and pulled out simultaneously) of cavity 204 . The result is powder bed 220 shown in FIG. 1C with a uniform thickness. Next, grille tube 227 of grille assembly 225 is inserted into cavity 204 so that grille plate 228 contacts the top of powder bed 220 , and so alignment pin 224 passes into alignment hole 202 , as shown in FIG. 1D . FIG. 1D and FIG. 2 shows a cross sectional side view and a top view, respectively, of grille assembly 225 , which comprises tube support 226 , thin walled tube 227 , grille plate 228 and alignment pin 224 . As shown in FIG. 2 , grille plate 228 includes a closely packed array of equally sized holes 229 that cover the powder bed.
Top block 208 and cylinder (or pin) 210 are preferably made from a corrosion resistant material that is harder than the powders that are processed. For many powders, a suitable material is unhardened stainless steel type 316. For very hard powders, a suitable material is case hardened stainless steel type 440C that is coated with a hard ceramic thin film, such as sapphire coating type MH provided by Surface Conversion Sciences Corporation in State College, Pa., USA. A suitable material for bottom plate 206 is unhardened stainless steel type 316, or a stainless steel grade with similar corrosion resistance.
The material for strike plate 207 should be softer than the coring tool tip if the tip contacts it (e.g., when tip is inserted completely through the packed bed), so as not to blunt the tool. The strike plate should be chosen so that powder bed 220 will preferably cling to it when pin 210 is removed, while also allowing a punched plug to be cleanly lifted off. For a given powder, bed packing tests should be conducted with different strike plate materials to find one that meets these latter two criteria. Suitable strike plate materials for pharmaceutical powders include, but are not limited to: aluminum, copper, polycarbonate, acrylic, polyester, polystyrene, and PVC. To facilitate a clean release, a thin anti-stick material such as Teflon, UHMW, or wax paper can be adhered to pin face 211 . For a given powder, bed packing tests should be performed to determine if these materials cling to the powder enough to mix the powder when pin 210 is rotated and thus create an even pack, while at the same time cleanly releasing when pin 210 is pulled out.
Suitable diameters for cavity 204 range from 2 mm to 50 mm depending on how much powder is available and how well it packs. Other sizes can also be used. Pinwall 212 , pinface 211 , and cavity wall 209 should preferably be ground and polished to a surface finish of 0.5 micrometers or less to minimize powder adhesion and thus waste. Pin 210 and cavity 204 preferably should be honed or ground to a roundness of under 7.5 micrometers and should be sized so the clearance between them is under 20 micrometers, to minimize intrusion of powder particles. Pin face 211 should deviate from a perfectly flat and perpendicular face by no more than 10 micrometers to produce a flat powder bed, and base 206 should be ground flat to within 10 micrometers. Strike plate 207 should be flat to within 10 micrometers in the region that contacts powder 200 to insure a flat powder bed.
A suitable material for grille plate 228 is 0.2 mm thick full hard Invar, and a suitable method for cutting the outer contour and holes such as hole 229 , which typically range in diameter from 0.5 mm to 4 mm, is precision laser cutting which provides +/−5 micrometer accuracy. Custom laser cut Invar grille plates can be fabricated and supplied to these specifications by Photo Etch Technology Company, 71 Willie St, Lowell, Mass. 01854, USA. Suitable materials for thin walled tube 227 and tube support 226 are stainless steel type 316. Tube 227 preferably has a wall thickness of less than 0.4 mm to maximize the punched area.
FIGS. 3A through 3D illustrate another method and apparatus for uniform powder bed preparation. A predetermined weight of powder 240 is placed in cavity, typically hollow cylinder 249 , of source receptacle assembly 250 , as shown in FIG. 3A . Source receptacle assembly 250 comprises block 251 with interior cavity 249 , cylinder 253 , strike plate 254 , and set screw 252 . As shown in FIG. 3B , slide plate 260 is affixed on top of block 251 with screw 261 . Then a predetermined force which results in a powder bed pressure typically in the range of about 0.5 psi to about 30 psi is applied to cylinder 253 . Cylinder 253 is then rotated through an angle of typically 90 degrees in either direction with the pressure applied. Then, as shown in FIG. 3C , set screw 252 is locked against cylinder 253 . Then, with screw 261 removed, slide plate 260 is lifted or slid off of powder bed surface 245 while remaining in sliding contact with block surface 255 . Next, as shown in FIG. 3D , grille assembly 270 is placed on block surface 255 so that alignment pins 274 and 275 fit into holes 247 and 248 to provide alignment over powder bed 245 . FIG. 3D and FIG. 4 show a cross sectional side view and a top view, respectively, of grille assembly 270 , which includes grille frame 272 , grille plate 271 , and alignment pins 274 and 275 . As shown in FIG. 4 , grille plate 271 comprises a closely packed array of equally sized holes such as hole 273 that cover the powder bed area.
Block 251 , cylinder 253 , and slide plate 260 are preferably made from a corrosion resistant material that is harder than the powders that are processed. For many powders, a suitable material is unhardened stainless steel type 316. For very hard powders, a suitable material is case hardened stainless steel type 440C that is coated with a hard ceramic thin film, such as sapphire coating type MH provided by Surface Conversion Sciences Corporation in State College, Pa., USA.
The material for strike plate 254 should be softer than the coring tool tip that will contact it, so as not to blunt the tool, and it should be chosen so that powder bed 245 will preferably cling to strike plate 254 when slide plate 260 is removed, while also allowing a punched plug to be cleanly lifted off. For a given powder, bed packing and punch tests must be conducted with different strike plate materials to find one that meets these latter two criteria. The embodiment shown in FIGS. 3A to 3D has the advantage over the embodiment shown in FIGS. 1A to 1D that the sliding action releases a cleaner powder bed surface with a greater variety of powders, including very sticky powders with a low pack density, than the pin lifting method does. Suitable materials for strike plate 254 for use with pharmaceutical powders include, but are not limited to, aluminum, copper, polycarbonate, acrylic, polyester, polystyrene, and PVC. Strike plate 254 is preferably adhered to cylinder 253 with a thin layer (less than 25 micrometers thick) of 5 minute or faster setting epoxy. To facilitate a clean release from powder bed 245 , a thin anti-stick material such as Teflon, UHMW, or wax paper can be adhered to slide plate surface 262 . Alternately, an assortment of slide plates can be provided with a variety of coatings on surface 262 . For a given powder, bed packing tests should be performed to determine if strike plate 254 and slide plate surface 262 cling to powder bed 245 enough so that when cylinder 253 is rotated the powder bed 245 is sheared and mixed thoroughly and thus is packed uniformly, while at the same time allowing for a clean release when slide plate 260 is slid off.
Suitable diameters for cavity 249 range from 2 mm to 50 mm depending on how much powder is available and how well it packs. Other diameters can also be used. Cavity wall 256 , block face 255 , cylinder wall 257 , slide plate surface 262 and block face 255 preferably should be ground and polished to a surface finish of 0.5 micrometers or less to minimize powder adhesion and thus waste. Cylinder 253 and cavity 249 should be ground to a roundness of under 7.5 micrometers and should be sized so the clearance between them is under 20 micrometers. Cylinder face 258 should deviate from a perfectly flat and perpendicular face by no more than 10 micrometers, and slide plate surface 262 and block face 255 should be ground flat to within 5 micrometers. Strike plate 254 should be flat to within 10 micrometers.
A suitable material for grille plate 271 is 0.2 mm thick full hard Invar, and a suitable method for cutting the outer contour and the holes such as hole 273 , which range in diameter from 0.5 mm to 4 mm, is precision laser cutting which provides +/−5 micrometer accuracy. Custom laser cut Invar grille plates can be fabricated to these specifications by Photo Etch Technology Company, 71 Willie St, Lowell, Mass. 01854, USA. A suitable material for grille frame 272 is stainless steel type 316.
FIG. 5 illustrates a specific method of fabricating a plug from a uniform powder bed. Coring tool 305 , which comprises a tube 306 and means of ejecting the plug of powder, e.g. a piston 307 , is positioned above hole 301 in grille 302 . Next, as shown in view 310 , tube 306 is pushed partially through the powder bed or completely through powder bed 300 until it contacts strike plate 303 on base 304 . Next, coring tool 305 is lifted and moved to a target location, as shown in view 315 , and a plug 320 is ejected out of tube 306 via means of ejecting the plug of powder, e.g. a piston 307 , liquid, compressed gas, vibration, etc. This process can be performed without using grille 302 ; however, for some powders the bed can break apart and portions can stick to the sides of the coring tube, causing large plug mass variation.
With the mass of the powder and the area of the cavity base predetermined, it is possible to calculate the average mass of powder per unit area, W. If, as in this example, the tube is circular and the tube is inserted all the way through the powder bed, then the mass of the plug is given by (1):
Powder plug mass=π( d/ 2) 2 W (1)
where d is the inner diameter of the tube and W is the mass per unit area of the powder bed. Similar relationships for square, hexagonal, and other tube shapes are well known to those skilled in the art. Thus, controlling the shape or interior volume of the tube controls the mass of the plug.
Plugs of powder may be lifted from the powder bed by simply removing the tube from the bed if the inner diameter of the tube is sufficiently small. For some solids and tube inner diameters, the plug may need to be compacted in order to adhere to the tube interior sufficiently to be lifted. FIG. 6 illustrates a specific method of fabricating and lifting a compacted plug from a uniform powder bed. Coring tool 335 , which comprises a tube 336 and means of ejecting the plug of powder, e.g., a piston 337 , is positioned above hole 331 in grille 332 . As shown in the next view of coring tool 340 , tube 336 is pushed through powder bed 330 until it contacts strike plate 333 on base 334 . Next, as shown in view 345 , piston 337 is pushed into powder bed 330 with a force sufficient to create a pressure in the range of about 5 to about 5000 psi. Next, coring tool 335 is lifted and moved to a target location, and, as shown in view 350 , a compacted plug 355 is ejected out of tube 336 via means of ejecting the plug of powder, e.g., a piston or pin 337 . This process can be performed without using grille 332 , however for some powders the bed can break apart and portions can stick to the sides of the coring tube, causing large plug mass variation.
Some powders will have properties that allow a plug with a controlled amount of mass to be produced from a thick bed that is punched multiple times in one place. This is desirable because it increases the number of punches that can be produced from a single packed bed. FIG. 7 illustrates a specific method of fabricating a plug from a uniform powder bed that is taller than the plugs produced. Coring tool 365 , which comprises a tube 366 and means of ejecting the plug of powder, e.g., a piston or pin 367 , is positioned above hole 361 in grille 362 . As shown in the next view of coring tool 370 , tube 366 is pushed into powder bed 360 either with a predetermined force, or a predetermined distance. Next, coring tool 365 is lifted and moved to a target location, as shown in view 375 , and a plug 376 is ejected out of tube 366 via means of ejecting the plug of powder, e.g., a piston or pin 367 . This process can be performed without using grille 362 ; however, for some powders the bed can break apart and portions can stick to the sides of the coring tool, causing large plug mass variation.
FIG. 8 illustrates another specific method of fabricating a plug from a uniform powder bed that is taller than the plugs produced. Coring tool 385 , which comprises a tube 386 and means of ejecting the plug of powder, e.g. a piston or pin 387 , is positioned above hole 381 in grille 382 . Pin 387 is held stationary to tube 386 so that the distance between piston face 388 and tube edge 389 remains at a fixed and specified value during punching. As shown in the next view of coring tool 390 , tube 386 is pushed into powder bed 380 either with a predetermined force, or a predetermined distance. Next, coring tool 385 is lifted and moved to a target location, and, as shown in view 395 , a plug 396 is ejected out of tube 386 via means of ejecting the plug of powder, e.g. a piston 387 . This process can be performed without using grille 382 ; however, for some powders the bed can break apart and portions can stick to the sides of the coring tool, causing large plug mass variation.
Commercially available coring tools that are intended for tissue sampling purposes can be used as punching tools for the present invention. A supplier of suitable coring tools for the present invention is Fine Science Tools Inc., 202-277 Mountain Highway, North Vancouver, BC V7J 3P2, Canada, which supplies punching tools with inner tube diameters of 0.35 mm, 0.5 mm, 0.8 mm, 1 mm, 2 mm, 3 mm, and 5 mm. These coring tools include a hardened stainless steel tube and an ejector pin which fits with less than 10 micrometers of clearance. The outside wall of the tube and ejector pin is chrome plated to reduce surface energy so cored materials are less prone to stick. For creating plugs from very hard powders, a custom tungsten carbide tube and pin assembly is appropriate. A tungsten carbide tube and close fitting pin can be manufactured with sufficient precision by Bird Precision, One Spruce Street, Waltham Mass., 02454-0569, USA.
FIG. 9 depicts a specific apparatus for manipulating a solid according to the previously described methods. Punching assembly 420 , comprising tube actuator 425 , pin actuator 423 , coring tool 415 , and mounting plate 427 , is mounted to y linear actuator 460 and y guide rail 462 , which are mounted to x linear actuator 463 . Tube actuator 425 and pin actuator 423 together allow a plug to be punched, compressed if desired, and ejected. X linear actuator 463 and y linear actuator 460 has sufficient range to move coring tool 415 over four stations: receiving plate 410 , source receptacle assembly 405 , wash station 430 , and weigh station 440 , each with the following functions. Receiving plate 410 is where production plugs are dispensed; source receptacle assembly 405 is where plugs are punched; wash station 430 is where the tip of coring tool or tube 415 can be washed and dried; and weigh station 440 is where plugs can be weighed to characterize and monitor the dispense process. These components are supported by a machine base 470 , a receiving plate pedestal 472 , and actuator supports 471 and 473 .
A suitable x linear actuator 463 is model ERB50-B02LA90-GSS600-A with a 600 mm stroke, a suitable y linear actuator 460 and guide rail 462 are models ERB32-B08LA90-FSS300-A and ERB32-IDLS-FSS300 model with 300 mm strokes, made by Parker Hannifin Corporation based in 6035 Parkland Boulevard Cleveland, Ohio 44124-4141, USA. A suitable product for x servo motor 464 and y servo motor 461 is motor model number NTE-207-CONS-000 by EMERSON, to be used in conjunction with servo drive model Ei-DN-20200-000, also manufactured by EMERSON (8000 West Florissant Avenue, St. Louis, Mo. 63136-8506, USA). Movement commands can be sent to the servo drives from a personal computer programmed with compatible driver software. Products that can be used for tube actuator 425 and pin actuator 423 are pneumatic actuator models MXS8-75A-F9PVL and MXS8-10A-F9PVL respectively, supplied by SMC Corporation of America, 3011 North Franklin Road, Indianapolis, Ind. 46226, USA.
Wash station 430 comprises receptacle 433 with solvent reservoir 431 and drying hole 432 . Solvent reservoir 431 is filled with a solvent capable of dissolving powder 400 , and the bottom of drying hole 432 is connected to port 434 which is held under vacuum. Suitable solvents for typical powders include, but are not limited to, ethanol, methanol, acetone, ethyl acetate, dimethylsulfoxide, or methylene chloride. An appropriate material for wash receptacle 433 is TEFLON (DuPont) or UHMW polymer (Crown Plastics), which are inert to most useful solvents. To wash and dry, coring tool 415 is first inserted into solvent reservoir 431 for a fixed period of time, and then into drying hole 432 for a fixed period of time. To agitate fluid at the tip and thus speed up washing and drying, pin actuator 423 can be extended and retracted while being washed or dried.
Weigh station 440 comprises microbalance 445 with weighing platform 444 , draft shield 441 , and weigh cup 442 to contain sample plugs 443 . To weigh a plug, coring tool 415 is moved over hole 446 and extended into weigh cup 442 , and a plug is ejected into the weigh cup. To allow the microbalance to settle to sufficient accuracy it may be necessary for all actuators to stop moving. The weigh station can be used to weigh a population of plugs to characterize a powder bed packed with predetermined conditions. To characterize a powder bed, typically 40 pellets are randomly sampled from the bed to obtain an average mass and a standard deviation. If the values are acceptable, subsequent beds are packed under the same conditions and production pellets are produced. A suitable microbalance for weighing plugs in the range from 1 microgram to 2 grams with an accuracy of +/−0.25 micrograms is microbalance model UMX2, manufactured by Mettler Toledo, GmbH, with corporate headquarters in Im Langacher, 8606 Greifensee, Switzerland.
To punch a plug, tube actuator 425 is retracted, coring tool 415 is moved over a grille hole in source receptacle assembly 405 , tube actuator 425 is extended to push coring tool 415 through a grille hole into powder bed 400 , and then actuator 425 is retracted. To eject a plug, coring tool 415 is moved to a target location, tube actuator 425 is extended, pin actuator 423 is extended to eject a plug, then actuator 423 is retracted and actuator 425 is retracted.
To reduce static electricity buildup ion blower 480 is mounted above coring tool 415 and blows ionized air onto the components below it. A suitable ion blower is model 4165 made by NRD LLC, 2937 Alt Blvd, PO Box 310, Grand Island, N.Y. 14072, USA.
Example 2
Manipulating Solids by Extruding a Plug of Powder
This example illustrates an alternative method and apparatus to produce a plug of powder. The average particle size of the powder should be less than about 200, 100, 50, 10, 5, 1, 0.1, or 0.01 micrometers. This embodiment has two significant advantages over the method described in Example 1. It requires less time and labor since a uniform powder bed does not have to be prepared, and secondly, it requires less powder to create the same number of plugs. In other words, this embodiment may prove to be more efficient and less wasteful than coring a plug of powder.
In a specific embodiment of this method and apparatus, plugs of powder are fabricated via the following process. First, as shown in FIG. 10A , a known mass of powder 501 (e.g., less than about 1 gram, 500 mg, 100 mg, 25 mg, 1 mg, 500 micrograms, 250 micrograms, or 100 micrograms) is dispensed into a cylindrical source chamber 502 with source piston 503 located in a downward position. Source block 504 is then clamped to slide plate 506 by keeper plate 509 , as shown in FIG. 10B .
Next, as shown in FIG. 10C , pneumatic cylinder 505 , or other means of moving the piston head closer to the slide plate 506 , presses source piston 503 with typically about 5 to about 50 psi of pressure and as such, powder 510 against slide plate 506 . Slide plate 506 is then moved so dose chamber 513 traverses over the powder surface 515 , for example, in a criss-cross trajectory 516 as shown in FIG. 11A . Alternatively, other trajectories such as a spiral trajectory 517 as shown in FIG. 11B can be employed. As a guideline, the traversed distance should be greater than ten times the source chamber diameter, and the path should cover different portions of the source area 515 to achieve repeatable filling of dose chamber 513 . To improve the flow of powder 510 into the dose chamber 513 , the powder in the source chamber can be subjected to vibration or mixing.
The size and mass of the plug can be changed by adjusting the height of the dose chamber 513 with micrometer device 508 shown in FIG. 10B . Preferably, the ratio of the height to the diameter of dose chamber 513 is greater than 0.2 and less than 0.8, otherwise a different diameter dose chamber should be installed.
After powder 510 fills dose chamber 513 , pressurized air to pneumatic cylinder 505 is switched off. Then, as shown in FIG. 12A , slide plate 506 is moved relative to source block 504 so dose chamber 513 is positioned above target well 518 . Next, as shown in FIG. 12B , pressurized air propels ejector pin 522 downwards and ejects plug 520 into target well 518 . Ejector piston 521 hits hard stop 523 and decelerates suddenly, thereby flinging powder off of ejector pin 522 . Ejector pin 522 is then retracted, slide plate 506 is moved back, and pressurized air is supplied to pneumatic cylinder 505 to press powder 510 again. The fill and eject processes are repeated until source powder height 524 (see FIG. 12B ) reaches a minimum, typically 0.4 mm, at which point source chamber 502 is refilled.
Slide plate 506 , ejector pin 512 , source block 504 and source piston 503 should be made from a hard, wear resistant material that provides a long wear life without lubrication. Suitable materials are tungsten carbide, zirconia, silicon carbide and alumina. If the device only needs to dispense soft powders, a less costly alternative is to use hardened 440C stainless steel coated with a hard ceramic thin film, such as sapphire coating type MH provided by Surface Conversion Sciences Corporation (State College, Pa.). Passive components of the dispense device are preferably made from corrosion resistant stainless steel, such as type 316. To create plugs that have a mass of 50 micrograms, a suitable dose chamber diameter is 0.5 mm, and a suitable source chamber diameter is 2 mm to 5 mm. Slide plate 506 should be 150 mm long or greater to allow a portion of it to remain clamped to source block 504 while allowing dose chamber 513 to reach all wells of an industry standard microtiter plate, which has a footprint of 85 mm by 127 mm.
The mating faces of slide plate 506 and source block 504 should be ground to a flatness of 2 micrometers or better to minimize escape of powder particles. Dose chamber 513 and source chamber 502 should be honed to a roundness of under 2 micrometers, and ejector pin 512 and source piston 503 should be lapped to a roundness of under 2 micrometers, to allow a nominal radial clearance between the respective parts to be within 5 micrometers. Surfaces of ejector pin 512 and source piston 503 that contact powder should be ground flat to within 2 micrometers. Edges on dose chamber 513 , source chamber 502 , ejector pin 512 and source piston 503 should be left sharp to discourage particles from lodging between the sliding surfaces. To minimize wear, all faces in sliding contact should be polished to a surface finish of less than 0.2 micrometers.
FIGS. 13A and 13B show the front and side view, respectively, of a machine that incorporates dispense device 507 which can dispense into receiving plate 599 and into weigh cup 595 on microbalance 597 . Receiving plates can be an industry standard 96 well, 384 well, or 1536 well format, or a custom format. Receiving plate 599 is supported by pedestal 600 on machine base 601 . Slide plate 506 is moved relative to source block 504 by x linear actuator 592 and y linear actuator 589 . Suitable actuators are from the ROBO CYLINDER® series made by Intelligent Actuator, Inc., Japan. Pneumatic cylinder 603 connected to yoke 587 presses slide plate 506 against source block 504 . Yoke 587 has feet 584 made from ultrahigh molecular weight, polyethylene to minimize sliding friction. Pushrod 607 of servo 592 connects to shuttle frame 590 , which in turn is connected to servo body 589 , thereby allowing x and y movement of slide plate 506 relative to source block 504 .
Linear actuator 582 , supported by columns 585 and 580 , moves dispense device 507 in the x direction to allow dispensing into receiving plate 599 . As shown in FIG. 13B , dispense device 507 is supported by C-frame 591 which connects to carriages 605 and 606 . Slave linear guide 504 provides added support for C-frame 591 . Suitable linear actuators and supporting control hardware and software are made by Intelligent Actuator, Inc., Japan.
Weigh station 583 shown in FIG. 13A allows plugs to be weighed for characterization and statistical tracking. Weigh station 583 comprises microbalance 597 with weighing platform 596 , weigh cup 595 , and draft shield 594 . Microbalance 597 is supported by granite pedestal 598 . A suitable microbalance is the UMX2 model made by Mettler Toledo, Switzerland.
Example 3
Manipulating Solids by Extruding Multiple Plugs of Powder Simultaneously
This example is based on a similar method and apparatus as Example 2 except that it demonstrates a new method and apparatus for extruding multiple plugs of powder simultaneously. To begin, FIG. 14A shows that a known mass of powder 640 (e.g., less than about 1 gram, 500 mg, 100 mg, 25 mg, 1 mg, 500 micrograms, 250 micrograms, or 100 micrograms) is dispensed into a source chamber 642 . Then, in FIG. 14B , assembly 648 comprising pneumatic cylinder 651 and source piston 649 is attached above source chamber 642 . At the base of source chamber 642 is slide plate 645 which is in between source block 641 and keeper 656 . Powder 640 is initially compressed inside source chamber 642 against slide plate 645 by supplying air to pneumatic cylinder 651 at typically about 5 to about 50 psi.
FIG. 14B also shows that source piston 649 has square cross section 665 sized to fit precisely into square source chamber 642 (round or other cross section shapes can also be used). Slide plate 645 includes multiple hollow partitions such as grid cutter 646 (See FIG. 15 ), which comprises frame 708 holding a grid of thin blades such as 660 which form square partitions such as 675 . FIG. 15 shows an isometric view of grid cutter 646 . Ejector pin 670 has a square cross section 674 , sized to fit precisely into grid partitions such as 675 . However, source chamber 642 , source piston 649 , ejector pin 670 , and partitions 675 in grid cutter 646 can be designed to have any arbitrary shape including, circular, rhombic, or hexagonal shape such that the parts fit appropriately within each other.
After powder 655 is initially compressed to achieve a uniform packing density of powder in source chamber 642 , the pressurized air supply to port 664 (See FIG. 16A ) of pneumatic cylinder 662 is released and slide plate 645 is moved directly below source chamber 642 . Then, as shown in FIG. 16A , pressurized air is supplied to port 664 to press powder 668 through blades 660 of grid cutter 646 . Pressurized air to port 664 is then switched off, and slide plate 645 is moved so plug 673 is under ejector pin 670 , as shown in FIG. 16B . Dispense device 659 is also moved so plug 673 is over target well 662 . Next, as shown in FIG. 16C , pressurized air is supplied to port 676 and it propels ejector pin 670 down to eject powder plug 673 into target well 662 . Ejector piston 678 hits hard stop 677 and decelerates suddenly, thereby flinging virtually all powder off ejector pin 670 . Slide plate 645 is then translated incrementally so another partition is under ejector pin 670 , and the eject process is repeated. The extrude and eject processes are repeated until source powder height 650 reaches a value that is less than the slide plate thickness. The minimum source powder height can be detected with a standard hall effect sensor.
For this embodiment shown in FIGS. 16A through 16C , the average packing density of powder 668 and the thickness of slide plate 645 determine the average mass of plugs produced. The average packing density of powder 668 is estimated by measuring rod height 647 ( FIG. 14B ) which determines powder height 650 , as shown in FIGS. 14 B and 16 A-C. For example, the average packing density is equal to the mass of powder 668 divided by the powder height 650 and the base area of source chamber 642 . Thus, the average mass of powder plug 673 is equal to the packing density times the thickness of slide plate 645 and base area of partition 675 . An assortment of slide plates with different thicknesses is made available to provide an average plug mass that is acceptably close to a target value. As a non-limiting example to install a new slide plate 657 , FIG. 17 shows dispense device 659 inverted and keeper 656 is removed and reattached. Alternatively, another embodiment is shown in FIGS. 18A and 18B where the height of each partition 746 in grid cutter 749 is controlled by independent micrometers 753 and 754 connected to individual ejector pins 742 .
Slide plate 645 , ejector pin 670 , source block 641 and source piston 649 should be made from a hard, wear resistant material that provides a long wear life without lubrication. Non-limiting suitable materials include tungsten carbide, zirconia, silicon carbide or alumina. If only soft powders are being deposited, a less costly alternative is to use hardened 440C stainless steel coated with a hard ceramic thin film, such as sapphire coating type MH provided by Surface Conversion Sciences Corporation (State College, Pa.). The structural components of the dispense device are preferably made from a corrosion resistant stainless steel, such as type 316. Grid cutter insert 646 is preferably made from a tungsten carbide plate whose faces are ground and polished. The partitions can be cut by plunge or wire electrical discharge machining.
Determining the various parameters necessary to make plugs of specific masses can be done using techniques and materials well known in the art. For example, to create plugs that have a mass of approximately 50 micrograms, a suitable thickness for slide plate 645 and cutter insert 646 is 0.4 mm, and a suitable partition dimension is 0.4 mm wide by 0.4 mm long. A suitable cutter wall thickness is 75 micrometers. The mating faces of slide plate 645 , source block 641 , and keeper 656 should be ground to a flatness of 2 micrometers or better to minimize escape of powder particles. Source chamber 642 walls should be lapped to an accuracy of under 2 micrometers, and ejector pin 670 and source piston 649 walls should be lapped to an accuracy of under 2 micrometers. The nominal clearance between square ejector pin 670 and a grid cutter partition such as 675 should be 10 micrometers or less. Ejector pin 670 and source piston 649 faces that contact powder 640 should be ground flat to within 2 micrometers. The edges on grid cutter 646 , ejector pin 670 , source chamber 642 , and source piston 649 should be left sharp to discourage particles from lodging between the sliding surfaces. To minimize wear, all of the faces in sliding contact should be polished to a surface finish of less than 0.2 micrometers.
FIGS. 19A and 19B show a machine that incorporates dispense device 659 , which can dispense into receiving plate 728 and into weigh cup 715 on microbalance 717 . Receiving plates can be an industry standard 96 well, 384 well, or 1536 well format, or a custom format. Receiving plate 728 is supported by pedestal 719 on machine base 718 .
Slide plate 645 is moved in both x and y directions relative to source block 641 by x servo 709 (See FIG. 19A ) and y servo 732 (See FIG. 19B ). Suitable servos are the ROBO CYLINDER® series made by Intelligent Actuator, Inc., Japan. Part 712 couples the x and y servos to slide plate 645 . Clamping pneumatic cylinders 709 and 710 force keeper 656 to hold slide plate 645 against source block 641 .
X linear actuator 725 and y linear actuator 721 move dispense device 659 relative to machine base 718 . Slave z linear guide 729 and y linear guide 721 provide added stiffness to the support of dispense device 659 . Suitable linear actuators and supporting control hardware and software are made by Intelligent Actuator, Inc., Japan.
Weigh station 713 allows plugs to be weighed for characterization and statistical tracking. As shown in FIG. 19A , it comprises microbalance 717 , weigh cup 715 on weighing platform 716 , and draft shield 714 . A suitable microbalance is the UMX2 model made by Mettler Toledo, Switzerland.
Example 4
Manipulating Solids by Producing a Slurry Suspension
The physical characteristics of some solids make them more amenable to manipulation using a carrier. Consequently, this invention encompasses a method of manipulating solids that utilizes slurries. In this method, a solid or mixture of solids is combined with a liquid vehicle to form a slurry mixture, which is dispensed by using standard liquid handling devices (e.g., pipettes). The liquid vehicle is then removed (e.g., by evaporation, filtration, or sedimentation) to provide the solids. Long drying times and low drying temperatures are preferably used to promote crystal formation. Advantageously, a liquid vehicle can be selected such that it allows the ready manipulation of a given solid but does not dissolve a substantial portion of solid. By avoiding the formation of a solution into which the solid is dissolved, the method allows the manipulation of controlled amounts of solids without substantially affecting their solid forms.
The selection of a liquid vehicle that can be used to provide a slurry of a solid that is easy to manipulate (e.g., prepare, handle, and/or dispense) can be done with little or no routine experimentation. Preferred liquid vehicles are readily removed (e.g., evaporated) and do not chemically react with the solid. The solid or solids being manipulated are also insoluble or have a low solubility (e.g., less than about 10 mg/mL, 1 mg/mL, 0.1 mg/mL, 0.01 mg/mL or 0.001 mg/mL) in preferred liquid vehicles. In a specific method, the liquid vehicle comprises a wetting agent and water. The purpose of the wetting agent is to lower the surface tension of the water. Examples of wetting agents include, but are not limited to, alcohols such as isopropyl alcohol and methanol, sodium lauryl sulfate, polyvinylpyrrolidone (PVP), and TWEEN®.
In a specific method, samples of the slurry suspension are collected into vials for high-performance liquid chromatography (HPLC) analysis during the dispensing step. These vials are used to validate how much solid was actually transferred during each dispense. In a specific method, solid-state analysis is performed after the liquid vehicle is removed (e.g., vacuum or evaporated) to verify that the solid has not substantially changed in form. Examples of techniques that can be used for this determination include, but are not limited to, NMR spectroscopy (e.g., 1 H and 13 C NMR), Raman spectroscopy (e.g., resonance Raman spectroscopy), X-ray spectroscopy, powder X-ray diffraction, absorption and emission spectroscopy (e.g., infrared, visible, and ultraviolet absorption and emission), birefringence, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA).
Example 5
Manipulating Solids by Using Adhesive Surfaces
In another embodiment of the invention, solids (e.g., powders) are manipulated using an adhesive surface to which a controlled amount of solid can be adhered. Particular methods of this embodiment utilize a surface comprised of two or more adhesive areas separated by non-adhesive areas (i.e., areas to which a given solid will not adhere or will adhere more weakly than it does to an adhesive area). Preferably, the adhesive areas are of approximately the same size and shape. Examples of specific sizes of adhesive areas include, but are not limited to, less than about 5 cm 2 , 2.5 cm 2 , 1 cm 2 , 50 mm 2 , 10 mm 2 , 1 mm 2 , and 0.5 mm 2 .
Adhesive areas can be formed in a variety of ways. Examples include, but are not limited to, adhering an adhesive to a non-adhesive backing, overlaying an adhesive backing with a non-adhesive mask, and treating regions of a non-adhesive backing with chemicals, radiation, plasma, or other means sufficient to render those regions adhesive. Such methods are well known in the art. See, e.g., U.S. Pat. Nos. 6,284,329, 6,221,268, and 6,096,156, each of which is incorporated herein by reference.
FIG. 20 provides various non-exhaustive illustrations of possible adhesive patch arrangements, which include arrays 815 , strips 820 , and wafers 825 . The surface area of the adhesive and particle size of the powder will affect the amount of solid attached to a specific area 825 . The pattern can be a familiar array of shapes, such as an array of circles, squares, lines, or other structures arranged in a pattern such as a grid or a spiral. Suitable backing materials can be stiff (e.g., made of glass or plastic) or flexible (e.g., plastic carrier film).
The patterned surface is preferably de-ionized using an ion-gun to reduce non-specific and undesirable electrostatic interactions that can affect powder adhesion. Powder is then applied to the surface by, for example, pushing the surface into a powder bed, dipping the surface into a powder, spreading the powder across the surface and tapping off the excess, or sprinkling the powder over the surface and tapping off the excess. If any powder remains electrostatically adhered to undesired sections of the surface, an ion air-gun can be used to gently blow it off of the surface. FIG. 21 illustrates an example of this embodiment, wherein sticky adhesive patches 805 on a de-ionized substrate 800 are contacted with a bed of powder 810 . In one embodiment, less than about 1 mg of powder is adhered to an adhesive area. In another embodiment, less than about 0.5 or 0.25 mg of powder is adhered to an adhesive area.
After the solid preferentially adheres to the adhesive areas, the solid is removed from the substrate and transferred to a container or receptacle for further utilization (e.g., study, or experimentation). In a specific method, the solid is dissolved in a solvent and the resulting solution is transferred to the receptacle. Preferably, the adhesive (if one is used) is not soluble or is only sparingly soluble in the solvent. In another method, the solid is transferred using a liquid or gel in which the solid is insoluble or only sparingly soluble, but to which it adheres or in which it is trapped with enough affinity to facilitate its removal from the adhesive area. An example of such a liquid is polyethylene glycol (PEG).
FIG. 22 illustrates a way by which a solid adhered to an adhesive area on a substrate or backing can be dispensed into a container (e.g., a well in a multi-well plate). According to this particular method, a reagent, solvent, or excipient 920 adhered or otherwise suspended on a backing is contacted with solid 925 adhered to a strip or array of adhesive areas 915 to provide a mixture 930 . The reagent, solvent, or excipient is selected such that the resulting mixture will not remain adhered to the strip or array 915 and will form an easily dislodged or displaced agglomeration 905 . The agglomeration can thus be readily dispensed into a suitable container 910 using, for example, a centrifuge, vibration, vacuum, or simply gravitational force. Preferred reagents do not react with, or substantially affect the form of, the solid being manipulated, and do not dissolve the adhesive. The reagent can optionally be removed using a variety of techniques such as, but not limited to, evaporation, filtration, and sedimentation.
Depending on the particular use to which the solid is put, it may or may not need to be removed from the adhesive area to which it is adhered. In one embodiment of the invention, the solid is utilized (e.g., studied) while still adhered to an adhesive area on a backing. For example, a variety of experiments can be conducted in series or in parallel directly on a sheet or strip of solid samples, such as those shown in FIG. 20 .
In a specific method, solid-state analysis is performed to verify that the solid has not substantially changed in form during transfer. Examples of techniques that can be used for this determination include, but are not limited to, NMR spectroscopy (e.g. 1 H or 13 C NMR), Raman spectroscopy (e.g., resonance Raman spectroscopy), X-ray spectroscopy, powder X-ray diffraction, absorption and emission spectroscopy (e.g., infrared, visible, and ultraviolet absorption and emission), birefringence, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA).
Example 6
Transferring Solids from One Container into Another Container
During the process of manipulating small amounts of solid, it may be necessary to transfer the solid content inside one container into a different container. For example, weighing small amounts of solid on a precision microbalance (e.g., the Sartorius SC2 Ultra Micro) requires a low-mass container (e.g., less than 2 g) in order to achieve sufficient mass resolution (e.g., 0.1 microgram readability). However, further processing of those solids may require a higher-strength container or a two-dimensional array format, both of which would exceed the mass limit of such a microbalance. For such applications and others, various methods and apparatuses for transferring solids from one container into another container are described below.
In a specific method and apparatus, the container that originally holds the solids 1000 is a conventional open-faced vessel 1001 that can be weighed by a microbalance 1005 as shown in FIG. 23A . The solids 1000 are transferred into a different container, such as a well in a multi-well plate, by employing a pneumatic clamp 1002 that is attached to a swing arm 1003 and grips the vessel 1001 . FIG. 23B shows a top view of the clamp 1002 and swing arm 1003 of the embodiment. As illustrated in FIG. 23C , the swing arm 1003 accelerates the vessel 1001 through an arc trajectory and impacts a hard stop 1004 which causes the solids 1000 to exit the open-faced vessel 1061 and enter a target well 1006 in a multi-well plate 1007 . The position of the target well 1006 is located by a pair of x and y linear actuators 1008 to be directly below the stopped-position of the vessel 1001 .
To increase the process throughput of the swing-arm embodiment, a carousel 1009 can be incorporated, as shown in FIG. 24 . The carousel 1009 rotates two or more vessels 1001 between the microbalance 1005 for weighing and the position of the pneumatic clamp 1002 for transfer. As a result, transfer and weighing can occur simultaneously.
To enhance the release of solids from the vessel 1001 in the swing-arm embodiment, a vibrating actuator 1010 can be incorporated to apply repeated taps either to the swing arm 1003 as shown in FIG. 25A , or directly to the vessel 1001 as shown in FIG. 25B . The frequency of the vibration would typically be between about 1 Hz and about 50 kHz. To prevent pre-mature release of the solids 1000 from the vessel during the swinging motion, a retractable shield 1011 can be placed over the open-faced vessel 1001 as shown in FIG. 26A , and retracted just prior to dispense as shown in FIG. 26B .
An example of an alternative method and apparatus to transfer solid content from one container to another utilizes a container 1012 that can be weighed by a microbalance 1005 as shown in FIG. 27 . The container 1012 incorporates a retractable bottom plate 1013 that can be removed to release the solids 1000 into a receiving container 1014 . To enhance the solids release from the container 1012 , the container can be shaken or impacted with an actuator, or a pulse of gas can be applied through the container.
Another example of a method and apparatus to transfer solids content from one container to another comprises a container 1015 that can be weighed by a microbalance 1005 as shown in FIG. 28A . The container 1015 incorporates a gas permeable bottom plate 1016 . To transfer the solids content 1000 , vacuum pressure is applied through the bottom plate 1016 , the container 1015 is inverted, and then, the vacuum pressure is removed or positive pressure is applied through the bottom plate to release the solids 1000 into the receiving container 1017 , as shown in FIG. 28A . To enhance the solids release from container 1015 , a receiving container 1018 can incorporate its own gas permeable bottom plate 1019 which allows a continuous current of gas to run through both containers, as shown in FIG. 28B .
In some cases, the solids content of a container may be strongly adhered to the container walls and require a release force greater than gravity, low-pressure gas, or inertial vibration. In such cases, an example of a method and apparatus to transfer the solids content from one container to another is illustrated in FIG. 29 . The solid-containing container 1020 can be weighed by a microbalance 1005 and is designed to allow an internal piston 1021 to slide through the container. The container 1020 is inverted and a pin 1022 is used to push the internal piston 1021 and solids content 1023 through the container 1020 and into a receiving container 1024 .
In a separate method and apparatus, the solids are not removed from their original container during transfer to expedite the process. As shown in FIG. 30 , the solid 1000 is transferred into a two-dimensional array format by utilizing a vessel 1025 that can be weighed by a microbalance 1005 and that fits inside a well 1026 in a receiving plate 1027 that has a two-dimensional array of wells. The vessel 1025 is manipulated by a robot arm or a pneumatic gripper 1028 mounted to x-linear stage 1029 and z-linear stage 1030 . The receiving plate 1027 sits on a y-linear stage 1031 . For certain applications, the vessel is designed to fit completely inside the well such that the receiving plate can be sealed with a conventional plate seal (e.g., a pressure-adhesive film, heat-activated film, or rubber capmat) for further processing of the solids. As shown in FIG. 31 , the throughput of this transfer process can be enhanced by incorporating a carousel 1032 that allows vessels to be weighed and transferred simultaneously.
Example 7
Mixing Small Amounts of Solids
In applications such as high-throughput preformulation screening of drug compounds, it is necessary to mix small amounts of different powders, with the total sample volume typically less than 1 mg. Mixing achieves intimate particulate contact between compounds such that any resulting chemical or physical interactions can be analyzed. Several methods and apparatuses to mix small amounts of solids are described here.
In a specific method and apparatus as shown in FIG. 32A , the solids 1100 (e.g., powders) are contained in a conventional multi-well plate 1101 with filter-bottom wells (e.g. Unifilterm plate by Whatman, Clifton, N.J.). The top of the microplate is sealed with a lid 1102 that seals each well independently from each other (e.g. Capmats by Whatman). The lid is pierced to inject gas into a well. One well can be mixed at a time, or several wells in parallel, or all the wells in the plate can be mixed simultaneously. By directing a jet of gas 1103 into each well, turbulent air flow is created and the powders are forced to mix. The filter at the bottom of each well allows the gas to escape while retaining the powders. Alternatively, it is also possible to seal the top of a multi-well plate 1101 with a filter plate 1104 , so that short bursts of gas 1105 can be cycled back and forth, across each well to mix the solids 1100 , without piercing the plate 1104 as shown in FIG. 32B .
In a separate method and apparatus, the powders are contained in a commercial microplate or individual vials carried in a block. The vials are sealed with screw, snap, or crimp caps and clamped down to the carrier block, or each well in the microplate is sealed with a lid. After sealing the powder receptacles, the powders are mixed by shaking or vibrating the microplate or carrier block at high or low frequency for a period of time. The microplate or carrier block can also be rotated around different axes to achieve powder mixing. To enhance mixing, a small magnetic stirrer or spherical ball coated with a chemically-inert material can be placed into each well or vial. After sealing the powder receptacles, the powders are mixed by either shaking the microplate/carrier block which causes the internal ball to mix the powders, or by shaking the magnetic stirrer with an oscillating magnet.
A similar method and apparatus for mixing involves using a pierceable seal 1106 on top of microplate 1107 or vial and inserting a flexible wire 1109 into each receptacle, as shown in FIG. 33 . The wire 1109 can be sheathed in a stationary housing 1108 while a motor spins the wire 1109 to mix the powders 1100 . Various designs of stirrer blades 1110 and blade motions 1111 can be utilized to mix the powders, as shown in FIG. 34 . After mixing, the stirrer wire 1109 or blade 1110 can be removed from the receptacle and cleaned. If the powder level in each receptacle is shallow enough, it is possible to mix the powders without sealing the receptacle. One well or vial can be mixed at a time, or several wells or vials can be mixed simultaneously.
FIG. 35 shows another example of mixing where the powder 1100 is contained in compressible vials 1112 or a microplate fabricated with compressible wells 1113 . For example, the vials or wells can be fabricated from an elastic material such as silicone rubber or they can be fabricated with collapsible plastic bellows. The vials are sealed with a flexible or gas-permeable cap 1114 , while the top surface of the microplate is sealed with a filter plate 1115 to allow air to escape. The vials or wells are squeezed repeatedly in the same or different directions to mix the powders.
In another example, instead of employing an active means of mixing compounds, it is possible to achieve particulate contact between different compounds by layering the powder dispensed inside each receptacle 1119 , as shown in FIG. 36 . This method would allow an active ingredient 1116 to interact with excipient 1117 and a different excipient 1118 .
Example 8
Dispensing and Weighing Solids in a Two-Dimensional Array Format with a Conventional Microbalance
Previously described in this invention are examples of methods and apparatuses to manipulate small amounts of powder. For applications such as high-throughput screening of drug compound stability, it is often desirable to dispense as well as weigh controlled amounts of solids rapidly and accurately without substantially affecting their form. Weighing small amounts (e.g., amounts less than about 5 mg, 2.5 mg, 1 mg, 750 micrograms, 500 micrograms, 250 micrograms, 100 micrograms, 50 micrograms, 25 micrograms, 10 micrograms, 5 micrograms, or 1 microgram) of solid on a conventional microbalance (e.g., SC2 Ultra Micro by Sartorius) restricts the total mass weighed (e.g., less than 2 g) in order to achieve sufficient mass resolution (e.g., 0.1 microgram readability). In other words, during mass measurement on a microbalance, the solids should be contained by a lightweight container. However, further processing of those solids may require them to be in a two-dimensional array format, such as a multi-well plate which is too massive for a precision microbalance.
FIG. 37 illustrates a method and apparatus that enables a controlled amount of solid 1200 to be dispensed by a dispensing device 1205 directly into a two-dimensional array format and weighed by a precision microbalance 1207 . The apparatus comprises a cradle 1203 that supports a tray 1204 that has a two-dimensional array of through-holes. Each through-hole supports a low-mass container 1201 such that the container can slide in and out of the hole easily. The cradle 1203 is attached to a vertical actuator 1211 which is mounted to an x-linear actuator 1209 and a y-linear actuator 1210 . The x and y actuators position the tray 1204 such that a desired container 1202 is directly above the weigh platform 1206 of the microbalance 1207 . Then, the vertical actuator lowers the tray 1204 such that the desired container 1202 is supported by the weigh platform 1206 and no longer in contact with the tray 1204 . As result, a controlled amount of solid 1200 can be dispensed into the desired container 1202 and weighed individually by the microbalance 1207 while it is part of a two-dimensional array. After the desired container 1202 is weighed, it is removed from the microbalance 1207 by employing the vertical actuator 1211 to lift the tray 1204 such that the container 1202 is supported by the tray again.
Example 9
Dispensing and Weighing Solids with an Integrated Mass Sensor
Previously described in this invention are the limitations of weighing small amounts (e.g., amounts less than about 5 mg, 2.5 mg, 1 mg, 750 micrograms, 500 micrograms, 250 micrograms, 100 micrograms, 50 micrograms, 25 micrograms, 10 micrograms, 5 micrograms, or 1 microgram) of solid particles with a conventional microbalance (e.g., SC2 Ultra Micro by Sartorius). The current example describes novel methods and apparatuses that can dispense and weigh solids without a conventional microbalance. A transfer device is used to capture and dispense a controlled amount of solid. Transfer devices of the present invention can comprise a coring tool as described in Example 1, micromechanical tweezers, or microelectrodes that attract particles using electric or magnetic fields. A mass sensor is designed to quantify the mass of the captured solids by measuring the mechanical response of the transfer device before and after the solids are captured. Similarly, the mass sensor can quantify the mass of dispensed solids by measuring the mechanical response of the transfer device before and after the solids are dispensed.
In general, the mechanical response of a structure to an applied input force exhibits a unique resonant frequency that is a function of its stiffness and mass. Therefore, the loading or unloading of solids onto a transfer device produces a proportional change in the resonant frequency of the device. As a result, the mass of the solids can be calculated from the measured shift in resonant frequency, assuming that the stiffness of the device does not change and that the solids are securely attached to the device. To increase the sensitivity of this measurement, the transfer device is preferably stiff and lightweight. Specific transfer devices of the invention are very small, and can be made using microfabrication techniques.
To generate a mechanical response from transfer device, a transient force is applied to the transfer device, preferably at a location away from the attached solids. This is done using any of a variety of motion transducers known in the art, such as a piezoelectric actuator, solenoid shaker, impact hammer, acoustic speaker, electrostatic comb drive, or similar means. Different excitation signals can be applied to the motion transducer, such as a sweeping sine wave, impulse, step, or noise inputs to cause the transfer device to resonate.
The mechanical response of the transfer device to the excitation is measured using any of a variety of instruments known in the art, such as a capacitance sensor, accelerometer, phase Doppler velocimeter, piezoelectric sensor, strain gauge, or similar means. Preferably, the sampling frequency of the motion sensor is at least two times faster than the resonant frequency of the transfer device to prevent aliasing. The motion sensor provides an analog voltage signal that corresponds to the movement of the transfer device. Commercial data-acquisition hardware and software is used to record and analyze the transient signal data to obtain a frequency spectrum of the transfer device's mechanical response. The frequency at which the device displays the maximum amplitude of vibration is its resonant frequency. If a piezoelectric transducer is used to impart motion to the transfer device, the resonant frequency of the piezoelectric transducer itself can be correlated to the added mass of attached particles. This can be accomplished with an oscillator circuit that takes advantage of the electrical impedance of resonance inherent to piezoelectric transducers.
FIG. 38 provides a general illustration of a particular embodiment of the invention, wherein a coring tool is utilized as the transfer device. The coring tool 1301 is a thin-walled stainless steel tube (25.5 standard gauge hypodermic tube, 9 mm in length). The coring tool 1301 contains an internal piston 1302 that is a stainless steel rod (0.34 mm in diameter, 10 mm in length) that slides through the tube to eject a plug 1303 of powder. The coring tool 1301 is securely mounted onto a fixture 1304 that is connected to a set of x- 1310 , y- 1311 , and z- 1312 linear actuators. The actuators manipulate the coring tool in and out of a powder bed 1313 to extract a plug of powder. Further details of the coring method and apparatus are given in Example 1.
In the embodiment shown in FIG. 38 , a piezoelectric ceramic actuator 1305 (Piezo Systems, Cambridge, Mass., Part No. T220/A4-203Y) is affixed between the coring tube 1301 and the fixture 1304 . When the internal piston 1302 is withdrawn from the tube 1301 , a swept-sine voltage signal, 2 V peak-to-peak between 6.3 kHz and 7.1 kHz, is generated by a function generator 1308 (Model 33120A, Agilent, Palo Alto, Calif.) and applied to the piezoelectric actuator which causes the tube to vibrate. The displacement of the coring tube 1301 in the direction perpendicular to its length is measured with a laser displacement sensor 1309 (e.g., Model LC-2420 by Keyence Corp of America, Woodcliffe, N.J.). For each measurement, 12 consecutive frequency spectra are acquired using commerical data-acquisition hardware (Model #PCI-6052E DAQ board, National Instruments, Austin, Tex.) and customized software (LabVIEW™ Sound and Vibration Toolset, National Instruments, Austin, Tex.). The spectra are averaged linearly with 25% overlap to reduce spectral noise. FIG. 39 shows a typical frequency response of the coring tube when it is empty. The peak 1315 in the spectrum indicates that the resonant frequency of the tube is about 6.8 kHz.
When the transfer device, or in this case the coring tube 1301 , captures a small amount of solid or releases a small amount of solid, its resonant frequency will shift from its original value. For example, FIG. 40 shows a 140 Hz increase in the resonant frequency of a coring tube when a solid pellet weighing 62.2 micrograms is dispensed by the coring tube. Therefore, two frequency measurements are made to resolve the mass of the amount added or substracted from the transfer device. In this embodiment, the relationship between the shift in resonant frequency and the amount of mass dispensed by the coring tube is determined by a calibration procedure. During calibration, the shift in resonant frequency is measured for several different samples whose masses are determined off-line by a conventional microbalance. For the system described in FIG. 38 , linear regression by least-squares fitting was performed on the calibration data to determine the following correlation (2):
m =3040×( f o −f m )/ f o −0.66 (2)
where m is the dispensed mass expressed in micrograms, and f m and f o are the resonant frequencies of coring tube expressed in Hertz, before and after the mass is dispensed, respectively. FIG. 41 illustrates strong agreement between the calibration curve and experimental data from weighed quantities of pharmaceutical powder, such as acetaminophen and naproxen, ranging from 26 micrograms to 38 micrograms.
FIG. 42 illustrates another embodiment of the invention, wherein the transfer device is an electrode assembly 1306 that attracts dielectric particles 1316 to its tip surface by imposing a non-uniform electric field near the particles. This phenomenon is scientifically referred to as dielectrophoresis and does not require particles to be charged in order to manipulate them. In dielectrophoresis, when the permittivity of a dielectric particle is greater than that of its surrounding medium, a non-uniform electric field causes uncharged dielectric particles to move towards regions of stronger electric field intensity, regardless of the polarity of the field.
There are various means by which a non-uniform electric field can be generated. Configurations suitable for use in the invention will be readily apparent to those of ordinary skill in the art. Examples of suitable configurations include, but are not limited to, concentric electrodes, parallel electrodes, and interdigitated electrodes. Increasing the number of electrodes or the perimeter of an electrode will tend to increase the amount of solid attached to it, since the electric field is usually greatest at the boundary or edge of an electrode.
Depending on the complex permittivity of the particles and the surrounding medium, the strength of the electric field necessary to attract and hold the particles will also depend on their size and nature. However, electric fields used in typical embodiments of the invention range in strengths from about 10 5 V/m to about 10 8 V/m, from about 10 6 V/m to about 10 7 V/m, or from about 2×10 6 V/m to about 5×10 6 V/m. Specific transfer devices and methods of their manufacture and use that may be used in methods and devices of the invention are disclosed in U.S. patent application Ser. No. 09/976,835, filed Oct. 12, 2001, the entirety of which is incorporated herein by reference.
In the particular embodiment shown in FIG. 42 , an assembly 1306 of two concentric metal electrodes (FHC Inc., Bowdoinham, Me., Part No. CBHFM75) is used as the transfer device. A high voltage power supply 1314 (Trek Inc., Medina, N.Y., Model No. 623B) applies positive voltage to the inner electrode while the outer electrode is grounded to create a non-uniform electric field at the tip of the assembly. The electrode assembly is supported by a fixture 1307 which is mounted to a set of x, y, and z linear actuators. The actuators manipulate the electrode assembly toward a powder bed 1315 to extract a controlled amount of dielectric powder 1316 .
Referring to FIG. 42 , the mechanical response of the transfer device is generated using a thin piezoelectric ceramic actuator 1305 (Piezo Systems, Cambridge, Mass., Part No. T220/A4-203Y) affixed between the base of the electrode assembly and the fixture. A swept-sine voltage signal, 1 V peak-to-peak between 3.6 kHz and 4.0 kHz, is generated by a function generator 1308 (Model 33120A, Agilent, Palo Alto, Calif.) and applied to the piezoelectric actuator to excite the electrode assembly. The displacement on the electrode assembly in the direction perpendicular to its length is measured with a laser displacement sensor 1309 (Keyence Corp., Woodcliff Lake, N.J., Model No. LC2420A). Here, a small piece of specular material 1317 (3M Radiant mirror film) is epoxied on the tip of the transfer device to aid in the measurement.
For each measurement, 10 consecutive frequency spectra are acquired using a commercial dynamic signal analyzer (Hewlett Packard, Model 35660A) and averaged linearly with 50% overlap to reduce spectral noise. FIG. 43 shows a typical frequency response of the electrode assembly. The peak 1318 in the spectrum indicates that the resonant frequency of the electrode assembly is about 3.7 kHz. In this embodiment, the relationship between the shift in resonant frequency and the amount of mass captured by the electrode assembly is determined by a calibration procedure. During calibration, the shift in resonant frequency is measured for several different samples whose masses are determined off-line by a conventional microbalance. For the system described in FIG. 42 , linear regression by least-squares fitting was performed on the calibration data to determine the following correlation (3):
m =6968×( f o −f m )/ f o −0.0586 (3)
where m is the captured mass expressed in micrograms, and f o and f m are the resonant frequencies of electrode assembly expressed in Hertz, before and after the mass is captured, respectively. FIG. 44 illustrates good agreement between the calibration curve and experimental data from weighed quantities of pharmaceutical powder, such as aspirin and avicel, ranging from 17 micrograms to 90 micrograms.
While the invention has been described with respect to particular embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as recited by the appended claims. | The invention relates to methods and apparatuses for manipulating small amounts of solids. Specific embodiments of the invention are particularly suited for the automated transfer of small amounts of solids. In one embodiment, a uniform powder bed is lightly compressed into plugs of powder and dispensed. In another embodiment, the solid is placed in a liquid carrier to form a slurry, dispensed, and the liquid component is subsequently removed. In yet another embodiment, solids are manipulated using adhesive surfaces. | 98,403 |
FIELD
Embodiments of the present invention relate in general to the field of information technology.
BACKGROUND
Over the last few years, information technology (IT) organizations have increasingly adopted standards and best practices to ensure efficient IT service delivery. In this context, the IT Infrastructure Library (ITIL) has been rapidly adopted as the de facto standard. ITIL defines a set of standard processes for the management of IT service delivery organized in processes for Service Delivery (Service Level Management, Capacity Management, Availability Management, IT Continuity Management and Financial Management) and Service Support (Release Management, Configuration Management, Incident Management, Problem Management and Change Management). The service support processes, such as Configuration Management, Incident Management, and Configuration Management are some of the more common processes IT organizations have implemented to bring their service to an acceptable level for their businesses.
The implementation of ITIL processes has yielded significant results to IT organizations by defining interfaces between service providers and consumers; by clarifying the IT organizational structures, roles, and responsibilities; and by designing internal processes for the management of IT operations. IT Service Management (ITSM) is a process-based practice intended to align the delivery of IT services with the needs of the enterprise, while emphasizing benefits to customers. ITSM focuses on delivering and supporting IT services that are appropriate to the business requirements of the organization, and it achieves this by leveraging ITIL-based best practices that promote business effectiveness and efficiency. Thus, the focus of ITSM is on defining and implementing business processes and interactions there between to achieve desired results. IT services are typically built around the processes. For example, in a manufacturing application, the ITSM may provide services built around a build-to-order manufacturing process scenario. The ITSM architecture generally provides services that are capable of being directly instantiated. With a focus on processes, presenting and packaging an organization's IT needs may be a challenge in an ITSM environment.
SUMMARY
Various embodiments of methods, systems, and computer program products for computer executable services are discussed herein. In one embodiment, a method comprises determining available hardware, determining computer executable services based in part on the available hardware, displaying a catalog of the computer executable services, receiving a selection of at least one service of the computer executable services, and instantiating the at least one service on the at least one server. The available hardware comprises at least one server.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A illustrates an example structure of a model for IT services, according to an embodiment.
FIG. 1B describes a state transition diagram for a two-phase model instantiation process, according to an embodiment.
FIG. 2A illustrates an architecture for a runtime environment described with reference to FIG. 1A , according to an embodiment.
FIG. 2B illustrates a block diagram of a configure-to-order system to implement an architecture described with reference to FIG. 2A , according to an embodiment.
FIGS. 3A , 3 B, and 3 C illustrate in a tabular form an example list of service operations supported by an architecture described with reference to FIGS. 2A and 2B , according to an embodiment.
FIG. 4 is a flow chart of a method for managing IT services, according to an embodiment.
FIG. 5 illustrates a block diagram of an active enclosure, according to an embodiment.
FIG. 6 illustrates an architecture for an active enclosure with a master-slave relationship, according to an embodiment.
FIG. 7 illustrates a block diagram of a management component of an active enclosure, according to an embodiment.
FIG. 8 is a flow chart of a method for managing IT services of an active enclosure, according to an embodiment.
DESCRIPTION OF EMBODIMENTS
Reference will now be made in detail to various embodiments of the present invention, examples of which are illustrated in the accompanying drawings. While the embodiments of the present invention will be described in conjunction with the various embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, embodiments of the present invention are intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the appended claims. Furthermore, in the following description of various embodiments of the present invention, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. In other instances, well known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the embodiments of the present invention.
The following terminology may be useful in understanding embodiments of the present disclosure. It is to be understood that the terminology described herein is for the purpose of description and should not be regarded as limiting.
Architecture—A blueprint or basic infrastructure designed to provide one or more functions. An architecture used in an IT environment may typically include hardware, software and services building blocks that are designed to work with each other to deliver core functions and extensible functions. The core functions are typically a portion of the architecture, e.g., an operating system, which may not be modifiable by the user. The extensible functions are typically a portion of the architecture that has been explicitly designed to be customized and extended by the user as a part of the implementation process. For example, services oriented architecture (SOA) is a type of an architecture used for addressing the need for structuring IT services that lowers cost and enhances reusability.
Model—A model can be a representation of the characteristics and behavior of a system, element, solution, or service. A model as described herein captures the design of a particular IT system, element, solution, or service. The model can be a declarative specification of the structural, functional, non-functional, and runtime characteristics of the IT system, element, solution, or service. The instantiation of a model creates a model instance. Unlike object oriented (OO) theory, in which an instance object can be a slot space, the model instance can be a design space that may be capable of accommodating refinement.
IT artifact—An IT artifact refers to a tangible attribute or property of an IT system. Examples of an IT artifact may include hardware, software, documentation, source code, test apparatus, project plans, educational and marketing material, and similar others. The IT artifact may be available for external or internal use.
Separation of concerns—A technique for addressing different issues of a problem individually, thereby making it possible to concentrate on each issue separately. Applying this principle may result in a decrease in the complexity by dividing the problem into different smaller issues; support division of efforts and separation of responsibilities; and improve the modularity of IT systems or artifacts.
Service—Utility or benefit provided by a provider to a consumer. The provider and the consumer may vary by application and may include an enterprise, a business unit, a business process, an application, a third party, an individual, and similar others. Enterprise services may be provided in the course of conducting the enterprise business. IT services generally refer to any application that enables the enterprise to provide utility or benefit by adding functionality to the IT infrastructure.
Service Model—A service model can be the representation of a service within a SOA. It defines the externally visible description, behavior, state, and operations available from a service to other services. As described herein, instantiation of a service model can be conducted in two phases—a binding phase and a grounding phase. The binding phase can be responsible for resolving dependencies between models. The grounding phase can be responsible for materializing the instances, e.g., by creating an IT artifact corresponding to the specification defined in the service model instance.
Meta Model—A meta model (or metamodel) can be a description of a set of building blocks, constructs and rules that define the model itself.
System—One or more interdependent elements, components, modules, or devices that co-operate to perform one or more predefined functions.
Configuration—Describes a set up of elements, components, modules, devices, and/or a system, and refers to a process for setting, defining, or selecting hardware and/or software properties, parameters, or attributes associated with the elements, components, modules, devices, and/or the system.
Applicants recognize that it would be desirable to provide a services architecture that would include tools and techniques to initially design, reuse, maintain, and refine services during their entire lifecycle, thereby ensuring alignment between IT services and IT infrastructure. That is, it would be desired to provide IT service lifecycle management tools and techniques that would promote the development, capture, and subsequent reuse and refinement of reliable and scalable services. Applicants further recognize that it would be desirable that the separation of concerns between the artifacts managed by the services be based on roles, e.g., a designer or developer and an end user of services. Therefore, a need exists to provide improved tools and techniques to be used in the automation of IT services lifecycle management.
Embodiments of systems and methods disclosed herein provide an architecture that is capable of designing and delivering IT services that are entered as a configure-to-order compared to a build-to-order provided by traditional ITSM services. An analogy may be made between a builder that is capable of building standard model homes that are orderable as a build-to-order home and an architect designed home that is capable of building a customized home in accordance with user specifications and that is orderable as a configure-to-order home. New features or functions of the configure-to-order home that were not included in the standard build-to-order home may be cataloged (with known price and delivery) and offered as re-usable features or functions that may be combined with existing model homes.
A Model for Information Technology (IT) Services
FIG. 1A illustrates an example structure of a model 100 , according to an embodiment. The model 100 captures the design of a particular IT element or solution, e.g., IT services captured as a service model. As described earlier, a service model can be the representation of a service within a SOA. It defines the externally visible description, behavior, state, and operations available from a service to other services. The model 100 includes one or more models 110 , 112 and 114 capable of being instantiated in a runtime environment 120 to generate corresponding model instances 130 , 132 and 134 and corresponding IT artifacts 140 , 142 , 144 and 146 generated in an IT infrastructure 150 . Thus, the instantiation of a model results in a generation of a virtual runtime object, e.g., the model instance, and also results in a generation of a real, tangible IT artifact in the IT infrastructure 150 . The IT infrastructure 150 may be a data center that includes hardware, software, communications, applications, services and similar other components to provide IT functions. The runtime environment 120 includes services that process the models 110 , 112 and 114 .
The model 100 can be a declarative specification of the structural, functional, non-functional, and runtime characteristics of an IT system. That is, the model 100 may use declarative programs that may include expressions, relationships, or statements of truth. The declarative programs may not include variables. Closely equivalent to the concept of a class in Object Oriented (OO) theory, the model 100 supports the principles of encapsulation and hiding of implementation detail. As in OO, the model 100 also supports recursive composition. Also as in OO theory, in which a class instantiation results in an object, the instantiation of a model results in the creation of a model instance. However, unlike OO, in which an instance object is a slot space, the model instance, e.g., each of model instances 130 , 132 and 134 , can be a design space that can accommodate refinement. In addition, as described earlier, a corresponding IT artifact becomes associated with the model. In the depicted embodiment, the bi-instantiation process for the models 110 , 112 and 114 is desirable to not only create a virtual runtime object that represents that particular instance of the model but in addition also generate an IT component or system in the real, tangible, IT Infrastructure 150 . A relationship between a model instance, e.g., one of the model instances 130 , 132 and 134 , and an IT artifact, one of the IT artifacts 140 , 142 , 144 and 146 , is therefore homomorphic. That is, one represents the other and a change in one is reflected in the other. Additional description of the two-phase instantiation process for a model is described with reference to FIG. 1B .
Referring back to FIG. 1A , in order to support initial design, reuse, maintain, and refinement during the entire lifecycle of the models, the model 100 supports the following example properties (among others): refinement, variability, polymorphism, composability, import, association, constructors, operations, deployment, monitors, declarative modeling language, and best practice. Recursive composability enables a designer to depend on and leverage existing designs in order to define or create new ones, which in turn are available to others to reuse. Refinement allows the instantiation process to be multi-step, thereby allowing for a greater flexibility in the model design. Encapsulation (also referred to as information hiding), use of clear boundary between the visibility into the internal design of a model and its publicly available characteristics, supports inter-model dependencies that allow changes to the internal specification without requiring changes in the model user. Characterization enables the expressing the outward nature of the model in terms that are directly relevant to the consumer of the model instead of in terms relevant to the implementer. Variation enables capturing variations in a single model. A model may be defined under several variations of its characteristics to reflect specific changes to the underlining design. Capturing these variations in a single model avoids combinatorial explosion of models and supports better model reuse. Declaration enables definition of models using declarative specifications. The models are defined in terms of their association to underlying design instead of as process steps for instantiation using programming code. Use of statements of truth to define the models reduce errors due to interpretation or avoid use of languages have meaning only during execution in the intended environment.
The models 110 , 112 and 114 can be defined by a meta model, thereby enabling the models 110 , 112 and 114 to be translated into other modeling languages. Thus, model 100 enables easy translation of user-defined models to other forms (both model-oriented and script-oriented forms) thereby enhancing its flexibility. In addition, model 100 provides the tools and techniques for the replacement of one modeling language with other modeling languages and for the coexistence of multiple structural modeling languages. As described herein, a meta model is a model that further explains or describes a set of related models. Specifically, the meta model includes an explicit description (of constructs and rules) of how a domain-specific model is built.
The model 100 may be specified by using various modeling languages including, among others, a unified modeling language (UML), the Resource Description Framework (RDF), Extensible Markup Language (XML) Schema, XML Metadata Interchange (XMI), and Java languages or a combination thereof. The RDF may include extensions such as RDF schema and languages such as the RDF Ontology Web Language (RDF/OWL).
The concept of refinement, which may be an example of an extensible feature of the model 100 , allows a smooth multi-valued transition from a model to a model instance. Whereas classic modeling approaches [OO, CIM, SML, UML] are based on a single value slot mechanism for instance creation, refinement can be based on a linked list approach that enables multi-slot capabilities for model elements. In addition, substitution can be supported, similar to XML schema. A refinable object or a refinable model element is any object/element that extends a refinable construct. The refinable construct carries metadata including: 1) allowRefinement: a Boolean attribute that can be used to stop the refinement process, 2) timestamp: a timestamp that record the time at which the refinement occurred, and 3) tag: a tag that records extra information such as purpose of the refinement or similar other.
FIG. 1B illustrates a state transition diagram for a two-phase model instantiation process, according to an embodiment. The instantiation of a model, e.g., any one of the models 110 , 112 and 114 , can be conducted in two phases: a binding phase 160 and a grounding phase 170 . In an example, non-depicted embodiment, the binding phase 160 may be implemented in a binding phase engine and a grounding phase 170 may be implemented in a grounding phase engine. In the binding phase 160 inter-model dependencies, e.g., made by a model to other models, can be resolved. An output of the binding phase 160 is a bound model instance 162 . Model instances 130 , 132 , and 134 are examples of the bound model instance 162 . The binding phase 160 may be viewed to provide a dynamic linking between model instances. Dependencies to other models can be abstract, refined or very specific and the binding phase 160 resolves these types of model references by reusing existing instances or creating new instances. The binding phase can be inherently recursive in that the binding of a dependent model can itself trigger a binding of its dependencies.
In the grounding phase 170 , the bound model instance 162 can be materialized to generate a bound and grounded model instance 172 . The materializing includes creating an IT artifact corresponding to the specification defined in the model instances. This can be achieved by recursively traversing the instance tree and creating, when appropriate, the corresponding artifacts in the IT infrastructure. IT artifacts 140 , 142 , 144 and 146 are examples of a bound and grounded model instance 172 .
An Architecture for a Runtime Environment
FIG. 2A illustrates an architecture 200 for a runtime environment 120 described with reference to FIG. 1A , according to an embodiment. The architecture 200 can be deployed to provide e-commerce for IT services. That is, the architecture 200 may be deployed as a configure-to-order business system in which a set of predefined models of IT systems are offered to customers (may include internal or external users, clients and similar others). FIG. 2B illustrates a block diagram of a configure-to-order system 202 to implement an architecture 200 described with reference to FIG. 2A , according to an embodiment.
Referring to FIGS. 2A and 2B , the predefined models are for IT services. It is understood that the models may be expressed for other aspects of IT within an enterprise. The architecture 200 includes a design service 210 operable to generate models 110 , 112 and 114 . The design service 210 may include design tools 212 and techniques (such as declarative programming) available to a designer or an architect of IT services to manage the lifecycle of the models from initial design to cataloging to refinement. In a particular embodiment, the design service 210 can be operable to capture declarative specifications of services as a service model.
A catalog service 240 can be operable to store a plurality of service offerings 242 . The plurality of service offerings 242 are models of services that are cataloged and are orderable by a customer. The catalog service 240 communicates with the design service 210 to access one or more service models that are new and not been previously cataloged. The service models may include modifications or refinements made to existing models included in the plurality of service offerings 242 . The one or more service models generated by the design service 210 are combined into the plurality of service offerings 242 to provide a catalog of orderable services 244 .
End users may access the features of the configure-to-order system 202 through the catalog service 240 and an Order Processing Service (OPS) 250 to browse, search, select, configure, and order the type of service model to be created and ordered or the type of changes desired to an existing model. In order to simplify the user interface, the catalog service 240 may filter model information provided to the user. That is, complex details about the model and its methods and properties, which may be provided to a designer or an architect, may be hidden from the user, thereby simplifying the user interface. For example, complex details of a blade server model having several processors arranged as a cluster may be presented to the user as a normal, high, and non-stop availability selection. Included in the information provided to the user is price and delivery associated with the order. In a particular embodiment, at least one orderable service 246 can be selectable from the catalog of orderable services 244 for placing an order. The selection may be performed by one of a user and an application program. In a particular embodiment, the OPS 250 can include a set of intermediate services for performing validation 252 , approval 254 and billing 256 of the end user order.
An order instantiation service 260 is coupled to receive the order (that has been validated and approved) for the at least one orderable service 246 from the OPS 250 . Specifically, upon validation and approval of the order by the OPS 250 , a request resolution service 258 can be triggered to initiate further processing of the order by the order instantiation service 260 . The order instantiation service 260 can be operable to instantiate the at least one orderable service 246 , thereby generating an instantiated ordered service 262 . The order instantiation service 260 includes a configuration management service (CMS) 220 operable to perform the binding phase 160 and generate the instantiated ordered service 262 . The CMS 220 includes tools and techniques for implementing the binding phase 160 of the two-phase instantiation process as well the management of the model instances, e.g., model instances 130 , 132 and 134 . The CMS 220 generates a service instance corresponding to each order.
An order fulfillment service 270 can be operable to fulfill the order in accordance with the instantiated ordered service 262 . The order fulfillment service 270 can include a request for change (RFC) scheduling 272 and a RFC execution service 274 for the sequencing of the various orders in the runtime environment 120 . The order fulfillment service 270 includes a creation and configuration service (CCS) 230 operable to perform the grounding phase 170 of instantiated ordered service 262 . The CCS 230 includes tools and techniques for the implementation of the grounding phase 170 , which includes creation of IT artifacts (such as artifacts 140 , 142 , 144 and 146 ) in the IT infrastructure 150 .
The connection between the runtime environment 120 and the IT infrastructure 150 can be performed through an actuator service 280 . The actuator service 280 may include two layers, a generic actuator 282 and a custom actuator 284 . In an embodiment, more than one generic actuators and more than one custom actuators may be included. The generic actuator 282 can be operable to dispatch instances to the custom actuator 284 . For example, a server model may be configured to define deployment and provisioning information related to a Rapid Deployment Pack (RDP) deployer. A deployment request can be triggered from the CCS 230 to a generic installer included in the generic actuator 282 , which in turn will search for a specialized deployer that can handle RDP deployment information. This technique enables a loose coupling between the runtime environment 120 and the IT infrastructure 150 and offers a high level of customization. That is, the architecture 200 provides IT service lifecycle management tools and techniques that promote the development, capture, and subsequent reuse and refinement of reliable and scalable services. In addition, the architecture 200 further provides the separation of concerns between the artifacts managed by the services be based on roles, e.g., a designer or developer (e.g., user of the design service 210 ) and an end user of services (e.g., user of the catalog service 240 ).
In a particular embodiment, the architecture 200 is scalable to be deployed in applications having varying scope and complexity starting from a blade server to a large scale, enterprise-wide IT service. In an example non-depicted embodiment, SmartRack can be an example name of an application of the architecture 200 that combines hardware, management software, and applications to provide customers with a unique, systematic experience to IT conceptualization, delivery, and consumption. This can be accomplished by both shipping the management software embedded with the hardware and by providing a systematic way of modeling applications that can be deployed. Once a SmartRack is powered on, the main point of user contact can be the catalog service. Service offerings can be presented to the user along with their available configuration options, each of which are characterized in terms of the resulting service's attributes, the cost, and time to build. Service offerings may be dynamically generated views based on a set of rich models, stored in the design service, that weave together the structural, functional, non functional, and runtime characteristics of a service using a set of best practices. In a typical deployment, SmartRacks may be configured with pre-populated foundation models. Other models may be either purchased and downloaded from Hewlett Packard Development Company, L.P. (HP) or 3rd parties, or developed in house by customers. Once the appropriate service offering is selected and ordered, it can be sent to the management services that will process it and ground (materialize) it using a set of installer services. If specified in the model, once grounded, the various elements of the model are automatically monitored by monitoring service(s). SmartRacks may be deployed in stand alone mode when a customer only desired one rack of blades. In addition, through its built-in federation capability, several SmartRacks can be combined together providing a unified management experience for the customer. Lastly, SmartRack, through its open SOA architecture and service proxy technology, can support the substitution of its services by external services allowing SmartRacks to reuse existing management software assets of the enterprise, and, allow more than one SmartRacks to be combined so that they are both managed through one user interface (instead of each being independent).
In an example, non-depicted embodiment, the architecture 200 can be a scaled up to a full enterprise architecture that puts services as the key economic principle of value transfer between business (or enterprise) and IT. IT may provide “IT-consumed services” to operate itself (tools and techniques to improve internal productivity). These are things like service desk technologies, change management systems, blades, facility services, networks, employees, legal services. These services can be thought of as the tooling of IT, and together they can be used to create the IT deliverable, the “IT-delivered service.” IT-delivered services can be created by IT for use by the business. Examples might include a consumer credit check service, employee expense reporting service, new employee set up service, a QA lab rental service, a private network and similar others. The IT delivered services can be delivered as an economic unit of value to the business. In other words, they are designed, constructed and delivered in a way such that the lines of business see its value, and are willing and able to purchase them. In fact, the IT-delivered service transforms into to a business-consumed service at the moment of payment. This payment can be indicative of the value as perceived the consumer, which in this case is the line of business. The IT-delivered services in and of themselves render IT as a service provider.
IT services provided to a business may be defined starting with a name (e.g. sales forecasting service), followed by a description (e.g. daily worldwide sales pipeline report and analysis for senior sales management). Every service may need additional artifacts and descriptors that are associated with the ongoing integrity of the service. These may include the service level agreements (SLAs) so that IT and the business are aligned around performance and availability, a logical and physical view of the configuration items that underpin the service, a view of dependant services, documentation, a continuity plan, knowledge entries, subscriber entitlements, and security and access provisions. The IT services may be defined by defining a service-line category structure. Just like consumer goods providers have product line categories, so do IT services. They may include employee services, application services, network services, others. Similar to consumer products, IT services may be established with a price, value and business outcome for each service. In order to qualify as an IT-delivered service, it is desirable that there is an associated, measurable business outcome. The IT services can be made available through a customer catalog service by developing a consistent way to articulate both a public characterization (business-facing) and private implementation (IT-facing). Service components can be reused whenever possible. Consistent design criteria for both the public and private facing aspects of the service can directly impact the process automation effort required to instantiate, monitor and manage the service throughout its lifecycle. Service visibility and integrity can be maintained at all levels including management stakeholders like the service desk, problem managers, change managers, application owners, IT finance managers, business relationship managers are able to view and manage activities around the service definition in a consistent way. When scaling up to the enterprise-wide architecture, IT provided services are defined as models and the services of the runtime environment are the embodiments of the IT consumed services.
Example Services Supported by the Architecture 200
FIGS. 3A , 3 B, and 3 C illustrate in a tabular form an example list of service operations supported by the architecture 200 described with reference to FIGS. 2A and 2B , according to an embodiment. In accordance with the principles of Service Oriented Architecture (SOA), components in the architecture 200 are conceived as services, that is, independent units of functionality with well specified interfaces and data models. The list of services may be described to perform a generic service (for aggregating data across data services), a data service (for the management of lifecycle of specific data models), a computational service (for the execution of business logic) or a combination thereof. An activation service 302 can be a generic actuator with responsibility to dispatch service activation requests to an appropriate custom activator. An approval service 304 (computational service) can be responsible for approving or not approving a received order. An authentication service 306 (data and computational service) can be responsible for the management of users, roles and access rights as well as granting authorizations. A billing service 308 (computational service) can be responsible for setting up charge back mechanism and proper billing for received orders.
A catalog service 312 (computational service) can be responsible for the generation of a service offerings. A configuration management service 314 (data service) can be responsible carrying out a binding phase of the instantiation process and for the management of the lifecycle of instances. A creation configuration service 316 (data service) can be responsible for carrying out a grounding phase of the instantiation process. A design service 318 (data service) can be responsible for the management of the lifecycle of models.
A discovery service 322 (computational service) can be a generic actuator responsible for triggering the discovery of assets in the infrastructure. To fulfill its responsibility, discovery service 322 can connect to custom discovery services. An incident service 324 (data service) can be responsible for the management of the lifecycle of incidents or events. An installer service 326 can be a generic actuator responsible to dispatch service installation requests to the appropriate custom activator. A logging service 328 (data service) can be responsible for the lifecycle management of log messages.
A monitoring service 332 can be a generic actuator which has the responsibility to dispatch service monitoring requests to the appropriate custom activator. An offering availability estimation service 334 (computational service) can be responsible for the generation of service offering availability and pricing. An order processing service 336 (data service) can be responsible for the management of the lifecycle of orders. A package model design service 338 (data service) can be responsible for the lifecycle management of a package model.
A policy service 342 (data and computational service) can be a generic service and has the responsibility of dispatching policy evaluation requests to the appropriate specific policy services. A request resolution service 344 (computational service) can be responsible for initiation of the instantiation process of models. A request for change (RFC) execution service 346 (data service) can be responsible for the management of the lifecycle of RFCs in the platform. A RFC scheduling service 348 (computational service) can be responsible for finding optimal schedules for RFC in the platform.
A session service 352 (data service) can be responsible for the management of the lifecycle of sessions. The create method generates a new session in the open state associated with a new, unique SessionKey. Changes to the session state, such as closing the session can be done through the update method. A validation service 354 (computational service) can be responsible for the validation of an order.
A change catalog service 356 can be responsible for the management of changes to the catalog, such as changes due to new features, software updates, hardware availability, etc. The consumer management service 358 can be responsible for providing an interface for consumers and manages retrieving service offerings, ordering services, retrieving changes, making order changes, establishing logins, and the like. The provider management service 360 can be responsible for providing an interface for providers, thus allowing management of users and profiles, designs, designs supported, pricing, and the like. In various embodiments, the consumer management service 358 and/or the provider management service 360 coordinates with the session service 352 to provide an interface for users.
FIG. 4 is a flow chart of a method for managing IT services, according to an embodiment. In a particular embodiment, the method may be used to manage the model 100 described with reference to FIGS. 1A and 1B . In an embodiment, the method may be used to manage IT services provided by the architecture 200 deployable in an e-commerce environment. At step 410 , declarative specifications of the services are captured as a service models. At step 420 the service models can be combined into a plurality of service offerings to provide a catalog of orderable services. At step 430 , an order can be received for at least one orderable service selectable from the catalog of orderable services. At step 440 , the at least one orderable service can be instantiated, thereby generating an instantiated ordered service. At step 450 , the order can be fulfilled in accordance with the instantiated ordered service.
It is understood, that various steps described above may be added, omitted, combined, altered, or performed in different orders. For example, a step may be added to refine the service models. At step 460 , the service models can be refined, the refining including a multi-step transition from the service models to a refined service model instance.
FIG. 5 illustrates a block diagram of an active enclosure 500 , according to an embodiment. The active enclosure 500 is a computer system and includes dedicated resources 510 , and may be coupled to one or more blade and hardware resources 520 . The dedicated resources 510 include a processor 530 coupled to a memory 540 . The memory 540 is operable to store program instructions 550 that are executable by the processor 530 to perform one or more functions. It should be understood that the term “computer system” is intended to encompass any device having a processor that is capable of executing program instructions from a memory medium. In a particular embodiment, the various functions, processes, methods, and operations described herein may be implemented using the active enclosure 500 . For example, the model 100 , the architecture 200 , the configure-to-order system 202 and similar others may be implemented using the active enclosure 500 .
Components of the active enclosure 500 comprise a server 560 . In some embodiments, the server 560 includes the dedicated resources 510 . In other embodiments, the server 560 includes the dedicated resources 510 and some hardware resources 520 .
The various functions, processes, methods, and operations performed or executed by the active enclosure 500 can be implemented as the program instructions 550 (also referred to as software or simply programs) that are executable by the processor 530 and various types of computer processors, controllers, central processing units, microprocessors, digital signal processors, state machines, programmable logic arrays, and the like. In an example, non-depicted embodiment, the active enclosure 500 may be networked (using wired or wireless networks) with other active enclosures and/or computer systems.
In various embodiments the program instructions 550 may be implemented in various ways, including procedure-based techniques, component-based techniques, object-oriented techniques, rule-based techniques, among others. The program instructions 550 can be stored on the memory 540 or any computer-readable medium for use by or in connection with any computer-related system or method. A computer-readable medium is an electronic, magnetic, optical, or other physical device or means that can contain or store a computer program for use by or in connection with a computer-related system, method, process, or procedure. Programs can be embodied in a computer-readable medium for use by or in connection with an instruction execution system, device, component, element, or apparatus, such as a system based on a computer processor, or other system that can fetch instructions from an instruction memory or storage of any appropriate type. A computer-readable medium can be any structure, device, component, product, or other means that can store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.
The dedicated resources 510 include hardware used for automated management of the dedicated resources 510 and/or the blade and hardware resources 520 . In some embodiments, the automated management includes management of resources external to the active enclosure 500 , as discussed further herein and in FIG. 6 .
The blade and hardware resources 520 are computer systems, computer components, and/or computer hardware, such as storage arrays, network switches, and the like. In some embodiments, the active enclosure 500 does not include blade and hardware resources 520 . In other embodiments, the active enclosure 500 includes one or more blade and hardware resources 520 including one or more computer systems. Hardware within the blade and hardware resources 520 may be coupled to each other, the dedicated resources 510 , and/or networked to other computer systems. In some embodiments, one or more program instructions are executed via the blade and hardware resources 520 .
In one embodiment, active enclosure 500 provides a turn key system that combines/integrates generic management software with hardware, wherein the management software acts as a runtime environment for the management of the hardware resources. Also, in various embodiments, the active enclosure 500 is self sufficient and may be configured to run independently of other software. In some embodiments, the active enclosure 500 is an open architecture in which management services may be substituted by other services running outside the active enclosure 500 .
FIG. 6 illustrates an architecture 600 for an active enclosure with a master-slave relationship, according to an embodiment. The architecture 600 includes an active enclosure 500 coupled to an active enclosure slave 620 . The active enclosure 500 includes a management component 610 . As discussed herein, through federation, one or more active enclosures, such as the active enclosure 500 , may be networked together and via the management component 610 coordinated one or more services operating on several computer systems. In various embodiments, federation may be performed via a master-slave pattern in which one active enclosure operates as a master and one or more other active enclosures operate as slaves, subordinate to the master. Using a master-slave relationship allows for coordination and/or collaboration of services, hardware and/or other software resources between several active enclosures. Federation allows easy, dynamic and scalable systems. In various embodiments, different services may be instantiated on the master server and/or on one or more different slaves.
FIG. 7 illustrates a block diagram 700 of a management component 610 of an active enclosure, according to an embodiment. In embodiments of block diagram 700 , the management component 610 includes a provider management service 360 , a consumer management service 358 , a design service 318 , an authentication service 306 , an offering availability estimation service 334 , a configuration management service 314 , an authentication service 306 , a catalog service 312 , an order processing service 336 , a change catalog service 356 , a request resolution service 344 , an approval service 304 , a billing service 308 , an RFC scheduling service 348 , a creation configuration service 316 , a monitoring service 332 , an activation service 302 , and an installer service 326 . In other embodiments, the management component 610 includes a combination of fewer, more and/or different services, such as a discovery service 322 , an incident service 324 , a logging service 328 , a policy service 342 , a session service 352 , like services and other services.
In various embodiments, the active enclosure 500 has one or more services that have a management interface, such as the provider management service 360 and consumer management service 358 . In some embodiments, the active enclosure 500 has several management interfaces and may be selected and/or determined by user privileges. For example, an administrator management interface may be accessed by an administer using an administrator management service, not depicted. The provider management service 360 is coupled to several other services, such as the design service 318 , the authentication service 306 , and the offering availability estimation service 334 . Similarly, the consumer management service 358 is coupled to several other services, such as the authentication service 306 , the catalog service 312 , the order processing service 336 , and the change catalog service 356 . In some embodiments, management services are standardized and commoditized which may lower overall development costs, provide guidelines for developers, and increase active enclosure value and usefulness.
The arrows depicted within the management component 610 show a flow direction of information. For example, the design service 318 requests information from and provides information to the offering availability estimation service 334 . In various embodiments, the information flow may be unidirectional and/or bi-directional.
FIG. 8 is a flow chart of a method for managing IT services of an active enclosure, according to an embodiment. In a particular embodiment, the method may be used to instantiate services offered by the active enclosure 500 with reference to FIG. 5 . In an embodiment, the method may be used to manage IT services provided by the architecture 200 deployable in an e-commerce environment. At step 810 , available hardware is determined, such as hardware from dedicated resources 510 and/or blade and hardware resources 520 . In various embodiments, the available hardware includes at least one server. The available hardware may be hardware currently available and/or hardware designed to be available. For example, if particular hardware is being used for another purpose, it may be determined that this particular hardware is not available at this time. In some embodiments, a hardware discovery service, such as discovery service 322 , is used to discover and to determine available hardware. Available hardware may be within the active enclosure, within a different active enclosure of the services performing the discovering, and/or outside an active enclosure. In various embodiments, the available hardware is supplied and/or modified via user input.
At step 820 , computer executable services are determined. The services are determined based in part on the available hardware, the hardware performance, and/or the services accessible by the active enclosure 500 . For example, if a service and/or a service level requires an aggregate and/or average computer performance, and the available hardware is insufficient for the service, the service will be determined as unavailable, that is, the service will not be displayed as an offering. Some computer performance characteristics include response time, throughput (the rate of processing), utilization rates, and availability. Some computer performance metrics may include availability, response time, channel capacity, latency, completion time, service time, bandwidth, throughput, relative efficiency, scalability, performance per watt, and speed up. In parallel computing, speedup refers to how much a parallel algorithm is faster than a corresponding sequential algorithm.
At step 830 , a catalog of the computer executable services are displayed. The displayed services may be dependent on a user interface, a user's permission level, and/or the determined hardware. Similar services may be displayed or grouped together for easier selection. Different levels and/or performance of the same or similar service levels may also be displayed. In some embodiments, the catalog displays granulation of services, such as different levels of security and/or performance levels. For example, a user is presented with a high level and medium level of security.
In various embodiments, the catalog display is dynamic. For example, if a user selects a service and only one particular operating system functions well with that service, previously presented operating systems may be removed as to narrow the selection of appropriate operating systems. In some embodiments, the management component 610 determines an operating system based in part on a selected service. In various embodiments, a display of computer executable services is dynamic as resources are allocated for selected services. For example, if ten high performance web servers are selected and the available hardware near full capacity, then some other services that would require more than a capacity of the available hardware is no longer displayed.
At step 840 , the active enclosure 500 receives a selection of a service of the computer executable services. In various embodiments, a selection may be a bundle of services and/or performance levels, for example, a high performance database may be bundled with an operating system. In some embodiments, the catalog options are dynamic and may change depending on a user's selection. For example, if a user selects a database with high performance, some options previously presented may be removed, as the combination of the selected service may not be optimal with the removed services. In some embodiments, the selectable services may change dynamically via communications between the consumer management service 358 , the catalog service 312 , the change catalog service 356 , and the offering availability estimation service 334 . In various embodiments, the received selection may be a selection of the declarative specification.
At step 850 , the selected service is instantiated. The service may be instantiated on the active enclosure 500 , on a slave active enclosure, such as active enclosure slave 620 , another computer, and/or a combination of computers, as in the case where multiple computers are used. The service is instantiated from a service model. The service model includes the selected service. In various embodiments, the service model includes one or more other service models containing multiple service selections. The service model may be saved and/or stored for later use. In various embodiments, a previous selection of services may be dynamically modified, increased, and/or decreased at any time. For example, if a user wished to downgrade from a high power web service to a medium power web server, the service model may be changed. Thereby, further instantiation of the service model may generate different end points on different resources. In some embodiments, management software allocates resources and end points for multiple service models upon instantiation.
In various embodiments, the management component 610 transfers data over the Internet to generate the service model. Data transferred may include a security key, a license, updates, and/or a full service application. In some embodiments, the management component 610 transfers data over the Internet to instantiate the service model. In various embodiments, service models capture a key value of a vendor, which allows new models to be added at run time without any changes to management software to deploy new services on hardware resources.
It is understood, that various steps described above may be added, omitted, combined, altered, or performed in different orders. For example, a step may be added to refine the service model, and then instantiate the service model. Additionally, at step 840 , the offered services can be refined, the refining including a multi-step transition from the service models to a refined service model instance.
The foregoing descriptions of example embodiments have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the teaching to the precise forms disclosed. Although the subject matter has been described in a language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims. | A method comprises determining available hardware, determining computer executable services based in part on the available hardware, displaying a catalog of the computer executable services, receiving a selection of at least one service of the computer executable services, and instantiating the at least one service on the at least one server. The available hardware comprises at least one server. | 53,970 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a signal recording apparatus and method, a signal reproducing apparatus and method, a medium, and an information assembly.
2. Description of the Related Art
As the high efficient encoding system employing the VLC (Variable Length Coding) or DCT (Discrete Cosine Transform), the DVCPRO (trade name, defined in SMPTE314M as the compression method) or the MPEG (Moving Picture Experts Group) compression is provided, but the details of these compression methods are different. For example, in order to convert a DVCPRO bit stream into an MPEG bit stream, it was necessary that the DVCPRO bit stream is once uncompressed to restore the image data, which is then MPEG compressed again.
However, with the above method, since the DVCPRO bit stream is once uncompressed to restore the image data, which is then MPEG compressed again, the video signal is compressed twice, resulting in a problem that the image quality is degraded inevitably.
On the contrary, the present inventor proposed a conversion method which is able to convert a bit stream subjected to the DVCPRO compression to an MPEG bit stream, only by employing the bit stream conversion (refer to Japanese Patent Laid-Open No. 2000-165879). However, the present inventor found a problem that the number of quantization steps may be sometimes extended to implement a compression method which is capable of such bit stream conversion, in which case the conventional compression method can not be employed.
SUMMARY OF THE INVENTION
In view of the above-mentioned problems, it is an object of the invention to provide a signal recording apparatus and method which can implement a compression method capable of expanding the number of quantization steps, a signal reproducing apparatus and method which can reproduce a signal compressed in accordance with the compression method, a medium, and an information assembly.
One aspect of the present invention is a signal recording apparatus, comprising:
quantization means of quantizing a signal employing a quantization step;
quantization information creating means of creating plural pieces of quantization information to specify said quantization step;
encoding means of generating an encoded signal from said quantized signal; and
recording means of recording a compressed signal having data containing said plural pieces of quantization information and said encoded signal.
Another aspect of the present invention is the signal recording apparatus wherein said quantization step is a product of a basic quantization step and a multiplier factor to be combined with said basic quantization step, and
said data is a quantization number for specifying said basic quantization step and the multiplier factor information for specifying said multiplier factor to be combined with said basic quantization step.
Still another aspect of the present invention is the signal recording apparatus wherein said quantization step is uniform in a macro block comprised of DCT blocks,
said quantization number is recorded for each said macro block, and
said multiplier factor information is recorded for each said DTC block.
Yet another aspect of the present invention is the signal recording apparatus further comprising range conversion means of range converting said quantized signal using a range conversion multiplier factor which is represented as the power of 2,
wherein said data had the information regarding said range conversion multiplier factor.
Still yet another aspect of the present invention is the signal recording apparatus wherein said quantization step is a product of a basic quantization step and a multiplier factor to be combined with said basic quantization step, and
said plural pieces of quantization information are a quatization number for specifying said basic quantization step and the multiplier factor information for specifying said multiplier factor to be combined with said basic quantization step,
wherein the information involving the range conversion multiplier factor means the overall multiplier factor information consisting of the information regarding the range conversion multiplier factor and the information on the basis of said multiplier factor information.
A further aspect of the present invention is the signal recording apparatus wherein the multiplier factor to be combined with said basic quantization step is the power of 2, said multiplier factor information being the power exponent,
and said overall multiplier factor information is a sum of its power exponent and the power exponent of the range conversion multiplier factor represented as the power of 2.
A still further aspect of the present invention is the signal recording apparatus wherein said quantization step is uniform in a macro block comprised of DCT blocks,
said quantization number is recorded for each said macro block, and
said sum is recorded for each said DTC block.
A yet further aspect of the present invention is the signal recording apparatus wherein said signal has 12 bits,
said range converted signal has 9 bits, and
said overall multiplier factor information had 2 bits or less.
A still yet further aspect of the present invention is a signal recording method, comprising the steps of:
quantizing a signal employing a quatization step;
creating plural pieces of quantization information to specify said quantization step;
generating an encoded signal from said quantized signal; and
recording a compressed signal having data containing said plural pieces of quantization information and said encoded signal.
A further aspect of the present invention is a signal reproducing apparatus, comprising:
reproduction means of reproducing the data containing plural pieces of quantization information for specifying a quantization step used in quantizing the signal and an encoded signal to be generated from said quantized signal from a compressed signal recorded as a signal having the data and said encoded signal;
quantization step configuration means of configuring a quantization step on the basis of plural pieces of said reproduced quantiztion information; and
inverse quantization means of making the inverse quantization in accordance with said configured quantization step on the basis of said reproduced encoded signal.
An additional aspect of the present invention is the signal reproducing apparatus wherein said quantized signal is range converted using a range conversion multiplier factor which is represented as the power of 2, and
said data has the information regarding said range conversion multiplier factor,
said signal reproducing apparatus comprising inverse range conversion means of making the inverse range conversion on the basis of said encoded signal and the information regarding said range conversion multiplier factor,
said inverse quantization in accordance with said configured quantization step being effected for said signal which has undergone the inverse range conversion on the basis of said encoded signal.
A still additional aspect of the present invention is the signal reproducing apparatus wherein said quantization step used in quantizing the signal is a product of a basic quantization step and a multiplier factor to be combined with said basic quantization step, and
said plural pieces of quantization information is a quantization number for specifying said basic quantization step and the multiplier factor information for specifying said multiplier factor to be combined with said basic quantization step,
wherein the information involving said range conversion multiplier factor means the overall multiplier factor information consisting of the information regarding its range conversion multiplier factor and the information of the basis of said multiplier factor information.
A yet additional aspect of the present invention is the signal reproducing apparatus wherein the multiplier factor to be combined with said basic quantization step is the power of 2, said multiplier factor information being the power exponent, and
said overall multiplier factor information is a sum of its power exponent and the power exponent of the range conversion multiplier factor represented as said power of 2.
A still yet additional aspect of the present invention is the signal reproducing apparatus wherein said quantization step used in quantizing said signal is uniform in a macro block composed of DCT blocks,
said quantization number is recorded for each said macro block, and
said sum is recorded for each said DTC block.
A supplementary aspect of the present invention is the signal reproducing apparatus wherein said quantization step configured is a product of a not greater value among the minimum value of the sums recorded for said DCT blocks within said macro block and the maximum value which the multiplier factor information for specifying the multiplier factor to be combined with the basic quantization step can take, and a quantization number recorded for each said macro block.
A still supplementary aspect of the present invention is a signal reproducing method, comprising the steps of:
reproducing the data containing plural pieces of quantization information for specifying a quantization step used in quantizing a signal and an encoded signal to be generated from said quantized signal from a compressed signal recorded as a signal having the data and said encoded signal;
configuring the quantization step on the basis of plural pieces of said quantization information reproduced; and
making the inverse quantization in accordance with said configured quantization step on the basis of said reproduced encoded signal.
A yet supplementary aspect of the present invention is a medium for carrying a program and/or the data for enabling a computer to execute all or some functions provided for means in whole or part of the invention wherein said medium can be processed by said computer.
A still yet supplementary aspect of the present invention is a medium for carrying a program and/or the data for enabling a computer to execute all or some operations provided for steps in whole or part of the invention wherein said medium can be processed by said computer.
Another aspect of the present invention is an information assembly which is a program and/or the data for enabling a computer to execute all or some functions provided for means in whole or part of the invention.
Still another aspect of the present invention is an information assembly which is a program and/or the data for enabling a computer to execute all or some operations provided for steps in whole or part of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an explanatory view for explaining an embodiment of the present invention;
FIG. 2 is a table for effecting a quantization step conversion in the embodiment of the invention (two tables are provided on account of space consideration);
FIG. 3 is a table for effecting a basic quantization number conversion in the embodiment of the invention;
FIG. 4 is a table for effecting a multiplier factor conversion in the embodiment of the invention;
FIG. 5 is a block diagram for explaining an embodiment 2 of the invention;
FIG. 6 is an explanatory view for explaining an embodiment 3 of the invention;
FIG. 7A is an explanatory view for explaining an input signal which is to be D-range converted in the embodiment of the invention.
FIG. 7B is an explanatory view for explaining an output signal which has been D-range converted in the embodiment of the invention;
FIG. 8 is a block diagram for explaining an embodiment 4 of the invention;
FIG. 9 is an explanatory view for explaining an embodiment 5 of the invention; and
FIG. 10 is a block diagram for explaining an embodiment 6 of the invention.
DESCRIPTION OF SYMBOLS
501 , 801 Input terminal
502 , 802 Blocking unit
503 , 803 Orthogonal transformation unit
504 , 804 Quantizer
505 , 806 Variable length encoder
506 , 807 Quantization step converter
507 , 809 Formatter
508 , 810 Recorder
509 , 811 , 1011 Magnetic tape
805 D-range converter
808 Adder
1001 Output terminal
1002 Inverse blocking unit
1003 Inverse orthogonal transformation unit
1004 Inverse quantizer
1005 D-range expander
1006 Variable length decoder
1007 Quantization step creating unit
1008 Minimum multiplier factor information detector
1009 Inverse formatter
1010 Reproducer
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present inventor proposed a conversion method which is able to convert a bit stream subjected to the DVCPRO compression to an MPEG bit stream, for example, only by employing the bit stream conversion, as described before (refer to Japanese Patent Laid-Open No. 11-264521). To implement the compression method capable of such bit stream conversion, it is often required to increase the number of quantization steps or the effective number of bits for the AC component after quantization. However, if they are simply increased, the data cannot be recorded in accordance with the conventional compression method.
Thus, the present inventor invented a new compression method capable of bit stream conversion as previously described, and a new reproduction method for reproducing a signal compressed in accordance with such compression method. These compression and reproduction methods will be described below with reference to the drawings.
(Embodiment 1)
Referring now to FIGS. 1 to 4 , a video signal recording method according to an embodiment 1 of the invention will be described below. FIG. 1 is an explanatory view for explaining the video signal recording method according to the embodiment 1. In this embodiment, it is assumed that the number of quantization steps that allows for the recording is 15 kinds, as represented in terms of four bits, and the number of quantization steps for use in the quantization is 31 kinds, as represented in terms of five bits.
As shown in FIG. 1 , an input signal is quantized, and a quantized signal and a quantization step used in the quantization, are output as the data. Normally, the quantized signal is variable length encoded and recorded together with the quantization step used, but because a greater number of quantization steps are used in this embodiment, they can not recorded directly. Therefore, the number of steps is reduced from 31 kinds to 15 kinds, employing the following method.
That is, the quantization step used in the quantization is divided into a basic quantization step and a multiplier factor, employing a table as shown in FIG. 2 (two tables are provided on account of space consideration). For example, if the quantization step used is 72, the basic quantization step is 18 and the multiplier factor is 4.
Then, the basic quantization step is converted into the quantization number, employing a table as shown in FIG. 3 , and the multiplier factor is converted into the multiplier factor information, employing a table-as shown in FIG. 4 . In the above example, the quantization step 18 and the multiplier factor 4 are converted into the quantization number 10 and the multiplier factor information 2 , respectively.
The quantization number and the multiplier factor information as obtained in this way are recorded together with the data obtained by variable length encoding the quantized signal.
Note that the location for recording the multiplier factor information as shown in the embodiment 1 is arbitrary. For example, it may be a location for recording the class information in a unit of DCT block in the DVCPRO compression, which is unnecessary to implement a compression method for creating a DVCPRO bit stream which can be bit stream converted into an MPEG bit stream, as explained in this embodiment (in this case, the multiplier factor itself may be recorded instead of the multiplier factor information). Of course, in the previous case, the location for recording the quantization number of MPEG bit stream may be, for example, the location at which the quantization number of the original MPEG bit stream has been recorded. In this way, the number of quantization steps can be extended by recording the quantization number corresponding to the basic quantization step for determining the quantization step and the multiplier factor information indicating the multiplier factor.
Note that if the multiplier factor information is recorded in a unit of DCT block, it is possible to limit the range of an error within a DCT block where the error has occurred, even when the error has occurred in the multiplier factor information recorded.
If the quantization step is divisible, as described above, the information required for the quantization is increased by the amount of multiplier factor (e.g., if each of 31 quantization steps is represented in terms of four bits, 4×31=124 bits are required in the embodiment 1, but the quantization step is divided as above described, 4×15(basic quantization step)+4×3(multiplier factor)=72 bits are only required). Accordingly, in the case where a quantization table containing the elements of quantization steps is defined, it is possible to suppress the increasing amount of information.
The quantization step, the basic quantization step, the multiplier factor, the quantization number, and the multiplier factor information as employed in the embodiment 1 and shown in FIGS. 2 to 4 are only illustrative. In brief, the quantization step for use may be a multiplication of the basic quantization step and the multiplier factor.
If the quantization step used in the quantization is converted into the quantization number and multiplier factor information which are recordable, as described above, the number of quantization steps for use in the quantization can be extended.
(Embodiment 2)
Referring now to FIG. 5 , the configuration of a video signal recording apparatus in an embodiment 2 will be described below. FIG. 5 is a block diagram for explaining the configuration of the video signal recording apparatus in the embodiment 2. In this embodiment, it is assumed that the recordable number of quantization steps is 15 kinds as represented in terms of four bits, and the number of quantization steps for use in the quantization is 31 kinds as represented in terms of five bits.
In FIG. 5 , reference numeral 501 denotes an input terminal for inputting a video signal, reference numeral 502 denotes a blocking unit for dividing the input signal into blocks, reference numeral 503 denotes an orthogonal transformation unit for making the discrete cosine transform of the input video signal, reference numeral 504 denotes a quantizer for quantizing the video signal which has undergone the discrete cosine transform, reference numeral 505 denotes a variable length encoder for variable length encoding the quantized video signal, reference numeral 506 denotes a quantization step converter for converting the quantization step used in the quantization, reference numeral 507 denotes a formatter for transforming the input signal into the recordable data format, reference numeral 508 denotes a recorder for recording the input signal, and reference numeral 509 denotes a magnetic tape.
The quantizer 504 corresponds to quantization means of the invention; the quantization step converter 506 corresponds to quantization information creating means of the invention; variable length encoder 505 corresponds to encoding means of the invention; and means comprising the formatter 507 and the recorder 508 corresponds to recording means of the invention.
Referring to FIG. 5 again, the operation of the video signal recording apparatus in this embodiment 2 will be described below.
The blocking unit 502 divides a video signal input via the input terminal 501 into DCT blocks, and builds up a macro block by collecting a plurality of DCT blocks. The orthogonal transformation unit 503 performs the discrete cosine transform for the DCT blocks within the macro block for output to the quantizer 504 .
The quantizer 504 quantizes an alternating current component of a DCT block having undergone the discrete cosine transform within the macro block, which is an input signal, employing any quantization step among 31 kinds of quantization steps as shown in FIG. 2 , and outputs the quantized signal to the variable length encoder 505 and the quantization step used to the quantization step converter 506 , respectively.
The quantization step converter 506 obtains the quantization number and the multiplier factor information from the input quantization step, employing the method as explained in the embodiment 1, and outputs them to the formatter 507 . Also, the variable length encoder 505 applies the variable length coding to the alternating current component of the input signal for output to the formatter 507 .
The formatter 507 converts the direct current component of the input DCT block within the macro block which has undergone the discrete cosine transform, the alternating current component which is variable length encoded, the quantization number, and the multiplier factor information into the data format for recording and outputs them to the recorder 508 .
The recorder 508 records the input signal on the magnetic tape 509 .
As described above, the quantization step converter 506 converts the quantization step used in the quantization into the quantization number and the multiplier factor information which are recordable. In this way, the quantization step for use in the quantization can be extended. Also, by recording the multiplier factor information in a unit of DCT block, as previously described, it is possible to limit the range of an error within a DCT block where the error has occurred, even when the error has occurred in the recorded multiplier factor information.
In the embodiment 2, the location at which the multiplier factor information is recorded is also arbitrary. The multiplier factor itself may be recorded. The quantization step, the basic quantization step, the multiplier factor, the quantization number, and the multiplier factor information are only illustrative, as in the embodiment 1, and may take different values.
The extension in this embodiment 2 is effective not only to the magnetic tape, but also to the data on the digital interface, which is output to the formatter 507 .
(Embodiment 3)
Referring now to FIGS. 6 and 7 , a video signal recording method according to an embodiment 3 of the invention will be described below. FIG. 6 is an explanatory view for explaining the video signal recording method according to the embodiment 3. In this embodiment, it is assumed that the recordable number of quantization steps is 15 kinds as represented in terms of four bits, and the number of quantization steps for use in the quantization is 31 kinds as represented in terms of five bits. It is also assumed that the bit precision of the AC component capable of variable length coding is nine bits, and the output of quantization is twelve bits.
In FIG. 6 , an input signal is quantized, and the quantized signal, and the quantization step used in the quantization are output as the data. In this embodiment 3, the quantization step used can not be recorded directly owing to the same reason as in the embodiment 1.
Therefore, the number of quantization steps is reduced from 31 kinds to 15 kinds, with reference to FIGS. 2 and 3 , owing to the same method as in the embodiment 1. In this embodiment 3, to record in combination with the multiplier factor taking place in making a D-range (dynamic range) transformation as will be described later, the multiplier factor introduced to record the quantization step is represented by 2 to the C-th power (the multiplier factor in FIG. 2 is already set to 2 to the C-th power and may be used directly). Herein, when the quantization step of FIG. 2 is used, the value of C takes three kinds, 0, 1 and 2.
The D-range conversion will be described below. In this embodiment 3, the bit precision of the AC component capable of variable length coding is nine bits, and the quantized output is twelve bits, as previously described.
An input signal with an effective bit number of twelve bits has an effective bit number of twelve bits after being quantized. However, since the effective bit number which can be treated with the variable length coding in this embodiment is nine bits, it is required that the effective number bit of the quantized input signal is reduced from twelve bits to nine bits.
Thus, the D-range conversion in a unit of DCT block will be performed employing an explanatory view of FIG. 7 . FIG. 7A is an explanatory view of the input signal which will undergo the D-range conversion, and FIG. 7B is an explanatory view of an output signal which has undergone the D-range conversion.
That is, for the quantized input signal, the D-range (absolute value excluding the sine bits (see FIG. 7 )) within each DCT block is first calculated, and the input signal of twelve bits is transformed into the data of nine bits and the multiplier factor by deleting upper bits and lower bits, depending on this value of D-range, as shown in FIG. 7 .
Herein, the value of 2 to the Z-th power is produced as the multiplier factor, in proportion to the number of bits in deleted lower bits. Note that the Z value takes four kinds, 0, 1, 2 and 3 in the conversion from twelve bits to nine bits in this embodiment.
Thus, the overall multiplier factor information in the embodiment 3 is obtained by adding this Z and an power exponent (coefficient) C of a multiplier factor represented as the power of 2 as explained in the embodiment 1. As shown in FIG. 2 , the value of C is equal to 1 or 2 when the quantization step is 10 or greater (see FIG. 2 ). At this time, since it can be considered that the effective bit number of the quantized input signal is within nine bits, the value of Z is always equal to zero (see FIG. 7 ) , and the overall multiplier factor information which is a sum of Z and C is either 1 or 2. As shown in FIG. 2 , when the quantization-step is 8 or less, the value of C is always zero, whereas the overall multiplier factor information which is a sum of Z and C is equal to 0, 1, 2 or 3 in this case (because the value of Z is 3 at maximum, when the quantization step is 1; the value of Z is 2 at maximum, when the quantization step is 2; the value of Z is 1 at maximum, when the quantization step is 4; and the value of Z is always zero, when the quantization step is 8). In effect, the overall multiplier factor information is 0, 1, 2 or 3, and can be represented in terms of within two bits.
Accordingly, by introducing the MPEG compression, for example, the overall multiplier factor information can be recorded in two bits of the class information in a unit of DCT block which is not employed in the DVCPRO compression as explained in this embodiment (refer to Japanese Patent Laid-Open No. 11-264521). For example, the quantization number as represented (see FIG. 3 ) by any number of 1 to 15 can be recorded in four bits where the quantization number of the DVCPRO compression is recorded, and the quantization number corresponding to the basic quantization step for determining the quantization step and the overall multiplier factor information indicating the multiplier factor is recorded, whereby the number of quantization steps and the effective bit number of the AC component after quantization can be extended in the same recording format as that of the DVCPRO compression as explained in this embodiment.
In this way, the overall multiplier factor information and the quantization number are recorded together with the data obtained by variable length coding the video signal which has been D-range converted. In this embodiment, since the D-range conversion is performed in a unit of DCT block, the overall multiplier factor information is also recorded in a unit of DCT block.
As described above, the quantization step used in the quantization is converted into the quantization number and the multiplier factor which are recordable. Further, the quantized signal is converted into the data with a smaller effective bit number and the multiplier factor by the D-range conversion, and the overall multiplier factor information obtained by adding these two kinds of multiplier factors is recorded, whereby changes of the number of quantization step used in the quantization and the dynamic range of the quantized data can be made.
In this embodiment, the D-range extension is performed in a unit of DCT block, but may be made in a unit of macro block. In this case, the overall multiplier factor information is recorded in a unit of DCT block, whereby it is possible to limit the range of an error within a DCT block where the error has occurred, even if the error has occurred in the overall multiplier factor information recorded.
In the embodiment 3, the location at which the overall multiplier factor information is recorded is also arbitrary. The multiplier factor (i.e., 2 to the power of the overall multiplier factor information) itself may be recorded. The quantization step, the basic quantization step, the multiplier factor, the quantization number, and the overall multiplier factor information are only illustrative, as in the embodiment 1, and may take different values. In effect, the quantization step used may be a multiplication of the basic quantization step and the multiplier factor.
(Embodiment 4)
Referring now to FIG. 8 , the configuration of a video signal recording apparatus in an embodiment 4 will be described below. FIG. 8 is a block diagram for explaining the configuration of the video signal recording apparatus in the embodiment 4. In this embodiment, it is assumed that the recordable number of quantization steps is 15 kinds as represented in terms of four bits, and the number of quantization steps for use in the quantization is 31 kinds as represented in terms of five bits. The bit precision of the AC component capable of variable length coding is nine bits, and the output of quantization is twelve bits.
In FIG. 8 , reference numeral 801 denotes an input terminal for inputting a video signal, reference numeral 802 denotes a blocking unit for dividing the input signal into blocks, reference numeral 803 denotes an orthogonal transformation unit for making the discrete cosine transform of an input video signal, reference numeral 804 denotes a quantizer for quantizing the video signal which has undergone the discrete cosine transform, reference numeral 805 denotes a D-range converter for making the D-range conversion for the quantized signal, reference numeral 806 denotes a variable length encoder for variable length coding the video signal which has been D-range converted, reference numeral 807 denotes a quantization step converter for converting the quantization step used in the quantization, reference numeral 808 denotes an adder for adding the signal produced by the quantization step conversion and the signal produced by the D-range conversion, reference numeral 809 denotes a formatter for converting the input signal into the recordable data format, reference numeral 810 denotes a recorder for recording the input signal, and reference numeral 811 denotes a magnetic tape.
The quantizer 804 corresponds to quantization means of the invention; the D-range converter 805 corresponds to the range converting means of the invention; means comprising the quantization step converter 807 and the adder 808 corresponds to quantization information creating means of the invention; variable length encoder 806 corresponds to encoding means of the invention; and means comprising the formatter 809 and the recorder 810 corresponds to recording means of the invention.
Referring to FIG. 8 again, the operation of the video signal recording apparatus in this embodiment 4 will be described below.
The blocking unit 802 divides a video signal input via the input terminal 801 into DCT blocks, and builds up a macro block by collecting a plurality of DCT blocks. The orthogonal transformation unit 803 performs the discrete cosine transform for the DCT blocks within the macro block, and outputs the transformed DCT blocks to the quantizer 804 .
The quantizer 804 quantizes an alternating current component of DCT blocks having undergone the discrete cosine transform within the macro block, which is the input signal, employing any quantization step among 31 kinds of quantization steps as shown in FIG. 2 , and outputs the quantized signal to the D-range converter 805 and the quantization step used to the quantization step converter 807 , respectively.
The quantization step converter 807 calculates the quantization number and the power exponent (coefficient) C of the multiplier factor as represented in the C-th power of 2 from the input quantization step, employing the method explained in the embodiment 3, and outputs the quantization number to the formatter 809 , and the value of C to the adder 808 , respectively.
The D-range converter 805 converts an alternating current component of the input signal for output to the variable length encoder 806 , employing a method as explained in the embodiment 3, and calculates the value of the power exponent (coefficient) Z of the multiplier factor for output to the adder 808 .
The adder 808 calculates a sum of C and Z which are input, and outputs the sum to the formatter 809 . Also, the variable length encoder 806 applies the variable length coding to the alternating current component of the input signal which has undergone the D-range conversion and outputs the encoded alternating current component to the formatter 809 .
The formatter 809 transforms the direct current component of input DCT block within the macro block which has undergone the discrete cosine transform, the alternating current component which has undergone the variable length coding, the quantization number, and the multiplier factor information into the data format for recording and outputs them to the recorder 810 .
The recorder 810 records the input signal on the magnetic tape 811 . Note that the multiplier factor information is recorded in accordance with the unit used in the D-range extension in this embodiment.
As described above, the quantization step converter 807 transforms the quantization step used in the quantization into the quantization number and the multiplier factor which are recordable. Further, the D-range converter 805 converts the quantized signal into the data with a smaller effective bit number and the multiplier factor by the D-range conversion. The adder 808 creates the overall multiplier factor information obtained by adding these two kinds of multiplier factors. In this way, changes of the number of quantization step used in the quantization and the dynamic range of the quantized data can be made.
In this embodiment 4, the D-range extension is performed in a unit of DCT block, but may be made in a unit of macro block. In this case, the overall multiplier factor information is recorded in a unit of DCT block, whereby it is possible to limit the range of an error within a DCT block where the error has occurred, even if the error has occurred in the overall multiplier factor information recorded.
In the embodiment 4, the location at which the overall multiplier factor information is recorded is also arbitrary. The multiplier factor (i.e., 2 to the power of the overall multiplier factor information) itself may be recorded. The quantization step, the basic quantization step, the multiplier factor, the quantization number, and the overall multiplier factor information are only illustrative, as in the embodiment 3, and may take different values.
The extension in this embodiment 4 is effective not only to the magnetic tape, but also to the data on the digital interface, which is output to the formatter 809 .
(Embodiment 5)
Referring to FIG. 9 , a video signal reproducing method according to an embodiment 5 will be described below. FIG. 9 is an explanatory view for explaining the video signal reproducing method according to the embodiment 5.
This embodiment 5 involves a new video signal reproducing method for reproducing the signal recorded by quantizing each DCT block within a macro block in the same quantization step, employing the video signal recording method as explained in the embodiments 3 and 4. This signal inversely formatted (reproduced) is composed of a variable length encoded signal, the overall multiplier factor information and the quantization number, as will be described later in the embodiment 6.
Thus, among the minimum value of the overall multiplier factor information C+Z and the maximum value which the multiplier factor information C for specifying the multiplier factor to be combined with the basic quantization step can take, a not greater value M is obtained within the macro block, and the D-range extension and the quantization step configuration are effected, as described below.
That is, the variable length encoded signal is decoded in variable length, and the D-range extension is performed, employing a value subtracted by the value M. Herein, supposing that the effective bit number of the signal decoded in variable length is Y bits, the effective bit number of the signal D-range extended is equal to Y bits×(2 to the (overall multiplier factor information−M)-th power)=X bits.
The quantization number is converted into the basic quantization step with reference to a table of FIG. 3 , and the quantization step is configured, employing the value M (i.e., the product of the basic quantization step and the M-th power of 2 is the quantization step) Of course, the inverse quantization of the signal of X bits D-range extended is performed, employing this quantization step.
The inversely quantized signal is subjected to the inverse discrete cosine transform and the inverse blocking, and output as a reproduced signal, as will be described later in the embodiment 6.
As described above, it is possible to reproduce a signal compressed in accordance with a new compression method capable of extending the number of quantization steps.
The reproducing operation with the new video signal reproducing method has been thus described. In the following, explanation will be given of the reason of employing the not greater value M among the minimum value of the overall multiplier factor information and the maximum value which the multiplier factor information for specifying the multiplier factor to be combined with the basic quantization step can take will be described below in connection with an instance of transforming the DVCPRO bit stream into the MPEG bit stream (refer to Japanese Patent Laid-Open No. 11-264521). The overall multiplier factor information is recorded as a sum of the D-range conversion information and the quantization step, as already described in the embodiment 3.
For example, in recording the signal, the overall multiplier factor information is 1 in the cases where in the macro block, (1) the quantization step is 7 (hence C=0) and the exponent (coefficient) Z in the D-range transform is 1, and (2) the quantization step is 14 (hence C=1) (automatically Z=0).
In this embodiment 5, the inverse quantization is made, employing the quantization step of 14 in either case (because the minimum value of the overall multiplier factor is one in either case). On the contrary, a method can be conceived in which the overall multiplier factor information itself (i.e., one) is used to make the D-range extension, and the basic quantization step (i.e., 7) is directly used as the quantization step, unlike this embodiment. Of course, it is possible to employ any of the method of this embodiment and the above method to obtain the same reproduced signal.
Herein, a case will be considered in which the inversely quantized signal as described above is stream transformed into the MPEG stream, without applying the inverse discrete cosine transform and the inverse blocking. Since the variable length coding of MPEG is applied at this time, the code amount can be reduced with the smaller value of AC component in the DCT block. Accordingly, if the reproduced signal is identical, the quantization step should be a greater value, and it is beneficial to make use of a not greater value among the minimum value of the overall multiplier factor information C+Z and the maximum value (herein, 2) which the multiplier factor information C for specifying the multiplier factor to be combined with the basic quantization step can take. This is the reason for using a not greater value M among the minimum value of the overall multiplier factor information and the maximum value which the multiplier factor information for specifying the multiplier factor to be combined with the basic quantization step can take in this embodiment.
As described above, a not greater value M among the minimum value of the overall multiplier factor information and the maximum value which the multiplier factor information for specifying the multiplier factor to be combined with the basic quantization step can take is obtained, and by reflecting its result, the quantization step is configured to be larger, whereby the code amount after the MPEG transcode can be reduced.
(Embodiment 6)
Referring to FIG. 10 , the configuration of a video signal reproducing apparatus will be described below. FIG. 10 is a block diagram for explaining the configuration of the video signal reproducing apparatus according to the embodiment 6. In this embodiment 6, the video signal recording method as explained in the embodiments 3 and 4 is employed to quantize each DCT block within a macro block by using the same quantization step to reproduce a signal.
In FIG. 10 , reference numeral 1011 denotes a magnetic tape on which the signal is recorded, reference numeral 1010 denotes a reproducer for reproducing a signal from the magnetic tape, reference numeral 1009 denotes an inverse formatter for inversely formatting the required information from the reproduced signal, reference numeral 1008 denotes a minimum multiplier factor information detector for detecting a minimum value of the overall multiplier factor information that has been input, reference numeral 1007 denotes a quantization step creating unit for creating the quantization step from an input signal, reference numeral 1006 denotes a variable length decoder for variable length decoding the input signal, reference numeral 1005 denotes a D-range extender for extending the D-range of the input signal, reference numeral 1004 denotes an inverse quantizer for inversely quantizing the input signal, reference numeral 1003 denotes an orthogonal transformer for making the inverse discrete cosine transform of the input signal, reference numeral 1002 denotes an inverse blocking unit for unblocking the input signal, and reference numeral 1001 denotes an output terminal for outputting the reproduced signal.
The inverse quantizer 1004 corresponds to inverse quantizing means of the invention; the D-range expander 805 corresponds to inverse range converting means of the invention; means comprising the quantization step creating unit 1007 and the minimum multiplier factor information detector 1008 corresponds to quantization step constructing means of the invention; and means comprising the inverse formatter 1009 and the reproducer 1010 corresponds to reproducing means of the invention.
Referring now to FIG. 10 again, the operation of the video signal reproducing apparatus in the embodiment 6 will be described below.
The reproducer 1010 reproduces the information from the magnetic tape 1011 , and outputs the reproduced information to the inverse formatter 1009 . The inverse formatter 1009 makes the inverse formatting to reproduce the direct current component, the alternating current component that is variable length encoded, the quantization number, and the overall multiplier factor information from the information reproduced by the reproducer 1010 .
The minimum multiplier factor information detector 1008 detects the minimum value of the overall multiplier factor information, employing the method as described in the embodiment 5, and outputs a not greater value among the minimum value of the overall multiplier factor information C+Z and the maximum value which the multiplier factor information C for specifying the multiplier factor to be combined with the basic quantization step can take to the D-range expander 1005 and the quantization step creating unit 1007 .
The quantization step creating unit 1007 constructs the quantization step, employing the method as described in the embodiment 5, and outputs the constructed quantization step to the inverse quantizer 1004 .
On the other hand, the variable length decoder 1006 variable length decodes the reproduced alternating current component for output to the D-range expander 1005 . Also, the D-range expander 1005 D-range extends the alternating current component input from the variable length decoder 1006 , employing the method as described in the embodiment 5, for output to the inverse quantizer 1004 .
The inverse quantizer 1004 inversely quantizes the alternating current component which is D-range extended by the D-range expander 1005 , using the quantization step input from the quantization step creating unit 1007 , and outputs this to the inverse orthogonal transformer 1003 .
The inverse orthogonal transformer 1003 makes the inverse discrete cosine transform of the alternating current component input from the inverse quantizer 1004 and the direct current component reproduced by the inverse formatter 1009 and input through the same path as the alternating current component, for output to the inverse blocking unit 1002 .
The inverse blocking unit 1002 unblocks a blocked signal, and outputs the reproduced signal to the output terminal 1001 .
As described above, the minimum multiplier factor information detector 1008 calculates the minimum value of the overall multiplier factor information, and the quantization step creating unit 1007 constructs the quantization step to be greater by reflecting the result. In this way, the code amount after the MPEG transcode can be reduced. In this embodiment, the signal can be decoded without obtaining the minimum value of the overall multiplier factor information. Since the minimum value multiplier factor detector 1008 can be dispensed with in such case of decoding, the configuration of the video signal reproducing apparatus can be simplified.
In the embodiments 1 to 4, the recordable number of quantization steps is 15 kinds as represented in terms of four bits, the number of quantization steps for use in the quantization is 31 kinds as represented in terms of five bits. In the embodiments 3 and 4, the bit precision of the AC component capable of variable length coding is nine bits, and the output of quantization is twelve bits. However, those values are adopted for explanation of the specific example, and the present invention is not limited thereto.
While the multiplier factor to be combined with the basic quantization step of the invention is the power of 2 in the above embodiments, the invention is not limited thereto but may take arbitrary number for such multiplier factor.
In the above embodiment, the overall multiplier factor information is a sum of the power exponent of the multiplier factor to be combined with the basic quantization step which is the power of 2, and the power exponent of the range conversion multiplier factor. However, the invention is not limited thereto, but the overall multiplier factor information may be a pair of the multiplier factor to be combined with the basic quantization step which is not the power of 2 and the range conversion multiplier factor itself, for example.
The quantization step used in the quantization of the signal according to the invention is uniform in the macro block composed of DCT blocks in the above embodiments, but may be different in each DCT block within the macro block, for example.
The quantized signal of the invention is range converted in the above embodiments, but may not be range converted, unless required. In the reproduction of such signal, the inverse range conversion is not necessary to perform, and the signal reproducing apparatus of the invention may not have the inverse range converting means.
A medium for carrying a program and/or the data for enabling a computer to execute all or some functions provided for means in whole or part of the above embodiments is produced, and may be used to enable the computer to perform the above operation in accordance with the read program and/or the data.
An information assembly for carrying a program and/or the data for enabling a computer to execute all or some functions provided for means in whole or part of the above embodiments is produced, and may be used to enable the computer to perform the above operation in accordance with the read program and/or the data structure.
Herein, the data involves the data structure, the data format, and the kind of data. Also, the medium involves the recording medium such as ROM, the transmission medium for the Internet, and the transmission medium for light, radio wave and sound wave. Also, the carrying medium involves the recording medium for recording the program and/or the data, and the transmission medium for transmitting the program and/or the data, for example. To be processable by the computer means to be readable by the computer in the case of the recording medium such as ROM, or to be handleable by the computer as a result of transmitting the program and/or the data in the case of the transmission medium. Also, the information assembly involves the software such as the program and/or the data, for example.
As will be apparent from the above description, the video signal recording method of the invention comprises quantizing an input video signal employing L (L≦M×N) kinds of quantization steps among M×N kinds of quantization steps of which the values are determined by the multiplication of M kinds (M≧1) of basic quantization steps and N kinds (N≧1) of multiplier factors, wherein the quantized signal is variable length encoded, the quantization number corresponding to the basic quantization step for determining the quantization step used in the quantization, the multiplier factor information corresponding to the multiplier factor, and the variable length encoded signal are recorded. Thereby, the number of quantization steps can be extended in the same recording format as employed in the DVCPRO compression.
The video signal recording apparatus of the invention comprises block division means of dividing an input video signal into DCT blocks and constructing a macro block from a plurality of DCT blocks, discrete cosine transform means of discrete cosine transforming each DCT block within the macro block, quantization means of quantizing an alternating current component of DCT block which has undergone the discrete cosine transform employing L (L≦M×N) kinds of quantization steps among MXN kinds of quantization steps of which the values are determined by the multiplication of M kinds (M≧1) of basic quantization steps and N kinds (N≧1) of multiplier factors, quantization information determination means of determining the quantization number corresponding to the basic quantization step and the multiplier factor information corresponding to the multiplier factor for determining the quantization step used in the quantization means, variable length coding means of variable length coding the alternating current signal quantized, and recording means of recording the direct current component of DCT block which has undergone the discrete cosine transform, the alternating current signal which is variable length encoded, the quantization number, and the multiplier factor information. Thereby, this video signal recording apparatus can exhibit the same effect as obtained with the video signal recording method of the invention, as described above.
The video signal recording method of the invention comprises quantizing an input video signal employing L (L≦M×N) kinds of quantization steps among M×N kinds of quantization steps of which the values are determined by the multiplication of M kinds (M≧1) of basic quantization steps and N kinds of multiplier factors as represented by 2 to the K-th (K=0, 1, 2, . . . ) power, range converting the quantized signal of X bits into Y (Y<X) bits×(2 to the Z-th power (Z=0, 1, 2, . . . )), variable length coding a Y-bit signal within the range converted signal, and recording the quantization number corresponding to the basic quantization step for determining the quantization step used in the quantization, the overall multiplier factor information corresponding to the sum of the exponent K of multiplier factor and Z obtained in the range conversion, and the variable length encoded signal. Thereby, the effective bit number of the AC component after quantization can be extended.
The video signal recording apparatus of the invention comprises block division means of dividing an input video signal into DCT blocks and constructing a macro block from a plurality of DCT blocks, discrete cosine transform means of discrete cosine transforming each DCT block within the macro block, quantization means of quantizing an alternating current component of DCT block which has undergone the discrete cosine transform employing L (L≦M×N) kinds of quantization steps among M×N kinds of quantization steps of which the values are determined by the multiplication of M kinds (M≧1) of basic quantization steps and N kinds of multiplier factors as represented by 2 to the K-th (K=0, 1, 2, . . . ) power to create a quantized alternating current signal having an effective bit number of X bits, range conversion means of converting the quantized alternating current signal of Xbits into Y (Y<X) bits×(2 to the Z-th (Z=0, 1, 2, . . . )), quantization information determination means of determining the quantization number corresponding to the basic quantization step for determining the quantization step used in the quantization and the exponent K of multiplier factor, multiplier factor determination means of determining the overall multiplier factor information by calculating the sum of K and Z, variable length coding means of variable length coding a Y-bit signal within the quantized alternating current signal which has undergone the range conversion, and recording means of recording the direct current component of DCT block which has undergone the discrete cosine transform, the quantized alternating current signal which is variable length encoded, the quantization number, and the overall multiplier factor information. Thereby, this video signal recording apparatus can exhibit the same effect as obtained with the video signal recording method of the invention, as described above.
A video signal reproducing method of the invention for reproducing a video signal recorded in accordance with the video signal recording method of the invention comprises reproducing the variable length encoded signal recorded, the quantization number and the overall multiplier factor information, and making the inverse quantization by variable length decoding the variable length encoded signal, employing the quantization step which is obtained by multiplying the basic quantization step corresponding to the quantization number by (2 to the P-th power) with the coefficient P corresponding to the overall multiplier factor information. Thereby, the signal recorded in accordance with the video signal recording method of the invention can be reproduced. Further, by using the minimum value of the overall multiplier factor information, the signal can be decoded with the reduced code amount transformed into the MPEG bit stream.
A video signal reproducing apparatus of the invention, which for example reproduces a video signal recorded by the video signal recording apparatus of the invention, comprises reproduction means of reproducing the direct current component recorded in a unit of macro block composed of a plurality of DCT blocks, the alternating current component which is variable length encoded, the quantization number and the overall multiplier factor information, variable length decoding means of variable length decoding the alternating current component which is variable length encoded to create an alternating current signal, quantization step determining means of determining the quantization step by calculating the basic quantization step corresponding to the quantization number and the exponent P corresponding to the overall multiplier factor information and multiplying the basic quantization step by (2 to the P-th power), and inverse quantization means of inversely quantizing the alternating current component with the quantization step. Thereby, the video signal reproducing apparatus of the invention can exhibit the same effect as obtained with the video signal reproducing method of the invention.
As described above, the present invention can provide a signal recording apparatus, a signal recording method, a signal reproducing apparatus, a signal reproducing method, a medium, and an information assembly, which are capable of changing a compression method with less degradation of data than conventionally.
As will be clear from the above description, the present invention has the advantage of implementing the compression method which is capable of extending the number of quantization steps. | A signal recording apparatus includes a quantizer for quantizing a signal employing a quantization step. The apparatus further includes a quantization information creator for creating plural pieces of quantization information to specify the quantization step, an encoder for generating an encoded signal from the quantized signal, and a recorder for recording a compressed signal having data containing the plural pieces of quantization information and the encoded signal. | 58,916 |
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to high speed communications, in particular, to an interface device between a transmitting device and a receiving device of a transmission system, wherein the transmitting device is capable of automatic compensation of cross-talk effects in the interface device by using information stored in an integrated circuit attached to that interface device. .
The present invention is particularly applicable to interfaces to logic and memory devices, to test equipment for testing semiconductor devices and to high speed communications.
2. Background of the Invention
It shall be appreciated that the invention can be applied to a wide variety of fields, though examples and background information, without limitation to the scope of the invention, represent automated semiconductor testing. Test equipment is typically used to determine whether a device under test (“DUT”) follows a set of timing specifications. Accordingly, timing accuracy plays a vital role in the design of test equipment because a discrepancy in the timing accuracy can result in an incorrect classification of a DUT.
A typical test equipment comprises a tester and a device interface board (DIB) connected thereto. A test socket adapted to receive a DUT is mounted on the interface board. A plurality of transmission lines such as coaxial cables or strip lines are provided which join contacts of the test socket and junctions of the interface board with the testing device. The tester and the interface board are interconnected by urging pin electrodes provided on one of them against planar electrodes provided on the other, by pressing planar electrodes provided on both of them against each other, or by engaging connectors provided on both of them with each other. A device to be tested is mounted on the test socket.
A signal generator in the tester generates a test signal of logical levels at specified timings, based on a pattern and a timing signal. The test signal is converted by a driver in the tester into a signal voltage of a predetermined level such as the ECL or TTL level, which is supplied from the tester to pins of the DUT via the transmission lines of the interface board. Then, the resulting DUT output response signals are provided via the transmission lines to the tester, wherein they are compared by a comparator with a reference voltage for the decision of their logical level. Each logical signal based on the decision is compared by a logical comparator with an expected value pattern contained in the data pattern, and the output from the logical comparator is used to determine whether the DUT is good or bad.
In this instance, it is necessary that the timing for sending out the test signal and the timing for fetching the DUT output response signal in the tester be determined taking into account not only the relative delay times between respective circuits in the tester corresponding to the pins of the DUT or delays in the transmission lines but also crosstalk or crosstalk artifacts times of the transmission lines of the interface board which are connected to the pins of the DUT.
The following methods have been proposed to adjust the test signal send-out timing and the DUT output response signal acquisition timing.
According to one of these methods, the transmission lines are made equal in length to make the above-mentioned delay times in the interface board constant, and in the tester, the above-said timing is corrected using data on the constant time. This method suffers from differences between the physical length—all wires are normally the same actual length, and the electrical length for a given pattern. According to another method, the actual lengths of the transmission lines and the delay times are measured, the measured data are stored in a memory provided in the tester and the above-said timing is adjusted using the data read out of the memory. This method tries to adjust delay times by measuring the electrical length of isolated traces. In practice, the electrical length is influenced heavily by crosstalk, so the electrical length during measurement is not an accurate representation of the electrical length in service.
According to still another method, such as described in U.S. Pat. No. 5,225,775, the DUT connection board is equipped with a nonvolatile storage for storing data on the delay times in the transmission line on the connection board corresponding to each terminal of the device under test, and the tester main body unit is so constructed as to adjust the test signal send-out timing and the device output response signal acquisition timing based on the data read out of the storage. Storing the actual topography and topography dependent parameters in a serial presence detect (SPD) memory and adjusting a control signal accordingly is known also from U.S. Pat. No. 6,321,282. This suffers the same problems as previously mentioned, i.e. the electrical length during isolated test differs from that in service due to the neglect of the crosstalk coefficients.
According to U.S. Pat. No. 5,225,775, a calibration procedure is performed by selecting one of a plurality of transmission lines on the connection board and measuring a time required for a signal to pass via this connection board, while all the other transmission lines are silent. Thus, cross-talk from adjacent lines is not taken into account.
As the speeds at which electronic devices operate have increased dramatically and it is not uncommon for these memory devices to run at frequencies at or greater than 100 MHz, the above mentioned methods fails to provide an adequate accuracy of timings. To test at such high frequencies, tester systems include a clock running at or above the maximum frequency at which devices can be tested. As clock frequencies increase, factors such as transmission line crosstalk or crosstalk artifacts such as uneven transmission line performance become significant. To compensate for such variations, some tester systems, such as production-oriented automatic test equipment (ATE) testers, use very high frequency (some as high as 1 GHz) to provide very fine resolutions. However, in these systems crosstalk in signal paths can influence greatly the accuracy of calibration.
Still one more problem arises when the number of testing signals required to test a semiconductor device increases and it becomes more and more complicated technically to compensate timing errors for individual signals in each separate transmission line.
The similar problems arise in high speed communications where it is required to reduce artifacts introduced into a communication channel from the limited and non-linear characteristics of the channel, such as by reflections not being absorbed efficiently or cross-talk between the transmission lines.
BRIEF SUMMARY OF THE INVENTION
Generally, the present invention is directed to an interface device, such as between a transmitter and a receiver in a communication channel, or such as an interface board for a tester system, provided with a means to compensate for uneven transmission line performance, e.g. caused by crosstalk or crosstalk artifacts using stored data on transmission characteristics.
According to one aspect of the invention, an interface device is provided for connecting a transmitting device having a first plurality of terminals and deriving a plurality of signals of a predetermined data pattern, the signals being arranged in groups, and a receiving device having a second plurality of terminals for receiving said signals;
the interface device having, respectively, input connectors connectable to said transmitter's terminals and output connectors connectable to said receiver's terminals, the inputs and outputs being interconnected by transmission lines within said interface device, the transmission lines being arranged in groups corresponding to said groups of signals; and
a storage for storing data on interconnections between said first plurality and second plurality of terminals and data on timing errors caused by crosstalk in each said group of transmission lines, measured with respect to a reference signal and relating to a specific data pattern, for each of said stored interconnection;
wherein the transmitting device is capable of compensating for timing errors in said groups of transmission lines using data read from said memory storage.
In another aspect, a test system is provided incorporating the interface device according to the invention.
In still another aspect, a method of compensation of timing errors in transmission lines is provided comprising the steps of:
transmitting via transmission lines a plurality of signals of a predetermined data pattern to be applied to a semiconductor device, the signals being driven in groups; comparing the output response of a group of signals with a reference signal level; storing in a non-volatile memory data on timing errors in said transmission lines relating to specific data patterns, for each separate group of signals; and compensating for timing errors in said transmission lines for each said group of signals using said data read from said nonvolatile memory.
In still another aspect, a method of testing semiconductor devices employing the above method of compensation is provided.
In FIG. 5 , a typical interface device 52 according to the invention is shown having a plurality of transmission lines within the device (not shown), input connectors 57 for connecting to a tester head, a DUT socket 55 with output connectors 51 for connecting to a DUT and a storage 54 for storing data on interconnections and correction coefficients for compensating for timing errors caused by crosstalk in transmission lines.
According to the present invention, a tester interface such as a DUT interface board (DIB) is equipped with a means for storing the results of measurements of transmission line behavior caused by the combination of crosstalk or crosstalk artifacts and physical manufacturing tolerances or impedance errors in signal paths in a test head and interface board. The timing errors are measured for a group of signals and compensated by applying correction coefficients to a whole group of signals which provides increasing greatly the effectiveness of compensation and reduces time consuming calibration operations. In testers, the information is used to enable accurate calibration of timings of signals associated with a DUT.
In the testing equipment of the above construction according to the present invention, the length of the transmission lines on the interface board corresponding to the respective groups of terminals of the DUT are all known precisely from PCB design software. This software enables the DIB card to be designed so as to completely eliminate inaccuracy caused by errors in trace lengths. What remains are manufacturing errors and crosstalk. While manufacturing errors may be measured at the production stage and the resulting correction coefficients may be stored in a memory storage mounted on a DIB, the effect of crosstalk is still the key source of inaccuracy left which depends on particular data pattern. Measurements of crosstalk and compensation thereof automatically equilibrates variations in manufacturing impedance due to fluctuations in PCB manufacturing process such as fluctuations in thickness, dielectric constants and other technology and material parameters which may be revealed to different extent during usage.
According to the present invention, the data on crosstalk and crosstalk artifacts is stored together with the information about interconnections required for a certain type of the DUT. The data on interconnections is stored in a storage device attached to the DIB and is retrieved automatically when the test is started. As the crosstalk and crosstalk artifacts depend on particular interconnection scheme, the measurements are conducted not only for each test pattern, but for each card interconnection. This is useful as the variety of DUT form factors requires many different DIB cards to be used in connection with each different DUT type. Though the interconnections for different DUT types are different, to unify the DIB card treatment by software, it is very convenient to store the information about DIB card interconnections comprising crosstalk information, in DIB card itself. A more detailed description of the DIB card of the present invention is presented in Attachment A.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a schematic block diagram of a testing device according to the invention;
FIG. 2 is a block diagram illustrating example equipment for measurement of crosstalk in transmission lines of a DIB according to the present invention;
FIG. 3 is a flowchart of the method of compensating crosstalk in test results;
FIG. 4 a is a diagram explaining the influence of crosstalk in the transmission lines of the interface board;
FIG. 4 b is a graph illustrating a calibration procedure in relation to reference signal, wherein the calibration is performed at a rising edge of a clock signal;
FIG. 4 c is a graph illustrating a calibration procedure in relation to reference signal, wherein the calibration is performed at a falling edge of a clock signal;
FIG. 5 is a plan view of an example embodiment of the device interface board.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be further described in detail with reference to the accompanying drawings illustrating an example embodiment of the device interface board for an IC tester. However, it shall be appreciated that the present invention is not limited to ATE and may be equally employed by a specialist in the art to communication equipment.
As shown in FIG. 1 , the DUT testing device is provided with a tester 1 and a device interface board (DIB) 2 . The tester includes a clock generator 11 , a pattern generator 12 , timing control circuits 13 , drivers 14 , receivers 15 and fault comparator 16 for storing the data for cycles containing differences between data provided by pattern generator 12 and DUT 3 . Delays 4 , 5 , 6 are used to provide compensation for timing errors in transmission lines within interface device 2 . The tester is controlled by a computer 18 through interface 17 . The controlling computer may be external as well as an internal computer may be provided.
The clock generator 11 generates, based on an internal operation clock CLK, a clock signal to be applied to the drivers 14 , receivers 15 and DUT 3 through timing control circuits 13 . Timing control 13 comprises a means to control the crosstalk or crosstalk artifacts in output signals from drivers 14 and crosstalk or crosstalk artifacts in receivers' 15 clock signals. The pattern generator 12 operates in synchronization with the system clock CLK from the clock generator 11 to generate patterns to be provided via timing control 13 to the terminal pins of the DUT 3 .
The DIB 2 comprises a storage 4 , such as non-volatile memory, e.g. flash memory, for storing data on timing errors caused by crosstalk or crosstalk artifacts in transmission lines in the board 2 corresponding to each terminal of the DUT to make corrections to the results of tests based on the data read out from the storage 4 . The storage memory shall be of a type allowing to read/write data after each calibration procedure and store them when the device is switched off.
The fault comparator 16 compares the obtained signal from the DUT with the expected value from the pattern generator 12 to produce test results which are downloaded by the computer 18 through interface 17 for further processing by a computer software. The said software uses the crosstalk or crosstalk artifacts data stored in the storage 4 for compensating timing errors in final results for a current data pattern. The same data may be used to manage the timing control circuitry 13 to compensate effects of crosstalk for each particular pattern by adding these data to values which shall define crosstalk or crosstalk artifacts in drivers 14 .
The above test system may be essentially the same as disclosed, for example, in U.S. application Ser. No. 60/209,613 “Test systems for protocol memories” filed on 6 Jun. 2000, or PCT/RU01/00234 filed on Jun. 06, 2001, the specification of which applications is incorporated herein by reference.
As shown in FIG. 2 , on the interface device 22 which is in this example a device interface board (DIB) there is mounted the DUT socket 25 and the transmission lines 26 are provided within the DIB 22 which connect contacts of the socket 25 to the junctions between the DIB 22 and the tester 21 .
The lengths of the transmission lines 26 are the same. Though the transmission lines are separated as a rule by insulation material, they have mutual capacitance and inductance caused by magnetic and electric fields having areas of intersections of force lines as illustrated in FIG. 4 . This cross-talk influence is exacerbated in synchronous systems wherein all the signals are synchronized, i.e. they change state at one and the same time. These effects cause a part of the signal to penetrate from one transmission line into another. As a result, a moment when the signal crosses the threshold at the output of transmission line depends on signals in other transmission lines, i.e. it depends on a particular data pattern. Thus, one of the important features of the present invention is that the timing errors caused by crosstalk effects are measured when the tester is running a test pattern to provide compensation of the timing error caused by this particular combination of signals. The knowledge of the influence of the signal crosstalk for each data pattern provides a basis for crosstalk compensation for each data pattern. Another important feature is that the timing errors are measured for a group of signals and the compensation coefficients are applied to these groups also to adjust the position of this group in whole with respect to a reference signal.
To the contrary, according to a method as described in U.S. Pat. No. 5,225,775, the measurements of the delay times and storing of the measured data into the storage are performed on the stage when the interface device has been fabricated, i.e. with no regard to a particular test pattern, also, the possibility of correcting these data during the exploitation of the interface device in a particular application is neither proposed, nor surmised.
Moreover, according to the known method, the delay times are stored for each transmission line and correction is applied to each signal. However, in practice, in high speed transmission of signals, it has been discovered that the skew between signals within one group is relatively low comparing to the skew between different groups of signals. Thus, it is assumed in the present invention that the timing skew of individual signals within one group is less than the skew of the group of signals in whole. For example, the group skew equal to ±250 ps means that the individual signal skew is lower than ±250 ps.
FIG. 2 illustrates a method according to which the aforementioned timing errors caused by crosstalk in the transmission lines of the interface device are measured and the measured data is stored in the storage on the interface device.
The interface device 22 comprises socket 25 , which can be for example, a DIMM socket. During the calibration, no DUT is mounted on the interface device. Instead, preferably, a crosstalk card 27 is installed in DUT socket 25 . Generally, the crosstalk card is a PCB having no electronic components mounted thereon and comprising contact points 28 which correspond to contact points of a real DUT (e.g. a DIMM) and which are made connectable to oscilloscope probes 29 . To provide maximum accuracy of measurements, the crosstalk card preferably has transmission lines of minimum electrical length and the test points arranged closely to the ground point.
However, in a general case, the use of this card is not necessary, while the probes may be connected directly to interface device 22 close to the DUT socket, or another suitable device may be used for this purpose.
A tester, such as a conventional tester for testing synchronous memory, e.g. BT72 manufactured by Acuid Corporation Limited (Guernsey), comprising a tester head 21 and a tester main body (not shown in FIG. 2 ), is powered on, and the selected data pattern is running. The tester shall be fully in operation and the tester head's flash memory (SPD, serial presence detect) and an interface device 22 shall be initialized with start-up values. At this stage the SPD Reader/Writer software tool is used to initialize the tester head's SPD. The next step is initialization of an SPD installed on the interface device 22 .
The SPD installed on the interface device, or DIB (device interface board), is generally designed so that it comprises at least three arrays of data that is read by the tester and provided to the controlling computer. In the first array, the number and type of the connector of the DIB is stored. In the second array, a table is stored relating to interconnection of contacts of the DUT and test signals. In the third array, correction coefficients are stored that are written to this memory during production and bears information on timing errors in transmission lines, measured during calibration. These correction coefficients are further adjusted according to the invention for crosstalk timing errors.
To obtain the required accuracy of measurements, an oscilloscope 20 is used, which may be a calibrated 1 GHz bandwidth, 4 GS/s sample, or better version digital oscilloscope having at least two active probes having input capacitance not more than 1 pF, for example, TDS794 manufactured by Tektronix Inc. (OR). One probe of the oscilloscope is connected to the crosstalk card 27 at a point CK 0 providing a signal used for triggering the scope, preferably, a clock signal. The second probe of the oscilloscope is connected sequentially to each of the other signal lines.
The signals are grouped in accordance with its functionality, so that, for example, data signals are arranged in separate groups, clock signals are arranged in other separate group, DQ (bi-directional data) signals are arranged in another groups. An example of typical signal grouping is shown in Appendix B.
The crosstalk timing error of a selected group of signals is measured with respect to the reference clock signal CK 0 . Another clock signal CK 1 is used to trigger the scope. Note that, for timing error measurement, all signals are observed on test points of crosstalk card 27 . Both rising and falling edges of a signal being measured are to be considered. To observe them simultaneously, the scope shall be configured so as to accumulate waveforms with reasonable persistence and triggered from a clock signal.
Timing error measurements are performed whilst the system is running a special crosstalk test. This test is running continuously to generate transitions on all signals to be checked. To achieve the best possible precision and resolution, the scope should have only one channel activated when taking measurements. This will ensure that the total sample rate is not divided between several channels but fully assigned to the channel which is used for measurements. The other channel is only used to trigger the scope. For a DDR memory, differential signals are used for measurements.
Before skew measurements, a clock signal delay is measured to provide high accuracy in subsequent calculations.
For initial tuning, a trigger channel connected to CK 1 is enabled and trigger level is adjusted, for example, to 1.4 for SDR memory, or 1.25V for a DDR type memory. When the expected rising edge of the clock is observed, the other channel is connected to CK 0 . This channel is selected as a reference signal for crosstalk measurements. A rising edge of the signal CK 0 is selected close to the edge of CK 1 , and then, the first channel (CK 1 ) is disabled.
If the timing error is measured at 1.4V level, the vertical position of the displayed signal shall be adjusted accordingly, so that the scope's central horizontal line would correspond to the 1.4V level. To measure time intervals, vertical cursors are enabled. The first cursor is set to the point where the center of the clock edge crosses the 1.4V level. Then, the second cursor is selected for measurements, while the position of the first one remains constant, as illustrated in FIG. 4 b and FIG. 4 c , where example diagrams are shown for SDR memory. It shall be mentioned that one and the same scope channel is used for both the reference and measured signals.
The measuring probe is disconnected from CK 0 and connected to a signal that is chosen for timing error measurement. Using the second vertical cursor, two crosstalk measurements are made on each signal, to define the leftmost (T left ) and rightmost (T right ) timing error caused by crosstalk in transmission line. The leftmost timing error is measured at the leftmost point where signal traces cross the selected level on the scope's screen. The rightmost timing error is measured at the rightmost point where signal traces cross 1.4V level on the scope's screen.
The individual signal timing error is a signed value. For points on the left of the reference cursor (read: of the Clock edge) the timing error has a negative value. For points on the right of the first cursor the timing error has a positive value.
The procedure of crosstalk adjustment is iterative, and several iterations of full measurement may be preferably needed.
According to the embodiment of the invention where all fast output signals on the header are driven by multi-bit registers, and each register has its own delay vernier, such as described in PCT/RU99/00194 filed on Oct. 06, 1999, the signals are grouped so that the signals controlled by a selected vernier form one group, and signals controlled by different verniers, form different groups. The skew measurements are performed for groups of signals instead of performing measurements for each individual signal, thereby, the accuracy of measurements is increased and the time consuming measurement operations are reduced.
According to another embodiment, signals are grouped with respect to pin cards, so that the signals relating to a selected pin card form one group. Other criteria may be chosen to group the signals and obtain the advantages mentioned above.
At the first stage, the crosstalk timing error is adjusted in each group of signals. In a first iteration, in each group only a signal having leftmost timing error and a signal having rightmost timing error are considered. The average of these two values is calculated as T update , as shown below.
The update T update to the propagation time for a given group is an additional delay value required to make the leftmost and the rightmost timing error symmetrical with respect to the reference clock. The update value is calculated as follows:
T update =( T left +T right )/2,
where
T left is a minimum left crosstalk timing error value among all the individual signal timing errors measured for signals of the given group;
T right is a maximum right crosstalk timing error value among all the individual signal timing errors measured for all signals of the given group.
The T update is passed on to the SPD card and used further by vernier to shift this group of signals so that the group is centered at this average value at the next step of iterations. Preferably, when the leftmost and the rightmost deviation from the reference are counted in each group, further iterations are performed using only these measurements, and T update values for groups are calculated for all iterations except the final one. The final measurement must be complete to ensure the maximum timing error requirement is met on all signals.
To facilitate the calibration, a special update table may be used with pre-calculated results. The table contains minimum and maximum timing error values entered during current iteration to the table for each group. Update values are calculated for each group in the bottom row of the table and shall be entered in to the respective group tables. As the update values are used in further calculations, they can be adjusted directly in the respective cells of the group tables.
The method of the invention is further illustrated with reference to FIG. 3 .
First, the memory storage that is mounted on the DIB, is initialized, i.e. some initial values shall be written in the memory, for example, zero update values. Second, the calibration procedure is running. The signal crosstalk artifact, such as delay, is measured as has been described in details above. Next step is measuring timing error with respect to the reference clock for fast DUT signals which are most likely to produce minimum and maximum timing error.
An example table providing typical DUT signals, which produce minimum and maximum skew in each Delay Vernier Group is shown below. This example is valid for SYNBASED baseboards and HDRDIMMG header boards.
Delay Vernier Group
Minimum Skew
Maximum Skew
7
DQ10, DQ36
DQ8, DQ38
8
DQ37
DQ39
11
DQ48
DQ60
12
DQ49
DQ63
10
BA1
A4
9
CB0
CB6
13
DQMB1
DQMB7
14
WE
CKE1
15
S2
S0
Once the reference line is selected and the position of the reference signal is fixed on the scope, a crosstalk timing error is calculated as defined by time difference between the position of the measured signal and the position of the reference signal, to obtain thus the relative values in respect to the selected reference. If the crosstalk timing error for these signals is within the desired range, e.g. within ±250 ps for the DDR memory, then, measurements are considered to be completed and the values are stored, otherwise, compensation coefficients are updated and the iterative procedure is continued as has been explained above.
The obtained relative data at the end of the measuring procedure is stored in the flash memory 4 for further usage by the controlling computer software as described above in detail.
As shown in a flow chart in FIG. 3 , the above procedure, as has been mentioned already, has an iterative character because the resulting crosstalk artifacts changes each time when a new compensation values applied and is performed sequentially until the crosstalk timing errors are minimized for a predetermined range when a single time control element, e.g. a vernier, is used to control several signals, or, eliminated, if each signal has a separate time control element.
The flow chart in FIG. 3 can be further modified by adding a step of reading interconnection data or in other way within the scope of the invention as shall be evident for a specialist in the art.
Another example embodiment of the procedure of the invention with respect to DDR memory is illustrated in the Attachment B.
It shall be appreciated also that other embodiments and modifications of the present invention are possible within the scope of the present invention. Thus, the invention may be applied to compensating timing errors in communication systems that can serve to increase the bandwidth of signal transmission. It can be applied to reduce timing dispersion of a signal in cases when signals are transmitted via an optical cable and in various other applications. | The present invention relates to high speed communications, in particular, to an interface device between a transmitting device and a receiving device of a transmission system, wherein the transmitting device is capable of automatic compensation of cross-talk timing errors in the interface device, for a group of signals, by using information stored in a storage attached to that interface device. Preferably, the data stored in said storage comprises data on interconnections between said first and second plurality of terminals and data on crosstalk timing errors in said transmission lines relating to a specific data pattern, for each of said stored interconnection. | 33,107 |
BACKGROUND OF THE INVENTION
The present invention relates broadly to methods and apparatus for controlling yarn package winders and, more specifically, to a method and apparatus for controlling such a winder to effect the relative positioning of the yarn strand during consecutive winds.
Surface winding of natural rubber yarn, spandex, or other elastomeric yarns is a difficult process with unique problems caused by the ability of the yarn to stretch. If the yarn stretches too much during winding, the wound yarn will be under internal tension and such poorly wound yarn can destroy the core about which it is wound or, in the case of rubber yarn, fuse together internally within the package thereby becoming unusable. A typical tension control technique for surface winding rubber yarn concerns the increase or decrease of the speed of the drum driving the yarn package. Since the yarn is under some tension when being wound, increasing the speed can increase the amount of tension experienced by the yarn.
One way the situation wherein the yarn is wound too tightly can become manifest is in the appearance of the wound yarn package itself. Since the yarn is being wound on a traverse, the traverse arm makes one complete cycle for a predetermined number of yarn package or spindle revolutions. The ratio of spindle revolutions to strokes of the traverse is known as the wind ratio. If the wind ratio remains constant throughout the winding process, the resultant process is known as a "precision wind."
As may be appreciated, varying this ratio can affect the pattern formed by the yarn when wound on a core. Typically, the proper appearance of a wound package appears in FIG. 3 wherein the yarn remains as individual strands tracing an individual path. Problems can arise when the yarn appears as in FIG. 4. There, the yarn no longer experiences individual yarn trajectories and ribbons can be formed. These ribbons are repetitive patterns in the wind resulting in a side-by-side closely adjacent parallel orientation of yarn. Due to the stretchability of the yarn and the aforesaid increased tension, packages wound with ribbons can experience localized internal stresses which can damage or destroy the yarn package. Therefore, when winding elastomeric yarn it is desirable to avoid creating ribbons on the package.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide a method and apparatus for the elimination of parallel, side-by-side orientation of yarn winding on a yarn package.
It is another object of the present invention to provide such a device and method for prediction of the approach or occurrence of ribbon patterns and to responsively alter winding parameters in response thereto.
It is another object of the present invention to use the wind ratio to predict the upcoming occurrence or approach of ribbons and to correct for the ribbons before they are formed.
As was previously stated, the wind ratio, namely, the revolutions of the spindle to the strokes of the traverse, can be useful in predicting the formation of ribbons or repetitive patterns on the surface of a random wind where the ratio W is constantly changing from its maximum value starting with the empty yarn tube to its minimum value with a maximum diameter of the finished package. Between these limits, whenever twice the ratio passes through any value that can be represented by a rational fraction, a repetitive pattern will be formed on the surface of the package. Since one stroke of the traverse represents one half traverse cycle, multiplying the wind ratio by two accounts for one complete cycle of traverse operation and repetitive patterns must be a multiple of complete traverse cycles. The computation may be simplified by multiplying the ratio (2W) by a factor which must be an integer. The integer factor will provide a simple way to rationalize the fractions into integers so that, if 2WN in equals any integer, a ribbon will be forming. This information may be used to predict the approach of ribbons and, if such an approach occurs, the speed of the traverse may be altered to prevent ribbon formation.
To that end, the present invention provides a method and apparatus to control the winding pattern on a yarn package for traverse winder used for winding elastomeric yarn to prevent repetitive orientation of individual yarn tracks on the package with method comprising the steps of providing an arrangement for monitoring the operation of a yarn package spindle; providing an arrangement for monitoring the operation of a traverse arm associated with a traverse winder; providing an assembly for predicting the occurrence of repetitive patterns of yarn; and providing an arrangement for adjusting the relative speed of the yarn package spindle to prevent the occurrence of the repetitive patterns of yarn. The method further includes the steps of monitoring the operation of the yarn package spindle, monitoring the operation of the traverse arm, predicting the occurrence of a repetitive pattern of yarn strands; and adjusting the relative speed of the yarn package spindle to prevent the occurrence of the repetitive patterns of yarn. It is preferred that the step for monitoring the operation of a yarn package as well as the means to accomplish that step include an arrangement for counting the number of revolutions experienced by the yarn package spindle. Further, the step of providing an arrangement for monitoring the operation of a traverse arm associated with the traverse winder includes providing an assembly for determining the occurrence of a complete traversing movement of the traverse arm associated with the traverse winder, defining a traverse cycle. It is preferred that the step of providing an arrangement for predicting the occurrence of repetitive patterns of yarn includes providing an arrangement for determining a ratio with the ratio being the number of revolutions experienced by the yarn package spindle per traverse cycle to determine a wind ratio and providing an assembly for predicting when the wind ratio will be a rational fraction. Further, the step of providing an assembly for adjusting the relative speed of the yarn package spindle and the traverse arm includes providing an arrangement for changing the speed of the traverse arm. Finally, the previously discussed steps are performed using the apparatus above described. It is further preferred that the wind ratio be doubled and the result multiplied by a predetermined factor with that factor being an integer to determine a derived wind ratio and the method includes providing an arrangement for predicting when the derived wind ratio will be an integer. It is preferred that the step of adjusting the relative speed of the yarn spindle and traverse arm be performed responsive to a determination that the derived wind ratio is approaching an integer.
It is preferred that the apparatus for determining the occurrence of a complete traversing movement of the traverse arm include providing a pulse generator for producing pulses associated with traversing movement. It is further preferred that the assembly for counting the number of revolutions experienced by the yarn package spindle includes providing a pulse counter that has a resolution of at least 0.001 revolution and the assembly for predicting when the wind ratio will be a rational fraction, or the derived wind ratio an integer, includes providing an electrical circuit formed as a comparator with the comparator receiving an input from the yarn package spindle pulse counter and the traverse pulse counter and the method further includes the steps of comparing the pulse counter value to a predetermined baseline value of less than zero to determine a wind ratio factor responsive to the presence of the traverse pulse and when the factor equals zero changing the relative speed of the yarn package spindle and the traverse arm using the arrangement for doing so to prevent repetitive patterns in the yarn.
By the above, the present invention provides a method and apparatus for controlling the appearance of repetitive patterns in a surface wound yarn package of elastomeric yarn.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of a yarn winder for winding elastomeric yarn;
FIG. 2 is an elevational view of a traverse winder;
FIG. 3A is an elevational view of a properly wound yarn package illustrating the relationship of individually wound portions of the strand;
FIG. 3B is a detailed view of the surface of the yarn package illustrated in FIG. 3A;
FIG. 4A is an elevational view of a yarn package improperly wound revealing the repetitive patterns on the yarn surface;
FIG. 4B is a detailed view of the surface of the yarn package illustrated in 4A; and
FIG. 5 is a block diagram of the apparatus for predicting the occurrence of repetitive patterns in the yarn wind.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to the drawings and, more particularly, to FIG. 1, a winder is illustrated generally at 10 and is configured for multiple traverse winding of individual yarn strands of natural rubber, spandex or other elastomeric yarns. The winder 10 includes several discrete systems mounted on a skeletal frame 12. While the remainder of the present invention will be described relative to the use of natural rubber yarn, it will be appreciated that the principles involved herein are equally applicable to spandex or other elastomeric yarns.
Natural rubber yarn is shipped as a fused tape of individual strands providing a flat, ribbon-like elongate strand 15 of several individual strands fused in a side-by-side relationship. The strand 15 is loosely coiled into a box 11 for shipment and is withdrawn from the box 11 by the winder 10. In that regard, the winder includes a support 14 for yarn leaving the box 11 and, from the support 14, the yarn goes through a stretcher 16 and a tractor/distribution mechanism 18 for ultimate winding on any one of a bank of 24 traverse mechanisms 22. A microcomputer 46 is provided for overall control of the winder 10.
A traverse mechanism 22 is illustrated in FIG. 2. There, a yarn package 28 is illustrated wound on a core 26 which is mounted to a spindle 24 which is in turn mounted to the frame 12 using journals 30. A pulse counter 25 is shown as a box associated with the spindle 24. At this point it should be noted that the present invention uses no esoteric or complex electronic gear to perform its function. Pulse generators, frequency counters, comparator circuits, and switching are all well within the skill of those skilled in the art of control systems. Therefore, the electronics are provided in diagrammatic form for clarity. Since the traverse mechanism 22 represents a surface drive system, a drive roll 32 is rotatably mounted to the frame 12 and is motor driven. The outer surface of the drive roll 32 frictionally contacts the outer surface of the yarn package 28 to drive the yarn package in a yarn take-up manner. A capstan 34 is rotatably mounted to a bracket 35 which is mounted to the frame 12. The capstan 34 provides a debarkation point for maintaining constant tension on the yarn strand 15 as it is being wound. A traverse arm 36 having an eyelet 36' formed in the distal end thereof is caused to oscillate in a traversing manner to guide the yarn 15 onto the package 28. The traverse arm 36 is mounted to a traversing mechanism 37 which is shown in diagrammatic form in FIG. 2 with a portion of the frame 12 broken open to reveal the traverse mechanism. A motor 38 drives a chain mechanism 39 which drives the traverse arm 36. A pulse generator 40 is attached to the motor arm for generating electronic pulses corresponding to the motor's armature rotation. This is one of many possible systems for generating a predetermined number of electrical pulses per traversing cycle.
Since it is known that if 2WN equals any integer, a repetitive pattern or ribbon will occur. Therefore, if it could be predicted when such an integer value would occur, the relative speed of the traverse arm movement and yarn package rotational speed could be adjusted to prevent the integer value of the derived wind ratio from occurring. Looking now at FIG. 5, a block diagram of the electronics required to accomplish the anticipation and avoidance of repetitive patterns is illustrated. The spindle 24 is fitted with a pulse generator 25 which produces, for example, 1,000 pulses per revolution. The pulses from this pulse generator 25 are fed into a countermodule so that the accumulated count will represent spindle revolutions with great accuracy, preferably to three decimal places. A similar pulse generator 41 is coupled to the traverse mechanism 37. This pulse generator 41 produces, for example, 250 pulses per revolution and, if the traverse driving mechanism requires two revolutions per stroke and two strokes per cycle, each 1,000 pulses represents one traverse cycle. These pulses are fed to a counter which will produce a trigger pulse every 1,000 counts. Essentially, a trigger pulse is produced for every traverse cycle. The trigger pulse is fed into the counter keeping track of the spindle revolutions. Upon triggering, the three least significant digits, or the fractional portion, of each sample count will be isolated and compared to a predetermined limit with the limit being set at slightly less than zero, i.e., 0.90 to 0.98. If the difference between the fractional portion of the spindle count and the predetermined limit is zero, then an integer value of the wind ratio is approaching. Consider that, if the wind ratio is an integer, the least three significant digits in the pulse count will also be zero and that means the repetitive pattern is occurring. If the least three significant digits are found to be approaching zero, as determined by the comparison or subtraction circuit, then the least three significant digits are approaching zero; therefore, the wind ratio is approaching zero, and therefore the repetitive pattern is approaching. As a result of this comparison, a signal or trigger pulse can be generated in the speed control circuit to slightly increase the speed, i.e., on the order of one percent to prevent the occurrence of the repetitive pattern.
As can be seen in FIG. 3, a proper random wind of a yarn package 40 offers a pattern 42 where individual winds or individual strand segments defined by circumventions of the yarn package are laid in a random manner, thereby randomly distributing the tension throughout the package and reducing the tendency of the winds to fuse together. As seen in FIG. 4, an improperly wound package 44 includes a series of repetitive patterns 46 seen as closely adjacent parallelly oriented winds. As previously stated, these repetitive patterns can have a detrimental effect on the resultant yarn package.
By the above, the present invention provides a method and apparatus for automatically predicting the occurrence of repetitive patterns of yarn strand segment on a yarn package and providing the necessary operational correction to avoid the patterns' ocurrence.
It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of a broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well asmany variations, modifications and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof. | An apparatus for controlling the winding pattern on a yarn package for traverse winder used for winding elastomeric yarn to prevent repetitive patterns of individual yarn segments on the package includes an apparatus for monitoring the operation of a yarn package spindle, an apparatus for monitoring the operation of a traverse arm associated with a winder, an arrangement for predicting the occurrence of repetitive patterns of yarn strands, and an arrangement for adjusting the relative speed of the yarn package spindle and the traverse arm to prevent the occurrence of thusly predicted repetitive patterns. | 16,486 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of United Kingdom Patent Application No. 0504810.3 filed Mar. 9, 2005.
FIELD OF THE INVENTION
The present invention relates to methods, apparatus and computer programs for consolidating updates to replicated data.
BACKGROUND OF THE INVENTION
A known server in a distributed system can maintain a cache of resources locally to provide independence from centralised infrastructure and/or performance benefits of avoiding network communications. Applications executing on that server make updates to the resources, generally being unaware of the existence of the local cache. If these updates are transactional, then the locks and log entries used to maintain the transactionality will also only have scope local to the server.
At some point it will be appropriate to reconcile the updates made locally with some master state held in a central server. At this point it May be discovered that the state of the updated resources has been changed since the last time the cache was reconciled. Either direct updates on the server may have taken place, or another peer distributed server may have successfully reconciled some changes to the same resources. Since the basis on which the applications made their updates to the cache are now invalid (or at least questionable) it would not be appropriate to reflect those updates in the master state.
In a replicated messaging system using optimistic locks, several applications acting on different replicas may attempt to consume the same message. These actions may be asynchronous. This will be resolved when an arbitrating server ultimately commits one of the optimistic transactions and rolls back all of the others.
U.S. Published Patent Application 2003/0149709 to Banks discloses enabling one or many replicas of a data resource to be updated independently of a master copy of the data resource, and then each replica to be separately consolidated with the master copy. If a data update is applied ‘optimistically’ to a local replica and conflicts with updates applied to the master copy (since the last consolidation with that replica), then the local update will not be applied to the master copy. All updates are treated the same and rolled back together.
Transactions in such a server fail due to contention when they try to consume or update data that no longer exists. This arises in cases where the updated data is shared between updaters—i.e. accessible to several of them. One of the reasons for failing is that one update, although not conflicting with a prior update, is dependent on a conflicting update.
A system holding a local cache may keep any records which are part of an optimistic transaction locked until the optimistic transaction is committed in the master server. This prevents any other applications running against that local cache from making changes dependent on the optimistic data. So once a cache has been updated, no more updates can be made until the optimistic transaction involving that message has been committed in the master server.
SUMMARY OF THE INVENTION
In one aspect of the present invention there is provided a method for managing updates to a replicated data resource, including the steps of: in response to a first update and one or more dependent updates applied to a first replica of the data resource at a first data processing system, and comparing the updates with a master copy of the data resource held at a second data processing system. For the updates which do not conflict with the master copy, the non-conflicting updates are applied to the master copy; and for the updates which conflict with the master copy due to other updates applied to the master copy, the method includes sending to the first data processing system an instruction to back out the conflicting updates from the first replica and to replace them in the first replica with the corresponding other updates applied to the master copy.
The appropriate time to reconcile the local updates with the master could be after every transaction on the server owning the cache. This would give rise to the behaviour similar to the technique of optimistic locking. However, in a distributed system where less frequent reconciliation is appropriate, it is not desirable to hold exclusive locks on updated resources until the reconciliation occurs. It is proposed that other transactions in the distributed server are allowed to execute and a composite reconciliation is performed following the execution of a set of transactions. Multiple transactions in the period between reconciliations may update the same cached resource. As the time between reconciliations increases, so will the number of updates that are at risk of failing to reconcile.
It is recognised that the set of transactional updates arising from a set of unreconciled transactions can be captured as a history in the distributed server that owns the cache. The set of transactional updates will have a number of dependencies with it—a second transaction may make a further update to a resource updated from the reconciled state by a first transaction.
During reconciliation, each transaction in the history is replayed against the master state. As each of the transactions originally performed on the distributed server against the cache is replayed it may encounter an initial state in the master that does not match that which was in the cache at the equivalent point. That transaction against the master state should be rolled-back, and any subsequent transaction in the history that depends upon state updated by that transaction should not be replayed, and also needs correcting in the cache from which the history is being replayed. This management of the replayed transactions must be robust even in the event of the rollback—the failure must assuredly provoke the corrective action.
The effect of this behaviour will be to propagate as many of the transactions as possible from the distributed server cache to the master state as possible. Depending on the likely contention for the same resource in the master state by applications executing in multiple distributed servers maintaining caches, the overall yield of successful transactions will vary with less contention leading to higher yield, and frequent reconciliation leading to less contention.
It can be observed that the replay of history from a set of transactions is somewhat similar to the process of forward recovery of a point in time backup of a database using a log. This invention assumes that multiple histories (logs) can be replayed, potentially concurrently, to bring the master state up to date.
This solution allows a chain of optimistic transactions. Optimistic transactions progress on the assumption that prior optimistic transactions commit. The chain of transactions can be arbitrarily long; however, long chains increase the probability of ultimate failure. The transactions may have arbitrary dependencies on the prior transactions. Chains of optimistic transactions may branch into multiple chains. Chains of optimistic transactions may also join together.
Applications running optimistic transactions against a replica of the messages record the history of their processing. When a communications connection is made with the master arbitrating server the optimistic transaction history is replayed against the master data store. If no conflicting updates are detected, i.e. there were no clashes of the optimistic locks, then the optimistic transaction becomes the ultimate transaction which commits, as an ACID transaction.
Optimistic transactions are replayed in the master server in the same order that they were generated against a particular replica, therefore they will only ultimately commit if an optimistic transaction they depend on has already committed.
An application can update a message in a local cache so long as no other application is in the process of updating that message. In other words it can make an update so long as no other application has updated that message as part of any uncommitted optimistic transaction run against that cache.
Once an optimistic update has been made in the local cache and optimistically committed, then further optimistic updates are allowed by applications as part of other optimistic transactions. Optimistic transactions are replayed in the master server in the same order that they were optimistically committed in each cache. If the master server detects that an optimistic transaction makes a conflicting update, then it is rejected, causing the optimistic transaction to be undone. All other optimistic transactions which also depend on the same conflicting change are also rolled back.
Some restrictions apply if a resource manager is joined using a classic ACID transaction with an optimistic transaction running against a local cache. For example, the transaction branch in the resource manager must be prepared before the optimistic transaction is sent to the master server and data modified in the resource manager as part of the transaction branch must remain locked until the outcome is received from the master server.
The solution should respect the following basic test case: two disconnected local caches, A and B, each share data replicated off a master server, with ‘cs’ being a shared replicated message.
Optimistic transaction 1 A on A: consume ‘cs’ and produce ‘pa’ Optimistic transaction 2 A on A: consume ‘pa’ and produce ‘paa’ Optimistic transaction 3 A on A: consume ‘paa’ and produce ‘paaa’ Optimistic transaction 1 B on B: consume ‘cs’
B connects to the master server and replicates before A—its optimistic transaction 1 B succeeds and commits. When A replicates, it should have failures reported for all 3 of its optimistic transactions. The tree can be persisted efficiently by keeping a transaction ID pair against each data resource element to indicate when it was produced and when (if) it was consumed. The tree can otherwise be kept in memory as a tree structure to allow fast deletes. In this case, before B connects and replicates, client A's data table would look like:
Client A:
Resource
Transaction Produced
Transaction Consumed
cs
0
1A
pa
1A
2A
paa
2A
3A
paaa
4A
Transactions applied on cached data, whose master copy is shared between independent applications, are not able to progress if they depend on changes made by prior transactions on the same items of data. This is because conflicting changes may have been made to the equivalent items of data in a separate cache and these changes may take priority. One known solution is to lock the cached data changed by the prior transaction until it has been successfully played back against the master copy. This delays the dependent transactions.
A solution relates to a sequence of two (or more) transactions operating on a cached data set, which depend on each other because they operate on (at least one) same items of data from the data set. The transactions are saved until the master copy of the data becomes available at which point they are played back against it. This continues until one of the played back transactions fails because another completely independent transaction, which operated on the same items of data but against a separate cached copy and originating from another independent application, was successfully played back on the master copy at an earlier moment in time. At this point, all subsequent transactions which depended on the failing one are rolled back on the cached copy (with appropriate failure reports generated) and activity resumes from there. This invention therefore allows “chained” (optimistic) transactions applied to cached data to progress by recording their dependencies so they can be undone when required.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention will now be described in more detail, by way of example, with reference to the accompanying drawings in which:
FIG. 1 is a schematic representation of a network in which the present invention may be implemented;
FIG. 2 is an example user view of seat availability within an aircraft within an airline reservation system implementing the present invention;
FIG. 3 is an example user view according to FIG. 2 after multiple transactions on replica 110 and consolidation between replica 120 and master copy 100 of a database reflecting seat reservations;
FIG. 4 is an example user view according to FIG. 2 and FIG. 3 after consolidation between replica 110 and master copy 100 ; and
FIG. 5 is a schematic flow diagram showing the sequence of steps of a method implementing the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following terms are used in this description. ‘Consumption’ means deletion of a message. An update is achieved by consumption of one message and production of another. The terms ‘consumption’ and ‘update’ are used interchangeably. ‘Asynchronous’ means that client transactions are made to their local cache as if it were the master data—therefore not needing to block for confirmation that their transaction was really successful. ‘Shared data’ means that the local cache or replica is a copy of data that is logically on offer to multiple consumers. ‘Optimistic transaction’ means the initial optimistic processing of the messages—operations are grouped and persisted in a transactional manner. ‘Ultimate transaction’ means the definitive step that records the ultimate result of an optimistic transaction's success.
As shown in FIG. 1 , a plurality of client data processing systems 10 are each running an application program 60 and a database manager program 20 and each hold a replica 30 of a database 40 . Each client system 10 is connectable to a server data processing system 50 which is also running a database manager program 20 and holds a master copy 35 of the database 40 . The present invention is applicable to any network of data processing systems in which the client systems are capable of running the database manager program to maintain their local replica of the database, but is particularly suited to applications in which a number of replicas are updated on mobile devices or desktop workstations before being consolidated with the master copy held on a back-end server computer. The invention is especially useful in environments in which either a large number of client systems may need to concurrently apply local updates to the database, or a number of the client systems rely on wireless communications to connect to the server computer and so cannot rely on permanent availability of connections.
An implementation of the present invention will now be described using the illustrative example of an airline reservation application in which users (such as travel agents and airline employees) working at a number of client workstations each need to be able to process their customers' requests to book seats on an airline.
The reservation application 60 sees each table of the local replica database as if it is the only copy, and as if only that application is accessing it. For illustration, the table could be a simple hash table of data and an index. Hidden from the application's view within a consolidation process 70 of the database manager 20 is some more state information.
For each element in the table, the following information can be held and sent as part of an update consolidation request (as will be described further below):
protected Object underlyingObject;
// The application object being contained.
protected Object oldUnderlyingObject;
// The before image, in case we back out.
protected Object key;
// The object identifier key.
protected long unitOfWorkIdentifier = 0;
// Unit of work for an update.
protected long tableSequenceNumber = 0;
// Server/Master sequence number of last
table update
// we received.
protected long sequenceNumber = 0;
// Sequence number of last object update we
made,
// incremented by 1.
int state;
// The current state of the managedObject.
// The lifecycle of the object.
static final int stateError = 0;
// A state error has occurred.
static final int stateConstructed = 1;
// Not yet part of a transaction.
static final int stateAdded = 2;
// Added.
static final int stateReplaced = 3;
// Replaced.
static final int stateDeleted = 4;
// Deleted.
The use of the protected Object oldUnderlyingObject (the before image), sequence numbers and consolidation processing will be described later.
For the table as a whole, the following information is also held and sent in update consolidation requests:
protected long highestTableSequenceNumber = 0; // The highest
tableSequenceNumber in the entire table.
// This may be higher than any recorded in our
version of the table
// because our update may have been the latest;
it also allows the
// master to detect that this is a repeat update.
The user's view of seat availability for the airline is as shown in FIG. 2 , with each specific seat being a separately identifiable data element of the database and being separately reservable. FIG. 2 shows three views of the data resource—the master copy 100 as updated at the server, a first replica 110 and a second replica 120 .
A first set of data elements 130 corresponding to seats in an aircraft have been updated and the replicas 110 , 120 of the data resource have each been consolidated with the master copy 100 so that the reservation is now reflected in each of the replicas. Subsequent to that consolidation, further updates are made concurrently to replica 110 and replica 120 . A first update 140 to replica 110 indicates a desire to reserve four seats in rows 3 and 4 . The replica 110 entry is not locked. However, for the nested updates involving modified entries are recorded as being dependent on the updates that modified them. All local updates are in-doubt (uncommitted) until the server has successfully applied itself and returned a confirmation of success.
An update 150 of replica 120 indicates a desire to reserve four seats in rows 2 and 3 , but the user of the client system of replica 110 has concurrently attempted to reserve two of these four seats. Replica 120 is optimistically updated concurrently with replica 110 . Again the updated elements within replica 120 are not locked and are available for further (dependent) updates. Which of these replicas 110 , 120 has its local updates successfully applied to the master copy 100 of the database depends on which client system is first to notify the server system of its desire for consolidation.
Let us assume that the client system maintaining replica 120 is the first to request consolidation 170 . Note that replica 110 still has local update 140 which has not been consolidated with other replicas, and which are now inconsistent with the master copy of the data. Since there is no consolidation processing currently in progress and there is no conflict between updates applied to the master copy and updates applied to replica 120 since their last consolidation, the updates will be successfully applied 170 to bring the replica 120 and the master copy 100 into a consistent state, see 160 and 160 ′ as shown in FIG. 3 . After consolidation between the master copy and replica 120 , further updates may be applied to the replica 120 or the master copy 100 , and further updates may also be optimistically applied to replica 110 .
Let us assume that two further updates 190 and 195 are applied to replica 110 as represented in FIG. 3 . Update 190 amends update 140 by cancelling a passenger from a window seat, therefore update 190 is dependent on update 140 . Update 195 assigns two unallocated window seats to two new passengers, therefore update 195 is not dependent on any previous update.
The client system maintaining replica 110 now attempts to consolidate 180 with the master copy 100 of the data. The results are shown in FIG. 4 . Update 140 now conflicts with the consolidated update 160 ′ to the master copy and it is not applied. Furthermore transaction 190 which does not conflict with transaction 160 ′ is not applied because it does depend on conflicting update 140 . However update 195 is applied to master copy 100 at 195 ′ because it does not conflict with any other update and does not depend on any update which conflicts. Updates 140 and 190 are backed out. The updating application running at the client system is notified, either by a return value to a synchronous consolidation request or, in the preferred embodiment, by an asynchronous callback to an asynchronous consolidation request. The local update is backed out by reinstating (temporarily) the “before update” image of the data.
Then the “before update” image is overwritten with the latest updates to the master copy 100 . The result of this is shown in FIG. 4 . In this example, all copies of the data are now consistent, with conflicting client updates not having been allowed to change the master copy. This has been achieved without complex programmatic conflict resolution processing at any of the systems in the network.
Note that at no point during this process has either of the client replica 110 or 120 been prevented from applying updates to any element of data.
Thus each travel agent and the airline has a copy of the seat reservations, and two or more agents may ‘optimistically’ update their own view of the data to attempt to reserve the same seat. Initially, these updates are not committed. On subsequent consolidation, one agent sees a successful consolidation with their updates committed, whereas the others see a failure of some updates due to the first agent now holding the seat. Neither agent needs a connection to the airline's copy of the database table in order to request the reservation, but the reservation will only be processed locally until the update is consolidated with the airline's copy.
It should be noted that the present invention does not require synchronization of all replicas at any one time (although this could be implemented using conventional techniques if global syncpoints are required for other reasons), and does not require the master copy to immediately reflect the very latest updates performed at client systems.
Instead, the invention allows each replica to be updated independently of each other and independently of the master copy, but for the update transactions to be held in doubt until they are subsequently consolidated with the latest version of the master copy of the data. Sufficient information is held for backing out conflicting updates (sequence number and the local replica's incremental changes—see above) and dependent updates, preferably without reliance on database logs. Any non-conflicting and nondependent updates are applied to the respective one of the local replica or master copy of the database, and any conflicting and dependent updates result in a back-out at the client. This backout is achieved by reinstating the image of the relevant database elements and then overwriting the relevant database elements at the client using the corresponding data from the server.
By handling each update as a separate transaction, only a small number of local replica updates have to be backed out in most cases, although it is preferred that all updates entered between consolidation points will be identifiable as a set in case they are deemed interdependent by the user or updating application program. In one embodiment of the invention, a set of updates to data elements (such as booking seats in an aircraft for a group) can be applied together as a single transaction or explicitly flagged as an interdependent set of transactions, so that if one update cannot be applied to the server's master copy of the data then they will be backed out as a set at the client.
A degree of short term inconsistency between replicas of the data resource has been accepted to achieve improved concurrency and availability of data, with optimistic updating of local replicas of the data and a backout processing. All updates are eventually applied to all replicas of the data unless they conflicted with updates applied to the master copy or are dependent, and problematic data conflicts are avoided by the decision to accept the master copy's validity in the case of conflicts.
A specific implementation will now be described in more detail with reference to FIG. 5 . As described above, updates can be applied to a local replica of a database without requiring continuous access to the master copy of the database held on a server, without requiring all replicas to be concurrently locked for synchronization, and without complex programmatic conflict resolution processing.
The client updates (step 500 ) elements in the local database replica as part of a local transaction. When updates are applied locally, the database manager program 20 updates the relevant rows and columns of the database 40 as one or more local transactions in response to user input via the local application program 60 .
The client records (step 505 ) dependencies of this transaction. The database manager program 20 is free to update the local modified rows again, however all updates that depend upon a prior, non-consolidated update are recorded as being dependent upon their prior update. When local updates are completed, the client records each update against elements in the replica. Each dependent update is recorded in a dependency table that identifies the depending update and the dependent update.
The client initiates consolidation (step 510 ) at the consolidation point. The client consolidates the updates performed on the local copy and any updates performed on the master copy of the database held at the server. This involves the local database manager program 20 sending an asynchronous request message to the server system 50 holding the master copy 35 of the database. The database manager program 20 running on the server 50 receives these requests and places them in a FIFO queue for serialization.
The request includes: a unique unit of work identifier for the request; the highest sequence number in the table (in order to determine which updates the replica has not yet applied); and, for each changed data element, the new state of each changed data element (i.e. added, deleted, replaced); the new data (if any); and the sequence number for the version of the master copy on which the update is based.
The client thread continues (step 530 ) and possibly terminates.
The server attempts (step 540 ) to apply the same updates to the master copy of the data in a server side transaction. When ready to process a next consolidation request, a consolidation manager process 70 within the database manager 20 of server computer 50 processes this information within the request to identify which rows of the database tables have been updated since the last consolidation with this replica. This is managed by comparing a replica database table row's sequence number with the sequence number of the corresponding row in the master copy.
The sequence number is incremented in the master copy of the database whenever the respective row of the master copy's database is updated, and this sequence number is copied to the corresponding row in a replica when that replica is consolidated with the master copy. Hence, the database table rows of the master copy always retain a sequence number which can be checked against the database rows of a local replica to determine a match. If they match, then that row of the master copy of the database has not been updated since it was consolidated with this local replica, and so any updates applied to that row of the local replica can be safely applied to the master copy at consolidation time. In that case, a set of one or more server side transactions applies to the master copy the updates defined in the request message and the transactions are committed 250 .
If they do not match, then that row has been updated in the master copy, and in that case the server side update transaction is backed out 250 . All dependent updates are not applied and marked as failed. This is notified to the client side and the in-doubt client-side transaction which applied the conflicting update is also backed out 260 along with all dependent updates. Next, the updates which had been applied to the master copy before consolidation (including those which led to the mismatch) are applied to the local replica.
The server response includes: a list of transaction results; a list of rows to insert; a list a rows to delete; and a new sequence number for the new version of the master copy.
No conflicting and no dependent updates are committed, the server commits 550 non-conflicting and nondependent updates. Hence, if the database rows updated in the local copy are different from the rows updated in the server-based master copy, all updates are successful. Whereas, if conflicts are identified when consolidation is attempted, all conflicting local updates since the last consolidation point are backed out and the relevant database table rows of the local replica are overwritten using the updates applied to the corresponding rows of the master copy of the database.
The server backs out (step 555 ) all conflicting and dependent updates.
A separate client thread can either commit (step 560 ) or back out the client side transactions, according to the result on the server.
If required, notification procedure is executed (step 570 ) in a separate client thread to deliver notification of the result of the consolidation.
The programming construct implemented by the present invention may be called a “Consolidation Point”—a place in the logic of a program where updates to a copy of a resource are to be merged with another copy. Although the preferred embodiment described above includes synchronous processing for the database merge operation, this could be completed asynchronously in alternative implementations.
The resource in question could be a database table, or a queue, or generally any data where a copy is held locally for update. The result of the merge is reported back to the program as success or failure of the merge. If the merge succeeds, the updated values persist in both copies of the resource. If the merge fails, perhaps due to some conflicting update in the merge processing, then the local copy of the resource elements is updated to be the same as the remote server copy. Thus, in the event of the merge processing failing because there are conflicting updates, the resource elements will be returned to a known consistent state. No elements are ever locked during these updates which reduces delay between operations. Failing updates will automatically trigger the failure of all the dependent updates as the server is aware of the dependencies and does not even attempt to apply them.
The invention applies to situations in which there are two copies of a table, or many copies.
The “Consolidation Points” define a section of program logic where either all of the changes to elements in the local copy within the scope of a single transaction are merged, or none of them are merged.
This programming construct is similar in concept to a “Synchronisation Point” in distributed transaction processing, however instead of fixing a place in the logic of the program where updates to resource managers commit or back out, this fixes a place in the logic of the program where a set of updates to a table are merged with another copy of the table, the merge either succeeds or fails. A “Consolidation Point” and the “Synchronisation Point” could be one and the same place in the program logic.
In preferred implementations, the state of the tables is well defined and easy to program to. It is either the state before or after all of the updates are applied, and if the merge of the two resources fails then the updates that were not applied are also well defined. Furthermore the updates to the replica can be coordinated with transactional resources by executing the prepare phase of a two phase commit where the entity performing the consolidation is also of the two phase commit coordinator.
In many conventional solutions, a replication error is reported in an error log. This has three significant disadvantages: it is not easily accessible to the program logic; the precise scope of the failure is not defined, in fact in most cases some of the updates are applied; and the updates cannot easily be coordinated with other updates.
Additional embodiments and variations of the embodiments described herein in detail will be clear to persons skilled in the art, without departing from the described inventive concepts. For example, the embodiments described above include submitting a request for consolidation which request includes all of the required information for identifying data conflicts, whereas alternative embodiments may include an asynchronous request for consolidation followed by the server establishing a synchronous communication channel with the client system for exchanging information and identifying conflicts.
In another implementation, some applications may require an automatic retry of one or more of the data element updates that are within a failed encompassing update transaction. If the application or the local replica's database manager program is notified of which data element update resulted in a conflict with the master copy, it will be possible to retry all or a subset of the other data element updates. This may be done as a set of separate transactions or as a single transaction which encompasses all of the failed transaction's data element updates except the one which caused the failure.
The present invention may be realized in hardware, software, or a combination of hardware and software. The present invention may be realized in a centralized fashion in one computer system or in a distributed fashion where different elements are spread across several interconnected computer systems. Any kind of computer system or other apparatus adapted for carrying out the methods described herein is suited. A typical combination of hardware and software may be a general purpose computer system with a computer program that, when being loaded and executed, controls the computer system such that it carries out the methods described herein.
The present invention also may be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which when loaded in a computer system is able to carry out these methods. Computer program in the present context means any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following: a) conversion to another language, code or notation; b) reproduction in a different material form.
This invention may be embodied in other forms without departing from the spirit or essential attributes thereof. Accordingly, reference should be made to the following claims, rather than to the foregoing specification, as indicating the scope of the invention. | A sequence of processing transactions operating on a cached data set, which depend on each other because they operate on the same items of data from the data set. The transactions are saved until the master copy of the data becomes available. The transactions are played back against the master copy until one of the played back transactions fails because another transaction which operated on the same items of data but against a separate cached copy and originating from another application, was successfully played back on the master copy at an earlier time. At this point, all subsequent transactions which depended on the failing transaction are rolled back on the cached copy (with appropriate failure reports generated) and activity resumes from there. “Chained” (optimistic) transactions can therefore be applied to cached data and can be allowed to progress by recording their dependencies so they can be undone when required. | 38,604 |
FIELD OF INVENTION
This invention relates generally to a system for the secure transfer of information from an industrial control system network, and in particular to a system for securely transferring information from a high integrity MODBUS network to a server on a non-secure remote network.
BACKGROUND OF THE INVENTION
MODBUS is a communications protocol published by Modicon in 1979 for use with programmable logic controllers (PLCs). Initially conceived as a serial communications link, more recent versions of the MODBUS protocol allow for communications over an Ethernet network using TCP/IP. Because it is simple and robust, MODBUS has since become a de facto standard communication protocol and is now one of the most commonly used means of connecting industrial electronic devices in industrial control systems (ICSs). For example, MODBUS is often used to connect a supervisory computer with one or more remote terminal units (RTUs) in supervisory control and data acquisition (SCADA) systems.
SCADA is one type of industrial control system (ICS). Industrial control systems are computer-controlled systems that monitor and control industrial processes that exist in the physical world. SCADA systems historically distinguish themselves from other ICS systems by being large scale processes that can include multiple sites, and large distances. These processes include industrial, infrastructure, and facility-based processes. Industrial processes include those of manufacturing, production, power generation, fabrication, and refining, and may run in continuous, batch, repetitive, or discrete modes. Infrastructure processes may be public or private, and include water treatment and distribution, wastewater collection and treatment, oil and gas pipelines, electrical power transmission and distribution, wind farms, civil defense siren systems, and large communication systems. Facility processes occur both in public facilities and private ones, including buildings, airports, ships, and space stations. They monitor and control HVAC, access, and energy consumption.
The security of SCADA and other ICS networks is important because compromise or destruction of these systems would impact multiple areas of society far removed from the original compromise. However, the move from proprietary technologies to more standardized and open solutions together with the increased number of connections between segregated control networks and office networks and the Internet has made such control networks more vulnerable to cyber-attack. There are two distinct threats to a modern segregated control network. The first threat is unauthorized access to the control software via changes induced intentionally or accidentally by virus infections and other software threats residing on the control host machine. The second threat is packet access to the network segments hosting SCADA devices. In many cases, there is rudimentary or no security on the actual packet control protocol, so anyone who can send packets to the SCADA device can control it. In many cases SCADA users assume that a VPN is sufficient protection and are unaware that physical access to SCADA-related network jacks and switches provides the ability to totally bypass all security on the control software and fully control those SCADA networks. These kinds of physical access attacks bypass firewall and VPN security and are best addressed by endpoint-to-endpoint authentication and authorization such as are commonly provided in the non-SCADA world by in-device SSL or other cryptographic techniques. The reliable function of SCADA systems in our modern infrastructure may be crucial to public health and safety. As such, attacks on these systems may directly or indirectly threaten public health and safety. Thus, there is a great motivation to maintain SCADA and other ICS networks secure by physically preventing any unauthorized access to such networks. The easiest way to do this is ensure that there is no interconnection whatsoever to any remote networks. However, often there is a need to transfer information from the secure SCADA or other ICS network to a non-secure location, e.g., a historian database on a remote network. Thus there is a conflict between providing the best level of security and transferring information to the remote network. This is because the transfer of information will typically require a two-way interface, and because such two-way interface could provide easy access for an external cyber-attack.
Highly engineered solutions, such as the Owl Computing Technologies Dual Diode, (described in U.S. Pat. No. 8,068,415, the disclosure of which is incorporated herein by reference) provide a one-way data link in the form of a direct point-to-point optical link between network domains in the low-to-high direction or in the low-to-high direction. The unidirectionality of the data transfer is enforced in the circuitry of the network interface cards at both network endpoints and in the cable interconnects. In this way, the hardware provides an added layer of assurance of unidirectional information flow and non-bypassable operation. In contrast to software based one-way data transfer systems, it is easy to prove that data is not bypassing the Dual Diode.
In such systems, shown in block diagram form in FIG. 1 , a first server (the Blue Server) 101 includes a transmit application 102 for sending data across a one-way data link, e.g., optical link 104 , from a first network domain coupled to server 101 to a second network domain coupled to server 111 . First server 101 also includes a transmit (here a phototransmission) component, e.g., optical emitter 103 . Transmit application 102 provides data to the optical emitter for transmission across the optical link 104 . A second server (the Red Server) 111 includes a receive (here a photodetection) component, e.g., optical detector 113 , for receiving data from the optical link 104 , which data is then provided to the receive application 112 for further processing. The first server 101 is only able to transmit data to second server 111 , since it does not include any receive circuitry (e.g., an optical detector comparable to detector 113 ) and the second server 11 is only able to receive data from first server 101 , since it does not include any transmit circuitry (e.g., an optical emitter comparable to emitter 103 ).
FIG. 2 shows a conventional MODBUS-based industrial control system 200 . A computer 210 running SCADA software 220 communicates via a MODBUS TCP/IP driver 225 with a series of MODBUS-enabled devices 241 to 244 over the plant process computer network 230 (e.g., an Ethernet network). Some of the MODBUS-enabled devices (i.e., device 243 in FIG. 2 ) may contain multiple slaves devices 261 , 262 coupled via a sub-network 250 . This type of system 200 can be vulnerable to both types of threats discussed above, i.e., unauthorized access to the control software and packet access to the network segments.
It is an object of the present invention to provide a secure way to transfer information from an ICS network while maintaining the integrity of network to ensure protection from remote cyber-attack.
SUMMARY OF THE INVENTION
The present invention provides a system for securely transferring information from a first network positioned within a secure domain. In a first embodiment, the system includes, within the secure domain, one or more remote terminal units, a first network coupling the one or more remote terminal units, one or more client computers, a second network coupling the one or more client computers and a send server coupled to the first network and to the second network. The send server has an output and is configured to act as a proxy for communications between at least one of the one or more client computers and at least one of the one or more remote terminals, to store first information provided by the at least one of the one or more remote terminals, and to transmit the stored first information on the output. The send server is also configured to transmit a poll request to at least one of the one or more remote terminal units via the first network, to store second information supplied on the first network in response to the poll request, and to transmit the second information on the output. The system also includes, outside the secure domain, a receive server having an input coupled to the output of the send server via a data link which allows communication only from the send server to the receive server. The receive server is configured to receive and store the first and second information provided via the input.
In a second aspect, the system includes, within the secure domain, one or more remote terminal units, a first network coupling the one or more remote terminal units, one or more client computers, a second network coupling the one or more client computers and a send server and coupled to the first network and to the second network. The send server has an output and is configured to act as a proxy for communications between at least one of the one or more client computers and at least one of the one or more remote terminals, to store information provided by the at least one of the one or more remote terminals, and to transmit the stored information on the output. The system also includes, outside the secure domain, a receive server having an input coupled to the output of the send server via a data link which allows communication only from the send server to the receive server. The receive server is configured to receive and store the information provided via the input.
In a third aspect, the system includes, within the secure domain, one or more remote terminal units, a first network coupling the one or more remote terminal units, and a send server coupled to the first network. The send server has an output and is configured to transmit a poll request to at least one of the one or more remote terminal units via the first network, to read information supplied on the first network in response to the poll request, and to transmit the read information on the output. The system also includes a receive server outside the secure domain having an input coupled to the output of the send server via a data link which allows communication only from the send server to the receive server and which is configured to receive and store the information provided via the input.
Preferably, the system may include, outside the secure domain, a third network coupled to the receive server and one or more client computers coupled to the third network, with the receive server further configured to provide at least part of the stored information in response to a request from one of the one or more client computers via the third network. Preferably, each of the remote terminal units is a MODBUS device or a MODBUS PLC. Preferably, the first and second networks are part of an industrial control system.
BRIEF DESCRIPTION OF THE DRAWINGS
The following detailed description, given by way of example and not intended to limit the present invention solely thereto, will best be understood in conjunction with the accompanying drawings in which:
FIG. 1 is a block diagram of a conventional one-way data transfer system;
FIG. 2 is block diagram of a conventional MODBUS-based industrial control system;
FIG. 3 is a block diagram of a secure information transfer system for a MODBUS-based industrial control system according to the present invention;
FIG. 4 is a block diagram of the secure information transfer system for a MODBUS-based industrial control system of the present invention showing a first aspect thereof; and
FIG. 5 is a block diagram of the secure information transfer system for a MODBUS-based industrial control system of the present invention showing a second aspect thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the present disclosure, like reference numbers refer to like elements throughout the drawings, which illustrate various exemplary embodiments of the presently disclosed system. Although the presently disclosed system will be discussed with reference to various illustrated examples, these examples should not be read to limit the broader spirit and scope of the present invention.
The system disclosed herein captures MODBUS data present within a secure network and then passes that data into a non-secure area using a one-way data link, e.g., the OWL Dual Diode Technology shown in FIG. 1 . In a first aspect, the system monitors existing MODBUS Master/Slave communications to collect the MODBUS data. In a second aspect, communication is directly with a MODBUS enabled device. In either aspect, the MODBUS data is collected within the secure environment and made available to customer client applications requiring MODBUS data which are positioned remotely, e.g., in a non-secure environment, without any communication whatsoever from the non-secure environment to the secure environment. In this manner, communication of information out of the is provided without any possibility of compromise of the secure environment. The system disclosed herein is very flexible, enabling a number of different configurations, each of allows information to be transmitted from the plant process computer network to outside the secure boundary without any breach of the security of that network. Existing systems can be modified to add the system disclosed herein to existing servers, or new servers may be added to handle the additional PLC and Dual Diode communications.
FIG. 3 shows an implementation of the entire system 300 , including a send server 310 positioned within the secure portion of the industrial control system network (i.e., the area below dotted line 360 ) and a receive server 350 positioned outside the secure area (i.e., the area above dotted line 360 ). Send server 310 is coupled to receive server 350 via a one-way data link consisting of, for example, transmit application 102 , optical emitter 103 , optical link 105 , optical detector 113 and receive application 112 . The one-way data link preferably operates in a manner identical to the Dual Diode circuit shown in FIG. 1 and described above, although one of ordinary skill in the art will readily recognize that other one-way data links may be provided to link send server 310 to receive server 350 within the scope of the present invention.
The send server 310 performs the physical communications with the field MODBUS PLC devices 241 - 244 . Although only MODBUS PLC devices are shown in FIG. 3 , one of ordinary skill in the art will readily recognize that any MODBUS device, e.g., a non-PLC device having a MODBUS I/O interface, can communicate on the actual MODBUS network 230 a . Send server 310 includes a MODBUS communication software interface 318 having two separate modes of operation, i.e., operations separately performed by MB read module 315 and MB monitor module 320 . The modules 315 , 320 are preferably provided as part of application software operating on send server 310 , but as one of ordinary skill in the art will readily recognize, may also be provided in part in software and in part in hardware, or completely in hardware. The two modules 315 and 320 may be implemented together in a single system based on the settings in the configuration file in send server 310 , as shown in FIG. 3 , or may be separately implemented, as shown in FIG. 4 (which only includes the MB monitor module 320 ) and in FIG. 5 (which only includes MB read module 315 ).
To enable the MB monitor mode, the send server 310 is positioned between a computer 210 running SCADA software 220 and the MODBUS devices 241 - 244 . In particular, as shown in FIG. 3 , the MB monitor module 320 separates the conventional network 230 of FIG. 2 into two parts, a first network 230 a directly coupling the MODBUS devices 241 - 244 with a first connection to the MB monitor module 320 in send server 310 and a second network 230 b directly coupling computer 210 with a second connection to the MB monitor module 320 in send server 310 (via the conventional MODBUS driver 225 within client computer 210 ). MODBUS devices often support concurrent access, and many end user configurations take advantage of this feature. For example, an end user may have multiple computers communicating on the network 230 of FIG. 2 , each of which is accessing the same MODBUS device using the same IP address and port. Each of these computers may request the same information or different information. The system disclosed herein supports this type of configuration by accepting multiple connections on its assigned port, and acting as a gateway to the physical MODBUS device (i.e., there may be a plurality of computers 210 coupled to network 230 b ). In the configuration shown in FIG. 3 , all pertinent data flowing to or from a MODBUS device on network 230 a can be identified and collected in MB monitor 320 . The data collected can then be made available to receive server 350 and its clients, e.g., computers 370 , 380 , via the one-way data link
In operation, the MB read module 325 actively polls each MODBUS device in a predefined manner, and then sends the information received as a result of such polling to the receive server 350 across the one-way data link.
The MODBUS interface 318 is controlled by a configuration file, which includes three parts: (1) an MB Options section; (2) an MB Read section; and (3) an MB Monitor section. The MB Options section defines the type of server, i.e., send or receive, and the address and port number of the UDP address for communications from send server 310 to receive server 350 . An example of the actual code portion for the MB Options section is shown below:
# MODBUS Configuration File
#
[OPTIONS]
;Main options section
OPT_SEND TRUE
;This is the Talker (Blue)
OPT_UDP_ADDR 192.168.100.69
;This is the OWL UDP address
OPT_UDP_PORT 11500
;This is the OWL UDP Port
Note that in all code portions shown herein, lines beginning with the character ‘#’ are comment lines. The [OPTIONS] header defines the options section of the configuration file. The OPT_SEND line tells the MODBUS interface 318 to act as the send server (when “TRUE” as shown above). The send server is the only server allowed to directly communicate with the MODBUS devices 241 - 244 . The OPT_UDP_ADDR and OPT_UDP_PORT lines define the UDP address and port number used to communicate to the receive server 350 . A single UDP connection (i.e., the one-way link defined, in part, by optical link 104 in FIG. 3 ) is used to pass all data from the send server to the receive server.
The MB Read section of the configuration file describes the entries in the configuration file on the send server required for each MODBUS device being polled directly. In operation, the MB Read module within the send server polls each defined device and then immediately sends the poll results to the receive server across the one-way data link. An example of the actual code portion for the MB Read section is shown below:
#
# PLC definition block
#
[PLCTEST Number 1]
;This can be any label that is
meaningful to the client
MODE Send
;We are the MODBUS Master, talking
to this PLC
PLC_RXTIMEOUT 3
;Wait 3 seconds for response from
PLC (default is 5)
IP_OUT 192.168.100.10
;IP address of the PLC
PORT_OUT 502
;Port address of the PLC
#
# POLL_COMMAND: Starting_Address Number_Of_Words
MODBUS_Command PLC_Addr scan_time [transaction_ID]
[Protocol_ID]
#
#
POLL_COMMAND
0
5
4
1
.1
POLL_COMMAND
5
10
4
1
.1
POLL_COMMAND
15
10
4
1
.1
POLL_COMMAND
10
20
3
1
.1
POLL_COMMAND
0
6
2
1
.1
POLL_COMMAND
16
16
2
1
.1
POLL_COMMAND
32
16
2
1
.1
POLL_COMMAND
20
10
4
2
.1
For RTU # 2
POLL_COMMAND
0
5
4
2
.1
For RTU # 2
POLL_COMMAND
20
10
4
2
.1
For RTU # 2
POLL_COMMAND
0
32
2
2
.1
For RTU # 2
POLL_COMMAND
40
18
2
2
.1
For RTU # 2
The command line labeled “[PLCTEST Number 1]” defines the start of a MODBUS device definition block. All information that follows is treated as information for a single MODBUS device.
The “MODE Send” command line shown above sets the send server 310 to act as a polling master, collecting data as defined by the listed Poll commands and then send the collected data over the one-way data link to the receive server 350 . All of the collected Poll Record data is refreshed to the receive server 350 at fixed intervals, preferably every thirty seconds. However, whenever a poll is executed, the data received is sent immediately to the receive server 350 , and, if the poll fails, the fail status for the poll record is also sent immediately to receive server 350 . If communications with the PLC itself fails, all poll records are marked as FAILED and sent immediately to the receive server 350 .
The “PLC RX Timeout” command line shown above sets the amount of time that that the MB Read module 315 will wait for a MODBUS device 241 - 244 to respond to a poll command. If no response is received within the given time frame, then that particular poll record is deemed FAILED and its status is sent immediately to the receive server 350 .
The “IP_OUT” and “PORT_OUT” command lines identify the physical address and port number, respectively, for the particular MODBUS device for which commands are being defined.
The poll commands (“POLL_COMMANDS”) command lines for each MODBUS device consist of the command type, starting address, number of words, scan rate, and, optionally, the transaction ID and the Protocol ID, if needed. The poll records for a given MODBUS device are specified in the configuration file for the send server 310 and in the configuration file for the receive server 350 (as discussed below). The following command types are preferably provided for the direct polling of a MODBUS Device:
Command Number
Description
MODBUS Registers
1
Read Coil Status
00001 -
2
Read Input Status
10001 -
3
Read Holding Register
40001 -
4
Read Input Register
30001 -
The starting address for a poll record is ‘0’ based. As shown above, the poll command includes: (1) Starting_Address; (2) Number_Of_Words; (3) MODBUS_Command; (4) PLC_Addr; (5) scan_time; (6) transaction_ID (optional); and (7) Protocol_ID (optional). The following is an example of a poll command:
POLL_COMMAND
10
20
3
1
.1
This poll command starts at the 0 based address of 10, for 20 additional words, reading the Holding Registers (command 3) from slave address (PLC addr.) 1 at 0.1 second intervals. So, the read starts at MODBUS register 40011, and continues for 20 consecutive addresses. Preferably, the scan time can be specified as any number of seconds. Preferably, the minimum scan time is 0.1 seconds. In addition, a given MODBUS TCP/IP address can have multiple slave addresses and thus all poll records required for a slave device (e.g., MODBUS slave devices 261 , 262 in FIG. 3 ) are also included in this section.
The MB Monitor section of in the configuration file for the send server 310 identifies the MODBUS devices which are being monitored. The MB monitor module 320 monitors the data flowing between the device (e.g., MODBUS PLC 241 in FIG. 3 ) and computer 210 , identifies the data of interest (as specified in the configuration file), and immediately sends the identified data to the receive server 350 . In operation, the MB monitor module 320 in the receive server 310 acts as a proxy for the connection between a MODBUS device, e.g., MODBUS PCL 241 and computer 210 . The MODBUS commands issued by the MODBUS driver 225 in computer 210 are intercepted by the MB monitor module 320 , since MODBUS driver 225 is only coupled to MB monitor 320 via network 230 b . The intercepted MODBUS commands are then relayed to the appropriate MODBUS PLC via network 230 a . MB monitor module 320 will then receive (on network 230 a ) any response made by the MODBUS PLC to such command, and then echo such response back to MODBUS driver 225 on computer 210 via network 230 b.
In operation, a user may either pre-define the information (poll records) to be captured or let the MB monitor module 320 capture all the poll records issued by the MODBUS client and dynamically generate the poll list. Preferably, the two modes are not mixed, either all poll records are statically pre-defined or all poll records are dynamically generated.
For dynamic poll generation, no poll records are defined in the configuration file. Instead, poll records are captured from the MODBUS client and the poll record definition is sent to MB listen module 355 on receive server 350 . In operation, each command type being issued is examined at the MB monitor module 320 and, if it is a command of interest, (e.g., MODBUS command 1, 2, 3, or 4 as identified above), then the poll records captured for the associated MODBUS PLC up to that pointe are examined. If the poll record/slave number does not match an existing poll record, then a new poll record is dynamically created and the new poll record definition is sent to MB listen module 355 on receive server 350 .
For static poll record definition, all poll records are defined in the configuration file. The MB monitor module 320 looks at the command type being issued. If it is a command of interest (e.g., one of MODBUS command 1, 2, 3, or 4) then the poll records in the configuration file for this MODBUS device are examined. If the poll record/slave number matches one of the defined poll records, then the poll records are updated with the response from the MODBUS device. Note that the poll records defined in the configuration file do not have to exactly match the poll commands as issued by the MODBUS TCP/IP driver on the client computer 210 . The MB monitor module may do a partial poll record update of the local poll record database by extracting pertinent data from the MODBUS communications stream.
The following provides an example of the MB Monitor Configuration File portion:
[PLCTEST Number 2]
;This can be any label that is
meaningful to the client
MODE Monitor
;We are Monitoring transactions to
this PLC
PLC_RXTIMEOUT 3
;Wait 3 seconds for response from
PLC (default is 5)
IP_OUT
192.168.100.13
;IP address of the PLC
PORT_OUT
502
;Port address of the PLC
IP_IN
192.168.100.113
;IP address to listen on
PORT_IN
502
;Port address to listen on
POLL_DYNAMIC FALSE
;Dynamic Poll generation disabled
#
# POLL_MONITOR: Starting_Address Number_Of_Words
MODBUS_Command PLC_Addr [transaction_ID]
[Protocol_ID]
#
#
POLL_MONITOR
0
5
4
1
POLL_MONITOR
5
10
4
1
POLL_MONITOR
15
10
4
1
POLL_MONITOR
10
20
3
1
POLL_MONITOR
0
16
2
1
POLL_MONITOR
16
16
2
1
POLL_MONITOR
32
16
2
1
POLL_MONITOR
20
10
4
2
For RTU # 2
POLL_MONITOR
0
5
4
2
For RTU # 2
POLL_MONITOR
20
10
4
2
For RTU # 2
POLL_MONITOR
0
32
2
2
POLL_MONITOR
40
18
2
2
The line “[PLCTEST Number 2]” defines the start of a MODBUS definition block. All information that follows this line is treated as information for the same PLC or other MODBUS device.
The line “MODE Monitor” instructs the MB monitor module 320 to monitor an existing MODBUS connection. As discussed above, MB monitor module 320 , when enabled, acts as a proxy by receiving MODBUS commands from the computer 210 and then passing those commands directly to the physical MODBUS device 241 - 244 via network 230 a . In operation, MB monitor module 320 collects data as defined by the poll commands, and sends it over the one-way data link to the receive server 350 . Preferably, all poll record data is refreshed to receive server 350 every thirty seconds. However, whenever a poll is executed, data obtained in response to that poll command is sent immediately to receive server 350 and, if the poll command fails, the fail status for the poll record is also sent immediately to receive server 350 . If communications with the same PLC or MODBUS device fails, all poll records are marked as FAILED and sent immediately to receive server 350 .
The line “PLC RX Timeout” sets the amount of time that to wait for polled MODBUS device to respond. If no response is received within the designated time frame, then that particular poll record is deemed FAILED and that status is sent immediately to receive server 350 .
The lines “IP_OUT” and “PORT_OUT” set the physical address and port number, respectively, for the PLC or MODBUS device.
The line “POLL_DYNAMIC” enables or disables the dynamic poll record generation feature. If the value is FALSE, then poll records will not be generated dynamically, and poll record definitions must be included in the configuration file. If the value is TRUE, then poll record definitions are captured from the client as they occur and also sent to the MB listen module 355 on receive server 350 .
The lines “IP_IN” and “PORT_IN” set the physical address and port number, respectively, for communication with the MODBUS driver 225 in computer 210 (i.e., the proxy address for the associated MODBUS device).
If dynamic poll generation is used, then no poll records (i.e., the “POLL_MONITOR” lines shown above) are defined in the configuration file for the particular MODBUS device. However, if static poll definition is in use, then each poll record must be defined. The poll commands for a particular MODBUS device consist of command type, starting address, number of words, and, optionally, the transaction ID and the Protocol ID if needed for the MODBUS device. Note that no scan rate is defined, because the scan rate is controlled by the poll commands as issued by the MODBUS driver 225 on the computer 210 . The poll records for a particular MODBUS device are specified in the configuration file for the send server 310 and in the configuration file for the receive server 350 , and must match. Note that the following command types are used for monitoring of a MODBUS device:
Command Number
Description
MODBUS Registers
1
Read Coil Status
00001 -
2
Read Input Status
10001 -
3
Read Holding Register
40001 -
4
Read Input Register
30001 -
The starting address for a poll record is ‘0’ based. As shown above, the poll command includes: (1) Starting_Address; (2) Number_Of_Words; (3) MODBUS_Command; (4) PLC_Addr; (5) transaction_ID (optional); and (6) Protocol_ID (optional). The following is an example of a poll command:
POLL_MONITOR
10
20
3
1
This poll command starts at the 0 based address of 10, for 20 additional words, reading the Holding Registers (command 3) from slave address (PLC addr.) 1. Whenever the MODBUS driver 225 in computer 210 issues a command, a check is made to see if any of the requested data intersects with any of the defined poll records. If it does, then that portion of the poll record is updated with the data coming back from the PLC. Note that a given MODBUS TCP/IP address can have multiple slave addresses. All poll records required for a slave must be included in this section. For example, in the configuration file shown above, one slave is polled at slave address 1, and another slave is polled at slave address 2.
Receive server 350 in FIG. 3 receives MODBUS poll record data from send server 320 , and makes that data available to MODBUS drivers 375 , 385 in respective client computers 370 , 380 . The only data that is made available to the client computers 370 , 380 is the data defined in the poll records. The poll records and the physical MODBUS devices themselves are defined in a configuration file that is read by the MB listen module 355 in receive server 350 upon startup. As discussed above, information defining the status of each poll record and the status of the MODBUS devices is fed forward to receive server 350 from send server 310 . If a poll record is in the FAILED state, then the respective client computer 370 , 380 will not receive a response to a request. All poll record data is forced from send server 310 to receive server 350 at fixed (preferably 30 second) intervals. In this way, the poll record data on receive server 350 can be assured to be accurate.
For poll record definition at receive server 350 , the user has an option of statically defining the poll records to be monitored or letting the MB listen module 355 dynamically generating the poll list by capturing the poll records issued by the MODBUS client. As evident based on the one-way data link coupling send server 310 to receive server 355 , and the lack of a link allowing any information to pass from receive server 355 to send server 310 , the MB listen module can only operate in a LISTEN mode and does not have any ability to communicate directly with any of the physical MODBUS devices 241 - 244 .
The MB listen module 355 is controlled by a configuration file, which is shown below in two segments for ease of discussion. The first OPTIONS Section includes the following:
# MODBUS Configuration File
#
[OPTIONS]
;Main options section
OPT_LISTEN
TRUE
;This is the listener (Red)
OPT_UDP_ADDR
192.168.100.69
;This is the OWL UDP address
OPT_UDP_PORT
11500
;This is the OWL UDP Port
OPT_UDP_TIMEOUT 30
;Inactivity timeout for UDP.
The “[OPTIONS]” line defines the options section of the configuration file. The “OP_LISTEN” line indicates that the installed software should operate as an MB listen module 355 on a receive server. The lines “OPT_UDP_ADDR” and “OPT_UDP_PORT” designate the UDP address and port number, respectively, used to collect data from the send server 310 . A single UDP connection is used to pass all data from send server 310 to receive server 350 . The “OPT_UDP_TIMEOUT” line defines the deadman timeout for the UDP connection between send server 310 and receive server 350 . If receive server 350 does not receive any data from send server 310 within this timeout period, then all MODBUS devices 241 - 244 coupled to receive server 350 via send server 310 are deemed failed. The “PLC Listen Mode” line describes the entries in the configuration file on receive server 350 for a designated MODBUS device. Send server 310 polls the data and immediately sends the poll results to receive server 350 . The polling data is then made available to client computers connected to receive server 350 (e.g., computers 370 , 380 shown in FIG. 3 ). As evident, the listen mode is the only mode supported at receive server 350 .
The second MB Listen portion of the configuration file is shown below:
PLC LISTEN Configuration File Entry
[PLCTEST Number 2]
;This can be any label that is
meaningful to the client
MODE Listen
;We are LISTENING for data across
the diode
IP_IN 192.168.100.113
;Clients talk to me on
this address
PORT_IN 502
; Clients talk to me on this port
PLC_DIAGREGISTERS 5000
;Start of diagnostic registers for
this PLC
POLL_DYNAMIC FALSE
;Dynamic Poll generation disabled
#
# POLL_MONITOR: Starting_Address Number_Of_Words
MODBUS_Command PLC_Addr [transaction_ID]
[Protocol_ID]
#
#
POLL_MONITOR
0
5
4
1
POLL_MONITOR
5
10
4
1
POLL_MONITOR
15
10
4
1
POLL_MONITOR
10
20
3
1
POLL_MONITOR
0
16
2
1
POLL_MONITOR
16
16
2
1
POLL_MONITOR
32
16
2
1
POLL_MONITOR
20
10
4
2
For RTU # 2
POLL_MONITOR
0
5
4
2
For RTU # 2
POLL_MONITOR
20
10
4
2
For RTU # 2
POLL_MONITOR
0
32
2
2
POLL_MONITOR
40
18
2
2
POLL_MONITOR
5000
250
3
1
;For Diagnostics
The “[PLCTEST Number 2]” line defines the start of a MODBUS definition block. All information that follows is treated as information for the same PLC or MODBUS device. The text between the brackets must be unique from the other PLC blocks in the configuration file, and it must match the name used for this PLC on send server 350 .
The “MODE Listen” line tells the software loaded in the receive server 350 to act as a MB listen module 355 . As discussed herein, the MB listen module 355 listens for data from send server 310 for the identified MODBUS device and acts as a proxy by receiving MODBUS commands from MODBUS drivers on client computers (e.g., MODBUS drivers 375 , 385 on computers 370 , 380 ) and then responding to those commands with data received from send server 310 . All poll record data is refreshed to the receive server at a fixed interval, e.g., every thirty seconds, from send server 310 .
The “IP_IN” and “PORT_IN” lines identify the proxy address and port number, respectively that MODBUS drivers 375 , 385 use for talking to the PLC (actually with receive server 350 as a proxy for the PLC).
The “PLC_DIAGREGISTERS” is an optional entry used to define a series of registers that can be accessed by client computers 370 , 380 to determine the status of a particular PLC and each of the poll records defined for that PLC. If this option is implemented, then there must be a corresponding poll record included in the poll definitions for the diagnostic registers. The address used can be any address between 1 and 60000. Note that the address used must not overlap any other poll record addresses for the selected PLC. The number of addresses actually used is dependent upon the number of poll records defined. For each poll record defined, 6 contiguous registers are required. In sample configuration shown above, the diagnostic registers start at location 5000. A client computer may can access diagnostic information starting at address 5000, with the layout of that information as follows:
Address
Definition
5000
0: PLC Failed, 1: PLC in service
5001
# of poll records in the system
5002
Poll record 1: Starting Address
5003
Poll record 1: slave address
5004
Poll record 1: MODBUS function code
5005
Poll record 1: # of messages received
5006
Poll record 1: Elapsed seconds since last receive
5007
Poll record 1: 0 = Poll record failed, 1 = Poll record OK
5008
Poll record 2: Starting Address
5009
Poll record 2: slave address
5010
Poll record 2: MODBUS function code
5011
Poll record 2: # of messages received
5012
Poll record 2: Elapsed seconds since last receive
5013
Poll record 2: 0 = Poll record failed, 1 = Poll record OK
The “POLL_DYNAMIC” field enables or disables the dynamic poll record generation feature. If the value is FALSE, then poll records will not be generated dynamically, and a user must place the poll record definitions into the configuration file. If the value is TRUE, then poll record definitions are captured from the client computer 370 , 380 in real time, and sent to the MB listen module 355 on receive server 350 . Receive server 350 then maintains a dynamic list of poll record definitions as captured from send server 310 .
The “Poll Monitor Definitions” are only used with static poll definition since each poll record must be statically defined. Poll commands for a MODBUS device consist of the command type, starting address, number of words, and, optionally, the transaction ID and the Protocol ID if needed for the device. No scan rate is defined because the scan rate is controlled by the rate at which data is collected on send server 310 . The poll records for a given MODBUS device are specified in the configuration file for send server 310 and in the configuration file for receive server 350 (and must match).
The following command types are preferably supported for monitoring of a MODBUS device:
Command Number
Description
MODBUS Registers
1
Read Coil Status
00001 -
2
Read Input Status
10001 -
3
Read Holding Register
40001 -
4
Read Input Register
30001 -
The starting address for a poll record is ‘0’ based. As shown above, the poll command includes: (1) Starting_Address; (2) Number_Of_Words; (3) MODBUS_Command; and (4) PLC_Addr. The following is an example of a poll command:
POLL_MONITOR
10
20
3
1
This poll command starts at the 0 based address of 10, for 20 additional words, reading the Holding Registers (command 3) from slave address (PLC addr.) 1. Whenever a MODBUS driver 375 , 385 in a client computer 370 , 380 issues a command, a check is made to see if all of the requested data intersects with the defined poll records. If it does, then the customer request is serviced with the data available in the poll record database. If any of the poll records are in the FAILED state, receive server 350 will not respond to the client request, thus simulating a MODBUS device failure. If the client computer 370 , 380 requests an address that is not contained in any of the poll records, the MB listen module 355 will respond to the client computer 370 , 380 with a standard “MODBUS illegal address” error code.
As discussed above, the system of FIG. 3 provides two different modes of operation: (1) monitoring communications within a secure area between a local computer 210 and a local MODBUS PLC device and sending data from such communications to a remote computer (e.g., computer 370 ) outside the secure area; and (2) directly reading information from a MODBUS PLC device within the secure area and sending the information read to a remote computer (e.g., computer 380 ) outside the secure area. These two modes may be implemented together in a single system, as shown in FIG. 3 , or separately, as shown in FIGS. 4 and 5 . Both modes provide for the transmission of information from a secure area to a non-secure remote computer outside the secure area while maintaining the security of the secure area based on the one-way data link used for transmission of the information outside the secure area.
FIG. 4 shows an implementation 400 based only on the first mode of operation. In FIG. 4 , a MODBUS PLC 410 is coupled to a local computer 420 via a local network 230 having a first portion 230 a and a second portion 230 b , the two portions separate. Local computer 420 includes a PLC query application 428 and a local database 423 for storing information obtained from PLC 410 . Local computer 420 and PLC 410 are within a secure area (e.g., a high integrity control network) shown in FIG. 4 as the area to the right of dotted line 360 . The area to the left of dotted line 360 is considered the remote portion outside the secure area. Send server 430 is also positioned within the secure area and includes a configuration file enabling MB monitor module 320 . MB monitor module is separately coupled to network 230 a and to network 230 b . MB monitor module 320 monitor communications between PLC 410 and computer 420 and, as discussed above, based on the poll records stored in the configuration file (generated either statically or dynamically), information of interest is captured and provided to the MB listen module 355 in receive server 350 via the one-way data link comprising transmit application 102 , diode 103 , optical link 104 , photodetector 112 and receive application 112 . MB listen module 355 then makes the information received available to clients via a remote network 390 based upon the configuration file in receive server 350 . In the embodiment shown in FIG. 4 , for example, a remote client 440 includes a data injection application 442 which communicates with the MB listen module 355 to read such information and store it within remote database 445 . Notably, remote client 440 is able to access information obtained from secure network 230 but without any ability to otherwise communicate to such network. This ensures the security of network 230 and prevents any disruption thereto.
FIG. 5 shows an implementation 500 based only on the second mode of operation. In FIG. 5 , a MODBUS PLC 510 is directly coupled to send server 520 via a local network 230 . Send server 520 and PLC 510 are within a secure area (e.g., a high integrity control network) shown in FIG. 5 as the area to the right of dotted line 360 . The area to the left of dotted line 360 is considered the remote portion outside the secure area. Send server 520 includes a configuration file enabling MB read module 315 . As discussed above and based upon the polling records defined in the configuration file, MB read module 315 polls each defined PLC device (PLC 510 in FIG. 5 ) and immediately sends the information obtained to the MB listen module 355 in the receive server 350 via the one-way data link comprising transmit application 102 , diode 103 , optical link 104 , photodetector 112 and receive application 112 . MB listen module 355 then makes the information received available to client 440 via a remote network 390 based upon the configuration file in receive server 350 in the same way as in the embodiment of FIG. 4 . This configuration also provides remote client 440 with access to information obtained from secure network 230 but does not allow remote client 440 with any ability to otherwise communicate to such network.
Although the present invention has been particularly shown and described with reference to the preferred embodiments and various aspects thereof, it will be appreciated by those of ordinary skill in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. It is intended that the appended claims be interpreted as including the embodiments described herein, the alternatives mentioned above, and all equivalents thereto. | A system for securely transferring information from an industrial control system network, including, within the secure domain, one or more remote terminal units coupled by a first network, one or more client computers coupled by a second network, and a send server coupled to the first and second networks. The send server acts as a proxy for communications between the client computers and the remote terminals and transmits first information from such communications on an output. The send server also transmits a poll request to a remote terminal unit via the first network and transmits second information received in response to the poll on the output. The system also includes, outside the secure domain, a receive server having an input coupled to the output of the send server via a one-way data link. The receive server receives and stores the first and second information provided via the input. | 62,654 |
CROSS-REFERENCES TO RELATED APPLICATIONS
The present application is also related to co-pending applications, application Ser. No. 11/761,968, filed on Jun. 12, 2007, entitled: Methods and Apparatus for Determining Network Risk Based upon Incomplete Network Configuration Data, application Ser. No. 11/761,977, filed on Jun. 12, 2007, entitled: Methods and Apparatus for Prioritization or Remediation Techniques for Network Security Risks, and application Ser. No. 11/761,982, filed on Jun. 12, 2007, entitled: Adaptive Risk Analysis Methods and Apparatus. The present application and co-pending applications claim benefit of priority under 35 U.S.C. 119(e) of U.S. provisional Application Nos. 60/804,552, filed on Jun. 12, 2006, 60/813,603 filed Jun. 12, 2006, and 60/804,930, filed Jun. 15, 2006. The above applications are hereby incorporated by reference for all purposes.
BACKGROUND OF THE INVENTION
The present invention relates to methods and apparatus for network analysis. More specifically, the present invention relates to methods and apparatus for determining vulnerability of a network (e.g. hosts, applications, data) to threats. Still more specifically, various embodiments of the present invention determination of vulnerabilities, prioritization of vulnerabilities of a network, visualization of vulnerabilities of a network to threats based upon incomplete configuration data (including vulnerabilities of hosts) of network devices. In various embodiments of the present invention, reference to a network and network configuration data includes not only network hardware and software, but also includes application host servers, and any other device forming part of a network, as well as software operating thereon.
Determination of threats to a network has been described in application Ser. No. 11/335,052 filed on Jan. 18, 2006, and herein by incorporated by reference for all purposes. In that application, one of the named inventors of the present application described determining a software model of the network based upon configuration data of “network devices” in the network. The “network devices” included routers, firewalls, host application servers, and other devices in the network. Based upon the software model, the previous application described determining potentially harmful traffic paths in the network by simulating the software model.
The inventors of the present application explicitly consider and address the problems of what happens if some or all configuration data (and host vulnerabilities) from the network, e.g. firewall, router, one or more host application servers, or the like, are incomplete, i.e. unavailable, not gathered, or the like. Problems such as how to determine threats based on incomplete data, how to prioritize threats that are determined based on incomplete data, how to provide visualization of threats determined based upon incomplete data, and the like are considered by the inventors.
The inventors of the present invention have determined that it would be advantageous to be provide such information to users such as network administrators even in cases where configuration data (and host vulnerabilities) from one or more host application servers is unavailable, incomplete, not gathered, or the like.
BRIEF SUMMARY OF THE INVENTION
The present invention relates to methods and apparatus for network security risk management. In various embodiments, network security risk management includes quantitizing security risk based upon incomplete network data; prioritizing between remediation actions; identifying changes in security risk based upon changes to the network, new threats, and the like; visualization of network security risks; and the like.
The inventors introduce the concept of “confidence” or “vulnerability certainty” to network analysis as one basis for prioritizing discovered threats or vulnerabilities. In various embodiments, “confidence” is typically based upon how much information may be known about one or more host servers. Such information may include the presence of a host server, network addresses associated with a host server, ports monitored by a host server, applications monitoring ports on the host server, versions of operating systems on the host server, versions of applications on the host server, vulnerability data of applications and operating systems, and the like. Unlike previous systems, embodiments of the present invention can operate with less than complete configuration information of the network e.g. host servers, or the like.
In various embodiments of the present invention, “harm probability,” “vulnerability exploitablility,” or “exposure” are associated with a threat or vulnerability. A “security risk” value or score is determined from the exposure and a “business value” or “asset value” associated with one or more host servers. The security risk score is considered when prioritizing the remediation of threats (vulnerabilities). Additionally, each host server may be associated with a confidence factor (vulnerability certainty), as discussed above.
In various embodiments, when determining threat paths within a network topology, the exposed risk and confidence factor are used to prioritize threats (prioritize the remediation of vulnerabilities). The quantization of security metrics, such as exposed risk, confidence factors, and the like, based upon incomplete network configuration data is herein termed “adaptive risk.” In some embodiments risk is evaluated as a (risk, confidence) number pair.
In some embodiments, adaptive risk=exposed risk*confidence factor. For example, a first host server has a high exposed risk (e.g. 90), a high confidence factor (0.90), and an adaptive risk of 81, and a second host server that has a high exposed risk 80 but a lower confidence factor (0.5), and an adaptive risk of 40. In such an example, the first host server may be prioritized as having a potential vulnerability that should be addressed before the potential vulnerability of the second host server. As another example, a first host server has a low exposed risk (e.g. 45), a high confidence factor (e.g. 0.9), and an adaptive risk of 40.5, and a second host server that has a low exposed risk (e.g. 50), a low confidence factor (e.g. 0.50), and an adaptive risk of 23. In such an example, again the potential vulnerability of the first host server may be prioritized over the potential vulnerability of the second host server based upon the adaptive risks. In other embodiments, with different weights or different combinations of the exposed risk and confidence factors, a different prioritization that shown above may be determined. In some general cases, the least “dangerous” or vulnerable situation for the network is where a host server has a low exposed risk and a high confidence factor; the most “dangerous” or vulnerable situation for the network is where a host server has a high exposed risk and a high confidence factor; and other weightings are in between these situations.
According to one aspect of the invention, methods for a computer system including a display are described. A technique includes determining a plurality of security metrics associated with a plurality of servers within a network, and displaying a tree map on the display representing at least a portion of the network. In various embodiments, the tree map comprises a plurality of shapes associated with servers from the plurality of servers, and a size of shapes in the plurality of shapes are determined in response to a first security metric from the plurality of security metric associated with the servers. In various embodiments, an appearance of the shapes are determined in response to a second security metric from the plurality of security metrics associated with the servers.
According to another aspect of the invention, a computer system is disclosed. One system includes a processor configured to determine a plurality of security metrics associated with a plurality of servers within a network, and a memory configured to store the plurality of security metrics. An apparatus includes a display for displaying a tree map on the display representing at least a portion of the network, wherein the tree map comprises a plurality of shapes associated with servers from the plurality of servers, wherein a size of shapes in the plurality of shapes are determined in response to a first security metric from the plurality of security metric associated with the servers, and herein an appearance of the shapes are determined in response to a second security metric from the plurality of security metrics associated with the servers.
According to other aspects, a computer program product including computer-system executable-code resident on a tangible media is described. A computer program product may include code that directs the computer system to determine a plurality of security metrics associated with a plurality of servers within a network. A computer program product may also include code that directs the computer system to display a tree map on the display representing at least a portion of the network, wherein the tree map comprises a plurality of shapes associated with servers from the plurality of servers, wherein a size of shapes in the plurality of shapes are determined in response to a first security metric from the plurality of security metric associated with the servers, and wherein an appearance of the shapes are determined in response to a second security metric from the plurality of security metrics associated with the servers. The tangible media may include optical media, magnetic media, semiconductor media, or the like.
According to other aspects, a graphical user interface for a computer system including a display is disclosed. A GUI includes a first portion configured to display a tree map on the display representing at least a portion of the network including a plurality of servers, wherein the portion of the network is associated with a plurality of security metrics, wherein the tree map comprises a plurality of shapes associated with servers from the plurality of servers, wherein a size of shapes in the plurality of shapes are determined in response to a first security metric from the plurality of security metrics associated with the servers, and wherein an appearance of the shapes are determined in response to a second security metric from the plurality of security metrics associated with the servers. A GUI may also include a second portion configured to display a textual display of security metrics from the plurality of security metrics.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to more fully understand the present invention, reference is made to the accompanying drawings. Understanding that these drawings are not to be considered limitations in the scope of the invention, the presently described embodiments and the presently understood best mode of the invention are described with additional detail through use of the accompanying drawings.
FIG. 1 is a block diagram of typical computer system according to an embodiment of the present invention;
FIG. 2 illustrates an example of an embodiment of the present invention;
FIGS. 3A and B illustrate a diagram of a flow chart according to one embodiment of the present invention;
FIGS. 4A-B illustrates screen shots according to embodiments of the present invention; and
FIGS. 5A-C illustrates additional screen shots according to other embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram of typical computer system 100 according to an embodiment of the present invention. In various embodiments, computer system 100 is an analysis server that performs the vulnerability analyses and prioritization described below.
In the present embodiment, computer system 100 typically includes a monitor 110 , computer 120 , a keyboard 130 , a user input device 140 , computer interfaces 150 , and the like.
In the present embodiment, user input device 140 is typically embodied as a computer mouse, a trackball, a track pad, a joystick, wireless remote, drawing tablet, and the like. User input device 140 typically allows a user to select objects, icons, text and the like that appear on the monitor 110 via a command such as a click of a button or the like.
Embodiments of computer interfaces 150 typically include an Ethernet card, a modem (telephone, satellite, cable, ISDN), (asynchronous) digital subscriber line (DSL) unit, FireWire interface, USB interface, and the like. For example, computer interfaces 150 may be coupled to a computer network, to a FireWire bus, or the like. In other embodiments, computer interfaces 150 may be physically integrated on the motherboard of computer 120 or the like.
In various embodiments, computer 120 typically includes familiar computer components such as a processor 160 , and memory storage devices, such as a random access memory (RAM) 170 , disk drives 180 , and system bus 190 interconnecting the above components.
In one embodiment, computer 120 includes one or more Xeon microprocessors from Intel. Further, in the present embodiment, computer 120 typically includes a UNIX-based operating system.
RAM 170 and disk drive 180 are examples of tangible media configured to store data such as configuration files, network topologies, vulnerability databases, embodiments of the present invention, including executable computer code configured to prioritize network vulnerabilities, or the like. Other types of tangible media include floppy disks, removable hard disks, optical storage media such as CD-ROMS, DVDs and bar codes, semiconductor memories such as flash memories, read-only-memories (ROMS), battery-backed volatile memories, networked storage devices, and the like.
In the present embodiment, computer system 100 may also include software that enables communications over a network such as the HTTP, TCP/IP, RTP/RTSP protocols, and the like. In alternative embodiments of the present invention, other communications software and transfer protocols may also be used, for example IPX, UDP or the like.
FIG. 1 representative of a computer system capable of embodying the present invention. It will be readily apparent to one of ordinary skill in the art that many other hardware and software configurations are suitable for use with the present invention. For example, the computer may be a desktop, portable, rack-mounted or tablet configuration. Additionally, the computer may be a series of networked computers. Further, the use of other micro processors are contemplated, such as Xeon™, Pentium™, Core™ microprocessors; Turion64™ or Athlon64™ microprocessors from Advanced Micro Devices, Inc; and the like.
Further, many types of operating systems are contemplated, such as Windows®, WindowsXP®, WindowsNT®, or the like from Microsoft Corporation, Solaris from Sun Microsystems, LINUX, UNIX, and the like. In still other embodiments, the techniques described above may be implemented upon one or more chips, an auxiliary processing board (e.g. graphics processor unit), or the like.
FIG. 2 illustrates an example of an embodiment of the present invention. In FIG. 2 , a network 200 is modeled including network infrastructure devices 210 , 220 and 230 . Also shown are host server locations 240 , 250 , 260 , and 270 . A server 280 and an analysis server are also illustrated.
In various embodiments of the present invention, network infrastructure devices 210 - 230 are typically devices such as network routers, firewalls, data bridges, or the like. Network infrastructure devices 210 - 230 are typically used to route traffic within a network. Accordingly, in other embodiments, network infrastructure devices 210 - 230 may be embodied in many forms, such as wireless routers, load balancing systems, or the like. In various embodiments, the configurations of network infrastructure devices 210 - 230 are typically specified by a system administrator. In some embodiments, the configurations may take the form of a configuration file. Some network infrastructure devices 210 - 230 may have default configurations which can be modified via the system administrator loading a new configuration file. Conversely, configuration files may be downloaded from network infrastructure devices 210 - 230 for analysis by a system administrator.
In various embodiments, host server locations 240 - 270 are locations where host application servers may be located. As will be described below, host server locations 240 - 270 are locations within network 200 where host server machines are predicted to be located, based upon configuration files of network infrastructure devices 210 - 230 .
As will be described below, server 280 is a location from which a system administrator will initially launch one or more attacks from. The location of server 280 may is arbitrary and may represent any server within network 200 or a server outside network 200 (e.g. the internet). In various embodiments, the attack may be any type of network threat such as a virus, a worm, a Denial of Service attack, key logger, spyware, or the like. Such threats are commonly profiled in publicly available threat or vulnerability reference libraries compiled by Computer Associates, McAfee, Cisco, the National Vulnerability Database, or the like.
Additionally, in FIG. 2 , an analysis server 290 is illustrated. In various embodiments, analysis server 290 is coupled to network infrastructure devices 210 - 230 and may be coupled to host server locations 240 - 270 .
FIGS. 3A and B illustrate a diagram of a flow chart according to one embodiment of the present invention. Description of the embodiment of FIG. 3 is made with respect to the diagram in FIG. 2 .
Initially, analysis server 290 requests configuration data (e.g. configuration files) from network infrastructure devices 210 - 230 , step 300 . This process may be initiated by a user, or automatically, upon a schedule or an event. Next, configuration data from network infrastructure devices 210 - 230 is received by analysis server 290 , step 310 . In various embodiments, a library of threats (e.g. a threat reference library) is also referenced. In other embodiments, such data may have previously been collected, and thus retrieved in these steps.
In various embodiments, based upon the configuration data of network infrastructure devices 210 - 230 , a network topology may be determined, step 320 . In other words, based upon the network traffic patterns allowed by network infrastructure devices 210 - 230 , the flow of data within network 200 may be determined.
Additionally, based upon the configuration data, host server locations 240 - 270 are determined, step 330 . In the example in FIG. 2 , it can be determined that network infrastructure device 210 is coupled to outside of network 200 , to host location 240 and 260 , network infrastructure device 220 is coupled to host locations 240 and 250 , and network infrastructure device 230 is coupled to host locations 260 and 270 .
It should be noted that in various embodiments, the identification of host locations does not imply that an actual host server is present at these host locations. Instead, as above, the host locations are typically identified based upon the configuration data of network infrastructure devices, or the like.
In various embodiments, data about host locations 240 - 270 may be retrieved, step 340 . For instance, data about host locations 240 - 270 may include whether a host machine is actually present at host locations 240 - 270 . In various embodiments, the presence of host machines may be indicated by a user via a questionnaire, via a network discovery module, via an asset management system, via a network netflow or sniffer device, patch management system, or the like. As another example, data may include system maintenance practices, a vulnerability management system, or the like of the user. For instance, data may include how often does the user push out software patches, software policy (e.g. only Microsoft products), software licenses, service plans, and the like. Similar to the above, such data may be indicated by a user via a questionnaire, via a policy file, or the like.
Additionally, in various embodiments, if a host machine is present, specific configuration data may also be received from host machines (e.g. host servers), step 350 . For instance, partial or complete hardware and software configurations of host servers may be returned. As examples, the specific configuration data may include and indication of network addresses (e.g. IP addresses) associated with the host servers, which ports, if any are monitored by the host servers, which applications (including operating system) are running on the host servers and monitoring the ports, which versions of the applications are running, and the like. In various embodiments, other similar types of information may also be determined. This data may be indicated by a user via a questionnaire, via querying of a host machine, or the like.
In various embodiments of the present invention, various levels of configuration information regarding a host server location may be determined, for example, the existence of a host server at the host server location, the existence of specific applications of a host server at the host server location, ports monitored on a host server at the host server location, confirmation of vulnerabilities of a host server at the host server location, identification of software patches applied to a host server at the host server location, potential vulnerabilities, confirmed vulnerabilities, and the like. In various embodiments, the amount of this configuration information known about a server is translated into a “coverage factor score” (CFS). For example, if 40 of 100 pieces of data regarding a host server are known, the CFS may be 0.4, and integer, or the like. In various embodiments, if a CFS is below a specified level, for example 10%, too many presumptions (90%) to the configuration of the host server have to be made for a given host server. Accordingly, the security risk score for the host may be ignored when considering remediation, quantization of risk, or the like.
In various embodiments, the knowledge, or lack of knowledge of the above information are used to determine a confidence factor (vulnerability certainty) of host servers. In various embodiments of the present invention, a confidence factor is then associated with each of host server locations 240 - 270 , step 360 . The confidence factor may be determined based upon how much is known or confirmed about a host server at the specific host server location, as discussed above.
As an example, if a host server 510 is present at host server location 260 , and the full software configuration is known and entered, host server location 260 may be associated with a high confidence factor (e.g. 0.90 in a 0 to 1 scale). Further in this example, if it is unknown whether a host server is present at host server location 270 , host server location 270 may be associated with an initial confidence factor that is low (e.g. 0.10 from 0 to 1). In various embodiments of the present invention, since host server location 270 is “downstream” from host server location 260 , the confidence factor for host server location 270 is also based upon the confidence factor of host server location 260 . In one example, if the confidence factors are multiplied, the confidence factor for host server location 270 is equal to 0.09 (0.09=0.90×0.10). In other embodiments, other types of combination, including weighted combinations are contemplated.
Continuing the example, if a host server 520 is present at host server location 240 , but nothing more about host server 520 is entered, host server location 240 may be associated with a lower confidence factor (e.g. 0.25 from 0 to 1). Further in this example, if it is unknown whether a host server is present at host server location 250 , host server location 250 may be associated with an initial confidence factor that is low (e.g. 0.10 from 0 to 1). Again, since host server location 250 is “downstream” from host server location 240 , the confidence factor for host server location 250 is also based upon the confidence factor of host server location 240 . In one example, the confidence factors are multiplied, the confidence factor for host server location 250 is equal to 0.025 (0.025=0.25×0.10). Again, in other embodiments, other types of combination, including weighted combinations are contemplated.
Next, a first host server location is selected, step 370 . In various embodiments, host server locations are prioritized based upon closeness to server 280 , the original attack source.
Next, a vulnerability profile for the host server location is determined, step 380 . In various embodiments, the vulnerability profile is determined by the type of network traffic pattern that is allowed to flow to the host server. Further, the vulnerability profile is determined by the data about the host application server determined in step 340 , for example if a host server is present or not, and the like. Still further, the vulnerability profile is determined by any configuration data associated with the host application server determined in step 350 , or lack thereof.
As an example, referring to FIG. 2 , the type of network traffic allowed from network infrastructure device 210 to host server location 260 may be TCP data. Further, in this example, host server 510 is known to be present at host server location 260 . Still further, in this example, host server 510 is known to run an Apache HTTP server, and the like. Accordingly, the vulnerability profile for host server location 260 is determined from these types of data: TCP traffic, Apache HTTP server.
As another example, the type of network traffic allowed from network infrastructure device 210 to host server location 240 may also be TCP data. In this example, host server 520 is known to be present at host server location 240 , however, no other configuration details regarding the configuration of host server 520 is known. In various embodiments, when configuration data is missing, it is assumed that host server 520 includes virtually all possible combinations of software, etc. In this simple example, it is assumed host server 520 runs an Apache HTTP server, a Microsoft Web server, or the like. It should be understood that many other types of configuration data may also be assumed, for example, many different versions of software (e.g. Oracle 9i and 11i databases, Microsoft SQL server 2000, 2005; or the like). In some embodiments, the range of applications assumed and the versions assumed can be limited by the user. In sum, in this example, because nothing is known about host server 520 , various embodiments assume a wide range of data within the vulnerability profile.
In embodiments of the present invention, based upon the vulnerability profile, one or more threats from the library of vulnerabilities (threats), discussed above, are identified, along with their mode of attack, step 390 . This step may also be referred to as determining reachability of threats or vulnerabilities to the host server location. In various embodiments, the reachability also refers to leapfroggable vulnerabilities.
In various embodiments of the present invention, the reachability data is incorporated into a threat map. In such embodiments, the threat map may be generated and displayed to a user as a directed graph having nodes representing subnets, and a root node representing a threat server. The reachability of the threat server to the host server location, discussed above, is reflected by the paths between the host server location and the threat server. In addition, in various embodiments, in the threat map, each node is associated with a known or presumed vulnerability of a host server location or subnet. For example, if nine out of ten pieces of configuration data are known for a host server, a worse-case presumption is made for the tenth piece of data. As an example, if version 1.0 of an application is vulnerable to an attack, but version 1.1 of an application in a host server is not vulnerable, and the specific version for a host server has not been determined, a presumption is made that the version of the application is 1.0.
Following this step, a “harm probability” or “vulnerability certainty” is determined for the threats that are reachable, step 400 . In various embodiments, harm probability may be determined based upon the harm probability specified for these threats (e.g. parameters or attributes of the threats). These attributes can typically be determined from the library of vulnerabilities. For instance, for threats that are relatively easy to implement, a harm probability may be high (e.g. 0.5 on a 0-1.0 scale; and for threats that are very difficult to implement (e.g. requires many events to occur), a harm probability or attribute may be low (e.g. 0.1 on a 0 to 1.0) scale. In additional embodiments, a severity of harm may also be determined from the threats that are reachable. For example, the severity may be low, if the threat can perform a ping, however, the severity may be very high, if the threat can get root access.
In various embodiments, as is discussed, the vulnerability certainty value for a host server may depend upon the amount of configuration data known about the host server or conversely, the amount of presumption of configuration data that is required (e.g. the coverage factor score). In various embodiments, the vulnerability certainty value is also determined in response to how vulnerable the host server is to a given vulnerability, given vulnerability attributes versus known configuration data of the host server. As an example, the coverage factor score may indicate that all configuration data of a host server is known, but given that configuration, the host server is not vulnerable to a threat. In such a case, the vulnerability certainty may be low. As another example, the coverage factor score may indicate that only half of the configuration data of a host server location is known, and presuming additional configuration data, the host is vulnerable to a threat. In such a case, the vulnerability certainty may be medium. As yet another example, the coverage factor score may indicate that almost all of the configuration data of a host server location is known, and presuming additional configuration data, the host is vulnerable to a threat. In such a case, the vulnerability certainty may be high.
In embodiments where more than one vulnerability may reach a target host server location, the harm probabilities of the vulnerabilities may be combined. For instance if threat A has a harm probability of 0.5 and threat B has a harm probability of 0.5, a combined harm probability for the host server location may be 0.75, for example. In various embodiments, many ways of combining multiple harm probabilities are also contemplated. In some embodiments, the severity of multiple threats reaching a target host server location may simply be the highest severity of the multiple threats, or a combination.
In the example in FIG. 2 , for host server 510 , the vulnerability profile includes TCP traffic and an Apache server. In this step, only a very difficult to exploit vulnerabilities from the library of vulnerabilities is identified that uses TCP as a protocol to attack Apache servers. In this example, the harm probability may be 0.1 from a range of 0 to 1.0 for example. Additionally, in this example, the attack may simply crash the host server 510 , the severity may be 0.5 from a range of 0 to 1.0.
In the case of host server 510 , the vulnerability profile includes TCP and a large number of assumed applications and versions. In this step, many easy to exploit vulnerabilities from the library of vulnerabilities are identified that use TCP as a protocol to attack applications such as: Oracle 9i and 11i databases, Microsoft SQL server 2000, 2005; or the like. In this example, the combination of the harm probabilities may be high, for example 0.9 from a range of 0 to 1.0, for example. In this example, the reachable vulnerability with the highest severity can obtain root access, accordingly, the severity may be 0.9 from a range of 0 to 1.0.
In various embodiments of the present invention, the process may be repeated for other host server locations that may be reachable by threats or vulnerabilities. In some embodiments, multiple threats may be used to penetrate a network via “leapfrogging” host servers. More specifically, host server locations can become a source of a threat within a network. In various embodiments, a leapfrogging analysis may repeat until the confidence factors decreases below a given threshold.
As an example, as discussed above, host server 520 is assumed to have many vulnerabilities able to reach it from server 280 . Further, at least one such reachable vulnerability provides root access. Accordingly, host server 520 may then serve as a source of attack within the rest of network 200 .
In this example, using the steps described above, it is first determined that a host server 530 is present at host server location 250 . However, not much else is known about host server 530 . Accordingly, similar to host server 520 , the harm probabilities may be 0.9 and the severity may be 0.9. An initial confidence factor may be 0.25, similar to host server 520 . However, since an attack on host server 530 depends upon an attack on host server 520 , in various embodiments, the initial confidence factor may be combined with the confidence factor of host server 520 . For example the confidence factor for host server 530 may be the product of the two confidence factors, e.g. 0.06, or any other combination of the confidence factors. In light of this, if a sophisticated attack on a network relies upon successive control of many servers, for example, smaller confidence factors are determined for servers further down the attack chain. As discussed, the process may continue until the confidence factors drop below a defined threshold. In other embodiments, the process may continue until any other factor is satisfied. For example, until a given percentage (e.g. 75%, 100%) of the host server locations have been analyzed, until a given number (e.g. 100) vulnerable host server locations have been identified, or the like.
In some embodiments of the present invention, after the process above, harm probabilities, severities, and confidence values for each host server location in a network can be determined. Typically, after this process is run upon a network, multiple host server locations may be associated with a high harm probability and a high severity.
In various embodiments, a “security risk score” (SRS) may be determined for host servers based upon business value of the host server and upon threat likelihood. In various embodiments, threat likelihood is determined based upon a number of factors such as, reachability of the threat to the host server; how recent or novel the vulnerability is (including vulnerability of the underlying components, dependency of the vulnerability, patches available, and the like); the severity of the vulnerability; difficulty of the vulnerability, and the like.
Accordingly, vulnerabilities of the host server locations can be prioritized, step 410 , and graphically displayed to the user, step 420 (as will be described further below). In some embodiments of the present invention, the SRS, described above is a metric used in prioritizing or highlighting the vulnerabilities, and/or the remediation actions.
In various embodiments, to help the user prioritize, a number of other factors may be provided about the host server locations/host servers. In one embodiment, an “asset value” or “business value” may be assigned to a host server. For example, a host server with confidential client data may be assigned a high asset value (initially by the user), and a host server with web graphics data may be assigned a lower asset value, e.g. 20 from 0 to 100. In some embodiments, the harm probability may be combined with the asset value to obtain an “exposed risk.” In one example, the exposed risk is simply the product of the two.
In the example in FIG. 2 , the asset value of host server 510 is 90, and the harm probability 0.1, thus the exposed risk is computed to be 9; and the asset value of host server 520 is 50 and the harm probability is 0.9, thus the exposed risk is computed 40 . Thus, according to one embodiment, host server 520 would be prioritized before host server 510 .
In various embodiments, if the associated confidence value is low for particular “reachable threats,” the user may enter additional configuration data about the host server locations, step 430 . Accordingly, in response to the prioritization, the user may obtain more information, to make a more informed decision about the network. As an example, for a first server location the exposed risk is 60 and a first confidence factor is 0.90 and for a second server location the exposed risk is 80 and a second confidence factor is 0.50. In such an example, the second server location may be prioritized before the first server location. As the second confidence factor is low (0.50), a first course of action may be the user determining more about the configuration of the host server location. For example, the second confidence factor may be a result of not knowing or not entering the list of applications running on a host server located at the host server location. In response, the user may run a software inventory of the host server, and enter that data into embodiments of the present invention. When the system is re-run with this additional information, the exposed risk of the second server location may drop, for example to 20, and the second confidence factor may rise, for example to 0.95. This process above may then be repeated until the user is satisfied with the level of confidence for some or all of the host server locations.
In various embodiments, a user may otherwise begin patching/fixing the vulnerabilities for the prioritized host application locations, step 440 . As is known, the user may install a patched version of one or more applications on a host server, the user may close ports on the host server, the user may change application software on the host server, or the like. Additionally, in various embodiments, this process may include patching or changing the configuration of particular network infrastructure devices.
In various embodiments, the process allows the user to supplement the system with additional configuration data or making changes to network infrastructure devices or host servers to address the prioritized vulnerabilities (e.g. install a firewall or filtering device, changing rules or policies, or the like.) The process above may be repeated to allow the user to address the next prioritized vulnerability, or the like. As discussed previously, the priority may be based upon a combination of many factors including value of data stored on a host server, an “exposed risk” (harm probability*value), whether the vulnerability is exploitable (e.g. root access), what level of data access is provided, and the like.
FIGS. 4A-B illustrates screen shots according to embodiments of the present invention. More specifically, FIGS. 4A-B illustrate exemplary graphical user interfaces that allow a user to view threats within a network, as referred to in step 420 , above.
FIG. 4A illustrates a threat graph (threat map) 500 of a portion of a network. In this example, the link risk distribution illustrates a plots harm potential (risk) versus number of servers. As is illustrated, the average harm potential for the network is 0.32. As is also illustrated, any number of ways to graphically illustrate data are enabled by this GUI. As shown, harm potential (probability) is illustrated by a red cylinder. In this example, the diameter of the red cylinder represents the harm potential, the diameter of the gray cylinder represents the asset value, and the greater the respective diameters, the greater the harm/value. For instance “widget supplier” servers have a large gray cylinder, and a red cylinder filling up the same cylinder, accordingly, this visually indicates that the widget supplier servers are very valuable and very vulnerable. In another example, the “Seattle Engr” servers are valuable, but is not as vulnerable to threats. As yet another example, the “customer service” servers are not very valuable and not very vulnerable.
In the example in FIG. 4A , links are shown connecting servers in the portion of the network. In various embodiments of the present invention, the thickness and/or color of the links may represent the confidence value of the source server. For example, if confidence in the configuration of a source server is high, a connecting line may be heavy, and if confidence in the configuration is low, the connecting line may be thinner.
In the present example, a link between “sfcorp-inside” server to “seattle engr” server has been highlighted and detailed in text below the image. As illustrated, many types of data may be presented to a user, for example, the source IP addresses, harm probabilities (“Prob.”) of different vulnerabilities on the source host servers, the attack mechanism (“Port”), the target host IP address, harm probability (“Prob.”) of the different vulnerabilities on the target host servers, “A/P/C” vulnerabilities, discussed below, severity of the vulnerability, impact of the vulnerability, discussed below, whether a patch is available for the vulnerability, and the like.
In various embodiments; A/P/C summarizes the vulnerability in response to what is known about the host configuration. A represents assumed harm, P represents presumed harm, and C represents Confirmed harm. In this example, the less that is known about a host server, the higher the Assumed harm, and the more that is known about the host server, the lower the Assumed harm. However, the more that is known about the host server, the presumed or confirmed harms may be higher or lower, with respect to a given vulnerability. In the example, for source host at IP address 192.168.0.101, the assumed harm may be identified specifically by identifier, such as A:2002-1000. Additionally, the harm may be identified by class, for example for engr — 03 server, the A/P/C counts are 1/0/0, respectively.
In various embodiments the type of impact are “CIAS.” As is known, C stands for the ability to reach confidential data (e.g. break-in), I stands for the ability to affect the integrity of the server (e.g. delete data), and A stands for the ability to affect the availability of the server (e.g. crash).
FIG. 4B illustrates a case where more information of “Engineering subnet” is displayed to the user. As is shown, another field that may be displayed to the user is an “exploitable” field. In various embodiments, this represents whether a threat may obtain root access to the target server. In cases where a threat is exploitable, the target server may serve as a basis for additional attacks within the server.
Additionally, shown in FIG. 4B is a histogram of harm probabilities of servers within the engineering subnet. As can be seen, the median harm probability is 0.5, and many servers within the subnet have harm probabilities in the range of 0.80 to 0.90. This histogram reports that many host servers are vulnerable to threats, and is not a desirable situation. To a user, it would indicate that corrective action for those servers is required.
In additional embodiments of the present invention, the above process may be run on the network before and after a change to the network, and the changes in vulnerabilities may be highlighted or detailed. For example, after the system is run a first time, the user enters additional data about a host server, and the system is run again. Based upon the additional data, the user may either see the new vulnerability state of the network, or the delta, the change in vulnerability state of the network. As an example, the user can see that the new information decreases the harm probability of the host server and other servers. As another example, based upon a first run of the system, the user sees that a host server is vulnerable, and decides to patch the host server. Running the system again, the user may see the effect of the patch is that the host server harm probability is lowered, but the harm probability of three other servers greatly increases. In such a case, the user may decide to push out the patch, and to also install an additional firewall in front of the three servers; alternatively, the user may decide any other way to address the vulnerability.
In other cases, other types of changes include changes to the network, new vulnerabilities discovered, and the like. These effect of these changes may also be reflected as a change in network vulnerabilities. For example, the user may update the given “value” of an asset, a new set of worms may be discovered, a new network infrastructure device is added to the network, a new application is added “upstream” from a vulnerable host server location, a certain amount of time has passed (e.g. one week, one month) or the like.
Embodiments of the present invention provide visualization of network-wide risk analysis in the form of a graphical user interface with customizable at-a-glance views of the network. In various embodiments, the nodes of the network that have the highest probability of exposure to known vulnerabilities may be indicated in red, for example. Other configurations of the GUI enable the user to quickly ascertain whether any server in a network is exposed to specific threats.
FIGS. 5A-C illustrates additional screen shots according to other embodiments of the present invention. More specifically, FIGS. 5A-C illustrate exemplary graphical user interfaces that allow a user to view threats within a network, as referred to in step 420 , above. As can be seen in FIGS. 5A-C , the inventor has adapted the concept of “tree maps” to the visualization of network vulnerabilities. As is known with “tree maps” portions of data that are of interest to a user may be magnified, while other portions are less magnified. For example, a first icon within the tree maps may be larger than a second icon indicating importance of a server represented by the first icon over a server represented by the second icon.
In various embodiments of the present invention, “importance” may depend upon the criteria specified by the user. For example, the user could specify importance as servers having the highest security risk score, servers having the highest business value, servers having the greatest increase in security risk score over a given time period, servers having the highest vulnerability certainty, deltas of the above values, and the like. Other criteria and combinations thereof are contemplated. In the example in FIG. 5B , the sizes of the nodes within the tree maps are determined in response to “Asset Value” of the nodes.
In some embodiments, the shape of the icons may be different. For example, more important icons may be shaped as a letter “X,” or skull-and-bones, or the like, and less important icons may be shaped as the letter “O,” a check-mark, or the like. In other embodiments, the color and steadiness of the icons may also reflect the above factors. As an example, an important icon may be red in color and/or blink (the rate of blinking may also depend upon the importance, as defined by the user specified criteria), whereas a less important icon may be yellow or green in color and/or be steady.
The examples in FIGS. 5 A-B may illustrate the affect of network changes between two different time periods, the affect of proposed changes to a network, the current or proposed vulnerabilities of the network or the like. For example, the change in vulnerability of the network before and after a patch, update, or the like, has been pushed out, giving the user feedback as to the new vulnerability state of the actual network, or the predicted vulnerability state of the network. Interestingly, because the change in vulnerabilities of the network can be visualized, the user can determine why a patch, update, or the like affects the network in the way indicated. For example, upgrading software to another version may open a host server up to a new set of vulnerabilities.
In this example, FIGS. 5A-C represents changes or proposed changes with respect to time. Such GUIs may allow the user to spot trends in security over time. Additionally, such GUIs may also allow the user to see the result of specific changes in the network. For example, an original risk tree map can be determined, a new network component can be added to the network (e.g. a firewall), and a new tree map can be determined. In such an example, the user may compare the original tree map to the new tree map to see the effect of the new network component. For example, at-a-glance, the user can see that certain nodes are now blue in color, indicating that the security risk score, for example, has improved and the network is more secure. In other embodiments, a network change may result in network security deteriorating. This may be reflected, at-a-glance, to the user, by certain nodes in the tree map being red in color.
The graph at left represents the change in harm probability with respect to count. In this graph, a positive (e.g. +0.60) number represents increase in harm probability, and is typically undesirable, and a negative number (e.g. −0.35) represents a decrease in harm probability, and is desirable. As can be seen, the yellow portion of the graph shows that that the vulnerability of the network has increased. In various embodiments, this may occur when new viruses, worms, or the like are released. In this example, in the main section, subnets are color-coded according to change in harm probability. Further, relative sizes of the boxes are used to represent asset value (value) of the host servers. With this GUI, the user may quickly focus upon those host servers that are most likely affected by either a change in network configuration, or the like.
In the example in FIG. 5C , a GUI is shown that illustrates remediation prioritization to a user. In this example, the sizes of the nodes in the tree map are determined by business value, and may be organized by user-selected criteria. For example, the tree map is organized by primary capability then by subnet. In this GUI, a lighter red color indicates vulnerabilities that are suggesl lted to be mitigated first. For example, the light red color indicates a higher security risk score (a higher security risk).
In various embodiments of the present invention, the GUI may display user-selected tree maps, as illustrated in FIG. 5A , or highly-user-customized tree-maps, as illustrated in FIG. 5B . As illustrated in the embodiments in FIGS. 5A-B , GUIs may also provide textual representations of information displayed. In these examples, the GUIs illustrate a “histogram” of data: server population count versus a user defined metric. For example, in FIG. 5A , the histogram represents the server population count versus trends in risk (over a defined time). In this GUI, at a glance, the user can see if whether the network security is improving (a positive value) or is getting worse (a negative value). In FIG. 5C , the histogram represents node count versus security risk score.
In various embodiments, in addition to the default information displayed to the user, the user may drill-down by selecting a node within the tree map. In response, more detailed information regarding the configuration of the subnet, server, or the like may be presented to the user. An example of this is illustrated in FIG. 5C , with the pop-up window on top of the tree map.
Further embodiments can be envisioned to one of ordinary skill in the art after reading this disclosure. In other embodiments, combinations or sub-combinations of the above disclosed invention can be advantageously made. The block diagrams of the architecture and graphical user interfaces are grouped for ease of understanding. However it should be understood that combinations of blocks, additions of new blocks, re-arrangement of blocks, and the like are contemplated in alternative embodiments of the present invention.
The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. It will, however, be evident that various modifications and changes may be made thereunto without departing from the broader spirit and scope of the invention as set forth in the claims. | A method for a computer system including a display includes determining a plurality of security metrics associated with a plurality of servers within a network, displaying a tree map on the display representing at least a portion of the network, wherein the tree map comprises a plurality of shapes associated with servers from the plurality of servers, wherein a size of shapes in the plurality of shapes are determined in response to a first security metric from the plurality of security metric associated with the servers, and wherein an appearance of the shapes are determined in response to a second security metric from the plurality of security metrics associated with the servers. | 53,886 |
CROSS REFERENCE OF RELATED APPLICATION
[0001] The present invention claims priority under 35 U.S.C. 119(a-d) to CN 201410360953.9, filed Jul. 25, 2014.
BACKGROUND OF THE PRESENT INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates to a video signal processing technology, and more particularly to a video quality evaluation method based on 3-dimensional (3D for short) wavelet transform.
[0004] 2. Description of Related Arts
[0005] With the rapid development of video coding technology and display technology, different kinds of video systems are applied more and more widely, and gradually become the research focus of the field of information processing. Because of a series of uncontrollable factors, video information will be inevitably distorted in video acquisition, compression, transmission, decoding and display stages, resulting in decrease of video quality. Therefore, how to accurately measure the video quality is the key for the development of video system. Video quality evaluation is divided into subjective and objective quality evaluation. As the visual information is eventually accepted by human eye, the subjective quality evaluation is the most reliable in accuracy. However, subjective quality evaluation requires scoring by observer, which is time-consuming and not easy to be integrated in the video system. The objective quality evaluation model is able to be well integrated in the video system for real-time quality evaluation, which contributes to timely parameter adjustment of the video system, so as to provide a video system application with high quality. Therefore, the objective video quality evaluation method, which is accurate, effective and consistent with human visual characteristics, has a very good application value. The conventional objective video quality evaluation method mainly simulates motion and time-domain video information processing methods of human eyes, and some objective image quality evaluation methods are combined. That is to say, time-domain distortion evaluation of the video is added into the conventional objective image quality evaluation, so as to objectively evaluate the video information quality. Although time-domain information of video sequences are described from different angles according to the above methods, understanding of processing methods of human eye when viewing video information is limited at present. Therefore, time-domain information description according to the above methods is limited, which means it is difficult to evaluate the video time-domain quality, and will eventually lead to poor consistency of objective evaluation results with subjective evaluation visual results.
SUMMARY OF THE PRESENT INVENTION
[0006] An object of the present invention is to provide a video quality evaluation method based on 3D wavelet transform which is able to effectively improve relativity between an objective quality evaluation result and subjective quality judged by human eyes.
[0007] Accordingly, in order to accomplish the above object, the present invention provides a video quality evaluation method based on 3D wavelet transform, comprising steps of:
[0008] a) marking an original undistorted reference video sequence as V ref , marking a distorted video sequence as V dis , wherein the V ref and the V dis both comprise N fr frames of images, wherein N fr ≧2 n , n is a positive integer, and nε[3,5];
[0009] b) regarding 2 n frames of images as a group of picture (GOP for short), respectively dividing the V ref and the V dis into n GoF GOPs, marking a No. i GOP in the V ref as G ref i , marking a No. i GOP in the V dis as G dis i , wherein
[0000]
n
GoF
=
⌊
N
fr
2
n
⌋
,
[0000] the symbol └ ┘ means down-rounding, and 1≦i≦n GoF ;
[0010] c) applying 2-level 3D wavelet transform on each of the GOPs of the V ref , for obtaining 15 sub-band sequences corresponding to each of the GOPs, wherein the 15 sub-band sequences comprise 7 level-1 sub-band sequences and 8 level-2 sub-band sequences, each of the level-1 sub-band sequences comprises
[0000]
2
n
2
[0000] frames of images, and each of the level-2 sub-band sequences comprises
[0000]
2
n
2
×
2
[0000] frames of images;
[0011] similarly, applying the 2-level 3D wavelet transform on each of the GOPs of the V dis , for obtaining 15 sub-band sequences corresponding to each of the GOPs, wherein the 15 sub-band sequences are 7 level-1 sub-band sequences and 8 level-2 sub-band sequences, each of the level-1 sub-band sequences comprises
[0000]
2
n
2
[0000] frames of images, and each of the level-2 sub-band sequences comprises
[0000]
2
n
2
×
2
[0000] frames of images;
[0012] d) calculating quality of each of the sub-band sequences corresponding to the GOPs of the V dis , marking the quality of a No. j sub-band sequence corresponding to the G dis i as Q i,j , wherein
[0000]
Q
i
,
j
=
∑
k
=
1
K
SSIM
(
VI
ref
i
,
j
,
k
,
VI
dis
i
,
j
,
k
)
K
,
1
≤
j
≤
15
,
1
≤
k
≤
K
,
[0000] K represents a frame quantity of a No. j sub-band sequence corresponding to the G ref i and the No. j sub-band sequence corresponding to the G dis i ; if the No. j sub-band sequence corresponding to the G ref i and the No. j sub-band sequence corresponding to the G dis i are both the level-1 sub-band sequences, then
[0000]
K
=
2
n
2
;
[0000] if the No. j sub-band sequence corresponding to the G ref i and the No. j sub-band sequence corresponding to the G dis i are both the level-2 sub-band sequences, then
[0000]
K
=
2
n
2
×
2
;
[0000] VI ref i,j,k represents a No. k frame of image of the No. j sub-band sequence corresponding to the G ref i , VI dis i,j,k represents a No. k frame of image of the No. j sub-band sequence corresponding to the G dis i , SSIM ( ) is a structural similarity function, and
[0000]
SSIM
(
VI
ref
i
,
j
,
k
,
VI
dis
i
,
j
,
k
)
=
(
2
μ
ref
μ
dis
+
c
1
)
(
2
σ
ref
-
dis
+
c
2
)
(
μ
ref
2
+
μ
dis
2
+
c
1
)
(
σ
ref
2
+
σ
dis
2
+
c
2
)
,
[0000] μ ref represents an average value of the VI ref i,j,k , μ dis represents an average value of the VI dis i,j,k , σ ref represents a standard deviation of the VI ref i,j,k , σ dis represents a standard deviation of the VI dis i,j,k , σ ref-dis represents covariance between the VI ref i,j,k and the VI dis i,j,k , c 1 and c 2 are constants, and c 1 ≠0, c 2 ≠0;
[0013] e) selecting 2 sequences from the 7 level-1 sub-band sequences of each of the GOPs of the V dis , then calculating quality of the level-1 sub-band sequences corresponding to the GOPs of the V dis according to quality of the selected 2 sequences of the level-1 sub-band sequences corresponding to the GOPs of the V dis , wherein for the 7 level-1 sub-band sequences corresponding to the G dis i , supposing that a No. p 1 sequence and a No. q 1 sequence of the level-1 sub-band sequences are selected, then quality of the level-1 sub-band sequences corresponding to the G dis i is marked as Q Lv1 i , wherein Q Lv1 i =w Lv1 ×Q i,p 1 +(1−w Lv1 )×Q i,q 1 , 9≦p 1 ≦15, 9≦q 1 ≦15, w Lv1 is a weight value of Q i,p 1 , the Q i,p 1 represents the quality of the No. p 1 sequence of the level-1 sub-band sequences corresponding to the G dis i , Q i,q 1 represents the quality of the No. q 1 sequence of the level-1 sub-band sequences corresponding to the G dis i ;
[0014] and selecting 2 sequences from the 8 level-2 sub-band sequences of each of the GOPs of the V dis , then calculating quality of the level-2 sub-band sequences corresponding to the GOPs of the V dis according to quality of the selected 2 sequences of the level-2 sub-band sequences corresponding to the GOPs of the V dis , wherein for the 8 level-2 sub-band sequences corresponding to the G dis i , supposing that a No. p 2 sequence and a No. q 2 sequence of the level-2 sub-band sequences are selected, then quality of the level-2 sub-band sequences corresponding to the G dis i is marked as Q Lv2 i , wherein Q Lv2 i =w Lv2 ×Q i,p 2 +(1+w Lv2 )×Q i,q 2 , 1≦p 2 ≦8, 1≦q 2 ≦8, w Lv2 is a weight value of Q i,p 2 , the Q i,p 2 represents the quality of the No. p 2 sequence of the level-2 sub-band sequences corresponding to the G dis i , Q i,q 2 represents the quality of the No. q 2 sequence of the level-2 sub-band sequences corresponding to the G dis i ;
[0015] f) calculating quality of the GOPs of the V dis according to the quality of the level-1 and level-2 sub-band sequences corresponding to the GOPs of the V dis , marking the quality of the G dis i as Q Lv i , wherein Q Lv i =w Lv ×Q Lv1 i +(1−w Lv )×Q Lv2 i , w Lv is a weight value of the Q Lv i ; and
[0016] g) calculating objective evaluated quality of the V dis according to the quality of the GOPs of the V dis , marking the objective evaluated quality as Q, wherein
[0000]
Q
=
∑
i
=
1
n
GoF
w
i
×
Q
Lv
i
∑
i
=
1
n
GoF
w
i
,
[0000] w i is a weight value of the Q Lv i .
[0017] Preferably, for selecting the 2 sequences of the level-1 sub-band sequences and the 2 sequences of the level-2 sub-band sequences, the step e) specifically comprises steps of:
[0018] e-1) selecting a video database with subjective video quality as a training video database, obtaining quality of each sub-band sequence corresponding to each GOP of distorted video sequences in the training video database by applying from the step a) to the step d), marking the No. n v distorted video sequence as V dis n v , marking quality of a No. j sub-band sequence corresponding to the No. i′ GOP of the V dis n v as Q n v i′,j , wherein 1≦n v ≦U, U represents a quantity of the distorted sequences in the training video database, 1≦i′≦n GoF ′, n GoF ′ represents a quantity of the GOPs of the V dis n v , 1≦j≦15;
[0019] e-2) calculating objective video quality of all the same sub-band sequences corresponding to all the GOPs of the distorted video sequences in the training video database, marking objective video quality of all the No. j sub-band sequences corresponding to all the GOPs of the V dis n v as VQ n v j , wherein
[0000]
VQ
n
v
j
=
∑
i
′
=
1
n
GoF
′
Q
n
v
i
′
,
j
n
GoF
′
;
[0020] e-3) forming a vector v X j with the objective video quality of all the No. j sub-band sequences corresponding to all the GOPs of the distorted video sequences in the training video database, wherein v X j =(VQ 1 j , VQ 2 j , . . . , VQ n v j , . . . , VQ U j ); forming a vector v Y with the subjective video quality of all the distorted video sequences in the training video database, wherein v Y =(VS 1 , VS 2 , . . . , VS n v , . . . , VS U ), wherein 1≦j≦15, VQ 1 j represents the objective video quality of the No. j sub-band sequences corresponding to all the GOPs of the first distorted video sequence in the training video database, VQ 2 j represents the objective video quality of the No. j sub-band sequences corresponding to all the GOPs of the second distorted video sequence in the training video database, VQ n v j represents the objective video quality of the No. j sub-band sequences corresponding to all the GOPs of the No. n v distorted video sequence in the training video database, VQ U j , represents the objective video quality of the No. j sub-band sequences corresponding to all the GOPs of the No. U distorted video sequence in the training video database; VS 1 represents the subjective video quality of the first distorted video sequence in the training video database, VS 2 represents the subjective video quality of the second distorted video sequence in the training video database, VS n v represents the subjective video quality of the No. n v distorted video sequence in the training video database, VS U represents the subjective video quality of the No. U distorted video sequence in the training video database;
[0021] then calculating a linear correlation coefficient of the objective video quality of the same sub-band sequences corresponding to all the GOPs of the distorted video sequences in the training video database and the subjective quality of the distorted sequences, marking the linear correlation coefficient of the objective video quality of the No. j sub-band sequence corresponding to all the GOPs of the distorted video sequences and the subjective quality of the distorted sequences as CC j , wherein
[0000]
CC
j
=
∑
n
v
=
1
U
(
VQ
n
v
j
-
V
_
Q
j
)
(
VS
n
v
-
V
_
S
)
∑
n
v
=
1
U
(
VQ
n
v
j
-
V
_
Q
j
)
2
∑
n
v
=
1
U
(
VS
n
v
-
V
_
S
)
2
,
1
≤
j
≤
15
,
[0000] V Q j is an average value of all element values of the v X j , V S is an average value of all element values of the v Y ; and
[0022] e-4) selecting a max linear correlation coefficient and a second max linear correlation coefficient from the 7 linear correlation coefficients corresponding to the 7 level-1 sub-band sequences out of the obtained 15 linear correlation coefficients, regarding the level-1 sub-band sequences respectively corresponding to the max linear correlation coefficient and the second max linear correlation coefficient as the two level-1 sub-band sequences to be selected; and selecting a max linear correlation coefficient and a second max linear correlation coefficient from the 8 linear correlation coefficients corresponding to the 8 level-2 sub-band sequences out of the obtained 15 linear correlation coefficients, regarding the level-2 sub-band sequences respectively corresponding to the max linear correlation coefficient and the second max linear correlation coefficient as the two level-2 sub-band sequences to be selected.
[0023] Preferably, in the step e), w Lv1 =0.71, and w Lv2 =0.58.
[0024] Preferably, in the step f), w Lv =0.93.
[0025] Preferably, for obtaining the w i , the step g) specifically comprises steps of:
[0026] g-1) calculating an average value of brightness average values of all the images in each of the GOPs of the V dis , marking the average value of the brightness average values of all the images of the G dis i as Lavg i , wherein
[0000]
Lavg
i
=
∑
f
=
1
2
n
∂
f
2
n
,
[0000] ∂ f represents the brightness average value of a No. f frame of image, a value of the ∂ f is the brightness average value obtained by averaging brightness values of all pixels in the No. f frame of image, and 1≦i≦n GoF ;
[0027] g-2) calculating an average value of motion intensity of all the images of each of the GOPs except a first frame of image in the GOP, marking the average value of motion intensity of all the images of G dis i except the first frame of image as MAavg i , wherein
[0000]
MAavg
i
=
∑
f
′
=
2
2
n
MA
f
′
2
n
-
1
,
2
≤
f
′
≤
2
n
,
[0000] MA f′ represents the motion intensity of the No. f′ frame of image of the G dis i ,
[0000]
MA
f
′
=
1
W
×
H
∑
s
=
1
W
∑
t
=
1
H
(
(
mv
x
(
s
,
t
)
)
2
+
(
mv
y
(
s
,
t
)
)
2
)
,
[0000] represents a width of the No. f′ frame of image of the G dis i , H represents a height of the No. f′ frame of image of the G dis i , mv x (s,t) represents a horizontal value of a motion vector of a pixel with a position of (s,t) in the No. f′ frame of image of the G dis i , mv y (s,t) represents a vertical value of the motion vector of the pixel with the position of (s,t) in the No. f′ frame of image of the G dis i ;
[0028] g-3) forming a brightness average value vector with the average values of the brightness average values of all the images of the GOPs of the V dis , marking the brightness average value vector as V Lavg , wherein V Lavg =(Lavg 1 , Lavg 2 , . . . , Lavg n GoF ), Lavg 1 represents an average value of the brightness average values of images of the first GOP of the V dis , Lavg 2 represents an average value of the brightness average values of images of the second GOP of the V dis , Lavg n GoF represents an average value of the brightness average values of images of the No. n GoF of the V dis ;
[0029] and forming an average value vector of the motion intensity with the average values of the motion intensity of all the images of the GOPs of the V dis except the first frame of image, marking the average value vector of the motion intensity as V MAavg , wherein V MAavg =(MAavg 1 , MAavg 2 , . . . , MAavg n GoF ), MAavg 1 represents an average value of the motion intensity of images of the first GOP of the V dis except the first frame of image, MAavg 2 represents an average value of the motion intensity of images of the second GOP of the V dis except the first frame of image, MAavg n GoF represents an average value of the motion intensity of images of the No. n GoF GOP of the V dis except the first frame of image;
[0030] g-4) normalizing every element of the V Lavg , for obtaining normalized values of the elements of the V Lavg , marking the normalized value of the No. i element of the V Lavg as v Lavg i,norm , wherein
[0000]
v
Lavg
i
,
norm
=
Lavg
i
-
max
(
V
Lavg
)
max
(
V
Lavg
)
-
min
(
V
Lavg
)
,
[0000] Lavg i represents a value of the No. i element of the V Lavg , max(V Lavg ) represents a value of the element with a max value of the V Lavg , min(V Lavg ) represents a value of the element with a min value of the V Lavg ;
[0031] and normalizing every element of the V MAavg , for obtaining normalized values of the elements of the V MAavg , marking the normalized value of the No. i element of the V MAavg as v MAavg i,norm , wherein
[0000]
v
MAavg
i
,
norm
=
MAavg
i
-
max
(
V
MAavg
)
max
(
V
MAavg
)
-
min
(
V
MAavg
)
,
[0000] MAavg i represents a value of the No. i element of the V MAavg , max(V MAavg ) represents a value of the element with a max value of the v MAavg , min(V MAavg ) represents a value of the element with a min value of the V MAavg ; and
[0032] g-5) calculating the weight value w i of the Q Lv i according to the v Lavg i,norm and the v MAavg i,norm , wherein w i =(1−v MAavg i,norm )×v Lavg i,norm .
[0033] Compared to the conventional technologies, the present invention has advantages as follows.
[0034] Firstly, according to the present invention, the 3D wavelet transform is utilized in the video quality evaluation, for transforming the GOPs of the video. By splitting the video sequence on a time axis, time-domain information of the GOPs is described, which to a certain extent solves a problem that the video time-domain information is difficult to be described, and effectively improves accuracy of objective video quality evaluation, so as to effectively improve relativity between the objective quality evaluation result and the subjective quality judged by the human eyes.
[0035] Secondly, for time-domain relativity between the GOPs, the method weighs the quality of the GOPs according to the motion intensity and the brightness, in such a manner that the method is able to better meet human visual characteristics.
[0036] These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] FIG. 1 is a block diagram of a video quality evaluation method based on 3D wavelet transform according to a preferred embodiment of the present invention.
[0038] FIG. 2 is a linear correlation coefficient diagram of objective video quality of the same sub-band sequences and a difference mean opinion score of all distorted video sequences in a LIVE video database according to the preferred embodiment of the present invention.
[0039] FIG. 3 a is a scatter diagram of objective evaluated quality Q judged by the video quality evaluation method and a difference mean opinion score DMOS of distorted video sequences with wireless transmission distortion according to the preferred embodiment of the present invention.
[0040] FIG. 3 b is a scatter diagram of objective evaluated quality Q judged by the video quality evaluation method and a difference mean opinion score DMOS of distorted video sequences with IP network transmission distortion according to the preferred embodiment of the present invention.
[0041] FIG. 3 c is a scatter diagram of objective evaluated quality Q judged by the video quality evaluation method and a difference mean opinion score DMOS of distorted video sequences with H.264 compression distortion according to the preferred embodiment of the present invention.
[0042] FIG. 3 d is a scatter diagram of objective evaluated quality Q judged by the video quality evaluation method and a difference mean opinion score DMOS of distorted video sequences with MPEG-2 compression distortion according to the preferred embodiment of the present invention.
[0043] FIG. 3 e is a scatter diagram of objective evaluated quality Q judged by the video quality evaluation method and a difference mean opinion score DMOS of all distorted video sequences in a video quality database according to the preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0044] Referring to the drawings and a preferred embodiment, the present invention is further illustrated.
[0045] Referring to FIG. 1 of the drawings, a video quality evaluation method based on 3D wavelet transform is illustrated, comprising steps of:
[0046] a) marking an original undistorted reference video sequence as V ref , marking a distorted video sequence as V dis , wherein the V ref and the V dis both comprise N fr frames of images, wherein N fr ≧2 n , n is a positive integer, and nε[3,5], wherein n=5 in the preferred embodiment;
[0047] b) regarding 2 n frames of images as a group of picture (GOP for short), respectively dividing the V ref and the V dis into n GoF GOPs, marking a No. i GOP in the V ref as G ref i , marking a No. i GOP in the V dis as G dis i , wherein
[0000]
n
GoF
=
⌊
N
fr
2
⌋
,
[0000] the symbol └ ┘ means down-rounding, and 1≦i≦n GoF ;
[0048] wherein in the preferred embodiment, n=5, therefore, each of the GOPs comprises 32 frames of images; in practice, if quantities of the frames of images of the V ref and the V dis are not positive integer times of 2 n , after a plurality of GOPs are obtained orderly, the rest images are omitted;
[0049] c) applying 2-level 3D wavelet transform on each of the GOPs of the V ref , for obtaining 15 sub-band sequences corresponding to each of the GOPs, wherein the 15 sub-band sequences comprise 7 level-1 sub-band sequences and 8 level-2 sub-band sequences, each of the level-1 sub-band sequences comprises
[0000]
2
n
2
[0000] frames of images, and each of the level-2 sub-band sequences comprises
[0000]
2
n
2
×
2
[0000] frames of images;
[0050] wherein the 7 level-1 sub-band sequences corresponding to the GOPs of the V ref comprise: a level-1 reference time-domain low-frequency horizontal detailed sequence LLH ref , a level-1 reference time-domain low-frequency vertical detailed sequence LHL ref , a level-1 reference time-domain low-frequency diagonal detailed sequence LHH ref , a level-1 reference time-domain high-frequency approximated sequence HLL ref , a level-1 reference time-domain high-frequency horizontal detailed sequence HLH ref , a level-1 reference time-domain high-frequency vertical detailed sequence HHL ref , and a level-1 reference time-domain high-frequency diagonal detailed sequence HHH ref ; the 8 level-2 sub-band sequences corresponding to the GOPs of the V ref comprise: a level-2 reference time-domain low-frequency approximated sequence LLLL ref , a level-2 reference time-domain low-frequency horizontal detailed sequence LLLH ref , a level-2 reference time-domain low-frequency vertical detailed sequence LLHL ref , a level-2 reference time-domain low-frequency diagonal detailed sequence LLHH ref , a level-2 reference time-domain high-frequency approximated sequence LHLL ref , a level-2 reference time-domain high-frequency horizontal detailed sequence LHLH ref , a level-2 reference time-domain high-frequency vertical detailed sequence LHHL ref , and a level-2 reference time-domain high-frequency diagonal detailed sequence LHHH ref ;
[0051] similarly, applying the 2-level 3D wavelet transform on each of the GOPs of the V dis , for obtaining 15 sub-band sequences corresponding to each of the GOPs, wherein the 15 sub-band sequences are 7 level-1 sub-band sequences and 8 level-2 sub-band sequences, each of the level-1 sub-band sequences comprises
[0000]
2
n
2
[0000] frames of images, and each of the level-2 sub-band sequences comprises
[0000]
2
n
2
×
2
[0000] frames of images;
[0052] wherein the 7 level-1 sub-band sequences corresponding to the GOPs of the V dis comprise: a level-1 distorted time-domain low-frequency horizontal detailed sequence LLH dis , a level-1 distorted time-domain low-frequency vertical detailed sequence LHL dis , a level-1 distorted time-domain low-frequency diagonal detailed sequence LHH dis , a level-1 distorted time-domain high-frequency approximated sequence HLL dis , a level-1 distorted time-domain high-frequency horizontal detailed sequence HLH dis , a level-1 distorted time-domain high-frequency vertical detailed sequence HHL dis , and a level-1 distorted time-domain high-frequency diagonal detailed sequence HHH dis ; the 8 level-2 sub-band sequences corresponding to the GOPs of the V dis comprise: a level-2 distorted time-domain low-frequency approximated sequence LLLL dis , a level-2 distorted time-domain low-frequency horizontal detailed sequence LLLH dis , a level-2 distorted time-domain low-frequency vertical detailed sequence LLHL dis , a level-2 distorted time-domain low-frequency diagonal detailed sequence LLHH dis , a level-2 distorted time-domain high-frequency approximated sequence LHLL dis , a level-2 distorted time-domain high-frequency horizontal detailed sequence LHLH dis , a level-2 distorted time-domain high-frequency vertical detailed sequence LHHL dis , and a level-2 distorted time-domain high-frequency diagonal detailed sequence LHHH dis ;
[0053] wherein the time-domain of the video is split with the 3D wavelet transform; the time-domain information is described from an angle of frequency components, and is treated in a wavelet-domain, which to a certain extent solves a problem that the video time-domain information is difficult to be described in the video quality evaluation, and effectively improves accuracy of the evaluation method;
[0054] d) calculating quality of each of the sub-band sequences corresponding to the GOPs of the V dis , marking the quality of a No. j sub-band sequence corresponding to the G dis i as Q i,j , wherein
[0000]
Q
i
,
j
=
∑
k
=
1
K
SSIM
(
VI
ref
i
,
j
,
k
,
VI
dis
i
,
j
,
k
)
K
,
[0000] 1≦j≦15, 1≦k≦K, K represents a frame quantity of a No. j sub-band sequence corresponding to the G ref i and the No. j sub-band sequence corresponding to the G dis i ; if the No. j sub-band sequence corresponding to the G ref i and the No. j sub-band sequence corresponding to the G dis i are both the level-1 sub-band sequences, then
[0000]
K
=
2
n
2
;
[0000] if the No. j sub-band sequence corresponding to the G ref i and the No. j sub-band sequence corresponding to the G dis i are both the level-2 sub-band sequences, then
[0000]
K
=
2
n
2
×
2
;
[0000] VI ref i,j,k represents a No. k frame of image of the No. j sub-band sequence corresponding to the G ref i , VI dis i,j,k represents a No. k frame of image of the No. j sub-band sequence corresponding to the G dis i , SSIM ( ) is a structural similarity function, and
[0000]
SSIM
(
VI
ref
i
,
j
,
k
,
VI
dis
i
,
j
,
k
)
=
(
2
μ
ref
μ
dis
+
c
1
)
(
2
σ
ref
-
dis
+
c
2
)
(
μ
ref
2
+
μ
dis
2
+
c
1
)
(
σ
ref
2
+
σ
dis
2
+
c
2
)
,
[0000] μ ref represents an average value of the VI ref i,j,k , μ dis represents an average value of the VI dis i,j,k , σ ref represents a standard deviation of the VI ref i,j,k , σ dis represents a standard deviation of the VI dis i,j,k , σ ref-dis represents covariance between the VI ref i,j,k and the VI dis i,j,k , c 1 and c 2 are constants for preventing unstableness of
[0000]
SSIM
(
VI
ref
i
,
j
,
k
,
VI
dis
i
,
j
,
k
)
=
(
2
μ
ref
μ
dis
+
c
1
)
(
2
σ
ref
-
dis
+
c
2
)
(
μ
ref
2
+
μ
dis
2
+
c
1
)
(
σ
ref
2
+
σ
dis
2
+
c
2
)
[0000] when the denominator is close to zero, and c 1 ≠0, c 2 ≠0;
[0055] e) selecting 2 sequences from the 7 level-1 sub-band sequences of each of the GOPs of the V dis , then calculating quality of the level-1 sub-band sequences corresponding to the GOPs of the V dis according to quality of the selected 2 sequences of the level-1 sub-band sequences corresponding to the GOPs of the V dis , wherein for the 7 level-1 sub-band sequences corresponding to the G dis i , supposing that a No. p 1 sequence and a No. q 1 sequence of the level-1 sub-band sequences are selected, then quality of the level-1 sub-band sequences corresponding to the G dis i is marked as Q Lv i , wherein Q Lv1 i =w Lv1 ×Q i,p 1 +(1−w Lv1 )×Q i,q 1 , 9≦p 1 ≦15, 9≦q 1 ≦15, w Lv1 is a weight value of the Q i,p 1 , the Q i,p 1 represents the quality of the No. p 1 sequence of the level-1 sub-band sequences corresponding to the G dis i , Q i,q 1 represents the quality of the No. q 1 sequence of the level-1 sub-band sequences corresponding to the G dis i ; from the No. 9 to the No. 15 sub-band sequences of the 15 sub-band sequences corresponding to the GOPs of the V dis are the level-1 sub-band sequences;
[0056] and selecting 2 sequences from the 8 level-2 sub-band sequences of each of the GOPs of the V dis , then calculating quality of the level-2 sub-band sequences corresponding to the GOPs of the V dis according to quality of the selected 2 sequences of the level-2 sub-band sequences corresponding to the GOPs of the V dis , wherein for the 8 level-2 sub-band sequences corresponding to the G dis i , supposing that a No. p 2 sequence and a No. q 2 sequence of the level-2 sub-band sequences are selected, then quality of the level-2 sub-band sequences corresponding to the G dis i is marked as Q Lv2 i , wherein Q Lv2 i =w Lv2 ×Q i,p 2 +(1−w Lv2 )×Q i,q 2 , 1≦p 2 ≦8, 1≦q 2 ≦8, w Lv2 is a weight value of the Q i,p 2 , the Q i,p 2 represents the quality of the No. p 2 sequence of the level-2 sub-band sequences corresponding to the G dis i , Q i,q 2 represents the quality of the No. q 2 sequence of the level-2 sub-band sequences corresponding to the G dis i ; from the No. 1 to the No. 8 sub-band sequences of the 15 sub-band sequences corresponding to the GOPs of the V dis are the level-2 sub-band sequences;
[0057] wherein in the preferred embodiment, w Lv1 =0.71, w Lv2 =0.58, p 1 =9, q 1 =12, p 2 =3, and q 2 =1;
[0058] wherein according to the present invention, selection of the No. p 1 and the No. q 1 level-1 sub-band sequences and selection of the No. p 2 and the No. q 2 level-2 sub-band sequences are processes of selecting suitable parameters with statistical analysis, that is to say, the selection is provided with a suitable training video database through following steps e-1) to e-4); after obtaining values of the p 2 , q 2 , p 1 and q 1 , constant values thereof are applicable during video quality evaluation of distorted video sequences with the video quality evaluation method;
[0059] wherein for selecting the 2 sequences of the level-1 sub-band sequences and the 2 sequences of the level-2 sub-band sequences, the step e) specifically comprises steps of:
[0060] e-1) selecting a video database with subjective video quality as a training video database, obtaining quality of each sub-band sequence corresponding to GOPs of distorted video sequences in the training video database by applying from the step a) to the step d), marking the No. n v distorted video sequence as V dis n v , marking quality of a No. j sub-band sequence corresponding to the No. i′ GOP of the V dis n v as Q n v i′,j , wherein 1≦n v ≦U, U represents a quantity of the distorted sequences in the training video database, 1≦i′≦n GoF ′, n GoF ′ represents a quantity of the GOPs of the V dis n v , 1≦j≦15;
[0061] e-2) calculating objective video quality of all the same sub-band sequences corresponding to all the GOPs of the distorted video sequences in the training video database, marking objective video quality of all the No. j sub-band sequences corresponding to all the GOPs of the V dis n v as VQ n v j , wherein
[0000]
VQ
n
v
j
=
∑
i
′
=
1
n
GoF
′
Q
n
v
i
′
,
j
n
GoF
′
;
[0062] e-3) forming a vector v X j with the objective video quality of all the No. j sub-band sequences corresponding to all the GOPs of the distorted video sequences in the training video database, wherein v X j =(VQ 1 j , VQ 2 j , . . . , VQ n v j , . . . , VQ U j ), wherein a vector is formed for each of the same sub-band sequences, that is to say, there are 15 vectors respectively corresponding to the 15 sub-band sequences; forming a vector v Y with the subjective video quality of all the distorted video sequences in the training video database, wherein v Y =(VS 1 , VS 2 , . . . , VS n v , . . . , VS U ), wherein 1≦j≦15, VQ 1 j represents the objective video quality of the No. j sub-band sequences corresponding to all the GOPs of the first distorted video sequence in the training video database, VQ 2 j represents the objective video quality of the No. j sub-band sequences corresponding to all the GOPs of the second distorted video sequence in the training video database, VQ n v j represents the objective video quality of the No. j sub-band sequences corresponding to all the GOPs of the No. n v distorted video sequence in the training video database, VQ U j represents the objective video quality of the No. j sub-band sequences corresponding to all the GOPs of the No. U distorted video sequence in the training video database; VS 1 represents the subjective video quality of the first distorted video sequence in the training video database, VS 2 represents the subjective video quality of the second distorted video sequence in the training video database, VS n v represents the subjective video quality of the No. n v distorted video sequence in the training video database, VS U represents the subjective video quality of the No. U distorted video sequence in the training video database;
[0063] then calculating a linear correlation coefficient of the objective video quality of the same sub-band sequences corresponding to all the GOPs of the distorted video sequences in the training video database and the subjective quality of the distorted sequences, marking the linear correlation coefficient of the objective video quality of the No. j sub-band sequence corresponding to all the GOPs of the distorted video sequences and the subjective quality of the distorted sequences as CC j , wherein
[0000]
CC
j
=
∑
n
v
=
1
U
(
VQ
n
v
j
-
V
_
Q
j
)
(
VS
n
v
-
V
_
S
)
∑
n
v
=
1
U
(
VQ
n
v
j
-
V
_
Q
j
)
2
∑
n
v
=
1
U
(
VS
n
v
-
V
_
S
)
2
,
1
≤
j
≤
15
,
[0000] V Q j is an average value of all element values of the v X j , V S is an average value of all element values of the v Y ; and
[0064] e-4) after obtaining the 15 linear correlation coefficients in the step e-3), selecting a max linear correlation coefficient and a second max linear correlation coefficient from the 7 linear correlation coefficients corresponding to the 7 level-1 sub-band sequences out of the obtained 15 linear correlation coefficients, regarding the level-1 sub-band sequences respectively corresponding to the max linear correlation coefficient and the second max linear correlation coefficient as the two level-1 sub-band sequences to be selected; and selecting a max linear correlation coefficient and a second max linear correlation coefficient from the 8 linear correlation coefficients corresponding to the 8 level-2 sub-band sequences out of the obtained 15 linear correlation coefficients, regarding the level-2 sub-band sequences respectively corresponding to the max linear correlation coefficient and the second max linear correlation coefficient as the two level-2 sub-band sequences to be selected;
[0065] wherein in the preferred embodiment, for selecting the No. p 2 and the No. q 2 level-2 sub-band sequences, and the No. p 1 and the No. q 1 level-1 sub-band sequences, a distorted video collection with 4 different distortion types and different distortion degrees based on 10 undistorted video sequences in a LIVE video quality database from University of Texas at Austin is utilized; the distorted video collection comprises: 40 distorted video sequences with wireless transmission distortion, 30 distorted video sequences with IP network transmission distortion, 40 distorted video sequences with H.264 compression distortion, and 40 distorted video sequences with MPEG-2 compression distortion; each of the distorted video sequences has a corresponding subjective quality evaluation result which is represented by a difference mean opinion score DMOS; that is to say, a subjective quality evaluation result VS n v of the No. n v distorted video sequence in the training video database of the preferred embodiment is marked as DMOS n v ; by applying from the step a) to the step e) of the video quality evaluation method on the above distorted video sequences, objective video quality of the same sub-band sequences corresponding to all GOPs of the distorted video sequence is obtained by calculating, which means that there are 15 objective video quality corresponding to the 15 sub-band sequences for each distorted video sequence; then by applying the step e-3) for calculating a linear correlation coefficient of the objective video quality of the sub-band sequence corresponding to the distorted video sequences and a corresponding difference mean opinion score DMOS of the distorted video sequences, linear correlation coefficients corresponding to the objective video quality of the 15 sub-band sequences of the distorted video sequences are obtained; referring to the FIG. 2 , a linear correlation coefficient diagram of the objective video quality of the same sub-band sequences and the difference mean opinion scores of all the distorted video sequences in the LIVE video database is illustrated, wherein in the 7 level-1 sub-band sequences, LLH dis has the max linear correlation coefficient, and HLL dis has the second max linear correlation coefficient, which means p 1 =9, and q 1 =12; wherein in the 8 level-2 sub-band sequences, LLHL dis has the max linear correlation coefficient, and LLLL dis has the second max linear correlation coefficient, which means p 2 =3, and q 2 =1; the larger the linear correlation coefficient is, the more accurate the objective quality of the sub-band sequence is when compared to the subject video quality; therefore, the sub-band sequences with the max and the second max linear correlation coefficients according to the subject video quality are selected from the level-1 and level-2 sub-band sequences for further calculating;
[0066] f) calculating quality of the GOPs of the V dis according to the quality of the level-1 and level-2 sub-band sequences corresponding to the GOPs of the V dis , marking the quality of the G dis i as Q Lv i , wherein Q Lv i =w Lv ×Q Lv1 i +(1−w Lv )×Q Lv2 i , w Lv is a weight value of the Q Lv1 i , in the preferred embodiment, w Lv =0.93; and
[0067] g) calculating objective evaluated quality of the V dis according to the quality of the GOPs of the V dis , marking the objective evaluated quality as Q, wherein
[0000]
Q
=
∑
i
=
1
n
GoF
w
i
×
Q
Lv
i
∑
i
=
1
n
GoF
w
i
,
[0000] w i is a weight value of the Q Lv i ; wherein for obtaining the w i , the step g) specifically comprises steps of:
[0068] g-1) calculating an average value of brightness average values of all the images in each of the GOPs of the V dis , marking the average value of the brightness average values of all the images of the G dis i as Lavg i , wherein
[0000]
Lavg
i
=
∑
f
=
1
2
n
∂
f
2
n
,
[0000] ∂ f represents the brightness average value of a No. f frame of image, a value of the ∂ f is the brightness average value obtained by averaging brightness values of all pixels in the No. f frame of image, and 1≦i≦n GoF ;
[0069] g-2) calculating an average value of motion intensity of all the images of each of the GOPs except a first frame of image in the GOP, marking the average value of motion intensity of all the images of G dis i except the first frame of image as MAavg i , wherein
[0000]
MAavg
i
=
∑
f
′
=
2
2
n
MA
f
′
2
n
-
1
,
2
≤
f
′
≤
2
n
,
[0000] MA f′ represents the motion intensity of the No. f′ frame of image of the G dis i ,
[0000]
MA
f
′
=
1
W
×
H
∑
s
=
1
W
∑
t
=
1
H
(
(
mv
x
(
s
,
t
)
)
2
+
(
mv
y
(
s
,
t
)
)
2
)
,
[0000] W represents a width of the No. f′ frame of image of the G dis i , H represents a height of the No. f′ frame of image of the G dis i , mv x (s,t) represents a horizontal value of a motion vector of a pixel with a position of (s,t) in the No. f′ frame of image of the G dis i , mv y (s,t) represents a vertical value of the motion vector of the pixel with the position of (s,t) in the No. f′ frame of image of the G dis i ; the motion vector of each of the pixels in the No. f′ frame of image of the G dis i is obtained with a reference to a former frame of image of the No. f′ frame of image of the G dis i ;
[0070] g-3) forming a brightness average value vector with the average values of the brightness average values of all the images of the GOPs of the V dis , marking the brightness average value vector as V Lavg wherein V Lavg =(Lavg 1 , Lavg 2 , . . . , Lavg n GoF ), Lavg 1 represents an average value of the brightness average values of images of the first GOP of the V dis , Lavg 2 represents an average value of the brightness average values of images of the second GOP of the V dis , Lavg n GoF represents an average value of the brightness average values of images of the No. n GoF GOP of the V dis ;
[0071] and forming an average value vector of the motion intensity with the average values of the motion intensity of all the images of the GOPs of the V dis except the first frame of image, marking the average value vector of the motion intensity as V MAavg , wherein V MAavg =(MAavg 1 , MAavg 2 , . . . , MAavg n GoF ), MAavg 1 represents an average value of the motion intensity of images of the first GOP of the V dis except the first frame of image, MAavg 2 represents an average value of the motion intensity of images of the second GOP of the V dis except the first frame of image, MAavg n GoF represents an average value of the motion intensity of images of the No. n GoF GOP of the V dis except the first frame of image;
[0072] g-4) normalizing every element of the V Lavg , for obtaining normalized values of the elements of the V Lavg , marking the normalized value of the No. i element of the V Lavg as v Lavg i,norm , wherein
[0000]
v
Lavg
i
,
norm
=
Lavg
i
-
max
(
V
Lavg
)
max
(
V
Lavg
)
-
min
(
V
Lavg
)
,
[0000] Lavg i represents a value of the No. i element of the V Lavg , max(V Lavg ) represents a value of the element with a max value of the V Lavg , min(V Lavg ) represents a value of the element with a min value of the V Lavg ;
[0073] and normalizing every element of the V MAavg , for obtaining normalized values of the elements of the V MAavg , marking the normalized value of the No. i element of the V MAavg as v MAavg i,norm , wherein
[0000]
v
MAavg
i
,
norm
=
MAavg
i
-
max
(
V
MAavg
)
max
(
V
MAavg
)
-
min
(
V
MAavg
)
,
[0000] MAavg i represents a value of the No. i element of the V MAavg , max(V MAavg ) represents a value of the element with a max value of the V MAavg , min(V MAavg ) represents a value of the element with a min value of the V MAavg ; and
[0074] g-5) calculating the weight value w i of the Q Lv i according to the v Lavg i,norm and the v MAavg i,norm , wherein w i =(1−v MAavg i,norm )×v Lavg i,norm .
[0075] For illustrating effectiveness and feasibility of the present invention, the LIVE video quality database from University of Texas at Austin is utilized for experimental verification, so as to analyze relativity of the objective evaluated result and the difference mean opinion score. The distorted video collection with 4 different distortion types and different distortion degrees is formed based on the 10 undistorted video sequences in the LIVE video quality database, the distorted video collection comprises: 40 distorted video sequences with wireless transmission distortion, 30 distorted video sequences with IP network transmission distortion, 40 distorted video sequences with H.264 compression distortion, and 40 distorted video sequences with MPEG-2 compression distortion. Referring to FIG. 3 a , a scatter diagram of objective evaluated quality Q judged by the video quality evaluation method and a difference mean opinion score DMOS of the 40 distorted video sequences with wireless transmission distortion is illustrated. Referring to FIG. 3 b , a scatter diagram of objective evaluated quality Q judged by the video quality evaluation method and a difference mean opinion score DMOS of the 30 distorted video sequences with IP network transmission distortion is illustrated. Referring to FIG. 3 c , a scatter diagram of objective evaluated quality Q judged by the video quality evaluation method and a difference mean opinion score DMOS of the 40 distorted video sequences with H.264 compression distortion is illustrated. Referring to FIG. 3 d , a scatter diagram of objective evaluated quality Q judged by the video quality evaluation method and a difference mean opinion score DMOS of the 40 distorted video sequences with MPEG-2 compression distortion is illustrated. And referring to FIG. 3 e , a scatter diagram of objective evaluated quality Q judged by the video quality evaluation method and a difference mean opinion score DMOS of all the 150 distorted video sequences is illustrated. In the FIGS. 3 a - 3 e , the higher concentration of the scatters, the better objective quality evaluation performance and relativity with the DMOS. According to the FIGS. 3 a - 3 e , the video quality evaluation method is able to well separate the sequences with low quality from the sequences with high quality, and has good evaluation performance.
[0076] Herein, 4 common parameters for evaluating the performance of video quality evaluation method are utilized, that is, Pearson correlation coefficient under nonlinear regression (CC for short), Spearman rank order correlation coefficient (SROCC for short), outlier ratio (OR for short), and rooted mean squared error (RMSE for short). CC represents accuracy of the objective quality evaluation method, and SROCC represents prediction monotonicity of the objective quality evaluation method, wherein the CC and the SROCC being closer to 1 means that the performance of the objective quality evaluation method is better. OR represents dispersion degree of the objective quality evaluation method, wherein the OR being closer to 0 means that the objective quality evaluation method is better. RMSE represents prediction accuracy of the objective quality evaluation method, the RMSE being smaller means that the objective quality evaluation method is better. CC, SROCC, OR and RMSE coefficients representing accuracy, monotonicity and dispersion ratio of the video quality evaluation method according to the present invention are illustrated in a Table. 1. Referring to the Table. 1, overall hybrid distortion CC and SROCC are both above 0.79, wherein CC is above 0.8. OR is 0, RMSE is lower than 6.5. According to the present invention, the relativity of the objective evaluated quality Q and the difference mean opinion score DMOS obtained is high, which illustrates sufficient consistency of objective evaluation results with subjective evaluation visual results, and well illustrates the effectiveness of the present invention.
[0000]
TABLE 1
Evaluation result of the 4 performance parameters according
to the method of the present invention
CC
SROCC
OR
RMSE
40 distorted video sequences with
0.8087
0.8047
0
6.2066
wireless transmission distortion
30 distorted video sequences with IP
0.8663
0.7958
0
4.8318
network transmission distortion
40 distorted video sequences with
0.7403
0.7257
0
7.4110
H.264 compression distortion
40 distorted video sequences with
0.8140
0.7979
0
5.6653
MPEG-2 compression distortion
All the 150 distorted video sequences
0.8037
0.7931
0
6.4570
[0077] One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting.
[0078] It will thus be seen that the objects of the present invention have been fully and effectively accomplished. Its embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims. | A video quality evaluation method based on 3D wavelet transform utilizes 3D wavelet transform in the video quality evaluation, for transforming the group of pictures (GOP for short) of the video. By splitting the video sequence on a time axis, time-domain information of the GOPs is described, which to a certain extent solves a problem that the video time-domain information is difficult to be described, and effectively improves accuracy of objective video quality evaluation, so as to effectively improve relativity between the objective quality evaluation result and the subjective quality judged by the human eyes. For time-domain relativity between the GOPs, the method weighs the quality of the GOPs according to the motion intensity and the brightness, in such a manner that the method is able to better meet human visual characteristics. | 97,196 |
This is a continuation of application Ser. No. 037,790, filed May 10, 1079, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to inductive low pressure radio frequency plasma reactions, and in particular to a plasma process for the deposition of glassy material onto a solid surface.
The inductive radio frequency plasma has been known for many years. The essential feature of the inductive discharge is that the power is introduced into the gas phase by inductive coupling and hence the conductor paths in the gas form closed paths within the container. This provides a hot intense plasma and has the advantage that no internal electrodes are required nor are there the problems with large potential drops, as can occur with capacitive coupling, at the walls of the containing vessel.
The term `radio frequency` as used herein is understood to include microwave frequencies.
An inductive discharge, or H-discharge, is produced by the magnetic field (H) of the exciting coil, unlike a capacitive discharge or E-discharge which is relatively diffused and is produced by electrostatic fields. It has been found that the H & E discharges become indistinguishable as the wavelength of the exciting radiation becomes comparable with the dimension of the discharge.
At low pressures the discharge tends to be most intense at the walls of a containing tube. At higher pressure 500 Torr the discharge becomes more restricted to the center of the tube.
The use of H-discharges for chemical processing has been limited previously to the atmospheric plasma torch. This device is essentially a high power H-discharge which is generally operated in argon to ease power requirements and at 3-10 MHz. Such a plasma torch has been used in the past to produce ultra-pure silica. The reactants were introduced into the tail flame of the plasma, as oxygen and silicon tetrachloride in high concentration tend to extinguish the plasma. Silica produced by such a torch was in the form of sub-micron spheres which had to be collected and sintered to form clear glass. While such an arrangement has proved effective for performing many chemical reactions it does not lend itself readily to the production e.g. of optical fiber preforms, in which it is preferred to deposit material directly as a glassy layer so as to avoid an intermediate sintering process.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a method of depositing a glass or its precursor by a radio frequency induced chemical vapor reaction using an inductively sustained plasma fed with gas at a pressure within the range 0.1 to 50 Torr, wherein the plasma discharge is such that its largest dimension is significantly less than the free space wavelength of the radio frequency employed to sustain the plasma, the plasma pressure and energy density being such that the deposit is non-porous.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will now be described with reference to the accompanying drawings in which:
FIG. 1 is a schematic diagram indicating the operating regimes of various types of plasma;
FIG. 2 is a schematic diagram of an inductive plasma deposition arrangement;
FIG. 3 indicates the plasma configuration obtained in the arrangement of FIG. 2;
FIG. 4 shows an alternative deposition arrangement;
FIG. 5 shows a further type of deposition arrangement; and
FIG. 6 shows an alternative arrangement employing a radio-frequency concentrator.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, it can be seen that the various defined types of plasma appear with various combinations of gas pressure and input power. Thus the conventional E-discharge is achieved at relatively low pressures and low power. The H-discharge, however, occurs at intermediate pressures e.g. between 0.1 and 50 Torr and requires medium to high input power for its maintenance. The various forms of plasma are discussed in greater detail by G.I. Babat, J. Inst. Elec. Eng. 94 27-37 (June 1947).
Referring to FIG. 2, there is shown an arrangement for the deposition of a solid material on the inner surface of an insulating, e.g. glass or silica, tube 11. The tube 11 is evacuated via a pump 12 coupled to a pressure gauge 13 and is supplied with reactant gases via valves 14. Thus, for example, if silica is to be deposited on the inner surface of a silica tube in the manufacture of optical fiber preforms, th reactant gases may be silicon tetrachloride (SiC1 4 ) and oxygen together with an inert carrier gas such as argon.
Radio frequency power is supplied to the tube 11 via a coil 15 coupled via a flexible RF feeder 10 and a loading coil 16 to a generator 17.
A grounded electrode 18 is provided at one end of the tube downstream from the coil 15 as it has been found that this aids the initiation of an inductive plasma within the coil 15 and causes any capacitive discharge to be confined downstream of the coil. It is essential that the lower potential or grounded end of the coil 15 faces the incoming gas flow to the system.
It has been found for example that, using a 2 inch silica tube, the mimimum power required to strike and sustain an inductive plasma at a frequency of 3 MHz is from 4 to 6 kW. However, as it is preferable to have an ample power reserve a 24 kW generator may be employed. Matching of the generator to the plasma is provided by adjustment of the loading coil 16 and, as will be apparent to those skilled in the art, by the particular design of the coil 15 surrounding the tube. In this respect it should be noted that, when an inductive plasma on H-discharge is struck within the tube, the parallel inductance effect of the plasma on the coil 15 reduces the effective inductance of that coil causing the generator frequency to rise. This is opposite to the effect observed with capacitors of E-discharge where striking of the plasma cause the generator frequency to fall.
Referring to FIG. 3, the plasma 31 is struck with the tube 11 evacuated to the desired pressure in the range 0.1 to 50 Torr by increasing the generator power until electrical breakdown of the gas occurs. The inductive plasma may then be sustained at a somewhat lower power level. As shown in FIG. 3, the plasma 31 is displaced from the center of the coil 15 by the gas flow along the direction of the arrow A forming a broad front 32 against the gas flow and having an extended tail portion 33. Solid material 34, e.g. silica, is deposited on the tube from the plasma forming a ring of material adjacent the front 32 of the plasma 31. Thus, by moving the coil 15 along the tube 11, or by moving the tube within the coil, a contiguous layer of material may be deposited along the inner surface of the tube. The generator power may be so controlled that, while maintaining the inductive plasma, the solid material 34 is deposited directly in a glassy condition without fusion of the silica tube 11 and without the need to sinter the deposited material. Relative movement of the coil 15 and the tube 11 prevent overheating and subsequent collapse of any one portion of the tube 11.
The technique is particularly advantageous for the manufacture of silica optical fiber preforms by the coated tube method. The various layers of doped and/or undoped silica may be deposited on the inner surfce of a silica tube without fusion of the tube and subsequent loss of tube geometry. The coated tube may then be collapsed into a preform tube and drawn into optical fiber in the normal way.
In a deposition process using the apparatus of FIG. 2, silica in glassy form may be deposited over a 40 cm length of 20 mm diameter silica tube by admitting 200 cc/min oxygen bubbled through silicon tetrachloride liquid at 20° C. and admitting an additional 200 cc/min of oxygen into the tube at a pressure of 7.0 Torr. Conveniently the work coil 16 may comprise a two layer coil, 5 turns on the first layer wound on a 3 cm former, and 3 turns on the second layer. The turns may be insulated with glass sleeving and the two layers separated e.g. with a silica tube. The inductive plasma may be maintained at 2.9 MHz at a power level sufficient to heat the tube to about 1000° C., the coil being reciprocated along the tube at a rate of 5 secs. per pass. This provides a deposition rate of glassy silica on the tube of 16 g/hour. Dopants commonly employed in the production of optical fibers may of course be included in the plasma to vary the refractive index of the deposited material.
It has been found that, using the arrangement of FIGS. 2 and 3, by adjusting the generator output and, if necessary, by local heating of the deposition tube an inductive plasma may be struck and conveniently confined to the region of the work coil at pressure up to 20 Torr. At pressures up to 50 Torr the tube diameter should be increased, i.e. above 20 mm, to improve matching and facilitate maintenance of the plasma.
FIG. 4 shows an inductive plasma deposition arrangement for the plasma deposition of material by a tube-in-tube process in which a tube 41 on which material is to be deposited rests or is supported in an outer tube 42. This technique, when applied to the coating of a silica tube e.g. for optical fiber production, has the advantage that the tube 41 may be maintained at a temperature approaching its softening point without the risk of collapse due to the relatively low pressure of the plasma. It is found with this arrangement that the plasma confines itself to the inside of the tube 41 and that deposition takes place therefore only on the inside of this tube. By this means the temperature of the inner tube may be raised to 1300° C. without risk of distortion.
FIG. 5 shows a modification of the arrangement of FIG. 4 in which provision is made for the treatment of a plurality of tubes 51 by a semi-continuous tube-in-tube process. The tubes 51 to be treated are stacked in a vacuum tight storage chamber 52 communicating with a tube 53 in which the tubes 51 are to be treated. Reactant gases are supplied to the system via an inlet 54 into the storage chamber 52. To effect inductive plasma deposition, the bottom tube 51 of the stack is pushed e.g. by a piston (not shown) into the tube 53 and plasma coated with the desired material, e.g. silica or doped silica, as previously described. When coating has been completed the next tube 51 of the stack is pushed into the tube 51 ejecting the previously coated tube 51 into a further storage chamber 55. The process is then continued until all the tubes 51 have been treated.
In the arrangement of FIG. 6, a current concentrator or RF transformer 61 is employed to localize and intensify the H-discharge. Hitherto it has not been possible to apply such a current concentrator, to plasma systems operating at atmospheric pressures.
Such a transformer can be employed to effectively isolate the high voltage associated with the primary coil 15 from the plasma region and also provide a step down--high current path which can be used to stabilize and concentrate the plasma to the required deposition zone. The concentrator, which should be water cooled, comprises a conductive, e.g. copper, hollow cylinder provided with a longitudinal slot 62 and closed at one end by a plate 63 provided with a keyhole slot 64 communicating with the slot 62. The discharge tube is placed in the keyhole slot 64 around which an intense RF current is induced by the surrounding work coil (not shown). As the concentrator is isolated from the generator it may be grounded thus eliminating any stray capacitive discharges or maintained at any desired potential. Other forms of concentrator known to those skilled in the art may of course be used.
The following examples illustrate the invention:
EXAMPLE 1
A silica deposition tube of 21 mm internal diameter was mounted in a vacuum pumped flow system of the type shown in FIG. 2. The tube was pumped by a rotary vacuum pump through a liquid nitrogen cold trap, the tubing between pump and deposition tube being designed to give a high flow conductance.
A coil was constructed from two layers of 1/4" copper tube wound with five turns on the inside layer and three turns on the outside. The coil was insulated with glass fiber sleeving and isolation between the two layers was achieved by means of a silica tube.
The coil was placed over the silica tube and connected by means of flexible water cooled leads to the tank circuit of a 35 kW RF generator. Provision was made for reciprocation of the coil along 50 cm of the silica tube.
As stray capacitor effects resulting from discharge from high RF voltage parts of the coil were found to promote sooty deposition incorporated in the glassy deposit, the coil was arranged with the grounded end on the inside of the coil and facing the incoming gas stream. Stray discharges were then more or less confined to the downstream end where no unreacted silicon tetrachloride existed.
The silica tube was pumped down to less than 0.01 Torr. With the pump operating 200 sccm of O 2 was admitted causing the pressure in the tube to rise to 2 Torr. The voltage to the oscillating valve was then increased briefly to 3 kv when an intense white plasma appeared within the tube confined to the coil region.
The frequency before the plasma appeared was 4.54 MHz and on appearance of the plasma this increased to 4.62 MHz as the inductance of the coil was reduced by the inductive plasma.
The voltage to the valve was then adjusted until the tube temperature rose to 1100° C.
Silicon tetrachloride was then admitted by bubbling oxygen through the liquid at 22° C. at a rate of 300 sccm causing the pressure to rise to 3 Torr. After one hour the tube was removed and it was found by weighing that 16 g of silica had been deposited in a glassy form.
EXAMPLE II
A coil and concentrator of the type shown in FIG. 6 were used. A ten turn coil was wound as before (Ex. 1) on an internal diameter of 55 mm. A water cooled copper concentrator was inserted and grounding provided to it by means of a switch. Note that in some applications the concentrator may be maintained at any chosen RF potential with respect to earth.
The coil and concentrator were connected to the tank circuit of the generator. The voltage on the valve was increased as before until an H-discharge appeared in the region of concentrator field. The voltage was then adjusted to give a tube temperature of 1200° C. The concentrator was then grounded and all trace of stray capacitive discharges disappeared.
Silicon tetrachloride and germanium tetrachloride were admitted in the usual way to cause a layer of doped SiO 2 /GeO 2 to be deposited on the tube.
While we have described above the principles of our invention in connection with specific apparatus it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of our invention as set forth in the objects thereof and in the accompanying claims. | The vitreous material, e.g. silica, is deposited on the inner surface of the tube from a hot, intense, inductive plasma, which plasma is formed by utilization of wavelengths substantially longer than the diameter of the plasma. The process may be employed in the production of preform tubes or step or graded index optical fiber manufacture by gradually varying the contents of the vapor introduced into the plasma. | 15,260 |
FIELD OF THE INVENTION
This invention is directed to a medical device and a method of treating mammals, especially humans, to alleviate the symptoms, including pain, of several conditions and symptoms, including hemorrhoids, vaginal inflammation and/or yeast infections, and open, draining wounds or incisions.
BACKGROUND OF THE INVENTION
Prior to the invention disclosed herein, conditions such as hemorrhoids have been treated with topical applications, or suppositories. One of the leading medicaments is phenylephrine (rectal). However, while the relief provided by this medicament is only temporary, it can be contra-indicated if the patient has high blood pressure and/or heart disease, thyroid disease, diabetes, and can lead to side effects, such as skin problems, including acne. Hemorrhoids have also been treated surgically, but of course, that is a much more involved and expensive method of treatment, which many patients are reluctant to undergo. Hemorrhoids may exist in several forms, including external, thrombosed, prolapsed internal, internal or combined (internal and external).
Thus, there exists a need for temporary treatment and relief of the symptoms of hemorrhoids, without the contra-indications and side effects of phenylephrine (rectal) or the more invasive, expensive surgical treatment.
SUMMARY OF THE INVENTION
In one aspect, the invention provides a medical device that can be used by the consumer who may have one or more of high blood pressure or heart disease, diabetes, thyroid disease or for the relief of tissue inflammation. On the other hand, the medical device of the invention will not cause side effects, such as acne.
In yet other embodiments of the invention, there is provided a method of treating hemorrhoids, vaginal inflammation and/or yeast infections and draining open wounds or incisions.
According to one embodiment of the invention, a low cost tubular element, having high heat capacity, which has been chilled, as by refrigeration or other mechanism (e.g., ice bath), can be inserted into the anal canal and/or rectum, vagina, or an open wound or incision of the patient. The chilling effect will bring temporary relief of the symptoms of hemorrhoids, such as the itching, burning sensations, in a non-chemical manner. Thus, there is no likelihood of the inducement of side effects or the contra-indications for patients as those for phenylephrine (rectal) noted above. For use in the treatment of inflammation in the vagina or in draining wounds or incisions, the cooling effect will provide temporary relief of these symptoms/conditions as well.
The method of use of the medical device includes the chilling (by refrigeration, ice-bath, or otherwise) of the medical device, formed of the high heat capacity materials, and insertion/placement of the chilled medical device into the affected area.
These and other embodiments of the invention will become apparent when read in light of the following detailed description of the preferred embodiments in conjunction with the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of typical hemorrhoids;
FIG. 2 is a schematic representation of the medical device of the invention in its most basic form;
FIG. 3 is a schematic representation of a medical device of the invention in another embodiment;
FIG. 4 is a schematic representation of the medical device of the invention with a bail or string to aid in removal of the device after use;
FIG. 5 is a further schematic representation of the medical device of the invention having a cross-sectional configuration which is triangular;
FIG. 6 is a schematic representation of a medical device of the invention having at least one protuberance, which could contain an aperture in the form of an eye, to retain the bail or string to assist in removal of the medical device after use;
FIG. 7 is a further variant having a groove at the proximal (nearer the external) end of the medical device when inserted for use to attach a bail or string to aid in removal of the device;
FIG. 8 is a still further variant of the shape of the medical device having flared proximal and distal edges;
FIG. 9 is a still further variant of the medical device of the invention, having an overall frusto-conical shape, but with numerous protuberances and surface striations.
FIG. 10 is a still further variant in which the medical device has a rectangular cross-sectional shape with an aperture therethrough;
FIG. 11 is a schematic representation of a medical device of the invention having at least one protuberance, which could be in the form of a hook, to retain the bail or string to assist in removal of the medical device after use; and,
FIG. 12 is a schematic representation of a further embodiment of the invention having a generally cross-sectional shape of a rectangle with curved corners, and further containing surface striations on its external surface, wherein this embodiment further contains a notch facilitating the attachment of a bail or string to aid in removal of the medical device after use.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates various forms of hemorrhoids in the human patient. As can be seen from FIG. 2 , the medical device 2 , in its simplest form can take the shape of a cylindrical tube, have a generally cylindrical outer surface 4 , with an aperture therein. The aperture could be a throughbore 6 , but it is to be understood that the aperture may be drilled or bored through a mass of material, after forming the device, or formed from a combination of boring and broaching, such that non-circular apertures could be formed, or it could be created in other variations, such as elliptical during forming of the material by extrusion, molding and other shaping techniques. Thus, while the term “throughbore” is used to describe the aperture, it should be expressly understood that as used throughout the specification and claims, both circular, flat-sided, and non-circular cross-sections of the aperture are encompassed by the term “throughbore”. The throughbore 6 is most conveniently placed along the center axis of the device 2 as seen in FIG. 2 , but such placement is not essential and it may occupy a position other than that of a central axis of the device 2 as seen in FIG. 2 .
FIG. 3 illustrates a second embodiment of the medical device in which device 12 has a general frusto-conical shaped outer surface 14 with a flared end 15 . As in FIG. 2 , a throughbore 16 is most conveniently placed along the center axis of the device 12 , but such is not essential as noted above.
FIG. 4 illustrates a third variant of the medical device 22 of the invention having an aperture having an opening 27 in an end face thereof, with the other end of the opening 28 existing in a lateral surface thereof to accommodate a string 29 (or plastic-coated fine wire or high strength plastic, such as dental floss) to aid in removal of the device 22 after use. As with the embodiments of FIGS. 2 and 3 , it has a throughbore 26 .
FIG. 5 is a further variation of the medical device 32 of the invention having an external surface 34 of a shape such that a cross-section thereof is triangular. As with the embodiments of FIGS. 2-4 , it has a throughbore 36 .
FIG. 6 illustrates a further embodiment of the medical device 42 , which includes a protuberance 47 on an outer surface of the device 42 . The protuberance 47 preferably takes the form of a notch therein, or has an aperture 48 therein. The purpose of the aperture 48 (or notch) is to secure a bail 45 , such as a string, plastic coated fine wire, or similar material, such as the plastic used for dental floss, as an aid for removing the used device 42 .
FIG. 7 is a further variant of the medical device 52 having a groove 53 at the proximal end of the device 52 . The purpose of groove 53 is to secure a bail 54 to aid in removal of the device 52 after use.
FIG. 8 is a still further variant of the shape of device 62 having flared proximal 64 and distal 66 edges, which may, in some patients, be more comfortable to retain in position while the chilled device 62 engages in heat transfer with the hemorrhoids. The embodiments of FIGS. 6-8 all have throughbores.
The throughbores in FIGS. 6, 7 and 8 are respectively numbered as 46 , 56 and 65 in these figures.
FIG. 9 is a still further variant of the medical device 72 of the invention, having an overall frusto-conical shape, but with numerous protuberances 75 - 78 and surface striations 79 . As with the other embodiments, the device 72 has a throughbore 73 . Although the surface striations are introduced with this embodiment, it is to be understood that the surface striations may appear in any of the embodiments disclosed herein, even though omitted from some drawing figures for purposes of clarity. The spacing of these surface striations is schematic, and they may take various forms such as being spaced 1/64 of an inch apart. Alternatively the surface striations can be 1/32; 3/64; 1/16; 5/64; 6/64; 7/64; ⅛; 9/64, etc. inches, or other increments, apart. The spacing of the surface striations may also be irregular, such that different spacing exists between adjacent striations. It is also to be understood that the striations may be formed as embossments or bumps (as in FIG. 9 ) or as grooves (as in FIG. 12 ). The purpose of these surface striations, which may be in the form of bumps, embossments, grooves or a roughened surface, is to assist with retention of the device in the body of the user or as a carrier for external ointments added thereon.
FIG. 10 is a still further variant in which the medical device 82 has a generally rectangular cross-sectional shape with rounded edges and is provided with a throughbore 86 .
FIG. 11 is a schematic representation of a medical device 92 of the invention having at least one protuberance, which could be in the form of a hook 95 , to retain the bail or string (not shown) to assist in removal of the medical device after use. As with the other devices, device 92 has a throughbore 96 .
FIG. 12 is a schematic representation of a still further embodiment of the invention, where the medical device 102 of the invention has a generally rectangular cross-sectional shape with rounded corners. A notch 105 is provided along one rounded edge of the device to receive a bail, string, plastic coated fine wire, or other element, such as dental floss to aid in removal of the device 102 from the user. Similar to other embodiments of the invention, the device 102 contains a throughbore 106 . A series of intersecting surface striations 108 covers at least opposed portions, but preferably all portions of outer surface of device 102 . As described above, the spacing between surface striations is shown schematically in the drawings but can be selected from the group consisting of 1/64; 1/32; 3/64; 1/16; 5/64; 6/64; 7/64; ⅛; 9/64, etc, inches, or other increments, apart. In this embodiment of the invention, the outer surface of the body 102 has surface striations, cross-hatching or roughened surface 108 . The purpose of the modified surface 108 on device 102 can accommodate various surface agents, such as lubricants, local anesthetics, antibiotics, astringents, or medically active substances, such as vinegar (for treating yeast infections).
In addition to the cylindric, frusto-conical, flared, triangular shapes illustrated herein, the shapes can be generally rectangular with rounded edges, or irregular in shape.
The dimensions of the outer diameter and length of the invention will vary according to the specific method of treatment but typically may be as small as ½ inch outer diameter and 2-7 inches in length.
In the most preferred use, the medical device of the invention is chilled (by refrigeration, ice bath or other techniques) to lower the temperature of the medical device. As heretofore described, the medical device is preferably formed from a high heat capacity material. Suitable material include artificial materials comprising a combination of hardened calcium carbonate/sodium carbonate materials, such as described in my previous U.S. Pat. Nos. 6,264,740 and 6,913,645 (each incorporated by reference in its entirety); natural materials, such as stone and jade; ceramics; rubbers; geo-polymers (such as described in U.S. Pat. No. 8,202,362, hereby incorporated by reference in its entirety); some composites of plastics/fillers; plastics/metal and metals and alloys. Geo-polymers are known to be based on inorganic materials. Cements are called geopolymeric cement because it contains geopolymer minerals, consisting of alkaline aluminosilicates, best known under the name of poly(sialate), poly(sialate-siloxo) and/or poly(sialate-disiloxo). The hardened calcium carbonate/sodium carbonate materials with a high sodium carbonate component have the advantage of breaking down in sewer/septic systems, and therefore are considered to be a preferred material for this invention.
In order to obtain the maximum effective time of use, the chilling should be to or at 32° F. (0° C.), or slightly above. Temperatures below the freezing point of water might induce thermal damage to the tissues surrounding the medical device of the invention and therefore should be avoided.
Chilling could be effective by placing a plurality of devices in a container having a fluid therein to simultaneously chill a plurality of the medical devices of the invention. The fluid can be vinegar, alcohol, wine, brine, an ice bath, witch hazel, and mixtures thereof, or other suitable liquid which does not freeze at the freezing point of water. Once properly chilled, a single device is selected and inserted, either by the patient or a medical practitioner, to provide immediate relief from the symptoms/conditions mentioned herein.
Alternatively, the medical devices of the invention could be individually packaged in foil packages surrounded by one of the fluids mentioned above, or in a material such as Benadryl, a lubricant, an astringent, a local anesthetic, an antibiotic, or other material, which packages can be chilled individually or as a group.
It will be understood that other variations, and uses, of the medical device of the present invention will be envisioned by those skilled in the art reading the present disclosure or viewing the drawings herein, and it is to be understood that all uses of the medical device of the invention are within the scope of the invention as defined by the appended claims. | This invention is directed to a medical device and a method of treating mammals, especially humans, to alleviate the symptoms, including pain, of several conditions and symptoms, including hemorrhoids, tissue inflammation and/or yeast infections, and open, draining wounds or incisions. | 15,025 |
This application is a continuation of application Ser. No. 07/939,819, filed on Sep. 3, 1992, now abandoned, entitled "METHOD AND SYSTEM FOR DISPLAYING ERROR MESSAGES", in the name of Steven H. Mueller.
TECHNICAL FIELD
The present invention relates to methods and systems in the field of interactive computer program development and more particularly to gathering, displaying and processing error data from a plurality of language processors.
BACKGROUND OF THE INVENTION
Computer programmers conventionally work by entering and modifying source code in files in the computer through the use of an editor. The plurality of files of source code are processed to create an executable program by having the computer translate the source code into an executable form by running a series of programs which might typically include combinations of a macro processor, various preprocessors, a compiler and linker. Each of these processors may generate error messages or error data which aid the programer in identifying the nature of the errors and the lines of code causing the errors so that the errors can be corrected. It is possible to link an editor, compiler, linker and a debugger into an integrated development system to allow the source code to be modified and processed without having to leave the development environment.
Compilers typically provide the programer with a "compiler listing" which lists the source code along with the errors. On mainframe computers, the list of errors was either at the end of the source listing, or interspersed through the source listing. On personal computers (PCs), many commercially available compilers, (such as the well known Borland Turbo C), display the errors in the same window in which the source file is being edited.
J. H. Downey has described a method which imbeds error messages into a "VS/PASCAL" source program. When a "VS/PASCAL" program is compiled, a listing file is generated containing possible errors. The "VS/PASCAL Program Debug Aid" parses the listing file and creates a new source file. The contents of the new source file includes comments placed next to the applicable error. To correct compile errors, the programmer need only edit the source file. When all errors have been corrected, the system allows for the automatic deletion of the imbedded error messages. (IBM Technical Disclosure Bulletin, 05-89, P.376).
Automatically having an editor display the line containing an error in a file for a source program having an error when an error is detected during translation of the source program has been described by M. Amano (published Japanese patent app. JP 02-244224, 09-28-90).
Special problems not solved by the prior art arise when the errors may come from multiple sources such as a local parser or compiler, as well as a remote compiler which runs on a second computer such as a mainframe host computer or minicomputer connected through a communication link. Additional problems arise when the errors occur in one or more of the plurality of files comprising the source code for a program.
SUMMARY OF THE INVENTION
The invention is a method and system for displaying error messages associated with a user's source code. The error messages may be generated by parsers, compilers or any program which processes source code or text. These processors may be local, i.e., execute on the same personal computer where the user edits the source code, or they may execute on a remote computer connected by standard communication means. The error messages are stored as error message data entries in an error list in the memory of the computer. Each entry designates an error type and specifies the location of the error in the source code. When the source code consists of multiple files the identifier of the specific file in which the error was found is also designated. All or part of the Error List is displayed for the user, preferably in a window. The user may select one error message data entry in the Error List and thereby cause the portion of the source code containing the error to be displayed for editing. When the user modifies or deletes the portion of the source code corresponding to a selected error message data entry, the Error List is updated to reflect the modification or deletion. The Error List may dynamically grow and shrink as the user corrects the source code and submits all or a unit of the code for local or remote processing. As the process is repeated responsive to keyboard input by the user, new errors will be stored in the Error List, the list will be redisplayed and errors will be deleted from the list until keyboard input indicative of a command to halt is received. When there are multiple files of source code and the user selects an error in the Error List, the file in which the error occurred may be loaded automatically into the editor. If a remote computer is connected, all or part of the source code is transmitted to the remote computer for processing when the user so requests. The error data is then received back from the remote computer and placed in the Error List. The error data may be transmitted to the Error List processor as message data when the system supports program to program messages, but it may also be communicated in file form.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an embodiment of the invention.
FIG. 2 is an overview of the information flow in an embodiment of the invention.
FIG. 3 is an example of an Error List window.
FIG. 4 illustrates the data structure containing the information used in the invention for the Error List window.
DETAILED DESCRIPTION OF THE INVENTION
Reference is made to FIG. 1. The detailed embodiment of the invention is implemented in a conventional personal computer or workstation having a CPU System which includes a microprocessor, memory and one or more communication links to any combination of mainframes, minicomputers and personal computers. The invention is intended to function interactively; therefore, means for presenting data to a user and for receiving input from a user are required. The standard display, keyboard, mouse and hard disk(s) are preferably present. The control of the display contents and the traditional editing functions are controlled by a source file editor (Editor) which has been modified to interact with an Error List Processor. The inputs to the Error List Processor are Error List Messages. An Events File Processor converts data in Events Files into a message stream for the Error List Processor. The Editor, the Error List Processor and the Events File Processor reside on the personal computer or workstation.
FIG. 2 will be used to illustrate the flow of information. Multiple language processors such as compilers can be executed by the Source File Editor, hereinafter called the Editor. These language processors may be local, i.e., execute on the personal computer with the Editor, or they may be remote, i.e., execute on a mainframe, minicomputer or another personal computer. The language processors create an Events File which contains the information identifying the file in which the error occurs, the error types and the locations of the error in the file when possible. If the Events File is remote, it is transmitted on the communication link back to the user's computer. If the Events File is local, it can be stored on disk or in the system's RAM. The Events File is processed by the Events File Processor which generates a set of program-to-program messages which are sent to the Error List Processor which builds the Error List. An alternative mechanism is provided for local language processors to send messages directly to the Error List Processor, thereby by-passing the Events File. In the detailed embodiment a local Parser is used by the Editor to parse source lines entered by the user as they are entered or as a batch process. In the detailed embodiment the Parser communicates with the Editor which interfaces with the Error List Processor. Alternatively the Parser could be designed to send messages to the Error List Processor. Both of these paths are shown in FIG. 2.
When an error is detected, either through a local process such as a syntax checker (parser) or a remote process (like a host compiler), this information is sent to the Error List. For each file containing an error, that file's name will be displayed in the Error List Window, followed by an indented list of all errors that were detected in that file (see FIG. 3). In the method of the invention a user (computer programmer) may select an error in the Error List and the file containing that error will be displayed on the workstation with the text that caused the error highlighted in the file. In the preferred embodiment the selection is made by placing a mouse cursor on the error field and pressing a button on the mouse (`clicking`). If the user modifies a line containing the text of the error, the Error List will be updated by either removing the error from the Error List or by checkmarking the error in the Error List (dependent on whether the error was detected by a local or host process). If the user modifies the source code file and creates a new error, if the error is detectable by a local process, it will be added to the Error List and highlighted immediately in the source code.
The method of the invention has the following features:
The user can see all errors in one location (the Error List), while still being able to easily locate the file and text containing the error.
The Error List has an Application Programming Interface (API) that allows information in the window to be modified. This allows programs like tokenizers and syntax checkers to add or delete errors from the Error List without having to generate an external file.
The Error List is language independent, so errors from multiple languages may be displayed in the window.
This mechanism is not restricted to compilers and programming languages. For example, it would be straightforward to get a batch text printing control product like IBM's BookMaster program to generate the information required to have its error displayed in the IDE Error List.
The invention's method has the following advantages:
The source code is not modified and all errors are listed. Other systems either embed the error messages in the source code, which makes it difficult to see where all the errors are located (like Borland's Turbo C), or stop compiling when the first error is detected to allow it to be fixed (like Borland's Turbo Pascal). Some systems produce a summary of all errors in a file, but the user has to look in multiple places to find all the errors for the project. After doing a MAKE, for example, you would have to look in multiple listing files or multiple windows.
The Error List API allows updating the Error List quickly when the source file is changed.
The system is not tied to the compiler or language processor being used because it has a general interface.
Displaying Errors
Two types of errors can be displayed in the detailed embodiment of the invention--parsing errors detected by the live parser (which is local), and errors detected by the compiler (which may be remote) after a compilation is done. Generally, when an error is detected, the token causing the error will be highlighted in all views of the file, and the actual error message will be shown in a window called the Error List. An exception is those errors not generally associated with a location in a file, such as out-of-storage conditions or invalid compile-time options. See "User Interactions" for details on how tokens are highlighted and error messages are displayed.
Invocation
To get error information from the live parser, the parser must be active. Select Language editing options . . . from the Options pull-down and activate the live parser using the options in the Parsing events group box, or use one of the syntax checking actions in the Go pull-down. To get compile-time errors, the file must be compiled with the compiler's compile-time option that causes an Events File to be created.
User Interactions
Several facilities exist to indicate where errors occurred in the file and to locate them. Errors in the file are displayed in a different font and color than normal text, and a special window will display the files that contain errors along with the errors for each file. Also, a method exists to search for errors in a file.
Highlighting Errors in the Source
Each token or line associated with an error message in the file may be shown in a specific font and/or in a specific color, e.g., red for errors, yellow for warnings, and green for informational messages. Both parser and compiler errors may use these fonts and colors by default. However, the user should be able to change the fonts and colors for parser and compiler errors independently of each other if he wants to know if a specific error came from the parser or a compiler. If more than one class of message occurs for a token or line, the color used to display it will be that of the most severe message. For example, if a token caused both a warning and an error, it would be displayed in red, not yellow. If the messages have the same severity, the font and color of the compiler messages will be chosen over those of the parser messages.
Whenever the user changes a line containing errors, if a parse is done on the line, any previous error highlighting on that line (and possibly others) will be lost. Any corresponding parser messages will also be removed from the Error List window, but any compiler messages in the Error List window corresponding to that line or token will have a check mark placed next to them (instead of being removed from the window). This is done because changing and re-parsing a line does not guarantee that compiler errors are fixed, and the user may need to find text containing compiler error messages even though the token or line causing the error will not be highlighted as an error. Keeping these messages in the Error List also allows the user to see which errors have possibly been fixed by changes made to the text. For example, one change could fix several errors or the user could have made multiple changes to the line. Performing another compile on the file will remove compiler messages from the Error List (assuming the errors that caused the messages were fixed). If parsing is not enabled, parser messages corresponding to a changed line will have a check mark placed next to them, too.
If the entire text range corresponding to a compiler message is deleted, the message in the Error List window will be grayed out and a check mark will be placed next to it. This will indicate that the error may no longer exist in the file. Because the message is no longer associated with text in the file, however, "Find error" and "Next error" will not work for the message. If the entire text range corresponding to a parser message is deleted, the message in the Error List window will be deleted.
If new parser errors are discovered during a parse, they will be highlighted and added to the Error List.
Errors Not Contained in a Source File
The previous section dealt with errors that were located in a source file, but not all errors are the result of problems in source files. Invalid compiler options, compilers running out of memory or disk space, and so on, are examples of these types of errors.
Errors of this type will be divided into two classes: fatal and non-fatal. Fatal errors, such as a compiler running out of memory, will be displayed in gray at the top of the appropriate file grouping with an octagonal icon (suggesting a stop sign) next to them. Non-fatal errors, such as invalid compiler options being specified, will be displayed in gray at the bottom of the appropriate file grouping with a downward-pointing triangle icon (suggesting a yield sign) next to them. The messages are displayed in gray to indicate that they do not correspond to any text in a source file.
The Error List Window
All error message information is shown in a read-only window (called the Error List). An example is shown in FIG. 3. It is a standard window which displays a list of files (Files #1, #2 and #3) containing errors and the error messages in those files. It shows the user all error messages for each file and provides the user with an easy way of displaying each file in the editor.
Methods of displaying the Error List and the various pull-downs in the Error List are described below.
Displaying the Error List: The Error List window will pop up if any errors were detected after a parse or during a compilation. This window should not have keyboard focus, however, to allow the user to continue to typing in the window he is currently using. If no errors occurred during any parsing or compiling, or all messages have been deleted by fixing them, then there are no error messages in the Error List, and the "Display error list" action in the Go pull-down is grayed out. If errors occur during compilation of a file, but the user exited the integrated development environment (IDE) during the compile (for example, during a batch compile), the next time the file is opened, errors will be highlighted in the source and the Error List window will appear.
If errors were detected in the file, but the version of the file compiled does not match the version of the file available to the IDE a message will be displayed in a message box to indicate that errors might not be displayed properly. The user can choose whether or not to display the errors in this case.
The Error List window can also be displayed by selecting the Display error list action from the Go pull-down. The Error List will be placed on top of all other windows, and a line will be selected in the window according to the following rules:
1. If "Display error list" was issued from a window containing no errors, the top line in the Error List window will be selected.
2. If "Display error list" was issued from a window containing no findable errors, from a window whose file is contracted or from a window whose file has all findable errors hidden, the file name line will be selected.
3. If the cursor is at the start of text corresponding to an error message, and the last "Next error" issued placed the cursor at this point, the message selected will be the one corresponding to the text selected by the "Next error".
4. If the cursor is at the start of text corresponding to an error message, and the last "Next error" issued did not place the cursor at this point, or if the cursor is not at the start of text corresponding to an error, the line selected will be that which would have been selected if a "Next error" was issued immediately preceding the "Display error list".
Edit Pull-down: The Edit pull-down menu allows the user to place information in the Error List in the clipboard and to locate the text that caused a given error. The "Copy" and "Find error" actions are selectable in the Edit pull-down. "Copy" is the standard clipboard action. "Find error" will find and select the line or token corresponding to the message selected in the Error List window. If the file containing the corresponding error is not in an edit window, it will be loaded into one. Double-clicking on the selected message also finds the error. If the message is not associated with any text in the file (in other words, grayed out), "Find error" will be grayed out, and double-clicking on the message will have no effect.
If multiple views of a given file are open, the view that last had focus will be the one used to locate the error. If the text corresponding to the error being searched for is not contained in the view, the cursor will be placed before the hidden section containing the text corresponding to the message and a system message will be issued. The user can either select a view where the text is visible or change the view so that the error is visible, and issue the "Find error" again. Pressing the OK button in response to the system message will cause the latter action to be done for the user.
View Pull-down: The View pull-down menu allows the user to view all error information or only a subset of it. The following described actions are available in the View pull-down.
Selecting "Contract file" will "contract" the selected file name and the error messages beneath it so that only the file name is displayed. If a "-" icon is shown next to the file name, the file can be contracted. Contracting can be done either by selecting the "Contract file" action, clicking on the "-" icon, or typing the "-" key (the accelerator for "Contract file").
Selecting "Expand file" will "expand" the selected file name so that the file name is displayed with associated error messages displayed beneath the file name. If a "+" icon is shown next to the file name, the file can be expanded. Expanding can be done either by selecting the "Expand file" action, clicking on the "+" icon, or typing the "+" key (the accelerator for Expand file).
"Contract all files" contracts all the files in the Error List window. "Expand all files" expands all the files in the Error List window. By default, all files are expanded when the Error List is first displayed. When an error message is added to the Error List window for a contracted file, the file is automatically expanded so that the new message is visible.
"Hide error" hides the selected error message. If a file name is selected, this action is grayed out. This action allows the user to temporarily remove error messages from the Error List that he believes he has fixed or that he believes have the same cause as another message in the Error List.
"Restore errors" restores all hidden error messages. This is especially useful if the user has accidentally hidden an error message. "Hide error" and "Restore errors" are independent of file contraction and expansion. If a message is hidden, the file containing the message is contracted, and when "Restore errors" is selected, the message will not be visible until the file is expanded again.
"Show error numbers" toggles the display of the assigned message numbers and severity codes to the left of the corresponding error messages. Message numbers are generally only useful for looking items up in a book or reporting problems to service, and so are not shown by default. A check is displayed next to this action when selected.
Searching for Errors
In addition to the Error List window, which allows a user to find a specific error in the file, a method is provided to find the next error after a given point in the file. In the search menu, the "Next error" action will select the next token or line containing an error in the file starting from the current cursor position. If no errors exist in the current file, "Next error" is grayed out. If multiple error messages exist for a token or line, the cursor will not move, but text corresponding to a different message (which could be the same text previously found) will be selected.
If the text corresponding to the next error is not contained in the current view, the cursor will be placed before the hidden section containing the text corresponding to the next error and a system message will be issued. The user can change the view so that the error is visible, and issue the "Next error" again. Pressing the OK button in response to the system message will cause this to be done for the user. If the bottom of the file is reached, the search will wrap and a system message will be displayed to indicate this wrapping. "Next error" will only find errors that are associated with text in the file. Thus, tokens or lines containing compiler errors which are not highlighted any more due to re-parsing will still be found, but errors not associated with a particular line or token in the file (for example, out-of-storage or invalid compiler option errors) will not be found.
This section describes the design of all interactions with the Error List window and error marking in the Edit Window. The main components of error feedback include:
Building the Error List from Messages and Events Files
Modifying data in the Error List
Handling user interactions with the Error List
Indicating and locating errors in the source file
Displaying the Error List
Locating the next error in a file
Displaying message help
The Error List is a data structure which is usually stored in RAM. There are two main ways to add or delete errors to the Error List--the Events File and a message interface to the Error List. The Events File is for use by compilers that cannot send messages directly to the Error List or that need special processing to locate errors in the original source file. The messages are for syntax checkers and compilers that can send messages to the Error List and know the exact locations of errors in the original source file. The system support for sending messages is outside of the invention and must be supplied by an operating system such as IBM's OS/2 or AIX. When an Events File is processed, messages contained in the Events File will be added to the Error List using the message interface. Therefore, a processor or program should use the message interface if at all possible, as it will avoid the overhead of processing an Events File.
The Error List window will be created at initialization, and the window handle will be stored in the Global Control Block (GCB), the main control block used by the IDE editor. A pointer in a structure pointed to by the Error List's window words will point to the start of the Error List data structure. If the Error List is empty, the "Display error list" action will be grayed-out, and the Error List window will not be in the window list. If the Error List is ever displayed, the Error List window will be added to the Window List. When the Error List is closed, it will be removed from the Window List.
The basic structure of the information needed by the IDE for displaying the Error List window is illustrated in the data structure shown in FIG. 4. File 1 has a pointer to File 2 and File 2 has a pointer back to File 1 and so forth. File information is kept in a doubly-linked list. For each file, a pointer points to the first error in the file (used when writing out the Error List window). File information is kept in a File Information Record (FIR). Each error in the file is kept in a doubly-linked list with a pointer back to the corresponding file. This pointer is used when "Find error" is selected to determine which file the message is located in. Error information is kept in an Error Information Record (EIR).
The information in this data structure is used to fill the Error List window. The Error List window itself is implemented as a list box. Each line in the list box corresponds to a filename or a message. Associated with each line is an item handle, which for a file is a pointer to the corresponding FIR, and for a message is a pointer to the corresponding EIR. This allows easy checking whether the selected line is a file or error message, and allows us to get the details of the item.
All requests to update the Error List will be initiated by sending messages to the Error List's window procedure. There are five actions that can cause the Error List to change:
Invoking the live parser or syntax checking all or part of the file
Compiling a file (using either a compiler or program verifier)
Issuing a Get events file . . . to retrieve an Events File (usually after a batch compile) Deleting a text range that contains an error
Changing a text range that contains an error
Actions which add a message to the Error List cause it to pop up. Other actions keep the Error List as it was, although changes will be visible if the Error List is visible and not minimized.
In the following sections, message names are arbitrary:
Updating the Error List after parsing: To make an update to the Error List, an EVF -- BEGINERRLISTUPDATE message is first sent to the Error List. An EVF -- DELMSGCLASSFROMERRLIST message is then sent with a File Location Information Record (FLIR) containing a pointer to the Edit Control Block (ECB) of the file and specifying the insertion point (IPT) range being parsed to delete messages corresponding to text in that range, followed by one EVF -- ADDMSGTOERRLIST for each new error detected. Finally, an EVF -- ENDERRLISTUPDATE is sent to complete the update process.
Updating the Error List after compiling: After compiling a file interactively or verifying a program, a call to the routine which processes Events Files should be made. This routine will process the Events File (if any), and then send messages to update and display the Error List if the Events File contains any error records. The messages sent are similar to those specified in "Updating the Error List after parsing" except that the EVF -- DELMSGCLASSFROMERRLIST should specify that Compiler errors are being deleted, and should place the Server name and File name instead of the pointer to the ECB in the FLIR. Also, the IPT range specified should be (0,0).
Updating the Error List after a Get events file action: The processing is similar to the actions that occur after compiling a program interactively.
Updating the Error List after deleting text corresponding to an error: When a text range containing an error is deleted, the internal editor label marking the error will be destroyed and a routine will be called to gray out and check a compiler message or delete a parsing error in the Error List.
Updating the Error List after changing text corresponding to an error: When a text range containing an error is changed, a routine will be called to place a check mark next to the message in the Error List.
Indicating and Locating Errors in the Source File
Each error in the source file will be marked using a label. The label will have a pointer to the corresponding EIR. This allows highlighting the appropriate message in the Error List when the user selects "Display error list".
Displaying the Error List
When the user selects the "Display error list" action, a routine bound to that action will be called which will determine which line in the Error List to select, then send a message to the Error List to display itself, highlighting that message.
Locating the Next Error in a File
When the user selects the "Next error" action, a routine bound to that action will be called which will locate the next error shown in the Error List, retrieve the IPT range of the error from the label corresponding to that message, and send a message to the Edit Window to select the text in that IPT range.
Displaying Message Help
When the user hits a selected function key, e.g. F1, while a message is selected, help for that message is displayed. To do this, the message ID of the selected message is used to perform a lookup in a table that associates message IDs with help IDs. This table is supplied in the Language Profile for a given language.
The lookup will first be tried using the profile associated with the Edit Window if the file containing the message is in an Edit Window. If the IPF ID is not found, a lookup will be tried in all profiles pointed to by the GCB. This second lookup is required in case the file is open, but not using the profile for the language the message is associated with (for example, the file is C code, but was opened with a default profile). This requires each processor to have unique message IDs. For example, RPG 400 could issue messages from the syntax checker, the Program Verifier, or the compiler. Each of these must produce different message IDs, even if the message says basically the same thing. After the lookup, if the IPF ID is found, the message is displayed.
External File Information Record (XFIR)
The XFIR is used when sending messages to the Error List. It points to either the server and file names of the file (for example, when processing an Events File), or to the ECB of the file (for example, when tokenizing a file).
______________________________________XFIR typedef struct .sub.-- xfir { PSZ pszServer; //Pointer to name of server PSZ pszFileName; //Pointer to name of file PECB pECB; //Pointer to ECB of file} XFIR; typedef struct .sub.-- xfir *PXFIR; //Pointer to XFIR______________________________________
External Error Information Record (XEIR)
The XEIR is used when sending messages to the Error List. It provides information on the type and location of the message. If the IPT range of the error is known, it should be saved in iptRange and fRangeValid should be set to TRUE. Otherwise, ulStartLine, ulStartCol, ulEndLine, and ulEndCol should be set, and fRangeValid should be set to FALSE.
______________________________________XEIR typedef enum { All, Parser, Scanner, Compiler } ERRCLASS; typedef enum { Top, Middle, Bottom } ANNOTCLASS; typedef struct .sub.-- xeir { ERRCLASS ErrClass; //Type of Error ANNOTCLASS AnnotClass; //Location of error in list ULONG ulStartLine; //Starting line of error ULONG ulStartCol; //Starting column of error ULONG ulEndLine; //Ending line of error ULONG ulEndCol; //Ending column of error EPIPTRANGE iptRange; //IPT range of error BOOL fRangeValid; //TRUE if valid iptRange PSZ pszMsgID; //Message ID CHAR Severity; //Severity of message PSZ pszMessage; //Text of message PSZ pszTag; //Used to differentiate //messages in same file} XEIR; typedef struct .sub.-- xeir *PXEIR; //Pointer to XEIR______________________________________
File Location Information Record (FLIR)
The FLIR is used when deleting a group of messages from the Error List. It points to the ECB of the file being edited; processors which create an Events File should set this to NULL. It also specifies an IPT range to process errors in; set both IPTs to zero if the whole file should be processed. Processors which create an Events File should set both IPTs to zero.
______________________________________FLIR typedef struct .sub.-- flir { PECB pECB; //Pointer to file's ECB IPTRANGE iptRange; //Range to process PSZ pszTag; //Used to differentiate //messages in same file} FLIR; typedef struct .sub.-- flir *PFLIR; //Pointer to FLIR______________________________________
The Events File
The Events File is produced sequentially. Each processor is simply appending new records to it. When an important event occurs, a record is written to the Events File. Thus every compilation process will produce an Events File.
On each platform, the external characteristics of the Events File (for example, record format, logical record length, access method, etc. on MVS) produced by the various processors should be the same. This is not required across platforms. Each record will be typed according to its contents. This allows future extensions by creating new records allowable in the Events File.
The definitions below may not work for mechanisms like the COBOL BASIS/INSERT/DELETE statements, which are, in essence, a language-specific update facility.
The following record types are defined:
Timestamp record--Indicates when the Events File creation started.
Processor record--Indicates a new processor has been invoked.
File ID record--Indicates an input file has been opened.
File end record--Indicates an input file has been closed.
Error information record--Indicates that an error has been detected in the input source code.
Program record--Indicates beginning of a second program source within the source code file being processed.
Map define record--Indicates a macro definition within the input source code.
Map start record--Indicates beginning of generated source code.
Map end record--Indicates end of generated source code.
Since different types of records will be included in this one file, the first word in each record will identify the record type. The formats of these record types are described below. In the syntax diagrams, each token should be separated by exactly one blank.
Timestamp Record
This record indicates when the Events File was created, and allows an application to determine if the Events File is current (if the timestamp is older than a file indicated in a File ID record, the Events File may be incorrect for that file). This record is always the first record in the Events File. It is not required that this record be written by a processor; it may be written by the caller of the first processor. This allows each processor to append to the Events File without having to determine if the file exists.
The timestamp record is described as follows:
______________________________________TIMESTAMP -- version -- timestamp Where Represents version The revision of this record, used for upward compatibility. timestamp The date and time the Events File was created in yyyymmddhhmmss format.______________________________________
Processor Record
This record indicates that a new processor has been invoked. One will always follow the timestamp record in the Events File (although there may be more than one).
The processor record is described as follows:
______________________________________PROCESSOR -- version -- output-id -- line-class Where Represents version The revision of this record, used for upward compatibility. output-id The file ID of an output file produced by this processor. If the output of this processor is intended to be used as input to another processor, this file ID represents that file, and the file ID record of the file will follow this record. If this is the last processor that will be invoked for which the IDE will be expected to display messages, the file ID is 0. line-class Method used to number lines. Specify zero if a temporary file or internal file containing an expanded source representation is being used; the line number represents the line number in the expanded source. Specify one if the line number represents the physical line number in the source file indicated in source file ID field.______________________________________
File ID Record
This record contains the full name of the source file processed and associates an integer with the file name. There should be one record of this type for each source file processed by the compiler, the main source file as well as any included source units (copylib members) and macros. Because the location where a file is included is important, if a file is included several times during processing, a file id record should be written for each inclusion. A processor should not keep track of files it has already included and only write a file id record if a file record had not been written for this file.
The file ID record is described as follows:
______________________________________FILEID -- version -- source-id -- line -- length -- filename Where Represents version The revision of this record, used for upward compatibility. source-id A file identifier expressed as an integer to be used in place of the file name to correlate an error record with the source file in which it occurred, without having to use the character based file name. Use zero if the input file is not known, such as input coming from a user exit. line Source file line number where a new file is referenced, or zero if the file was not referenced from a file. length Length of the file name filename The name should be the fully-qualified physical file name. If none exists (for example, getting text from the user) or the name can't be determined, place a null string here.______________________________________
File End Record
This record indicates that an included file is ending. It provides a method for viewing a file which includes a file containing an error. This is useful when the included file does not contain enough information to determine what caused the error.
The file end record is described as follows:
______________________________________FILEEND -- version -- file-id -- expansion Where Represents version The revision of this record, used for upward compatibility. file-id The file ID of this file. expansion Number of expanded source lines in this file, including any nested includes and macro expansions.______________________________________
Error Information Record
A record of this type contains information required to highlight a token or line causing a message in the source file, as well as enough information to allow the message itself to be displayed. This information includes location information (such as what file and line the error occurred on) and information related to the error itself (such as the number, text, and severity of the message).
The error information record is described as follows:
______________________________________ERROR -- version -- file-id -- annot-class -- stmt-line -- start-err-line -- token-start -- end-err-line -- token-end -- msg-id -- sev-char -- sev-num -- length -- msg Where Represents version The revision of this record, used for upward compatibility file-id The file ID number of the source file containing this error.annot-class Indicates where in a listing of messages this message should be placed. The following positions are defined: Class Meaning 0 Top of list. Generally used for very important messages that aren't really associated with a specific line in a file (for example, compiler ran out of storage). The sorting order for multiple instances of messages of this type is not defined. Because no text generally corresponds to this error, no highlighting will be done in the edit window. 1 Middle of list. Generally used for messages which are associated with a single line or token (for example, an undeclared identifier). Multiple messages of this type are sorted by line number. 2 Bottom of list. Generally used for less important messages that aren't really associated with a specific line in a file (for example, compiler option invalid). The sorting order for multiple instances of messages of this type is not defined. Because no text generally corresponds to this error, no highlighting will be done in the edit window.stmt-line Line number (in the source file associated with the above source file ID number) of the first line of the statement containing the error. This is required in case the error does not occur on the first line of the statement. This number is interpreted using the line class field of the Processor Record. start-err-line Line number (in the source file associated with the above source file ID number) containing the start of the error. This number is interpreted using the line class field of the Processor Record. token-start Column (or character in the line) of the start of the token in error. If this information is not available, a zero here will cause the first column (or character) to be used as the start of the error. end-err-line Line number (in the source file associated with the above source file ID number) containing the end of the error. This number is interpreted using the line class field of the Processor Record. token-end Column (or character in the line) of the end of the token in error. If this information is not available, a zero here will cause the last column (or character) to be used as the end of the error. msg-id Message ID, left justified. For example, AMPX999 sev-char Severity code letter (I, W, E, S, or T). sev-num Severity level number. For some systems, this is the return code associated with the severity code letter (I=0, W=4, E=8, S=12, T=16). length The actual length of the next field (message text). msg The message text of the error message. Any replacement of fields should have already been done.______________________________________
Program Record
This record indicates a new program in the same source file is being compiled. It is used when multiple programs are contained in one file. Expanded source line is assumed to start over at 1 when this record is written. It is not needed to indicate the first program in the file.
The program record is described as follows:
______________________________________PROGRAM -- version -- line Where Represents version The revision of this record, used for upward compatibility. line The position in the file that this program starts.______________________________________
Map Define Program Record
This record indicates that a macro is being defined. It is used to allow errors to be reflected back to a macro definition instead of the place the macro is used.
The map define record is described as follows:
______________________________________MAPDEFINE -- version -- macro-id -- line -- length -- macro-name Where Represents version The revision of this record, used for upward compatibility. macro-id Integer representing this macro definition. It should be incremented sequentially within a specific file. line Physical line in the current file where the macro definition starts. length Length of the macro name. macro-name The name of the macro being defined.______________________________________
Map Start Record
This record indicates that source expansion is starting. It is used where any textual replacement is being done (for example, a macro).
The map start record is described as follows:
______________________________________MAPSTART -- version -- macro-id -- line Where Represents version The revision of this record, used for upward compatibility. macro-id Identifier of a macro specified in a map definition record. line Physical line in the current file where expansion starts.______________________________________
Map End Record
This record indicates that source expansion is complete. It is used at the end of a textual replacement to show how many lines were created.
The map start record is described as follows:
______________________________________MAPEND -- version -- macro-id -- line -- expansion Where Represents version The revision of this record, used for upward compatibility. macro-id Identifier of a macro specified in a map definition record. line Physical line in the current file where expansion ends. expansion Number of lines resulting from this macro expansion, including any nested expansions.______________________________________
Using the foregoing specifications the invention may be implemented using standard programming and/or engineering techniques. The resulting program(s) may be stored on disk, diskettes, memory cards, ROM or any other memory device. For execution, the program may be copied into the RAM of the computer. User input may be received from keyboard, mouse, pen, voice, touch screen or any other means by which a human can input data to a computer. One skilled in the art of computer science will easily be able to combine the software created as described with appropriate general purpose or special purpose computer hardware to create a computer system embodying the invention. While the preferred embodiment of the present invention has been illustrated in detail, it should be apparent that modifications and adaptations to that embodiment may occur to one skilled in the art without departing from the scope of the present invention as set forth in the following claims. | A method and system for interactively displaying error messages, such as parser or compiler messages, associated with a user's source code is described. The processors generating the messages may execute on a remote computer. Whether locally or remotely generated, the error messages are stored as error message data entries in an error list. Each entry designates an error type and specifies the location of the error in the source code. When the source code consists of multiple files the identifier of the specific file in which the error was found is also designated. When the error list is displayed for the user, the user may select one error message data entry in the error list and thereby cause the portion of the source code containing the error to be displayed for editing. When the user modifies or deletes the portion of the source code corresponding to a selected error message data entry, the Error List is updated to reflect the modification or deletion. The file in which the error occurred may be loaded automatically into the editor. If a remote computer is connected, the source code is transmitted to the remote computer for processing and the error data is then transmitted back. | 49,111 |
REFERENCE TO RELATED APPLICATION
This application is a divisional of application Ser. No. 08/477,377, filed Dec. 7, 1995, now abandoned, which is a continuation-in-part of application Ser. No. 08/354,944, filed Dec. 13, 1994, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to compositions and methods for treating mammalian disease conditions that are debilitating, fatal, hereditary, degenerative and/or undesirable. More specifically, the present invention relates to the transplantation of normal, or genetically transduced, or cytocline-converted myogenic cells into malfunctioning, and/or degenerative tissues or organs.
2. Description of the Prior Art
MYOBLAST PROPERTIES
In mammals, myoblasts are the only cell type which divide extensively, migrate, fuse naturally to form syncytia, lose their major histocompatibility Class I (MHC 1) antigens soon after fusion, and develop to occupy 50% of the body weight in humans. These combined properties render myoblasts ideal for gene transfer and somatic cell therapy (SCT). Myoblast therapy is a combined SCT and gene therapy.
MYOBLAST THERAPY
Although the role of myoblasts/satellite cells in myogenesis and muscle regeneration dated back to the early 1960s (Konigsberg, I. R., Science, 140:1273 (1963). Mauro, A. J., Biophys. Biochem. Cytol., 9:493-495 (1961)), their use in animal therapy was not reported until 1978 (Law, P. K., Exp. Neurol., 60:231-243 1978)).
The first myoblast transfer therapy (MTT) on a Duchenne muscular dystrophy (DMD) boy on Feb. 15, 1990 marked the first clinical trial on human gene transfer. Its success was reported (Law, P. K. et al., Lancet, 336:114-115 (1990); Kolata, G. The New York Times, Sunday, (Jun. 3, 1990)). Unlike bone marrow transplant which strictly replaces genetically abnormal cells with normal ones, MTT actually inserts, through natural cell fusion, all the normal genes within the nuclei of the donor myoblasts into the dystrophic myofibers to repair them. In addition, donor myoblasts also fuse among themselves, forming genetically normal myofibers to replenish degenerated ones. Thus, full complements of normal genes are integrated, through a natural developmental process of regeneration, into the abnormal cells and into the abnormal organ.
The U.S. Patent Office issued to this inventor a patent (U.S. Pat. No. 5,130,141) entitled “Composition for and methods of treating muscle degeneration and weakness” on Jul. 14, 1992.
In October, 1993, the Food and Drug Administration (FDA) officially began regulating somatic cell therapy (SCT) with a definition of “autologous, allogenic, or xenogeneic cells that have been propagated, expanded, selected, pharmacologically treated, or otherwise altered in biological characteristics ex vivo to be administered to humans and applicable to the prevention, treatment, cure, diagnosis, or mitigation of disease or injuries.” (Federal Register, 58:53248-53251 (1993)).
MTT falls under the umbrella of SCT and myoblasts and its physical, genetic or chemical derivatives become potential biologics in the treatment of mammalian diseases.
As of May 25, 1994 the FDA has granted permission for Cell Therapy Research Foundation (CTRF) to charge $63,806 per subject. CTRF is an non-profit 501 (c) (3) research foundation founded by the inventor in 1991. Authorization by the FDA for CTRF to recover costs from subjects of these clinical trials is extremely important to establish the scientific credibility MTT and CTRF deserve, quoting the Jun. 17, 1994 edition of the Memphis Health Care News, “Permission to bill for an Investigational product is granted rarely,” says FDA spokesman Monica Revelle, “Applicants must endure numerous procedures, and must have what looks like a viable product at the end of the rainbow. It's used mainly to support testing of promising technology by small companies.” This statement was made in regard to research at CTRF.
At this time CTRF holds the first and only FDA-approved human clinical trial under an Investigational New Drug (IND) application on MTT. It is extremely important to realize that CTRF has been working closely with the FDA to establish criteria and policies in the approval process of this IND for genetic cell therapy. The use of viral vector mediated gene therapy on human neuromuscular diseases has not met FDA approval.
CELL THERAPY WITH MYOBLASTS
The cell is the basic unit of all lives. It is that infinitely small entity which life is made of. With the immense wisdom and knowledge of the human race, we have not been able to produce a living cell from nonliving ingredients such as DNA, ions, and biochemicals.
Cell Culture is the only method known to man for the replication of cells in vitro. With proper techniques and precautions, normal or transformed cells can be cultured in sufficient quantity to repair, and to replenish degenerates and wounds.
Cell transplantation bridges the gap between in vitro and in vivo systems, and allows propagation of “new life” in degenerative tissues or organs of the living yet genetically defective or injured body.
Cell fusion transfers all the normal genes within the nucleus like delivering a repair kit to the abnormal cell. It is important to recognize that, for proper installation and future operation, the software packaged in the chromosomes needs other cell organelles as hardware to operate.
Correction of a gene defect occurs spontaneously at the cellular level after cell fusion. The natural integration, regulation and expression of the full complement of over 80,000 normal genes impart the normal phenotypes onto the heterokaryon. Protein(s) or factor(s) that were not produced by the host genome because of the genetic defect are now produced by the donor genome that is normal. Various cofactors derived from expression of the other genes corroborate to restore the normal phenotype.
GENE THERAPY WITH MYOBLASTS
The use of myoblasts as gene transfer vehicles has been researched by this inventor extensively. In mammals, myoblasts are the only cell type which divide extensively, migrate, fuse naturally to form syncytia, lose MHC-1 antigens soon after fusion, and develop to occupy 50% of the body weight in humans. These combined properties render myoblasts ideal for gene transfer.
Natural transduction of normal nuclei ensures orderly replacement of dystrophin and related proteins at the cellular level in DMD. This ideal gene transfer procedure is unique to muscle. After all, only myoblasts can fuse and only muscle fibers are multinucleated in the human body. By harnessing these intrinsic properties, MTT transfers all normal genes to effect genetic repair. Since donor myoblasts also fuse among themselves to form normal fibers in MTT, the muscles benefit from the addition of genetically normal cells as well.
MYOBLAST THERAPY IS THE MEDICINE OF THE FUTURE
Health is the well-being of all body cells. In hereditary or degenerative diseases, sick cells need repairing and dead cells need replacing for health maintenance.
Cell culture is the only way to generate new, live cells that are capable of surviving, developing and functioning in the body after transplantation, replacing degenerated cells that are lost.
Myoblasts are the only cells in the body capable of natural cell fusion. The latter allows the transfer of all of the normal genes into genetically defective cells to effect phenotypic repair through complementation. MTT on DMD is the first human gene therapy demonstrated to be safe and effective. The use of MTT to transfer any other genes and their promoters/enhancers to treat other forms of diseases is underway. Myoblasts are efficient, safe and universal gene transfer vehicles, being endogenous to the body. Since a foreign gene always exerts its effect on a cell, cell therapy will always be the common pathway to health. After all, cels are what life is made of.
DMD: A SAMPLE DISEASE
DMD is a hereditary, degenerative, debilitating, fatal, and undesirable mammalian disease. It is characterized by progressive muscle degeneration and loss of strength. These symptoms begin at 3 years of age or younger and continue throughout the course of the disease. Debilitating and fatal, DMD affects 1 in 3300 live male births, and is the second most common lethal hereditary disease in humans. DMD individuals are typically wheelchair-bound by age 12, and 75% die before age 20. Pneumonia usually is the immediate cause of death, with underlying respiratory muscle degeneration and failure of DMD individuals to inhale sufficient oxygen and to expel lung infections. Cardiomyopathic symptoms develop by mid-adolescence in about 10% of the DMD population. By age 18, all DMD individuals develop cardiomyopathy, but cardiac failure is seldom the primary cause of death.
Before 1950, over 80 chemicals were evaluated and 33 were reported as potentially beneficial (Milhorat, A. T., Medical Annals of the District of Columbia , 23:15 (1954)). None are currently being used (Wood, D. S., In: Kakulas, B. A. and Mastaglia, F. L., eds.: Pathogenesis and therapy of Duchenne and Becker muscular dystrophy. New York: Raven Press; 85-99 (1990)). Unconfirmed therapeutic benefits in DMD have been reported with vitamins, amino acids (Van Meter, J. R., Calif. Med ., 79:297 (1953)), ATP (Nakahara, M., Arzneim. Forsch ., 15:591(1965)), coenzyme Q (Folkers, K. et al., Excerpta Med. Int. Congr. Ser ., 334:158 (1974)), adenylosuccinic acid (Bonsett, C. A., Indiana Medicine , 79:236 (1986)) and growth hormone inhibitor (Coakley, J. H. et al., Lancet, 1(8578): 184 (1988)). Several hundred drugs have been screened (Wood, supra), with some studies showing consistent benefits from steroids (Entrikin, R. K. et al., Muscle Nerve , 7:130-136 (1984)).
The beneficial effects of prednisone on DMD was first reported almost 20 years ago (Drachman, D. B. et al., Lancet , 2:1409-1412 (1974)). The researchers reported that prednisone could delay the degenerative process and in some cases even transiently strengthen DMD muscles. The evidence substantiating prednisone is not without debate (see Munsat, T. L. and Walton, J. N., Lancet , 1:276-277 (1985); Rowland, L. P., Lancet , 1:277 (1975); and Siegel, I. M. et al., I. M. J., 145:32-33 (1974)). Although the mechanism(s) through which prednisone mediates its effect is undefined. Prednisone causes numerous side-effects, and prolonged use induces adverse reactions that by far out-weigh the questionable benefits reported.
Gene manipulation and transfer are other approaches that are being used to treat hereditary and degenerative diseases. However, it will be quite some time before this type of treatment finds clinical application for DMD (Law, P. K., In: Kakulas, B. A. et al., eds.: Pathogenesis and therapy of Duchenne and Becker muscular dystrophy. New York: Raven Press, 190 (1990); and Watson, J. D. et al., Recombinant DNA. New York: W. H. Freeman and Co.; 576 (1992)). Success claimed over intramuscular DNA injections (Acsadi, G. et al., Nature , 352: 815-818 (1991); and Wolff, J. A. et al., Science , 247:1465-1468 (1990)) and arterial delivery of immature muscle cells, also known as myoblasts, to skeletal muscle (Neumeyer, A. M. et al., Neurology, 42:2258-2262 (1992)) is very limited and questionable. Attempt of using transfected autologous myoblasts has resulted in low efficiency and mutation in transfection (Barr, E. and Leiden, J. M., Science , 254: 1507-1509 (1991); Dhawan, J. et al., Science , 254: 1509-1512 (1991); and Smith, B. F. et al., Mol. Cell. Biol ., 10: 3268-3271 (1990)). Such approach will yield insufficient myogenic cells to provide for a whole body myoblast transfer therapy (MTT) to treat DMD patients (Law, supra). Clinical trials are currently underway for cystic fibrosis (CF) based on transgenic mice studies (Hyde, S. C. et al., Nature , 362: 250-255-(1993)). Clinical trials with gene therapy have also been attempted on severe combined immunodeficiency. (SCID). Unlike CF and SCID whose genetic defects are mediated through enzymic deficiencies, the genetic defect of DMD manifested as the absence of a structural protein called dystrophin in the cell membrane rather than a regulatory protein.
Although dystrophin serves as a good genetic/biochemical marker (Hoffman, E. P. et al., Cell , 51: 919-928 (1987)) in the evaluation of muscle improvements, dystrophin replacement constitutes only part of the treatment process. This has already been demonstrated, among others, by the present inventor using MTT in mdx mice (Chen, M. et al., Cell Transplantation , 1:17-22 (1992); Karpati, G. et al., Am. J. Pathol ., 135: 27-32 (1989); and Patridge, T. A., et al., Nature , 337:176-179 (1989)) and in humans (Gussoni, E., et al., Nature , 356: 435-438 (1992); Huard, J. et al., Clin. Sci ., 81:287-288(1991); Huard, J. et al., Muscle Nerve , 15:550-560 (1992); Law, P. K. et al., Lancet , 336:114-115 (1990); Law, P. K. et al., Acta Paediatr. Jpn ., 33:206-215 (1991); Law, P. K. et al., Adv. Clin. Neurosci ., 2:463-470 (1992); Law, P. K. et al., In: Angelini, C. et al., eds. Muscular dystrophy research. New York: Elsevier Science Publishers, 109-116 (1991); and Law, P. K. et al., Acta Cardiomiologica , 3:281-301 (1991)). Because DMD pathology is one of muscle degeneration and weakness, structural and especially functional improvements are of primary concern. These two parameters have been extensively studied using the dy 2J dy 2J dystrophic mouse as an animal model of hereditary muscle degeneration (Law, P. K., Exp. Neurol ., 60:231-243 (1978); Law, P. K., Muscle Nerve , 5:619-627 (1982); Law, P. K. et al., Transplant Proc ., 20:1114-1119 (1988); Law, P. K. et al., In: Griggs, R. C.; Karpati, G., eds. Myoblast Transfer Therapy. New: Plenum Press; 75-87 (1990); Law, P. K. et al., Muscle Nerve , 11:525-533 (1988); Law, P. K. et al., In: Kakulas, B. A.; Mastaglia, F. L., eds. Pathogenesis and therapy of Duchenne and Becker muscular dystrophy. New York: Raven. Press; 101-118 (1990); and Law, P. K. and Yap, J. L., Muscle Nerve , 2:356-363 (1979)). These studies lead to the first MTT clinical trial or single muscle treatment (SMT) (Gussoni, E. et al., Nature , 356:435-438 (1992); Huard, J. et al., Clin. Sci ., 81:287-288 (1991); Huard, J. et al., Muscle Nerve , 15:550-560 (1992); Law, P. K. et al., Lancet , 336:114-115 (1990); Law, P. K. et al., Acta Paediatr. Jpn ., 33:206-215 (1991); Law, P. K. et al., Adv. Clin. Neurosci ., 2:463-470 (1992); Law, P. K. et al., In: Angelini, C. et al., eds. Muscular dystrophy research. New York: Elsevier Science Publishers: 109-116 (1991); and Law, P. K. et al., Acta Cardiomiologica 3:281-301 (1991)).
The feasibility, safety, and efficacy of MTT were assessed by this inventor in experimental lower body treatments involving 32 DMD boys aged 6-14 years of age, half of whom were non-ambulatory (Law, P. K. et al., Cell Transplantation , 2;485-505 (1993)). Through 48 injections, 5 billion (55.6×10 6 /mL) normal myoblasts were transferred into 22 major muscles in both lower limbs in each of the subjects. Results at 9 months after MTT indicated, interalia, that (1) MTT is a safe treatment; (2) MTT improves muscle function in DMD; and (3) more than 5 billion myoblasts are necessary to strengthen both lower limbs of a DMD boy between 6 and 14 years of age.
OTHER DISEASE CONDITIONS
Potentially every genetic disease can be benefited by MTT. Through natural cell fusion, donor myoblasts insert full complement of normal genes into genetically abnormal cells to effect repair. Promoters and enhancers of the defective gene can be supplied or activated or repressed to achieve gene transcription and translation with the release of hormone(s) or enzyme(s) from transplanted myogenic cells. Likewise, structural protein(s) can be produced to prevent or to alleviate disease conditions.
Alternatively transduced myoblasts can be used. The procedure consists of a) obtaining a muscle biopsy from the patient, b) transfecting a “seed” amount of satellite cells with the normal gene, c) confirming the myogenicity of the transfected cells, d) proliferating the transfected myoblasts to an amount enough to produce beneficial effect and e) administering the myoblasts into the patient.
Retroviral vectors have been used to transfer genes into rat and dog myoblasts in primary cultures under conditions that permit the transfected myoblasts to differentiate into myotubes expressing the transferred genes (Smith, B. F. et al., Mol. Cell Biol., 10:3268-3271 (1990)). Furthermore, mice injected with murine myoblasts that are transfected with human growth hormone (hGH) show significant levels of hGH in both muscle and serum that are stable for 3 months (Dhawan, J. et al., Science, 254:1509-1512 (1991); Barr E. and J. M. Leiden, Science, 254:1507-1509 (1991)).
The transduced myoblast transfer was inspired by a similar approach on adenosine deaminase (ADA) deficiency. In the latter situation, T cells from the patient were transfected with functional ADA genes and returned to the patient after expansion in the number of the transfected cells through cell culture (Culver, K. W. et al., Transpl. Proc., 23:170-171 (1991)).
Similar approach has already been tested in animals using genetically transduced myoblasts to treat hemophilia B (Yao, S. N. et al., Gene Therapy, 1:99-107 (1994)), cardiomyopathy (Marelli, D., Cell Transplantation, 1:383-390 (1992); Koh, G. Y. et al., J. Clin. Inves., 92:1548-1554 (1993)), anemia (Hamamori, Y. et al., Human Gene Therapy, 5:1349-1356 (1994)). Undoubtedly, there will be many hereditary diseases to which myoblast therapy will apply.
Although differentiated, myoblasts are nonetheless embryonic cells that are capable of de-differentiated or even converted. Thus, myoblasts have recently been shown to be converted into osteoblasts with bone morphogenetic protein-2 (Katagiri, T. et al., J. Cell Biol., 127:1755-1766 (1994)). This study demonstrates that cytocline-converted myoblasts can be administered to patients with bone/cartilage degenerative diseases. Alternatively, it has been demonstrated that mouse dermal fibroblasts can be converted to a myogenic lineage (Gibson, A. J. et al, J. Cell Sci., 108:207-214 (1995)).
The implicated usage of myoblast transfer therapy to treat cancer and type II diabetes mellitus is described below.
WHY MYOBLAST THERAPY
In hereditary or degenerative diseases, gene defects cause cells to degenerate and die with time. An effective treatment must not only repair degenerating cells, but replenish dead cells as well. This can best be achieved by the transplantation of genetically normal cells, or somatic cell therapy. The advent of molecular genetics favors single gene manipulation which is currently being explored to treat genetic diseases. Like pharmaceuticals, single gene manipulation cannot replenish lost cells. Further, there is very limited evidence that these approaches can repair degenerating cells.
In U.S. Pat. No. 5,130,141, this inventor disclosed for the first time compositions and methods for treating muscle degeneration and weakness. A composition comprised of genetically normal myoblasts from a donor was injected into one or more of the muscles of a host having a hereditary neuromuscular disorder. Muscle structure and function were greatly improved with the injection, thereby preventing or reducing muscle weakness which is a primary cause of crippling and respiratory failure in hereditary muscular dystrophies. This transplantation of genetically normal muscle cells into the diseased muscles of patients with hereditary muscular dystrophy is known as MTT.
MTT differs significantly from the conventional single gene transfer format in several respects. In this latter gene therapy, single copies of the down-sized dystrophin gene are transduced as viral conjugates into the mature dystrophic myofibers in which many proteins, both structural and regulatory, are lost previously. Multiple gene insertion is necessary to replace these lost proteins (FIG. 1 ). More gene insertion is needed to produce the cofactors to regulate and to express these lost proteins in order to repair the degenerating cell.
SUMMARY OF THE INVENTION
The demonstration of preliminary feasibility, safety, and efficacy (Law et. al., Cell Transplantation , 2:485 (1993)) of myoblast transfer therapy MTT prompted this inventor to initiate a whole body trial (WBT) injecting 25 billion myoblasts into each of 64 Duchenne muscular dystrophy (DMD) boys and a boy with infantile facioscapulohumeral dystrophy (IFSH). The randomized double-blind clinical trial protocol, approved by the FDA (IND Phase II) and the Essex IRB involves two MTT procedures separated by 3 to 9 months. Each procedure delivers 200 injections or 12.5 billion myoblasts, to either 28 muscles in the upper body (UBT) or to 36 muscles in the lower body (LBT). Injected muscles include those in the neck, shoulder, back, chest, abdomen, arms, hips, and legs. Subjects take oral cyclosporine for 3 months after each MTT. One IFSH and 10 DMD boys have received WBT and 20 more DMD boys have received UBT or LBT in the past 17 months with no adverse reaction. These preliminary results indicate that the WBT is feasible and safe. While blinding will continue until the end of the study as to which side of the biceps brachii or quadriceps received myoblasts or placebo, five subjects have demonstrated immunocytochemical evidence of dystrophin in one of these muscle biopsies 3 to 9 months after MTT. The contralateral muscle biopsies show no dystrophin. The pulmonary function (FVC) either shows no deterioration, or has improved by 15 to 25% in over 80% of the subjects 3 to 6 month after MTT. About 50% of the subjects report behavioral improvement in running, balancing, climbing stairs and playing ball. One 14 yr-old DMD subject has stayed active without the need of a wheelchair after MTT (Law, P. K. et al., Amer Soc Neural Transpl Abst ., p. 27 (1995); Law, P. K. et al., J. Cellular Biochem.Supp , 21A:367, (1995)).
This demonstration of feasibility and safety in administering 30 billion myoblasts into a human subject provides the pivotal evidence that myoblasts can be used as a biologic to treat human diseases. The demonstration of the dosage effectiveness further confirms the idea that myoblast therapy can be used to treat a whole variety of mammalian diseases be it a hereditary, degenerative, debilitating, fatal, or undesirable disease condition.
The present invention provides compositions and methods for repairing degenerating cells and replenishing lost cells in patients with hereditary or degenerative diseases, in particular those characterized by muscle malfunction, degeneration and weakness. In practicing the present invention, any myogenic cell may be used, regardless of whether it is of skeletal, smooth, or cardiac in origin. Transferred cell types include myoblasts, myotubes and/or young muscle fibers. The myogenic cells may be primary-cultured or cloned from muscle biopsies of normal donors. They may also be cytocline converted or genetically transduced myogenic cells. Typically, the parents, siblings, or friends of the dystrophic patient are the donors. In addition, it is contemplated that the establishment of superior cell. lines of myoblasts, whether from humans or animals, will provide a ready access of healthy donor cells for patients who do not otherwise have a suitable donor (FIGS. 2 to 5 , also Law, P. K., Myoblast Transfer , Landes, Austin, (1994)). It is further contemplated that the cell transplantation procedure will augment size, shape, appearance or function, and/or alleviate the disease conditions.
The present invention provides a method for controlling, initiating, or facilitating cell fusion once the myoblasts are injected into one or more of the muscles of a patient with the degenerative disease. By artificially increasing the concentration of the large chondroitin-6-sulfate proteoglycan (LC6SP) over the patient's endogenous level, fusion of the transferred donor myoblasts among themselves or with other cell types can be enhanced and controlled. (Law, P. K., Myoblast Transfer Landes , Austin (1994)). It is yet another object of the invention to improve the fusion rate between the host and donor cells. To this end, various injection methods were tested and compared including injecting diagonally through the myofibers, perpendicular to the myofiber surface, parallel to the myofibers, and at a single site into the muscle. The goal is to achieve maximum cell fusion with the least number of injections (FIGS. 6 to 8 , also Law, P. K., Myoblast Transfer , Landes Austin, (1994)).
In a further embodiment, the technologies of in vitro fertilization and blastomere recombination can be used on known Duchenne carriers to incrgease their chances of having normal children (FIGS. 9 to 13 ; also Law, P. K., Myoblast Transfer , Landes, Austin, (1994)).
It is yet another object of the present invention to provide an automated cell processor, a highly efficient means for producing mass quantities (over 100 billion in one run) of viable, sterile, genetically normal as well as functional myogenic cells whether genetically transduced or cytocline-converted. The cell processor has an intake system which will hold biopsies of various human tissues. The cell processor's computer will be programmed to process tissue(s), and will control time, space, proportions of culture constituents and apparatus functions. Cell conditions can be monitored at any time during the process. The output system provides a supply of cells suitable for transfer in cell therapy or for shipment (FIGS. 14 to 15 ).
It is yet another embodiment in which myoblasts, and/or their physical, genetic, chemical derivatives, are used to treat cancer. FIGS. 16 to 18 illustrate melanoma cancer cell death upon exposure to myoblasts in fusion medium. According to Cancer Prevention and Control edited by Greenwald, P., Kramer, B. S., and Weed, D. L. (Marcel Dekker, Inc. New York, 1995), skeletal muscles appear to be devoid of cancer, though malignant tumor and metastases are found in every other organ. The very few cases of sarcoma reported are rare exceptions.
The recent immunocytochemical demonstration of dystrophin in DMD muscles 9 months after MTT indicated long term correction of genetic defect(s) can result from myoblast therapy (FIG. 19 ). This principle can apply to treat malfunctional insulin resistant muscles in Type II diabetes mellitus. As a universal gene transfer vehicle, donor myoblasts insert the whole normal genome and this can repair any malfunction of skeletal muscle cells, rendering them insulin sensitive (FIG. 20 ).
Additional features and advantages are described in and will be apparent from the detailed description of the presently preferred embodiments and from the drawings. Further, all references described herein are incorporated by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of some of the known protein defects in DMD muscle cells that differ from normal muscle cells. These include membrane structural proteins that are decreased or absent in DMD such as dystrophin (DIN), dystrophin-related-protein (DRP) and dystrophin-associated-glycoproteins (DAG), enzymes elevated in serum levels of DMD patients such as creatinine phosphokinase (CPK), aldolase (AID) and aspartate transaminase (AST), and mitochondrial (Mito) protein differences. Although these protein defects are caused primarily or secondarily by the dystrophin gene defect, their correction will require multiple gene (G1 to G7) transfer.
FIG. 2 illustrates MHC-negative myoblasts and MHC-positive myoblasts. (A) represents human myoblasts assayed with anti-MHC class I antibodies and viewed under fluorescent microscopy. The arrow indicates the MHC-negative myoblast. (B) is of the same slide viewed under a regular light microscope. The arrow indicates the MHC-negative myoblast. Bar=20 μm.
FIG. 3 illustrates an analysis of myoblasts by cytofluorometry. Control: myoblasts reacted without anti-MHC class I antibodies. Samples: myoblasts reacted with anti-MHC class I antibodies.
FIG. 4 is a scatter diagram of the separation of the myoblasts that were negative for MHC-I antigen expression by cytofluorometry.
FIG. 5 illustrates fluorescent intensities of two groups of myoblasts after separation by cytofluorometry. (A) represents MHC-positive myoblasts. (B) represents MHC-negative or weakly expressed myoblasts. (A) and (B) are of the same magnification and the pictures were similarly processed. Bar=30 μm.
FIG. 6 illustrates the angle of injection that determines myoblast distribution. (A) Oblique myoblast injection delivers donor myoblasts to the greatest number and area of recipient muscle fibers with the least leakage, resulting in the formation of the most mosaic fibers. (B) Transverse injection delivers donor myoblasts to a large number of fibers, but covers a smaller area and is more likely to result in leakage from the injection. (C) Longitudinal injection results in donor myoblasts fusing with each other, with fewer mosaic fibers being formed. (D) Focal injection results in only a small area of a few recipient muscle fibers being injected with donor myoblasts.
FIG. 7 illustrates donor myoblast nuclei labeled with fluoro-gold (FG), and are present in host muscle at seven days after MTT. (A) Mosaic myofiber with donor and recipient nuclei (black arrow) and donor myotube with, donor myonuclei (white arrow). (B) Mosaic myofibers with donor (white arrows) and recipient (black arrows) nuclei.
FIG. 8 illustrates distributions of donor myoblasts labeled with FG in host muscle. Even distribution of donor myoblasts can be achieved with oblique myoblast injection (A,B), or donor nuclei may appear in patches (C,D, white arrows) which gradually show more abnormal nuclei and debris. (C) represents a transverse injection and (D) a longitudinal injection.
FIG. 9 illustrates the production of allophenic twins with the mechanism of allophene formation.
FIG. 10 illustrates three littermates: 1 normal, 1 allophene, 1 dystrophic (top to bottom).
FIG. 11 illustrates physiological recordings of maximal isometric twitch and tetanus tensions at 80 Hz elicited from the soleus muscles of the normal, allophenic, and dystrophic littermates. The allophene recordings resemble the normal, rather than the dystrophic recordings.
FIG. 12 illustrates soleus cross-sections from allophenic mice demonstrating core fibers (arrows) characteristic of muscle from DMD carriers. Whereas most myofibers remain normal in appearance, some degenerative characteristics such as fiber splitting and central nucleation are apparent.
FIG. 13 further illustrates soleus cross-sections from allophenic mice demonstrating core fibers (arrows) characteristic of muscle from DMD carriers. Although most myofibers remain normal in appearance, some degenerative characteristics are visible such as fiber splitting and central nucleation.
FIG. 14 illustrates the general layout of an automated cell processor.
FIG. 15 illustrates the detailed design of culture and harvest automated actions.
FIG. 16 is a comparison of cancer cell growth media with myoblast growth media on cultured melanoma (CRL6322) cells. (A, C, E, G) low magnification; (B, D, F, H) high magnification. (A, B) Melanoma cells cultured in cancer cell growth media for 9 days appear healthy, as evidenced by their numbers, elongated shapes, and branching processes. (C, D) Similar amount of melanoma cells seeded and cultured in myoblast growth media for 9 days are more numerous and differentiated. (E, F) After 14 days in cancer cell growth media, the melanoma cells, while numerous, have become spherical in shape and detached from the surface, indicating that the cells are dead (E). At higher magnification only a few healthy cells remain (F). (G, H) After 14 days in myoblast growth media, the melanoma cells still appear numerous and healthy.
FIG. 17 illustrates myoblasts and melanoma cells (2:1 concentration ratio) co-cultured in myoblast growth media. (A, C) low magnification; (B, D) high magnification. (A, B) After 9 days in culture myoblasts and melanoma cells are numerous and remain differentiated. (C, D) After 14 days in culture myoblasts dominate the culture, with melanoma cells still surviving.
FIG. 18 illustrates myoblasts and melanoma cells co-cultured in myoblast growth medium for 4 days and then in myoblast fusion medium. (A, C, E, G) low magnification; (B, D, F, H) high magnification. (A, B) Myoblasts and melanoma cells (1:1 concentration ratio) after 5 days in myoblast fusion medium. Many melanoma cells have become spherical and detached from the surface and are not surviving in this medium. Myoblasts remain healthy and are beginning to fuse. (C, D) Myoblasts and melanoma cells (1:1 concentration ratio) after 10 days in myoblast fusion medium show numerous dying cells. Only a few can survive in this medium for this long, and they are detached and dying (D). (E, F) Myoblasts and melanoma cells (1:1 concentration ratio) after 19 days in myoblast fusion media. The surviving myobalasts retain their spindle shape and align with each other. Melanoma cells have become spherical and detached. (G, H) Myoblasts and melanoma cells (3:1 concentration ratio) after 19 days in myoblast fusion medium. Myoblasts have begun to fuse, forming myotubes.
FIG. 19 is an immunocytochemical demonstration of dystrophin in human muscle. Sarcolemmal localization of dystrophin is shown in normal control muscle (A) but not in DMD muscle (B). (C, D) DMD biceps brachii muscles from a subject who received MTT in one biceps and placebo injections in the contralateral muscle 9 mo before biopsies. Since blinding continues until the end of the study, the designation of the MTT muscle cannot be revealed. However, only one muscle shows sarcolemmal localization of dystrophin. (B), (C), and (D) were intentionally over-exposed to show immuno-reactive background elements not associated with the sarcolemma.
FIG. 20 illustrates (a) normal skeletal muscle metabolizing glucose with insulin. (b) In Type II diabetes mellitus, the major sequela of insulin resistance is decreased muscle uptake of glucose. It is possible that the glucose transporter in muscle is abnormal. It is known that insulin-mediated stimulation of tyrosine kinase and autophosporylation are impaired. These latter defects can. be corrected by MTT by normal gene expression (from Metabolism 6:6, 1993).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The compositions and methods described herein will be illustrated for the treatment of individuals having hereditary neuromuscular diseases. However, it is contemplated that other hosts and other disease states may be treated with the inventive compositions and methods.
A. CONTROLLED CELL FUSION
Myoblasts have the unique ability to fuse with other cells. With the use of normal myoblasts, a full complement of normal genes can be introduced into any genetically abnormal cells through cell fusion. For example, the genetically abnormal cell could be a liver cell, heart muscle cell, or even a brain cell. The idea is to introduce a full complement of normal genes into abnormal cells and, therefore, treat the genetic disease at the gene level and not at the hormonal or biochemical level.
For treating genetic diseases that involve structural protein abnormalities rather than regulatory protein abnormalities, it would be useful to control, initiate or facilitate cell fusion once myoblasts were injected into the body. It is known that myoblasts fuse readily at low serum concentrations in culture. The process is more complex in the in vivo situation. As the myoblasts are injected intramuscularly into the extracellular matrix (ECM), injection trauma causes the release of basic fibroblast growth factor (bFGF) and large chondroitin-6-sulfate proteoglycan (LC6SP) (Young, H. E., et al., J. Morph ., 201:85-103 (1989)). These latter growth factors stimulate myoblasts proliferation. Unfortunately, they also stimulate the proliferation of fibroblasts that are already present in increased amounts in the dystrophic muscle. It is, therefore, necessary to inject as pure as possible fractions of myoblasts in MTT without contaminating fibroblasts.
Controlled cell fusion can be achieved by artificially increasing the local concentration of LC6SP over the endogenous level at the transfer site. In muscles, this is achieved by including approximately 5 μM of LC6SP in the transfer medium. In addition, insulin facilitates the developmental process in vitro, and may result in the formation of myotubes soon after myoblast injections. The use of LC6SP (ranging from approximately 5 μM to about 5 mM) in the transfer medium will likely lead to greater MTT success.
B. MYOBLASTS: THE UNIVERSAL GENE TRANSFER VEHICLES
Whereas MTT results in the formation of genetic mosaicism with gene transfer occurring in vivo, the production of heterokaryons in vitro has immense medical application. This can be achieved by controlled cell fusion with myoblasts.
This research relates to the in culturo transfer of the normal nuclei with all of their normal genes from donor myoblasts into the genetically normal and/or abnormal cells, e.g. the cardiomyocytes. This development is especially important considering that cardiomyopathic symptoms develop in mid- adolescence in about 10% of the DMD population. By age 18, all DMD individuals develop cardiomyopathy. Undoubtedly, the ability to replenish degenerated and degenerating cardiomyocytes will have an immense impact on heart diseases even in the normal population where there is a great shortage of hearts for transplantation.
Normal cardiomyocytes have a very limited ability to proliferate in vivo or in vitro. The heart muscles damaged in heart attacks or in hereditary cardiomyopathy cannot repair themselves through regeneration. By integrating the skeletal muscle cell characteristic, mitosis, heterkaryotic cardiomyocytes will be able to proliferate in vitro.
Controlled cell fusion between normal myoblasts and normal cardiomyocytes may result in heterokaryons exhibiting the characteristics of both parental myogenic cell types. Clones can be selected based on their abilities to undergo mitosis in vitro to develop desmosomes, gap junctions, and to contract strongly in synchrony after cell transplantation.
These genetically superior cells can then be delivered through catheter pathways of the type described by Jackman WM, et al. (In: Zipes DP, and Jalife J, eds. Cardiac electrophysiology . From Cell to Bedside. Philadelphia: WB Saunders Company, 491-502, (1990)) after mapping of the injured sites. With the ability to grow large quantity of these cardiomyocytes, the correction of structural, electrical and. contractile abnormalities in cardiomyopathy can be tested first in dystrophic, cardiomyopathic hamsters and then in humans.
The genetic transfer of the mitotic property of myoblasts onto cardiomyocytes with in vitro controlled cell fusion enables the resulting heterokaryotic cardiomyocytes to multiply, yielding enough numbers of cells for the cell transplant to be effective.
Recently, it was reported that fetal mouse cardiomyocytes grafted into the myocardium of syngeneic hosts formed nascent intercalated disks between host and donor cells (Soonpaa MH, et al., Science , 264:98-(1994)). The use of fetal cells for cell transplant has and will continue to raise ethical questions. The fact still remains that fetal cells will not produce enough cardiomyocytes to mend a myocardial infarct. The bioengineering of mitotic cardiomyocytes using myoblasts provides a solution to the problem in view of reported studies that recombinant genes introduced into cardiomyocytes are expressed for at least 6 months, and appear to be regulated normally by humoral signals.
Whereas myoblast transfer into the dystrophic myocardium followed by in vivo controlled cell fusion may provide a structural impediment at the infarct, it remains to be shown that the myoblasts will integrate well with the cardiomyocytes, considering that the pumping action of the heart will disaggregate the developing cells from the host myocardium.
C. COSMETIC USAGE
In a broader sense, the cell therapy concept can significantly contribute to the field of plastic surgery. With cell therapy, implantation of silicone could be avoided. The use of myoblasts and/or fat cells could be used in a much more natural way to replace silicone injections for facial, breast and hip augmentation. Modified adipose tissue involving mixing and/or hybridization of myoblasts and fat cells can be used to control size, shape and consistency of body parts. Since muscle cells do not break down as easily as fat cells, good results may be long-lasting. Today, body builders are in search of increasing muscle mass and function at the right places. The use of myoblast transfer to boost muscle mass is a natural solution.
D. SUPERIOR CELL LINES
The establishment of superior cell lines of myoblasts is a high-risk challenge, but its benefits are numerous. These cell lines should be highly myogenic, nontumorigenic, nonantigenic, and will develop very strong muscles.
A unique property of myoblasts is their loss of major histocompatibility complex class I (MHC-I) surface antigens soon after they fuse. This has important implications in the usage of an immunosuppressant after myoblast transfer therapy. (See Huard J, et al., Muscle Nerve , 17:224-34 (1994); Roy R, et al., Transpl Proc , 25:995-7 (1993); and Huard J, et al. Transpl Proc , 24:3049-51 (1992)). The immunosuppression period depends on how soon the myoblasts lose their MHC-I antigens after MTT. Even more ideal is the establishment of a myoblast cell line in which MHC-I antigens are absent, thereby allowing MTT without immunosuppression.
In our study, human myoblasts were cultured from normal muscle biopsies in accordance with the methods disclosed in Law, P. K., et al., Cell Transplantation , 1:235 (1992) and Law, P. K., et al., Cell Transplantation , 2:485 (1993). The MHC-I antigens expressed on the myoblasts were demonstrated with fluorescent immunoassay. Cell cycle synchronization of myoblasts was carried out by adding colchicin in the growth medium and incubating for 48 hours. The myoblast preparations used in the experiment were 98% pure as assessed by immunostaining with the monoclonal antibody (MAb) anti-Leu-19.
Myoblasts were incubated with anti-MHC-I MAb (mouse 1:25 dilution, Silenus Lab, Australia) at room temperature. After washing, the myoblasts were incubated with FITC conjugated anti-mouse-IgG (Sigma) for 45 minutes and examined under fluorescence microscope with wide band ultraviolet (UV) excitation filter. Cytofluorometry was performed with a Becton-Dickinson cell sorter operated at 488 mM. Myoblast control was carried out by omitting the first antibodies in the immunoassay as the background of autofluorescence.
91.7% of the myoblasts reacted with MHC-I MAb. The reactions ranged from strong to weak. The remaining 8.3% of the myoblasts were negative for MHC-I antigen expression. FIG. 2 illustrates both MHC-negative myoblasts and MHC-positive myoblasts. The MHC-negative myoblasts were successfully separated by cytofluorometry, which is illustrated in FIGS. 3 , 4 . Both groups of myoblasts were then cultured for three weeks without significant difference in proliferation.
The lack of MHC-I antigens on these myoblasts may enhance survival of these myoblasts in recipients after MTT. FIG. 5 illustrates the fluorescent intensities of both MHC-positive myoblasts and MHC-negative or weakly expressed myoblasts after separation by cytofluorometry.
The immunosuppressant, cyclosporine, has many side effects and by suppressing the immune system, allows infection to prevail. Myoblasts without MHC-I antigen expression may contribute to a new cell line more capable of surviving in the host than the regular myoblasts. This superior cell line will eliminate the need to use the immunosuppressant, and will provide a ready access for patients who do not have a donor.
These superior cell lines have to be derived from clones of primary myoblast cultures because they are selected for their unique properties. Unfortunately, it has been shown that all clones of myoblasts eventually produce tumors if allowed to proliferate excessively. Thus, these cell lines should not be allowed to proliferate over 30 generations.
E. MYOBLAST INJECTION METHODS
Aside from donor cell survival in an immunologically hostile host, cell fusion is the key to strengthening dystrophic muscles with MTT. To improve the fusion rate between host and donor cells, various injection methods aimed at wide dissemination of donor myoblasts were tested and compared. These included injecting diagonally through the myofibers, perpendicular to the myofiber surface, parallel to the myofibers, and at a single site into the muscle. FIG. 6 illustrates myoblast distribution as a function of the angle of the injection. The goal was to achieve maximum cell fusion with the least number of injections.
Fluoro-gold (FG, 0.01%) labeled human or mouse (C57BL/6J-gpi-lc/c) myoblasts (0.05 ml of a 10 5 cells/ml solution) were injected into the gastrocnemius muscles of twenty normal 3-month old normal mice (C57BL/6J-gpi-lb/b). Host mice were immunosuppressed with a daily subcutaneous injection of cyclosporine at 50 mg/kg body weight. Groups of mice were sacrificed on day 7, 14, 24, 34, and 44 after cell injection. Transverse. sections of injected muscles were examined with fluorescence microscopy. The cell fusion rates were estimated by calculating the percentage of host muscle fibers bearing donor nuclei out of the total number of muscle fibers in the area of donor cell covered. The glucose phosphate isomerases (GPI) of the injected muscles were also examined with agarose gel electrophoresis (200 V anode to cathode, 3 hours, pH 8.6). The first appearance of mosaic myofibers in the tissue sections was within seven days after cell injection. This is illustrated in FIG. 7 . The highest fusion rate achieved was 72.2%. The electrophoreograms of GPI showed host donor and mosaic GPI in muscle specimens at least up to 44 days after MTT. Myoblasts injected obliquely through the myofibers were widely and evenly distributed with ejection of the myoblasts as the needle is withdrawn. This is shown in FIG. 8 . Myoblasts injected perpendicular to the myofibers were partially distributed, while myoblasts that were injected longitudinally through the core of the muscles and parallel to the myofibers were poorly distributed. Similarly, injection at one spot gave poor distribution and fusion. Considering that a small volume of a concentrated solution causes less muscle damage than a larger volume of a relatively less concentrated solution, and in view of the trauma caused by injection decreases the regenerative capability of dystrophic muscles, the technique of myoblast delivery is essential for MTT success.
Although oblique injection has been used in our clinical trials, there is room for improvement since human muscles are larger and the myofiber orientation of different muscle groups have to be well-studied by the orthopedic surgeons who administer myoblast injections. Judging from previous mouse studies, 20% normal myonuclei were able to maintain normal phenotype in dystrophic myofibers.
F. EXERCISE AND PHYSICAL THERAPY
Strenuous exercise causes damage to dystrophic myofibers. Lack of dystrophin causes the vulnerable sarcolemma to tear upon contraction. Other cell types are somewhat spared from degeneration because they do not contract. Thus, body building is counter-productive in DMD patients to compensate for loss of muscle mass and strength.
The use of exercise, however, in relation to MTT has not been studied. In dystrophic animals, it is well known that exercise hastens the degeneration of myofibers and thus aggravates the dystrophic condition, that is with dystrophic muscle fibers alone. The situation is different from MTT in which an attempt is made to produce a mosaic muscle containing normal, mosaic, and dystrophic fibers. The essence of MTT is to reconstruct the genetics and improve the phenotypes of dystrophic muscles. Thus, intensive exercise may induce the release of host satellite cells that will fuse with normal myoblasts to produce mosaic fibers. Undoubtedly, such dystrophic degeneration will induce normal muscle regeneration. Implanted myoblasts not only fuse to the newly sealed regions of damaged myofibers, but also survive as satellite cells. Mild exercise done shortly after MTT can be designed to facilitate myoblast mixing, alignment, and fusion, and to provide physical therapy to the newly formed fibers. Moderate exercise after innervation of newly formed fibers is likely to enhance the development of normal and mosaic fibers. Disuse plays a major role in the continued deterioration of dystrophic muscles, and physical therapy is prescribed for dystrophic patients. Disuse or lack of cross-bridge interaction results in a decrease of calcium binding. As a result, the excessive intracellular calcium promotes muscle damage in dystrophic muscles.
G. MYOTUBE TRANSFER
In the later stages of DMD, there remains fewer myofibers to be repaired with MTT. Formation of new fibers to replenish degenerated cells is further complicated by the presence of excessive connective and fat tissues. While it takes approximately 1 to 3 weeks for donor myonuclei to be incorporated into dystrophic fibers for repair, it takes over 4 months for donor myoblasts to develop into mature normal fibers de novo to replenish lost cells. Meanwhile, the impediment to developing myotubes to be vascularized, innervated, and connected to tendons all threaten their survival. Enough nutrients have to be present for the developing fibers to lay down the contractile filaments myosin and actin. Neither electrical nor contractile activity is normal for the development of the fibers. This is the time when myotube transfer may be of help.
Transplants of newborn normal muscles or myotubes into dy 2J dy 2J dystrophic mouse muscles have been shown by this inventor to produce normal muscle function and structure. (See Law, P. K. and Yap, J. L., Muscle Nerve , 2:356-63 (1979)). Myotubes are easily obtained in culturo through natural myoblast fusion by exposing confluent cultures to the fusion medium. In fact, small muscles have been produced with spontaneously contracting fibers in culture. The young fibers exhibit sarcomeres and immunostain positively for myosin.
Myotube transfer can be administered through injection with larger gauge needles. Better still, they can be surgically implanted into the beds of fat and connective tissues dissected and removed by surgeons. Since muscles can develop great forces and scar tissues are inert, the developing muscles will force the scar tissues aside throughout their existence.
Myotube transfer provides bioengineered young fibers in vitro. These fibers have lost their MHC-I surface antigens and are thus nonantigenic. Myotube transfer will not need to be administered with cyclosporin. For patients previously infected with cytomegalovirus (CMV). or other viruses, myotube transfer will be the choice.
In addition, for autosomal dominant diseases such as facioscapulohumeral dystrophy (FSH), myotonia congenita, myotonia dystrophica and certain forms of congenital muscular dystrophy and limb-girdle dystrophy, formation of mosaic fibers may not be useful since nuclear complementation may not be effective. The use of entirely normal myotubes through myotube transfer will undoubtedly open new avenues for treatment.
H. ALLOPHENIC MICE
Allophenic mice or mouse chimaeras are mice mosaics with two or more genotypes. They are produced by blastomere recombination (see Hogan B., et al. Manipulating the Mouse Embryo. A Laboratory Manual. Cold Spring Harbor Laboratory, (1986)) or by the artificial aggregation of embryos from two different strains of mice. In addition to being important specimens to study the clonal origins of somites and their muscle derivatives, allophenic mice have been shown by this inventor and others to demonstrate dystrophy suppression on natural development when genetically normal and dystrophic myogenesis coexist.
By aggregating half embryos of normal (129 strain) and dystrophic (C57BL/6J dy 2J dy 2J strain) mice as shown in the diagram of FIG. 9, sets of allophenic twins were produced consisting of chimaeric mice and their normal and dystrophic littermates (FIG. 10 ). Although the dystrophic gene was present in the muscle fibers according to genotype marker analyses, these allophenic mice showed normal behavior, life span, and essentially normal muscle function shown in FIG. 11 and structure in FIGS. 12 and 13.
Muscle fibers of these allophenic mice highly resemble those of the Duchenne female carriers. Whereas the dystrophic soleus contains 70% or more degenerating fibers, only 3 to 5% of the allophenic soleus fibers are abnormal. Many of these abnormal fibers showed “cores” as seen in the Duchenne carriers. Through natural cell fusion, normal myoblasts fuse with dystrophic ones to form mosaic myotubes that develop into phenotypically normal fibers.
I. NORMAL CHILD FOR A DUCHENNE CARRIER
Conceivably the technology of in vitro fertilization and blastomere recombination used in the allophenic mouse studies can be applied to human. Known carriers may thus have better chances of bearing normal children.
Accordingly, ova from a carrier and from a normal female can be obtained and fertilized in vitro with sperm recovered from the carrier's husband. The fertilized egg of the carrier has a 50/50 chance of being normal or dystrophic. Regardless of its genotype, its mixing with the normal fertilized egg will ensure the development of a normal phenotype. After culturing the embryo into the blastocyst stage, it can be implanted into the uterus of the carrier. The latter can be induced to be pseudo-pregnant with human gonadotrophin, thus allowing easy implantation.
The use of in vitro fertilization protects the mother. Abnormal developing embryos after blastomere recombination can be discarded. Furthermore, no blastomere needs to be removed for genetic analysis.
Since the fertilized egg of the carrier has 50% chance of being normal, a PCR analysis for dystrophin messenger RNA can be conducted on blastomeres removed from the embryo at the blastocyst stage. Unfortunately, this risks damaging the embryo by removing part of it at an early developmental stage.
J. AUTOMATED CELL PROCESSORS
With the great demand for normal myoblasts, myotubes and young muscles, the labor intensiveness and high cost of cell culturing, harvesting and packaging, and the fallibility of human imprecision, an automated cell processor is needed. Such a processor would be capable. of producing mass quantities, over 100 billion per run, of viable, sterile, genetically well-defined and functionally demonstrated biologics, for example, myogenic cells.
The automated cell processor will be one of the. most important offspring of modern day computer science, mechanical engineering and cytogenetics (FIG. 14 ). The intakes will be for the biopsies of various human tissues. The computer will be programmed to process tissue(s), with precision control in time, space, and proportions of culture ingredients and apparatus maneuvers. Cell conditions can be monitored at any time during the process, and flexibility is built-in to allow changes. Different protocols can be programmed into the software for culturing, controlled cell fusion, harvesting and packaging. The outputs will supply cells, which will be ready for shipment or for injection using cell therapy. The automated cell processor will be self-contained in a sterile enclosure large enough to house the hardware in which cells are cultured and manipulated (FIG. 15 ).
This inventor has developed a transfer medium that can sustain the survival and myogenicity of packaged myoblasts for up to 3 days at room temperature. Survival up to 7 days can be achieved when the myoblasts are refrigerated. This will allow the cell packages to be delivered to remote points of utilization around the world.
The automated cell processor will simply replace current bulky inefficient culture equipment and elaborate manpower. Its contribution to human healthcare will undoubtedly be significant, and the manufacturing costs are expected to be relatively low.
K. CELL BANKS
The automated cell processors will constitute only a part of cell banks. Ideally, donor muscle biopsies can be obtained from young adults aged 8 to 22 to feed the inputs of the automated cell processor. This will depend on the availability of healthy volunteer donors. Each donor has to undergo a battery of tests that are time-consuming and expensive. Based on the test results and the donor's physical condition, one can determine if the donor cells are genetically defective or infected with viruses and/or bacteria. These are the advantages of biopsies of mature tissues from adults. The major disadvantage, however, is that mature cells often do not divide, and even if they do, there is a limited number of generations that can propagate before becoming tumorigenic or nonmitotic.
Human fetal tissues can potentially provide unlimited supplies of dividing cells. However, aside from ethical issues, it is difficult to determine the genetic normality of these cells, notwithstanding the existence of polymerase chain reaction (PCR) which is used to screen many human genetic diseases.
As for the muscular dystrophies, the use of muscle primordia of fetal calves derived from in vitro fertilization of genetically well-defined background may be an alternative. Sperms and ova can be recovered from inbred strains of cattles that are known for their muscle strength and mass. In vitro fertilization will be followed by embryo culture and implantation into the uteruses of pseudo-pregnant cows. The fetuses are removed by Sicilian sections at specific developmental stages of the embryos. The muscle primordia that are rich in myoblasts can then be dissected out to feed into the automated cell processors.
Transplantation of cattle cells into humans constitutes xenografting. Due to the significant differences between the human and the cattle immune systems, these xenografts will likely survive, develop and function in the recipients without the need for immunosuppressants. However, the method will be tested. with and without immunosuppressants.
L. MYOBLAST DERIVATIVES VS. CANCER
Evolution is one continual experiment through ages with numerous statistics. The near absence of cancer metastases in skeletal muscles suggests that the physical, electrical, mechanical or chemical presence of myogenic cells and derivatives prevents or annihilates cancer.
In our study we showed that the physical and biochemical conditions of myoblast at the cell fusion stage caused the death of melanoma cancer cells (FIGS. 16 to 18 ). This does not preclude the potential effect of similar or different conditions, including electrical and mechanical, of other myogenic cells at different developmental stages.
It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be covered by the appended claims. | Compositions and methods of treating mammalian diseases using myoblasts, and/or their physical, genetic, chemical derivatives. Myogenic cells that are normal, or genetically or phenotypically altered are cultured and transplanted into malfunctioning and/or degenerative tissues or organs to alleviate conditions that are hereditary, degenerative, debilitating, undesirable, and/or fatal. Treatment of these conditions is not limited to the usage of mechanical, electrical or physical properties of these myogenic cells, but includes the usage of biochemicals secreted/released by the latter. The present invention discloses the use of normal myoblasts to deliver the complete normal genome to effect genetic repair, or to augment the size, or the function of tissues or organs. Certain conditions may be better served with genetically altered myogenic cells derived from gene transduction, whereas others may be better served with cytoclimes converter cells. Endogenous biochemical(s) are used to control cell fusion of myoblasts among themselves or with other cell types. An automated cell processor within a cell bank which enables the manufacture, at a single run, of unprecedented large quantities (greater than 100 billion) of normal or genotypically or phenotypically altered myogenic cells is also disclosed. | 60,779 |
This is a continuation of application Ser. No. 616,291 filed Jun. 1, 1984, now abandoned.
BACKGROUND OF THE INVENTION
The invention relates to an multiple player game data processing system with wager accounting for keeping track of holdings, winnings, or accumulated points among a plurality of players. Particularly, in a preferred embodiment, the invention is used as a tallying, game and player sequencing device in a game of poker.
In the game of poker, two or more players receive cards and bet or wager against each other in accordance with known rules. Bets are tracked by use of cash or colored chips, each representing points scored or a denomination of money. A player buys chips from the bank or house and plays with chips as the equivalent of money in making wagers during the game or games. At the end of play, the player cashes the chips for money. The allotment and cashing of chips is time consuming, susceptible to error and inconvenient.
Sometimes during a game, betting errors occur. For example, it is difficult to keep track of which players are in or out of the game and for what wager amount, especially when there are multiple raises. There are also other inconveniences associated with chips or cash. For example, table space is occupied, chips must be stacked after each transaction and chip stacks are sometimes upset and must be re-stacked.
The present invention eliminates the foregoing difficulties and, in addition, adds excitement and a new strategic dimension to the game of poker. For example, the invention displays for all players the pot at stake in a particular game. The wagered amount the raise, and the amount necessary for a player to stay in may be displayed to an individual player upon demand. It also displays which players are in the game, whether a bet exceeds a player's wealth, whose turn it is to be, and the winner at the completion of a hand. The order of betting is strictly enforced, except during the ante phase when random betting and entry is permitted.
In addition, individual players have private access to data indicative of their personal total wealth and their personal stake in each individual on-going game. The game is accellerated for additional excitement because play is not seriously interrupted for the banking tasks and annoying pot and game status inquiries of inattentive players.
SUMMARY OF THE INVENTION
There has provided a multiple player game data processing system with wager accounting for determining respective aggregate points or wealth, gains and losses and the stake of each of a plurality of players wagering against each other in a game of chance. The system includes means for determining an aggregate amount, or pot, wagered by the players, means for determining the amount necessary for a player to enter and remain in the game as initial and successive wagers are made, and means for increasing and decreasing each player's respective aggregate wealth or accumulated points in accordance with the wagers made and the outcome of the game. The system includes a player game entry device or station for each player including respective wealth acknowledgement means for acknowledging and receiving wealth upon demand, wager selector means for registering and indicating an amount wagered and withdrawal selector means for registering withdrawal from the game. Player wealth inquiry means for each respective player station is operative only at such station for selectively indicating a wealth amount for the respective player. A central processing unit is operatively coupled to the player stations for receiving the respective wagers and computing and indicating the pot at stake; for reducing such player's registered wealth in accordance with that player's respective wager; and for comparing the amount of each player's registered wager with a successive higher wager, for calculating the difference therebetween and for registering and indicating an amount necessary for such player to wager in order to remain in the game. Means at the central station is operative to register and indicate a win and the amount thereof in response to the operation of the withdrawal selector means by all of the players but the winner of said game. The wealth selector means communicates with the central station and the winner's player station for increasing the wealth amount of the winner by the pot amount registered by the central station in response to wealth acknowledgement by the winning player.
Means is provided for designating one player station with bank function, and for changing said designation in response to a signal from such station designating another as the bank and an acknowledgement from said station.
DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic block diagram of the gaming device of the present invention showing eight player stations and a central station.
FIG. 2 is a schematic illustration of the layout of the system including a player station, interfaces and a central processing unit.
FIG. 3A-3C taken together from left to right make up a schematic diagram of a typical player station.
FIGS. 4A-4C taken together from left to right make up a schematic diagram of an interface between each of the player stations and the central processing unit showing inputs and outputs, along with system RAM and lamp and display drives.
FIGS. 5A-5B taken together from left to right make up an electrical schematic of the central processing unit with inputs and outputs.
FIG. 6 is a block diagram illustrating game and flow chart sequencing for various game phases of the present invention.
FIGS. 7A-7B from top to bottom make up a flow chart illustrating program functions of the gaming device of the present invention.
FIGS. 8A-8C make up a flow chart illustrating more details of program functions set forth in FIGS. 7A-7B.
FIG. 8D is a chart showing the arrangement of drawings for FIGS. 8A-8C.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 there is shown a gaming device 10 of the present invention. The preferred device 10 is, as hereinbefore described, an electrical system for keeping track of the various aspects of an on-going poker game among a plurality of players. The game comprises a master or central station 12 and a plurality of, preferably eight (8), player stations 14 (1-8) interconnected to the master station 12 over dedicated channels 16 (1-8). Although eight player stations 14 (1-8) are shown, in a preferred embodiment, fewer may be used in a game. Suffixes (1-8) refer to particular player stations and are not used when referring to devices generally.
The master station 12 has a plurality of sets of indicators 18 (1-8), one for each player station 14. Each display 18 is dedicated to give information relevant to a player sitting opposite the same. Each set of indicators 18 includes a plurality of colored lights respectively indicating: WIN (red), IN/OUT (green), PLAYER UP (white), and WEALTH EXCEEDED (amber). In addition, a plurality of digital displays 20 are provided for giving numerical information. The indicators 18 and displays 20 are conveniently located so that each player can see the information conveyed by the master station 12. Although 4 digital displays 20 are shown, more or less may be used if desired because, unlike the indicators 18 (1-8), the digital displays 20 show information common to the game rather than individual players.
Each player station 14 has an alpha numeric keyboard 24 having individual keys 33 for inputting information and functional tasks to the system. The keys 33 are labeled or coded as follows:
______________________________________Key Name Function______________________________________0-9 Numerical inputs(.) Decimal PointsBET/RAISE/WIN ACK Bet, raise, win acknowledgeand NEW GAME and new gameOUT Withdraw from gameINC WA Increase Wealth AccountDEC WA Decrease Wealth AccountBA Display Bet AccountPA Display Personal AccountWA Display Wealth AccountHA Display Hand AccountCLEAR Clear DisplayABORT Exit House/Bank ModeOS/ACK Initiate Bank move and Acknowledge Bank move______________________________________
The function of the keys 33 and corresponding operation of the device 10 shall be hereinafter described in detail in conjunction with a description of the various functional elements of the device.
System Operation
Referring to FIG. 2, there is shown in block form the central station 12 incorporating therein a central processing unit (CPU) 26 and a general interface 28G. There is also shown in detail one of the eight player stations 14 (1) connected in parallel to the central station 12 over the corresponding channel 16 (1). Each player station 14 has a player station interface 28P which couples the keyboard 24 of the player station 14 with the CPU 26 via the general interface 28G and the respective dedicated channel 16.
In FIG. 2, the CPU 26 is coupled to the general interface 28G over data bus 30D and address bus 30A. Each player station 14 is coupled in parallel to the data bus 30D of the central station general interface 28G via a dedicated channel 16. A station address line SA, hereinafter described, addresses each player station 14 by a dedicated code unique to such station. The CPU thus communicates with each player station 14 individually and exclusively.
Player Station 14
For a description of the player station 14, reference is directed to FIGS. 2 and 3A-C. Each player station 14 comprises a keyboard 24 with decoder 21 and display 22 and a player station interface 28P. One such keyboard 24, with decoder 21 and display 22 is incorporated into a hand-held calculator (not shown) such as Model No. TI-1000 manufactured by Texas Instruments. The device accepts inputs by mechanically shorting a matrix of respective horizontal and vertical wires 32 and 34. In FIG. 3C, such an arrangement is shown. The wires 32 and 34 selectively intersect at normally open contacts 38. Each of said horizontal wires 32 receives phase shifted pulse inputs 32a-32e from a ring counter (not shown) for sequentially activating the wires in a known manner.
Actuators or keys 33 close the contacts 38 for producing coded outputs along an input/output (I/O) bus 30. Although more or less lines may be used depending on the number of keys and game parameters, in the preferred embodiment, the I/O bus has nine lines 30a-30i. If, for example, key 33C is actuated, contacts 38C are closed and outputs c and e produce pulsed outputs as high signals 32c and 32e while the ring counter is disabled and all other outputs are low. A coded output unique to the closure of said switch 38c is thus produced. An input/output couples the I/O bus 30 of the keyboard 24 to display 22 via decoder 21. In a preferred embodiment, cable 40 also couples bus 30 to the player station interface 28P, which couples outputs of the keyboard 24 to the master station 12 over the channel 16 and vice versa. It should be understood that a cordless arrangement between player stations 14 and Central Station 12 is possible.
The player station interface 28P is hereinafter described. The I/O bus 30 of the keyboard 24 is coupled via cable 40 to a buffer 42 comprising a plurality of dedicated hex-buffer gates 42a-42i respectively coupled to the lines 30a-30i of the I/O bus 30. The buffer 42 steps down signals from the keyboard 24 to an appropriate voltage for the next stage. Each gate 42a-42i may be a CD 4050 integrated circuit manufactured, for example, by RCA. The buffer 42 is coupled as shown over output lines a-i to an erasable programmable read-only memory (EPROM) 44 which acts as a decoder. The EPROM 44 may be a 2708 integrated circuit manufactured by Intel. The EPROM 44 decodes the signals over the lines a-i therefrom, and produces a coded output over its output lines a-h to a peripheral interface adaptor (PIA) 48, such as 6821 large scale integrated circuit interface manufactured by Motorola. PIA's are known as devices which provide parallel interfacing between some external device according to instructions from a central processing unit. Because the buffer 42 merely steps down the signals from the keyboard, the inputs and outputs are logically the same. The PIA 48 operates as an input/output gating device to the CPU 26 as shown in FIGS. 2 and 5, hereinafter described.
In a preferred embodiment, upon the occurrence of a key stroke, a selected output (g) of the buffer 42 goes low and provides a tag bit for setting a one-shot multi-vibrator or pulse stretcher 46, which is coupled to a trigger input (i) of the PIA 48. The pulse stretcher 46, including an exemplary gate, diode and RC network shown, maintains the PIA 48 in a receive mode for the inputs a-h of EPROM 44 and causes PIA 48 to produce an interrupt to the CPU 26 as hereinafter described. Thus, when a key 32 on the keyboard 24 is actuated, selected outputs a-i of the I/O bus 30 are activated, stepped down by the corresponding buffer 42 and decoded by EPROM 44 as inputs to PIA 48. The pulse stretcher 46 produces a gating pulse to PIA 48 which responds by producing an interrupt signal. The pulse stretcher 46 holds the PIA 48 in an interrupt mode for a time sufficient to blank random noise and allow the coded inputs a-h from EPROM 44 to be received by the CPU 26. The CPU 26 recognizes a low going edge of an interrupt. Therefore, unless data on EPROM 44 is accomplished by a key stroke, such data will not be generated on the low going edge of the (g) output of EPROM 44, which is coupled to input (i) of PIA 48 via the pulse stretcher 46. Thus, if (g) goes low, another signal from the particular player station cannot generate an interrupt until the pulse shutter times out. Thereafter, data gated by the PIA 48 is transmitted to CPU over data bus 30D.
As hereinbefore mentioned, the PIA 48 is an interface device providing parallel data to CPU 26. Data output from the CPU may be gated to the player station 14 by means of other circuits in the player station interface 28P hereinafter described. Such data includes wealth information, the player's personal account or stake in the game, the bet required to stay in the game, etc.
It should also be understood that when CPU outputs data, an input interrupt will occur. During such time, the CPU recognizes and processes the input data from the station receiving output, but discards the data so obtained from that station upon completion of the output sequence. The falling edge of the signal generated by the pulse stretcher 46 generates the interrupt. However, during output the interrupt is masked. The system does not recognize the interrupt generated by the station while receiving the output.
The PIA 48 has outputs a-f which are coupled to a buffer 50 having step-up gates 50a-50f, such as 7407 integrated circuits manufactured by National Semiconductor. The buffer 50 has outputs a-f coupled to a decoder 52 (FIG. 3B). The decoder 52 includes three decoders 52a-52c such as CD4028 integrated circuits manufactured by RCA and sometimes referred to as "one of eight" decoders. The decoders 52a-52c receive selected outputs a-f of the buffer 50. For example, each decoder 52a-52c receives outputs a-c of the buffer 50 at its corresponding input a-c. Further, each decoder 52a-52c respectively receives one each of the remaining outputs d-f of the buffer 50 at a respective corresponding input d', e' and f'. Therefore, the outputs a-c of buffer 50 provide coded data, and the outputs d-f, when energized, select one of the decoders 52a-52c to receive such data. For example, when output f of the buffer 50 is high or on, outputs d and e are low. Thus, only decoder 52c receives an input f' enabling it to receive the data from the outputs a-c. Likewise, when output e of the buffer 50 is high, the d and f outputs are low, and only decoder 52b receives an input e' to render it active.
The decoder 52 is coupled to a switching device 54, which preferably includes analog switches 54a-54e such as CD4016 analog switch devices 54a-54e manufactured by RCA. Each switch 54a-54e closes or short circuits selected outputs a-h thereof in response to coded inputs from the decoder 52. In the drawing, it can be seen that the decoder 52a has outputs a-d coupled to corresponding inputs a-d of the analog switch 54a. The remaining outputs e-h of decoder 52a are coupled to inputs a-d of analog switch 54b. Likewise, decoder 52b has half of its inputs a-d coupled to the analog switch 54d. Finally, decoder 52c has four outputs coupled to the analog switch 54e. Other outputs of the decoder 52c (not shown) are spares and not used in this particular circuit. It should be understood that while an output to display 22 is occuring, the system software does not permit or recognize an input from the particular player station. Thus, a conflict of signals is avoided.
Outputs from the decoders 52 actuate inputs to the various analog switch devices 54a-54e for selectively closing or short circuiting selected outputs thereof. For example, the decoder 52a, when energized by actuation of its d' input as hereinbefore described, transmits the coded data from the inputs a-c for driving selected ones of its outputs a-h to an "on" condition. It should be noted that alternate outputs a, c, e and g of the switch 54a are coupled to the I/O bus 30 of the keyboard 24 as leads a, b, c and d over wire 40. Outputs b, d, f, and h are joined together along a common lead to the I/O bus 30 as lead e. Likewise, the switch 54b is similarly arranged so that leads a, c, e and g are coupled in parallel as leads a, b, c and d of I/O bus 30. Common leads b, d, f, and h are coupled to lead f of I/O bus 30. Switches 54c-e are likewise coupled in parallel with I/O bus 30, but with respective common leads g, h and i coupled to I/O bus 30 as shown. If the output c of the decoder 52a is driven high, outputs e-f of the analog switch 54a become short circuited by internal circuitry thereof. Thus, when the outputs e-f of switch 54a are closed, wires c and e of the I/O bus 30 are shorted. This is analogous to the closure of a switch 33C at intersection 38C'. When corresponding horizontal and vertical wires 32 and 34 of keyboard 24 are closed at 38C' by switch 54a, it is as if switch 33C had been manually closed. The player station 14 therefore responds by providing a digital output to decoder 21 driving display 22, as hereinbefore described. In 54a-54e have corresponding outputs which are coupled in parallel with the respective normally open contacts 38 of the matrix hereinbefore described.
The player station interface 28P thus provides input data to the central station 12 from the keyboard 24, which input data is simultaneously decoded at 21 and displayed on the player statio display 22 by virtue of the closure of the selected normally open contacts 38. Likewise, the player station interface 28P couples data transmitted from the central station 12 to the corresponding player station 14 by closing selected switches in parallel with the normally open contacts 38 of the keyboard 24 for decoding at 21 and display on the player station display 22.
The PIA 48, hereinbefore described, performs other functions as well as the routing of input and output data between the player station 14 and the central station 12. The operation and programming of the 6821 is explained in detail in the 6821 manual. In a preferred embodiment, port A is programmed as an output port. Port B is an input port that has been conditioned to accept an interrupt as hereinbefore defined. Data port D accepts and transmits Data, and control port C accepts or transmits control functions by interrupt IR, read/write R/W, Reset R, Clock C, Enable EN, and station address or selection data SO, SI and SA.
The PIA 48 gates data from the CPU 26 over data bus 30D only when it is properly addressed. This occurs when a station address (SA) lead is actuated at control port C. Similarly, PIA is operative for communicating data at data port D to and from the CPU 26 over data bus 30D when conditioned by the CPU 26. Selection of such an input or output mode of the PIA 48 is accomplished by selecting or addressing the on condition of respective input SI or output SO register selects of PIA 48. Similarly, the CPU is conditioned to read or write data only if the read/write R/W input of the PIA is properly conditioned.
In connection with the foregoing, the present invention utilizes a memory mapped system. Upon initialization of the system, codes generated in CPU 26 produce coded inputs to each PIA 48 (1-8) unique thereto. The codes condition the PIAs 48 (1-8) such that selected terminals act as inputs or outputs etc. This system software handles input output functions of the PIAs 48 (1-8). In other words, the PIAs 48 (1-8) are programmed on initialization to act in the manner desired (for example addressing input and output register selects SI and SO), such that, it is only necessary to call on a particular PIA and its output port A or input port B acts accordingly. Other systems are possible for selecting input and output function, and the like. However, the memory mapped software of the present invention has been found to be a preferred and efficient system for accomplishing the task.
When the particular player station 14-1 has been addressed by Station Address (SA) and R/W is in write or low, PIA 48 transmits data from the CPU 26 to the display 22 over the buffer 50, decoder 52, and switch 54 as hereinbefore described. When PIA 48 is addressed in a read mode, the R/W input is in a state opposite from above. Input data produced as a result of closure of certain ones of the normally open contacts 38 (resulting from mechanical key strokes) is transmitted to the CPU 26 by PIA via buffer 42 and EPROM 44 as hereinbefore described.
PIA 48 has a clock input (C), which is produced by a clock (hereinafter described) at the central station 12. The clock produces pulses which hold the PIA 48 in synchronism with all the other player stations 14 (1-8) and the central station 12.
The PIA 48 has an interrupt output IR coupled to the central station 12 over the channel 16. The IR output is actuated or goes low whenever the tag bit (t) produced by EPROM 44 drives the pulse stretcher 46 on, thereby holding input i of the PIA 48 on as hereinbefore described. The interrupt IR communicates a pulse to the central station 12 indicating that data is available from the keyboard 24 for interpretation by the central station 12.
The PIA 48 may be reset to an initial condition by means of the reset input R as shown. When the system is initially turned on, a reset pulse is coupled to the PIAs 48 (1-8) for enabling the circuits and registers of the PIAs to receive the coded signals from the CPU 26 whereby the portsof PIAs 48 are mapped or conditioned to act as inputs and outputs.
Master Station 12
For a description of the master or central station 12 reference is directed to FIGS. 2, 4A-4C and 5A-5B. The master station 12 includes the CPU 26 and general interface 28G. Each player station interface 28P is coupled in parallel with general interface 28G over its respective channel 16 including data bus 30D Each player station 14 (1-8) is operative for communicating with the master station 12 to the exclusion of all the other player stations 14 by means of an interrupt function of the CPU, which processes one interrupt at a time. CPU 26 recognizes the station by selective actuation of the respective Station Address (SA) for the particular player station 14 and testing the polled station for the presence of a valid address code.
In a preferred embodiment, the CPU 26 processes data and produces outputs to the player stations 14 (1-8), the master displays 20 and indicator lights 8 (1-8). In the event of a key stroke produced at any play station, the CPU 26 completes the program instruction (i.e. line) at hand and recognizes the interrupt The CPU 26 polls the stations 14 one by one and takes in data from the interrupting station. Thereafter the CPU 26 resumes the program function. The data received from the player station is later processed in accordance with the system software.
The general interface 28G includes inverting bidirectional driver 62 including two DM 8835 integrated circuits 62W, 62R manufactured by National Semiconductor. The drive 62 is coupled into the CPU 26 data bus 30D.
Communication between the CPU 26 and player stations 14 (1-8) is accomplished by means of selectively addressing each of the player stations 14 (1-8) separately over select address line SA (1-8). Address bus 30A is coupled to the general interface 28G as shown. The address bus 30A is coupled to the channels 16 (1-8) carrying respective select address lines SA (1-8) dedicated to respective player stations 14 (1-8).
The general interface 28G includes a random access memory (RAM) 64, addressed as shown by address lines A0-A8. RAM 64 includes three RAM devices 64A-64C (shown in FIG. 4 and sometimes referred to as chips) or integrated circuits such as 6810 devices manufactured by Motorola. The RAM 64 is capable of holding at least 384 bytes of eight bit data (128 in each RAM 64A-64C) information and may be used to store values to be displayed, temporary results of arithmetic routines, system control, variable accounts, game statistics, etc.
The read/write (R/W) input to each RAM 64A-64C selectively enables each to operate in either a read or write mode in correspondence with the read or write mode of the CPU 26. Thus, in accordance with instructions established in the computer program, the RAM 64 contains or stores non-conflicting input and output data for each player station 14 (1-8) and the central station 12.
The clock line C operates the RAM 64 in synchronism with all other devices in the apparatus. A valid address VA line carries a signal that verifies that the information on address bus 30A is in fact a valid address.
In the preferred embodiment, the CPU 26 respectively reads and writes information to and from the various player stations 14 (1-8). In addition, the CPU 26 provides visual indication in the central station 12 of the information common to all the players by means of the digital display 20 and the particular information relevant to a player station 14 associated with a set of indicator lights 18 as hereinbefore noted.
The RAM 64 is coupled to the CPU 26 via the address bus 30A and the data bus 30D. The RAM 64 is a read/write device, that is, information stored in the RAM is readily accessible by the CPU 26 acting in a read mode, and the CPU 26 can change that information at a selected address in the RAM 64 when acting in a write mode. When properly addressed on the address bus 30A, the RAM 64 produces an output on the data bus 30D which is coupled to the CPU 26. Other portions of the system, including the indicators 18, displays 20 and player stations 14, are not responsive to data on the data bus 30D unless they have been preconditioned to be responsive thereto. In other words, if the RAM 64 has been initialized to communicate with the CPU 26, other portions of the system are simultaneously initialized not to be responsive to the RAM 64. If it is necessary to change RAM 64 in any way, the address bus 30A is selectively actuated to reach the proper address in RAM 64, and data is transmitted from the CPU 26 over the data bus 30D to the input of the RAM 64.
The CPU 26 communicates with the player stations 14 (1-8) and vice-versa. The RAM 64 and the player stations 14 (1-8) do not directly communicate with each other. When communication is open between the RAM 64 and the CPU 26, communication is closed between the player stations 14 and the CPU 26.
The CPU 26 controls the indicators 18 and displays 20 in the central station 12 by means of a peripheral interface adaptor (PIA) 66. The PIA 66 includes three peripheral interface adaptors 66A, 66B and 66C such as 6821 integrated circuits manufactured by Motorola. Each PIA 66 receives coded data from CPU 26 over data bus 30D representing information commonly available to all players in the game, e.g., Win, In/Out, Wealth Exceeded, Player Up, and Pot Value Information. A selector 88, coupled to PIA 66, enables it to operate selected outputs for actuating indicators 18 and displays 20.
The PIA s 66A-66C are coupled to the data bus 30D as shown. The PIA s 66A and 66B are selectively enabled to be responsive to the data on the data bus 30D for providing input to indicators 18. The data is communicated from the PIA s 66A and 66B to a solid state switching device 68 which includes a plurality of solid state switches 68a-68h, such as Sprague UD4181 power drive integrated circuits. The switching device 68 selectively enables certain ones of the lights: Win, 18W (1-8), Player Up 18P (1-8), Wealth Exceeded 18WE (1-8), and Player In 18M (1-8), depending on the game condition and the status of the player in question.
In a preferred embodiment, all of the outputs of the PIA's 66A-66B are in a high or activated state. Coded information from the CPU 26 causes one or more of the outputs of the PIA s 66A and 66B to become low for causing the selected switches 68a-68h to drive one or more of the indicator lights 18 on.
The PIA 66C is dedicated to be responsive to the data from the CPU for driving selected inputs of the digital display 20 to an on condition thereby creating an alpha numeric display of information relevant to the game. The PIA 66C has one set of outputs a-h coupled to booster 82, including a pair of booster circuits 82a and 82b, such as integrated circuits 7437, manufactured by National Semiconductor.
The booster 82 raises the level of the outputs a-h of the PIA 66 to an appropriate level for driving displays, hereinafter described. Outputs i, j and k of the PIA 66C are not amplified.
The booster 82 outputs f-h and PIA 66C outputs i, j and k are coupled to decoder 90. The decoder 90 includes three one of eight decoders 90a, 90b and 90c, such as 7442 integrated circuits manufactured by National Semiconductor. The one of eight decoders 90a-90c cooperate as the decoder 52 in the player stations as described above.
Outputs a-e of the booster 82 are coupled via respective pot display connectors 92a-92d to pot displays 93a-93d such as HP 5082-7300 manufactured by Hewlett-Packard. The pot displays 93a-93d each include six display windows 94a-94f each of which receives and decodes the inputs a-e for producing alpha numeric displays in each of the windows 94a-94f of the displays 93a-93c.
Outputs i-k of the PIA 66C are coupled to strobe inputs i'-k' of the decoder 90. As a coded input from decoder 82 appears on the lines a-e of each window 94a-94f of the pot displays 93, the strobe inputs i'-k' cause its respective decoder 90a-90c to strobe selected outputs a-x in succession. Thus, the windows 94a-94f of each pot display 93a-93d are selectively activated with a numerical symbol representing data from the central processing unit 26.
A selector 88, such as a 74S138 one of eight decoder manufactured by National Semiconductor, on the general interface 28G has inputs a-c and an inverted VA input. The inputs a-c provide eight combinations of binary logic for controlling the selector 88. Respective outputs a-h of the selector 88 are coupled to PIA's 66 respective select address inputs SA (1-3) and SA (1-8) of the player stations 14 (1-8). When a VA signal coupled to enable selec 88 is present and outputs are available on the lines a-h of the selector 88, one or two of the PIAs 48 or PIAs 66 is selected for communication with the central station over its respective select address lines SA (1-3) or SA (1-8). Thus, means is provided for selectively utilizing the selector 88 as a decoding device for each of the player stations 14 as well as a decoding device for selectively operating the various indicators 18 and displays 20.
Address bit A5 shown in FIG. 4B is provided for assuring that the outputs a, b, and c of the selector 88 are not confused with the outputs a-h of the same selector when in communication with the player stations 14 (1-8). This occurs as follows: a tag bit provided by the address bus 30A at line A5 is coupled to enabling inputs EN of the PIA's 66A-66C. The tag bit A5 is coupled to similar enabling inputs EN on each of the PIA's 48 for the player stations 14. However, the bit A5 is inverted (See FIG. 4B) between the general interface 28G and the player stations 14 so that when A5 is present, PIAs 66A-66C are enabled and the player station PIAs 48 (1-8) are disabled, and the absent A5 is converted into an enable signal for enabling the of the various player stations 14 (1-8). Thus, the 88 operates for selecting the various PIA's 66 and 48 only when a selected enable signal is available from the CPU 26, and the use of address bit A5 differentiates between the local indicators at the general interface 28G and the remote indicators at each of the player stations 14.
In FIGS. 2 and 4A, signals from memory decoder 116 and address bus 30A are coupled to inputs of logic 70. In the preferred embodiment, a signal A15 corresponding to the addresses not allocated to the PIAs and a signal corresponding to the addresses not allocated to RAM (8000) are used. These signals are inverted by invertors 71 and 73 respectively and then OR'd by OR gate 77 to produce a signal that is in a high state when either a PIA or RAM is addressed by the CPU. The output of OR gate 77 is used as an input to enable NAND gate 79, while the other input to NAND gate 79 is the R/W signal. The output of NAND gate 79 will then be in the low state only when the CPU is in the READ mode and either a PIA or RAM is being addressed. Signals VA and C are OR'd by OR gate 83 to produce a signal which is in the low state only when the clock and valid address lines are in the high or true state. The output of OR gate 83 and NAND gate 79 are inputs to OR gate 81. OR gate 81 therefore is in a low state only when the CPU is in a valid READ mode involving either a PIA or RAM. Otherwise, OR gate 81 is in a high state.
The output of OR gate 81 is applied to the input of 62I and the read-enable-on-low input of bidirectional devices 62R-62W. The output of gate 62I is applied to the write-enable-in-low input of 62. When the CPU is reading from a RAM or PIA, the output of OR gate 81 is low and therefore driver 62 is in the READ mode. When any other section of memory is addressed, a write operation is occurring, or an invalid memory location, the driver 62 is in a write mode. This prevents invalid data from the general interface from interferring with data on the CPU bus, i.e. cross-talk. Note that a corresponding bi-directional driver 102 operates in a similar manner under CPU control so that signal direction is maintained.
Central Processing Unit 26
The central processing unit CPU 26 is described hereinafter with respect to FIGS. 2 and 5A-5B.
CPU 26 is coupled to the general interface 28G described hereinbefore over the data bus 30D and the address bu s 30A, which is a subset of the address bus of the CPU. Data output from the CPU 26 is coupled to the data bus 30D through a bi-directional inverting driver 102 which may be an 8835 integrated circuit similar to the bi-directional driver 62 hereinbefore described. The data output of the CPU is thus inverted. Double inversion by the drivers 62 and 102 assures compatable polarity of the data signals from the CPU 26 and the general interface 28G.
The CPU includes a micro-processor 104, which may be a 6800 integrated circuit manufactured by Motorola. The micro-processor 104 communicates with the data bus 30D as shown. Similarly, the micro-processor 104 communicates over the address bus 30A via a driver 108 which may be a DM 8097 manufactured by National Semiconductor. A read only memory ROM 106 includes a plurality of ROM circuits 106a-106d, such as 2708 EPROMs manufactured by Intel. The ROM 106 is loaded with the program for operating the game in accordance with the flow charts hereinafter described. The CPU 104 addresses the ROM over the address bus 30A for accessing information relative to the game program, which information is coupled to the micro-processor 104 over the data bus 30D. A decoder 116 is responsive to certain address lines on the address bus 30A for producing outputs indicative of the particular memory segments addressed by the micro-processor 104, one example of which has been described with respect to logic 70. Outputs of the decoder 116 are utilized for logically gating other portions of the system hereinafter described. A clock 110 is coupled to the micro-processor 104 and to other portions of the system over the clock lead C as hereinbefore noted. The clock 110 produces pulses for driving the system in synchronism.
As with most computer operated systems, the computer or micro-processor 104 shares its time among various portions of the system. Accordingly, means is provided for selectively gating the micro-processor 104 so that it selectively communicates with various portions of the system without contention. Further, the peripheral devices coupled to the micro-processor 104 produce signals which are selectively received or blanked in accordance with means for sorting or keeping track of the various signals. Accordingly, selected outputs of the micro-processor 104 are logically coupled to various peripheral devices, hereinbefore described, for selectively actuating certain ones and deactuating others in accordance with the operation of the system.
The operating system of the 6800 micro-processor is described in a 1978 publication of Motorola, Inc., entitled M6800 Micro Computer System Design, Data, 2nd printing, which publication is incorporated herein by reference. The control signals and operating system of the present invention are comparable with the micro-processor described in said publication.
The micro-processor 104 is operative for communicating with the selected player stations 14 (1-8) for transmitting information to such stations. Similarly, the micro-processor 104 is conditioned for receiving information from the player stations 14 (1-8) in response to interrupts and other signals necessary for such communication. The micro-processor 104 communicates in accordance with its interpretation of the instructions stored in its ROM 106.
In FIGS. 5A-5B, various individual circuits of the CPU 26 are illustrated in detail. Micro-processor 104 has certain inputs and outputs including the interrupt IR, read write R/W, valid address VA, reset R, clock C, data lines DO-D7 and address lines A0-A15.
Interrupts IR are communicated to the micro-processor 104 by each of the player stations 14 (1-8) and as described above.
The CPU generates read/write R/W pulses for selectively enabling and disabling devices in communication with the CPU in accordance with the operating systems of the micro-processor. For example, the micro-processor 104 reads the program from ROM 106. The micro-processor 104 reads and writes to the RAM 64 in the general interface 28G by means of read write line R/W.
The clock produces clock pulses for driving the micro-processor 104 and other devices hereinbefore described in synchronism. The clock 110 may also produce other time signals as necessary. The clock 110 also produces a reset upon actuation of the system during the power up or initialization phase of the system operation. Initialization occurs in accordance with ordered instructions in software. Instruction manuals of the various IC's describe initialization requirements which need not be described here.
GAME PLAY
The actual use of the invention involves following a procedure not unlike the normal play in a game of poker. Each player, by means of the keyboard, is able to communic.ate with the central station for performing certain betting and housekeeping tasks.
Table I below lists the keys available for use on the keyboard by symbol printed thereon and by key name, When the key is actuated, the display shown on the player's station and the central station, if appropriate, is listed. The key function(s) is summarized in the right hand column. Table II lists the indicator lamps by color and the meaning of the same with respect to a particular player's station or status.
TABLE I______________________________________Key Display/Symbol(s) Name Indictator Function______________________________________C CLEAR Zero Clears player station display and station in- put memory to Zero. Decimal Decimal Separates dollars and Point cents in displayWA Wealth $ Displays wealth of Account player at Player's Station onlyINC/WA Increase $ $ + INC/WA in- Wealth creases wealth Account account of playerDEC/WA Decrease $ $ + DEC/WA de- Wealth creases wealth Account account of playerPA Personal $ Displays total amount Account bet by player in current gameBA Bet Account $ Displays amount to stay inHA Hand $ Largest personal Account account in handOS/ACK House # # + OS/ACK by Acknowledge Bank or House indi- cates house mode for named player station Player OS/ACK by player Acknowledge adds or substracts wealth attributed by house in WA aboveOUT Out Green light Player withdraws goes out from gameBET/RAISE Bet/Raise $ Bet and/or Raises Dis- play sets new WA, allows game entry in ante phase Win/ $ Acknowledges a win Acknowledge to permit transfer of pot to winning player's wealth account New Game Zero House starts new game0-9 Numbers $ or # To display $ To indicate a player station #ABORT Abort Zero exit house or bank operation with- out transaction______________________________________ Legend: $ = Numbers indicative of money or points # = Numbers indicative of station identity.
TABLE II______________________________________INDICATOR LAMPS PLAYER STATION STATUS IF LIT______________________________________Green Player InWhite Player UpAmber Wealth ExceededRed Win______________________________________
Some of the keys have multiple functions, noted above, depending upon whether it is used by the individual player as a player or by the house in performing housekeeping tasks hereinafter described.
In a game of poker or other game of chance where players compete against each other using chips and the like to represent wagers, the players purchase the chips from the house or bank in various denominations, and use the chips for making wagers in one or more games by placing the chips in a pot. Normally, a game begins, if the rules so provide, by each player placing an ante or initial bet in the center of the table or pot. Thereafter, the cards are dealt, and the player to the left of the dealer has the option to check, meaning pass, or bet a specific amount of money or drop out. The first player to bet places chips representing the wager in the pot. Other players wishing to remain in the game must meet the initial bet. In addition, any player or players in succession may raise the bet by adding to the bet amount an additional amount representing a raise. Players thereafter must meet the initial bet plus the aggregate of raises in order to stay in. Play continues until all of the players but one have dropped out. The remaining player is declared the winner and sweeps the pot, thereby accumulating wealth.
As hereinbefore described, the winning player normally stacks the chips in accordance with the denominations while another hand is dealt. Play may continue until all of the players leave the table or until an agreed time. If a player decides to drop out of the game, he may cash the chips by returning the same to the house in exchange for the equivalent value in money. At the end of play, the chips are all cashed and stacked and returned to a receptacle for use at another time.
In the present invention, the game of poker is played in essentially the same way as hereinbefore described. Players ante to enter the game, receive cards, place and raise bets, drop out and ultimately a winner is declared. The difference is that, with the present invention, no chips change hands because the device tallies and keeps track of the amounts represented in each player's account and the pot in accordance with the normal rules of poker.
Banking Phase
In order to initiate the first game, the system is turned on. At this state, the object is to distribute wealth to the players in a way similar to the distribution of chips. When the system is turned on, one station, for example, player station 14-1 is automatically designated as the house. One at a time, the players deposit funds with the bank or house. Thereafter, the person operating the bank or house player station 14-1 presses the player station number (#) depositing money and OS/ACK. This conditions the particular player station, e.g., 14-2, to receive a credit for the amount deposited. The house hits the CLEAR button, the amount deposited, e.g. $1,000.00, and then hits the INCR/WA button to transfer the funds to the account of the player station in question. The amount then appears on the display of the player station receiving the wealth. That player station player hits his OS/ACK key to acknowledge that the amount is correct and received. If the player thereafter hits his WA button for wealth account, the $1,000 should display on his individual display only. The aforegoing series of operations is repeated for each player entering the game.
Ante Phase
The next stage of play is the actual beginning of the game. Games normally begin with the ante phase. All eligible players enter the game at this time. The players may enter in any order because sequence of play is not enforced at this time. The entry of the first ante bet begins the game. For example, player station 14-2 hits 10 and the RAISE/BET key. $10 appears on the pot display of the central station, player station 14-2 IN/OUT green light turns on and any remaining wealth at player station 14-2 appears on his individual display. In the example above, if player two had $1,000 in the original wealth account, $990 would appear, representing the original wealth amount less the $10 ante.
All players who accept the initial ante now become part of the game in progress. Such players may accept the ante by merely hitting their respective RAISE/BET key which causes the pot amount to increase $10 as each player enters the game and the green light for the particular player to go on. Each player receives an indication of his or her remaining wealth and players may drop out by pressing the OUT button.
Raise/Bet Phase
After the cards are dealt, the first active player who makes a bet starts the Raise phase of the game. For example, player station 14-4 may open with a $10 bet. The $10 is added to the previous amount in the pot display and the remaining wealth is displayed on the display of the player making the bet. As in the ante phase above, any player may leave the game at any time by pressing the OUT buttom. Once this occurs, the player may not re-enter that particular game. This is true for any game phase.
After the first player bets, the Player Up or white light appears on the station for the next eligible player to the left. If, for example, the player at station 14-4 began the game or opened with a bet and the player at station 14-5 had previously droppdd out, the next eligible station player would be the player at 14-6. The Player Up light at 14-6 would therefore go on. Player six may call the bet by merely pressing the RAISE/BET key, or he may raise the bet by hitting numbers indicating the amount of the raise and the RAISE/BFT key. (For example, 2 and 0 for $20 and the RAISE/BET key). The original $10 bet plus the $20 raise will be added to the pot display. In the example above, the bet is now $30 to the next eligible player. This amount will enter in his display along with the energization of the white light. Assume that there are only three players in this particular game, e.g. 1, 4 and 6, player one must meet the initial $10 bet plus the $20 raise in order to stay in the game. Thus, $30 appears at his display when his white Player Up light goes on. When it is the 4th player's turn, because player four had made the initial bet, he need only to match the $20 raise. Therefore, $20 appears in his display along with the white light indicating that it is his turn to either call or raise the bet or go out. Calling or raising the bet activates the next eligible player station.
Win Phase
The betting pattern continues as the game is played with the cards until the winner is declared. In an actual game of poker, if all the bets are called, according to the rules, the player making the last bet must show his cards to the other players. If the cards are winners, the other players hit their respective OUT buttons. As a result, the red WIN light goes on at the station of the called player who had not dropped out. If another player shows better cards, the called player and other players hit their respective OUT buttons and the WIN light lights at the player showing the better cards. The final pot for winning amount is displayed in the pot display and in the winner's station. The winner hits the RAISE/BET key to acknowledge and accept winnings as indicated on the pot of the central display. This amount is added to his wealth amount, which is displayed to him.
It should be understood that multiple winners may be declared (i.e., a shared pot). For example, the sequence may be initiated by a decimal numeral key stroke indicative of the pot percentage claimed as won preceding the OUT key stroke. When all players are either out or claiming to be winners and the values claimed equal one hundred percent of the pot displayed, the winnings are displayed in the respective winner's display and each acknowledges the amount won.
New Game Phase
A new game is begun when the player representing the house hits the RAISE/BET key. At that time, all of the indicator lights are turned off, the pot display is cleared, and everyone's remaining wealth is displayed in their individual respective displays. The first player thereafter making an ante bet starts the betting process again.
Cashing Out
Any player may cash out by requesting the same from the house. The house presses the player station number, e.g., 2, plus the OS/ACK key. The house hits the CLEAR button and the amount withdrawn, e.g. $1595 and the DEC/WA (Decrease Wealth Account) button. The player examines this figure and, if correct, he hits the OS/ACK to acknowledge that the transaction is correct. His remaining wealth appears on his display. If the decremented amount equals the wealth account, $0 is displayed. Thus, the player is effectively out of the game and cannot bet unless and until the wealth account is replenished
Wealth Exceeded
In the preferred embodiment, any time a player exceeds his wealth amount by making a bet which is more than the amount in his wealth account, at that time the amber WEALTH EXCEEDED light for the player goes on and the player is precluded from making a bet. The player may increase his wealth amount by paying in as described above, in the banking phase, after which the player may make a bet.
It should be understood that the present invention may be used as a tallying device in any game in which players compete against each other or the house, as in Black Jack. However, a different program must be provided to accomplish such result. The present invention is most conveniently and preferably applied to the game of poker in various forms as hereinbefore described.
GAME LOGIC AND FLOWCHARTS
In FIGS. 7A-7B and 8A-8C, there are shown two flow charts of the system. In FIG. 6, GAME SEQUENCING is shown. After start up, the system is designated to move through a series of game phases in an ordered sequence In the ANTE PHASE, random entry into the game is allowed. Ante bets are processed between the Taskhandler and Ante software in primary loop I. If any player in the game initiates a raise over and above the initial ante, the GAME SEQUENCING moves into GAME software. Thereafter, bets and raises are strictly ordered and random entry is forbidden. Thereafter, system software moves between game functions and the Taskhandler functions in Loop II. In the preferred embodiment, after all bets and raises have been made and all but one player has been eliminated, the GAME SEQUENCING goes into the WIN software. Win acknowledgement tasks associated with the win phase of the game are processed in Loop III. After all wins are acknowledged, GAME SEQUENCING moves to the NEW GAME SOFTWARE upon actuation of the RAISE/BET (new game) key by the house. Tasks are processed in Loop IV. Once all new game tasks are accomplished (e.g. calculations and initializations are complete), GAME SEQUENCING goes back to ANTE as shown. The system thus controls the instruction sets available for each phase of the game. In FIG. 7A-7B a more detailed general system flow chart is shown. Operations are written in rectangular boxes and questions or inquiries are written in diamond-shaped boxes in accordance with known flow chart drafting techniques.
During the start up of the game, individual players pay in and increment their wealth accounts in accordance with the previously described sequences. Thereafter, players enter a game playing sequence. The sequence includes the ANTE phase, a GAME (raise/bet) phase, a WIN phase and a NEW GAME phase as hereinbefore described.
The system software as outlined in the flow charts of FIGS. 6-8 anticipates the various phases. Power On at 200 indicates that the system has been initially turned on. The Initialization operation at 202 results from a reset pulse from the CPU 26 for initializing the various memory devices and the lik to an initial condition. Further, memory displays and the like are initialized to begin the game e.g., the game status lamp registers are cleared in memory and then the various game status lights are turned off, indicating no activity.
The system goes to Instructed Return Point at 203 after initialization at 202. Because the system cycles through the various loops I-IV, it has instructions in software for cycling the instructions which, in effect, skip earlier instructions which are not needed. Instructed Return Point 203 is a flow chart routing mechanism for instructions which will be further discussed hereinafter.
Start task function 204 begins a sequence of tasks, i.e., routing various program sequences to sub-routines and the like. The system begins in ANTE phase. See FIG. 6. A Task Present inquiry at 206 asks the system whether a task has been initiated. If the response is NO, as indicated by N, the system loops back to the Start Tasks routine at 204. If the answer is YES, as indicated by the Y, the system proceeds to a Determine Source routine at 208. The question is then asked whether the task is a Clear task at 210 or something else. A Clear task means that the system shall operate the Clear Source operation at 212 through a Clear Status Bit function at 214 and return to the Start Task function at 204.
The Clear Status Bit function 214 is a housekeeping and programming task which is known in the art. Although not always noted, the Clear Status Bit function 214 is shown in the drawings at various places, and it should be understood that it occurs before each cycle.
If the Clear inquiry 210 is a negative, the question is then presented whether the function or task is a Bank Task at 216. If the answer is affirmative, a Test for Bank Mode 217 and a Test for Function at 218 is made for the function. Such functions include Reassign the house or banking station at 220, Increase/Decrease wealth account WA at 222, and an Abort at 224. The affirmative of Reassign inquiry is coupled to Reassign Routine at 226. After completion, the system returns to the Start Tasks at 204 through Exit Bank Mode 231 and Clear Status Bit at 214. Similarly, Increase/Decrease WA Routine at 228 operates in response to an affirmative inquiry from the Inc/Dec WA Inquiry at 222. Finally, if an error is made in the sequencing of keys, the operator may hit the ABORT key which enables an affirmative of Abort Inquiry at 224 to operate Abort Routine 230 and return to Start Tasks 204 via the Exit Bank Mode 231, Clear Status Bit 214 and Instructed Return Point 203. Further, a negative response to Abort Inquiry 224 at this stage of play causes the system to Abort also. This appears redundant. However, this software sequence avoids a potential program loop by default.
If the Bank Task inquiry at 216 is negative, the system inquires if Decimal String=0 at 232. The Decimal String is a representation of the series of numbers which precede the operation of a function key. If numbers do not precede the function key code, the answer is affirmative. For example, if a player wishes to make a bet of $10, the player activates the 1 and 0 keys and then the RAISE/BET key. The Decimal String is not equal to zero in this case. If, however, a player wishes to meet a bet, but not raise it, the player merely activates the RAISE/BET key. In such case, Decimal String is equal to zero. By default, the system automatically credits the pot in the amount of the unstated bet. The Decimal String is a way of determining whether the particular task is purely a betting task or some other player task.
If the Decimal String=0 Inquiry 232 is affirmative, it indicates that a bet or ante has been met; a bank function is occurring; or a player function is occurring. Out inquiry at 234 following Decimal String=0 inquiry asks whether the player is in or out. If the Player Out inquiry at 234 is affirmative, a Remove Player Routine 236 is employed. Thereafter, a question is asked at 238 whether there is One Player Left. If the response is negative, the system goes to Clear Status Bit 214 and returns to Start Tasks at 204. If the response is affirmative, Win Routine 240 is activated. The red light at the winner's station is activated and the pot amount is displayed in the central display and at the particular player station as well as the central display. As hereinafter described, the system deals with a win situation by interaction with the bank and the particular player described below.
If the Out? question at 240 is negative, i.e., if the player is not taking himself out of the game, then the function following the Decimal String=0 inquiry 232 may be a bet. The Bet Key inquiry at 242 may be affirmative or negative. If negative, the system goes to Player Station Function Routine 244. Such a player station function may be to acknowledge an increase or decrease in the wealth account or re-assignment from the house or bank. The particular inquiries are not shown in the drawing because it is believed a verbal explanation is sufficient and the drawing may be unduly cluttered thereby. If the Bet inquiry at 242 is affirmative, the system moves to go to proper routine (as determined by instructed return point) at 246. In this way the software returns to the phase of the game it has been instructed to be in at such time, i.e., Ante Routine 248, Game (Bet Raise) Routine 250, Win Routine 252 and New Game Routine 254. If the system is in any of the foregoing routines, it may loop back through the Taskhandler via start tasks at 204. Once the system moves from the Ante Routine 248 to the Game Routine 250, it does not return until a new game starts. Similarly, if the system moves to the Win Routine 252, the loop back through Start Tasks 204 bypasses the Ante and Game Routines. Finally, in the New Game Routine 254, the system does the new game functions and returns to Start Tasks 204, by-passing the routines associated with win acknowledge, ante and raise bets. Each of the foregoing routines 248-254 is described hereinafter with respect to FIGS. 8A-8C. At present,however, further inquiries are required before this flow chart is satisfied.
If the Decimal String=0 inquiry at 232 is affirmative, it is apparent from the foregoing that a player is either performing certain player station functions or making a bet without a raise. If the Decimal String=0 inquiry 232 is negative, it is possible that certain house or banking functions are in process or a raise situation has occurred. For example, during a re-assignment, the house depresses a player station number and then a function key. Similarly, during an increase or decrease wealth account function, the house depresses numbers plus the function key for increasing or decreasing numbers plus the function key for increasing or decreasing the wealth account. Thus, the Decimal String preceding the function is not equal to zero. (Also, in a raise bet situation, a player raises a bet by first placing the amount of the wager or raise on the keyboard and then hitting the RAISE/BET key.)
In the situation where the Decimal String inquiry at 232 is negative, a Bank Key inquiry is made at 256. If affirmative, the system switches to Bank Mode Routine at 258. (A negative response to the Bank Key inquiry 256 indicates a betting situation). The system may not be in a betting mode and a bank mode at the same time. Thus, there is a check on the house mode to prevent cheating.
If it is a bank function, Bank Mode Routine 258 is executed and the system returns to the Start Tasks Routine at 204. In operating through such a Start Tasks Routine at 204, it can be seen from the flow chart that the system will run through Task present at 206, Determine Source at 208, Clear at 210, look at the Bank Task inquiry at 216, and Test for Bank Mode 217, and Test for Function at 218. The subsequent inquiries at 220 and 222 as well as the ABORT at 224 and Exit Bank Mode at 231 are made as hereinbefore described.
If the Bank Key inquiry 256 is negative, then a non-zero Decimal String is a Raise Bet situation. A Raise/Bet inquiry is made at 260. If the answer is affirmative, a flag is set at Set First Bet Flag 262, and an Ante inquiry at 268 is made as to whether the Raise Bet is an Ante. If the answer is affirmative, return via Ante Routine 270 is operative to hold the system in Ante Routine at 248. If the answer is negative, the system moves to Go To Game Routine at 272 and then Go To Proper Routine at 246 as shown. Finally, if the Raise/Bet inquiry at 260 is negative, there must be an error and a system Error Routine 274 is operative to loop the system back to the Start Tasks at 204.
Select Game Phase
Referring now to FIGS. 8A-8C (see FIG. 8D for Drawing Arrangement), the flow chart resumes with Return Via Ante 270, Instructed Return Point 203, Clear Status Bit 214, and Start Tasks 204 illustrated in FIGS. 7A and 7B. As hereinbefore noted, once instructed to return to a particular game phase routine, the system stays in that routine until instructed to move on to another.
The above concept is illustrated in FIGS. 8A-8C as follows. In Ante Phase it is assumed that play is about to begin in such a way that players may ante in random order As hereinbefore stated the system interprets an initial ante as a first raise, because the pot starts at zero. Thus, a non-zero decimal string preceeding a player RAISE/BET key stroke is interpreted as a Raise. The question Raise ? at 280 initiates an inquiry or test to determine which of two possible returns is possible. For example, if the answer to the Raise inquiry at 280 is affirmative, such raise may be the first raise of the game e.g. the initial ante. It may, however, be a second raise, that is, an increase in the initial ante, not just a matching thereof. For example, if a player wishes to meet an ante, the player strikes the RAISE/BET only after the initial ante has been entered. Thus, the decimal string preceding the key stroke is zero and the system interprets the key stroke as a BET. In usual play, if after the players have all entered an ante, a player wishes to make an additional bet i.e. a raise, the player depresses the bet amount plus the RAISE/BET key. The system interprets this as a raise. If the ante has occured, this raise, occurring after the ante, is interpreted at inquiry 282 as a secon raise whereby the system exits or goes to game routine at 246G.
In the Game Phase, betting order is important. Therefore, once a bet is made, and a raise of such bet has been made, the order and sequencing is fixed. The system will not go to the game routine before ante bets are complete. Therefore, a negative response to the Second Raise inquiry at 280 means that the system is entering the ante phase, and the system produces a command to raise an Ante Flag at 284. In the ante phase a non-numerical raise/bet keystroke is merely meeting a bet or meeting the ante.
If the ante flag at 284 goes up, the system executes Set Initial Ante at 286 and moves to process the ante by inquiries whether the bet is less than or equal to the wealth account at 283. A negative response produces a Wealth Exceeded Error at 285 and a loop to return via ante 270 as shown. If the response to inquiry at 283 is affirmative, the player has sufficient funds or points to stay in and the player in status lamp at 287 is turned on. The player's wealth account is decreased at 289 and the pot is increased at 291. Thereafter, the system returns via ante 270.
After the initial ante, a negative response to raise inquiry at 280 results in a Has Ante Occurred? inquiry at 293. A positive response to the inquiry causes the system to execute Set Bet Equal to Ante at 295. Thereafter, processing proceeds as described above via the inquiry at 293. A negative response to Has Ante Occurred 293 produces an error at Cannot Enter Without Ante routine 297, because a player cannot ante nothing or zero in order to play, (i.e. first raise has not yet occurred).
The system continues to loop back to Return Via Ante 270 as long as the second raise has not occurred. Once it does occur, the system exits the Second Raise inquiry at 282, moves to Go to Game Routine 246G, return via Game Routine 247, and Clear Status bit 214 to Start-Tasks in Game Mode 204G via the Game Routine (i.e. Loop II in FIG. 6).
As mentioned above, after a second raise has been made player sequencing is important. Thus, an Is Correct Player Up inquiry is made at 292 after Start Tasks 204G. If the response is negative, an Out of Turn Error 294 occurs and the game sequences back to the Start Tasks 204G via the above noted loop. If the response to Is Correct Player Up at 292 is positive, then the bet is processed at Calculate Bet Routine 296. An Is Bet Greater Than Wealth Account Inquiry is made at 298 as to whether the player has exceeded his wealth. If the answer is affirmative, the Wealth Exceeded Error occurs at 300, sending the system to Start Task at 204G via Go To Game Routine 246G. If the response is negative, the Compute Accounts Routine at 302 (FIG. 8B) provides information as to the wealth amount, the bet amount, the pot amount, and other parameters.
For purposes of explanation, various error sequences are noted (e.g. Out of Turn Error 294 and Wealth Exceeded Error 300). However, the system software uses essentially the same error routine whenever an error occurs. That is, the system cycles back to the beginning of the loop where the error occurred and the player in error receives a display of all eights (888888) on his player station display.
After a bet is completed, a Player Status Routine 304 moves the player out of up status and increments to the next available player at Increment Game Station Number (GSN) 306. An inquiry is thereafter made at 308 as to whether the new GSN equals 9. A positive response engages Set New GSN=1 at 310. The logic is that because there are only eight player stations, if player 8 is the last one to make a bet, then the game must be moved up to the next player station, i.e., one. If the New Game Station Number GSN is not 9, the logic moves to the next inquiry as to whether the new GSN=Old GSN at 312. A negative response means that there is a player in the game available to make a bet. Therefore, the software executes to Set Next Player Up at 314 and Calculate and Display the Bet Account which displays the amount to stay in game on the player station and turns on his Player Up lamp, for the particular player and returns to Start Task at 204G, at which time the player may call the bet, raise the bet, or drop out in accordance with the game.
It should be understood that the system software can bypass a player station not in the game for functions, etc., but the system polls the stations in order. Then a station that is out is still counted, the GSN increments and the system moves on.
If the response to the question of whether the new GSN=Old GSN at 312 is positive, the system responds by executing Only One Player, Indicate Win+Display Amount 318. At such time the red light on the winning player station is activated and a display amount of the pot is transferred or displayed simultaneously in the pot display and in the player station display. The software then moves to Go To Win Routine at 346W, Return via Win Mode 322, Clear Status Bit 214, and the system moves on to the Start Task in the Win mode at 204W.
In the Win mode, the system inquires whether a Win Acknowledgement is Correct at 324 (FIG. 8C); that is, has the correct winning player pressed the Win Acknowledge button. If incorrect, Win Acknowledgement Error Routine 326 (similar to Errors noted Above) is executed, whereupon the system cycles back to the Start Task in the Win mode at 204W. If the proper player acknowledges the win by an affirmative at 324, the system goes to Compute New Wealth and Display Routine 328
The system moves then to the Go To New Game Routine at 330, return via New Game 331, Clear Status Bit 214, and the Start Tasks in the New Game Mode at 204N. A Bank Start New Game Inquiry is made at 334. A negative response means that the wrong player has pressed the RAISE/BET key for starting a new game and New Game Error Routine at 336 returns the system to the Start Tasks at 204 N. An affirmative response from the Bank Start New Game inquiry at 334 causes the system to Re-initialize and Clear Flags at 338 and Go To Ante Routine at 246A. Thereafter, the system displays each player's respective wealth account at the respective display for each player by means of Display Wealth Account Routine 340, Clear Status Bit 214, and the system recycles to the original Start Tasks at 204, shown in FIG. 7A.
There are other routines for operating various logic sequences in the game which are not described in these flow charts. However, it is believed that because certain routines such as calculating, adding, subtracting, multiplying and dividing are readily known by those skilled in the art, such a description herein is believed to be unnecessary.
Further, multiple winners may be accounted for by a non-zero decimal string preceding an OUT key stroke. Thus, the player is counted out but may be later counted as a winner requiring acknowledgement in the win phase.
It should also be understood that the system may provide other types of game play. For example, a player may purchase a wealth account at the rack track and place bets at a remote location from the betting window, such as his restaurant table. The system would require identifying the player station and player game entry device such as a credit card or card entry device. | A data processing system is provided for tallying wealth accumulation among a plurality of competing players. Each player has a game entry device coupled to a central processing unit. The CPU receives data on an interrupt basis from each of the player stations and regulates the ordered play among the competitors. The CPU is responsive to the data for indicating a winner, calculating the accumulated point total or wealth of each of the players and for indicating the amount necessary for a player to risk in order to stay in the competition. Anyone of the player stations designated may perform house or banking functions in addition to player functions. | 73,582 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Under 35 USC § 120, this application is a continuation application and claims the benefit of priority to U.S. patent application Ser. No. 10/387,847, filed Mar. 13, 2003 entitled “Method for Message Distribution to a Heterogeneous System”, all of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to messaging in distributed network processing systems and more specifically to message distribution in heterogeneous distributed network processing systems.
BACKGROUND OF THE INVENTION
[0003] FIG. 1 is a schematic block diagram of a distributed network processing system 100 . System 100 includes a control point (CP) 105 that is communicated to one or more network processors (NP) 110 by a switch 115 . CP 105 communicates to the NPs 110 by use of messages sent through switch 115 . Each message is marked with a destination address that is used by switch 115 to route the message. The destination address may be a unicast address or a multicast address. A unicast address identifies a single destination while a multicast address identifies one or more destinations. Switch 115 has a lookup table with an entry for each multicast address that indicates the members of the multicast set.
[0004] CP 105 includes a number of software components. There is a layer of software referred to as the Network Processor Application Services (NPAS) in CP 105 that provides services to User Applications to control NPs 110 . An application programming interface (API) exists between the NPAS and the user application. The user application defines programming calls and returns that are used to communicate with the NPAS. A management application 120 learns about each NP 115 through the NPAS. For example, the hardware version and the software version of each NP 115 is provided to management application 120 by the NPAS. A user is thereby enabled to know which level of hardware and software exists for each NP 110 .
[0005] The NPAS often is divided into multiple components, for example a first component 125 , a second component 130 and a controller 135 , with each of the components controlling a different NPAS function coordinated by control 135 . For example, component 125 may control an internet protocol (IP) function and component 130 may control a multi-protocol layer switch (MPLS) function. The components are often independent but are able to share common utilities within the NPAS.
[0006] The components take requests from the user application, process those requests, build messages based upon the requests and issue the messages to the appropriate NP or NPs. The appropriate NPs are indicated by the application through use of an address parameter in an API call. The address in the address parameter is often the same address used by the switch to direct the messages to the appropriate NP or NPs as it may be a unicast or a multicast address.
[0007] FIG. 2 is a schematic process flow diagram for a processing operation 200 of the NPAS shown in FIG. 1 . Processing operation 200 begins with an API call 205 from an application. Processing operation 200 first checks the call inputs for validity at step 210 . After step 210 , processing operation 200 processes the call inputs at step 215 . This processing step 215 includes performing calculations or consulting internal data structures. Next at step 220 , processing operation 200 builds an appropriate message according to the processing results. The appropriate message is then sent to the appropriate NPs in step 225 and control is returned to the application.
[0008] In a homogeneous network environment in which all the NPs all have the same or equivalent versions the processing operation of FIG. 2 operates satisfactorily. However, in a heterogeneous environment in which one or more NPs having a different or nonequivalent version are introduced into the network system a problem can arise. For purposes of this discussion, a different version of an NP is having a different hardware level or operating with a different software level as compared to a reference NP. An NP of a different version may require different messages or different message formats or have different functional capabilities as compared to the reference NP. For purposes of this discussion, an equivalent version for an NP as compared to a reference NP is one having a different version but the messages, the formats of these messages and the functional capabilities are the same for purposes of a particular API call or other relevant metric.
[0009] When the versions of the NPs are nonequivalent, the NPAS components need to perform different processing and send different messages and/or different message formats to various subsets of NPs as a result of a single API call. It is desirable to allow the processing overhead and burdens consequent to heterogeneous networks to be virtually transparent to any user application. What is needed is a solution that (a) reduces/minimizes an impact on current APIs, (b) reduces/minimizes an impact on NPAS components, (c) reduces/minimizes the number of messages sent through the switch, (d) the components should be independent of a coverage algorithm and (e) the NPAS components should not have to be aware of the many versions of hardware and/or software in the network system. Specifically, in (a), user applications may not be aware of the different versions of the NPs and it is preferable that a user application be able to operate in a heterogeneous system the same as it operates in a homogeneous network and to provide a single address (unicast or multicast) indicating the entire set of targeted NPs. In (b), it is not desirable to change the components in the NPAS when one or more NPs with a different version are introduced into a system. In (c), it is desirable to use multicast whenever possible to distribute the messages in order to minimize switch bandwidth usage. For (d), it is preferable that any algorithm used for determining the messaging subsets should be a common utility or function shared by all components. And (e), it would be advantageous that any additions of a new version NP not necessitate any change to any NPAS component.
[0010] Accordingly, what is needed is a method and system for providing transparent NP messaging in a heterogeneous network. The present invention addresses such a need.
SUMMARY OF THE INVENTION
[0011] A system and method is disclosed for communicating with a first network processor having a first operating environment and a second network processor having a second operating environment different from the first operating environment. The system includes a destination management service (DMS) including a memory, the memory registering (a) an application programming interface (API) call and recording an associated operating environment supporting the API call, (b) a messaging method appropriate for the API call in each operating environment; (c) a unicast address for each of the network processors and the operating environment for the network processor at each unicast address, and (d) a multicast address including the unicast addresses for the network processors; and a network processor application service, responsive to the API call from a user application identifying one or more network processors using a call address, the call address including the multicast address of one of the unicast addresses, for passing an identifier for the API call and the call address to the destination management service and for receiving a set of messaging methods for issuing the API call in appropriate form for the one or more operating environments implemented by the network processors addressed by the call address. The method for communicating with a plurality of network processors, one or more of the processors having a different operating environment, includes receiving an application programming interface (API) call from a user application, the API call including a call address identifying one or more of the network processors; and accessing a memory that identifies an appropriate form for the API call for each operating environment implemented by each network processor identified by the call address; and building one or more messages for the network processors identified by the call address, each of the one or more messages including the appropriate form for the API call for the operating environment of each of the network processors to receive any particular message.
[0012] The present invention permits transparent NP messaging in a heterogeneous network.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a schematic block diagram of a distributed network processing system;
[0014] FIG. 2 is a schematic process flow diagram for a processing operation of the NPAS shown in FIG. 1 ;
[0015] FIG. 3 is a flowchart of a preferred embodiment of the present invention for a message distribution process in a heterogeneous network;
[0016] FIG. 4 is a schematic block diagram of a distributed network processing system;
[0017] FIG. 5 is a schematic process flow diagram for a processing operation of an NPAS component shown in FIG. 4 including DMS message sets with associated messaging methodologies.
DETAILED DESCRIPTION
[0018] FIG. 3 is a flowchart of a preferred embodiment of the present invention for a message distribution process 300 in a heterogeneous network. The preferred embodiment introduces a destination management service (DMS) into the NPAS in lieu of the previous control 135 shown in FIG. 1 , as well as an architecture for components that are called messaging methods. In this new architecture, there are five entities including the user application, the NPAS component, a messaging entity, a transmission services and the new destination management service (DMS). The DMS tracks the various NP versions in a network system and determines a preferred set of messaging methods to be used for API call. The DMS interacts with the management component of the user application and the NPAS components in message distribution method 300 as shown in FIG. 3 .
[0019] Process 300 performs a registration step 305 when the NPAS software is initialized. Each NPAS component registers with DMS. The NPAS component registers each API call within the component with the set of versions supported by the specific API call. Also indicated during the registration are the messaging methods required to process those versions. Versions are grouped as ranges so that all versions are not enumerated
[0020] After registration step 305 , message distribution process 300 performs another registration step 310 . Registration step 310 is performed during application initialization in which the user management function registers with the DMS all the unicast addresses in the system giving the version number associated with the NP at that address.
[0021] After registration step 310 , message distribution process 300 performs another registration step 315 . Registration step 315 is also performed during application initialization in which the user management application registers with the DMS all the multicast addresses in the system and provides the unicast addresses that make up the multicast set.
[0022] Thereafter message distribution process 300 , at API step 320 , includes an NPAS component receiving a request from an application. This request is an API call and includes a unicast or multicast address as a parameter.
[0023] At invocation step 325 the NPAS component receiving the API call invokes the DMS by passing it the API call (or an identifier to the API call) and the destination address from the API call parameter.
[0024] In response to invocation step 325 , message distribution process 300 executes DMS process 330 . DMS process 330 computes a preferred/optimal set of messages that must be sent to achieve the result requested in the original API. DMS process 330 also associates the proper messaging method for each message in the message set and returns the message set and methods to the NPAS component that invoked the DMS. It is believed that there are different ways of computing the message set and associating the methods with the messages, each may be preferable in a various scenario or specific embodiment. The present invention contemplates that each of these ways may be used in the preferred embodiment. DMS process 330 does consider the various versions of the NPs included within the destination address when computing the message set and methods to return.
[0025] After DMS process step 330 , message distribution process 300 processes the API call at step 335 . The NPAS component that receives the message set and associated messages processes the API call by using the messages of the message set using the messaging methods prescribed by the DMS and sends the messages to the addresses (also identified by the DMS).
[0026] FIG. 4 is a schematic block diagram of a distributed network processing system 400 according to the preferred embodiment. System 400 includes a control point (CP) 405 that is communicated to one or more network processors (NP) 410 by a switch 415 . CP 405 communicates to the NPs 410 by use of messages sent through switch 415 . Each message is marked with a destination address that is used by switch 415 to route the message. The destination address may be a unicast address or a multicast address. A unicast address identifies a single destination while a multicast address identifies one or more destinations. Switch 415 has a lookup table with an entry for each multicast address that indicates the members of the multicast set.
[0027] CP 405 includes a number of software components. There is a layer of software referred to as the Network Processor Application Services (NPAS) in CP 405 that provides services to User Applications to control NPs 415 . An application programming interface (API) exists between the NPAS and the user application that defines programming calls and returns used to communicate with the NPAS. A management application 420 learns about each NP 415 through the NPAS. For example, the hardware version and the software version of each NP 415 is provided to management application 420 by the NPAS. A user is thereby enabled to know which level of hardware and software exists for each NP 415 .
[0028] The NPAS often is divided into multiple components, for example a first component 425 , a second component 430 and a controller 435 , with each of the components controlling a different NPAS function coordinated by destination management service (DMS) 435 . For example, component 425 may control an internet protocol (IP) function and component 430 may control a multi-protocol layer switch (MPLS) function. The components are often independent but are able to share common utilities within the NPAS.
[0029] The components take requests from the user application, process those requests, build messages based upon the requests and issue the messages to the appropriate NP or NPs. The appropriate NPs are indicated by the application through use of an address parameter in an API call. The address in the address parameter is often the same address used by the switch to direct the messages to the appropriate NP or NPs as it may be a unicast or a multicast address.
[0030] FIG. 5 is a schematic process flow diagram for a processing operation 500 of an NPAS component including DMS message sets with associated messaging methodologies. Processing operation 500 begins with an API call 505 from an application (like step 205 shown in FIG. 2 ). Processing operation 500 first checks the call inputs for validity at step 510 . After step 510 , processing operation 500 calls DMS at step 515 . DMS returns the set of processing methods and processing operation 500 iteratively uses the processing methods as indicated by the DMS to process the inputs (step 520 ), to build the appropriate message (step 525 ) and to send the appropriate message (step 530 ). After sending a message, processing operation 500 returns to perform step 520 through step 530 for each processing method until all processing methods have been executed by processing, building and sending all messages to all the addressed NPs. Once all processing methods are executed, processing operation 500 returns control to the application issuing the API call.
[0031] Although the present invention has been described in accordance with the embodiments shown, one of ordinary skill in the art will readily recognize that there could be variations to the embodiments and those variations would be within the spirit and scope of the present invention. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims. | A system is disclosed for communicating with a plurality of network processors, one or more of the processors having a different operating environment, includes receiving an application programming interface (API) call from a user application, the API call including a call address identifying one or more of the network processors; and accessing a memory that identifies an appropriate form for the API call for each operating environment implemented by each network processor identified by the call address; and building one or more messages including the appropriate form for the API call for the operating environment of each of the network processors to receive any particular message. | 17,534 |
FIELD OF THE INVENTION
This invention relates to carbon dioxide capture and energy recovery from the exhaust gas stream of an internal combustion engine in order to reduce carbon dioxide emissions into the atmosphere.
BACKGROUND OF THE INVENTION
The currently accepted thinking is that global warming is due to emissions of greenhouse gases such as carbon dioxide (CO 2 ) and methane (CH 4 ). About a quarter of global human-originated CO 2 emissions are currently estimated to come from mobile sources, i.e., automobiles, trucks, buses and trains that are powered by an internal combustion engine (ICE). This proportional contribution is likely to grow rapidly in the foreseeable future with the projected surge in automobile and truck ownership in developing countries. At present, the transportation sector is a major market for crude oil, and controlling CO 2 emissions is both an environmentally responsible and a desirable goal in order to maintain the viability of the crude oil market in the transportation sector in the face of challenges from alternative technologies, e.g., cars powered by electric motors and storage batteries.
Carbon dioxide management from mobile sources presents many challenges including space and weight limitations, the inability to achieve economies of scale and the dynamic nature of the operation of the ICE powering the mobile source.
Prior art methods for the capture of CO 2 from combustion gases have principally focused on stationary sources, such as power plants. Processes have been developed that use, for example, amines and amine-functionalized liquids and solutions to absorb CO 2 at temperatures ranging from ambient up to about 80° C. At temperatures above 100° C., and particularly in the range of from about 130° C. to 600° C. that are encountered in vehicles powered by an ICE, the amines exhibit low capacity for CO 2 absorption. Thus, the high temperature of the ICE exhaust gas makes direct treatment to remove CO 2 with liquid amine solutions impractical.
Aqueous ammonia has also been used in power plants to capture not only carbon dioxide, but SO x and NO x compounds. The absorption process must be conducted at relatively low temperatures to be effective, so that the solution must be cooled, e.g., to about 27° C. The so-called chilled ammonia process is described in international patent application WO 2006/022885 (2006), the disclosure of which is incorporated herein by reference.
An accepted prior art thermodynamic process used in stationary or fixed sources such as electrical power generation facilities for converting thermal energy into usable mechanical power is the Kalina Cycle. The Kalina Cycle can be implemented in order to increase the overall efficiency of the energy recovered from the fuel source. The process is a closed system that utilizes an ammonia-water mixture as a working fluid to improve system efficiency and to provide more flexibility under varying operating conditions that have cyclical peak energy demand periods. The Kalina Cycle would not be suitable for use on board a mobile source as a separate mechanical energy/work producing system due to the added weight and associated capital expense as compared to Rankine cycle systems.
Historically, the capture of CO 2 from mobile sources has generally been considered too expensive, since it involves a distributed system and a reverse economy of scale. The solution to the problem must take into account the practical considerations of on-board vehicle space limitations, the additional energy and apparatus requirements and the dynamic nature of the vehicle's operating cycle, e.g., intermittent periods of rapid acceleration and deceleration.
Some prior art methods that address the problem of reducing CO 2 emissions from mobile sources employ sorbent materials that can be subjected to regeneration and reuse of the CO 2 capture agent and make use of waste heat recovered from the various on-board sources. Oxy-combustion processes employed with stationary sources using only oxygen require an oxygen-nitrogen separation step which is more energy-intensive than separating CO 2 from the exhaust gases and would be more problematic if attempted on board a vehicle.
For purposes of describing the present invention, “mobile source” means any of the wide variety of known conveyances that can be used to transport goods and/or people that are powered by one or more internal or external combustion engines that produce a hot exhaust gas stream containing CO 2 . This includes all types of motor vehicles that travel on land, as well as trains and ships where the exhaust from the combustion is discharged into a containing conduit before it is discharged into the atmosphere.
As used herein, the term “waste heat” is the heat that a typical internal combustion engine (ICE) produces that is contained principally in the hot exhaust gases (˜300° C. to 650° C.) and the hot coolant (˜90° C. to 120° C.). Additional heat is emitted and lost by convection and radiation from the engine block and its associated components, and other components through which the exhaust gas passes, including the manifold, pipes, catalytic converter and muffler. This heat energy totals about 60% of the energy that typical hydrocarbon (HC) fuels produced when combusted.
As used herein, the term “internal heat exchanger” means a heat exchanger in which the respective heating and cooling fluids originate in the mobile source.
As used herein, “stationary source” means any of the wide variety of known industrial systems and processes that burn carbon-containing fuels and emit CO 2 to produce heat, work, electricity or a combination thereof and that are physically fixed.
As used herein, the term “lean loading” means the amount of CO 2 remaining in the lean adsorption/absorption solution coming out of the bottom of the CO 2 stripper. In accordance with established usage in the field, loading is defined as the moles of CO 2 per mole of the amine group or other compound that captures the CO 2 by adsorption or relative absorption. As used herein, the terms “CO 2 -rich solution” and “CO 2 -lean solution” are synonymous with “rich loaded CO 2 solution” and “lean loaded CO 2 solution”.
The problem of improving the efficiency of the energy recovered from hydrocarbon fuel combustion in an ICE has been addressed by taking advantage of the waste heat that is present in the engine coolant, the exhaust gas stream and the engine block, manifolds and other metal parts.
Incorporating an energy recovery system requires space, added weight and a specific capital expenditure. However, this investment can be worthwhile if the energy recovery system improves the overall efficiency of the fuel conversion to mechanical power, while reducing the CO 2 emissions into the atmosphere, and does this without substantially increasing fuel consumption.
It had long been the practice to use CO 2 as a non-toxic and non-flammable refrigerant gas in air conditioning systems prior to the use of chlorofluorocarbon (CFC) refrigerants. It has been proposed more recently in order to improve vehicle efficiency to operate an air conditioning system in reverse, utilizing heat from the vehicle's hot exhaust gas stream to generate additional power for use on board the vehicle. See, e.g., Chen et al., Theoretical Research of Carbon Dioxide Power Cycle Application in Automobile Industry to Reduce Vehicle's Fuel Consumption, Applied Thermal Engineering 25 (2005) 2041-2053. The systems contemplated are closed systems and are based on the moderate value of the critical pressure of CO 2 . There is no capture and recovery of CO 2 from the exhaust gas stream in order to reduce CO 2 emissions into the environment.
A so-called thermal engine for power generation has been described that uses waste heat from the flue gases produced by a stationary source in a closed loop system that uses supercritical CO 2 (ScCO 2 ) as the working fluid. See Persichilli et al., Transforming Waste Heat to Power Through Development of a CO 2 -Based Power Cycle, Electric Power Expo 2011 (May 2011) Rosemont, Ill. The ScCO 2 passes in heat exchange with hot flue stack gases and then through a turbine where the waste heat is converted to mechanical shaft work to produce electricity. A recuperator recovers a portion of the residual heat and the remainder is discharged from the system through a water or air-cooled condenser, from which the CO 2 exits as a subcooled liquid for passage to the pump inlet. Again, this closed system is adapted for integrated use with an industrial heat source to improve the overall efficiency of the associated system. It does not capture CO 2 for the purpose of directly reducing its emission into the atmosphere with the exhaust gases.
Incorporating a CO 2 capture system on board a mobile source to reduce CO 2 emissions adds weight, energy consumption, capital expenditures and maintenance. The problem is to provide a compact system that is easy to operate and maintain at an acceptable and competitive cost of manufacture.
Another problem addressed by the present invention is how to provide an effective and efficient CO 2 capture system in combination with an energy recovery and conversion system to produce the electrical and/or mechanical energy needed to compress the CO 2 for on-board storage, operate the associated systems and power the mobile source accessories.
A related problem is how to combine the CO 2 capture and energy recovery systems to increase the overall efficiency and reduce the number of components, weight, capital expenditure, and maintenance of the overall system and the vehicle.
Technical problems associated with CO 2 capture from mobile sources include how to further increase the efficiency of on-board CO 2 capture so that operating a conventional ICE powered by hydrocarbon fuels will remain economically and environmentally competitive with the all-electric and hybrid automobiles. These traditional problems are addressed by the processes and systems disclosed, for example in WO/2012/100149, WO/2012/100165, WO/2012/100157 and WO/2012/100182 which integrate CO 2 capture, heat recovery and CO 2 capture agent regeneration and reuse systems, hereinafter referred to as “multiple systems”. However, utilizing multiple systems in mobile applications also increases weight, energy consumption, capital expenditure, and maintenance associated with operation of the vehicle.
The problem remains of further improving the efficient on-board capture of CO 2 from the hot exhaust gas stream from the ICE powering a mobile source.
SUMMARY OF THE INVENTION
The present invention broadly comprehends a process and an integrated system for use on board a vehicle powered by an internal combustion engine (ICE) that combines power generation with CO 2 capture and on-board CO 2 densification and storage that reduces irreversibilities and increases the overall efficiency of the process and the operating system to thereby maximize the recovery of useful energy from the hydrocarbon fuel used to power the vehicle.
More specifically, the present invention is directed to a process and system for CO 2 capture and energy recovery from an exhaust gas stream to reduce CO 2 emissions from a variety of conventional mobile applications in which the captured CO 2 is retained in the working fluid in an energy production cycle to produce work and the CO 2 is subsequently separated from the working fluid, compressed and temporarily stored on-board for eventual on-board conversion or recovery from the mobile source. The principal method and system of the invention are also applicable to CO 2 from recovered stationary sources for disposition, e.g., by sequestration.
The process of the invention uses a CO 2 -absorbing liquid, sometimes referred to in this description and in the claims as the “solution,” or the “sorbent solution”, in an absorption zone by direct contact or indirect contact, e.g., using a membrane absorber, with a CO 2 -containing exhaust gas stream to absorb all or a portion of the CO 2 that would otherwise be discharged into the atmosphere.
Water is a preferred solvent in which amines and other CO 2 absorbents such as bicarbonates are dissolved to operate the system for reasons of economics, availability and the absence of environmental concerns if it is discharged from the system in favor of a replacement with fresh water. Alcohols can be used to capture CO 2 and can be used as the solvent or as the solute. Colloidal solutions that contain, for example, water as a solvent and suspended solid sorbents that capture CO 2 can also be used in the process of this invention. Heating such solutions will result in CO 2 desorption from the solid particles and water evaporation to drive the turbine. As will be apparent to one of skill in the art, families of CO 2 absorbents and adsorbents and solvents can be selected based on the specific conditions of use including climate, availability of sorbent and solute materials, and the type of ICE. For the purposes of the following description, water is selected as the working fluid.
The operation of the process is similar to that of prior art systems such as the Kalina Cycle and absorption systems. However, both of those processes are closed systems, used for power generation in the case of the Kalina Cycle and for cooling or heating in the case of absorption systems.
As used in the description that follows and in the claims, the term “external heat exchanger” means a heat exchanger which is air-cooled or water cooled, i.e., the energy sink that is required to close the energy loop is external to the process or system.
The CO 2 -rich solution exiting the absorber is heated via one or more heat exchangers and passed to a boiler that is heated by the hot exhaust gas stream from the ICE. In the boiler, the CO 2 is desorbed from the sorbent solution and at least a portion of the water in the solution is evaporated to form steam. Thereafter, the vapor phase is passed to a separation zone in which a hot liquid/vapor separator produces a stream of the now-concentrated sorbent solution having a higher concentration of the CO 2 -absorbing compound.
The CO 2 /water vapor stream from the separation zone is then passed to a superheating zone where it is subjected to heat exchange with the hot exhaust gas stream passed directly from the ICE that is at a temperature in the range of from 200° C. to 800° C. The superheated vapor phase is expanded in one or more turbines to generate power. In the case of multiple turbines, inter-stage heating by heat exchange with the hot exhaust gases is employed to maximize the cycle efficiency of the working fluid containing the captured CO 2 .
The liquid CO 2 -lean solution leaving the liquid/vapor separator is passed to a first internal heat exchanger to heat the CO 2 -rich solution and increase the cycle efficiency. The CO 2 -lean solution is then expanded in a turbine or through an expansion valve and it is then cooled, in an external heat exchanger by contact with ambient air or the engine coolant, to the desired absorber temperature for passage to the absorption zone.
The CO 2 /water stream leaving the turbine is passed to a second internal heat exchanger to provide heat to the CO 2 -rich solution and increase the cycle efficiency before it is cooled, by an external heat exchanger operated by contact with ambient air or the engine coolant, to the temperature of a CO 2 /water separator from which a CO 2 -rich gas stream is recovered and condensed water is recovered as a liquid.
All or a portion of the condensed water can be mixed with the concentrated sorbent solution from the separator to restore the desired concentration to the solution, which is then pumped to the absorber inlet. The CO 2 -rich gas stream is compressed in a multi-stage CO 2 compressor with inter-stage cooling and a water knock-out to remove any water carried over with the CO 2 from the condenser/separator. The compressed pure CO 2 is passed to a high pressure tank for temporary on-board storage pending ultimate disposition. Moderate or no compression can also be practical for CO 2 conversion by a chemical change or storage of CO 2 in a high-capacity retention material, such as metal-organic frameworks (MOFs) and covalent-organic frameworks (COFs). In the case of CO 2 captured from a stationary CO 2 source for permanent disposition, the captured CO 2 can be conveyed in a pipeline for permanent storage, e.g., by underground sequestration.
The power produced by the turbine(s) can be used to drive one or more absorbent liquid pumps and/or CO 2 compressors. Any excess power can be used to charge the vehicle's battery or to power on-board electrical components.
The present invention provides a highly efficient process and system that recovers energy from the waste heat of the exhaust gas stream by utilizing the captured CO 2 as a component in a heated and pressurized working fluid in a process which produces mechanical and/or electric energy to meet the requirements of the pumps and/or CO 2 compressors on board the vehicle.
From the above description, it will be understood that the invention is directed to a process for reducing the amount of CO 2 released into the atmosphere with the exhaust gas stream produced by the combustion of a hydrocarbon fuel in an ICE used to power a vehicle by capturing at least a portion of the CO 2 with a sorbent on board the vehicle, recovering the CO 2 from the sorbent and compressing the CO 2 for temporary storage on board the vehicle, the process characterized by
a. passing the hot exhaust gas stream from the ICE through a plurality of heat exchangers in a first heat exchange zone to reduce the temperature of the exhaust gas stream to a value in a predetermined temperature range; b. contacting the cooled exhaust gas stream in an absorption zone with a liquid CO 2 sorbent solution at a temperature within a predetermined temperature range, the solution comprising water in which is dissolved at least one compound that reversibly combines with CO 2 to capture at least a portion of the CO 2 from the exhaust gas stream to provide a CO 2 -rich solution; c. separating the CO 2 -rich solution from the remaining exhaust gas stream that is of reduced CO 2 content; d. discharging the remaining exhaust gas stream of reduced CO 2 content into the atmosphere; e. pressurizing the CO 2 -rich solution and passing it into a boiler for passage in a first heat exchange relation with a partially-cooled exhaust gas stream to raise its temperature to desorb the CO 2 and provide a concentrated CO 2 -lean sorbent solution and to vaporize a portion of the water from the sorbent solution to provide a vaporized water/CO 2 mixture; f. separating the CO 2 -lean sorbent solution from the vaporized water/CO 2 mixture in a first separation zone; g. passing the vaporized water/CO 2 mixture into a superheating zone where it passes in a second heat exchange relation with the hot exhaust gas stream directly from the ICE to further increase the temperature of the mixture to about 400° C.; h. passing the superheated water/CO 2 mixture to a turbine and expanding the mixture to a predetermined lower pressure value; i. passing the hot expanded water/CO 2 mixture in heat exchange with the pressurized CO 2 -rich solution; j. passing the water/CO 2 mixture to a condensing heat exchanger to lower its temperature to condense substantially all of the water vapor to the liquid state; k. separating the condensed water from the CO 2 in a second separation zone and mixing all or a portion of the condensed water with the sorbent solution upstream of the absorption zone or discharging the water from the vehicle; l. recovering the substantially pure CO 2 from the second separation zone and passing it to a compression zone to densify the CO 2 and discharging any remaining water; m. recovering the pressurized pure CO 2 and passing it to an on-board vessel for storage or for further processing to reduce its volume by a physical and/or chemical change of state; n. passing the pressurized CO 2 -lean solution from the first separation zone in heat exchange relation to increase the temperature of the pressurized CO 2 -rich solution from the absorption zone; o. introducing the pressurized CO 2 -lean solution into an expansion device to produce mechanical energy; p. passing the reduced-pressure concentrated CO 2 -lean solution from the expansion device to a mixing valve through which water is added to restore the desired concentration of the sorbent solution; q. cooling the CO 2 -lean solution to the predetermined temperature range prior to passing it into the absorption zone; and r. pressurizing the CO 2 -lean sorbent solution upstream of the absorption zone.
As will be understood by one of ordinary skill in the art, the temperature of the superheated vaporized water/CO 2 mixture in step (g) above can vary from 400° C. and will depend on the optimum operating conditions of the system. The reduction in volume of the CO 2 can be achieved by maintaining it in a liquid, solid or super-critical state. As also noted above, solvents other than water can be employed in the practice of the process.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be further described below and with reference to the attached drawings in which the same or similar elements are identified by the same number, and in which:
FIG. 1 is a schematic diagram of an embodiment of the process of the invention in a basic cycle in which CO 2 is captured and compressed in a power production cycle;
FIG. 2 schematically illustrates an embodiment of the invention that includes an optional re-heat step;
FIG. 3 schematically illustrates an embodiment of the invention in which the pressure at the turbine exit is reduced to below atmospheric pressure (vacuum) in order to increase expansion power recovery;
FIG. 4 schematically illustrates a fourth embodiment of the invention in which an additional internal heat exchanger extracts heat from the exhaust gas stream; and
FIG. 5 is a screenshot of an Aspen simulation for a process that is similar to the process described in FIG. 2 .
DETAILED DESCRIPTION OF INVENTION
As discussed above, the process of the present invention operates as a semi-closed system that captures CO 2 from an exhaust gas stream of an ICE and produces mechanical energy, or work, utilizing a working fluid that contains the CO 2 in the power generation cycle. The process can be used to advantage for CO 2 capture from a mobile source powered by an internal combustion engine (ICE).
Referring to an embodiment of the invention schematically illustrated in FIG. 1 , a simplified cycle of the process is depicted in which CO 2 is captured and compressed in a power production cycle.
A lean loaded CO 2 absorbing solution (hereafter referred to as “solution”) such as aqueous potassium carbonate is transferred via pump ( 10 ) as stream ( 102 ) to the absorption unit ( 20 ) to capture CO 2 from the exhaust gas stream at atmospheric or near atmospheric pressure.
The CO 2 absorption unit ( 20 ) can be a direct contact liquid/gas column such as packed column or an indirect contact membrane absorption device such as gas-liquid membrane contactor. For convenience, the description that follows will refer to the practice of the process of the invention in a direct contact absorption unit. However, as will be understood by those of ordinary skill in the art, an indirect absorber can be employed with substantially the same effect.
The hot exhaust gas stream ( 901 ) exiting the ICE is first cooled by passage through the superheater ( 31 ) and enters the boiler ( 30 ) as reduced temperature stream ( 902 ). The exhaust gas stream ( 903 ) exiting the boiler ( 30 ) is further cooled to a predetermined temperature between 30° C. and 100° C. in a heat exchanger ( 36 ) and the cooled stream ( 904 ) enters the absorption unit ( 20 ) where CO 2 is absorbed by the cooled CO 2 -lean loaded solution that enters the absorber ( 20 ) via stream ( 102 ) at a temperature between 30° C. and 100° C.
The remaining exhaust gas ( 905 ) leaves the absorber ( 20 ) after CO 2 capture and is discharged into the atmosphere.
The CO 2 -rich solution leaves the absorber ( 20 ) via stream ( 200 ) and is pressurized by pump ( 11 ) to the high pressure value of the system, e.g., to 4 MPa, and passes as stream ( 201 ) to a first internal heat exchanger ( 34 ) where it is heated about 100° C. by the CO 2 /water stream ( 403 ) leaving turbine ( 51 ) as will be described in further detail below.
The pressurized CO 2 -rich solution ( 202 ) exits the internal heat exchanger ( 34 ) and passes through a second internal heat exchanger ( 33 ) for further heating. The second internal heat exchanger ( 33 ) is heated by the high pressure CO 2 -lean solution ( 300 ). The high pressure CO 2 -rich solution ( 203 ) then enters boiler ( 30 ).
The high pressure CO 2 -rich solution ( 203 ) is partially evaporated in boiler ( 30 ) which is heated by the hot exhaust gas stream ( 902 ) downstream of the superheater ( 31 ) which is in close proximity to the exhaust manifold of the ICE; the CO 2 and water are vaporized because of their lower normal boiling points.
The high pressure CO 2 -rich liquid/gas mixture ( 205 ) leaves the boiler ( 30 ) at an increased temperature of, e.g., about 210° C., and enters a liquid/vapor separator ( 40 ) that separates the gaseous CO 2 /water mixture from the remaining high pressure CO 2 -lean solution ( 300 ).
The high pressure CO 2 -lean solution ( 300 ) leaves the liquid/vapor separator ( 40 ), enters internal heat exchanger ( 33 ) and passes as stream ( 301 ) to an expansion device ( 50 ), e.g., a turbine or throttle valve, where it is expanded to a lower pressure before passing to the liquid header ( 100 ) as stream ( 302 ). The expansion device ( 50 ) recovers power P for the system from the waste heat and provides mechanical energy to pumps ( 10 ) and ( 11 ).
The CO 2 /water vapor mixture ( 401 ) exiting the liquid/vapor separator ( 40 ) passes through the superheater ( 31 ) that is heated by the exhaust gas stream ( 901 ) and exits as superheated stream ( 402 ) at a temperature of approximately 400° C. and expands in a turbine ( 51 ) to produce power, exiting at approximately atmospheric pressure as stream ( 403 ).
The power P from the turbine ( 51 ) is applied to operate pumps in the system, to compress CO 2 and/or to operate the process utilities, as required.
The low pressure CO 2 /water exiting the turbine ( 51 ) as stream ( 403 ) passes through an internal heat exchanger ( 34 ) and exits via stream ( 406 ) to another heat exchanger ( 37 ) where it is further cooled to approximately 40° C. in order to condense the water. After exiting the heat exchanger ( 37 ) via stream ( 407 ), the low pressure CO 2 /water passes to a separator ( 41 ) where the condensed water is separated from the CO 2 gas. The condensed water stream ( 500 ) exiting the separator ( 41 ) is composed of water with some dissolved CO 2 , all or a portion of which can be passed to the liquid header ( 100 ) as stream ( 502 ); any excess water can be discharged from the system as stream ( 501 ).
The liquid solution ( 100 ) is further cooled in heat exchanger ( 35 ) to the desired CO 2 absorption temperature before it is fed to the suction line ( 101 ) of pump ( 10 ) that feeds the CO 2 absorber ( 20 ).
The vapor stream ( 600 ) consisting principally of CO 2 passes from the separator ( 41 ) to the compression zone ( 60 ) where it is compressed to produce a high-purity CO 2 stream ( 601 ). The high-purity CO 2 stream ( 601 ) can be passed to on-board storage in mobile applications and to storage and/or a pipeline in the case of stationary or fixed CO 2 sources. Any remaining water is condensed by intercooling and phase separation and discharged from the system as water stream ( 700 ).
All or a portion ( 704 ) of the condensed water ( 700 ) can optionally be returned via a three-way valve ( 702 ) to the loop ( 100 ) or to the pump suction line ( 101 ) in order to control the water content of the lean absorption solution in the process and prevent salt precipitation. Fresh make-up water can also be used for this purpose, alone or in combination with condensed water stream ( 700 ). Alternatively, the condensed water ( 700 ) can be discharged ( 706 ) from the system.
In another embodiment of the invention schematically illustrated in FIG. 2 , an optional re-heating step is provided in which the exiting vapor stream is re-heated after a first expansion of the working fluid in order to increase the overall cycle efficiency.
In this embodiment, the hot exhaust gas stream ( 900 ) enters the system through heat exchanger ( 32 ) where the medium pressure CO 2 /water mixture ( 403 ) at, e.g., one Mpa, is re-heated to about 400° C. and exits as heated stream ( 404 ).
The cooled exhaust gas stream ( 901 ) from heat exchanger ( 32 ) enters the superheater ( 31 ) and follows the same path that was described in FIG. 1 .
The superheated CO 2 /water stream ( 402 ) from superheater ( 31 ) is expanded in turbine ( 51 ) to a medium pressure of about 1 MPa and exits as stream ( 403 ). Stream ( 403 ) passes to heat exchanger ( 32 ) to be re-heated by the entering exhaust gas stream ( 900 ) to a temperature of about 400° C. and then passes as stream ( 404 ) to turbine ( 52 ). The expanded low pressure stream ( 405 ) exits the turbine ( 52 ) at approximately atmospheric pressure and passes to internal heat exchanger ( 34 ) to exchange heat with the high pressure CO 2 rich solution stream ( 201 ), and exits as stream ( 406 ).
The process steps of stream ( 406 ) are the same as those described above in conjunction with the embodiment of FIG. 1 .
The re-heating step is followed by a further expansion step to reduce the irreversibilities in the system and increase the overall system efficiency. Other aspects of the process of FIG. 1 , including the use of the condensate stream ( 700 ) that may be injected back into the loop via line ( 100 ) or ( 101 ) as make-up water in order to control the water content in the process and prevent salt precipitation is also applicable to the embodiment of FIG. 2 .
In a third embodiment of the invention that is schematically illustrated in FIG. 3 , the pressure at the turbine exit is reduced to below atmospheric pressure, e.g., to a vacuum in order to increase expansion power recovery.
This advantage can be realized because the CO 2 water saturation pressure at ambient temperature is less than atmospheric pressure allowing for a higher power recovery from the fluid expansion and an increase in the net power and efficiency of the process of the invention.
The process in FIG. 3 is similar to the first embodiment as described above in connection with FIG. 1 , with the difference being that the outlet pressure of stream ( 403 ) exiting the turbine ( 51 ) is reduced to, i.e., 20 kPa absolute pressure and a pump ( 12 ) is added to the process to pressurize the liquid stream ( 500 ) to near atmospheric pressure.
The superheated CO 2 /water stream ( 402 ) leaving the superheater ( 31 ) is expanded in turbine ( 51 ) to 20 kPa in order to recover the expansion energy. The CO 2 /water stream leaves the turbine via stream ( 403 ) to enter internal heat exchanger ( 34 ) and the CO 2 water stream exits as stream ( 406 ).
The CO 2 /water stream ( 406 ) is further cooled in heat exchanger ( 37 ) to achieve the desired separation of the CO 2 by condensing the water. Stream ( 407 ) exiting heat exchanger ( 37 ) passes to a separator ( 41 ) where a CO 2 -rich stream ( 600 ) is recovered under a vacuum, e.g., 20 kPa, and compressed in the multi-stage compressor ( 60 ) to the required outlet pressure and the pressurized stream ( 601 ) and passed for storage or further processing.
The condensate stream ( 500 ) composed mainly of water is pressurized by pump ( 12 ) to the liquid header line ( 100 ) pressure, e.g., 100 kPa to complete the cycle. Stream ( 510 ) exiting pump ( 12 ) is conveyed in whole or in part for addition to stream ( 100 ) via stream ( 502 ), the excess being discharged from the system as stream ( 501 ).
The same vacuum condensation principle can be applied to the re-heat configuration by reducing the outlet pressure of turbine ( 52 ), e.g., to 20 kPa, in order to recover additional work energy and increase the efficiency of the process.
In a fourth embodiment of the invention that is schematically illustrated in FIG. 4 , the exhaust gas stream ( 903 ) is further cooled exchanging heat with the high pressure CO 2 -rich solution stream ( 202 ) in a step to increase the overall cycle efficiency, capturing more CO 2 or providing more power for a same CO 2 capture rate.
The process in FIG. 4 is similar to the embodiment as described above in connection with FIG. 3 , with the difference of the inclusion of an additional internal heat exchanger ( 39 ) between heat exchanger ( 30 ) and external heat exchanger ( 36 ) on the exhaust gas line, and between heat exchanger ( 34 ) and heat exchanger ( 33 ) on the high pressure CO 2 -rich solution.
The exhaust gases leaving heat exchanger ( 30 ) in stream ( 903 ) heat the high pressure CO 2 -rich solution stream ( 202 ) exiting heat exchanger ( 34 ). The cooler exhaust gas stream ( 934 ) leaves heat exchanger ( 39 ) to enter heat exchanger ( 36 ) and continue the process as described in FIG. 3 .
The high pressure CO 2 -rich solution stream ( 202 ) leaving heat exchanger ( 34 ) is heated in heat exchanger ( 39 ) by the hot exhaust gases before entering heat exchanger ( 33 ) for further heating via stream ( 222 ). Afterwards, the high pressure CO 2 -rich solution undergoes the same steps described in FIG. 3 of the process.
In yet another embodiment, it is possible to integrate heat exchanger ( 39 ) in the re-heat configuration of the system as described in FIG. 2 or in the above atmospheric pressure outlet configuration as described above and represented in FIG. 1 of the invention.
As will be apparent to one of ordinary skill from the above description of the process and system, the fluids circulated to the three heat exchanges (e.g., 33 , 34 and 39 ) can be varied depending upon the operating characteristics and requirements of the process. For example, the thermodynamic characteristics can be adjusted in order to obtain additional power from the turbines ( 50 , 51 , 52 ), as discussed further below.
As described above in connection with the previous embodiments, all or a portion of water stream ( 700 ) can be injected back into the loop in line ( 100 ) or ( 101 ) in order to control the water content of the solution used in the process and prevent salt precipitation. Fresh make-up water can also be used for this purpose, either alone or in combination with water from stream ( 700 ).
It is noted that the process shown in FIG. 4 also includes a re-heat step as was previously shown in FIG. 2 to further increase process efficiency.
The process according to the invention can be operated to achieve a predetermined CO 2 capture goal, e.g., 25%, or to produce a predetermined required amount of power.
In a CO 2 capture application, CO 2 compression is the main energy-intensive component of the system and the net power output is the net power produced by the turbines minus the power consumed by the pumps and in the CO 2 compression step or steps.
Since pumps are indispensable to the operation of the system, there can be little or no variation in meeting requirements for the operation of the pump; however, the extent of CO 2 compression can be varied and is dependent on the CO 2 capture rate and/or the on-board storage capacity.
In a power-oriented operational mode with no CO 2 capture rate requirements, the rate can be adjusted according to the desired net power output, e.g., by reducing the CO 2 capture rate to reduce the CO 2 compression power requirement, thereby increasing the net power output of the system.
Alternatively, if the CO 2 capture rate is to be fixed, e.g., within a given range, or not less than a predetermined value, the system should operate at the required CO 2 capture flow rate with no degree of freedom on the net power production.
The choice of the pressure and temperature throughout the system dictates the parameters of the production cycle and the potential CO 2 capture rate. For example, superheating and re-heating can be used to increase the power output and reduce the irreversibilities in the system. As a result, superheating and re-heating do not affect the CO 2 capture rate, but do affect the net power produced.
An important parameter that does affect the CO 2 capture rate is the temperature and pressure of stream ( 205 ) exiting heat exchanger ( 30 ) and entering separator ( 40 ) since the conditions of this stream will determine how much CO 2 and water go into the vapor phase in separator ( 40 ).
The temperature and pressure at the outlet of heat exchanger ( 37 ), as well as the operating temperature and pressure of separator ( 41 ) relate to the actual rate of CO 2 capture because the temperature and pressure of separator ( 41 ) control the ratio between the liquid and vapor phase. It is therefore possible to regulate the system's operation to achieve the desired power production and/or level of CO 2 capture and emissions reduction by controlling the temperature and pressure in these devices ( 37 , 41 ).
The process according to the invention can use, in addition to the heat of the exhaust gas stream, one or more different sources of energy such as engine coolant energy, solar energy, or any other available form of recoverable thermal energy, to support the operation of the heat exchangers ( 30 ) and/or ( 31 ) and/or ( 32 ) and/or ( 39 ) to maximize the power production.
Recoverable energy such as kinetic, mechanical and/or electrical energy can be used in the process to increase the output of the turbines and/or operate the CO 2 compressor. Energy recovery systems and devices that are used on all-electric or hybrid motor vehicles can also be employed on vehicles powered by an ICE to provide electrical power directly or through a storage battery or other device.
Any cooling device in the process used to cool a stream with an ambient or external stream, e.g., an air-cooled heat exchanger ( 36 ), can be replaced by an energy recovery device, e.g., a thermo-electric device or other device that captures and converts heat to energy while cooling the working fluid stream to the desired temperature, and the recovered energy can be utilized in the process. For example, instead of cooling the exhaust gas stream from 200° C. to 60° C. in a heat exchanger, a thermoelectric device can be utilized to cool stream ( 903 ) to the desired temperature while producing electricity from the recovered energy.
The process of the invention can also be modified by changing the position of the pumps or replacing the pumps with ejectors. It is also possible, depending on the type of the absorber ( 20 ), i.e., closed type, membrane absorber, or other, to combine pump ( 10 ) and pump ( 11 ) in a single pump that is either upstream of the absorption unit ( 20 ) or, preferably in the location of downstream pump ( 11 ) in order to carry out the absorption at a lower solution pressure.
The process of the invention can also employ various processes for CO 2 and water separation such as membranes or other separation means.
The CO 2 absorbing solution used in the process according to the invention can be a water-based solution containing salts and/or amines and/or other molecules that capture CO 2 , by either a physical or chemical process. The CO 2 sorbent solution used in the process of the invention can be selected from the following:
a. a solvent-based solution containing salts and/or amines and/or other molecules that physically or chemically absorb CO 2 ; b. a solvent-based or water-based carrier in which solid CO 2 adsorbent particles are dispersed and the CO 2 is adsorbed by the particles at low temperature and desorbed from the particles at high temperatures, the particles being regenerated and recycled, and the liquid carrier also preferably adsorbs or absorbs the CO 2 physically or chemically at low temperatures and desorbs the CO 2 at high temperatures in order to reduce the flow rate and contactor size; c. a colloid fluid or crystalloid fluid reversibly absorbing and/or adsorbing CO 2 and desorbing CO 2 at the appropriate conditions; and d. a mixture of absorbing and adsorbing liquids.
As will be understood from the above descriptions and examples, the process of the invention broadly comprehends the combination of CO 2 capture in an integrated system that reduces irreversibilities and thereby increases the overall efficiency of the processing and operating system.
In addition to increased efficiency and waste heat recovery in mobile applications, the process of the invention includes the advantages of requiring a reduced number of components as compared to separate heat recovery and CO 2 recovery systems. The integrated system saves space and weight on board mobile sources and reduces capital expenditures and operational maintenance costs.
FIG. 5 is a screen shot of an Aspen Plus Simulation flowsheet representing an embodiment of the invention similar to the process that is depicted in FIG. 2 .
Example
The process according to the best mode of the embodiment illustrated in FIG. 3 for the practice of the process of the invention for mobile applications will be described in further detail in this example. A lean aqueous potassium carbonate CO 2 absorbing solution is pressurized by pump ( 10 ) and introduced as stream ( 102 ) into the absorption unit ( 20 ) to capture CO 2 from the cooled exhaust gas stream. The CO 2 absorption unit ( 20 ) can be a direct contact liquid-gas column or an indirect contact membrane absorption device that operates at atmospheric or near atmospheric pressure.
The hot exhaust gas stream ( 901 ) is cooled in passes through superheater ( 31 ) and boiler ( 30 ). The exhaust gas stream ( 903 ) exiting the boiler ( 30 ) is further cooled to a predetermined temperature between 30° C. and 100° C., depending on ambient conditions, in a heat exchanger ( 36 ) and the cooled exhaust gas stream ( 904 ) enters the absorption unit ( 20 ) where CO 2 is absorbed by the CO 2 -lean solution ( 102 ) to complete the absorption.
The remaining portion of the exhaust gas stream ( 905 ) of reduced CO 2 content exits the absorber ( 20 ) and is discharged into the atmosphere. In an alternative embodiment, prior to its discharge into the atmosphere, the flue gas stream ( 905 ) can be reheated, e.g., to expand its volume. The reheating of stream ( 905 ) can be accomplished using the heat from stream ( 903 ) entering heat exchanger ( 36 ). In this embodiment, heat exchanger 36 can be replaced by an internal heat exchanger or the system can incorporate an internal heat exchanger upstream of heat exchanger ( 36 ) in which stream ( 903 ) provides heat to stream ( 905 ).
The CO 2 -rich solution ( 200 ) exits the absorber ( 20 ) and is pressurized by pump ( 11 ) to the high pressure value of the system, e.g., to 4 MPa, and passes as pressurized stream ( 201 ) to a first internal heat exchanger ( 34 ) where it is heated by the CO 2 /water stream ( 403 ) leaving turbine ( 51 ) as will be described in further detail below.
The heated high pressure CO 2 -rich solution ( 202 ) exits the first internal heat exchanger ( 34 ) and passes through a second internal heat exchanger ( 33 ) for additional heating. The second internal heat exchanger ( 33 ) is heated by the hot high pressure CO 2 -lean solution ( 300 ) from which CO 2 has previously been recovered. The high pressure CO 2 -rich solution ( 203 ) then enters the boiler ( 30 ).
The pressurized CO 2 -rich solution ( 203 ) is partially evaporated in boiler ( 30 ) which is heated by the hot exhaust gas stream ( 902 ); the portion of absorbed CO 2 is desorbed and some water is vaporized because of their lower normal boiling points. As the concentration of the potassium carbonate increases, the boiling point of the solution also rises, so that the solution remains in a flowable liquid state.
The high pressure CO 2 -rich solution ( 205 ) passes from the boiler at a temperature of about 210° C. and enters a liquid/vapor separator ( 40 ) that separates the CO 2 /water gaseous mixture from the remaining pressurized CO 2 -lean solution.
The pressurized CO 2 -lean solution ( 300 ) leaves the liquid/vapor separator ( 40 ), passes through internal heat exchanger ( 33 ) and then as stream ( 301 ) enters expansion device ( 50 ), e.g., a turbine or throttle valve, where it is expanded to a lower pressure before passing as stream ( 302 ) to the lower pressure process liquid header or conduit ( 100 ).
The expansion device ( 50 ) can be a throttle valve or a turbine that recovers the power P required for the operation of pumps ( 10 ), ( 11 ) and as in FIG. 4 ( 12 ). The expansion device ( 50 ) is preferably linked directly to the shaft of the high pressure pump ( 11 ). Alternatively, electric power can be recovered to charge a battery that delivers the electricity to drive the pumps. In another embodiment, one or more pumps can be connected to a common drive shaft from the turbine.
The CO 2 /water vapor mixture ( 401 ) exiting the liquid/vapor separator ( 40 ) passes through the superheater ( 31 ) that is heated by the hot exhaust gas stream ( 901 ) and exits as a superheated CO 2 /water mixture ( 402 ) at a temperature around 400° C. Stream ( 402 ) is expanded in a turbine ( 51 ) to the vacuum pressure value of the system, e.g., 20 kPa, and produces power P which is applied as needed to operate pumps in the system, to compress CO 2 and to operate the process utilities
The low pressure CO 2 /water mixture leaves the turbine ( 51 ) as stream ( 403 ) to enter internal heat exchanger ( 34 ) and then heat exchanger ( 37 ) as stream ( 406 ).
The CO 2 /water stream ( 406 ) is cooled to condense the water to achieve the desired separation of CO 2 and water. Stream ( 407 ) exits heat exchanger ( 37 ) and passes to separator ( 41 ) where a CO 2 -rich stream ( 600 ) is recovered under vacuum, e.g., 20 kPa.
The vapor stream ( 600 ) is composed mainly of CO 2 and passes to the compression zone ( 60 ) where it is compressed to provide the compressed high-purity CO 2 stream ( 601 ). The high purity CO 2 stream ( 601 ) can be passed to on-board storage in mobile applications, and eventually to permanent underground or other storage via pipeline. Any remaining water is condensed by intercooling and phase separation and discharged from the system as waste water stream ( 700 ).
The condensate stream ( 500 ) from the separator ( 41 ) is mainly composed of water with some dissolved CO 2 and is pressurized by pump ( 12 ) for introduction into the liquid header line ( 100 ) at a pressure of about 100 kPa. Stream ( 510 ) exiting pump ( 12 ) is passed in whole or in part to sorbent solution stream ( 100 ) as stream ( 502 ), any excess being discharged from the system as stream ( 501 ).
The absorbent solution stream ( 100 ) is further cooled in heat exchanger ( 35 ) to the predetermined CO 2 absorption temperature and then passed to the suction line ( 101 ) of pump ( 10 ) for introduction into the CO 2 absorber ( 20 ).
No systems of the prior art concerned with reduction of CO 2 emissions contemplate the utilization of CO 2 from exhaust streams as a working fluid in energy recovery systems.
Example
A computer analysis/simulation was prepared using the Aspen Technology program model in lieu of bench testing. The model corresponds generally to the schematic arrangement depicted in FIG. 1 . The calculations are based on a 25% CO 2 capture rate with no pressure drop across the equipment.
It will be understood that the results are indicative and although some uncertainties remain, the results provide useful data for the specified condition. The following Table includes the characteristics of the various streams described above for the Aspen Simulation presented in FIG. 5 .
TABLE
(Based on Aspen Simulation)
Temperature
Pressure
Vapor
Mass Flow Rate
Stream
(° C.)
(kPa)
Fraction
(kg/sec)
901
600
100
1
1
902
562
100
1
1
903
242
100
1
1
904
35
100
1
1
905
40
100
1
0.91
200
39
200
0
3.5
201
40
4000
0
3.5
202
62
4000
0
3.5
203
222
4000
0.02
3.5
205
241
4000
0.05
3.5
300
241
4000
0
3.34
301
65
4000
0
3.34
302
65
100
0
3.34
401
241
4000
1
0.16
402
400
4000
1
0.16
403
99
100
1
0.16
406
45
100
0.16
0.16
407
40
100
0.14
0.16
500
40
100
0
0.1
600
40
100
1
0.06
601
40
10000
1
0.06
While various exemplary embodiments of the invention have been described above and in the attached drawings, further modifications will be apparent to those of ordinary skill in the art from these examples and the description. The scope of the invention is to be determined with reference to the claims that follow. | A process for reducing the amount of CO 2 released into the atmosphere with the exhaust gas stream produced by the combustion of a hydrocarbon fuel in an internal combustion engine (ICE) used to power a vehicle by capturing at least a portion of the CO 2 in a liquid sorbent on board the vehicle, recovering the CO 2 from the sorbent and compressing the CO 2 for temporary storage on board the vehicle, where the process is operated as a semi-closed system in which the liquid sorbent that captures the CO 2 serves as a working fluid and retains the CO 2 during the power generation cycle to produce mechanical energy or work, after which the CO 2 is desorbed for densification and recovery as an essentially pure gas stream and the working fluid is recycled for use in the process. | 54,194 |
RELATED APPLICATIONS
This application is a Divisional of U.S. application Ser. No. 12/394,477, filed on Feb. 27, 2009, now U.S Pat. No. 7,786,488 which is a Continuation of U.S. application Ser. No. 11/055,599, filed Feb. 11, 2005, now U.S. Pat. No. 7,535,082, which is a Divisional of U.S. application Ser. No. 10/665,483, filed Sep. 22, 2003, now U.S. Pat. No. 6,875,082, claiming priority of Japanese Patent Application Nos. 2003-128060, filed on May 6, 2003, and 2003-281647, filed on Jul. 29, 2003, the entire contents of each of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to distortion and smoothness of nitride semiconductor wafers which can be utilized as a substrate wafer for making blue light emitting devices (laser diodes (LDs) or light emitting diodes (LEDs)).
This application claims the priority of Japanese Patent Application No. 2003-128060 filed on May 6, 2003 and Japanese Patent Application No. 2003-281647 filed on Jul. 29, 2003, which are incorporated herein by reference.
2. Description of Related Art
Sapphire (α-Al 2 O 3 ) single crystals have been exclusively utilized as substrate wafers for making InGaN-type blue light emitting diodes and InGaN-type blue light laser diodes. GaN thin films, InGaN thin films or other nitride thin films are heteroepitaxially grown on a sapphire single crystal wafer. Light emitting devices are produced by piling n-type and p-type GaN and InGaN thin layers epitaxially on the GaN thin film grown on the sapphire wafer. Sapphire wafers are sold on the market and are easily obtained. Sapphire wafers have given satisfactory achievements as an essential part of blue light sources. Sapphire wafers, however, have weak points. Sapphire, which is an insulator, cannot lead electric current. Sapphire prevents us from making n-type or p-type sapphire. A sapphire substrate forbids us to make an n-electrode on a bottom of a device chip. An n-electrode should be formed upon a conductive n-type GaN layer grown upon a sapphire substrate. Both p- and n-electrodes are formed upon a top of an LED or LD device chip.
The top n-electrode requires a wide extra surface for the device chips. Existence of the top n-electrodes inhibits device makers from reducing chip sizes of LEDs or LDs. The top electrode is one drawback of sapphire wafers. Another weak point of sapphire is non-cleavage. Sapphire (α-Al 2 O 3 ) has low symmetry which deprives the crystal of natural cleavage. High mechanical rigidity is a further drawback for sapphire wafers. Without relying upon natural cleavage, a device-produced sapphire wafer is cut into individual chips by mechanical dicing, which raises manufacturing costs and lowers yields. Lattice misfitting between the sapphire wafer and GaN layers makes a lot of dislocations and degenerates a light emitting property of chips.
No GaN single crystal wafer has been available till now. Thin films of GaN are grown on a foreign material substrate. Use of sapphire substrates, silicon carbide substrates (SiC), gallium arsenide substrates (GaAs) and spinel substrates has been reported. The most prevalent foreign material substrate is a sapphire substrate as described hitherto. Since the materials of substrates and films are different, strong stress occur at an interface between films and foreign material substrates. The films grown on the foreign substrate exfoliate from the substrate due to the strong stress at an early stage. For avoiding the exfoliation, interposition of a low-temperature grown buffer layer and separation growth of individual GaN nuclei via small windows of a mask (ELO method) have been proposed. The low-temperature made GaN buffer layer has a function of alleviating inner stress at a film/substrate interface. The ELO (epitaxial lateral overgrowth) method can make thin GaN layers on a sapphire substrate by covering the sapphire substrate with a mask (e.g., SiO 2 or SiN), perforating the mask into small windows regularly aligning in a hexagonal pattern composed of repetitions of many equilateral-triangles for exposing the underlying substrate via the window, growing GaN nuclei on the separated exposed windows and reducing the inner stress.
{circle around (1)} PCT-application, WO99/23693, {circle around (2)} Japanese Patent Laying Open No. 2000-22212 (Japanese Patent Application No. 10-183446), {circle around (3)} Japanese Patent Laying Open No. 2000-12900 (Japanese Patent Application No. 10-171276), {circle around (4)} Akira Usui, “Thick Layer Growth of GaN by Hydride Vapor Phase Epitaxy”, IEICE, C-II Vol. J81-C-II No. 1, pp. 58-64, January 1998, {circle around (5)} Kensaku Motoki, Takuji Okahisa, Naoki Matsumoto, Masato Matsushima, Hiroya Kimura, Hitoshi Kasai, Kikurou Takemoto, Koji Uematsu, Tetsuya Hirano, Masahiro Nakayama, Seiji Nakahata, Masaki Ueno, Daijirou Hara, Yoshinao Kumagai, Akinori Koukitu, and Hisashi Seki, “Preparation of Large Freestanding GaN Substrates by Hydride Vapor Phase Epitaxy Using GaAs as a Starting Substrate”, Jpn. J. Appl. Phys. Vol. 40 (2001) pp. L140-L143, describe the ELO of GaN films on GaAs or sapphire substrates. The ELO method, which is inherently a method of making thin films, can produce no thick layer. If a thick GaN layer piles on a substrate by the ELO method, a number of dislocations are produced and big inner stress is yielded. The large inner stress would exfoliate the GaN layer from the substrate. Thus, the ELO fails to make a freestanding GaN substrate. The ELO is insufficient to produce a thick single crystal GaN substrate wafer. Another improvement is required for making GaN freestanding single crystal bulks besides the ELO.
{circle around (6)} Japanese Patent Laying Open No. 2001-102307 (Japanese Patent Application No. 11-273882), which has the same applicant as the present invention, proposed a facet growing method of GaN. Instead of maintaining a mirror-flat c-plane on the top, the facet growth method intentionally makes facets and facet pits, maintains the facets and the facet pits on a growing surface, displaces dislocations by the facets, gathers the dislocations from neighboring regions into centers of the facet pits, reduces dislocation density in other regions, and obtains low dislocation GaN single crystals. The facet growth method of {circle around (6)} enabled us to make a large freestanding GaN wafer of good single crystal for the first time. {circle around (6)} cannot predetermine spots of the facet pits, because {circle around (6)} lacks a contrivance of determining positions of the pits and the pits are born at random spots.
{circle around (7)} Japanese Patent Laying Open No. 2003-165799 (Japanese Patent Application No. 2002-230925) gave the GaN facet growing method an improvement of predetermining the positions of facet pits by depositing seeds on an undersubstrate, making facet pits following to the seeds. The seeds initiate closed defect assembling regions (H). Positions of the closed defect assembling regions coincide with the positions of the seeds on the undersubstrate. Other parts except the closed defect assembling regions (H) are good single crystal GaN.
Polishing is another important matter for the present invention. Polishing technology has not matured for nitride semiconductors, since independent, freestanding nitride crystal bulk wafers have not been produced on a practical scale yet. Thus, current polishing technology for other materials should be considered.
In the case of silicon semiconductors, silicon wafers are mechanically polished with alumina powder. Besides the mechanical polishing, processed silicon wafers having devices are polished for flattening rugged surfaces by chemical mechanical polishing (CMP) which makes use of colloidal silica and corrosive liquid. GaAs wafers are also treated with the chemical mechanical polishing (CMP), since some corrosive liquid for GaAs is known. People have believed that the CMP is impossible for sapphire and GaN. Sapphire is a refractory oxide. GaN is a sturdy nitride. Sapphire and GaN are chemically stable materials. A corrosive liquid for sapphire and GaN has not been reported.
{circle around (8)} Japanese Patent Laying Open No. 10-166259 (166259/1998) (Japanese Patent Application No. 8-332120) declared that it proposed a chemical mechanical polishing (CMP) of sapphire for the first time by an alkali liquid. However, {circle around (8)} makes a secret of details of the polishing liquid. {circle around (8)} disclosed no concrete components of the alkali liquid. Nobody can obtain knowledge of the detail of the alkali. What is the alkali liquid as a polishing liquid for sapphire is still outstanding in spite of {circle around (8)}.
{circle around (9)} J. L. Weyher, S. Muller, I. Grzegory and S. Porowski, “Chemical polishing of bulk and epitaxial GaN”, Journal of Crystal Growth 182 (1997), p 17-22, reported that they CM-polished GaN (0001) crystal bulks with an NaOH or KOH solution. But, {circle around (9)} insisted that CMP (chemical-mechanical polishing) was still impossible for high quality GaN crystals.
{circle around (10)} J. A. Bardwell, J. B. Webb, H. Tang, J. Fraser and S. Moisa, “Ultraviolet photoenhanced wet etching of GaN in K 2 S 2 O 8 solution”, J. Appl. Phys., vol. 89, No. 7, p 4142-4149, (2001), disclosed that GaN was wetly etched with a K 2 S 2 O 8 solution.
{circle around (11)} Japanese Patent Laying Open No. 2002-356398 (Japanese Patent Application No. 2001-166904) was contrived by the same inventor as the present invention and related to chamfering of a periphery of a GaN wafer. Freestanding circular GaN wafers had not existed, but it was possible to make them for the first time. Therefore, the inventor contrived to chamfer the periphery of the GaN wafer and to make OF for indicating a specified direction.
The technology of making a bulk GaN single crystal wafer is not fully matured yet. Technology of producing AlN and InN is far behind GaN. 50 mmφ (2-inchφ) freestanding GaN single crystal wafers are not produced on a commercial scale and do not come onto the market yet. The applicant of the present invention has a potential of making a circular 50 mmφ GaN freestanding single crystal wafer. 45 mmφ GaN wafers are also available for the applicant. Circular GaN freestanding wafers larger than 45 mmφ are suitable for substrate wafers for making light source devices (LEDs and LDs) owing to circularity and size-sufficiency. However, such large GaN wafers made by the state-of-the-art technology are annoyed by poor flatness, large distortion and bad roughness. GaN bulks made in vapor phase are annoyed by large distortion height H which randomly ranges between 200 μm and 30 μm. Thickness fluctuation exceeds 50 μm. Due to lack of a pertinent polishing method, surface roughness is over 10 μm. No circular GaN wafers prepared by the current technology satisfy the requirements of flatness, thickness uniformity and smoothness at present yet. GaN is chemically stable and physically rigid. GaN, however, is not tough and fragile. It is not easy to polish chemically-tenacious, physically-rigid but fragile GaN crystals. Slight physical shocks easily break GaN crystals. GaN, which has a hexagonal system, has asymmetric plane properties for a (0001)-plane and (000-1)-plane. The (0001)-plane is a surface consisting of Ga atoms. Thus, the (0001)-plane is sometimes called “(0001)Ga-plane”. The (000-1) plane is a surface consisting of N-atoms. The (000-1) surface is called “(0001)N-plane”. Two surfaces of the Ga-plane and N-plane are different in chemical and physical properties. Namely, the chemical and physical properties of GaN wafers have orientation dependence. The chemical obstinacy, physical rigidity, fragility and orientation dependence enhance difficulties of lapping (grinding) and polishing (whetting) of GaN bulk crystals.
GaN is transparent for visible light. A GaN wafer looks like a glass plate. Silicon (Si) wafers or gallium arsenide (GaAs) wafers are opaque. Unlike Si or GaAs, GaN wafers have difficulty of discriminating a top or bottom surface by difference of finishing for the top/bottom.
GaN has other many problems. Here, attention should be paid to distortion and roughness of GaN bulk crystals. GaN has a hexagonal system having three-fold symmetry around a c-axis. A large GaN crystal is unobtainable. A foreign material plate is employed as a starting substrate, which is called an “undersubstrate” for distinguishing the object GaN substrate wafer. For example, a GaAs (111) single crystal plate is adopted for an undersubstrate.
Collaboration of the ELO method and the facet-growth method grows a thick GaN single crystal layer on the (111) GaAs substrate in vapor phase. Then, the GaAs undersubstrate is eliminated and a GaN freestanding thick layer is obtained. GaAs and GaN have large lattice misfitting and big thermal expansion rate difference. The lattice misfit and thermal expansion difference cause large inner stress in the GaN film. The large stress is released by eliminating the GaAs undersubstrate. The released inner stress deforms the GaN film. Distortion is a serious problem for the GaN wafers.
A top convex distortion in which a top surface lifts at the center upward is defined as a positive distortion. A top concave distortion in which a top surface sinks at the center is defined as a negative distortion. Distortion is not eliminated by neither ordinary grinding nor ordinary polishing. Single surface polishing comprises the steps of sticking a wafer upon a polishing disc on a reverse side, bringing the polishing disc into contact with a whetting cloth covering a polishing turntable, pressing the polishing disc to the turntable, supplying polishing liquid, rotating the polishing disc and revolving the turntable in reverse directions. The object bottom surface of the wafer is whetted by the polishing cloth glued to the turntable. When the wafer is stuck to a flat bottom of the polishing disc before polishing, the wafer is flattened. When the wafer is removed from the flat disc after polishing, the wafer deforms back to the original distortion. Distortion of a wafer is not eliminated by polishing but survives the polishing. It is impossible to rid a wafer of distortion by the ordinary polishing. Large wafer distortion increases difficulties in wafer process and enhances probability of breaking, splitting and cracking. The wafer distortion makes it difficult to adjust a focus on the wafer in the masked exposure in photolithography and increases errors of patterning.
Simultaneous double surface polishing is composed of the steps of preparing a template having a plurality of round holes, laying the template on a lower turntable with a whetting cloth, putting object wafers on the lower turntable in the holes of the template, lowering an upper turntable onto the lower one, pressing the object wafers between the upper and lower turntables, supplying whetting liquid, rotating the upper and lower turntables in reverse directions and giving a planetary motion to the template. A top and bottom surfaces of the object wafers are polished simultaneously by the upper/lower turntables. When the wafers are picked up from the polishing machine, the wafers deform into the original distortion. Also in the double polishing, the distortion and inner stress survive the polishing. In general, lapping (grinding) and polishing (whetting) are ineffective for reducing or removing distortion from wafers. Polished or lapped wafers recover the original deformation. Annihilation of distortion is a formidable problem for GaN wafers.
Another problem is fluctuation of thicknesses of wafers. Thickness variations induce fluctuation of properties of devices produced on the wafer. Thickness should be constant in the overall area of a wafer for avoiding fluctuation of properties of devices. Suppression of the thickness fluctuation is another significant matter. There are several different kinds of estimation of the thickness fluctuation.
Here, a parameter TTV (total thickness variation) is adopted for expressing the fluctuation of thickness. The TTV is, in short, a difference between the largest thickness and the smallest thickness among defined sampling points. The TTV is obtained by mounting an object wafer on a flat stage with a vacuum chuck, pulling one surface flatly on the stage, measuring heights of the other surface at sample points two-dimensionally-aligning at a predetermined spatial sampling period, deducing the maximum thickness and minimum thickness on the whole object wafer, and subtracting the minimum from the maximum. The TTV depends upon the spatial period d of measuring spots. The spatial period d which is a distance between neighboring spots can be arbitrarily determined. For example, d=5 mm is available. Otherwise, d=1 mm or 0.5 mm is also available. A suitable spatial (sampling) period d should be defined by taking account of a texture of surfaces, size of wafers and required accuracy. The TTV is a value which is obtained by subtracting the smallest thickness from the largest thickness. The TTV is not microscopic fluctuation of thickness but macroscopic difference between the maximum and the minimum. Thus, the TTV is essentially a macroscopic value, although thickness should be measured at many spots aligning in a two-dimensional lattice at a constant interval. Actual values of the TTV may slightly differ for different spatial periods d for the same specimen. A decrement of the sampling period d increases measured TTV. But, the TTV would uniformly converge at a definite value TTV 0 at an infinitesimal limit of d→0, Smaller d gives more precise value of TTV 0 but takes more time to measure heights at all sampling points. Here, d=0.1 mm is adopted. Surface heights are measured at sampling spots which are two-dimensionally aligned in a lattice at the sampling period d=0.1 mm. Then, TTV is obtained by subtracting the minimum from the maximum.
Another problem is roughness of wafer surfaces. At present top surfaces of GaN wafers are mirror-polished but bottom surfaces are roughened. Difference of roughness discriminates the top from the bottom. The top surface should be mirror-smooth, because devices are fabricated upon the top by lithography. Since devices are not built upon the bottom surface, the roughened texture is allowable for the bottom surface. The inventors of the present invention are aware that a rough bottom surface incurs some problems. In the case of prevalent Si wafers, GaAs wafers and InP wafers, a final washing step eliminates fine particles adhering to top and bottom surfaces by oxidizing and reducing the surfaces of the wafers. The elimination of particles from surfaces is called “lift-off”. The oxidization/reduction treatment succeeds in removing particles from wafer surfaces of Si, GaAs and InP which are chemically active and subject to oxidization. GaN is chemically more stable and more inactive than Si, GaAs and InP. GaN prevents a final washing step from lifting-off particles by oxidizing and reducing GaN surfaces with wet etchants. Rugged surfaces are far more likely to absorb and hold particles than smooth surfaces. If fine particles once stick to rugged bottom surfaces of GaN wafers, it is very difficult to remove the particles from the rugged surfaces. Roughened bottom surfaces of current GaN wafers, in particular, are apt to wear many fine particles which are tiny fragments of polishing material, wax or others. The final washing step allows some of the particles to remove from the bottom and to adhere to the top surface. FIG. 11 , which has an abscissa of bottom surface roughness and an ordinate of top surface particle numbers, denotes that an increase of bottom surface roughness invites a conspicuous rise of particle numbers on the top surface.
FIG. 11 indicates the requirement of decreasing the bottom roughness for reducing contamination of top surfaces.
GaN freestanding bulk crystals are rigid but fragile. GaN lacks toughness unlike Si or GaAs. The rigid-fragility of GaN incurs another problem deriving from distortion. If a GaN wafer is strongly distorted, polishing steps are likely to induce occurrence of cracks originating from convex/concave extremes of the distortion. FIG. 3 , which has an abscissa of curvature radii and an ordinate of crack occurrence rates, shows that stronger distortion with a shorter radius yields a higher rate of occurrence of cracks. FIG. 3 requests reducing distortion of wafers for avoiding occurrence of cracks.
SUMMARY OF THE INVENTION
A purpose of the present invention is to provide a freestanding nitride semiconductor wafer which ensures good morphology of films epitaxially grown on the nitride wafer. Another purpose of the present invention is to provide a freestanding nitride semiconductor wafer which is endowed with high yield of via-mask exposure in photolithography. A further purpose of the present invention is to provide a nitride semiconductor wafer which has a top surface with low probability of particle contamination in wafer processes. Another purpose of the present invention is to provide a gross-polishing method for reducing inherent distortion of nitride wafers. A further purpose of the present invention is to provide a chemical/mechanical polishing method for polishing rigid/fragile nitride semiconductor wafers into mirror-smoothness without fear of breaks.
The present invention proposes a freestanding nitride semiconductor wafer having maximum distortion height Hm less than 12 μm irrespective of having one, two, three or any other number of mode of distortion. The restriction Hm≦12 μm is required for all wafers bent in any modes of distortion.
The words of “modes of distortion” are yet ambiguous. Distortion should be described by maxima, minima and numbers of maxima and minima. For example, when a wafer has more than two maxima T 1 , T 2 , T 3 . . . and more than two minima K 1 , K 2 , K 3 . . . in the diametrical direction or in the angular direction, the wafer bends in saddle-point type distortion. Even in such cases, the distortion height H can be exactly defined by keeping all the minima in contact to a flat plane, measuring heights of all the maxima and taking the maximum of the measured heights. In the complex distortion also, the present invention requires the fundamental inequality Hm≦12 μm.
More favorable distortion height is Hm≦5 μm in the present invention. Distortion less than 5 μm still further improves morphology of epitaxial films piled on a wafer, enhances the yield of the via-mask exposure in photolithography and succeeds with a higher rate in preventing cracks from occurring in wafer processes.
When a wafer has a single maximum T 1 , the wafer is bent in a single-mode distortion as shown in FIG. 6 ( 1 ). In the single-mode distortion, H and R can be related with each other by a simple equation which will be later described. In the case of a 45 mmφ wafer, a distortion height H=12 μm corresponds to a curvature radius R=21 m. Although the restriction by the peak height is valid for any diameter or any distortion mode, the restriction defined by the minimum curvature radius depends upon radii and modes of distortion. Here, restrictions of a curvature radius R for a 45 mmφ wafer, which is the minimum diameter proposed by the present invention, are described. Then, the curvature radius R of distortion should be longer than 21 m for a 45 mmφ wafer (R≧21 m). The optimum restriction H≦5 μm means R≧50 m in the case of a 45 mmφ wafer (R≧50 m).
In the case of a single-mode distortion, the present invention requires that the distortion height Hm should satisfy inequalities,
(1) Hm≦12 μm in the case of 45 mmφ, in general, R≧21 m.
More favorably,
(2) Hm≦5 μm in the case of 45 mmφ, in general R≧50 m.
The restriction defined by Hm depends upon the size of the object wafer. Otherwise, the condition expressed by curvature radius R is common for any size of wafers. Restrictions by R and Hm are equivalent only for 45 mmφ wafers. The maximum height requirements Hm≦12 μm and more favorable Hm[5 μm are valid for a number of distortion peaks.
In many cases, GaN wafers are distorted in a single distortion mode, which has a single extreme. In addition to the single distortion mode, double or thrice distortion mode happens at smaller rates. The double distortion sometimes has two maximum extremes and two minimum extremes align on a diameter. Instead of simple linear aligning extremes, more complex multiple-distortion mode has two pairs of maximum and minimum extremes positioned at corners of a virtual square imagined on an object wafer, in which all the four extremes form saddle points. In the saddle point mode, two minimum extremes and three maximum extremes align on a diameter and two maximums and three minimums align on another diameter.
FIG. 10 shows a complex distortion of a wafer having three minimum extremes K 1 , K 2 and K 3 and two maximum extremes T 1 and T 2 on a diameter. This example happens to have five extremes aligning on a diameter. The four saddle point case mentioned above has a section of three modes of distortion as shown in FIG. 10 . In this case, a three distortion mode has peak points K 1 , K 2 and K 3 . If the three mode case should have a common allowable distortion height H, the allowable curvature radius R of the three distortion mode should be far smaller than the simple single distortion.
The three mode distortion decreases the size of a deforming area to one third (⅓) of the single mode. The allowable curvature radius decreases to one ninth ( 1/9) of the single mode case. In the three-mode distortion, an allowable curvature radius R should be longer than 2.3 m, since the height H should be less than 12 μm (R≧2.3 m for H≦12 μm). More favorably, a curvature radius should be larger than 5.6 m for the restriction of H≦5 μm (R≦5.6 m for H≦5 μm).
Instead of the pressed top turntable of the conventional polishing, the present invention adopts a non-pressing top turntable and distorted wafers in a no weight-polishing by pulling up the top turntable with a force nearly equal to the weight of the upper turntable. The polishing machine allows the upper and lower turntables to make a air gap which is wider than a thickness of a wafer. Pressure P acting upon a wafer should be less than 60 g/cm 2 for the present invention (P≦60 g/cm 2 ). 60 g/cm 2 means 60 g weight acting upon a unit area of 1 cm 2 . Here, g/cm 2 is not an MKS SI(international system) unit but a practical technological unit. There are many different units for signifying pressure. The same critical pressure as 60 g/cm 2 should be expressed in other units.
P= 60 g/cm 2 =0.06 kg/cm 2 =60 g×980 cm/sec 2 ×1/cm 2 =58800 dyn/cm 2 =5880N/m 2 =5880 Pa=44.1 Torr=58.8 mbar=0.0580 atm.
Since normal polishing presses an object at several of kg/cm 2 , the above 60 g/cm 2 is very small pressure which is effectively zero. The state of pulling up the upper turntable (P≦60 g/cm 2 ) is called “pressureless”. What features this invention is pressureless polishing which polishes a wafer in a quasi-free state.
Instead of pressing down the upper turntable, the present invention lifts up the upper turntable for gross-polishing an object wafer. A wide air gap is kept between the upper and lower turntables. The air gap is wider than the net thickness of the wafer but narrower than the distorted thickness of the wafer. The air gap allows the wafer to keep the inherent distorted shape in a quasi-free state.
Since the wafer is bent between the upper and lower turntables, protrusion portions and sharply edging portions keep contact with the polishing clothes on the turntables. Concave parts are separated from the polishing clothes. Only the protruding and the edging portions are eliminated but concave recesses are left untouched. The projecting portions and edging portions are decreased, which indicates decrement of distortion.
After a long time polishing, flat wafers without distortion are obtained by the free-state polishing of the present invention. The free-state polishing enables the present invention to eliminate any mode of distortion, e.g., double-mode, triplet-mode or other higher mode of distortion ( FIG. 10 ) of nitride wafers in addition to the simple single-mode distortion as shown in FIG. 5 . The polishing method takes much time but is effective for removing inherent distortion of nitride wafers. The problem of distortion of nitride wafers is solved by the present invention.
Another important property is surface roughness. The present invention requires that a roughness RMS of a top surface of nitride wafers should be less than 5 nm. The lower limit is 0.1 nm, which derives from the restriction of the technology of polishing of the present invention. The RMS is a root mean square of heights. There are Rmax, Ra and other parameters for signifying the roughness. Here, the present invention employs the RMS for representing the roughness. The roughness of the top is thus represented by 0.1 nm≦RMS≦5 nm.
The conventional GaN wafers have never been polished up to such smoothness, since no CMP (chemical/mechanical polishing) was available. As explained before, since nitride crystals are rigid and fragile, mechanical polishing alone cannot produce mirror smoothness of nitride wafers yet. Success of the CMP enables the present invention to give such high smoothness to surfaces. The CMP will be described later in detail.
FIG. 1 shows a relation between surface morphology after epitaxial growth and surface roughness or TTV(total thickness variation). Greater roughness induces a decline of morphology of an epitaxial wafer which has epitaxially grown films upon the bare GaN wafer having ragged surfaces. FIG. 1 indicates that epitaxial films have a tendency of transcribing the roughness of the substrate wafer and smoothness of wafer surfaces is important for making good epitaxial films.
More favorable smoothness of the top surface is defined to be less than 0.5 nm. Thus, the preferable requirement can be represented by 0.1 nm≦RMS≦0.5 nm.
The single crystal nitride semiconductor wafer of the present invention should have a bottom of roughness lower than RMS 5000 nm, which is far smaller than the current bottom roughness. The minimum of the roughness of the bottom should be 0.1 nm which is a technical limit of polishing. Thus, the bottom surface roughness RMS of the present invention can be briefly expressed by an inequality 0.1≦nm≦RMS (bottom)≦5000 nm.
FIG. 11 shows a tendency of an increase of a top surface particle number as bottom roughness rises. It is because the particles once adhering to the bottom separate from the bottom, turn around and contaminate the top. This invention can decrease the adhesion of particles on the top since the bottom has a smooth surface of small roughness. The above-mentioned CMP is effective to the bottom polishing.
In brief, the present invention requires that both surfaces should have the following roughness,
[General requirements]
top surface roughness
0.1 nm ≦ RMS ≦ 5 nm
bottom surface roughness
0.1 nm ≦ RMS ≦ 5000 nm
[More sophisticated requirements]
top surface roughness
0.1 nm ≦ RMS ≦ 0.5 nm
bottom surface roughness
0.1 nm ≦ RMS ≦ 2 nm
A freestanding single crystal nitride semiconductor wafer of the present invention has a diameter larger than 45 mmφ and a TTV (total thickness variation) less than 10 μm in the case of a 45 mmφ wafer in addition to the above-described roughness and distortion.
Here, the relation between the height H and the curvature radius R of distortion is described in short. FIG. 9 shows a relation between a central wafer height H and a curvature radius R which are different expressions of distortion of wafers in a simple mode. A diameter of a wafer is denoted by FMG. The diameter D of the wafer FMG is FG (D=FG). Curvature FMG is a part of a large sphere which has a center O. The distortion FMG has a curvature radius R=OF=OM=OG. The central height H is equal to MN (H=MN). The wafer diameter D satisfies an equation of D=FG=2RsinΘ. As Θ is a small angle, D=2RΘ in approximation.
The height H satisfies H=MN=MO−NO. MO=R and NO=OGcosΘ=RcosΘ. The height H is given by
H=R−R cos Θ=2 R sin(Θ/2) 2 =D 2 /8 R. (1)
This is an approximation equation for determining the relation between H and R. Since D/R is far smaller than 1, the approximation is a good one. The curvature radius R is reversely proportional to H. This relation equation includes the wafer diameter D as a parameter. A proportion constant includes a square of the diameter D. Unless D is determined, the relation is not fully decided. The present invention aims at a wafer which is larger than 45 mmφ (D≧45 mm). If R should be denoted by a meter unit and H should be signified in μm (micrometer) unit, Equation (1) is written as
For D= 45 mm R=253 /H . ( R; m and H;μ m) (2)
For D= 50 mm R=312 /H , ( R ;m and H ;μm) (3)
In the case of a 2 inch wafer (D=50 mm), a curvature radius R=26 m gives a height H=12 μm. A curvature radius R=62 m gives H=5 μm for D=50 mm.
In the case of 45 mmφ wafers, the present invention can determine a distortion curvature R (denoted by a m unit) larger than D 2 /96 (denoted by a mm unit) from the above equation (1).
The present invention restricts an allowable distortion height H to be less than 12 μm (H≦12 μm). H=12 μm is the maximum of allowable distortion heights. Thus, in the case of a 50 mmφ wafer, the minimum allowable curvature Rm is Rm=26 m and curvature R and height H should satisfy inequalities R≧26 m and H≦12 μm. Although the allowable maximum H is common, the minimum curvature radius Rm depends upon the wafer diameter D. For a 45 mmφ wafer, H≦12 μm or, equivalently, R≧21 m.
More preferable height should be less than 5 μm (H≦5 μm) in the present invention. For maintaining H at a value less than 5 μm, R≧62.5 m for D=50 mm and R≧50.6 m for D=45 mm.
In the case of a uniform distortion as shown in FIG. 6 ( 1 ), as a curvature radius R of distortion rises, a mask/resist exposure yield in photolithography improves. Namely, a smaller height H and a larger radius R are favorable for making devices with higher yield. It is important to reduce distortion. The present invention requires that the distortion should be suppressed at most to be a 12 μm height.
Distortion necessarily accompanies any freestanding GaN single crystal which has been made in vapor phase upon a foreign material (e.g., GaAs) undersubstrate. The present invention gross-polishes (or laps) a wafer in a pressureless state. It takes long time to lap a distorted wafer in a quasi-free state. But the pressureless gross-polishing or lapping of the present invention succeeds in eliminating distortion from the object wafer down to H≦12 μm which is equivalent to R≧26 m in the case of 50 mmφ(2 inch) wafers or to R≧21 m in the case of 45 mmφ. The present invention further recommends to reduce the distortion down to H≦5 μm which is equivalent to R≧60 m in the case of 50 mmφ, which takes still longer time than the standard of H≦12 μm.
Gallium nitride (GaN) is rigid but fragile. Rigidity/fragility is a drawback of GaN or other nitride semiconductors. Application of strong pressure causes breaks of wafers in polishing process. The fragility prohibits mechanical polisher from applying strong pressure upon a nitride wafer. Mechanical polishing making use of silicon carbide, alumina or diamond powder cannot finish nitride wafers into mirror smoothness due to the restricted pressure application. GaN has longed for chemical-mechanical polishing which would dispense with strong pressure application.
GaN is chemically inactive. It has been believed that chemical-mechanical polishing is impossible for GaN. The inventors of the present invention examined various alkalis, acids or other chemicals for seeking probability of CMP of GaN. The inventors finally found out a probability of the GaN CMP by potassium peroxodisulfate (K 2 S 2 O 8 ) and ultraviolet rays. Potassium peroxodisulfate has strong oxidizing power. GaN is resistant to potassium peroxodisulfate itself. Potassium peroxodisulfate is not corrosive to GaN. Irradiation of ultraviolet rays, however, enhances the action potassium peroxodisulfate. Ultraviolet-excited potassium peroxodisulfate strengthens oxidizing power. The inventors discovered that ultraviolet rays enable potassium peroxodisulfate and polishing powder (e.g., colloidal silica) to chemically polish GaN crystals. It turns out that silicon carbide, alumina or diamond powder is also effective as polishing powder in addition to the colloidal silica. This is the first success of CMP of GaN. The ultraviolet-enforced potassium peroxodisulfate chemical/mechanical polishing is useful for both rough-polishing and minute-polishing. A set of polishing powder, potassium peroxodisulfate and ultraviolet rays enables the inventors to chemical-mechanical polish rigid but fragile GaN wafers up to sufficient mirror smoothness with small pressure. The ultraviolet-excited potassium peroxodisulfate has strong corrosive power for chemically high resistant GaN. Chemical corrosion prepares active surfaces and helps powder granules to polish GaN wafers physically at low pressure. Since applied pressure is weak enough, fragile GaN wafers do not break. The inventors further confirmed that the ultraviolet-enhanced potassium peroxodisulfate with polishing granules is effective for polishing other nitride semiconductors, AlGaN, AlN and InN.
The conventional GaN wafers had a roughened bottom surface which is likely to attract particles and allow them to adhere thereon. The present invention polishes also a bottom surface into mirror smoothness. A smoothed bottom surface of a nitride wafer of the present invention is immune from particle contamination. Reduction of the particle contamination is an advantage of the present invention. Another advantage derives from small TTV (total thickness variation) less than 10 μm (TTV≦10 μm). The thickness of the wafer is nearly constant allover on the surface. The small TTV can suppress the fluctuation of properties of devices made upon the wafers. For example, surface morphology after epitaxial film-growth is improved by the low fluctuation of thickness (TTV) realized by the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph of a relation between morphology of a GaN wafer after epitaxial growth and TTV(total thickness variation) or roughness RMS(μm) for showing that an increase of the TTV or RMS degrades surface morphology of the wafer piled with epitaxial thin films thereon.
FIG. 2 is a graph denoting a relation between a yield of mask exposure wafers in photolithography and a curvature radius of distortion R(m) for showing that large wafer distortion lowers the yield of mask-exposed wafers. The ordinate is the yield. An upward direction denotes better yield and a downward direction denotes worse yield.
FIG. 3 is a graph of a relation between an occurrence rate of cracks in wafer-process and a curvature radius of distortion R(m) for showing that large distortion causes cracks on processed wafers.
FIG. 4 is a flow chart of processing as-grown GaN wafers into mirror wafers including the steps of rough shaping an anomalous disc into a circular one, bevelling or chamfering of peripheries, gross-polishing for eliminating distortion, minute (second) polishing for producing mirror smooth surfaces, washing and testing.
FIG. 5 is a schematic sectional view of a part of a gross-polishing machine for showing pressureless polishing which pulls up the upper turntable, maintains a distorted state of an object distorted wafer and eliminates protruding portions and edgy portions.
FIG. 6 is a set of sectional views of a wafer being processed by the pressureless gross-polishing step which lifts up an upper shaft for keeping the distorted state of the wafer.
FIG. 7 is a sectional view of a pressureless gross-polishing machine which eliminates distortion from deformed wafers by inserting the distorted wafers in holes of templates on a lower turntable, putting an upper turntable above the lower turntable with a sufficient air gap, and revolving the turntables without pressing the wafers.
FIG. 8 is a sectional view of a CMP machine which polishes a GaN wafer by supplying a chemical/mechanical polishing liquid including potassium peroxodisulfate (K 2 S 2 O 8 ), potassium hydroxide (KOH) and colloidal silica and irradiating by ultraviolet rays for making mirror smooth wafers without occurrence of breaks and scratches.
FIG. 9 is an explanatory figure for clarifying a relation of a wafer central height (H) of a diameter (D) and a curvature radius (R) for signifying distortion of a wafer.
FIG. 10 is a section of a triplet-bending mode wafer having two maxima T 1 and T 2 and three minima K 1 , K 2 and K 3 along a diameter.
FIG. 11 is a graph of a relation between bottom roughness RMS (μm) and top particle number showing that an increase of the bottom roughness induces a rise of the number of particles lying on the top surface. The abscissa is bottom, surface roughness RMS (μm). The ordinate is particle numbers on the top surface after wafer processes.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Since there have been rare freestanding circular GaN wafers till now, processing of as-grown GaN wafers has not been established at present. Then, the inventors treated GaN circular wafers by a series of steps as shown in FIG. 4 . The processing treatment comprises rough shaping, bevelling (or chamfering), gross polishing, minute polishing, washing and testing steps. An as-grown GaN is not circular. The rough shaping step reforms the as-grown wafer into a circular one. The chamfering step grinds the circumference into slanting edges for avoiding occurrence of breaks or splitting. Improvement of the following gross and minute polishing steps is a purpose of the present invention.
The polishing is done step by step by changing the size of powder. The polishing processes can be divided into the first (gross) polishing at a higher speed and the second (minute) polishing at a slower speed. Another role of the first polishing is to rid the wafer of the distortion. The second polishing is now done by a new CMP method contrived by the inventors of the present invention. Both kinds of polishing are described in detail.
Ordinary rough polishing for Si or GaAs wafers makes use of a round plate having a shaft for fixing a wafer on a side, pushes the round plate upon a lower turntable, revolves the turntable and rotates the round plate around the shaft. Even if the object wafer has inherent distortion, fitting the wafer upon a flat plate evens the wafer. The wafer is uniformly polished in a flattened state under strong pressure. When the polished wafer is taken off from the plate, the wafer retrieves the inherent distortion. The distortion remains intact. The ordinary single-side polishing is ineffective for reducing distortion. The present invention takes weightless, pressureless gross polishing with very small pressure less than 60 g/cm 2 in quasi-free state for alleviating distortion by eliminating only protruding, edging portions. The pressureless polishing sandwiches a distorted wafer between lower and upper turntables in a bent state and whets the distorted wafer slowly without pressing down. The upper turntable is not pressed down but lifted up for keeping a wide air gap between the upper and lower turntables, which allow the wafer to bend in the inherent distortion.
FIG. 5 is a schematic view of a weightless polishing of the present invention for gross-polishing a deformed GaN circular wafer. A polishing machine has a coaxial set of an upper turntable 3 and a lower turntable 4 which can rotate, rise and sink. A distorted wafer 2 is freely sandwiched between the lower turntable 4 and the upper turntable 3 with a wide air gap. The wafer is not stuck to a polishing disc which is prevalently used for wafer polishing. Polishing discs are useless, because the polishing discs hold a wafer in a forced flattened state. Both the upper and lower turntables are metallic turntables coated with polishing cloths. A polishing liquid is supplied between the upper and lower turntables. The upper and lower turntables rotate in the reverse direction or in the same direction at different rotation velocities for gross-polishing an object wafer in a distorted state. The polishing liquid includes water and free whetting granules, for example, silicon carbide (SiC), alumina (Al 2 O 3 ) or diamond (C) granules. Unlike an ordinary polishing machine, the upper turntable 3 is not pressed down but is lifted upward. Lifting up of the upper turntable 3 makes an air gap which is wider than a net thickness of an object wafer. The object wafer exists between two turntables in a free distorted state. In the example, a bottom circumference η or λ touches the lower turntable 4 and a top γ center is in contact with the upper turntable 3 .
FIG. 6 shows sections of a distorted wafer at various steps of the pressureless, weightless, quasi-free gross-polishing of the present invention for eliminating distortion from the object distorted GaN wafer. At first the object wafer has a single-mode distortion with a center upward bending and a periphery downward bending. FIG. 6 ( 1 ) denotes a free state of the wafer. A top convex curve, a left side, a bottom concave curve and a right side are designated by αβγδεθτκλν. The wafer is upward convex at the beginning step. The pressureless polishing allows the wafer to distort in a free state. A protruding central top γ is in contact with a polishing cloth of an upper turntable and edging bottom peripheries λ and η touch a polishing cloth of a lower turntable. Other portions are left intact. Only the protruding top γ and the edging η and λ are polished away. As shown in FIG. 6 ( 2 ), a flat round top βδ and flat fringes οπ and ρσ are created by the weightless polishing at the second step. Lower top portions αβ and δε and a concave bottom part θτκ is left untouched. The polishing continues by gradually lowering the upper turntable for maintaining partial contact with the top of the wafer. The pressureless polishing is widening the top flat part ξτυ and the bottom flat annular fringes φχ and ψω, as shown in FIG. 6 ( 3 ). At a final step, top lower circumferences ευ, ξα and a bottom concave θτκ are polished away. A flat wafer having a flat top μqs and a flat bottom ζtyzv is obtained as shown in FIG. 6 ( 4 ).
FIG. 5 shows a principle of the pressureless polishing for a single wafer on the teaching of the present invention. Actually, a plurality of wafers are simultaneously polished at both surfaces in a planetary motion in a polishing machine.
FIG. 7 shows a structure of a gross-polishing machine which polishes a plurality of wafers in a pressureless state. The polishing machine are not novel. But, a relation among upper, lower turntables, a template and wafers is novel. An upper turntable 3 faces downward a lower turntable 4 . Polishing cloths 5 and 6 are glued to the turntables 3 and 4 . The upper turntable 3 is rotated by an upper driving shaft 26 . The lower turntable 4 is rotated by a lower driving shaft 27 . Two turntables rotate around a common axial line. The upper turntable 3 can be lifted up and can be maintained at an arbitrary height for making an air gap between the upper and lower turntables.
The machine has a sun gear 20 , a plurality of templates 22 with an outer-toothed planetary gear meshing with the sun gear 20 and an outer internal gear 23 meshing with the template 22 between the upper turntable 3 and the lower turntable 4 . The central sun gear 20 and the outer internal gear 23 rotate in inverse directions. The templates 22 are thin plastic discs having a plurality of round holes 25 for holding circular wafers 2 . The templates 22 are thinner than the wafers. Tops and bottoms of the wafers 2 are in contact with the upper and lower turntables. When m templates having n holes are employed, nm wafers can be treated at a time. The templates 22 revolve around the main axis and rotate around a center of the holes in a planetary motion.
A polishing liquid should be supplied between the upper and lower turntables. As mentioned before, mechanical polishing and chemical/mechanical polishing are available for the first (gross) polishing. Here, the first polishing employs a pure mechanical polishing. Then, the polishing liquid includes polishing powder and a liquid for dispersing the powder and for obtaining a lubricating property. In the case of mechanical polishing, the liquid is water or the like for dispersing powder granules. In the case of chemical/mechanical polishing, the liquid should include the above-described potassium peroxodisulfate. Rough polishing (first polishing) is here a mechanical polishing making use of silicon carbide (SiC), alumina or diamond granules dispersed in the liquid. In FIG. 7 , wafers 2 held in the holes 25 of the template 22 are gross-polished by supplying the polishing liquid between the turntables, and rotating the sun gear 20 at an angular velocity Ωs, the internal gear 23 at an angular velocity Ωi, the upper turntable 3 at an angular velocity Ωu and the lower turntable 4 at an angular velocity Ωd, where the definition of the angular velocities include directions and counterclockwise rotations are determined to be positive. The sun gear 20 has a shaft extending upward or downward to a motor. The motor rotates the sun gear. The upper and lower turntables are revolved by the upper and lower shafts 26 and 27 . The upper turntable 3 can be revolved either in the same direction or in the reverse direction to rotation of the lower turntable 4 . The internal gear 23 can be also revolved by another motor at an arbitrary rate. Here, S, P and I denote tooth numbers of the sun gear, the planetary gear and the internal gear. The tooth numbers satisfy a relation of S+2P=I. A revolving velocity Ωc of the template 22 is ruled by an equation of SΩs+IΩH=(S+I)Ωc. A planetary rotating velocity Ωc of the template (planetary gears) and a rotation velocity Ωi of the internal gear satisfy PΩt=IΩi. Arbitrary rotation speed Ωt and revolving speed Ωc are realized by adjusting Ωu, Ωd, Ωs and Ωi which are all independent controllable parameters. Such a structure is favorable for remedying inherent distortion in accordance with the teaching of the present invention, because the machine need not fix an object wafer on a flat disc on one side.
What is significant in the machine in FIG. 7 is the upper turntable 3 being pulled upward by force F, air gaps being formed, and wafers being gross-polished in a free-distorted state in the air gaps. Projecting portions, e.g., bottom edgy peripheries and protruding top centers in the example, are polished but concave portions, e.g., bottom recesses and lower top peripheries, which are not in contact with the turntables, are not polished. Maintaining small area contact and small pressure with the wafers, the upper turntable 3 is gradually descended. Protrusions and edges are all polished away. Extra parts which protrude beyond an imaginary flat disc are eliminated. The distortion of the wafers are essentially removed by the pressureless polishing. Finally, flat, distortion-free wafers are obtained by the free-state gross polishing.
The wafers should be further treated by a second (minute) polishing for making mirror wafers. The chemical/mechanical polishing should be employed for the minute polishing for enhancing flatness and smoothness of surfaces without applying excess high pressure. FIG. 8 shows the CMP fine polishing which supplies a mixture liquid 9 including powder, potassium hydroxide (KOH) and potassium peroxodisulfate (K 2 S 2 O 8 ) between the upper and lower turntables, and irradiates the liquid with ultraviolet rays. The composition of the polishing liquid, the polishing powder and the ultraviolet ray source are as follows.
Polishing liquid 2M KOH (potassium hydroxide) 0.5M K 2 S 2 O 8 (potassium peroxodisulfate) Polishing granules colloidal silica: granule size=50 nmφ to 450 nmφbest size=200 nmφ Ultraviolet ray source mercury lamp (Hg): wavelength λ=254 nm power P=10 mW/cm 2
As a polishing liquid of the second polishing step, the present invention can employ a polishing liquid including potassium hydroxide from 0.5M to 4M, potassium peroxodisulfate from 0.2M to 2M and polishing powder. The potassium peroxodisulfate is known as an oxidizing material. As described before, people have believed that it is impossible to chemical/mechanical-polish GaN which is chemically resistant. The inventors of the present invention found out that the ultraviolet-excited potassium peroxodisulfate enables us to CMP-polish GaN crystals. Potassium peroxodisulfate itself is inactive to GaN. But, ultraviolet rays enhance oxidization power of the potassium peroxodisulfate and give the potassium peroxodisulfate corrosive action to GaN.
The present invention has succeeded in CMP of GaN by the use of ultraviolet-enhanced potassium peroxodisulfate and polishing granules (e.g., colloidal silica) for the first time. The CMP can finish rigid but fragile nitride semiconductor wafers into mirror smoothness of 0.1 nm≦RMS≦5 nm without strong pressure. Without potassium peroxodisulfate, polishing granules (e.g., colloidal silica) cannot solely polish the GaN wafer into mirror smoothness. The potassium peroxodisulfate plays a main role of polishing.
What determines the final smoothness is, however, the size of polishing granules. The surface roughness can be raised by changing sizes of granules step by step. Larger diameter granules polish more rapidly than smaller diameter granules. Smaller diameter granules can finish wafers into higher smoothness than larger diameter granules. For example, in the case of colloidal silica, sizes of granules should be varied from 450 nmφ to 50 nmφ.
The sizes of granules rule the speed and the final roughness. But, what enables the granules to polish nitride wafers is the potassium peroxodisulfate. Another factor which determines the final roughness is time. It takes longer time to obtain more smoothly finished surfaces. RMS=0.1 nm is a lower limit originating from technical restrictions. The above written 0.1 nm≦RMS≦5 nm is sufficient smoothness to a top surface. Surface morphology of the films grown epitaxially upon the top surface of 0.1 nm≦RMS≦55 nm is satisfactory. However, 0.1 nm≦RMS≦0.5 nm is still better for the top surface roughness.
In the case of a bottom surface, 0.1 nm≦RMS≦5000 nm of smoothness is allowable. RMS≦5000 nm is enough for the bottom surface to maintain a top surface being immune from contamination of particles. But, RMS≦2 nm is more favorable for the roughness of the bottom surface.
[General requirements]
top surface roughness
0.1 nm ≦ RMS ≦ 5 nm
bottom surface roughness
0.1 nm ≦ RMS ≦ 5000 nm
[More favorable requirements]
top surface roughness
0.1 nm ≦ RMS ≦ 0.5 nm
bottom surface roughness
0.1 nm ≦ RMS ≦ 2 nm
Embodiment 1
2-Inchφ GaN Freestanding Wafer
2-inch GaN freestanding wafers are made by an HVPE method which grows GaN films on a GaAs circular undersubstrate from a Ga-melt, HCl gas and NH 3 gas in a furnace by reactions of Ga+HCl→GaCl and GaCl+NH 3 →GaN. The HYPE method makes the best use of the ELO (epitaxial lateral overgrowth) and the facet-growth which produces intentionally facet pits for gathering dislocations at bottoms of the pits and eliminates the GaAs undersubstrate and obtains a low-dislocation freestanding thick GaN film.
As-HVPE-grown GaN bulk wafers have rugged surfaces, random peripheral fringes, distortion and fluctuation of thickness. The rough-shaping step of FIG. 4 reforms the as-grown wafers into circular wafers by eliminating the random peripheral fringes.
The bevelling (chamfering) step of FIG. 4 eliminates sharp edges at circumferences of the circular wafers. Some of the prepared circular wafers have single-mode distortion and others have triple-mode or larger mode of distortion.
After the rough shaping and the chamfering, the pre-treated GaN circular wafers are processed by two steps of polishing in accordance with the teaching of the present invention.
[Conditions of Gross-polishing]
The first (gross) polishing includes three steps using different sizes of granules. Polishing liquids including SiC granules of various sizes are employed.
Polishing liquid:
Powder: silicon carbide (SiC)
First step; average size 15 μm (#800) Second step; average size 6 μm (#2500) Third step; average size 2 μm (#6000)
Liquid: oil slurry
Upper turntable: cast iron 380 mmφ Lower turntable: cast iron 380 mmφ Rotation speeds: upper-, lower-turntables: 20 to 60 rpm
Sun gear: 10 to 30 rpm Internal gear: 0 to 10 rpm
Liquid supply: 500 cm 3 /min (circulation) Pressure: 30 to 60 g/cm 2 Polishing speed: first step 0.3 μm/min
second step 0.05 μm/min third step 0.02 μm/min
Polishing margin: total 60-80 μm (top+bottom)
Although silicon carbide (SiC) is utilized as a polishing powder of the first polishing step here, one of colloidal silica, alumina and diamond powders with an average diameter of 20 μm to 0.5 μm can be suitably chosen. The first (rough-) polishing is done by sandwiching deformed wafers between the lower and upper turntables without pressure, polishing top and bottom surfaces at a slow speed and eliminating protruding portions and edges, as shown in FIG. 5 and FIG. 6 . The inherent distortion of the wafer is removed by the pressureless polishing. In practice, object wafers are allotted in holes of templates, which make a planetary gear motion, and are maintained between the turntables. The polishing speeds are slow, which results from the pressureless polishing. The wafers after the free-state rough polishing have very small distortion or no distortion. Then, the wafers are treated by a second (minute) polishing.
[Conditions Of Minute-polishing]
The second (minute) polishing is a chemical/mechanical polishing making use of ultraviolet-excited potassium peroxodisulfate.
Polishing liquid:
Powder: colloidal silica; average size 0.2 μm(200 nm) Liquid: KOH+K 2 S 2 O 8 Ultraviolet rays: mercury (Hg) lamp λ=254 nm
Polishing cloth: nonwoven fabric Upper turntable: cast iron 380 mmφ Lower turntable: cast iron 380 mmφ Rotation speeds: upper-, lower-turntables: 20 to 60 rpm
Sun gear: 10 to 30 rpm Internal gear: 0 to 10 rpm
Liquid supply: 1000 cm 3 /min
A 2-inch (50 mmφ) wafer (A) polished by the processes has a single-mode distortion of R=100 m. Roughness of the top surface and the bottom surface was measured by an AFM (atomic force microscope). The measured roughness was RMS=0.3 nm to 0.5 nm in a square of 10 μm×10 μm for both the top and the bottom surfaces. Although the top and bottom surfaces cannot be discerned by the difference of roughness any more, a G-plane is defined as a top surface and an N-plane is defined as a bottom surface.
The fluctuation of thickness was TTV=3.5 μm (measured at a 0.1 mm interval). The obtained distortion R=100 m corresponds H=3.5 μm (for 50 mmφ) which satisfies the prescribed restriction H≦12 μm. The roughness (RMS=0.3 nm to 0.5 nm) also satisfies the requirements 0.1 nm≦RMS≦5 nm(top) and 0.1 nm≦RMS≦5000 nm(bottom). The measured thickness fluctuation (TTV=3.5 μm) suffices the predetermined condition TTV≦10 μm.
Another 2-inch (50 mmφ) wafer (B) polished by the same processes has a three-mode distortion with saddle points as shown in FIG. 10 . A peak height H is H=2 μm. H=2 μm satisfies the requirement of 1-112 μm. AFM-measured roughness is RMS=0.2 nm to 0.4 nm in a sample square of 10 μm×10 μm for both the top and the bottom. The roughness (RMS=0.2 nm to 0.4 nm) also satisfies the requirements 0.1 nm≦RMS≦5 nm (top) and 0.1 nm≦RMS≦5000 nm (bottom). The fluctuation of thickness was TTV=3.1 μm at a 0.1 mm interval. The thickness fluctuation (TTV=3.1 μm) suffices the condition TTV≦10 μm. | Nitride semiconductor wafers which are produced by epitaxially grown nitride films on a foreign undersubstrate in vapor phase have strong inner stress due to misfit between the nitride and the undersubstrate material. A GaN wafer which has made by piling GaN films upon a GaAs undersubstrate in vapor phase and eliminating the GaAs undersubstrate bends upward due to the inner stress owing to the misfit of lattice constants between GaN and GaAs. | 63,220 |
This is a division of application Ser. No. 52,306, filed June 26, 1979, now U.S. Pat. No. 4,308,763.
BACKGROUND OF THE INVENTION
The invention is directed to a new shoe stiffening and likewise non-slip inner material and to a heel region of customary street shoes having this shoe inner material; it is not concerned for example with light, counterless shoes and/or shoes free of stiffening heel pieces in the heel portion.
The customary street shoes in the heel region consist of at least three shaped layers: First the leg or leg material (also called the upper material), second the stiffening heel piece (cap) or the stiffening material (also designated as rear heel piece material or short heel piece material) and third the slip band or non-slip material. In reciting these layers there are not counted the customary adhesive layers or coats.
SUMMARY OF THE INVENTION
The new inner shoe material serving to stiffen the heel region of street shoes is suitably produced in the form of continuous sheets or lengths and used in blanks (pieces) produced therefrom. It is thermoplastic, i.e. deformable under the action of heat or softenable by the action of solvent. It consists of a single layered fiber structure (thus it is not constructed multiplyed). It is loaded or filled with at least one synthetic resin acting as stiffener at normal temperature (about 15° to 25° C.) up to about 60°, specifically in amounts of 100 to 900 grams per square meter of fiber structure in which the loading set forth in a given case contains additional fillers, dyestuffs, pigments, plasticizers, stabilizers, propellants, processing aids and/or known extenders in each case in customary amounts. The inner material of the shoe advantageously is finely porous and absorbent for water and solvents.
Suitably one of the large surface sides of the shoe inner material continuous length or the blank made therefrom is provided with a coat based on a synthetic resin, preferably a thermoplastic synthetic resin, brought to the adhesive condition by the action of heat or the action of a solvent or mixture of solvents. In order to be able to produce with the new shoe inner material, the effect of the previously used non-slip materials in the production of shoes, this surface has a shape or character which is slip or slide diminishing. The surface of the new material thus has a certain roughness which prevents or makes more difficult the slipping out of the heel. It is particularly advantageous when the side of the new material which comes in contact with the heel or the hose by this procedure maintains a velvet-like character that the surface in question is treated mechanically, for example, by buffing on appropriate known apparatus (buffing rolls).
The above described inner shoe material is worked into the heel portion of the shoe and secured there suitably by gluing. Surprisingly and contrary to the structure of the previous conventional street shoes the new shoe inner material replaces both the function of the stiffening shoe capping material and the function of the non-slip material which should prevent the easy slipping out of the heel from the back part of the shoe, i.e. the inner material can be designated to be skid preventive too. This bifunctionality of the new shoe inner material simplifies the production of shoes in considerable measure and reduces the production costs which is of advantage in the developing countries because of the type of shoes produced there. The previous long time practice in the production of shoes of adding both flexible, pliable non-slip materials and besides that also stiffening effecting capping materials now can be unexpectedly changed by the present invention and be substantially simplified. The invention permits the more economical production of particularly simple footwear.
The consequently produced new heel region of shoe thus no longer has a separate customary heel stiffener and it consists of the accurate last shaped shoe inner material blank of the above described type and of the leg glued therewith.
Accordingly to the invention there is also claimed the process of stiffening the heel portions of shoes which is characterized by fastening by securely sewing or similar method a suitable blank of the new moldable shoe inner material at the upper edge of the inner side of an upper material without a counter to simultaneously stiffen the heel region and produce the non-slip effect. In the case of the insertion of the shoe inner material which is not provided with an adhesive layer the inner side of the blank is provided with an adhesive coating and then the combination worked on the last through the effect of pressure and if desired of heat and thus the cementing is effected.
If the shoe inner material on one side is provided with a dry, thus not adhesive, but activatable adhesive layer and has been cut for use, the above described stiffening process is varied and simplified by softening the shoe inner material blank fastened or securely sewn on the upper by means of a solvent or a mixture of solvents which at the same time brings said layer into the adhesive condition after which the upper and inner material blank are molded together on the shoe last in customary manner during which the adhesion of the two takes place. The solvent or solvent mixture can be applied in simple manner for example with a brush to the side of the inner shoe material not provided with an adhesive whereupon the solvent (or mixture of solvents) gradually penetrates into and through the shoe inner material, it softens and then even activates the adhesive film. Consequently it is possible with the correct selection of the solvent or solvent mixture in sufficient time to mold the softened shoe inner material blank in customary manner together with the upper and at the same time to adhere them. The shoe inner material blank can also be so immersed in the solvent (or mixture of solvents) that practically only the blank and not the upper is wetted by the solvent whereupon the described molding and adhering takes place.
The new shoe inner material has very good tear resistance properties both in the dry and in the wet state and it has a good shape retention even after the influence of moisture. The abrasion resistance as well as the water absorption and release of water, which latter are comparable with the uptake and release of foot perspiration, as well as the stitch tear strength are likewise very good. The new shoe inner material also exhibits a favorable stress-strain ratio as well as small swelling and shrinkage values. All of these valuable properties make the new material especially suited for use as a shoe inner material.
The fiber structures used are cloth, knitted fabrics, non-wovens and preferably fleece made of natural or synthetic fibers such as cotton, wool, rayon staple, rayon and/or synthetic fibers of polyamide (e.g., polycaprolactam or polyhexamethylene-adipamide), polyacrylonitrile, polyvinyl chloride, polyvinylidene chloride, polypropylene and especially polyesters such as, e.g., polyethylene glycol terephthlate (e.g. Dacron). The fiber structure has a square meter weight between 80 and 500 grams, preferably between 150 and 400 grams; as fleece it is 150 to 400 grams.
The synthetic resins acting as stiffening agents which are suited for loading include particularly polymers of styrene and copolymers of styrene and butadiene and also polyvinyl chloride, polyvinyl acetate, polyvinylidene chloride, vinyl chloride-vinyl acetate copolymer and the like known polymers. They are used in such amounts that the loading finally amounts to 0.1 to 0.9 kg, preferably 0.2 to 0.7 kg, per square meter of fiber structure (dry weight without fiber structure weight). The synthetic resins mentioned advantageously also can be used with known natural resins such as rosin or synthetic resins such as ureaformaldehyde or melamine-formaldehyde resins or their precondensates and/or with polyvinyl alcohols, particularly those types of polyvinyl alcohols which are obtained by substantial to complete hydrolysis of a polyvinyl ester, e.g. polyvinyl acetate.
Additionally there can be used for the loading fillers such as kaolin, chalk, talc, clays, silica fillers, siliceous chalk, keiselguhr as well as in a given case titanium dioxide, carbon blacks and other pigments in amounts of about 10 to 200 parts by weight, preferably up to 80 parts by weight based on 100 parts by weight of the synthetic resin. Other auxiliaries which can be present in the loading are dyestuffs, pigments, plasticizer, stabilizers, propellants, processing aids and/or extenders in customary amounts. The mixture provided for the loading, according to its composition, its amounts of constituents and condition, e.g., as dispersion, paste or dough, is so chosen that the loaded or filled as well as dried fiber structure stands or remains at normal temperatures up to 60° C. stiffly-elastic and relatively hard. Therefore there are preferably added as synthetic resins polystyrene and copolymers of styrene and butadiene with styrene contents between about 85 and 60 as well as between about 40 to 20 weight percent, balance butadiene, in amounts of 250 to 600 grams per square meter of fiber structure. With advantage the styrene butadiene copolymers can be so called carboxylated copolymers, thus copolymers with carboxyl groups in the molecule. The loading mixture suitably is a pasty brushable composition.
As solvents which softens the shoe inner material and in a given case the adhesive layer there are employed the customary fast and slow evaporation solvents, volatile organic compounds such as ketones, e.g., acetone, esters, e.g. methyl acetate, ethyl acetate and butyl acetate, volatile hydrocarbons, e.g. gasoline and benzene, alcohols, e.g. methyl alcohol, ethyl alcohol, isopropyl alcohol and n-butyl alcohol, tetrahydrofuran, ethers, e.g. diethyl ether and dibutyl ether and their mixtures, especially methyl propyl ketone, ethyl butyl ketone, methyl isobutyl ketone and methyl-n-butyl ketone, as well as preferably methyl ethyl ketone and diethyl ketone.
The synthetic resin provided for the adhesive layer brought into the adhesive condition by the action of heat or through the action of solvent is preferably a thermoplastic synthetic resin. The adhesive thus is one based on at least one of the following polymers polychlorobutadiene, polyvinyl acetate, polyacrylic acid esters, e.g., polyalkyl acrylates such as poly (methyl acrylate), poly (ethyl acrylate), poly (butyl acrylates), poly (2-ethylhexyl acrylate), nitrile rubber (i.e. butadiene acrylonitrile) or preferably an ethylene-vinyl acetate copolymer. These adhesive bases can, if desired and frequently with advantage, be mixed in with other resins, for example natural resins, e.g. rosin, phenol resins (e.g., phenolformaldehyde resins), maleinate resins, modified colophony resins or the like known resins and in customary proportions.
The adhesive is brushed on in corresponding preparation, e.g. in the mixture with the solvent or as dispersion, on the shoe inner material or on the blank. This can take place mechanically e.g. immediately after the production of the continuous sheet material or the blank can be coated with the adhesive preparation in the production of the shoe. In the latter case the adhesion can be undertaken immediately. If the shoe inner material already has a dry adhesive layer then this material can be activated again as described above with heat or by the effect of solvent.
The loading of the fiber structure is attained by steeping, impregnating or coating, e.g. using a trough containing the loading composition through which the fiber structure is led. The loading can also be carried out as a coating during which the fiber structure rests upon a rubber blanket or there can also be employed a doctor blade conventionally used for coating purposes during which there is used a loading mass having an appropriate viscosity. By suitable apparatus such as squeeze rolls or doctor blades the desired amount of coating is applied and consequently the desired total weight of the shoe inner material is obtained (in grams per square meter of surface area).
Preferably the drying takes place on heated drying rolls arranged in succession or in drying conduits or in drying ovens, through which the continuously running sheet is conducted by known means.
The application of the adhesive layer on one side of the loaded or coated continuous sheet also can be carried out besides as described above by melting, spraying, knife coating or dusting whereby the synthetic resin must have the necessary form of consistence for each of the stated process variants as for example the form of a powdery granulate or a paste (dispersion).
To improve the surface of the continuous sheet this can be smoothed by using heated rolls, by pressure, heat and the like known processes or preferably can be finished by a mechanical treatment such as for example buffing. Through the buffing (with buffing paper or sand paper) it receives advantageously a particular uniform, velvet like surface.
The new shoe inner material subsequent to the production in continuous length is cut into sheets of for example one by one meter size or in suitable blanks. The shoe producers mostly prefer to produce the blank itself from said sheets, for example by means of a cutting die to make a blank according to the non-slip model or size.
Frequently these cut-pieces or blanks are not skived, this means using blanks without having removed their edges by skiving. The ability of the material to be skived without problem is an important advantage, because the skived blanks or shapes improve the appearance and the wearability of the shoe. The skiving of the edges is performed either only on the upper line or also on the sides of the blanks which is subsequently sewn onto the upper, i.e. either only on the upper line or also on the sides. In the production of lined shoes the material according to the invention can be bound by sewing or gluing with the lining, too.
Now the preforming is done with a so-called preform machine and simultaneously there is performed the adhesion by the heated mold, the adhesive used being activated by the heat involved. If preform machines are not available the shaping according to the last can be carried out also by brushing on the blank with one of the above mentioned organic solvents or a mixture of solvents by which the blank becomes soft and flexible, and subsequently shaping is done.
The remaining operations on the shoe are as is customary.
The finished shoe with the new shoe inner material is distinguished by a line according to the last resulting in a slim counter form. The valuable advantage is that in place of the customary three layers (upper material, counter and non-slips only two layers (upper material and the new shoe inner material) form the heel region of the shoe.
Unless otherwise indicated all parts and percentages are by weight. The compositions can comprise, consist essentially of, or consist of the materials set forth and the process can comprise, consist essentially of or consist of the steps set forth.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
There were produced the following mixtures as loading compositions for the later coating, steeping or impregnating of a fiber structure. For this purpose the individual components of the mixture were mixed together in the stated sequence under slow stirring and further stirred at room temperature until complete homogeneity.
The parts (for short P) given below are always by weight.
I
1. 75.0 P of an aqueous dispersion of a homopolymer of styrene containing 50 weight percent dry material (solids) and a pH of 11.5; the styrene polymerizate itself had a softening temperature of about 105° C. and formed a closed film at 185° C. (film forming temperature),
2. 23.0 P of an aqueous, colloidal dispersion of poly-2-chlorobutadiene containing 58 weight percent of polymer and a pH of 13.0; the poly-2-chlorobutadiene itself is a type having only a slight tendency toward crystallization and in the dispersion has an average particle size of about 160 microns.
3. 2.0 P of a plasticizer-emulsifier mixture of 60.0 P dibutyl phthalate, 5.0 P of a commercial emulsifier (OFA-emulsifier of Chemische Werke Huls A.G. in Marl, Germany) and
4. 35.0 P water.
II
1. 85.0 P of an aqueous dispersion of a carboxylated styrene-butadiene copolymer with 50 weight percent dry material and a pH of 8.0 to 9.0 produced from a copolymer containing 81% styrene (Dow Latex 210 of Dow Chemical S.A. Europe in Zurich, Switzerland) and
2. 15.0 P of a natural, crystalline, finely ground calcium carbonate.
III
1. 14.0 P of an aqueous dispersion of a carboxylated styrene-butadiene-copolymer (same dispersion as under II, 1.).
2. 50.0 P of an aqueous dispersion of a carboxylated styrene-butadiene copolymer containing 48 weight percent of dry material and a pH of 8.0 to 9.0 produced from a copolymer containing 63% of butadiene (Synthomer Latex 9340 of Synthomer Chemie GmbH, Franfurt am Main, Germany),
3. 5.8 P of a water containing precondensate of urea and formaldehyde (Urecoll® 181 of BASF A.G. in Ludwigshafen, Germany), with a viscosity of 5 to 8 Pa s (viscosity determination according to DIN 53015 (German Industrial Standard 53015) in a 4% aqueous solution), containing 70 weight percent dry material, a density of 1.3 and a pH of 8.0 to 9.0 wherein the precondensate (as dry material) has a nitrogen content of 18 to 19 weight percent,
4. 1.2 P ammonium chloride and
5. 29.0 P of a natural, crystalline, finely ground calcium carbonate (same product as under II, 2.)
(a) The loading composition according to I was now applied to a continuous fleece with help of an impregnating apparatus (from impregnating tank with composition I and an immersed return guide roll as well as a dosing pair of rolls at the edge of the tank). This fleece was a customary endless fiber fleece of 3.5 dtex size fibers of poly ethylene glycol terephthalate held together by known binders and had a weight of about 180 g/m 2 . The loaded fleece was then dried until constant weight at an increasing temperature up to about 130° C. and subsequently brought to a thickness of about 1.5 mm with help of conventional calender rolls. The total weight of the finished goods was 750 g/m 2 , which corresponds to a loading of 570 g/m 2 .
The goods had a pleasant homogeneous appearance visible over the entire surface and the desired feel which was found to be slip and skid resistant and felt somewhat napped or of good hand.
About half the entire metric (i.e. the footage) of this goods was now buffed on one of the large surface sides with the help of a conventional grinder or roll buffing apparatus whose buffing rolls were coated with an abrasive-coated paper having a 120 mesh grain.
Through this the buffed surface of the good receive a pleasant, velvet like character. These goods are suitably so used that the buffed side, later worked into the shoe is turned to the heel or the hose.
(b) The loading composition according to II was applied with a conventional brushing machine one a web of the following type and composition: staple fiber-crosshead, both sides napped; weight about 250 g/m 2 ; fiber density 27/19 fibers per cm. Count of yarn Nm=28/14. The loading was 500 g/m 2 . Final weight of the finished goods 750 g/m 2 ; thickness 0.90 mm. It was especially suited as stiffener and at the same time non-slip material for shoes.
(c) The loading composition III was applied on a cotton fabric napped on both sides (weight 250 g/m 2 ; fiber density 17/15 fibers per cm. Count of yarn Nm=34/8 calico construction) with a conventional coating machine. After the drying and calendering the goods weighed 780 g/m 2 , had a thickness of 1 mm and is very well suited for stiffening the rear caps of shoes.
(d) To apply color to the loadening composition III a mixture of pigments was mixed into it, i.e. per 100 kg of loading composition 140 grams brown, 120 grams yellow and 19 grams black (Volcanosol® pigments of BASF A.G. in Ludwigshafen, Germany) and the finished composition applied on the above described endless fiber fleece in such an amount that the loaded, dry goods then weighed 750 g/m 2 . The calendering gave a goods thickness of around 1.1 mm. As was described under (a) the goods were then buffed on one side whereby its appearance became uniform and its feel was less rough.
For the working into the shoe there were now cutted out pieces from the continuous length cut into size and these skived on one side. The pieces, worked into the heel region of the shoe gave this a permanent, last accurate heel shape and simultaneously there was prevented the easy slipping out of the heel part of the shoe.
(e) The shoe inner material described above under (a) with a surface buffed on one side was provided on the other side with an adhesive layer of the following composition:
(1) 22.0 P of an ethylene-vinyl acetate copolymer (containing 40% vinyl acetate; melt index 2-5 [grams per 10 minutes at 190° C. and 2.16 kp load]; Mooney-viscosity ML4=20).
(2) 16.5 P of a terpene-phenol resin (melting range 120°-130° C.; acid number 60-70, determined as milligrams KOH per grams solid resin),
(3) 16.5 P of a maleinate resin (melting range 108°-118° C., acid number 120, determined in the manner stated above) and
(4) 45.0 P of toluene as solvent for (1) and (3).
The toluene solution was applied to a continuous length of the loaded fleece with help of a conventional blanket coater with a doctor knife and dried on a subsequent tenter. After evaporating the toluene there was ascertained an increase of weight of the continuous length of material of around 100 grams per square meter.
The dry adhesive coat is easily brought again into the adhesive condition by the action of heat or through solvents. In the further processing together with this activation of the adhesive the cutted and skived piece becomes pliable and moldable and is molded on the last. This implies an advantageous simplification of the process.
There is hereby incorporated by reference the priority German applications Nos. P 28 28 509.8 and G 78 19 462.4. | There are provided thermoplastic or through the action of solvent shapable, shoe stiffening and likewise non-slip inner material for the heel region in the form of continuous sheets or blanks consisting of an embedded fiber structure which is loaded or filled with at least one synthetic resin acting as a stiffening agent at normal temperature up to about 60° C. in an amount of 0.1 to 0.9 kg per square meter fiber structure in the course of which the loading in a given case can contain fillers, dyestuffs, pigments, plasticizers, propellants, stabilizers, processing aids and/or extenders in the customary amounts. | 22,674 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the treatment of wastewater, such as, for example, municipal, industrial or concentrated animal feeding operation (CAFO) wastewaters. This invention is especially useful in facilitating direct removal of contaminants from wastewaters and enhancement of biological processes for treating wastewater.
2. Prior Art
The treatment of contaminated wastewater from municipal, industrial or CAFO sources involves a sequence of processing steps for maximizing water purification at minimum costs. Industrial effluents, particularly wastewater from oil refineries and chemical factories, include a broad spectrum of contaminants, and, consequently, such wastewater is usually more difficult to decontaminate than wastewater from municipal sewage systems. Four main sequential process treatments are used to decontaminate such industrial effluents although similar treatment is given municipal effluents, or combined municipal/industrial effluents. These are primary, intermediate, secondary, and tertiary treatments. The primary treatment calls for removal of gross amounts of oil and grease and solids from the wastewater. In municipal and CAFO wastewater treatment, generally little free oil is present but solids removal is still needed. The intermediate treatment is the next process and it is designed to adjust water conditions so that the water entering the secondary treatment zone will not impair the operation of the secondary treatment processes. In other words, intermediate treatment is designed to optimize water conditions so that the secondary treatment process will operate most efficiently. The secondary treatment calls for biologically degrading dissolved organics and ammonia in the water. One of the most common biological treatment processes employed is the activated sludge process discussed below in greater detail. The tertiary treatment calls for removing residual biological solids present in the effluent from the secondary treatment zone and further removing trace contaminants which contribute to impairing water clarity or adversely affecting water taste and odor. This is usually a filtration of the water, preferably through beds of sand, or combinations of sand and coal, followed by treatment with activated carbon.
The activated sludge process is a conventional wastewater treating process which produces a high degree of biological treatment in a reasonably compact format. The application of this process to the treatment of industrial and CAFO wastewater has, however, been relatively slow compared with municipal applications. Industrial applications of this process are nevertheless increasing rapidly. Currently, the activated sludge process is capable of reliably achieving about 85% to 98% reduction in the five-day biochemical oxygen demand (BOD.sub.5). However, the BOD.sub.5 contaminants present in industrial wastewater are typically small compared with the total oxygen demanding contaminants present in such wastewater as measured by the chemical oxygen demand (COD) test. For example, the BOD.sub.5 contaminants present in the effluent from an activated sludge process typically ranges from 2 to 20 parts per million parts of water. It is not uncommon to also find present in such effluent 10 to 20 times this amount of COD.
The activated sludge process generally has at least two, but preferably four stages of treatment. In the first stage, contaminated water is contacted with the activated sludge. The sludge includes microorganisms which feed on the contaminants in the water and metabolize those contaminants to form cellular structure and intermediate products. This decontaminated water flows into a second clarifier stage where suspended sludge particles are separated from the decontaminated water. A portion of the sludge is recycled to the first stage and the remainder can be forwarded to the third and fourth stages as is taught in Grutsch et al., U.S. Pat. Nos. 4,073,722 and 4,292,176. This sludge forwarded to the third and fourth stages includes water. In the third stage the sludge is thickened to remove excess water and in the fourth stage the thickened sludge is permitted to digest, that is, the microorganisms feed upon their own cellular structure and are stabilized. The digestion step stabilizes the microorganisms. U.S. Pat. No. 4,073,722 teaches dewatering, thickening, and digestion of activated sludge and powdered activated carbon mixtures.
Activated carbon is often used in tertiary treatment as a final cleanup for water discharged from the second stage clarifier. Some have taught that activated carbon, fine carbon (e.g., powdered anthracite) or fine particle clays such as bentonite and Fuller's earth can be used to treat wastewater in a biological treatment process. U.S. Pat. No. 3,904,518 teaches that between about 50 and 1500 parts of activated carbon or between about 250 and 2500 parts of adsorptive bentonite or Fuller's earth per million parts of feed wastewater can be beneficial in water purification. The carbon or Fuller's earth has a surface area of at least 100 square meters per gram and the activated carbon will typically have a surface area of between 600-1400 square meters per gram.
While a variety of powdered inorganic adsorbent materials have been used in biological treatment systems, powdered activated carbon remains the material most commonly used. Several mechanisms have been suggested as to how these materials enhance the treatment of wastewater: improved buffering; increased biological surface area for key organisms such as nitrifying bacteria that favor attached growth; decreased system sensitivity to toxic substances; improved phase separation, and adsorption. Adsorption is most important when the system is operated at low solids retention times (SRT)—namely, before particles are colonized by attached growth bacteria and other microorganisms. Thus, as particle surface area becomes less accessible, the role of adsorption decreases and the other mechanisms dominate.
The relatively high cost of activated carbon has served as a strong deterrent to common use of the material in activated sludge treatment of municipal, industrial and CAFO wastewaters. One approach to reducing cost of activated carbon has been recovery, regeneration and recycling of the activated carbon. This is best illustrated in the appropriately labeled Powdered Activated Carbon Treatment (PACT.TM.) system disclosed in U.S. Pat. Nos. 3,904,518 and 4,069,148, by Hutton et al. The PACT.TM. treatment system operates as a continuous flow process with an aeration basin followed by a discrete clarifier to separate biologically active solids and carbon from the treated wastewater. The recovered, regenerated powdered activated carbon is then returned to the aeration basin along with a portion of the recovered sludge.
Rehm and coworkers have further refined the use of activated carbon in the aerobic oxidation of phenolic materials by using microorganisms immobilized on granular carbon as a porous biomass support system. Utilizing the propensity of microorganisms to grow on and remain attached to a surface, Rehm used a granular activated carbon support of high surface area (1300 m.sup.2/g) to which cells were attached within the macropores of the support and on its surface, as a porous biomass support system in a loop reactor for phenol removal. H. M. Ehrhardt and H. J. Rehm, Appl. Microbiol. Biotechnol., 21, 32-6 (1985). The resulting “immobilized” cells exhibited phenol tolerance up to a level in the feed of about 15 g/L, whereas free cells showed a tolerance not more than 1.5 g/L. It was postulated that the activated carbon operated like a “buffer and depot” in protecting the immobilized microorganisms by adsorbing toxic phenol concentrations and setting low quantities of the adsorbed phenol free for gradual biodegradation. This work was somewhat refined using a mixed culture immobilized on activated carbon [A. Morsen and H. J. Rehm, Appl. Microbiol. Biotechnol., 26, 283-8 (1987)] where the investigators noted that a considerable amount of microorganisms had “grown out” into the aqueous medium, i.e., there was substantial sludge formation in their system.
Suidan and coworkers have done considerable research on the analogous anaerobic degradation of phenol using a packed bed of microorganisms attached to granular carbon [Y. T. Wang, M. T. Suidan and B. E. Rittman, Journal Water Pollut. Control Fed., 58 227-33 (1986)]. For example, using granular activated carbon of 16 times 20 mesh as a support medium for microorganisms in an expanded bed configuration, and with feed containing from 358-1432 mg phenol/L, effluent phenol levels of about 0.06 mg/L (60 ppb) were obtained at a hydraulic residence time (HRT) of about 24 hours. Somewhat later, a beri-saddle-packed bed and expanded bed granular activated carbon anaerobic reactor in series were used to show a high conversion of COD to methane, virtually all of which occurred in the expanded bed reactor; P. Fox, M. T. Suidan, and J. T. Pfeffer, ibid., 60, 86-92 (1988). The refractory nature of ortho- and meta-cresols toward degradation also was noted.
The impregnation of flexible polymeric foams with activated carbon is known to increase the ability of fabrics and garments to resist the passage of noxious chemicals and gases see for example, U.S. Pat. Nos. 4,045,609 and 4,046,939. However, these patents do not teach the use of these foams in wastewater treatment, or that these foams are a superior immobilization support for the growth and activity of microorganisms.
Givens and Sack, 42nd Purdue University Industrial Waste Conference Proceedings, pp. 93-102 (1987), performed an extensive evaluation of a carbon impregnated polyurethane foam as a microbial support system for the aerobic removal of pollutants, including phenol. Porous polyurethane foam internally impregnated with activated carbon and having microorganisms attached externally was used in an activated sludge reactor, analogous to the Captor and Linpor processes which differ only in the absence of foam-entrapped carbon. The process was attended by substantial sludge formation and without any beneficial effect of carbon.
The Captor process itself utilizes porous polyurethane foam pads to provide a large external surface for microbial growth in an aeration tank for biological wastewater treatment. The work described above is the Captor process modified by the presence of carbon entrapped within the foam. A two-year pilot plant evaluation of the Captor process itself showed substantial sludge formation with significantly lower microbial density than had been claimed. J. A. Heidman, R. C. Brenner and H. J. Shah, J. of Environmental Engineering, 114, 1077-96 (1988). A point to be noted, as will be revisited below, is that the Captor process is essentially an aerated sludge reactor where the pads are retained in an aeration tank by screens in the effluent line. Excess sludge needs to be continually removed by removing a portion of the pads via a conveyor and passing the pads through pressure rollers to squeeze out the solids.
In U.S. Pat. No. 6,395,522 DeFilippini and coworkers describe a biologically active support system for providing removal of pollutants such as aliphatics, aromatics, heteroaromatics and halogenated derivatives from waste streams. The support contains a particulate adsorbent such as activated carbon bound by a polymer binder to a substrate such as a polymeric foam, and a bound pollutant-degrading microorganism. They claim that the biologically active support can be used in conventional aerobic biological waste treatment systems such as continuous stirred reactors, fixed-bed reactors and fluidized bed reactors.
H. Bettmann and H. J. Rehm, Appl. Microbial. Biotechnol., 22, 389-393 (1985) have employed a fluidized bed bioreactor for the successful continuous aerobic degradation of phenol at a hydraulic residence time of about 15 hours using Pseudomonas putida entrapped in a polyacrylamide-hydrazide gel. The use of microorganisms entrapped within polyurethane foams in aerobic oxidation of phenol in shake flasks also has been reported; A. M. Anselmo et al., Biotechnology B.L., 7, 889-894 (1985).
Known bioremediation processes suffer from a number of inherent disadvantages. For example, a major result of increased use of such processes is an ever increasing quantity of sludge, which presents a serious disposal problem because of increasingly restrictive policies on dumping or spreading untreated sludge on land and at sea. G. Michael Alsop and Richard A. Conroy, “Improved Thermal Sludge Conditioning by Treatment With Acids and Bases”, Journal WPCF, Vol. 54, No. 2 (1982), T. Calcutt and R. Frost, “Sludge Processing—Chances for Tomorrow”, Journal of the Institute of Water Pollution Control, Vol. 86, No. 2 (1987) and “The Municipal Waste Landfill Crisis and A Response of New Technology”, Prepared by United States Building Corporation, P.O. Box 49704, Los Angles, Calif. 90049 (Nov. 22, 1988). The cost of sludge disposal today may be several fold greater than the sum of other operating costs of wastewater treatment.
A slightly different biophysical treatment process is described by McShane et al., in “Biophysical Treatment of Landfill Leachate Containing Organic Compounds”, Proceedings of Industrial Waste Conference, 1986 (Pub. 1987), 41st, 167-77. In this process a biological batch reactor is used with powdered activated carbon and the system is operated in the “fill and draw” mode, also known as the sequenced batch reactor (SBR) mode. A similar scheme for treatment of leachate is disclosed in U.S. Pat. No. 4,623,464 by Ying et al. in which an SBR is operated with both biologically active solids and carbon present to treat a highly toxic PCB and dioxin-containing leachate. Supplementation with powdered activated carbon has been successfully demonstrated to improve treatment of widely differing wastewater streams in all such variations of the activated sludge process. Use of powdered activated carbon in this manner remains, nevertheless, rare—particularly in treatment of municipal wastewaters where cost factors are paramount. Most wastewater treatment plant owners and treatment plant managers and system operators deem the cost of doing so to be excessive.
The literature and prior art does not provide any instruction on substituting renewable powdered natural lignocellulosic materials for the carbon and clays and other inorganic and manufactured adsorbents now deemed to be too costly by potential users. A number of such materials, notably kenaf core, have available surface area to weight ratios that are comparable to activated carbon and greatly exceed those of fine clays and carbon dust. Because they are generally cropped materials, these renewable resources can be delivered at much lower cost than activated carbon. Because they are biodegradable, they can also easily be disposed of along with the other sludge constituents. As such, these natural materials hold potential to succeed in achieving widespread usage where activated carbon, clays and carbon dust have not succeeded.
SUMMARY OF THE INVENTION
This invention relates to the treatment of wastewater. Most commonly, the pH of wastewater is from about 4 to about 11, or is treated with chemicals so as to adjust the pH into this range. Commonly the wastewater contains about 25 to about 15,000 mg/l of total suspended solids.
It is an object of this invention to provide an improved wastewater treating process that is generally applicable to treatment of municipal, industrial and CAFO waste streams which may differ significantly as to their characteristics—ranging from high to low with respect to BOD, COD, TOC, suspended solids, dissolved material, total nitrogen, total phosphorus, and presence of greases, oils, toxins and heavy metals. It is an object of this invention to provide both physical and biological treatment processes that can more efficiently and economically decontaminate municipal, industrial and CAFO waste streams through the supplementary use of powdered kenaf core (PKC) and other powdered natural lignocellulosic materials (PNLM).
It is another object of this invention to provide an improved PNLM and/or PKC enhanced activated sludge process that significantly reduces sludge production and therefore sludge disposal costs.
Yet another object of this invention is to provide a PNLM and/or PKC enhanced activated sludge process that significantly enhances the floc and settling characteristics of activated sludge solids, thus increasing the speed and efficiency of sludge settling, lowering the profile of settled sludge in clarifiers, and therefore increasing the hydraulic throughput capacity of those clarifiers.
A further object of this invention is to provide improved pre- and post-treatment of wastewaters in which fresh PNLM and/or PKC inputs are employed to remove adsorbable materials, dissolved and suspended, both before and after treatment by an activated sludge process—thus greatly improving both the efficiency of the activated sludge process and the final quality of the treated discharged effluent.
Still another object of this invention is to provide a PNLM and/or PKC enhanced activated sludge process with in situ recovery or recycling of unregenerated PNLM and/or PKC that is applicable to continuous and batch operated biological treatment systems and to all biological processes including aerobic, anaerobic and anoxic in which a means is provided to remove potentially biotoxic materials such as heavy metals and PCBs or phenols so as to create and to maintain non-biotoxic conditions. Accordingly, a broad embodiment of this invention is directed to any activated sludge process for the biological treatment of contaminated waste streams comprising, in combination, the steps of:
(a) contacting a raw, contaminated waste stream with fresh PNLM and/or PKC to physically remove oils, greases, colloidal and adsorbable materials in a pre-treatment phase before onset of activated sludge processing;
(b) separating by floatation and gravity the powdered PNLM and/or PKC and adsorbed materials from the pretreated waste stream;
(c) contacting a contaminated waste stream with both fresh and unregenerated recycled PNLM and/or PKC adsorbent and activated sludge comprising cellular microorganisms for a time sufficient to biologically degrade contaminates in the waste stream, thereby producing a decontaminated waste stream;
(d) separating by gravity the activated sludge and the powdered PNLM and/or PKC adsorbent from the decontaminated waste stream;
(e) recycling the recovered adsorbent and activated sludge for recontact with a contaminated waste stream, the recovered adsorbent remaining unregenerated prior to recontact.
(f) contacting an activated sludge treated waste stream with fresh PNLM and/or PKC to physically remove residual solids and adsobable materials in a post-treatment phase following completion of activated sludge processing;
(g) separating by gravity the powdered PNLM and/or PKC and adsorbed materials from the post-treated waste stream;
Note that the three sequences—(a) through (b), (c) through (e), and (f) through (g)—can be performed independently or in combination.
It is still further an object of this invention to provide a powdered kenaf core having good adsorption and separation characteristics.
These as well as other embodiments of the present invention will become evident from the following, more detailed description of certain preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic flow diagram of one embodiment of the invention in which wastewater is intermittently introduced into the primary treatment zone.
FIG. 2 is a schematic flow diagram of another embodiment of the invention in which wastewater flows continuously into the primary treatment zone.
FIG. 3 is a schematic flow diagram of one embodiment of the invention in which wastewater is continuously introduced, following pretreatment for solids, grit and grease removal, to an anoxic mixing tank.
FIG. 4 is a schematic flow diagram of another embodiment of the invention in which wastewater, following pretreatment for solids, grit and grease removal, is continuously treated using a variety of sequencing batch reactor circumstances.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides an improved process for treating water in which powdered natural lignocellulosic material (PNLM), especially powdered kenaf core (PKC), is added to the wastewater. The preferred kenaf core material has a surface area greater than about 200, more preferably greater than about 400, and still more preferably greater than about 500 square meters per gram. Commonly such kenaf core is in powdered form and has a particle size such that at least 50 percent of it will pass through 100 mesh per inch sieve, although generally about 70 to about 99 percent will pass through such a sieve.
In many cases wastewater is contacted with about 1 to about 5000 mg/l PNLM and/or PKC, but commonly about 1 to about 1000 mg/l is used. One especially preferred process for treating wastewater through contact with PKC comprises adding powdered kenaf core to the wastewater at a concentration of 1 to 40 mg/l based on feed water while said kenaf is present in the water at a concentration substantially in excess of the addition concentration. This can be accomplished, for example, by recycling the kenaf with the activated sludge.
PNLM and/or PKC is generally used in an integrated, multi-step wastewater treating process. It can optionally be used in each step to enhance treatment—providing both physical and biological advantages to the various steps of the process. In primary treatment, gross amounts of oil, grease and solids are removed from the wastewater. In treating municipal wastewater, generally little oil is present but solids removal is carried out using clarifiers of conventional design. The effluent from this primary treatment typically includes from about 25 to about 150 parts of suspended solids per million parts of water and from about 25 to about 300 parts of oil and grease per million parts of water. In treating municipal waste, the oil level may be even lower. As is not commonly recognized, such wastewater containing relatively large amounts of oil and/or solids, cannot be fed directly into an activated sludge process where the sludge age is in excess of about ten days without upsetting the activated sludge process. Generally, if the water entering the activated sludge process contains more than about twenty parts of solids per million parts of water and/or more than about twenty parts of oil and grease per million parts of water, downstream treatment is greatly impaired. In many cases, more than about ten parts per million of solids and/or about ten parts per million of hydrocarbon can be detrimental. Excessive amounts of oil and hydrocarbon can result in gross quantities of oily, emulsified material collecting in the first stage or mixed liquor tank of the activated sludge process. Such oily, emulsified solids impair or prevent the activated sludge from decontaminating the water, causing the effectiveness of the activated sludge process to be substantially diminished. Therefore it is often important to reduce chemical oxygen demand and remove excessive oil and solids from the wastewater by intermediate treatment.
After primary treatment, wastewater is then commonly subjected to intermediate treatment where excessive solids and/or hydrocarbons are removed, chemical oxygen demand is reduced, and contaminant concentrations are equalized so that such concentrations of contaminants remain more or less constant even though the contaminant concentration in the influent to the equalization treatment stage sharply changes from time to time. If, for instance, wastewater from a petroleum-chemical complex is being treated, it is desirable that the waste streams be combined and then subjected to intermediate treatment. If contaminant concentration in the influent changes and such change is sustained, this will ultimately result in a change in the contaminant concentration in the effluent from the equalization section. In staged equalization zones, this change will occur gradually over a relatively long time interval. This permits the microorganisms in the downstream activated sludge process to adapt or acclimate to this change in contaminant concentration while maintaining process purification efficiency. In circumstances where oil and/or colloidal and solids content is high, PNLM and/or PKC may be added to the pre- or primary treatment step with good results. Powdered kenaf core, in particular, has been recognized by the US Navy to be the most oil adsorbent natural material known to exist—picking up between 8 and 12 times its weight in oil, depending on that material's viscosity (United States Naval Facilities Engineering Center, “Evaluation of Bio-Based Industrial Products for Navy and DOD use: Phase I Kenaf Absorbent”, NFESC Technical Report, TR-2101-ENV, March 1999). The high surface to weight ratio of powdered kenaf core also greatly facilitates flocculation and coagulation of colloidal material and suspended solids. Relatively small amounts of fresh PKC, when mixed well with raw wastewater in a pre- or primary treatment step will quickly produce a relatively compact floating coagulant mass containing oils and greases that is easily removed by skimming, and a relatively compact, settled coagulated floc that can be continuously removed from the bottom of a settling basin or by screening or filtration using conventional equipment and methodologies.
Intermediate treatment generally also includes equalization (along with such filtration and solids and oil removal). Equalization can be conducted in a basin having two, preferably three or even four or more compartments. These compartments are mixed and arranged in series so that water flows from one compartment to the next succeeding compartment. The total retention time of water in the basin is less than about 20 to 30 hours. Consequently, heat loss is minimized. Normally, the difference in temperature between the influent and effluent water is 20. degree. F. or less. Preferably the retention time in each compartment is 30 to 500 minutes.
In circumstances where industrial wastewaters are high, flows from the various sources are mixed in the first compartment, and the contaminant concentration is monitored. Usually pH, toxic metals, known toxic compounds, COD contaminants, phenolic, and ammonia concentrations are measured either manually or automatically. Since wastewaters from multiple sources are fed into the relatively confined space in the first compartment, several advantages occur. First it is easy to monitor contaminant concentration and readily detect any drastic change in concentration indicating, for example, a break in a chemical line. The reason is because the first compartment in a multiple compartment system will more rapidly increase in concentration to more readily detectable levels than a single compartment system. Also, neutralization is achieved. For example, one source of water may be highly acidic and another highly basic. Neutralization occurs as these streams mix in the first compartment. Waste streams from municipal sources generally do not vary greatly in the acid/basic content. It is important to adjust the pH in the equalization basin in order to maximize oxidation of certain contaminants, particularly sulfides. pH may be adjusted by adding acid or base to the water in the second compartment until the water has a pH ranging from about 6.5 to about 9.5, preferably between 7.5 and 8.5 In some cases at least about one part, preferably about three parts, still more preferably about five parts, of dissolved oxygen per million parts of water must be present to satisfy the immediate oxygen demand (IOD) of the contaminants in the water at a reasonable rate of oxidation when certain contaminants such as sulfides are present. Preferably catalysts such as hydroquinone or gallic acid are added to the water to catalyze the oxidation of IOD contaminants. If this IOD is not satisfied, the downstream activated sludge process can be adversely affected. Consequently, the water in the equalization basin should be aerated. Conventional floating aerators may be used. Aeration is more effective in a confined zone. About 0.15 or more horsepower per thousand gallons of water generally provides excellent aeration. Aeration also thoroughly agitates and mixes the water with the result that colloidal and suspended oils and solids are mechanically flocculated and accumulate on the water surface. These oily solids are removed by skimming. In order to ensure that the water to the activated sludge process includes less than about twenty parts of hydrocarbon, such as oil and grease, per million parts of water and/or less than about twenty parts of solids per million parts of water, PNLM and/or PKC (or another flocculating agent) may be added to the water in the equalization basin or to the stream of water flowing to the activated sludge process. It is preferable to reduce the solids and/or hydrocarbon content of the wastewater to less than about ten parts per million respectively. The PNLM and/or PKC (or other comparable coagulating and/or flocculating agent) destabilizes colloidal particles which then aggregate. The aggregates are carried with the effluent stream to a filter and removed prior to introduction of the stream to the activated sludge process. Air is preferably introduced into the stream of water flowing into the downstream activated sludge process to ensure that the immediate oxygen demand to the water is satisfied. In circumstances where influent COD is extremely high—such as is common with industrial and CAFO wastewaters—it is extremely desirable to substantially reduce chemical oxygen demand prior to biological treatment. Commonly the chemical oxygen demand is reduced by about fifty percent, but preferably by about seventy percent. In a more preferred mode of operation chemical oxygen demand is reduced to essentially the soluble organic component prior to biological treatment.
Water from intermediate treatment generally flows through an activated sludge plant. In preferred activated sludge processes the sludge-water mix undergoes at least one anoxic stage, at least one aeration stage and at least one clarifying stage, and the sludge of different ages from different stages is recycled to one or more upstream stages of the activated sludge process. In a preferred first stage, water from the intermediate treatment is mixed with returned, clarified sludge in an anoxic zone/stage. This is followed by aeration and then clarification, with a portion of recovered sludge returned to the anoxic sequence and a portion further treated downstream. These steps or phases can be accomplished in multiple vessels or tanks, a continuous sequenced channel or alternatively in batch mode in a single vessel or tank.
The effluent from the clarifier or third stage of the activated sludge process is filtered or otherwise clarified to remove biological solids in the effluent and then may again be contacted with PNLM and/or PKC to remove odor causing and other residual trace components by adsorption. Chemical agents and flocculants may also be added to the clarifier effluent to destabilize colloidal suspensions and assist filtration. However, where interstage aeration has increased the oxygen content of water to at least one, preferably at least three parts, more preferably five parts, of dissolved oxygen per million parts of water, organisms collected in the filter and on the PNLM and/or PKC are maintained in an aerobic condition, and odor and any degradation in quality of the filtered effluent is avoided. Further, the effluent water to the receiving stream has a high level of oxygen in it. Thus, it does not contribute to deterioration of the water quality of the receiving stream.
Although PNLM and/or PKC can be added, with good effect, to any wastewater stream there are preferred points of addition in a multistage wastewater treatment process. We have already noted the possibility of adding PNLM and/or PKC during pre- or primary treatment to remove high oil, grease and/or volatile solids content (BOD and COD) of influent wastewater. It is most common to add PNLM and/or PKC to the first or second stages of an activated sludge process. It is also preferred to introduce PNLM and/or PKC before the first stage of an activated sludge process, such as to the sludge being returned from the clarifier to the anoxic phase. In this manner, fresh PNLM and/or PKC is exposed to the equilibrium residual soluble organic contaminants and essentially eliminates any mixing or short circuiting problems in the aeration tank that would expose fresh PNLM and/or PKC to incoming organics. This can prevent the adsorption by active sites on the PNLM and/or PKC with the wrong organics. The rundown line between first and second stages, when used with a wide-well clarifier can provide extended contact time between the wastes and the PNLM and/or PKC.
Another preferred point of addition for PNLM and/or PKC is after the third stage of the activated sludge process, for example, to the decontaminated water leaving the third stage. In this manner, fresh PNLM and/or PKC (i.e., material that has not already been colonized by microorganisms) is exposed to only residual soluble contaminants and said PNLM and/or PKC can be removed by an additional clarification step or captured by downstream final filters. The PNLM and/or PKC captured by the filters contributes the attributes of a granular media bed to the PNLM and/or PKC system and exposes PNLM and/or PKC for long periods to the residual contaminants, thereby more fully utilizing the adsorptive capacity of the material. When the final filters begin to deactivate or clog, they can be backwashed to the first stage so that PNLM and/or PKC with residual organics resistant to bio-oxidation are returned to the aeration tank, or to the fourth stage or the aerobic stabilization tank. When backwashed to the aerobic stabilization tank, the PNLM and/or PKC presents a concentrate of resistant organics to the microorganisms for an extended period of time which encourages the proliferation of species capable of metabolizing the resistant organics. Recirculation of a slipstream of this sludge system and combining with the principle sludge mass encourages the reduction of the resistant organics by the principal sludge mass, thereby minimizing the load on PNLM and/or PKC.
Another preferred point of addition of PNLM and/or PKC is into the portion of the digested sludge from the fourth stage which is mixed with water and sludge entering the second stage. If the biochemical system for minimizing residual COD resistant to removal depends on exoenzymes from slow reproducing organisms, this point of addition will expose fresh PNLM and/or PKC to a preferred point in the process for adsorbing these enzymes. Acting as a carrier for these enzymes, the PNLM and/or PKC provides a means for their capture and incorporation into the sludge mass rather than permitting them to escape in the effluent.
A preferred method of operating a multi-stage wastewater treating process is to use PNLM and/or PKC in conjunction with high sludge age. Generally an average sludge age greater than about 10 days is advisable, preferably greater than about 20 days and still more preferably greater than about 30 days. The higher sludge ages maximize PNLM and/or PKC utilization and result in extremely high PNLM and/or PKC concentrations, while also allow time for slowly reproducing autotrophic bacteria (nitrifying bacteria, specifically) to fully colonize the PNLM and/or PKC. This results in more efficient and more effective water purification. In circumstances featuring highly contaminated influent wastewater (such as landfill leachate), it is most desirable to operate at sludge ages in excess of 75 days or even 150 days. It should be noted that when adding fresh PNLM and/or PKC, for example, to the wastewater entering the first stage and also operating at high sludge age, there tends to be an accumulation of PNLM and/or PKC in certain parts of the system. This allows the addition of low levels of PNLM and/or PKC on a per gallon or per pound of wastewater basis, while concentrating the PNLM and/or PKC within the system. This leads to better utilization of PNLM and/or PKC and higher process effectiveness. Also, high sludge age has the merits of good stability and high effectiveness. In order to operate at a high sludge age, it is preferred that the oil and grease and suspended solids level and chemical oxygen demand be reduced by intermediate treatment as previously discussed.
An example of the use of high sludge age would be in the activated sludge process wherein a first and second stage contaminated water is contacted with activated sludge for a period of time sufficient to biologically degrade contaminants in the water and in a third stage where decontaminated water is separated from the activated sludge. A first portion of said separated sludge is recycled for recontact with the water in the first anoxic stage and a second portion of said separated sludge is treated in downstream operations. About 1 to about 500 mg/l of PNLM and/or PKC is introduced into the wastewater so that the PNLM and/or PKC is present in the first stage, and the activated sludge system is operated at an average sludge age in excess of ten days. Preferably about 1 to about 200 mg/l of PNLM and/or PKC is introduced into the wastewater and the activated sludge system is operated at an average sludge age in excess of twenty days. Still more preferably 1 to 40 mg/l of PNLM and/or PKC is introduced into the wastewater. Still more preferably the activated sludge system is operated at an average sludge age in excess of thirty days.
First Preferred Embodiment
Referring to FIG. 1 , a wastewater containing organic and adsorbable pollutants is introduced into a primary treatment zone or tank 10 including an aeration and settling zone 12 .
If the wastewater contains an excessive amount of oils and/or solids, it can be pretreated and clarified by settling, decantation or filtration to reduce the solids content prior to treatment in the primary treatment zone 10 . Any such pretreatment will preferably include use of PNLM and/or PKC to enhance removal of solids and/or oils in the manner described above. The clarified or unclarified wastewater is introduced via a conduit 14 into the aeration and settling zone 12 wherein it is aerated with a pressurized oxygen containing gas, such as air, in the presence of sufficient amounts of a powdered PNLM and/or PKC adsorbent and biologically active solids to reduce the BOD, COD, TOC and adsorbable pollutants to desired levels.
The PNLM and/or PKC adsorbent must be finely divided and readily dispersible in an aqueous medium. Various adsorbents useful in purifying wastewaters can be used. Suitable adsorbents include sphagnum moss, hemp hurd, jute stick, balsa wood, other hard and soft woods, kenaf core, straws, grass specie stems, bamboo specie stems, reed stalks, peanut shells, coconut husks, pecan shells, rice husk, corn stover, cotton stalk, sugar cane bagasse, conifer and hardwood barks, corn cobs, other crop residuals and any combination thereof, with powdered kenaf core (PKC) being preferred. The adsorbent can be added to the aeration and settling zone 12 in any suitable manner, for example, as an aqueous slurry introduced through a conduit 16 or added to the incoming wastewater in the conduit 14 .
The amount of adsorbent present in the aeration and settling zone 12 varies, depending primarily on the nature of the wastewater and the degree of treatment desired, i.e., the desired resulting levels of BOD, COD and TOC. Generally, this amount usually is about 50 to about 5,000 milligrams of adsorbent per liter of wastewater. However, some more toxic wastewaters require up to as much as 20,000 milligrams of adsorbent per liter of wastewater and adsorbent concentrations as low as 5 milligrams per liter of wastewater are effective for some less toxic wastewaters.
The biologically active solids present in the aeration and settling zone 12 are suspended solids containing different types of bacteria formed by contacting wastewater, bacteria and oxygen. They can be activated sludge or activated solids found in oxidation ponds and other biological water treatment processes. Generally, the amount of biologically active solids present in the aeration zone provides a total suspended solids concentration (a combination of both adsorbent and biologically active solids) of about 10 to about 50,000 parts per million wastewater.
For some wastewaters, particularly some industrial and CAFO wastewaters, it may be necessary to add biologically active solids to the aeration and settling zone 12 during start up to obtain the desired concentration thereof. The process produces its own biologically active solids which can be recycled to the aeration and settling zone 12 from the contact zone, as described below, to ensure the proper level of bacteria in the aeration zone. Once a suitable concentration of biologically active solids has been reached in the aeration and settling zone 12 , that level usually can be maintained without the external addition of the biologically active solids. The above concentration of adsorbent present in the aeration and settling zone 12 includes fresh adsorbent added to the aeration and settling zone via the conduit 14 or the conduit 16 , as well as adsorbent recycled to the aeration and settling zone along with biologically active solids.
The adsorbent and biologically active solids (mixed liquor solids) are mixed with the wastewater by a pressurized oxygen-containing gas, such as air, introduced into the aeration and settling zone 12 by an aeration system 18 including a sparger 20 to which the pressurized oxygen-containing gas is supplied via a conduit 22 . Other suitable aeration distribution means which causes dissolution of oxygen in the mixture and produces agitation can be used. Also, this aeration may be supplemented by mechanical stirring means.
In the embodiment illustrated in FIG. 1 , as a predetermined quantity of wastewater is being introduced into the primary treatment zone 10 , it is mixed by aeration in the aeration and settling zone 12 with biologically active solids and powdered natural lignocellulosic adsorbent added via the conduit 16 or to the incoming wastewater flowing through the conduit 14 . The amount of wastewater introduced can be controlled by various suitable means such as a liquid level control which is operable to close a flow control valve (not shown) or terminate operation of a pump (not shown) in response to the liquid level in the aeration and settling zone 12 reaching a predetermined upper limit. After a predetermined reaction time of about 20 minutes to about 24 hours, aeration is terminated to permit a majority of the suspended solids to settle by gravity in the aeration and settling zone 12 and produce a partially-treated wastewater or first clarified aqueous phase and a first settled solid phase. Additional adsorbent can be added to the aeration and settling zone 12 during the reaction period after the predetermined amount of wastewater has been introduced into the primary treatment zone 10 .
To accelerate the settling of these solids, a flocculation aid can be added via a conduit 24 to the aeration and settling zone 12 . The flocculent aid preferably is added shortly before aeration and agitation are terminated in order to ensure homogeneous mixing with the partially-treated wastewater without causing premature settling of the solids. The flocculant aid will preferably consist of relatively small quantities of fresh PNLM and/or PKC, but it can optionally include other common materials such as alum or polymers. The settling period can be varied to meet the requirements of the wastewater being treated. Generally, the settling period is for a time sufficient to permit a majority of the solids to settle and only a relatively small amount of solids (e.g., 5 to 500 milligrams of total suspended solids per liter of the first clarified aqueous phase) remains in the first clarified aqueous phase.
After completion of the settling period, a predetermined amount of the first clarified aqueous phase is withdrawn from the aeration and settling zone 12 via a conduit 26 and transferred to a contact tank 28 for further treatment. This can be controlled by various suitable means such as a liquid level control which is operable to terminate the operation of a pump (not shown) in response to the liquid level in the aeration and settling zone 12 dropping to a predetermined lower limit.
The contact tank 28 includes a mixing and settling zone 29 which is at least partially filled with the partially-treated wastewater withdrawn from the aeration and settling zone 12 . As the mixing and settling zone 29 is being filled, fresh powdered natural lignocellulosic adsorbent, which preferably is the same as that used in the aeration and settling zone 12 (e.g., powdered kenaf core), is introduced via a conduit 30 into the mixing and settling zone 29 and mixed with the incoming partially-treated wastewater by a suitable agitation means. Alternatively, fresh powdered adsorbent can be added to the incoming partially-treated wastewater as it flows through the conduit 26 . While the agitation means can be a mechanical stirring means, in the specific embodiment illustrated, it is an aeration system 32 , similar to the one used in the aeration and settling zone 12 and includes a sparger 34 to which a pressurized oxygen-containing gas is supplied through a conduit 36 . Agitation by aeration is preferred because oxygen is provided to the bacteria present in the biologically active solids carried over in the partially-treated wastewater from the primary treatment zone 10 and enhances metabolization of pollutants present in the mixing and settling zone 29 . The amount of adsorbent added to the partially-treated wastewater in the mixing and settling zone 29 varies, depending primarily on the degree of treatment desired, i.e., desired maximum levels of BOD, COD and TOC in the effluent. Generally, this amount may be as low as about 10 and as much as about 10,000 milligrams of adsorbent per liter of the incoming partially-treated wastewater. After a predetermined reaction time, which can be as short as about 20 minutes and up to as much as about 100 hours, agitation is terminated to permit the suspended solids to settle by gravity and produce a substantially solids-free second clarified aqueous phase and a second solids phase containing adsorbent and biologically active solids.
To accelerate settling of these solids, a flocculation aid like that used in the aeration and settling zone 12 can be added via a conduit 38 to the mixing and settling zone 29 . The flocculent aid preferably is added shortly before agitation is terminated in order to ensure homogeneous mixing with the partially-treated wastewater without causing premature settling of the solids. The amount of flocculant aid added is sufficient to promote the desired settling of the solids, primarily the adsorbent. Generally, this amount is about 0.1 to about 10 milligrams of flocculant aid per liter of partially-treated wastewater. The settling period can be varied to meet the requirements of the wastewater being treated. For instance, if the suspended solids are difficult to settle, the settling time can be increased as required. After completion of the settling period, a predetermined amount of the second clarified aqueous phase is withdrawn from the contact tank 28 via a conduit 40 for disposal or reuse. These fill, agitation, settling and draw steps are then repeated. The length of fill time for the contact tank 28 usually is governed by the predetermined amount of the first clarified aqueous phase withdrawn from the aeration and settling zone 12 . The contact tank 28 can include control means (not shown) for terminating agitation a predetermined time after the liquid level in the mixing and settling zone 29 has reached a predetermined upper limit, commencing introduction of the flocculant aid a predetermined time after the liquid level reaches the upper limit and before termination of agitation, and terminating withdrawal of the second clarified aqueous phase when the liquid level drops to a predetermined lower limit.
All or a portion of the settled second solids phase (powdered natural lignocellulosic adsorbent such as powdered kenaf core and biologically active solids) can be withdrawn from the contact tank 28 via a conduit 42 and pump 44 and recycled via a conduit 46 to the primary treatment zone 10 , either by combining with the incoming wastewater (as illustrated) or added directly to the primary treatment zone 10 , to maintain the desired concentration of total suspended solids in the aeration and settling zone as mentioned above. If desired, all or a portion of the solids withdrawn from the contact tank 28 can be discharged via a conduit 48 to waste after dewatering or other further treatment. Withdrawal of these solids can be controlled by suitable control means which, after completion of the draw cycle, operates the pump 44 when the solids level in the contact tank 28 reaches a predetermined level.
The retention time of solids in the primary treatment zone 10 can be controlled by withdrawing a portion of the mixed liquor solids with a pump 50 or the like and discharging via a conduit 52 to waste, after dewatering or other further treatment. While the primary treatment zone 10 and the contact tank 28 are illustrated as separate units, they can share common walls. For example, the contact tank 28 can be a walled off portion of a large aeration basin and include the appropriate controls for liquid and solids flow to provide the desired flow scheme.
Second Preferred Embodiment
In the embodiment illustrated in FIG. 2 , the contact tank 28 is arranged and operates in the same manner as described above. Accordingly, components common with those illustrated in FIG. 1 are designated with the same reference numerals. In this embodiment wastewater flows continuously into the primary treatment zone 53 ; however, the aeration and settling zone 12 is operated in a batchwise manner. The operating conditions for the aeration and settling zone 12 can be substantially the same as those described above. Components of the primary treatment zone 53 common with those illustrated in FIG. 1 are designated with the same reference numerals. The primary treatment zone 53 includes a downwardly extending baffle 54 defining a turbulent inlet zone 56 which is substantially isolated from and is in continuous fluid communication with the aeration and settling zone 12 . The wastewater flowing from the inlet zone 56 into the aeration and settling zone 12 is mixed therein by aeration with biologically active solids and powdered adsorbent which can be added to the aeration and settling zone 12 , to the turbulent inlet zone 56 via the conduit 16 or to the incoming wastewater flowing through the conduit 14 . Aeration is terminated when the liquid level in the aeration and settling zone 12 reaches a first predetermined upper limit. The inflow of wastewater is controlled so there is sufficient time for the desired reaction to occur by the time the liquid level reaches the first predetermined upper limit. A flocculant aid can be added to the aeration and settling zone 12 via the conduit 24 prior to termination of aeration and agitation as described above. The flocculant aid will preferably consist of relatively small quantities of fresh PNLM and/or PKC, but it can optionally include other common materials such as alum or polymers.
The settling period continues until the liquid level in the aeration and settling zone 12 reaches a predetermined second upper limit, at which time a predetermined amount of the partially-treated wastewater is withdrawn from the aeration and settling zone 12 and transferred to the contact tank 28 . A level control means (not shown) or other suitable means can be used for terminating withdrawal of the partially-treated wastewater from the aeration and settling zone 12 when the liquid level therein drops to a predetermined lower limit. After withdrawal of the partially-treated wastewater has been completed, the fill and aeration, settling and draw steps for the primary treatment zone 53 are repeated. During the settling and draw periods, the baffle 54 minimizes disturbance of the solids settling in the aeration and settling zone 12 by the wastewater continuously flowing into the inlet zone 56 .
The embodiment illustrated in FIG. 2 provides a number of advantages. Operating the primary treatment zone to control the concentration of solids in the first aqueous phase or partially-treated wastewater flowing therefrom eliminates the need for downstream clarifier equipment. By so limiting the amount of solids entering the contact zone, it can operate with free settling, rather than hindered settling as is the case when large concentrations of suspended solids are present. Contacting the partially-treated wastewater containing a reduced concentration of suspended solids with a fresh PNLM and/or PKC adsorbent in the contact zone improves removal of pollutants. Pollutants which are poorly adsorbed in the aeration and settling zone and carried over into the contact zone are contacted with fresh and more active adsorbent, thereby providing improved removal of these pollutants. The biologically active solids present in the partially-treated wastewater further metabolize pollutants in the contact zone, particularly when aeration with an oxygen-containing gas is used for agitation. The contact or agitation period and the settling period in the contact zone can be conveniently adjusted to meet the requirements for the particular wastewater being treated. While wastewater can be continuously introduced into the primary treatment zone the overall process can be operated as a two-stage batch process.
From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of the invention and, without departing from the spirit and scope thereof, make various changes and modifications to adapt it to various usages.
Third Preferred Embodiment
Referring to FIG. 3 , a screened raw wastewater containing organic and adsorbable pollutants is introduced by conduit 15 into a mixing tank 1 which incorporates a mixing device. The wastewater is mixed with return activated sludge solids (RASS) removed continuously from the bottom of clarifier 2 . Oxygen concentration is lowered in the mixing process to between 0.05 and 0.4 mg/l. Detention time can range between 1 and 12 hours. If the wastewater contains an excessive amount of solids, it can be pretreated and/or clarified by settling, decantation or filtration to reduce the solids content prior to introduction to the anoxic mixing tank 1 .
Wastewater is removed continuously from the anoxic mixing basin 1 via a conduit 16 into the aeration zone 2 wherein it is aerated with a pressurized oxygen containing gas (such as air) (from 14 via conduit 28 ), surface rotating aerators or by any other suitable means 14 (via conduit 28 ) in the presence of sufficient amounts of a powdered adsorbent and biologically active solids to reduce the BOD, COD, TOC, Nitrogen, Phosphorus and adsorbable pollutants to desired levels. Average detention time can range between 1 and 12 hours. Oxygen levels should be maintained in the range of 1 to 4 mg/l.
The natural lignocellulosic adsorbent must be finely divided and readily dispersible in an aqueous medium. Various adsorbents useful in purifying wastewaters can be used. Suitable adsorbents include sphagnum moss, hemp hurd, jute stick, balsa wood, other hard and soft woods, kenaf core, straws, grass specie stems, bamboo specie stems, reed stalks, peanut shells, coconut husks, pecan shells, rice husk, corn stover, cotton stalk, sugar cane bagasse, conifer and hardwood barks, corn cobs, other crop residuals and any combination thereof, with powdered kenaf core (PKC) being preferred. The adsorbent 13 can be added to the anoxic zone 1 or the aeration zone 2 in any suitable manner, for example, as an aqueous slurry introduced through a conduit 30 , or the return activated sludge solids (RASS) through conduit 29 . Preferred delivery is through RASS to the anoxic zone 1 . This allows better mixing and dispersion of the adsorbent throughout the mixed liquor prior to aeration. Fresh PKC may be optionally added to the clarification zone 3 , post aeration, to aid setting through conduit 31 .
The amount of adsorbent present in the aeration zone 2 varies, depending primarily on the nature of the wastewater and the degree of treatment desired, i.e., the desired post-treatment levels of BOD, COD, TOC, TSS, TKN and phosphorus. Generally, this amount usually is about 50 to about 5,000 milligrams of adsorbent per liter of wastewater. However, some more toxic wastewaters require up to as much as 20,000 milligrams of adsorbent per liter of wastewater and adsorbent concentrations as low as 5 milligrams per liter of wastewater are effective for some less toxic wastewaters. The biologically active solids present in the aeration zone 2 are suspended solids containing different types of bacteria, protozoa, ciliates, rotifers and other microorganisms formed by contacting wastewater, those same organisms and oxygen. They can be activated sludge or activated solids found in oxidation ponds and other biological water treatment processes. Generally, the amount of biologically active solids present in the aeration zone provides a total suspended solids concentration (combination of both adsorbent and biologically active solids) of about 10 to about 50,000 milligrams per liter of wastewater being treated.
For some wastewaters, particularly some industrial and CAFO wastewaters, it may be necessary to add biologically active solids to the aeration zone 2 during start up to obtain the desired concentration thereof. The process produces its own biologically active solids which can be recycled to the aeration zone 2 from the settling and clarification zone 3 , as described below, to ensure the proper level of bacteria and other microorganisms in the aeration zone. Once a suitable concentration of biologically active solids has been reached in the aeration and settling zone 3 , that level usually can be maintained without the external addition of the biologically active solids. The above concentration of adsorbent present in the aeration zone 2 includes fresh adsorbent added to the anoxic, aeration and settling zones via conduits 29 , 30 and 31 , as well as adsorbent recycled to the anoxic zone along with biologically active solids via conduit 19 .
The adsorbent and biologically active solids (mixed liquor solids) are first mechanically mixed with influent wastewater in anoxic zone 1 , subsequently, they are further mixed by a pressurized oxygen-containing gas, such as air, introduced into the aeration zone 2 by an aeration system 14 to which the pressurized oxygen-containing gas is supplied via a conduit 28 . Other suitable aeration distribution means which cause dissolution of oxygen in the mixture and produces agitation can be used. Aeration may also be supplemented by mechanical stirring and mixing means.
Wastewater is removed continuously from the aeration zone 2 via a conduit 17 into the settling zone (clarifier) 3 wherein it is allowed to settle under quiescent conditions. Concentrated mixed liquor solids and adsorbent (RASS) are continuously removed from the bottom of the settling zone 3 through conduit 19 and recycled to anoxic mixing zone 1 where they are blended and mixed with incoming primary screened effluent and fresh adsorbent introduced through conduit 29 . Decant from the settling zone (clarifier) 3 is removed continuously via conduit 24 for passage through an optional sand, activated carbon or organic medium charged filtration zone 4 and subsequent chlorination, ozone or ultraviolet treatment in disinfection zone 5 . Final treated effluent may then, optionally be discharged through conduit 29 to receiving stream 12 or passed to a recycling function 11 via conduit 27 .
When mixed liquor suspended solids (a combination of biologically active microorganisms and adsorbent) concentration reaches some prescribed level (ranging from 2000 mg/l to 50,000 mg/l, depending on wastewater being treated and specific treatment objectives), the mixture of concentrated mixed liquor solids and adsorbent being continuously recovered from the bottom of the clarifier may be partially diverted via conduit 32 to a digester 6 wherein it will be further concentrated and thickened under either aerobic or anaerobic conditions. Decant from the digester 6 is returned to the anoxic mixing zone 1 via conduit 33 . Thickened sludge solids may then be passed via conduit 20 to sludge dewatering and/or stabilization zone 7 or directly land applied 10 as a liquid sludge via conduit 20 . Dewatered, stabilized sludge may subsequently be disposed of through incineration 8 , landfill deposition 9 or land application 10 using transport 21 , 22 or 23 , respectively. Stabilization may, among other methods, include addition of lime.
Depending on the strength of the wastewater being treated and the treatment objectives to be served, a second complete aeration, settling and anoxic cycle may replace filtration zone 5 , or optionally precede filtration zone 5 . That cycle would treat a significantly lower strength (BOD, COD TSS, TKN) effluent (than was treated in the first cycle), but would be operated, nevertheless, according to similar principles. Concentrations of mixed liquor solids, powdered natural lignocellulosic adsorbent (preferably powdered kenaf core) and detention times would be tailored appropriately to the wastewater strength and treatment objectives.
From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of the invention and, without departing from the spirit and scope thereof, make various changes and modifications to adapt it to various usages.
Fourth Preferred Embodiment
Referring to FIG. 4 , a screened raw wastewater containing organic and adsorbable pollutants is introduced sequentially by conduit 15 into one of two or more batch reactor vessels 1 , 2 containing a prescribed residual of concentrated biologically active solids and powdered natural lignocellulosic adsorbent (preferably powdered kenaf core). The combined raw wastewater, biologically active solids and powdered natural lignocellulosic adsorbent is continuously mixed in such a manner as to minimize incorporation of oxygen while also maximizing contact by the residual solids with the influent wastewater. An anoxic phase, which can vary at the operators discretion, depending on influent wastewater strength (BOD, COD, TOC, TSS, TKN, phosphorus and other adsorbable pollutants), is followed by an aerobic phase during which aeration is supplied with a pressurized oxygen containing gas (such as air), 14 via conduit 28 , surface rotating aerators or by any other suitable means in the presence of sufficient amounts of a powdered adsorbent and biologically active solids to reduce the BOD, COD, TOC, Nitrogen, Phosphorus and adsorbable pollutants to desired levels. Average detention time during the aerobic phase can range between 30 minutes and 12 hours. Dissolved oxygen levels should be raised to and maintained in the range of 1 to 4 mg/l. The aerobic sequence is followed by a settling sequence in which the combination of biologically active solids and powdered natural lignocellulosic adsorbent is allowed to settle to the bottom of the reactor vessel 1 , 2 . Clarified effluent supernatant is then discharged via conduit 24 for passage through an optional sand, activated carbon or organic medium charged filtration zone 4 and subsequent chlorination, ozone or ultraviolet treatment in disinfection zone 5 . Final treated effluent may then, optionally be discharged through conduit 29 to receiving stream 12 or passed to a recycling function 11 via conduit 27 . Excess sludge is removed from the bottom of reactor vessel 1 , 2 and passed via conduit 19 to digester 6 for subsequent thickening and/or conditioning.
Makeup powdered natural lignocellulosic adsorbent (preferably powdered kenaf core) is introduced directly into the batch reactor vessel 1 , 2 via conduit 16 in amounts sufficient to develop and or maintain desired concentrations of said adsorbent in the reactor vessel 1 , 2 . Generally, this amount is about 50 to about 5,000 milligrams of adsorbent per liter of wastewater. However, some more toxic wastewaters require up to as much as 20,000 milligrams of adsorbent per liter of wastewater and adsorbent concentrations as low as 5 milligrams per liter of wastewater are effective for some less toxic wastewaters. The adsorbent must be finely divided and readily dispersible in an aqueous medium. Various adsorbents useful in purifying wastewaters can be used. Suitable adsorbents include sphagnum moss, hemp hurd, jute stick, balsa wood, other hard and soft woods, kenaf core, straws, grass specie stems, bamboo specie stems, reed stalks, peanut shells, coconut husks, pecan shells, rice husk, corn stover, cotton stalk, sugar cane bagasse, conifer and hardwood barks, corn cobs, other crop residuals and any combination thereof, with powdered kenaf core (PKC) being preferred. The adsorbent 13 can be added to the reactor vessel during the anoxic fill sequence in any suitable manner, for example, as an aqueous slurry introduced through a conduit 19 .
The biologically active solids present in the batch reactor vessel 1 , 2 are suspended solids containing different types of bacteria, protozoa, ciliates, rotifers and other microorganisms formed by contacting wastewater, a base population of those same organisms and oxygen. They can be activated sludge or activated solids found in oxidation ponds and other biological water treatment processes. Generally, the amount of biologically active solids present in the filled batch reactor vessel provides a total suspended solids concentration (both adsorbent and biologically active solids) of about 10 to about 50,000 parts per million of wastewater being treated.
For some wastewaters, particularly some industrial and CAFO wastewaters, it may be necessary to add biologically active solids to the reactor vessel 1 , 2 during start up to obtain the desired concentration thereof. The process produces its own biologically active solids which can be recycled within the system to ensure the proper level of bacteria and other microorganisms during the anoxic and aerobic sequences. Once a suitable concentration of biologically active solids has been reached, that level usually can be maintained without the external addition of the biologically active solids. The above concentration of adsorbent present in the reactor vessel 1 , 2 includes fresh adsorbent added during the anoxic fill sequence as well as adsorbent recycled following the settling sequence.
Reactor vessel 2 begins an anoxic fill sequence upon reactor vessel 1 having been filled, and vice versa. Other vessels may also be used in sequence, with the influent stream switching from one to the next as each completes the full anoxic fill, anoxic, aerobic, settle and discharge sequence cycle.
Decant (supernatant) discharged from the reactor vessel following the settle sequence (clarification) is removed via conduit 24 for passage through an optional sand, activated carbon or organic medium charged filtration zone 4 and subsequent chlorination, ozone or ultraviolet treatment in disinfection zone 5 . Final treated effluent may then, optionally, be discharged to receiving stream 12 through conduit 26 or passed to a recycling function 11 via conduit 27 .
Excess mixed liquor suspended solids (a combination of biologically active organisms and adsorbent) is removed from the bottom of the reactor vessel 1 , 2 upon conclusion of the settling sequence, and diverted via conduit 19 to a digester 6 wherein it will be further concentrated and thickened under either aerobic or anaerobic conditions. Decant (supernatant) from the digester 9 is merged with the influent raw wastewater stream via conduit 33 . Thickened sludge solids may then be passed via conduit 20 to sludge dewatering and/or stabilization zone 7 or directly land applied 10 as a liquid sludge via conduit 20 . Dewatered, stabilized sludge may subsequently be disposed of through incineration 8 , landfill deposition 9 or land application 10 using transport 21 , 22 or 23 , respectively. Stabilization may, among other methods, include addition of lime.
Depending on the strength of the wastewater being treated and the treatment objectives to be served, a second complete SBR system, may replace filtration zone 4 , or optionally precede filtration zone 5 . That cycle would treat a significantly lower strength (BOD, COD TSS, TKN) effluent (than was treated in the first cycle), but would be operated, nevertheless, according to similar principles. Concentrations of mixed liquor solids, powdered natural lignocellulosic adsorbent (preferably powdered kenaf core) and detention times would be tailored appropriately to the wastewater strength and treatment objectives.
From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of the invention and, without departing from the spirit and scope thereof, make various changes and modifications to adapt it to various usages.
The following examples are merely illustrative and representative of our invention which is of considerably larger scope. These examples should not be considered limiting in any way.
EXAMPLE 1
An extended aeration activated sludge wastewater treatment plant treating an average municipal-industrial wastewater flow of approximately 2 million gallons per day (MGD) was selected for full scale testing of our invention. This selection followed the rationale that such a plant fit the profile of a typical future user of the invention. The configuration of the plant conforms with the flow diagram depicted in FIG. 3 .
The experimental protocol called for gradually increasing the concentration of finely powdered kenaf core (PKC) in the system to a stable level equivalent to 500 mg/l of total activated sludge mixed liquor. The average sludge age of the wastewater treatment plant was estimated to be 30 days.
Finely powdered kenaf core was prepared by fracturing kenaf core with a conventional hammer mill and passing it through a 70 mesh (200 micron) screen. Other methods of grinding, milling and/or refining may have been used in its preparation. The powdered kenaf was packed in 2 cubic foot dissolving plastic bags—20 lbs to a bag.
PKC was introduced into the wastewater treatment plant by sequentially placing 20 lb bags of the material (packed in dissolving plastic bags) into the return line conveying return activated sludge solids (RASS) from the clarifier(s) to the approximately 800,000 gallon capacity anoxic raw influent-RASS mixing basin. The resulting PKC-supplemented mixed liquor then passed continuously to the approximately 800,000 gallon capacity aeration basin where oxygen was supplied by four 50 hp floating aerators. PKC was initially introduced into the activated sludge at a rate of 1500 lbs per week on a Monday, Wednesday, Friday schedule (500 lbs per episode). This schedule was maintained from Jun. 16, 2004 through Jul. 26, 2004. When local wastewater treatment plant managers pronounced themselves satisfied that the wastewater treatment system was not “suffering,” inputs were increased to 500 lbs per day through August 8. The concentration of PKC in the wastewater treatment plant activated sludge mixed liquor, assuming an average daily decay rate of 1%, was calculated to be 426 mg/l on August 9. June 16 through August 8 was considered to be an acclimation period during which target nitrifying bacteria attached to (colonized) the PKC. On August 8 all digester sludge was removed and land applied. Wastewater treatment plant managers agreed to maintain an active experiment “until the next requirement to remove sludge from the digesters”—i.e., when the digesters were next filled to their capacity and land application would be mandated. The managers' primary objective was to see if a lowering of sludge disposal costs could be achieved.
After August 8, a “maintenance” level input of PKC required to maintain PKC concentrations in the mixed liquor at “approximately 500 mg/l, was calculated to be 1500 lbs per week. A Monday, Wednesday, Friday input (500 lbs per episode) schedule was followed and maintained through Nov. 29, 2004. Average PKC concentration during that period was calculated to be 473 mg/l.
The same calendar interval (August through November) during 2003 served as a control to allow a reasonable estimate of the efficacy of PKC inputs. Measurement of system efficacy was, necessarily, limited to system variables measured during the control period for routine system control purposes. These were:
Influent Flow Influent Temperature Influent pH Influent BOD Influent TSS Mixed Liquor Solids Oxygen Levels (Anoxic and Aeration Zones) Oxygen Uptake Rates Return Activated Sludge Solids Sludge Settling Speed (30 minutes) Effluent Ammonia Effluent Nitrate Effluent TKN Effluent Phosphorus Effluent pH Effluent BOD Effluent TSS Clarifier Sludge Profiles (levels) Sludge Wasted to Digester (gallons) Sludge Wasted to Digesters (total solids) Profile of Thickened Digester Sludge Land Applied
Gallons Nitrogen Phosphorus Total Solids
TABLE 1
Basic System Comparison between the Control (No PKC) and
Experimental Period (PKC).
System Variable
No
With
Measured
PKC
PKC
PKC Advantage
Influent Wastewater
2.07
2.02
2.52% Lower During PKC
Flow (MGD)
Testing
Average Mixed Liquor
23.72
24.18
1.92% Higher During
Temperature (deg. C.)
PKC Testing
Average Influent
151.41
118.42
21.79% Lower During PKC
BOD (mg/l)
Testing
Average Influent
148.70
120.94
18.67% Lower During PKC
TSS (mg/l)
Testing
Note that both influent BOD and TSS levels were somewhat higher during the control period, but temperature was comparable in both periods.
TABLE 2
Comparative System Performance - Control (No PKC) Versus Experimental
Period (PKC).
Performance Variable Measured
No PKC
With PKC
PKC Advantage
Average Effluent BOD
5.27
3.38
35.88% Lower with PKC
Average % BOD Reduction
96.46%
97.02%
0.58% Lower with PKC
Effluent BOD as % of Influent BOD
3.54%
2.98%
15.89% Lower with PKC
Total BOD Reduction (mg/l)
146.14
115.04
21.28% Lower with PKC
Average Effluent TSS (mg/l)
4.88
5.48
12.30% Higher with PKC
Average TSS % Reduction
95.93%
95.19%
0.77% Lower with PKC
Avg. Effluent TSS as % of influent TSS
6.07%
4.69%
22.79% Lower with PKC
Avg. Total TSS Reduction (mg/l)
111.75
115.46
3.32% Higher with PKC
Avg. Effluent Ammonia Levels (mg/l)
0.62
0.37
39.98% Lower with PKC
Avg. TSS Nitrate Levels (mg/l)
1.76
2.13
20.80% Higher with PKC
Avg. TSS TKN (nitrogen) Levels (mg/l)
2.17
1.59
26.54% Lower with PKC
Avg. Effluent Phosphorus Levels (mg/l)
0.77
1.10
42.95% Higher with PKC
Avg. FPKC Concentration (mg/l)
0
473.67744
Sludge Settling in 30 Minutes (2 ltr to --> mls)
650
723
11.24% Higher with PKC
Sludge Settling Rate (mls/min)
34
31
7.90% Lower with PKC
Oxygen Uptake Rate (ml/min)
0.259
0.260
0.34% Higher with PKC
Zone Settling Velocity (ft/hr)
0.571
0.423
25.92% Slower with PKC
Average MLS Concentration (mg/l)
4051.875
3912.748
3.43% Lower with PKC
Organism Only Avg MLS Concentration (mg/l)
4052
3439
15.12% Lower with PKC
RASS Concentration (mg/l)
6749
5863
13.13% Lower with PKC
RASS to MLS Ratio
1.661
1.499
9.72% Lower with PKC
RASS Wasted (glns)
18204
14065
22.74% Lower with PKC
Sludge Solids Wasted per day (kgs)
457.715
313.9823
31.40% Lower with PKC
FPKC Wasted per day (kgs)
0
38.45
Microorganism Base Load (tonnes)
44
37
15.12% Lower with PKC
Sludge Microorganism Production (kgs/day)
457.715
275.5298
39.80% Lower with PKC
Sludge Organism Production Rate (kgs/tonne/day)
10.56815
7.378487
30.18% Lower with PKC
#1 Clarifier Sludge Level A.M. (ft)
1.86328
1.786304
4.13% Lower with PKC
#1 Clarifier Sludge Level P.M. (ft)
1.946747
1.872823
3.80% Lower with PKC
#2 Clarifier Sludge Level A.M. (ft)
1.999435
1.866935
6.63% Lower with PKC
#2 Clarifier Sludge Level P.M. (ft)
2.029247
2.01453
0.73% Lower with PKC
#3 Clarifier Sludge Level A.M. (ft)
2.040417
1.820538
10.78% Lower with PKC
#3 Clarifier Sludge Level P.M. (ft)
2.175565
1.910013
12.21% Lower with PKC
Days of Digester Sludge Accumulation to Disposal
63
103
63% Higher with PKC
Digester Sludge % Solids at Disposal
3.82%
3.63%
5% Lower with PKC
Daily Digester Solids Accumulation (kgs)
874
540
38% Lower with PKC
Nitrogen Content of Digester Solids at Disposal
43550
54200
24% Lower with PKC
(mg/kg)
Daily Nitrogen Accumulation in Digester Solids
38
29
23% Lower with PKC
(kg/day)
Phosphorus Content of Digester Solids (mg/kg)
13983
18100
29% Higher with PKC
Daily Phosphorus Accumulation in Digester Solids
12
10
20% Lower with PKC
(kgs/day)
From a wastewater treatment plant operator's perspective, the key results of this example are the significant reduction in effluent ammonia and total nitrogen, the significant decrease in total sludge production and the improvement in clarifier sludge profile and sludge floc characteristics. The latter characteristic allowed operators to continue operating aerators during high rain events when aerators would normally be shut down and the “event” allowed to “flow over the top and out.” Consequently, there was no discharge of untreated sewage, no permit violation and therefore no fine during implementation of the experimental protocol. The decrease in total sludge production resulted in a 40% reduction in sludge disposal costs. The reduction in effluent nitrogen, the improvement in clarifier sludge profile and the improvement in sludge floc characteristics were felt to hold potential consequences for increasing the treatment plant's rated capacity and thus lowering the municipality's potential future capital outlays.
Plant operators noted, with satisfaction, that BOD and TSS reduction performance was comparable, despite maintenance of a significantly lower base microorganism population. Both variables were maintained within effluent discharge permit limits throughout. An increase in effluent phosphorus content was attributed to lower total sludge production. While this had no immediate bearing on the treatment plant's permitted discharge levels, the increase was significant and notable. Subsequent experiments demonstrated that, with maintenance of somewhat higher mixed liquor base organism loads and higher PKC concentrations phosphorus reduction actually improved significantly in the experimental system over the control (No PKC)—See example 2 (below). This operating condition would, however, negate some of the lower sludge production advantage.
Plant operators noted that the ability to maintain lower sludge microorganism base loads within the treatment plant's activated sludge mixed liquor, combined with a higher oxygen uptake rate for PKC-enhanced mixed liquor translated to an ability to lower, significantly, the amount of energy invested in aeration. They noted that aerator electricity was, aside from sludge disposal, the single most costly item on the wastewater treatment plant's annual budget.
Plant operators also noted, in small bench level testing, the improved ability of PKC-supplemented activated sludge solids to pick up phenols, oils, arsenic, copper, zinc, iron and lead over non-PKC supplemented activated sludge solids. These improvements could not be made apparent in the major complete system test results because such data had not been routinely collected during the 2003 control period. Plant operators also noted external test results which showed that PKC's ability to filter out water borne organic and inorganic compounds was comparable to that of granular activated carbon. They recognized that this would have an impact on their ability to cater to “high dollar” industrial clients, some of which were then prevented from supplying effluent streams to the treatment plant due to that plant's limited capacity to remove certain toxic elements and compounds. They noted that this could potentially result in a significant increase in future revenues.
Plant operators and managers considered the experiment to be a “success,” noting that, when the product became commercially available, they would be amenable to adopting its use.
EXAMPLE 2
Two small 300 gallon sequencing batch reactor wastewater treatment systems were constructed on the perimeter of the activated sludge aeration basin located at the wastewater treatment plant employed for example 1. The purpose of the two systems was to determine the immediate effects of relatively high adsorbent loadings on activated sludge wastewater treatment systems—particularly sludge floc and settling characteristics and impact on nitrogen and phosphorus reduction.
Each system comprised a 0.5 HP pump for internal mixing and batch discharge, a 1 hp air pump, a 1 square foot tablet diffuser, an electronic timer and a 200 watt heater. Each was operated on a 24 hour cycle in batch mode, beginning with a 6 hour anoxic-fill sequence, followed by a 12 hour (half hour on and half hour off) aeration sequence, a 5 hour settling sequence, and finally a 1 hour supernatant discharge sequence. Powdered Kenaf Core (PKC) adsorbent was added upon commencement of the fill sequence.
Each small system was initially charged with 250 gallons of mixed liquor, drawn directly from the main activated sludge aeration basin. Initial MLSS concentration was measured to be 3240 mg/l. Initial PKC adsorbent concentrations in each system were calculated to be 473 mg/l. Upon filling, a 5 hour settling sequence, followed by a 1 hour discharge sequence (150 gallons of treated supernatant) commenced. The discharge pump then converted back to its mixing mode, and each system was charged with 150 gallons of screened raw wastewater. During loading of raw wastewater, the “experimental” system was also charged with a measured amount of PKC. Upon completion of the anoxic mixed fill sequence normal operations commenced—i.e., aeration, settling, discharge, anoxic fill, PKC (experimental system only), aeration etc. This same sequence was repeated daily for the 64-day duration of the experiment. Daily testing was conducted on each system for effluent ammonia nitrogen and sludge settling characteristics. Occasional testing was conducted for effluent nitrate nitrogen, phosphorus, MLSS concentration, and influent ammonia nitrogen. System wide data (main wastewater treatment plant) was already available for influent BOD, TSS, pH and temperature.
PKC inputs commenced with daily injections of 60 grams of the adsorbent into the experimental system. After 12 days the schedule changed to every other day. On day 33 the kenaf injection level was doubled to 120 grams, with the every other day schedule remaining unchanged. This same protocol was then continued until day 64.
Basic System Data (shared by both SBR systems—control and experimental system)
Relative System Performance Data
Performance Variable Measured
Average Influent BOD (mg/l)
127.92
Average Influent TSS (mg/l)
140.05
Average Influent pH
7.12
Average Influent Ammonia (mg/l)
12.49
Performance Variable Measured
Low PKC
High PKC
Relative Performance of High PKC System
Average Ammonia (mg/l)
0.75
0.41
45.57% Less Than Low PKC
Average Nitrate (mg/l)
2.29
1.71
25.16% Less Than Low PKC
Average Phosphorus (mg/l)
1.65
0.97
40.90% Less Than Low PKC
Average Settling (2 ltrs to --> mls)
565.09
526.29
6.87% Less Than Low PKC
Average PKC Concentration (mg/l)
355.65
1393.82
291.90% Greater Than Low PKC
Average Flow Treated
150.00
150.00
0.00%
Day 34 MLSS
4830.00
5340.00
10.56% Greater than Low PKC
Day 1 MLSS
3240.00
3240.00
0.00%
Average Daily MLSS Increase (mg/l)
48.18
63.64
32.08% Greater than Low PKC
Day 34 PKC Concentration
329.66
1518.98
360.78% Greater Than Low PKC
Day 1 PKC Concentration
473.36
473.36
0.00%
Average Daily PKC Increase (mg/l)
−4.35
31.69
Average Daily Increase of Organisms
52.54
31.95
39.18% Less than Low PKC
Average Daily PKC input (kgs/day)
0
0.06
Length of Study (days)
69
69
0.00%
The SBR configuration generally outperform the larger, adjacent extended aeration wastewater treatment plant. The high PKC system also outperformed the diminishing PKC (“low PKC”) system, with advantages generally mirroring those identified with the extended aeration system (see EXAMPLE 1, above). One notable exception to this was phosphorus reduction. While the PKC-charged (approximately 500 mg/l) extended aeration system demonstrated lower phosphorus removal than its comparable 2003 control sequence, the high PKC SBR system demonstrated significantly better phosphorus removal than the low PKC SBR system. This may be generally attributable to maintenance of a higher MLSS concentration and/or, more specifically, to the considerably higher PKC concentrations in the MLSS. Phosphorus content of land applied digester solids incorporating PKC also demonstrated a 20% increase in phosphorus content (% of total solids basis) over non-PKC digester solids, suggesting enhanced pickup (on a per weight of solids basis) of phosphorus by PKC-enhanced MLSS.
While the MLSS concentration of the high PKC SBR system grew more quickly than did the control system, it is notable that the growth attributable to activated sludge organisms was measured to be approximately 40% lower than the control. This confirms the “lower sludge production” result of EXAMPLE 1 (above)
Other notable enhanced performance demonstrated by the high PKC SBR system, was a significant advantage in both ammonia (45% improvement) and nitrate (25% improvement) reduction over the low PKC control system.
With PKC concentrations rising to approximately 2300 mg/l (of total mixed liquor), there was no discernable “irregularity” in sludge settling behavior. Sludge settling was notably quicker than that of the low PKC control. | A process for treating wastewater through the use of powdered natural ligno-cellulosic materials (PNLM) for (a) physically removing colloidal and suspended volatile solids through adsorption and enhanced floc-formation and settling during pretreatment; (b) adsorbing toxic substances and elements that interfere with biological processes, thus serving to reduce their contact with and exposure to activated sludge organisms effecting wastewater treatment functions; (c) providing fixed surfaces in activated sludge wastewater treatment bioreactors for bacteria and other organisms favoring attached growth in circumstances devoid of such surfaces; (d) reducing production of biological sludge, while also helping to maintain high treatment efficiencies; and (e) following aeration, enhancing the settling characteristics of sludge with respect both to speed of settling and the vertical profile of the settled sludge. | 98,065 |
FIELD OF INVENTION
[0001] The present invention relates to a game involving opposing teams, using opposing goals and a ball, as well as a scoring goal for scoring points in the game.
BACKGROUND
[0002] There are, of course, many ball games involving opposing goals, including soccer, basketball and American football. Scoring points in sports games using a ball or the like involves a wide variety of mechanisms. For example, in basketball the object is to throw the ball through a hoop ten feet above the playing surface. In soccer, the object is to kick the ball into a net guarded by a goal keeper, and the same idea exists in ice hockey (which uses a puck instead of a ball) and in other sports as well. In American football, the objective of scoring points is achieved by advancing the ball into the opposing team's endzone over a goal line or kicking the ball over a goal post.
[0003] In target sports such as darts and archery, the object used by the players to shoot or throw, i.e. a dart or an arrow, is adapted to strike a target and at least partially penetrate the target.
[0004] However, insofar as is known, there is no game utilizing opposing teams in which it is an object to score points by throwing a ball or the like in such a way so as to strike a target on an opponent's goal post with the ball or the like, and thereby score points, and without adhering to the target.
SUMMARY OF INVENTION
[0005] The present sport game can be played co-ed or by all males or all females, and is played with two teams. Each team desirably has approximately ten players, but preferably a minimum of only four players per team are allowed to play at a single time.
[0006] The present sport game is desirably played on a court which may be 100 feet by 50 feet, but can be larger or smaller, preferably no more than about 20 percent larger or smaller. If played on a court, indoor and outdoor, the court surface may be any hard surface, and playing on surfaces such as dirt, gravel and grass is not desired because the ball will not react properly and because of the preferred rules of the game.
[0007] At each end of the court there is located a scoring goal post with a backboard the top of which is desirably about 15-18 feet off the surface of the court, plus or minus about 15 percent. If the backboard is less than 12 feet above the court or more than 20 feet above the court, it becomes difficult to play the game according to the desired objectives. Each backboard at the top of the goal post has an area of preferably approximately five feet by five feet containing preferably three striking and scoring pads, each desirably of circular configuration and each having a diameter of about 12-18 inches, the three scoring pads preferably and desirably being arranged in a triangle shape.
[0008] The object of the game is for the players, at least four on each side, to throw or smack a ball so as to forcefully strike/slam the pads on or behind the backboard of the opposing team with the ball or the like.
THE DRAWINGS
[0009] FIG. 1 is an example of a court in accordance with the present invention.
[0010] FIG. 2 is a prospective view of a backboard for use in the game of the present invention, such backboard having three scoring/striking pads thereon.
[0011] FIG. 3 shows a facing side view of the goal posts including backboards.
[0012] FIG. 4 shows a back perspective view of such a backboard including supporting structure.
[0013] FIG. 5 shows a pair of goal posts including backboards, shown from the rear.
[0014] FIG. 6 shows an alternate embodiment of the backboard.
[0015] FIG. 7 shows the erection of such a goal post including backboard, without striking/scoring pads.
DETAILED DESCRIPTION
[0016] According to one embodiment, the sport game of the present invention is played in a league called “SKY BALL® LEAGUE” having the following preferred game rules:
[0017] SKY BALL® games are played with four active players vs. four active players, e.g. co-ed, wherein each team can have a maximum of ten players on the team roster, and the players desirably wear a SKY BALL® glove to facilitate smacking the ball.
[0018] SKY BALL® games consist of four ten-minute quarters with a three minute overtime if the score is tied at the end of regulation play.
[0019] SKY BALL® games have free substitutions throughout play.
[0020] To initiate play at the beginning of the game and at each quarter, the referee “slams” the ball with a “starting slam” at center court so that the ball bounces upwardly about 40-75 feet off the court into the air. After a score by the other team, a player must pass the ball when crossing half court to a team mate with a “passing slam” by hitting the ball so that the ball bounces off the court, for example 8-10 feet into the air. However, opposing team players can attempt to make a steal, in which case the opposing team does not need to start with a “slam.” A “smack” is the contact that a player uses to propel the ball, so a player “smacks” the ball using his/her gloved hand, either directly towards the goal attempting to score, or to a team mate, or into the court surface to create a bounce.
[0021] SKY BALL® games have scoring means or mechanisms at each end of the court and desirably comprise three scoring pads 10 which are 12-17 feet above the court surface 12 .
[0022] In SKY BALL® scoring, each time a player smacks or throws the SKY BALL® and hits a scoring pad, the scoring team receives one point. However, a player smacks the SKY BALL with sufficient force to register a “smash”, especially while using/wearing a SKY BALL® glove, the scoring team will receive three points. In another presently preferred embodiment as shown in FIG. 6 , the backboard is provided with holes 14 of diameter 12-18 inches through which the ball passes to score, and approximately 5 to 9 inches behind the hole is a scoring pad 10 ′.
[0023] A SKY BALL® player fouls out of the game once he or she reaches four (4) fouls. The foul rules are similar to those of basketball, although less contact is intended to result in fouls because the game may be played co-ed. Acceptable forms of contact among or between opposing players include intercepting a pass, interceptions during a loose ball, and blocked shots. An opposing team player can “steal” the ball without fouling, so long as no more than minimal physical contact between the players occurs.
[0024] If a player is fouled, his or her team automatically restarts an offensive series. If a player is fouled while smacking or throwing the SKY BALL® at the scoring mechanism, he or she receives a free smash at the SKY BALL® foul line. The smack must be a smash in this case (foul situation) worth one point if the fouled player scores, in which case the opposing team gets the ball after the score. If the fouled player misses, the ball is in play.
[0025] At the end of the four quarters, the team with the highest points total wins.
[0026] The type of ball used is a SKY BALL® desirably of size 10 cm (4 inches) diameter. The SKY BALL® is disclosed in Kessler U.S. Pat. No. 8,123,638.
[0027] As indicated above, the terms “smack” and “smash” are similar to a smack or smash in volleyball, and to be distinguished from a throw. A “smash” is a type of “smack” directed at a goal to score, and which registers to produce a three point score. To distinguish a “smash”, each pad 10 or 10 ′ may be provided with an electronic sensor which registers when the pad is impacted sufficiently hard by the ball, although other sensing means could be used such as pads which create a non-electronic sound, e.g. a rattle, when impacted by the ball or ball substitute.
[0028] For desirable and optimum play of the present sport game, the goal post and the ball are particularly important. As indicated above, the ball desirably has a diameter of 10 cm and is capable of a very great ability to bounce, such as shown in Kessler U.S. Pat. No. 8,123,638, and sold under the trademark “SKY BALL®. The goal post 16 has a height of approximately 15 feet and carries a backboard 18 , desirably of a flexible metal mesh or fabric mesh, having a plurality of scoring pads, e.g. three scoring pads 10 as shown in FIG. 2 .
[0029] As indicated in FIG. 2 , there are preferably three pads 10 , and these are preferably each 12-18 inches in diameter and placed in a triangular pattern as shown in FIG. 2 . As indicated above, the scoring pads 10 can be made of a material that rattles upon contact, have pockets to capture balls instead of or in addition to the pads, or can trigger an electronic sensing device, such as lights or sounds.
[0030] The backboard 18 on the goal post 16 is desirably an open mesh having resilience and flexibility and the mesh is desirably an open weave fabric or metal mesh, of dimensions which are desirably approximately 5 feet by 5 feet in the preferred embodiment. The metal mesh or fabric mesh backboard is resilient and absorbs the impact of the ball, allowing it to drop downwardly rather than expressively bounce backwards, and thus keeping the ball in play.
[0031] The rules of the game permit a player to throw the ball to a team mate, shoot the ball at a scoring pad by throwing or smacking the ball toward the pad, or to dribble the ball. Running or “travelling” as in basketball is not permitted.
[0032] As indicated above, the scoring surfaces comprise pads 10 , preferably three pads on or behind the backboard 18 , the pads being in any desired arrangement, e.g. preferably arranged in a triangle. The pads 10 are desirably circular, each being preferably about 12-18 inches in diameter in a preferred embodiment. Electronic sensors are desirably located in the pads to signal scoring when a pad is impacted by a smacked ball or the like.
[0033] The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without undue experimentation and without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. The means, materials, and steps for carrying out various disclosed functions may take a variety of alternative forms without departing from the invention.
[0034] Thus the expressions “means to . . . ” and “means for . . . ”, or any method step language, as may be found in the specification above and/or in the claims below, followed by a functional statement, are intended to define and cover whatever structural, physical, chemical or electrical element or structure, or whatever method step, which may now or in the future exist which carries out the recited function, whether or not precisely equivalent to the embodiment or embodiments disclosed in the specification above, i.e., other means or steps for carrying out the same functions can be used; and it is intended that such expressions be given their broadest interpretation. | A sports game is played on a field or court having opposing goals, each goal having a plurality of striking pads at least 12 feet above the height of the field or court. Two teams are provided, each having at least four players. A ball of high bouncing ability and capability is used. Each opposing goal has a backboard and preferably three scoring pads either on the backboard or behind the backboard. The object of a team is to throw or smack the ball so as to strike a scoring pad and thereby score points. | 11,773 |
FIELD OF THE INVENTION
This disclosure involves the field of computer system networks and is specifically directed to handling the problems of power control in each of the various units involved in the system network, by the use of a master-slave logic system.
CROSS REFERENCES TO RELATED APPLICATIONS
This disclosure is related to a patent application filed Sept. 25, 1984 as U.S. Ser. No. 654,080, now U.S. Pat. No. 4,635,195 issued Jan. 6, 1987 entitled "Power Control Network Using Reliable Communications Protocol" by inventors James H. Jeppesen, III and Bruce E. Whittaker.
BACKGROUND OF THE INVENTION
In the present day advance of computer and communications network technology, it is now possible that many types of units are interconnected both by direct bus connection and by remote telephone lines. These networks may involve a variety of processors, a variety of input/output systems located in separate cabinets, plus other cabinetry in addition to large portions of memory cabinetry.
In such a separate and complex network, one major problem often arises as to the conditions of the supply power at each of the individual units in order that this system may operate intercooperatively and effectively.
For example, it is never known what the status or power condition of each of the interconnected units may be in relationship to the units which are powered up and operating.
Many times certain areas of the network may not be desired for use and in order to save power and energy, it is desired that these units be turned off for certain periods of time when not in use. Likewise, other units of this system may be desired for use and will need to be controlled or checked to make sure that the power conditions in these units are properly up.
Thus, in order to provide control and flexibility in a system and to make sure that all those units that are needed are powered up and operable, and those units which are not needed can be turned off to save energy and unnecessary use, it is important to system operators that some means be devised for knowing the power status of each and every unit in the system and also for being able to "centrally control", that is to say, to power up or to power down, each and every unit in the system as required.
To this end, the problems have been handled in this arrangement only catch as catch can, with the hope that each unit is powered up properly and each unit is sufficiently powered up to operate properly. Generally there has been no flexibility as to be able to shut down certain unused units when they are not needed also.
The presently devised power control network system overcomes the major inadequacies involved in a large computer system network by providing a centralized power control logic system whereby the each and every one of the modules or cabinet units in this system may be communicated to, in order to find out their power status; and further commands may be transmitted to each addressed element in the system in order to power-up or to power-down the unit thus to provide the utmost flexibility and also provide the utmost in energy conservation permissible under the circumstances.
SUMMARY OF THE INVENTION
It has long been a problem in a complex system network which involves a multitude of independent processors, independent I/O systems, and independent memory systems to regulate the "on-off-ness" of power and the power status of each of the units in the system when all the units are able to communicate with each other.
The present system provides a central master power control logic unit which can communicate with a slave power control logic unit which is located in each individual system cabinet of the system. The central master power control logic unit can poll, and selectively address each and every unit in the system in order to control the condition of its power as to being on or off, or to select marginal voltage conditions, or to find out the power status of that particular unit.
Thus, one central location can operate to control and monitor the power conditions of each unit in the entire system so that no unit is inadvertently off-line or shut down or depowered without the knowledge of the central master power control logic unit.
In this regard, a master logic unit and slave logic unit operate with a specialized protocol having exceptional reliability where the master transmits a unique address to all slave units and the "properly-addressed" slave unit returns its unique address to the master unit. It is only then that the master will transmit instructional command data to the slave unit.
The slave logic unit then transmits power control instructions to a power control circuit which executes power on/off operations or executes marginal step voltage adjustments on various ones of the power supply modules attached to that power control circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a network of cabinets which house processors, I/O systems and memories whereby a power control network is connected to command and control the power conditions within each and every one of the connected cabinets.
FIG. 2 is a block diagram of a typical processor type cabinet and its connection to the power control network.
FIG. 3 shows a "dependently-powered" input/output cabinet in block diagram form and its connection to the power control network.
FIG. 4 is a block diagram showing an "independently-powered" cabinet and its connection to the power control network.
FIG. 5 is a basic block diagram of the power control network showing the central power net master logic unit connected to control various power net slave logic units in this system.
FIG. 6 is a block diagram showing the interconnection between the master logic unit and the slave logic units in the system.
FIG. 7 is a block diagram of a typical power slave logic unit.
FIG. 8 is a block diagram of the master network power logic unit showing the interconnections to the other parts of the system network.
FIG. 9 is a block diagram of the peripheral power slave logic unit showing its connection to a peripheral cabinet and to the power control network of FIG. 5.
FIG. 10 is a schematic diagram showing the protocol used for communication between master and slave units and additionally the byte format used.
FIG. 11 is a flow diagram which summarizes the protocol activity for the master power network logic unit.
FIG. 12 is a flow diagram which summarizes the protocol activity of the slave power control logic unit.
FIG. 13 is an illustration showing the output signals from the slave logic to the power control circuit.
FIG. 14 is an illustration showing the input signals from the power control circuit to the slave logic unit.
FIG. 15 shows a block diagram illustrating the circuitry for failure detection and power control.
FIG. 16 is a block diagram illustrating the circuitry for margin control voltages in local and remote modes.
GENERAL OVERVIEW
This subsystem relates to a computer network and system which interconnects the following type of cabinets:
(a) processor cabinets;
(b) dependently-powered I/O cabinets;
(c) independently-powered I/O cabinets;
(d) independently-powered memory cabinets.
A "dependently-powered" cabinet is a cabinet which derives its AC power and its high voltage input DC power from another cabinet (other than itself)--in this case the other cabinet is called the "processor cabinet". Thus, the "dependently-powered" cabinet must be physically attached to the source cabinet.
An "independently-powered" cabinet is a cabinet which has its own AC power Source. It may, therefore, be considered as a "free-standing" unit.
FIG. 1 indicates a block diagram of the network power control subsystem 10. Shown therein are a dependent power I/O cabinet 20 and 30, in addition to two processor cabinets 40 and 50. Additionally connected to the power control network are the independent power I/O cabinets 60 and 70.
FIG. 2 shows the power components of processor cabinets 40 and 50 which were shown in FIG. 1. The power energization of the processor cabinets 40 and 50 is controlled by the power control card 80 shown in FIG. 2. The power control card 80 is controlled by a "system operator" through the cabinet control circuits via an "operator panel" 44, and by the operating maintenance personnel who work through the control display 45 (maintenance switches and indicators) within the processor cabinet.
The power control card 80 additionally monitors the cabinet environmental conditions such as over-temperature and cooling air-loss. This card is further described later under the title of "Power Control Subsystem".
The state of the cabinet power is further controlled by the power control network (PCN) through a card called the Power Net Slave Card 90. The processor cabinet (40, 50) also provides an AC power module 41 and a DC power module 43 for providing a high voltage DC to the attached-dependently-powered cabinets such as 20, 30.
FIG. 3 illustrates the power components involved in the "dependently-powered" cabinets such as 20 and 30 of FIG. 1. The power for these "dependently-powered" cabinets is controlled by the power control card 80 d . This power control card 80 d is controlled by a system operator (operating technician) through the cabinet control circuits and operator panel 44 d , and also by the operating maintenance personnel through the control display 45 d (via maintenance switches and indicators) inside the cabinet.
The power control card 80 d also is used to monitor the cabinet environmental conditions such as over-temperature and the cooling air-loss.
The power in the dependently powered I/O cabinet of FIG. 3 is also controlled by the power control network through the power net slave card 90 d .
As seen in FIG. 3 the "dependently-powered" I/O cabinet (such as 20 and 30) receive their AC and their high voltage DC input voltage from the attached processor cabinets such as 40 and 50 of FIG. 1.
In FIG. 4 there is shown a block diagram of the various power components of the "independently-powered" cabinets such as 60 and 70 of FIG. 1. The power for these independently-powered cabinets is controlled by the power control card 80 i . The power control card 80 i is controlled by a "system operator" through the cabinet control circuits and operator panel 44 i ; and also by the operating maintenance personnel through the control display 45 i (via maintenance switches and indicators inside the cabinet).
Likewise, as previously described, the power control card 80 i also monitors the environmental conditions in the cabinet such as over-temperature or the loss of "air". The cabinet power of the independently-powered cabinet of FIG. 4 is also controlled by the power control network through the power net slave card 90 i .
As seen in FIG. 4 the "independently-powered" I/O cabinets contain two I/O backplanes which are referred to as backplane A, 70 a , and also backplane B, 70 b , in addition to two interface panels described hereinafter. The DC power to each backplane is separately controlled. The DC power to both interface panels will be supplied the same as on backplane A, 70 a .
The operator panel 44 i will provide separate controls for each backplane. The power control network (PCN) will also provide separate controls for each of the backplanes 70 a and 70 b .
The DC power to each backplane is controlled separately. The operator panel 44 i will provide separate controls for each backplane and also the power control network connections 95 n shown in FIG. 4 will provide separate controls for each backplane.
Thus, the independently-powered cabinets will have their own AC power source and therefore may be considered as "free standing".
Additionally, the "independently-powered" memory cabinet may provide a remote support interface adapter. This adapter adds the power net master logic card to the cabinet as discussed hereinafter.
DESCRIPTION OF PREFERRED EMBODIMENT
Power Control Network (PCN):
To provide an integrated system, a Power Control Network (PCN, FIGS. 1 and 5, via 95 n ) connects all system cabinets. This allows a "SINGLE-POINT" of on-site operator control of the entire system of many cabinets. That is, the on-site operator need only depress a single power-on or power-off switch to control the entire system.
In addition to the single-point of on-site control, the PCN provides total "power control" from an external remote support center 300 via telephone connection. With the integrated PCN system, only a single remote connection is needed to drive the entire system.
In addition to the basic power on and off control functions, the PCN provides a number of system failures and status monitoring functions and system maintenance controls. These functions are described in paragraphs that follow.
The PCN allows the capability for an UNATTENDED site, that is, no local system operator is required. All system power controls, failure condition monitoring, and maintenance controls are available via the PCN to the remote center, 300.
The PCN is specifically implemented through power net slave cards contained in each system cabinet and interconnected to the PCN. Each slave card is "always" powered, that is, is powered if the AC breaker for its cabinet is on. The slave within a cabinet is powered whether the cabinet operating DC power is on or not.
The power net master logic card 100 of FIG. 8, which is part of the before mentioned remote support interface adapter (contained within an independently-powered memory cabinet), drives the Power Control Network and therefore all the power net slaves. The master logic unit 100 provides the central hub between the power control functions (Power Control Network), the remote support center (300) telephone connection and the system maintenance (200, FIG. 8) subsystem. The master card 100 is also "always" powered.
TABLE I______________________________________OPERATOR PANELS______________________________________Operator Control PanelsThe Operator Control Panels 44, 44.sub.d, 44.sub.i,FIGS. 2, 3, 4, are accessible to the operator on theoutside of the respective cabinets. The panels providethe following functions:PROCESSOR CABINET OPERATOR PANEL (44)POWER-ON/POWER-OFF indicator & switch.CABINET/SYSTEM MODE indicator & switch.POWER FAIL/AIR LOSS indicator.DEPENDENTLY-POWEREDI/O CABINET OPERATOR PANEL (44.sub.d)POWER-ON/POWER-OFF indicator & switch.CABINET/SYSTEM MODE indicator & switch.POWER FAIL/AIR LOSS indicator.INDEPENDENTLY-POWEREDMEMORY CABINET OPERATOR PANEL (44.sub.i)POWER-ON/POWER-OFF BACKPLANE A indicator& switch.POWER-ON/POWER-OFF BACKPLANE B indicator& switch.CABINET/SYSTEM MODE indicator & switch.POWER FAIL/AIR LOSS indicator.REMOTE MODE ENABLE key switch.INDEPENDENTLY-POWEREDI/O CABINET OPERATOR PANEL (44.sub.i)POWER-ON/POWER-OFF BACKPLANE A indicator& switch.POWER-ON/POWER-OFF BACKPLANE B indicator& switch.CABINET/SYSTEM MODE indicator & switch.POWER FAIL/AIR LOSS indicator.______________________________________
(A) Cabinet Power Control Functions:
The cabinet power control circuitry controls and monitors all the power modules of the various cabinets. It also monitors the various cabinet environmental conditions such as over-temperature, etc.
The power control circuitry of the network system can be controlled from three sources:
(1) by the operator through the cabinet operator panel 44;
(2) by maintenance personnel through the control display 45;
(3) by the power control network through the network interface slave as will be discussed in connection with FIG. 5.
The operator panel control switches, in element 44, are active only when the cabinet is in the "cabinet mode" with the exception of the processor's power-on/power-off functions, and the cabinet/system switch. Table I indicates the switches for both the cabinet mode or system mode.
The maintenance switches are active only when the cabinet is in the "cabinet mode".
The power control network drive functions (the switch type functions) are active only when the cabinet is in the "system mode". The power control network monitor functions (that is the status) are always valid.
When a cabinet is changed from the "system" to the "cabinet" mode, the power state of the cabinet will not change, except that marginal conditions will follow the cabinet margin switches.
When a cabinet is changed from the "cabinet" to the "system" mode, the power state of the cabinet will follow the external power control signals derived from the slave units, as 90, 90 d , 90 i , etc.
(B) Functions of the Cabinet Maintenance Power Control:
Maintenance personnel can control the following maintenance functions from the control display 45 (FIGS. 2, 3, 4) within a cabinet:
(a) Margin indicators; these are used to indicate that the associated logic voltages within the cabinets are in a marginal high or marginal low state;
(b) Margin switches--these will manually set the associated logic voltages within the cabinet to the marginal high or marginal low state. These switches are active in the "cabinet" mode only;
(c) Power fail indicators--these indicate that a power failure has occurred in one of the power modules within the cabinet. This indicator is valid in either the "cabinet" or in the "system" mode;
(d) Over temperature/air loss failure indicators--will indicate an over temperature or an air loss condition in the cabinet. This indicator operates in either the cabinet or the system mode;
(e) Power fault indicators--these will indicate faults in the various power modules in the cabinet and they will operate validly in either the "cabinet" mode or the "system" mode.
(C) Operator Power Control Functions:
Certain functions are controlled by the "system operator" from the cabinet control operator panel 44. These are:
(1) Power-on/power-off switch indicator: in the "cabinet" mode this switch controls the state of the cabinet power (on or off). In the "system" mode this switch is inactive except for the processor cabinet switch. The processor power-on/power-off switch, in the "system" mode, acts as system control switches. Activation of this switch in the "system" mode will cause a "power-on" request or a "power-off" request to be sent to the power control network. The network may then drive the power-on or drive the power-off to all system cabinets which are in the "system" mode. All cabinet "power-on/power-off" indicators are valid for either the cabinet mode or the system mode.
(2) The cabinet/system mode switch: this controls the "mode" of the cabinet. This switch is always active whether the cabinet is in the "cabinet" mode or the "system" mode.
(3) Power fail/air loss indicators: these indicate the respective failure conditions within the cabinet and the indicators are valid in either the cabinet mode or the system mode;
(4) Remote enable switch: this key lock switch enables the connection to be made to the remote system support center 300. This key switch is active in either the cabinet mode or the system mode.
(D) Power Control Network (PCN) Functions:
Table I and paragraph C above described the functions that an on-site operator can control via the operator panels 44 for each cabinet. Paragraph B above described the additional functions that a maintenance engineer can control from the maintenance panels "internal" to each cabinet. The Power Control Network allows remote control of all the above mentioned functions. In this context, "remote" means distant from a cabinet, that is, single-point on-site control; or distant from the site itself, that is, via telephone connection.
Each system cabinet is uniquely addressable over the Power Control Network (PCN). PCN commands are actions to a cabinet driven by the PCN. PCN commands can only affect a cabinet when it is in "system" mode, described in paragraph A above. PCN status is information about the cabinet returned over the PCN. PCN status is available in either "system" or "cabinet" local modes. For cabinets with separately controllable backplanes, the PCN functions are selected separately for each backplane.
The PCN (Power Control Network) functions are:
(1) Power-On Command: Turns the addressed cabinet to power on.
(2) Power-Off Command: Turns the addressed cabinet to power off.
(3) Reset Command: Resets, clears any power fault conditions within the addressed cabinet.
(4) Set Margins Commands: Sets voltage margins conditions within the addressed cabinet for the selected voltage source to either high or low states. This is controllable for the +5 VDC, -2 VDC and -4.5 VDC supplies.
(5) Send Status Command: Requests the addressed cabinet to send specified "status" information over the PCN.
(6) Miscellaneous Control Bit Commands: Command activates or deactivates four external signals which may be used to control clock or other sources in dual processor systems.
(7) Power-On/Off Status: Indicates the power "on or off" state of the addressed cabinet.
(8) System/Cabinet Mode Status: Indicates whether the addressed cabinet is in "cabinet" local mode (no "external" control allowed) or "system" mode (external control via PCN allowed).
(9) Over-Temperature Failure Status: Indicates that the addressed cabinet has experienced an over temperature condition and is shut down.
(10) High-Temperature Warning Status: Indicates that the addressed cabinet is running under conditions outside of range and over-temperature failure may be imminent.
(11) Air Loss Failure Status: Indicates that the addressed cabinet has lost cooling fan(s) and is shut down.
(12) Power Fault Status: Indicates that the addressed cabinet has experienced a power supply fault condition and is shut down. This is reported for the +5 VDC, -2 VDC, -4.5 VDC, +-12 VDC and 15 KW supplies.
(13) Voltage Margin Status: Indicates a specific voltage supply is running in a margin condition. This is reported for +5 VDC, -2 VDC, and -4.5 VDC supplies in both high and low conditions.
(14) Power-On Request Status: Reported only by processor cabinets in "system" mode. It indicates that the power-on switch was depressed by the operator. In system mode, this switch is the power-on switch for the entire site.
(15) Power-Off Request Status: Reported only by processor cabinets in "system" mode. It indicates that the power-off switch was depressed by the operator. In system mode, this switch is the power-off switch for the entire site.
Power Control Network Electrical/Mechanical Characteristics:
The PCN shown in FIGS. 5 and 6 is serially routed, two-wire, twisted-pair. The PCN circuit uses RS422 standard differential drivers and receivers (FIG. 6).
Connected on the PCN will be numerous power net slaves and peripheral slaves and one power net master. The total number of connections is 64. The maximum transfer rate may reach 10K bits/second.
FIG. 6 shows the connection of the RS422 drivers and receivers for slave cards and the master card. Also shown is the network termination resistors of 120 and 470 ohms.
Each slave and master card provides two PCN (Power Control Network) connectors. One connector receives the PCN cable from the previous unit and the other connector sends the PCN cable to the next unit. The PCN is thus serially routed.
For PCN connections between units within attached cabinets, the PCN cable is a simple, inexpensive, twisted-pair cable.
For PCN connections to non-attached cabinets, the PCN cables first are routed through interface panel cards in an I/O cabinet through RFI shielded cable into the non-attached cabinet.
FIG. 7 shows a block diagram for a power net slave card. The diagram shows the controlling microprocessor 92 and the address switches 94 which give each cabinet an unique PCN address. Each slave has two parallel connecting ports 96, 97 to the power control cards of its cabinet. The slave also provides, via circuit 98, clock select or other signals and connects the RS422 interface to the PCN network itself.
FIG. 8 shows the power net master logic unit 100 card block diagram, and FIG. 9 shows a peripheral-slave card block diagram. This slave can also control the power-on and power-off of a peripheral cabinet (disk pack controller).
Power Network Slave Logic:
As seen in FIG. 7, the power network slave logic shows a logic card connected between the power control circuits of a cabinet and the power control network.
A major element of the slave logic card is a microprocessor such as an 8748 chip which contains internal program PROM and internal RAM. A typical chip of this designation is manufactured by Intel Corporation, whose address is 3065 Bowers Avenue, Santa Clara, California, and wherein this chip is described in a publication entitled "Microcontroller User's Manual", Order #210359-001, copyright 1982, and published by Intel Corporation, Literature Dept. SU3-3, of 3065 Bowers Avenue, Santa Clara, California.
Each slave logic unit has a unique address which is set within the card by means of switches shown as element 94, address switches, in FIG. 7. The slave logic is connected to the power control network of FIG. 5 using the circuits shown in FIG. 6, which are RS422 receiver and driver chips. The RS422 receiver and driver chips are those such as typically manufactured by Advanced Micro Devices Company of 901 Thompson Place, (P.0. Box 453), Sunnyvale, California. These circuits are described in a publication entitled "Bipolar Microprocessor Logic & Interface Data Book" published by Advanced Micro Devices Company, copyright 1983.
The power network slave logic in FIG. 7 has two ports designated as port A interface 96 and port B interface 97. These interfaces connect to the power control circuits within each of the cabinets such, for example, as power control card 80 of FIG. 2, power control card 80 d of FIG. 3, and power control card 80 i of FIG. 4. The signals to and from the port A96 and port B97 are described hereinafter.
The power network slave logic unit 90 has four output signals (shown in FIG. 7 at the extreme right side) which may be activated or deactivated under the control of commands sent over the power control network. Thus, these four output signals may be used in cabinets containing a DPM (dual port memory), or for independent memory cabinets, in order to select the source for the DPM clocks. These four signals are individually controlled, raised or lowered, by commands from over the power net from the power net master logic unit 100 of FIG. 5.
These four output signals are driven by the slave logic of FIG. 7 by means of high-drive transistor type logic (TTL) inverter buffer chips. The output physical connection to the slave logic unit card is by "slip-on" posts to which clock-type, backplane type coaxial cables can be attached. A grounded post is provided with each signal post.
Thus, the Select Circuits 98 of FIG. 7 use the inverter-buffer chips to provide a signal from the slave logic over a coaxial cable over to the DPM (Dual Port Memory) back plane.
The power network slave logic unit 90 requires the use of control signals or "always power" from the cabinet in which it resides.
Two on-board indicators and one switch are used to control each of the power network slave logic units 90, 90 i , 90 d , 90 p . A push-button switch (the re-set switch) is used to initialize the slave logic to run its own "self-test". This is the same function that occurs at slave power-up time. One indicator (self-test) is "on" when the slave self-test program is in operation. If a self-test error occurs, this indicator will remain "on".
The second indicator (NET ERROR) is "on" whenever the slave logic detects a "NET" problem while the slave is communicating on "NET". These NET errors include a framing error (too few or too many discs), a parity error, a NET protocol error, and an invalid command. The "NET ERROR" indicator will be deactivated when a "good" net communication to the slave logic unit occurs.
Power Network Master Logic:
A block diagram of the power network master logic is shown in FIG. 8. The power network master logic 100 of FIG. 8 is housed in an independently-powered memory cabinet within the system, such as cabinet 70 of FIG. 1. The power network master logic will require power from this cabinet.
The master logic 100 is the controlling device on the power control network of FIG. 5. It initiates all communications over the network; and thus, all communications over the network are effectuated between the master 100 and a slave logic unit such as 90. There is only one "active" master logic unit, such as 100, which may be connected to the power control network of FIG. 5 at any given time.
The network master logic 100 also interfaces to the Maintenance Subsystem (200 shown in FIG. 8) through the System Control Network shown in FIG. 5. Also, as indicated in FIG. 5, the power network master logic is the single point of connection of the system to a Remote Support Center (RSC, 300 in FIGS. 5 and 8).
FIG. 8 also shows the connections to the Remote Support Center 300 and also to the power control network of FIG. 5.
As seen in FIG. 8, the power network master logic unit 100 is provided with a microprocessor 100 u to which are connected a PROM 100 m1 and EEPROM 100 m2 in addition to a RAM unit 100 a . A power control interface 100 p connects the microprocessor to the power control network and a remote support interface 100 r connects the microprocessor to the remote support center 300. A time of day circuit 100 t with battery back-up provides time signals for the unit.
The power network master logic unit 100 of FIG. 8 provides a central interconnection point for the power control network of FIG. 5, in addition to the system control network which is connected through the interface 100 s . It is also the central interconnection point for the remote support center interface (remote diagnostic) of element 100 r .
The power network master logic unit 100, as the master unit for the power network, controls all the actions on this network.
In any multi-processor system, there may be only one "active" power network master logic unit. Since, however, this unit is of considerable importance to the system operation and maintenance, there is generally provided a spare power network master logic unit, even though a failure in the power subsystem will not affect the operation of the overall processing unit.
The microprocessor 100 u (Intel 8088) of FIG. 8 may be set to run at 8 megahertz. It executes its code out of the 32K bytes of PROM 100 m1 . The 8K bytes of RAM 100 a are used for data buffers and for operating stacks. The 256 bytes of electrically erasable PROM 100 m2 are used to store configuration-dependent option flags. The time of day circuit 100 t is backed up by a battery for use during times of power failure. Six indicators and five switches are provided on the master logic unit 100 for maintenance of the master card itself.
Peripheral Slave Power Control Adaptor:
As seen in FIG. 5, the power control network may include peripheral devices which are provided with a peripheral slave power control adaptor 90 p .
FIG. 9 shows a block diagram of such a peripheral slave power control adaptor 90 p . Provided therein is a microprocessor 92 p which connects to a peripheral power control driver circuit 95 p having connections to the peripheral cabinet. Also provided are address switches 94 p which provide an input to the microprocessor 92 p , and also a driver-receiver circuit 99 p which connects to the power control network of FIG. 5.
The peripheral slave power control adaptor, such as 90 p of FIG. 9, is located in an interface panel within the I/O cabinets such as 60 and 70 of FIG. 1, and also in cabinets 20 and 30 of FIG. 1.
The peripheral slave power control adaptor 90 p of FIG. 9 connects between the power control network of FIG. 5 and any selected system peripheral cabinets. There are certain cabinet types to which the peripheral slave power control adaptor may be connected. These are:
(a) a disk pack controller (without status signals)
(b) a disk pack controller (with status signals)
(c) a disk pack exchange unit (without status signals).
The peripheral slave adaptor 90 p provides only "power-on" and "power-off" control for these cabinets.
The peripheral slave adaptor 90 p is logically a simple slave unit. The microprocessor 92 p may use an 8748 microprocessor chip (previously described) and interfaces to the power control network with the RS422 driver receiver chip designated 99 p .
The peripheral slave logic of FIG. 9 differs from the internal power slave logic unit of FIG. 7 in that, in place of the port A and port B interfaces (96, 97) of FIG. 7, the "peripheral" slave logic has special driver circuits 95 p in order to control the "on/off" state of the connecting peripheral cabinets.
Power Control Network Communications:
All commands and communications over the power control network are initiated by the power net master logic unit 100 of FIGS. 5 and 8.
FIG. 10 is an illustrative drawing showing the particular sequence of events over the network. The master logic unit 100 first sends the Address byte shown in line 1 of the drawing of FIG. 10. This Address is the address of the desired slave unit to be addressed. Each slave unit receives and evaluates the Address received and then the appropriate slave unit will return its Address to the master power unit 100.
If the "correct" slave address is returned to the master power logic unit 100, as shown in line 2 of FIG. 10, then the master logic unit 100 will send a Command byte (shown in line 3) to the previously addressed slave unit, such as 90 of FIG. 7.
The slave unit, such as 90, then returns the Command byte to the master as illustrated in line 4 of FIG. 10. Thus, when the slave has received the Command byte, it returns it to the master and if the byte received by the master logic unit 100 then agrees with the byte that it (master unit) had previously sent, the master logic unit 100 re-sends the Command byte again, as illustrated in line 5 showing the Command byte being re-sent from master to slave.
If the second Command agrees with the first Command byte, the slave logic unit 90 will decode and execute the Command received. The slave will then return its General Status byte to the master as seen in line 6 of FIG. 10.
If the Command was a Send Status Command, then the specified Status byte is returned instead of the General Status byte.
If the command sent by the master logic unit 100 to a slave logic unit 90 was either a "power-on" or a "power-off", then the General Status byte which is returned to the slave logic unit 90 will not reflect the new power state of the cabinet involved. It will show the status of the cabinet "prior to" the command. To check the new state of the cabinet involved, a Send Status Command will be sent about 15 seconds later after the power on/off Command was sent.
Thus FIG. 10 indicates the general network flow for the master power logic unit 100 as it polls the various slaves 90 over the network. After the master logic unit 100 sends an Address, it waits for the return of the addressed slave unit's address. If an incorrect address is returned from the slave logic unit 90, the master power logic unit 100 will re-try the expected address. It will try the desired address three times before it assumes that the Address slave logic unit 90 may be "bad".
The master power logic unit 100 also does the same re-try/time-out procedures for the Command bytes. When the master power logic unit 100 finds an "improperly" responding slave logic unit 90, while polling, it will report the condition to the maintenance subsystem 200 over the system control network connected as shown in FIG. 8.
FIG. 10 also indicates the network byte format for the power network. As shown therein, there is one bit used for a start bit, then 8 bits are used for a data byte, then one bit is used for odd parity, and one bit is used as a stop bit.
FIG. 11 shows a drawing of a flow chart showing the network flow for the master power control logic unit 100 which summarizes the various protocol steps used in FIG. 10 on lines 1-6.
FIG. 12 is a flow chart diagram which summarizes the protocol involved for the slave power logic unit in the system operation.
Table II shows one scheme on which Addresses may be provided for the processor cabinets, the independent memory cabinets, the I/O cabinets, and the various peripheral cabinets, whereby the power control network system may address and communicate with specific cabinets in order to provide Command and Control functions in the power network system.
TABLE II______________________________________POWER NETWORK ADDRESS BYTE DEFINITIONSAddress Bits7654 3210______________________________________1000 0000 Power Control Network (Maintenance only)1000 00xx (Spare)1000 01xx Processor Cabinets1000 1xxx Independently-Powered Memory Cabinets1001 xxxx Dependently-Powered I/O Cabinets101x xxxx Independently-Powered I/O Cabinets1100 1xxx Disk Exchange Cabinets1101 0xxx Disk Controller Cabinets1101 1xxx Disk Controller Cabinets -- Memorex Type______________________________________ Note: Only 64 connections are allowed on the network.
Power Control Network Protocol:
Since the PCN has "great power" over a system, that is, it can turn off a system, it is necessary that the network protocol be fault tolerant and reliable. The PCN protocol was designed with several layers of redundancy and checking.
FIG. 10 shows the PCN byte format. The PCN byte contains one start bit, eight bits of information (data byte), one odd-parity bit and one stop bit.
FIG. 10 also shows the PCN message transfer protocol between the power net master card and a slave card. All transfers on the PCN are initiated by the master. All transactions follow the steps described below:
(1) Master sends an address byte to all slaves. An address byte has a "one" in the most significant bit position. Each slave compares the address byte to its address switches. Each slave has an unique address and that address values are predefined and grouped to also indicate that type of cabinet in which the slave is located. The master program can generate an address or pull an address from memory 100 a of FIG. 8. The master program gives the address to microprocessor 100 u which transmits it from master logic 100 to slave units 90, 90 d , 90 i , etc. via the network lines of FIG. 6.
(2) The slave, whose address switches equal the address byte value, then returns its address over the PCN to the master. The master checks the received value with the sent value to ensure the proper cabinet is responding. Thus, the slave program receives the transmitted address when it matches its own unique address and retransmits its address via the network of FIG. 6. The program gets its address from the settable address switches 94 of FIG. 7. The master program in the master logic unit compares the received-back address which comes through 100 p of FIG. 8. This address came from the slave unit 90 (or 90 d or 90 i , etc.) via FIG. 6.
(3) The master then sends a command byte to the addressed slave. A command byte has a zero in the most significant bit position. The master program can generate an instruction or pull one from memory 100 a of FIG. 8 in the master logic unit. The microprocessor 100 u will instruct 100 p , FIG. 8, to transmit it via the circuit of FIG. 6.
(4) If the command is a good command, the slave returns the command over the PCN. The slave logic unit receives the instruction and the slave program checks the instruction for validity, then retransmits the instruction (if valid) via the circuit of FIG. 6 back to the master unit 100.
(5) The master compares the returned command with the sent command; if it compares accurately, it re-sends the command byte to the slave. Thus, the master program then causes the master logic unit 100 to compare the "returned-instruction" from slave unit 90 with the originally sent instruction. When these two instructions are verified as being in agreement, the program instructs master logic unit 100 to transmit the instruction again over to the addressed slave unit via 100 p of FIG. 8 and FIG. 6.
(6) The slave compares the second command byte with the first command byte; if they agree, it checks the command, and if valid, the slave will begin execution of the command. Thus here, the slave unit receives the instruction for the second time and the slave unit program compares this instruction with the originally received instruction whereupon (if both instructions coincide) the slave unit generates control signals. These generated control signals are placed on circuits 96, 97 or 98, FIG. 7 (depending on the instruction) and especially to the Power Control Card 80 i (FIG. 4) or to 80 d (FIG. 3) or 80 (FIG. 2) via the port interfaces 96, 97 of FIG. 7. In the case of the peripheral slave unit 90 p (FIG. 8), the slave unit generates a pulse which is sent to the peripheral cabinet (disk control unit of FIG. 9) via circuit 95 p .
(7) In response to the second command byte, the slave returns a status byte of information to the master. The normal status byte returned contains "general status" information about the cabinets condition: on/off, system/cabinet local modes, any failure condition, any margin condition, on/off request. If the command was a "send status" command, the slave will send the specific information desired: specific margin conditions, specific cabinet power failure conditions, clock select signal states. Thus, after generating the needed control signals, the slave unit will get "cabinet status" information via circuits 96, 97 of FIG. 7. This information creates the "general status" byte (or other status byte depending on the instruction from the master unit 100). The slave unit (90, 90 d , 90 i , etc.) will then transmit the status information to the master unit 100 via, for example, the driver 90 d of FIG. 6. When the master unit 100 gets the status information (via 100 p of FIG. 8), the master program can act on the basis of the type of information it received.
(8) One additional safety check is performed by the master card on the status byte returned. Since power-on request and power-off request status bits are so critical to the entire system, these status bits are double-checked if they are returned in the general status byte. This is done as follows:
(a) A "send status" command is sent; the general status byte is received for the second time to see if the power-on/off request status bit is still active.
(b) A reset command is sent to the slave in question. This clears the power-on/off request bit.
(c) A "send status" command is again sent (the request status should now be inactive).
(d) If each step above was correct, the master will execute the power-on or power-off request sequence to the system.
Any time-outs or miscompares, in any of steps 1-8 above, abort the transfer and prevent the execution of any action to cabinets in the system. FIG. 11 gives the master flow (less steps a-d). FIG. 12 gives the slave flow.
Power Control Subsystem
The power control subsystem shown in FIGS. 13, 14, 15 and 16 is used to controllably sequence various power supply modules either "on" or "off" and to detect failures in the power modules or cooling systems that could damage the logic cards, interfaces or memory storage devices.
The power sequence control and failure detection is oriented around the power control circuit card 80 (80 i , 80 d ) in conjunction with its interface to the slave logic units 90 (90 i , 90 d ) as shown in FIGS. 13 and 14. FIG. 13 shows the output control signals from the slave logic 90 to the power control circuit 80. Then FIG. 14 shows the various "indicator" signals which the power control circuit provides to the slave logic 90.
In order to control each power supply module on or off, a transistor type logic (TTL) compatible signal is sent to each power supply module from the power control circuit card 80, according to instructional data received from the slave logic unit 90.
Each power supply module (as 41, 43, 70 a , 70 b , of FIGS. 2, 3, 4) will send a TTL signal back to the power control circuit 80 (80 i , 80 d ) to indicate if that module failed or was under voltage, over voltage, over current or over temperature. Thus, the over temperature or air loss sensors of FIG. 15 can send failure signals to the sequencer 80 q in power control circuit 80.
As indicated in FIG. 16, a precision reference voltage unit 80 r has programmable voltage steps of + (plus) or - (minus) 5 percent which can be controlled by input signals via a local interface from margin switches 80 s , or via a remote interface from slave logic 90. This permits "margining" of the output voltages on each power supply module.
The voltage output of the logic power supplies (+5 V, -4.5 V and -2.0) can thus be adjusted + or -5% via the "margin step function". Each power supply module has a +5V reference supplied by reference unit 80 r which controls the output voltage of each power module, and any change in reference voltage causes a proportional change in output voltage.
The precision +5 V reference voltage has two programmable inputs for effecting +5% and -5% voltage change steps. The margin steps can be activated "locally" by a switch or "remotely" by the slave logic 90. Each logic power module has its own separate reference voltage and margin circuit.
The main AC power module (such as the 15KW input module 41 of FIG. 15) can be set on or off via a TTL signal "S" from the power control circuit 80.
The cabinet control panel 44 (FIGS. 2, 15) enables "local mode" operation by a technician or system operator, and has an on/off push button with light-indicator, with power-failure/temperature-failure indicator and local/remote switch with indicator light.
Thus, the two modes for controlling power on/off are the "local" mode and the "remote" mode.
The local mode requires an "on-site" operator to manually start the power control on/off responses by use of an ON/OFF switch on cabinet control panel 44.
The remote mode allows the "system control" in the network whereby the master logic 100 (FIG. 8) instructs the appropriate slave logic 90 to command certain actions to its power control circuit 80.
The local/remote keyswitch in the cabinet control panel 44 enables or disables the local/remote interface (FIG. 16) in the power control circuit 80. Then depending on what mode the system is in, the sequencer 80 q turns each power supply module on/off in the appropriate sequential order.
If a failure signal occurs on a power module, air sensor or temperature line (FIG. 16), then the sequencer 80 q will power off the power modules in the appropriate sequence.
On "power-up" the proper sequence is to first turn on the main AC supply 41 after which power is turned on to the 12 V supply, then the 5 V supply and the 4.5 V and 2.0 V supplies.
On "power-off", the sequence is effected in the reverse order.
As indicated in FIG. 15, each power module can furnish a TTL compatible "fail" signal to the sequencer 80 p in the power control circuit 80.
The power sequencer 80 q is a circuit which ensures that the main power module 41 is operating before checking the subordinate power modules, after which any incoming failure signal which is detected will make the sequencer shut off all the power modules in that subsystem. The sequencer 80 q will also signal the slave logic 90 with a TTL compatible signal. Any failures are also indicated by light-emitting diodes which make reference to each power module. A similar failure indicator on the cabinet control panel 44 is also turned on.
There has herein been described a power control network which interconnects a multitude of digital modules where each digital module has a slave logic unit capable of receiving power control instructions from a master logic unit. The communications protocol between the master logic unit and any addressed slave logic unit insures that accurate instruction transfer will occur without error in all cases.
While a preferred embodiment of the power control subsystem has been described, it should be understood that other possible embodiments may be devised within the framework of the following claims: | A power network control system has a plurality of digital modules interconnected. A master logic unit in the network communicates with a specialized protocol to slave logic units in each module. The slave logic unit can instruct a power control circuit to turn-off or turn-on various power supply modules in addition to adjusting a power module in steps of plus or minus fixed percentage amounts. | 50,556 |
FIELD OF THE INVENTION
[0001] The present invention relates to an apparatus and method for downhole water chemistry analysis.
BACKGROUND OF THE INVENTION
[0002] Well operators commonly need to understand downhole water chemistry to help them decide production strategies and determine corrosion rates, scale formation rates, formation geochemistry etc.
[0003] More specifically, the pH and qualitative/quantitative analysis of the presence of specific ions in downhole water are often required.
[0004] Conventionally, water chemistry measurements are performed in the laboratory on fluid samples retrieved from below ground. However, water chemistry is not often preservable over the temperature and pressure changes typically induced by transportation from subterranean locations to the surface, and so a chemistry measurement of a sample collected for laboratory analysis will not always provide a result that can be related to the downhole value. Consequently, the water chemistry measured in the laboratory may vary significantly from that existing downhole.
SUMMARY OF THE INVENTION
[0005] An object of the present invention is to provide a more reliable analysis of downhole water chemistry.
[0006] Accordingly, in a first aspect, the present invention provides an apparatus for analysing water chemistry, the apparatus being adapted to operate downhole and comprising:
[0007] a colouring agent supply device for supplying a colouring agent to a water sample, the colour of the water sample thus supplied being indicative of the water sample chemistry, and
[0008] a calorimetric analyser arranged to determine the colour of the water sample.
[0009] An advantage of the apparatus is that it allows in situ analysis to be performed, thereby avoiding the problems associated with transporting water samples to the surface. The present invention is at least partly based on the realisation that colorimetric analysis is a technique that can be adapted for performance downhole, i.e. in relatively demanding and hostile conditions.
[0010] In one embodiment the apparatus is installed downhole (e.g. in a hydrocarbon well or an aquifer).
[0011] Preferably the calorimetric analyser is connected to a processor for determining the water sample chemistry from the colour of the water sample. The processor may also be adapted for use downhole, or alternatively it may be intended for remote installation e.g. at the surface. For example the processor may be a suitably programmed computer.
[0012] The water sample colour may be indicative of e.g. water pH or a selected ion concentration level.
[0013] In one embodiment the calorimetric analyser comprises a spectrometer. An advantage of a spectrometer-based approach to colour analysis is that it has the potential to provide fast answers to questions of pH, corrosion chemistry and scale formation, which can be crucial for deciding e.g. completion design and materials and scale treatment programs.
[0014] A further aspect of the present invention provides for the use of the apparatus of the previous aspect for in situ analysis of downhole water chemistry.
[0015] In another aspect the present invention provides a method for analysing downhole water chemistry, the method comprising the steps of:
[0016] (a) supplying a colouring agent to a downhole water sample, the colour of the water sample thus supplied being indicative of the water sample chemistry, and
[0017] (b) determining the colour of the water sample,
[0018] wherein steps (a) and (b) are performed in situ.
[0019] In another aspect the present invention provides a method for monitoring contamination of downhole water, the method comprising the steps of:
[0020] (a) adding a tracer agent to a fluid which is a potential contaminant of the downhole water,
[0021] (b) supplying a colouring agent to a sample of the downhole water, the colour of the water sample thus supplied being indicative of the presence of the tracer agent, and
[0022] (c) determining the colour of the water sample,
[0023] wherein steps (b) and (c) are performed in situ.
[0024] The potential contaminant may be drilling mud filtrate. The downhole water may be either connate or injected water.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Specific embodiments of the present invention will now be described with reference to the following drawings in which:
[0026] FIG. 1 shows a schematic diagram of a Live Fluid Analyser installed on a flow line,
[0027] FIG. 2 a shows the room temperature absorbance spectra of (a) the acid form of phenol red, (b) the base form of phenol red, (c) phenol red in a pH 8 solution, and (d) a weighted sum of the acid and base form spectra fitted to the pH 8 solution absorbance spectrum,
[0028] FIG. 2 b shows graphs of base fraction of phenol red (right hand vertical axis) and calculated pH (left hand vertical axis) as functions of prepared solution pH,
[0029] FIG. 3 a shows the room temperature absorbance spectra obtained from (a) phenol red in deionised water and (b) phenol red in deionised water after heat treatment at 150° C. for 24 hours, and
[0030] FIG. 3 b shows the absorbance spectra obtained from (a) phenol red in a pH 7.4 buffer solution at 22° C. and (b) phenol red in the pH 7.4 buffer solution at 150° C.
DETAILED DESCRIPTION OF THE INVENTION
[0031] In general terms, the present invention relates to downhole colorimetric analysis. A preferred approach for the determination of pH and detection of the presence of specific ions involves injecting a specific indicator or reagent into a sample of water and determining the resulting colour of the fluid with an optical spectrometer.
[0032] Ions of interest for detection include those of Ca, Ba, Sr, Al, Cl, F, Fe, Mg, K, Si, Na, and ions containing sulphur and carbon (for example carbonate, bicarbonate, sulphate). Use of colorimetric and spectrometric analysis along with procedures and reagents required to determine the presence/quantity of some of these ions have been described in the literature (Vogel, A. I., Text - Book of Quantitative Inorganic Analysis, 3 rd Edition, Chapter 10, John Wiley, 1961; Sandell E. B., Colorimetric Determination of Traces of Metals, 3 rd Edition, Interscience Publishers, 1959). However, we propose, for the first time, the application of these methods, in a downhole environment, to the analysis of downhole water as found in oil and gas fields, as well as aquifers. Typical temperatures and pressures found in a downhole environment are in the range of 125° C. and 10,000 psi, respectively; however they can go up to as high as 175° C. and 20,000 psi.
[0033] To perform quantitative measurements of pH or ion concentration, the optical absorption of the unknown species can be determined either relative to a standard solution (which could be the water sample itself prior to indicator/reagent addition) or with a stable and previously calibrated spectrometer.
[0034] Desirably, the spectrometer should be capable of operating over the visible spectrum of 400 to 760 nm, which is from ultraviolet to infrared respectively.
[0035] In one embodiment we propose fitting a known Modular Dynamic Tester (MDT) with a Live Fluid Analyzer (LFA) module (R. J. Andrews et al., Oilfield Review, 13(3), 24-43). The LFA would inject coloured indicators to the water flowing through the MDT so that pH can be determined. It can also add suitable reagents to the water for determination of the presence/concentration of selected ions.
[0036] FIG. 1 shows a schematic diagram of the LFA installed on a flow line 1 , the other parts of the MDT not being shown. An arrow indicates the direction of water flow in the flow line. The LFA has an upstream dye injector 6 and a downstream optical analyser 2 . The analyser comprises a light source 3 on one side of the flow line and a facing light detector 4 on the opposite side of the flow line. When a preselected indicator or reagent 5 is injected into flow line it mixes with the water and is carried downstream to the analyser, whereupon the detector generates a signal indicative of the colour of the water. If required a mixer, not shown in the figure, such as a double helix, can be used to promote mixing of the water and dye. A processor (not shown) then determines the water chemistry from the signal e.g. using approaches discussed below.
[0037] Such colorimetric analysis also allows contamination of formation water by water-based mud filtrate to be detected. This can be achieved by suitable indicator/reagent selection such that the water-based mud filtrate and formation water generate different respective colours.
[0038] Another option is to add a tracer ion or other species (for example, nitrate, iodide or thiocyanate ions) to the drilling fluid. A reagent can then be used in the LFA, which produces a colour change in the presence of the tracer so that the tracer can be detected and preferably quantified. In this way real-time monitoring of connate water for contamination by the filtrate can be achieved.
[0039] A possible reagent for detecting iodide is the iodobismuthite ion, formable from a solution of bismuth in dilute sulphuric acid. This ion gives a yellow orange colouration and is sensitive up to 1% iodide (Vogel, A. I., Text - Book of Quantitative Inorganic Analysis, 3 rd Edition, Chapter 10, p803 John Wiley, 1961).
[0040] We now describe how indicator colouration can be used to measure pH. However, similar considerations apply when the colour of any reagent is being used to measure ion concentration.
[0041] For pH measurements the choice of indicator depends to a significant extent on the accuracy with which the pH is required. As an example, we take a universal indicator, a volume of which has been injected into the sample flowline upstream of the optical detector. The indicator volume is determined by the flow rate of the water and intensity of the colour and is usually a small fraction of the total volume. The universal indicator may be formed e.g. from a mixture of 0.2 g of phenolphthalein, 0.4 g methylred, 0.6 g dimethylazobenzene, 0.8 g bromothymol blue, and 1 g of thymol blue in 1 l ethanol. To this solution is added NaOH(aq) until the solution appears yellow. The colours of the solution as a function of pH are listed in the table below (Vogel, A. I., Text - Book of Quantitative Inorganic Analysis, 3 rd Edition, Chapter 1.30, p59 John Wiley, 1961).
pH 2 4 6 8 10 12 Colour Red Orange Yellow Green Blue Purple
[0042] An alternative is to use a plurality of indicators each of which is specific to a respective pH range. This may result in a more precise determination of pH.
[0043] The pH of an unknown solution may be obtained using the equation below (R. G. Bates, Determination of pH: Theory and Practice , Chapter 6, John Wiley, 1964):
pH = pKa + log γ B γ A + log B A ( 1 )
where Ka is the thermodynamic equilibrium constant for the indicator and is a function of temperature; A and B are the respective fractions of the acid and base forms of the indicator; and γ A and γ B are respective activity coefficients of the acid and base forms of the indicator, and depend on ionic strength of the solution and temperature. Both Ka and activity coefficients could be weak functions of pressure as well.
[0044] The fraction of the indicator that exists in the acid form (A) and base form (B) may be measured spectroscopically. The absolute concentration of the dye does not appear in the equation and hence the pH calculation is independent of the volume of dye injected or the flow rate of the water stream as long as the concentration is such that Beer's law is satisfied. The functional dependence of Ka on temperature (T) has been studied and measured for a number of reactions and a general equation that can describe this dependence is (D. Langmuir, Aqueous Environmental Geochemistry , Chapter 1, Section 1.6.2, Prentice Hall, 1997):
log Ka = a + bT + c T + d log T + ⅇ T 2 ( 2 )
[0045] The parameters in this equation may be obtained by calibration in the laboratory over the desired temperature range using standard buffers of known pH. Dependence on pressure may also be obtained through experimental calibration if necessary. Several models have been proposed for activity coefficient estimation. For example, the Debye-Huckel equation is commonly used for low ionic strength solutions and the Pitzer model at higher ionic strengths (D. Langmuir, Aqueous Environmental Geochemistry , Chapter 4, Section 4.2, Prentice Hall, 1997). Ionic strengths can be derived from downhole water sample conductivity/resistivity measurements as is done in the MDT or alternatively from other wireline measurements such as resistivity logs. For very dilute solutions and/or for acid and base forms that have similar behaviours, the activity coefficient term may be neglected. Thus equation (1) provides a means for determining pH under downhole conditions for most temperatures, pressures and ionic strengths encountered in practice.
[0046] As an example, FIG. 2 a shows the room temperature absorbance spectra of (a) the acid form of phenol red and (b) the base form of phenol red. The acid form has a peak at about 432 nm and the base form at about 559 nm. FIG. 2 a also shows (c) the measured absorbance spectrum of phenol red in a pH 8 solution, and (d) a weighted sum of the acid and base form spectra fitted to the measured absorbance spectrum, the weightings providing the base and acid fraction of phenol red in the pH 8 solution.
[0047] Similar analyses can be performed for solutions prepared with different pH levels. FIG. 2 b shows a graph of base fraction of phenol red (right hand vertical axis) as a function of prepared solution pH (horizontal axis). Using equation (1) it is then possible to, calculate the pH of each solution. The calculated pH values (left hand vertical axis) are also plotted on FIG. 2 b . They show that, in this example, pH determined by spectroscopy is highly accurate for phenol red base fractions in the range of about 0.05 to 0.95 corresponding to pH values from 6.5 to 9. The range of pH measurement can be increased to 6 to 9.5 if the acid and base fractions can be spectroscopically detected at lower levels of 0.02.
[0048] The accuracy of the pH measurement is higher when the pH is close to the pKa value and decreases when the pH departs from the pKa. Thus, if the likely pH range is known, an indicator can be selected which has a pKa value such that a desired level of accuracy can be achieved. A combination of indicators may be chosen to cover the pH range typically expected in formation waters. In this way, provided the optical analyser has suitable wavelength windows to observe the colour changes, the pH can be obtained to within a value of a few tenths. Depending on how the indicators interact with each other, multiple injectors in series or parallel may be used for the different indicators or a single injector with a mixed indicator solution may be deployed.
[0049] The analysis may be performed using a stable and calibrated colorimeter/spectrophotometer. Alternatively, the absorbance spectra of the water sample in the flow line prior to indicator injection can yield the baseline. Yet another option is to use a reference solution to calibrate the colorimeter/spectrophotometer. The last two options provide a means of compensating for any possible inherent water colour.
[0050] Further improvements may be obtained if a series of buffer reference solutions are supplied, each differing in pH e.g. by about 0.2 and covering the range around the expected pH value. Indicator is then added to known volumes of the buffer solution and the water sample and the colours compared to determine the pH. To ensure accuracy, preferably the water sample is a captured sample.
[0051] For downhole use, the indicator should be stable and chemically active at the temperatures expected downhole. As an example, FIG. 3 a shows the room temperature absorbance spectra obtained from (a) phenol red in deionised water and (b) phenol red in deionised water after heat treatment at 150° C. for 24 hours. The heat treatment results in only a 10% loss in absorbance, demonstrating that the phenol red indicator can survive prolonged exposure to temperatures of up to 150° C.
[0052] However, it may be necessary to calibrate each indicator/reagent for the different temperatures and ionic strengths to which it will be exposed downhole. FIG. 3 b shows the spectra obtained from (a) phenol red in a 7.4 pH buffer solution at 22° C. and (b) phenol red in the 7.4 pH buffer solution at 150° C. At 150° C. the phenol red is still chemically active, the increase in base fraction at the higher temperature being due to changes in pKa and the pH of the buffer solution with temperature.
[0053] While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention. | The invention concerns an apparatus for analysing water chemistry. According to the invention, the apparatus is adapted to operate downhole and comprises a colouring agent supply device for supplying a colouring agent to a water sample, the colour of the water sample thus supplied being indicative of the water sample chemistry, and a colorimetric analyser arranged to determine the colour of the water sample. | 18,587 |
FIELD OF THE INVENTION
The present invention relates to a chip crushing device more particularly the present invention relates to surface designs for cooperating working surfaces adapted to squeeze wood chips there between and modify the structure of the chip to make it more uniformly receptive to impregnating chemicals.
BACKGROUND TO THE INVENTION
In the manufacture of pulp and paper wood is usually chipped into wood particles using a chipper. Many types of chippers available, however the conventional chipper cuts across the wood at an angle to the grain to define the length of the chip and the thickness is determined by splitting along the grain. Therefore, despite the fact that major investigations have been made on cutting angles of the knives etc., the thickness of the chips produced by such conventional chippers is not accurately controlled.
Wafer chippers have also been used to produce chips for pulping, such chippers or waferizers as they are sometimes called cut generally along (parallel to) and across the grain with the main cutting edge parallel to the grain to produce chips that have a uniform thickness and therefore a more uniform impregnation characteristic. However, the benefits derived from wafer chips can only be obtained if only wafer chips are used to charge the digester. However, since it is normal practice to purchase chips from a variety of different suppliers and not all suppliers have the same type of wafer chipper the uniformity in thickness obviously is not obtained and therefore neither would the benefits. Furthermore the wafer chipper is much more expensive to maintain since it generally requires the use of a plurality of discrete knives, each of which cuts a single chip.
It has been proposed to treat chips produced by a conventional chipper to render them more uniformly impregatable for example by shredding of conventional chips to reduce them to smaller particles which may be more quickly and more uniformly impregnated, however, such shredding generally increases the number of fines which cause problems during digestion that to a degree defeat the purpose of the shredding operation.
It is also proposed to crush chips using a chip crusher such as the crusher shown in Canadian patent No. 825,416 issued Oct. 29, 1969 to Kutchers et al which utilizes a pair of rolls to crush the chips and fissure them to render them more easily and more uniformly penetrable by cooking liquor in the pulping process.
In the said Kutchera et al patent a specific surface design is proposed wherein each of the rolls are provided with ribs spaced 0.375 to 0.91 inch and have uniform heights between about 0.007 and 0.13 inch, and surfaces or land areas of 0.12 inch to 0.2 inch with the rib height ratio of the two rolls never exceeding about 4 to 1.
The device of the Kutchera et al patent has been tried but it is believed it is no longer in operation, part of the problem being the limited capacity of the equipment.
U.S. Pat. No. 3,962,966 issued June 15, 1976 to Lapointe describes an improved arrangement for increasing the throughput through the crusher. In this device the chips are fed axially onto a rotating disc which flings them out radially in a substantially one chip thickness layer, that passes between a roll and a working surface of the disc to squeeze chips of greater than a certain thickness.
BRIEF DESCRIPTION OF THE INVENTION
It is an object of the present invention to provide a new surface design of the working surfaces of a crusher such as those shown in the said Canadian patent of Kutchera et al or in the Lapointe type crusher shown in U.S. Pat. No. 3,962,966.
Broadly the present invention relates to a chip crusher composed of a pair of co-operating surfaces defining a pressing nip, said surfaces being mounted to move in substantially the same direction through said nip, one of said surfaces being provided with a plurality of land areas separated by valleys, said land areas being substantially continuous and extending substantially in said direction of movement as said one surface passes through said nip, each of said land areas being between about 0.1 to 0.04 inch in width in the direction perpendicular to said direction of movement and being spaced centre to centre of said land areas by 0.2 to 0.6 inch said valley having a depth of at least 0.03 inch and having sloping side walls extending no greater than 160° and preferrably between 135° and 160° to said land areas, the other of said surfaces forming the periphery of a roll being provided with a plurality of teeth with the crown of each said looth defining a line preferably extending substantially perpendicular to said direction of movement through said nip and having a tooth depth of between about 0.05 inch and 0.1 inch and having their crowns spaced between about 0.1 and 0.6 inch.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features, objects and advantages will be evident in the following detailed description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings in which.
FIG. 1 is a section through a plate or roll illustrating the surface configuration of one of the surfaces.
FIG. 2 is an end view of a roll incorporating the co-operating or mating surface.
FIG. 3 is a cross section of the preferred embodiment of a device employing the mating crushing surfaces of the present invention.
FIG. 4 is a plan view of the two discs used in the embodiment of FIG. 3.
FIG. 5 is an alternative embodiment incorporating the present invention in a chip crusher of the type described in the said Kutchera et al patent.
FIG. 6 is a plan view schematically illustrating the pressure pattern applied to a chip passing through a nip formed between a pair of surfaces incorporating the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The configurations of the two mating surfaces are depicted in FIGS. 1 and 2.
The surface 10 of FIG. 1 is composed of a plurality of spaced land areas designated at 12. Each being positioned in the same plane and having a width W and spaced from the adjacent land areas 12 by a distance centre to centre as indicated at S. The valleys 14 between each of the land areas 12 are formed by a pair of sloping sidewalls 16 and 18 extending between the surfaces or land areas 12 and the planer bottom sections 20 of the valleys. The sections 20 are substantially parallel to the areas 12. These sidewalls 16 and 18 extend at an angle θ to the sections 20 at the bottom of the valleys 14 and thus to the land areas 12. The sections 20 each have a width generally indicated at Z in FIG. 1.
The land areas 12 and thus the valley 14 there between extend generally in the direction of relative movement between the surface 10 and the co-operating surface 22 shown in FIG. 2. If the surface 10 is incorporated on the disc as shown in FIG. 4 the land areas 12 form concentric rings spaced by the valleys 14 or if the surface 10 is provided on a roll such as that indicated schematically in FIG. 5 the land areas 12 will extend circumferentially on the roll and form a plurality of spaced ring pressure members each on substantially the same radius extending circumferentially around the roll as right circular rings.
It has been found by experiment that the width of the land areas 12 as indicated by the letter W must be within certain limits as must the spacing S between the land areas 12 if proper fissuring of the chips is to be obtained. These dimensions may vary depending on the thickness and or length of the chip to be treated using the device however they will generally lie within the following ranges W=0.1 to 0.04 inch, S=0.2 to 0.6 inch and θ should never be less than about 20°, i.e. the angle between the land area and the side wall should not exceed 160°, it being important that the depth d i.e. the total depth of the valleys between the land areas 12 and the bottom surfaces 14 be at least 0.03 inch, obviously the dimension Z will depend on the angle θ spacing S and width W as well as the depth d for any given configuration. The spacing S should be such that the nominal chip length to be treated will substantially always contact at least two land areas.
The mating surface 22 adapted to cooperate with the surface 10 is provided on a roll such as the roll indicated at 24 in FIG. 2 since at least one of the surfaces 22 or 10 will be the surface of a roll to form a nip. The peripheral surface 22 of the roll 24 is formed by plurality of uniformly spaced teeth having their apex ends or crowns 26 extending in lines substantially longitudinal of the axis of rotation of the roll (see FIGS. 2 and 3). Each of these teeth has its crown 26 formed by the extention of a front face 28 and a trailing face 30 which form a saw tooth like configuration. These faces 28 and 30 preferably meet at 90° generally between about 60° and 120° and the faces 30 will preferably be at an angle α to a tangent to the surface of the roll 24. The angle α will be between about 5 and 45 degrees, preferably about 15°. The circumferencial spacing C between a pair of adjacent crowns 26 will generally be about equal about 0.1 to 0.6 inch so that 2 teeth will normally engage a chip and the depth of these teeth i.e. the height of the walls 28 as indicated by D will be at least 0.03 inch and generally will not exceed 0.1 inch.
The radius of the roll 24 i.e. of the crowns 26 of the teeth determines the angle of attack of the teeth to the chip thus when the roll diameter changes it may be desirable to modify the size and shape of the teeth. The diameter of the roll should be chosen to ensure the chips will be drawn into the nips by the action of the two surfaces 10 and 22. The diameter of the roll for use in a roll and disc combination as illustrated in FIGS. 3 and 4 should be between about 3 and 12 inches preferably between 5 and 8 inches. The height of gap or clearence G (see FIG. 5) of the nip for either the disc and roll combination or the pair of rolls embodiments will depend on the maximum tickness chip to be fed to the nip and the thickness of the treated chips or spacing between fissures in the treated chips. Generally the nips will have gaps G of 0.04 to 0.1 inch. In one design a roll having a diameter of about 5 3/4 inches, with the angle α=15°, depth D=0.06 inch and the spacing C=0.4 inch, the height or gap G was set at 0.06 inch for treating chips having a maximum thickness of slightly over 0.25 inch using a disc with W=0.06 inch, S=0.3 inch, Z=0.06 inch and d=0.055.
As above indicated mating surfaces extend such that the ridges or crowns 26 are substantially perpendicular to the longitudinal axis of the land areas 12 in the nip formed between the surfaces 10 and 22.
In the embodiment illustrated in FIG. 3 and 4 the roll 24 is mounted on a fixed housing in a device somewhat similar to that described in the above referred to Lapointe patent. The chips enter each nip 32 formed between the surface 10 on the rotating disc 34 and the surface 22 on the mating rotating roll 24. The disc 34 as illustrated in FIG. 4 is provided with the spaced land areas 12 in the form of concentric rings extending around the axis of rotation of the disc 34 as shown for example in FIG. 4 with the valleys 14 as formed by the walls 16, 18 and the bottom wall 20 there between.
The preferred crusher arrangement uses the disc 34 and roll 24 in combination similar to that disclosed in the said Lapointe U.S. Pat. No. 3,962,966 modified to use the orienting mechanism described in copending Lapointe application 360,827 filed March 23, 1982. The chips enter through the inlet 36 and are flung by flingers or orienting bars 38 up an inclined orienting surface 40 wherein the chips are laid on their larger area face and the oversized material acted on to reduce it to a certain predetermined thickness to pass out through the outlet passage 42 formed by a pair of substantially parallel walls one on the disc 46 and the other on the housing 44, for further details see the said copending Lapointe application. Chips that pass through outlet 42 are flung from the disc 46 onto the disc 34 for movement through the nip 32 between the disc 34 and the roll 24. A plurality of rolls 24 will be spaced around the circumference of the disc 34 to provide a plurality of spaced apart nips 32 through which chips may pass. The disc 46 preferably is driven by a drive belt 48 at a speed higher than the speed of rotation of the disc 34 which is driven via a belt 50 i.e. the angular velocity of the disc 46 is higher than that of the annular ring formed by the disc 34. The rolls 24 may also be driven via a suitable motor such as that indicated at 52 through suitable belt drives such as that schematically illustrated at 54 in FIG. 3. The roll surface 22 preferably will travel at about the same speed and in substantially the same direction as the surface of the disc through the nip 32. (Obviously the surface 22 of roll 24 at any one time has the same tangential velocity in the direction of movement through the nip while the tangential velocity of the disc varies with the radius and thus provision must be made for the drive for the roll 24 to permit some slippage. Usually the surface 22 will be driven by drive 52 at a velocity substantially equal to the velocity of the surface 10 at the mid point of the nip and obviously if the roll 24 is driven by the surface 10 through a chip the velocity of the roll will vary depending on the radial location of the chip relative to the surface 10.
The surface of the disc 46 preferably will be slightly lower than the wall of the outlet 42 formed by the disc 46 so that the chips pass from the disc 46 and at least part way across the surface 10 in free flight.
If desired the present invention may also be applied to a pair of mating compression rolls such as those indicated at 56 and 58 in FIG. 5, the roll 56 may be provided with a working surface equivalent to the surface 10 as illustrated in FIG. 1 and the roll 58 with a surface configuration such as the surface configuration 22 used on the roll 24. In any event the nip 60 formed between these rolls will function in a manner quite similar to the nip 32 formed between the roll 24 and the annular disc 34. However, the radius of the two rolls may be larger than 12 inches for this embodiment provided the approach angle between the two rolls will accept the chips to be fed thereto.
In any embodiment employing the present invention the concept is to have a pressure applied to the chips at spaced locations longitudinally and transversly of the chips. These spaced locations as indicated by the blackened areas 62 are formed where the land area mates with the apexes 26 of the teeth on the roll 24 as shown in FIG. 6 as the apex 26 of one of the teeth comes down and approaches the surface 10 of say the disc 34, pressure points are developed between the land areas 12 and the adjacent points or crowns 26. The first tooth 26 shown in FIG. 6 provides a first line of areas 62 extending across the chip generally indicated at 64 by a dot dash line, press the chip between the surfaces 10 and 22 at points 62, this pressing tends to force the chip into the valleys between the land areas 12 and thereby deflect the chip beyond the elastic limit while simultanously compressing the chip (depending on the chip thickness) so that internal cracking and fissuring occurs either longitudinally of the chip or transversly of the chip depending on the orientation of the chip relative to the teeth 26 and to the land areas 12 but substantially always along fibre boundries. These pressure points 62 are repeated further along the chip 64 as indicated by the areas 62' as defined by the second tooth 26' the spacing between the pressure points 62 and 62' being determined by the spacing between the tips 26 of the teeth and the rate of rotation of the surface 22 relative to the movement of the chip 64. Obviously the illustration is schematic and the pressure points 62 will take place in the same vertical plane as the pressure points 62' in spaced locations along the surfaces 10 and 22.
In operation the surfaces 10 and 22 cooperate in the nip to apply forces as above described to compress thick chips with localized spaced high pressure points or with thinner chips to apply local spaced compression points without substantially densifying the surface at the chip to resist impregnation yet with sufficient force to fissure and crack oversize chips to render them more easily impregnated and facilitate more uniform impregnation of the chips.
Having described the invention, modifications will be evident to those skilled in the art without departing from the spirit of the invention as defined in the appended claims. | The cooperating surfaces defining a pressing nip in a chip crusher are formed with specific patterns to treat the chips by fissuring to facilitate penetration by cooking chemical for the making of pulp for papermaking and the like. One of the surfaces is provided with a plurality of land areas separated by valleys, the land areas being substantially continuous and extending in the direction of movement of the surface as it passes through the crushing nip. The surface cooperates with the surface of a roll which defines the other side of the nip, the roll surface is provided with a plurality of teeth with the crown of each tooth defining a line preferably extending substantially perpendicular to the direction of movement of the roll surface through the nip. | 17,016 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to and is a continuation-in-part application of U.S. patent application Ser. No. 10/315,338, filed Dec. 9, 2002 now U.S. Pat. No. 6,742,448.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
REFERENCE TO A MICROFICHE APPENDIX
Not Applicable.
BACKGROUND OF THE INVENTION
The present invention relates to compaction apparatus, particularly waste paper balers and to control apparatus therefore responsive to timers and to chamber door, loading door, and/or platen position sensors for detecting possible unsafe operation of the baler and for disabling or otherwise preventing hazardous operation modes. The particular invention is directed to the use of gas springs in association with the movement of the doors on the baler.
SUMMARY OF THE INVENTION
The present invention relates to compaction equipment for commercial and industrial trash compaction and waste paper baler equipment utilized in paper recycling, which are important and widely used tools in the field of waste management. It is very desirable that this equipment be both efficient and reliable. As with all powerful mechanical equipment, safety hazards should be eliminated to the maximum extent possible, recognizing that there is a tendency for human operators to be less careful than they should be.
Although the invention with which this application is concerned is particularly useful in waste paper balers, this background discussion also concerns itself with trash compactors, since they are both widely used and common forms of equipment. The detailed description below will fully describe balers incorporating the invention. The commercial or industrial waste compactor or baler which will be referred to herein as a “compactor” is found in many situations where there are large volumes of waste to be disposed of in landfills or baled for recycling. Thus, compactors including waste compactors and balers are found in shopping centers, industrial complexes, associated with large discount stores or department stores, and in some residential complexes.
The operation and control of balers according to the invention includes features for controlling the starting, stopping, and reversing of the ram used for driving the platen and compressing the waste paper (usually corrugated paper board from packages and cartons). Features such as interlocks and fault detection functions are included which are important to promote and ensure safety at the point of operation of such powerful mechanical equipment. Also of particular note is the use of gas springs to control the movement of the operator activated doors.
Although operational control of compaction apparatus in years past was usually implemented by simple switches and relays, there has been a tendency in recent years to employ computer microprocessors and somewhat sophisticated computer programs and algorithms stored in computer memory in, or associated with, the microprocessor.
U.S. Pat. No. 4,953,109 to Burgis, U.S. Pat. No. 5,016,197 to Neumann, et al., and U.S. Pat. No. 5,558,013 to Blackstone, Jr. are examples of trash compaction systems utilizing rather complex computer programs to implement the desired control system (including fullness determination in compaction apparatus). These may be compared with U.S. Pat. No. 3,802,335 to Longo, U.S. Pat. No. 4,643,087 to Fenner, et al., and U.S. Pat. No. 6,055,902 to Harrop, et al., which do not employ computer microprocessors but execute simple logic with electrical relays.
Compactors including waste compactors and balers are typically exposed to harsh environments including wide ranges of temperatures and potential exposure to power surges. In addition, it is very important that the compaction equipment operate reliably and operate in a safe manner and not be subject to malfunction because of failure or error conditions in its electrical controls. For that reason, there are many users and others who consider that a relatively simply relay based control system has advantages with regard to reliability, durability, and safety over microprocessor controlled by complex software.
Compactors of the present invention have advantages of simple electromechanical related based control systems as shown in U.S. Pat. No. 6,055,902, disclosure of which is incorporated herein by reference, and at the same time provide an advantage of simple maintainability and low component cost that previous electromechanical related based control systems do not provide.
Included in the operating and control system are combination magnetic locks and position sensors which operate effectively for locking, releasing, and sensing the position of the loading door and the bale chamber door while reducing the total number of sensors and/or interlocks needed in the system.
The present invention departs from the teaching of prior art waste baler paper systems by providing apparatus which is simple, durable, reliable, and capable of being programmed with special features and which provides safe and uncomplicated operation for operating personnel. An important feature of the present invention is the employment of programmable electronic relay networks in a manner to achieve the simplicity and reliability of electrical relay based control systems while achieving the flexibility, programmability, and reduced component costs associated with electromechanical relay or solid state relay control networks.
In addition to providing the features and advantages referred to above, it is an object of the present invention to provide compaction apparatus such as waste paper balers which have the advantages of simple relay-implemented control systems including a safety interlock feature for the bale chamber door, and the loading door while obtaining the advantages of programming flexibility, increased reliability, and reduced component costs.
It is another object of the present invention to utilize combination electromagnetic lock and sensor units for providing control signals to the programmable relay network and receiving control signals from the programmable relay network, thereby reducing the mechanical and electrical elements associated with the control system.
It is yet another object of the present invention to provide waste paper balers with controls utilizing programmable relay networks for timing functions which would otherwise require separate timing elements with less adjustability, greater cost, and greater assembly expense.
It is a further object of the present invention to provide a programmable relay control system for waste paper balers which maximizes simplicity of operation while assuring that electromagnetic interlocks and other safety features prevent improper or unintended operation which could cause property damage or personal injury.
Yet a further object of the present invention is the provision for a damped movement for the operator controlled doors of the baler to provide smoother operation of the doors for improved safety, simplification of operation, and reliability.
In addition to the features and advantages of the baler apparatus according to the invention described above, further advantages thereof will be apparent from the following description in conjunction with the appended drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is an isometric view of a baler according to the present invention;
FIG. 2 is an isometric view of the apparatus of FIG. 1 broken away to show functional elements thereof;
FIG. 3 is an enlarged view of the control panel from FIG. 1 ;
FIGS. 4A through 4E is a diagram of one embodiment of programmable relay configuration for controlling the baler of FIGS. 1 and 2 ;
FIG. 5 is a schematic circuit diagram showing connections of the programmable relay and other electrical components of the baler of FIGS. 1 , 2 , and 3 ;
FIG. 6 is an isometric view of a baler according to the present invention defining the detail A;
FIG. 7 is a magnified view of the Detail A area shown in FIG. 6 ;
FIG. 8 is an alternative schematic circuit diagram showing connections of the programmable relay and other electrical components of the baler of FIGS. 1 , 2 , and 3 ; and
FIGS. 9A through 9E is a diagram of another embodiment of programmable relay configuration for controlling the baler of FIGS. 1 and 2 .
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 , 2 , and 3 , a baler 11 according to the invention is shown having a bale chamber 13 to receive waste which is to be compacted. Hydraulic ram 19 of conventional construction serves to raise and lower a platen 21 to provide the compressing force on the waste material for compaction. A loading door 31 slides in vertical tracks to provide a closeable opening for loading waste into the chamber 13 . In FIG. 1 , door 31 is broken away to show the structure behind it but door 31 is shown in its entirety in FIG. 2 .
As shown in FIGS. 6 and 7 , in one preferred embodiment, the loading door 31 is not provided with a conventional counterweight and cable mechanism, but is rather provided with gas springs 81 of conventional form mounted on each side of the loading door 31 . Gas spring 81 is a readily available component, used extensively in the automotive industry for hoods and rear cargo doors on vans and sport utility vehicles.
The detail of the gas spring 81 mounting may be seen in FIGS. 6 and 7 . The loading door 31 is mounted on vertical slides 116 consisting of guide bearings 120 attached to the door 31 that slide on vertical guide rods 118 mounted to the frame 104 . The gas spring 81 includes an extending rod 100 and an outer rod casing 102 . The first casing end 104 is connected to the door by door bracket 108 and the second casing end 106 of the outer rod casing 102 is retained to the frame 104 by means of frame retention bracket 110 .
The extending rod 100 includes a first rod end 112 and a second rod end 114 . The first rod end 112 travels inside the outer rod casing 102 as is known in convention gas springs 81 . The second rod end 114 of the gas spring 81 is connected to the frame 104 by frame bracket 115 . The gas spring 81 is provided with a vertically protected area by its positioning on the outside of the door slides 116 so that items inserted into the compactor will not directly impact the springs 81 .
Each gas spring 81 is chosen for characteristics appropriate to overcome the weight of the door 31 to raise the door 31 to the upward position at any time when the door 31 is not engaged by interlock 78 . One of the main advantages of the gas spring 81 is the ability to control the end travel movement of the loading door 31 and to eliminate the harsh impact that an undamped system provides due to the inertia of the moving door 31 . The preferred gas springs 81 are partially damped gas springs 81 configured with the loading door 31 of particular size and weight so that when the door 31 is released from the electromagnetic interlock 78 , the door 31 will raise at moderate speed smoothly and softly upward to its fully opened position. These damping features are preferably active over at least a portion of the travel of the gas spring 81 . Only moderate damping is needed in the spring 81 for one to five inches of travel prior to the extended position. The damping features should be active over at least one inch of the travel preceding full compression. Preferably, the extent of damping of travel is less than five inches.
Smooth, quiet operation and easy manual pull down is attained by the relation of gas spring 81 characteristics. The door 31 had an associated weight and the corresponding lifting forces of each gas spring 81 can range from a minimum to a maximum. For example, with a typical loading door 31 weighing 55 pounds, each spring 81 force is preferably about 45 pounds each at compression to provide a force of 164 percent of the weight of the door 31 (45×2/55). Springs with a 45 pound maximum force will have a minimum force of approximately 40 pounds each. Thus, these springs provide a minimum gas spring force as a percentage of door weight of about 145 percent (40×2/55). Thus, the gas springs 81 may be chosen using these types of characteristics. In this manner, a pair of gas springs 81 is configured with the loading door 31 to apply an upward force sufficient to raise the loading door 31 to its uppermost position.
While the gas spring 81 arrangement for the loading door 31 is a very desirable feature, the system would be fully operative with some other damped or undamped counterweight or spring arrangement as known in the art.
Unloading opening 33 at the front of the baler 11 is closed by a chamber door 35 having a lock 36 . It is opened when it is desired to access a bale for tying and/or for ejecting it. A dump tray 41 in the bottom of the baler chamber is pivoted at its front edge and allowed to rotate up and forwardly to cause ejection of a finished bale. In the center of back 17 of the baler 11 is a vertically extending dump link bar 43 permanently engaged to the platen 21 to move therewith and selectively engageable with the dump tray 41 . In FIG. 2 the baler 11 is shown with the dump tray 41 broken away to show a dump control link 49 extending fore and aft at the bottom of the dump tray 41 . Control link 49 causes the dump tray 41 to be engaged by the dump link bar 43 (but only when dump link bar 43 is allowed to assume a forward with door 35 not closed). Spring 55 on control link 49 serves to urge it forward except when door 35 is closed.
From the foregoing description, it will be seen that the dump tray 41 is inactive so long as door 35 is closed, but may be raised by the hydraulic ram to eject a bale due to being coupled to platen 21 when door 35 is open. Other known embodiments of bale ejection apparatus or as shown in prior patents could be employed with the control apparatus rather than using the preferred embodiment shown and described above.
An enlarged view of the preferred control panel arrangement for the apparatus is shown in FIG. 3 . A mode selector switch for selecting manual up, manual down, and auto modes of operation is shown at 71 . The function of this switch will be described more fully hereinafter. An off/on/start key switch 73 is positioned below the mode selector switch 71 . A key switch is provided to give control over authorization to operate the baler. Other access control devices such as biometric controls and magnetic card readers could also be used for operator access control for the baler. Electrical operation of switch 73 is more fully explained below.
Below the key switch 73 is a stop/pull to raise button 75 . In addition to serving as an emergency stop switch the stop/pull to raise button 75 serves as the control for manually raising the platen to eject a finished bale. It must be manually pulled out and held by an operator for that operation. This is a safety feature that will be further explained in connection with the control system for the baler. A power on light 89 in this preferred embodiment is associated with the mode selector switch 71 but this is an optional feature and a different form of power on light could be provided if desired. An alternative embodiment places a stop/pull to raise buttom 75 to the right of key switch 73 .
Key switch 73 , among other things, controls the motor 90 with motor starter 92 which provides power for hydraulic ram 19 . The hydraulic system and valves therefore are conventional and their function will be understood by those skilled in the art so that the details thereof are not shown. In the interest of clarity, details of well known elements of balers and other compaction equipment are not shown and described.
The programmable controller for the baler 11 preferably takes the form of a programmable relay 61 (shown in FIG. 5 ) utilizing relay ladder logic as shown in FIGS. 4A through 4E . For an explanation of relay ladder logic processors refer to U.S. Pat. No. 5,777,869, issued Jul. 7, 1998 to Welch and U.S. Pat. No. 6,018,797, issued Jan. 25, 2000 to Schmidt, et al., incorporated herein by reference, and to the references cited in those patents. A very brief explanation of ladder logic processors will be helpful in describing FIGS. 4A through 4E . As seen in FIGS. 4A through 4E , ladder logic programming, as expected, looks like a ladder. It probably has more similarities to a flow chart than the usual multi-line computer program. There are two vertical lines coming down the program chart, one on the left and one on the right. “Rungs” between the lines have conditionals on the left that lead to outputs on the right as will be apparent in FIGS. 4A through 4E . The most used elements in ladder logic are the relay conditionals —| |— and —|/|— and the output coils —( )—. The relay conditional with a space means “closed only if energized” while the relay conditional with the slash means “closed if not energized.” The output coil generally means “if its relay is closed energize this output element.”
The delay timing notations and other notations in the ladder logic chart of FIG. 4A through E are self-explanatory. Ladder rung numbers appear at the left margin.
The operation of the baler control system will be explained first for the “AUTO” mode. The conditions for the initial set-up are:
Mode selector switch 71 is in the center position for “AUTO” mode;
Key switch 73 is in the center position for “POWER ON”;
Stop button 75 is in the center position for normal operation;
Baler chamber door 35 is closed and latched;
Platen 21 is fully retracted;
Loading door 31 is open;
Electromagnetic interlock 78 is energized.
The software under which the ladder logic program runs operates in a scanning mode with a scan cycle on the order of ten milliseconds. The program status of the ladder logic program at set-up is as follows.
Set-up PROGRAM:
Rung 1, I4 closed, I5 closed, M1 energized
Rung 2, I4 open, I5 closed, M2 not energized
Rung 3, I4 closed, I5 open, M3 not energized
Rung 4, M3 closed, I8 open, I1 closed, M4 not energized
Rung 5, M3 open, I8 closed
Rung 6, M4 open, M10 closed, T3 closed, M5 not energized
Rung 7, M5 open, I2 open, T4 closed, M6 not energized
Rung 8, M7 open
Rung 9, M6 open, I7 open
Rung 10, M3 open
Rung 11, I3 open, I8 open, I7 open, M7 not energized
Rung 12, M7 open, I7 open
Rung 13, M6 open, M11 closed, Q1 not energized
Rung 14, Q1 open, M3 closed, Q4 closed, Q3 not energized
Rung 15, Q3 open, T1 not energized
Rung 16, T1 open, M9 (S) not energized
Rung 17, I3 open
Rung 18, M10 open, M9 (R) energized
Rung 19, Q1 closed
Rung 20, Q1 open, M1 closed, M9 open, Q4 not energized
Rung 21, Q4 open
Rung 22, M3 closed, M7 open
Rung 23, M3 open, I3 open
Rung 24, Q4 open, T2 not energized
Rung 25, M3 open, Q1 open
Rung 26, T2 open, M10 not energized
Rung 27, I7 closed, Q4 open, M3 closed
Rung 28, I1 open, M11 closed, T4 closed
Rung 29, Q1 open, T3 not energized
Rung 30, M10 open, I8 open, M12 closed, M11 not energized
Rung 31, M2 open, T1 open
Rung 32, M11 open, T4 closed, M12 closed
Rung 33, I8 open, M3 open, I3 open
Rung 34, M11 closed, Q2 energized
Rung 35, M11 open, T4 not energized
Rung 36, I8 open, T4 open, I1 closed
Rung 37, I7 open
Rung 38, T4 open, I1 open, M12 not energized
Rung 39, M12 open
For transition to the initial operation mode, the loading door 31 is closed and when the striking plate 79 closes with the electromagnetic interlock 78 the loading door 31 locks. The status of the ladder logic program then becomes
AUTO READY OPERATION PROGRAM:
Rung 1, I4 closed, I5 closed, M1 energized
Rung 2, I4 open, I5 closed, M2 not energized
Rung 3, I4 closed, I5 open, M3 not energized
Rung 4, M3 closed, I8 closed, I1 closed, M4 energized
Rung 5, M3 open, I8 open
Rung 6, M4 closed, M10 closed, T3 closed, M5 energized
Rung 7, M5 closed, I2 open, T4 closed, M6 not energized
Rung 8, M7 open
Rung 9, M6 open, I7 open
Rung 10, M3 open
Rung 11, I3 open, I8 closed, I7 open, M7 not energized
Rung 12, M7 open, I7 open
Rung 13, M6 open, M11 closed, Q1 not energized
Rung 14, Q1 open, M3 closed, Q4 closed, Q3 not energized
Rung 15, Q3 open, T1 not energized
Rung 16, T1 open, M9 (S) not energized
Rung 17, I3 open
Rung 18, M10 open, M9 (R) energized
Rung 19, Q1 closed
Rung 20, Q1 open, M1 closed, M9 open, Q4 not energized
Rung 21, Q4 open
Rung 22, M3 closed, M7 open
Rung 23, M3 open, I3 open
Rung 24, Q4 open, T2 not energized
Rung 25, M3 open, Q1 open
Rung 26, T2 open, M10 not energized
Rung 27, I7 closed, Q4 open, M3 closed
Rung 28, I1 open, M11 closed, T4 closed
Rung 29, Q1 open, T3 not energized
Rung 30, M10 open, I8 closed, M12 closed, M11 not energized
Rung 31, M2 open, T1 open
Rung 32, M11 open, T4 closed, M12 closed
Rung 33, I8 closed, M3 open, I3 open
Rung 34, M11 closed, Q2 energized
Rung 35, M11 open, T4 not energized
Rung 36, I8 closed, T4 open, I1 closed
Rung 37, I7 open
Rung 38, T4 open, I1 open, M12 not energized
Rung 39, M12 open
For start operation, the key switch is turned to the right to the “START” position causing the motor powering the hydraulic ram 19 to start and the platen 21 to begin its descent. The ladder logic program status then becomes
AUTO START OPERATION PROGRAM:
Rung 1, I4 closed, I5 closed, M1 energized
Rung 2, I4 open, I5 closed, M2 not energized
Rung 3, I4 closed, I5 open, M3 not energized
Rung 4, M3 closed, I8 closed, I1 closed, M4 energized
Rung 5, M3 open, I8 open
Rung 6, M4 closed, M10 closed, T3 closed, M5 energized
Rung 7, M5 closed, I2 closed, T4 closed, M6 energized
Rung 8, M7 open
Rung 9, M6 closed, I7 open
Rung 10, M3 open
Rung 11, I3 open, I8 closed, I7 open, M7 not energized
Rung 12, M7 open, I7 open
Rung 13, M6 closed, M11 closed, Q1 energized
Rung 14, Q1 closed, M3 closed, Q4 closed, Q3 energized
Rung 15, Q3 closed, T1 energized (timing)
Rung 16, T1 open, M9 (S) not energized
Rung 17, I3 open
Rung 18, M10 open, M9 (R) not energized
Rung 19, Q1 open
Rung 20, Q1 closed, M1 closed, M9 open, Q4 not energized
Rung 21, Q4 open
Rung 22, M3 closed, M7 open
Rung 23, M3 open, I3 open
Rung 24, Q4 open, T2 not energized
Rung 25, M3 open, Q1 closed
Rung 26, T2 open, M10 not energized
Rung 27, I7 open, Q4 open, M3 closed
Rung 28, I1 open, M 11 closed, T4 closed
Rung 29, Q1 closed, T3 energized (timing)
Rung 30, M10 open, I8 closed, M12 closed, M11 not energized
Rung 31, M2 open, T1 open
Rung 32, M11 open, T4 closed, M12 closed
Rung 33, I8 closed, M3 open, I3 open
Rung 34, M11 closed, Q2 energized
Rung 35, M11 open, T4 not energized
Rung 36, I8 closed, T4 open, I1 closed
Rung 37, I7 open
Rung 38, T4 open, I1 open, M12 not energized
Rung 39, M12 open
In the descending operation the safety interlock switch 78 will close as the platen 21 descends about three inches and the key switch 73 should by then be released to return to the center or “POWER ON” position. The status in descent operation is:
DESCENT OPERATION PROGRAM:
Rung 1, I4 closed, I5 closed, M1 energized
Rung 2, I4 open, I5 closed, M2 not energized
Rung 3, I4 closed, I5 open, M3 not energized
Rung 4, M3 closed, I8 closed, I1 closed, M4 energized
Rung 5, M3 open, I8 open
Rung 6, M4 closed, M10 closed, T3 closed, M5 energized
Rung 7, M5 closed, I2 open, T4 closed, M6 energized
Rung 8, M7 open
Rung 9, M6 closed, I7 closed
Rung 10, M3 open
Rung 11, I3 open, I8 closed, I7 closed, M7 not energized
Rung 12, M7 open, I7 closed
Rung 13, M6 closed, M11 closed, Q1 energized
Rung 14, Q1 closed, M3 closed, Q4 closed, Q3 energized
Rung 15, Q3 closed, T1 energized (timing)
Rung 16, T 1 open, M9 (S) not energized
Rung 17, I3 open
Rung 18, M10 open, M9 (R) not energized
Rung 19, Q1 open
Rung 20, Q1 closed, M1 closed, M9 open, Q4 not energized
Rung 21, Q4 open
Rung 22, M3 closed, M7 open
Rung 23, M3 open, I3 open
Rung 24, Q4 open, T2 not energized
Rung 25, M3 open, Q1 closed
Rung 26, T2 open, M10 not energized
Rung 27, I7 open, Q4 open, M3 closed
Rung 28, I1 open, M11 closed, T4 closed
Rung 29, Q1 closed, T3 energized (timing)
Rung 30, M10 open, I8 closed, M12 closed, M11 not energized
Rung 31, M2 open, T1 open
Rung 32, M11 open, T4 closed, M12 closed
Rung 33, I8 closed, M3 open, I3 open
Rung 34, M11 closed, Q2 energized
Rung 35, M11 open, T4 not energized
Rung 36, I8 closed, T4 open, I1 closed
Rung 37, I7 closed
Rung 38, T4 open, I1 open, M12 not energized
Rung 39, M12 open
The platen 21 will continue to be in the descend mode until the accumulated extend time is equal to the preset value of the extend timer, at which time the platen 21 will start retracting. Since this operation is a matter of timing only, the time during which the force of the platen is applied to compact the trash may vary somewhat. The ladder logic program status for retract operation is:
RETRACT OPERATION PROGRAM:
Rung 1, I4 closed, I5 closed, M1 energized
Rung 2, I4 open, I5 closed, M2 not energized
Rung 3, I4 closed, I5 open, M3 not energized
Rung 4, M3 closed, I8 closed, I1 closed, M4 energized
Rung 5, M3 open, I8 open
Rung 6, M4 closed, M10 closed, T3 closed, M5 energized
Rung 7, M5 closed, I2 open, T4 closed, M6 energized
Rung 8, M7 open
Rung 9, M6 closed, I7 closed
Rung 10, M3 open
Rung 11, I3 open, I8 closed, I7 closed, M7 not energized
Rung 12, M7 open, I7 closed
Rung 13, M6 closed, M11 closed, Q1 energized
Rung 14, Q1 closed, M3 closed, Q4 open, Q3 not energized
Rung 15, Q3 open, T1 (timed out) (not energized)
Rung 16, T1 closed, M9 (S) energized, T1 returns to open, M9 (S) not energized
Rung 17, I3 open
Rung 18, M10 open, M9 (R) not energized
Rung 19, Q1 open
Rung 20, Q1 closed, M1 closed, M9 closed, Q4 energized
Rung 21, Q4 closed
Rung 22, M3 closed, M7 open
Rung 23, M3 open, I3 open
Rung 24, Q4 closed, T2 energized (timing)
Rung 25, M3 open, Q1 closed
Rung 26, T2 open, M10 not energized
Rung 27, I7 open, Q4 closed, M3 closed
Rung 28, I1 open, M11 closed, T4 closed
Rung 29, Q1 closed, T3 energized (timing)
Rung 30, M10 open, I8 closed, M12 closed, M11 not energized
Rung 31, M2 open, T1 closed, T1 returns to open
Rung 32, M11 open, T4 closed, M12 closed
Rung 33, I8 closed, M3 open, I3 open
Rung 34, M11 closed, Q2 energized
Rung 35, M11 open, T4 not energized
Rung 36, I8 closed, T4 open, I1 closed
Rung 37, I7 closed
Rung 38, T4 open, I1 open, M12 not energized
Rung 39, M12 open
The platen 21 will retract until it moves to open the safety interlock 78 or when the accumulated retract time is equal to the preset value in the retract timer. In either case, the motor powering the ram 19 will stop and the electromagnetic interlock 78 will de-energize for three seconds to unlock the loading door 31 allowing it to open. The ladder logic program status is as follows:
RETRACT OPERATION PROGRAM:
Rung 1, I4 closed, I5 closed, M1 energized
Rung 2, I4 open, I5 closed, M2 not energized
Rung 3, I4 closed, I5 open, M3 not energized
Rung 4, M3 closed, I8 closed, I1 closed, M4 energized
Rung 5, M3 open, I8 open
Rung 6, M4 closed, M10 open, T3 closed, M5 not energized, M10 returns to closed, M5 energized
Rung 7, M5 open, I2 open, T4 closed, M6 not energized, M5 returns to closed
Rung 8, M7 open
Rung 9, M6 open, I7 open
Rung 10, M3 open
Rung 11, I3 open, I8 closed, I7 open, M7 not energized
Rung 12, M7 open, I7 open
Rung 13, M6 open, M11 open, Q1 not energized
Rung 14, Q1 open, M3 closed, Q4 closed, Q3 not energized
Rung 15, Q3 open, T1 not energized
Rung 16, T1 open, M9 (S) not energized
Rung 17, I3 open
Rung 18, M10 closed, M9 (R) energized, M10 returns to open
Rung 19, Q1 closed
Rung 20, Q1 open, M1 closed, M9 open, Q4 not energized
Rung 21, Q4 open
Rung 22, M3 closed, M7 open
Rung 23, M3 open, I3 open
Rung 24, Q4 open, T2 not energized (timed out)
Rung 25, M3 open, Q1 open
Rung 26, T2 closed, M10 energized, T2 returns to open, M10 not energized
Rung 27, I7 closed, Q4 open, M3 closed
Rung 28, I1 open, M11 open, T4 closed
Rung 29, Q1 open, T3 not energized
Rung 30, M10 closed, I8 closed, M12 closed, M11 energized, M10 returns to open
Rung 31, M2 open, T1 open
Rung 32, M11 closed, T4 closed, M12 closed
Rung 33, I8 closed, M3 open, I3 open
Rung 34, M11 open, Q2 not energized
Rung 35, M11 closed, T4 energized (timing)
Rung 36, I8 closed, T4 open, I1 closed
Rung 37, I7 open
Rung 38, T4 open, I1 open, M12 not energized
Rung 39, M12 open
After the loading door opening mechanism opens the loading door 31 , the electromagnetic interlock 78 will re-energize. The ladder logic program status will be:
END OPERATION MODE PROGRAM:
Rung 1, I4 closed, I5 closed, M1 energized
Rung 2, I4 open, I5 closed, M2 not energized
Rung 3, I4 closed, I5 open, M3 not energized
Rung 4, M3 closed, I8 open, I1 closed, M4 not energized
Rung 5, M3 open, I8 closed
Rung 6, M4 open, M10 closed, T3 closed, M5 not energized
Rung 7, M5 open, I2 open, T4 closed, M6 not energized
Rung 8, M7 open
Rung 9, M6 open, I7 open
Rung 10, M3 open
Rung 11, I3 open, I8 open, I7 open, M7 not energized
Rung 12, M7 open, I7 open
Rung 13, M6 open, M11 closed, Q1 not energized
Rung 14, Q1 open, M3 closed, Q4 closed, Q3 not energized
Rung 15, Q3 open, T1 not energized
Rung 16, T1 open, M9 (S) not energized
Rung 17, I3 open
Rung 18, M10 open, M9 (R) energized
Rung 19, Q1 closed
Rung 20, Q1 open, M1 closed, M9 open, Q4 not energized
Rung 21, Q4 open
Rung 22, M3 closed, M7 open
Rung 23, M3 open, I3 open
Rung 24, Q4 open, T2 not energized
Rung 25, M3 open, Q1 open
Rung 26, T2 open, M10 not energized
Rung 27, I7 closed, Q4 open, M3 closed
Rung 28, I1 open, M11 open, T4 closed, M11 returns to closed
Rung 29, Q1 open, T3 not energized
Rung 30, M10 open, I8 open, M12 closed, M11 not energized
Rung 31, M2 open, T1 open
Rung 32, M11 open, T4 open, M12 closed, T4 returns to closed
Rung 33, I8 open, M3 open, I3 open
Rung 34, M11 closed, Q2 energized
Rung 35, M11 open, T4 not energized (timed out)
Rung 36, I8 open, T4 closed, I1 closed, T4 returns to open
Rung 37, I7 open
Rung 38, T4 closed, I1 open, M12 not energized, T4 returns to open
Rung 39, M12 open
The “AUTO” operation described above is that which would be used in accumulating waste and compacting it in a series of operations to form a bale.
The “MANUAL DOWN” mode of operation described below is used when such is desired, particularly when sufficient waste has been accumulated and compacted to form a bale, so that it can be removed from the baler. The set-up conditions for the “MANUAL DOWN” mode of operation are as follows:
Mode selector switch 71 is in the 60 degree down position for “MANUAL DOWN” mode.
The key switch is in the center position for “POWER ON”.
The stop button 75 is in the center position for normal operation.
The baler chamber door 35 is closed and latched.
The platen 21 is fully retracted.
The loading door 31 is open.
The electromagnetic interlock 78 is energized.
The set-up status for the ladder logic program is
MANUAL DOWN SETUP PROGRAM:
Rung 1, I4 open, I5 closed, M1 not energized
Rung 2, I4 closed, I5 closed, M2 energized
Rung 3, I4 open, I5 open, M3 not energized
Rung 4, M3 closed, I8 open, I1 closed, M4 not energized
Rung 5, M3 open, I8 closed
Rung 6, M4 open, M10 closed, T3 closed, M5 not energized
Rung 7, M5 open, I2 open, T4 closed, M6 not energized
Rung 8, M7 open
Rung 9, M6 open, I7 open
Rung 10, M3 open
Rung 11, I3 open, I8 open, I7 open, M7 not energized
Rung 12, M7 open, I7 open
Rung 13, M6 open, M11 closed, Q1 not energized
Rung 14, Q1 open, M3 closed, Q4 closed, Q3 not energized
Rung 15, Q3 open, T1 not energized
Rung 16, T1 open, M9 (S) not energized
Rung 17, I3 open
Rung 18, M10 open, M9 (R) energized
Rung 19, Q1 closed
Rung 20, Q1 open, M1 open, M9 open, Q4 not energized
Rung 21, Q4 open
Rung 22, M3 closed, M7 open
Rung 23, M3 open, I3 open
Rung 24, Q4 open, T2 not energized
Rung 25, M3 open, Q1 open
Rung 26, T2 open, M10 not energized
Rung 27, I7 closed, Q4 open, M3 closed
Rung 28, I1 open, M11 closed, T4 closed
Rung 29, Q1 open, T3 not energized
Rung 30, M10 open, I8 open, M12 closed, M11 not energized
Rung 31, M2 closed, T1 open
Rung 32, M11 open, T4 closed, M12 closed
Rung 33, I8 open, M3 open, I3 open
Rung 34, M11 closed, Q2 energized
Rung 35, M11 open, T4 not energized
Rung 36, I8 open, T4 open, I1 closed
Rung 37, I7 open
Rung 38, T4 open, I1 open, M12 not energized
Rung 39, M12 open
Preliminary to starting the MANUAL DOWN operation, the loading door 31 is closed. When striking plate 79 closes with the electromagnetic interlock 78 , the loading door 31 locks. The ladder logic program status is
START MANUAL DOWN PROGRAM:
Rung 1, I4 open, I5 closed, M1 not energized
Rung 2, I4 closed, I5 closed, M2 energized
Rung 3, I4 open, I5 open, M3 not energized
Rung 4, M3 closed, I8 closed, I1 closed, M4 energized
Rung 5, M3 open, I8 open
Rung 6, M4 closed, M10 closed, T3 closed, M5 energized
Rung 7, M5 closed, I2 open, T4 closed, M6 not energized
Rung 8, M7 open
Rung 9, M6 open, I7 open
Rung 10, M3 open
Rung 11, I3 open, I8 open, I7 open, M7 not energized
Rung 12, M7 open, I7 open
Rung 13, M6 open, M11 closed, Q1 not energized
Rung 14, Q1 open, M3 closed, Q4 closed, Q3 not energized
Rung 15, Q3 open, T1 not energized
Rung 16, T1 open, M9 (S) not energized
Rung 17, I3 open
Rung 18, M10 open, M9 (R) energized
Rung 19, Q1 closed
Rung 20, Q1 open, M1 open, M9 open, Q4 not energized
Rung 21, Q4 open
Rung 22, M3 closed, M7 open
Rung 23, M3 open, I3 open
Rung 24, Q4 open, T2 not energized
Rung 25, M3 open, Q1 open
Rung 26, T2 open, M10 not energized
Rung 27, I7 closed, Q4 open, M3 closed
Rung 28, I1 open, M11 closed, T4 closed
Rung 29, Q1 open, T3 not energized
Rung 30, M10 open, I8 closed, M12 closed, M11 not energized
Rung 31, M2 closed, T1 open
Rung 32, M11 open, T4 closed, M12 closed
Rung 33, I8 closed, M3 open, I3 open
Rung 34, M11 closed, Q2 energized
Rung 35, M11 open, T4 not energized
Rung 36, I8 closed, T4 open, I1 closed
Rung 37, I7 open
Rung 38, T4 open, I1 open, M12 not energized
Rung 39, M12 open
For MANUAL DOWN START operation, the key switch 73 is turned to the right to the “START” position causing the motor powering the hydraulic ram 19 to start and the platen 21 to begin its descent. The ladder logic program status then becomes:
START MANUAL DOWN OPERATION PROGRAM:
Rung 1, I4 open, I5 closed, M1 not energized
Rung 2, I4 closed, I5 closed, M2 energized
Rung 3, I4 open, I5 open, M3 not energized
Rung 4, M3 closed, I8 closed, I1 closed, M4 energized
Rung 5, M3 open, I8 open
Rung 6, M4 closed, M10 closed, T3 closed, M5 energized
Rung 7, M5 closed, I2 closed, T4 closed, M6 energized
Rung 8, M7 open
Rung 9, M6 closed, I7 open
Rung 10, M3 open
Rung 11, I3 open, I8 closed, I7 open, M7 not energized
Rung 12, M7 open, I7 open
Rung 13, M6 closed, M11 closed, Q1 energized
Rung 14, Q1 closed, M3 closed, Q4 closed, Q3 energized
Rung 15, Q3 closed, T1 energized (timing)
Rung 16, T1 open, M9 (S) not energized
Rung 17, I3 open
Rung 18, M10 open, M9 (R) not energized
Rung 19, Q1 open
Rung 20, Q1 closed, M1 open, M9 open, Q4 not energized
Rung 21, Q4 open
Rung 22, M3 closed, M7 open
Rung 23, M3 open, I3 open
Rung 24, Q4 open, T2 not energized
Rung 25, M3 open, Q1 closed
Rung 26, T2 open, M10 not energized
Rung 27, I7 closed, Q4 open, M3 closed
Rung 28, I1 open, M11 closed, T4 closed
Rung 29, Q1 closed, T3 energized (timing)
Rung 30, M10 open, I8 closed, M12 closed, M11 not energized
Rung 31, M2 closed, T1 open
Rung 32, M11 open, T4 closed, M12 closed
Rung 33, I8 closed, M3 open, I3 open
Rung 34, M11 closed, Q2 energized
Rung 35, M11 open, T4 not energized
Rung 36, I8 closed, T4 open, I1 closed
Rung 37, I7 open
Rung 38, T4 open, I1 open, M12 not energized
Rung 39, M12 open
In the descending operation, the safety interlocks switch 78 will close as the platen 21 descends about three inches and the key switch 73 should by then be released to return to the center or “POWER ON” position. The status in descent operation is
DESCENT OPERATION PROGRAM:
Rung 1, I4 open, I5 closed, M1 not energized
Rung 2, I4 closed, I5 closed, M2 energized
Rung 3, I4 open, I5 open, M3 not energized
Rung 4, M3 closed, I8 closed, I1 closed, M4 energized
Rung 5, M3 open, I8 open
Rung 6, M4 closed, M10 closed, T3 closed, M5 energized
Rung 7, M5 closed, I2 open, T4 closed, M6 energized
Rung 8, M7 open
Rung 9, M6 closed, I7 closed
Rung 10, M3 open
Rung 11, I3 open, I8 closed, I7 closed, M7 not energized
Rung 12, M7 open, I7 closed
Rung 13, M6 closed, M11 closed, Q1 energized
Rung 14, Q1 closed, M3 closed, Q4 closed, Q3 energized
Rung 15, Q3 closed, T1 energized (timing)
Rung 16, T1 open, M9 (S) not energized
Rung 17, I3 open
Rung 18, M10 open, M9 (R) not energized
Rung 19, Q1 open
Rung 20, Q1 closed, M1 open, M9 open, Q4 not energized
Rung 21, Q4 open
Rung 22, M3 closed, M7 open
Rung 23, M3 open, I3 open
Rung 24, Q4 open, T2 not energized
Rung 25, M3 open, Q1 closed
Rung 26, T2 open, M10 not energized
Rung 27, I7 open, Q4 open, M3 closed
Rung 28, I1 open, M11 closed, T4 closed
Rung 29, Q1 closed, T3 energized (timing)
Rung 30, M10 open, I8 closed, M12 closed, M11 not energized
Rung 31, M2 closed, T1 open
Rung 32, M11 open, T4 closed, M12 closed
Rung 33, I8 closed, M3 open, I3 open
Rung 34, M11 closed, Q2 energized
Rung 35, M11 open, T4 not energized
Rung 36, I8 closed, T4 open, I1 closed
Rung 37, I7 closed
Rung 38, T4 open, I1 open, M12 not energized
Rung 39, M12 open
The platen 21 will continue to be in the descent mode until its accumulated extend time is equal to the pre-set value of the extended value at which time the motor powering the ram 19 will stop and the electromagnetic interlock 78 will de-energize to unlock the loading door 31 for three seconds. The ladder logic program for this portion is
COMPLETE MANUAL DESCENT OPERATION PROGRAM:
Rung 1, I4 open, I5 closed, M1 not energized
Rung 2, I4 closed, I5 closed, M2 energized
Rung 3, I4 open, I5 open, M3 not energized
Rung 4, M3 closed, I8 closed, I1 closed, M4 energized
Rung 5, M3 open, I8 open
Rung 6, M4 closed, M10 closed, T3 closed, M5 energized
Rung 7, M5 closed, I2 open, T4 closed, M6 energized
Rung 8, M7 open
Rung 9, M6 closed, I7 closed
Rung 10, M3 open
Rung 11, I3 open, I8 closed, I7 closed, M7 not energized
Rung 12, M7 open, I7 closed
Rung 13, M6 closed, M11 open, Q1 not energized
Rung 14, Q1 open, M3 closed, Q4 closed, Q3 not energized
Rung 15, Q3 closed, T1 energized (timed out), Q3 opens, T1 not energized
Rung 16, T1 closed, M9 (S) energized, T1 returns to open, M9 (S) not energized
Rung 17, I3 open
Rung 18, M10 open, M9 (R) energized
Rung 19, Q1 closed
Rung 20, Q1 open, M1 open, M9 closed, Q4 not energized, M9 returns to open
Rung 21, Q4 open
Rung 22, M3 closed, M7 open
Rung 23, M3 open, I3 open
Rung 24, Q4 open, T2 not energized
Rung 25, M3 open, Q1 open
Rung 26, T2 open, M10 not energized
Rung 27, I7 open, Q4 open, M3 closed
Rung 28, I1 open, M11 open, T4 closed
Rung 29, Q1 open, T3 not energized
Rung 30, M10 open, I8 closed, M12 closed, M11 energized
Rung 31, M2 closed, T1 closed, T1 returns to open
Rung 32, M11 closed, T4 closed, M12 closed
Rung 33, I8 closed, M3 open, I3 open
Rung 34, M11 open, Q2 not energized
Rung 35, M11 closed, T4 energized (timing)
Rung 36, I8 closed, T4 open, I1 closed
Rung 37, I7 closed
Rung 38, T4 open, I1 open, M12 not energized
Rung 39, M12 open
Loading door opening mechanism opens the loading door 31 and after three seconds, the electromagnetic interlock 78 will re-energize. The status preparatory to opening the chamber door to tie the finished bale is as follows:
BEGIN MANUAL DOOR OPERATION
Rung 1, I4 open, I5 closed, M1 not energized
Rung 2, I4 closed, I5 closed, M2 energized
Rung 3, I4 open, I5 open, M3 not energized
Rung 4, M3 closed, I8 open, I1 closed, M4 not energized
Rung 5, M3 open, I8 closed
Rung 6, M4 open, M10 closed, T3 closed, M5 not energized
Rung 7, M5 open, I2 open, T4 closed, M6 not energized
Rung 8, M7 open
Rung 9, M6 open, I7 open
Rung 10, M3 open
Rung 11, I3 open, I8 open, I7 open, M7 not energized
Rung 12, M7 open, I7 open
Rung 13, M6 open, M11 closed, Q1 not energized
Rung 14, Q1 open, M3 closed, Q4 closed, Q3 not energized
Rung 15, Q3 open, T1 not energized
Rung 16, T1 open, M9 (S) not energized
Rung 17, I3 open
Rung 18, M10 open, M9 (R) energized
Rung 19, Q1 closed
Rung 20, Q1 open, M1 open, M9 open, Q4 not energized
Rung 21, Q4 open
Rung 22, M3 closed, M7 open
Rung 23, M3 open, I3 open
Rung 24, Q4 open, T2 not energized
Rung 25, M3 open, Q1 open
Rung 26, T2 open, M10 not energized
Rung 27, I7 closed, Q4 open, M3 closed
Rung 28, I1 open, M11 open, T4 closed, M11 returns to closed
Rung 29, Q1 open, T3 not energized
Rung 30, M10 open, I8 open, M12 closed, M11 not energized
Rung 31, M2 closed, T1 open
Rung 32, M11 open, T4 open, M12 closed, T4 returns to closed
Rung 33, I8 open, M3 open, I3 open
Rung 34, M11 closed, Q2 energized
Rung 35, M11 open, T4 not energized (timed out)
Rung 36, I8 open, T4 closed, I1 closed, T4 returns to open
Rung 37, I7 open
Rung 38, T4 closed, I1 open, M12 not energized, T4 returns to open
Rung 39, M12 open
In preparation for removing a finished bale, the chamber door is opened and the finished bale is tied before instituting the “MANUAL UP” mode.
For operation of the baler control system in the “MANUAL UP” mode, the conditions for the initial set-up are:
Mode selector switch 71 is in the 60 degree UP position selecting “MANUAL UP”.
The key switch 73 is in the center position for “POWER ON”.
The stop button 75 is in the center position for normal operation.
The bale chamber door 35 is open and the finished bale is tied.
The platen 21 is extended to the top of the finished bale.
The loading door 31 is open.
The status of the ladder logic program then becomes:
MANUAL UP SET-UP PROGRAM
Rung 1, I4 closed, I5 open, M1 not energized
Rung 2, I4 open, I5 open, M2 not energized
Rung 3, I4 closed, I5 closed, M3 energized
Rung 4, M3 open, I8 open, I1 closed, M4 energized
Rung 5, M3 closed, I8 closed
Rung 6, M4 closed, M10 closed, T3 closed, M5 energized
Rung 7, M5 closed, I2 open, T4 closed, M6 not energized
Rung 8, M7 open
Rung 9, M6 open, I7 open
Rung 10, M3 closed
Rung 11, I3 open, I8 open, I7 open, M7 not energized
Rung 12, M7 open, I7 open
Rung 13, M6 open, M11 closed, Q1 not energized
Rung 14, Q1 open, M3 open, Q4 closed, Q3 not energized
Rung 15, Q3 open, T1 not energized
Rung 16, T1 open, M9 (S) not energized
Rung 17, I3 open
Rung 18, M10 open, M9 (R) energized
Rung 19, Q1 closed
Rung 20, Q1 open, M1 open, M9 open, Q4 not energized
Rung 21, Q4 open
Rung 22, M3 open, M7 open
Rung 23, M3 closed, I3 open
Rung 24, Q4 open, T2 not energized
Rung 25, M3 closed, Q1 open
Rung 26, T2 open, M10 not energized
Rung 27, I7 closed, Q4 open, M3 open
Rung 28, I1 open, M11 closed, T4 closed
Rung 29, Q1 open, T3 not energized
Rung 30, M10 open, I8 open, M12 closed, M11 not energized
Rung 31, M2 open, T1 open
Rung 32, M11 open, T4 closed, M12 closed
Rung 33, I8 open, M3 closed, I3 open
Rung 34, M11 closed, Q2 energized
Rung 35, M11 open, T4 not energized
Rung 36, I8 open, T4 open, I1 closed
Rung 37, I7 open
Rung 38, T4 open, I1 open, M12 not energized
Rung 39, M12 open
The “MANUAL UP” operation, which also causes ejection apparatus (described elsewhere) to eject the finished bale from the baler, is initiated by the key switch 73 being turned to the right (“START”) position. The motor starter 92 will then start the motor 90 but the platen 21 will not move. The status for the ladder logic program will be:
MANUAL UP STOP OPERATION PROGRAM
Rung 1, I4 closed, I5 open, M1 not energized
Rung 2, I4 open, I5 open, M2 not energized
Rung 3, I4 closed, I5 closed, M3 energized
Rung 4, M3 open, I8 open, I1 closed, M4 energized
Rung 5, M3 closed, I8 closed
Rung 6, M4 closed, M10 closed, T3 closed, M5 energized
Rung 7, M5 closed, I2 closed, T4 closed, M6 energized
Rung 8, M7 open
Rung 9, M6 closed, I7 open
Rung 10, M3 closed
Rung 11, I3 open, I8 open, I7 open, M7 not energized
Rung 12, M7 open, I7 open
Rung 13, M6 closed, M11 closed, Q1 energized
Rung 14, Q1 closed, M3 open, Q4 closed, Q3 not energized
Rung 15, Q3 open, T1 not energized
Rung 16, T1 open, M9 (S) not energized
Rung 17, I3 open
Rung 18, M10 open, M9 (R) not energized
Rung 19, Q1 open
Rung 20, Q1 closed, M1 open, M9 open, Q4 not energized
Rung 21, Q4 open
Rung 22, M3 open, M7 open
Rung 23, M3 closed, I3 open
Rung 24, Q4 open, T2 energized (timing)
Rung 25, M3 closed, Q1 closed
Rung 26, T2 open, M10 not energized
Rung 27, I7 closed, Q4 open, M3 open
Rung 28, I1 open, M11 closed, T4 closed
Rung 29, Q1 closed, T3 energized (timing)
Rung 30, M10 open, I8 open, M12 closed, M11 not energized
Rung 31, M2 open, T1 open
Rung 32, M11 open, T4 closed, M12 closed
Rung 33, I8 open, M3 closed, I3 open
Rung 34, M11 closed, Q2 energized
Rung 35, M11 open, T4 not energized
Rung 36, I8 open, T4 open, I1 closed
Rung 37, I7 open
Rung 38, T4 open, I1 open, M12 not energized
Rung 39, M12 open
When the key switch 73 is released to return to the center or “POWER ON” position, the controller is ready for manual raising of the platen and the status of the ladder logic program is:
MANUAL UP READY PROGRAM
Rung 1, I4 closed, I5 open, M1 not energized
Rung 2, I4 open, I5 open, M2 not energized
Rung 3, I4 closed, I5 closed, M3 energized
Rung 4, M3 open, I8 open, I1 closed, M4 energized
Rung 5, M3 closed, I8 closed
Rung 6, M4 closed, M10 closed, T3 closed, M5 energized
Rung 7, M4 closed, I2 open, T4 closed, M6 energized
Rung 8, M7 open
Rung 9, M6 closed, I7 open
Rung 10, M3 closed
Rung 11, I3 open, I8 open, I7 open, M7 not energized
Rung 12, M7 open, I7 open
Rung 13, M6 closed, M11 closed, Q1 energized
Rung 14, Q1 closed, M3 open, Q4 closed, Q3 not energized
Rung 15, Q3 open, T1 not energized
Rung 16, T1 open, M9 (S) not energized
Rung 17, I3 open
Rung 18, M10 open, M9 (R) not energized
Rung 19, Q1 open
Rung 20, Q1 closed, M1 open, M9 open, Q4 not energized
Rung 21, Q4 open
Rung 22, M3 open, M7 open
Rung 23, M3 closed, I3 open
Rung 24, Q4 open, T2 energized (timing)
Rung 25, M3 closed, Q1 closed
Rung 26, T2 open, M10 not energized
Rung 27, I7 closed, Q4 open, M3 open
Rung 28, I1 open, M11 closed, T4 closed
Rung 29, Q1 closed, T3 energized (timing)
Rung 30, M10 open, I8 open, M12 closed, M11 not energized
Rung 31, M2 open, T1 open
Rung 32, M11 open, T4 closed, M12 closed
Rung 33, I8 open, M3 closed, I3 open
Rung 34, M11 closed, Q2 energized
Rung 35, M11 open, T4 not energized
Rung 36, I8 open, T4 open, I1 closed
Rung 37, I7 open
Rung 38, T4 open, I1 open, M12 not energized
Rung 39, M12 open
In order to raise the platen causing the finished bale to eject, an operator must be at the control panel on the side of the baler where the operator is out of the path of the ejected bale and is in a position to see that the ejection of the bale onto an appropriate carrier is provided for in a safe manner. The operator must pull out on the (STOP/PULL TO RAISE) stop button 75 causing the platen to retract only as long as the operator continues to hold out on the stop/pull to raise button. For the platen to raise the ladder logic program has the following status:
MANUAL UP RAISE PLATEN OPERATION PROGRAM
Rung 1, I4 closed, I5 open, M1 not energized
Rung 2, I4 open, I5 open, M2 not energized
Rung 3, I4 closed, I5 closed, M3 energized
Rung 4, M3 open, I8 open, I1 closed, M4 energized
Rung 5, M3 closed, I8 closed
Rung 6, M4 closed, M10 closed, T3 closed, M5 energized
Rung 7, M5 closed, I2 open, T4 closed, M6 energized
Rung 8, M7 open
Rung 9, M6 closed, I7 open
Rung 10, M3 closed
Rung 11, I3 closed, I8 open, I7 open, M7 not energized
Rung 12, M7 open, I7 open
Rung 13, M6 closed, M11 closed, Q1 energized
Rung 14, Q1 closed, M3 open, Q4 closed, Q3 not energized
Rung 15, Q3 open, T1 not energized
Rung 16, T1 open, M9 (S) energized
Rung 17, I3 closed
Rung 18, M10 open, M9 (R) not energized
Rung 19, Q1 open
Rung 20, Q1 closed, M1 open, M9 closed, Q4 energized
Rung 21, Q4 open
Rung 22, M3 open, M7 open
Rung 23, M3 closed, I3 closed
Rung 24, Q4 open, T2 energized (timing)
Rung 25, M3 closed, Q1 closed
Rung 26, T2 open, M10 not energized
Rung 27, I7 closed, Q4 open, M3 open
Rung 28, I1 open, M11 closed, T4 closed
Rung 29, Q1 closed, T3 energized (timing)
Rung 30, M10 open, I8 open, M12 closed, M11 not energized
Rung 31, M2 open, T1 open
Rung 32, M11 open, T4 closed, M12 closed
Rung 33, I8 open, M3 closed, I3 closed
Rung 34, M11 closed, Q2 energized
Rung 35, M11 open, T4 not energized
Rung 36, I8 open, T4 open, I1 closed
Rung 37, I7 open
Rung 38, T4 open, I1 open, M12 not energized
Rung 39, M12 open
If the button is released, the platen will stop and the status of the ladder logic program will be:
STOP PLATEN RAISE OPERATION PROGRAM
Rung 1, I4 closed, I5 open, M1 not energized
Rung 2, I4 open, I5 open, M2 not energized
Rung 3, I4 closed, I5 closed, M3 energized
Rung 4, M3 open, I8 open, I1 closed, M4 energized
Rung 5, M3 closed, I8 closed
Rung 6, M4 closed, M10 closed, T3 closed, M5 energized
Rung 7, M5 closed, I2 open, T4 closed, M6 energized
Rung 8, M7 open
Rung 9, M6 closed, I7 open
Rung 10, M3 closed
Rung 11, I3 open, I8 open, I7 open, M7 not energized
Rung 12, M7 open, I7 open
Rung 13, M6 closed, M11 closed, Q1 energized
Rung 14, Q1 closed, M3 open, Q4 closed, Q3 not energized
Rung 15, Q3 open, T1 not energized
Rung 16, T1 open, M9 (S) not energized
Rung 17, I3 open
Rung 18, M10 open, M9 (R) not energized
Rung 19, Q1 open
Rung 20, Q1 closed, M1 open, M9 closed, Q4 not energized
Rung 21, Q4 open
Rung 22, M3 open, M7 open
Rung 23, M3 closed, I3 open
Rung 24, Q4 open, T2 energized (timing)
Rung 25, M3 closed, Q1 closed
Rung 26, T2 open, M10 not energized
Rung 27, I7 closed, Q4 open, M3 open
Rung 28, I1 open, M11 closed, T4 closed
Rung 29, Q1 closed, T3 energized (timing)
Rung 30, M10 open, I8 open, M12 closed, M11 not energized
Rung 31, M2 open, T1 open
Rung 32, M11 open, T4 closed, M12 closed
Rung 33, I8 open, M3 closed, I3 open
Rung 34, M11 closed, Q2 energized
Rung 35, M11 open, T4 not energized
Rung 36, I8 open, T4 open, I1 closed
Rung 37, I7 open
Rung 38, T4 open, I1 open, M12 not energized
Rung 39, M12 open
When the accumulated retract time is equal to the reset value in the retract timer, the motor powering ram 19 will stop, concluding the “MANUAL UP” operation. The status of the ladder logic program will be:
MANUAL UP END OPERATION PROGRAM
Rung 1, I4 closed, I5 open, M1 not energized
Rung 2, I4 open, I5 open, M2 not energized
Rung 3, I4 closed, I5 closed, M3 energized
Rung 4, M3 open, I8 open, I1 closed, M4 energized
Rung 5, M3 closed, I8 closed
Rung 6, M4 closed, M10 open, T3 closed, M5 not energized, M10 returns to closed
Rung 7, M5 open, I2 open, T4 closed, M6 not energized
Rung 8, M7 open
Rung 9, M6 open, I7 open
Rung 10, M3 closed
Rung 11, I3 open, I8 open, I7 open, M7 not energized
Rung 12, M7 open, I7 open
Rung 13, M6 open, M11 closed, Q1 not energized
Rung 14, Q1 open, M3 open, Q4 closed, Q3 not energized
Rung 15, Q3 open, T1 not energized
Rung 16, T1 open, M9 (S) not energized
Rung 17, I3 open
Rung 18, M10 closed, M9 (R) energized, M10 returns to open
Rung 19, Q1 closed
Rung 20, Q1 open, M1 open, M9 open, Q4 not energized
Rung 21, Q4 open
Rung 22, M3 open, M7 open
Rung 23, M3 closed, I3 open
Rung 24, Q4 open, T2 not energized (timed out)
Rung 25, M3 closed, Q1 open
Rung 26, T2 closed, M10 energized, T2 returns to open, M10 not energized
Rung 27, I7 closed, Q4 open, M3 open
Rung 28, I1 open, M11 closed, T4 closed
Rung 29, Q1 open, T3 not energized
Rung 30, M10 closed, I8 open, M12 closed, M11 not energized, M10 returns to open
Rung 31, M2 open, T1 open
Rung 32, M11 open, T4 closed, M12 closed
Rung 33, I8 open, M3 closed, I3 open
Rung 34, M11 closed, Q2 energized
Rung 35, M11 open, T4 not energized
Rung 36, I8 open, T4 open, I1 closed
Rung 37, I7 open
Rung 38, T4 open, I1 open, M12 not energized
Rung 39, M12 open
When the operator has followed the procedures above, the finished bale should be ejected completing the “MANUAL UP” operation and concluding the cycle so that the “AUTO” mode can be initiated again as described above.
FIG. 5 is a schematic circuit diagram showing the hard wired connections of the programmable relay with other electrical components of the baler of FIGS. 1 and 2 . Programmable relay 61 is the part of the controller for the baler and is a conventional solid-state electronics device readily available and well known as indicated by the referenced patents.
Electrical outputs of programmable relay 61 are labeled Q 1 , Q 2 , Q 3 , and Q 4 . Output Q 1 supplies a control signal to motor starter 92 for the motor 90 powering hydraulic ram 19 for raising and lowering platen 21 (ram 19 and platen 21 being shown in FIG. 1 ). An overload protector 91 is shown in circuit with motor starter 92 .
Output Q4 controls the interlock solenoid shown schematically at 77 . Output Q3 controls the hydraulic extend valve solenoid shown schematically at 93 and output Q2 controls the hydraulic retract valve solenoid shown schematically at 95 .
Programmable relay 61 is provided with power terminals L and N receiving AC power from transformer secondary 85 having a fuse 87 in series therewith for protection thereof. As shown at 73 , off/on/start key switch is configured to provide power from transformer secondary 85 to all elements of the circuit of FIG. 5 in all positions except the off position. Power on condition is indicated by power on light 89 . The three-phase power system for the motor of hydraulic ram 19 is conventional and not shown in detail.
Safety interlock switch 78 is connected to Input 6 . Mode select switch 71 is connected to Inputs 4 and 5 , being closed to both at the center position.
The off/on/start key switch 73 also has a contact and connection to Input 2 . The pull to raise/stop button 75 has contacts connecting input 3 and 1 respectively.
Other operation features may not be readily apparent from the foregoing description. They include the following.
If the stop button is pushed in while the motor is on and if the loading door is closed, the motor will stop and the electromagnetic interlock will de-energize to unlock the loading door. The loading door opening mechanism will open the loading door as it does whenever the electromagnetic interlock is de-energized. The magnetic door interlock will remain un-energized for three seconds and then re-energize.
If the stop button is pushed in while the motor is off and if the loading door is closed, the electromagnetic interlock will de-energize to unlock the loading door. The loading door opening mechanism will open the loading door. The electromagnetic interlock will remain un-energized for three seconds and then re-energize.
If the key switch is moved to the “off” position, all control voltage is off and there is no power to the programmable relay.
If the stop/pull to raise button is pulled out while the motor is running, and if the platen is extended and if the loading door is closed, the platen will shift direction and retract until the accumulated retract time is equal to the preset value in the retract timer. The motor then will stop and the electromagnetic interlock will de-energize to unlock the loading door. The loading door opening mechanism will open the loading door. The electromagnetic interlock will remain un-energized for three seconds and then re-energize.
If the stop/pull to raise button is pulled out while the motor is off and if the key switch is in the “POWER ON” position and if the platen is extended and if the loading door is closed, the motor will start and the platen will retract until the accumulated retract time is equal to the preset value in the retract timer. The motor will stop and the electromagnetic interlock will be de-energized to unlock the loading door. The loading door opening mechanism will open the loading door. The electromagnetic interlock will remain un-energized for three seconds and then re-energized.
FIG. 8 shows an alternative schematic circuit diagram showing connections of the programmable relay and other electrical components of the baler of FIGS. 1 , 2 , and 3 . Note that a top safety interlock switch 122 has been added to the schematic and connected into input contact 17 . Otherwise, the connections of this schematic are very similar to those discussed in FIG. 5 .
FIGS. 9A through 9E show a diagram of another embodiment of the programmable relay configuration for controlling the baler of FIGS. 1 and 2 . The following provides a description of the program running in the controller: Symbols used:
“I” Represents input contacts that are driven by various switches.
“Q” Represents output contacts that drive various solenoids and coils.
“T” Represents timers that when the coil is energized will begin to time and when the accumulated time value is equal to the preset time value the contacts used throughout the program will change state.
“M” Represents relays that when the coil is energized the contacts used throughout the program will change state.
“M”(S)Represents relays that when the coil is energized the contacts used throughout the program will change state and remain that way if the coil is un-energized until it is reset.
“M”(R) Represents relays that when the coil is energized will reset the “M(S)” contacts.
Inputs “I”:
“I1” The Stop contact is a normally closed contact that is controlled by the position of the stop button. Pushed in, the contact will be open. In the center (normal operating position) and when pulled out in the pull to raise position, the contact will be closed. Where used:
Position “IN”
Position “CENTER”
Position “OUT”
Rung #4
OPEN
CLOSED
CLOSED
Rung #29
CLOSED
OPEN
OPEN
Rung #37
OPEN
CLOSED
CLOSED
Rung #39
CLOSED
OPEN
OPEN
“I2” The Start contact is a normally open contact that is controlled by the position of the key start switch. Turned to the left (OFF position), the contact will be open. In the center (POWER ON position), the contact will be open and when turned to the right (START position), the contact will be closed. Where used:
Position “OFF”
Position “POWER ON”
Position “START”
Rung
OPEN
OPEN
CLOSED
#7
“I3” The Raise contact is a normally closed contact that is controlled by the position of the stop button. Pushed in and in the center (normal operating position), the contact will be open. When pulled out in the pull to raise position, the contact will be closed. Where used:
Position “IN”
Position “CENTER”
Position “OUT”
Rung #11
OPEN
OPEN
CLOSED
Rung #18
OPEN
OPEN
CLOSED
Rung #24
OPEN
OPEN
CLOSED
Rung #34
OPEN
OPEN
CLOSED
“I4” The Mode select contact #1 is a normally closed contact that is controlled by the position of the mode selector switch. Turned to the center (AUTO position) up (MANUAL UP position), the contact will be closed. In the down (MANUAL DOWN position), the contact will be open. Where used:
Position “UP”
Position “CENTER”
Position “DOWN”
Rung #1
CLOSED
CLOSED
OPEN
Rung #2
OPEN
OPEN
CLOSED
Rung #3
CLOSED
CLOSED
OPEN
“I5” The Mode select contact #2 is a normally open contact that is controlled by the position of the mode selector switch. Turned to the center (AUTO position), the contact will be closed. In the up (MANUAL UP position), the contact will be open and in the down (MANUAL DOWN position), the contact will be closed. Where used:
Position “UP”
Position “CENTER”
Position “DOWN”
Rung #1
OPEN
CLOSED
CLOSED
Rung #2
OPEN
CLOSED
CLOSED
Rung #3
CLOSED
OPEN
OPEN
“I6” The electromagnetic door lock contacts are normally open contacts that will close when the lock is energized and the strike plate mounted on the loading door is mated to the surface. Where used:
DOOR DOWN
DOOR UP
Rung #4
CLOSED
OPEN
Rung #5
OPEN
CLOSED
Rung #11
CLOSED
OPEN
Rung #16
CLOSED
OPEN
Rung #31
CLOSED
OPEN
Rung #34
CLOSED
OPEN
Rung #37
CLOSED
OPEN
“I7” The Top safety switch contact is a normally open contact that will close when the magnet mounted on the loading door (door is closed) is in proximity to the surface of the switch mounted to a plate on the baler main frame that will open when the platen is retracted. Where used:
PLATEN RETRACTED PLATEN EXTENDED Rung #9 OPEN CLOSED Rung #11 OPEN CLOSED Rung #12 OPEN CLOSED Rung #28 CLOSED OPEN Rung #38 OPEN CLOSED
Outputs “Q”:
The output coil will be energized when the conditions in the rung preceding the coil are in their closed state. When the coil is energized, the contacts used throughout the program will change state (open will close and closed will open).
“Q1” When the coil is energized, the Q1 contacts on the controller will close and energize the motor starter to start the motor. Where used:
Rung #13
COIL
ENERGIZED
UN-ENERGIZED
Rung #14
CLOSED
OPEN
Rung #20
OPEN
CLOSED
Rung #21
CLOSED
OPEN
Rung #26
CLOSED
OPEN
Rung #30
CLOSED
OPEN
“Q2” When the coil is energized, the Q2 contacts on the controller will close and energize the electromagnetic door lock. Where used:
Rung #35
COIL
“Q3” When the coil is energized, the Q3 contacts on the controller will close and energize the extend solenoid on the directional control valve to make the platen extend. Where used:
Rung #14
COIL
ENERGIZED
UN-ENERGIZED
Rung #15
CLOSED
OPEN
“Q4” When the coil is energized, the Q4 contacts on the controller will close and energize the retract solenoid on the directional control valve to make the platen retract. Where used:
Rung #21 COIL ENERGIZED UN-ENERGIZED Rung #14 OPEN CLOSED Rung #22 CLOSED OPEN Rung #25 CLOSED OPEN Rung #28 CLOSED OPEN
Timers “T”:
The timer coil will be energized when the conditions in the rung preceding the coil are in their closed state. When the coil is energized, the contacts used throughout the program will change state (open will close and closed will open) when the coil remains energized until the preset time value is equal to the accumulated time value.
“T1” (Extending timer) When the coil is energized, the platen extend time will be monitored and when the accumulated extend time is equal to the preset time, the contacts used throughout the program will change state. Where used:
Rung #15
COIL
ENERGIZED
UN-ENERGIZED
TIMED OUT
OR TIMING
Rung #16
CLOSED
OPEN
Rung #17
CLOSED
OPEN
Rung #32
CLOSED
OPEN
“T2” (Retracting timer) When the coil is energized, the platen retract time will be monitored and when the accumulated retract time is equal to the preset time, the contacts used throughout the program will change state. Where used:
Rung #25
COIL
ENERGIZED
UN-ENERGIZED
TIMED OUT
OR TIMING
Rung #27
CLOSED
OPEN
“T3” (Max run timer) When the coil is energized, the maximum run time will be monitored and when the accumulated extend time is equal to the preset time, the contacts used throughout the program will change state. Where used:
Rung #30
COIL
ENERGIZED
UN-ENERGIZED
TIMED OUT
OR TIMING
Rung #6
OPEN
CLOSED
“T4” (Unlatch timer) When the coil is energized, the time the electromagnetic door lock is un-energized will be monitored and when the accumulated extend time is equal to the preset time, the contacts used throughout the program will change state. Where used:
Rung #36 COIL ENERGIZED UN-ENERGIZED TIMED OUT OR TIMING Rung #7 OPEN CLOSED Rung #29 OPEN CLOSED Rung #33 OPEN CLOSED Rung #37 CLOSED OPEN Rung #39 CLOSED OPEN
Relays “M”:
The relay coil will be energized when the conditions in the rung preceding the coil are in their closed state. When the coil is energized, the contacts used throughout the program will change state (open will close and closed will open).
“M1” (Auto) When the coil is energized, the M1 contacts used throughout the program will change state. Where used:
Rung #1
COIL
ENERGIZED
UN-ENERGIZED
Rung #21
CLOSED
OPEN
“M2” (Manual down) When the coil is energized, the M2 contacts used throughout the program will change state. Where used:
Rung #2
COIL
ENERGIZED
UN-ENERGIZED
Rung #16
CLOSED
OPEN
Rung #20
OPEN
CLOSED
Rung #32
CLOSED
OPEN
“M3” (Manual up) When the coil is energized, the M3 contacts used throughout the program will change state. Where used:
Rung #3
COIL
ENERGIZED
UN-ENERGIZED
Rung #4
OPEN
CLOSED
Rung #5
CLOSED
OPEN
Rung #10
CLOSED
OPEN
Rung #14
OPEN
CLOSED
Rung #23
OPEN
CLOSED
Rung #24
CLOSED
OPEN
Rung #26
CLOSED
OPEN
Rung #28
OPEN
CLOSED
Rung #34
CLOSED
OPEN
“M4” (Safe to run) When the coil is energized, the M4 contacts used throughout the program will change state. Where used:
Rung #4
COIL
ENERGIZED
UN-ENERGIZED
Rung #6
CLOSED
OPEN
“M5” (Okay to run) When the coil is energized, the M5 contacts used throughout the program will change state. Where used:
Rung #6
COIL
ENERGIZED
UN-ENERGIZED
Rung #7
CLOSED
OPEN
“M6” (Start) When the coil is energized, the M4 contacts used throughout the program will change state. Where used:
Rung #7
COIL
ENERGIZED
UN-ENERGIZED
Rung #9
CLOSED
OPEN
Rung #13
CLOSED
OPEN
“M7” (Raise/Reverse) When the coil is energized, the M7 contacts used throughout the program will change state. Where used:
Rung #11
COIL
ENERGIZED
UN-ENERGIZED
Rung #8
CLOSED
OPEN
Rung #12
CLOSED
OPEN
Rung #23
CLOSED
OPEN
“M9” (Extended latch) When the coil is energized, the M9 contacts used throughout the program will change state. Where used:
Rung #17
LATCH COIL
Rung #19
RESET COIL
LATCHED
RESET
Rung #21
CLOSED
OPEN
“M10” (Retracted) When the coil is energized, the M10 contacts used throughout the program will change state. Where used:
Rung #27
COIL
ENERGIZED
UN-ENERGIZED
Rung #6
OPEN
CLOSED
Rung #19
CLOSED
OPEN
Rung #31
CLOSED
OPEN
“M11” (Unlatch door) When the coil is energized, the M11 contacts used throughout the program will change state. Where used:
Rung #31
COIL
ENERGIZED
UN-ENERGIZED
Rung #13
OPEN
CLOSED
Rung #29
OPEN
CLOSED
Rung #33
CLOSED
OPEN
Rung #35
OPEN
CLOSED
Rung #36
CLOSED
OPEN
“M12” (Reset unlatch) When the coil is energized, the M12 contacts used throughout the program will change state. Where used:
Rung #39
COIL
ENERGIZED
UN-ENERGIZED
Rung #31
OPEN
CLOSED
Rung #33
OPEN
CLOSED
Rung #40
CLOSED
OPEN
From the foregoing discussion, it will be seen that the control circuit and the programmable relay provide for both expected and unexpected operator actions at the control panel thereby preventing problems with a control system function that could require supervisory activity beyond the operator's ability.
From FIGS. 1–9 it will be seen that the control system of the programmable relay and associated components serve to effectively provide all of the functions of the baler including waste acceptance, compaction, and bale ejection in a safe and efficient manner with a minimum of complexity using a relatively small number of interlocking and locking devices.
While the control program and circuit described above is explained in relation to cooperation with a particular form of bale dump tray and ejection mechanism coupling the bale dump tray and the baler platen, its usefulness is not limited to this particular form of baler and ejection mechanism but is suitable with or adaptable to other forms of compaction apparatus.
In addition to the alternative forms of implementation of the apparatus shown, suggested, or described above, it will be apparent to those skilled in the art that other modifications and variations to the apparatus can be employed and accordingly the scope of the invention is not to be limited to the variations explicitly described but is rather to be determined by reference to the appended claims. | A baler utilizing gas springs for controlling the movement of a loading door. Also disclosed is a baler for paper recycling having a control system responsive to switches and digital timers, and an electromagnetic interlock coupling a loading door and a chamber door, said control system including a programmable relay having outputs to motor starter, control valves, and electromagnetic interlock. A mode selection switch enables automatic, manual down, and manual up modes, the latter of which is used to eject a bale. The electromagnetic interlock performs multiple functions reducing the number of components needed in the system, improving reliability and reducing maintenance. | 98,550 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 10/418,536 filed on Apr. 18, 2003. The entire disclosure of the above application is incorporated herein by reference.
TECHNICAL FIELD
This invention relates to a fuel cell stack assembly and more particularly to a bipolar plate assembly having a pair of stamped metal plates bonded together to provide coolant volume therebetween.
BACKGROUND OF THE INVENTION
Fuel cells have been proposed as a power source for many applications. One such fuel cell is the proton exchange member or PEM fuel cell. PEM fuel cells are well known in the art and include an each cell thereof a so-called membrane-electrode-assembly or MEA having a thin, proton conductive, polymeric membrane-electrolyte with an anode electrode film formed on major face thereof and a cathode electrode film formed on the opposite major face thereof. Various membrane electrolytes are well known in the art and are described in such U.S. Pat. Nos. 5,272,017 and 3,134,697, as well as in the Journal of Power Sources , vol. 29 (1990) pgs. 367-387, inter alia.
The MEA is interdisposed between sheets of porous gas-permeable, conductive material known as a diffusion layer which press against the anode and cathode faces of the MEA and serve as the primary current collectors for the anode and cathode as well as provide mechanical support for the MEA. This assembly of diffusion layers and MEA are pressed between a pair of electronically conductive plates which serve as secondary current collectors for collecting the current from the primary current collectors and for conducting current between adjacent cells internally of the stack (in the case of bipolar plates) and externally of the stack (in the case of monopolar plates at the end of the stack). Secondary current collector plates each contain at least one active region that distributes the gaseous reactants over the major faces of the anode and cathode. These active regions also known as flow fields typically include a plurality of lands which engage the primary current collector and define therebetween a plurality of grooves or flow channels through which the gaseous reactant flow between a supply header and a header region of the plate at one of the channel and an exhaust header in a header region of the plate at the other end of the channel. In the case of bipolar plates, an anode flow field is formed on a first major face of the bipolar plate and a cathode flow field is formed on a second major face opposite the first major face. In this manner, the anode gaseous reactant (e.g., H 2 ) is distributed over the surface of the anode electric film and the cathode gaseous reactant (e.g., O 2 /air) is distributed over the surface of the cathode electrode film.
Various concepts have been employed to fabricate a bipolar plate having flow fields formed on opposite major faces. For example, U.S. Pat. No. 6,099,984 discloses bipolar plate assembly having a pair of thin metal plates with an identical flow field stamped therein. These stamped metal plates are positioned in opposed facing relationships with a conductive spacer interposed therebetween. This assembly of plates and spacers are joined together using conventional bonding technology such as brazing, welding, diffusion bonding or adhesive bonding. Such bipolar plate technology has proved satisfactory in its gas distribution function, but results in a relatively thick and heavy bipolar plate assembly and thus impacts the gravimetric and volumetric efficiency of the fuel cell stack assembly.
In another example, U.S. Pat. No. 6,503,653 discloses a single stamped bipolar plate in which the flow fields are formed in opposite major faces thereof to provide a non-cooled bipolar plate. A cooled bipolar plate using this technology again requires a spacer element interposed between a pair of stamped plates, thereby increasing the thickness and weight of the cooled plate assembly. U.S. Pat. No. 6,503,653 takes advantage of unique reactant gas porting and staggered seal arrangements for feeding the reactant gases from the header region through the port in the plate to the flow field formed on the opposite side thereof. This concept is very desirable in terms of cost but its design constraints on flow fields may rule out some application. Furthermore, this design concept does not lend itself readily to providing an internal cooling flow.
Applications with high powered density requirements need cooling in about every other fuel cell. Thus, there is an ever present desire to refine the design of a bipolar plate assembly to be efficiently used in a fuel cell stack to provide a high gravimetric power density, high volumetric power density, low cost and higher, reliability. The present invention is directed to a stamped fuel cell bipolar plate that offers significant flow field design flexibility while minimizing the weight and thickness thereof.
SUMMARY OF THE INVENTION
The present invention is directed to a bipolar plate assembly having two thin metal plates formed with conventional stamping processes and then joined together. In another aspect, the centerlines of the flow fields must be arranged to align the channels for plates on opposite sides of the MEA wherever possible to further provide uniform compression of the diffusion media. In another aspect, the configuration of the flow fields formed in each of the two stamped metal plates are such that the contact area therebetween is maximized to enable the bipolar plate assembly to carry compressive loads present in a fuel cell stack. Thus, the centerlines of the flow fields formed in the two thin metal plates of a bipolar plate assembly need to be coincident in many places to carry the compressive loads. However, since the interior volume defined between the plates and their context areas form an interior cavity for coolant flow, it is necessary to have sufficient instances where the centerlines are not coincident in order to allow adequate coolant flow. The present invention achieves these two apparently opposing objections with a unique flow field design in which adjoining areas of the flow channels adjacent the inlet and exhaust margins provide a geometric configurations to provide the desired flow field and contact area requirements.
The present invention provides a bipolar plate assembly which includes a pair of plates having reactant gas flow fields defined by a plurality of channels formed the outer faces of the plates. The plates are arranged in a facing relationship to define an interior volume therebetween. A coolant flow field is formed in an interior volume defined between the pair of plates at the contact interface therebetween. The coolant flow field has an array of discrete flow disruptors adjacent a coolant header inlet and a plurality of parallel channels interposed between the array and the coolant exhaust header. Fluid communication is provided from the coolant inlet header through the coolant flow field to the coolant exhaust header.
The present invention also provides a separator plate which includes a thin plate having an inlet margin with a pair of lateral inlet headers and a medial inlet header formed therethrough, an exhaust margin including a pair of lateral exhaust headers and a medial exhaust header formed therethrough and a reactant gas flow field formed on a major face of the thin plate. The reactant gas flow field includes a first set of flow channels, each having an inlet leg with a first longitudinal portion in fluid communication with one of the pair of lateral inlet headers and a first transverse portion, a serpentine leg having a first end in fluid communication with the first transverse portion and a second end and an exhaust leg having a second transverse portion in fluid communication with the second end of the serpentine leg and a second longitudinal portion in fluid communication with one of the pair of lateral exhaust headers. Either of the transverse portion of the inlet leg adjacent the medial inlet header and the transverse portion of the exhaust leg adjacent the medial exhaust header may be defined by an undulating flow channel.
These and other aspects of the present invention provide a bipolar plate assembly which increases the design flexibility in terms of flow field options, while achieving the cooling requirements as well as providing a relatively high gravimetric power density and high volumetric power density from a fuel cell stack incorporating the bipolar plate assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood when considered in the light of the following detailed description of a specific embodiment thereof which is given hereafter in conjunction with the several figures in which:
FIG. 1 is a schematic isometric exploded illustration of a fuel cell stack;
FIG. 2 is an isometric exploded illustration of a bipolar plate assembly and seal arrangement in accordance with the present invention;
FIG. 3 is a plan view of the flow field formed in the major face of an anode plate in the bipolar plate assembly shown in FIG. 2 ;
FIG. 4 is a plan view of the flow field formed in the major face of a cathode plate in the bipolar plate assembly shown in FIG. 2 ;
FIG. 5 is a plan view showing the contact areas at the interface between the anode and cathode plates;
FIG. 6 is an isometric view of multiple cells within the fuel cell stack and further showing a section taken through the cathode header;
FIG. 7 is a cross-section taken through the coolant header and showing the coolant flow path;
FIG. 8 is a cross-section taken through the anode header and showing the anode gas flow path; and
FIG. 9 is a cross-section taken through the cathode header and showing the cathode flow path.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. With reference to FIG. 1 , a two-cell stack (i.e., one bipolar plate) is illustrated and described hereafter, it being understood that a typical stack will have many more such cells and bipolar plates. FIG. 1 depicts a two-cell bipolar PEM fuel cell stack 2 having a pair of membrane-electrode-assemblies (MEAs) 4 , 6 separated from each other by an electrically conductive, liquid-cooled bipolar plate 8 . The MEAs 4 , 6 and bipolar plate 8 are stacked together between clamping plates 10 , 12 and monopolar end plates 14 , 16 . The clamping plates 10 , 12 are electrically insulated from the ends plate 14 , 16 . The working face of each monopolar end plates 14 , 16 , as well as both working faces of the bipolar plate 8 contain a plurality of grooves or channels 18 , 20 , 22 , 24 defining a so-called “flow field” for distributing fuel and oxidant gases (i.e., H 2 and O 2 ) over the faces of the MEAs 4 , 6 . Nonconductive gaskets 26 , 28 , 30 and 32 provide seals and electrical insulation between the several components of the fuel cell stack. Gas-permeable diffusion media 34 , 36 , 38 , 40 press up against the electrode faces of the MEAs 4 , 6 . The end plates 14 , 16 press up against the diffusion media 34 , 40 respectfully, while the bipolar plate 8 presses up against the diffusion media 36 on the anode face of MEA 4 , and against the diffusion media 38 on the cathode face of MEA 6 .
With reference to FIG. 2 , the bipolar plate assembly 8 includes two separate metal plates 100 , 200 which are bonded together so as to define a coolant volume therebetween. The metal plates 100 , 200 are made as thin as possible (e.g., about 0.002-0.02 inches thick) and are preferably formed by suitable forming techniques as is known in the art. Bonding may, for example, be accomplished by brazing, welding diffusion bonding or gluing with a conductive adhesive as is well known in the art. The anode plate 100 and cathode plate 200 of a bipolar plate assembly 8 are shown having a central active region that confronts the MEAs 36 , 38 (shown in FIG. 1 ) and bounded by inactive regions or margins.
The anode plate 100 has a working face with an anode flow field 102 including a plurality of serpentine flow channels for distributing hydrogen over the anode face of the MEA that it confronts. Likewise, the cathode plate 200 has a working face with a cathode flow field 202 including a plurality of serpentine flow channels for distributing oxygen (often in the form of air) over the cathode face of the MEA that it confronts. The active region of the bipolar plate 8 is flanked by two inactive border portions or margins 104 , 106 , 204 , 206 which have openings 46 - 56 formed therethrough. When the anode and cathode plates 100 , 200 are stacked together, the openings 46 - 56 in the plates 100 , 200 are aligned with like openings in adjacent bipolar plate assemblies. Other components of the fuel cell stack 2 such as gaskets 26 - 32 as well as the membrane of the MEAs 4 and 6 and the end plates 14 , 16 have corresponding openings that align with the openings in the bipolar plate assembly in the stack, and together form headers for supplying and removing gaseous reactants and liquid coolant to/from the stack.
In the embodiment shown in the figures, opening 46 in a series of stacked plates forms an air inlet header, opening 48 in series of stacked plates forms an air outlet header, opening 50 in a series of stacked plates forms a hydrogen inlet header, openings 52 in a series of stacked plates forms a hydrogen outlet header, opening 54 in a series of stacked plates forms a coolant inlet header, and opening 56 in a series of stacked plates forms a coolant outlet header. As shown in FIG. 1 , inlet plumbing 58 , 60 for both the oxygen/air and hydrogen are in fluid communication with the inlet headers 46 , 50 respectively. Likewise, exhaust plumbing 62 , 64 for both the hydrogen and the oxygen/air are in fluid communication with the exhaust headers 48 , 52 respectively. Additional plumbing 66 , 68 is provided for respectively supplying liquid coolant to and removing coolant from the coolant header 54 , 56 .
FIG. 2 illustrates a bipolar plate assembly 8 and seals 28 , 30 as they are stacked together in a fuel cell. It should be understood that a set of diffusion media, an MEA, and another bipolar plate (not shown) would underlie the cathode plate 200 and seal 30 to form one complete cell. Similarly, another set of diffusion media and MEAs (not shown) will overlie the anode plate 100 and seal 28 to form a series of repeating units or cells within the fuel cell stack. It should also be understood that an interior volume or coolant cavity 300 is formed directly between anode plate 100 and cathode plate 200 without the need of an additional spacer interposed therebetween.
Turning now to FIG. 3 , a plan view of the anode plate 100 is provided which more clearly shows the anode flow field 102 formed in the working face of anode plate 100 . As can also be clearly seen in FIG. 3 , the inlet margin 104 of anode plate 100 has a pair of lateral inlet headers 46 and 50 to transport cathode gas and anode gas, respectively, through the fuel cell stack and a medial inlet header 54 to transport a coolant through the stack. Similarly, the exhaust margin 106 has a pair of lateral exhaust headers 48 , 52 for transporting anode affluent and cathode affluent, respectively through the fuel cell stack, and a medial exhaust header 56 for transporting coolant through the fuel cell stack.
The anode flow field 102 is defined by a plurality of channels formed to provide fluid communication along a tortuous path from the anode inlet header 50 to the anode exhaust header 52 . In general, the flow channels are characterized by an inlet leg 108 having a longitudinal portion 110 with a first end in fluid communication with the anode inlet header 50 and a second end in fluid communication with a transverse portion 112 . As presently preferred, the transverse portion 112 of the inlet leg 108 branches to provide a pair of transverse inlet legs associated with each longitudinal portion 110 . Furthermore, the path of these transverse inlet portions 112 undulate within the plane of the anode plate 100 to provide an undulating flow channel adjacent the coolant inlet header 54 as represented in the area designated 114 . The transverse portion 112 of inlet leg 108 is in fluid communication with a serpentine leg 116 . The flow channel 108 further includes an exhaust leg 118 having transverse portions 120 and a longitudinal portion 122 to provide fluid communication from the serpentine leg 116 to the anode exhaust header 52 . The exhaust leg portion 118 is configured similar to the inlet leg portion 108 in that each longitudinal portion 122 is associated with a pair of transverse portions 120 . The path of the transverse exhaust portions 120 undulate within the plane of the anode plate 100 to provide an undulating flow channel adjacent the coolant exhaust header 56 as represented in the area designated 124 .
Turning now to FIG. 4 a plan view of the cathode plate 200 is provided which more clearly shows the cathode flow field 202 formed in the working face of cathode plate 200 . As can also be clearly seen in FIG. 4 , the inlet margin 204 of cathode plate 200 has a pair of lateral inlet headers 46 , 50 to transport cathode gas and anode gas, respectively, through the fuel cell stack and a medial inlet header 54 to transport a coolant through the stack. Similarly, the exhaust margin 206 has a pair of lateral exhaust headers 48 , 52 for transporting anode affluent and cathode affluent, respectively through the fuel cell stack, and a medial exhaust header 56 for transporting coolant through the fuel cell stack.
The cathode flow field 202 is defined by a plurality of channels formed to provide fluid communication along a tortuous path from the cathode inlet header 46 to the cathode exhaust header 48 . In general, the flow channels are characterized by an inlet leg 208 having a longitudinal portion 210 with a first end in fluid communication with the cathode inlet header 46 and a second end in fluid communication with a transverse portion 212 . A single transverse portion 212 is associated with each longitudinal portion 210 . Thus, the transverse portion 212 of the inlet leg 208 does not branch off to provide a pair of transverse inlet portions as the transverse portion 112 of anode inlet leg 108 . The path of the transverse inlet portions 212 undulate within the plane of the cathode plate to provide an undulating flow channel adjacent the coolant inlet header 54 as represented in the area designated 214 . The flow channel further includes a serpentine leg 216 which is in fluid communication with the end of transverse inlet portion 212 . The flow channel further includes an exhaust leg 218 having a transverse portion 220 and a longitudinal portion 222 . The exhaust leg portion 218 is configured similar to the inlet leg portion 208 to provide fluid communication from the serpentine leg 216 to the cathode exhaust header 48 . The path of the transverse exhaust portions 220 undulate within the plane of the cathode plate to provide an undulating flow channel adjacent the coolant exhaust header 56 as represented in the area designated 224 .
Referring now to FIGS. 2 and 6 , the anode plate 100 and the cathode plate 200 are positioned in an opposed facing relationship such that the various inlet and exhaust headers are in alignment. The anode plate 100 and the cathode plate 200 are then joined together using conventional techniques. The centerlines of the anode flow fields 102 and cathode flow fields 202 are arranged to align the flow channels on opposing plates (e.g. on opposite sides of the MEA as shown in FIG. 6 ) wherever possible to provide uniform compression of the diffusion media and the MEA. Likewise, the contact area between the adjacent, joined anode plate 100 and cathode plate 200 (as shown in FIG. 2 ) are coincident in many places so as to carry the compressive loads imposed on the fuel cell stack. Specifically, the flow channels of anode flow field 102 formed in the working face of anode plate 100 provide a complimentary contact surface on an inner face opposite the working face. Similarly, the flow channels of the cathode flow field 202 formed in the working face of the cathode plate 200 define a contact surface on an inner face of the cathode plate 200 . Thus, when the anode plate 100 and cathode plate 200 are joined together, an interference or contact area is defined therebetween.
With reference now to FIG. 5 , the contact area between the anode plate 100 and the cathode plate 200 defines a coolant flow field 302 between an inlet margin 304 and an exhaust margin 306 within coolant cavity 300 . The coolant flow field 302 includes an array of discrete flow disruptors 308 adjacent the coolant inlet manifold 54 formed at the interface of the anode inlet legs 108 and the cathode inlet legs 208 . Similarly, a set of flow disrupters 310 are formed adjacent the coolant exhaust header 56 at the interface of the anode exhaust leg 118 and the cathode exhaust legs 218 . The coolant flow field 302 further includes a plurality of parallel flow channels 312 interposed between the inlet margin 304 and the exhaust margin 306 which are defined at the interface of the serpentine legs 116 and the serpentine legs 216 . In accordance with the configuration of the anode flow field 102 and cathode flow field 202 , the array of discrete flow disruptors 308 extend obliquely from the area of the coolant flow field 302 adjacent the coolant inlet header 54 as indicated by directional arrow 314 into the parallel flow channels 312 . Likewise, the array of discrete flow disruptors 310 extend from the parallel flow channels 312 obliquely towards the coolant exhaust header 56 as indicated by directional arrow 316 .
Turning now to FIGS. 6-9 , the present invention incorporates a staggered seal and an integral manifold configuration for directing fluid communication from the header into the appropriate flow field. For example, the location of the seal beads between the inlet margin 104 , 204 and the flow field structure 102 , 202 step left and right (as seen in FIGS. 7-9 ) for each successive layer. Thus, the seal position shifts to provide fluid communication therebetween. Ports in the form of holes or slots penetrate vertically through the anode plate 100 or cathode plate 200 to provide means for fluid communication from the header to the flow field. In this manner, the present invention employs a staggered seal concept similar to that disclosed in U.S. Pat. No. 6,503,653, which is commonly owned by the assignee of the present invention and whose disclosure is expressly incorporated by reference herein. This approach allows the combined seal thicknesses to equal the repeat distance minus the thickness of the anode plate and cathode plate. This approach also provides an advantage over other conventional fuel cell stack design in which the thickness available for seals is reduced by the height required for the fluid passage from the header region to the active area region. By utilizing a staggered seal concept, the present invention affords the use of thicker seals which are less sensitive to tolerance variations.
The present invention further improves upon the staggered seal concept disclosed in U.S. Pat. No. 6,503,653 with the use of separate anode plate 100 and cathode plate 200 in each bipolar plate assembly. Specifically, a second plate enables the use of an integral manifold with the space between the plates. Reactant gases or coolant fluid can now enter on the top side of the upper plate, travel between the upper and lower plate through such integral manifolds and then enter the lower side of the upper plate to feed the bottom side of the MEA. As a result, the width of the region where the reactant gases enter the flow field is twice as wide as that disclosed in U.S. Pat. No. 6,503,653, thereby lowering the overall pressure drop across a given flow field. This aspect of the present invention is best illustrated in FIGS. 7-9 . Specifically, as illustrated in FIG. 7 , the coolant flow path is indicated by the arrows A showing flow from the coolant header (not shown) between the anode plate 100 and the cathode plate 200 and into the coolant flow field 302 defined therebetween. Similarly, in FIG. 8 the anode gas flow path is indicated by the arrows B showing flow from the anode header (not shown) between the cathode plate 200 and the anode plate 100 and into the anode flow field 102 . Similarly, in FIG. 9 the cathode gas flow path is indicated by the arrows C showing flow from the cathode header (not shown) between the anode plate 100 and the cathode plate 200 and into the cathode flow field 202 . In this manner, a wider manifold region is provided between the header region and the flow field region for each of the fluids passed through the fuel cell stack.
As presently preferred, the design of the bipolar plate assembly further includes an additional feature to support the seal loads given the effect of widening the inlet manifold region between the headers and the active flow fields. Specifically, as best seen in FIGS. 4 and 6 an in-situ support flange 226 extends transversely across the inlet margin through the cathode inlet header 46 , the coolant inlet header 54 and the anode header 50 . This support flange 226 is formed with a wavy or corrugated configuration to allow inlet fluids to freely pass from the header region through the manifold region into the flow field region while at the same time providing through-plane support for the bipolar plate assembly. For example, as best seen in FIG. 6 , the support flange 226 for the cathode plate 200 of the bipolar plate 8 occurs directly over the support flange 126 for the anode plate 100 of the neighboring cell. In this manner, compressive loads are readily transmitted through the fuel cell stack. Alternately, the support function could be provided with grooved blocks of a non-conductive material or similar features which could be formed in the seals to replace the in-situ configuration provided by the transverse support flange.
When using this configuration, these adjacent regions must be insulated since they are at different electrical potentials. Various suitable means are available such as the use of a non-conductive coating such as that disclosed in U.S. application Ser. No. 10/132,058 entitled “Fuel Cell Having Insulated Coolant Manifold” filed on Apr. 25, 2002 which is commonly owned by the assignee of the present invention and the disclosure of which is expressly incorporated by reference. Alternately, a film of non-conductive plastic tape may be interposed for providing electrical isolation therebetween.
The present invention provides a two piece bipolar plate assembly having a coolant flow field formed therebetween. The configuration of the various flow fields are such that the bipolar plate assembly may be a formed of relatively thin material, and still support the required compressive loads of the fuel cell stack. Furthermore, the present invention provides much greater design flexibility in terms of flow field options. In this regard, the present invention provides an improvement in the gravimetric and volumetric power densities of a given fuel cell stack as well as significant material and cost savings.
The description of the invention set forth above is merely exemplary in nature and, thus, variations that do not depart from the jest of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention. | An electro-conductive plate assembly for a fuel cell has a pair of stamped plates joined together to define a coolant volume therein. Each of the pair of stamped plates has a flow field on a major outer surface arranged to maximize the contact area between major inner surfaces of the plates while allowing coolant to distribute and flow readily within the coolant volume. The flow fields formed on the major outer surfaces provide corresponding sets of lands on the major inner surfaces that contact to form a third flow field of the coolant volume. The third flow field formed by the lands includes a plurality of longitudinal channels and an array of flow disruptors. The bipolar plate assembly further includes a seal arrangement and integral manifolds to direct reactant gas and coolant flow through the fuel cell. | 28,634 |
BACKGROUND OF THE INVENTION
The present invention relates to treatment of waste paper, waste paperboard or the like furnish to be recycled.
Due to the ecological and environmental considerations, the cost of virgin fibre and other factors, the optimizing of the recycling of waste paper etc. has now for some time been recognized as a very important aspect of papermaking technology.
One of the problems associated with paper recycling is the removal of print, coating or the like surface treatment to which the paper or cardboard may have been previously subjected. The removal of these components is subject of de-inking technology in paper making. The present invention is particularly, but not exclusively, directed to this field.
Industrial application of the presently available de-inking technologies is associated with relatively heavy use of de-inking chemicals which is expensive and environmentally undesirable. The known methods of deinking of waste paper or the like also require heavy use of cleaning and washing equipment which results in the requirement of a high investment capital. The demands for treatment water are also very high. Energy consumption associated with deinking and cleaning is also relatively high. And the presently available deinking technology has been shown to be inadequate for some furnished, so that the industry is not able to successfully reprocess all of the materials available.
Attempts have been made to alleviate at least some of the problems associated with the deinking of waste paper. For instance, in an article by H. Mamers. "The Siropulper--a new concept in wastepaper recovery" (APPITA, vol. 32, No. 2, pp. 124-128, September, 1978), the use of an explosive release digester is described for defibration purposes which may be used in de-inking. The article suggests that hydrodynamic forces of the explosive discharge combine with the chemical effects of the cooking process to release the ink particles from the fibres, reducing the chemical demand of the process. The increase of the pressure to achieve the required hydrodynamic conditions is effected by injecting pressurized inert gas into a reactor or digester.
The last mentioned method presents advance in that it contains the promise of reduced use of de-inking chemicals thus providing the potential for environmental improvement. The shortening of the processing period is another improvement over previous methods. Yet, certain disadvantages are still associated with this method. In particular, tests conducted in order to determine feasibility of the method described have shown that the quality of the final product of the method often does not reach the desired standard, particularly with respect to the appearance parameters of the final product.
SUMMARY OF THE INVENTION
It is an object of the present invention to further advance the art of recovery of wastepaper and the like material and in particular to maintain the lowest possible use of de-inking chemicals or to even entirely eliminate their use while providing a high quality of the appearance and other parameters of the final product.
In general terms, the present invention provides a method for treatment of waste paper, waste paperboard or the like furnish, or mixtures thereof, containing contaminants that had been introduced in printing, coating or the like surface treatment of the paper, paperboard or the like contained in said furnish, said method comprising the steps of:
i) feeding said furnish into a digester;
ii) feeding into said digester saturated steam at superatmospheric pressure and increasing the pressure in said digester to a superatmospheric pressure, substantially due to the saturated steam, to produce a furnish/steam mixture;
iii) raising the temperature of the furnish contained within the digester, substantially due to the superatmospheric saturated steam introduced in step ii), to a temperature ranging from about 160° C. to about 230° C.;
iv) maintaining said mixture within the digester at said temperature for a predetermined dwell time;
v) discharging the furnish from said digester; and
vi) subjecting the thus discharged furnish to further processing eventually resulting in the production of a recycled sheet of paper, paperboard or the like.
The term "surface treatment" as used in this specification includes techniques such as printing, coating or the like, all well known to those skilled in the art.
The invention is based on a surprising discovery that if wastepaper or the like furnish is cooked in a digester in saturated steam, then the cooking temperatures may be in a substantially higher range than previously accepted temperatures for this stock without impairment of mechanical quality of the final sheet produced from the recycled furnish.
It was further surprising that the high temperatures, in the range as defined above, result in significantly smaller residual contaminant particle sizes than those formed from convention repulping. The degree of reduction of the size of the particles is significant as smaller sized particles are more easily dispersed throughout the sheet. They are less offensive to the eye. Some of them are too small to be seen by the eye.
The smallness of particle size achieved by the inventive process appears to be accompanied by a more effective stripping of the particles from the fiber and, in many instances, in the ability of the papermaking cleaning and screening process to more effectively subsequently remove the particle.
Laboratory tests conducted with the inventive method further show that the need for de-inking chemicals is not only reduced but, in many instances, entirely eliminated, while the final products exhibit visual and other qualities equal to or surpassing those made by presently known methods including the above prior art reference.
In our research, we have found that the temperature, not the pressure used in the digester, is the main factor for achieving the desired quality. The injecting of inert gas was found unnecessary. Also surprisingly, while the explosive discharge from the digester (as opposed to a gradual release of pressure) is advantageous in some instances, it does not appear significantly to influence the de-inking efficiency in other tests conducted.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in detail with reference to the following examples based on laboratory tests, and also referring to the drawings, wherein:
FIG. 1 is a microscopic photograph of a sheet made from a control furnish of coated paper CP 15 C, as referred to hereinafter;
FIG. 2 is a microscopic photograph of a sheet made from furnish CP 15 referred to hereinafter;
FIGS. 3 and 4 are similar to FIGS. 1 and 2, but show the sheets of furnishes CP2C and CP2, respectively;
FIGS. 5 and 6 are diagrammatic representations of the definition of steam treatment severity showing the relationship between temperature and dwell time.
DETAILED DESCRIPTION
Test Conditions
The following data, tables and examples are the results of multiple experiments using multiple furnishes and evaluated by multiple evaluation techniques. As we progressed from one experiment to another we expanded and/or modified our experimental design frequently. Thus it will be seen that not all samples were prepared or tested in the same manner from one experiment to another.
The major evaluation techiques used include:
% Debris--a measure of the reduction in contaminant particle size by measuring the amount (%) of reject upon passage through a 0.006" slotted screen.
Image Analysis--a state-of-the-art computer assisted technique using a contrasting magnifier and integrator to identify and quantify residual contaminants in various size ranges. Data presented includes the averate spot size in mm 2 and the mm 2 dirt/ft 2 paper. Generally speaking, the two readings are most beneficial when interpreted together, but average spot size alone has consistently demonstrated the superiority of products made according to the present invention.
Bauer McNett fiber classification--a screening technique used to classify fiber by length. For purposes of the present experimentation, no significant changes in fiber length classifications suggest no changes or degradation to the fibers during repulping.
Tear, breaking length and stretch--common paper industry standard tests to evaluate strength of various pulps and papers.
Expert panel evaluation--Wisconsin Tissue Mills and Chesapeake Corp. belong to industry leaders in the fields of deinking and secondary fiber usage. Various experts within the two companies were used as panelists for sample evaluation. Evaluation techniques included paired comparisons between variables, paired comparisons between a variable and a control and simple judgement descriptions.
Three different furnishes were selected at first. They were groundwood (GR), coated paper (CP) and office waste (OW). Each furnish was processed independently through explosion pulping process using processing variables of consistency, soak chemistry, pulping temperature and pulping time. The pulps thus produced were made into handsheets. Control handsheets were made from the same furnish. Judgements as to handsheet qualities of the first tests conducted were made by visual estimations only. That is to say, the respective pulps were not tested for fibre strength, or general fibre quality. Rather, the judgements included brightness, whiteness, cleanliness, degree of ink dispersion, and the general overall appearance of the handsheets.
The pulping of the furnish was done by taking 50 g of furnish and subjecting it to a pre-processing chemical soak. The chemistries of the soak included:
a) water only;
b) 0.4% (w/w) of Wetsan WT-225 surfactant (a tradename of SANTEC Chemical Co.--active ingredients include <10% 2-butoxyethanol and <20% phosphoric acid) along with 1.25% (w/w) of caustic soda in water. (This is subsequently referred to as "WTM chemistry" for convenience);
c) 0.4% (w/w) Wetsan WT-225+1.25% (w/w) of caustic soda+2.0% (w/w) of hydrogen peroxide in water; and
d) 4% (w/w) citric acid in water.
The furnish consistency in the chemical soak was either 50% or 30%. Following the soak (generally about 1/2 hour), the pulp samples were inserted into the laboratory reactor.
The laboratory reactor was the product of Stake Technology. It is a jacketed, enclosed stainless steel container with a capacity of about 1 liter. Raw, presoaked material furnish was added via a top Kamyr ball valve. The discharge valve opened into a reservoir for the recovery of the processed material.
Saturated steam (up to 450 psig) was produced by a high pressure boiler and introduced via an accumulator into the reactor. Two inlets of steam were present, one located immediately below the sampling lid and the other immediately above the Kamyr ball valve.
In a typical operation, pre-soaked raw material was introduced into the reactor which was then closed. Saturated steam at a desired temperature (pressure) was added to bring the reactor and sample temperature and pressure to the desired setting. The controlled temperature variables were 160° C., 170° C., 190° C., 210° C. or 230° C. (corresponding to pressures of about 75, 100, 165, 261 and 391 psig, respectively).
For a predetermined duration of 1, 3, 4 or 10 minutes, the pulps were allowed to stay in the reactor chamber. The material was then discharged explosively across the bottom Kamyr valve by the sudden release of pressure from the pressure prevailing in the reactor to the atmospheric pressure in the reservoir. Test were also conducted in which the explosive release was substituted by gradual pressure release (bleed). The reservoir door was subsequently opened to recover the discharged material for further evaluation.
At the same time, the same furnishes were also pulped in a laboratory, according to the standard prior art technique: 30 g of shreddedfibre was placed in 500 ml H 2 O, to which has been added 0.5 ml of a 50% caustic soda solution and 0.1 ml of the Wetsan WT-225. The mixture was agitated by a Lightning mixer at a temperature of 160° F. for 20 minutes to 1 hour and then handsheets were prepared. Such samples were then labelled "controls" (e.g. GR2C).
For certain comparative tests referred to hereafter, the Stake Technology reactor was modified to enable injection of inert gases (such as nitrogen) into the reactor before or during the steam treatment of the raw material in the reactor. Gas was introduced from a regulated gas tank via a gas line which opened into the reactor. This setup permitted the simulation of the de-inking method as described in the reference mentioned at the outset by enabling increase in reactor pressure over the steam pressure used in the treatment.
The samples were removed and carefully washed three times to remove any residual chemicals. The pulping samples thus obtained were then made into handsheets for evaluation.
Paired comparisons of the various cells were then made, based on single processing variable changes. The winners of these comparisons were then judged by a panel of papermaking experts to be "acceptable" or "unacceptable" to Wisconsin Tissue of Menasha, Wis. (WTM) as a processed pulp furnish, and were then further compared to the WTM handsheets controls to see which was better. The ratings were based on visual inspection and included the collective and combined judgements of the experts. The experts noted samples on overall appearance, brightness, degree of uniformity, and general past experience and knowledge of the trade.
As a result of the encouraging observations made from these experiments, additional samples were then prepared and laboratory comparisons were made by checking Canadian Standard Freeness (Freeness, CSF), bulk, brightness and opacity, tear, breaking length, stretch. Bauer McNett fibre classification was used as a fibre length fractionation technique. Other evaluative techniques included image analysis by way of a computer aided technique identifying, quantifying, and integrating particles visible on the surface of a paper as they contrast with the background. The various options of evaluation used from image analysis in the experiments included mean particle size of residual contaminants and total sample area covered by residual contaminants. Other comparisons involved the % debris collected on a 0.006" screen and, as already mentioned, visual ratings by a panel.
Image analysis measurements show that the mean particle size of the residual contaminants had decreased from those evident in the controls. Furthermore, within the experimental ranges tried, there does not appear to be any serious or consistent change in fibre quality as a function of the processing variable used. Thus, it is assumed that the time, temperature and chemical ranges described are valid for the particular furnish.
Visual examination by experts, and image analysis of residual particle size consistently demonstrates the superiority of pulps and papers produced by the art disclosed in this invention. On a case by case basis, one can often actually pinpoint an optimum blend of processing conditions. In other cases it can be seen that extrapolation or interpolation within the available matrix points readily suggest the best processing conditions and/or limits.
The tests referred to in the following examples are taken from laboratory and industrial tests conducted jointly by the assignees of the present application, Stake Technology Ltd. of Norval, Ont., Canada; and Chesapeake Resources Company, of Richmond, Va., U.S.A. For easy reference the samples or cells referred to hereafter are designated with their original numbering allocated during the respective tests. The sample numbers appearing in some of the tables therefore are seemingly random and not in a consecutive order with certain numbers left out depending upon the particular Example mentioned. The particular designation numbers, however, are consistent throughout the disclosure.
EXAMPLE 1
A total of nine (9) different cells of office waste furnish (post-consumer waste, consisting of office files, computer printouts, envelopes, etc.) were run, encompassing variations of two consistencies, two chemical pre-treatments, four pulping temperatures and three dwell times. Seven paired comparisons were made. The trial matrix and cell comparison data are shown in TABLE 1 and TABLE 2.
TABLE 1______________________________________OFFICE WASTE FURNISH TRIAL SOAK SOAK PULPING PULPINGSAMPLE CONSIS- CHEM- TEMPER. TIMENUMBER TENCY ISTRY °C. (MIN)______________________________________18 30 WTM 190 119 30 WTM 170 120 30 WTM 170 327 30 WTM 190 4137 50 WTM 210 4138 50 WTM 230 4139 50 H.sub.2 O 230 4 5 50 WTM 190 1 6 50 H.sub.2 O 190 1______________________________________
Table 1 shows that the tests conducted with samples or cells 18-20; 27; 137-139; 5 and 6 were soaked at different consistencies. The soak chemistry corresponded to the WTM chemistry referred to above. In two cells, Nos. 139 and 6, no chemicals were added to the presoak water. The range of temperatures shown is from 170° to 230° C. and the pulping or dwell time range 1 to 4 minutes.
Various pairs of the above cells were then compared with each other to obtain indication of the superiority of the inventive technology and to compare the possible influence of the different processing variables. Expert panel rankings showed that samples preapred by the inventive technology were superior to the controls and that some directions in processing technology variables could be suggested.
With the preliminary results at hand, a larger scale of laboratory tests were conducted with a number of samples, referred to as runs OW 1-18, which included two comparison runs OW2C and OW13C which were processed by way of standard deinking procedure as referred to above. The results are contained in TABLES 2A and 2B, the latter being the continuation of the former. TABLES 2A, 2B also show the process conditions including the chemicals added.
TABLE 2A__________________________________________________________________________DEINKING OF OFFICE WASTES (PART ONE)DESIG.: OW; RUN NO: 1 2 2C 3 4 5 6__________________________________________________________________________(a) YIELDS (%): 69.32 65.9(b) FREENESS (CSF, ml.): 416 430 558 432 431 469 470(c) BULK (cm.sup.2 /g): 1.97 1.87 2.07 1.91 1.89 1.99 2.12(d) BRIGHTNESS (3.0 g, %): 60.5 -- -- 60.2 61.4 59.3 55.4(e) BRIGHTNESS (1.2 g, %): 61.0 61.5 73.3 60.2 61.7 59.7 55.9(f) OPACITY (%): 92.5 90.3 86.6 93.2 91.9 93.0 93.6(g) HANDSHEET BASE WT (g): 63.3 62.0 59.5 61.8 58.8 59.2 60.7(h) TEAR (mN*M.sup.2 /g): 10.4 10.5 11.8 10.6 10.5 10.2 10.9(i) BREAKING LENGTH (km): 3.7 3.3 3.5 3.7 3.7 3.2 3.8(j) STRETCH (%): 2.4 2.8 2.4 2.5 2.5 2.3 2.0 FIBER CLASSIFICATION (BAUER MCNETT %):(k) +14 7.1 7.1 5.0 5.6 11.2 8.0 113(l) +28 10.7 20.3 16.5 16.6 17.3 19.7 17.2(m) +48 36.0 22.6 22.4 26.2 30.1 29.3 26.5(n) +100 19.3 23.0 19.1 20.0 19.1 19.4 15.8(o) +200 7.9 8.6 6.7 9.3 7.7 7.9 7.0(p) -200 19.0 18.4 30.3 22.3 14.6 15.7 22.2 PROCESSING CONDITIONS:(q) CONSISTENCY: 50 50 5.4 50 50 50 50 CHEMICALS:(r) WETSAN (% W/W) 0.4 0.4 0.4 0.4 -- -- --(s) NaOH (% W/W) 1.25 1.25 1.25 1.25 -- -- --(t) Na.sub.2 CO.sub.3 (% W/W) -- -- -- -- -- -- --(u) TEMPERATURE (°C.): 203 203 71 203 203 203 190(v) TIME (MIN): 2 4 60 6 2 4 6__________________________________________________________________________
TABLE 2B__________________________________________________________________________DEINKING OF OFFICE WASTES (CONT.)# 7 8 9 10 11 12 13 13C 14 15 16 17 18__________________________________________________________________________(a)(b) 423 391 367 415 481 410 442 470 456 474 510 458 454(c) 1.93 1.97 2.09 2.04 2.04 1.85 1.99 2.04 1.99 1.98 1.88 2.11 2.23(d) 64.4 54.2 49.6 59.6 64.1 69.1 -- -- 64.7 63.2 67.5 62.2 66.3(e) 63.9 56.2 47.6 59.8 64.8 69.0 66.3 61.6 65.2 63.0 67.6 63.4 67.9(f) 88.0 94.4 98.3 93.9 90.0 90.6 92.2 88.6 92.1 92.6 89.4 92.9 92.3(g) 60.8 59.8 61.6 57.9 60.4 61.8 60.3 60.4 62.3 61.2 60.8 57.8 58.4(h) 10.6 10.8 7.4 9.0 11.5 10.5 11.4 10.3 11.7 11.9 8.7 11.5 12.2(i) 4.6 3.0 2.2 3.3 3.2 3.6 2.8 3.6 3.2 3.4 3.4 4.0 2.8(j) 2.6 2.5 2.0 2.4 2.6 2.6 2.5 2.2 2.4 2.8 2.7 2.6 2.5(k) 11.1 9.7 7.3 8.7 12.3 10.2 9.0 10.1 9.9 12.2 8.1 9.2(l) 21.5 17.6 16.7 16.5 14.9 16.7 18.8 9.8 16.8 16.2 14.7 14.6(m) 32.5 28.5 27.0 28.4 29.9 28.6 22.4 15.5 27.7 25.9 26.1 26.5(n) 19.0 17.3 18.1 17.9 17.5 16.8 21.7 12.2 17.5 15.6 16.9 17.2(o) 2.8 9.8 11.3 7.8 7.7 7.6 8.7 5.4 7.0 6.8 7.9 8.1(p) 13.1 17.1 19.6 20.7 17.7 20.0 19.4 37.0 21.1 23.3 26.3 24.4(q) 50 50 50 50 50 50 50 5.3 50 50 50 50 50(r) 0.4 0.4 0.4 -- -- -- -- -- 0.4 -- -- 0.4 --(s) 1.25 1.25 1.25 -- -- -- 1.25 1.25 -- 1.25 -- 1.25 1.25(t) -- -- -- -- -- -- * * -- -- * -- *(u) 190 190 190 190 190 190 203 71 203 203 203 210 210(v) 2 4 6 2 4 6 4 60 4 4 4 4 4__________________________________________________________________________ *to pH 11
TABLE 3 shows some results of image analysis conducted for the runs OW1-OW18, utilising a state of the art quantitative photographic analysis of background spots (contaminants). The particular program used differentiated and quantified the spots in classes ranging from 0.0400 mm 2 to 500.00 mm 2 . The data presented in the table includes four important counts used in image analysis. The accumulated field area was 15731.49 sq. mm (0.1693 sq. ft.) for each sample.
TABLE 3______________________________________IMAGE ANALYSIS OF PROCESSED OF OFFICE WASTE AVER. SPOT SQ. MM DIRT/RUN SIZE (mm.sup.2) SQ. FT PAPER______________________________________OW1 0.2886 839OW2 0.2736 903OW3 0.293 746OW4 0.2888 517OW5 0.2878 707OW6 0.2795 577OW7 0.2729 1350OW8 0.286 785OW9 0.4727 324OW10 0.3687 1145OW11 0.2678 429OW12 0.3287 598OW13 0.3368 549OW14 0.3321 804OW15 0.3078 275OW16 0.2944 563OW17 0.2698 400OW18 0.2715 545OW2C 1.5911 987OW13C 0.5148 875______________________________________
The surprising result is to be seen in several aspects apparent from the tables. First, very high temperatures, much higher than the accepted norm--see the control samples, when used under the conditions of the present invention, do not result in noticeably higher degradation of the fibre, as witnessed by the values of items (a) through (p) of TABLES 2. Secondly, the absence of any added chemicals in runs OW4-OW6 and OW10-OW12 further indicates the potential of reduced chemical costs and reduced costs of treatment of effluents. Finally, the substantial shortening of the pulping time is also to be noted. TABLE 3 shows that image analysis demonstrates them to be superior to products of conventional deinking methods in that the mean residual particle size is significantly smaller than those found in the control samples.
EXAMPLE 2
Eight different cells of coated furnish (numbered 21-23, 28, 135, 136, 3 and 4) were run encompassing variations of two (2) consistencies, two (2) chemical pre-treatments, three (3) pulping temperatures and three pulping times. The furnish contained bleached sulphite or sulphate papers, printed or unprinted in sheets, shavings, guillotined books or quire waste. A reasonable percentage of papers containine fine groundwood may be present. Eight (8) paired comparisons were made. Matrix processing variables may be found in Table 5.
TABLE 4______________________________________COATED FURNISH TRIAL MATRIX SOAK SOAKSAMPLE CONSIS- CHEM- PULPING PULPINGI.D. TENCY ISTRY TEMP. TIME______________________________________21 30 WTM 170° 122 30 WTM 170° 323 30 WTM 190° 128 30 WTM 190° 4135 50 H.sub.2 O 190° 4136 50 H.sub.2 O 210° 4 3 50 WTM 190° 1 4 50 H.sub.2 O 190° 1______________________________________
The encouraging results seen by a panel of experts dictated further experimentation.
A subsequent upscale trial of coated furnish was conducted with samples CP1 to CP16, and compared with control runs CP2C and CP15C. The procedure used and results obtained are tabulated in TABLES 5A and 5B, the latter being a continuation of the former. Likewise, TABLE 6 shows the result of the results of image analysis of the samples CP1-CP16. Reference may also be had to FIGS. 1-2 and 3-4 showing microscopic photographs of the sheets made from the respective furnishes. Each unit on the scale shown in the drawings corresponds to 25/1000 mm.
TABLE 5A__________________________________________________________________________DEINKING OF COATING PAPER RUN NO: CP1 CP2 CP2C CP3 CP4 CP5 CP6__________________________________________________________________________(a) YIELDS (%):(b) FREENESS (CSF, ml.): 508 495 531 508 529 538 536(c) BULK (cm.sup.2 /g): 1.67 1.69 1.72 1.70 1.65 1.72 162(d) BRIGHTNESS (3.0 g, %): 54.5 -- -- 54.6 56.4 55.8 55.2(e) BRIGHTNESS (1.2 g, %): 52.6 53.0 49.6 52.6 54.4 54.1 53.8(f) OPACITY (%): 99.3 98.7 99.2 98.8 99.2 99.3 98.5(g) HANDSHEET BASE WT (g): 60.2 62.6 60.0 60.2 61.4 61.5 59.7(h) TEAR (mN*M.sup.2 /g): 10.9 10.7 11.3 11.4 10.8 10.1 10.6(i) BREAKING LENGTH (km): 4.6 3.9 4.3 4.4 3.9 3.7 3.6(j) STRETCH (%): 2.6 2.9 2.4 2.6 2.6 2.7 2.8 FIBER CLASSIFICATION (BAUER MCNETT %):(k) +14 3.4 5.0 3.1 4.7 11.2 2.6 4.3(l) +28 14.5 17.7 14.7 13.5 17.3 11.3 14.9(m) +48 18.6 13.7 13.6 20.9 30.1 12.1 15.0(n) +100 20.3 22.7 18.5 15.8 19.1 17.2 20.6(o) +200 7.7 11.8 8.7 6.6 7.7 8.1 8.6(p) -200 16.5 29.1 41.4 38.5 39.7 48.7 36.6 PROCESS CONDITIONS:(q) CONSISTENCY: 30 30 5.4 30 30 30 30 CHEMICALS:(r) WETSAN (% W/W) 0.4 0.4 0.4 0.4 -- -- --(s) NaOH (% W/W) 1.25 1.25 1.25 1.25 -- -- --(t) Na.sub.2 CO.sub.3 (% W/W) -- -- -- -- -- -- --(u) H.sub.2 O.sub.2 -- -- -- -- -- -- --(v) Na.sub.2 SiO.sub.3 -- -- -- -- -- -- --(w) Na.sub.2 S.sub.2 O.sub.4 -- -- -- -- -- -- --(x) TEMPERATURE (°C.): 190 190 71 190 190 190 190(y) TIME (MIN): 2 4 60 6 2 4 6__________________________________________________________________________
TABLE 5B__________________________________________________________________________DE-INKING OF COATED PAPER (CONT.)CP 7 8 9 10 11 12 13 14 15 15C 16__________________________________________________________________________(a)(b) 572 580 528 519 523 541 528 556 481 5351.93 508(c) 1.76 1.74 1.56 1.65 1.66 1.61 1.64 1.68 1.68 -- 1.67(d) 53.6 56.5 56.9 52.6 54.3 53.2 54.3 54.4 -- 51.7 54.7(e) 54.6 54.9 54.0 51.7 52.2 52.6 52.6 53.7 54.9 98.4 51.7(f) 98.3 98.5 99.0 98.6 99.4 98.7 98.6 99.0 98.0 60.7 99.2(g) 58.7 59.9 60.4 60.4 60.8 61.9 61.3 60.7 60.5 13.9 60.6(h) 12.3 8.3 9.6 11.9 11.2 11.6 11 11.4 11.3 3.9 10.2(i) 3.2 3.1 4.3 5.3 4.2 4.3 4.7 4.1 4.7 2.4 4.6(j) 2.2 2.6 2.6 3.0 2.7 2.9 2.8 2.9 3.1 2.6(k) 3.0 4.0 4.5 6.4 5.1 5.7 5.5 4.0 6.5 4.2(l) 13.4 13.6 14.9 16.0 13.9 15.3 14.5 13.3 18.9 12.4(m) 13.8 14.4 15.0 24.5 21.6 18.5 21.5 18.4 17.4 20.5(n) 20.5 21.3 20.1 18.9 15.8 21.4 17.6 16.5 24.9 16.2(o) 8.3 9.8 8.3 7.2 6.3 7.4 6.6 6.7 9.3 6.4(p) 41.0 36.9 37.2 27.0 37.3 31.7 34.3 41.1 23.0 40.3(q) 50 50 340 30 30 30 30 30 30 5.4 30(r) 0.4 -- 0.4 -- -- -- -- -- 0.4 0.4 0.4(s) 1.25 -- -- 1.25 1.25 1.25 -- -- 1.25 1.25 1.25(t) -- -- -- -- -- pH 1 pH 1 -- -- --(u) -- -- -- 2.0 -- -- -- -- 2.0 2.0 --(v) -- -- -- 3.0 -- -- -- -- 3.0 3.0 --(w) -- -- -- -- -- -- -- 1.0 -- -- --(x) 190 190 190 190 190 190 190 190 190 71 170(y) 4 4 4 4 4 4 4 4 4 60 4__________________________________________________________________________
TABLE 6______________________________________IMAGE ANALYSIS OF COATED PAPER AVER. SPOT SQ. MM DIRT/RUN SIZE (mm.sup.2) SQ. FT PAPER______________________________________CP1 0.1151 13.59CP2 0.0657 1.94CP3 0.1023 5.44CP4 0.1105 16.31CP5 0.1262 18.64CP6 0.0958 19.80CP7 0.1388 14.75CP8 0.1377 60.18CP9 0.1188 37.69CP10 0.0986 1.16CP11 0.1315 10.87CP12 0.07 0.41CP13 0.0877 1.55CP14 0.2893 8.54CP15 0 0.00CP16 0.1315 10.87CP2C 0.1681 295.30CP15C 0.2486 1860.88______________________________________
EXAMPLE 3
The third series of tests was conducted with groundwood furnish. The furnish was comprised of coated groudwood sections including new printed coated groundwood papers in sheet, section, or shavings, or guillotined books. This grade does not include news quality groundwood papers. In this example, ten (10) different cells were run, encompassing variations of two (2) consistencies, three (3) chemical pre-treatments, four (4) pulping temperatures, and three (3) pulping times. Ten (10) paired comparisons were made. The trial pulping temperatures and three (3) pulping or dwell times. Ten (10) paired comparisons were made. The trial matrix and cell comparison data may be found in TABLE 7.
TABLE 7______________________________________GROUNDWOOD FURNISH, TRIAL MATRIX SOAK SOAKSAMPLE CONSIS- CHEM- PULPING PULPINGI.D. TENCY ISTRY TEMP. TIME______________________________________24 30 WTM 190° 125 30 WTM 170° 126 30 WTM 170° 329 30 WTM 190° 430 30 WTM & 190° 1 H.sub.2 O.sub.2131 50 WTM 210° 4132 50 WTM 230° 4133 50 H.sub.2 O 210° 4134 50 H.sub.2 O 230° 4 7 50 WTM 190° 1 8 50 H.sub.2 O 190° 1______________________________________
Again, a series of panel comparisons were rated by a panel of experts and the inventive technology gave superior quality products warranting further experimentation.
A subsequent upscale trial of groundwood furnish was conducted with samples GR1 to GR11, and compared with control runs GR2C and GR10C. The procedure used and results obtained are tabulated in TABLES 8A and 8B, the latter being a continuation of the former. Likewise, TABLE 9 shows the result of image analysis of the samples GR1-GR11.
TABLE 8A__________________________________________________________________________DEINKING OF GROUNDWOOD RUN NO: GR1 GR2 GR2C GR3 GR4 GR5__________________________________________________________________________(a) YIELDS (%):(b) FREENESS (CSF, ml.): 219 205 239 249 283 259(c) BULK (cm.sup.2 /g): 1.91 1.93 1.91 1.74 1.83 1.78(d) BRIGHTNESS (3.0 g, %): 63.2 64.5 -- 63.7 64.0 63.2(e) BRIGHTNESS (1.2 g, %): 61.8 63.1 61.8 62.8 63.5 62.6(f) OPACITY (%): 98.2 98.5 98.2 98.4 97.9 98.1(g) HANDSHEET BASE WT (g): 60.7 60.5 60.7 60.4 59.6 59.0(h) TEAR (mN*M.sup.2 /g): 9.7 9.6 9.7 9.7 9.4 9.1(i) BREAKING LENGTH (km): 3.3 4.3 3.3 4.2 4.0 4.0(j) STRETCH (%): 2.1 2.8 2.1 2.5 2.6 2.6 FIBER CLASSIFICATION (BAUER MCNETT %):(k) +14 7.3 5.3 4.2 15.5 5.5 5.7(l) +28 15.8 16.2 17.5 15.1 15.1 12.2(m) +48 6.8 15.5 15.8 18.8 20.1 8.9(n) +100 26.9 14.3 14.2 12.3 12.9 14.0(o) +200 8.4 6.7 9.3 7.5 8.0 7.8(p) -200 34.8 42.0 39.0 30.8 38.4 51.4 PROCESS CONDITIONS:(q) CONSISTENCY: 30 30 5.4 30 30 30 CHEMICALS:(r) WETSAN (% W/W) 0.4 0.4 0.4 0.4 -- --(s) NaOH (% W/W) 1.25 1.25 1.25 1.25 -- --(s1) H.sub.2 O.sub.2 (% W/W) -- -- -- -- -- --(s2) Na.sub.2 SiO.sub.3 -- -- -- -- -- --(t) Na.sub.2 S.sub.2 O.sub.4 (% W/W) -- -- -- -- -- --(u) TEMPERATURE (°C.): 190 190 71 190 190 190(v) TIME (MIN): 2 4 60 6 2 4__________________________________________________________________________
TABLE 8B__________________________________________________________________________DEINKING OF GROUNDWOOD (CONT.) RUN GR NO: 6 7 8 9 10 10C 11__________________________________________________________________________(a) YIELDS (%):(b) FREENESS (CSF, ml.): 261 274 254 218 175 280 200(c) BULK (cm.sup.2 /g): 1.82 1.80 1.84 1.80 2.01 1.93 1.89(d) BRIGHTNESS (3.0 g, %): 63.7 61.9 61.2 64.5 65.8 -- 64.7(e) BRIGHTNESS (1.2 g, %): 63.4 61.3 54.3 64.0 64.3 65.0 63.7(f) OPACITY (%): 98.3 97.7 99.4 97.6 97.9 97.8 98.1(g) HANDSHEET BASE WT (g): 60.2 59.9 60.8 60.2 60.4 62.8 60.6(h) TEAR (mN*M.sup.2 /g): 9.0 9.7 9.6 9.7 10.8 9.2 9.3(i) BREAKING LENGTH (km): 3.9 3.7 3.7 4.5 4.9 3.5 4.5(j) STRETCH (%): 2.6 2.8 2.7 2.7 2.6 2.3 2.7 FIBER CLASSIFICATION (BAUER MCNETT %):(k) +14 5.4 7.8 5.1 5.3 6.8 5.1(l) +28 1.40 15.9 14.4 14.9 18.2 14.7(m) +48 19.3 18.1 18.3 19.8 15.6 19.7(n) +100 10.9 13.3 7.9 7.1 15.4 12.3(o) +200 8.2 8.3 12.8 11.9 7.7 7.4(p) -200 42.2 36.6 41.5 41.0 36.3 40.8 PROCESS CONDITIONS:(q) CONSISTENCY: 30 50 50 30 30 5.4 30 CHEMICALS:(r) WETSAN (% W/W) -- 0.4 -- -- 0.4 0.4 --(s) NaOH (% W/W) -- 1.25 -- 1.25 1.25 1.25 --(s1) H.sub.2 O.sub.2 (% W/W) -- -- -- 2.0 2.0 2.0 --(s2) Na.sub.2 SiO.sub.3 -- -- -- 3.0 3.0 3.0(t) Na.sub.2 S.sub.2 O.sub.4 (% W/W) -- -- -- -- -- -- 1.0(u) TEMPERATURE (°C.): 190 190 190 190 190 71 190(v) TIME (MIN): 6 4 4 4 4 60 4__________________________________________________________________________
TABLE 9______________________________________IMAGE ANALYSIS OF GROUNDWOOD AVER. SPOT SQ. MM DIRT/RUN SIZE (mm.sup.2) SQ. FT PAPER______________________________________GR2 0.2137 5.05GR3 0.263 12.42GR4 0.3068 32.61GR5 0.2475 24.85GR6 0.1863 6.60GR7 0.2959 10.48GR8 0.2446 36.11GR10 0.263 7.77GR11 0.526 21.74GR2C 0.5917 27.96______________________________________
The tests of groundwood also included experiments with old newsprint (ONP) and old telephone books (OTB) with very promising results.
EXAMPLE 4
Two samples of ONP--old newsprint (Nos. 1/2 and 3/4) were processed in accordance by the inventive method using explosive release.
Test sample 1/2 was cooked for 2 minutes at 160° C. Water only was used as chemistry, and temperature was the only processing variable. The following appearance values prevailed: % debris1.7; mean particle size after release: 1.0649; total particle area: 508.818. The expert rating was "excellent".
Subsequent sample 3/4 was cooked at 170° C. for 2 minutes. Water only was used chemistry, and temperature was the only processing variable. The following appearance values prevailed: % debris:0.56; mean particle size in mm 2 :0.8484; total particle area in mm 2 :285.09. The rating by the panel of experts was "excellent".
EXAMPLE 5
The testing series of groundwood also included samples Nos. 5, 6, 7, 10 and 11, all being furnishes of old telephone books. It is known that the processing of telephone books is severly hindered by the bindings. This prevents the majority of waste paper recyclers from enjoying the benefits of using old telephone books as a cheap and commodeous furnish. We have found that the re-processing of the pages of telephone books posed no problem for the inventive technology, so we challenged the inventive technology with a furnish of concentrated old telephone book binders only. The test results are tabulated in the following TABLE 10. The table shows that the temperature range tested was from 200° to 220° C. All telephone book furnishes listed have been processed with water only, with no chemicals added. However, it can be reasonably assumed that certain chemicals, if added, would improve the results still further.
TABLE 10__________________________________________________________________________OLD PHONE BOOKS - PROCESS AND TEST RESULTS MEAN TOTAL PARTICLE PARTICLE %SAMPLE TIME TEMP. SIZE AREA DEBRIS RANKINGS__________________________________________________________________________#11 6 220° C. 0.4334 49.843 0.25 browning#9 2 220° C. .2297 49.843 1.7 excellent#7 6 210° C. .2794 38.003 0.91 very good#6 2 210° C. .2753 139.324 1.3 excellent#5 4 200° C. .3004 95.826 0.81 excellent#10 4 220° C. .2711 46.899 1.1 very good__________________________________________________________________________
Old telephone books are primarily groundwood, but are more difficult to repulp because of the bindings. The success generated by the low mean particle sizes, low % debris and "very good" to "excellent" panelist ratings agains shows the superiority of the inventive technology and process. It can be reasonably assumed from the following discussion and process severity formula establishing the relationship between temperatures and dwell time, that 180° C. is the lower limit for OTB.
EXAMPLE 6
The invention was also tested extensively with the old corrugate container furnish (OCC) (baled corrugate containers having liners of either test liner, jute or kraft) with surprisingly good results tabulated in TABLE 14, together with the respective process data.
TABLE 11__________________________________________________________________________OLD CORRUGATE CONTAINERS MEAN TOTAL PARTICLE PARTICLE % EXPERTFURNISH TIME TEMP. SIZE (mm.sup.2) AREA (mm.sup.2) DEBRIS RATINGS__________________________________________________________________________Good OCC 220° C. 0.2924 426.627 -- ETC*LFHD control -- -- 0.2653 44.313 -- averageSFHD control -- -- 0.3727 99.145 -- averageBad OCC 2 230° C. -- -- 3.4% excellentBad OCC 2 210° C. -- -- 12.6% excellentUMc, OCC 2 215° C. -- -- -- SCQ**waxy OCC 6 220° C. -- -- -- ***Wet strength 8 220° C. 0.4432 17.726 0.16% excellentOCC__________________________________________________________________________ *ETC = equivalent to commercial **SCQ = superior to commercial quality *** = better than possible with conventional commercial equipment
In TABLE 11, LFHD and SFHD stand for long fibre high density and short fibre high density, respectively. These represent fibres which have been fully cleaned and screened in a conventional commercial deinking system and which have also then been fractionated by fibre length as the last processing prior to use. The fact that the experimental sample shows a roughly equivalent mean residual particle size without any cleaning clearly demonstrates the superiority of the pulps processed by this invention.
Processing treatment for all samples in Table 11 was water only. The combination of image analysis and expert ratings has shown that the inventive technology works for furnishes such as wet strength OCC where it is known that conventional processing is inadequate.
EXAMPLE 7
In this group of examples and tests, comparisons were made to establish the influence of explosive release on the overall de-inking efficiency of the method according to the present invention.
The testing was performed using a batch steam explosion reactor which was modified to accommodate inert gas injection. Shredded office waste and coated paper were used as furnishes for de-inking. Only water was used to give a moisture content of 50% (w/w) in the furnish before processing. The processing was performed based on the publication referred to above for relatively clean wastepaper: 100°-180° C. with nitrogen gas addition to give a 300 psig pressure in the reactor prior to explosive decompression. To test the effect of explosion, a study was performed by slowly releasing the pressure of the reactor (bleed-down) to atmospheric pressure to material discharge. The condition is described as "no explosion".
All treated furnish without further treatment was sent to a laboratory for evaluation of % debris; image analysis (sq. mm of direct per sq. ft. of paper); this is an and average spot size (sq. mm).
The following Table 12 shows the result of tests performed with office waste. Tests A1 and A2 were conducted in accordance with the present invention at high temperatures bringing the pressure within the digester to 261 psig.
The second group of tests B1 and B2 was conducted in accordance with the literature referred to above, the pressurization of the digester to 300 psig having been made by N 2 .
TABLE 12__________________________________________________________________________OW - HIGH PRESSURE VS. HIGH TEMPERATUREPROCESS % IMAGE ANALYSIS AVERAGE SPOTCONDITIONS DEBRIS (SQ. MM/SQ. FT.) SIZE (SQ. MM)__________________________________________________________________________A. High Temperature 210° C./4 min no 0.45% 185 0.31 N.sub.2 (261 psig) explosion 210° C./4 min no 0.70% 302 0.39 N.sub.2 (261 psig) no explosionB. Low Temperature 100° C./4 min add 25.2% 4635 2.69 N.sub.2 to 300 psig explosion 180° C./4 min add 1.30% 557 0.42 N.sub.2 to 300 psig explosion__________________________________________________________________________
Table 12 shows several interesting aspects of the present invention. Firstly, even with the raising of the pressure by N 2 , but at a increased temperature of 180°, the result was drastically superior to the processing in similar way a mere 100° C. By the same token, the data of the present invention at a lower pressure but higher temperature were superior to the higher pressure and lower temperature of the method described in literature.
Data from the use of the present invention in this comparison further suggest that with explosive discharge, there is only a marginal improvement over non-explosion. This would appear to suggest that pressure is not the major factor in determining the de-inking deficiency.
A similar comparison was made with coated paper and the result from this comparison is tabulated in Table 13. Table 13 points out again to the importance of high temperature, not high pressure for the de-inking efficiency.
TABLE 13__________________________________________________________________________CP - HIGH PRESSURE VS HIGH TEMPERATUREPROCESS % IMAGE ANALYSIS AVERAGE SPOTCONDITIONS DEBRIS (SQ. MM/SQ. FT.) SIZE (SQ. MM)__________________________________________________________________________A. High Temperature 190° C./4 min (167 0.36% 111 0.28 psig) no N.sub.2 explosion 190° C./4 min Add 0.34% 116 0.40 N.sub.2 to 300 psig explosion 190° C./4 min no 0.24% 56 0.82 N.sub.2 no explosionB. High Pressure 100° C./4 min add 1.6% 1330 0.78 N.sub.2 to 300 psig explosion 180° C./1 min add 0.50% 129 0.35 N.sub.2 to 300 psig explosion 180° C./4 min add 0.41% 118 0.24 N.sub.2 to 300 psig explosion__________________________________________________________________________
The tests with coated paper lead to the same general conclusion which can be summarized as follows:
(1) steam temperature (and time) and not pressure is the predominant factor in determining de-inking effectiveness;
(2) injection of inert gases to increase operating pressure does not lead to enhanced de-inkability;
(3) explosive decompression from high pressure may not be an absolute prerequisite to effective de-inking.
Other furnishes, not listed in the above examples and test results, including UV-ink coated papers, latex-bonded air laid cellulosic nonwovens and milk cartons such as were tested during the tests, all with promising results, at least matching and mostly surpassing comparative samples processed by the presently used methods.
The conditions and limits suggested by the experiments described above are not meant to be absolute. Rather, they are intended to show to those skilled in the art that careful balances are necessary between time, temperature, and chemistry in order to optimize the condition of the pulp with specific regard to the attributes required in the final grade of paper, paperboard or the like produced therefrom. For instance, those skilled in the art will quickly recognize that the percentage added of any given chemical is not to be taken as an absolute limiting factor in this invention. The functional specificity of the chemical and its relative strength both play an important role in the determination of exactly how much chemical is added. For example, it is often desirous to raise the pH of the furnish in the deinking operation. It is also well known that there are any number of acceptable chemicals available for this purpose including sodium hydroxide, potassium hydroxide and sodium carbonate. The cationic group (sodium or potassium) may be changed while still yielding the same final effect on the furnish. Or the anionic group (hydroxide or carbonate) may be changed while still yielding the same final effect on the furnish. And of course, there are also the entire spectrum of both inorganic and organic chemicals to chose from. However, due to strength differences and ionization constants of different chemicals different amounts may be required to achieve the same effect. For example, a 0.1N solution of sodium hydroxide in water will be expected to yield a pH of 13. Whereas a 0.1N solution of sodium carbonate in water will be expected to yield a pH of 11.6. Therefore, theoretically, it should take over 10 times as much sodium carbonate as it would sodium hydroxide to achieve the same high pH. But it is also known to those skilled in the art that the addition of further quantities of some chemicals does not bring about a further change in pH, but instead results in a buffering action. Yet, the net effect on the furnish with regards to deinking may be the same.
Furthermore, it will also be recognized that matters are complicated by the sort of dual functionality exhibited by some chemicals. Does one add sodium carbonate to raise the pH? Or does one add sodium carbonate to act as a buffer? Or does one use it for both purposes? Should it therefore be called an alkalating agent, buffer, or both?
As regards the scope of temperatures and dwell times, Stake Technology, one of the co-assignees of the invention, has adopted the concept of severity parameter as recently proposed by Overend and Chornet (Overend, R. P. and E. Chornet, 1987. Fractionation of lignocellulosics by steam-aqueous pretreatments. Phil. Trans. R. Soc. London. Volume A 321, Pages 523-536). Steam treatment severity is defined as:
Ro=t* exp.sup.[(T-100)/14.75]
where
Ro is the severity parameter;
t is the residence time in the reactor (in minutes); and
T is the steam temperature (in °C.)
The equation basically states that a particular treatment severity could be achieved by using various combinations of steam temperatures and residence times. It is expected that similar (though not identical) process results (including product quality, downstream processing performance, etc.) will be achieved when the same process severity is used for a particular raw material under conditions which are constant in all other aspects. The Ro as a function of the temperatures and times for the range of 200°- 230° C. for 1-6 minutes was illustrated by FIGS. 5 and 6.
The concept of treatment severity is particularly valuable in that it unifies the two major parameters involved in steam treatment: steam temperature and residence times, into a single concept in determining the process conditions. The validity of the concept has been convincingly demonstrated in various applications utilizing Stake Tech's steam-explosion technology. It is likely that the same concept will hold for the wastepaper recycling application even though the concept to data applies primarily to situations which does not involve the use of exogenous chemicals.
In view of the above comments, it will be appreciated that many different combinations may exist in different temperature and dwell time ranges which may differ from the ranges described in the Examples, without departing from the scope of the present invention.
Accordingly, we wish to protect by Letters Patent issued on this application all such embodiments of the method as reasonably fall within the scope of our contribution to the art. | Method is disclosed of treatment of waste paper or the like at high temperatures in the range of 160° C. to about 230° C. The furnish is treated in a digester with or without added chemicals but in the presence of saturated steam. The preferred dwell times are in the range of about 1 minute to about 6 minutes. The treated furnish is then discharged from the digester, preferably, but not exclusively, by an explosive discharge.
The advance in the art is in an improved de-inking effect, reduced consumption of chemicals and power. Also, some furnishes previously unsuitable for re-cycling, have been successfully processed by the method of the invention. | 62,870 |
This is a continuation-in-part of application Ser. No. 07/815,248, filed Dec. 31, 1991, entitled "Jumper Ready Battery," now U.S. Pat. No. 5,214,368.
BACKGROUND OF THE INVENTION
This invention relates to batteries, in general; and, in particular, to apparatus for conveniently storing jumper cables in proximity to a vehicle battery for jump-starting the vehicle.
Several problems face the motorist, confronted with a "dead" battery, who seeks to jump-start an automobile. Jumper cables get lost, and are never with you when you need them. Establishing electrical connection using jumper cable clamps, between your automobile battery and the battery of another automobile is a nuisance. Battery posts are not always readily accessible, and knowing whether good contact has been made is always a problem, especially when (as is good safety practice) the last clamp attachment is made indirectly through the automobile frame. Unless good contact is confirmed, you can never be sure whether a breakdown is caused by a "dead" battery, or not.
The jumper cable attachment of the invention provides conveniently readily accessible jumper cables, that are easy to use and offer beneficial contact establishing advantages. The jumper cable attachment of the invention eliminates the need to carry a separate set of jumper cables.
SUMMARY OF THE INVENTION
In accordance with the invention a jumper cable attachment is provided for an automobile or similar battery, either internally or externally, to give significant jump start related improvements. The attachment includes a set of retractable jumper cables that are pre-attached to the positive and negative poles of the battery. The retractable cables are housed inside the battery or in an auxiliary structure closely associated with the battery. The battery clamps may be made luminescent, to glow in the dark. For contact confirmation purposes, the battery is augmented to include a small flashlight that can be used either as a mechanic's light or to assist in the jumping process. The retractable cables are preferably four gauge wire with a length of six to ten feet. In one illustrative embodiment, described in greater detail below, the cables are housed in a separate chamber formed within the battery casing itself. In other embodiments, a "jumper ready battery" is provided by means of a retractable cable fixture mounted as an add-on to a conventional battery housing.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention have been chosen for purposes of illustration and description, and are shown in the accompanying drawings, wherein:
FIG. 1 is a view of a jumper cable attachment in accordance with the invention, incorporated as part of the battery itself;
FIG. 2 is a view of a jumper cable attachment in the form of a battery add-on unit;
FIG. 3 is a circuit diagram of the attachment of FIG. 2;
FIG. 4 is a view of another form of add-on attachment unit; and
FIG. 5 is a view of a modified form of the attachment unit of FIG. 4.
Throughout the drawings, like elements are referred to by like numerals.
DESCRIPTION OF PREFERRED EMBODIMENTS
As shown in FIG. 1, an automobile battery 10 includes positive and negative terminal posts 11, 12 connected via seals 13, 14 through cover 15 of a container 16 to post straps 17 and plate lugs 18 for electrical communication with plates 19 immersed in an electrolyte 20, such as a water-based solution of sulfuric acid. This connection is made in conventional manner, with caps 21 of vent plugs being located on the cover 15 to enable gas evacuation and replenishment of electrolyte. In conventional manner, conductors 23, 24 connect the battery terminals 11, 12, respectively, to positive and negative sides of an automobile electrical system 25; the negative connection being made, as is customary, by attachment of the conductor 24 to the automobile frame 26. The base of the battery casing 16 is supported in suitable fashion, such as in a tray 27 mounted on the frame 26. Well-known means (not shown) are utilized to lock the battery 10 within the tray 27.
In accordance with the invention, the container 16 includes a separate chamber 30, isolated from the electrolyte chamber 31, and within which jumper cables 34, 35 are stored. Each cable includes, at one end, an alligator clamp or similar mechanism 36 for establishing electrical contact between the associated cable 34, 35 and a corresponding positive or negative post of a remote battery of another automobile used for jumping purposes. For ease of manipulation in the dark, the handle parts of the clamps 36 are coated with a luminous material, such as phosphorescent paint. At its other end, each cable 34, 35 includes means for establishing electrical connection to the respective positive or negative pole 11, 12 of the battery 10. For the embodiment of FIG. 1, such communication is established by a lead 37 which electrically couples the inside end of the cable 34, 35 through a seal 38 to the appropriate post strap 17.
The cables 34, 35 are made retractable by attachment about a spool 41 of a retracting mechanism 40 mounted in the chamber 30. Suitable mechanisms 40 may be of a type such as used to retract the electrical cord of a canister vacuum cleaner (see, e.g., the cord reel assembly Part No. 700858 of a Kenmore vacuum cleaner, Model No. 116.2399182) or of a mechanic's guarded work lamp (see, e.g., the mechanism used to retract the cord of a commercially available Quality cord reel). The electrical connection of the lead 37 to the spool-mounted end of the jumper cables 34, 35 is made using brushes, rotating contacts, or similar known devices. To prevent retraction of the clamps 36 into the interior of chamber 30, so that they remain accessible, externally-opening cavities 42, 43 are formed in the cover 15 over the chamber 30. The cavities 42, 43 have open box-like constructions adapted for receiving a major portion of the clamps 36 therein. The bases 44 of the cavities 42, 43 have openings 45, dimensioned to pass the insulated wire portion of the cables 34, 35 but block movement of the clamps 36 into the interior of chamber 30.
For the embodiment illustrated in FIG. 1, the chamber 30 is formed integrally within the same container 16 as the chamber 31 which contains the conventional battery components. The clamps 36 will normally be located in conveniently accessible storage positions (as shown by the right clamp 36 in FIG. 1), within the open cavities 42, 43 formed in the cover 15. When it is desired to jump the battery 10, the cables 34, 35 are drawn out of the cavities 42, 43 (to a position such as shown by the left clamp 36 in FIG. 1) and attached in known manner to the corresponding posts of a remote battery or similar jumping source. Of course, normal safety procedures (such as attachment of the clamp 36 of the negative cable 35 to a frame rather than directly to the remote negative terminal post) must be observed. When the jumping procedure is completed, the clamps 36 are retrieved and the mechanisms 40 are operated to retract the insulated wire portions of the cables 34, 35 about the respective spring-loaded spools mounted for rotation within the chamber 30. The mechanisms 40 are advantageously of a spring-action, ratcheted-type which permit the cables to be withdrawn and held at any one of a plurality of selected uncoiled lengths. In the illustrated embodiment 10, each cable 34, 35 has its own associated retracting mechanism 40.
The described battery 10 provides security and convenience for the motorist, by enabling convenient location of the jumper cables 34, 35 at all times, with one end of each cable 34, 35 already situated in attachment with the associated battery posts 11, 12.
FIGS. 2 and 3 illustrate another form 110 of a battery jumper cable attachment in accordance with the invention. The embodiment 110 is constructed using a conventional battery 10' to which an abutting separate chamber 30' has been added by attachment of an auxiliary container 116. The container 116 is dimensioned to match the casing of the conventional battery 10' and is suitably secured thereto by mating Velcro straps 112, 113, joined to opposite sides of casing 116 and wrapped about the casing 16' of battery 10'.
In variation of the structure of the embodiment 10, the embodiment 110 utilizes a single retracting mechanism 40' for retracting the cables 34, 35. The inner lengths of those cables are joined together and wrapped about a single spool 41', configured in accordance with known principles, to provide electrical attachment of the inner ends of cables 34, 35 to the respective positive and negative terminal posts 11, 12. For the illustrated structure, leads 37' connect externally to the posts 11, 12, thereby requiring no separate seals 38 as in FIG. 1.
According to another advantageous feature of the invention, a flashlight 120 is provided in conjunction with the cables 34, 35. The flashlight 120 includes a hand-operable switch 121 and a bulb 122, electrically connected as shown in FIG. 3. The switch 121 has three positions A, B, C, as indicated. Position A operates flashlight 120 so that bulb 122 is illuminated conventionally by a dry cell battery source 123 installed within the interior of the flashlight housing 125. Position B is the flashlight "off" position, whereby the bulb 122 is open-circuited. And, position C connects the bulb 122 between the cables 34, 35. With the switch 121 in position C, the conventional automobile battery terminals 11, 12, to which the auxiliary jumper housing casing 116 is attached, will operate the flashlight 120. Such connection provides significant advantages. First with a "live" battery 10', good connection between cables 37' and posts 11, 12 can be confirmed. With switch 121 in position C, bulb 122 will light only if good connection exists. Second, with a "dead" battery 10' good connection between clamps 36 and the terminals (i.e., terminal and automobile frame) of a remote jumping battery can be confirmed. With switch 121 in position C, bulb 122 will light only if good connection exists. It is very frustrating in jumping a "dead" battery, when there is no way to check whether the clamps are making adequate contact. Use of a visual indicator, such as the bulb 122 of flashlight 120 connected as shown in FIG. 3, provides the needed assurance.
A modified cavity 42', larger than cavities 42, 43, is formed in the cover 115 of the container 116 to receive both the flashlight 120 and clamps 36 in retrievable storage position. An opening 45' in the base wall 44' of cavity 42' permits the insulated wire portions of the cables 34, 35 and the narrow rear of flashlight 120 to pass into the interior of cavity 30', but does not pass the enlarged bulb end of the flashlight 120. The flashlight 120 can be secured to one or both of the insulated wire portions of the cables 34, 35, as shown, or may be mounted on its own separate insulated wire. Mounting the light 120 in this manner, provides a convenient retractable work light, operable off the automobile battery, for checking the engine. The negative clamp 36 can be attached to the automobile frame structure to hang the lamp.
FIG. 4 illustrates yet another form 210 of a battery jumper cable attachment in accordance with the invention. The embodiment 210, like the embodiment 110 discussed above, takes the form of an add-on unit for attachment to the casing 16' of a conventional battery 10'. As with embodiment 110, a retracting mechanism 40' is housed within a chamber 30" defined by an auxiliary container 216. Unlike container 116, however, container 216 has a dimension which is made variable to match differences in spacing between terminals 11, 12 found in different battery sizes. Length adjustability is achieved by constructing container 216 in two parts 217, 218, one telescopingly received within the other. Each part 217, 218 has a box-like rectangular configuration, with a closed outer end and an open inner end. A cable retracting mechanism, which may be identical to the mechanism 40' of attachment 110, is located within the interior 219 of inner part 218 and clamps 36 are housed within a cavity 42" made accessible externally on outer part 217.
For the illustrated embodiment 210, each part 217, 218 includes horizontally extending upper and lower surfaces 220, 221, between corresponding extreme corners of which extend identical terminal displacement elements 224. Each element 224 comprises a block of conductive material including a downwardly opening vertical bore 225 at its bottom end and an upwardly directed vertical post 226 at its top end. Bore 225 is made accessible from the underside of surface 221 and is dimensioned to fit in electrical contact over a corresponding battery terminal post 11, 12. Post 226 projects upwardly through surface 220 and is dimensioned to simulate the corresponding post 11, 12 received within the associated bore 225.
The illustrated arrangement enables container 216 to be matched to the top of container 16' of battery 10' by positioning lower surface 221 over the top of battery 10', with one terminal displacement element 224 brought over battery terminal post 11 and the other terminal displacement element 224 brought over battery terminal post 12, with part 218 is shifted into or out of the open end of part 217 as needed to match the spacing of posts 11, 12. Conductors 23, 24 (see FIG. 1) can then be attached in vertically displaced positions to the upper end posts 226 of elements 224, instead of attaching them in conventional manner to the correspondingly dimensioned posts 11, 12 of the battery.
Clamps 36 may conveniently be housed within a cavity 42" formed by a rectangular compartment 227 made accessible centrally between projections 226 of elements 224 on upper surface 220 of container 216. Compartment 227 may comprise vertically extending walls 228, between opposing ones of which is pivotally mounted a lid 229 dimensioned, configured and adapted to normally cover the open top of compartment 227. Base 44" of compartment 227 has an opening 45" through which jumper cable leads 34, 35 extend into chamber 30" and cavity 219 for connection to the wind-up spool of the cable retraction mechanism. Opening 45" is large enough to enable the cables to be drawn therethrough, but is sufficiently small to block passage of clamps 36 into the interior of container 216. For the purpose of establishing a flat storage orientation of clamps 36 within the closed compartment 227, dummy posts 230 are located in laterally spaced positions away from opening 45". Walls 228 and dummy posts 230 are dimensioned, configured and adapted so that clamps 36 lay flat when attached to dummy posts 230 and lid 229 can be closed over clamps 36 and dummy posts 230, while maintaining a minimum height profile. Connection between clamp leads 34, 35 and terminal displacement conductive elements 224 is established by electrical connection of leads 37" between the retracting mechanism and points of attachment 231.
Accommodation is also made in apparatus 210 of FIG. 4, for electrical connection to terminals of batteries which are located in other than vertically extended positions. For the embodiment 210, each lead 37" is also connected through a conductive member 233 to a terminal connector 234 accessible through a side surface 235 of each telescoping part 217, 218. Electrical connection between terminal connector 234 and the battery posts can then be established by means of a conductor, such as the wire strap 236 which can be attached to a threaded protrusion 237 of connector 234 by a corresponding fastener 238.
FIG. 5 shows a modified embodiment 210' having conductive cables 236' which connect to elements 224 internally of container 216 and extend externally through openings 239. As shown in FIG. 5, the lower surface 221 of housing 216 can be provided with peel-off adhesive or other known permanent or removable bonding elements 240, for securing container 216, after size adjustment, to the top of battery 10'.
Those skilled in the art to which the invention relates will appreciate that other substitutions and modifications can be made to the described embodiment without departing from the spirit and scope of the invention as described by the claims below. | A standard automobile battery is modified to contain a set of retractable jumper cables, pre-attached to the positive and negative terminals of the battery. The cables are housed in a separate chamber formed either internally in a modified battery casing or externally in an auxiliary structure augmenting the usual casing. A bulb is connected across the cables to provide visual indication of good cable contact. Jumper clamps are made luminescent. | 16,747 |
FIELD OF THE INVENTION
[0001] This invention relates to image processing and particularly to a restoration of colour components in a system for storage or acquisition of digital images.
BACKGROUND OF THE INVENTION
[0002] Blurring or degradation of an image can be caused by various factors, e.g. out-of-focus optics, or any other aberrations that result from the use of a wide-angle lens, or the combination of inadequate aperture value, focal length and lens positioning. During the image capture process, when long exposure times are used, the movement of the camera, or the imaged subject, can result in motion blurring of the picture. Also, when short exposure time is used, the number of photons being captured is reduced, this results in high noise levels, as well as poor contrast in the captured image.
[0003] Various methods for restoring images that contain defects, e.g. blurring, are known from related art. For example spatial error concealment techniques attempt to hide a defect by forming a good reconstruction of the missing or corrupted pixels. One of the methods is to find a mean of the pixels in an area surrounding the defect and to replace the defect with the mean pixel value. A requirement for the variance of the reconstruction can be added to equal the variance of the area around the defect.
[0004] Different interpolation methods can also be used for restoration. For example a bilinear interpolation can be applied to pixels on four corners of the defect rectangle. This makes a linear, smooth transition of pixel values across the defect area. Bilinear interpolation is defined by the pixel value being reconstructed, pixels at corners of the reconstructed pixel and a horizontal and vertical distance from the reconstructed pixel to the corner pixels. Another method is edge-sensitive nonlinear filtering, which interpolates missing samples in an image.
[0005] The defect block can be replaced also with the average of some of all of the surrounding blocks. One example is to use three blocks that are situated above the defect. Further there is a method called “best neighbours matching” which restores images by taking a sliding block the same size as the defect region and moves it through the image. At each position, except for ones where the sliding block overlaps the defect, the pixels around the border of the sliding block are placed in a vector. The pixel values around the border of the defect are placed in another vector and the mean squared error between them is computed. The defect region is then replaced by the block that has the lowest border-pixel.
[0006] The purpose of image restoration is to remove those degradations so that the restored images look as close as possible to the original scene. In general, if the degradation process is known; the restored image can be obtained as the inverse process of the degradation. Several methods to solve for this inverse mathematical problem are known from the prior art. However, most of these techniques do not consider the image reconstruction process in the modelling of the problem, and assume simplistic linear models. Typically, the solutions in implementations are quite complicated and computationally demanding.
[0007] The methods from related art are typically applied in restoration of images in high-end applications such as astronomy and medical imaging. Their use in consumer products is limited, due to the difficulty of quantifying the image gathering process and the typical complexity and computational power needed to implement these algorithms. Some of the approaches have been used in devices that have limited computational and memory resources. The methods from the related art are typically designed as a post-processing operation, which means that the restoration is applied to the image, after it has been acquired and stored. In a post-processing operation each colour component has a different point spread function that is an important criteria that can be used to evaluate the performance of imaging systems. If the restoration is applied as post-processing, the information about the different blurring in each colour component is not relevant anymore. The exact modelling of the image acquisition process is more difficult and (in most cases) is not linear. So the “inverse” solution is less precise. Most often, the output of the digital cameras is compressed to .jpeg-format. If the restoration is applied after the compression (which is typically lossy), the result can amplify unwanted blocking artefacts.
SUMMARY OF THE INVENTION
[0008] The aim of this invention is to provide an improved way to restore images. This can be achieved by a method, a model, use of a model, a device, a module, a system, a program module and a computer program product.
[0009] According to present invention the method for forming a model for improving image quality of a digital image captured with an imaging module comprising at least imaging optics and an image sensor, where the image is formed through the imaging optics, said image consisting of at least one colour component, wherein degradation information of each colour component is found, an image degradation function is obtained and said each colour component is restored by said degradation function.
[0010] According to present invention also the model for improving image quality of a digital image is provided, said model being obtainable by a claimed method. According to the present invention also use of the model is provided.
[0011] Further according to present invention the method for improving image quality of a digital image captured with an imaging module comprising at least imaging optics and an image sensor is provided, where the image is formed through the imaging optics, said image consisting at least of one colour component, wherein degradation information of each colour component of the image is found, a degradation function is obtained according to the degradation information and said each colour component is restored by said degradation function.
[0012] Further according to present invention a system for determining a model for improving image quality of a digital image with an imaging module is provided, said module comprising at least imaging optics and an image sensor, where the image is formed through the imaging optics, said image consisting of at least one colour component, wherein the system comprises first means for finding degradation information of each colour component of the image, second means for obtaining a degradation function according to the degradation information, and third means for restoring said each colour component by said degradation function.
[0013] Further according to present invention the imaging module is provided, comprising imaging optics and an image sensor for forming an image through the imaging optics onto the light sensitive image sensor wherein a model for improving image quality is related to said imaging module. Further according to present invention a device comprising an imaging module is provided.
[0014] In addition, according to present invention the program module for improving an image quality in a device is provided, comprising an imaging module, said program module comprising means for finding degradation information of each colour component of the image, obtaining a degradation function according to the degradation information, and restoring said each colour component by said degradation function. Further the computer program product is provided, comprising instructions for finding degradation information of each colour component of the image, obtaining a degradation function according to the degradation information, and restoring said each colour component by said degradation function.
[0015] Other features of the invention are described in appended dependent claims.
[0016] In the description a term “first image model” corresponds to such an image, which is already captured with an image sensor, such as a CCD (Charged Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor), but not processed in any way. The first image model is raw image data. The second image model is the one for which a degradation information has been determined. It will be appreciated that other sensor types, other than CMOS or CCD can be used with the invention.
[0017] The first image model is used for determining the blurring of the image, and the second image model is restored according to the invention. The restoration can also be regulated according to the invention. After these steps have been done, other image reconstruction functions can be applied to it. If considering the whole image reconstruction chain, the idea of the invention is to apply the restoration as a pre-processing operation, whereby the following image reconstruction operations will benefit from the restoration. Applying the restoration as a pre-processing operation means that the restoration algorithm is targeted directly to the raw colour image data and in such a manner, that each colour component is handled separately.
[0018] With the invention the blurring caused by optics can be reduced significantly. The procedure is particularly effective if fixed focal length optics is used. The invention is also applicable to varying focal length systems, in which case the processing considers several deblurring functions from a look-up table depending on the focal position of the lenses. The deblurring function can also be obtained through interpolation from look-up tables. One possibility to define the deblurring function is to use continuous calculation, in which focal length is used as a parameter to deblurring function. The resulting images are sharper and have better spatial resolution. It is worth mentioning that the proposed processing is different from traditional sharpening algorithms, which can also result in sharper images with amplified high-frequencies. In fact, this invention presents a method to revert the degradation process and to minimize blurring, which is caused e.g. by optic, whereas the sharpening algorithms use generic high-pass filters to add artefacts to an image in order to make it look sharper.
[0019] The model according to the invention is more viable for different types of sensors that can be applied in future products (because of better fidelity to the linear image formation model). In the current approach, the following steps and algorithms of the image reconstruction chain benefit from the increased resolution and contrast of solution.
[0020] Applying the image restoration as a pre-processing operation may minimize non-linearities that are accumulated in the image capturing process. The invention also may prevent over-amplification of colour information.
[0021] The invention can also be applied for restoration of video.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The invention is illustrated with reference to examples in accompanying drawings and following description.
[0023] FIG. 1 illustrates an example of the system according to the invention,
[0024] FIG. 2 illustrates another example of the system according to the invention,
[0025] FIG. 3 illustrates an example of a device according to the invention, and
[0026] FIG. 4 illustrates an example of an arrangement according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The description of the restoration of images according to the invention can be targeted to three main points, wherein at first the blur degradation function is determined, e.g. by measuring a point-spread function (PSF) for at least one raw colour component. Secondly, a restoration algorithm is designed for at least one raw colour component. Thirdly, a regularization mechanism can be integrated to moderate the effect of high pass filtering. In the description the optics in mobile devices are used as an example, because they may generally be limited to a wide focus range. It will, however, be apparent to the man skilled in the art, that the mobile devices are not the only suitable devices. For example the invention can be utilized by digital cameras, web cameras or similar devices, as well as by high end applications. The aim of this algorithm is to undo or attenuate a degradation process (blurring) resulting from the optics. Due to the algorithm the resulting images becomes sharper and have an improved resolution.
[0028] Wherever a term “colour component” is used, it relates to various colour systems. The example in this invention is RGB-system (red, green, blue), but a person skilled in the art will appreciate other systems such as HSV (Hue, Saturation, Value) or CMYK (Cyan, Magenta, Yellow, Black) etc.
[0029] The image model in the spatial domain can be described as:
g i ( m,n )= h i ( u,v )* f i ( m,n )+ n i ( m,n ) (1)
where g i is a measured colour component image, f i is an original colour component, h i is a corresponding linear blurring in the colour component and n i is an additive noise term. g i , f i , n i are defined over an array of pixels (m, n) spanning the image area, whereas h i is defined on the pixels (u, v) spanning blurring (point-spread function) support. The index i={1, 2, 3, 4} denotes respectively the data concerning colour components, such as red, green 1, blue and green 2 colour components. The invention is described in more detail by means of FIGS. 1 and 2 each illustrating a block diagram of the image restoration system according to the invention.
Blur Specification
[0030] The procedure for estimating the degradation ( FIG. 1, 110 ) in the image that has been captured by an optical element ( 100 ) is described next. As can be seen in FIG. 2 , the degradation can be estimated by means of the point-spread function 210 corresponding to the blur in three colour channels (in this example R, G, B) (raw data). The point-spread functions are used to show different characteristics for each colour channel. The point-spread function is an important criterion that can be used to evaluate the performance of imaging systems.
[0031] The point-spread function changes as a function of the wavelength and the position in the camera field of view. Because of that, finding a good point-spread function may be difficult. In the description an out-of-focus close range imaging and a space invariant blurring are assumed. The practical procedure for estimating the point-spread function (h i ) that is associated with each colour component, can also be used as stand-alone application to help in the evaluation process of camera systems.
[0032] Given a blurred image corresponding to one colour component of a checker-board pattern, the four outer corner points are located manually, and first a rough estimate of the corner positions is determined. The exact locations (at subpixel accuracy) are recalculated again by refining the search within a square window of e.g. 10×10 pixels. Using those corner points, an approximation for the original grid image f i can be reconstructed by averaging the central parts of each square and by asserting a constant luminance value to those squares.
[0033] The point-spread function is assumed to be space invariant, whereby the blur can be calculated through a pseudo-inverse filtering method (e.g. in Fourier domain). Since the pseudo-inverse technique is quite sensitive to noise, a frequency low-pass filter can be used to limit the noise and the procedure can be applied with several images to obtain an average estimate of the point-spread function. (The normalized cut-off frequency of the mentioned low pass filter is around 0.6, but at least any value from 0.4 to 0.9 may be applicable).
[0034] In order to quantify the extent of blur that occurs with each colour channel, a simple statistics is defined, which statistics is determined as a mean of the weighted distance from the centre of the function (in pixels), said weight corresponding to the value of the normalized point-spread function at that point:
S psf ( h i ) = M 1 N 1 ∑ m , n h i ( m , n ) ∑ m = 0 M 1 ∑ n = 0 N 1 ( m 2 + n 2 ) h i ( m , n ) ( 2 )
wherein M 1 and N 1 are the support of the point-spread function filter. S psf describes the extent of the blurring. Experiments confirm that the channels have different blurring patterns. For example when studying Mirage-1 camera, the obtained S psf values were:
S psf ( h i ) = { 5 , 42 i = 1 ( red ) 5 , 01 i = 2 ( green ) 4 , 46 i = 3 ( blue )
[0035] It can be seen from the results, that the red component was most blurred and noisy, whereby the least blurred was the blue component, which also had the least contrast.
[0000] Restoration Algorithm
[0036] The data concerning colour components is measured by a sensor 120 e.g. by Bayer sensor 220 (in FIG. 2 ), like a CMOS or CCD sensor. The colour component can be red (R), green 1 (G 1 ) blue (B) and green 2 (G 2 ) colour components as illustrated in FIG. 2 . Each of these colour “images” is quarter size of the final output image.
[0037] The second image model is provided for to be restored ( 130 ; 250 ). The images are arranged lexicographically into vectors, and the point-spread function h i is arranged into a block-Toeplitz circulant matrix H i . The second image model is then expressed as:
{overscore (g)} i =H i {overscore (ƒ)} i +{overscore (η)} i (3)
[0038] Having a reasonable approximation of H i the purpose of image restoration is to recover the best estimate {overscore (ƒ)} i from the degraded observation {overscore (g)} i . The blurring function H i is non-invertible (it is already defined on a limited support, so its inverse will have infinite support), so a direct inverse solution is not possible. The classical direct approach to solving the problem considers minimizing the energy between input and simulated re-blurred image, this is given by the norm:
J LS =∥{overscore (g)} i −H i {overscore ({circumflex over (ƒ)})} i ∥ 2 (4)
thus providing a least squares fit to the data. The minimization of the norm also leads to the solution of the maximum-likelihood, when the noise is known to be Gaussian. It also leads to the generalized inverse filter, which is given by:
( H T H ) {overscore ({circumflex over (ƒ)})} i =H T {overscore (g)} i (5)
[0039] In order to solve for this, it is common to use deterministic iterative techniques with the method of successive approximations, which leads to following iteration:
f _ ^ i ( 0 ) = μ H T g _ i
f _ ^ i ( k + 1 ) = f _ ^ i ( k ) + μ H T ( g _ i - f _ ^ i ( k ) ) ( 6 )
This iteration converges, if
0 < μ < 2 λ max ,
where λ max is the largest eigenvalue of the matrix H T H. The iteration continues until the normalized change in energy becomes quite small.
[0040] It can be seen from FIGS. 1 and 2 that the restoration ( 130 ; 250 ) is made separately for each of the colour components R, G, B.
[0041] The main advantages of iterative techniques are that there is no need to explicitly implement the inverse of the blurring operator and that the restoration process could be monitored as it progresses.
[0042] The last squares can be extended to classical least squares (CLS) technique. When spoken theoretically, the problem of image restoration is ill-posed, i.e. a small perturbation in the output, for example noise, can result in an unbounded perturbation of the direct least squares solution that is presented above. For this reason, the constrained least squares method is usually considered in the literatures. These algorithms minimize the term in equation (4) subject to the (smoothness) regularization term, which consists of a high-pass filtered version of the output. The regularization term permits the inclusion of prior information about the image.
[0000] Regularization Mechanism
[0043] In practise, the image sensor electronics, such as CCD and CMOS sensors, may introduce non-linearities to the image, of which the saturation is one of the most serious. Due to non-linearities unaccounted for in the image formation model, the separate processing of the colour channels might result in serious false colouring around the edges. Hence the invention introduces an improved regularization mechanism ( FIG. 2 ; 240 ) to be applied to restoration. The pixel areas being saturated or under-exposed are used to devise a smoothly varying coefficient that moderates the effect of high-pass filtering in the surrounding areas. The formulation of the image acquisition process is invariably assumed to be a linear one (1). Due to the sensitivity difference of the three colour channels, and fuzzy exposure controls, pixel saturation can happen incoherently in each of the colour channels. The separate channel restoration near those saturated areas results in over-amplification in that colour component alone, thus creating artificial colour mismatch and false colouring near those regions. To avoid this, a regularization mechanism according to the invention is proposed. The regularization mechanism is integrated in the iterative solution of equation (6). The idea is to spatially adapt μ in order to limit the restoration effect near saturated areas. The adapted step size is given as follows:
μ adap ( m,n )=β sat ( u, m )μ (9)
where μ is the global step-size as discussed earlier, and β sat is the local saturation control that modulates the step size. β sat is obtained using the following algorithm:
for each colour channel image g i , i={1 . . . 4}, consider the values of the window (w x w ) surrounding the pixel location g i (m, n), count the number of saturated pixels S i (m,n) in that window. The saturation control is given by the following equation:
β sat (m, n)=max(0,( w 2 −Σ i=1 4 S i ( m, n ))/ w 2 ).
β sat varies between 0 and 1 depending on the number of saturated pixels in any of the colour channels.
Image Reconstruction Chain
[0048] The previous description of the restoration of each of the colour component is applied as the first operation in the image reconstruction chain. The other operations ( 140 , 260 ) will follow such as for example Automatic White Balance, Colour Filter Array Interpolation (CFAI), Colour gamut conversion, Geometrical distortion and shading correction, Noise reduction, Sharpening. It will be appreciated that the final image quality ( 270 ) may depend on the effective and optimized use of all these operations in the reconstruction chain. One of the most effective implementations of the image reconstruction algorithms are non-linear. In FIG. 1 the image processing continues e.g. with image compression ( 150 ) or/and downsampling/dithering ( 160 ) process. Image can be viewed ( 180 ) by camera viewfinder or display or be stored ( 170 ) in compressed form in the memory.
[0049] The use of restoration as the first operation in the reconstruction chain ensures the best fidelity to be assumed linear imaging model. The following algorithms, especially the colour filter array interpolation and the noise reduction algorithms act as an additional regularization mechanism to prevent over amplification due to excessive restoration.
[0000] Implementation
[0050] The system according to the invention can be arranged into a device such as a mobile terminal, a web cam, a digital camera or other digital device for imaging. The system can be a part of digital signal processing in camera module to be installed into one of said devices. One example of the device is an imaging mobile terminal as illustrated as a simplified block chart in FIG. 3 . The device 300 comprises optics 310 or a similar device for capturing images that can operatively communicate with the optics or a digital camera for capturing images. The device 300 can also comprise a communication means 320 having a transmitter 321 and a receiver 322 . There can also be other communicating means 380 having a transmitter 381 and a receiver 382 . The first communicating means 320 can be adapted for telecommunication and the other communicating means 380 can be a kind of short-range communicating means, such as a Bluetooth™ system, a WLAN system (Wireless Local Area Network) or other system which suits local use and for communicating with another device. The device 300 according to the FIG. 3 also comprises a display 340 for displaying visual information. In addition the device 300 comprises a keypad 350 for inputting data, for controlling the image capturing process etc. The device 300 can also comprise audio means 360 , such as an earphone 361 and a microphone 362 and optionally a codec for coding (and decoding, if needed) the audio information. The device 300 also comprises a control unit 330 for controlling functions in the device 300 , such as the restoration algorithm according to the invention. The control unit 330 may comprise one or more processors (CPU, DSP). The device further comprises memory 370 for storing data, programs etc.
[0051] The imaging module according to the invention comprises imaging optics and image sensor and means for finding degradation information of each colour component and using said degradation information for determining a degradation function, and further means for restoring said each colour component by said degradation function. This imaging module can be arranged into the device being described previously. The imaging module can be also arranged into a stand-alone device 410 , as illustrated in FIG. 4 , communicating with an imaging device 400 and with a displaying device, which displaying device can be also said imaging device 400 or some other device, like a personal computer. Said stand-alone device 410 comprises a restoration module 411 and optionally other imaging module 412 and it can be used for image reconstruction independently. The communication between the imaging device 400 and the stand-alone device 410 can be handled by a wired or wireless network. Examples of such networks are Internet, WLAN, Bluetooth, etc.
[0052] The foregoing detailed description is provided for clearness of understanding only, and not necessarily limitation should be read therefrom into the claims herein. | This invention relates to a method for improving image quality of a digital image captured with an imaging module comprising at least imaging optics and an image sensor, where the image is formed through the imaging optics, the image consisting of at least one colour component. In the method degradation information of each colour component of the image is found and is used for obtaining a degradation function. Each colour component is restored by said degradation function. The image is unprocessed image data, and the degradation information of each colour component can be found by a point-spread function. The invention also relates to a device, to a module, to a system and to a computer program product and to a program module. | 28,051 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority benefit of provisional patent 61/615,884, “SIGNAL MODULATION METHOD RESISTANT TO ECHO REFLECTIONS AND FREQUENCY OFFSETS”, inventors Ronny Hadani and Shlomo Selim Rakib, filed Mar. 26, 2012; this application is also a continuation in part of U.S. patent application Ser. No. 13/117,119, ORTHONORMAL TIME-FREQUENCY SHIFTING AND SPECTRAL SHAPING COMMUNICATIONS METHOD, inventors Selim Shlomo Rakib and Ronny Hadani, filed May 26, 2011; Ser. No. 13/117,119 in turn claimed the priority benefit of US provisional application 61/349,619, “ORTHONORMAL TIME-FREQUENCY SHIFTING AND SPECTRAL SHAPING COMMUNICATIONS METHOD”, Inventors Selim Shlomo Rakib and Ronny Hadani, filed May 28, 2010; the contents of both applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention is in the general field of communications protocols and methods, and more specifically in methods of modulating communication signals that are resistant to echo reflections, frequency offsets, and other communications channel impairments.
[0004] 2. Description of the Related Art
[0005] Modern electronics communications, such as optical fiber communications, electronic wire or cable based communications, and wireless communications all operate by modulating signals and sending these signals over their respective optical fiber, wire/cable, or wireless mediums. These signals, which generally travel at or near the speed of light, can be subjected to various types of degradation or channel impairments. For example, echo signals can potentially be generated by optical fiber or wire/cable medium whenever the modulated signal encounters junctions in the optical fiber or wire/cable. Echo signals can also potentially be generated when wireless signals bounce off of wireless reflecting surfaces, such as the sides of buildings, and other structures. Similarly frequency shifts can occur when the optical fiber or wire/cable pass through different regions of fiber or cable with somewhat different signal propagating properties or different ambient temperatures; for wireless signals, signals transmitted to or from a moving vehicle can encounter Doppler effects that also result in frequency shifts. Additionally, the underlying equipment (i.e. transmitters and receivers) themselves do not always operate perfectly, and can produce frequency shifts as well.
[0006] These echo effects and frequency shifts are unwanted, and if such shifts become too large, can result in lower rates of signal transmission, as well as higher error rates. Thus methods to reduce such echo effects and frequency shifts are of high utility in the communications field.
[0007] In parent application Ser. No. 13/117,119, a novel method of wireless signal modulation was proposed operated by spreading data symbols over a larger range of times, frequencies, and spectral shapes (waveforms) than was previously employed by prior art methods (e.g. greater than such methods as Time Division Multiple Access (TDMA), Global System for Mobile Communications (GSM), Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency-Division Multiplexing (OFDM), or other methods). This newer method, which in Ser. No. 13/117,119 was termed “Orthonormal Time-Frequency Shifting and Spectral Shaping (OTFSSS)”, and which here will be referred to by the simpler “OTFS” abbreviation, operated by sending data in larger “chunks” or frames than previous methods. That is, while a prior art CDMA or OFDM method might encode and send units or frames of “N” symbols over a communications link over a set interval of time, the Ser. No. 13/117,119 invention would typically be based on a minimum unit or frame of N 2 symbols, and often transmit these N 2 symbols over longer periods of time. With OTFS modulation, each data symbol or element that is transmitted is spread out to a much greater extent in time, frequency, and spectral shape space than was the case for prior art methods. As a result, at the receiver end, it will generally would take longer to start to resolve the value of any given data symbol because this symbol must be gradually built-up or accumulated as the full frame of N 2 symbols are received.
[0008] Put alternatively, parent application Ser. No. 13/117,119 taught a wireless combination time, frequency and spectral shaping communications method that transmitted data in convolution unit matrices (data frames) of N×N (N 2 ), where generally either all N 2 data symbols are received over N spreading time intervals (each composed of N time slices), or none are. To determine the times, waveforms, and data symbol distribution for the transmission process, the N 2 sized data frame matrix would be multiplied by a first N×N time-frequency shifting matrix, permuted, and then multiplied by a second N×N spectral shaping matrix, thereby mixing each data symbol across the entire resulting N×N matrix (termed the TFSSS data matrix in '119). Columns from this N 2 TFSSS data matrix were then selected, modulated, and transmitted, on a one element per time slice basis. At the receiver, the replica TFSSS matrix was reconstructed and deconvoluted, revealing the data.
BRIEF SUMMARY OF THE INVENTION
[0009] In the present application, we have both revised and extended the earlier OTFS modulation scheme testing to more fully cover additional types of communications media (i.e. optical, electronic wire/cable, as well as wireless). Additionally, we have also expanded upon the earlier OTFS concepts, and have explored in additional detail how advanced signal modulation schemes utilizing cyclically time shifted and cyclically frequency shifted waveforms can be quite useful for correcting channel impairments in a broad range of situations.
[0010] According to the present extension of the earlier '119 OTFS concept, in some embodiments, the invention may be a method of transferring a plurality of data symbols using a signal modulated to allow automatic compensation for the signal impairment effects of echo reflections and frequency offsets. This method will generally comprise distributing this plurality of data symbols into one or more N×N symbol matrices, and using these one or more N×N symbol matrices to control the signal modulation of a transmitter. Here, at the transmitter, for each N×N symbol matrix, the transmitter uses each data symbol to weight N waveforms. These N waveforms are selected from a N 2 sized set of all permutations of N cyclically time shifted and N cyclically frequency shifted waveforms determined according to an encoding matrix U. The net result produces, for each data symbol, N symbol-weighted cyclically time shifted and cyclically frequency shifted waveforms. Generally this encoding matrix U is chosen to be an N×N unitary matrix that has a corresponding inverse decoding matrix U H . Essentially this constraint means that the encoding matrix U produces results that can ultimately be decoded.
[0011] Again at the transmitter, for each data symbol in the N×N symbol matrix, the transmitter will sum the corresponding N symbol-weighted cyclically time shifted and cyclically frequency shifted waveforms, and by the time that the entire N×N symbol matrix is so encoded, produce N 2 summation-symbol-weighted cyclically time shifted and cyclically frequency shifted waveforms.
[0012] The transmitter will then transmit these N 2 summation-symbol-weighted cyclically time shifted and cyclically frequency shifted waveforms, structured as N composite waveforms, over any combination of N time blocks or frequency blocks.
[0013] To receive and decode this transmission, the transmitted N 2 summation-symbol-weighted cyclically time shifted and cyclically frequency shifted waveforms are subsequently received by a receiver which is controlled by the corresponding decoding matrix U H . The receiver will then use this decoding matrix U H to reconstruct the original symbols in the various N×N symbol matrices.
[0014] This process of transmission and reception will normally be done by various electronic devices, such as a microprocessor equipped, digital signal processor equipped, or other electronic circuit that controls the convolution and modulation parts of the signal transmitter. Similarly the process of receiving and demodulation will also generally rely upon a microprocessor equipped, digital signal processor equipped, or other electronic circuit that controls the demodulation, accumulation, and deconvolution parts of the signal receiver. Although, because often wireless transmitters and receivers lend themselves to discussion, in this specification often wireless examples will be used, it should be understood that these examples are not intended to be limiting. In alternative embodiments, the transmitter and receiver may be optical/optical-fiber transmitters and receivers, electronic wire or cable transmitters and receivers, or other types of transmitters in receivers. In principle, more exotic signal transmission media, such as acoustic signals and the like, may also be done using the present methods.
[0015] As previously discussed, regardless of the media (e.g. optical, electrical signals, or wireless signals) used to transmit the various waveforms, these waveforms can be distorted or impaired by various signal impairments such as various echo reflections and frequency shifts. As a result, the receiver will often receive a distorted form of the original signal. Here, the invention makes use of the insight that cyclically time shifted and cyclically frequency shifted waveforms are particularly useful for detecting and correcting for such distortions.
[0016] Because the communications signal propagates trough its respective communications media at a finite speed (often at or near the speed of light), and because the distance from the original transmitter to the receiver is usually substantially different than the distance between the transmitter, the place(s) where the echo is generated, and the distance between the place(s) where the echo is generated and the receiver, the net effect of echo reflections is that at the receiver, both the original transmitted waveforms, and a time-shifted version of the original waveforms, are received, resulting in a distorted composite signal.
[0017] By using cyclically time shifted waveforms, however, a time deconvolution device at the receiver can analyze the cyclically time varying patterns of the waveforms, determine the repeating patterns, and use these repeating patterns to help decompose the echo distorted signal back into various time-shifted version of the various signals. The time deconvolution device can also determine how much of a time-offset (or multiple time offsets) is or are required to enable the time delayed echo signal(s) to match up with the original or direct signal. This time offset value, here called a time deconvolution parameter, can both give useful information as to the relative position of the echo location(s) relative to the transmitter and receiver, and can also help the system characterize some of the signal impairments that occur between the transmitter and receiver. This can help the communications system automatically optimize itself for better performance.
[0018] In addition to echo reflections, other signal distortions occur that can result in one or more frequency shifts. Here, an easy to understand example is the phenomenon of Doppler shifts. Doppler shi or Doppler effects are the change in wave frequency that occurs when a wave transmitter moves closer or further away from a wave receiver. These frequency shifts can occur, for example, when a wireless mobile transmitter moves towards or away from a stationary receiver. If the wireless mobile transmitter is moving towards the stationary receiver, the wireless waveforms that it transmits will be offset to higher frequencies, which can cause confusion if the receiver is expecting signals modulated at a lower frequency. An even more confusing result can occur if the wireless mobile transmitter is moving perpendicular to the receiver, and there is also an echo source (such as a building) in the path of the wireless mobile transmitter. Due to Doppler effects, the echo source receives a blue shifted (higher frequency) version of the original signal, and reflects this blue shifted (higher frequency) version of the original signal to the receiver. As a result, the receiver will receive both the direct wireless waveforms at the original lower frequency, and also a time-delayed higher frequency version of the original wireless waveforms, causing considerable confusion.
[0019] Here the use of cyclically time shifted waveforms and cyclically frequency shifted waveforms can also help solve this type of problem, because the cyclic variation provides important pattern matching information that can allow the receiver to determine what portions of the received signal were distorted, as well as how much distortion was involved. Here, these cyclically varying signals allow the receiver to do a two-dimensional (e.g. time and frequency) deconvolution of the received signal. For example, the frequency deconvolution portion of the receiver can analyze the cyclically frequency varying patterns of the waveforms, essentially do frequency pattern matching, and decompose the distorted signal into various frequency shifted versions of the various signals. At the same time, this portion of the receiver can also determine how much of a frequency offset is required to cause the frequency distorted signal match up with the original or direct signal. This frequency offset value, here called a “frequency deconvolution parameter”, can give useful information as to the transmitter's velocity relative to the receiver. It can help the system characterize some of the frequency shift signal impairments that occur between the transmitter and receiver.
[0020] As before, the time deconvolution part of the receiver can analyze the cyclically time varying patterns of the waveforms, again do time pattern matching, and decompose the echo distorted signal back into various time-shifted versions of the original signal. The time deconvolution portion of the receiver can also determine how much of a time-offset is required to cause the time delayed echo signal to match up with the original or direct signal. This time offset value, again called a “time deconvolution parameter”, can also give useful information as to the relative positions of the echo location(s), and can also help the system characterize some of the signal impairments that occur between the transmitter and receiver.
[0021] The net effect of both the time and frequency deconvolution, when applied to transmitters, receivers, and echo sources that potentially exist at different distances and velocities relative to each other, is to allow the receiver to properly interpret the impaired echo and frequency shifted communications signals.
[0022] Further, even if, at the receiver, the energy received from the un-distorted form of the original transmitted signal is so low as to have a undesirable signal to noise ratio, by applying the appropriate, appropriate time and frequency offsets or deconvolution parameters, the energy from the time and/or frequency shifted versions of the signals, which would otherwise be contributing to noise, can instead be harnessed to contribute to the signal instead.
[0023] As before, the time and frequency deconvolution parameters can also provide useful information as to the relative positions and velocities of the echo location(s) relative to the transmitter and receiver, as well as the various velocities between the transmitter and receiver. These in turn can help the system characterize some of the signal impairments that occur between the transmitter and receiver, as well as assist in automatic system optimization methods.
[0024] Thus in some embodiments, the invention may also provide a method for an improved communication signal receiver where, due to either one or the combination of echo reflections and frequency offsets, multiple signals due to echo reflections and frequency offsets result in the receiver receiving a time and/or frequency convoluted signal representing time and/or frequency shifted versions of the N 2 summation-symbol-weighed cyclically time shifted and frequency shifted waveforms previously sent by the transmitter. Here, the improved receiver will further perform a time and/or frequency deconvolution of the impaired signal to correct for various echo reflections and frequency offsets. This improved receiver method will result in both time and frequency deconvoluted results (i.e. signals with higher quality and lower signal to noise ratios), as well as various time and frequency deconvolution parameters that, in addition to automatic communications channel optimization, are also useful for other purposes as well. These other purposes can include channel sounding (i.e. better characterizing the various communication system signal impairments), adaptively selecting modulation methods according to the various signal impairments, and even improvements in radar systems.
[0025] Other extensions of the '119 OTFS methods, such as alternate methods of sending blocks of waveforms, will also be discussed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 shows an example of how transmitting cyclically time shifted waveforms can be useful to help a receiver perform time deconvolution of the received signal in order to compensate for various types of echo reflections.
[0027] FIG. 2 shows an example of how transmitting both cyclically time shifted waveforms and cyclically frequency shifted waveforms can be useful to help a receiver to perform both time and frequency of the received signal to compensate for both echo reflections and frequency shifts—in this example Doppler effect frequency shifts.
[0028] FIG. 3 shows an example of some of the basic building blocks (base vector, data vectors, Fourier Vector and Transmit vectors) that may be used to generate the cyclically time shifted and cyclically frequency shifted waveforms.
[0029] FIG. 4 shows a diagram of a cyclic time and frequency shifting transmitting method that may be used to encode and transmit data.
[0030] FIG. 5 shows a diagram of a cyclic time and frequency shifting receiving method that may be used to receive data.
[0031] FIG. 6A shows that the various composite waveform blocks transmitted by the transmitter can be either transmitted as a series of N consecutive time blocks (i.e. no other blocks in-between) or alternatively can be transmitted either time-interleaved with the blocks from a different symbol matrix (which in some cases may be from a different transmitter). Alternatively these waveform blocks may be frequency transposed to a one or more very different frequency ranges, and transmitted in parallel at the same time.
[0032] FIG. 6B shows that the various composite waveform blocks transmitted by the transmitter can be either transmitted as shorter duration time blocks over one or more wider frequency ranges, or as longer duration time blocks over one or more narrower frequency ranges.
[0033] FIG. 7 shows an example of a transmitter transmitting a series of N consecutive time blocks. In some embodiments, the transmitter may further incorporate a pre-equalization step to pre-compensate for various communications channel impairments such as echo reflections and frequency shifts.
[0034] FIG. 8A shows an example of improved receiver that mathematically compensates for the effects of echo reflections and frequency shifts. This time and frequency deconvolution series of math operations can additionally output deconvolution parameters that can also give information pertaining to the extent to which the echo reflections and frequency shifts distorted the underlying signal.
[0035] FIG. 8B shows an example of an improved receiver that utilizes a time and frequency deconvolution device to correct for the effects of echo reflections and frequency shifts. This time and frequency deconvolution device can additionally output deconvolution parameters that can also give information pertaining to the extent to which the echo reflections and frequency shifts distorted the underlying signal.
[0036] FIG. 9A shows an example of how echo reflections and frequency shifts can blur or impair or distort the transmitted signal.
[0037] FIG. 9B shows an example of an adaptive linear equalizer that may be used to correct for such distortions.
[0038] FIG. 9C shows an example of an adaptive decision feedback equalizer that may be used to correct for such distortions.
[0039] FIG. 10 shows a time-frequency graph giving a visualization of the various echo (time shifts) and frequency shifts that a signal may encounter during transmission. This can also be called the channel impulse response.
[0040] FIG. 11 shows an example of the functions that the feed forward (FF) portion of the adaptive decision feedback equalizer performs.
[0041] FIG. 12 shows an example of the functions of the Feedback (FB) portion of the adaptive decision feedback equalizer in action.
[0042] FIG. 13 shows that it may be useful to transmit various different time blocks in an interleaved scheme where the time needed to transmit all N blocks may vary between different data matrices D, and wherein the interleaving scheme is such as to take the latency, that is the time needed to transmit all N blocks, into account according to various optimization schemes.
DETAILED DESCRIPTION OF THE INVENTION
[0043] Matrix notation: In certain places, to better convey the fact that a number of the software controlled transmitter and receiver functions can be more precisely expressed using matrix mathematics notation, often the N×N matrices such as “D”, “U”, and the like will be expressed using matrix bracket notation such as [D] or [U]. Note however that, in general, if the text refers a particular N×N matrix either with or without the bracket notation, the intent and results are the same. The use of brackets is intended only as a way to make the underlying N×N matrix nature of that particular matrix (e.g. D or [D]) more apparent on initial reading.
[0044] As previously discussed in parent application Ser. No. 13/117,119, in one embodiment, the OTFS methods may be viewed as being a method of transmitting at least one N×N matrix of data symbols (i.e. one frame of data [D]) over a communications link, where each frame of data is a matrix of up to N 2 data elements or symbols, and N would be greater than 1. This method would generally comprise obtaining a hybrid analog and digital wireless transmitter, both usually microprocessor controlled, and assigning each data element to a unique waveform (corresponding waveform) which is derived from a basic waveform of duration N time slices over one spreading time interval (i.e. the time needed to send one block of data), with a data element specific combination of a time and frequency cyclic shift of this basic waveform. According to this method, each data element in the frame of data [D] would be multiplied by its corresponding waveform producing N 2 weighted unique waveforms. Here, over one spreading time interval, all N 2 weighted unique waveforms corresponding to each data element in the fame of data [D] are then simultaneously combined, and a different unique basic waveform of duration N time slices may be used for each consecutive time-spreading interval.
[0045] Here, the notion of a time-slice will be somewhat deemphasized. Here, the main criteria is that depending on the waveforms used, the time expended to transmit the waveforms (previously termed N time slices) should be long enough, with respect to the waveform(s) to allow the waveforms to be fully transmitted. The '119 concept of a time spreading interval can be understood as the length of time needed to adequately transmit these waveforms. This was previously also termed equivalent to N time slices. In the present terminology, this may be understood a corresponding to the time needed to transmit a time block of data.
[0046] '119 taught that typically, for each consecutive time spreading interval, a set of N unique waveforms would be used, and this set of N unique waveforms would generally form an orthonormal basis.
[0047] '119 also taught that to receive this data, the receiver would receive at least one frame of data [D] over the communications link, said frame of data comprising a matrix of up to N 2 data elements, again N being greater than 1. The receiver would in turn correlate the received signal with the set of all N 2 waveforms previously assigned to each data element by the transmitter for that specific time spreading interval, and produce a unique correlation score for each one of the N 2 data elements. Then for each data element, the receiver would sum these correlation scores over N time-spreading intervals. The summation of these correlation scores would then reproduce the N 2 data elements of the at least one frame of data [D].
[0048] More specifically Ser. No. 13/117,119 taught a method of transmitting and receiving at least one N×N frame of data ([D]) over a wireless communications link; where the frame of data comprising a matrix of up to N 2 data elements, N being greater than 1. Here, the data elements of the frame of data ([D]) were convoluted (in the present application, the alternate term “encoded” is generally used instead for this to avoid confusion with the present teaching of time and frequency deconvolution methods) so that the value of each data element, when transmitted, would be spread over a plurality of wireless waveforms, each waveform having a characteristic frequency, and each waveform carrying the convoluted (encoded) results from a plurality of data elements from the data frame. The '119 method would transmit the convoluted (encoded) results by cyclically shifting the frequency of this plurality of wireless waveforms over a plurality of times so that the value of each data element is transmitted as a plurality of cyclically frequency shifted waveforms sent over a plurality of times. The method would also receive and deconvolute (decode) this plurality of cyclically frequency shifted waveforms sent over a plurality of times, thereby reconstructing a replica of said at least one frame of data ([D]). '119 also taught the constraint that this convolution and deconvolution would be such that an arbitrary data element of an arbitrary frame of data ([D]) could not be guaranteed to be reconstructed with full accuracy until substantially all of said plurality of cyclically frequency shifted waveforms have been transmitted and received. Here this constraint is somewhat relaxed since error correction methods can, in principle, supply some missing data. However the general thought that a substantial majority of the waveforms should be transmitted and received still remains.
[0049] '119 also taught that generally each data element (symbol) would be assigned a unique waveform, often derived from a basic waveform of duration N time slices over one spreading time interval, with a data element specific combination of a time and frequency cyclic shift of said basic waveform. '119 also taught further multiplying this data element from the frame of data [D] by its corresponding waveform, producing N 2 weighted unique waveforms. In some embodiments of '119, over one spreading time interval, all N 2 weighted unique waveforms corresponding to each data element in the fame of data [D] would be simultaneously combined. '119 also taught as well that often a different unique basic waveform of duration N time slices could be used for each consecutive time-spreading interval. Generally a set of N unique waveforms could be used for each consecutive time-spreading interval (e.g. a time block according to present nomenclature), and this set of N unique waveforms would form an orthonormal basis.
[0050] In the present application, the basic '119 OTFS concept is generalized and extended, with particular emphasis to showing, in more detail, the advantages and applications of using cyclically time shifted and cyclically frequency shifted waveforms. To do this, it is useful to focus less on the matrix math used to generate the complex waveforms, and more on the underlying cyclic time shifted and cyclically frequency shifted nature of the waveforms. As a result, in the present application, the matrix math discussion of '119, although still useful as one specific method of producing the cyclic time shifted and cyclic frequency shifted waveforms, will be deemphasized, although parts of the earlier discussion will be reiterated. For a more complete discussion of various exemplary matrix math methods potentially suitable for some embodiments of the present invention, please refer to Ser. No. 13/117,119, incorporated herein by reference.
[0051] FIG. 1 shows an example of how transmitting cyclically time shifted waveforms can be useful to help a receiver perform time deconvolution of the received signal in order to compensate for various types of echo reflections.
[0052] Here, remember that the various signals all travel at a finite speed (often at or near the speed of light). In FIG. 1 , a wireless transmitter ( 100 ) is transmitting a complex cyclically time shifted and cyclically frequency shifted wireless waveform ( 102 ) in multiple directions. Some of these signals ( 104 ) go directly to the receiver ( 106 ). Other signals ( 108 ) bounce off of a wireless reflector, such as a building ( 107 ). These “echo” reflections ( 110 ) have to travel a longer distance to reach receiver ( 106 ), and thus end up being time delayed. As a result, receiver ( 106 ) receives a distorted signal ( 112 ) that is the summation of both the original ( 104 ) and the echo waveforms ( 110 ).
[0053] However since the invention relies on the transmission of cyclically time shifted waveforms, a time deconvolution device at the receiver (alternatively a time equalizer) ( 114 ) can analyze the cyclically time varying patterns of the waveforms, essentially do pattern matching, and decompose the rather complex and distorted signal back into various time-shifted versions ( 116 ) corresponding to ( 104 ), and ( 118 ) corresponding to ( 110 ) of the various signals. At the same time, the time deconvolution device ( 114 ) can also determine how much of a time-offset ( 120 ) is required to cause the time delayed echo signal ( 118 ), ( 110 ) to match up with the original or direct signal ( 116 ), ( 104 ). This time offset value ( 120 ), here called a time deconvolution parameter, can give useful information as to the relative position of the echo location(s) relative to the transmitter and receiver, and can also help the system characterize some of the signal impairments that occur between the transmitter and receiver.
[0054] FIG. 2 shows an example of how transmitting both cyclically time shifted waveforms and cyclically frequency shifted waveforms can be useful to help a receiver to perform both time and frequency of the received signal to compensate for both echo reflections and frequency shifts—in this example Doppler effect frequency shifts.
[0055] In FIG. 2 , a moving wireless transmitter ( 200 ) is again transmitting a complex cyclically time shifted and cyclically frequency shifted wireless waveform ( 202 ) in multiple directions. Here, for simplicity, assume that transmitter ( 200 ) is moving perpendicular to receiver ( 206 ) so that it is neither moving towards nor away from the receiver, and thus there are no Doppler frequency shifts relative to the receiver ( 206 ).
[0056] Here also assume that the transmitter ( 200 ) is moving towards a wireless reflector, such as a building ( 207 ), and thus the original wireless waveform ( 202 ) will be, by Doppler effects, shifted towards a higher frequency (blue shifted) relative to the reflector ( 207 ).
[0057] Thus those these signals ( 204 ) that go directly to the receiver ( 206 ) will, in this example, not be frequency shifted. However the Doppler shifted wireless signals ( 208 ) that bounce off of the wireless reflector, here again building ( 207 ), will echo off in a higher frequency shifted form. These higher frequency shifted “echo” reflections ( 210 ) also still have to travel a longer distance to reach receiver ( 206 ), and thus also end up being time delayed as well. As a result, receiver ( 206 ) receives a doubly distorted signal ( 212 ) that is the summation of both the original ( 204 ) and the time and frequency shifted echo waveforms ( 210 ).
[0058] However since, as before, the invention relies on the transmission of cyclically time shifted waveforms, a time and frequency deconvolution device (alternatively a time and frequency adaptive equalizer) at the receiver ( 214 ) can analyze the cyclically time varying and frequency varying patterns of the waveforms, essentially do pattern matching, and decompose the very complex and distorted signal back into various time-shifted and frequency shifted versions ( 216 ) corresponding to ( 204 ), and ( 218 ) corresponding to ( 210 ) of the various signals. At the same time, the time and frequency deconvolution device ( 214 ) can also determine how much of a time-offset ( 220 ) and frequency offset ( 222 ) is required to cause the time delayed and frequency shifted echo signal ( 218 ), ( 210 ) to match up with the original or direct signal ( 216 ), ( 204 ). This time offset value ( 220 ), here called a time deconvolution parameter, and frequency offset value ( 222 ), here called a frequency deconvolution parameter, can give useful information as to the relative position of the echo location(s) relative to the transmitter and receiver, and can also help the system characterize some of the signal impairments that occur between the transmitter and receiver.
[0059] The net effect of both time and frequency deconvolutions, when applied to transmitters, receivers, and echo sources that potentially exist at different distances and velocities relative to each other, is to allow the receiver to properly interpret the impaired signal. Here, even if the energy received in the primary signal is too low, with the application of appropriate time and frequency offsets or deconvolution parameters, the energy from the time and/or frequency shifted versions of the signals can be added to the primary signal, resulting in a less noisy and more reliable signal at the receiver. Additionally, the time and frequency deconvolution parameters can useful information as to the relative positions and velocities of the echo location(s) relative to the transmitter and receiver, as well as the various velocities between the transmitter and receiver, and can also help the system characterize some of the signal impairments that occur between the transmitter and receiver.
[0060] Thus in some embodiments, the invention may also be a method to provide an improved receiver where, due to either one or the combination of echo reflections and frequency offsets, multiple signals due to echo reflections and frequency offsets result in the receiver receiving a time and/or frequency convoluted signal representing time and/or frequency shifted versions of the N 2 summation-symbol-weighed cyclically time shifted and frequency shifted waveforms. Here, the improved receiver will further time and/or frequency deconvolute the time and/or frequency convoluted signal to correct for said echo reflections and frequency offsets. This will result in both time and frequency deconvoluted results (i.e. signals, typically of much higher quality and lower signal to noise ratio), as well as various time and frequency deconvolution parameters that, as will be discussed, are useful for a number of other purposes.
[0061] Before going into a more detailed discussion of other applications, however, it is useful to first discuss the various waveforms in more detail.
[0062] The invention generally utilizes waveforms produced by distributing plurality of data symbols into one or more N×N symbol matrices, and using these one or more N×N symbol matrices to control the signal modulation of a transmitter. Here, for each N×N symbol matrix, the transmitter may use each data symbol to weight N waveforms, selected from a N 2 sized set of all permutations of N cyclically time shifted and N cyclically frequency shifted waveforms determined according to an encoding matrix U, thus producing N symbol-weighted cyclically time shifted and cyclically frequency shifted waveforms for each data symbol. This encoding matrix U is chosen to be an N×N unitary matrix that has a corresponding inverse decoding matrix U H . The method will further, for each data symbol in the N×N symbol matrix, sum the N symbol-weighted cyclically time shifted and cyclically frequency shifted waveforms, producing N 2 summation-symbol-weighted cyclically time shifted and cyclically frequency shifted waveforms. According to the invention, the transmitter will transmit these N 2 summation-symbol-weighted cyclically time shifted and cyclically frequency shifted waveforms, structured as N composite waveforms, over any combination of N time blocks or frequency blocks.
[0063] Although a number of different schemes may be used to implement this method, here it is useful to briefly review some of the methods previously discussed in '119. Although not intended to be limiting, the method's and schemes of '119 provide one way to implement the present invention's modulation scheme.
[0064] As previously discussed, in parent application Ser. No. 13/117,119, again incorporated herein by reference, various waveforms can be used to transmit and receive at least one frame of data [D] (composed of a matrix of up to N 2 data symbols or elements) over a communications link. Here each data symbol may be assigned a unique waveform (designated a corresponding waveform), which is derived from a basic waveform.
[0065] For example, the data symbols of the data matrix [D] may be spread over a range of cyclically varying time and frequency shifts by assigning each data symbol to a unique waveform (corresponding waveform) which is derived from a basic waveform of length N time slices (in the present application the preferred terminology would be the time required to transmit this waveform, such as a time block), with a data symbol specific combination of a time and frequency cyclic shift of this basic waveform.
[0066] In '119, each symbol in the frame of data [D] is multiplied by its corresponding waveform, producing a series of N 2 weighted unique waveforms. Over one spreading time interval (or time block interval), all N 2 weighted unique waveforms corresponding to each data symbol in the fame of data [D] are simultaneously combined and transmitted. Further, a different unique basic waveform of length (or duration) of one time block (N time slices) may be used for each consecutive time-spreading interval (consecutive time block). Thus a different unique basic waveform corresponding to one time block may be used for each consecutive time-spreading interval, and this set of N unique waveforms generally forms an orthonormal basis. Essentially, each symbol of [D] is transmitted (in part) again and again either over all N time blocks, or alternatively over some combination of time blocks and frequency blocks (e.g. assigned frequency ranges).
[0067] In '119, to receive data over each time block of time, the received signal is correlated with the set of all N 2 waveforms previously assigned to each data symbol by the transmitter for that specific time block. (Thus just like other encoding/decoding methods, where the receiver has knowledge of the set of N 2 waveforms that the transmitter will assign to each data symbol). Upon performing this correlation, the receiver may produce a unique correlation score for each one of the N 2 data symbols. This process will be repeated over some combination of time blocks and frequency blocks until all N blocks are received. The original data matrix [D] can thus be reconstructed by the receiver by, for each data symbol, summing the correlation scores over N time blocks or frequency blocks, and this summation of the correlation scores will reproduce the N 2 data symbols of the frame of data [D].
[0068] '119 FIG. 3 shows an example of some of the basic building blocks (base vector, data vectors, Fourier Vector and Transmit vectors) that may be used to encode and decode data according to the invention. Here the data vector ( 300 ) can be understood as being N symbols (often one row, column, or diagonal) of the N×N [D] matrix, the base vector ( 302 ) can be understood as being N symbols (often one row, column, or diagonal) of an N×N [U 1 ] matrix, the Fourier vector ( 304 ) can be understood as being N symbols (often one row, column, or diagonal) of an N×N [U 2 ] matrix, which will often be a Discrete Fourier Transform (DFT) or Inverse Discrete Fourier Transform (IDFT) matrix. The transmit vector ( 306 ) can be understood as controlling the transmitter's scanning or selection process, and the transmit frame ( 308 ) is composed of units Tm ( 310 ) each of which is essentially a time block or spreading time interval, which itself may be viewed as composed of a plurality of time slices. Thus the transmit vector can be understood as containing N single time-spreading intervals or N time blocks ( 122 ) ( 310 ), which in turn are composed of multiple (such as N) time slices.
[0069] Note that in contrast to '119, in some embodiments of the present invention, some of these N time blocks may be transmitted non-consecutively, or alternatively some of these N time blocks may be frequency shifted to an entirely different frequency range, and transmitted in parallel with other time blocks from the original set of N time blocks in order to speed up transmission time. This is discussed later and in more detail in FIG. 6 .
[0070] Here, as previously discussed, to allow us to focus more on the underlying cyclically time shifted and cyclically shifted waveforms, the detailed aspects of one embodiment of a suitable modulation scheme, such as those previously discussed in more detail in parent application Ser. No. 13/117,119, will often be generalized and also discussed in simplified form. Thus here, for example, one way to implement the present method of “selecting from an N 2 set of all permutations of N cyclically time shifted and N cyclically frequency shifted waveforms” may correspond, at least in part, to an optional permutation operation P as well as to the other steps discussed in '119 and briefly reviewed here in FIGS. 3-5 . Additionally, the N 2 set of all permutations of N cyclically time shifted and N cyclically frequency shifted waveforms may be understood, for example, to be at least partially described by a Discrete Fourier transform (DFT) matrix or an Inverse Discrete Fourier Transform matrix (IDFT). This DFT and IDFT matrix can be used by the transmitter, for example, to take a sequence of real or complex numbers and modulate them into a series of different waveforms.
[0071] As one example, the individual rows for the DFT and IDFT matrix that can be used to generate these N cyclically time shifted and N cyclically frequency shifted waveforms can be understood as Fourier Vectors. In general, the Fourier vectors may create complex sinusoidal waveforms of the type:
[0000]
X
j
k
=
(
-
*
2
*
π
*
j
*
k
)
N
[0072] where, for an N×N DFT matrix, X is the coefficient of the Fourier vector in row k column N of the DFT matrix, and j is the column number. The products of this Fourier vector can be considered to be one example of the how the various time shifted and frequency shifted waveforms suitable for use in the present invention may be generated, but again this specific example is not intended to be limiting.
[0073] In FIG. 3 , the lines ( 312 ) indicate that each Fourier vector waveform ( 304 ) is manifested over the spreading time interval T m ( 310 ), which here corresponds to one time block.
[0074] FIG. 4 shows a diagram of one example of a cyclic convolution method that a transmitter can use to encode data and transmit data. As previously discussed in '119, particularly in the case where [U 1 ] is composed of a cyclically permuted Legendre number of length N, then on a matrix math level, the process of convoluting the data and scanning the data can be understood alternatively as being a cyclic convolution of the underlying data. Here the d 0 , d k , d N−1 can be understood as being the symbols or symbols of the data vector ( 300 ) component of the [D] matrix, the b m coefficients can be understood as representing the base vector ( 302 ) components of the [U 1 ] matrix, and the X coefficients can be understood as representing the Fourier vector ( 304 ) components of the [U 2 ] matrix. In FIG. 4 , the sum of the various [b m *X k ] can also be termed a “composite waveform”. Thus the full [D] matrix of symbols will ultimately be transmitted as N composite waveforms.
[0075] FIG. 5 shows a diagram of a cyclic deconvolution method that a receiver may use to decode the received data according to the second form of the invention. Again, as previously discussed in '119, particularly in the case where [U 1 ] is composed of a cyclically permuted Legendre number of length N, then the matrix math process of deconvoluting the data and reconstructing the data, that represents some of the methods used by the receiver, can be understood alternatively as being a cyclic deconvolution (cyclic decoding) of the transmitted data previously convoluted (encoded) in FIG. 4 . Here the ˜d 0 , ˜d k , ˜d N−1 can be understood as being the reconstructed symbols (symbols) of the data vector ( 400 ) component of the [D] matrix, the b m coefficients again can be understood as representing the base vector ( 302 ) components of the [U 1 ] matrix, and the X coefficients can again be understood as representing the Fourier vector ( 304 ) components of the [U 2 ] matrix. Here (R m ) ( 402 ) is a portion of the accumulated signal ( 230 ) received and demodulated by the receiver.
[0076] Although '119 mainly focused on the example where the various waveforms were sent in a time sequential manner, here other possibilities will be discussed in more detail.
[0077] FIG. 6A shows that the various waveform blocks transmitted by the transmitter ( 600 ) can be transmitted as a series of N consecutive time blocks (i.e. no other blocks inbetween). These consecutive time blocks can either be contiguous (i.e. with minimal or no time gaps inbetween various waveform blocks) ( 602 ) or they can be sparsely contiguous ( 604 ) (i.e. with time gaps between the various waveform bocks, which may in some embodiments be used for synchronization, hand shaking, listening for other transmitters, channel assessment and other purposes.
[0078] Alternatively, the various waveform time blocks can be transmitted either time-interleaved with the blocks from one or more different symbol matrices ( 606 , 608 ) (which in some cases may be from a different transmitter) in a contiguous or sparse interleaved manner ( 610 ).
[0079] As yet another alternative, some of the various waveform time blocks may be frequency transposed to entirely different frequency bands or ranges ( 612 ), ( 614 ), ( 616 ). This can speed up transmission time, because now multiple waveform time blocks can now be transmitted at the same time as different frequency blocks. As shown in ( 618 ) and ( 620 ), such multiple frequency band transmissions can also be done on a contiguous, sparse contiguous, contiguous interleaved, or sparse contiguous interleaved manner.
[0080] Here ( 622 ) and ( 628 ) represents one time block, and ( 624 ) and ( 630 ) represents the next time block. Here the various frequency ranges ( 612 ), ( 614 ), ( 616 ) can be formed, as will be described shortly, by modulating the signal according to different frequency carrier waves. Thus, for example, frequency range or band ( 612 ) might be transmitted by modulating a 1 GHz frequency carrier wave, frequency range or band ( 614 ) might be transmitted by modulating a 1.3 GHz frequency carrier wave, and band ( 615 ) might be transmitted by modulating a 1.6 GHz frequency carrier wave, and so on.
[0081] Put alternatively, the N composite waveforms, themselves derived from the previously discussed N 2 summation-symbol-weighted cyclically time shifted and cyclically frequency shifted waveforms, may be are transmitted over at least N time blocks. These N time blocks may be either transmitted consecutively in time (e.g. 602 , 604 ) or alternatively transmitted time-interleaved with the N time blocks from a second and different N×N symbol matrix.
[0082] FIG. 6B shows that the various composite waveform blocks transmitted by the transmitter can be either transmitted as shorter duration time blocks over one or more wider frequency ranges, or as longer duration time blocks over one or more narrower frequency ranges.
[0083] Note that the differences from FIG. 6A . FIG. 6B shows the tradeoffs between frequency bandwidth and time. Whereas in ( 640 ), the available bandwidth for each frequency range ( 612 ), ( 614 ), and ( 616 ) is relatively large, in ( 642 ), the available bandwidth for each frequency range ( 632 ), ( 634 ) and ( 636 ) is considerably less. Here, the invention can compensate by allowing more time per time block. Thus where as for ( 640 ), with high bandwidth available, the time blocks ( 622 ) and ( 624 ) can be shorter, in ( 642 ), with lower bandwidth available, the time blocks ( 626 ) needed to transmit the composite waveforms must be made correspondingly longer.
[0084] For both FIGS. 6A and 6B then, if there is only one fundamental carrier frequency, then all N blocks must be transmitted consecutively in time as N time blocks. If there are less than N multiple fundamental carrier frequencies available, then all N blocks can be transmitted as some combination of N time blocks and N frequency blocks. If there are N or more fundamental frequencies available, then all N blocks can be transmitted over the duration of 1 time block as N frequency blocks.
[0085] FIG. 7 shows an example of a transmitter, similar to those previously discussed in '119, transmitting a series of N consecutive waveform time blocks. Here, again, the length of the time block corresponds to the N time slices previously discussed in '119. Note that this example is not intended to be limiting.
[0086] This transmitter can comprise a more digitally oriented computation end ( 701 ) and a more analog signal oriented modulation end ( 702 ). At the digital end ( 701 ), a electronic circuit, which may be a microprocessor, digital signal processor, or other similar device will accept as input the data matrix [D] ( 703 ) and may either generate or accept as inputs the [U 1 ] ( 704 ) (e.g. a DFT/IDFT matrix) and [U 2 ] ( 705 ) (e.g. the encoding matrix U as discussed elsewhere) matrices as well as the permutation scheme P, previously described here and in parent application Ser. No. 13/117,119, again incorporated herein by reference, as well as in the example later on in the document. The digital section will then generate what was referred to in '119 as the TFSSS matrix, and what can alternatively be termed the OTFS(time/frequency shift) matrix. Once generated, individual elements from this matrix may be selected, often by first selecting one column of N elements from the TFSSS matrix, and then scanning down this column and picking out individual elements at a time ( 706 ). Generally one new element will be selected every time block.
[0087] Thus every successive time slice, one element from the TFSSS matrix ( 708 ) can be used to control the modulation circuit ( 702 ). In one embodiment of the invention, the modulation scheme will be one where the element will be separated into its real and imaginary components, chopped and filtered, and then used to control the operation of a sin and cosine generator, producing a composite analog waveform ( 720 ). The net, effect, by the time that the entire original N×N data symbol matrix [D] is transmitted, is to transmit the data in the form of N 2 summation-symbol-weighted cyclically time shifted and cyclically frequency shifted waveforms, structured as N composite waveforms. In the example shown in FIG. 7 , the data is transmitted over N consecutive waveforms over N time blocks. However as discussed elsewhere, other schemes are also possible, such as schemes in which some of composite waveforms are transposed to a different frequency range, and transmitted in parallel at the same time. In general the composite waveforms may be transmitted over any combination of N time blocks or frequency blocks.
[0088] Thus in this scheme (again neglecting overhead effects), elements t 1,1 through t n,1 from the first column of matrix ( 708 ) can be sent as a composite waveform in the first time block. The next elements t 1,2 through t n,2 from the second column of matrix ( 708 ) can be sent as a composite waveform in the next time block, and so on.
[0089] The various waveforms then travel to the receiver, where they may be demodulated and the data then reconstructed.
[0090] In some embodiments, the transmitter may further incorporate a pre-equalization step ( 703 ), and the output can be either regular OTFS signals ( 720 ) or pre-equalized OTFS signals ( 730 ). Thus if the receiver detects, for example that the transmitter's un-compensated for signal is subjected to specific echo reflections and frequency shifts, then the receiver can transmit corrective information to the transmitter pertaining to these echo reflections and frequency shifts, and the transmitter, at pre-equalization step ( 703 ), can then shape the signal so to compensate. Thus for example, if there is an echo delay, the transmitter can send the signal with an anti-echo cancellation waveform. Similarly if there is a frequency shift, the transmitter can perform the reverse frequency shift to compensate.
[0091] FIG. 8A shows an example of improved receiver that mathematically compensates for the effects of echo reflections and frequency shifts. This time and frequency deconvolution series of math operations can additionally output deconvolution parameters that can also give information pertaining to the extent to which the echo reflections and frequency shifts distorted the underlying signal. This can be done by a deconvolution device or adaptive equalizer operating at step ( 802 A).
[0092] FIG. 8B shows an example of an improved receiver that utilizes a time and frequency deconvolution device ( 802 B) (similar to devices ( 114 ) and ( 224 ) previously discussed in FIGS. 1 and 2 ) to correct for the effects of echo reflections and frequency shifts. This time and frequency deconvolution device can additionally output deconvolution parameters ( 808 ) (similar to deconvolution parameters ( 120 ), ( 220 ), and ( 2220 previously discussed in FIGS. 1 and 2 ) that can give information pertaining to the extent to which the echo reflections and frequency shifts distorted the underlying signal ( 720 ).
[0093] In FIGS. 8A and 8B , assume that composite waveform ( 720 ) has, since transmission, been distorted by various echo reflections and/or frequency shifts as previously shown in FIGS. 1 and 2 , producing a distorted waveform ( 800 ) (here for simplicity a simple echo reflection delayed distortion is drawn). Whereas in FIG. 8A , this effect is corrected for mathematically, in FIG. 8 B, in order to clean up the signal, a time and frequency deconvolution device ( 802 A or 802 B) (e.g. an adaptive equalizer) can analyze the distorted waveform ( 800 ) and, assisted by the knowledge that the original composite waveform was made up of N cyclically time shifted and N cyclically frequency shifted waveforms, determine what sort of time offsets and frequency offsets will best deconvolute distorted waveform ( 802 A or 802 B) back into a close representation of the original waveform ( 720 ), where here the deconvoluted waveform is represented as waveform ( 804 ). In the FIG. 8B scheme or embodiment, this deconvoluted waveform is then fed into the receiver previously shown in FIG. 5 ( 806 ) where the signal can then be further processed as previously described. In FIG. 8A embodiment, the time and frequency deconvolution can be done inside receiver ( 806 ).
[0094] In the process of doing this deconvolution, either the time and frequency deconvolution device ( 802 A or 802 B) or the mathematical deconvolution process will produce a set of deconvolution parameters ( 808 ). For example, in the simple case where the original waveform ( 720 ) was distorted by only a single echo reflection offset by time t offset , and by the time the original waveform ( 720 ) and the t offset echo waveform reach the receiver, the resulting distorted signal ( 800 ) is 90% original waveform and 10% t offset echo waveform, then the deconvolution parameters ( 808 ) can output both the 90% 10% signal mix, as well as the t offset value. Typically, of course, the actual distorted signal ( 800 ) will typically consist of a number of various time and frequency offset components, and here again, in addition to cleaning this up, the time and frequency deconvolution device ( 802 ) can also report the various time offsets, frequency offsets, and percentage mix of the various components of signal ( 800 ).
[0095] As previously discussed in FIGS. 6A and 6B , the various composite waveforms in the N time blocks can be transmitted in various ways. In addition to time consecutive transmission, i.e. a first block, followed (often by a time gap which may optionally be used for handshaking or other control signals) by a second time block and then a third time block, the various blocks of composite waveforms can be transmitted by other schemes.
[0096] In some embodiments, for example in network systems where there may be multiple transmitters and potentially also multiple receivers, it may be useful to transmit the data from the various transmitters using more than one encoding method. Here, for example, a first set of N time blocks may transmit data symbols originating from a first N×N symbol matrix, and from a first transmitter using a first unitary matrix [U 1 ]. A second set of N time blocks may transmit data symbols originating from a second N×N symbol matrix, and from a second transmitter using a second unitary matrix [U 2 ]. Here depending on the embodiment, [U 1 ] and [U 2 ] may be identical or different. Because the signals originating from the first transmitter may encounter different impairments (e.g. different echo reflections, different frequency shifts), some schemes of cyclically time shifted and cyclically shifted waveforms may operate better than others. Here these waveforms, as well as the previously discussed unitary matrices [U 1 ] and [U 2 ], may be selected based on the characteristics of these particular echo reflections, frequency offsets, and other signal impairments of the system and environment of said first transmitter, said second transmitter and said receiver.
[0097] Here, for example, a receiver operating according to FIG. 8 may, for example, use its particular deconvolution parameters ( 808 ) to propose an alternative set of cyclically time shifted and cyclically frequency shifted waveforms that might give superior operation in that environment. The receiver might then and transmit this suggestion (or command) to that corresponding transmitter. This type of “handshaking” can be done using any type of signal transmission and encoding scheme desired. Thus in a multiple transmitter and receiver environment, each transmitter may attempt to optimize its signal so that its intended receiver is best able to cope with the unique impairments of that particular transmitter-receiver-communications-media situation.
[0098] In some cases, before transmitting large amounts of data, or any time as desired, a given transmitter and receiver may choose to more directly test the various echo reflections, frequency shifts, and other impairments of the transmitter and receiver's system and environment. This can be done, by, for example having the transmitter send a test signal where the plurality of data symbols are selected to be known test symbols, and the receiver knows (i.e. has a record of these particular test symbols). Since the receiver knows exactly what sort of signal it will receive, the receiver will generally have a better ability to use its time and frequency deconvolution device ( 802 ) and obtain even more accurate time and frequency deconvolution parameters ( 808 ). This will allow the system to determine the characteristics of the echo reflections, frequency offsets, and other signal impairments of the said transmitter and said receiver's system and environment even more accurately. This in turn can be used to command the transmitter to shift to more optimal communications schemes (e.g. various U matrices) suitable to the situation.
[0099] In some embodiments, when the transmitter is a wireless transmitter and the receiver is a wireless receiver, and the frequency offsets are caused by Doppler effects, the more accurate determination of the deconvolution parameters, i.e. the characteristics of the echo reflections and frequency offsets can be used in a radar system to determine the location and velocity of at least one object in said environment of said transmitter and receiver.
EXAMPLES
[0100] A microprocessor controlled transmitter may package a series of different symbols “d” (e.g. d 1 , d 2 , d 3 . . . ) for transmission by repackaging or distributing the symbols into various elements of various N×N matrices [D] by, for example assigning d 1 to the first row and first column of the [D] matrix (e.g. d 1 =d 0,0 ), d 2 to the first row second column of the [D] matrix (e.g. d 2 =d 0,1 ) and so on until all N×N symbols of the [D] matrix are full. Here, once we run out of d symbols to transmit, the remaining [D] matrix elements can be set to be 0 or other value indicative of a null entry.
[0101] The various primary waveforms used as the primary basis for transmitting data, which here will be called “tones” to show that these waveforms have a characteristic sinusoid shape, can be described by an N×N Inverse Discrete Fourier Transform (IDFT) matrix [W], where for each element w in [W],
[0000]
w
j
,
k
=
2
π
j
k
N
[0000] or alternatively w j,k =e ijθ k or w j,k =[e iθ k ] j . Thus the individual data elements d in [D] are transformed and distributed as a combination of various fundamental tones w by a matrix multiplication operation [W]*[D], producing a tone transformed and distributed form of the data matrix, here described by the N×N matrix [A], where [A]=[W]*[D].
[0102] To produce the invention's N cyclically time shifted and N cyclically frequency shifted waveforms, the tone transformed and distributed data matrix [A] is then itself further permuted by by modular arithmetic or “clock” arithmetic, creating an N×N matrix [B], where for each element of b of [B], b i,j =a i,(i+j)mod N . This can alternatively be expressed as [B]=Permute([A])=P(IDFT*[D]). Thus the clock arithmetic controls the pattern of cyclic time and frequency shifts.
[0103] The previously described unitary matrix [U] can then be used to operate on [B], producing an N×N transmit matrix [T], where [T]=[U]*[B], thus producing a N 2 sized set of all permutations of N cyclically time shifted and N cyclically frequency shifted waveforms determined according to an encoding matrix [U].
[0104] Put alternatively, the N×N transmit matrix [T]=[U]*P(IDFT*[D]).
[0105] Then, typically on a per column basis, each individual column of N is used to further modulate a frequency carrier wave (e.g. if we are transmitting in a range of frequencies around 1 GHz, the carrier wave will be set at 1 GHz), and each column the N×N matrix [T] which has N elements, thus produces N symbol-weighted cyclically time shifted and cyclically frequency shifted waveforms for each data symbol. Effectively then, the transmitter is transmitting the sum of the N symbol-weighted cyclically time shifted and cyclically frequency shifted waveforms from one column of [T] at a time as, for example, a composite waveform over a time block of data. Alternatively the transmitter could instead use a different frequency carrier wave for the different columns of [T], and thus for example transmit one column of [T] over one frequency carrier wave, and simultaneously transmit a different column of [T] over a different frequency carrier wave, thus transmitting more data at the same time, although of course using more bandwidth to do so. This alternative method of using different frequency carrier waves to transmit more than one column of [T] at the same time will be referred to as frequency blocks, where each frequency carrier wave is considered its own frequency block.
[0106] Thus, since the N×N matrix [T] has N columns, the transmitter will transmit the N 2 summation-symbol-weighted cyclically time shifted and cyclically frequency shifted waveforms, structured as N composite waveforms, over any combination of N time blocks or frequency blocks, as previously shown in FIG. 6A or 6 B.
[0107] On the receiver side, the transmit process is essentially reversed. Here, for example, a microprocessor controlled receiver would of course receive the various columns [T] (e.g. receive the N composite waveforms, also known as the N symbol-weighted cyclically time shifted and cyclically frequency shifted waveforms) over various time blocks or frequency blocks as desired for that particular application. If for example there is a lot of available bandwidth and time is of the essence, then the transmitter will transmit, and the receiver will receive, the data as multiple frequency blocks over multiple frequency carrier waves. On the other hand, if available bandwidth is more limited, and/or time (latency) is less critical, then the transmit will transmit and the receiver will receive over multiple time blocks instead.
[0108] So effectively the receiver tunes into the one or more frequency carrier waves, and over the number of time and frequency blocks set for that particular application eventually receives the data or coefficients from original N×N transmitted matrix [T] as an N×N receive matrix [R] where [R] is similar to [T], but may not be identical due to various communications impairments.
[0109] The microprocessor controlled receiver then reverses the transmit process as a series of steps that mimic, in reverse, the original transmission process. The N×N receive matrix [R] is first decoded by inverse decoding matrix [U H ], producing an approximate version of the original permutation matrix [B], here called [B R ], where [B R ]=([U H ]*[R]).
[0110] The receiver then does an inverse clock operation to back out the data from the cyclically time shifted and cyclically frequency shifted waveforms (or tones) by doing an inverse modular mathematics or inverse clock arithmetic operation on the elements of the N×N [B R ] matrix, producing, for each element b R of the N×N [B R ] matrix, a i,j R =b i,(j−i)mod N R . This produces a “de-cyclically time shifted and de-cyclically frequency shifted” version of the tone transformed and distributed form of the data matrix [A], here called [A R ]. Put alternatively, [A R ]=Inverse Permute ([B R ]), or [A R ]=P −1 ([U H ]*[R]).
[0111] The receiver then further extracts at least an approximation of the original data symbols d from the [A R ] matrix by analyzing the [A] matrix using an N×N Discrete Fourier Transform matrix DFT of the original Inverse Fourier Transform matrix (IDFT).
[0112] Here, for each received symbol d R , the d R are elements of the N×N received data matrix [D R ] where [D R ]=DFT*A R , or alternatively [D R ]=DFT*p −1 ([U H ]*[R]).
[0113] Thus the original N 2 summation-symbol-weighted cyclically time shifted and cyclically frequency shifted waveforms are subsequently received by a receiver which is controlled by the corresponding decoding matrix U H (also represented as [U H ]) The receiver (e.g. the receiver's microprocessor and associated software) uses this decoding matrix [U H ] to reconstruct the various transmitted symbols “d” in the one or more originally transmitted N×N symbol matrices [D] (or at least an approximation of these transmitted symbols).
[0114] As previously discussed, there are several ways to correct for distortions caused by the signal impairment effects of echo reflections and frequency shifts. One way is, at the receiver front end, utilize the fact that the cyclically time shifted and cyclically frequency shifted waveforms or “tones” form a predictable time-frequency pattern, and a “dumb” deconvolution device situated at the receiver's front end can recognize these patterns, as well as the echo reflected and frequency shifted versions of these patterns, and perform the appropriate deconvolutions by a pattern recognition process. Alternatively the distortions may be mathematically corrected by the receiver's software, here by doing suitable mathematical transformations to essentially determine the echo reflected and frequency shifting effects, and solve for these effects. As a third alternative, once, by either process, the receiver determines the time and frequency deconvolution parameters of the communication media's particular time and frequency distortions, the receiver may transmit a command to the transmitter to instruct the transmitter to essentially pre-compensate or pre-encode for these effects. That is, if for example the receiver detects an echo, the transmitter can be instructed to transmit in a manner that offsets this echo, and so on.
[0115] FIG. 9A shows an example of how echo reflections and frequency shifts can blur or impair or distort the transmitted signal ( 900 ) by inducing additive noise ( 902 ). These distortions can be modeled as a 2-dimensional filter acting on the data array. This filter represents, for example, the presence of multiple echoes with time delays and Doppler shifts. To reduce these distortions, the signal can either be pre-equalized before receiver subsequent receiver processing ( 904 ), or alternatively post-equalized after the D R matrix has been recovered at ( 906 ). This equalization process may be done either by analog or digital methods. The equalized form of the received D matrix, which ideally will completely reproduce the original D matrix, is termed D eq .
[0116] FIG. 9B shows an example of an adaptive linear equalizer that may be used to correct for such distortions. This adaptive linear equalizer can function at either step ( 904 ), optionally as a more analog method or step ( 906 ), generally as a more digital and mathematical process.
[0117] The equalizer may, in some embodiments, described in more detail in copending provisional patent 61/615,884, the contents of which are incorporated herein by reference, operate according to the function:
[0000]
Y
(
k
)
=
∑
L
=
Lc
Rc
C
(
l
)
*
X
(
k
-
l
)
+
η
(
k
)
.
[0118] Please see application 61/615,884 for term definitions and further discussion.
[0119] FIG. 9C shows an example of an adaptive decision feedback equalizer that may be used to correct for such distortions. This equalizer both shifts the echo and frequency shifted signals on top of the main signal in a forward feedback process ( 910 ), and also then uses feedback signal cancelation methods to further remove any residual echo and frequency shifted signals in ( 912 ). The method then effectively rounds the resulting signals to discrete values.
[0120] The equalizer may, in some embodiments, also described in more detail in copending provisional application 61/615,884, operate according to the function:
[0000]
X
s
(
k
)
=
∑
l
=
L
F
R
F
F
(
l
)
*
Y
(
k
+
l
)
-
∑
l
-
L
B
-
1
B
(
l
)
*
X
h
(
k
+
l
)
[0121] Where X H (k)=Q(X s (k))
[0122] As before, please see application 61/615,884 for term definitions and further discussion.
[0123] FIG. 10 shows a time-frequency graph giving a visualization of the various echo (time shifts) and frequency shifts that a signal may encounter during transmission. This can also be called the channel impulse response. If there were no echo (time shift) or frequency shifts at all, then graph 10 would show up as a single spike at a defined time and frequency. However due to various echos and frequency shifts, the original signal which could be represented as a spike at ( 1000 ) is instead spread over both time ( 1002 ) and frequency ( 1004 ), and here the problem is to correct for these effects, either before further processing at the receiver ( 904 ), or later after the receiver has taken the processing to the D R stage ( 906 ). The other alternative, pre-equalizing at the transmitter stage by pre-equalizing the signal ( 908 ) prior to transmission, can be handled by a related process.
[0124] FIG. 11 shows an example of the functions that the feed forward (FF) portion ( 910 ) of the adaptive decision feedback equalizer ( FIG. 9C ) performs. To simplify, this portion ( 910 ) of the equalizer works to shift the echo or frequency shifted signals to once again coincide with the main signal, and thus enhances the intensity of the main signal while diminishing the intensity of the echo or frequency shifted signals.
[0125] FIG. 12 shows an example of the functions of the Feedback (FB) portion ( 912 ) of the adaptive decision feedback equalizer ( FIG. 9C ) in action. After the Feed forward (FF) portion ( 910 ) of the equalizer has acted to mostly offset and the echo and frequency shifted signals, there will still be some residual echo and frequency signals remaining. The Feedback (FB) portion ( 912 ) essentially acts to cancel out those trace remaining echo signals, essentially acting like an adaptive canceller for this portion of the system.
[0126] The quantizer portion of the adaptive decision feedback equalizer ( 914 ) then acts to “round” the resulting signal to the nearest quantized value so that, for example, the symbol “1” after transmission, once more appears on the receiving end as “1” rather than “0.999”.
[0127] As previously discussed, an alternative mathematical discussion of the equalization method, particularly suitable for step 802 B, is described in provisional application 61/615,884, the contents of which are incorporated herein by reference.
[0128] Final interleaving discussion:
[0129] Returning to the interleaving concepts, FIG. 13 shows that it may be useful to transmit various different time blocks in an interleaved scheme where the time needed to transmit all N blocks may vary between different data matrices D, and wherein the interleaving scheme is such as to take the latency, that is the time needed to transmit all N blocks, into account according to various optimization schemes. | A method of modulating communications signals, such as optical fiber, wired electronic, or wireless signals in a manner that facilitates automatic correction for the signal distortion effects of echoes and frequency shifts, while still allowing high rates of data transmission. Data symbols intended for transmission are distributed into N×N matrices, and used to weigh or modulate a family of cyclically time shifted and cyclically frequency shifted waveforms. Although these waveforms may then be distorted during transmission, their basic cyclic time and frequency repeating structure facilitates use of improved receivers with deconvolution devices that can utilize the repeating patterns to correct for these distortions. The various waveforms may be sent in N time blocks at various time spacing and frequency spacing combinations in a manner that can allow interleaving of blocks from different transmitters. Applications to channel sounding/characterization, system optimization, and also radar are also discussed. | 82,824 |
TECHNICAL FIELD OF THE INVENTION
[0001] The invention generally relates to the field of data communication, and particularly, relates to a method and system for processing SIP (Session Initiation Protocol) messages, and more particularly, relates to a method and system for binarizing SIP messages to reduce the load of SIP server (abbreviated as offload hereinbelow) and benefit for selectively processing SIP messages.
BACKGROUND OF THE INVENTION
[0002] One foundational session control protocol is becoming an emerging workload in the telecom Next-Generation-Network (NGN) and IT collaborative solution. SIP is one text-based message protocol. It operates independently of the underlying network transport protocols, establishing sessions between multiple users irrespective of whether the transferred data is text data, audio data, or video data. In the SIP protocol stack, however, some computation-intensive operations, such as token parsing and security processing, will occupy a large amount of CPU cycles. As SIP-based applications are becoming popular, these operations could be potential performance bottlenecks for SIP servers, such as proxy servers or application servers.
[0003] To address this, SIP Offload Engine (SOE) architecture is proposed. As shown in FIG. 1 , a front end 110 parses a SIP message, binarizes it, and generates an “SIP Offload Engine (SOE) message”, abbreviated as SOE message hereinbelow. The objective of applying such offload technology is to offload the computation-intensive operations from the server end to some special appliances, such as front ends. In particular, the front end will parse the tokens in the SIP message, and transform the text-based message to a binary SOE message, and then the server will parse the SOE message. The term “token” is defined as an indecomposable part provided to an upper-layer logic through an interface, which is a character string separated by separators, such as semicolons, spaces. Thus, at server end more CPU cycles may be freed up for upper-layer applications to improve the overall performance.
[0004] The SIP protocol enables end users to communicate with each other via messages. The basic form of a message could either be a request sent from a client to a server or a reply from the server to the client. A message consists of a start-line, one or more header fields, a null line indicating the end of the header fields, and an optional message-body. The generic structure of an SIP message is shown as below:
[0000]
generic-message = start-line
message header field 1
message header field 2
..
..
CRLF
message-body [optional]
start-line = Request-Line/Status-Line
[0005] 1. SIP Request Message
[0006] A request may be recognized by the presence of a Request-Line as the start-line. The format of a request-line is shown as below:
Request-Line=Method SP Request-URI SP SIP-Version CRLF
[0008] A method is an action associated with a session between end users. The examples of a method comprise: REGISTER, INVITE, OPTIONS, ACK, CANCEL, BYE, defined in RFC3261 specification; and other methods defined in other separate RFC specifications. The Request-URI is the recipient of the SIP message. The SIP Version is currently SIP/2.0 and is to be included in all messages. The CRLF terminates the Request-Line.
[0009] 2. SIP Response Message
[0010] A response may be recognized by the presence of a Status-Line as the start-line. The format of a status-line is shown as below:
Status-Line=SIP-Version SP Status-code SP Reason-Phrase CRLF
[0012] The Status-Code represents the result of the action taken due to the request. The result of a request is categorized below:
[0013] (a) 100-199: A request was received, processed in progress.
[0014] (b) 200-299: The request was received, understood, and accepted.
[0015] (c) 300-399: Further action needs to be taken to complete the processing of the request.
[0016] (d) 400-499: The request cannot be processed at the server, possibly due to bad syntax.
[0017] (e) 500-599: The server failed to process the request. The request could have been invalid.
[0018] (f) 600-699: Global failure. The request cannot be processed by any server. The Reason-Phrase is an English-like equivalent of the Status-Code. For example, for Status-Code 200, the Reason-Phrase is “OK”.
[0019] Both the Request/Response messages may have multiple message headers. These SIP header fields form a part of the SIP message. Each header conveys some information for the destination. The format of an SIP message header is shown as below:
field-name: [field-value]
[0021] It is noted that the field value could extend over multiple lines.
[0022] The type of a header field can be thought of to be based on the function performed by that header. 44 types of headers are defined in RFC3261 specification. The major header types comprise, but not limit to:
[0023] 1. Originator fields: From, To
[0024] 2. Routing fields: Via
[0025] 3. Authentication: Proxy-Authenticate
[0026] It can be seen from above that an SIP message has the following three features: a) a large number of token values with variable lengths; b) line-by-line structure; and c) multiple tokens in each line. Therefore, how to binarize SIP messages is critical for the implementation of the offload technology.
[0027] As one of the existing approaches, ASN.1 can be used for accommodating the token information in a way of <Type, Length, Value> (TLV). But this TLV approach is not efficient since most of the values in an SIP message are strings with variable lengths, then the parser will have to go through the whole message to get the information needed.
[0028] Another existing approach is to allocate a fixed position for each token. But this approach also has multiple defects. First, the storage efficiency is affected, as there will be waste storage space between tokens with different lengths. Second, the blank storage space must be skipped while processing messages, which also affects the processing efficiency. Third, there is no sufficient space reserved for “optional” tokens.
[0029] Therefore, there is a need for an approach to binarize an SIP message efficiently.
SUMMARY OF THE INVENTION
[0030] The invention is proposed in order to solve the above problems. According to one aspect of the invention, a method for processing session initiation protocol messages is proposed, comprising the following steps:
[0031] receiving a session initiation protocol message by a front end;
[0032] parsing the session initiation protocol message by the front end, grouping the token types and the token contents in the session initiation protocol message respectively, and setting up corresponding links between the token types and the token contents, wherein the session initiation protocol message, after parsing, is transformed to the session initiation protocol offload engine message with the following three parts: a session initiation protocol offload engine message header part, for storing message level information; a token type part, for storing token type information, wherein it comprises a plurality of fixed-length entries; and a token content part, for storing token contents, wherein it comprises a plurality of variable-length entries; and
[0033] processing the transformed session initiation protocol offload engine message at the server end.
[0034] According to another aspect of the invention, a system for processing session initiation protocol messages is proposed, comprising:
[0035] a front end, which comprises a message parser;
[0036] a server, which comprises a message processing means;
[0037] wherein,
[0038] a session initiation protocol message is received by the front end;
[0039] the session initiation protocol message is parsed by the message parser, the token types and the token contents in the session initiation protocol message are grouped respectively, and corresponding links are set up between the token types and the token contents, the session initiation protocol message, after parsing, is transformed to the session initiation protocol offload engine message with the following three parts: a session initiation protocol offload engine message header part, for storing message level information; a token type part, for storing token type information, wherein it comprises a plurality of fixed-length entries; and a token content part, for storing token contents, wherein it comprises a plurality of variable-length entries; and
[0040] the transformed session initiation protocol offload engine message is processed by the message processing means.
[0041] According to still another aspect of the invention, there is provided a program product embodied in a computer readable medium comprising computer executable program code for performing steps of the above method.
[0042] The method and system for binarizing SIP messages for offload and selective processing proposed by the present invention transform text-based SIP messages to binary-based SOE messages efficiently and rapidly, thereby significantly reducing the working load of the server while taking the storage efficiency into account.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] The invention itself and its preferred mode, together with further objects and advantages, will be best appreciated from the reading of the following detailed description of the illustrative embodiments taken in conjunction with the drawings, in which:
[0044] FIG. 1 illustrates an illustrative diagram of the SOE architecture;
[0045] FIG. 2 illustrates an illustrative diagram of the overall structure of an SOE message according to a preferable embodiment of the invention;
[0046] FIG. 3 illustrates the data structure of an SOE message according to a preferable embodiment of the invention;
[0047] FIG. 4 illustrates a flowchart of a method for binarizing SIP messages according to an embodiment of the invention;
[0048] FIG. 5A illustrates an illustrative diagram of the SOE header part according to a preferable embodiment of the invention;
[0049] FIG. 5B illustrates an illustrative diagram of the token type part according to a preferable embodiment of the invention;
[0050] FIG. 5C illustrates an illustrative diagram of the encoding for the fixed-length value in the token content part according to a preferable embodiment of the invention;
[0051] FIG. 5D illustrates an illustrative diagram of the encoding for the variable-length value in the token content part according to a preferable embodiment of the invention;
[0052] FIG. 6 illustrates a flowchart of a method for selectively processing messages at the server end;
[0053] FIG. 7 illustrates a structural schematic diagram of processing SIP messages in different granularities and in different time sequences according to preferable embodiments of the invention; and
[0054] FIG. 8 illustrates a schematic diagram of a system for processing SIP messages according to a preferable embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0055] In order to binarize SIP messages efficiently, the invention proposes a new SOE message structure. As seen from FIG. 2 , the overall structure of an SOE message according to a preferable embodiment of the invention comprises three parts:
An SOE header part 210 , for storing the SOE message level information. A token type entry part 220 , for storing the token type information, wherein it may comprise a plurality of fixed-length (aligned) entries. A token content entry part 230 , for storing the token value, wherein it may comprise a plurality of variable-length entries.
[0059] FIG. 3 illustrates the data structure of an SOE message according to a preferable embodiment of the invention. Referring to FIG. 3 , in the present invention, the tokens contained in an SIP message are transformed to token type entries 310 and token content entries 320 in a certain format, and both are grouped respectively. The token type is denoted with TYPE_A.TYPE_B in the type entries 310 , wherein, the TYPE_A part distinguishes which header the token is in, and the TYPE_B part tells the detailed type information of the token. Such type denotation just fits the characters of the SIP message format and semantic. Each of them has a fixed length. In the type entries 310 , the type entries of all tokens are grouped together, for enabling fast information retrieval. The type entries 310 also comprise VALUE_OR_PTR fields, in each of which it contains a pointer to the location where there is the certain value in the content entry corresponding to the type entry field, or, if the certain value is less than the field length defined for the field, then the value is stored directly in the VALUE_OR_PTR field. The content entries 320 are stored separately from the type entries 310 . The content entries of all tokens are grouped together, and indexed by the VALUE_OR_PTR fields in the type entries. Thus, the complete information of each token can be accessed independently.
[0060] It can be seen from above that in the SOE message structure according to the preferable embodiment of the invention, since the type entries of all tokens are grouped together, stored with a plurality of fixed-length (aligned) entries, and indexed by the VALUE_OR_PTR between the type entries and the content entries, it is possible to rapidly retrieve the information of some certain token. Thus, not only does the SOE message structure according to the preferred embodiment of the invention reduce the load of the SIP server and improve the processing efficiency of the SIP server, but also it facilitates the SIP server to selectively process the information of the certain tokens in an SIP message according to a particular application.
[0061] Based on the above SOE message structure, the invention first proposes a method for binarizing SIP messages in conjunction with the preferable embodiment. A front end will parse each token in SIP messages by taking full advantage of its message processing ability and encode them into SOE messages. The binarizing transformation performed according to the method of the present invention has the following features:
No information is lost during the transformation; The transformation is performed per message based on stateless principles, that is, the front end does not need to maintain any state for message transformation when the message passes through it; No string parsing is needed at the server end; Space storage efficiency is considered for the SOE message.
[0066] Now referring to FIG. 4 , FIG. 4 is a flowchart of a method for binarizing SIP messages according to an embodiment of the invention. It is noted that the details of the above-mentioned three parts of the SOE message are to be introduced in detail with respect to FIG. 5A-5D in the process of describing the method of the invention. In FIG. 4 , the method starts with Step 400 , and then proceeds to Step 405 , in which an SIP message is received by a front end. Then in Step 415 , the token count is reset, that is, the token count is set to zero. Then in Step 420 , each token in the SIP message is parsed. In Step 425 , it is determined whether a new line is being parsed in the SIP message. If so, then in Step 430 the line type is obtained and the process proceeds to Step 435 . If not, it proceeds to Step 435 directly. In Step 435 , the token type is obtained. Then in Step 440 , the token type is attached to the type field part of the token type entry part 220 , as shown in FIG. 5B . FIG. 5B is an illustrative diagram of the token type entry part 220 . In the token type entry part 220 , every 4 bytes will contain the encoding of one token and one value or a pointer to one value. For processing efficiency, each entry is restricted to the 4-byte boundary. For message space efficiency, each entry may be placed right after the previous one. In either case, the required value can be determined accurately with the pointer and the value length.
[0067] All the tokens will be encoded in the format of TYPE_A.TYPE_B, which is denoted as a token in the style of Method.Field or Header.Field. Namely, the token type part 220 comprises three fields: TYPE_A, TYPE_B, and VALUE_OR_PTR. The descriptions for each field in the token type entry part 220 are introduced in the following Table 1.
[0000]
TABLE 1
Field descriptions for token type entry part
Field
Field Name
Width
Field Definition
TYPE_A
1 Byte
In the TYPE_A part, each method has a
corresponding code, and some codes are reserved
for more methods to be appeared in the future. And
the response is encoded with one value despite of
the detailed status code, which is treated as a field
to be encoded in TYPE_B. Likewise, the header
type is also encoded in the TYPE_A part, and some
codes are reserved for more headers to be appeared
in the future. For the body, or the content, of the
SIP message, another code will be allocated.
TYPE_B
1 Byte
The TYPE_B part is used for encoding fields and
parameters. Parameters are in the format of
“Parameter Name = Parameter Value
(PName = PValue)”. For fields that are not in the
above format, a corresponding code is given for
each possible field in TYPE_B. Some
known/important parameters will be treated
similarly as a field with a code allocated. All other
parameters will be encoded with a pair of codes,
one for “general parameter name” and the other for
“general parameter value”.
VALUE_OR_PTR
2 Bytes
If the value determined by TYPE_A and TYPE_B is
a 16-bit value, then it is directly put into the field.
Otherwise, in the field there will be a pointer to the
content part, which is an offset from the beginning of the
content part.
[0068] Continuing the process of the method of the invention, after the Step 440 completes, in Step 445 , the token value is obtained. In Step 450 , it is determined whether the token value has a variable length. If not, the token value has a fixed length, and in Step 460 the token value is attached to the value part of the token content part 230 . It is noted that the token value will be directly attached to the VALUE_OR_PTR field of the above token type entry part 220 if it is less than 2 bytes. And the token value will be attached to the token content entry part 230 , as shown in FIG. 5C if it is more than 2 bytes. FIG. 5C is an illustrative diagram illustrating the encoding for the fixed-length value in the token content entry part 230 . The token content entry part 230 is used for storing the value determined according to TYPE_A and TYPE_B defined above. Referring to FIG. 5C , if the length of the value determined by TYPE_A and TYPE_B is fixed and it exceeds 2 bytes, then the fixed-length value is directly put into this part, and is pointed to by the pointer in the corresponding token type entry part.
[0069] If the determination in Step 450 is yes, then the token value has variable length, and in Step 455 the token value, together with its length, is attached to the token content entry part 230 as shown in FIG. 5D . FIG. 5D is an illustrative diagram illustrating the encoding for the variable-length value in the token content entry part 230 . Referring to FIG. 5D , if the field and the known parameter value are variable in length, then the value is stored in the format shown in FIG. 5D , wherein the value appears after its VALUE_LENGTH field. The field descriptions for the variable-length value in the token content entry part 230 are introduced in the following Table 2.
[0000]
TABLE 2
Field descriptions for variable-length value in token content entry part
Field Name
Field Width
Field Definition
VALUE_LENGTH
2 Bytes
Length of the value in bytes,
counted from the start
to the end of the value,
excluding the 2 bytes
of this field itself.
VALUE
Variable, and
Usually a string.
specified by
VALUE_LENGTH
[0070] It is noted that, for a general parameter, since it has a pair of codes, one for parameter name and the other for parameter value, each of them is still fit into the format shown in FIG. 5D .
[0071] It is further noted that, as the evolution of SIP standards is going on, a new method or a new header can be defined. Before a new code is assigned to it and the corresponding processing logic is ready, the new method or the new header will be encoded as an unknown method or an unknown header. For an unknown method, one code will be assigned in TYPE_A, and its value will be a string pointed by the pointer, denoting what the method is. The rest of the request line is parsed and encoded just like that for a known method. For an unknown header, it is necessary to maintain the name and the rest of the header. Therefore, the unknown header will have two codes assigned, just like those for a general parameter.
[0072] Continuing the process of the method of the invention, after the Step 455 or 460 completes, it proceeds to Step 465 , in which a pointer is set up between the token type entry part 220 and the token content entry part 230 . Then in Step 470 , the token count is incremented by 1. In Step 475 it is determined whether the message ends. If not, the process returns to Step 420 to continue to parse the message. If yes, it proceeds to Step 480 , the SOE header with token count, as shown in FIG. 6A , is constructed. FIG. 6A is an illustrative diagram illustrating the SOE header part 210 . The SOE header part 210 is a general part for all SOE messages. As shown in FIG. 6A , the SOE header part 210 comprises: SOE_ID, SOE_Version, Message_Length, Entry_Number, and Reserved. The field descriptions in the SOE header part 210 are introduced in the following Table 3.
[0000]
TABLE 3
Field descriptions for SOE header part
Field Name
Field Width
Field Definition
SOE_ID
1 Byte
The field is used for distinguishing SOE messages
from SIP messages. Since SIP messages are text-
based, one value that will not appear as a character in
the text is selected.
SOE_Version
1 Byte
Version of SOE Specification. Currently it is linked
with the SIP version. The high 4 bits are the major
version, and the low 4 bits are the minor version.
Message_Length
2 Bytes
Length of the total message in bytes, from the
SOE_ID to the last byte of the token content part.
Entry_Number
2 Bytes
Number of the token entries in the token entry part.
Reserved
2 Bytes
Reserved for further extension.
[0073] After Step 480 completes, the process of the method of the invention ends in Step 485 .
[0074] A method for binarizing SIP messages is introduced hereinabove based on the structure of the SOE message according to the preferable embodiment of the invention. The reference encoding for an SOE message and the example of the SIP-SOE message transformation is given in the end of the text.
[0075] After the SIP message is binarized by the front end, the SOE message is generated. As recited above, in the SOE message according to the preferable embodiment of the invention, since the type entries of all tokens are grouped together, stored with a plurality of fixed-length (aligned) entries, and indexed by VALUE_OR_PTR between the type entries and the content entries, it is possible to rapidly retrieve the information of some certain token. Thus, the structure of the SOE message according to the preferable embodiment of the present invention also facilitates the SIP server to selectively process the information of certain tokens in an SIP message according to a particular application.
[0076] FIG. 6 illustrates a flowchart of a method for selectively processing messages at the SIP server end. In FIG. 6 , the method starts with Step 600 , and then proceeds to Step 605 , in which a message is received by the server. Then in Step 610 , it is determined whether the SOE header exists. If not, then the message is not an SOE message but an SIP message, and the process proceeds to Step 615 in which the general SIP parsing is performed directly. If so, then it proceeds to Step 620 and 625 , in which the token count and the type in the token type entry part are obtained in turn.
[0077] Then in Step 630 , the line of interests in the type of the token type entry part corresponding to the application running on the server is selected. In Step 635 , the token of interests in the type of the token type entry part corresponding to the application running on the server is selected. In Step 640 , the pointer information is obtained with the line type and the token type. Then in Step 645 , the value in the token content entry part is located with the pointer.
[0078] In Step 650 it is determined whether the value has a variable length. If so, in Step 655 the value is obtained with its length. Otherwise in Step 660 the value is obtained directly. After Step 655 or 660 or 615 , in Step 665 the processing corresponding to the application after message parsing is performed. After Step 665 completes, the process of the method of the invention ends in Step 670 .
[0079] A method for binarizing SIP messages and a method for selectively processing messages at the server end according to the embodiments of the invention are introduced as above.
[0080] In the above embodiments, in the process of binarizing SIP messages, it is the respective tokens that are parsed in the SIP messages. It is apparent for the person with ordinary skills in the art that it is possible to only parse the specified type of tokens, the specified SIP message lines in the front end according to the application running on the back-end server end. Moreover, the parsing granularity is not limited to tokens. For an SIP message not interested by the current application, it is possible to encapsulate parts of message lines or even the whole message as an entry in the SOE message. Further, at the back-end server end it is possible to only process the parts of SOE message of one's interests. Thus, the structure of the SOE message according to the invention may process SIP messages in different granularities and in different time sequences.
[0081] FIG. 7 illustrates a structural schematic diagram of processing SIP messages in different granularities and in different time sequences according to preferable embodiments of the invention. In FIG. 7 , one or more front ends and optional other functional nodes are linked to one or more servers, to form a homogeneous, hierarchical, and distributed SIP processing path, so that it is able to processing SIP messages in different granularities (which may be any of the following granularities: token, line, header, whole message) and in different time sequences.
[0082] Under the same inventive concept, the invention also proposes a system for processing SIP messages. FIG. 8 illustrates a schematic diagram of a system for processing SIP messages according to a preferable embodiment of the invention. The system comprises a front end 110 and a server 120 , wherein the front end 110 comprises a message parser 810 , a storage 820 , a communication means 830 , a granularity controller 840 , and an application profile 850 ; the server 120 comprises an SOE message processing means 860 , an SIP message processing means 870 , a selective control means 880 , and a communication means 890 . The communication means 830 in the front end 110 and the communication means 890 in the server 120 are communicated with each other to set up a data transmission mechanism. The message parser 810 is used for parsing the SIP messages received by the front end based on the information from the granularity controller 840 , wherein the parsing granularity may be any of the following granularities: token, line, header, whole message. The granularity controller 840 is used for determining the parsing granularity of the message parser 810 according to the need of the application at the server end or based on the application profile 850 . The application profile 850 is used for storing the attributes of various applications and the message lines or tokens they are interested. The SOE message processing means 860 is used for selectively processing the received messages under the control of the selective control means 880 .
[0083] Reference encoding for SOE message and example of SIP-SOE message transformation
[0084] In order to facilitate the understanding of the binarizing transformation of the present invention, the reference encoding for TYPE_A is provided hereinbelow by referring to Table 4. The italic parameters in Table 4 indicate that they contain other parameters or fields, which are further listed in the first column of Table 5 hereinbelow.
[0000]
TABLE 4
TYPE_A encoding for methods and headers
TYPE_A Code Table
Type
Name
Code
TYPE_B parameters or fields available for this TYPE_A Code
Unknown
Unknown Method
−1
method-name
Unknown Header
−2
Header-name
header-value
Body
Message Body
−3
Content
Response
RESPONSE
0
major-version
minor-version
status-code
reason-
phrase
Method
INVITE
1
addr-spec
major-version
minor-
version
REGISTER
2
addr-spec
major-version
minor-
version
BYE
3
addr-spec
major-version
minor-
version
ACK
4
addr-spec
major-version
minor-
version
CANCEL
5
addr-spec
major-version
minor-
version
OPTIONS
6
addr-spec
major-version
minor-
version
REFER
7
addr-spec
major-version
minor-
version
SUBSCRIBE
8
addr-spec
major-version
minor-
version
NOTIFY
9
addr-spec
major-version
minor-
version
MESSAGE
10
addr-spec
major-version
minor-
version
INFO
11
addr-spec
major-version
minor-
version
PRACK
12
addr-spec
major-version
minor-
version
UPDATE
13
addr-spec
major-version
minor-
version
Header
Accept
33
q-param
m-type
m-subtype
m-
parameter
Accept-Encoding
34
q-param
encoding
Accept-Language.
35
language-range
q-param
Alert-Info
36
absolute-uri
Allow.
37
method-param
Authentication-
38
ain-info
Info
Authorization
39
dig-resp
Call-ID
40
call-id string
call-id host
Call-Info
41
absolute-uri
info-param
generic-
param
Contact
42
name-addr
q-param
expires
generic-
param
Content-
43
disp-type
disp-param
Disposition
Content-Encoding
44
Encoding
Content-Language
45
language-tag
Content-Length
46
content-length
Content-Type
47
m-type
m-subtype
m-parameter
CSeq
48
seq-number
Method
Date
49
rfc1123-date
Error-Info
50
absolute-uri
generic-param
Expires
51
delta-seconds
From
52
name-addr
tag
generic-
param
In-Reply-To
53
call-id-first-
call-id-second-
part
part
Max-Forwards
54
max-forwards
Min-Expires
55
delta-seconds
MIME-Version
56
major-version
minor-version
Organization
57
Name
Priority
58
Priority
Proxy-
59
digest-cln
other-challenge
Authenticate
Proxy-
60
dig-resp
Authorization
Proxy-Require
61
option-tag
Record-Route
62
name-addr
generic-param
Reply-To
63
name-addr
addr-spec
generic-
param
Require
64
option-tag
Retry-After
65
delta-seconds
generic-param
Route
66
name-addr
generic-param
Server
67
product-name
product-version
Subject
68
Name
Supported
69
option-tag
Timestamp
70
Timestamp
To
71
name-addr
tag
generic-
param
Unsupported
72
option-tag
User-Agent
73
product-name
product-version
Via
74
sent-protocol
sent-by
via-params
Warning
75
warn-code
warn-agent
warn-text
WWW-
76
digest-cln
other-challenge
Authenticate
[0085] The possible fields and parameters are listed hereinbelow in Table 5. Some parameters/fields may appear in different headers. For completeness, the complete possibilities that these parameters/fields appear in the corresponding headers are listed.
[0000]
TABLE 5
List of possible parameters/fields
VALUE_OR_PTR
Dividable
for this TYPE_B
parameters
code (blank
or fields
Parameters or fields
denotes a pointer)
method-name
header-name
header-value
Content
generic-param
generic-param-name
generic-param-value
addr-spec
Scheme
User
Password
Host
Port
Value
Scheme-data
uri-parameters
headers (each header is
processed as generic-param)
Host
Hostname
ipv4address
ipv6address
name-addr
Scheme
user/telephone-subscriber
password
Host
port number
Absolute-uri
display-name
uri-param
transport-param
user-param
method-param
ttl-param
Value
maddr-param=host
lr-param
Value
compression-param
other-param=generic-param
callid
call-id-first-part
call-id-second-part
algorithm
nonce
media-type
m-type
m-subtype
m-parameter
m-parameter
m-attribute
m-value
ainfo
nextnonce
message-qop
response-auth
nonce
nonce-count
dig-resp
username
realm
nonce
digest-uri = add-spec
dresponse
algorithm
cnonce
opaque
message-qop
nonce-count
auth-param
auth-param
auth-param-name
auth-param-value
digest-cln
realm
domain
nonce
opaque
stale
Value
algorithm
qop-options
auth-param
rfc1123-date
wkday
date
month
year
time
sent-protocol
protocol-name
protocol-version
transport=trasport-param
via-params
via-ttl=ttl-param
via-maddr=maddr-param
via-received
via-branch
via-extension=generic-param
via-received
other-chanllenge
auth-scheme
auth-param
language-tag=language-range
sent-by
host
port
disp-param
handling-param
generic-param
absolute-uri=scheme-data
accept-param=q-param
option-tag= tag
content-coding=encoding
expires=delta-seconds
info-param=purpose
domain
delay
seq-number
major-version
minor-version
tag
option-tag
product-name
product-version
encoding
q-param
language-range
purpose
delta-seconds
wildcard
disp-type
handling-param
content-length
seq-number
max-forwards
name
priority
duration
via-received
via-branch
protocol-name
protocol-version
warn-code
Value
warn-text
warn-agent
status-code
Value
reason-phrase
[0086] The reference encoding for TYPE_B is provided hereinbelow by referring to Table 6. In Table 6 some examples of fields or parameters are listed.
[0000]
TABLE 6
TYPE_B encoding for parameters/fields
VALUE_OR_PTR
for this
Parameter or Field Name
Code
TYPE_B code
Example
method-name
−1
header-name
−2
header-value
−3
Content
−4
generic-param-name
0
generic-param-value
1
Scheme
2
SIP
User
3
bob
password
4
abcdefg
hostname
5
biloxi.com
Port
6
Value
5060
scheme-data
7
http://www.biloxi.com
IPv4address
8
192.0.2.1
IPv6address
9
3ffe:3201:1401:1:280:c8ff:fe4d:db39
display-name
10
Bob
transport-param
11
udp
User-param
12
user=phone
method-param
13
INVITE
ttl-param
14
Value
ttl=15
Maddr-param
15
maddr=224.2.0.1
lr-param
16
Value
lr
callid-first-part
17
a84b4c76e66710
callid-second-part
18
atlanta.example.com
algorithm
19
algorithm=MD5
Nonce
20
nonce=“MzQ0a2xrbGtmbGtsZm9wb2tsc2tqaHJzZXNy9uQyMzMzMzQK=”
username
21
username=“bob”
Realm
22
Realm=“atlanta.example.com”
digest-uri
23
sip:[email protected]:5060
dresponse
24
Ptr+Fixed
response=“dfe56131d1958046689d83306477eccd”
Cnonce
25
nonce=“ea9c8e88df84f1cec4341ae6cbe5a359”
Opaque
26
opaque=“”
Message-qop
27
qop=“auth”
nonce-count
28
Ptr+Fixed
Auth-scheme
29
Auth-param-name
30
Auth-param-value
31
nextnonce
32
response-auth
33
m-attribute
34
m-attribute EQUAL m-value
m-value
35
domain
36
Stale
37
Value
Stale=FALSE
qop-options
38
timestamp
39
Ptr+Fixed
delay
40
Ptr+Fixed
weekday
41
Thu
Day
42
21
month
43
Feb
year
44
2002
hour
45
12
minute
46
33
second
47
56
Uri-param-name
48
Uri-param-value
49
major-version
50
Ptr+Fixed
2
minor-version
51
Ptr+Fixed
0
Tag
52
option-tag
53
product-name
54
product-version
55
2.0.0
encoding
56
Gzip
q-param
57
Ptr+Fixed
0.8
language-range
58
en-gb
purpose
59
delta-seconds
60
Ptr+Fixed
7200
wildcard
61
disp-type
62
handling-param
63
content-length
64
Ptr+Fixed
142
Seq-number
65
Ptr+Fixed
314159
max-forwards
66
Ptr+Fixed
70
name
67
priority
68
duration
69
Ptr+Fixed
Via-received
70
Via-branch
71
branch=z9hG4bK74b76
protocol-name
72
protocol-version
73
warn-code
74
Value
301
warn-text
75
Incompatible network address type ‘E.164’
warn-agent
76
status-code
77
Value
200
reason-phrase
78
OK
m-type
79
Application
m-subtype
80
Sdp
[0087] In the field of “VALUE_OR_PTR for this TYPE_B code”, blank denotes that there will be a variable-length value, with a “VALUE_LENGTH” field in the token content part, and “Ptr+Fixed” denotes that the value is fixed in length, so that there is no “VALUE_LENGTH” field in the token content part.
[0088] The details of the fixed-length fields in the token content part are shown as below in Table 7.
[0000]
TABLE 7
Fixed-length fields in the token content part
Field Name
Appeared in
Length
content-length
Content-Length header
Integer, 4 Bytes
seq-number
CSeq header
Integer, 4 Bytes
delta-seconds
Expires, Retry-After and other
Integer, 4 Bytes
headers
max-forwards
Max-Forwards header
Integer, 4 Bytes
duration
Retry-After header
Integer, 4 Bytes
major-version
SIP Version
Integer, 4 Bytes
minor-version
SIP Version
Integer, 4 Bytes
q
Many headers, such as Accept-
Float, 4 Bytes
Encoding
timestamp
Timestamp header
Float, 4 Bytes
delay
Timestamp header
Float, 4 Bytes
dresponse
Many headers
String, 32 Bytes
nonce-count
Many headers
String, 8 Bytes
[0089] Two SIP messages, one INVITE message and one REGISTER message, will be used as examples to show the SOE transformation with the encoding mechanism according to the invention by referring to Table 8 and Table 9 hereinbelow.
[0000]
TABLE 8
Encoding example of INVITE message
Encoding Example of INVITE Message
Message
INVITE sip:[email protected] SIP/2.0
in
Via: SIP/2.0/UDP pc33.atlanta.com;branch=z9hG4bKnashds8
String
Max-Forwards: 70
To: Bob <sip:[email protected]>
From: Alice <sip:[email protected]>;tag=1928301774
Call-ID: a84b4c76e66710
CSeq: 314159 INVITE
Contact: <sip:[email protected]>
Content-Type: application/sdp
Content-Length: 142
...(BODY)...
VALUE_OR_PTR (16 bits)
Message
TYPE_A (8 bits)
TYPE_B (8 bits)
Value or buffer content
in Binary
Name
Code
Name
Code
Type
pointed by Ptr
INVITE
1
scheme
2
Ptr
“SIP”
INVITE
1
user
3
Ptr
“bob”
INVITE
1
hostname
5
Ptr
“biloxi.com”
INVITE
1
major-version
50
Ptr
2
INVITE
1
minor-version
51
Ptr
0
Via
74
protocol-name
72
Ptr
“SIP”
Via
74
protocol-version
73
Ptr
“2.0”
Via
74
transport-param
11
Ptr
“UDP”
Via
74
hostname
5
Ptr
“pc33.atlanta.com”
Via
74
via-branch
71
Ptr
“z9hG4bKnashds8”
Max-Forwards
54
max-forwards
66
Ptr
“70”
To
71
display-name
10
Ptr
Bob
To
71
scheme
2
Ptr
“SIP”
To
71
user
3
Ptr
“bob”
To
71
hostname
5
Ptr
“biloxi.com”
From
52
display-name
10
Ptr
Alice
From
52
scheme
2
Ptr
“SIP”
From
52
user
3
Ptr
“alice”
From
52
hostname
4
Ptr
“atlanta.com”
From
52
tag
52
Ptr
“1928301774”
Call-ID
40
call-id-first-part
17
Ptr
“a84b4c76e66710”
CSeq
48
seq-number
65
Ptr
314159
CSeq
48
method-param
13
Ptr
“INVITE”
Contact
42
scheme
2
Ptr
“SIP”
Contact
42
user
3
Ptr
“alice”
Contact
42
hostname
5
Ptr
“pc33.atlanta.com”
Content-Type
47
m-type
79
Ptr
“application”
Content-Type
47
m-subtype
80
Ptr
“sdp”
Content-Length
46
content-length
64
Ptr
142
Message-Body
−3
content
−4
Ptr
“...(BODY)...”
[0000]
TABLE 9
Encoding example of REGISTER message
Encoding Example of REGISTER Message
Message
REGISTER sip:registrar.biloxi.com SIP/2.0
in
Via: SIP/2.0/UDP bobspc.biloxi.com:5060;branch=z9hG4bKnashds7
String
Max-Forwards: 70
To: Bob <sip:[email protected]>
From: Bob <sip:[email protected]>;tag=456248
Call-ID: 843817637684230@998sdasdh09
CSeq: 1826 REGISTER
Contact: <sip:[email protected]>
Expires: 7200
Content-Length: 0
Message
VALUE_OR_PTR (16 bits)
in
TYPE_A (8 bits)
TYPE_B (8 bits)
Value or buffer
Binary
Name
Code
Name
Code
Type
content pointed by Ptr
REGISTER
2
Scheme
2
Ptr
“SIP”
REGISTER
2
Hostname
5
Ptr
“registar.biloxi.com”
REGISTER
2
major-version
50
Ptr
2
REGISTER
2
minor-version
51
Ptr
0
Via
74
protocol-name
72
Ptr
“SIP”
Via
74
protocol-version
73
Ptr
“2.0”
Via
74
transport-param
11
Ptr
“UDP”
Via
74
Hostname
5
Ptr
“bobspc.biloxi.com”
Via
74
Port
6
Value
5060
Via
74
via-branch
71
Ptr
“z9hG4bKnashds7”
Max-Forwards
54
max-forwards
66
Ptr
70
To
71
display-name
10
Ptr
Bob
To
71
Scheme
2
Ptr
“SIP”
To
71
User
3
Ptr
“bob”
To
71
Hostname
5
Ptr
“biloxi.com”
From
52
display-name
10
Ptr
Bob
From
52
Scheme
2
Ptr
“SIP”
From
52
User
3
Ptr
“bob”
From
52
Hostname
5
Ptr
“biloxi.com”
From
52
Tag
52
Ptr
“456248”
Call-ID
40
call-id-first-part
17
Ptr
“843817637684230”
Call-ID
40
call-id-second-part
18
Ptr
“998sdasdh09”
CSeq
48
seq-number
65
Ptr
1826
CSeq
48
method-param
13
Ptr
“REGISTER”
Contact
42
Scheme
2
Ptr
“SIP”
Contact
42
User
3
Ptr
“bob”
Contact
42
ipv4address
8
Ptr
“192.0.2.4”
Expires
51
delta-seconds
60
Ptr
7200
Content-Length
46
content-length
64
Ptr
0
[0090] The detailed descriptions of a method and system for binarizing SIP messages for offload and selective processing according to the invention are provided hereinabove with reference to the embodiments. As appreciated by the person with ordinary skills in the art, the present invention may be embodied as a method, a system, and/or a computer program product. Therefore, the present invention can be embodied in the form of hardware, software, or the combination thereof. Additionally, the present invention may be embodied as a computer program product contained on machine-readable media where the computer executable program instructions for programming a computer system to execute the process according to the invention are stored. The term “machine-readable media” used herein include any media that provide the computer system with instructions for execution. Such media may take various forms, including but not limited to: non-volatile media, volatile media, and transmission media. Non-volatile media commonly comprise, for example, floppy disk, floppy magnetic disk, hard disk, magnetic tape, or any other magnetic media, CD-ROM or any other optical media, slotting card or any other physical media with hole pattern, PROM, EPROM, EEPROM, flash memory, any other memory chip or cartridge, or any other media that can be read by the computer system and are appropriate for storing instructions.
[0091] Additionally, it should be appreciated that each block in the flow chart or block chart and the combination of some blocks may be implemented by some computer program instructions. These computer program instructions may be provided to a general purpose computer, a specific purpose computer, or a processor of other programmable data processing device, to produce a machine, in which these instructions, when executed by the computers or the processor of other programmable data processing device, can create the means for implementing the functions indicated by the blocks of the block chart and/or the flow chart.
[0092] Although the present invention has been presented and described specifically by reference to the preferred embodiments, it is not intended to be exhaustive or limited the invention in the form disclosed. Many modifications on forms and details will be apparent to those ordinary skills in the art without deviating from the spirit and scope of the invention. The embodiments were chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated. | A method and system for processing session initiation protocol messages including receiving a session initiation protocol message by a front end, parsing the session initiation protocol message by the front end, grouping the token types and the token contents in the session initiation protocol message respectively, and setting up corresponding links between the token types and the token contents, wherein the session initiation protocol message, after parsing, is transformed to the session initiation protocol offload engine message with a session initiation protocol offload engine message header part, for storing message level information, a token type part, for storing token type information, wherein it comprises a plurality of fixed-length entries, and a token content part for storing token contents, wherein it comprises a plurality of variable-length entries, and processing the transformed session initiation protocol offload engine message at the server end. | 99,973 |
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] The present application is a divisional application of U.S. patent application Ser. No. 12/518,274, filed Jan. 13, 2010 (Jan. 13, 2010), now U.S. Pat. No. 8,819,989, issued Sep. 2, 2014 (Sep. 2, 2014), which claims priority to U.S. Utility patent application Ser. No. 11/452,034, filed on Jun. 12, 2006 (Jun. 12, 2006), all of which applications are incorporated in their entirety by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a gelatinous substrate for controllably delivering water and nutrients to plant tissue such as the root ball of a living plant.
[0004] 2. Background Discussion
[0005] The commercial product DRiWATER Gel (“DriWATER”) embodies U.S. Pat. No. 4,865,640 (“the '640 patent”), the entire specification of which is incorporated herein. The product has been used throughout the world for the past several years and has successfully provided users with a time-released water delivery product for plants. DRiWATER is a carboxymethylcellulose crosslinked polymer comprised of 97.85% water, 2.0% sodium carboxymethylcellulose (“CMC”), and 0.15% aluminum sulfate. When mixed together in a high sheer mixer, cross linkage between the carboxylic acid groups of the carboxymethylcellulose compound and aluminum in aluminum sulfate traps the water in a heavy gel stabilizing at a final viscosity of 45,000+ centipoises.
[0006] The time release feature of the commercially available product results from the action of micro-organisms that utilize the gel as a food source. The gel is eventually degraded by microorganisms to yield free water. Cellulose degrading microorganisms can be found in all soil types and produce enzymes for breakdown of cellulose. This technology can be thought of as a slow release method for watering plants. DRiWATER has also be used to control the rate of water release so as to not over-water any plant species. The DRiWATER product would be more beneficial to plants if it provided some value other than watering alone such as increasing roots. An increase in the root mass will result in more growth, better appearance, and improve nutrition uptake by plants. The DRiWATER Gel is packaged in cartons, cups, synthetic casing or any other suitable container that can be partially or totally opened for application in close proximity to the rhyzosphere of the plant.
[0007] Plants need 18 elements for normal growth. Carbon, hydrogen and oxygen are found in air and water. Nitrogen, phosphorus, potassium, magnesium, calcium and sulfur and carbon are found in the soil. The above mentioned elements are referred to as “macronutrients” by those skilled in the art because plants use these elements in large amounts. The nine other elements that are used in much smaller amounts are referred to as “micro-nutrients” or “trace elements” and are found in the soil. These nine micro-nutrients are iron, zinc, molybdenum, nickel, manganese, boron, copper, cobalt and chlorine. All 18 elements, both macro-nutrients and micro-nutrients are essential for plant growth. In most locations, it is likely that there are sufficient macro-nutrients in the soil that are not readily available to the plants due to a zinc deficiency.
[0008] It is a fact that the soils in at least 42 of the 48 contiguous states are deficient in zinc. Plant growth is enhanced when zinc is added. The importance of zinc for crop production has been recognized for many years. Zinc deficiency has many symptoms including; stunted growth, light green areas between the veins of new leaves, smaller leaves, shortened internodes, and broad white bands on each side of the midrib in corn and grain sorghum. Zinc is essential to many enzyme systems in plants with three main functions including catalytic, co-catalytic, and structural integrity. Zinc contributes in the production of important growth regulators that affect photosynthesis, new growth, and the development of roots. Zinc promotes the cell growth needed for increasing root development and extended root systems—improving nutrient uptake, formation of new leaves and vigorous shoot growth, more even maturity, and improved stress tolerance. If zinc is in short supply, plant utilization of other plant nutrients such as nitrogen will decrease. When zinc is deficient in soils, only small amounts are needed if placed close to the rhizospere at planting. It would therefore be advantageous to provide DRiWATER with zinc. It is a known fact that, if you mix sodium bicarbonate or any other highly alkaline product with citric acid or any other powdered acid and then add water, the result will be a violent chemical reaction. The chemical reaction neutralizes the PH and therefore will have no effect on plant material.
[0009] It would be further advantageous in many instances, if the dry ingredients of the present invention could be shipped to the end user for their mixing at the point of application. However due to the hydroscopic nature of the dry ingredients, it has not been possible to get good cross linkage without the use of a high sheer mixer. The fact that the present invention is 96 to 99% water makes it very expensive to ship.
SUMMARY OF THE INVENTION
[0010] The present invention is directed to a substrate which releases impregnated water, gas, and nutrients when interacting with biological organisms comprising a mixture of a cellulosic compound ranging from 0.6 to 3% by weight of the water to be used, having an average molecular weight ranging between 90,000 and 700,000 represented by the formula: R—O—COOM in which “M” is a metal substituted for hydrogen on said carboxyl group of the cellulose compound and “R” is cellulosic chain, a hydrated metallic salt ranging from 0.1% to 0.3% by weight of the weight of water being used, water ranging from 96.0% to 99.5% by weight, a micro-nutrient selected from the group consisting of zinc and zinc salts, the concentration of zinc ranging from 0.006% to 0.72% by weight of the weight of water being used, at least one plant growth additive selected from the group consisting of plant growth hormones and plant growth regulators ranging from 0.00001% to 0.0003% by weight of the weight of water being used, at least one preservative selected from the group consisting of sodium benzoate, potassium sorbate, and acetic acid ranging from 0.01% to 0.3% by weight of the weight of water being used, a surfactant ranging from 0.0025% to 0.006% by weight of the weight of water being used, and an acetic acid component selected from the group consisting of acetic acid or acetic acid salts, the concentration of acetate ranging from 0.1% to 0.48% by weight of the weight of water being used.
[0011] The invention is also directed to a method of providing water, gas, and nutrients to a plant in soil at a predetermined, time release rate comprising placing a substrate in the soil, the substrate comprising a mixture of a cellulosic compound ranging from 1 to 3% by weight including glucose units and having a molecular weight ranging between 90,000 and 700,000 represented by the formula: R—O—CH2-COOM where “M” is a metal substituted on said glucose units of the cellulose compound and “R” is a cellulose chain, a hydrated metallic salt ranging from 0.1% to 0.03% by weight, water ranging from 96.0% to 99.5% by weight, a micro-nutrient selected from the group consisting of zinc and zinc salts, the concentration of zinc ranging from 0.006% to 0.72% by weight of the weight of water being used, at least one plant growth additive selected from the group consisting of plant growth hormones and plant growth regulators ranging from 0.00001% to 0.0003% by weight of the weight of water being used, at least one preservative selected from the group consisting of sodium benzoate, potassium sorbate, and acetic acid ranging from 0.01% to 0.3% by weight of the weight of water being used, a surfactant ranging from 0.0025% to 0.006% by weight of the weight of water being used, and an acetic acid component selected from the group consisting of acetic acid or acetic acid salts, the concentration of acetate ranging from 0.1% to 0.48% by weight of the weight of water being used, and placing the plant roots in the vicinity of the substrate.
[0012] The present invention relates to the DRiWATER moisturizing substrate for controllably delivering water, micro-nutrients such as zinc, macro-nutrients, plant growth additives (including plant growth hormones and plant growth regulators), preservatives, and surfactants to the plant in the same manner to the entire vertical root system of a plant. It would appear to be obvious to anyone of ordinary skill in the art, that adding macro-nutrients and micro-nutrients to the DRiWATER Gel would be beneficial to the plants. However, zinc is a divalent cation (when in an aqueous solution depending on pH) and would therefore interfere with cross linkage between the cellulose compound and the aluminum in aluminum sulfate causing the effect of an unstable viscosity. For example, the addition of fertilizer components, without the addition of the ionic counter-balancing chemicals, will destroy the gel cross-linkage and destabilize the gel viscosity or in some cases liquefy the gel entirely. Therefore the composition as well as the rate at which zinc is put into the gel system with ionic counter balancing chemicals is rate sensitive. A combination of zinc sulfate and acetic acid were incorporated into the DRiWATER gel at a rate of 0.167% (weight/weight) zinc sulfate and 0.07% (weight/weight) acetic acid. Scientific experiments have shown this combination of zinc sulfate and acetic acid in DRiWATER yielded the greatest increase in rooting of pepper plants, an increase of 208% to 283% greater root mass than treatments with original DRiWATER.
[0013] Furthermore, as discussed above, preliminary experiments have shown that the addition of plant growth additives, preservatives, and surfactants has negatively affected the viscosity of the DRiWATER gel. These compounds also must be incorporated at exact rates so as to not destabilize the viscosity. The compounds must also be in specific mathematically calculated mole equivalents of each other to prevent destabilization of the DRiWATER gel. Further, this principle is hormone/nutrient selective, meaning that some hormones/nutrients cannot be incorporated at all because they destroy gel cross-linkage. It should also be noted that each compound requires a specific balancing/countering chemical component. That is, the specific hormone/nutrient combination for each hormone/nutrient is selective and acts chemically different then every other hormone/nutrient. Therefore each hormone/nutrient requires a different balancing/countering chemical component.
[0014] One embodiment of the present invention is further directed to control the liquefaction rate of DRiWATER plus nutrients based on factors other than the degree of exposure to micro-organisms. The surface area exposed to the micro-organisms in the soil controls liquefaction rate of DRiWATER. The greater the surface area exposed, the faster the DRiWATER Gel will liquefy.
[0015] One embodiment of the present invention relates to the addition of Sodium Bicarbonate, or any other highly alkaline material and citric acid, or any other powdered acid to the other dry ingredients mentioned above. Sodium Bicarbonate ranging from 0.15 to 0.33% and citric acid ranging from 0.22 to 0.44% were added to the above mentioned formulations with the exception of acetic acid. The above percentages are by weight of the weight of the water to be added at point of application.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0016] FIG. 1 is a graph showing viscosity changes resulting from the addition of zinc sulfate and acetic acid to the gel, according to one embodiment of the present invention.
[0017] FIG. 2 is a diagram of a plant treated with original DriWATER, according to one embodiment of the present invention.
[0018] FIG. 3 is a diagram of a plant treated with DRiWATER plus 0.167% (w/w) zinc sulfate and 0.07% (w/w) acetic acid, according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] The present invention is directed to the distribution of the DRiWATER gelatinous moisturizing substrate for controllably delivering water, micro-nutrients, macro-nutrients, plant growth additives, preservatives, and surfactants to plant tissue such as the entire vertical root system of a plant. The present invention delivers water and the aforementioned nutrition to plants, thus enhancing plant development and growth at a pre-determined rate for a pre-determined period of time and providing the desired maintenance for plants.
[0020] It is commonly known that the addition of nutrients, and hormones to plants improve plant growth. For example, many micro-nutrients can be found in most standard fertilizers, but must be in an ionic form (most elements ionize in water) to be taken up by the plant. In traditional watering, nutrients were provided to plants by mixing fertilizers and nutrients with water and pouring or dripping the mixture around a plant. However, any excess water and fertilizer that the soil was unable to retain will eventually ended up in underground aquifers.
[0021] It is the object of this invention to controllably delivering water, micro-nutrients, macro-nutrients, plant growth additives, preservatives, and surfactants to plant tissue via the DRiWATER gel. However, preliminary experiments demonstrated that the addition of most nutrients and hormones negatively affect the viscosity of the DRiWATER gel, causing the DRiWATER gel to function improperly. The present invention is directed to incorporating a rooting compound into DRiWATER without destabilizing the gel's viscosity.
[0022] Without wanting to be limited to any one theory, it is believed that the compositions of the present application help to promote the cell growth needed for extended root systems, formation of new leaves, vigorous shoot growth, more even maturity, and improved stress tolerance.
[0023] All percentages, ratios and proportions herein are by weight of the composition, unless otherwise specified. All temperatures are in degrees Celsius (° C.) unless otherwise specified. All documents cited are incorporated herein by reference in their entireties. Citation of any reference is not an admission regarding any determination as to its availability as prior art to the claimed invention.
[0024] As previously stated, the importance of zinc for crop production has been recognized for many years. Zinc is essential to many enzyme systems in plants with three main functions including catalytic, co-catalytic, and structural integrity. For example, in the plant, the plant growth hormone, indole-3-acetic acid (IAA)(anion in aqueous solution depending on pH), is a naturally occurring auxin. It also occurs in many bacteria, fungi, and algae. IAA regulates cellular elongation, phototropism, geotropism, apical dominance, root initiation, ethylene production, fruit development, parthenocaarpy, abscission, and sex expression, all of which are necessary for normal plant growth. To maintain plants normal growth, IAA must be produced and regulated by the plant. Zinc is a co-factor in the transformation of the amino acid tryptophan to the auxin IAA. Adding zinc will help maintain IAA levels in the plant and promote growth, rooting, and health.
[0025] The selection of zinc sulfate as the source of zinc was based on scientific literature. Many sources of zinc have been tested to see which compound would be utilized more efficiently by plant species. Zinc sulfate is the most readily available form for plants. Zinc sulfate also contains a sulfate ion. The sulfate ion (SO 4 2− ) is a beneficial nutrient and naturally occurring in soils. Sulfur is used to bind amino acids together by sulfide bridging to create enzymes and proteins, the building blocks of life.
[0026] Research indicates that the presence of acetic acid will improve uptake of minerals. Acetic acid is also known as a preservative and will aid in preserving the gel's viscosity as well as help protect the gel from microorganism degradation. It is essential to note that without the correct molar combination of the zinc sulfate and acetic acid components, the gel viscosity will dramatically decrease or increase to the point at which it would provide little or no benefit for any plant species.
[0027] The following experiment was conducted to illustrate that zinc sulfate and acetic acid were formed to stimulate the greatest root growth and is not intended to be in any way limiting of the invention, as many variations thereof are possible without departing from the spirit and scope of the invention:
Experiment Methods and Materials.
[0028] Materials: Sodium carboxymethylcellulose (CMC), aluminum, preservatives, surfactants, zinc sulfate heptahydrate, acetic acid and pure water. It is noted that when preparing the substrate, the concentration of water may range between 96.0% to 99.5% by weight.
[0029] Aluminum, preservatives, surfactants, zinc sulfate heptahydrate, and acetic acid were poured into 400 mL beaker and were mixed for approximately 20 minutes or until all solids were dissolved. The solution was then poured into a 10 speed Osterizer blender (6) and set to “Ice Crush”, with a maximum output of 450 watts. The blade speed was 1100 RPM.
[0030] CMC was then poured into the blender. CMC was added at a consistent rate over 15 seconds while the blender was mixing. Mixing was continued for an additional 70 seconds, for a total mix time of 85 seconds. Approximately 300 mL of gel were formed and a viscosity reading was taken approximately 15 minutes after formation to allow gel to cool to room temperature. The gel volume measured was of approximately 200 mL in a 250 mL beaker analyzed with a Brookfield HADV-II+ viscometer. The viscosity was measured in units of centipoises (cP) to ensure the gels stability. Nine oz. of the gel were then weighed and inserted into a plastic casing to limit air exposure and contamination. The gel was then allowed to stabilize in plastic casings for a minimum of 3 days to achieve a viscosity that represents that of the consumer product. Five different formulated gels labeled Gel 1 through Gel 5 were made. Each gel formulation was tested using 3 replications of each. The original DRiWATER gel was used as the control (3 replications).
[0031] Anaheim peppers were planted in a defined native Arizona soil grown for approximately three weeks. Anaheim pepper plants used were selected to be of similar height and stem size for the tests.
[0032] Approximately 12-15 centimeter slit was made on each gel casing. Each gel casing was opened slightly to expose the gel to soil. Exposed gel in the casing was laid on the soil in which the Anaheim pepper plants were growing. Each plant was watered thoroughly on first day of treatment.
[0033] No watering was done for a period of 30 days. Plants were grown in a greenhouse with an approximate daily temperature of 65° F. Observations were made daily. On day 30 of the experiment, Plants were removed from soil. Roots were cleaned and pictures were taken. Then plants were cut at the cotyledonary nodes and the fresh weight of the root mass and hypocotyls were measured. Plants were then cut at the crown of roots and the fresh weight of the root mass was measured. Fresh weight was measured and compared for all formulations.
[0034] Results and Observations
[0000]
TABLE 1
Formulations
Ingredient
Percent by weight (%)
Grams (g)
Gel 1
CMC
1.997
5.990
Alum
0.150
0.449
Sodium Benzoate
0.040
0.120
Potassium Sorbate
0.040
0.120
Zinc Sulfate
0.056
0.168
Acetic Acid
0.023
0.070
Water
97.690
293.071
RA-2
0.005
0.0150
Total Weight
100.001
300
Gel 2
CMC
1.995
5.986
Alum
0.150
0.449
Sodium Benzoate
0.040
0.120
Potassium Sorbate
0.040
0.120
Zinc Sulfate
0.112
0.335
Acetic Acid
0.047
0.140
Water
97.613
292.839
RA-2
0.005
0.015
Total Weight
100.001
300
*Gel 3
CMC
1.994
5.981
Alum
0.150
0.449
Sodium Benzoate
0.040
0.120
Potassium Sorbate
0.040
0.120
Zinc Sulfate
0.167
0.502
Acetic Acid
0.070
0.210
Water
97.536
292.607
RA-2
0.005
0.015
Total Weight
100.001
300
Gel 4
CMC
1.992
5.976
Alum
0.149
0.448
Sodium Benzoate
0.040
0.120
Potassium Sorbate
0.040
0.120
Zinc Sulfate
0.223
0.669
Acetic Acid
0.093
0.279
Water
97.459
292.376
RA-2
0.005
0.015
Total Weight
100.001
300
Gel 5
CMC
1.990
5.971
Alum
0.149
0.448
Sodium Benzoate
0.040
0.119
Potassium Sorbate
0.040
0.119
Zinc Sulfate
0.278
0.835
Acetic Acid
0.116
0.349
Water
97.382
292.145
RA-2
0.005
0.015
Total Weight
100.001
300
Control
CMC
1.998
5.04
Alum
0.150
0.378
Sodium Benzoate
0.040
0.1008
Potassium Sorbate
0.040
0.1008
Zinc Sulfate
0.000
0
Acetic Acid
0.000
0
Water
97.767
246.58
RA-2
0.005
0.0126
Total Weight
100.000
252.2122
*Bold Asterisk represents best results.
[0000]
TABLE 2
Average Gel pH and Viscosity
Average
Standard
Zn-sulfate
Acetic Acid
gel Viscosity
Deviation
Average
Gel #
% (w/w)
% (w/w)
(cP)
(cP)
gel pH
1
0.056
0.023
12829.91
608.81
5.28
2
0.112
0.047
16614.11
777.26
5.13
*3
0.167
0.07
17700
843.15
5.08
4
0.223
0.093
20470.83
905.34
4.95
5
0.278
0.116
24297.65
1134.79
4.9
Control
0
0
0
N/A
N/A
*Bold asterisk represents best results.
[0000]
TABLE 3
Soil pH Values after 30 days of DRiWATER treatment
pH of soil after
Average pH of soil
Plant #
Trial
gel treatment
after gel treatment
Std. Dev. pH
Control 1
1
7.15
7.00
0.13
2
6.91
3
6.94
1
1
7.06
6.76
0.36
2
6.37
3
6.86
2
1
6.9
6.82
0.09
2
6.73
3
6.83
*3
1
6.56
6.52
0.08
2
6.43
3
6.56
4
1
6.81
6.63
0.16
2
6.6
3
6.49
5
1
6.74
6.59
0.16
2
6.42
3
6.6
The pH of the native soil prior to testing was 5.8.
*Bold asterisk represents best results.
[0000]
TABLE 4
Fresh weight roots and hypocotyls
Increased % of
Fresh Root Weight of
Average Fresh Root
root/hypocotyl
Plant
roots and hypocotyls
Weight of roots and
Std. Dev.
compared to
Treatment
Repetition
Grams (g)
hypocotyls Grams (g)
Grams (g)
control
Control
1
0.516
0.620
0.090
N/A
2
0.677
0.620
0.090
N/A
3
0.667
0.620
0.090
N/A
gel 1
1
0.253
0.399
0.131
64.355
2
0.505
0.399
0.131
64.355
3
0.439
0.399
0.131
64.355
gel 2
1
0.949
1.009
0.128
162.742
2
0.922
1.009
0.128
162.742
3
1.156
1.009
0.128
162.742
*gel 3
1
1.447
1.287
0.339
207.634
2
0.898
1.287
0.339
207.634
3
1.517
1.287
0.339
207.634
gel 4
1
0.997
0.863
0.126
139.194
2
0.846
0.863
0.126
139.194
3
0.746
0.863
0.126
139.194
gel 5
1
0.447
1.198
0.650
193.172
2
1.592
1.198
0.650
193.172
3
1.554
1.198
0.650
193.172
*Bold asterisk represents best results.
[0000]
TABLE 5
Fresh weight of roots
Average
Fresh
Fresh
Increased
Weight
Weight
% of roots
Plant
of roots
of roots
Std. Dev.
compared to
Treatment
Repetition
Grams (g)
Grams (g)
Grams (g)
control
Control
1
0.186
0.271
0.074
N/A
2
0.305
0.271
0.074
N/A
3
0.323
0.271
0.074
N/A
gel 1
1
0.132
0.193
0.056
71.341
2
0.242
0.193
0.056
71.341
3
0.206
0.193
0.056
71.341
gel 2
1
0.544
0.523
0.043
193.112
2
0.474
0.523
0.043
193.112
3
0.552
0.523
0.043
193.112
*gel 3
1
0.892
0.769
0.244
283.764
2
0.488
0.769
0.244
283.764
3
0.927
0.769
0.244
283.764
gel 4
1
0.552
0.448
0.101
165.191
2
0.441
0.448
0.101
165.191
3
0.35
0.448
0.101
165.191
gel 5
1
0.203
0.715
0.450
263.838
2
0.892
0.715
0.450
263.838
3
1.05
0.715
0.450
263.838
The Data stated in Table 4 and Table 5 was taken immediately after the Anaheim peppers were removed from the soil.
*Bold asterisk represents best results
[0035] The results of this experiment confirm that although the addition of nutrients, fertilizers, and hormones to DRiWATER would be beneficial to plants, the addition of most nutrients and hormones negatively affect the viscosity of the DRiWATER gel (see FIG. 1 ). The objective of the experiment was to incorporate a rooting compound into DRiWATER without destabilizing the gel's viscosity. The experiment has shown that the combination of zinc sulfate and acetic acid in DRiWATER yielded the greatest increase in rooting of pepper plants—an increase of 208% to 283% (see Table 4, Table 5, and FIG. 3 ) if delivered in the proper rates. There was greater root mass than treatments with original DRiWATER, which lacked the aforementioned nutrients (see Table 4, Table 5, and FIG. 2 .). This demonstrates that the optimum rate for rooting with acetic acid and zinc sulfate was established with a concentration of 0.167% zinc sulfate and 0.07% acetic.
[0036] As previously discussed, the present invention is directed to the distribution of the DRiWATER gelatinous moisturizing substrate for controllably delivering water and nutrients to plant tissue. For example, some elements and micro/macro nutrients found in fertilizers can be incorporated into the DRiWATER Gel, but only with the addition of specialized chemicals used to counteract the viscosity reducing elements. The addition of nutrients to DRiWATER, without destroying the viscosity of the gel, would be beneficial to plants. The following nutrients may be combined with DRiWATER at the disclosed percentage combinations to maintain gel viscosity and provide optimum results to the plant.
[0037] For example, as previously discussed, a well known plant hormone is the auxin IAA. Other auxins include, but are not limited to IBA, NAA, 2,4-D, 2,4-DB, etc. IAA is a naturally occurring auxin known to improve rooting and protect against high salt activity. Because enzymes and light degrade this auxin it is impractical to work with. However, indole-3-butyric acid (“IBA”) (anion or cation in aqueous solution depending on pH) has been established in the plant world as a compound that mimics IAA in many ways. The difference is that IBA is practical to work with and will not easily degrade. As further discussed in the experiment below, IBA concentration at a range of 0.00001% to 0.0003% by weight of the weight of the water being used improves rooting and protect against high salt activity of the plant, while not destroying the viscosity of the DRiWATER gel.
[0038] Cytokinins (kinetin, zeatin, etc.,) are another well known group of plant hormones that are growth regulators. More specifically, kinetin aids in cell division in various plants and in yeast. Kinetin (anion or cation in aqueous solution depending on pH) is known to increase cell division and delay senescence in plants, but only in the presence of auxin. Therefore it would be beneficial to include an auxin with kinetin in formulation. As futher discussed in the experiment below, kinetin concentration at a range of 0.00001% to 0.0001% by weight of the weight of water being used increases cell division and delay senescence of the plant, while not destroying the viscosity of the DRiWATER gel.
[0039] Gibberellic Acid (“GA3”) (anion in aqueous solution depending on pH) is the most outstanding of the plant growth promoting metabolites in a group of plant hormones called gibberellins (GA3, GA4, GA7, etc.). Gibberellic acid is especially beneficial for new seedling growth and promoting germination of seeds. All of the above mentioned hormones are very active in physiologically low rates and although they are beneficial independently, in combination they have an additive, or in some cases a synergistic effect. As further discussed in the experiment below, GA3 concentration at a range of 0.00001% to 0.0003% by weight of the weight of water being used improves seedling growth and germination of seeds while not destroying the viscosity of the DRiWATER gel.
[0040] It is perceived that in this invention, auxins other than IBA, gibberellic acid composed of other gibberellins, and cytokinins other than kinetin can be used, as long as the concentration does not destroy the viscocity of the DRiWATER gel.
[0041] As previously stated, preservatives aid in preserving the DRiWATER gel's viscosity as well as help protect the gel from microorganism degradation. Preservatives can be selected from sodium benzoate, potassium sorbate, and acetic acid, but are not specifically limited to the above. Research at the DRiWATER lab has demonstrated that acetic acid will slow gel degradion in soil. This is done by acetic acid acting as a preservative. This is another desirable characteristic of the above additions. By adding preservatives to the composition of the present invention, such as sodium benzoate and potassium sorbate, but not limited to these preservatives, the liquefaction rate can be further regulated. A combination of two preservatives is required: one to control mold, one to control bacterial activity although there may be some activity of each to the sets of microorganisms. The concentration of each preservative can range from 0.01% to 0.3% of the weight of water being used while not destroying the viscosity of the DRiWATER gel
[0042] By adding a surfactant to the composition of the present invention, such as sodium sesquicarbonate, but not limited to this surfactant, water penetration into the soil is improved. The surfactant can be sodium sesquicarbonate or any other environmentally friendly surfactant that is compatible. The surfactant concentration at a range from 0.0005% to 0.005% of the weight of the weight of water being used improves seedling growth and germination of seeds while not destroying the viscosity of the DRiWATER gel.
[0043] An example of the invention is set forth hereinafter by way of illustration and is not intended to be in any way limiting of the invention, as many variations thereof are possible without departing from the spirit and scope of the invention.
Example 1
[0044] As an example, the present invention composition according to the preferred embodiment can comprise: 246.58 g water, 5.04 g sodium carboxymethylcellulose, 0.378 g aluminum sulfate, 0.1008 g sodium benzoate, 0.1008 g potassium sorbate, 0.423 g zinc sulfate, 0.0015 mg of other plant growth regulators and 0.0126 g sodium sesquicarbonate. This formulation combination yields one 9 oz. gelpac of DRiWATER with zinc acetate, plant growth regulators, preservatives, and surfactant added. The preferred embodiment of the present invention comprises a mixture of the following by percent weight: 97.6% water, 2.0% sodium CMC, 0.15% aluminum sulfate, 0.04% sodium benzoate, 0.04% potassium sorbate, 0.237% zinc acetate, 0.00009% kinetin, 0.00004% IBA, 0.00003% GA3 and 0.005% sodium sesquicarbonate. The DRiWATER Gel with zinc, acetic acid, plant growth regulators, preservatives and surfactant is advantageous because it waters, provides nutrition, and promotes plant development and growth on a continual time release basis and improves water penetration into the soil. The amount and type of zinc, acetic acid, and other plant growth regulators may vary dependent on the requirements of a particular plant species.
[0045] Table 1 lists examples of the present invention according to different embodiments.
[0000]
Sodium
Potassium
Growth
CMC
Alum
Benzoate
Sorbate
Zinc Acetate
Regulators
Surfactant
(gal)
(lbs)
(lbs)
(lbs)
(lbs)
(lbs)
(oz)
(lbs)
2,500
400
30
4
4
14
0.5
1
2,500
200
20
2
2
32
1.0
0.5
2,500
132
13.2
6
6
48
1.5
0.1
2,500
300
25
8
8
32
0.75
0.75
2,500
350
27.5
2
2
48
0.90
0.90
[0046] For example, Gibberellic Acid (GA3) regulates growth; application of very low concentration can have a profound effect. Indole-3-Butyric Acid is especially effective for initiating roots of both stems and leaves.
[0047] Although the process, composition and methods of the present invention have been described with reference to specific exemplary embodiments, it will be evident to those of ordinary skill in this art that various modifications and changes may be made to these embodiments without departing from the scope of the invention as set forth in the claims. Accordingly, the specification is to be regarded as illustrative and not restrictive.
[0048] According to one embodiment, the present invention provides a method of delivering the dry ingredients to the point of application and adding the water at that time. The dry ingredients were placed in the desired size container in exact proportions. Citric Acid and Sodium Bicarbonate were added, in dry form, in specific amounts in relation to the dry ingredients. The ingredients were blended by shaking the container. Water was added in proportion to the dry ingredients. The chemical reaction between the Sodium Bicarbonate and the citric acid blended the ingredients and formed a semi firm gel. This method works well for volumes up to one quart/liter which is a good size for application. According to this embodiment of the present invention, adding Sodium Bicarbonate and citric acid to the method of composition may provide a way to transport the present invention as dry ingredients. One will appreciate that actual ingredient percentages will vary dependent on the desire gel. The following chart of materials and percentage variations.
[0000]
Sodium
Potassium
Zinc
Growth
Citric
Sodium
CMC
Alum
Benzoate
Sorbate
Sulfate
Regulators
Surfactant
Acid
Bicarbonate
0.06--3%
0.1-0.3%
0.01-0.3%
0.01-0.3%
.006-.72%
0.00001-0.0003%
0.0025-0.006
.22-.44%
0.15-0.33% | The present invention relates to a gelatinous moisturing substrate for controllably delivering water and oxygen to the root zone of growing plants with micro nutrients, auxins, preservatives and surfactants added comprising a mixture, by percent weight, 97.6%, 2.0% carboxy methol cellulose, 0.15% aluminum sulfate, 0.04% sodium benzoate, 0.04% potassium sorbate, 0.0167% zinc sulfate (22.23% zinc), 0.07% acetic acid (99%.0 pure) and 0.005% sodium sesquicarbonate. The composition maintains substrates viscosity. As a result, the moisturing agent releases water, oxygen and the added nutrients, preservatives and surfactant into the root zone of the growing plant at a controlled rate. | 59,144 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation application of U.S. application Ser. No. 12/276,035 filed Nov. 21, 2008, now U.S. Pat. No. 8,050,777 issued Nov. 1, 2011, which is a continuation of U.S. application Ser. No. 10/913,023 filed Aug. 6, 2004, now U.S. Pat. No. 7,457,670 issued Nov. 25, 2008, which claims the benefit of prior U.S. Provisional Application Ser. No. 60/493,531, filed Aug. 7, 2003 and entitled “Gobo Virtual Machine.”
BACKGROUND
Stage lighting effects have become increasingly complex, and are increasingly handled using more and more computing power. During a show, commands for various lights are often produced by a console which controls the overall show. The console has a number of encoders and controls which may be used to control any number of lights.
Complex effects may be controlled by the console. Typically each effect is individual for each light that is controlled.
SUMMARY
The present system teaches an apparatus in which a computer produces an output which is adapted for driving a projector according to commands produced by a console that controls multiple lights. The projector produces the light according to the commands entered on the console.
According to an aspect, certain commands are in a special generic form which enables them to be processed by many different computers.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other aspects will now be described in detail with reference to the accompanying drawings, wherein:
FIG. 1 shows a block diagram of the overall system;
FIG. 2 shows a block diagram of the connection between the console and the box;
FIG. 3 shows a combination of multiple layers forming a final displayed image; and
FIG. 4 shows the way that the code can be compiled for a special kind of processor.
DETAILED DESCRIPTION
The output of the console 100 may be in various different formats, including DMX 512 , or ethernet. The console 100 may be an ICON™ console. This console produces a number of outputs 110 , 114 to respectively control a number of lighting units 112 , 116 . Console is shown producing output 110 to control light 112 . Similarly, output 114 may be produced to control light 116 .
Another output 120 may be produced to control a digital light shape altering device. Such a light may be the icon M, aspects of which are described, for example, in U.S. Pat. Nos. 6,549,326, 6,617,792, 6,736,528. In this embodiment, however, the output 120 which is intended for the light is actually sent to a computer 130 which runs software to form an image according to commands from the console. The computer 130 produces an output 135 which may be a standard video output. The video output 135 may be further processed according to a dimmer 140 . The output of the dimmer is connected to a projector 150 . The projector may be, for example, a projector using digital mirror devices or DMD's.
The projector produces output according to its conventional way of producing output. However, this is based on the control 120 which is produced by the console.
In the embodiment, the computer 130 may actually be a bank of multiple computers, which respectively produce multiple outputs for multiple projectors 150 , 151 , 152 . FIG. 2 shows further detail about the connection between the console and the computer. The output of the console may be in any network format. In this embodiment, the output of the console may be in ethernet format, containing information that is directed to three different channels.
The computer 130 is actually a standalone half-height rack, on wheels, with three rack-mounted computers therein. The ethernet output 120 is coupled to an ethernet hub 125 which directs the output to each of the three computers. The three computers are shown as computer 1 ; designation 200 , computer 2 ; designation 202 , and computer 3 ; designation 204 . Each of these computers may be standard computers having keyboard input and display outputs. The outputs of each of the computers are connected to the interface board 140 .
Board 140 produces and outputs a first dimmed output 145 adapted for connection to the projector. The second, typically non-dimmed output 210 is connected to a three-way KVM switch. Each of the three computers have outputs which are coupled to the KVM switch. The KVM switch produces a single output representative of the selected computer output.
A single rack-mounted keyboard and monitor are located within the rack and driven by the KVM switch. The keyboard 220 is also connected to the KVM switch 230 , and produces its output to the selected computer. For example, when computer 3 is selected, the KVM switch sends the output from keyboard 222 to computer 3 and the output from computer 3 is sent to display 225 .
Any type of switch can be used, however standard KVM switches are typically available. Moreover, while this embodiment describes three different computers being used, there is practically no limit on the number of computers that can share input and output with a KVM switch.
The dimmer board may carry out dimming by multiplying each video output by analog values supplied by the associated computer. Moreover, the KVM switch is shown outside of the rack for simplicity, but in reality the KVM switch is rack-mounted within the rack.
As described above, the console produces a signal for each of many lights. That signal represents the desired effect. Different kinds of effects that can be produced may be described herein. The computer which actually does the image processing to form the desired result requested by the console. The computer processes the signal by receiving the command, converting that command into an image which forms a layer, and combining the multiple layers to form an overall image to be displayed by the projector/lamp.
The final image is formed by combining a plurality of layers. Each layer can have a number of different characteristics, but primarily, each layer may be considered to have a shape, a color, and/or an effect. The layers are combined such that each layer covers, adds to, subtracts, or allows transparency, to a layer below it.
An example of the operation is shown in FIG. 3 . FIG. 3 shows a first layer 300 which is an animation of clouds. The animation is continuous, so that the user sees the effect of traveling through those clouds.
Layer 2 is overlaid on the layer one. Layer 2 is shown as 310 , and corresponds to a rectangle which is rotating in a clockwise direction at a specified speed. In this layer, the perimeter area 312 is effectively black and opaque, while the interior area 314 is clear. Accordingly, as this layer is superimposed over the other layer, the area 314 allows the animation of layer 1 to show through, but the area 312 blocks the animation from showing through. The resultant image is shown as 330 , with the rotating triangle 314 being transparent and showing portions of the cloud animation 300 through it. A third layer 320 is also shown, which simply includes an orange circle 322 in its center. In the resultant image 330 , the orange circle 322 forms an orange filter over the portion of the scene which is showing.
Each layer can have a number of different effects, besides the effects noted above. An incomplete list of effects is:
color
shape
intensity
timing
rotation
Parameters associated with any of these effects can be specified. For example, parameters of rotation can be selected including the speed of rotation, the direction of rotation, and the center of rotation. One special effect is obtained by selecting a center of rotation that is actually off axis of the displayed scene. Other effects include scaling
Blocking (also called subtractive, allowing defining a hole and seeing through the hole).
Color filtering (changing the color of any layer or any part of any layer).
Decay (which is a trailing effect, in which as an image moves, images produced at previous times are not immediately erased, but rather fade away over time giving a trailing effect).
Timing of decay (effectively the time during which the effect is removed).
A movie can also be produced and operations can include
coloring the movie
scaling the movie
dimming of the image of the movie
Shake of the image, in which the image is moved up and down or back-and-forth in a specified shaking motion based on a random number. Since the motion is random, this gives the effect of a noisy shaking operation.
Wobble of the image, which is effectively a sinusoidal motion of the image in a specified direction. For wobble of the image, different parameters can be controlled, including speed of the wobble.
Forced redraw—this is a technique where at specified intervals, a command is given to produce an all-black screen. This forces the processor to redraw the entire image.
Other effects are also possible.
The computer may operate according to the flowchart of FIG. 4 . The image itself is produced based on information that is received from the console, over the link 120 . Each console command is typically made up of a number of layers. At 400 , the data indicative of these multiple layers is formed.
Note that this system is extremely complex. This will require the computer to carry out multiple different kinds of highly computation-intensive operations. The operations may include, but are not limited to, playing of an animation, rotating an image, (which may consist of forming the image as a matrix arithmetic version of the image, and rotating the matrix), and other complicated image processes. In addition, however, all processors have different ways of rendering images.
In order to obtain better performance, the code for these systems has been highly individualized to a specified processor. For example, much of this operation was done on Apple processors, and the code was individualized to an Apple G4 processor. This can create difficulties, however, when new generations of processors become available. The developers are then given a choice between creating the code, and buying outdated equipment.
According to this system, the code which forms the layers is compiled for a specified real or hypothetical processor which does all of the operations that are necessary to carry out all of the image processing operations. Each processor, such as the processor 200 , effectively runs an interpreter which interprets the compiled code according to a prewritten routine. In an embodiment, a hypothetical processor may be an Apple G4 processor, and all processors are provided with a code decompilation tool which enables operating based on this compiled code. Notably, the processor has access to the open GL drawing environment which enables the processor to produce the image. However, in this way, any processor is capable of executing the code which is produced. This code may be compiled versions of any of the effects noted above.
Although only a few embodiments have been disclosed in detail above, other modifications are possible. All such modifications are intended to be encompassed within the following claims. | Producing complicated effects based on image processing operations. The image processing operations are defined for a processor which may be different than the processor which is actually used. The processor that is actually used runs an interpreter that interprets the information into its own language, and then runs the image processing. The actual information is formed according to a plurality of layers which are combined in some way so that each layer can effect the layers below it. Layers may add to, subtract from, or form transparency to the layer below it or make color filtering the layer below it. This enables many different effects computed and precompiled for a hypothetical processor, and a different processor can be used to combine and render those effects. | 11,551 |
CROSS-REFERENCE
[0001] This application claims priority to Chinese Patent Application No. 201310379265.2 titled “COMMUNICATION ESTABLISHMENT METHOD. MOBILE STATION AND TRANSFER DEVICE BASED ON TRANSFER MODE” and filed with the Chinese State Intellectual Property Office on Aug. 27, 2013, which is incorporated herein by reference in its entirety.
FIELD
[0002] The present disclosure relates to the field of communication technology, and in particular to a method for communication establishment, a mobile station and a transfer device based on a transfer mode.
BACKGROUND
[0003] A mobile station establishes communications mainly in a direct mode and in a transfer mode. In the transfer mode, different mobile stations establish communications through a transfer device (a base station or a transfer station), and proper timeslot synchronization between a mobile station which triggers communications and the transfer device is essential to establish correct communications between different mobile stations. For example, timeslots of the transfer device includes timeslot 1 and timeslot 2 (the timeslot number may be user-defined, and the number of the timeslots of the transfer device is determined based on an applied communication standard), and timeslots available for the mobile station are timeslot 1 and timeslot 2 (the timeslot number may be also user-defined) respectively. If a preset synchronization rule is that timeslot 1 of the transfer device is synchronized with timeslot 1 of the mobile station, and the mobile station distributes timeslot 1 as a communication timeslot, other mobile stations operating at timeslot 1 may properly receive and analyze a signal only in a case that the mobile station transmits information at timeslot 1 and the transfer device transfers the information at timeslot 1 . Similarly, if a preset synchronization rule is that timeslot 2 of the transfer device is synchronized with timeslot 2 of the mobile station, and the mobile station distributes timeslot 2 as a communication timeslot, other mobile stations operating at timeslot 2 may properly receive and analyze a signal only in a case that the mobile station transmits information at timeslot 2 and the transfer device transfers the information at timeslot 2 .
[0004] In current DMR and PDT standards, a method for establishing communications between the mobile stations based on a transfer mode is defined as follows.
[0005] When the mobile station which triggers a communication service (referred to as the mobile station) communicates with other mobile stations via a transfer device, the mobile station directly transmits control information and service information to the transfer device, where the control information is mainly used for the transfer device and the other mobile stations to obtain a service type, and to get ready for the communications corresponding to the service type. The transfer device directly transfers the service information after receiving the service information. When transferring the service information, the transfer device only transfers the service information at a currently default operating timeslot, since the transfer device does not know and cannot obtain the timeslot used by the mobile station.
SUMMARY
[0006] Applicant finds that, there are some defects in conventional methods for communication establishment based on a transfer mode, i.e., a transfer device cannot obtain a timeslot used by a mobile station, and can only transfer at a default operating timeslot, which may cause an error in timeslot synchronization between the mobile station and the transfer device, so that some mobile stations cannot receive service information correctly. If the transfer device has two optional timeslots, a probability of this problem is basically 50%. The larger the number of timeslots of the transfer device, the higher the error rate for communication link establishment, which is far from enough to satisfy the requirements of communication system performance.
[0007] Thus, a method for communication establishment, a mobile station and a transfer device based on a transfer mode are provided according to embodiments of the disclosure, to address the issue of high error rate (low communication success rate) for communication link establishment between the mobile stations due to the transfer device being unaware of the timeslot used by the mobile station in conventional technology.
[0008] In view of this, a method for communication establishment, a mobile station and a transfer device based on a transfer mode are provided in the disclosure. The technical solution is provided as follows.
[0009] A method for communication establishment based on a transfer mode is provided. The method includes:
[0010] transmitting, by a first mobile station, control information to a transfer device, where the control information includes a timeslot used by the first mobile station and a control signaling corresponding to a service type, so that the transfer device determines a transfer timeslot and gets ready for communications based on the control signaling, and the transfer timeslot is a timeslot of the transfer device which is synchronous with the timeslot used by the first mobile station; and
[0011] communicating, by the first mobile station, with a target mobile station group at the transfer timeslot, where the target mobile station group includes at least one mobile station.
[0012] A mobile station is further provided. The mobile station includes a transmitting module and a communication establishment module.
[0013] The transmitting module is configured to transmit control information to a transfer device, where the control information includes a timeslot used by a first mobile station and a control signaling corresponding to a service type, so that the transfer device determines a transfer timeslot and gets ready for communications based on the control signaling, where the transfer timeslot is a timeslot of the transfer device which is synchronous with the timeslot used by the first mobile station.
[0014] The communication establishment module is configured to communicate with a target mobile station group at the transfer timeslot, where the target mobile station group includes at least one mobile station.
[0015] A method for communication establishment based on a transfer mode is further provided. The method includes:
[0016] receiving, by a transfer device, control information transmitted from a first mobile station, where the control information includes a timeslot used by the first mobile station and a control signaling corresponding to a service type;
[0017] determining, by the transfer device, a transfer timeslot based on the control information, and getting ready for communications based on a control signaling, wherein, the transfer timeslot is a timeslot of the transfer device which is synchronous with a timeslot used by the first mobile station; and
[0018] transferring, by the transfer device, information between the first mobile station and a target mobile station group at the transfer timeslot when the first mobile station communicates with the target mobile station group at the transfer timeslot, where the target mobile station group includes at least one mobile station.
[0019] A transfer device is further provided. The device includes a receiving module, a synchronizing module, and a transferring module.
[0020] The receiving module is configured to receive control information transmitted from a first mobile station, where the control information includes a timeslot used by the first mobile station and a control signaling corresponding to a service type.
[0021] The synchronizing module is configured to determine a transfer timeslot based on the control information and gets ready for communications based on the control signaling.
[0022] The transferring module is configured to transfer information between the first mobile station and the target mobile station group at the transfer timeslot for the first mobile station to communicate with a target mobile station group at the transfer timeslot, where the target mobile station group includes at least one mobile station.
[0023] A system for communication establishment based on a transfer mode is provided. The system includes at least two mobile stations according to any of the mobile stations mentioned above and transfer devices according to any of the transfer devices mentioned above.
[0024] In the technical solution of the disclosure, when the service of the first mobile station is triggered, the first mobile station transmits the control information to the transfer device. The control information includes the timeslot used by the first mobile station and the control signaling corresponding to the service type. Since the control information includes the timeslot used by the first mobile station, the transfer device may determine a timeslot to be used after receiving the control information transmitted by the mobile station, and get ready for communications based on the control signaling in the control information. Subsequently, the first mobile station may communicate with the target mobile station group at the transfer timeslot. When the communications are established, the transfer device may exactly obtain information of the timeslot used by a communication initiator, and the transfer device may transfer at a correct transfer timeslot when the service begins, thereby achieving accurate communications between the mobile stations, and reducing an error rate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In order to illustrate clearly technical solutions in embodiments of the present disclosure or a conventional technology, drawings used in the embodiments or the conventional technology are illustrated briefly. Obviously, the drawings described below are only some embodiments recited in the present application, and other drawings can be obtained by those skilled in the art based on these drawings without any creative work.
[0026] FIG. 1 is a signal flow graph of voice communications in the conventional technology;
[0027] FIG. 2 is a signal flow graph of data communications in the conventional technology;
[0028] FIG. 3 is a schematic structural diagram of a data frame, a voice frame and VSF in the conventional technology;
[0029] FIG. 4 is a flow chart of a method for communication establishment based on a transfer mode according to a first embodiment of the disclosure;
[0030] FIG. 5 is a schematic diagram of a process that a first mobile station generates FAC based on VH;
[0031] FIG. 6 is a schematic diagram of a process that a transfer device reconstructs VH based on FAC;
[0032] FIG. 7 is a schematic diagram of a process that the first mobile station generates FAC based on PC;
[0033] FIG. 8 is a schematic diagram of a process that the transfer device reconstructs PC based on FAC;
[0034] FIG. 9 is a flow chart of a method for communication establishment based on a transfer mode according to a second embodiment of the disclosure;
[0035] FIG. 10 is a schematic diagram of a process for generating FAEVH based on VH;
[0036] FIG. 11 is a flow chart of a method for communication establishment based on a transfer mode according to a third embodiment of the disclosure;
[0037] FIG. 12 is a flow chart of a method for communication establishment based on a transfer mode according to a fourth embodiment of the disclosure;
[0038] FIG. 13 is a schematic diagram of a process for reconstructing VH based on FAEVH;
[0039] FIG. 14 is a flow chart of a method for communication establishment based on a transfer mode according to a fifth embodiment of the disclosure;
[0040] FIG. 15 is a flow chart of a method for communication establishment based on a transfer mode according to a sixth embodiment of the disclosure;
[0041] FIG. 16 is a schematic structural diagram of a mobile station according to an embodiment of the disclosure; and
[0042] FIG. 17 is a schematic structural diagram of a transfer device according to an embodiment of the disclosure.
DETAILED DESCRIPTION
[0043] To make those skilled in the art understand the technical solution better, the technical solutions according to embodiments of the disclosure will be described clearly and completely in conjunction with drawings hereinafter. Apparently, the described embodiments are just a few rather than all of the embodiments of the disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of the disclosure without any creative work will fall within the protection scope of the disclosure.
[0044] For better understanding of the technical solutions of the disclosure, terminology to be used in the embodiments of the disclosure and a principle for establishing communications in a transfer mode in the conventional technology are described. For ease of description, terminologies of the disclosure hereinafter are in a form of abbreviations. Referring to Table 1, abbreviations and explanations of the terminologies to be used in the disclosure are shown, where MS (mobile station) is a mobile station.
[0000]
TABLE 1
Abbreviations and explanations of the terminologies
Full name in
Full name in
Abbreviation
English
Chinese
Description
DMR
Digital Mobile
Digital interphone
Radio
standard set by
ETSI
PDT
Police Digital
Digital trunking
Trunking
standard set by
China
TDMA
Time Divide Multi
Address
PDU
Protocol Data Unit
An information
unit including
protocol control
information and
user data
MS
Mobile Station
BS
Base Station
CACH
Common
Outbound
Announcement
announcement
Channel
signalling of the
transfer device to
carry control
information such
as timeslot
numbers
CSBK
Control Signalling
A Control
Block
Signalling format
in DMR/PDT
standards
A
Activation
A PDU required to
be transmitted
when a mobile
station activates a
transfer device
Idle
Idle
Data frame
transmitted when
there is no data to
be transferred
after the transfer
device is activated
FAC
Fast Activate
A PDU required to
CSBK
be transmitted
when a
communication in
transfer mode is
established
FAEVH
Fast Activate
Control
Embedded Voice
information
Header
embeddable in a
voice super frame
for transmission
VH
Voice Header
A PDU
transmitted before
an actual voice in
a voice service
VA
Voice Frame A
A
A first voice frame
of the voice super
frame
VB
Voice Frame B
B
A second voice
frame of the voice
super frame
VC
Voice Frame C
C
A third voice
frame of the voice
super frame
VD
Voice Frame D
D
A fourth voice
frame of the voice
super frame
VE
Voice Frame E
E
A fifth voice
frame of the voice
super frame
VF
Voice Frame F
F
A sixth voice
frame of the voice
super frame
VSF
Voice Super
A basic unit
Frame
including 6
ordinary voice
frames
PC
PreCSBK
A PDU
transmitted before
actual data in a
data service
DH
Data Header
A PDU
transmitted before
actual data in a
data service
DB
Data Block
A PDU carrying
actual user data in
a data service
CBF
CSBK Blocks to
A field in the PDU
follow
showing the
number of CSBK
blocks to follow
Inbound
Inbound
A direction from
the MS to the
transfer device
Outbound
Outbound
A direction from
the transfer device
to the MS
[0045] Further, referring to FIG. 1 to FIG. 2 , signal flow graphs of service communications in the conventional technology are shown. FIG. 1 corresponds to a signal flow graph of voice communications, FIG. 2 corresponds to a signal flow graph of data communications. The mobile station directly transmits control information. For a voice service, the mobile station transmits VH first, and for a data service, the mobile station transmits PC first. The transfer device establishes “synchronization” with the mobile station and transfers the control information directly. Since the transfer device cannot know the timeslot used by the mobile station, it is possible that the “synchronization” established herein is not correct, and there are communication errors. For the voice service, it should be noted that, a voice super frame VSF is used as a basic unit in a communication process defined by a DMR/PDT standard in actual transmitting, i.e., every 6 voice frames form a VSF, as shown in FIG. 3 . Frame synchronization information is in the middle of a first voice frame A, to find a starting position of a VSF. Embedded signaling information (e.g., information where VH may be embedded) is in the middle of each of other 5 voice frames. For the voice, voice frame synchronization information is embedded in the middle of the first voice frame of each VSF. For the data, data frame synchronization information is embedded in the middle of each data frame.
[0046] Based on the forgoing, FIG. 4 shows a flow chart of a method for communication establishment based on a transfer mode according to a first embodiment of the disclosure. The embodiment is described based on the DMR/PDT standard. The embodiment may include steps 401 to 402 .
[0047] In step 401 , a first mobile station transmits control information to a transfer device.
[0048] When the mobile station is in an idle state, and a user triggers a service of the first mobile station, the first mobile station generates the control information based on a type of the triggered service. The control information includes a timeslot used by the first mobile station and a control signaling corresponding to the type of the service. The transfer device receives the control information, determines a timeslot of the transfer device which is synchronous with the timeslot used by the first mobile station as a transfer timeslot, and get ready to communicate based on the control signaling. To illustrate the technical solution according to the embodiment, control information generated based on the DMR/PDT standard is described herein. In a case that the type of the service is a non-voice service, the control information is a fast activate control frame FAC generated based on a standard preamble control frame PC; and in a case that the type of the service is a voice service, the control information may be a fast activate control frame FAC generated based on a standard voice header VH. For different types of services, structures of information units of the FAC are similar, and only differ in content with which fields are filled. Referring to Table 2 and Table 3, structures of VH and PC defined in the DMR/PDT standard are shown.
[0000]
TABLE 2
Structure of VH defined in the DMR/PDT standard
Information Element
Length
Remark
Message Dependent Elements
Protect Flag(PF)
1
This bit shall be set to 0 2
Reserved(R)
1
This bit shall be set to 0 2
Feature Elements
FLCO (Full-Link Control Code)
6
Shall be set to 000000 2
Feature Set ID(FID)
8
SFID
Service_Option
8
Target Address
24
Source Address
24
[0000]
TABLE 3
Structure of PC defined in the DMR/PDT standard
Information Element
Length
Remark
Message Dependent Elements
Lask Block(LB)
1
This bit shall be set to 1 2
Protect Flag(PF)
1
This bit shall be set to 0 2
Feature Elements
CSBK Opcode(CSBKO)
6
Shall be set to 111101 2
Feature Set ID(FID)
8
SFID
Data/CSBK
1
0 2 -CSBK 1 2 -Data
Individual/Group(IG)
1
0 2 -Individual 1 2 -Group
Reserved(R)
6
These bits shall be set to 000000 2
CSBK Blocks to follow(CBF)
8
Target Address
24
Source Address
24
[0049] A case with 2 timeslots is taken as an example, structure of the FAC generated based on the structures defined in Table 2 and Table 3 is shown in Table 4.
[0000]
TABLE 4
Structure of FAC
Information Element
Length
Remark
Message Dependent Elements
Lask Block(LB)
1
This bit shall be set to 1 2
Protect Flag(PF)
1
This bit shall be set to 0 2
Feature Elements
CSBK Opcode(CSBKO)
6
Feature Set ID(FID)
8
TDMA channel(TC)
1
0 2 -Slot1 1 2 -Slot2
(Timeslot Number)
IG (Individual/Group)
1
0 2 -Individual 1 2 -Group
Service Type(ST)
2
00 2 -CSBK content follows
preambles
01 2 -Data content follows
preambles
10 2 -Voice content follows LC
header
11 2 -Reserved
Encryption Type(ET)
2
00 2 -No Encryption
01 2 -Encryption Type1
10 2 -Encryption Type2
11 2 -Reserved
Reserved
2
These bits shall be set to 00 2
Service_Option/CBF
8
Follow VH or PC
Target Address
24
Source Address
24
[0050] A field TC represents the timeslot used by the first mobile station, a field IG represents an individual call or a group call. Implementations of the solution are the same for the individual call or the group call, and only differ in information with which PDU is filled. A field ET represents an encryption method used, and subsequent service information to be transmitted varies depending on different encryption methods. Only unencrypted services are illustrated in this example, and encrypted services are processed similarly to the unencrypted services. A field ST represents a type of service required to be transferred subsequently. In a case that the ST is a voice service, a following field Service_Option/CBF needs to be filled with correct Service Option information, and in a case that the ST is a non-voice service (the non-voice service mainly includes a data service and some signaling services), the following field Service_Option/CBF needs to be filled with correct CBF information, and definitions of other parts are the same as the conventional standard.
[0051] In step 402 , the first mobile station communicates with a target mobile station group at the transfer timeslot.
[0052] The TC in the FAC shows the timeslot number used by the first mobile station, the transfer device receives the FAC and analyzes the FAC to obtain a required transfer timeslot (to achieve timeslot synchronization). In a case that the target mobile station group includes only one mobile station, the service is an individual call, and in a case that the target mobile station group includes multiple mobile stations, the service is a group call. When the first mobile station communicates with the target mobile station group, the first mobile station transmits service information of a corresponding service type to the transfer device at a timeslot at which the FAC is transmitted, and then, the transfer device transfers the service information to a target mobile station group at the transfer timeslot, to achieve information transmission between the first mobile station and the target mobile station group.
[0053] Preferably, in a case that the service type is a non-voice service, after obtaining the transfer timeslot, the transfer device needs to transmits the FAC or the standard preamble control frame PC reconstructed based on the FAC to the target mobile station group, and the target mobile station group get ready for communications based on a non-voice service type and a control signaling corresponding to the non-voice service carried in the FAC or the PC; after that, the first mobile station transmits the non-voice service information to the transfer device at the timeslot at which the FAC is transmitted, and the transfer device transfers received non-voice service information to the target mobile station group at the transfer timeslot, to achieve non-voice service information transmission between the first mobile station and the target mobile station group.
[0054] In a case that the service type is a voice service, after obtaining the transfer timeslot, the transfer device needs to transmits the FAC or a standard voice header VH reconstructed based on the FAC to the target mobile station group, and the target mobile station group get ready for communications based on a voice service type and a control signaling corresponding to the voice service carried in the FAC or the VH. After that, the first mobile station transmits a voice super frame (carrying voice service information) to the transfer device at the timeslot at which the FAC is transmitted, and the transfer device transfers the received voice super frame to the target mobile station group at the transfer timeslot, to achieve voice service information transmission between the first mobile station and the target mobile station group.
[0055] The VH or PC is reconstructed for compatibility with existing mobile stations. If the target mobile station group cannot identify the FAC, a communication link can only be successfully established based on the VH or PC rather than based on the FAC. Specifically, FIG. 5 and FIG. 6 show processes that the first mobile station generates the FAC based on the VH and the transfer device reconstructs the VH based on the FAC. FIG. 7 and FIG. 8 show processes that the first mobile station generates the FAC based on the PC and the transfer device reconstructs the PC based on the FAC.
[0056] In the technical solution according to the embodiment, when a service of the first mobile station is triggered, the first mobile station transmits the control information to the transfer device. The control information includes the timeslot used by the first mobile station and the control signaling corresponding to the service type. Since the control information includes the timeslot used by the first mobile station, the transfer device may determine a timeslot to be used after receiving the control information transmitted by the mobile station, and get ready for communication based on the control signaling in the control information. Subsequently, the first mobile station may communicate with the target mobile station group at the transfer timeslot. When the communications are established, the transfer device may exactly obtain information of the timeslot used by a communication initiator, to ensure that the transfer device may transfer at a correct transfer timeslot when the service begins, thereby achieving accurate communication between the mobile stations, and reducing an error rate.
[0057] In the first embodiment, new control information i.e., the fast activate control frame FAC, is constructed based on the DMR/PDT standard. For compatibility with an existing transfer device, based on the first embodiment, a method for communication establishment based on the transfer mode according to a second embodiment is further provided. FIG. 9 is a flow chart of the method for communication establishment based on the transfer mode according to the second embodiment of the disclosure. For implementation of steps related to the first embodiment, steps in the embodiment mentioned above may be referred to, which is not repeated herein. The second embodiment includes steps 901 to 905 .
[0058] In step 901 , a first mobile station transmits control information to a transfer device.
[0059] For a non-voice service, the control information is an FAC generated based on a PC. For a voice service, the control information is an FAC generated based on a VH. After the transfer device receives the control information, the control information may be processed with reference to step 402 , which is not repeated herein.
[0060] In step 902 , for a non-voice service, the first mobile station transmits the PC to the transfer device at a transfer timeslot at which the FAC is transmitted.
[0061] In step 903 , for a voice service, the first mobile station transmits the VH to the transfer device at the transfer timeslot at which the FAC is transmitted.
[0062] The objective of steps 902 - 903 is mainly to avoid a failure of communication link establishment when the transfer device does not receive the FAC or cannot identify the FAC. If the transfer device does not receive the information or cannot identify the FAC, it is required to transmit a standard control signaling PC or VH to the transfer device after transmitting the FAC to ensure the establishment of subsequent communications. In this case, even if the transfer device cannot transfer information to the target mobile station group due to inability to identify the FAC, the transfer device may transfer the information to the target mobile station group at a default timeslot after receiving the VH or PC, to achieve communication link establishment. On this occasion, the transfer device is still unable to know the timeslot used by the first mobile station, and a communication error may still occur.
[0063] After establishing communications with the target mobile station group, the first mobile station may execute the following steps, to transmit service information.
[0064] In step 904 , for a non-voice service, the first mobile station transmits non-voice service information to the transfer device at a timeslot at which the FAC is transmitted.
[0065] The non-voice service information includes data information or signaling information. In this case, the transfer device determines a transfer timeslot based on the FAC, and transmits the non-voice service information to the target mobile station group at the transfer timeslot. If the transfer device does not receive the FAC or cannot identify the FAC, the process of establishing communications between the first mobile station and the target mobile station group is the same as the conventional technology, and the transfer device transfers the non-voice service information to the target mobile station group at a default timeslot.
[0066] In step 905 , for a voice service, the first mobile station transmits a voice super frame to the transfer device at a timeslot at which the FAC is transmitted.
[0067] It should be noted that, for the voice service, there is an issue of lagging access, i.e., a communication interrupt occurs to the transfer device due to a temporary failure or a bad signal, the first mobile station is unable to know this case during transmitting and continues to transmit the signal, and the transfer device needs to continue to transfer the service information of the first mobile station after recovery. For a method for communication establishment where the mobile station transmits the control information to the transfer device, though the communications may be continued after the recovery of the transfer device, the transfer device is unable to correctly obtain the timeslot used by the first mobile station currently for a preceding FAC is missed, and a communication error may still occur.
[0068] To address the issue of lagging access, when the first mobile station communicates with the target mobile station group, only a VSF carrying a VH may be transmitted during transmitting of the VSF on an established communication link, in order to be compatible with existing transfer devices. But an error rate of communications cannot be reduced. Thus, preferably, a voice super frame VSF carrying a fast activate embedded voice header FAEVH generated based on the VH may be transmitted during subsequent transmitting of the VSF, wherein, the FAEVH carries information of the timeslot used by the first mobile station and a control signaling corresponding to the voice service. The transfer device may re-obtain a correct transfer timeslot in time based on the information of the timeslot used by the first mobile station in the FAEVH carried by the VSF after recovery, so as to establish a correct communication link.
[0069] Referring to FIG. 3 , a structural diagram of a VSF is shown. A voice frame has 264 bits, the middle 48 bits are generally special information such as frame synchronization information or embedded information, and bits on both ends are voice payload information. Voice frames except voice frame A (carrying voice frame synchronization information) may each carry 48 bits of embedded information in the middle thereof, and the VH or FAEVH occupies more bits, may be divided into 4 parts and may be respectively filled into middle positions of 4 voice frames for carrying, thus a corresponding FAEVH may be worked out through receiving embedded information in the middle of 4 different voice frames.
[0070] Taking account of compatibility of the transfer device, a VSF carrying a VH and a VSF carrying an FAEVH may be transmitted alternately in practice. Referring to Table 5, structure definition of the FAEVH is shown. A process that the mobile station generates the FAEVH based on the VH is shown in FIG. 10 .
[0000]
TABLE 5
Structure definition of FAEVH
Information Element
Length
Remark
Message Dependent Elements
Protect Flag(PF)
1
This bit shall be set to 0 2
TDMA channel(TC)
1
0 2 -Slot1 1 2 -Slot2
Feature Elements
FLCO
6
Feature Set ID(FID)
8
Service_Option
8
Target Address
24
Source Address
24
[0071] The technical solution according to this embodiment has beneficial effects of the first embodiment, and takes account of compatibility with existing transfer devices. Standard service signaling information may be transmitted to the transfer device after the transmitting of the FAC; in addition, the FAEVH is introduced for voice communications, so that correct communications may be restored in case of lagging access of the transfer device.
[0072] Based on the first and second embodiments, a method for communication establishment based on a transfer mode according to a third embodiment of the disclosure is provided. FIG. 11 is a flow chart of the method for communication establishment based on the transfer mode according to the third embodiment of the disclosure. For implementation of steps related to the first and second embodiments, steps in the embodiments mentioned above may be referred to, which are not repeated herein. The third embodiment may include steps 1101 to 1103 .
[0073] In step 1101 , a transfer device receives control information transmitted from a first mobile station.
[0074] In step 1102 , the transfer device determines a transfer timeslot based on the control information, and gets ready for communications based on a control signaling.
[0075] The control information includes a timeslot used by the first mobile station and a control signaling corresponding to a service type. For a non-voice service, the control information is a fast activate control frame FAC generated based on a standard preamble control frame PC, and for a voice service, the control information is a fast activate control frame FAC generated based on a standard voice header VH.
[0076] In step 1103 , when the first mobile station communicates with a target mobile station group at the transfer timeslot, the transfer device transfers information between the first mobile station and the target mobile station group at the transfer timeslot.
[0077] For implementation of steps related to this embodiment, description of relevant steps in the first embodiment may be referred to, and the technical solution according to this embodiment has the same beneficial effects as the first embodiment, which is not repeated herein.
[0078] Based on the third embodiment, a method for communication establishment based on a transfer mode according to a fourth embodiment of the disclosure is provided, and the fourth embodiment may be regarded as an implementation based on the third embodiment. FIG. 12 is a flow chart of the method for communication establishment based on the transfer mode according to the fourth embodiment of the disclosure. For implementation of steps related to the third embodiment, steps in the embodiments mentioned above may be referred to, which are not repeated herein. The fourth embodiment may include steps 1201 to 1202 .
[0079] In step 1201 , a transfer device receives control information transmitted from a first mobile station.
[0080] The control information includes a timeslot used by the first mobile station and a control signaling corresponding to a service type.
[0081] In step 1202 , the transfer device determines a transfer timeslot based on the control information, and gets ready for communications based on the control signaling.
[0082] In a case that the control information is an FAC, the transfer device may directly transfer the FAC to the target mobile station group at the transfer timeslot. For compatibility with an existing mobile station, the embodiment may further include the following preferable steps 1203 to 1204 .
[0083] In step 1203 , for a voice service, the transfer device reconstructs a VH based on the FAC, and for a non-voice service, the transfer device reconstructs a PC based on the FAC.
[0084] In step 1204 , the transfer device transfers the reconstructed VH or PC to the target mobile station group.
[0085] To avoid a case that the transfer device is unable to identify the FAC and communications cannot be established, the first mobile station may further transmits a standard signaling information VH or PC to the transfer device after transmitting the FAC. The following preferable steps 1205 to 1206 may be referred to.
[0086] In step 1205 , for a non-voice service, the transfer device receives the PC transmitted from the first mobile station, and transfers the PC to the target mobile station group.
[0087] In step 1206 , for a voice service, the transfer device receives the VH transmitted from the first mobile station, and transfers the VH to the target mobile station group.
[0088] After determining a transfer timeslot, the transfer device transfers a received VH or PC to the target mobile station group at the transfer timeslot. If the transfer device does not receive the control information or cannot identify the control information, the transfer device transfers a received VH or PC to the target mobile station group at a default timeslot, and communications are established between the first mobile station and the target mobile station group through the VH or PC.
[0089] After a communication link is established between the first mobile station and the target mobile station group, the first mobile station transmits service information through the transfer device. Specifically, the following preferable step 1207 may be referred to.
[0090] In step 1207 , for a non-voice service, the transfer device transfers non-voice service information to the target mobile station group, and for a voice service, the transfer device transfers a voice super frame to the target mobile station group.
[0091] The non-voice service information includes data information or signaling information, and the voice super frame carries service information. The voice super frame may further carry a VH or an FAEVH besides the service information, i.e., the voice super frame is a VSF carrying the VH and/or the FAEVH, and the FAEVH carries a timeslot information used by the first mobile station and a control signaling corresponding to the voice service.
[0092] For the non-voice service, there is no issue of lagging access. A voice may be received from the middle, while data cannot be correctly restored as long as it is missed, thus lagging access is completely meaningless for data communications, and the first mobile station only needs to directly transmit the signaling information or data information after communications are established between the first mobile station and the target mobile station group. For the voice service, to address the issue of lagging access, the first mobile station may transmit a VSF carrying the VH and/or the FAEVH when transmitting the VSF. The transfer device may directly transfer the received VSF. For compatibility with an existing mobile station, preferably, for the voice service, the transfer device may convert the FAEVH in the VSF into the VH, and then transfer a converted VSF carrying the VH to the target mobile station group. Specifically, a process that the transfer device reconstructs a VH based on an FAEVH is shown in FIG. 13 .
[0093] The technical solution according to this embodiment may realize the beneficial effects of the third embodiment, and takes account of compatibility with existing transfer devices. The transfer device may reconstruct the VH or PC based on the FAC after receiving the FAC, and the FAEVH is introduced to reconstruct the VH based on the FAEVH, thereby providing compatibility with an existing mobile station, addressing the issue of lagging access of the transfer device, and reducing a communication error rate.
[0094] Referring to FIG. 14 , a flow chart of a method for communication establishment based on a transfer mode according to a fifth embodiment of the disclosure is shown. This embodiment is a general flow chart of communication establishment based on a transfer device. For implementation of related steps, the embodiments mentioned above may be referred to, which is not repeated herein. The fifth embodiment may include steps 1401 to 1404 .
[0095] In step 1401 , a first mobile station transmits control information to a transfer device.
[0096] The control information includes a timeslot used by the first mobile station and a control signaling corresponding to a service type.
[0097] In step 1402 , the transfer device receives a message carrying the control signaling transmitted from the first mobile station to the transfer device.
[0098] In step 1403 , the transfer device determines a transfer timeslot based on the control information, and gets ready for communications based on the control signaling.
[0099] In step 1404 , the first mobile station communicates with a target mobile station group at the transfer timeslot, and the transfer device transfers information between the first mobile station and the target mobile station group at the transfer timeslot.
[0100] Referring to FIG. 15 , a method for communication establishment based on a transfer mode according to a sixth embodiment of the disclosure is provided. This embodiment may be regarded as an implementation based on the fifth embodiment. For implementation of related steps, the embodiments mentioned above may be referred to, which is not repeated herein. This embodiment may include steps 1501 to 1504 .
[0101] In step 1501 , a first mobile station transmits control information to a transfer device.
[0102] In step 1502 , the transfer device receives control information transmitted from the first mobile station.
[0103] The following steps are illustrated with an FAC as an example.
[0104] In step 1503 , the transfer device determines a transfer timeslot based on the FAC, and gets ready for communications based on a control signaling carried in the FAC.
[0105] In step 1504 , the transfer device transfers the FAC or a VH or a PC reconstructed based on a service type carried in the FAC to a target mobile station group at the transfer timeslot.
[0106] For compatibility with an existing transfer device, the embodiment may further include steps 1505 to 1510 .
[0107] In step 1505 , the first mobile station transmits the VH or PC to the transfer device at a timeslot at which the FAC is transmitted.
[0108] For a voice service, the first mobile station transmits the VH to the transfer device at the timeslot at which the FAC is transmitted; and for a non-voice service, the first mobile station transmits the PC to the transfer device at the timeslot at which the FAC is transmitted.
[0109] In step 1506 , the transfer device receives the VH or PC transmitted from the first mobile station.
[0110] In step 1507 , the transfer device transfers the received VH or PC to a target mobile station group.
[0111] In step 1508 , for a non-voice service, the first mobile station transmits non-voice service information to the transfer device at the timeslot at which the FAC is transmitted.
[0112] The non-voice service information includes data information or signaling information.
[0113] In step 1509 , for a voice service, the first mobile station transmits a voice super frame to the transfer device at the timeslot at which the FAC is transmitted.
[0114] The voice super frame is a VSF carrying a VH and/or an FAEVH, and the voice super frame carries voice service information.
[0115] In step 1510 , the transfer device transfers the non-voice service information or the voice super frame to the target mobile station group.
[0116] In a case that the voice super frame is a VSF carrying an FAEVH, the FAEVH may be converted into a VH and transferred to the target mobile station group, for compatibility with an existing transfer device. With regard to details, related steps in the embodiments mentioned above may be referred to, which are not repeated herein.
[0117] It should be noted that, in the embodiments mentioned above, information received by the transfer device are transferred at the transfer timeslot in a case that the transfer device determines the transfer timeslot. In a case that the transfer device does not determine the transfer timeslot, the transfer device transfers information at a default timeslot, and in this case, for communications between the first mobile station and the target mobile station group, implementations in the conventional technology may be referred to, which are not repeated herein.
[0118] In the embodiments mentioned above, the FAC is taken as an example for description for a voice service. In practical operation, the control information which the first mobile station transmits to the transfer device may be the FAEVH, and in this case, the FAEVH carrying timeslot information and a service control signaling is embedded in the VSF for transmission. The VSF includes an FAEVH carrying information which may indicate the timeslot used by the first mobile station, and further includes the voice service information. The transfer device extracts information about the timeslot used by the first mobile station after receiving a VSF with an FAEVH embedded, and determines the transfer timeslot, thereby ensuring a correct communication link established between the first mobile station and the target mobile station group after the transfer device receives the VSF carrying the FAEVH. For compatibility with an existing mobile station, the transfer device may convert the FAEVH carried in the VSF to a VH, and transmit a VSF carrying the VH to the target mobile station group. Unlike the lagging access in the second embodiment, if a failure occurs in a base station and causes communication interrupt after correct communications are established, the VSF with the FAEVH embedded is adopted to address the issue of lagging access and achieve correct communications. Control information which the first mobile station transmits to the transfer device may be the FAEVH, in other words, communications established before the first mobile station transmits the voice super frame for the first time is implemented based on the conventional technology and cannot achieve a correct communication establishment, and the FAEVH is embedded in the voice super frame when the voice super frame including the voice service information is transmitted, so that the base station may identify a correct transfer timeslot, thereby achieving a subsequent correct communication link.
[0119] Corresponding to the method embodiments, a mobile station is proved accordingly. Referring to FIG. 16 , a schematic structural diagram of a mobile station in the disclosure is shown. The mobile station includes a transmitting module 1601 and a communication establishment module 1602 .
[0120] The transmitting module 1601 is configured to transmit control information to a transfer device. The control information includes a timeslot used by the first mobile station and a control signaling corresponding to a service type, so that the transfer device determines a transfer timeslot and gets ready for communications based on the control signaling. The transfer timeslot is a timeslot of the transfer device which is synchronous with the timeslot used by the first mobile station.
[0121] The communication establishment module 1602 is configured to communicate with a target mobile station group at the transfer timeslot. The target mobile station group includes at least one mobile station.
[0122] Preferably, in a case that a service type is a non-voice service, the control information is a fast activate control frame generated based on a standard preamble control frame. The communication establishment module 1602 is specifically configured to:
[0123] transmit non-voice service information to the transfer device at a timeslot at which the fast activate control frame is transmitted, so that the transfer device transfers the received non-voice service information to the target mobile station group at the transfer timeslot, after the transfer device transmits the fast activate control frame or a standard preamble control frame reconstructed based on the fast activate control frame to the target mobile station group, and the target mobile station group gets ready for communications based on a non-voice service type and a control signaling corresponding to the non-voice service carried in the fast activate control frame or the standard preamble control frame.
[0124] Or, in a case that the service type is a voice service, and the control information is a fast activate control frame generated based on a standard voice header, the communication establishment module 1602 is specifically configured to:
[0125] transmit a voice super frame to the transfer device at a timeslot at which the fast activate control frame is transmitted, so that the transfer device transfers a received voice super frame to the target mobile station group at the transfer timeslot, after the transfer device transmits the fast activate control frame or a standard voice header reconstructed based on the fast activate control frame to the target mobile station group, and the target mobile station group gets ready for communications based on a voice service type and a control signaling corresponding to the voice service carried in the fast activate control frame or the standard voice header.
[0126] Or, in a case that the service type is a voice service, and the control information is a fast activate embedded voice header generated based on a standard voice header, the control information is embedded in a voice super frame and transmitted to the transfer device, and the communication establishment module 1602 is specifically configured to:
[0127] sequentially transmits a voice super frame to the transfer device at a timeslot at which the voice super frame is transmitted, so that the transfer device transfers a received voice super frame to the target mobile station group at the transfer timeslot, after the transfer device transmits the voice super frame with the fast activate embedded voice header embedded to the target mobile station group, and the target mobile station group gets ready for communications based on a voice service control signaling carried in the fast activate embedded voice header of the voice super frame, or, the transfer device reconstructs a standard voice header base on the fast activate embedded voice header of the voice super frame and transmits the voice super frame with the standard voice header embedded to the target mobile station group, and the target mobile station group gets ready for communications based on a voice service control signaling carried in the standard voice header of the voice super frame.
[0128] Preferably, the transmitting module 1601 is further configured to transmit a voice super frame carrying a standard voice header and/or a voice super frame carrying a fast activate embedded voice header generated based on the standard voice header to the transfer device after the target mobile station group gets ready for communications.
[0129] Preferably, the transmitting module 1601 is further configured to, for a non-voice service, transmit a PC to the transfer device at a timeslot at which the control information is transmitted, and for a voice service, transmit a VH to the transfer device at the timeslot at which the control information is transmitted, so that the transfer device determines a transfer timeslot based on the control information, and transfers a received VH or PC to the target mobile station group at the transfer timeslot. In a case that the transfer device does not receive the control information or cannot identify the control information, the transfer device transfers the received VH or PC to the target mobile station group at a default timeslot of the transfer device.
[0130] Referring to FIG. 17 , a schematic structural diagram of a transfer device according to an embodiment of the disclosure is shown. The transfer device may include a receiving module 1701 , a synchronizing module 1702 and a transferring module 1703 .
[0131] The receiving module 1701 is configured to receive control information transmitted from a first mobile station. The control information includes a timeslot used by the first mobile station and a control signaling corresponding to a service type.
[0132] The synchronizing module 1702 is configured to determine a transfer timeslot based on the control information and gets ready for communications based on the control signaling. The transfer timeslot is a timeslot of the transfer device which is synchronous with the timeslot used by the first mobile station.
[0133] The transferring module 1703 is configured for the first mobile station to communicate with a target mobile station group at the transfer timeslot, for information transfer between the first mobile station and the target mobile station group at the transfer timeslot. The target mobile station group includes at least one mobile station.
[0134] Preferably, for a non-voice service, the control information is a fast activate control frame generated based on a standard preamble control frame. The transferring module 1703 may include a first transmitting sub module, a receiving sub module, and a second transmitting sub module.
[0135] The first transmitting sub module is configured to transmit a fast activate control frame or a standard preamble control frame reconstructed based on the fast activate control frame to the target mobile station group, so that the target mobile station group gets ready for communications based on a non-voice service type and a control signaling corresponding to the non-voice service carried in the fast activate control frame or the standard preamble control frame.
[0136] The receiving sub module is configured to receive non-voice service information transmitted by the first mobile station at a timeslot at which the fast activate control frame is transmitted.
[0137] The second transmitting sub module is configured to transfer the received non-voice service information to the target mobile station group at the transfer timeslot.
[0138] Or, in a case that the service type is a voice service, and the control information is a fast activate embedded voice header generated based on a standard voice header, the control information is embedded in a voice super frame and transmitted to the transfer device. The transferring module 1703 may include a third transmitting sub module, a second receiving sub module, and a fourth transmitting sub module.
[0139] The third transmitting sub module is configured to transmit a voice super frame with a fast activate embedded voice header embedded to the target mobile station group, so that the target mobile station group gets ready for communications based on a voice service control signaling carried in the fast activate embedded voice header of the voice super frame, or, reconstruct a standard voice header based on the fast activate embedded voice header of a voice super frame, and transmit a voice super frame with the standard voice header embedded to the target mobile station group, so that the target mobile station group gets ready for communications based on a voice service control signaling carried in the standard voice header of the voice super frame.
[0140] The second receiving sub module is configured to receive a voice super frame sequentially transmitted by the first mobile station to the transfer device at a timeslot at which the voice super frame is transmitted.
[0141] The fourth transmitting sub module is configured to transfer a received voice super frame to the target mobile station group at the transfer timeslot.
[0142] Or, in a case that the service type is the voice service, and the control information is a fast activate control frame generated based on a standard voice header, the transferring module 1703 may include a fifth transmitting sub module, a third receiving sub module, and a sixth transmitting sub module.
[0143] The fifth transmitting sub module is configured to transmit the fast activate control frame or a standard voice header reconstructed based on the fast activate control frame to the target mobile station group, so that the target mobile station group gets ready for communications based on a voice service type and a control signaling corresponding to the voice service carried in the fast activate control frame or the standard voice header.
[0144] The third receiving sub module is configured to receive voice service information transmitted by the first mobile station at a timeslot at which the FAC is transmitted.
[0145] The sixth transmitting sub module is configured to transfer the received voice service information to the target mobile station group at the transfer timeslot.
[0146] Preferably, the receiving module is configured to, after the target mobile station group gets ready for communications, receive a voice super frame carrying the standard voice header and/or a voice super frame carrying the fast activate embedded voice header generated based on the standard voice header, which are transmitted by the first mobile station to the transfer device. In a case that the voice super frame is a voice super frame carrying the fast activate embedded voice header, the transferring module 1703 is specifically configured to reconstruct a standard voice header based on the fast activate embedded voice header carried in the voice super frame, and transfer a voice super frame carrying a reconstructed standard voice header to the target mobile station group.
[0147] Preferably, the receiving module 1701 is further configured to, for a non-voice service, receive a PC transmitted by the first mobile station at a timeslot at which the control information is transmitted, and for a voice service, receive a VH transmitted by the first mobile station at the timeslot at which the control information is transmitted. The transferring module is specifically configured to, after the synchronizing module determines the transfer timeslot based on the information, transfer the received VH or PC to the target mobile station group at the transfer timeslot, and in a case that the receiving module 1701 does not receive the control information or cannot identify the control information, transfer the received VH or PC to the target mobile station group at a default timeslot of the transfer device.
[0148] Accordingly, a communication establishment system based on a transfer mode is provided according to an embodiment of the disclosure. The system includes at least two mobile stations according to any of the embodiments mentioned above and transfer devices according to any of the embodiments mentioned above.
[0149] Functions implemented through the modules of the devices correspond to steps of the methods according to the method embodiments, which are not repeated herein.
[0150] Furthermore, hardware structures of a mobile station entity and a transfer device entity are provided respectively according to the embodiments of the disclosure. The hardware may include at least one processor (such as a CPU), at least one network interface or other communication interfaces, storage, and at least one communication bus, to implement direct connection and communications for these devices. The processor is configured to execute an executable module stored in the storage such as computer programs. The storage may include high-speed random access memory (RAM: Random Access Memory), and may further include non-volatile memory, such as at least one disk storage. Communication connection between the system gateway and at least one other network element may be implemented through at least one network interface, which may be wired or wireless, such as internet, wide area network, local network, metropolitan area network, and private network.
[0151] In practical implementations, the storage of the mobile station entity stores program instructions, and the processor thereof may execute the following steps based on the program instructions:
[0152] transmitting control information to a transfer device, where the control information includes a timeslot used by a first mobile station and a control signaling corresponding to a service type, so that the transfer device determines a transfer timeslot and gets ready for communications based on the control signaling, and the transfer timeslot is a timeslot of the transfer device which is synchronous with the timeslot used by the first mobile station; and
[0153] communicating with a target mobile station group at the transfer timeslot, where the target mobile station group includes at least one mobile station.
[0154] Accordingly, the storage of the transfer device entity also stores program instructions, and the processor thereof may execute the following steps based on the program instructions stored in the storage:
[0155] receiving control information transmitted by a first mobile station, where the control information includes a timeslot used by the first mobile station and a control signaling corresponding to a service type;
[0156] determining a transfer timeslot based on the control information, and getting ready for communications based on the control signaling, where the transfer timeslot is a timeslot of the transfer device which is synchronous with the timeslot used by the first mobile station; and
[0157] transferring the information between the first mobile station and a target mobile station group at the transfer timeslot when the first mobile station communicates with the target mobile station group at the transfer timeslot, where the target mobile station group includes at least one mobile station.
[0158] It should be noted that, in the technical solutions according to the embodiments of the disclosure, a transfer timeslot required for the mobile station may be indicated through other methods, or through a custom control frame based on an actually used communication protocol. For an implementation principle, implementations of the embodiments of the disclosure may be referred to, which are not repeated herein. The system embodiment basically corresponds to the method embodiment, thus for related parts thereof, description of the method embodiment may be referred to. The described system embodiment is merely exemplary, the units described as separate components may be or may be not separated physically, and the components shown as units may be or may not be physical units, i.e., the units may be located at one place or may be distributed onto multiple network units. All of or part of the units may be selected based on actual needs to implement the objectives of the solutions according to the embodiments of the disclosure. Those skilled in the art may understand and implement the solutions without creative effort.
[0159] The described embodiments are just preferable embodiments of the disclosure. It should be noted that, various changes and modifications may be made by those skilled in the art without departing from a principle of the disclosure, and the modifications and polish should be regarded as the protection scope of the disclosure. | A communication establishment method, mobile station and transfer device based on transfer mode. The method comprises: a first mobile station sends to the transfer device control information including the slot used by the first mobile station and the control signalings corresponding to different service types, in order that the transfer device determines a transfer slot and gets ready for communication according to the control signalings; and the first mobile station communicates with a target mobile station group through the transfer slot. The transfer device can accurately acquire the slot used by the mobile station, thus reducing communication error rate and solving the problem that the transfer device can not identify the slot in the use of the mobile station and can not support delayed access. Meanwhile, the technical solution can be compatible with existing transfer device and mobile station. | 85,195 |
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 10/240,367, filed on Oct. 30, 2002, a 35 U.S.C. §371 National Stage of International Application Number PCT/GR01/00017 filed on Mar. 28, 2001. U.S. application Ser. No. 10/240,367 claims priority to Greek National Application Serial No. 20000100102, filed on Mar. 28, 2000 and to U.S. National application Ser. No. 09/739,089 filed on Dec. 15, 2000.
FIELD OF THE INVENTION
[0002] The present invention is directed to a method and apparatus for the in vivo, non-invasive detection and mapping of the biochemical and/or functional pathologic alterations of human tissues.
BACKGROUND OF THE INVENTION
[0003] Cancer precursor signs are the so-called pre-cancerous states, which are often curable if they are detected at an early stage. If left untreated, the pre-cancerous state can develop into invasive cancer, which can subsequently metastasize. At this stage, the possibilities of successful therapy are dramatically diminished. Consequently, the early detection and the objective identification of the severity of the pre-cancerous state are of crucial importance.
[0004] Conventional methods that utilize optical instruments are very limited in their ability to detect cancerous and pre-cancerous tissue lesions. This is due to the fact that the structural and metabolic changes, which take place during the development of the disease, do not significantly and specifically alter the spectral characteristics of the pathological tissue.
[0005] In order to obtain a more accurate diagnosis, biopsy samples are obtained from suspicious areas, which are submitted for histological examination. However, biopsies pose several problems, such as a) a risk for sampling errors associated with the visual limitations in detecting and localizing suspicious areas; b) a biopsy can alter the natural history of the intraepithelial lesion; c) mapping and monitoring of the lesion require multiple tissue sampling, which is subjected to several risks and limitations; and d) the diagnostic procedure performed with biopsy sampling and histologic evaluation is qualitative, subjective, time consuming, costly and labor intensive.
[0006] In recent years, a few methods and systems have been developed to overcome the disadvantages of the conventional diagnostic procedures. These methods can be classified into two categories: a) methods which are based on the spectral analysis of tissues in vivo, in an attempt to improve the diagnostic information, and b) methods which are based on the chemical excitation of tissues with the aid of special agents, which can interact with pathologic tissue and alter its optical characteristics selectively, thus enhancing the contrast between lesion and healthy tissue.
[0007] In the first case, the experimental use of spectroscopic techniques has been motivated by the ability of these techniques to detect alterations in the biochemical and/or the structural characteristics of tissue as the disease progresses. In particular, fluorescence spectroscopy has been extensively used in various tissues. With the aid of a light source (usually laser) of short wave length (blue-ultraviolet range), the tissue is first excited. Next, the intensity of the fluorescent light emitted by the tissue as a function of the wavelength of the light is measured.
[0008] Garfield and Glassman in No. U.S. Pat. No. 5,450,857 and Ramanajum et al. in U.S. Pat. No. 5,421,339 have presented a method based on the use of fluorescence spectroscopy for the diagnosis of cancerous and pre-cancerous lesions of the cervix. The main disadvantage of fluorescence spectroscopy is that the existing biochemical modifications associated with the progress of the disease are not manifested in a direct way as modifications in the measured fluorescence spectra. The fluorescence spectra contain limited diagnostic information for two basic reasons: a) Tissues contain non-fluorescent chromophores, such as hemoglobin. Absorption by such chromophores of the emitted light from fluorophores can result in artificial dips and peaks in the fluorescence spectra. In other words the spectra carry convoluted information for several components and therefore it is difficult assess alterations in tissue features of diagnostic importance; and b) The spectra are broad because a large number of tissue components are optically excited and contribute to the measured optical signal. As a result, the spectra do not carry specific information of the pathologic alterations and thus they are of limited diagnostic value. In short, the aforementioned fluorescent technique suffers from low sensitivity and specificity in the detection and classification of tissue lesions.
[0009] Aiming to enhance the sensitivity and specificity of the preceding method, Ramanujan et al. in the Patent No. WO 98/24369 have presented a method based on the use of neural networks for the analysis of the spectral data. This method is based on the training of a computing system with a large number of spectral patterns, which have been taken from normal and from pathologic tissues. The spectrum that is measured each time is compared with the stored spectral data, facilitating in this way the identification of the tissue pathology.
[0010] R. R. Kortun et al, in U.S. Pat. No. 5,697,373, seeking to improve the quality of the measured diagnostic information, have presented a method based on the combination of fluorescence spectroscopy and Raman scattering. The latter has the ability of providing more analytical information; however, Raman spectroscopy requires complex instrumentation and ideal experimental conditions, which substantially hinders the clinical use thereof.
[0011] It is generally known that tissues are characterized by the lack of spatial homogeneity. Consequently the spectral analysis of distributed spatial points is insufficient for the characterization of their status.
[0012] Dombrowski in U.S. Pat. No. 5,424,543, describes a multi-wavelength, imaging system, capable of capturing tissue images in several spectral bands. With the aid of such a system it is possible in general to map characteristics of diagnostic importance based on their particular spectral characteristics. However, due to the insignificance of the spectral differences between normal and pathologic tissue, which is in general the case, inspection in narrow spectral bands does not allow the highlighting of these characteristics and even more so, the identification and staging of the pathologic area.
[0013] D. R. Sandison et al., in U.S. Pat. No. 5,920,399, describe an imaging system, developed for the in vivo investigation of cells, which combines multi-band imaging and light excitation of the tissue. The system also employs a dual fiber optic bundle for transmitting light from the source to the tissue, and then from the tissue to an optical detector. These bundles are placed in contact with the tissue, and various wavelengths of excitation and imaging are combined in attempt to enhance the spectral differentiation between normal and pathologic tissue.
[0014] In U.S. Pat. No. 5,921,926, J. R. Delfyett et al. have presented a method for the diagnosis of diseases of the cervix, which is based on the combination of Spectral Interferometry and Optical Coherence Tomography (OCT). This system combines three-dimensional imaging and spectral analysis of the tissue.
[0015] Moreover, several improved versions of colpo scopes have been presented, (D. R. Craine et al., U.S. Pat. No. 5,791,346 and K. L. Blaiz U.S. Pat. No. 5,989,184) in most of which, electronic imaging systems have been integrated for image capturing, analysis of tissue images, including the quantitative assessment of lesion's size.
[0016] For the enhancement of the optical differentiation between normal and pathologic tissue, special agents are used in various fields of biomedical diagnostics, which are administered topically or systematically. Such agents include acetic acid solution, toluidine blue, and various photosensitizers (porphyrines) (S. Anderson Engels, C. Klinteb erg, K. Svanberg, S. Svanberg, In vivo fluorescence imaging for tissue diagnostics, Phys Med. Biol. 42 (1997) 815-24). The selective staining of the pathologic tissue arises from the property of these agents to interact with the altered metabolic and structural characteristics of the pathologic area. This interaction enhances progressively and reversibly the differences in the spectral characteristics of reflection and/or fluorescence between normal and pathologic tissue. Despite the fact that the selective staining of the pathologic tissue is a dynamic phenomenon, in clinical practice the intensity and the extent of the staining are assessed qualitatively and statically.
[0017] Furthermore, in several cases of early pathologic conditions, the phenomenon of temporary staining after administering the agent, is short-lasting and thus the examiner is not able to detect the alterations and even more so, to assess their intensity and extent. In other cases, the staining of the tissue progresses very slowly, resulting in patient discomfort and the creation of problems for the examiner in assessing the intensity and extent of the alterations, since they are continuously changing. The above have as direct consequence the downgrading of the diagnostic value of these diagnostic procedures. Thus, their usefulness is limited to facilitating the localization of suspected areas for obtaining biopsy samples.
[0018] Summarizing the above, the following conclusions are drawn:
[0019] a) Various conventional light dispersion spectroscopic techniques (fluorescence, elastic, non-elastic scattering, etc.) have been proposed and experimentally used for the in vivo detection of alterations in the structural characteristics of pathologic tissue. The main disadvantage of these techniques is that they provide point information, which is inadequate for the analysis of the spatially non-homogenous tissue. Multi-band imaging has the potential to solve this problem by providing spectral information, of lesser resolution as a rule, in any spatial point of the area under examination. These imaging and non-imaging techniques, however, provide information of limited diagnostic value because the structural tissue alterations, which accompany the development of the disease, are not manifested as significant and characteristic alterations in the measured spectra. Consequently, the captured spectral information cannot be directly correlated with the tissue pathology, a fact that limits the clinical usefulness of these techniques.
[0020] b) The conventional (non-spectral) imaging techniques provide the capability of mapping characteristics of diagnostic importance in two or three dimensions. They are basically used for measuring morphological characteristics and as clinical documentation tools.
[0021] c) The diagnostic methods that are based on the selective staining of pathologic tissue with special agents allow the enhancement of the optical contrast between normal and pathologic tissue. Nevertheless they provide limited information for the in vivo identification and staging of the disease.
[0022] The selective interaction of pathologic tissue with the agents, which enhance the optical contrast with healthy tissue, is a dynamic phenomenon. It is therefore reasonable to suggest that the measurement and analysis of kinetic properties could provide important information for the in vivo detection, identification and staging of tissue lesions. In a previous publication, in which one of the inventors is a co-author, (C. Balas, A. Dimoka, E. Orfanoudalci, E. koumandakis, “In vivo assessment of acetic acid-cervical tissue interaction using quantitative imaging of back-scattered light: Its potential use for the in vivo cervical cancer detection grading and mapping”, SPIEOptical Biopsies and Microscopic Techniques, Vol. 3568 pp. 31-37, (1998)), measurements of the alterations in the characteristics of the back-scattered light as a function of wave-length and time are presented. These alterations occur in the cervix by the topical administration of acetic acid solution. In this particular case, a general-purpose multi-spectral imaging system built around a tunable liquid crystal monochromator was used for measuring the variations in intensity of the back-scattered light as a function of time and wavelength at selected spatial points. It was found that the lineshapes of curves of intensity of back-scattered light versus time provide advanced information for the direct identification and staging of tissue neoplasias. Unpublished results of the same research team indicate that similar results can also be obtained with other agents, which have the property of enhancing the optical contrast between normal and pathologic tissue. Nevertheless, the experimental method employed in the published paper is characterized by quite a few disadvantages, such as: The imaging monochromator requires time for changing the imaging wavelength and as a consequence it is inappropriate for multispectral imaging and analysis of dynamic phenomena. It does not constitute a method for the mapping of the grade of the tissue lesions, as the presented curves illustrate the temporal alterations of intensity of the back-scattered light in selected points. The lack of data modeling and parametric analysis of kinetics data in any spatial point of the area of interest restricts the usefulness of the method in experimental studies and hinders its clinical implementation. The optics used for the imaging of the area of interest is of general purpose and does not comply with the special technical requirements for the clinical implementation of the method. Clinical implementation of the presented system is also hindered by the fact that it does not integrate appropriate means for ensuring the stability of the relative position between the tissue surface and image capturing module during the snapshot imaging procedure. This is very important since small movements of the patient (i.e. breathing) are always present during the examination procedure. If, after the application of the agent, micro-movements occur while an image is being recorded, then the spatial features of the captured images may not be accurate. This may substantially reduce the accuracy of the calculation of the curves in any spatial point that express the kinetics of marker-tissue interaction.
SUMMARY OF THE INVENTION
[0023] The present invention provides a method for monitoring the effects of a pathology-differentiating agent on a tissue sample. The method includes applying a pathology differentiating agent, e.g., acetic acid, on a tissue sample and measuring a spectral property, such as an emission spectrum, of the tissue sample over time, thereby monitoring the effects of a pathology differentiating agent on a tissue sample. The tissue may be a sample from: the cervix of the uterus, the vagina, the skin, the uterus, the gastrointestinal track or the respiratory track. Without intending to be limited by theory, it is believed that the pathology-differentiating agent induces transient alterations in the light scattering properties of the tissue, e.g, the abnormal epithelium.
[0024] In another aspect, the present invention features a method for the in vivo diagnosis of a tissue abnormality, e.g., a tissue atypia, a tissue dysplasia, a tissue neoplasia (such as a cervical intraepithelial neoplasia, CINI, CINII, CINIII) condylomas or cancer, in a subject. The method includes applying a pathology differentiating agent, e.g., an acetic acid solution or a combination of solutions selected from a plurality of acidic and basic solutions, to a tissue. The method further includes exposing the tissue in the subject to optical radiation, and monitoring the intensity of light emitted from the tissue over time, thereby diagnosing a tissue abnormality in a subject. The optical radiation may be broad band optical radiation, preferably polarized optical radiation.
[0025] The non-invasive methods of the present invention are useful for in vivo early detection of tissue abnormalities/alterations. The methods are also useful for mapping the grade of abnormalities/alterations in epithelial tissues during the development of tissue atypias, dysplasias, neoplasias and cancers.
[0026] In one embodiment, the tissue area of interest is illuminated with a broad band optical radiation and contacted with a pathology differentiating agent, e.g., an agent or a combination of agents which interact with pathologic tissue areas characterized by an altered biochemical composition and/or cellular functionality and provoke a transient alteration in the characteristics of the light that is re-emitted from the tissue. The light that is re-emitted from the tissue may be in the form of reflection, diffuse scattering, fluorescence or combinations or subcombinations thereof. The intensity of the light emitted from the tissue may be measured, e.g., simultaneously, in every spatial point of the tissue area of interest, at a given time point or over time (e.g., for the duration of agent-tissue interaction). A diagnosis may be made based on the quantitative assessment of the spatial distribution of alterations in the characteristics of the light re-emitted from the tissue at given time points before and after the optical and chemical excitation of the tissue. The diagnosis may also be made based on the spatial distribution of parameters calculated from kinetics curves obtained from the light re-emitted from the tissue. These curves are simultaneously measured in every spatial point of the area under examination during the optical and chemical excitation of the tissue.
[0027] In one embodiment of the invention, the step of tissue illumination comprises exposing the tissue area under analysis to optical radiation of narrower spectral width than the spectral width of the light emitted by the illumination source. In another embodiment, the step of measuring the intensity of light comprises measuring the intensity of the re-emitted light in a spectral band, the spectral width of which is narrower than the spectral width of the detector's sensitivity. In yet another embodiment, the step of measuring the intensity of light comprises measuring simultaneously the intensity of the re-emitted light in a plurality of spectral bands, the spectral widths of which are narrower than the spectral width of the detector's sensitivity.
[0028] In yet another aspect, the present invention features an apparatus for the in vivo, non-invasive early detection of tissue abnormalities/alterations and mapping of the grade of these tissue abnormalities/alterations caused in the biochemical and/or in the functional characteristics of epithelial tissues, during the development of tissue atypias, dysplasias, neoplasias and cancers. The apparatus includes optics for collecting the light re-emitted by the area under analysis, selecting magnification and focusing the image of the area. The apparatus may also include optical imaging detector(s), means for the modulation, transfer, display and capturing of the image of the tissue area of interest. In addition, the apparatus can include a computer, which has data storage, processing and analysis means, a monitor for displaying images, curves and numerical data, optics for the optical multiplication of the image of the tissue area of interest, and a light source for illuminating the area of interest. The apparatus may also include optical filters for selecting the spectral band of imaging and illumination, means for transmitting light and illuminating the area of interest, control electronics, and optionally, software for the analysis and processing of data. The software can help with the tissue image capturing and storing in specific time points and for a plurality of time points, before and after administration of the pathology-differentiating agent.
[0029] Using the foregoing apparatus, an image or a series of images may be created which express the spatial distribution of the characteristics of the kinetics of the induced alterations in the tissue's optical characteristics, before and after the administration of the agent. Pixel values of the image correspond to the spatial distribution of the alterations in the intensity of the light emitted from the tissue at given times, before and after the optical and chemical excitation of tissue. The spatial distribution of parameters may be associated with pixel gray values as a function of time. The foregoing function may be calculated from the measured and stored images and for each row of pixels with the same spatial coordinates.
[0030] In one embodiment, the step of optical filtering the imaging detector comprises an optical filter that is placed in the optical path of the rays that form the image of the tissue, for the recording of temporally successive images in a selected spectral band, the spectral width of which is narrower than the spectral width of the detector's sensitivity.
[0031] In yet another embodiment, the image multiplication optics includes light beam splitting optics that creates two identical images of the area of interest. The images are recorded by two imaging detectors, in front of which optical filters are placed. The filters are capable of transmitting light having a spectral width that is shorter than the spectral width of the detector's sensitivity, so that two groups of temporally successive images of the same tissue area are recorded simultaneously, each one corresponding to a different spectral band.
[0032] In another embodiment, the image multiplication optics include more than one beam splitter for the creation of multiple identical images of the area of interest. The images are recorded by multiple imaging detectors, in front of which optical filters are placed. The filters have different transmission characteristics and are capable of transmitting light of spectral width shorter than the spectral width of the detector's sensitivity. Thus, multiple groups of temporally successive images of the same tissue area are recorded simultaneously, each one corresponding to a different spectral band.
[0033] In a further embodiment, the image multiplication optics comprise one beam splitter for the creation of multiple identical images of the area of interest, which are recorded by multiple imaging detectors, in front of which optical filters are placed with, preferably, different transmission characteristics and capable of transmitting light of spectral width shorter than the spectral width of the detector's sensitivity, so that multiple groups of temporally successive images of the same tissue area are recorded simultaneously, each one corresponding to a different spectral band.
[0034] In yet a further embodiment, the image multiplication optics include one beam splitter for the creation of multiple identical images of the area of interest, which are recorded in different sub-areas of the same detector. Optical filters having different transmission characteristics are placed in the path of the split beams. The filters are capable of transmitting light of spectral width shorter than the spectral width of the detector's sensitivity. Multiple groups of temporally successive images of the same tissue area are recorded simultaneously in the different areas of the detector, each one corresponding to a different spectral band.
[0035] In another embodiment, the step of filtering the light source comprises an optical filter, which is placed in the optical path of an illumination light beam, and transmits light of spectral width shorter than the spectral width of sensitivity of the detector used.
[0036] In a further embodiment, the step of filtering the light source includes providing a plurality of optical filters and a mechanism for selecting the filter that is disposed in the path of the illumination light, thus enabling the tuning of the center wavelength and the spectral width of the light illuminating the tissue.
[0037] In another embodiment, the mapping of the grade of the alterations associated with the biochemical and/or functional characteristics of the tissue area of interest is based on the pixel values of one image from the group of the recorded temporally successive images of the tissue area of interest.
[0038] In a further embodiment, this mapping is based on the pixel values belonging to a plurality of images, which are members of the group of the recorded temporally successive images of the tissue area of interest.
[0039] In another embodiment, this mapping is based on numerical data derived from the pixel values belonging to a plurality of images, which are members of the group of the recorded temporally successive images of the tissue area of interest.
[0040] In a further embodiment, a pseudo-color scale, which represents with different colors the different pixel values of the image or of the images used for the mapping of abnormal tissue areas, is used for the visualization of the mapping.
[0041] In one embodiment, the image or images are used for the in vivo detection, and identification of the borders of epithelial lesions.
[0042] In another embodiment, the pixel values of the image or of the images, which are determined for the mapping of the grade of alterations in biochemical and/or functional characteristics of tissue, are used as diagnostic indices for the in vivo identification and staging of epithelial lesions.
[0043] In yet another embodiment, the image or the images can be superimposed on the color or black and white image of the same area of tissue under examination displayed on the monitor. Abnormal tissue areas are highlighted and their borders are demarcated, facilitating the selection of a representative area for taking a biopsy sample, the selective surgical removal of the abnormal area and the evaluation of the accuracy in selecting and removing the appropriate section of the tissue.
[0044] In a further embodiment, the image or the images which are determined for the mapping of the grade of alterations in biochemical and/or functional characteristics of tissue are used for the evaluation of the effectiveness of various therapeutic modalities such as radiotherapy, nuclear medicine treatments, pharmacological therapy, and chemotherapy.
[0045] In another embodiment, the optics for collecting the light re-emitted by the area under analysis includes optomechanical components employed in microscopes used in clinical diagnostic examinations, surgical microscopes, colposcopes and endoscopes.
[0046] In one embodiment of the invention directed to colposcopy applications, the apparatus may comprise a speculum, an articulated arm onto which the optical head is attached. The optical head includes a refractive objective lens, focusing optics, a mechanism for selecting the magnification, an eyepiece, a mount for attaching a camera, and an illuminator. The speculurn is attached so that the central longitudinal axis of the speculum is perpendicular to the central area of the objective lens. Thus, when the speculum is inserted into the vagina and fixed in it, the relative position of the image-capturing optics and of the tissue area of interest remain unaltered, regardless of micro-movements of the cervix, which are taking place during the examination of the female subject.
[0047] In a further embodiment, the apparatus may further comprise an atomizer for delivering the agent. The atomizer is attached to the articulated arm-optical head of the apparatus and in front of the vaginal opening, where the spraying of the tissue may be controlled and synchronized with a temporally successive image capturing procedure with the aid of electronic control means.
[0048] In another embodiment of the apparatus of the invention, the image capturing detector means and image display means include a camera system. The camera system has a detector with a spatial resolution greater than 1000×1000 pixels and a monitor of at least 17 inches (diagonal), so that high magnification is ensured together with a large field of view while the image quality is maintained.
[0049] In a further embodiment directed to microscopes used in clinical diagnostic examinations, surgical microscopes and colposcopes, a system includes an articulated arm onto which the optical head is attached. The optical head includes an objective lens, focusing optics, a mechanism for selecting the magnification, an eyepiece, a mount for attaching a camera, an illuminator and two linear polarizers. One linear polarizer is disposed in the optical path of the illuminating light beam and the other in the optical path of the rays that form the image of the tissue. The polarization planes of these polarizers may be rotated. When the planes are perpendicular to each other, the contribution of the tissue's surface reflection to the formed image is eliminated.
[0050] In another embodiment directed to endoscopy, an endoscope may include optical means for transferring light from the light source to the tissue surface. The optical means may also allow the collection and transferring of rays along substantially the same axis.
[0051] The optical means also allow the focusing of the rays that form the image of the tissue. The endoscope may also include two linear polarizers. One linear polarizer is disposed in the optical path of the illuminating light beam and the other in the optical path of the rays that form the image of the tissue. The polarization planes of these polarizers may be rotated. When the planes are perpendicular to each other, the contribution of the tissue's surface reflection to the formed image is eliminated.
[0052] In another embodiment, microscopes used in clinical diagnostic examinations, surgical microscopes and colposcopes may include a reflective objective lens that replaces a refractive lens. The reflective objective lens is contracted so that a second reflection mirror is disposed in the central part of its optical front aperture. In the rear, non-reflective part of this mirror, illumination means are attached from which light is emitted toward the object. With or without illumination zooming and focusing optics, the central ray of the emitted light cone is coaxial with the central ray of the light beam that enters the imaging lens. With the aid of illumination zooming and focusing optics, which may be adjusted simultaneously and automatically with the mechanism for varying the magnification of the optical imaging system, the illuminated area and the field-of-view of the imaging system can vary simultaneously and proportionally. Any decrease in image brightness caused by increasing the magnification is compensated with the simultaneous zooming and focusing of the illumination beam.
[0053] Other features and advantages of the invention will be apparent from the following detailed description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0054] FIG. 1 is a schematic representation of the present method's basic principle.
[0055] FIG. 2 , illustrates an embodiment of the invention comprising a method for capturing in two spectral bands simultaneously and in any spatial point of the area under analysis, the kinetics of the alterations in the characteristics of the remitted from the tissue light, before and the after the administration of the contrast enhancing agent
[0056] FIG. 3 illustrates another embodiment of the invention comprising a method for capturing in different spectral bands simultaneously and in any spatial point of the area under analysis, the kinetics of the alterations in the characteristics of the remitted from the tissue light, before and the after the administration of the contrast enhancing agent.
[0057] FIG. 4 illustrates a schematic diagram of a medical microscope comprising a light source (LS), a magnification selection mechanism (MS), an eyepiece (EP) and a mount for attaching the image capturing module (CA), (detector(s), readout electronics etc).
[0058] FIG. 5 illustrates an endoscope comprising an eyepiece (EP), which can be adapted to an electronic imaging system, optical fibers or crystals for the transmission of both illumination and image rays, optics for the linear polarization of light, one interposed to the optical path of the illumination rays (LE) and one to the path of the ray that form the optical image of the tissue (II).
[0059] FIG. 6 depicts a colposcopic apparatus comprising an articulated arm (AA), onto which the optical head (OH) is affixed, which includes a light source (LS), an objective lens (0133), an eye-piece (EP) and optics for selecting the magnification (MS).
[0060] FIG. 7 illustrates an optical imaging apparatus which comprises a light source located at the central part of its front-aperture.
DETAILED DESCRIPTION OF THE INVENTION
[0061] The present invention is directed to a method and system for the in vivo, noninvasive detection and mapping of the biochemical and or functional alterations of tissue, e.g., tissue within a subject. Upon selection of the appropriate pathology differentiating agent that enhances the optical contrast between normal and pathologic tissue (depending on the pathology of the tissue), this agent is administered, e.g., topically, to the tissue.
[0062] As used herein a pathology differentiating agent is any agent capable of altering the optical property of a tissue, e.g., an agent capable of altering the reflection characteristics or the fluorescence characteristics of a tissue. The pathology differentiating agent may be an acidic solution, a basic solution, a porphyrine solution or a porphyrine precursor solution. Preferred examples of a pathology differentiating agent for use in the methods of the invention include an acetic acid solution, e.g., a weak acetic acid solution, or 5-amino luvelinic acid.
[0063] In FIG. 1 , the tissue (T), is sprayed using an atomizer (A), which contains the agent, e.g., acetic acid. At the same time, the tissue is illuminated with a source that emits light having a frequency within a specific spectral band that depends on the optical characteristics of both the agent and the tissue. The characteristics of the light emitted from the source can be controlled by choosing particular sources (LS), and optical filters (OFS). Sources of light for illuminating the tissue include light emitting diodes, and lasers.
[0064] For imaging the area of interest, light collection optics (L) may be used, which focus the image onto a two-dimensional optical detector (D). The output signal of the latter is amplified, modulated and digitized with the aid of appropriate electronics (EIS) and finally the image is displayed on a monitor (M) and stored in the data-storing means of a personal computer (PC). Between tissue (T) and detector (D), optical filters (OFI) can be interposed. The filter can be interposed for tissue (T) imaging in selected spectral bands, at which the maximum contrast is obtained between areas that are subjected to different grade of alterations in their optical characteristics after administering the appropriate agent.
[0065] Before administration of the latter, images can be obtained and used as references. After the agent has been administered, the detector (D) helps to capture images of the tissue, in successive time instances, which are then stored in the computer's data-storage means. The measuring rate is proportional to the rate at which the tissue's optical characteristics are altered, following the administration of the agent.
[0066] As used herein, an optical property, P, is a property that arises from the interaction of electromagnetic waves and a material sample, e.g., a tissue, such as a tissue within a subject. For example, the property can be the intensity of light after it interacts with matter, as manifested by an absorption, emission, or Raman spectrum. A dynamic optical property is a property that is obtained from a time-dependent optical property, P(t), and is determined from the measurement of P(t) at more than one time. For example, a dynamical optical property can be a relaxation time, or a time integral of P(t).
[0067] In FIG. 1 , images of the same tissue area are schematically illustrated, which have been stored successively before and after administering the agent (STI). In these images, the black areas represent tissue areas that do not alter their optical characteristics (NAT), while the gray-white tones represent areas that alter their optical characteristics (AT), following the administration of the agent. The simultaneous capture of the intensity of the light re-emitted from every spatial point of the tissue area under analysis and in predetermined time instances, allows the calculation of the kinetics of the induced alterations.
[0068] In FIG. 1 , two curves are illustrated: pixel value at position xy (Pvxy), versus time t. The curve ATC corresponds to an area where agent administration induced alterations (AT) in the tissue's optical characteristics. The curve (NATC) corresponds to an area where no alteration took place (NAT).
[0069] Each pixel, (x,y), can be associated with a pixel value, such as intensity I, which generally depends on time. For example, at time ti and pixel (x,y), the pixel value can be denoted by PV xy (ti). One useful dynamical spectral property, which can be obtained by measuring pixel value versus time at a particular pixel (x,y), is the relaxation time t ret (x,y). Letting the maximum of a PV time curve be denoted by A, then t ret (x,y) satisfies PV xy (t ret )=A/e, where e is the base of the natural logarithm. For example, if the pixel value versus time curve can be approximated by an exponential with relaxation rate r, PV xy (t)=A exp(−rt), where r>0, then t rel (x,y)=1/r.
[0070] The calculation of these parameters (P) at every spatial point of the area under analysis allows kinetic information (KI) to be obtained, with pixel values that are correlated with these parameters. These values can be represented with a scale of pseudocolors (P min , P max ), the spatial distribution of which allows for immediate optical evaluation of the intensity and extent of the induced alterations. Depending on the correlation degree between the intensity and the extent of the induced alterations with the pathology and the stage of the tissue lesion, the measured quantitative data and the derived parameters allow the mapping, the characterization and the border-lining of the lesion. The pseudocolor image of the phenomenon's kinetics (KI), which expresses the spatial distribution of one or more parameters, can be superimposed (after being calculated) on the tissue image, which is displayed in real-time on the monitor. Using the superimposed image as a guide facilitates the identification of the lesion's boundaries, for successful surgical removal of the entire lesion, or for locating suspicious areas to obtain a biopsy sample(s). Furthermore, based on the correlation of the phenomenon's kinetics with the pathology of the tissue, the measured quantitative data and the parameters that derive from them can provide quantitative clinical indices for the in vivo staging of the lesion or of sub-areas of the latter.
[0071] In some cases it is necessary to capture the kinetics of the phenomenon in more than one spectral band. This can help in the in vivo determination of illumination and/or imaging spectral bands at which the maximum diagnostic signal is obtained. Furthermore, the simultaneous imaging in more than one spectral band can assist in minimizing the contribution of the unwanted endogenous scattering, fluorescence and reflection of the tissue, to the optical signal measured by the detector. The measured optical signal comprises the optical signal generated by the marker-tissue interaction and the light emitted from the endogenous components of the tissue. In many cases, the recorded response of the components of the tissue constitutes noise since it occludes the generated optical signal, which carries the diagnostic information. Therefore, separation of these signals, based on their particular spectral characteristics, results in the maximization of the signal-to-noise ratio and consequently in the improvement of the obtained diagnostic information.
[0072] FIG. 2 illustrates a method for measuring in two spectral bands simultaneously and in any spatial point of the area under analysis, the kinetics of the alterations in the characteristics of the light emitted from the tissue, before and the after the administration of the contrast enhancing agent. The light emitted from the tissue is collected and focused by the optical imaging module (L) and allowed to pass through a beam splitting (BSP) optical element. Thus, two identical images of the tissue (T) are generated, which can be captured by two detectors (D 1 , D 2 ). In front of the detector, appropriate optical filters (Of λ1 ), (Of λ2 ) can be placed, so that images with different spectral characteristics are captured. Besides beam splitters, optical filters, dichroic mirrors, etc., can also be used for splitting the image of the object. The detectors (D 1 ), (D 2 ) are synchronized so that they capture simultaneously the corresponding spectral images of the tissue (Ti λ1 ), (Ti λ2 ) and in successive time-intervals, which are stored in the computer's data storage means. Generalizing, multiple spectral images can be captured simultaneously by combining multiple splitting elements, filters and sources.
[0073] FIG. 3 illustrates another method for capturing in different spectral bands simultaneously and in any spatial point of the area under analysis, the kinetics of the alterations in the characteristics of the light emitted from the tissue, before and the after the administration of the contrast enhancing agent. With the aid of a special prism (MIP) and imaging optics, it is possible to form multiple copies of the same image onto the surface of the same detector (D). Various optical filters (OF λ1 ), (OF λ2 ), (OF λ3 ), and (OF λ4 ), can be interposed along the length of the optical path of the rays that form the copies of the object's image, so that the multiple images correspond to different spectral areas.
[0074] For the clinical use of the methods of the invention, the different implementations of imaging described above can be integrated to conventional optical imaging diagnostic devises. Such devises arc the various medical microscopes, colposcopes and endoscopes, which are routinely used for the in vivo diagnostic inspection of tissues. Imaging of internal tissues of the human body requires in most cases the illumination and imaging rays to travel along the same optical path, through the cavities of the body. As a result, in the common optical diagnostic devices the tissue's surface reflection contributes substantially to the formed image. This limits the imaging information for the subsurface characteristics, which is in general of great diagnostic importance. This problem becomes especially serious in epithelial tissues such as the cervix, larynx, and oral cavity, which are covered by fluids such as mucus and saliva. Surface reflection also obstructs the detection and the measurement of the alterations in the tissue's optical properties, induced after the administration of agents, which enhance the optical contrast between normal and pathologic tissue. More specifically, when an agent alters selectively the scattering characteristics of the pathologic tissue, the strong surface reflection that takes place in both pathologic (agent responsive) and normal (agent non responsive) tissue areas, occludes the diagnostic signal that originates from the interaction of the agent with the subsurface features of the tissue. In other words, surface reflection constitutes optical noise in the diagnostic signal degrading substantially the perceived contrast between agent responsive and agent non-responsive tissue areas.
[0075] For accurate diagnoses using the aforementioned imaging devices, appropriate optics can be used to eliminate noise arising from surface reflection. FIG. 4 illustrates a schematic diagram of a medical microscope that includes a light source (LS), a magnification selection mechanism (MS), an eyepiece (EP) and a mount for attaching the image capturing module (CA), (detector(s), readout electronics etc). To eliminate surface reflection, a pair of linear polarizers is employed. Light from the source passes through a linear polarizer (LPO) with the resulting linearly polarized light (LS) then impinging on the tissue. The surface reflected light (TS) has the same polarization plane as the incident light (Fresnel reflection). By placing another linear polarizer (IPO), oriented at a right angle with respect to the first, in the path of the light emitted from the tissue, the contribution of the surface reflected light is eliminated. The light that is not surface reflected enters the tissue, where due to multiple scattering, light polarization is randomized. Thus, a portion of the re-emitted light passes through the imaging polarization optics, carrying improved information for the subsurface features.
[0076] FIG. 5 illustrates an endoscope that includes an eyepiece (EP), which can be adapted to an electronic imaging system, and optical fibers or crystals for the transmission of both illumination and image rays. The endoscope also includes a first linear polarizer (LPO), disposed in the optical path of the illumination rays (LE), and a second polarizer (IPO), oriented at right angles to the first, disposed in the path of the light emitted by the tissue (II). The polarizer (LPO) can be disposed as shown in the figure, or, alternatively, where the light enters the endoscope (IL). In the latter case, the endoscope has to be constructed using polarization preserving crystals or fiber optics for transferring the light. If polarization preserving light transmission media are used, then the polarizers for the imaging rays can be disposed in their path, in front or in back of the eyepiece (EP).
[0077] A problem for the effective clinical implementation of the method described above involves the micro-movements of the patient, which are present during the snapshot imaging of the same tissue area. This problem is eliminated when the patient is under anesthesia (open surgery). In most cases, however, the movements of the tissue relative to the image capturing module, occurring during the successive image capturing time-course, result in image pixels, with the same image coordinates, which do not correspond to exactly the same spatial point x,y of the tissue area under examination.
[0078] This problem is typically encountered in colposcopy. A method for eliminating the influence to the measured temporal data of the relative movements between tissue and image capturing module is presented below.
[0079] A colposcopic apparatus, illustrated in FIG. 6 , includes an articulated arm (AA), onto which the optical head (OH) is affixed. The head (OH) includes a light source (LS), an objective lens (OBJ), an eyepiece (EP) and optics for selecting the magnification (MS). The image-capturing module is attached to the optical head (OH), through an opto-mechanical adapter. A speculum (K.D), which is used to open-up the vaginal canal for the visualization of the cervix, is connected mechanically to the optical head (OH), so that its longitudinal symmetry axis (LA) is perpendicular to the central area of the objective lens (OBJ). The speculum enters the vagina and its blades are opened up compressing the side walls of the vagina. The speculum (I(D), being mechanically connected with the optical head (OH), transfers any micromovement of the patient to the optical head (OH), which, being mounted on an articulated arm (AA), follows these movements. Thus the relative position between tissue and optical head remains almost constant.
[0080] An important issue that must also be addressed for the successful clinical implementation of the diagnostic method described herein is the synchronization of the application of the pathology differentiating agent with the initiation of the snapshot imaging procedure. FIG. 6 , illustrates an atomizer (A) attached to the optical head of the microscope. The unit (MIC) is comprised of electronics for controlling the agent sprayer and it can incorporate also the container for storing the agent. When the unit (MIC) receives the proper command from the computer, it sprays a predetermined amount of the agent onto the tissue surface, while the same or another command initiates the snapshot image capturing procedure.
[0081] The diagnostic examination of non-directly accessible tissues located in cavities of the human body (ear, cervix, oral cavity, esophagus, colon, stomach) is performed with the aid of common clinical microscopes. In these devices, the illumination-imaging rays are near co-axial. More specifically, the line perpendicular to the exit point of light into the air, and the line perpendicular to the objective lens, form an angle of a few degrees. As a result, these microscopes operate at a specific distance from the subject (working distance), where the illuminated tissue area coincides with the field-of view of the imaging system. These microscopes are found to be inappropriate in cases where tissue imaging through human body cavities of small diameter and at short working distances is required. These technical limitations hinder the successful clinical implementation of the method described herein. As discussed above, elimination of surface reflection results in a substantial improvement of the diagnostic information obtained from the quantitative assessment of marker-tissue interaction kinetics. If a common clinical microscope is employed as the optical imaging module, then as a result of the above-mentioned illumination-imaging geometry, multiple reflections occur in the walls of the cavity before the light reaches the tissue under analysis. Multiple reflections are more numerous in colposcopy because of the highly reflective blades of the speculum, which is inserted into the vagina to facilitate the inspection of the cervix.
[0082] If the illuminator of the imaging apparatus emits linearly polarized light, the multiple reflections randomize the polarization plane of the incident light. As discussed above, if the light impinging on the tissue is not linearly polarized, then the elimination of the contribution from the surface reflection to the image can not be effective.
[0083] FIG. 7 illustrates an optical imaging apparatus that includes a light source located at the central part of its front-aperture. With this arrangement, the central ray of the emitted light cone is coaxial with the central ray of the light beam that enters the imaging apparatus. This enables illumination rays to directly reach the tissue surface under examination before multiple reflections occur with the wall of the cavity or speculum. A reflective-objective lens is used, which includes a first reflection (1RM) and a second reflection (2RM) mirror. A light source (LS) is disposed at the rear of the second reflection mirror (2RM), together with, if required, optics for light beam manipulation such as zooming and focusing (SO). The reflective-objective lens (RO), by replacing the common refractive-objective used in conventional microscopes, provides imaging capability in cavities of small diameter with the freedom of choosing the working distance. The zooming and focusing optics of the light beam can be adjusted simultaneously with the mechanism for varying the magnification of the optical imaging system so that the illumination area and the field-of-view of the imaging system vary simultaneously and proportionally. Thus, image brightness is preserved regardless of the magnification level of the lens. The imaging-illumination geometry embodied in this optical imaging apparatus, along with the light beam manipulation options, helps to eliminate the surface reflection contribution to the image and consequently helps to efficiently implement the method described herein.
EQUIVALENTS
[0084] Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims. | The present invention provides a method and an apparatus for the in vivo, non-invasive, early detection of alterations and mapping of the grade of these alterations, causing in the biochemical and/or in the functional characteristics of the epithelial tissues during the development of tissue atypias, dysplasias, neoplasias and cancers. The method is based, at least in part, on the simultaneous measurement of the spatial, temporal and spectral alterations in the characteristics of the light that is re-emitted from the tissue under examination, as a result of a combined tissue excitation with light and special chemical agents. The topical or systematic administration of these agents result in an evanescent contrast enhancement between normal and abnormal areas of tissue. The apparatus enables the capturing of temporally successive imaging in one or more spectral bands simultaneously. Based on the measured data, the characteristic curves that express the agent-tissue interaction kinetics, as well as numerical parameters derived from these data, are determined in any spatial point of the examined area. Mapping and characterization of the lesion, are based on these parameters. | 53,902 |
The present application is a national phase application under 35 U.S.C. §371 of International Application No. PCT/CA2005/000131, filed 2 Feb. 2005, which claims the benefit of U.S. Provisional Application No. 60/541,259, filed 4 Feb. 2004. The entire text of these applications are incorporated by reference.
TECHNICAL FIELD
The invention relates to a novel process for the synthesis of thiophene-based oligo- and polyazomethines and their subsequent doping for use in a variety of applications, including conducting materials and electronic devices. The invention further comprises the oligo- and polyazomethines that are produced by this process.
BACKGROUND OF THE INVENTION
Conjugated polymers have received much attention because of the many new possibilities these polymers can provide for modern devices. A few such applications of conjugated polymers involve organic light emitting diodes (OLEDs) and molecular wires to be used in flexible light displays and/or low power consumption products. 2,3 Because of the many interesting properties they possess—including unique optical, electrical, and mechanical properties 1 —these materials have been heavily investigated.
Synthesis of these industrially relevant materials has evolved from elimination reactions to more elegant coupling strategies. As attractive as these polymers are for their physical properties, the main synthetic methods pursued are not straightforward 4,6 and require Suzuki, 7 Wittig, 8 or Mitsunobu 9 synthetic strategies, or electropolymerization. 10 Such methods subsequently entail challenging and tedious purifications to isolate the desired polymers and remove unwanted metal bi-products. In addition, traditional synthetic methods result in only low to moderate yields. 4,5
There is a need, therefore, for novel oligo- and polyazomethines. There is also a need for a simpler, more efficient synthetic process to prepare these novel oligo- and polyazomethines. The present invention seeks to meet these and related needs.
SUMMARY OF THE INVENTION
Even though conjugated aromatic polyazomethines have been known for many years, and their properties and methods of preparation have been reviewed, 11 the present invention is believed to represent the first synthesis of such polyazomethines involving thiophene units. The advantage of the present synthetic process involving a condensation strategy is the ease of purification with the reaction being amenable to a plethora of reagents. Moreover, it does not necessitate the use of anhydrous solvents and strict oxygen free reaction environments, unlike conventional conjugation methods. The main driving force of this simple oligomerization is the thermodynamically desirable conjugation formation leading to a new class of stable thiophene-containing materials exhibiting interesting photophysical and conducting properties. The methodology also allows for selectively controlled addition condensation leading to either symmetric or unsymmetric conjugated compounds.
More specifically, the invention relates to the synthesis of conjugated aromatic oligo- and polyazomethines that are prepared by reacting one or more aromatic diamines with one or more aromatic dialdehydes either in solution or in a molten state, using the procedures described herein. Of these aromatic oligo- and polyazomethines, one is a thiophene core affording the polyazomethine 10 or 11 illustrated in Scheme 4, below.
In one embodiment of the present invention, the oligo- and polyazomethines are prepared by the reaction of a dialdehyde with an equimolar amount of a diamine, or of a diamine with an equimolar amount of one dialdehyde with one or both aryl components being a thiophene. The integer Y from Scheme 4 may be a 6-member homoaromatic ring, a 6-membered heteroaromatic ring comprising one to three nitrogen atoms, or a 5-membered heteroaromatic ring comprising a sulfur, nitrogen, tellurium, or selenium atom. The integers R 1 , R 2 , R 3 , R 4 , and R 5 may be aliphatic, aromatic, heteroatomic, hydrophilic, or hydrophobic. These groups may be aliphatic C 1 -C 12 , aliphatic C 1 -C 4 aliphatic chains, C 6 -C 14 aromatic systems, ester groups CO 2 Z with Z being aliphatic C 1 -C 12 .
In one embodiment, the present invention relates to a conjugated conducting oligomer or polymer of the general structure of 8 of Scheme 3, above, obtained by the condensation of a bifunctional monomer, the monomer being both aryl monoamine and monoaldehyde (structure 7 in Scheme 3) wherein the integers R 1 and R 2 may be aliphatic, aromatic, heteroatomic, hydrophilic, or hydrophobic.
In another embodiment, the present invention relates to multifunctional aryl moieties comprising more than two aldehyde or amine moieties. The integers R 3 may include electron donating or electron withdrawing groups, aliphatic C 1 -C 12 , C 1 -C 4 chains, C 6 -C 14 aromatic systems, ester groups CO 2 Z with Z being aliphatic C 1 -C 12 , or cyano, nitro, diakylamines, aldehydes, esters, halogens, carboxylic acids, amines, carboxaldehydes, wherein R 3 may be identical or different.
In yet another embodiment, the present invention relates to materials that can be spin coated into thin films of varying thickness from casting of solutions using solvents such as but not limited to THF, chloroform, dichloromethane, alcohols, DMF, etc. The conjugated materials can be made conducting by doping with p-type dopants such as iodine. The conjugated materials can be made conducting by doping with n-type dopants such as sodium naphthalide, SbF 5 , AsF 5 , PF 5 , AgX, NO 2 X, and NOX where X is an unreactive, non- to moderately nucleophilic anion. The molecular weight of the resulting polymers can be controlled by variation in the reaction concentrations.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 : Normalized ground state absorption of Example 5 (open circles), Example 32 (closed squares), and Example 34 (open squares). Inset: Reciprocal of the number of units along the conjugated backbone versus the absorption maximum.
FIG. 2 : Crystal structure of oligothiophene 3 of Scheme 6.
FIG. 3 : Thiophene spectroscopic and cyclic voltammetry a values measured in anhydrous acetonitrile.
FIG. 4 : Selected crystallographic data.
FIGS. 5 and 6 : Kinetics of Poly-DAT reaction.
FIG. 7 : Absorbance spectra of polyimines 1 (●) and 2 (□) recorded in DMF.
FIG. 8 : Fluorescence of polyimines 1 (●) and 2 (□) measured in DMF excited at 290 nm for 1 and 300 nm for 2 nm.
FIG. 9 : Cyclic voltamograms of polyimines 1 (●) and 2 (□) measured in DMF with sweep rate of 500 mV/sec.
FIG. 10 : The effect of polymerization concentration on the polymer molecular weight.
DETAILED DESCRIPTION OF THE INVENTION
(i) General Method of Oligoazomethine Synthesis
Selective oligomerization leading to a dimer such as 2 can be carried out at temperatures ranging from 25° C. to 120° C. open to the atmosphere or under inert atmosphere such as nitrogen or argon with alcohol solvents, including but not limited to ethanol, methanol, isopropanol, butanol; benzene and/or toluene by azeotropic distillation; wet or anhydrous DMF; wet or anhydrous DMSO; wet or anhydrous THF; etc. The use of acid catalysts between 5-10 mol % is not strictly required but may be in the form of organic or mineral acids including but not limited to trifluoroacetic acid, acetic acid, hydrochloric acid, sulphuric acid, etc., to accelerate oligomerization. Dehydrating reagents, including but not limited to anhydrous magnesium sulfate, anhydrous sodium sulfate, activated molecular sieves, activated neutral or acidic aluminum oxide, anhydrous silica gel, etc., can be used to shift the equilibrium in favour of the product. Generally, one stoichiometric equivalent of aldehyde is added to one stoichiometric equivalent of diamine and allowed to react between 0.5 to 36 hours until judged complete by TLC analyses. The solvent is subsequently removed under vacuum and the product obtained is used as is, or purified if required. Purification can be in the form of flash chromatography over silica gel or activated neutral aluminum oxide. Selective oligomerization leading to a trimer such as symmetric 5 (Scheme 2; R 3A equal to R 3B ) can be carried out according to the procedure outlined for the preparation of 2 through the use of approximately two stoichiometric equivalents of aldehyde with one stoichiometric equivalent of diamine. Asymmetric trimer analogues of 3 (Scheme 2; R 3A not equal to R 3B ) can be obtained by reaction conditions as outlined for the preparation of 2 using one stoichiometric equivalent of aldehyde added to one stoichiometric equivalent of diamine followed by the addition of about one equivalent of aldehyde added to the reaction mixture upon complete dimer formation.
(ii) General Method of Polyazomethine Synthesis
For reactive monomers, typically 80 to 100 mg of the diamine monomer are charged into a 100 ml round bottom flask, then dissolved in approximately 60-75 ml of the polymerization solvent to which is then added an exact stoichiometric amount of dialdehyde monomer. Suitable polymerization solvents are absolute ethanol, chloroform, methanol, anhydrous toluene, DMSO (methyl sulfoxide), DMF (N,N-dimethyl formamide), NMP (N-methylpyrrolidinone), water, but may also include others. For the polymers examined, DMSO promotes the fastest polymerization rates. A catalyst is not required for some monomers, but in general, the apparent rates of reaction are greatly accelerated with its use. One can add 10% molar of, typically trifluoroacetic acid or acetic acid, but may also include mineral and other organic acids. The polymerization reaction also proceeds in the absence of solvent. The reaction mixture is then heated between 50°-130° C. for approximately 0.5 to 16 hours. In the case of low boiling point solvents, the polymer is isolated by removing the solvent under reduced pressure and then dried under vacuum. For less volatile solvents, the polymers are subsequently used without isolation. For polymerization in water, the reaction is typically done at room temperature under moderately alkaline conditions. An emulsion catalyst such as benzyltriethyl ammonium chloride, may also be used for imine polymerization involving hydrophobic and hydrophilic monomers.
Part I: Precursors and Thiophene Compounds (Examples 1-21)
The following are non-limiting examples of conjugated aromatic oligo- and polyazomethines and precursors that may be used in the preparation of compositions of the present invention. The compounds of Examples 2, 6 and 14 are shown in Reaction Scheme 1 of the Summary section, above.
Example 1
Synthesis of Cyano-Acetic Acid Decyl Ester
Cyanoacetic acid (20.85 g, 0.245 mol) was added to decanol (47 mL, 0.25 mol) and methane sulfonic acid (0.5 mL, 7.8 mmol), followed by heating under reduced pressure while removing the water by-product through the use of a dean stark trap. The reaction was cooled upon completion, providing the title compound in quantitative yield.
1 H-NMR (400 MHz, [D] chloroform): δ=4.17 (t, 2H, J=6.7), 3.45 (s, 2H), 1.65 (m, 2H), 1.24 (14H), 0.854 (t, 3H)
13 C (400 MHz, [D] chloroform): δ=163.48, 113.57, 67.42, 32.23, 29.86, 29.65, 29.51, 26.06, 25.09, 23.03, 14.45.
Example 2
Synthesis 2,5-diamino-thiophene-3,4-dicarboxylic acid diethyl ester (1)
Similar to other reports, 12-14 sulphur (4.53 g, 0.141 mol) and triethylamine (7.09 mL, 0.0509 mol) were stirred at room temperature in DMF (15 mL) in a 250 mL three necked flask whereupon the solution turned red in colour after 30 minutes. Ethylcyanoacetate (20.4 mL, 0.192 mol) diluted in DMF (5 mL) was subsequently added dropwise over 30 minutes resulting in the deepening of the colour. The opaque solution was allowed to stir under ambient condition for three days after which the solvent was pumped off under vacuum leaving a brown solid. The solid was loaded onto a silica gel column and eluted with a hexane gradient up to 35% ethyl acetate. The procedure was repeated a second time to obtain the 2.15 g (22% yield) of the title compound as gold flaky crystals. M.p. 155-158° C. 1 H-NMR (300 MHz, [D] DMSO): δ=4.06 (q, 4H, J=7.1), 1.17 (t, 6H, J=7.1). 13 C (300 MHz, [D] chloroform): δ=165.6, 148.9, 104.5, 60.4, 14.8. EI-MS: m/z 258.1 ([M]+, 80%), 212 ([M-C 2 H 5 O]+, 100%). Anal. calc. For C 10 H 14 N 2 O 4 S (258.30): C, 46.50; H, 5.46; N, 10.85, O, 4.78, S, 12.41 found: C, 45.89, H, 5.10, N, 10.47, S, 12.01. λ max (acetonitrile)=304 nm, λ fl (acetonitrile)=566 nm.
Due to the volatility of TEA, a small amount was added periodically. It was found that DMF must be removed without heating to avoid decomposition and side reactions becoming problematic. Sulphur was difficult to remove during the purification process due to its solubility. It was advantageous to dissolve the crude product in isopropanol and filter before loading onto the column.
Example 3
Synthesis of 3,4-diamino-thiophene-2,5-dicarboxylic acid didecyl ester
Sulphur (2.81 g, 0.0878 mol) and triethylamine (4.1 mL, 0.0.0293 mol) were stirred in DMF (10 mL) in a three necked flask. Decylcyanoacetate (25 g, 0.117 mol) was added dropwise over 30 min (DMF; 5 mL). The color darkened immediately and the solution was allowed to stir for just over a week. The solvent was then removed via vacuum leaving a dark brown solid. This crude product was loaded onto a column and eluted with a hexane gradient up to 35% EtOAc. A second column was needed to obtain pure product. Yield=3.28 g (brown oil).
The compound appears to decompose quite easily making it hard to get a good 1 H-NMR and C 13 spectrum. Better spectrums may be obtained in DMSO. The compound must be stored in the refrigerator.
FAB-MS: m/z 482.3 ([M] + , 100%)
1 H-NMR (300 MHz, [D] chloroform): δ=4.20 (t, 4H), 1.67 (m, 4H), 1.26 (28H), 0.87 (t, 6H)
Example 4
Synthesis of 5-diethylaminothiophene-2-carbaldehyde
In a round flask (100 mL) was added 5-bromothiophene-2-carboxaldehyde (1.37 mL) in 15 mL of distilled water. Diethylamine (12 mL) was added slowly, followed by refluxing for six days. Purification by flash chromatography provided the title compound as a brownish oil (1.13 g, 54%). 1 H-NMR (300 MHz, [D] acetone): δ=9.46 (s, 1H), 7.56 (d, 1H, 3 J=4.4 Hz), 6.07 (d, 1H, 3 J=4.4 Hz), 3.485 (q, 4H, 3 J=7.1 Hz), 1.23 (t, 6H, 3 J=7.1 Hz). 13 C-NMR (300 MHz, [D] acetone): δ=179.2, 166.0, 140.8, 125.9, 102.8, 47.6, 11.8.
Example 5
Synthesis of 5-formyl-2,2′bithiophene
In a round bottom flask, phosphorus oxychloride (1.83 g) was added at 0° C. to 15 mL of DMF. After 30 minutes, 2,2′-bithiophene (500 mg) was further added and the solution stirred at room temperature for 30 minutes before heating to 50° C. until completion. Diluted hydrochloric acid was added at 0° C., the solution warmed to room temperature and the crude product extracted with ethyl acetate. Purification by flash chromatography (SiO 2 ) yielded the title product as a light brown powder (81%). 1 H-NMR (300 MHz, [D] acetone): δ=9.89 (s, 1H), 7.70 (d, 1H, 3 J=3.9 Hz), 7.39 (d, 2H, 3 J=4.3 Hz), 7.28 (d, 1H, 3 J=3.9 Hz), 7.11 (t, 1H, 3 J=4.4 Hz). 13 C-NMR (50 MHz, [D] acetone): δ=183.0, 147.6, 142.1, 137.8, 136.5, 128.8, 127.5, 126.6, 124.7. EI-MS: m/z ([M] + , 100%).
Example 6
Synthesis of 2-amino-5-[(thiophen-2-ylmethylene)-amino]-thiophene-3,4-dicarboxylic acid diethyl ester (2)
In a 250 mL flask comprising 50 ml absolute ethanol, was dissolved 2,5-diamino-thiophene-3,4-dicarboxylic acid diethyl ester (470 mg, 5.0 mmol) followed by 2-thiophene carboxaldehyde (646 mg, 2.5 mmol). After the addition of one drop of acetic acid, the solution was stirred at room temperature for 4 days. The solvent was then removed from the resulting orange solution and the residue was purified by flash chromatography (SiO 2 ) using 20% ethyl acetate/hexane to afford the title compound as a yellow solid (454 mg, 52%). M.p.=145°-147° C. 1 H-NMR (200 MHz, [D] chloroform): δ=9.94 (s, 1H), 8.06 (s, 1H), 7.20 (t, 1H), 7.18 (d, 1H), 7.12 (m, 1H), 7.02 (m, 1H), 4.41 (t, 2H), 4.24 (q, 2H), 1.48 (t, 3H), 1.29 (t, 3H). 13 C-NMR (50 MHz, [D] chloroform): δ=164.5, 159.9, 145.9, 142.7, 134.0, 131.2, 130.2, 127.9, 102.9, 61.6, 60.3, 14.5, 14.3. FAB-MS: m/z 351.8 ([M]+, 100%). Anal. calc. for C 15 H 16 N 2 O 4 S 2 (352.06): C, 51.12, H, 4.58, N, 7.95, O, 18.16, S, 18.20 found: C, 51.21; H, 4.63; N, 7.77, S, 17.81. λ max (DMSO)=402 nm. ε (DMSO)=3.6×10 4 M −1 dm −1 ; λ max (acetonitrile)=408 nm, λ fl (acetonitrile)=604 nm.
The title compound can also be quantitatively obtained with the same amount of reagents by refluxing in ethanol for 4 hours.
Examples 7-10
In the following Examples, the R group is modified as indicated.
Example 7
Synthesis of 2-amino-5-[(thiophen-2-ylmethylene)-amino]-thiophene-3,4-dicarboxylic acid diethyl ester (R═H)
In a round bottom flask (50 mL), 2,5-diamino-thiophene-3,4-dicarboxylic acid diethyl ester (50 mg) was added to 20 mL isopropanol to which was added 2-thiophenecarboxaldehyde (24 mg) and a catalytic amount of trifluoroacetic acid (TFA). The mixture was refluxed for 20 hours. Complete removal of the solvent provides an orange solid which was purified by flash chromatography (SiO 2 ), yielding the title compound as an orange solid (81%). M.p.: 114°-116° C. 1 H-NMR (300 MHz, [D] acetone): δ=8.24 (s, 1H), 7.63 (d, 1H, 3 J=5.0 Hz), 7.52 (dd, 1H, 3 J=3.7 Hz and 4 J=0.7 Hz), 7.48 (s, 2H), 7.14 (dd, 1H, 3 J=5.0 Hz and 3.7 Hz), 4.32 (q, 2H, 3 J=7.2 Hz), 4.19 (q, 2H, 3 J=7.1 Hz), 1.37 (t, 3H, 3 J=7.1 Hz), 1.26 (t, 3H, 3 J=7.1 Hz). 13 C-NMR (300 MHz, [D] acetone): δ=165.0, 164.3, 161.1, 161.0, 146.1, 143.2, 132.8, 132.1, 130.5, 128.4, 101.8, 61.0, 60.0, 14.3, 14.1.
Example 8
Synthesis of 2-amino-5-[(5-nitro-thiophen-2-ylmethylene)-amino]-thiophene-3,4-dicarboxylic acid diethyl ester (R═NO 2 )
In a 50 mL round bottom flask, 30 mg of 2,5-diamino-thiophene-3,4-dicarboxylic acid diethyl ester was dissolved in 20 mL of isopropanol. To this solution, 5-nitro-2-thiophenecarboxaldehyde (91 mg) was added with vigorous stirring, followed by the addition of a catalytic amount of TFA. The reaction was refluxed for 30 minutes. The title compound was isolated as a dark black-purple powder (87%) by flash chromatography (SiO 2 ). M.p.: 194°-196° C. 1 H-NMR (300 MHz, [D] acetone): δ=8.21 (s, 1H), 8.00 (d, 1H, 3 J=4.4 Hz), 7.74 (s, 2H), 7.50 (d, 1H, 3 J=4.4 Hz), 4.37 (q, 2H, 3 J=7.1 Hz), 4.22 (q, 2H, 3 J=7.1 Hz), 1.40 (t, 3H, 3 J=7.1 Hz), 1.27 (t, 3H, 3 J=7.1 Hz).
Example 9
Synthesis of 2-amino-5-[(5-diethylamino-thiophen-2-ylmethylene)-amino]-thiophene-3,4-dicarboxylic acid diethyl ester (R═NEt 2 )
In a 50 mL round bottom flask, 67 mg of 2,5-diamino-thiophene-3,4-dicarboxylic acid diethyl ester was dissolved in 20 mL of anhydrous toluene to which was subsequently added 1,4-diazabicyclo[2.2.2]octane (DABCO, 32 mg), 286 μL of titanium(IV) chloride, 1.0M solution in toluene at 0° C. and 5-diethylamino-thiophene-2-carbaldehyde (52 mg). The mixture was refluxed for two hours and the solvent removed. Purification by flash chromatography (SiO 2 ) yielded the title product as a yellow-orange solid (67%). 1 H-NMR (300 MHz, [D] acetone): δ=7.96 (s, 1H), 7.23 (s, 2H), 7.21 (d, 1H, 3 J=4.4 Hz), 5.93 (d, 1H, 3 J=4.2 Hz), 4.27 (q, 2H, 3 J=7.2 Hz), 4.17 (q, 2H, 3 J=7.1 Hz), 3.43 (q, 4H, 3 J=7.1 Hz), 1.35 (t, 3H, 3 J=7.1 Hz), 1.24 (t, 3H, 3 J=7.1 Hz), 1.21 (t, 3H, 3 J=7.1 Hz). 13 C-NMR (300 MHz, [D] acetone): δ=164.5, 162.3, 159.3, 146.9, 135.7, 125.5, 124.5, 102.2, 101.7, 60.7, 59.7, 47.3, 14.2, 14.1, 12.0.
Example 10
Synthesis of 2-amino-5-[([2,2′]bithiophenyl-5-ylmethylene)-amino]-thiophene-3,4-dicarboxylic acid diethyl ester (R=2-thiophene)
2,5-Diamino-thiophene-3,4-dicarboxylic acid diethyl ester (30 mg, 0.25 mmol) was mixed with 5-formyl-2,2′bithiophene (40 mg, 0.25 mmol) in isopropanol and refluxed for five hours following the catalytic addition of TFA. The solvent was removed and the product isolated as a yellow solid after purification by flash chromatography (42 mg, 64%). 1 H-NMR (300 MHz, [D] DMSO): δ=8.19 (s, 1H), 7.89 (s, 2H), 7.58 (d, 1H, 3 J=5.2 Hz), 7.50 (d, 1H, 3 J=3.9 Hz) 7.41 (d, 1H, 3 J=3.6 Hz), 7.34 (d, 1H, 3 J=3.9 Hz), 7.11 (t, 1H, 3 J=3.6 Hz), 4.25 (q, 2H, 3 J=7.1 Hz), 4.12 (q, 2H, 3 J=7.2 Hz), 1.31 (t, 3H, 3 J=7.2 Hz), 1.19 (t, 3H, 3 J=7.0 Hz). 13 C-NMR (300 MHz, [D] acetone): δ=165.5, 164.8, 161.7, 146.1, 142.3, 141.9, 137.7, 137.6, 133.5, 133.4, 131.1, 129.2, 126.9, 125.8, 125.3, 61.5, 60.5, 14.8, 14.6. EI-MS: m/z 434.9 ([M] + , 96%).
Examples 11-13
In the following Examples, the R group is modified as indicated.
There are two precursors required for these Examples.
2-Aminothiophene-3-carbonitrile
To a solution of 1,4-dithiane-2,5-diol (12.12 g, 78 mmol) and malononitrile (10.52 g, 157 mmol) in 55 ml of DMF was added DBU (10 ml, 78 mmol, 1 eq.) at 0° C. The solution turned maroon after a few minutes and was allowed to stir for 1 hour at room temperature followed by heating to 60° C. for 8 hours. The reaction mixture was hydrolysed with 120 ml of 0.4 M acetic acid then extracted with ether. The organic layer was dried with MgSO 4 and then concentrated. The resulting solid was recrystallized from ethyl acetate to afford the title compound was a light yellow solid (11 g, 89 mmol, yield 57%). 1 H-NMR (CDCl 3 , 400 MHz): 6.72, 6.34, 4.82. 13 C-NMR (CDCl 3 , 75 MHz): 162.25, 125.56, 125.34, 110.29, 88.35.
Ethyl 2-aminothiophene-3-carboxylate
The same procedure as 2-aminothiophene-3-carbonitrile was used except replacing malononitrile with ethyl cyano acetate. 1 H-NMR (CDCl 3 , 400 MHz): 6.95, 6.15, 4.26, 1.32.
Example 11
Synthesis of 2-[(thiophen-2-ylmethylene)-amino]-thiophene-3-carbonitrile (R═H)
2-Amino-thiophene-3-carbonitrile (50 mg) and thiophene-2-carboxaldehyde (54 mg) were mixed in isopropanol with TFA and refluxed for 20 hours. The reaction was then purified by flash chromatography, resulting in 61 mg (70%) of the title compound as an orange solid. M.p. 58°-60° C. 1 H-NMR (300 MHz, [D] acetone): δ=8.49 (s, 1H), 7.90 (d, 1H, 3 J=5.0 Hz), 7.82 (dd, 1H, 3 J=3.7 Hz and 1.0 Hz), 7.42 (d, 1H, 3 J=5.7 Hz), 7.27 (m, 2H, 3 J=5.6 Hz). 13 C-NMR (300 MHz, [D] acetone): δ=163.4, 155.4, 141.8, 136.2, 133.9, 129.0, 128.1, 122.5, 114.6, 105.8.
Example 12
Synthesis of 2-[(5-nitro-thiophen-2-ylmethylene)-amino]-thiophene-3-carbonitrile (R═NO 2 )
2-Amino-thiophene-3-carbonitrile (30 mg) and 5-nitro-thiophene-2-carboxaldehyde (41 mg) were mixed in isopropanol with TFA and refluxed for 28 hours. The reaction was then purified by flash chromatography, resulting in 45 mg (71%) of the title compound as an orange powder. M.p.: 192°-194° C. 1 H-NMR (300 MHz, [D]acetone): δ=8.98 (s, 1H), 8.12 (d, 1H, 3 J=4.3 Hz), 7.85 (d, 1H, 3 J=4.3 Hz), 7.61 (d, 1H, 3 J=5.7 Hz), 7.38 (d, 1H, 3 J=5.7 Hz). 13 C-NMR (300 MHz, [D] acetone): δ=161.2, 154.3, 147.3, 133.7, 130.0, 128.6, 125.9, 125.1, 109.5, 108.5.
Example 13
Synthesis of 2-[(5-diethylamino-thiophen-2-ylmethylene)-amino]-thiophene-3-carbonitrile (R═NEt 2 )
In a round bottom flask (50 mL), 30 mg of 2-amino-thiophene-3-carbonitrile was added to 20 mL isopropanol to which was further added 5-diethylamino-thiophene-2-carbaldehyde (48 mg) and a catalytic amount of TFA. The mixture was refluxed for 3 hours. Complete removal of the solvent leads to an orange oil which was purified by flash chromatography (SiO 2 ). The title compound was isolated as an orange solid (63%). 1 H-NMR (300 MHz, [D] acetone): δ=8.44 (s, 1H), 7.54 (d, 1H, 3 J=4.5 Hz), 7.09 (s, 2H), 6.13 (d, 1H, 3 J=4.5 Hz), 3.54 (q, 4H, 3 J=7.1 Hz), 1.27 (t, 6H, 3 J=7.1 Hz). 13 C-NMR (300 MHz, [D] acetone): δ=166.1, 153.2, 141.2, 131.9, 127.9, 123.3, 118.8, 116.0, 104.5, 101.5, 48.2, 12.4.
Example 14
Synthesis of 2,5-bis-[(thiophen-2-ylmethylene)-amino]-thiophene-3,4-dicarboxylic acid diethyl ester (3)
17.7 μL of 2-thiophene carboxaldehyde (21.7 mg, 0.1935 mmol), and 0.995 μL of trifluoroacetic acid (1.487 mg, 0.0129 mmol, 16.7 mol %) were added to 10 mL of anhydrous ethanol. 20 mg of 2,5-diamino-thiophene-3,4-dicarboxylic acid diethyl ester (0.0774 mmol) were dissolved into the solution, and the resulting mixture was allowed to stir under reflux for 2 days. The solvent was removed by rotary evaporation, and the remaining solid was washed with several portions of n-hexane, then recrystallized from acetone to yield fine red needle-like crystals (19.0 mg, 55%). FAB-MS: m/z 447.1 ([M+], 70%). λ max (acetonitrile)=418 nm, ε (acetonitrile)=2.3×10 5 M −1 dm −1 , λ fl (acetonitrile)=564 nm.
Alternative synthetic approaches to produce the title compound are possible. The direct one-pot approach involves 5-diamino-thiophene-3,4-dicarboxylic acid diethyl ester (100 mg, 0.4 mmol) and 2-thiophenecarboxaldehyde (99.4 mg, 0.8 mmol) were stirred in isopropanol (10 ml) in a 25 ml one necked flask followed by the addition of a catalytic amount of trifluoroacetic acid. The solution turned orange then red in colour after refluxing for 8 hours and then was concentrated in vacuum to near dryness. The crude product was loaded onto a silica column and eluted with hexane/ethyl acetate (85/15) up to hexane/ethyl acetate (75/25) to give unoptimized 65 mg (40%) of a red solid. M.p.=128°-129° C. 1 H-NMR (400 MHz, [D] Acetone): d=8.75 (s, 2H), 7.85 (d, 2H, J=4.96), 7.76 (d, 2H, J=3.68), 7.26 (d, 2H, J=5.21), 4.32 (q, 2H, J=7.16), 1.37 (t, 4H, J=7.16). 13 C-NMR (200 MHz, [D] Acetone): d=206.02, 163.39, 153.95, 142.82, 135.47, 133.56, 129.26, 61.55, 14.52. ESI-MS: m/z 447.1 ([M]+, 100%). Anal. calc. for C20H18N2O4S3 (446.1): C, 53.79; H, 4.06; N, 6.27, O, 14.33, S, 21.54 10 found: C, 54.95 H, 4.19 N, 5.97 S, 21.51.
The title compound can also be obtained by combining equivalent amounts of 2-thiophene and 2,5-bis-[(thiophen-2-ylmethylene)-amino]-thiophene-3,4-dicarboxylic acid diethyl ester in isopropanol and following the same procedure as above.
Examples 15-19
In the following Examples, the R group is modified as indicated.
Example 15
Synthesis of diethyl-2,5-bis((5-nitrothiophen-2-yl)methyleneamino)thiophene-3,4-dicarboxylate (R 1 ═R 2 ═NO 2 )
5-Nitrothiophene-2-carbaldehyde (40 mg) was mixed with DABCO (29 mg) and TiCl 4 (255 μL, 1M in toluene) in toluene at 0° C. Diethyl 2,5-diaminothiophene-3,4-dicarboxylate (32 mg) was added and the solvent was refluxed for 4-5 hours. The title compound was isolated as a purple-grey solid after flash chromatography (26 mg, 38%). M.p.: 255 0 -257° C. 1 H-NMR (300 MHz, [D] acetone): δ=8.84 (s, 2H), 8.10 (d, 2H, 3 J=4.5 Hz), 7.80 (d, 2H, 3 J=4.4 Hz), 4.37 (q, 4H, 3 J=7.1 Hz), 1.39 (t, 6H, 3 J=7.1 Hz). 13 C-NMR (300 MHz, [D] acetone): δ=164.8, 163.3, 156.2, 147.0, 137.5, 131.3, 130.0, 127.8, 60.6, 14.4.
Example 16
Synthesis of diethyl-2,5-bis((5-(diethylamino)thiophen-2-yl)methyleneamino) thiophene-3,4-dicarboxylate (R 1 ═R 2 ═NEt 2 )
5-(Diethylamino)thiophene-2-carbaldehyde (50 mg) was mixed with DABCO (31 mg) and TiCl 4 (273 μL, 1M in toluene) in toluene at 0° C. Diethyl 2,5-diaminothiophene-3,4-dicarboxylate (32 mg) was added and the reaction was refluxed for 3-4 hours. The solvent was removed and the product isolated as a purple-grey solid after purification by flash chromatography (64 mg, 88%). 1 H-NMR (300 MHz, [D] acetone): δ=8.26 (s, 2H), 7.39 (d, 2H, 3 J=4.4 Hz), 6.05 (d, 2H, 3 J=4.4 Hz), 4.24 (q, 4H, 7.1 Hz), 3.49 (q, 8H, 7.1 Hz), 1.34 (t, 6H, 3 J=7.1 Hz), 1.25 (t, 12H, 7.1 Hz). 13 C-NMR (300 MHz, [D] acetone): δ=164.2, 163.8, 150.6, 149.1, 138.4, 124.3, 124.2, 103.3, 60.5, 47.6, 14.2, 12.0.
Example 17
Synthesis of 2-[(5-nitro-thiophen-2-ylmethylene)-amino]-5-[(thiophen-2-ylmethylene)-amino]-thiophene-3,4-dicarboxylic acid diethyl ester (R 1 ═H; R 2 ═NO 2 )
5-Nitrothiophene-2-carbaldehyde (9 mg) was mixed in toluene under nitrogen at 0° C. with DABCO (7 mg), TiCl 4 in solution in toluene (59 μL) and 2,5-bis-[(thiophen-2-ylmethylene)-amino]-thiophene-3,4-dicarboxylic acid diethyl ester (12 mg). The mixture was refluxed for six hours, concentrated and the product isolated as a red powder after purification by flash chromatography. M.p.: 220°-222° C. 1 H-NMR (300 MHz, [D] acetone): δ=8.81 (s, 1H), 8.79 (s, 1H), 8.10 (d, 1H, 3.2 Hz), 7.91 (d, 1H, 3 J=4.1 Hz), 7.81 (d, 1H, 2.9 Hz), 7.78 (d, 1H, 3 J=4.6 Hz), 7.29 (dd, 1H, 2.7 Hz and 3.8 Hz), 4.38 (q, 2H, 3 J=5.3 Hz), 4.32 (q, 2H, 3 J=5.3 Hz), 1.41 (t, 3H, 3 J=5.3 Hz), 1.36 (t, 3H, 3 J=5.3 Hz). 13 C-NMR (300 MHz, [D] acetone): δ=176.9, 174.2, 169.1, 166.5, 155.1, 151.7, 146.6, 142.2, 140.9, 136.1, 135.9, 134.0, 132.7, 130.0, 129.0, 127.5, 61.5, 61.3, 14.2, 14.0.
Example 18
Synthesis of 2-[(5-diethylamino-thiophen-2-ylmethylene)-amino]-5-[(5-nitro-thiophen-2-ylmethylene)-amino]-thiophene-3,4-dicarboxylic acid diethyl ester (R 1 =NEt 2 ; R 2 ═NO 2 )
5-Nitrothiophene-2-carbaldehyde (23 mg) was mixed in toluene under nitrogen at 0° C. with DABCO (16 mg), TiCl 4 in solution in toluene (146 μL) and 2-amino-5-[(5-diethylamino-thiophen-2-ylmethylene)-amino]-thiophene-3,4-dicarboxylic acid diethyl ester (56 mg) and refluxed for seven hours. The reaction affords a purple-grey powder (53 mg, 72%) after purification by flash chromatography. 1 H-NMR (300 MHz, [D] acetone): δ=8.55 (s, 1H), 8.36 (s, 1H), 8.06 (d, 1H, 3 J=4.3 Hz), 7.66 (d, 1H, 3 J=4.4 Hz), 7.55 (d, 1H, 3 J=4.6 Hz), 6.19 (d, 1H, 3 J=4.6 Hz), 4.36 (q, 2H, 3 J=7.3 Hz), 4.25 (q, 2H, 3 J=7.1 Hz), 3.55 (q, 4H, 3 J=7.5 Hz), 1.39 (t, 3H, 3 J=7.1 Hz), 1.34 (t, 3H, 3 J=7.2 Hz), 1.28 (t, 6H, 3 J=7.1 Hz). 13 C-NMR (300 MHz, [D] acetone): δ=173.0, 167.5, 164.1, 162.9, 149.7, 143.7, 132.9, 131.6, 131.3, 130.2, 130.1, 129.7, 129.1, 127.6, 114.0, 104.9, 61.4, 60.2, 39.2, 14.2, 13.8, 10.8. +TOF-MS: m/z 563.10838. Calculated for C 24 H 26 O 6 N 4 S 3 563.10872.
Example 19
Synthesis of diethyl 2,5-bis((5-(thiophen-2-yl)thiophen-2-yl)methyleneamino)thiophene-3,4-dicarboxylate (R 1 ═R 2 =2-thiophene)
Thiophene-2,5-diamino-3,4-dicarboxylic acid diethyl ester (49 mg) and 5-formyl-2,2′bithiophene (75 mg) were refluxed in isopropanol for 3-4 hours in the presence of a TFA catalyst and the product isolated as a red powder (58 mg, 50%). M.p.: 130°-132° C. 1 H-NMR (300 MHz, [D] acetone): δ=8.69 (s, 2H), 7.76 (d, 2H, 3 J=4.1 Hz), 7.66 (d, 2H, 3 J=6.1 Hz), 7.53 (d, 2H, 3 J=3.7 Hz), 7.46 (d, 2H, 3 J=4.0 Hz), 7.16 (t, 2H, 3 J=3.6 Hz), 4.26 (q, 4H, 3 J=6.9 Hz), 1.30 (t, 6H, 3 J=7.3 Hz). 13 C-NMR (300 MHz, [D] acetone): δ=173.0, 163.0, 152.8, 140.9, 136.4, 131.6, 129.2, 129.0, 127.3, 126.2, 125.2, 123.9, 66.3, 13.8. EI-MS: m/z 610.9 ([M] + , 100%).
Part II: Synthesis of Thiophene-Containing Polymers (Examples 20-21)
The following non-limiting examples describe the synthesis of representative oligomers that are representative of the present invention. The compounds of Examples 20 and 21 are shown in Reaction Schemes 1 and 3, respectively, of the Summary section, above.
The polymer molecular weights were determined relative to polystyrene standards by gel-permeation-chromotography (GPC) using DMF as eluent. Alternatively, MALDI-TOF was done with polymer solid samples using an appropriate matrix. The average degree of polymerization (DP) for the dehydration reaction can be calculated from the measured polymer molecular weight divided by the molecular weight of the monomer repeating units. The terms “DP” and “n”, in the reaction below, are synonymous and can be interchanged.
calculation example is the following:
DP
=
MW
polymer
MW
monomer
A
+
MW
monomer
B
-
MW
water
=
n
Example 20
Synthesis of Thiophene Polyazomethine (4)
Commercially available 2,5-thiophenedicarboxaldehyde (6.5 mg, 0.046 mmol) was added to a 5 ml round bottom flask followed by 2,5-diamino-thiophene-3,4-dicarboxylic acid diethyl ester (11.9 mg, 0.041 mmol) and 5-10 mol % of trifluoroacetic acid. The mixture was subsequently heated under nitrogen atmosphere for 12 hours without solvent. The resulting oil was used through the next step without further purification and was cooled, and the low molecular weight oligomers removed by washing with ethanol. The resulting purple polymer is soluble in DMSO, DMF, and NMP to name but a few. DP=3 601, M n =87 541 g/mol. λ max (DMSO)=497 and 542 nm. Anal. calc. for C 16 H 14 N 2 S 2 ×35.85H 2 O: C, 37.85; H, 8.67; N, 10.50, S, 5.79 found: C, 34.94; H, 8.67; N, 10.89, S, 4.66.
Alternatively, 2,5-thiophenedicarboxaldehyde (4 mg, 0.029 mmol) was added to a 25 ml round bottom flask followed by 2,5-diamino-thiophene-3,4-dicarboxylic acid diethyl ester (7.9 mg, 0.029 mmol) and 5-10 mol % of trifluoroacetic acid. The mixture was subsequently refluxed under nitrogen atmosphere for 12 hours using absolute ethanol and the polymer isolated upon removal of the solvent and was used without further purification. The resulting purple polymer is soluble in DMSO, DMF, and NMP to name but a few. DP=74, M n =26 686 g/mol. λ max (DMSO)=478 nm.
Alternatively, in 7 ml anhydrous toluene was added under argon 2,5-diamino-3,4-ethyl ester thiophene (146 g, 0.56 mmol) followed by 1,4-diaza-bicyclo[2.2.2]octane (DABCO; 411 mg, 3.66 mmol) followed by titanium (IV) chloride (100 μl, 0.91 mmol). The temperature was raised and thiophene-2,5-dicarboxaldehyde (79 g, 0.56 mmol) dissolved in 10 ml anhydrous toluene was added. This mixture was refluxed under argon for 24 hours. The red wine coloured mixture obtained was cooled to room temperature and the precipitate was isolated by vacuum filtration. The polymer was isolated as deep blood red flakes readily soluble in alcoholic solvents, DMSO, DMF, and marginally soluble in chloroform.
For less reactive monomers, the polymerization was undertaken as follows. Typically, in a 50 mL flask, 150 mg of diamine monomer were dissolved in 10 ml of anhydrous THF and then 1,4-diaza-bicyclo[2.2.2]octane (DABCO; 411 mg, 3.66 mmol) was added under nitrogen atmosphere. To this solution was added 1.5 stoichiometric equivalents of titanium (IV) chloride (100 ml, 0.91 mmol). The reaction mixture was then heated to reflux following the addition of one stoichiometric equivalent of monomer dialdehyde, for a period of 24 hours. The polymer precipitated from solution and was isolated by filtration by filtration and washed with toluene and chloroform.
Example 21
Synthesis of poly(4,4′-diiminostilbene-2,2′-disulfonic acid thiophene) (9)
A volume of 60 ml distilled water and a few drops of 2M sodium hydroxide was required to dissolve the commercially available 4,4′-diaminostilbene-2,2′-disulfonic acid (155 mg, 0.41 mmol). After the addition of 40 ml THF, 2,5-thiophene dicarboxaldehyde (58 mg, 0.42 mmol) was added along with a catalytic amount of benzyltriethyl ammonium chloride. The red coloured solution was stirred at room temperature for two days. The solvent was removed under reduced pressure to afford the polymer as a red solid that was recrystallized from ethanol. λ max (water): 305 and 338 nm. M w =148 094, PDI=2.3, DP=286. 1 H-NMR (200 MHz, [D] DMSO): δ=8.92 (br, s, 2H), 8.21 (br, s, 2H), 7.80 (br, s, 6H), 7.39 (br, s, 2H). Anal. cald. C 20 H 12 O 6 N 2 S 3 Na 2 .7.2H 2 O: C, 37.06, H, 4.11, N, 4.32, S, 14.84 found C, 37.27; H, 3.90; N, 4.28, S, 14.62. The 1 S 0,0 - 0 S 0,0 (HOMO-LUMO) transition was calculated to be 65 kcal/mol (2.83 eV). From the absorption onset in the red region of the spectrum, a value can be calculated for the band gap of 51.3 kcal/mol (2.23 eV) for 9.
NB: The sodium counterion can be replaced with K, Rb or Cs.
Part III: Fluorene-Containing Compounds and Other Thiophene Oligomers (Examples 22-34)
Example 22
Synthesis of bis((thiophen-2-yl)methylene)-9H-fluorene-2,7-diamine
2-Thiophenecarboxaldehyde (131 mg, 1.2 mmol) was added to 2,7-diaminofluorene (100 mg, 0.51 mmol) in anhydrous isopropanol and refluxed for 2 days with a catalytic amount of TFA. The solvent was evaporated and no further purification was required. The title compound was obtained as a yellow powder. (196 mg, mmol, 100%) M.p.: 201° C. 1 H-NMR (300 MHz, [D] DMSO): δ=7.88 (d, 2H, 3 J=11 Hz), 7.81 (d, 2H, 3 J=6.5), 7.69 (d, 2H, 3 J=4), 7.50 (s, 2H), 7.30 (d, 2H, 3 J=11 Hz), 7.22 (t, 2H, 3 J=5.0 Hz), 3.96 (s, 2H). 13 C-NMR (300 MHz, [D] DMSO): δ=152.91, 148.43, 142.22, 139.53, 129.74, 127.43, 127.10, 125.82, 123.63, 120.34, 36.52. HR-MS: m/z target 385.08277, measured 385.08388, mass error (ppm) 2.89. C.V. −1.36, −0.77, −0.10, 1.27 V. In 0.1 M TBAPF 6 as supporting electrolyte in degassed anhydrous acetonitrile λ max =381 nm. λ em =318 and 606 nm. E g =452 nm, 63.23 Kcal/mol. ΔE=298.8 nm, 95.65 Kcal/mol.
Example 23
Synthesis of ((thiophen-2-yl)methylene)-9H-fluoren-2-amine
2-Thiophenecarboxaldehyde (80.4 mg, 0.72 mmol) was added to 2-aminofluorene (100 mg, 0.55 mmol) and refluxed in isopropanol for 12 hours with a catalytic amount of TFA. The solvent was evaporated and the product was purified by flash chromatography using anhydrous basic activated alumina gel (AlO 2 ) and 40% ethyl acetate and 60% hexanes. The title compound was obtained as a yellow product. (45.4 mg, 0.165 mmol, 30%). M.p.: 143° C. 1 H-NMR (300 MHz, [D] DMSO): δ=8.65 (s, 1H), 7.89 (t, 2H, 3 J=10.9 Hz), 7.81 (d, 1H, 3 J=6.7 Hz), 7.69 (dd, 1H, 3 J=4.8 Hz, 4 J=1.4 Hz), 7.57 (d, 1H, 3 J=9.76 Hz), 7.50 (s, 1H), 7.37 (t, 1H, 3 J=9.88 Hz), 7.32 (t, 2H, 3J=11 Hz), 7.22 (dd, 1H, 3J=4.84 Hz, 4J=1.8 Hz), 3.94 (s, 2H). 13 C-NMR (300 MHz, [D] DMSO): δ=152.9, 148.4, 144.2, 143.1, 144.4, 141.0, 129.7, 128.8, 128.2, 128.4, 127.4, 127.1, 126.8, 125.8, 123.6, 120.3, 36.5. C.V. −1.36, −0.96, −0.56, −0.02, 0.62, 1.39 V. In 0.1 M TBAPF6 as supporting electrolyte in degassed anhydrous acetonitrile λ max =352 nm. λ em =302 nm. E g =454 nm, 62.95 Kcal/mol. ΔE=300 nm, 95.26 Kcal/mol.
Example 24
Synthesis of (30E,31E)-N2-((5-((25E)-((Z)-5-((thiophen-2-yl)methyleneamino)-3,4-dimethylcarboxylatethiophen-2-ylimino)methyl)thiophen-2-yl)methylene)-3,4-dimethylcarboxylate-N-5-((thiophen-2-yl)methylene)thiophene-2,5-diamine
2-Thiophenedicarboxaldehyde (67.3 mg, 0.48 mmol) was added to diethyl 2,5-diaminothiophene-3,4-dicarboxylate (247.8 mg, 0.96 mmol) in anhydrous isopropanol under an N 2 atmosphere and a catalytic amount of TFA. The reaction was slowly heated without refluxing for 2 days. A red colored powder was purified using flash column chromatography on silica (SiO 2 ) with 1:1 ethyl acetate and hexanes as solvent. The reaction yielded the title compound (90 mg, 0.15 mmol, 30%). 1 H-NMR (300 MHz, [D] DMSO): δ=8.20 (s, 2H), 8.00 (s, 4H), 7.54 (s, 2H), 4.26 (q, 4H, 3 J=7.04 Hz), 4.14 (q, 4H, 3 J=7.04 Hz), 1.32 (t, 6H, 3 J=7.12 Hz), 1.20 (t, 6H, 3 J=7 Hz). 13 C-NMR (300 MHz, [D] DMSO): δ=162.3, 160.2, 153.0, 135.6, 134.9, 129.0, 126.6, 126.5, 60.9, 14.1.
Example 25
Synthesis of 2,5-bis-[(thiophen-2-ylmethylene)-amino]-thiophene-2,5-diamine
2-Thiophenecarboxaldehyde (58.9 mg, 0.53 mmol) was added to bis(diethyl 2,5-diaminothiophene-3,4-dicarboxylate)-thiophene-2,5-diamine (16.3 mg, 0.027 mmol) in anhydrous isopropanol with a catalytic amount of TFA under N 2 . The reaction was heated mildly for 2 days. The product was purified using activated basic alumina gel (AlO 2 ) and CH 2 Cl 2 . The title compound was obtained as a red colored powder was obtained (13 mg, 0.016 mmol, 60%). 1 H-NMR (400 MHz, [D] DMSO): δ=8.1 (d, 2H, 3 J=5.7 Hz), 7.94 (d, 2H, 3 J=4.83 Hz), 7.76 (s, 2H), 7.50 (d, 2H, 3 J=3.63 Hz), 7.23 (dd, 2H, 3 J=5.1, 3 J=5.04 Hz), 6.54 (d, 2H, 3 J=5.7 Hz), 3.06 (m, 8H), 1.26 (m, 12H).
Example 26
Synthesis of N2-((thiophen-2-yl)methylene)-9H-fluorene-2,7-diamine
2-Thiophenecarboxaldehyde (22 mg, 0.19 mmol) was added to 2,9-diaminofluorene (50 mg, 0.26 mmol) in anhydrous ethanol with a catalytic amount of TFA under an N2 atmosphere. The reaction was refluxed for 12 hours. The solvent was evaporated and no further purification was required. The title compound was obtained as a yellow colored powder (73 mg, 0.25 mmol, 98%). 1 H-NMR (400 MHz, [D] DMSO): δ=8.90 (s, 1H), 7.82 (s, 1H), 7.77 (s, 1H), 7.64 (dd, 1H, 3 J=7.64 Hz), 7.54 (d, 1H, 3 J=8.32 Hz), 7.44 (s, 1H), 6.80 (s, 1H), 6.72 (s, 1H), 6.63 (d, 1H, 3J=8.44 Hz), 6.52 (d, 1H, 3J=7.72 Hz), 5.27 (s, 2H), 3.80 (s, 2H).
Example 27
Synthesis of bis(((thiophen-2-yl)methylene)carbox-aldehyde))-9H-fluorene-2,7-diamine
To 2,9-diaminofluorene (100 mg, 0.51 mmol), 2,5-thiophenedicarboxadehyde (142.8 mg, 1.02 mmol) was added in anhydrous isopropanol, under an N 2 atmosphere and with a catalytic amount of TFA. The reaction was heated mildly for 12 hours until an orange precipitate was formed and filtered (213 mg, 0.48 mmol, 95%). 1 H-NMR (400 MHz, [D] DMSO): δ=10.0 (s, 2H), 9.04 (s, 2H), 7.80 (d, 2H, 3 J=4.04 Hz), 7.86 (d, 2H, 3 J=4.04 Hz), 7.44 (d, 2H, 3 J=8.02 Hz), 7.32 (d, 2H, 3 J=9.76 Hz), 6.77 (s, 2H), 4.35 (s, 2H). 13 C-NMR (300 MHz, [D] DMSO): δ=182.5, 154.2, 152.9, 148.4, 144.4, 143.5, 139.5, 137.4, 129.2, 129.7, 123.6, 120.3, 36.5. C.V. −1200, −1212, −969, 763, 1249 V. In 0.1 M TBAPF 6 as supporting electrolyte in degassed anhydrous acetonitrile. λ max =424 nm. λ em =328 and 622 nm. E g =569 nm, 50.23 Kcal/mol. Δ E =300 nm, 25.26 Kcal/mol.
Example 28
Synthesis of N-((9H-fluoren-2-yl)methylene)-9H-fluoren-2-amine
2-Fluorenecarboxaldehyde (100 mg, 0.51 mmol) was added to aminofluorene (93.3 mg, 0.51 mmol) in anhydrous isopropanol under N 2 with a catalytic amount of TFA. No heating was required. The reaction was run for 12 hours until a green precipitate was filtered, yielding 183.7 mg of the title compound.
Example 29
Synthesis of N2-((9H-fluoren-2-yl)methylene)-9H-fluorene-2,7-diamine
2-Fluorenecarboxaldehyde (49.5 mg, 0.25 mmol) was added to 2,7-diaminofluorene (50 mg, 0.25 mmol) in anhydrous isopropanol, under an N 2 atmosphere and a catalytic amount of TFA. No heating was required. The reaction was run for 12 hours until a green precipitate was filtered, yielding 94.9 mg. of the title compound.
Example 30
Synthesis of N2-((9H-fluoren-2-yl)methylene)-N7-((9H-fluoren-7-yl)methylene)-9H-fluorene-2,7-diamine
Fluorenecarboxaldehyde (99 mg, 0.51 mmol) was added to 2,7-diaminofluorene (50 mg, 0.25 mmol) in anhydrous isopropanol, under an N 2 atmosphere and a catalytic amount of TFA. No heating was required. The reaction was run for 12 hours. The title compound was obtained as an orange precipitate (140 mg).
Example 31
Synthesis of Alternating Fluorene and Thiophene Azomethine Oligomer
2,5-Thiophenedicarboxaldehyde (7.1 mg, 0.05 mmol) was added to 2,9-diaminofluorene (10 mg, 0.05 mmol) in anhydrous DMF, under an N 2 atmosphere and a catalytic amount of TFA. The original solution was diluted by a factor of 5 and 20. The reactions were heated to 70° C. for 12 hours under nitrogen. The original solution at the end was red, the solution diluted by a factor of 5 was orange and the solution diluted by a factor of 20 was yellow leading to absorbances of λ max =319, 323, and 335 nm, respectively.
The reaction can also be run under ambient atmosphere with the use of alcoholic solvents, DMSO, DMAC, or halogenated solvents under reflux temperatures. The reaction can also be run neet under inert atmosphere by and heating the mixture to the melting temperature.
Example 32
Synthesis of 2-amino-5-[([2,2′]bithiophenyl-5-ylmethylene)-amino]-thiophene-3,4-dicarboxylic acid diethyl ester
5-(Thiophen-2-yl)thiophene-2-carbaldehyde (40 mg, 0.25 mmol) was added to diethyl 2,5-diaminothiophene-3,4-dicarboxylate (30 mg, 0.25 mmol) in isopropanol and refluxed for five hours after the addition of a catalytic amount of TFA. The solvent was removed and the title product was isolated as a yellow solid after purification by flash chromatography (42 mg, 64%). 1 H-NMR (300 MHz, [D] DMSO): δ=8.19 (s, 1H), 7.89 (s, 2H), 7.58 (d, 1H, 3 J=5.2 Hz), 7.50 (d, 1H, 3 J=3.9 Hz) 7.41 (d, 1H, 3 J=3.6 Hz), 7.34 (d, 1H, 3 J=3.9 Hz), 7.11 (t, 1H, J=3.6 Hz), 4.25 (q, 2H, 3 J=7.1 Hz), 4.12 (q, 2H, 3 J=7.2 Hz), 1.31 (t, 3H, 3 J=7.2 Hz), 1.19 (t, 3H, 3 J=7.0 Hz). 13 C-NMR (60 MHz, [D] acetone): δ=165.5, 164.8, 161.7, 146.1, 142.3, 141.9, 137.7, 137.6, 133.5, 133.4, 131.1, 129.2, 126.9, 125.8, 125.3, 61.5, 60.5, 14.8, 14.6. EI-MS: m/z 434.9 ([M] + , 96%).
Example 33
Synthesis of diethyl 2-((5-(thiophen-2-yl)thiophen-2-yl)methyleneamino)-5-((thiophen-2-yl)methyleneamino)thiophene-3,4-dicarboxylate
This compound can be synthesized either step-wise or one-pot. Step-wise formation was achieved by adding 5-(thiophen-2-yl)thiophene-2-carbaldehyde (30 mg, 0.15 mmol) to diethyl 2,5-diaminothiophene-3,4-dicarboxylate (48 mg, 0.19 mmol) followed by refluxing in isopropanol for 12 hours with a catalytic amount of TFA. The intermediate product was isolated as a yellow powder 3 (50 mg, 1.1 mmol 74%) after purification by flash chromatography. To the resulting product was added 2-thiophene carboxaldehyde (13 mg, 1.2 mmol) in isopropanol with a catalytic amount of TFA. The reaction was refluxed for 12 hours. The title product was isolated as a red colored powder following flash chromatography (37.5 mg, 0.1 mmol, 46%). 1 H-NMR (400 MHz, [D] acetone): δ=8.75 (s, 1H), 8.69 (d, 1H, 3 J=3.6), 7.86 (d, 1H, 3 J=4.96), 7.78 (d, 1H, 3 J=2.84), 7.71 (d, 1H, 3 J=3.88), 7.59 (dd, 1H, 3 J=5.04, 4 J=0.76), 7.51 (d, 1H, 3 J=3.68), 7.26 (dd, 1H, 3 J=3.76, 4 J=1.2), 7.17 (dd, 1H, 3 J=3.68, 4 J=1.36), 4.35 (m, 4H), 1.40 (m, 6H).
As an alternative, 2,5-diaminothiophene-3,4-dicarboxylate (100 mg, 3.8 mmol) and 2-thiophene carboxaldehyde (36 mg, 3.2 mmol) were combined in ethanol along with a catalytic amount of TFA. After 12 hours of refluxing, a yellow powder was isolated after purification by flash chromatography (7.5 mg, 2.2 mmol, 69%). 5-(thiophen-2-yl)thiophene-2-carbaldehyde (43 mg, 2.2 mmol) in isopropanol was added to the isolated product with a catalytic amount of TFA. A red colored powder (61 mg, 1.1 mmol, 52%) was isolated after flash column chromatography (SiO 2 ).
One-step synthesis of the title compound can be achieved by combining 2,5-diaminothiophene-3,4-dicarboxylate (15 mg, 0.5 mmol) with 2-thiophene carboxaldehyde (6.5 mg, 0.6 mmol), followed by refluxing in ethanol for 12 hours in the presence of a catalytic amount of TFA. After removal of the solvent, 5-(thiophen-2-yl)thiophene-2-carbaldehyde (11.3 mg, 0.5 mmol) in isopropanol was added in addition to a catalytic amount of TFA and the solution refluxed for 12 hours. The title compound was isolated as a red powder (20.9 mg, 0.4 mmol, 63%) after flash chromatography (SiO 2 ).
Example 34
Synthesis of diethyl 2,5-bis((5-(thiophen-2-yl)thiophen-2-yl)methyleneamino)thiophene-3,4-dicarboxylate (5)
5-(Thiophen-2-yl)thiophene-2-carbaldehyde (75 mg) was added to diethyl 2,5-diaminothiophene-3,4-dicarboxylate (49 mg) and the solution was refluxed in isopropanol for four hours in the presence of a catalytic amount of TFA. The title compound was isolated as a red powder (58 mg, 50%) following column chromatography. M.p.: 130°-132° C. 1 H-NMR (300 MHz, [D] acetone): δ=8.69 (s, 2H), 7.76 (d, 2H, 3 J=4.1 Hz), 7.66 (d, 2H, 3 J=6.1 Hz), 7.53 (d, 2H, 3 J=3.7 Hz), 7.46 (d, 2H, 3 J=4.0 Hz), 7.16 (t, 2H, 3 J=3.6 Hz), 4.26 (q, 4H, 3 J=6). 9 Hz), 1.30 (t, 6H, 3 J=7.3 Hz). 13 C-NMR (60 MHz, [D] acetone): δ=173.0, 163.0, 152.8, 140.9, 136.4, 131.6, 129.2, 129.0, 127.3, 126.2, 125.2, 123.9, 66.3, 13.8. EI-MS: m/z 610.9 ([M] + , 100%).
Part IV: Conjugated Thiophenes from One-Pot Snap Together Molecules
A simple one-pot selective process for synthesizing symmetric and unsymmetric conjugated oligomers with varying number of thiophene units is presented. This process results in materials that exhibit interesting and enhanced properties relative to their carbon analogues, 15 and provide a means for fine-tuning the physical properties. Moreover, these simple yet robust connections are attractive because of their isoelectronic character relative to its carbon analogue, 16 which is known for its conductive properties.
Scheme 5: Selective One-Pot Azomethine Formation
The one-pot approach entails the snapping together of modules in the form of a novel thiophene diamine (1) with its complementary aldehydes (Scheme 5). This method requires no stringent reaction conditions. In contrast, conventional methods take upwards of seven steps, suffer from complicated reaction conditions and do not readily permit the formation of unsymmetric compounds. The one-pot approach not only allows for the formation of a product analogous to the product formed using the seven-step method, but it allows for the capability of forming unsymmetric compounds. Unsymmetric compounds are particularly useful because they allow for fine-tuning of the various properties of the products formed. This is what in turn allows for the myriad of possibilities in the application of these compounds for electronic industrial needs not easily achieved using conventional methods.
The diaminothiophene 1 was obtained in large quantities by a modified one-pot Gewald batch process. 17 Coupling of the complementary modules (a diamine with an aldehyde) leads to the compounds illustrated in Scheme 6 in standard organic solvents, without the need of anhydrous solvents, metal catalysts, or other delicate conditions. The required reaction protocols are extremely lenient and do not require oxygen-free environments or dehydrating reagents. They can also be run using a wide variety of temperatures including room temperature or moderate heating. The driving force behind the reaction is the generation of a thermodynamically stable conjugated bond (azomethine). This is also responsible for shifting the equilibrium of an otherwise reversible reaction in favor of the products. In fact, the formed azomethine bond is sufficiently robust that no apparent decomposition occurs with heating in the presence of water and acid. The stability of the azomethine bond is further evidenced by its lack of reduction with common reducing reagents. 18
Selective product formation of either the mono- (3) or di-adduct (4, 5) can be controlled by the number of aldehyde equivalents or through the choice of solvent. Because of the deactivating ester groups on 2 decreasing the amine nucleophilicity, mono-addition is favored even with conditions that would otherwise shift the equilibrium towards the products, leading to the dimer. Symmetric diimine formation is possible with two equivalents of the aldehyde 1 by using isopropanol directly from 2. Alternatively, unsymmetrical (4) can also be obtained one-pot using 2 and either an excess or stoichiometric amount of aldehyde 1 with refluxing in ethanol. Substituting for isopropanol once 3 is formed and adding one equivalent of 2-thiophene carboxaldehyde affords the product (4) after further refluxing.
The extent of oligomerization can be followed through the formation of a visible color change. The change in absorption maximum ( FIG. 1 ) is indicative of the conjugation formation resulting from the azomethine bond. The color found in the visible region is dominated by the lowering of the excited electronic π-π* levels, owing to the stabilization of the oligomer conjugation, and responsible for the bathochromic shifts. The linear trend observed for the reciprocal of the number of atoms along the conjugated framework with the bathochromic absorption shift further supports the conjugated nature of the azomethine bond. Extrapolation of the observed trend leads to the potential absorption maxima for an alternating polymer of DP=∞ comprising thiophene-bisthiophene repeating motifs, being approximately 550 nm (Inset FIG. 1 ). The absorption spectra further provide information relating to the energy differences between the excited and ground states for the thiophene azomethines. The energy gap (ΔE) reported in FIG. 3 for the azomethines is lower than for its carbon analogues 6 and 7. This is a result of the energy levels undergoing a pronounced stabilization from the heteroconjugated bond and the electron withdrawing ester functions. The lower band gap and net stabilized levels for these thiophene oligomers implies the easy condensation method is a suitable means for obtaining conductive materials via facile conjugation formation relative to their carbon analogues that are obtained by conventional methods. This is further supported by the cyclic voltammetry data in FIG. 4 .
The crystal structure for 3 ( FIG. 2 ) shows a planar configuration with the heteroatom units orientating themselves in an anti-parallel arrangement. This ensures a linear configuration which is desired for higher order oligomers. The crystallographic data also shows the azomethine bond distances to be shorter than its carbon analogue 19,20 further expected to convey an ideal conductive behavior for these easily synthesized materials. 21
Part V: Thiophene-Containing Conjugated Polymers
The following examples are to demonstrate molecular mass variation of the polymers as a function of their concentration and solvent.
Polymerisation Reactions
a) Synthesis of poly-DAT
In a 5 ml round bottom flask, thiophene-2,5-dicarbaldehyde (27.1 mg, 0.19 mmol, 1 eq.), and 2,5-diamino-thiophene-3,4-dicarboxylic diethyl ester acid (50 mg, 0.19 mmol, 1 eq.) were combined along with 2 drops of TFA previously diluted in isopropanol. The flask was heated at 105° C. for 16 h. A black powder was thereby obtained. Dissolution of this powder in DMF resulted in a red solution.
Characteristics
Reference: MB-109
Black powder
Absorbance: 500 nm (butanol)
Fluorescence: 600 nm (butanol)
Lifetime: 0.93 ns for χ 2 =0.998
Cyclic voltammetry (CV)
MALDI-TOF: 14 000 g/mol, 85 000 g/mol
Using the same protocol, 2,5-diamino-thiophene-3,4-dicarboxylic diethyl ester acid may be replaced with 2,5-diamino-thiophene-3,4-dicarboxylic didecyl ester acid.
b) Synthesis of poly-DAT
A solution of thiophene-2,5-dicarbaldehyde (87.8 mg, 0.62 mmol, 1 eq.) and 2,5-diamino-thiophene-3,4-dicarboxylic diethyl ester acid (165.2 mg, 0.62 mmol, 1 eq.) in 12.5 ml isopropanol anhydrous is prepared. The solution is subjected to ultrasound for a few minutes to facilitate dissolution. Two drops of TFA, previously diluted in isopropanol are added to the solution. The solution is then heated at 70° C. for 48 h. A red solution is obtained.
Characteristics
Absorbance: 480 nm (DMF)
The molecular weights determined by GPC in DMF are 40 000 g/mol.
Alternative reaction conditions for synthesis of poly-DAT are listed in Table 1.
TABLE 1
Alternative Reaction Conditions for Synthesis of Poly-DAT
T
Concentration
Absorbance
Compound
Solvent
t (h)
(° C.)
(mg/ml)
λ max (nm)
Poly-DAT
Isopro-
48
70
20
489
panol
Poly-DAT
Isopro-
48
70
10
482
panol
Poly-DAT
Isopro-
48
70
5
475
panol
Poly-DAT
Isopro-
48
70
2
479
panol
Poly-DAT
DMF
24
65
20
478
Poly-DAT
DMF
24
65
10
476
Poly-DAT
DMF
24
65
5
474
Poly-DAT
DMF
24
65
2
474
Poly-DAT
butanol
48
70
5
480
Poly-DAT
butanol
48
90
5
550
The kinetics of the reaction are shown in FIGS. 5 and 6 . FIG. 5 shows absorption (colour) increase resulting from the polymerization of thiophene-2,5-dicarbaldehyde (5 mg/ml) and diethyl 2,5-diaminothiophene-3,4-dicarboxylate (5 mg/ml) in butanol with catalytic amount of TFA at 70° C. The spectra were recorded at 1 hour intervals.
Similarly, FIG. 6 shows absorption (colour) increase resulting from the polymerization of thiophene-2,5-dicarbaldehyde (5 mg/ml) and diethyl 2,5-diaminothiophene-3,4-dicarboxylate (5 mg/ml) in butanol with catalytic amount of TFA at 90° C. The spectra were recorded at 1 hour intervals.
Autopolymerisation
Synthesis of Monomers
To a solution of 1,4-dithiane-2,5-diol (12.12 g, 78 mmol, 1 eq.) and of malononitrile (10.52 g, 157 mmol, 2 eq.) in 55 ml of DMF, DBU (10 ml, 78 mmol, 1 eq.) is added dropwise at 0° C. After a few minutes, the solution turned brown. Following the addition, the solution was stirred for 1 h at room temperature before being heated at 60° C. for an additional 8 h.
The solution was hydrolysed with 120 ml acetic acid (0.4 M). The solution was then extracted with ether. The ether phase was dried on MgSO 4 , then concentrated. The resulting solid was purified by recrystallization in a mixture of ethyl acetate and hexane (70/30) (11 g, 89 mmol, yield 57%), providing a very clear yellow powder.
Anhydrous DMF (10 ml) was introduced into a previously flamed two-neck flask placed under nitrogen and cooled to 0° C. POCl 3 (3 ml, 32 mmol, 4 eq.) is added dropwise. After 20 min, 2-amino-thiophene-3-carbonitrile (1.00 g, 8 mmol, 1 eq.) is added dropwise quickly. The reaction mixture is stirred at room temperature for 30 min.
The solution was hydrolysed with 50 g of ice. The solution was then extracted with ethyl. The organic phase was dried on MgSO 4 then concentrated. The resulting solid was purified by flash chromatography using the following eluent: ethyl acetate, hexane (40/60) (220 mg, 1.1 mmol, yield 14%). The final product was a clear yellow powder.
Caracteristics
2-amino-5-formyl-thiophene-3-carbonitrile (2)
1 H-NMR (CDCl 3 , 400 MHz): 9.62, 7.85, 7.65, 3.20
2-amino-5-formyl-thiophene-3-carbonitrile
1 H-NMR (CDCl 3 , 400 MHz): 9.62, 7.50, 5.50
Alternative reactants and solvents yield different products, as shown in Table 2.
TABLE 2 Alternative Reactants and Solvents for Synthesis of Thiophene Monomers Reactant A Reactant B Reactant C Solvent Product DBU DMF DBU DBU DMF DBU DMF Elemental sulfur, along with either DBU, diethylamine, triethylamine or Hunig's base DMF The products are called 2-amino-5-formyl-3-X-thiophene.
Deprotection
To remove the DMF protected aldehyde, three approaches were used:
1. 20 mg of compound to be deprotected were diluted in 1.5 ml water, 1 ml ethanol, a few drops of H 3 PO 4 , and a few drops of NaOH (30%). The solution was heated for 2 h at 80° C. The solution was then acidified with HCl (30%) before being stirred for 16 h. A red precipitate appeared. The precipitate was filtered. 2. 20 mg of compound to be deprotected were diluted in 5 ml formic acid diluted to 50% in volume, to which 2 drops of concentrated HCl were added. The solution was heated at 110° C. for 30 min. The initially yellow solution turned a clear brown and then pink. An LC-MS analysis confirms that 2-amino-5-formyl-thiophene-3-carbonitrile was the main product. 3. 20 mg of compound to be deprotected were diluted in 5 ml formic acid diluted to 50% in volume. The solution was heated to 110° C. After five minutes, the solution was pink. Heating and solid evaporation resulted in a dark red product that is indicative of the occurrence of polymerization.
Polymerisation
During deprotection, it was observed that when the solution was heated longer, it turned orange, then red and even violet. In this way, during the deprotection of 2-amino-thiophene-3-carbonitrile, a violet precipitate was produced with a mass of 2780 g/mol as confirmed by MALDI-TOF.
Producing a Thin Film
A thin film was produced on a glass support by spin-coating trimer (Example 8) which was previously dissolved in dichloromethane.
TABLE 3 Photophysical properties of doped conjugated materials Absorbance Fluorescence λ = 322 nm λ = 560 nm λ = 466 nm λ = 600 nm
Doping
A degassed solution of anhydrous acetonitrile anhydride containing trimer (Example 8), was prepared in a manner to avoid an absorbance near 0.5. A diluted solution of H 2 SO 4 (1 drop in 10 ml acetonitrile) was prepared. In two separate cuvettes, the following were added:
1 drop of diluted H 2 SO 4 solution; and 1 drop of concentrated H 2 SO 4 .
In the second cuvette, a change of colour from yellow to orange-red appeared immediatel in the IR region. A bathochromic shift (440 nm→500 nm) was observed for the concentrated solution. A decomposition of the product was noted in the case of the diluted solution. Doping may also be performed with FeCl 3 , AlCl 3 , GaCl 3 , trifluoroacetic acid, HCl, other organic acids, and gaseous iodine. The photophysical properties of a sample doped conjugated material are indicated in Table 3.
Part VI: Simple Room Temperature Synthesis of Conjugated Living Polymers Capable of Reversible Polymerization/Depolymerization (Including Examples 35-36)
The term “living”, applied to polymers, implies the polymerization can be resumed after the initial reaction has been stopped. Subsequently, higher molecular weights can be achieved either by linking the same monomers or different monomers. The polyazomethines described in this invention are living because they have two terminal groups (amine and aldehyde) that can undergo further condensation with their complementary units. We show the living character of polyazomethines by first forming the polymers through biphasic polymerization at room temperature under alkaline conditions. These reactions are done at different concentrations to show that polymer molecular weight is proportional to the reaction concentration, hence living. Once the polymers are formed, lyophilization (increasing concentration by removing water) results in higher molecular because the polymers condense with themselves via the active terminal groups, illustrating the living character. This is schematically represented in step B Scheme 7.
The living character of the reactive terminal groups can be demonstrated by selectively condensing a blocking group at one end. In the case of the polyazomethines, either a mono-amine compound can be condensed with the terminal aldehyde, or a mono-aldehyde can be condensed with the terminal amine, which leads to an azomethine capping agent (see Scheme 8). The uncapped terminal end can subsequently be reacted leading to continued polymerization. The polymer “glue” consisting of either a diamine or dialdehyde can be added to connect the polymers resulting in increased molecular weight.
The living character of the polyazomethines is further illustrated by a change in pH. The highly conjugated polyazomethines are depolymerized to their constitutional monomers when the pH is less than 7. Increasing the pH to greater than 7, promotes the polymerized back to the polyazomethines. The depolymerization/polymerization cycles can be continued indefinitely, providing the monomers remain in solution.
Biphasic Polymerization
A 50 ml stock solution of 4,4′-diaminostilbene-2,2′-disulfonic acid (3.9 mM) was prepared in phosphate buffer solution at pH 8. Another stock solution of 2,5-thiophene dicarboxaldehyde was prepared in dichloromethane. Roughly equally volumes of the two monomers were combined in flask and stirred at room temperature for 8 hours at pH 8 after the addition of a catalytic amount of benzyltriethyl ammonium chloride. The resulting conjugated polymers are found in the aqueous layer as noted by the intense deep red colour and strong absorbances between 445 to 550 nm. The resulting polymer molecular weights were measured by GPC. Polymer formation is also confirmed by NMR in D 2 O through the characteristic azomethine (N═CH) bond that resonates at 8.5 ppm. The reaction conditions must be at pH greater than 7. pH values less to 7 do not promote polymerization.
Biphasic Polymerization Leading to Aqueous Soluble Conjugated Thiophene-Based Polymers
The following describes simple means of synthesizing conjugated aromatic azomethines at room temperature which exhibit interesting photophysical and electrochemical properties. The simple means of polymer synthesis entails the condensation of aryl diamines and dialdehydes, as shown in Scheme 9, below, at room temperature under biphasic conditions in the presence of a phase transfer catalyst. This self-assembly approach has the advantage of relative ease with which the polymers are formed. The formation of the Schiff base is isoelectronic to its carbon analogue, 22-24 which is known for its conductive properties. As a result, the self-assembled polyimines are expected to possess similar conducting properties relative to their carbon analogues with the advantage of easier synthetic formation.
Instrumentation. Gel permeation chromatography (GPC) was used to determine molecular weights and molecular weight distributions, M w /M n , of polymer samples with respect to polystyrene standards (Polysciences Corporation). The system configuration consisted of a Waters GPC system using Waters ultrastyragel column. 1 H-NMR spectra of the polymers were obtained on a Bruker 300 spectrometer using 5 mm o.d. tubes in [D]DMSO. Absorption measurements were done on a Cary-500i UV-Visible spectrometer by Varian while emission studies were done using a Varian Cary Eclipse fluorimeter after degassing the sample thoroughly with argon for 20 minutes. Cyclic voltammetry measurements were performed with a standard system from Bioanalytic Systems Inc. in anhydrous deareated DFM (99.8% Aldrich) at 0.1 M concentrations with NBu 4 .PF 6 . The electrodes consisted of two platinum electrodes as working and auxiliary electrodes, silver wire as pseudo reference and ferrocene as internal reference and the scan rate used as 500 mV/s.
Example 35
Synthesis of poly(4,4′-diiminostilbene-2,2′-disulfonic acid thiophene) (1)
Distilled water (60 ml) and a few drops of 2M sodium hydroxide was required to dissolve 4,4′-diaminostilbene-2,2′-disulfonic acid (155 mg, 0.41 mmol). After the addition of 40 ml THF, 2,5-thiophene dicarboxaldehyde (58 mg, 0.42 mmol) was added along with a catalytic amount of benzyltriethyl ammonium chloride. The red coloured solution was stirred at room temperature for two days and the solvent removed under reduced pressure to afford the polymer as a red solid that was recrystallized from ethanol. λ max (water): 305 and 338 nm. M w =148 094, PDI=2.3, DP==286. 1 H-NMR (200 MHz, [D] DMSO): δ=8.92 (br, s, 2H), 8.21 (br, s, 2H), 7.80 (br, s, 6H), 7.39 (br, s, 2H). Anal. cald. C 20 H 12 O 6 N 2 S 3 Na 2 .7.2H 2 O: C, 37.06; H, 4.11; N, 4.32, S, 14.84 found C, 37.27, H, 3.90, N, 4.28, S, 14.62.
Example 36
Synthesis of poly(4,4′-diiminostilbene-2,2′-disulfonic acid terephthalate) (2)
4,4′-Diaminostilbene-2,2′-disulfonic acid (160 mg, 0.45 mmol) was added to a round bottom flask along with 30 ml water to give a suspension. A few of drops of 2M sodium hydroxide were added to render the reaction medium alkaline and to solubilize the reagent. Approximately 15 ml of THF was then added followed by the addition of the terephthalic dicarboxaldehyde (61 mg, 0.45 mmol) dissolved in 3 ml THF. The colour immediately became yellow and the reaction was allowed to stir at room temperature for 30 minutes before a catalytic amount of benzyltriethyl ammonium chloride was added. The reaction mixture was stirred at room temperature for two days then the solvent removed under reduced pressure to give the polymer as a yellow solid which was recrystallized from ethanol. λ max (water): 262 and 339 nm. M w =41 888, PDI=1.9, DP=82, MW=10 000. 1 H-NMR (200 MHz, [D] DMSO): δ=8.80 (br, s, 2H), 8.15 (br, s, 4H), 7.80 (br, s, 4H), 7.39 (br, s, 4H). Anal. cald. C 22 H 14 O 6 N 2 S 2 Na 2′ 11H 2 O: C, 37.18, H, 5.11, N, 3.94, S, 9.02 found C, 36.93; H, 4.81; N, 3.95, S, 8.93.
Results
The synthetic approach involving the simple condensation of aryl diamines and dialdehydes leading to azomethines (imine or Schiff bases) by dehydration conditions yields the desired polymers in high yields with ease of isolation. Their structures have been confirmed by NMR, MS and UV-vis and fluorescence spectroscopies, and their electrochemical properties have been characterized by cyclic voltammety. The polymers synthesized (1 and 2) represented above were readily characterized by conventional methods using NMR in deuterated DMSO or D 2 O by following the formation of the N═CH imine bond that resonates at ca. 8.5 ppm for both polymers. This method also allows the monitoring of the reaction progress since resonances of the terminal aldehyde group and the reagent are clearly separated in the NMR spectrum. Integration of the terminal aldehyde with respect to the imine protons leads to a rough representation of the polymers' M n . More accurate molecular weight determination can easily be performed with conventional polymer characterization techniques while UV-visible spectroscopy yields qualitative results of the polymerization degree through the bathochromic absorption shifts association with increased conjugation.
Polymerization of Water Soluble Conjugated Polyimines 1 and 2
The extent of polymerization was followed through the formation of a colour change from yellow to red for 1 and coloured to deep yellow/orange for 2. The change in absorption maxima is indicative of the increase in degree of polymerization concurrent with an increase in the conjugation degree. The colour found in the visible range dominates the lowering of the excited electronic π-π* levels owing to the stabilization of the conjugation of the polymer. The large bathochromic shift observed for 1 relative to 2 denotes a higher degree of conjugation, hence a higher degree of polymerization. This is evident from the molecular weight determinations by GPC. The absorption and emission spectra further provide information relating to the difference in excited and ground states of the polymers. The intercept of the absorption and fluorescence spectra of the polymers gives information relating to their relative energy differences of the ground and excited states. From the spectra shown in FIGS. 7 and 8 , the 1 S 0,0 - 0 S 0,0 (HOMO-LUMO) transition was calculated to be 65 kcal/mol (2.83 eV) for 1 and 74 kcal/mol (3.2 eV) for 2. From the absorption onset in the red region of the spectrum, a value can be calculated for the band gap of 51.3 kcal/mol (2.23 eV) for 1 and 69.9 kcal/mol (3.03 eV) for 2, respectively. The relatively low band gap for 1 is consistent with polythiophenes obtained by conventional polymerization methods.
The absorption spectra of the polyazomethines show a hypochromic shift for 1 concomitant with a broadening of the peak at 475 nm ascribed to a decrease in the molar absorption while the harmonic oscillatory remains the same. This behaviour is typical for highly conjugated materials.
Cyclic voltammetric measurements of the conjugated polymers were done in DMF owing to the difficulty in measuring the reduction potential and reversible redox properties of the polymers in water. The results obtained, as shown in FIG. 9 , are consistent with other polyazomethines studies. 25 Polymers 1 and 2 exhibit three distinct oxidation potentials. Conversely, the polyazomethines display only two reduction potentials implying both polymers undergo two reversible and one irreversible process. The two primary processes are understood to be the reversible oxidation-reduction leading to the radical cation followed by the cation formation upon further oxidation. Due to the inhomogeneity of the polymers studied, the onset of the reduction and oxidation potentials cannot be easily determined from the voltamograms and the band gaps cannot be accurately determined by this method.
The advantage of the self-assembly approach is the relative ease with which the polymers are formed. Water is the only by-product and thereby requires no further purification. The biphasic method ensures the correct stoichiometry for the reaction leading to high molecular polymers. It also simplifies purification with the undesired aldehyde reagent being left in the organic layer upon polymer precipitation. The terminal groups remain active even after polymerization is complete. Consequently, polymerization can be resumed with different monomers, leading to co-block polymerization, which in turn generates materials with varying band gaps. The self-assembly approach can effectively be used to control molecular weight by varying the reaction concentrations generating polymers with “living” type qualities. This is impossible with traditional condensation of conducting materials. 26 The formation of the conjugated network is a thermodynamic driving force that renders the Schiff base resistant to acid catalyzed hydrolysis 26 and capable of reversible reduction/oxidation. 27 Linearity and planarity of the imines ensures suppression of macrocycles, hence high molecular weight polymers required for electronic applications can be obtained. 28,29
The above demonstrates that conjugated polymers leading to conducting materials can easily be synthesized by simple and efficient condensation methods requiring little to no post polymerization purification. The thermodynamically desirable conjugation drives the formation of the otherwise reversible Schiff base leading to new stable materials exhibiting interesting photophysical and conducting properties. This method can easily be implemented with organic soluble monomers leading to simple alternatives for new conducting materials.
Biphasic polymerization is conducted using an organic solvent that is not miscible with water including halogenated organic solvents, ethylacetate, THF, DMSO, DMF, dioxane, acetonitrile, alkanes, and is usually dichloromethane. The hydrophobic compound usually the aldehydes 4-6 (Scheme 10) are dissolved in the organic layer. The sulfonic acids, usually 1-3 (Scheme 10), are rendered soluble in water with the use of an inorganic base such as sodium hydroxide, phosphonate bases, or organic bases. The polymerization occurs at room temperature at pH values greater than 7. Rigorous mixing and the addition of a phase transfer catalyst, typically benzyl triethyl ammonium chloride or other quartenary ammonium salts induce the polymerization. Typical reaction times range from 30 minutes to 24 hours.
The molecular weight of the polymer is proportional to the concentration of the sulfonic acid in the aqueous phase, ranging from 300 to 3 million. Polymers resulting from the addition of 6 with the diamines are yellow to orange in colour, while 5 gives light yellow polymers. The bathochromic shift in the colour is proportional the degree of polymerization and hence the polymer conjugation. High degrees of conjugations are obtained from the aldehyde 4 with diamines 1 or 3 that give deep red polymers that eventually precipitate from solution and are solution in DMF, DMAC, and DMSO.
The conjugated polymers can be doped with concentrated sulfuric acid, hydrochloric gas, trifluoroacetic acid, iodine, AlCl 3 , FeCl 3 , GaCl 3 , etc. which induce a strong bathochromic shift resulting in a blue colour.
The conjugated polymers can be depolymerized back into their monomers units by adjusting the pH to less than 7 which induces the colour disappearance. The sample then can be repolymerized back to the conjugated polymer by adjusting the pH to greater than 7. The process of depolymerization/repolymerization can be cycled indefinitely until the monomers are separated into their restive organic/aqueous phases.
Biphasic conditions for the polymerization of 4,4′-diaminostilbene-2,2′-disulfonic acid are shown in Table 4.
TABLE 4
Biphasic conditions for the polymerization of 4,4′-diamino-
stilbene-2,2′-disulfonic acid with 2,5-thiophene dicar-
boxaldehyde and the resulting polymer molecular weight
Monomer
Concentration
Degree of
Sample
(mol L −1 )
M w (g/mol)
polymerization
1A
0.25
39 000-490 000
2A
0.125
45 000-290 000
3A
0.0645
30 000-300 000
4A
0.0125
2 145 780
4 317
1C
0.05
2C
0.0375
3C
0.0125
4C
0.005
924 222
1 859
1I
0.056
2I (diluted
0.0056
58 11 530
1 1693
from 1I)
3I (diluted
0.00056
from 2I)
4I (diluted
0.000056
from 3I)
5I (diluted
0.0000056
from 4I)
1Z
0.028
3 819 1234
76 843
2Z. (diluted
0.014
17 896 440
36 009
from IZ)
3Z (diluted
0.0028
1 519 049
3056
from 2Z)
4Z (diluted
0.0022
618 067
1 243
from 2Z)
5Z (diluted
0.0011
510 595
1 027
from 4Z)
6Z (diluted
0.00014
176 270
355
from 3Z)
The effect of polymerization concentration on the molecular weight of the polymer is shown in FIG. 10 .
Living Polymerization
Sample 4C represents the initial sample polymerized by the standard biphasic conditions. While still in solution, a fraction of this solution was removed and lyophilized to dryness to afford sample 4CI. This sample undergoes a molecular weight increase from the reactive terminal groups that react with themselves according to Scheme 7. To the parent solution of 4C, was added one equivalent amount of 2,5-thiophene dicarboxaldehyde in dichlormethane followed by a catalytic amount of benzyltriethyl ammonium chloride. The reaction was allowed to stir at room temperature overnight. The dialdehyde unit serves as “polymer glue” to bond the complementary polymers together resulting in an increase in molecular weight for 4D, reported in Table 5. From a small aliquot of the parent sample 4C, was added one equivalent of 2,5-thiophene dicarboxaldehyde solubilized in a small amount of DMF and the reaction is allowed to proceed overnight resulting in 4E.
TABLE 5 Polymer molecular weights measured for biphasic polymerization illustrating the living characteristic of the polyazomethines M w Sample (g/mol) DP 4C 924 222 1 859 4D 1 227 422 2 469 4E 2 036 266 4 097 4Cl 1 132 256 2 278
End-Group Capping
Measured polymer molecular weights of polymers containing an acetaldehyde capping agent are shown in Table 6. A slight excess of acetaldehyde was added to samples 4A while one equivalent of 2-thiophene aldehyde was added 4B. The aldehyde units serve as selective terminal amine capping agent. The aqueous solutions at pH 8 were allowed to stir at room temperature for 12 hours. They were then subjected to lyophilization to remove the residual acetaldehyde and the solvent. Sample 4B1, corresponding to the thiophene capped polymer 4B, shows no real increase in molecular weight. This implies the terminal thiophene unit efficient caps the amino terminal group which cannot react any further. Contrarily, the acetaldehyde group is a poor capping agent that does not prevent the terminal amine group from further polymerization as observed by the increased molecular weight with 4A1.
TABLE 6 Measured polymer molecular weights of polymers containing the acetaldehyde capping agent M w Sample (g/mol) DP 4A 2 145 780 4 317 4A1 3 025 188 6 086 4B 383 703 772 4B1 400 143 805
Reversible Polymerization
To the solution of freshly prepared polyazomethine containing both the aqueous and organic layers described above, the pH is adjusted to less than pH 7 with concentrated sulfuric acid. The addition of acid first results in azomethine protonation visible by the intense blue colour at ca. 825 nm. After 10 minutes, depolymerization to the constitutional monomers occurs as observed by the disappearance of all colour. The addition of sodium bicarbonate neutralizes the acid and increases the pH above 7. Within 15 minutes of vigorous stirring, the original intense red colour of the polyazomethine appears. The molecular weights of the resulting reformed polymers are consistent with the original polymers. The polymerization/depolymerization cycles can be repeated many times.
Part VII: Electrical Conductivity, Polymer Doping and Industrial Applications (Examples 37-40)
Example 37
Preparation of Pellets
Pellets for electrical conductivity testing were prepared by adding a measured amount of the polymer powder to a Beckman IR pellet press. The pellets were 1.3 cm in diameter with a thickness determined by the amount of material pressed and the pressure used.
Reliable conductivity data was obtained by drying the material thoroughly in vacuum at 25° to 100° C. at 0.2 mm Hg for several hours after preparation of the pellets. The anhydrous pellets normally were removed and stored under nitrogen until testing.
Example 38
Preparation of P-Type Doped Pellets
Iodine doping was done through the addition of iodine crystal to a chamber containing a pellet of polymer. The chamber then was evacuated causing immediate sublimation of iodine. Gaseous iodine remained in contact with a pellet for a period from about 1.5 to about 17 hours, whereupon the doped pellet was removed and stored under nitrogen until being tested.
Example 39
Preparation of N-Doped Pellets
Doping of a polymer with sodium naphthalide may be accomplished by contacting the polymer powder with a slurry of sodium naphthalide in dry tetrahydrofuran. After the mixture is stirred under nitrogen for 24 hours, excess sodium naphthalide and solvent may be removed. The remaining solvent may be evaporated in a stream of nitrogen and the doped polymer may be dried as described above but at room temperature.
Example 40
Applications
The inherently conductive conjugated materials described herein can be used for the following devices/applications:
Organic light emitting diodes (OLEDs)
Polymer light emitting diodes (PLEDs)
Conducting wires
Thin films
Active Matrices
Such emitting devices can in turn be used for flexible and/or low power consuming displays including; microdisplays, laptop computers, televisions, computer monitors, car stereos, cellular telephones, store displays, large sign displays, electronic newspapers, active matrices, optical devices, etc. The light emitting properties can also be exploited for sensors including biosensors and detectors. They can be used as replacements for inorganic based display materials and liquid crystal devices. Additionally, the conjugated materials can find applications in fuel cells and their compartment separators, battery storage devices, photovoltaics, solar cells, etc.
In summary, the present invention provides the first example of an easy modular route for conjugated oligothiophene analogues in a selective fashion consisting of up to five thiophene units. The snapped together bonds are suitable for conducting materials and do not require any stringent reaction conditions, unlike conventional methods. The thermodynamically favorable conjugation displaces the equilibrium of the otherwise reversible Schiff base in favor of new stable materials, leading to robust covalent connections similar to their carbon analogues. Through selective unsymmetric and symmetric conjugated motifs, band-gap tuning among other properties is possible in a one-pot synthesis.
Although the present invention has been described by way of particular embodiments and examples thereof, it should be noted that it will be apparent to persons skilled in the art that modifications may be applied to the present particular embodiment without departing from the scope of the present invention.
LIST OF REFERENCES
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(23) Yang, C.-J.; Jenekhe, S. A. Macromolecules 1995, 28, 1180-1196.
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(29) Rowan, S. J.; Cantrill, S. J.; Cousins, G. R. L.; Sanders, J. K. M.; Stoddart, J. F. Angew. Chem. Int. Ed. 2002, 41, 898-952. | The present invention relates to conjugated oligomers and polymers comprising aromatic thiophene cores. The conjugated materials are obtained by simple and efficient condensation of an aryl diamine and an aryl dialdehyde or a bifunctional aryl moiety comprising both an aldehyde and an amine. Condensation of the complementary moieties at temperatures ranging from ambient to refluxing temperatures in various solvents resulted in conjugated oligomers and polymers that can subsequently be cast into thin films. Oligomerization and polymerization can be done under mild conditions with removal of the resulting water bi-product responsible for shifting the equilibrium in favor of the conjugated products. The resulting conjugated compounds can be made conducting with dopants affording electrically conducting materials of either p-type or n-type conductors depending on the dopant selected. | 98,779 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of priority to U.S. Provisional Patent Application Ser. No. 60/959,811 filed Jul. 16, 2007 and U.S. Provisional Patent Application Ser. No. 60/923,832, filed Apr. 17, 2007, which applications are hereby incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to surgical methods and devices therefor, including surgical access devices. Particularly, the present invention is directed to surgical access ports for use in endoluminal or transluminal procedures, such as through the human esophagus or lower gastrointestinal tract, and related methods.
[0004] 2. Description of Related Art
[0005] A variety of devices are known in the art for assisting surgical procedures-including cannulas for accessing internal cavities of a patient, and other devices, such as endoscopes.
[0006] Endoscopy is a term for a range of medical procedures that allow a doctor to observe the inside of the body without performing major surgery. An endoscope (e.g., a fibrescope) is a long tube with a lens at the distal end and an eyepiece and/or camera at the proximal end. The end with the lens is inserted into a patient. Light is transmitted through the tube (via bundles of optical fibres) to illuminate the surgical site, and the eyepiece magnifies the area so the doctor can visualize the surgical site. Usually, an endoscope is inserted through one of the body's natural openings, such as the mouth, urethra or anus, but depending on the particular procedure, may require a small incision through the skin. Such procedures are often performed under general or local anesthetic. Specially designed endoscopes are used to perform simple surgical procedures, such as tubal ligation (“tying” of the female fallopian tubes); locating, sampling or removing foreign objects or tumors from the lungs or digestive tract; removal of the gallbladder; taking small samples of tissue for diagnostic purposes (biopsy).
[0007] A range of endoscopes have been developed for many parts of the body. Each has its own name, depending on the part of the body it is intended to investigate. For example, an arthroscope is inserted through a small incision to examine a skeletal joint. A bronchoscope is inserted down the trachea (windpipe) to examine the lungs. A colonoscope is inserted through the anus to examine the colon. A gastroscope is inserted down the esophagus to examine the stomach. A hysteroscope is inserted through the cervix to examine the uterus. A laparoscope is inserted through a small incision to examine the abdominal organs. A cystoscope is inserted via the urethra to examine the urethra and urinary bladder. Many of the foregoing procedures can be carried out with one or more instruments used in conjunction with an endoscope. Such procedures often also require an opening through which the endoscope and/or instruments can pass. Such working channels can be natural openings—e.g. the mouth and esophagus, or artificial openings such as an incision made in the abdomen of a patient.
[0008] Applicants recognize that current endoscopic systems suffer from various limitations, particularly when used in conjunction with certain medical procedures. Some endoscopes may be configured with an integral working channel. Such working channels are often small, and may or may not be suitable for a particular instrument to be inserted therethrough. Moreover, it can prove difficult to obtain good working instruments in very small sizes. Further, imaging through fibers can be limiting-often due to low resolution images. If an endoscope is provided with an imaging chip on a scope having a circular cross-section, this can restrict the size and quality of images obtained therefrom. Moreover, if insufflation is required for a particular procedure, insufflation through an endoscope is typically maintained with mechanical seals. Even state-of-the-art mechanical seals typically present difficulty for a surgeon due to substantial friction, which results in difficult manipulation and restricted instrument access.
[0009] Applicants recognize that with the foregoing problems in the art, there remains a need for improved visualization and access devices that allow for easier access and movement and better quality imaging. The present invention provides a solution for these problems.
SUMMARY OF THE INVENTION
[0010] The purpose and advantages of the present invention will be set forth in and apparent from the description that follows. Additional advantages of the invention will be realized and attained by the devices and methods particularly pointed out in the written description and claims hereof, as well as from the appended drawings. The present invention is directed to devices, as described hereinbelow, as well as to methods utilizing such devices.
[0011] To achieve these and other advantages and in accordance with the purpose of the invention, as embodied, the invention includes an access device adapted and configured to be inserted through a natural biological orifice is provided. The access device includes a body, a nozzle means and means for delivering a pressurized flow of fluid to the nozzle means. The body is configured and dimensioned to be inserted through a natural bodily orifice and has proximal and distal end portions and defines at least one lumen therethrough to accommodate passage of one or more surgical instruments. The nozzle means is operatively associated with the body for directing pressurized fluid into the lumen to develop a pressure differential in an area within a region within the lumen to form a fluid seal around the one or more surgical instruments passing therethrough.
[0012] In accordance with the invention, the body can be substantially rigid or substantially flexible, or include both rigid and flexible elements, as required. The access device can include at least one control element for manipulation of the curvature of the access device. Alternatively, two individual control elements can be used to control orthogonal motion—e.g., with respect to X and Y axes. Such control elements can further be provided in one or more opposing pairs. Such control elements can be, for example flexible or semi-rigid rods, wires or ribbons. Manipulation of the curvature of the entire access device can be controlled, or alternatively, the curvature of only the distal tip can be controlled, depending on the precise implementation.
[0013] One or more image sensors can be arranged in the distal end portion of the access device, which are adapted and configured to capture images of a region distal the distal end portion of the access device. If multiple image sensors are provided, they can facilitate stereoscopic imaging of the subject region. One or more working channels can be provided in the wall of the access device, and one or more of said working channels can be configured and adapted to provide irrigation to a surgical site. Alternatively or additionally, one or more of said working channels can be configured and adapted to provide drainage to a surgical site and one or more channels can be configured to allow a surgical instrument to pass therethrough.
[0014] One or more light sources can be arranged in the distal end portion of the access device, and adapted and configured to illuminate a region distal the distal end portion of the access device. Alternatively or additionally, illumination means can be provided in the wall of the access device.
[0015] Further, one or more guide elements adapted and configured to guide surgical instruments in the lumen of the access device can be provided. One or more pressure sensing channels can be arranged in the wall of the access device, and be configured and adapted to be in fluid communication with a surgical site.
[0016] Devices in accordance with the invention can be of any length desired or required. For example, the length of the body can be between about 30 cm and about 50 cm, depending on the precise application. A range of length between about 30 cm and 40 cm is particularly advantageous for a transesophageal access route for an endoluminal intra-gastric procedure—accessing a patient's stomach or duodenum. In alternate embodiments, the length of the body can be between about 40 cm and 50 cm, which range of length is particularly advantageous for transluminal access to internal organs via a trans-gastric route—that is, accessing a an organ through the wall of a patient's stomach. If desired, devices in accordance with the invention can be in the range of about 15 cm to about 20 cm for use as an anoscope and transanal access to the rectum, and can be up to about 160 cm in length for use as, or in conjunction with, a colonoscope, depending on the precise implementation. In accordance with one embodiment of the invention, a device provided with integral optics and illumination is between about 90 cm and 130 cm in length, preferably about 110 cm in length. Internal diameters of access devices in accordance with the invention can be any size that is practical for the application, but preferably range between about 10 mm and 20 mm, and in a preferred embodiment, between 15 mm and 18 mm.
[0017] Access devices in accordance with the invention can further comprise an integral image display provided in the proximal end portion thereof.
[0018] In accordance with another aspect of the invention, an insertion device is provided for inserting access devices in accordance with the invention. Such insertion devices can have a tip portion to facilitate insertion of the access device through a natural orifice. The tip can taper to a substantially blunt end and/or can include a dilating element. The tip portion can include at least one transparent region. The insertion device can be provided with illuminating means for illuminating a region distal the insertion device. Also, the insertion device can be configured and adapted to interface with an endoscope to facilitate guidance of the user during insertion. The insertion device can further include an integral lens arranged in a distal end portion thereof.
[0019] Further in accordance with the invention, a method of accessing an internal region of a body is provided. The method includes inserting through a natural body orifice an elongated body having longitudinally opposed proximal and distal end portions. The body defines at least one lumen configured and dimensioned to accommodate passage of one or more surgical instruments. The body further includes nozzle means operatively associated with the body for directing pressurized fluid into the lumen to develop a pressure differential in an area within a region within the lumen to form a fluid seal around the one or more surgical instruments passing therethrough. The method further includes the steps of delivering pressurized fluid to the nozzle means to create said pressure differential; and inserting one or more surgical instruments through the body to access the interior of the body.
[0020] In accordance with another aspect of the invention, an access device is provided which is adapted and configured to be inserted through an orifice. The access device includes a body, a nozzle means, means for delivering a pressurized flow of fluid to the nozzle means and at least one control element. The body is configured and dimensioned to be inserted through an orifice and has proximal and distal end portions and defines at least one lumen therethrough to accommodate passage of one or more surgical instruments, and is flexible in at least one region. The nozzle means is operatively associated with the body for directing pressurized fluid into the lumen to develop a pressure differential in an area within a region within the lumen to form a fluid seal around the one or more surgical instruments passing therethrough. The at least one control element is arranged within the body and is adapted and configured to effect a change in curvature of the at least one flexible region of the body. In accordance with the invention, the orifice can be a natural biological orifice, or alternatively can be formed from an incision made in the patient.
[0021] In accordance with still another aspect of the invention, a method for performing a cholecystectomy is provided. The method includes the steps of inserting a first access device through the esophagus of a patient and into the stomach, penetrating the stomach wall and extending the first access device through the stomach wall, inserting a second access device through the umbilicus of the patient, inserting an endoscope through the first access device, retracting the gallbladder, exposing the cystic duct and cystic artery, applying at least two dips on each of the cystic duct and artery, transecting each of the cystic duct and artery, dissecting and removing the gallbladder from the liver bed, and removing the gallbladder.
[0022] It is to be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The accompanying drawings, which are incorporated in and constitute part of this specification, are included to illustrate and provide a further understanding of the method and system of the invention. Together with the description, the drawings serve to explain the principles of the invention, wherein:
[0024] FIG. 1 a illustrates a first embodiment of an access device in accordance with the invention, having a generally elliptical cross-section;
[0025] FIG. 1 b is a proximal end view of the embodiment of FIG. 1 a;
[0026] FIG. 1 c is a distal end view of the embodiment of FIG. 1 a;
[0027] FIG. 2 a illustrates a further embodiment of an access device in accordance with the invention, in which the wall of the device houses additional working channels;
[0028] FIG. 2 b is a cutaway view of a portion of the access device of FIG. 2 a , illustrating a fluid seal in accordance with the invention;
[0029] FIG. 2 c is a distal end view of the embodiment of FIG. 2 a , illustrating working channels and other features;
[0030] FIG. 3 a illustrates an access device in accordance with the invention, which is flexible and manipulable, in which instrument guides can be provided integrally with the access device, or can be provided in an attachable cap;
[0031] FIG. 3 b is a partial view of the access device of FIG. 3 a , illustrating surgical instruments inserted through the access device;
[0032] FIG. 3 c is a proximal end view of the access device of FIG. 3 a , illustrating an instrument guide provided therewith;
[0033] FIG. 3 d is a partial view of the distal end of the access device of FIG. 3 a , illustrating an insertion device inserted therethrough;
[0034] FIG. 4 a illustrates an access device in accordance with the invention having a proximal display, such as an LCD display;
[0035] FIG. 4 b is a distal end view of the access device of FIG. 4 a;
[0036] FIG. 5 illustrates a further embodiment of an access device in accordance with the invention, including control knobs which manipulate control elements provided within the access device;
[0037] FIG. 6 is an enlarged cross-sectional view of a distal end portion of an access device in accordance with the invention, through which an insertion device has been inserted;
[0038] FIG. 7 a illustrates a flexible access device, that is particularly configured and adapted for transanal insertion;
[0039] FIG. 7 b illustrates a rigid access device that is particularly configured and adapted for transanal insertion;
[0040] FIG. 7 c is a distal end view of the access devices of FIGS. 7 a and 7 b;
[0041] FIG. 7 d is a proximal end view of the access devices of FIGS. 7 a and 7 b , illustrating instrument guides provided thereon.
[0042] FIG. 8 is a side view of a further embodiment of an access device constructed in accordance with the invention having a distal end with open distal side portion;
[0043] FIG. 9 is an illustration of the access device of FIG. 8 inserted through a patient's esophagus into the stomach;
[0044] FIG. 10 is a side view of another embodiment of an access device constructed in accordance with the invention, with a distal end having a side-grasping feature with undulating grasping elements;
[0045] FIG. 11 is a partial view of the distal end of a variation of the embodiment of FIG. 10 , with straight grasping elements;
[0046] FIG. 12 illustrates three stages of an example procedure utilizing the access device of FIG. 10 ;
[0047] FIG. 13 a is a partial view of the distal end of a further embodiment of an access device constructed in accordance with the invention having internal steering elements;
[0048] FIG. 13 b is a cutaway view of the distal end of the access device of FIG. 13 a;
[0049] FIG. 14 is a schematic representation of a cholecystectomy in accordance with the invention; and
[0050] FIG. 15 are side and end views of a frangible tip in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0051] Reference will now be made in detail to select embodiments of the invention, examples of which are illustrated in the accompanying drawings.
[0052] The devices and methods presented herein may be used as surgical access ports, particularly for endoluminal or transluminal medical procedures. The devices described and set forth herein can incorporate any feature from the following U.S. patent applications and patents, which are each incorporated herein by reference in their entirety: U.S. patent application Ser. No. 11/517,929, filed Sep. 8, 2006 (U.S. Patent Publication No. US 2007/0088275, published Apr. 19, 2007), which is a continuation-in-part of U.S. patent application Ser. No. 10/776,923, filed Feb. 11, 2004 (now U.S. Pat. No. 7,338,473), which is a continuation-in-part of U.S. patent application Ser. No. 10/739,872, filed Dec. 18, 2003 (now U.S. Pat. No. 7,285,112), which is a continuation-in-part of U.S. patent application Ser. No. 10/441,149, filed May 17, 2003 (now U.S. Pat. No. 7,182,752). Each of the foregoing applications also claims priority to U.S. Provisional Application Ser. No. 60/461,149, filed Apr. 8, 2003, which itself is also hereby incorporated by reference in its entirety. The devices described and set forth herein can further incorporate any feature from U.S. patent application Ser. No. 11/544,856 (U.S. Patent Publication No. US 2008/0086167), and U.S. Provisional Application Ser. No. 60/850,006 both filed Oct. 6, 2006, which are also incorporated herein by reference in their entirety.
[0053] FIGS. 1 a - 1 c illustrate a first embodiment of an access device 100 in accordance with the invention. This embodiment has a generally elliptical cross-section, as can be seen at its proximal end 101 ( FIG. 1 b ). Further, this access device 100 , as embodied in FIGS. 1 a - 1 c , is sufficiently flexible to navigate a natural body orifice through which it is intended to be inserted. The access device 100 includes an insufflation input 120 a , and a pressure sensing channel having proximal and distal openings 110 a , 110 b , respectively. The body of the access device 100 includes a lumen 170 , and can be embodied so as to include manipulating elements 180 , such as wires, to effect curvature of the access device 100 , when desired. An image sensor 130 may be provided at the distal end region, as may be at least one light source 140 . In this embodiment it is contemplated that the at least one light source, may be one or more light-emitting diodes (LEDs), and that one or more CMOS, CCD or other small image sensors may be mounted at the distal end of the device and used as image sensors. Images can be transmitted to the external environment through conductive elements provided on or within the access device 100 , or can be provided wirelessly, such as by radio frequency transmission to a receiver. Alternatively, it is contemplated that the access device might not contain integrated optics and that known types of viewing devices may be inserted through the central lumen or a working channel of the access device for viewing purposes.
[0054] Devices in accordance with the invention can be of any length desired or required. For example, the length of the body can be between about 30 cm and about 50 cm, depending on the precise application. A range of length between about 30 cm and 40 cm is particularly advantageous for a transesophageal access route for an endoluminal intra-gastric procedure. In alternate embodiments, the length of the body can be between about 40 cm and 50 cm, which range of length is particularly advantageous for transluminal access to internal organs via a trans-gastric route—that is, accessing a an organ through the wall of a patient's stomach. If desired, devices in accordance with the invention can be in the range of about 15 cm to about 20 cm for use as an anoscope and transanal access to the rectum, and can be up to about 160 cm in length for use as, or in conjunction with, a colonoscope, depending on the precise implementation. In accordance with one embodiment of the invention, a device provided with integral optics and illumination is between about 90 cm and 130 cm in length, preferably about 110 cm in length. Internal diameters of access devices in accordance with the invention can be any size that is practical for the application, but preferably range between about 10 mm and 20 mm, and in a preferred embodiment, between 15 mm and 18 mm.
[0055] Additional features that can be incorporated into access devices in accordance with the invention include, but are not limited to having an outer cross-sectional shape ranging from circular, through an elliptical shape to near linear in shape.
[0056] With respect to the embodiment of FIGS. 1 a - 1 c , one or more fluid seals 120 b are provided to seal between instruments passing through the lumen 170 , and the wall of the lumen, in order to maintain pressure within an operative space. Various embodiments of access devices having fluid seals (or alternatively “air seals” or “pneumatic seals”) are set forth in the documents referenced above. Although mechanical sealing can additionally be incorporated into different embodiments of access devices described therein, as well as into those described in connection with the present invention, such mechanical seals can equally be absent, allowing substantially unencumbered movement of instruments through and within such access devices.
[0057] In accordance with the present invention the access device 100 of FIG. 1 or any access device set forth herein can be provided with a fluid seal, as described in the documents referenced above. The subject access devices can further include one or more of the following features: one or more endoscopes; one or more working channels; illumination capability; and/or the capability to be steered by a user. Incorporation of non-mechanical seals into endoluminal and transluminal access devices in accordance with the invention can allow for easier, safer procedures as well as new approaches to procedures.
[0058] Fluid seals in accordance with the invention can be embodied in a variety of suitable manners. Nozzles can be provided that are substantially annular in configuration, or alternatively, if desired, a plurality of discrete nozzle apertures can be defined in place one such annular nozzle. These discrete nozzle apertures can be arranged as necessary, about the wall of the access device, to form an effective barrier to proximal egress of insufflation gas from a surgical site. Such discrete nozzles can each be substantially round in shape, or alternatively can be oblong or another shape. The nozzles can be placed at regular intervals about the circumference of the lumen, can extend part way around, or can be spaced from each other in groups. If turbulence is desired, surface features such as protrusions, vanes, grooves, surface texture can be added in the path of fluid flow, as desired. Further, one or more nozzles or groups of nozzles can be provided in access devices in accordance with the invention, with such nozzles being located in one region, or in a plurality of regions along the length of the access device.
[0059] FIGS. 2 a - 2 c illustrate a further embodiment of an access device 200 , in accordance with the invention. The access device 200 includes an insufflation fluid input 220 a , which is in fluid communication with a fluid seal 220 b . The fluid seal may be positioned within the proximal housing of the device or may be positioned at any desired location between the proximal housing and the distal tip of the device. A lumen 270 serves as a working channel for passage of surgical instruments and the like, and is defined by the wall 275 of the access device 200 . The wall 275 itself also houses additional working channels, such as an irrigation port 260 , drainage port 261 and pressure sensing port 210 a . Additional ports can be used for additional functions, as desired or required. Optionally, illumination can be provided by way of one or more light sources, which can be provided directly in the wall 275 , or whose light can be transmitted through the wall 275 , to the distal end thereof by one or more fiber optic elements 250 . Further, one or more optional image sensors 230 can be provided in the wall 275 in order to capture images of a surgical site.
[0060] In accordance with the invention, the foregoing and following embodiments can be flexible or rigid, as desired or required. Further the foregoing and below-described access devices allow a user to pass a plurality of surgical instruments through a natural lumen into the human body. Such natural openings include, for example, the mouth and esophagus, the anus and rectum or vagina.
[0061] Entrance through such natural openings can provide access into the digestive tract without surgical incisions penetrating the external abdominal wall. Furthermore, gastrointestinal pressures can be maintained within the organ(s), such as the stomach, without any interference with inserted instruments which would typically be caused by mechanical seals used in a typical endoscope, colonoscope, trocar, cannula or other access systems. Moreover, manipulation of surgical instruments is less encumbered, as compared with more conventional devices having mechanical seals. The subject access devices suffer less from frictional resistance between inserted instruments and the access device. Reducing such interference and friction is advantageous, and may reduce torque and other forces transmitted from the inserted instrument through the access device to surrounding tissue, which can cause trauma and prolong healing and recovery. The access device may also allow crossing of paths of the inserted instruments, as when switching hands, without having to retract and then reinsert an instruments.
[0062] Endoscopic surgical or exploratory access via a transesophageal or transanal route can be intraluminal—that is, it can be used for accessing the natural lumen itself (e.g., the esophagus, stomach, rectum, colon), or can be transluminal, that is—used to access other anatomy through the wall of such structures. Such an approach can be referred to as Natural Orifice Transluminal Endoscopic Surgery™ (“NOTES”). Such access can allow for imaging, insertion of one or more surgical instruments, removal of a tissue specimen, or insufflation of the lumen (e.g., the stomach). For example, access to a patient's peritoneum can be achieved through an internal endoluminal route. Moreover, insufflation of the peritoneum is possible using access devices in accordance with the invention. The following is a sample list of minimally-invasive procedures that can be accomplished by surgeons operating through access devices as described herein:
Endoluminal Access to the Upper GI Tract
[0063] Reflux procedures, such as fundoplication
[0064] Obesity procedures, such as gastric restriction
[0065] Diabetes procedures such as duodenal bypasses
[0066] Gastric tumor removal
Endoluminal Access to the Lower GI Tract
[0067] Tumor removal
[0068] Diverticulum removal, repair
Transluminal Access Through Esophagus, Rectum or Vagina
[0069] All current abdominal and pelvic surgery such as:
Gallbladder Appendectomy Ovarian cysts Oophorectomy Sterilization Hernia repair
[0076] Devices in accordance with the invention can allow, in general, for new approaches to accessing anatomy. Any instrument inserted through the lumen of an access device equipped with one or more fluid seals in accordance with the invention will experience markedly reduced frictional resistance, due to replacement of mechanical seals with fluid seals. It may, at times, prove useful to include one or more mechanical valves, such as for example a duckbill valve or other so-called “zero seal” intended to seal the access device when no instrument is inserted therethrough. However, typically the number of such valves will be reduced if not eliminated, for every fluid seal that is used. Without mechanical seals protruding into a lumen of access devices in accordance with the invention, more space for instruments is available, while free insertion and movement of the instruments is not hampered by mechanical seals.
[0077] Further, gas, such as carbon dioxide, can be supplied to such fluid seals in a continuous manner—thereby insufflating an operative space while also sealing the operative space. Such a continuous flow of insufflation gas is distinct from prior systems, in that prior insufflation technologies operate in a cyclic manner—alternately insufflating and sensing pressure. Such systems do not allow for insufflation when pressure is being sensed. A further advantage to access devices in accordance with the invention, is that maintaining a pressure barrier in an access device, between an insufflated space and the surrounding environment without the use of elastomeric seals provides the capability for safe relief from pressure buildup from any possible system failures or sources of additional pressure. Additionally, bucking is reduced when operating using devices in accordance with the invention. Bucking is the phenomenon where a patient tightens his diaphragm while his abdomen is insufflated. This tightening dramatically increases pressure within the abdomen. Further, if used in laparoscopic procedure, fluid seals incorporated with devices constructed in accordance with the invention all use of open type instrumentation.
[0078] Additionally, access devices in accordance with the invention allow for more freedom in instrument design. Because contact seals are not required, instruments inserted through access devices in accordance with the invention do not need to conform to the shape and size of such mechanical seals. Accordingly, instruments having a non-symmetrical shape can be used, which may be more efficient and cost-effective, and multiple instruments can be inserted simultaneously to improve manipulation through the access device. Advantageously, the absence of mechanical seals reduces the likelihood of smudging of optical components of surgical instruments inserted through access devices constructed in accordance with the invention.
[0079] Moreover, devices in accordance with the present invention can be provided with various cross-sectional shapes, including, but not limited to circular, elliptical, or as set forth above, cross-sectional shapes that approach a linear morphology when not in use. If embodied in an elliptical shape, access devices in accordance with the invention advantageously allow insertion of instruments of various sizes, such as instruments having an oblong cross-section. An elliptical cross-section can also allow for insertion of the access device in regions of the anatomy that would otherwise not allow insertion of an access device having a round cross-sectional shape.
[0080] Surgical instruments that can be used through access devices in accordance with the invention include, but are not limited to rigid or flexible versions of the following, depending on the procedure: graspers, scissors, snares, staplers, ultrasonic imaging devices, ultrasonic cutting and/or coagulating devices, vessel sealing devices, RF devices, microwave energy delivery devices glue delivery devices and suturing devices.
[0081] Access devices in accordance with the invention can further incorporate various imaging technologies. One or more image sensors can be utilized for image acquisition, which sensors can be incorporated into an access device, for example at or near the distal end thereof. Alternatively, standard fiber optic imaging technology may be inserted through the fluid seal or may be incorporated into a wall of the access device, such that an objective (lens) is at the distal end portion of the access device, and an image sensor and/or eyepiece is provided elsewhere, such as at the proximal end thereof. Such imaging devices can be embodied so as to obtain still images, but video images can alternatively or additionally be obtained to allow for real-time guidance of a procedure, and can allow for guidance during insertion of the access device itself. Additionally, illumination can be provided in the subject access devices in the form of integrated fiber-optics, connected to an external light source and/or integrated sources of light, such as LEDs (light-emitting diodes) integrated into the distal end portion of the access device. Capability for infrared imaging for diagnostic purposes can further be provided, in the form of an optical sensor capable of capturing light in the infrared region, and additionally, if needed, an infrared light source.
[0082] FIGS. 3 a - 3 d illustrate a surgical access device 300 in accordance with the invention, which is flexible and manipulable, as with foregoing embodiments. One or more fluid seals 320 b are provided therein, to which fluid (such as compressed air or inert gas, or in the case of arthroscopic or other surgery which utilizes liquid, saline or other suitable biocompatible liquid) is supplied via a fluid input 320 a . A sensing input 310 is also provided, as described above in connection with other embodiments. If desired, instrument guides 385 (shown in the end view of FIG. 3 c ) can be provided integrally formed with the access device 300 , or in the form of an attached cap 380 ( FIG. 3 a ). As shown in FIG. 3 b , surgical or exploratory instruments 305 a , 305 b , 305 c pass through the guides 385 , and thereby are prevented from moving undesirably, or unnecessarily interfering with one another.
[0083] Further in accordance with the invention, an insertion device 390 can be provided, which is inserted into the access device 300 , prior to insertion in a patient. The insertion device 390 includes a tip 395 , which facilitates insertion into a patient. Tip 295 may be blunt or sharp, rounded or pointed or such other configuration as appropriate for the intended insertion. Tip 395 also may be transparent to provide optical viewing during or after insertion.
[0084] As illustrated in FIG. 4 a , a proximal display 489 , such as an LCD display, can be provided with access devices in accordance with the invention, such as access device 400 of FIGS. 4 a and 4 b . Such displays 489 can be integrated with respective access devices, or can be attached thereto in order to provide optimum viewing nearer the location in which the procedure is taking place, rather than on a display mounted far from the operating table. Such displays can provide high resolution direct images of the anatomy. In the embodiment of FIGS. 4 a and 4 b , the display 489 receives images from an image sensor 430 arranged in the distal end region of the access device 400 . If desired, video signals from the image sensor 430 can be additionally output to display monitors by one or more wired and/or wireless connections. Of course, images may alternatively or additionally be displayed on a traditional monitor in the vicinity.
[0085] As best seen in FIG. 4 b , illumination elements 451 may also be provided at the distal end region of the access device 400 , and can include light sources, such as light-emitting diodes (LEDs) or alternatively or additionally, fiberoptic conduits that deliver light from an external light source. It is preferable, generally, that such illumination elements 451 be capable of providing bright, controllable illumination and be relatively small in size. As can be seen in FIG. 4 b , the foregoing elements can be provided directly in a wall of the access device 400 , which has a lumen 470 , running therethrough, with openings 470 a ( FIG. 4 a ), 470 b at proximal and distal ends of the access device 400 , respectively.
[0086] The nature of access devices in accordance with the invention, particularly because fluid seals can be integrated therewith, allows the ability to use new flexible instruments of different shapes, geometries and mechanics. Such instruments might otherwise not be satisfactorily sealable with conventional sealing techniques. The absence of mechanical seals also can allow for passage of instrument drive and steering mechanisms, as well as for tissue manipulation, repair and/or retrieval.
[0087] FIG. 5 illustrates a further embodiment of an access device 500 in accordance with the invention. The access device 500 includes control knobs 581 , 583 , which manipulate control elements provided within the access device 500 . When the control elements are placed in tension, the access device will tend to bend toward that control element. Conversely, when a control element is placed in compression, the access device 500 , will tend to bend away from that control element. In the embodiment of FIG. 5 , two controls 581 , 583 control bending of the access device in two orthogonal directions, such as “X” and “Y” in a Cartesian coordinate system.
[0088] FIG. 6 is an enlarged cross-sectional view of a distal end portion of an access device 600 , in accordance with the invention, through which an insertion device 660 has been inserted. The insertion device 660 may receive an endoscope 670 therethrough, which views the insertion site through one or more transparent windows or lenses 665 . The lenses 665 can also be adapted to provide illumination to the insertion site. In this embodiment, the insertion device 660 may terminate in an elongate tip 661 , which may facilitate dilation of a natural orifice through which the insertion device 660 and access device 600 assembly pass during insertion. Further, the contour 663 of the insertion device provides a relatively smooth transition to the diameter of the access device 600 from that of the tip 661 .
[0089] FIGS. 7 a - 7 d illustrate rigid and flexible access devices 700 a , 700 b , respectively, that are particularly configured and adapted for transanal insertion into the rectum of a patient. Features for these embodiments can be any of those set forth in connection with foregoing embodiments, including but not limited to use with an insertion device, incorporation of one or more fluid seals or insufflation means and/or steerability (in the case of flexible access devices). Further, as illustrated in FIG. 7 d , which is a proximal end view of a cap for attachment to the access device 700 a , 700 b , instrument guides 785 can be provided. As best seen in the distal end view of FIG. 7 c , irrigation channels 781 , illumination capability 783 , visualization components, such as one or more image sensors 787 , or fiber optics to allow image transmission, and drainage capacity, such as in the form of drainage channels 789 can be incorporated. The foregoing elements can be arranged within the wall 775 of the access devices 700 a , 700 b , as with the embodiment described in connection with FIGS. 2 a - 2 c , for example. Additionally, an insertion device 790 can be utilized to facilitate insertion into the body of a patient.
[0090] FIG. 8 is a side view of a further embodiment of an access device 800 constructed in accordance with the invention. The access device 800 has a distal end 870 with open distal side portion 875 . This embodiment allows instrumentation to be oriented to act on the side as an alternative to or in addition to through a distal end aperture. This arrangement is particularly advantageous when performing a procedure on the wall of a passage, such as the esophagus, stomach or duodenum, for example. A wall of such passage can be sucked via vacuum or pulled by mechanical means into contact with the access device 800 to facilitate a procedure. When in contact with the access device 800 , steps including cutting, stapling and removal of tissue can be carried out. Vacuum can be applied in a number of ways, in accordance with the invention. Preferably, suction is applied directly through the access device 800 . A single pump can be provided, which is adapted and configured to both provide insufflation pressure to the access device 800 and to provide suction to the access device 800 . Use of a single pump allows for more streamlined surgical equipment and controls—reducing unnecessary clutter in the operating room and reducing cost by obviating a second pumping device. Naturally, if desired, separate pumps can be connected to the access device 800 , and selectively activated in order to switch between insufflation and suction. Alternatively still, a secondary suction device can be utilized—either inserted through a central internal lumen of the access device 800 or external thereto.
[0091] Additionally, the access device 800 can be flexible to allow manipulation through the anatomy of a patient, as seen in FIG. 9 . Moreover, the overall shape of the access device 800 can be preformed, as illustrated, so that the device has a tendency to revert to a shape that facilitates insertion and/or comfortable retention in the patient. The entire access device 800 , or a portion thereof, such as the distal end portion, can be steerable to aid insertion of the access device and procedures performed therewith.
[0092] A fluid seal can be provided in the proximal end portion 815 of the access device 800 , or additionally or alternatively at one or more other locations throughout the length of the access device 800 .
[0093] FIG. 10 is a side view of another embodiment of an access device 1000 constructed in accordance with the invention. The access device 1000 is similar to that of FIGS. 8 and 9 , but includes at its distal end 1070 , a side-grasping feature with undulating grasping elements 1071 . Alternatively, the side-grasping elements can be straight grasping elements 1171 as illustrated in FIG. 11 .
[0094] FIG. 12 illustrates the side grasping elements in closed, open and grasping positions, respectively. The grasping elements can be used to engage a wall of a passage, internal organ or other element, for example, to move the wall or steady the wall for another step, such as a puncture or incision. Actuation can be effected in any suitable manner. In accordance with one aspect of the invention, tension within the wall 1079 of the distal end 1071 is adjusted to effect closure or opening of the grasping elements 1071 . Such tension can be adjusted by way of, for example, shape-memory alloy ribs 1278 arranged within the wall of the distal end 1070 . Such ribs 1278 can have a first shape at normal room and/or body temperatures. The ribs 1278 can be electrically connected to a power source, such that when voltage is applied, resistive heating of the ribs 1278 effects a change in shape of the ribs to a second shape. Depending on the desired implementation, the normal state of the ribs can be open or closed.
[0095] Alternatively, the grasping elements 1071 can be actuated by providing one or more control elements (e.g., wires) terminating in a plurality of ends that terminate in or near the grasping elements 1071 , within the wall 1079 of the distal end 1071 . Accordingly, applying compression to such control cables will cause the grasping elements to close.
[0096] FIGS. 13 a and 13 b illustrate a distal end portion 1370 of a surgical access device constructed in accordance with the invention having a steerable distal end portion 1370 . Control elements 1310 , such as wires are provided within or adjacent the wall 1379 of the access device. The control elements 1310 are anchored in one or more locations 1320 to the wall of the access device. Although illustrated within the lumen 1340 of the access device, the control elements 1310 are provided with in the wall 1379 . Tension applied to one or more control elements 1310 effects a change in curvature of the distal end portion 1370 . In conjunction with applied rotation to the entire access device by a surgeon, navigation through the patient's anatomy is facilitated.
[0097] The present invention also relates to surgical procedures performed utilizing devices set forth herein. FIG. 14 illustrates an endoluminal and transluminal access device 1400 being used in a trans-gastric cholecystectomy (removal of gall bladder). As illustrated, the access device 1400 is inserted by way of the esophagus 1490 of a patient, into the stomach 1420 of the patient. Access is made by way of an incision through the wall of the stomach 1420 , into the abdominal cavity 1410 . An incision is made in any suitable manner, but preferably by an endoscopic cutting implement placed through the lumen of the access device 1400 , which induces coagulation, such as by electrocautery or ultrasonic vibrations.
[0098] Either preceding or following this step, a second access device 1450 is inserted through the navel or umbilicus 1411 of the patient. This mode of external access obscures any scarring that may occur. Naturally, the trans-esophageal entry of the access device 1400 carries no risk of visible scarring.
[0099] Prior to or upon entering the abdominal cavity 1410 , the cavity may be insufflated by way of the access device 1400 . Alternatively, the abdominal cavity can be insufflated by way of the second access device 1450 and/or still another element, such as a veress needle.
[0100] In the illustrated embodiment, a flexible endoscope 1405 is inserted through the transluminal access device 1400 . Any number of additional instruments that can physically fit through the lumen of the access device 1400 can be inserted therethrough, and the fluid seal formed by the access device 1400 will maintain a seal around the instruments. An entire cholecystectomy can be performed via this access device 1400 . At present it is more effective to close the incision made in the stomach wall by accessing the stomach 1420 from the outside, and for this reason, the second access device 1450 is used with a surgical stapler 1457 to close the incision made in the stomach. Therefore, the second access device 1450 is also used during the cholecystectomy. Through the channel of the second access device, an endoscope, grasper shears or any other necessary instrument can be inserted.
[0101] Upon severing the cystic duct, vascular tissue and connecting tissue, the gall bladder can be removed by either the transluminal access device 1400 or the second access device 1450 . If necessary, the gall bladder can be separated into smaller pieces for removal, as by a morcellator or the like.
[0102] In accordance with one embodiment of the invention, a method for performing a cholecystectomy includes the steps of:
Inserting a first access device in accordance with the invention through the esophagus of a patient and into the stomach; Penetrating the stomach wall and extending the first access device through the stomach wall; Inserting a second access device through the umbilicus of the patient; Inserting an endoscope through the first access device; Retracting the gallbladder with the at least one grasper; Exposing the cystic duct and cystic artery; Applying at least two clips on each of the cystic duct and artery; Transecting each of the cystic duct and artery with surgical scissors or another suitable instrument; Dissecting and removing the gallbladder from the liver bed; and Removing the gallbladder.
In accordance with this method, the second access device can have, for example, a diameter of 21 mm. The endoscope can be flexible and can have a diameter, for example, of about 10 mm. The cystic duct and artery can be exposed with dissectors, such as 5 mm dissectors. One or more graspers can be inserted through the second access device to manipulate the gallbladder. Clips can be applied with a 5 mm clip applier. The scissors can be 5 mm scissors, for example. Dissecting and removing the gallbladder can be accomplished with shears, such as ultrasonic shears. The gallbladder can be removed through the second access device. Alternatively, the gallbladder can be removed from the first access device, and can be removed from either access device whole or morcellated.
[0113] FIG. 15 illustrates one embodiment of a distal end portion of an access device in accordance with the invention. The access device of FIG. 15 includes a frangible tip 1510 that maintains sterility of the lumen of the access device during insertion through a cavity, such as the gastrointestinal tract, until a point when the tip is ruptured or intentionally cut. The frangible tip may have any shape, and may include lines of weakness 1513 , such as regions of decreased material thickness or score lines.
[0114] Having a sealed tip, instruments, such as endoscopes inserted through the access device benefit from a sterile path essentially the entire way to the surgical site. This reduces or eliminates any problems in sterilizing equipment, such as endoscopes with working channels. Advantageously, utilizing access devices in accordance with the invention eliminates the need for using endoscopes with integral working channels, because instruments can be inserted in parallel with the endoscope while maintaining a seal around all instruments. Even though sterility using access devices in accordance with the invention is enhanced as compared with simply inserting such instruments through a particular bodily opening, by including a sealed tip, sterility of a working channel is further enhanced.
[0115] Other types of tips or seals can be provided at the distal end of access devices in accordance with the invention, such as a removable cap, a sheath capable of being remotely withdrawn proximally, away from the distal tip or hinged hemispheric shutters, that function similarly to an eyelid and close over the distal opening of the lumen.
[0116] In accordance with the invention, transluminal access can be made through the rectum, colon, stomach (as illustrated in FIG. 14 ), esophagus or vagina, for example. Instruments that can be inserted through access devices in accordance with the invention include, but are not limited to dissectors, clip appliers, shears, automatic suturing devices, endoscopes, graspers, morcellators, suction tubes, electrocautery or coagulation devices, specimen retrieval tools, surgical staplers, as well as specialized tools for specific procedures.
[0117] Surgical procedures which may be performed with devices set forth herein, and in accordance with methods set forth herein include: cholecystectomy, appendectomy bariatric procedures, such as adjustable gastric banding (lap band), gastrectomy, such as sleeve gastrectomy, any of a variety of procedures to alleviate gastroesophageal reflux disease (GERD), tubal ligation, oophorectomy, nephrectomy, prostatectomy, colorectal procedures, hernia repair, gynecological resection, resection of the spleen, and splenectomy.
[0118] Such procedures, as well as others applicable in accordance with the invention, can mitigate damage caused by or aide recovery from such conditions as obesity, diabetes, gastroesophageal reflux disease (GERD), gallstones, appendicitis, colon disease, ideopathic thrombocytopenia purpura (ITP) and other diseases.
[0119] It should be noted that features described and/or illustrated in connection with one embodiment described herein can be combined with or substituted for other features described and/or illustrated in connection with any other embodiment set forth herein. Although a feature may be described in one particular embodiment, it should be understood that such a feature is not limited to being provided precisely in that manner or only in that embodiment.
[0120] The access devices and related methods of the present invention, as described above and shown in the drawings, provide, among other things, access devices with superior properties including the capability to provide substantially frictionless sealing of instruments passing therethrough. Endoluminal and transluminal procedures advantageously require less time for recovery than traditional procedures, among other benefits. It will be apparent to those skilled in the art that various modifications and variations can be made in the device and method of the present invention without departing from the spirit or scope of the invention. | An access device adapted and configured to be inserted through a natural biological orifice, and related surgical methods are provided. The access device includes a body, a nozzle means and means for delivering a pressurized flow of fluid to the nozzle means. The body is configured and dimensioned to be inserted through a natural bodily orifice and has proximal and distal end portions and defines at least one lumen therethrough to accommodate passage of one or more surgical instruments. The nozzle means is operatively associated with the body for directing pressurized fluid into the lumen to develop a pressure differential in an area within a region within the lumen to form a fluid seal around the one or more surgical instruments passing therethrough. | 55,474 |
[0001] This invention relates to improved training ammunition and to a method of modifying a gun to fire the training ammunition.
BACKGROUND OF THE INVENTION
[0002] Low powered training cartridges are known, and examples of such cartridges are disclosed in PCTGB98/00620, PCT/GB99/02859, PCT/GB99/02556, GB 9819928.4 and U.S. Pat. No. 5,492,063. Training cartridges are characterised in that they impart much less energy to a projectile than a live (“killing”) round. Thus, whereas a live round may impart 800 ft/lbs of energy to a bullet and a shotgun may impart as much as 1000 ft/lbs of energy to the shot, training cartridges are much less energetic. For example, the energy imparted to a projectile by a training cartridge is typically less than 5 ft/lbs and more usually less than 4 ft/lbs. The term “training cartridges” as used herein therefore refers to such low energy cartridges, unless the context indicates otherwise.
[0003] The aforementioned training cartridges typically contain only a primer and do not contain a conventional amount of propellant. Consequently, they must be carefully designed to ensure that there is sufficient energy both to recycle a weapon and eject a projectile such as a bullet. Many training cartridges, see for example the cartridges disclosed in the patent documents supra, are of the expanding type in which the body of the cartridge comprises a “piston and cylinder” arrangement. With such cartridges, part of the energy of the primer is used to force the piston and cylinder apart (i.e. expand the cartridge) and drive the rear end of the cartridge back to recycle the weapon, and part of the energy is used to discharge the projectile from the front end of the cartridge. Careful control of gas flow within the cartridge is required in order to make sure that the projectile is discharged at a consistent and appropriate velocity and that the weapon is recycled at every firing.
[0004] All (so far as the Applicants are aware) current training ammunition, and most live military ammunition, is of the centre fire variety. Exceptions are certain 0.22″ (5.56 mm) rounds generally used in target shooting (and occasionally in military training) which are of the rimfire type. Live cartridges of the centre fire variety generally have a primer carried in a cup or “can” set into the rear end of the cartridge. However, with live rounds of the rim fire type (for example the 0.22″ rounds referred to above) the primer is not carried in a cup or can but is held in the hollow rim of the cartridge case itself.
[0005] FIG. 1 shows a sectional elevation through the primer for a centre fire cartridge of the type typically used in live military ammunition. The primer comprises a can 2 formed from, for example, nickel plated brass, and containing a suitable pyrotechnic primer material 4 . The can is held in a recess in the centre of the rear surface (not shown) of the cartridge. An anvil 6 is set into the front of the can 2 to close the can and retain the primer in place. As the anvil is inserted into the can, the protruding central part 6 a of the anvil greatly compresses the primer to create a compressed region 4 a which is highly sensitive to shock. The region 4 a which is sensitive to shock has an approximate width I, and this represents the impact area for the firing pin of a centre fire weapon. Thus, a centre fire firing pin will impact against the impact area and further compress the primer between the wall of the can and the anvil thereby detonating the primer. However, it will be appreciated that the firing pin of a rimfire weapon would impact against the can outside the impact area I and hence would not detonate the primer.
[0006] Although training cartridges that are constructed to provide consistent low energy discharge of bullets are generally safe per se, safety problems can arise when live killing cartridges are inadvertently mixed with or substituted for low powered training cartridges. As stated above, all of the known existing training cartridges use centre fire type of primers which are very similar and often identical to the types of primers used in the equivalent live killing cartridge for a particular gun type. Attempts have been made to prevent confusion between the two types of cartridge by modifying the gun so that it will not fire the cartridge type usually fired from the gun, but will only fire a training cartridge. Unfortunately, this safety feature can sometimes be bypassed by using a different live cartridge type which, when chambered, fits the gun, or by using damaged live cartridges. In such circumstances, firing live cartridges rather than training cartridges can result in serious injury or death.
[0007] It is an object of the present invention to provide a solution to the aforementioned problems by preventing live killing cartridges from being fired inadvertently in place of training cartridges.
SUMMARY OF THE INVENTION
[0008] The present invention makes use of peripheral fire primers in the training cartridges, and a gun modification which allows the firing pin of the gun to strike the periphery (i.e. rim) of the primer which fires a cartridge. If any type of centre fire cartridge is fitted into the gun whilst the conversion is fitted, the firing pin cannot set off the centre fire primer as the point of impact of the firing pin is beyond the sensitive part of the centre fire primer. Thus, the present invention prevents the standard centre fire military ammunition from being fired inadvertently instead of low velocity training ammunition.
[0009] Accordingly, in one embodiment the invention provides a training cartridge having a peripheral fire primer.
[0010] The primer typically takes the form of a cup or “can” which is set into the rear end of the cartridge. The cup typically has a hollow peripheral rim in which the primer material is located, the primer material being in a compressed state and highly sensitive to shock. The primer material can thus be detonated when the peripheral rim of the can is impacted by a firing pin. This arrangement is in contrast to conventional live rimfire cartridges (i.e. 0.22″ calibre) in which the primer material is located in the rim of the cartridge itself rather than the peripheral rim of a cup set into the rear of the cartridge.
[0011] The training cartridges of the invention are preferably expandable upon firing, expansion of the cartridge serving to urge a rear surface of the cartridge rearwardly against a breech block of a gun to initiate recycling of the gun.
[0012] For example, in one embodiment, there is provided an expandable training cartridge configured to enable a projectile (e.g. a bullet) to be mounted in or on a nose portion thereof, a gas passage though the nose portion providing communication between the cartridge interior and the projectile. The cartridge has valve means for controlling propellant gas flow through the gas passage to the projectile, and a movable member which upon firing is propelled rearwardly from the cartridge against a breech block of the firearm by the pressure of propellant gas within the cartridge so as to recycle the firearm. The valve means is preferably arranged to close in order to stop or substantially reduce the flow of propellant gas through the said gas passage after the projectile has been fired from the cartridge, thereby to facilitate rearwards propulsion of the movable member.
[0013] The precise nature of the training cartridge is not critical but, for example, the training cartridge can be of the general type described in any one of PCT98/00620, PCT/GB99/02859, PCT/GB99/02556 and GB 9819928.4, but with an appropriately modified primer. The diameter of the training cartridge is generally greater than the diameter (usually approximately 0.375″ (9 mm)) of live 0.22″ (5.65 mm) rounds although the training cartridge may carry a 0.22″ (5.65 mm) bullet or projectile, and may be provided with a primer of a diameter typically associated with a 0.22″ (5.65 mm) round.
[0014] In general, the primer is the only pyrotechnic material in the cartridge; i.e. there is no propellant other than the primer. The primer is such that the cartridge produces an energy of less than 4 ft/lbs, more preferably less than 3 ft/lbs, for example less than 2.5 ft/lbs, and most preferably 2 ft/lbs or less.
[0015] In another aspect, the invention provides a method of modifying a gun to prevent it from firing live ammunition but permit the firing of a rimfire primer training cartridge, which method comprises (i) replacing a centre fire firing pin with a rim fire firing pin and/or (ii) replacing a barrel of the gun such that a centre firing pin is misaligned for centre firing of the cartridge but is aligned for rim firing of the cartridge, but excluding the modification of a gun capable of firing live 0.22″ (5.56 mm) cartridges by replacing the centre firing pin with a rimfire firing pin.
[0016] In a further aspect, the invention provides a method of modifying a gun to prevent it from firing live ammunition but permit the firing of a rimfire primer training cartridge other than a 0.22″ (5.56 mm) calibre cartridge, which method comprises replacing a centre fire firing pin with a rim fire firing pin.
[0017] In another aspect, the invention provides the combination of a training cartridge having a rimfire primer and a gun that has been modified to fire a rimfire primer-containing training cartridge.
[0018] In a further aspect, the invention provides a peripheral fire primer for use in a cartridge as hereinbefore defined, the primer comprising a cup for setting into the rear end of the cartridge, the cup having a hollow peripheral rim containing compressed primer material.
[0019] In a further aspect, the invention provides a method of modifying a gun to prevent it from firing live ammunition but permit the firing of a rimfire primer training cartridge, which method comprises selecting a gun having a centre fire firing pin and replacing the barrel of the gun with a barrel in which the breech is offset such that the centre fire firing pin can impact against and fire the rimfire primer training cartridge but not a centre fire cartridge.
[0020] In a still further aspect, the invention provides a gun having a centre fire firing pin and a barrel in which the breech is offset such that the centre fire firing pin can impact against and fire a rimfire primer cartridge but not a centre fire primer cartridge.
[0021] Which modification is selected will depend upon the nature of the gun. For pistols or other guns which have sliding or removable barrels, a barrel conversion may offer the simplest means of modifying the weapon. On the other hand, if the barrel is fixed, and the breech block is slidable, as with most rifles and machine guns, then the simplest conversion is to modify or change the firing pin to a rimfire firing pin.
[0022] In the case of a barrel modification, the centre fire firing pin of a gun prior to modification is arranged such that it strikes at a location which is central with regard to the bore or breech of the barrel, i.e. the centre line of the firing pin is coincident with the centre line of the barrel. After modification in accordance with the invention, the centre line of the bore of the barrel is offset relative to the centre line of the firing pin. This means that a firing mechanism incorporating a centre fire firing pin will not impact against the sensitive central area of a centre fire cartridge but will instead impact against the rim. Thus, the modification to the barrel allows rimfire training cartridges to be fired but prevents the corresponding centre fire live ammunition from being detonated.
[0023] A further advantage of the offset of the bore is that the bore can be inclined with respect to the axis of the barrel thereby providing a means of correcting the trajectory of the low velocity projectile without the user of the gun needing to make any changes to his normal sighting.
[0024] In cases where it is more appropriate to modify the firing pin, rather than the barrel, the centre line of the firing pin may still be aligned with the centre line of the bore of the barrel but the modified pin typically has a laterally extended leading end portion, the laterally extended leading end portion having a leading surface profiled such that it impacts against the rim of a rimfire primer but not against the centre of a centre fire primer. The laterally extended leading end portion can be laterally extended in one plane or in two planes.
[0025] For example, when it is extended in one plane, the end of the pin can take the form of a flat spade-like structure that slides in a slot cut into the breech block. The flat spade-like structure may have one or two (and preferably two for balance) forwardly oriented projections at the edges thereof for impacting against the rim of a rimfire primer but not the central impact area of a centre fire primer.
[0026] When the leading end portion of the modified firing pin is laterally extended in two planes, it can, for example, have a cylindrical form. In such a case, the leading surface can have one or more (preferably more than one) discrete projections protruding forwardly therefrom, or the leading surface can be provided with a forwardly projecting annular rim having a diameter such that it impacts against the impact area of a rimfire primer but not the impact area of a centre fire primer.
[0027] In order to reduce still further the possibility of a centre fire primer being detonated by the modified pin (for example as a consequence of a piece of particulate matter or debris between the firing pin and cartridge), the region of the leading surface between or inwardly of the projection(s) can be cut away, at least over the area that would overlap with the impact area of a centre fire primer.
BRIEF DESCRIPTION OF THE DRAWING
[0028] The invention will now be illustrated, but not limited, by reference to the particular embodiments shown in the accompanying schematic drawings, FIGS. 1 to 9 .
[0029] FIG. 1 is a side sectional elevation through a centre fire primer.
[0030] FIG. 2 is a side sectional elevation through a rimfire primer.
[0031] FIG. 3 is a schematic elevation of a conventional arrangement of a centre fire primer in a gun fitted with a centre fire firing pin.
[0032] FIG. 4 is a schematic elevation of a conventional arrangement of a rimfire primer in a gun fitted with a rimfire firing pin.
[0033] FIG. 5 illustrates schematically part of a standard centre fire pistol having a barrel containing a centre fire primer cartridge.
[0034] FIG. 6 illustrates schematically the centre fire gun of FIG. 5 but wherein the barrel has been replaced by a modified barrel.
[0035] FIG. 7 illustrates a standard rifle fitted with a centre fire firing pin and containing a centre fire primer cartridge.
[0036] FIG. 8 illustrates the rifle of FIG. 7 but with a modified firing pin.
[0037] FIG. 9 illustrates an explosive blank cartridge having a peripheral fire primer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] A peripheral fire primer for use in a cartridge according to the invention is shown in FIG. 2 and comprises a can 102 , the closed end of which is formed to provide a hollow peripheral rim area 103 . A pyrotechnic primer composition 104 is placed in the can and the can is spun thereby forcing the pyrotechnic material into the hollow peripheral rim area 103 . With the primer of FIG. 2 , the impact area I′ is annular in shape and extends around the peripheral rim of the primer. As can be seen from FIGS. 1 and 2 together, for cartridges of the same calibre, there will be a dead zone S between the impact region I of a centre fire primer, and the impact region I′ of a peripheral fire region in which any impact will not detonate the primer. When a cartridge containing the primer of FIG. 2 is placed in a weapon having an appropriately configured and aligned firing pin and the weapon is fired, the firing pin strikes impact area I′ and compresses the pyrotechnic composition between the two walls 103 a and 103 b of the hollow rim region 103 , the shock imparted to the pyrotechnic composition causing it to detonate.
[0039] Referring now to FIG. 3 , there is shown a conventional arrangement of a gun 200 having a centre firing pin 202 , a training cartridge 204 being inserted into the breech thereof. In this case, in accordance with conventional practice, the cartridge 204 has a centre fire primer 206 fitted into the end thereof, the primer being of the type shown in FIG. 1 . It will be noticed that the centre line L 1 of the firing pin 202 is coincident with the centre line L 2 of the barrel of the gun.
[0040] In FIG. 4 , there is shown an arrangement in which a gun 300 has been modified to provide it with a peripheral fire firing pin 302 which is offset from the centre line of the barrel so that it can fire a training cartridge 304 having a peripheral fire primer 306 of the type shown in FIG. 2 .
[0041] As indicated above, a problem with centre fire training cartridges is that on occasions training cartridges and live killing ammunition can become confused. In order to avoid this problem the invention provides a training cartridge which is detonated by impact on the peripheral rim of the primer, and makes use of a gun which is specially modified to allow use of the peripheral fire primer.
[0042] FIG. 5 shows a standard centre fire pistol into which has been inserted a cartridge having a centre fire primer. The arrangement shown in this Figure corresponds to FIG. 3 except that the barrel of the pistol is removable. FIG. 6 shows a modification of the gun shown in FIG. 5 . As demonstrated in FIG. 6 , the gun is still provided with a centre fire firing pin 410 which, with a normal gun barrel, would allow the firing of centre fire cartridges. However, in order to prevent centre fire cartridges from being fired, the gun is converted by replacing the normal gun barrel with a gun barrel 412 in which the bore 414 is offset. As can be seen from FIG. 6 , the bore 414 is inclined at an angle α with regard to the axis 16 of the barrel. The centre line of the bore 414 is also inclined with respect to the centre line of the firing pin 410 .
[0043] If a training cartridge having a peripheral fire primer is inserted into the breech, the relative geometry of the gun barrel and firing pin are such that the firing pin can fire the cartridge. On the other hand, if a centre fire cartridge (for example a live killing cartridge) is inserted into the gun barrel, the firing pin 410 will fail to strike the centre fire impact area 318 , and hence the cartridge will not detonate. Thus, the modification of the invention greatly enhances the safety in that it prevents live killing ammunition from being inadvertently mixed with training ammunition.
[0044] A further advantage of the arrangement shown in FIG. 6 is that it can enable training ammunition to be used more accurately. One of the problems with training ammunition is that the low velocity means that the bullet will often fall away before it reaches a target, and consequently there will be a tendency for the user to compensate for this by aiming above the target. Thus shooting at targets using low velocity ammunition can be less realistic than is desirable. With the gun barrel arrangement shown in FIG. 6 , the user of the gun can fix his sights on the target in the normal way, and the angle of the bore, rather than the angle of the barrel, provides the necessary correction to enable the projectile to reach its target. Thus, the range of the training ammunition is much closer to the range of normal live killing ammunition.
[0045] The modification shown in FIG. 6 is particularly suited to pistols since in many cases the barrel of a pistol can be removed fairly easily. However, the barrels of rifles are typically fixed and hence a barrel modification of the type shown in FIG. 6 would involve somewhat more complex alterations to the gun and would not be a practical proposition.
[0046] Therefore, with rifles and machine guns and other firearms with fixed non-sliding barrels, it is easier to modify the firing pin and this is demonstrated in FIGS. 7 and 8 .
[0047] FIG. 7 shows a part of a conventional rifle equipped with a centre firing pin and having a centre fire training bullet inserted in the breech thereof. FIG. 8 illustrates the same rifle but wherein the firing pin has been modified. Thus the firing pin is no longer pin-shaped but instead has a leading end which is extended laterally to give a spade-like shape. The leading surface of the leading end has forwardly oriented projections 512 at either edge thereof, the projections being aligned with the impact region 514 of the peripheral fire primer 513 of the cartridge. The central part 516 of the leading end is recessed, the width of the recess being at least as great as the width of the impact area of the centre fire primer 318 . In use, when the weapon is fired, the projections 512 on the edges of the leading end of the modified firing pin impact against the sensitive impact region of the peripheral fire primer to detonate the primer. However, if a cartridge (e.g. a live killing round) having a centre fire primer is inadvertently inserted into the gun, it will not be detonated. The safety of the modified firing pin arrangement shown in FIG. 8 is further enhanced by virtue of the recessed central region 516 which ensures that centre fire primers cannot accidentally be detonated as a result of the presence of particles of debris between the firing pin and cartridge.
[0048] The modified firing pin of FIG. 8 can be fitted, for example, by shortening an existing firing pin, cutting a thread on the end thereof, and fixing the threaded end into a suitably profiled end piece. The circular channel or opening in which the firing pin normally slides is machined out to form a slot to accommodate the spade-like shape of the end piece.
[0049] FIG. 9 illustrates an explosive blank cartridge that can be fired in the modified gun of FIG. 8 . The blank cartridge comprises a casing 602 closed at its nose 604 and containing an explosive material 606 . The rear end of the blank cartridge has a flange 608 to enable the spent cartridge to be extracted from the breech in the usual manner. Thus far, the blank cartridge is of conventional construction. However, the cartridge differs from conventional blank cartridges in that the primer 610 set into the centre of the rear of the cartridge is a peripheral fire primer. The primer 610 , which can be of the form shown in FIG. 2 or an appropriate modification thereof, comprises a cup or can 612 having a hollow peripheral rim 614 containing compressed primer material. In use, the off centre firing pin 616 of the gun impacts against the peripheral rim 614 thereby detonating the primer material which in turn detonates the explosive material 606 . Expanding gases created by the detonation of the primer and explosive material burst through the nose 604 in the usual manner to give a realistic bang.
[0050] The foregoing examples illustrate merely some of the ways in which the invention can be put into effect, and it will readily be apparent that numerous modifications and alterations can be made to the arrangements shown in the accompanying drawings without departing from the principles underlying the invention. All such modifications and alterations are intended to be embraced by this application. | The invention provides a training cartridge having a peripheral fire primer and a gun modified to fire the cartridge. The combination of modified gun and peripheral fire cartridge avoids the potentially adverse consequences that could arise if live ammunition and training ammunition were to become inadvertently confused or mixed up by preventing the firing of live center fire ammunition. | 24,502 |
TECHNICAL FIELD
[0001] The present disclosure is directed to methods and systems to evaluate resource allocation costs of a data center with respect to resource allocation costs of a cloud computing industry.
BACKGROUND
[0002] In recent years, enterprises have shifted much of their computing needs from enterprise owned and operated computer systems to cloud computing providers. Cloud computing providers charge enterprises to store and run their applications in a cloud-computing facility and allow enterprises to purchase other computing services in much the same way utility customers purchase a service from a public utility. A typical cloud-computing facility is composed of numerous racks of servers, switches, routers, and mass data-storage devices interconnected by local-area networks, wide-area networks, and wireless communications that may be consolidated into a single data center or distributed geographically over a number of data centers. Enterprises typically run their applications in a cloud-computing facility as virtual machines (“VMs”) that are consolidated into a virtual data center (“VDC”) also called a software defined data center (“SDDC”). A VDC recreates the architecture and functionality of a physical data center for running an enterprise's applications. Because the vast numbers of VDCs and dynamic nature of VDCs running in a typical cloud-computing facility, VDC's introduce management challenges to information technology (“IT”) managers. Many IT managers lack the insight needed to objectively identify computational resource shortages and where future investment in computational resources should be made.
SUMMARY
[0003] This disclosure is directed to methods and systems to evaluate resource allocation costs of a data center. Methods and systems compute resource allocation costs of a cloud computing industry to obtain industry benchmarks that are compared with the resource allocation costs of the data center. The comparisons enable IT managers to objectively identify computational resource shortages, resource over investments, and where future investment in computational resources should be made for the data center.
DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 shows a general architectural diagram for various types of computers.
[0005] FIG. 2 shows an Internet-connected distributed computer system.
[0006] FIG. 3 shows cloud computing.
[0007] FIG. 4 shows generalized hardware and software components of a general-purpose computer system.
[0008] FIGS. 5A-5B show two types of virtual machine and virtual-machine execution environments.
[0009] FIG. 6 shows an example of an open virtualization format package.
[0010] FIG. 7 shows virtual data centers provided as an abstraction of underlying physical-data-center hardware components.
[0011] FIG. 8 shows virtual-machine components of a virtual-data-center management server and physical servers of a physical data center.
[0012] FIG. 9 shows a cloud-director level of abstraction.
[0013] FIG. 10 shows virtual-cloud-connector nodes.
[0014] FIG. 11 shows an example of a system to collect cost information from physical data centers that combined represents a cloud computing industry.
[0015] FIGS. 12A-12C show examples of preprocessing the resource utilization data produced by physical data centers.
[0016] FIG. 13 shows a data center and associated resource costs.
[0017] FIG. 14 shows a control-flow diagram of a method to evaluate data center resource allocation costs of a data center.
[0018] FIG. 15 shows a control-flow diagram of the method “compute resource allocation cost of industry benchmarks” called in FIG. 14 .
[0019] FIG. 16 shows a control-flow diagram of the method “compute data center resource allocation costs” called in FIG. 14 .
[0020] FIGS. 17A-17B show a control-flow diagram of the method “compute resource allocation gaps” called in FIG. 14 .
[0021] FIG. 18 shows a control-flow diagram of the method “compute monetary impact of gaps” called in FIG. 14 .
DETAILED DESCRIPTION
[0022] A general description of physical data centers, hardware, virtualization, virtual machines, and virtual data centers are provided in a first subsection. Computational methods and system to evaluate resource allocation costs of a data center with respect to resource allocation cost of a cloud computing industry are provided in a second subsection.
Computer Hardware, Complex Computational Systems, and Virtualization
[0023] The term “abstraction” is not, in any way, intended to mean or suggest an abstract idea or concept. Computational abstractions are tangible, physical interfaces that are implemented, ultimately, using physical computer hardware, data-storage devices, and communications systems. Instead, the term “abstraction” refers, in the current discussion, to a logical level of functionality encapsulated within one or more concrete, tangible, physically-implemented computer systems with defined interfaces through which electronically-encoded data is exchanged, process execution launched, and electronic services are provided. Interfaces may include graphical and textual data displayed on physical display devices as well as computer programs and routines that control physical computer processors to carry out various tasks and operations and that are invoked through electronically implemented application programming interfaces (“APIs”) and other electronically implemented interfaces. There is a tendency among those unfamiliar with modern technology and science to misinterpret the terms “abstract” and “abstraction,” when used to describe certain aspects of modern computing. For example, one frequently encounters assertions that, because a computational system is described in terms of abstractions, functional layers, and interfaces, the computational system is somehow different from a physical machine or device. Such allegations are unfounded. One only needs to disconnect a computer system or group of computer systems from their respective power supplies to appreciate the physical, machine nature of complex computer technologies. One also frequently encounters statements that characterize a computational technology as being “only software,” and thus not a machine or device. Software is essentially a sequence of encoded symbols, such as a printout of a computer program or digitally encoded computer instructions sequentially stored in a file on an optical disk or within an electromechanical mass-storage device. Software alone can do nothing. It is only when encoded computer instructions are loaded into an electronic memory within a computer system and executed on a physical processor that so-called “software implemented” functionality is provided. The digitally encoded computer instructions are an essential and physical control component of processor-controlled machines and devices, no less essential and physical than a cam-shaft control system in an internal-combustion engine. Multi-cloud aggregations, cloud-computing services, virtual-machine containers and VMs, communications interfaces, and many of the other topics discussed below are tangible, physical components of physical, electro-optical-mechanical computer systems.
[0024] FIG. 1 shows a general architectural diagram for various types of computers. Computers that receive, process, and store event messages may be described by the general architectural diagram shown in FIG. 1 , for example. The computer system contains one or multiple central processing units (“CPUs”) 102 - 105 , one or more electronic memories 108 interconnected with the CPUs by a CPU/memory-subsystem bus 110 or multiple busses, a first bridge 112 that interconnects the CPU/memory-subsystem bus 110 with additional busses 114 and 116 , or other types of high-speed interconnection media, including multiple, high-speed serial interconnects. These busses or serial interconnections, in turn, connect the CPUs and memory with specialized processors, such as a graphics processor 118 , and with one or more additional bridges 120 , which are interconnected with high-speed serial links or with multiple controllers 122 - 127 , such as controller 127 , that provide access to various different types of mass-storage devices 128 , electronic displays, input devices, and other such components, subcomponents, and computational devices. It should be noted that computer-readable data-storage devices include optical and electromagnetic disks, electronic memories, and other physical data-storage devices. Those familiar with modern science and technology appreciate that electromagnetic radiation and propagating signals do not store data for subsequent retrieval, and can transiently “store” only a byte or less of information per mile, far less information than needed to encode even the simplest of routines.
[0025] Of course, there are many different types of computer-system architectures that differ from one another in the number of different memories, including different types of hierarchical cache memories, the number of processors and the connectivity of the processors with other system components, the number of internal communications busses and serial links, and in many other ways. However, computer systems generally execute stored programs by fetching instructions from memory and executing the instructions in one or more processors. Computer systems include general-purpose computer systems, such as personal computers (“PCs”), various types of servers and workstations, and higher-end mainframe computers, but may also include a plethora of various types of special-purpose computing devices, including data-storage systems, communications routers, network nodes, tablet computers, and mobile telephones.
[0026] FIG. 2 shows an Internet-connected distributed computer system. As communications and networking technologies have evolved in capability and accessibility, and as the computational bandwidths, data-storage capacities, and other capabilities and capacities of various types of computer systems have steadily and rapidly increased, much of modern computing now generally involves large distributed systems and computers interconnected by local networks, wide-area networks, wireless communications, and the Internet. FIG. 2 shows a typical distributed system in which a large number of PCs 202 - 205 , a high-end distributed mainframe system 210 with a large data-storage system 212 , and a large computer center 214 with large numbers of rack-mounted servers or blade servers all interconnected through various communications and networking systems that together comprise the Internet 216 . Such distributed computing systems provide diverse arrays of functionalities. For example, a PC user may access hundreds of millions of different web sites provided by hundreds of thousands of different web servers throughout the world and may access high-computational-bandwidth computing services from remote computer facilities for running complex computational tasks.
[0027] Until recently, computational services were generally provided by computer systems and data centers purchased, configured, managed, and maintained by service-provider organizations. For example, an e-commerce retailer generally purchased, configured, managed, and maintained a data center including numerous web servers, back-end computer systems, and data-storage systems for serving web pages to remote customers, receiving orders through the web-page interface, processing the orders, tracking completed orders, and other myriad different tasks associated with an e-commerce enterprise.
[0028] FIG. 3 shows cloud computing. In the recently developed cloud-computing paradigm, computing cycles and data-storage facilities are provided to organizations and individuals by cloud-computing providers. In addition, larger organizations may elect to establish private cloud-computing facilities in addition to, or instead of, subscribing to computing services provided by public cloud-computing service providers. In FIG. 3 , a system administrator for an organization, using a PC 302 , accesses the organization's private cloud 304 through a local network 306 and private-cloud interface 308 and also accesses, through the Internet 310 , a public cloud 312 through a public-cloud services interface 314 . The administrator can, in either the case of the private cloud 304 or public cloud 312 , configure virtual computer systems and even entire virtual data centers and launch execution of application programs on the virtual computer systems and virtual data centers in order to carry out any of many different types of computational tasks. As one example, a small organization may configure and run a virtual data center within a public cloud that executes web servers to provide an e-commerce interface through the public cloud to remote customers of the organization, such as a user viewing the organization's e-commerce web pages on a remote user system 316 .
[0029] Cloud-computing facilities are intended to provide computational bandwidth and data-storage services much as utility companies provide electrical power and water to consumers. Cloud computing provides enormous advantages to small organizations without the devices to purchase, manage, and maintain in-house data centers. Such organizations can dynamically add and delete virtual computer systems from their virtual data centers within public clouds in order to track computational-bandwidth and data-storage needs, rather than purchasing sufficient computer systems within a physical data center to handle peak computational-bandwidth and data-storage demands. Moreover, small organizations can completely avoid the overhead of maintaining and managing physical computer systems, including hiring and periodically retraining information-technology specialists and continuously paying for operating-system and database-management-system upgrades. Furthermore, cloud-computing interfaces allow for easy and straightforward configuration of virtual computing facilities, flexibility in the types of applications and operating systems that can be configured, and other functionalities that are useful even for owners and administrators of private cloud-computing facilities used by a single organization.
[0030] FIG. 4 shows generalized hardware and software components of a general-purpose computer system, such as a general-purpose computer system having an architecture similar to that shown in FIG. 1 . The computer system 400 is often considered to include three fundamental layers: (1) a hardware layer or level 402 ; (2) an operating-system layer or level 404 ; and (3) an application-program layer or level 406 . The hardware layer 402 includes one or more processors 408 , system memory 410 , various different types of input-output (“I/O”) devices 410 and 412 , and mass-storage devices 414 . Of course, the hardware level also includes many other components, including power supplies, internal communications links and busses, specialized integrated circuits, many different types of processor-controlled or microprocessor-controlled peripheral devices and controllers, and many other components. The operating system 404 interfaces to the hardware level 402 through a low-level operating system and hardware interface 416 generally comprising a set of non-privileged computer instructions 418 , a set of privileged computer instructions 420 , a set of non-privileged registers and memory addresses 422 , and a set of privileged registers and memory addresses 424 . In general, the operating system exposes non-privileged instructions, non-privileged registers, and non-privileged memory addresses 426 and a system-call interface 428 as an operating-system interface 430 to application programs 432 - 436 that execute within an execution environment provided to the application programs by the operating system. The operating system, alone, accesses the privileged instructions, privileged registers, and privileged memory addresses. By reserving access to privileged instructions, privileged registers, and privileged memory addresses, the operating system can ensure that application programs and other higher-level computational entities cannot interfere with one another's execution and cannot change the overall state of the computer system in ways that could deleteriously impact system operation. The operating system includes many internal components and modules, including a scheduler 442 , memory management 444 , a file system 446 , device drivers 448 , and many other components and modules. To a certain degree, modern operating systems provide numerous levels of abstraction above the hardware level, including virtual memory, which provides to each application program and other computational entities a separate, large, linear memory-address space that is mapped by the operating system to various electronic memories and mass-storage devices. The scheduler orchestrates interleaved execution of various different application programs and higher-level computational entities, providing to each application program a virtual, stand-alone system devoted entirely to the application program. From the application program's standpoint, the application program executes continuously without concern for the need to share processor devices and other system devices with other application programs and higher-level computational entities. The device drivers abstract details of hardware-component operation, allowing application programs to employ the system-call interface for transmitting and receiving data to and from communications networks, mass-storage devices, and other I/O devices and subsystems. The file system 436 facilitates abstraction of mass-storage-device and memory devices as a high-level, easy-to-access, file-system interface. Thus, the development and evolution of the operating system has resulted in the generation of a type of multi-faceted virtual execution environment for application programs and other higher-level computational entities.
[0031] While the execution environments provided by operating systems have proved to be an enormously successful level of abstraction within computer systems, the operating-system-provided level of abstraction is nonetheless associated with difficulties and challenges for developers and users of application programs and other higher-level computational entities. One difficulty arises from the fact that there are many different operating systems that run within various different types of computer hardware. In many cases, popular application programs and computational systems are developed to run on only a subset of the available operating systems, and can therefore be executed within only a subset of the various different types of computer systems on which the operating systems are designed to run. Often, even when an application program or other computational system is ported to additional operating systems, the application program or other computational system can nonetheless run more efficiently on the operating systems for which the application program or other computational system was originally targeted. Another difficulty arises from the increasingly distributed nature of computer systems. Although distributed operating systems are the subject of considerable research and development efforts, many of the popular operating systems are designed primarily for execution on a single computer system. In many cases, it is difficult to move application programs, in real time, between the different computer systems of a distributed computer system for high-availability, fault-tolerance, and load-balancing purposes. The problems are even greater in heterogeneous distributed computer systems which include different types of hardware and devices running different types of operating systems. Operating systems continue to evolve, as a result of which certain older application programs and other computational entities may be incompatible with more recent versions of operating systems for which they are targeted, creating compatibility issues that are particularly difficult to manage in large distributed systems.
[0032] For all of these reasons, a higher level of abstraction, referred to as the “virtual machine,” (“VM”) has been developed and evolved to further abstract computer hardware in order to address many difficulties and challenges associated with traditional computing systems, including the compatibility issues discussed above. FIGS. 5A-B show two types of VM and virtual-machine execution environments. FIGS. 5A-B use the same illustration conventions as used in FIG. 4 . FIG. 5A shows a first type of virtualization. The computer system 500 in FIG. 5A includes the same hardware layer 502 as the hardware layer 402 shown in FIG. 4 . However, rather than providing an operating system layer directly above the hardware layer, as in FIG. 4 , the virtualized computing environment shown in FIG. 5A features a virtualization layer 504 that interfaces through a virtualization-layer/hardware-layer interface 506 , equivalent to interface 416 in FIG. 4 , to the hardware. The virtualization layer 504 provides a hardware-like interface 508 to a number of VMs, such as VM 510 , in a virtual-machine layer 511 executing above the virtualization layer 504 . Each VM includes one or more application programs or other higher-level computational entities packaged together with an operating system, referred to as a “guest operating system,” such as application 514 and guest operating system 516 packaged together within VM 510 . Each VM is thus equivalent to the operating-system layer 404 and application-program layer 406 in the general-purpose computer system shown in FIG. 4 . Each guest operating system within a VM interfaces to the virtualization-layer interface 508 rather than to the actual hardware interface 506 . The virtualization layer 504 partitions hardware devices into abstract virtual-hardware layers to which each guest operating system within a VM interfaces. The guest operating systems within the VMs, in general, are unaware of the virtualization layer and operate as if they were directly accessing a true hardware interface. The virtualization layer 504 ensures that each of the VMs currently executing within the virtual environment receive a fair allocation of underlying hardware devices and that all VMs receive sufficient devices to progress in execution. The virtualization-layer interface 508 may differ for different guest operating systems. For example, the virtualization layer is generally able to provide virtual hardware interfaces for a variety of different types of computer hardware. This allows, as one example, a VM that includes a guest operating system designed for a particular computer architecture to run on hardware of a different architecture. The number of VMs need not be equal to the number of physical processors or even a multiple of the number of processors.
[0033] The virtualization layer 504 includes a virtual-machine-monitor module 518 (“VMM”) that virtualizes physical processors in the hardware layer to create virtual processors on which each of the VMs executes. For execution efficiency, the virtualization layer attempts to allow VMs to directly execute non-privileged instructions and to directly access non-privileged registers and memory. However, when the guest operating system within a VM accesses virtual privileged instructions, virtual privileged registers, and virtual privileged memory through the virtualization-layer interface 508 , the accesses result in execution of virtualization-layer code to simulate or emulate the privileged devices. The virtualization layer additionally includes a kernel module 520 that manages memory, communications, and data-storage machine devices on behalf of executing VMs (“VM kernel”). The VM kernel, for example, maintains shadow page tables on each VM so that hardware-level virtual-memory facilities can be used to process memory accesses. The VM kernel additionally includes routines that implement virtual communications and data-storage devices as well as device drivers that directly control the operation of underlying hardware communications and data-storage devices. Similarly, the VM kernel virtualizes various other types of I/O devices, including keyboards, optical-disk drives, and other such devices. The virtualization layer 504 essentially schedules execution of VMs much like an operating system schedules execution of application programs, so that the VMs each execute within a complete and fully functional virtual hardware layer.
[0034] FIG. 5B shows a second type of virtualization. In FIG. 5B , the computer system 540 includes the same hardware layer 542 and operating system layer 544 as the hardware layer 402 and the operating system layer 404 shown in FIG. 4 . Several application programs 546 and 548 are shown running in the execution environment provided by the operating system 544 . In addition, a virtualization layer 550 is also provided, in computer 540 , but, unlike the virtualization layer 504 discussed with reference to FIG. 5A , virtualization layer 550 is layered above the operating system 544 , referred to as the “host OS,” and uses the operating system interface to access operating-system-provided functionality as well as the hardware. The virtualization layer 550 comprises primarily a VMM and a hardware-like interface 552 , similar to hardware-like interface 508 in FIG. 5A . The virtualization-layer/hardware-layer interface 552 , equivalent to interface 416 in FIG. 4 , provides an execution environment for a number of VMs 556 - 558 , each including one or more application programs or other higher-level computational entities packaged together with a guest operating system.
[0035] In FIGS. 5A-5B , the layers are somewhat simplified for clarity of illustration. For example, portions of the virtualization layer 550 may reside within the host-operating-system kernel, such as a specialized driver incorporated into the host operating system to facilitate hardware access by the virtualization layer.
[0036] It should be noted that virtual hardware layers, virtualization layers, and guest operating systems are all physical entities that are implemented by computer instructions stored in physical data-storage devices, including electronic memories, mass-storage devices, optical disks, magnetic disks, and other such devices. The term “virtual” does not, in any way, imply that virtual hardware layers, virtualization layers, and guest operating systems are abstract or intangible. Virtual hardware layers, virtualization layers, and guest operating systems execute on physical processors of physical computer systems and control operation of the physical computer systems, including operations that alter the physical states of physical devices, including electronic memories and mass-storage devices. They are as physical and tangible as any other component of a computer since, such as power supplies, controllers, processors, busses, and data-storage devices.
[0037] A VM or virtual application, described below, is encapsulated within a data package for transmission, distribution, and loading into a virtual-execution environment. One public standard for virtual-machine encapsulation is referred to as the “open virtualization format” (“OVF”). The OVF standard specifies a format for digitally encoding a VM within one or more data files. FIG. 6 shows an OVF package. An OVF package 602 includes an OVF descriptor 604 , an OVF manifest 606 , an OVF certificate 608 , one or more disk-image files 610 - 611 , and one or more device files 612 - 614 . The OVF package can be encoded and stored as a single file or as a set of files. The OVF descriptor 604 is an XML document 620 that includes a hierarchical set of elements, each demarcated by a beginning tag and an ending tag. The outermost, or highest-level, element is the envelope element, demarcated by tags 622 and 623 . The next-level element includes a reference element 626 that includes references to all files that are part of the OVF package, a disk section 628 that contains meta information about all of the virtual disks included in the OVF package, a networks section 630 that includes meta information about all of the logical networks included in the OVF package, and a collection of virtual-machine configurations 632 which further includes hardware descriptions of each VM 634 . There are many additional hierarchical levels and elements within a typical OVF descriptor. The OVF descriptor is thus a self-describing, XML file that describes the contents of an OVF package. The OVF manifest 606 is a list of cryptographic-hash-function-generated digests 636 of the entire OVF package and of the various components of the OVF package. The OVF certificate 608 is an authentication certificate 640 that includes a digest of the manifest and that is cryptographically signed. Disk image files, such as disk image file 610 , are digital encodings of the contents of virtual disks and device files 612 are digitally encoded content, such as operating-system images. A VM or a collection of VMs encapsulated together within a virtual application can thus be digitally encoded as one or more files within an OVF package that can be transmitted, distributed, and loaded using well-known tools for transmitting, distributing, and loading files. A virtual appliance is a software service that is delivered as a complete software stack installed within one or more VMs that is encoded within an OVF package.
[0038] The advent of VMs and virtual environments has alleviated many of the difficulties and challenges associated with traditional general-purpose computing. Machine and operating-system dependencies can be significantly reduced or entirely eliminated by packaging applications and operating systems together as VMs and virtual appliances that execute within virtual environments provided by virtualization layers running on many different types of computer hardware. A next level of abstraction, referred to as virtual data centers or virtual infrastructure, provide a data-center interface to virtual data centers computationally constructed within physical data centers.
[0039] FIG. 7 shows virtual data centers provided as an abstraction of underlying physical-data-center hardware components. In FIG. 7 , a physical data center 702 is shown below a virtual-interface plane 704 . The physical data center consists of a virtual-data-center management server 706 and any of various different computers, such as PCs 708 , on which a virtual-data-center management interface may be displayed to system administrators and other users. The physical data center additionally includes generally large numbers of server computers, such as server computer 710 , that are coupled together by local area networks, such as local area network 712 that directly interconnects server computer 710 and 714 - 720 and a mass-storage array 722 . The physical data center shown in FIG. 7 includes three local area networks 712 , 724 , and 726 that each directly interconnects a bank of eight servers and a mass-storage array. The individual server computers, such as server computer 710 , each includes a virtualization layer and runs multiple VMs. Different physical data centers may include many different types of computers, networks, data-storage systems and devices connected according to many different types of connection topologies. The virtual-interface plane 704 , a logical abstraction layer shown by a plane in FIG. 7 , abstracts the physical data center to a virtual data center comprising one or more device pools, such as device pools 730 - 732 , one or more virtual data stores, such as virtual data stores 734 - 736 , and one or more virtual networks. In certain implementations, the device pools abstract banks of physical servers directly interconnected by a local area network.
[0040] The virtual-data-center management interface allows provisioning and launching of VMs with respect to device pools, virtual data stores, and virtual networks, so that virtual-data-center administrators need not be concerned with the identities of physical-data-center components used to execute particular VMs. Furthermore, the virtual-data-center management server 706 includes functionality to migrate running VMs from one physical server to another in order to optimally or near optimally manage device allocation, provide fault tolerance, and high availability by migrating VMs to most effectively utilize underlying physical hardware devices, to replace VMs disabled by physical hardware problems and failures, and to ensure that multiple VMs supporting a high-availability virtual appliance are executing on multiple physical computer systems so that the services provided by the virtual appliance are continuously accessible, even when one of the multiple virtual appliances becomes compute bound, data-access bound, suspends execution, or fails. Thus, the virtual data center layer of abstraction provides a virtual-data-center abstraction of physical data centers to simplify provisioning, launching, and maintenance of VMs and virtual appliances as well as to provide high-level, distributed functionalities that involve pooling the devices of individual physical servers and migrating VMs among physical servers to achieve load balancing, fault tolerance, and high availability.
[0041] FIG. 8 shows virtual-machine components of a virtual-data-center management server and physical servers of a physical data center above which a virtual-data-center interface is provided by the virtual-data-center management server. The virtual-data-center management server 802 and a virtual-data-center database 804 comprise the physical components of the management component of the virtual data center. The virtual-data-center management server 802 includes a hardware layer 806 and virtualization layer 808 , and runs a virtual-data-center management-server VM 810 above the virtualization layer. Although shown as a single server in FIG. 8 , the virtual-data-center management server (“VDC management server”) may include two or more physical server computers that support multiple VDC-management-server virtual appliances. The VM 810 includes a management-interface component 812 , distributed services 814 , core services 816 , and a host-management interface 818 . The management interface 818 is accessed from any of various computers, such as the PC 708 shown in FIG. 7 . The management interface 818 allows the virtual-data-center administrator to configure a virtual data center, provision VMs, collect statistics and view log files for the virtual data center, and to carry out other, similar management tasks. The host-management interface 818 interfaces to virtual-data-center agents 824 , 825 , and 826 that execute as VMs within each of the physical servers of the physical data center that is abstracted to a virtual data center by the VDC management server.
[0042] The distributed services 814 include a distributed-device scheduler that assigns VMs to execute within particular physical servers and that migrates VMs in order to most effectively make use of computational bandwidths, data-storage capacities, and network capacities of the physical data center. The distributed services 814 further include a high-availability service that replicates and migrates VMs in order to ensure that VMs continue to execute despite problems and failures experienced by physical hardware components. The distributed services 814 also include a live-virtual-machine migration service that temporarily halts execution of a VM, encapsulates the VM in an OVF package, transmits the OVF package to a different physical server, and restarts the VM on the different physical server from a virtual-machine state recorded when execution of the VM was halted. The distributed services 814 also include a distributed backup service that provides centralized virtual-machine backup and restore.
[0043] The core services 816 provided by the VDC management server 810 include host configuration, virtual-machine configuration, virtual-machine provisioning, generation of virtual-data-center alarms and events, ongoing event logging and statistics collection, a task scheduler, and a device-management module. Each physical server 820 - 822 also includes a host-agent VM 828 - 830 through which the virtualization layer can be accessed via a virtual-infrastructure application programming interface (“API”). This interface allows a remote administrator or user to manage an individual server through the infrastructure API. The virtual-data-center agents 824 - 826 access virtualization-layer server information through the host agents. The virtual-data-center agents are primarily responsible for offloading certain of the virtual-data-center management-server functions specific to a particular physical server to that physical server. The virtual-data-center agents relay and enforce device allocations made by the VDC management server 810 , relay virtual-machine provisioning and configuration-change commands to host agents, monitor and collect performance statistics, alarms, and events communicated to the virtual-data-center agents by the local host agents through the interface API, and to carry out other, similar virtual-data-management tasks.
[0044] The virtual-data-center abstraction provides a convenient and efficient level of abstraction for exposing the computational devices of a cloud-computing facility to cloud-computing-infrastructure users. A cloud-director management server exposes virtual devices of a cloud-computing facility to cloud-computing-infrastructure users. In addition, the cloud director introduces a multi-tenancy layer of abstraction, which partitions VDCs into tenant-associated VDCs that can each be allocated to a particular individual tenant or tenant organization, both referred to as a “tenant.” A given tenant can be provided one or more tenant-associated VDCs by a cloud director managing the multi-tenancy layer of abstraction within a cloud-computing facility. The cloud services interface ( 308 in FIG. 3 ) exposes a virtual-data-center management interface that abstracts the physical data center.
[0045] FIG. 9 shows a cloud-director level of abstraction. In FIG. 9 , three different physical data centers 902 - 904 are shown below planes representing the cloud-director layer of abstraction 906 - 908 . Above the planes representing the cloud-director level of abstraction, multi-tenant virtual data centers 910 - 912 are shown. The devices of these multi-tenant virtual data centers are securely partitioned in order to provide secure virtual data centers to multiple tenants, or cloud-services-accessing organizations. For example, a cloud-services-provider virtual data center 910 is partitioned into four different tenant-associated virtual-data centers within a multi-tenant virtual data center for four different tenants 916 - 919 . Each multi-tenant virtual data center is managed by a cloud director comprising one or more cloud-director servers 920 - 922 and associated cloud-director databases 924 - 926 . Each cloud-director server or servers runs a cloud-director virtual appliance 930 that includes a cloud-director management interface 932 , a set of cloud-director services 934 , and a virtual-data-center management-server interface 936 . The cloud-director services include an interface and tools for provisioning multi-tenant virtual data centers on behalf of tenants, tools and interfaces for configuring and managing tenant organizations, tools and services for organization of virtual data centers and tenant-associated virtual data centers within the multi-tenant virtual data center, services associated with template and media catalogs, and provisioning of virtualization networks from a network pool. Templates are VMs that each contains an OS and/or one or more VMs containing applications. A template may include much of the detailed contents of VMs and virtual appliances that are encoded within OVF packages, so that the task of configuring a VM or virtual appliance is significantly simplified, requiring only deployment of one OVF package. These templates are stored in catalogs within a tenant's virtual-data center. These catalogs are used for developing and staging new virtual appliances and published catalogs are used for sharing templates in virtual appliances across organizations. Catalogs may include OS images and other information relevant to construction, distribution, and provisioning of virtual appliances.
[0046] Considering FIGS. 7 and 9 , the VDC-server and cloud-director layers of abstraction can be seen, as discussed above, to facilitate employment of the virtual-data-center concept within private and public clouds. However, this level of abstraction does not fully facilitate aggregation of single-tenant and multi-tenant virtual data centers into heterogeneous or homogeneous aggregations of cloud-computing facilities.
[0047] FIG. 10 shows virtual-cloud-connector nodes (“VCC nodes”) and a VCC server, components of a distributed system that provides multi-cloud aggregation and that includes a cloud-connector server and cloud-connector nodes that cooperate to provide services that are distributed across multiple clouds. VMware vCloud™ VCC servers and nodes are one example of VCC server and nodes. In FIG. 10 , seven different cloud-computing facilities are shown 1002 - 1008 . Cloud-computing facility 1002 is a private multi-tenant cloud with a cloud director 1010 that interfaces to a VDC management server 1012 to provide a multi-tenant private cloud comprising multiple tenant-associated virtual data centers. The remaining cloud-computing facilities 1003 - 1008 may be either public or private cloud-computing facilities and may be single-tenant virtual data centers, such as virtual data centers 1003 and 1006 , multi-tenant virtual data centers, such as multi-tenant virtual data centers 1004 and 1007 - 1008 , or any of various different kinds of third-party cloud-services facilities, such as third-party cloud-services facility 1005 . An additional component, the VCC server 1014 , acting as a controller is included in the private cloud-computing facility 1002 and interfaces to a VCC node 1016 that runs as a virtual appliance within the cloud director 1010 . A VCC server may also run as a virtual appliance within a VDC management server that manages a single-tenant private cloud. The VCC server 1014 additionally interfaces, through the Internet, to VCC node virtual appliances executing within remote VDC management servers, remote cloud directors, or within the third-party cloud services 1018 - 1023 . The VCC server provides a VCC server interface that can be displayed on a local or remote terminal, PC, or other computer system 1026 to allow a cloud-aggregation administrator or other user to access VCC-server-provided aggregate-cloud distributed services. In general, the cloud-computing facilities that together form a multiple-cloud-computing aggregation through distributed services provided by the VCC server and VCC nodes are geographically and operationally distinct.
Computational Methods and System to Evaluate Resource Allocation Costs of a Data Center with Respect to Resource Allocation Cost of a Cloud Computing Industry
[0048] FIG. 11 shows an example of a system to collect computational resource costs from M separate physical data centers that combined represents a cloud computing industry. The resources may be CPUs, memory, and data storage. Each of the M physical data centers may be configured as described above with reference to FIG. 7 to run one or more VDCs as described above with reference to FIG. 9 . Each physical data center generates log files, configuration files, resource utilization data, such as usage data regarding CPU's, memory, and data storage, and stores the data in one or more data-storage devices. For example, CPU utilization, memory utilization, and data storage utilization by the VMs that run in each of the M physical data centers may be recorded periodically, such as daily, weekly, or monthly. Each of the M physical data centers also compute a total VDC cost of running one or more VDCs. The resource utilization data and total VDC costs may be sent via the Internet 1101 to a cloud computing service facility 1102 that stores the resource utilization data and total VDC cost. A data center 1103 accesses the resource utilization data and total VDC costs of the M physical data centers maintained by the cloud compute service facility 1102 in order to compute resource allocation costs of the cloud computing industry. The resource allocation costs serve as cloud computing industry benchmarks that may be compared with resource allocation costs of the data center 1103 . Differences between the allocation cost of the data center 1103 and the allocation costs of the cloud computing industry may be used to adjust operations of the data center 1103 in order to shift allocation cost and total VDC cost of the data center 1103 into closer alignment with the allocation costs and total VDC costs of the cloud computing industry.
[0049] The resource utilization data and total VDC costs of the M physical data centers maintained by the cloud computing services facility 1102 may be sent to the data center 1103 on a regular basis, such as daily, weekly, or monthly. The data center 1103 stores the resource utilization data and total VDC costs in a data-storage device 1104 . In the example of FIG. 11 , the data center 1103 runs three VDC's, such as VDC 1105 . One or more of the VDC's may form a private cloud. In the example of FIG. 11 , up to three private clouds may be run in the data center 1103 .
[0050] The resource utilization data and total VDC costs of the M physical data centers stored in the one or more data-storage devices 1104 are preprocessed to organize the resource utilization data and total VDC costs. The resource utilization data includes CPU utilization, number of CPU cores, memory utilization, memory capacity, storage utilization, and storage capacity for each of the data centers that collectively comprise a cloud computing industry resource utilization data. FIGS. 12A-12C show examples of preprocessing the resource utilization data produced by each of the M physical data centers. In the example of FIG. 12A , the number of CPU cores and CPU utilization of the VMs that run in the M physical data centers are collected. CPU utilization is the amount of time a CPU was used for processing instructions of one or more VMs. The number of CPU cores used by VMs run in the m-th data center are denoted by No.CPUCore m and the CPU utilization of the VMs that run in the m-th data center is denoted by CPUUtilization m , where the index m=1, . . . , M. In the example of FIG. 12B , the memory utilization and memory capacity of each of the M data centers are collected. Memory includes any of various different kinds of random access memory (“RAM”). Memory capacity of the m-th data center is denoted by MemCapacity m and memory utilization of the m-th data center is denoted by MemUtilization m . The MemCapacity m is the amount of memory available in the m-th data center and MemUtilization m is to the actual amount of memory used by the VMs that run in the m-th data center. In the example of FIG. 12C , the data storage utilization and data storage capacity of each of the M data centers are collected. The data storage capacity of the m-th data center is denoted by StorCapacity m and the data storage utilization of the m-th data center is denoted by StorUtilization m . The StorCapacity m is the total amount of data storage available in the data-storage devices of the m-th data center, and StorUtilization m is to the amount of data storage used to store data generated by the VMs that run in the m-th data center.
[0051] The resource utilization data and total VDC costs of the M data centers may be used to calculate resource allocation cost industry benchmarks that may be compared with resource allocation costs of a data center, such as the data center 1103 . Allocation cost refers to the VDC costs associated with running VMs, and unallocated costs refers to the VDC cost not associated with running VMs (e.g., unused hardware and unused labor).
[0052] CPU allocation cost industry benchmarks (“IBs”) are computed as follows. A total CPU utilization of the M physical data centers is computed by summing the CPU utilization of each of the M physical data centers:
[0000]
TotalCPUUtil
(
IB
)
=
∑
m
=
1
M
CPUUtilization
m
(
1
)
[0000] A CPU allocation cost of the cloud computing industry may be computed as follows:
[0000] CPUAlloCost(IB)=TotalCPUUtil(IB)×CPU_base_rate (2)
[0053] where CPU_base_rate is the cost per unit of CPU utilization (e.g., dollars per unit of time).
[0054] The CPU allocation cost of Equation (2) is the cost of CPU utilization across the cloud computing industry. A total CPU capacity of the cloud computing industry may be computed as follows:
[0000]
TotalCPUCap
(
IB
)
=
(
∑
m
=
1
M
No
.
CPUCores
m
)
×
CPU_speed
(
3
)
[0055] where CPU_speed may be an average CPU speed per core.
[0000] A total CPU cost of the cloud computing industry may be computed from the total CPU capacity of Equation (3) and the CPU base rate as follows:
[0000] TotalCPUCost(IB)=TotalCPUCap(IB)×CPU_base_rate (4)
[0000] The total CPU cost of Equation (4) is the total cost of CPUs across of the cloud computing industry. The portion of cost allocated to CPU usage in the cloud computing industry to the total cost of CPU capacity in the cloud computing industry may be calculated as follows:
[0000]
CPUAlloFrac
(
IB
)
=
CPUAlloCost
(
IB
)
TotalCPUCost
(
IB
)
(
5
)
[0000] The CPU allocation fraction given by Equation (5) represents the fraction or proportion of total cost of CPUs in the cloud computing industry that is attributed to CPU allocated cost, which may also be represented as a percentage.
[0056] The CPU allocation cost IBs computed in Equations (1)-(5) may be compared with associated CPU allocation costs of a data center, such as the data center 1103 . FIG. 13 shows the data center 1103 and three VDCs. The total CPU utilization, TotalCPUUtil(DC), by the VMs comprising the three VDCs of the data center 1103 may be used to compute the CPU allocation cost for the data center 1103 as follows:
[0000] CPUAlloCost(DC)=TotalCPUUtil(DC)×CPU_base_rate (6)
[0000] The number of CPU cores in the data center 1103 , No.CPUCores(DC), may be used to compute the total CPU capacity of the data center 1103 as follows:
[0000] TotalCPUCap(DC)=No.CPUCores(DC)×CPU_speed (7)
[0000] The total CPU total of the CPU cores in the data center 1103 may calculated as follows:
[0000] TotalCPUCost(DC)=TotalCPUCap(DC)×CPU_base_rate (8)
[0000] The fraction of cost allocated to CPU usage in the data center 1103 of the total cost of CPU capacity of the data center 1103 may be calculated as follows:
[0000]
CPUAlloFrac
(
D
C
)
=
CPUAlloCost
(
D
C
)
TotalCPUCost
(
D
C
)
(
9
)
[0000] The CPU allocation fraction given by Equation (9) represents the fraction or proportion of total cost of CPUs in the data center 1103 that is attributed to CPU allocated cost, which may also be represented as a percentage.
[0057] The difference between the CPU allocation fraction of the data center 1103 given by Equation (9) and the CPU allocation fraction of the cloud computing industry given by Equation (5) is computed as follows:
[0000] CPUAlloGap=CPUAlloFrac(IB)−CPUAlloFrac(DC) (10)
[0000] The CPU allocation gap of Equation (10) represents the degree to which cost attributed to CPU allocation in the data center 1103 differs from the cost attributed to CPU allocation across the cloud computing industry.
[0058] A CPU threshold, T CPU , may be used to assess the degree to which CPU allocation cost in the data center 1103 are aligned with CPU allocation cost across the cloud computing industry. When
[0000] |CPUAlloGap|≦ T CPU (11)
[0000] the cost attributed to CPU allocation in the data center 1103 is considered closely aligned with the cost attributed to CPU allocation across the cloud computing industry.
[0059] On the other hand, when
[0000] |CPUAlloGap|> T CPU (12)
[0000] the cost attributed to CPU allocation in the data center 1103 is not considered closely aligned with the cost attributed to CPU allocation across the cloud computing industry. In this case, if CPUAlloGap>0, then investment in additional processors may be a next area of growth investment for the data center. If CPUAlloGap<0, then the investment in processors exceeds that of the cloud computing industry, which may be an indication of CPU wastage, and no further investment in processors should be made.
[0060] The monetary impact of the gap between the cost of CPU allocation of the data center 1103 and the cost of CPU allocation across the cloud computing industry may be computed as follows:
[0000] MonetaryCPUAlloImpact=CPUAlloGap×TotalCPUCost(DC) (13)
[0000] The monetary CPU allocation impact computed according to Equation (13) is a monetary value of the degree to which the cost of CPU allocation for the data center 1103 is less than or greater than the cost of CPU allocation for the cloud computing industry. MonetaryCPUAlloImpact<0 may be used as an indicator of CPU cost wastage, and MonetarCPUAlloImpact>0 may be used as an indicator of how much money should be invested in processors.
[0061] Memory allocation cost IBs are computed as follows. A total memory utilization of the M physical data centers is computed by summing the memory utilization of each of the M physical data centers:
[0000]
TotalMemUtil
(
IB
)
=
∑
m
=
1
M
MemUtilization
m
(
14
)
[0000] Memory allocation cost of the cloud computing industry may be computed as follows:
[0000] MemAlloCost(IB)=MemTotalUtil(IB)×Mem_base_rate (15)
[0062] where Mem_base_rate is the cost per number of bytes of memory (e.g., gigabytes). The memory allocation cost of Equation (15) is the cost of memory utilization across the cloud computing industry. A total memory capacity of the cloud computing industry may be computed summing the memory capacity of each of the M physical data centers as follows:
[0000]
TotalMemCap
(
IB
)
=
∑
m
=
1
M
MemCapacity
m
(
16
)
[0000] A total memory cost of the cloud computing industry may be computed from the total memory capacity of Equation (16) and the memory base rate as follows:
[0000] TotalMemCost(IB)=TotalMemCap(IB)×Mem_base_rate (17)
[0000] The total memory cost of Equation (17) is the total cost of memory across of the cloud computing industry. The portion of cost allocated to memory in the cloud computing industry to the total cost of memory capacity in the cloud computing industry may be calculated as follows:
[0000]
MemAlloFrac
(
IB
)
=
MemAlloCost
(
IB
)
TotalMemCost
(
IB
)
(
18
)
[0000] The memory allocation fraction given by Equation (18) represents the fraction or proportion of total cost of memory in the cloud computing industry that is attributed to memory allocation cost, which may also be represented as a percentage.
[0063] The memory allocation cost IBs computed in Equations (14)-(18) may be compared with associated memory allocation costs of a data center, such as the data center 1103 . Returning to FIG. 13 , the total memory utilization, TotalMemUtil(DC), by the VMs of the three VDCs running in the data center 1103 may be used to compute the memory allocation cost for the data center 1103 as follows:
[0000] MemAlloCost(DC)=TotalMemUtil(DC)×Mem_base_rate (19)
[0000] The amount of memory in the data center 1103 , TotalMemCap(DC), may be used to compute the total memory cost associated with the data center 1103 as follows:
[0000] TotalMemCost(DC)=TotalMemCap(DC)×Mem_base_rate (20)
[0000] The fraction of cost allocated to memory usage in the data center 1103 of the total cost of memory capacity of the data center 1103 may be calculated as follows:
[0000]
MemAlloFrac
(
D
C
)
=
MemAlloCost
(
D
C
)
TotalMemCost
(
D
C
)
(
21
)
[0000] The memory allocation fraction given by Equation (21) represents the fraction or proportion of total cost of memory in the data center 1103 that is attributed to memory allocation cost, which may also be represented as a percentage.
[0064] The difference between the memory allocation fraction of the data center 1103 given by Equation (21) and the memory allocation fraction of the cloud computing industry given by Equation (18) is computed as follows:
[0000] MemAlloGap=MemAlloFrac( BM )−MemAlloFrac(DC) (22)
[0000] The memory allocation gap of Equation (22) represents the degree to which cost attributed to memory allocation in the data center 1103 differs from the cost attributed to memory allocation across the cloud computing industry.
[0065] A memory threshold, T Mem , may be used to assess the degree to which memory allocation cost in the data center 1103 are aligned with memory allocation cost across the cloud computing industry. When
[0000] |MemAlloGap|≦ T Mem (23)
[0000] the cost attributed to memory allocation in the data center 1103 is considered closely aligned with the cost attributed to memory allocation across the cloud computing industry. On the other hand, when
[0000] |MemAlloGap|> T Mem (24)
[0000] the cost attributed to memory allocation in the data center 1103 is not considered closely aligned with the cost attributed to memory allocation across the cloud computing industry. In this case, if MemAlloGap>0, then investment in additional memory may be a next area of growth investment for the data center. If MemAlloGap<0, then the investment in memory exceeds that of the cloud computing industry, which may be an indication of wastage, and no further investment in memory should be made.
[0066] The monetary impact of the gap between the cost of memory allocation of the data center 1103 and the cost of memory allocation across the cloud computing industry may be computed as follows:
[0000] MonetaryMemAlloImpact=MemAlloGap×TotalMemCost(DC) (25)
[0000] The monetary memory allocation impact computed according to Equation (25) is a monetary value of the degree to which the cost of memory allocation of the data center 1103 is less than or greater than the cost of memory allocation for the cloud computing industry. MonetaryMemAlloImpact<0 may be used as an indicator of memory wastage, and MonetaryMemAlloImpact>0 may be used as an indicator of how much money should be invested in memory.
[0067] Data storage allocation cost IBs are computed as follows. A total data storage utilization of the M physical data centers is computed by summing the data storage utilization of each of the M physical data centers:
[0000]
TotalStorUtil
(
IB
)
=
∑
m
=
1
M
StorUtilization
m
(
26
)
[0000] Data storage allocation cost of the cloud computing industry may be computed as follows:
[0000] StorAlloCost(IB)=TotalStorUtil(IB)×Stor_base≦rate (27)
[0000] where Stor_base_rate is the cost per number of bytes of data storage (e.g., gigabytes).
The data storage allocation cost of Equation (15) is the cost of data storage utilization across the cloud computing industry. A total data storage capacity of the cloud computing industry may be computed summing the data storage capacity of each of the M physical data centers as follows:
[0000]
TotalStorCap
(
IB
)
=
∑
m
=
1
M
StorCapacity
m
(
28
)
[0000] A total data storage cost of the cloud computing industry may be computed from the total data storage capacity of Equation (16) and the data storage base rate as follows:
[0000] TotalStorCost(IB)=TotalStorCap(IB)×Stor_base_rate (29)
[0000] The total data storage cost of Equation (17) is the total cost of data storage across of the cloud computing industry. The portion of cost allocated to data storage in the cloud computing industry to the total cost of data storage capacity in the cloud computing industry may be calculated as follows:
[0000]
StorAlloFrac
(
IB
)
=
StorAlloCost
(
IB
)
TotalStorCost
(
IB
)
(
30
)
[0000] The data storage allocation fraction given by Equation (18) represents the fraction or proportion of total cost of data storage in the cloud computing industry that is attributed to data storage allocation cost, which may also be represented as a percentage.
[0068] The data storage allocation cost IBs computed in Equations (26)-(30) may be compared with associated data storage allocation costs of a data center, such as the data center 1103 . Returning to FIG. 13 , the total data storage utilization, TotalStorUtil(DC), by the VMs of the three VDCs running in the data center 1103 may be used to compute the data storage allocation cost for the data center 1103 as follows:
[0000] StorAlloCost(DC)=TotalStorUtil(DC)×Stor_base_rate (31)
[0000] The amount of data storage in the data center 1103 , TotalStorCap(DC), may be used to compute the total data storage cost associated with the data center 1103 as follows:
[0000] TotalStorCost(DC)=TotalStorCap(DC)×Stor_base_rate (32)
[0000] The fraction of cost allocated to data storage usage in the data center 1103 of the total cost of data storage capacity of the data center 1103 may be calculated as follows:
[0000]
StorAlloFrac
(
D
C
)
=
StorAlloCost
(
D
C
)
TotalStorCost
(
D
C
)
(
33
)
[0000] The data storage allocation fraction given by Equation (33) represents the fraction or proportion of total cost of data storage in the data center 1103 that is attributed to data storage allocation cost, which may also be represented as a percentage.
[0069] The difference between the data storage allocation fraction of the data center 1103 given by Equation (33) and the data storage allocation fraction of the cloud computing industry given by Equation (30) is computed as follows:
[0000] StorAlloGap=StorAlloFrac(IB)−StorAlloFrac(DC) (34)
[0000] The data storage allocation gap of Equation (34) represents the degree to which cost attributed to data storage allocation in the data center 1103 differs from the cost attributed to data storage allocation across the cloud computing industry.
[0070] A storage threshold, T Stor , may be used to assess the degree to which data storage allocation cost in the data center 1103 are aligned with data storage allocation cost across the cloud computing industry. For example, when
[0000] |StorAlloGap|≦ T Stor (35)
[0000] the cost attributed to data storage allocation in the data center 1103 is considered closely aligned with the cost attributed to data storage allocation across the cloud computing industry. When
[0000] |StorAlloGap|> T Stor (36)
[0000] the cost attributed to data storage allocation in the data center 1103 is not considered closely aligned with the cost attributed to data storage allocation across the cloud computing industry. In this case, if StorAlloGap>0, then investment in additional data storage may be a next area of growth investment for the data center. If StorAlloGap<0, then the investment in data storage exceeds that of the cloud computing industry, which may be an indication of wastage, and no further investment in data storage should be made.
[0071] The monetary impact of the gap between the cost of data storage allocation of the data center 1103 and the cost of data storage allocation across the cloud computing industry may be computed as follows:
[0000] MonetaryStorAlloImpact=StorAlloGap×TotalStorCost(DC) (37)
[0000] The monetary data storage allocation impact computed according to Equation (37) is a monetary value of the degree to which the cost of data storage allocation for the data center 1103 is less than or greater than the cost of data storage allocation for the cloud computing industry. MonetaryStorAlloImpact<0 may be used as an indicator of data storage wastage, and MonetarStorAlloImpact>0 may be used as an indicator of how much money should be invested in data storage.
[0072] A total resource allocation cost of CPUs, memory, data storage by the cloud computing industry may be calculated by summing the CPU allocation cost of Equation (6), the memory allocation cost of Equation (19), and the storage allocation cost (27) as follows:
[0000] TotalAlloCost(IB)=CPUAlloCost(IB)+MemAlloCost(IB)+StorAlloCost(IB) (38)
[0000] A total resource allocation fraction for the cloud computing industry may be computed as follows:
[0000]
TotalAlloFrac
(
IB
)
=
TotalAlloCost
(
IB
)
TotalVDCCost
(
IB
)
where
TotalVDCCost
(
IB
)
=
∑
m
=
1
M
TotalVDCCost
m
(
39
)
[0000] and TotalVDCCost m is the total cost of one or more VDCs that run in the m-th physical data center.
[0073] A total resource allocation cost of CPUs, memory, and data storage for the data center 1103 may be calculated by summing the CPU allocation cost of Equation (6), the memory allocation cost of Equation (19), and the storage allocation cost (27) as follows:
[0000] TotalAlloCost(DC)=CPUAlloCost(DC)+MemAlloCost(DC)+StorAlloCost(DC) (40)
[0000] A total resource allocation fraction for the data center 1103 may be computed as follows:
[0000]
TotalAlloFrac
(
D
C
)
=
TotalAlloCost
(
D
C
)
TotalVDCCost
(
D
C
)
(
41
)
[0000] where TotalVDCCost(DC) is the total cost of the three VDCs that run in the m-th physical data center.
[0074] The difference between the resource allocation fraction of the data center 1103 given by Equation (33) and the resource allocation fraction of the cloud computing industry given by Equation (30) is computed as follows:
[0000] TotalAlloGap=TotalAlloFrac(IB)−TotalAlloFrac(DC) (42)
[0000] The resource allocation gap of Equation (34) represents the degree to which cost attributed to resource allocation in the data center 1103 differs from the cost attributed to resource allocation across the cloud computing industry.
[0075] A total resource threshold, T Tot , may be used to assess the degree to which resource allocation cost in the data center 1103 are aligned with resource allocation cost across the cloud computing industry. For example, when
[0000] |TotalAlloGap|≦ T Tot (43)
[0000] the cost attributed to resource allocation in the data center 1103 is considered closely aligned with the cost attributed to resource allocation across the cloud computing industry. On the other hand, when
[0000] |TotalAlloGap|> T Tot (44)
[0000] the cost attributed to resource allocation in the data center 1103 is not considered closely aligned with the cost attributed to resource allocation across the cloud computing industry.
[0076] The monetary impact of the gap between the cost of resource allocation of the data center 1103 and the cost of resource allocation across the cloud computing industry may be computed as follows:
[0000] MonetaryTotalAlloImpact=TotalAlloGap×TotalVDCCost(DC) (45)
[0000] The monetary data resource allocation impact computed according to Equation (45) is a monetary value of the degree to which the cost of resource allocation for the data center 1103 is less than or greater than the cost of resource allocation for the cloud computing industry.
[0077] Consider, for example, a cloud computing industry total allocation fraction of 0.60 or 60% (i.e., otalAlloFrac(IB)=0.60) computed according to Equation (39). Suppose total VDC cost for the data center 1103 is $1,000,000 (i.e., TotalVDCCost(DC)=$1,000,000) and total resource allocation cost for the VMs that run in the data center 1103 is $500,000 (i.e., TotalAlloCost(DC)=$500,000). The total resource allocation fraction for the data center 1103 computed according to Equation (41) is is 0.50 or 50% (i.e., TotalAlloFrac(DC)=0.50). The total resource allocation gap is 0.10 (i.e., TotalAlloGap=0.60−0.5=0.10). The monetary impact of the gap between the cost of resource allocation of the data center 1103 and the cost of resource allocation across the cloud computing industry is $100,000 (i.e. MonetaryTotalAlloImpact=0.10×$1,000,000=$100,000).
[0078] FIG. 14 shows a control-flow diagram of a method to evaluate data center resource allocation costs of a data center. In block 1401 , resource utilization data is collected from a number of data centers that represents a cloud computing industry as described above with reference to FIG. 11 . The resources may be computational resources, such as CPU's, memory, and data storage, of the data centers. The resource utilization data includes CPU utilization, number of CPU cores, memory utilization, memory capacity, storage utilization, and storage capacity for each of the data centers that collectively comprise a cloud computing industry resource utilization data, as described above with reference to FIGS. 12A-12C . In block 1402 , the resource utilization data are pre-processed by sorted according to the type of resource, as described above with reference to FIGS. 12A-12C . In block 1403 , a routine “compute resource allocation cost of industry benchmarks” is called to compute resource allocated costs for the data centers that are representative of the cloud computing industry. In block 1404 , a routine “compute data center resource allocation costs” is called to resource allocations for the resources of the data center. In block 1405 , a routine “compute resource allocation gaps” is called to compute gaps between resource allocation of the data center and the cloud computing industry. In block 1406 , a routine “compute monetary impact of gaps” is called to compute the monetary impact of the resource allocation gaps computed in block 1405 .
[0079] FIG. 15 shows a control-flow diagram of the method “compute resource allocation cost of industry benchmarks” called in block 1403 of FIG. 14 . In block 1501 , a CPU allocation cost is computed as described above with reference to Equations (1) and (2). In block 1502 , a total CPU cost is computed as described above with reference to Equations (3). In block 1503 , memory allocation cost is computed as described above with reference to Equations (14) and (15). In block 1504 , total memory cost is computed as described above with reference to Equations (16) and (17). In block 1505 , data storage allocation cost is computed as described above with reference to Equations (26) and (27). In block 1506 , total data storage cost is computed as described above with reference to Equations (28) and (29). In block 1507 , a total resource allocation cost is computed from the allocation cost computed in blocks 1501 , 1503 , and 1505 , as described above with reference to Equation (38).
[0080] FIG. 16 shows a control-flow diagram of the method “compute data center resource allocation costs” called in block 1404 of FIG. 14 . In block 1601 , a CPU allocation cost is computed as described above with reference to Equation (6). In block 1602 , a total CPU cost is computed as described above with reference to Equations (8). In block 1603 , memory allocation cost is computed as described above with reference to Equation (19). In block 1604 , a total memory cost is computed as described above with reference to Equation (20). In block 1605 , data storage allocation cost is computed as described above with reference to Equation (31). In block 1606 , total data storage cost is computed as described above with reference to Equation (32). In block 1607 , a total resource allocation cost is computed from the allocation cost computed in blocks 1601 , 1603 , and 1605 , as described above with reference to Equation (40).
[0081] FIGS. 17A-17B show a control-flow diagram of the method “compute resource allocation gaps” called in block 1405 of FIG. 14 . In block 1701 , a CPU allocation fraction is computed for the cloud computing industry according to Equation (5) based on the CPU allocation cost and the total CPU cost computed in corresponding blocks 1501 and 1502 of FIG. 15 . In block 1702 , a CPU allocation fraction is computed for the data center according to Equation (9) based on the CPU allocation cost and the total CPU cost computed in corresponding blocks 1601 and 1602 of FIG. 16 . In block 1703 , a CPU allocation gap between the CPU allocation fractions computed in blocks 1701 and 1702 is computed as described above with reference to Equation (10). In decision block 1704 , the absolute value of the CPU allocation gap is greater than a CPU threshold, as described above with reference to Equation (12), control flows to block 1705 . Otherwise, control flows to block 1706 . In block 1705 , an alert is generated that indicates CPU allocation costs are not aligned with CPU allocation cost of the cloud computing industry. In block 1706 , a memory allocation fraction is computed for the cloud computing industry according to Equation (18) based on the memory allocation cost and the total memory cost computed in corresponding blocks 1503 and 1504 of FIG. 15 . In block 1707 , a memory allocation fraction is computed for the data center according to Equation (21) based on the memory allocation cost and the total memory cost computed in corresponding blocks 1603 and 1604 of FIG. 16 . In block 1708 , a memory allocation gap between the memory allocation fractions computed in blocks 1706 and 1707 is computed as described above with reference to Equation (22). In decision block 1709 , the absolute value of the memory allocation gap is greater than a memory threshold, as described above with reference to Equation (24), control flows to block 1710 . Otherwise, control flows to block 1711 . In block 1710 , an alert is generated that indicates memory allocation costs are not aligned with memory allocation cost of the cloud computing industry. In block 1711 , a data storage allocation fraction is computed for the cloud computing industry according to Equation (30) based on the data storage allocation cost and the total data storage cost computed in corresponding blocks 1505 and 1506 of FIG. 15 . In block 1712 , a data storage allocation fraction is computed for the data center according to Equation (33) based on the data storage allocation cost and the total data storage cost computed in corresponding blocks 1605 and 1606 of FIG. 16 . In block 1713 , a data storage allocation gap between the data storage allocation fractions computed in blocks 1711 and 1712 is computed as described above with reference to Equation (34). In decision block 1714 , the absolute value of the data storage allocation gap is greater than a data storage threshold, as described above with reference to Equation (36), control flows to block 1715 . Otherwise, control flows to block 1716 . In block 1715 , an alert is generated that indicates data storage allocation costs are not aligned with data storage allocation cost of the cloud computing industry. In block 1716 , a total resource allocation fraction is computed as described above with reference to Equation (39) based on the total resource allocation cost computed in 1507 of FIG. 15 and the total VDC cost of the cloud computing industry. In block 1717 , a total resource allocation fraction is computed as described above with reference to Equation (41) based on the total resource allocation cost computed in 1607 of FIG. 16 and the total VDC cost of the data center. In block 1718 , a total resource allocation gap is computed based on the total resource allocation fractions computed in blocks 1716 and 1717 as described above with reference to Equation (42). In decision block 1719 , when the absolute value of the total resource allocation gap is greater than a total resource threshold as described above with reference to Equation (44) control flows to block 1720 . In block 1720 , an alert is generate that indicates the total resource allocation cost is not aligned with total resource allocation cost of the cloud computing industry.
[0082] FIG. 18 shows a control-flow diagram of the method “compute monetary impact of gaps” called in block 1406 of FIG. 14 . In block 1801 , a monetary CPU allocation impact is computed as described above with reference to Equation (13). In block 1802 , a monetary memory allocation impact is computed as described above with reference to Equation (25). In block 1803 , a monetary data storage allocation impact is computed as described above with reference to Equation (37). In block 1804 , a monetary data resource allocation impact is computed as described above with reference to Equation (45). In blocks 1805 and 1806 , the monetary allocation impact data computed in blocks 1801 - 1804 are stored and may be displayed for viewing, such as displaying on a monitor or other display device.
[0083] The methods described above with reference to FIGS. 14-18 may be encoded in machine-readable instructions stored in one or more data-storage devices of a programmable computer, such as the computer described above with reference to FIG. 1 .
[0084] It is appreciated that the various implementations described herein are intended to enable any person skilled in the art to make or use the present disclosure. Various modifications to these implementations will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other implementations without departing from the spirit or scope of the disclosure. For example, any of a variety of different implementations can be obtained by varying any of many different design and development parameters, including programming language, underlying operating system, modular organization, control structures, data structures, and other such design and development parameters. Thus, the present disclosure is not intended to be limited to the implementations described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. | This disclosure is directed to methods and systems to evaluate resource allocation costs of a data center. Methods and systems compute resource allocation costs of a cloud computing industry to obtain industry benchmarks that are compared with the resource allocation costs of the data center. The comparisons enable IT managers to objectively identify computational resource shortages, resource over investments, and where future investment in computational resources should be made for the data center. | 98,382 |
[0001] The present invention relates to the connection of a lithium or lithium alloy foil electrode or electrodes to a contact lead, so as to promote good electrical and mechanical contact therebetween.
BACKGROUND
[0002] Primary and rechargeable batteries using metallic lithium as the active material for the negative electrode are known to have the highest energy per unit weight. In such batteries, the negative electrode, or anode, may be a lithium or lithium alloy foil component having a negative potential. The negative electrode may also include a current collector and a contact tab.
[0003] A current collector is an electrically conductive metallic foil, sheet or mesh that is generally used to provide a path for electrons from the external electrical circuit to the electrochemically active portion of the battery. A current collector will typically include a contact tab.
[0004] A contact tab is typically a metal foil portion of the current collector, which does not take part in the electrochemical process. It may extend from an edge of the main body of the current collector and is used to form the mechanical base for a weld to a contact lead.
[0005] A contact lead is a piece of electrically conductive metallic material used to form an electrical contact from the contact tab through a hermetically sealed battery container to the external electrical circuit. It is typically welded (in cells where metallic lithium is not used) or mechanically connected to the contact tab.
[0006] The contact lead must be connected or joined to the lithium in such a manner that a low resistance electrical connection is formed. Further, the connection or join must be mechanically strong enough to last for the expected life of the battery.
[0007] The current collectors in lithium primary batteries are typically composed of a metallic conductor other than lithium. The contact lead may be exposed to the electrolyte in an electrochemically active zone of the battery. This is not generally a problem in primary batteries; however it may cause problems in rechargeable (or secondary) batteries. In secondary batteries, lithium must be electrochemically deposited when the battery is recharged. In order to provide good reproducibility of performance, when the battery is repeatedly recharged, an excess of lithium is used so that lithium is only ever deposited onto lithium. If the contact lead or current collector is left exposed, then lithium will be plated onto a non-lithium substrate. This greatly increases the probability of unpredictable lithium deposition and hence poor cycling performance. This typically takes the form of active dendrite formation resulting in the quick degradation of the rechargeable lithium system. Examples of such failure mechanisms are described in U.S. Pat. No. 5,368,958, the full disclosure of which is incorporated into the present application by reference.
[0008] In a secondary battery with a lithium-based anode, the lithium is typically connected to the external circuit by one of two methods. Either a contact lead similar in design to that described for primary lithium batteries is used; as in U.S. Pat. No. 7,335,440, the full disclosure of which is incorporated into the present application by reference. U.S. Pat. No. 7,335,440 discloses the provision of a current collector in the form of a flat, solid piece of titanium, nickel, copper or an alloy of nickel or copper. The current collector is provided with a contact tab. A relatively long strip of alkali metal foil, having a width similar to the height of the current collector, is placed under the current collector and the two are pressed together. It is to be noted that, following assembly of the battery, the current collector (which is not made of an alkali metal) is immersed in electrolyte. Moreover, U.S. Pat. No. 7,335,440 states that this arrangement has problems in coiled, anode-limited cells of the type disclosed therein since there is a potential for a short circuit to be formed between the cathode material and the anode current collector when the thin layer of lithium has substantially depleted into the cathode in the outermost winding.
[0009] A variation of this method uses the metallic cell casing for the dual purpose of collecting current from the lithium, as in U.S. Pat. No. 7,108,942, the full disclosure of which is incorporated into the present application by reference. Additionally, the reverse face of the lithium electrode may be pressed or rolled against a thin metal current collector, as in U.S. Pat. No. 5,368,958, the full disclosure of which is incorporated into the present application by reference. The current collector can then be welded to a metal contact lead. However, if the current collector becomes exposed to the electrolyte, there is a risk that lithium will be plated onto the non-lithium current collector with the possible formation of dendrites that may short-circuit the battery. The metal current collector also adds unnecessary mass to the battery and reduces its specific energy.
[0010] In all of the examples described above, the metallic lithium is merely placed or pressed into contact with the current collector; there is no physical or chemical bond. This may be acceptable for primary batteries. However, for lithium metal rechargeable batteries such contact is not reliable. Indeed due to the reactive character of metallic lithium, corrosion layers may readily form on the interface of the mechanical connection between the lithium and the current collector. This may result in lower battery reliability as well as faster degradation in the capacity and cycle life of rechargeable lithium metal batteries.
BRIEF SUMMARY OF THE DISCLOSURE
[0011] Viewed from one aspect, there is provided a method of connecting at least one electrode to a contact lead, wherein the electrode comprises a sheet or foil having a contact zone, and wherein the contact lead comprises an electrically conductive lead with an end portion, the method comprising the steps of:
[0012] positioning the end portion of the contact lead and the contact zone of the at least one electrode so that there is overlap between the end portion and the contact zone;
[0013] ultrasonically welding the contact zone to the end portion so as to join the at least one electrode to the contact lead,
[0014] wherein at least the contact zone of the sheet or foil is formed from an alkali metal or an alloy of an alkali metal.
[0015] Preferably, the entire sheet or foil is formed from an alkali metal or an alloy of an alkali metal. The alkali metal may be lithium. Lithium metal and lithium allows are preferred as these tend to be useful as anode materials in secondary batteries, and are also soft and malleable, which allows a good connection to be made with the end portion of the contact lead when the welding step is performed.
[0016] Preferably, the contact zone is provided on a tab that protrudes from the edge of the sheet or foil. In a preferred embodiment, the tab provides the only point of contact between the sheet or foil and the end portion of the contact lead. Accordingly, the sheet or foil of the electrode may include a region for contact with the electrolyte that is not in direct contact with the end portion of the contact lead. The ultrasonic weld is preferably provided in a region that is not in contact with any of the electrolyte in the electrochemical cell or battery.
[0017] Preferably, there is no current collector in direct contact with the region for contact with the electrolyte. In fact, the electrode may be devoid of a current collector altogether.
[0018] Preferably, the end portion is formed from a metal that does not form an alloy with the alkali metal or alloy of alkali metal used to form the tab. Examples include metals or metal alloys comprising at least one of copper and/or nickel.
[0019] Without wishing to be bound by any theory, the ultrasonic welding step is believed to cause metal of the tab and/or the end portion to melt or soften, allowing the tab and end portion to be welded together under the applied pressure. The ultrasonic acoustic vibrations may also remove or disperse at least part of the alkali metal oxide layer formed on the tab, facilitating the formation of the bond. An advantage of the present invention is that melting or softening can be confined to the area of the join or weld, allowing a strong bond to be formed over a relatively small area. The area of the weld may be less than 50%, preferably less than 30%, more preferably less than 20%, yet more preferably, less than 10% (e.g. 1-5%) of the area of the sheet or foil.
[0020] Preferably, the ultrasonic welding step is carried out at frequencies of 15 to 70 kHz, more preferably 20 to 60 kHz, even more preferably 20 to 40 kHz, for example, about 40 kHz. The ultrasonic welding step may be carried out at a maximum pressure of 0.4 MPa, preferably 0.1 to 0.4 MPa, for example, 0.2 MPa.
[0021] The ultrasonic welding step may be carried out at a power of 100 to 5000 Watts. Amplitudes of 2 to 30 urn may be used.
[0022] In one embodiment, the ultrasonic welding step is carried out using an apparatus comprising a first clamping portion and a second clamping portion. The first clamping portion and second clamping portion are movable relative to one another from a first spaced apart position to a second position in which the first and second clamping portions are closer to one another. Preferably, only the second clamping portion is movable; the position of the first clamping portion is fixed.
[0023] The first clamping portion acts as a support for the materials to be welded. The second clamping portion is configured to vibrate at an ultrasonic frequency. To perform the welding step, the end portion of the contact lead is placed in contact with the contact zone of the at least one electrode so that there is overlap between the end portion and the contact zone. The overlapping structure is then placed between the first and second clamping portions, preferably on top of the first clamping portion. Optionally, a positioning jig may be used to support the overlapping structure in position. The second clamping portion is then moved relative to the first clamping portion so as to apply a clamping pressure between the materials to be welded. The second clamping portion is then vibrated at ultrasonic frequency. This pre-shapes and rubs the electrode and end portion of the contact lead against one another to prepare the surfaces for the formation of a join. The amplitude of the ultrasonic vibrations plays an important part in pre-shaping and preparing the relevant parts for weld formation. The first clamping portion is typically held in a fixed position while the second clamping portion vibrates. The contact zone of the electrode and end portion of the contact zone are then welded together in the main welding phase.
[0024] The end portion of the contact lead may be substantially flat or planar, or may take other shapes or configurations depending, for example, on the shape or configuration of the welding equipment that is used.
[0025] In one embodiment, a method of connecting at least one electrode to a contact lead, wherein the electrode comprises a sheet or foil having a contact zone, and wherein the contact lead comprises an electrically conductive lead with an end portion, the method comprising the steps of:
[0026] positioning the end portion of the contact lead and the contact zone of the at least one electrode so that there is overlap between the end portion and the contact zone;
[0027] ultrasonically welding the contact zone to the end portion so as to join the at least one electrode to the contact lead,
[0028] wherein at least the contact zone of the sheet or foil is formed from an alkali metal or an alloy of an alkali metal.
[0029] In some embodiments, there may be provided a plurality of electrodes, each comprising a sheet or foil with a tab (defining a contact zone) protruding from each sheet in substantially the same location, so that the tabs of the stack of electrodes are substantially aligned when the electrodes are aligned with each other and arranged as an electrode stack. For the avoidance of doubt, the tab defining the contact zone is formed of an alkali metal or an alloy of an alkali metal, preferably lithium or lithium alloy.
[0030] In these embodiments, the end portion of the contact lead may be placed on top of the tabs of the electrode stack, underneath the tabs of the electrode stack, or at an intermediate position between the top and the bottom (i.e. with at least one tab above and at least one tab below). The tabs of the electrode stack may be pressed together before the end portion is placed on top of or underneath the compressed tabs and the ultrasonic welding is performed.
[0031] In embodiments where there is provided a stack of electrodes, the welding step causes the tabs to bond together physically. Preferably, the ultrasonic welding step causes the tabs (contact zones) of at least two sheets or foils formed from an alkali metal or an alloy of an alkali metal to be welded together. In a preferred embodiment, the ultrasonic welding step creates, for example, a lithium to lithium weld in addition to a weld between lithium and the end portion of the contact lead.
[0032] The end portion of the contact lead may be planar and devoid of through-holes. Alternatively, the end portion may optionally be perforated, punched or have a mesh-like or reticulated form. When such through-holes are present, it is important is that the metal of the tabs is sufficiently malleable to enable it to pass through the through holes so as to cause the end portion to become embedded in what is preferably a single phase of the first metal. This forms an intimate contact between the metals of the end portion of the contact lead and the contact zone of the electrode, and thus between the contact lead and the electrode.
[0033] Where the end portion has through-holes, the openness of the end portion may be defined as the ratio of open area to the full surface area of the end portion. The openness of the end portion of the contact lead may be in the range of 5% to 95%, preferably 20% to 90%, for example, 50% to 80%.
[0034] The electrically conductive lead of the contact lead may itself be generally planar, for example in the form of a ribbon, although other profiles may be useful. The electrically conductive lead may be made of the same metal as the end portion, or of a different metal.
[0035] In this way, it is possible for form a reliable connection with a contact lead made of a metal other than the metal of the electrode. It will be understood that the contact lead, which will generally be exposed outside the casing of the battery, must be made of a metal that has good electrical conductivity but is not highly reactive when exposed to air or moisture. Suitable metals include nickel, copper, stainless steel or various alloys.
[0036] Moreover, the metal of the contact lead, since it is connected only to the protruding tabs of the electrodes, is desirably not directly exposed to electrolyte when the battery is assembled.
[0037] A further advantage is that a good connection can be made to the at least one electrode without the electrode as a whole needing to be formed or disposed on a current collector made of a metal other than the metal used in the sheet or foil of the electrode. In other words, the main part of the electrode that is exposed to the electrolyte consists solely of the first metal (e.g. lithium or a lithium alloy), with no need for a copper or nickel or other current collector that would add unnecessary weight and act as a substrate for the formation of dendrites during cycling.
[0038] Moreover, it is important that the metal of the contact lead is selected so that it does not form an alloy with the metal of the electrode. This is in order to avoid reduction of the amount of the first metal that is available to the electrochemical system of the battery. For example, lithium will form an alloy with aluminium, but not with nickel or copper.
[0039] According to a further aspect of the invention, there is provided a device obtainable according to the method described above. The device comprises at least one electrode comprising a sheet or foil having a contact zone formed from an alkali metal or an alloy of an alkali metal, and a contact lead comprising an electrically conductive lead with an end portion, wherein the end portion of the contact lead overlaps and is ultrasonically welded to the contact zone of the at least one electrode.
[0040] Preferably, the device comprises at least two electrodes comprising a sheet or foil having a contact zone formed from an alkali metal or an alloy of an alkali metal, and wherein at least a portion of said contact zones are ultrasonically welded to one another. Thus, for example when the contact zone is formed from lithium or a lithium alloy, an ultrasonic weld between lithium/lithium alloy and lithium/lithium alloy is formed.
[0041] In one embodiment of the device, at least two electrodes are aligned with each other and arranged as an electrode stack. The end portion of the contact lead may be placed on top of or underneath the electrode stack, such that the end portion overlaps and is ultrasonically welded to the contact zone of the at least one electrode. Alternatively, the end portion of the contact lead may be placed at an intermediate position between the top and the bottom of the electrode stack. In the latter embodiment, the contact zones on either side of the end portion of may preferably also be ultrasonically welded to one another. Accordingly, an alkali metal/alkali metal alloy to alkali metal/alkali metal alloy ultrasonic weld may also be formed.
[0042] Viewed from another aspect, there is provided a method of connecting at least one electrode to a contact lead, wherein the electrode comprises a sheet or foil of a first metal with a tab protruding from an edge of the sheet or foil, and wherein the contact lead comprises an electrically conductive lead with an end portion made of a second metal that does not alloy with the first metal and having a plurality of through holes, the method comprising the steps of:
[0043] i) positioning the end portion of the contact lead and the tab of the at least one electrode so that there is substantial overlap between the end portion and the tab;
[0044] ii) causing the metal of the tab to penetrate through the through holes of the end portion so as to join the at least one electrode to the contact lead.
[0045] In step ii), the metal of the tab may be caused to penetrate through the through holes by pressing and welding, for example by way of ultrasonic welding, thermal contact welding, laser welding or induction welding. Advantageously, the welding is effected in such a way so as not to cause significant thermal deformation or changes in the main laminar sheet or foil of the at least one electrode, but to concentrate the applied energy in the locality of the tab.
[0046] The end portion of the contact lead may be substantially flat or planar, or may take other shapes or configurations depending, for example, on the shape or configuration of any welding equipment that is used.
[0047] In some embodiments, there may be provided a plurality of electrodes, each comprising a sheet or foil of metal with a tab protruding from each sheet in substantially the same location, so that the tabs of the stack of electrodes are substantially aligned when the electrodes are aligned with each other and arranged as an electrode stack.
[0048] In these embodiments, the end portion of the contact lead may be placed on top of the tabs of the electrode stack, underneath the tabs of the electrode stack, or at an intermediate position between the top and the bottom (i.e. with at least one tab above and at least one tab below). The tabs and the perforated end portion are then pressed together and the first metal (of the tabs) is caused to penetrate through the holes in the perforated planar end portion (made of the second metal) of the contact lead. Alternatively, the tabs of the electrode stack may be pressed together before the perforated end portion is placed on top of or underneath the compressed tabs and the penetration of step ii) is performed.
[0049] In embodiments where there is provided a stack of electrodes, the pressing and welding step causes the tabs to join together physically as well as to penetrate into the through holes of the contact lead. Preferably, the welding step is an ultrasonic welding step. This welding step preferably causes the tabs of at least two sheets or foils (preferably formed from an alkali metal or an alloy of an alkali metal) to be welded together. In a preferred embodiment, the ultrasonic welding step creates, for example, a lithium to lithium weld between at least two lithium tabs in addition to a weld between at least one lithium tab and the end portion of the contact lead.
[0050] Particularly preferred metals for the first metal are lithium and lithium alloys, since these tend to be useful as anode materials in secondary batteries, and are also soft and malleable, which allows a good connection to be made with the perforated end portion of the contact lead when the pressing and welding step is performed.
[0051] The end portion of the contact lead may be perforated, punched or have a mesh-like or reticulated form. What is important is that when the first metal of the tabs is sufficiently malleable that it can pass through the through holes so as to cause the second metal of the end portion to become embedded in what is preferably a single phase of the first metal. This forms an intimate contact between the first and second metals, and thus between the contact lead and the electrodes.
[0052] The greater the openness or surface area of the end portion of the contact lead, the better the electrical (and physical) connection between the contact lead and the electrodes. The openness of the end portion may be defined as the ratio of open area to the full surface area of the end portion. The openness of the end portion of the contact lead may be in the range of 5% to 95%.
[0053] The electrically conductive lead of the contact lead may itself be generally planar, for example in the form of a ribbon, although other profiles may be useful. The electrically conductive lead may be made of the same metal as the second metal forming the end portion, or of a different metal.
[0054] In this way, it is possible for form a reliable connection with a contact lead made of a metal other than the metal of the electrode. It will be understood that the contact lead, which will generally be exposed outside the casing of the battery, must be made of a metal that has good electrical conductivity but is not highly reactive when exposed to air or moisture. Suitable metals include nickel, copper, stainless steel or various alloys.
[0055] Moreover, the metal of the contact lead, since it is connected only to the protruding tabs of the electrodes, is not directly exposed to electrolyte when the battery is assembled.
[0056] A further advantage is that a good connection can be made to the at least one electrode without the electrode as a whole needing to be formed or disposed on a current collector made of a metal other than the first metal. In other words, the main part of the electrode that is exposed to the electrolyte consists solely of the first metal (e.g. lithium or a lithium alloy), with no need for a copper or nickel or other current collector that would add unnecessary weight and act as a substrate for the formation of dendrites during cycling.
[0057] Moreover, it is important that the second metal (of the contact lead) is selected so that it does not form an alloy with the first metal (of the electrode). This is in order to avoid reduction of the amount of the first metal that is available to the electrochemical system of the battery. For example, lithium will form an alloy with aluminium, but not with nickel or copper.
[0058] In certain embodiments, the electrode is configured as an anode, or negative electrode, for a battery. However, it will be appreciated that the method is applicable also to cathodes, or positive electrodes, where these are made of a metal that is suitable for pressing and welding to a perforated second metal as described.
[0059] Viewed from a third aspect, there is provided, in combination, at least one electrode for a battery and a contact lead, wherein the electrode comprises a sheet or foil of a first metal with a tab protruding from an edge of the sheet or foil, and wherein the contact lead comprises an electrically conductive lead with an end portion made of a second metal that does not alloy with the first metal and having a plurality of through holes, wherein the first metal of the tab has been pressed and welded so as to penetrate through the through holes of the second metal end portion.
[0060] Embodiments of the present invention seek to provide a negative electrode (anode) eliminating the need for the current collector, and a method of forming a reliable physical contact between different pieces of metallic lithium and the contact lead, thereby to promote good electrical contact between metallic lithium and the material of the contact lead.
[0061] In preferred embodiments, an excess of metallic lithium is used such that at the end of the battery life there is a substantial amount of lithium metal which serves as the current collector for the negative electrode. The use of lithium as the current collector eliminates mechanical contact between metal lithium and another current collector material.
[0062] In some embodiments, there may be provided a plurality of electrodes, each comprising a sheet or foil of the first metal with a tab protruding from each sheet in substantially the same location, so that the tabs of the stack of electrodes are substantially aligned when the electrodes are aligned with each other and arranged as an electrode stack.
[0063] The lithium metal of the negative electrode in the region of the tabs may form a single phase connection from lithium electrode to lithium electrode in the electrode stack. Such connection is achieved by using pressing and welding as hereinbefore described.
[0064] The contact lead, or at least the end portion thereof, may be thin (for example, with a thickness of 5 to 50 μm), or may be thick (for example, with a thickness of 50 to 10,000 μm).
[0065] The contact lead may be substantially linear, or may have a ‘T’-shaped or ‘L’-shaped configuration.
[0066] The sheet or foil of the electrode may have a thickness of 30 to 150 μm, for example, 50 to 100 μm prior to the welding or joining step.
[0067] The end portion of the contact lead may be an integral part of the contact lead (in other words, formed from the same material as the rest of the contact lead and integral therewith), or may be a separate metal component, not necessarily of the same material as the rest of the contact lead, and welded thereto (for example by ultrasonic welding, thermal contact welding, laser welding, induction welding or other types of welding).
[0068] The electrodes described above may be used in a battery or electrochemical cell, preferably a lithium cell, such as a lithium-sulphur cell. The electrodes may be used as the anode of such cells. In one embodiment, the cell comprises i) at least one electrode as described above as the anode(s), and ii) at least one cathode, such as a cathode comprising sulphur as an active material. The anode(s) and cathode(s) may be placed in contact with a liquid electrolyte comprising a lithium salt dissolved in an aprotic organic solvent. A separator may be positioned between the anode and cathode. The electrolyte may be sealed within a container to prevent it from escaping. Preferably, the seal also prevents the alkali metal of the sheet or foil from being exposed to the surrounding environment. Thus, the weld between the contact zone or tab and the end portion of the contact leas is preferably located within the container, while at least a portion of the conductive lead accessible from outside of the sealed container.
BRIEF DESCRIPTION OF THE DRAWINGS
[0069] Embodiments of the invention are further described hereinafter with reference to the accompanying drawings, in which:
[0070] FIGS. 1 a to 1 c shows a battery stack with anodes, cathodes and tabs, and three alternative positionings for a contact lead;
[0071] FIGS. 2 a to 2 e show possible designs for the contact lead;
[0072] FIG. 3 shows the contact lead being ultrasonically welded to the tabs; and
[0073] FIGS. 4 a to 4 d show an apparatus suitable for use in forming an ultrasonic weld in use.
DETAILED DESCRIPTION
[0074] A battery can be formed by an alternating stack of numerous cathodes and anodes. Each of these layers is divided by a separator. An ionic pathway is maintained by the presence, between each electrode, of an electrolyte. Each electrode 1 features a tab 2 protruding from its electrochemically active area and beyond the edge of the separator. These tabs 2 provide the first surface through which the stack 3 of lithium anodes will be welded to each other and joined to a contact lead 4 . The tabs 2 are first folded and/or formed by pressing. A contact lead 4 is then positioned at the top ( FIG. 1 a ) or bottom ( FIG. 1 b ) of the stack 5 of tabs 2 , or it may be positioned between any two lithium tabs 2 ( FIG. 1 c ).
[0075] The contact leads 4 may take a number of forms ( FIGS. 2 a to 2 e ). The body 6 is composed of a conductive metal ribbon, typically nickel, copper, stainless steel or some composite conductor. The end portion 7 (the area to be welded) may be perforated, meshed or punched. Alternatively, the end portion 7 may be devoid of any through-holes (not shown). The end portion 7 may be an integral part of the metal ribbon 6 , or it may be a separate piece welded to the ribbon 6 . Where the end portion 7 is a separate piece welded to the ribbon 6 , it may be made of a different metal to that of the ribbon 6 . The contact may be linear, “T” or “L” shaped. The perforations, when present, may be rhombic, circular, square, rounded, polygonal or any other suitable shape.
[0076] The tabs 2 and the contact lead 4 are then positioned between the two weld fixtures 8 of an ultrasonic welder ( FIG. 3 ). The ultrasonic welder then simultaneously applies pressure and an ultrasonic wave to the weld area. This causes the numerous lithium layers 2 to fuse together to form a lithium-lithium weld. Further, where the contact lead 4 includes through holes, the softened lithium percolates through the perforated or meshed area 7 of the contact lead 4 . The contact lead 4 is hence joined to the lithium 2 as the mesh 7 is intimately surrounded by lithium. The high surface area contact between the mesh 7 of the contact lead 4 and the lithium electrode 1 produces a low resistance and a mechanically strong electrical contact. When the ultrasonic wave ceases and the pressure is released, the contact lead 4 will be joined to the lithium anodes 1 .
[0077] FIGS. 4 a to 4 e depict an apparatus that may be used for forming an ultrasonic weld. The apparatus comprises a first clamping portion 12 and a second clamping portion 14 that are movable from a first spaced apart position to a second position where the portions 12 , 14 are closer to one another. The apparatus also includes a positioning jig 16 for supporting the parts 18 to be welded in position. The second clamping portion 14 is configured to vibrate at ultrasonic frequencies.
[0078] As best seen in FIG. 4 a , the parts 18 to be welded are placed on top of the first clamping portion 12 while the clamping portions are in their first spaced apart position. The second clamping portion 14 is then moved relatively towards the first clamping portion 12 to apply a clamping pressure between the parts 18 to be welded. The second clamping portion 14 is then vibrated at ultrasonic frequency ( FIG. 4 b ). This pre-shapes and rubs the parts 18 together, so that their surfaces are prepared for weld formation. In the main welding phase, the parts 18 are joined together (see FIG. 4 c ). The first and second clamping portions 12 , 14 are then moved apart to allow the welded parts 18 to be removed from the apparatus (see FIG. 4 d ).
Example 1
[0079] A linear nickel contact lead, composed of 50 μm thick nickel ribbon, was used. The endmost 5 mm of the contact lead was expanded to form a mesh. A battery with 60 lithium anodes, each of 78 μm thickness, was assembled. A stack of lithium contact tabs protruded from the battery. The lithium contact tabs were formed and trimmed to produce a flat welding area and to ensure that each of the tabs, regardless of its position, in the stack used the minimum quantity of lithium. The formed stack of lithium tabs was then positioned between the welding fixtures of an ultrasonic welder. The contact lead was then positioned on top of the stack of lithium tabs, such that the meshed region overlapped with the flat lithium welding zone. The welding conditions listed in Table 1 were then entered into an AmTech 900B 40 kHz ultrasonic welder. A single weld was then performed. Each of the 60 lithium layers were welded firmly to each other. A strong join was produced between the lithium and the contact lead. This join had been created by the softened lithium penetrating through the mesh of the contact lead.
[0000]
TABLE 1
The welder setting used in Example 1.
Energy/J
Amplitude/μm
Trigger Pressure/Psi
Pressure/Psi
180
5
20
20
Example 2
[0080] A “T” shaped contact lead was made by welding a piece of nickel ribbon (50 μm thick) to a piece of copper mesh. The mesh opening was approximately 200×700 μm, with a bar width of 100 μm. The mesh was thrice as long as the nickel ribbon was wide. The mesh was 5 mm wide; the same as the welding zone. The mesh was positioned centrally to form the cross of the “T” and welded into position by an ultrasonic welder using the conditions given in Table 2, weld A. The contact lead was positioned between the welding fixtures of an ultrasonic welder such that the meshed region fell into the welding zone.
[0081] A battery with 20 lithium anodes, each of 78 μm thickness, was assembled. A stack of lithium contact tabs protruded from the battery. The stack of lithium contact tabs was formed and trimmed to produce a flat welding area and to ensure that each of the contact tabs, regardless of its position, in the stack used the minimum quantity of lithium.
[0082] The stack of lithium contact tabs was then positioned on top of the contact lead, between the welding fixtures of an ultrasonic welder. The copper mesh “arms” of the “T” shaped contact lead were then folded around the stack of lithium contact tabs. The welding conditions listed in Table 2, weld B were then entered into an AmTech 900B 40 kHz ultrasonic welder. A single weld was then performed. Each of the 20 lithium layers were welded firmly to each other. A strong join was produced between the lithium and the contact lead. This join had been created by the softened lithium penetrating through the mesh of the contact lead.
[0000]
TABLE 2
The welder settings used in Example 2
Weld
Energy/J
Amplitude/μm
Trigger Pressure/Psi
Pressure/Psi
A
70
80
80
5
B
10
5
20
20
Example 3
[0083] An “L” shaped contact lead was manufactured by photochemical etching from a sheet of 100 μm thick stainless steel. The upright section of the “L” is continuous steel foil. The base of the “L” was etched with a mesh pattern. The mesh opening was 500×500 μm and the bar width was 100 μm. The base of the “L” was twice the width of the upright section. The width of the base section was 5 mm, the same as the weld zone.
[0084] A battery with 20 lithium anodes, each of 78 μm thickness, was assembled. A stack of lithium contact tabs protruded from the battery. The contact lead was positioned between the top face to the lowermost lithium contact tab and the bottom face of the remainder of the stack. The remainder of the stack of lithium contact tabs was pushed down onto the meshed region of the contact lead. The protruding meshed section of the contact lead was folded over the stack of contact tabs. The contact assembly was positioned between the welding fixtures of an ultrasonic welder such that the meshed regions fell into the welding zone.
[0085] The welding conditions listed in Table 3 were then entered into an AmTech 900B 40 kHz ultrasonic welder. A single weld was then performed. Each of the 20 lithium layers were welded firmly to each other. A strong join was produced between the lithium and the contact lead. This join had been created by the softened lithium penetrating through the mesh of the contact lead.
[0000]
TABLE 3
The welder settings used in Example 3
Energy/J
Amplitude/μm
Trigger Pressure/Psi
Pressure/Psi
40
5
20
20
Example 4
Nickel
[0086] A square shaped contact lead was made by cutting a piece of plane nickel foil (100 μm thick). The contact lead was positioned between the welding fixtures of an ultrasonic welder such that the welding zone was 1 mm from the tab edge. The welding zone was a rectangle (20×6 mm).
[0087] A battery with 9 lithium anodes, each of 100 μm thickness, was assembled. A stack of lithium contact tabs protruded from the battery. The stack of lithium contact tabs was formed and trimmed to produce a flat welding area and to ensure that each of the contact tabs, regardless of its position, in the stack used the minimum quantity of lithium. The trimmed edges of lithium tabs fully covered the welding zone at the nickel foil.
[0088] The stack of lithium contact tabs was then positioned on top of the contact lead, between the welding fixtures of an ultrasonic welder. The welding conditions are listed in Table 4. The welder is a NewPower Ultrasonic Electronic Equipment CO., LTD 40 kHz ultrasonic welder. A single weld was performed. Each of the 9 lithium layers were welded firmly to each other. A strong join was produced between the lithium and the nickel contact lead. This join had been tested per peel test procedure.
[0000]
TABLE 4
Frequency
40 kHz
Welding Time sectors:
Delay
0.15 s
Welding
0.18 s
Take off
0.20 s
Amplitude
50% (of 10 μm)
Pressure
0.21 MPa
Power
350 W
Energy
350 J
Example 5
Copper
[0089] A square shaped contact lead was made by cutting a piece of plane copper foil (100 μm thick). The contact lead was positioned between the welding fixtures of an ultrasonic welder such that the welding zone was placed 1 mm from the tab edge. The welding zone was a rectangle (20×6 mm).
[0090] A battery with 9 lithium anodes, each of 100 μm thickness, was assembled. A stack of lithium contact tabs protruded from the battery. The stack of lithium contact tabs was formed and trimmed to produce a flat welding area and to ensure that each of the contact tabs, regardless of its position, in the stack used the minimum quantity of lithium. The trimmed edges of lithium tabs fully covered the welding zone at the copper foil.
[0091] The stack of lithium contact tabs was then positioned on top of the contact lead, between the welding fixtures of an ultrasonic welder. The welding conditions are listed in Table 5. The welder is a NewPower Ultrasonic Electronic Equipment CO., LTD 40 kHz ultrasonic welder. A single weld was then performed. Each of the 9 lithium layers were welded firmly to each other. A strong join was produced between the lithium and the copper contact lead. This join had been tested per peel test procedure.
[0000]
TABLE 5
Frequency
40 kHz
Welding Time sectors:
Delay
0.15 s
Welding
0.16 s
Take off
0.20 s
Amplitude
50% (of 10 μm)
Pressure
0.20 MPa
Power
300 W
Energy
300 J
Example 6
Stainless Steel, 316
[0092] A square shaped contact lead was made by cutting a piece of plane stainless steel foil (58 μm thick). The contact lead was positioned between the welding fixtures of an ultrasonic welder such that the welding zone was placed 1 mm from the tab edge. The welding zone was a rectangle (20×6 mm).
[0093] A battery with 9 lithium anodes, each of 100 μm thickness, was assembled. A stack of lithium contact tabs protruded from the battery. The stack of lithium contact tabs was formed and trimmed to produce a flat welding area and to ensure that each of the contact tabs, regardless of its position, in the stack used the minimum quantity of lithium. The trimmed edges of lithium tabs fully covered the welding zone at the stainless steel foil.
[0094] The stack of lithium contact tabs was then positioned on top of the contact lead, between the welding fixtures of an ultrasonic welder. The welding conditions are listed in Table 6, were then entered into the NewPower Ultrasonic Electronic Equipment CO., LTD 40 kHz ultrasonic welder. A single weld was then performed. Each of the 9 lithium layers were welded firmly to each other. A strong join was produced between the lithium and the stainless steel contact lead. This join had been tested per peel test procedure.
[0000]
TABLE 6
Frequency
40 kHz
Welding Time sectors:
Delay
0.15 s
Welding
0.18 s
Take off
0.20 s
Amplitude
80% (of 10 μm)
Pressure
0.21 MPa
Power
350 W
Energy
350 J
[0095] Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to”, and they are not intended to (and do not) exclude other moieties, additives, components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.
[0096] Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.
[0097] The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference. | There is disclosed a method of connecting a lithium electrode to a contact lead in a rechargeable battery. The electrode comprises a sheet or foil of lithium or lithium alloy with a tab protruding from an edge of the sheet or foil. The contact lead comprises an electrically conductive lead with an end portion made of a second metal that does not alloy with lithium and has a plurality of through holes. The end portion of the contact lead and the tab of the electrode are positioned so that there is substantial overlap between the end portion and the tab. The metal of the tab is then caused, for example by pressing and welding, to penetrate through the through holes of the end portion so as to join the electrode to the contact lead. A combination electrode/contact lead assembly made by this method is also disclosed. | 51,396 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to fire-fighting equipment, and more specifically to equipment coupled to a fire hose or pipeline for integrating an additive to a water stream.
[0002] Fire fighting systems typically include a fire truck, such as truck T in FIG. 1 , which includes a pumping unit P that pumps water under high pressure from a tanker truck or a nearby fire hydrant, through a fire hose H 1 , H 2 and nozzle N. While water alone is sufficient for most fires, some fires cannot be efficiently controlled or extinguished by water alone. In this case, certain chemical additives are introduced into the water line to be discharged onto the particular type of fire. Incidents involving flammable liquids or hazardous materials often require the use of a foam that is spread over the fire to starve the fire of oxygen or to suppress noxious vapors. For instance, Class A foam concentrates are used for wildland, rural and urban fire suppression on Class A fuels, such as wood, paper and other solid materials. Class B foam concentrates are primarily intended for Class B materials, such as flammable liquids containing hydrocarbons or polar solvents, and can be used for vapor suppression or extinguishment.
[0003] There are numerous approaches to introducing chemical additives or foam concentrates into the flow through firefighting water lines. Some systems utilize additive pumps for forced injection of the chemical into the water line. Such systems are generally complicated and are not portable. On the other hand, portable systems rely upon the movement of water through the fire hose to educe the chemical. In the context of the present invention, educe or induct means that liquid is drawn into the system, such as by the flow of another liquid. In one typical arrangement, a foam bucket F contains a liquid foam concentrate that is induced into the fire hose H 2 by a foam eductor valve E. This typical eductor valve E relies upon venturi flow to draw the foam concentrate from the foam bucket F into the water stream passing through the eductor E.
[0004] The chemical additives or foam concentrates are often corrosive and usually expensive. Thus, the typical eductor valve E includes a check valve system to prevent backflow of water into the chemical supply. For instance, the by-pass eductor described in U.S. Pat. No. 5,960,887, includes a ball check valve integrated into a foam concentrate metering valve.
[0005] While the check valve is important to prevent water backflow, it can be problematic with respect to cleaning the eductor valve E. In fire-fighting equipment back-flow typically occurs when the discharge nozzle N is shut off or when the hose H 2 is kinked so that fluid discharge is terminated. Without cleaning, the chemicals passing through the valve may congeal and foul the valve or the metering orifice used to control the quantity of chemical introduced into the water stream. In an extreme case, the valve may be stuck open or closed. Prior devices require disengaging the eductor valve from the water line, connecting the water supply hose H 1 to the chemical inlet of the eductor valve E, and flushing the valve with water. This process is cumbersome, but perhaps more significantly this approach can be hazardous. In particular, disengaging a eductor valve filled with a chemical additive of foam concentrate will necessarily result in a chemical spill.
[0006] What is needed is an eductor valve apparatus that satisfies all of the necessary functions of an eductor, but that is easy and safe to clean. Such an apparatus would allow controlled flushing so that the chemicals can be safely collected without risk of spilling. A further need is the ability to readily determine the position of the check valve and to manually alter it.
SUMMARY OF THE INVENTION
[0007] To address this unmet need, the present invention contemplates a system for preventing actuation of a check valve within an eductor assembly. In one embodiment, the present invention contemplates an eductor assembly for use with firefighting equipment that comprises an eductor body defining a fluid inlet connectable to a source of a firefighting fluid (e.g., high pressure water), a fluid outlet for dispensing fluid therefrom in fluid communication with the fluid inlet, and an additive inlet connectable to a source of an additive to the firefighting fluid and in fluid communication with the fluid outlet. The additive can be, for example, a foam concentrate that is educed to mix with the high pressure water under venturi flow.
[0008] The eductor assembly further comprises a check valve disposed between the additive inlet and the fluid outlet that is moveable, in response to a flow of water through the fluid inlet, between a first position operable to prevent back flow of water through the additive inlet and a second position to permit flow of additive through the additive inlet to the fluid outlet. In other words, the check valve is open to permit the eduction of the additive under proper venturi conditions, but otherwise closes the additive inlet.
[0009] In one important feature of the invention, means are provided for holding the check valve in its open position while allowing water back flow through the additive inlet. This feature allows the additive fluid circuit to be back flushed and thus cleaned after use. In one embodiment, this means includes an actuator operable from outside the eductor body to move the check valve to the second position. In a more specific embodiment, this actuator is an elongated pin having a proximal end manually accessible outside the eductor body and an opposite working end engageable with the check valve to move the check valve to the second position. The actuator preferably includes a push button mounted to the proximal end of the pin to facilitate manual operation of the actuator.
[0010] Preferably, the actuator pin is sized so that it does not contact the check valve in its non-actuated position. In the preferred embodiment, means are provided for biasing the pin to this non-actuated position away from engagement with the check valve. When the push button is manually pressed, the pin moves against this biasing means to contact and push the check valve to its open position.
[0011] The eductor assembly further comprises a metering head in fluid communication with the additive inlet, in which the metering head includes a metering inlet connectable to the source of the additive and an adjustable metering element disposed between the metering inlet and the additive inlet. The actuator is supported by the metering head to engage the check valve to move the check valve to the second position. Where the actuator is an elongated pin, the pin is slidably disposed within the metering head and has a proximal end manually accessible outside the metering head and an opposite working end engageable with the check valve to move the check valve to the second position.
[0012] In one embodiment, the metering element is connected to a proportioning knob movably mounted to the metering head, and the knob defines a recess for receiving the push button and a bore communicating with the recess slidably receiving the pin therethrough. In a further feature, the eductor assembly includes a mating assembly between the metering head and the additive inlet of the eductor body for removably coupling the metering head thereto. This mating assembly allows removal of not only the additive metering components, but also the actuator pin and push button.
[0013] Preferably, the actuator includes a spring between the push button and the proportioning knob within the recess. The spring is arranged to bias the pin away from engagement with the check valve. In certain embodiments, the pin extends through the metering element, which can comprise a hollow proportioning ball defining a plurality of differently sized metering openings arranged to be selectively aligned with the metering inlet, and a hollow stem coupled to the proportioning ball and defining a passageway to slidingly receive the pin. A fluid sealing element or seal ring may be disposed between the pin and the hollow stem.
[0014] In the preferred embodiment, the check valve includes a valve disc sized to close the additive inlet in the first position and a number of alignment wings projecting from the valve disc into the additive inlet when the check valve is in either of the first and second positions. Thus, the wings maintain the position of the check valve as it moves between its open and closed positions. The wings are sufficiently dispersed to allow substantially unimpeded flow of additive of water back flow through the additive inlet. In a specific embodiment, the number of wings defines a hub arranged to be engaged by the actuator pin when the actuator is operated to move the check valve to the second position.
[0015] The invention further contemplates a method of cleaning an eductor assembly used to introduce an additive to a flow of water through a venturi nozzle. The eductor assembly includes an eductor body defining the venturi nozzle, an additive inlet in fluid communication with the venturi nozzle and a check valve disposed between the additive inlet and the venturi nozzle that is open when the venturi nozzle produces suction to educe additive through the additive inlet, and is otherwise closed to prevent back flow through the additive inlet of water passing through the venturi nozzle. The preferred embodiment of the method comprises the steps of moving the check valve to its open position, holding the check valve in that position and then flowing water through the venturi with the check valve open to produce back flow of water through the additive inlet. Preferably, the holding step includes manually depressing an actuator pin slidably disposed within the eductor assembly to push the check valve into its open position.
[0016] It is one object of the present invention to provide a system and method for cleaning an eductor assembly that is used for introducing a chemical additive, such as foam concentrate, into a flow of water used to battle a fire.
[0017] One benefit of the invention is that the inventive eductor valve apparatus satisfies all of the necessary functions of an eductor, but is easy and safe to clean. A further benefit of the apparatus is that it allows controlled flushing so that the chemicals can be safely collected without risk of spilling. Yet another benefit is provided by the ability to readily determine the position of the check valve and to manually alter it.
[0018] Other objects and benefits of the invention will become apparent upon consideration of the following written description, taken together with the accompanying figures.
DESCRIPTION OF THE FIGURES
[0019] FIG. 1 is a pictorial representation of a fire truck equipped for dispensing a foam for fire or vapor suppression or extinguishment.
[0020] FIG. 2 is a perspective view of the components of an eductor assembly in accordance with one embodiment of the invention.
[0021] FIG. 3 is an exploded view of the eductor assembly depicted in FIG. 2 .
[0022] FIG. 4 is a side partial cross-sectional view of the eductor assembly shown in FIGS. 2-3 .
[0023] FIG. 5 is an enlarged perspective view of a check valve for use in one embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification. It is understood that no limitation to the scope of the invention is thereby intended. It is further understood that the present invention includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the invention as would normally occur to one skilled in the art to which this invention pertains.
[0025] In accordance with one embodiment of the invention, the eductor valve E shown in FIG. 1 includes an eductor assembly 10 , as illustrated in FIG. 2 . This assembly includes a main body 11 having a water inlet 13 and an outlet 15 . A foam inlet 17 intersects the inlet and outlet and is configured to mate with a metering head 20 . The metering head 20 is connected to a suction hose 22 that terminates in a wand 23 . The wand 23 is configured to engage the foam bucket F ( FIG. 1 ) in a conventional manner to draw foam concentrate from the bucket by venturi flow of water through the main body 11 . The metering head 20 includes a mating ring assembly 27 that is configured for quick connect and disconnect to the foam inlet 17 . A proportioning knob 25 can be rotated to adjust the quantity of chemical additive fed through the metering head 20 into the main body 11 .
[0026] As shown in the detail view of FIGS. 3 and 4 , the eductor assembly as thus far described is of known construction. For instance, the main body 11 is hollow and defines a plenum 12 ( FIG. 4 ) into which the chemical or foam additive is drawn. A blending tube 35 is situated at the inlet 13 of the body 11 , terminating in a nozzle end 37 within the plenum 12 . A coupling assembly 39 mounts the blending tube 35 within the body and provides an interface for engagement to a fire hose H 1 ( FIG. 1 ). The coupling assembly 39 can be of known construction, including, for instance, a ball bearing mounted threaded coupling ring sized to mate with a 1½ inch fire hose connection. The coupling assembly 39 facilitates ready removal and replacement of the blending tube 35 to substitute a tube sized for different water flow rates.
[0027] At the outlet 15 , the body 11 mates with a discharge nozzle 42 . The nozzle 42 terminates in a nozzle end 44 within the plenum 12 and is arranged to receive water or a water/chemical mixture when water is supplied under pressure at the inlet 13 . The discharge nozzle 42 includes a coupling end 45 that is configured in a known manner for engagement to a hose H 2 or nozzle N. The discharge nozzle 42 is configured for threaded engagement within the main body 11 . Different discharge nozzles can be provided with differently sized outlets 15 to achieve selectable exit flow rates. In addition, the size of the inlet 13 to the eductor is preferably correlated to the discharge nozzle outlet size to achieve these flow rates.
[0028] The metering head 20 mates with the additive or foam inlet conduit 47 of the main body 11 . The mating ring assembly 27 can be configured in a known manner to provide a quick connect/disconnect fitting arrangement, as depicted in FIG. 3 . The mating ring assembly 27 allows a number of metering heads to be engaged to an eductor body depending upon the desired chemical/foam flow rate.
[0029] The metering head 20 includes a metering body 50 that defines a foam inlet 52 . A fitting assembly 24 connects the suction hose 22 to the metering body in a known manner. The metering body defines a cavity 51 that communicates with the inlet 52 . A proportioning ball 54 resides in and is rotatable within the cavity to align a plurality of differently sized metering orifices 56 with the inlet 52 . In a specific example, the proportioning ball includes five orifices of different sizes and shapes to correspond to different proportional settings for foam consumption, as well as a no flow or “off” setting in which the foam inlet 52 is blocked. In this specific example, the orifices correspond to ¼%, 1 / 2 %, 1%, 3% and 6% ratios of foam concentrate to water volume. The two smaller settings correspond to small orifice diameters and are typically better suited for Class A foams. The larger settings are typically better suited for Class B foams.
[0030] The proportioning ball 54 includes a stem 60 that extends through a bore 53 in the metering body. The stem 60 is connected to the proportioning knob 25 to rotate with the knob. In a specific embodiment, the stem 60 extends through a bore 76 in the knob and includes a notch 61 that can interlock with a rib (not shown) within the bore so that the two components rotate together. An O-ring 58 between the proportioning ball 54 and the metering body helps prevent leakage through the bore 53 . As best seen in FIG. 4 , the metering ball 54 provides a fluid path from the foam inlet 52 through a selected metering orifice 56 and into the cavity 51 of the metering body. The knob preferably includes indicia corresponding to the position of the proportioning ball 54 relative to the foam inlet 52 .
[0031] When the metering head 20 is mounted on the eductor main body 11 , the metering cavity 51 communicates with the plenum 12 through a passageway 49 defined in the additive inlet conduit 47 . As is known in the art, water flowing from the nozzle end 37 of the blending tube 35 into the nozzle end 44 of the discharge nozzle 42 causes a pressure drop within the plenum. This pressure drop pulls or educts fluid from the foam bucket F through the wand 23 , creating a high speed flow of the chemical additive or foam concentrate. This educed fluid mixes with the water as it is discharged through the discharge nozzle 42 .
[0032] In order to prevent unwanted backflow of water from the plenum into the metering head 20 , a check valve 30 is provided within the foam inlet conduit 47 , as shown in FIGS. 3-4 . In a preferred embodiment of the invention, the check valve 30 includes a valve disc 85 that has a diameter greater than the diameter of the passageway 49 defined in the inlet conduit 47 . More specifically, the valve disc 85 is sized to engage a valve seat 49 a to completely close the passageway 49 to prevent the backflow of water into the inlet conduit and metering head.
[0033] The check valve 30 includes an arrangement of wings 87 projecting upward from the disc 85 into the passageway 49 . The wings are configured to constrain and guide the check valve so that it translates along the axis of the passageway and so that the valve disc 85 seats flush with the valve seat 49 a in the main body 11 to close the passageway 49 . The upper surface of the disc 85 can include a resilient seal ring 91 to improve the sealing capability of the check valve. Alternatively, the disc itself can be formed of a resilient material that deforms slightly under fluid pressure to form a tight seal against the main body. In the preferred embodiment, the check valve, including the disc 85 and wings 87 , is formed of a plastic material.
[0034] The wings 87 have a height calibrated so that the wings remain substantially disposed within the passageway even when the valve disc 85 is in contact with one or both of the nozzle ends 37 , 44 . Under normal operating conditions, the valve disc 85 will remain trapped between the nozzle ends and the additive inlet as the venturi suction pulls the disc downward and induces chemical fluid flow through the metering head 20 . However, once the venturi suction falls below a threshold value, or when no fluid is flowing through the metering head, the inlet water pressure will push the check valve upward until the valve disc seals against the main body and closes the inlet passageway 49 . This condition will occur in response to a termination of the flow downstream, such as when the nozzle N is shut off or when the hose H 2 is kinked. Under normal operating conditions, the check valve will remain closed (preventing backflow into the metering head) when the fire hose nozzle N ( FIG. 1 ) is off, since there is no flow through the eductor to produce venturi suction. However, once the nozzle is opened, water flow commences and the check valve opens to draw the chemical additive or foam concentrate into the plenum 12 .
[0035] As thus far described, the check valve 30 presents the same problem experienced by the prior eductor valves with respect to cleaning the eductor assembly 10 . In order to alleviate this problem, the present invention contemplates a system for holding the check valve 30 in an open position—i.e., with the valve disc 30 unseated or offset from the eductor body, leaving the passageway 49 substantially unobstructed even under water pressure. In order to achieve this objective, the preferred embodiment of the invention includes a back flush pin 65 ( FIGS. 3-4 ) that bears against a contact hub 89 defined at the peak of the wings 87 (see FIG. 5 ). The pin 65 is slidably disposed within a passageway 62 defined in the stem 60 of the proportioning ball 54 . Thus, while the proportioning ball is fixed in translation along the cavity 51 , the pin 65 is free to move vertically downward into contact with the hub 89 of the check valve 30 to push the valve downward away from the passageway 49 . For the purposes of the present disclosure, the “vertical” direction is defined as along the axis of the metering body 50 , and “downward” is movement toward the eductor body 11 .
[0036] In the illustrated embodiment, the proportioning knob 25 defines a recess 75 within the metering body 50 that communicates with the bore 76 . As explained above, the stem 60 of the proportioning ball 54 interlocks with the knob 25 within this bore. 0 -ring 58 provides a fluid tight seal between stem 60 and metering body 50 . A cross pin 69 passes through a bore 68 ( FIG. 3 ) in the back flush pin to set an upper limit for the travel of the pin. An O-ring 73 is mounted within a seal ring groove 74 in the pin 65 to provide a fluid-tight seal between the pin and the passageway 62 as the pin translates within the bore.
[0037] A push button 79 is threaded onto the end of the back flush pin 65 , trapping a return spring 77 within the recess 75 . The top end of the back flush pin 65 defines an internally threaded bore 71 to receive a locking screw 81 for fixing the back flush pin 65 to the push button 79 . The push button 79 is accessible above the proportioning knob 25 so that the button can be manually depressed when it is desired to clean the eductor assembly 10 . When the button is pushed, the back flush pin 65 is driven downward to push against the check valve 30 . With the button 79 fully depressed, the check valve is clear of the passageway, creating a back flush flow path from the water inlet 13 through the eductor assembly 10 . The eductor assembly does not need to be disconnected from the water supply, but instead remains connected as it was during the firefighting action. Water from the pumping unit P of the fire truck T, through fire hose H 1 , can be supplied directly to the eductor assembly to flush all of the chemicals out of the assembly components. The flushed liquid is discharged through the suction hose 22 and wand 23 , which means that the wand can be placed within an appropriate receptacle to receive the back flush liquid waste.
[0038] In a typically cleaning process after use, the wand is removed from the foam supply F and optionally placed in a discharge container. The water flow through the supply hose H 1 is significantly reduced from the typical fire-fighting water pressure and flow rate. In a specific embodiment, the back flush water pressure is reduced to below 45 psi (as compared to a typical operating pressure of about 200 psi). With the nozzle N closed (to prevent water flow through the hose H 2 ), the back flush button 79 is depressed to release the check valve 30 and allow the water to flow back through the metering body 50 , suction hose 22 and suction wand 23 . The proportioning knob 25 rotated as the water continues to back flush so that water passes through every foam metering orifice 56 in the proportioning ball 54 . Back flushing continues at each metering setting until there is no visible foam in the flush water. At that point, the water supply is stopped and the metering head 20 is removed from the main body 11 by manipulating the mating ring assembly 27 . The residual water within the metering body 50 and main body 11 can be gravity drained.
[0039] Under certain conditions, the check valve 30 may not properly engage the valve seat 49 a ( FIG. 4 ) to fully close the passageway 49 . In order to ensure a proper sealing engagement, the check valve 30 may be provided with a return element 100 , as shown in FIG. 5 . The return element 100 includes a ring 102 that defines an opening that is preferably larger than the flow path through the outlet 15 so as not to impede the flow of fluid through the eductor 10 . A base 104 is provided on the ring to bear against the wall of the plenum 12 .
[0040] The element 100 further includes an elongated stem 106 projecting upward from the ring 102 . The stem passes through a bore 107 defined in the hub 89 of the check valve 30 . In the preferred embodiment, the stem 106 is long enough to pass completely through the check valve bore 107 .
[0041] The ring 102 is formed of a corrosion resistant material that is flexible and resilient. In a preferred embodiment, the ring is formed of a thermoplastic elastomer, such as ALCRYN®. When the back flush pin 65 is depressed, the check valve 30 bears against the ring 102 to deform the ring. In a preferred embodiment, the ring 102 is circular in its installed shape, and becomes generally oval as it is deformed under pressure from downward movement of the check valve. The return element is configured so that it can be deformed when the check valve opens under venturi pressure. In the preferred embodiment, the opening force due to venturi pressure is about ½ ounce. In addition, when the back flush pin 65 is depressed, the check valve 30 bears against the ring 102 to deform the ring. When the back flush pin is release, the ring 102 seeks its neutral shape so that it springs back to its original oval shape. In so doing, the ring 102 pushes the check valve 30 upward into engagement with the valve seat 49 a. Moreover, as the ring 102 pushes the valve upward, the stem 106 keeps the check valve in proper alignment so the disc 85 bears fully against the valve seat.
[0042] In certain embodiments, the ring 102 is sized so that in its neutral or un-deformed shape the base 104 contacts the wall of the plenum 12 while the top of the ring is also in contact with the disc 85 of the check valve. Alternatively, the ring may be sized so that the top of the ring 102 is slightly offset from the disc 85 so as not to impede the downward movement of the check valve under venturi pressure only. However, in this alternative, the ring is sized so that the ring may be deformed when the back flush pin 65 is fully depressed.
[0043] In the preferred embodiment, the return element is in the form of a ring so that the return spring force produced by the element 100 will be directed substantially along the axis of the elongated stem 106 . Other forms of the return element may be contemplated provided that the element does not interfere with the flow of fluid through the eductor and that the element operates to accurately return the check valve to the valve seat. For example, in lieu of the complete ring 102 , the return element 100 may include a pair of resilient legs extending downward and outward from the check valve to contact the side walls of the plenum 12 .
[0044] The internal components of the eductor assembly 10 are formed of materials that are compatible with the types of chemical additives or foam concentrates flowing through the assembly. The component materials are preferably non-reactive with the chemicals and resistant to the corrosive effects of these chemicals. In a specific embodiment, the wand 23 and the back flush pin 65 , and ancillary hardware are formed of stainless steel, as is the back flush pin 65 . On the other hand, the blending tube 35 can be formed of a high density plastic. Preferably, all the other components are formed of a metal, such as aluminum that has been hard anodized. The proportioning ball 54 and integral stem 60 are also preferably formed of a high density plastic, which beneficially provides a smooth sliding surface for the O-ring 73 as the back flush pin 65 reciprocates within the passageway 62 .
[0045] While the invention has been illustrated and described in detail in the drawings and foregoing description, the same should be considered as illustrative and not restrictive in character. It is understood that only the preferred embodiments have been presented and that all changes, modifications and further applications that come within the spirit of the invention are desired to be protected.
[0046] For instance, while the illustrated embodiment of the check valve contemplates a disc valve, other one-way valves can be utilized. For instance, a ball valve can be situated within the plenum 12 so that the ball seals against the passageway 49 . A cage may contain the ball in alignment with the passageway. The same back flush pin 65 described above can be arranged to bear against the check ball to prevent it from seating over the passageway. In this instance, the pin 65 and inlet conduit 47 would be commensurately sized so that the pin is clear of the ball valve during normal use but is capable of extension into contact with the ball when it is desired to back flush the eductor assembly.
[0047] Similarly, the check valve can be a resilient valve, such as a duckbill valve. With this type of valve, the working end of the back flush pin can be modified to hold open the duckbill when the pin is pushed through the valve.
[0048] As a further example, the illustrated embodiment contemplates a push button feature for actuating the back flush pin 65 . Other means and mechanisms for actuating the pin are contemplated by the present invention. For instance, a pivoting or sliding lever can be integrated into the side wall of the metering body so that manipulation of the lever will push the check valve to its open position. Non-contact actuation is also contemplated, such as a magnetically coupled valve. | An eductor assembly includes an inlet connectable to a high pressure water source useful in firefighting, an outlet connectable to a fire hose and/or nozzle, and a venturi therebetween. An additive inlet communicates with the venturi so that a chemical additive, such as a foam concentrate, is educed into the output stream. A check valve is positioned at the additive inlet to open under venturi flow conditions and remain closed otherwise. An actuator is provided that holds the check valve in its open position while water flows through the eductor assembly under non-venturi conditions to produce a back flow through the additive inlet and ultimately through the additive fluid circuit, including the additive metering valve components. A return element may be disposed within the eductor body to return the check valve to its closed position when the back flow ceases. | 31,148 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional Patent Application 61/338,271 filed Feb. 16, 2010, which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates to haptics, robotics and motor control. In particular, the invention relates to motor control amplifiers exploiting the inate motor dynamics of DC motors.
BACKGROUND OF THE INVENTION
[0003] Haptic interfaces allow users to feel virtual or remote environments by interacting with a robotic master device coupled to a computer simulation or robotic slave. The effective rendition of interactions ranging from free motion to rigid contact with a virtual surface is a central goal in haptic simulation. Two types of interfaces are commonly discussed, admittance and impedance, describing the causality of the user interaction. The invention is concerned with impedance-type haptic devices which try to accomplish this by producing forces in response to contacts in the virtual environment as a result of motion caused by the user. In the case of free motion, these devices work very well, since they are generally designed to be easily back-driven by the user. Stable simulation of high-stiffness contact, on the other hand, remains a challenge. The present invention addresses this challenge.
SUMMARY OF THE INVENTION
[0004] The present invention pertains to methods of controlling an haptic device with particular attention to motor control amplifiers exploiting the inate motor dynamics of DC motors (linear or rotary motors). The control method encompasses a digital and analog circuit. In the digital circuit, a command voltage is determined by a digital controller utilizing sensed motion information of the haptic device and a motion command signal. In the analog circuit, an amplifier applies a voltage to an electrical DC motor. The applied voltage incorporates the determined command voltage from the digital controller and a to voltage to reduce the electrical dynamics of the electrical DC motor (i.e. resistance and/or inductance). The electrical dynamics of the DC motor can be reduced by a voltage according to (i) a positive current feedback voltage, (ii) a positive feedback compensator, or (iii) a negative impedance convertor. Exemplary descriptions are included pertaining to rotary motor, but are not limited to these type of motors as they can also be applied to linear motors.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 shows according to an exemplary embodiment of the invention the mapping of motor inductance and residual resistance from the electrical domain to the mechanical domain.
[0006] FIG. 2 shows according to an exemplary embodiment of the invention 3-phase BLDC motor windings in WYE configuration.
[0007] FIG. 3 shows according to an exemplary embodiment of the invention frequency-dependant rendered stiffness of the combined spring drive and controller. The unmodified motor dynamics (dotted curve) are included for comparison.
[0008] FIG. 4 shows according to an exemplary embodiment of the invention a purely motion based virtual environment-device interaction.
[0009] FIG. 5 shows according to an exemplary embodiment of the invention a system block diagram: A drift-compensating mid-level controller interfacing the quasi-static environment to the device, which is operated as a motion source.
[0010] FIG. 6 shows according to an exemplary embodiment of the invention cartesian stiffness ellipses K x inv and K x trans with α=λ min [(JJ T )−1] for a 2-DOF manipulator (PHANTOM with locked base joint).
DETAILED DESCRIPTION
1. Spring Drive
[0011] The use of a voltage motor drive with resistive or resistive and inductive load compensation, which we will refer to as a spring drive for brevity, improves the haptic rendering of rigid contact when compared to standard current drive motor amplifiers. The key idea underlying this improvement is slowing the electrical dynamics and allowing the inductance to be utilized as a high-stiffness haptic coupling. This concept and the corresponding notation are covered briefly in this section.
[0012] The electrical dynamics of a typical brushed dc motor are
[0000]
e
A
(
t
)
=
Ri
(
t
)
+
L
i
(
t
)
t
+
e
B
(
t
)
(
1
)
[0000] with coupling equations:
[0000] e B ( t )= k T {dot over (θ)}( t ) (2)
[0000] τ( t )= k T i ( t ), (3)
[0000] where e A is the applied voltage, e B is the back-EMF, k T is the torque/speed constant, τ is the motor torque, i is the winding current, {dot over (θ)} is the rotor velocity, and R and L are the winding resistance and inductance, respectively. To pursue a haptic perspective on the effects of driving a motor with the spring drive, it is useful to interpret R and L as an equivalent mechanical spring K L
[0000]
K
L
=
k
T
2
L
(
4
)
[0000] and damper B R ,
[0000]
B
R
=
k
T
2
R
,
(
5
)
[0000] where K L and B R are connected in series. The spring drive approach couples the haptic device to the virtual environment through K L , which is available at all frequencies, inherently stable, and very stiff for small L. It does this by eliminating the series B R through cancellation the winding resistance.
[0013] Resistance cancellation is accomplished by setting
[0000] e A ={circumflex over (R)}i+e W (6)
[0000] where {circumflex over (R)} is a conservative estimate of R. This effectively cancels the voltage drop across the winding resistance, while allowing additional voltage inputs e W . Since the motor resistance R varies with temperature and brush commutation, a residual uncancelled resistance
[0000] dR ( T ,θ)= R ( T ,θ)− {circumflex over (R)}, (7)
[0000] will remain. It corresponds to the residual series damper
[0000]
B
dR
=
k
T
2
R
.
(
8
)
[0014] FIG. 1 shows the mapping of winding inductance L and residual resistance dR into the mechanical domain, leaving {circumflex over (R)} to be canceled by Equation 6. By the electromechanical coupling (Equation 2), the intermediate voltages e W and e S relate to the velocities {dot over (θ)} W and {dot over (θ)} S , respectively; where e W is the applied node voltage between the series resistances {circumflex over (R)} and dR, e S is the node voltage between R and L, {dot over (θ)} W is the velocity of the setpoint of the mechanical equivalent series spring-damper, and {dot over (θ)} S is the velocity of the connection point between the series spring and damper. With the inductance and residual resistance interpreted in the physical domain, voltage commands to the spring drive are equivalent to velocity commands to the set-point of the series spring-residual damper
[0000] e W =k T θ W . (9)
[0015] Therefore, the spring drive operates the dc motor as an approximate motion source. This is in contrast with the current drive motor amplifiers typically used in haptic devices, which speed up the electrical dynamics and operate the motor as a torque source. By recasting the motor as a motion source, it becomes necessary to design the digital controller as a motion controller, again in contrast to the impedance control typically paired with the current drive.
[0016] It is important to note that L may be canceled in addition to R, effectively increasing the stiffness K L . In this case (Equation 6) becomes
[0000]
e
A
=
R
^
i
+
L
^
i
(
t
)
t
+
e
W
(
10
)
[0000] where {circumflex over (L)} is an estimate of L.
1.1. Spring Drive Implementation
[0017] Implementation of Equation 6 may be realized via various analog circuit architectures. One option is to use a sense resistor to measure current through the motor, apply a gain of {circumflex over (R)} to the resulting voltage signal, and use a positive feedback loop to route this signal to the input of a suitable voltage amplifier that drives the motor. The command signal e W is summed with the current feedback signal to produce e A , which is the input to the voltage amplifier. To add cancellation of L, the derivative term
[0000]
L
^
i
(
t
)
t
[0000] is added to the positive current feedback path.
[0018] Another option is to employ a negative impedance converter (NIC). A NIC is an analog op-amp circuit that acts like a negative load. Here, a power op-amp NIC with an effective impedance of −{circumflex over (R)} or −({circumflex over (R)}+{circumflex over (L)} S ) is used to drive the motor.
2. Brushless DC Motor
[0019] The compensation of brushed DC motor dynamics described above utilizes a single-value model of R. Brushed DC motors, however, experience resistance discontinuities due to commutation, and this can cause discontinuities in the haptic force experienced by the user during. Here, we extend the idea of utilizing the natural motor dynamics through resistance compensation to brushless DC (BLDC) motors, in part to address this issue. More generally, however, BLDC motors out-perform brushed DC motors, exhibiting higher power density, reliability, and efficiency. They also have lower rotor inertia and torque ripple (with sinusoidal commutation). This section will review the operation and dynamics of BLDC motors before a description of BLDC resistance compensation in the next section.
[0020] Brushless DC motors are constructed with the permanent magnet located on the rotor and several (usually three) windings on the stator. By moving the permanent magnet to the rotor, there is no need to supply current to the rotating element, and brushes or slip rings are unnecessary. In the case of the three phase BLDC motor, the windings are each separated by an angle of 120 degrees. Each winding experiences a sinusoidal back-EMF voltage. External circuitry and control is necessary to commutate a BLDC motor, and several methods are available, most notably six-step block commutation and sinusoidal commutation. The former is inexpensive, requiring only three Hall sensors, which are usually integrated into the motor. Sinusoidal commutation requires position feedback via an encoder or resolver, but theoretically has no torque ripple and can be used for positioning applications.
[0021] The electrical dynamics of a three-phase BLDC are,
[0000]
e
A
1
(
t
)
-
e
n
(
t
)
=
R
1
i
1
(
t
)
+
L
1
i
1
(
t
)
t
+
e
B
1
(
11
)
e
A
2
(
t
)
-
e
n
(
t
)
=
R
2
i
2
(
t
)
+
L
2
i
2
(
t
)
t
+
e
B
2
(
12
)
e
A
3
(
t
)
-
e
n
(
t
)
=
R
3
i
3
(
t
)
+
L
3
i
3
(
t
)
t
+
e
B
3
(
13
)
[0000] with the back-EMF voltages,
[0000] e B 1 =k T {dot over (θ)} sin(θ) (14)
[0000] e B 2 =k T {dot over (θ)} sin(θ−120°) (15)
[0000] e B 3 =k T {dot over (θ)} sin(θ+120°) (16)
[0022] Note that by definition the three currents add to zero
[0000] i 1 +i 2 +i 3 =0 (17)
[0000] and each winding contributes a torque in a sinusoidal fashion
[0000] τ 1 =k T i 1 sin(θ) (18)
[0000] τ 2 =k T i 2 sin(θ−120°) (19)
[0000] τ 3 =k T i 2 sin(θ+120°) (20)
[0000] with the total torque
[0000] τ=τ 1 +τ 2 +τ 3 . (21)
[0023] FIG. 2 shows the corresponding BLDC windings in a wye configuration.
[0024] Sinusoidal commutation is used to provide constant torque versus the rotor angle and allow for position control. This means that for a given voltage command, e W , the commutated voltage commands to each winding are,
[0000] e W 1 =e W sin(θ) (22)
[0000] e W 2 =e W sin(θ−120°) (23)
[0000] e W 3 =e W sin(θ+120°) (24)
3. Exploiting BLDC Motor Dynamics
[0025] Utilizing the natural dynamics of a BLDC motor to couple a user to the virtual environment is conceptually identical to the approach taken for brushed DC motors. However, now the resistances of three separate windings must be canceled by a trio of compensators. For the following analysis an ideal case is considered where the resistances and inductances of each of the three windings are identical and equal to R and L, respectively. As a consequence, by adding Equations 11-13 the common node voltage is the mean of the three terminal voltages,
[0000]
e
n
=
e
A
1
+
e
A
2
+
e
A
3
3
(
25
)
[0026] All three drivers cancel the resistance, while allowing sinusoidally commutated voltage input eW
[0000] e A 1 ( t )= {circumflex over (R)}i 1 ( t )+ e W sin(θ) (26)
[0000] e A 2 ( t )= {circumflex over (R)}i 2 ( t )+ e W sin(θ−120°) (27)
[0000] e A 3 ( t )= {circumflex over (R)}i 3 ( t )+ e W sin(θ+120°) (28)
[0000] such that from Equation 25 and Equation 17 the common node voltage en=0. Substituting Equations 26-28 into Equations 11-13 yields,
[0000]
i
1
t
=
-
k
T
L
θ
.
sin
(
θ
)
(
29
)
i
2
t
=
-
k
T
L
θ
.
sin
(
θ
-
120
°
)
(
30
)
i
3
t
=
-
k
T
L
θ
.
sin
(
θ
+
120
°
)
(
31
)
[0027] Integrating and substituting each i into Equations 18-20, 21 provides the result,
[0000]
τ
(
t
)
=
-
k
T
2
L
[
cos
(
θ
0
)
sin
(
θ
)
+
cos
(
θ
0
-
120
°
)
sin
(
θ
-
120
°
)
+
cos
(
θ
0
+
120
°
)
sin
(
θ
+
120
°
)
]
(
32
)
[0000] where θ 0 =θ(0) with τ(0)=0. This simplifies to
[0000]
τ
(
t
)
=
-
3
k
T
2
2
L
sin
(
θ
-
θ
0
)
.
(
33
)
[0028] Thus, over small angles the equivalent inductive spring for a BLDC motor is
[0000]
K
L
=
3
k
T
2
2
L
(
34
)
[0029] In the case where the current feedback gain of the controller is not exactly R, a small resistance dR remains uncancelled leading to an equivalent resistive damper:
[0000]
B
R
=
3
k
T
2
2
dR
(
35
)
[0030] It is important to note that B R causes drift at low frequencies, while K L dominates at high frequencies. The cutoff frequency between the two effects is
[0000]
ω
cutoff
=
dR
L
.
[0000] As in Equation 10 the BLDC drivers may also compensate for L to produce a higher inductive stiffness.
4. Mid-Level Drift Compensation
[0031] Before any high-level controller can be successfully implemented, the fact that a residual damper B dR exists between the commanded location θ W and the output must be addressed. Without compensation, B dR will allow θ S and θ to drift unboundedly under low frequency external loads. In haptic applications this drift will degrade the simulation by making sustained rigid contacts feel like dampers. Therefore, position feedback with PD compensation is added digitally to combat drift and yields the control law
[0000] e W =k T {dot over (θ)} S d +K D ({dot over (θ)} S d −{dot over (θ)})+ K P (θ S d −θ), (36)
[0000] where K P and K D are the error gains and θ S d and {dot over (θ)} S d are the desired motion of the setpoint of the haptic coupling. We assume a first order filter with cutoff frequency λ on the differentiated velocity signal {dot over (θ)}. This constitutes a mid-level controller interface between the analog inductive stiffness of the spring drive and the high-level motion controller described in the next section. It is applicable to both brushed DC and BLDC motors. Implementation of this mid-level controller establishes a hybrid coupling between the user and the virtual environment consisting of the physical motor dynamics, analog electronics modifying these dynamics, and digital drift compensation. The combined physical and analog components comprise the series spring-damper shown in FIG. 1 , while the digital component connects the parallel spring-damper of Equation 36 between θ and θ S d . Functionally, the analog stiffness K L dominates for high frequency deflections, while the digital mid-level controller pro-vides low to mid frequency stiffness. The frequency-dependent stiffness transfer function for the complete coupling is found by substituting Equation 36 into the resistance-canceled motor dynamics. For the modified brushed DC motor dynamics
[0000]
e
W
(
t
)
=
dRi
(
t
)
+
L
i
(
t
)
t
+
e
B
(
t
)
(
37
)
[0000] the stiffness transfer function is
[0000]
K
θ
(
s
)
=
τ
θ
(
s
)
=
-
k
T
Ls
+
dR
λ
s
+
λ
[
(
(
k
T
+
K
D
+
K
P
λ
)
s
+
K
P
)
+
k
T
s
2
λ
]
.
(
38
)
[0032] The corresponding BLDC motor stiffness transfer function may be found similarly.
[0033] The magnitude Bode plot of Equation 38 shown in FIG. 3 illustrates the combination of several factors that shape stiffness over frequency. Starting from the natural motor dynamics represented by the dotted curve, the spring drive lowers the corner frequency from R/L to dR/L. The proportional term in the mid-level controller then pulls the low frequency rolloff caused by B dR up to a dc stiffness
[0000]
K
DC
=
k
T
K
P
dR
,
(
39
)
[0000] while the derivative term boosts stiffness at midrange frequencies before the filter rolls it off to the high frequency stiffness
[0000]
K
HF
=
K
L
=
k
T
2
L
.
(
40
)
[0034] As described earlier, K L may be increased by electrically reducing L in addition to R, replacing L in the equations above with a residual inductance dL.
[0035] Thus, for a given motor the spring drive approach calls for the robustly stable minimization of dR and maximization of K P and K D to achieve the highest possible maximum stiffness at all frequencies. This tuning is then locked in place and the resulting K θ (s) is treated as a passive coupling between the rotor angle θ and the setpoint θ S d . This K θ (s), which we will refer to as the coupling stiffness, represents the stiffest contact that the virtual environment can render on this actuator.
5. Motion Control of Haptic Devices: One-DOF
[0036] By treating the spring driven DC motor and the mid-level drift compensator as a black-boxed motion source that accepts setpoint motion commands θ S d and θ S d , we now describe a high-level motion controller in the form of a quasi-static virtual environment (VE). This approach combines the excellent free-space performance of an impedance-type device with the improved contact performance of an admittance-like controller. The structure of this VE is developed here for the one-DOF case before generalization to multiple degrees of freedom in the next section.
[0037] As noted, θ S d and {dot over (θ)} S d command the setpoint of the coupling stiffness K θ (s). Thus, it is sufficient for the haptic simulation to implement a very simple, purely motion-based VE that uses a virtual proxy or tool to determine θ S d , effectively using the coupling stiffness as the connection between the user and the VE. Rigid contact is easily rendered by commanding zero motion and locking the coupling stiffness
[0000] {dot over (θ)} S d =0 θ S d=θ 0 , (41)
[0000] where θ 0 is the location of the contact constraint. Freespace is accomplished by setting the desired motion to track the user
[0000] {dot over (θ)} S d ={dot over (θ)} θ S d =θ. (42)
[0038] A slight lag in filtering the velocity may cause the system to create slight non-zero forces, equivalent to an added mass. Given the low bandwidth of human actions compared to the speed of filtering, however, any added mass tends to fall far below perceptible levels.
[0039] Finally, compliant contact is achieved by setting the desired motion to a fraction of the user motion. The full dynamic range of the VE can be represented by
[0000] θ S d =η{dot over (θ)} θ S d =ηθ+(1−η)θ 0 (43)
[0000] where 0≦η≦1, and η=0 and η=1 correspond to rigid contact and freespace, respectively. The low-frequency output stiffness is reduced by the factor η.
[0040] FIG. 4 shows the interaction between the virtual environment and the haptic device. The block diagram in FIG. 5 illustrates the implementation of the full system, including the spring drive, mid-level drift compensator, and virtual environment.
[0041] As a motion-based VE, no absolute force values are available, either explicitly via measurement or implicitly by commanding motor current. Output stiffnesses, therefore, may no longer be programmed exactly, but must be specified as a fraction of the device's maximum achievable stiffness. Knowledge of K θ (s), particularly K DC , can be used to estimate values.
6. Motion Control of Haptic Devices: Multi-DOF
[0042] In extending the above approach to multi-DOF haptics, we recognize the application's requirements. Though we wish to display the maximum achievable stiffness, force directions need to be rendered accurately to convey proper geometric surface properties. For example, forces should always fall perpendicular to frictionless surfaces. To support this requirement, perceived output stiffnesses need to be spatially uniform.
[0043] Given an n-DOF device, one drift-compensated spring drive is used to drive each joint motor. Thus, each joint independently replicates the one-DOF system previously described, acting as a joint motion source with a stiffness described by Equation 38. We assume here that all joints exhibit the same stiffness, though relative scaling between joints could be incorporated if necessary.
[0044] We define a desired Cartesian location {right arrow over (x)} S d and velocity {right arrow over ({dot over (x)} S d , and collect the individual joint values into a joint position vector {right arrow over (q)} and velocity vector q with equivalent desired position {right arrow over (q)} S d and velocity {right arrow over ({dot over (q)} S d ,
[0000] {right arrow over (q)} S d =invkin ( {right arrow over (x)} S d ) {right arrow over ({dot over (q)} S d =J −1 {right arrow over ({dot over (x)} S d (44)
[0000] obtained by inverting the mechanism's kinematics, where J is the Jacobian matrix of the mechanism's forward kinematics. This will produce joint torques
[0000] {right arrow over (τ)}= K q Δ{right arrow over (q)} (45)
[0000] via a diagonal joint stiffness matrix
[0000] K q =K θ ( s ) I, (46)
[0000] which maps to a Cartesian stiffness of
[0000] K x inv =J −T K q J −1 =K θ ( s )( JJ T ) −1 (47)
[0000] remembering that
[0000] {right arrow over (F)}=K x inv Δ{right arrow over (χ)} {right arrow over (τ)}= J T {right arrow over (F)} Δ{right arrow over (χ)}=JΔ{right arrow over (q)}. (48)
[0045] Where is the Cartesian force at the end effector, Δ{right arrow over (χ)}=({right arrow over (χ)} Sd −{right arrow over (χ)}), and Δ{right arrow over (q)}=({right arrow over (q)} Sd −{right arrow over (q)}). We denote the stiffness matrix with ‘inv’ to indicate the joint values were set by an inverse Jacobian kinematic algorithm. Unfortunately, this Cartesian stiffness is non-spherical such that forces are not necessarily generated along displacement vectors. FIG. 6 depicts such a stiffness ellipsoid for a simple 2-DOF case. Proper haptic rendering of force requires that the multi-DOF motion controller reshape this ellipsoid into a sphere. We instead calculate
[0000] {right arrow over (q)} Sd ={right arrow over (q)}+αJ T ( {right arrow over (x)} Sd −{right arrow over (x)} ) (49)
[0000] where α is a scalar, and approximate the set-point derivative as
[0000] {right arrow over ({dot over (q)} Sd ={right arrow over ({dot over (q)}+αJ T ( {right arrow over ({dot over (x)} Sd −{right arrow over ({dot over (x)} ), (50)
[0000] where we ignore the Jacobian's derivative. By construction this simplification only affects forces rendered at high velocities and high frequencies with minimal impact on user perception as discussed at the end of this section. This delivers a Cartesian force vector {right arrow over (F)} of
[0000] {right arrow over (F)}=J −T K q αJ T Δ{right arrow over (x)} (51)
[0000] and the Cartesion stiffness
[0000] K x trans =αJ −T K q J T . (52)
[0046] Since K q is the scaled identity matrix, K x trans collapses to the diagonal
[0000] K x trans =αK θ ( s ) I. (53)
[0047] Effectively, the transpose equation 49 has reshaped the ellipsoid into a sphere and restored the force directions to parallel any deflections.
[0048] Having resolved the force direction problem, there is now the issue of what value to select for α. To address this, first recall that each joint is tuned for a maximum joint stiffness K θ (s). Also note that locking each joint results in the Cartesian stiffness K x inv . Thus, K x inv represents the maximum achievable Cartesian stiffness for a given configuration, limited by the stability of each joint. Using the Jacobian transpose solution to the inverse kinematics has reshaped K x inv into the Cartesian stiffness ball K x trans , which must now be appropriately scaled by α. Intuitively, K x trans cannot be scaled arbitrarily large, as this would allow the effective Cartesian stiffness to be increased without bound. Indeed, if the magnitude of K x trans exceeds that of K x inv in any direction, we would be asking for a stiffness beyond the stable maximum. Doing this would effectively increase the gains of one or more joint controllers and compromise their stability. Therefore, taking K x inv as the upper bound to maintain stability, the eigenvalues of K x trans must satisfy
[0000] λ max ( K x trans )≦λ min ( K x inv ). (54)
[0049] Substituting (53) and (47), this condition simplifies to
[0000] α≦λ min [( JJ T ) −1 ], (55)
[0000] where λm in [(JJ T )−1] may be computed on the fly to maximize K x trans independently for each configuration, or computed over the entire workspace offline to select the global minimum for a consistent K x trans at all configurations.
[0050] FIG. 6 illustrates in an example the ellipses K x inv and K x trans with α=λ min [(JJ T )−1] for a PHANTOM constrained to 2-DOF by locking its base motor (three-degree of freedom, impedance-type haptic device).
[0051] The stiffness shape compensation performed by this multi-DOF VE does not have infinite bandwidth. As a result K x inv will still exist at high frequencies, and impulsive force vectors may be directed incorrectly. Since these direction discrepancies exist only at high frequency, however, the user will likely be unable to detect them kinesthetically, due to a low perceptual bandwidth of 20 Hz to 30 Hz. Tactile detection of the discrepancy may fare better, the direction discrimination threshold is only about 25 degrees, determined for perception of low frequency forces. Experience with a multi-DOF implementation on a PHANTOM 1.0 suggests that these discrepancies are not perceptible, and certainly not disruptive to the haptic simulation. Similar to the one-DOF case, compliant surfaces and free space may be obtained by setting
[0000] {right arrow over ({dot over (x)} Sd =η{right arrow over ({dot over (x)} {right arrow over (x)} Sd =η{right arrow over (x)} +(1−η){right arrow over (x)} 0 , (56)
[0000] with 0≦η≦1. | A control method for an haptic device is provided with particular attention to motor control amplifiers exploiting the inate motor dynamics of DC motors. The control method encompasses a digital and analog circuit. In the digital circuit, a command voltage is determined by a digital controller utilizing sensed motion information of the haptic device and a motion command signal. In the analog circuit, an amplifier applies a voltage to an electrical DC motor. The applied voltage incorporates the determined command voltage from the digital controller and a voltage to reduce the electrical dynamics of the electrical DC motor. | 63,091 |
CROSS-REFERENCES TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to liquid product filling heads, more particularly, to a pneumatic control unit for automatically shutting off a liquid product filling head filling a container upon sensing that the container is full.
2. Description of the Related Art
There are a number of automatic container filling machines in the art wherein a sensing tube extends into a container to be filled and when the lower end of the tube is blocked by the product in the container, back pressure through the tube actuates a control device to stop the flow of product into the container. In particular, U.S. Pat. No. 5,161,586 discloses a pneumatic control unit that responds to a sensed back pressure to shut off liquid to the filling container. The shortcomings of the disclosed design are discussed in detail below relative to the present invention.
BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to provide a pneumatic control unit for a liquid filling head that is easier and less expensive to manufacture and that is easier to maintain than pneumatic control units of the prior art.
The present invention is a pneumatic control head for controlling the supply of a product into a container via a filling head with a sensing tube that extends into the container. The control head has a manifold with several air inputs. A main air input receives main air at an operating pressure, typically at about 60 psi. A blow down air input receives blow down air for cleaning the filling head as needed. A filling head output connects to the sensing tube. A cylinder for operating the filling head attaches to the manifold.
The majority of the control unit is built in a manifold. The manifold has a pilot air duct for conducting pilot air at a pressure near that of the main air operating pressure. A start valve takes in the main air and outputs it to the pilot air duct when actuated by a mechanical switch. The switch includes a ball bearing captured by a collar whereby the switch is actuated when the ball bearing is pressed into the collar.
A pilot valve in the manifold takes in the main air and allows it into a cylinder air duct to activate the cylinder in response to air pressure in the pilot air duct. Optionally, there is a no container switch that exhausts air from the pilot air duct in the event that there is no container under the filling head.
A flow regulator mounted to the manifold receives sensing air and outputs regulated sensing air at a sensing pressure. Optionally, a sensing air shut off valve precedes the flow regulator. The sensing air shut off valve is controlled by the main air to the cylinder so that if the cylinder is not actuated, there is no sensing air to cause the filling product to bubble.
The regulated sensing air passes through a filling head source valve to a filling head output. Normally the filling head source valve routs the regulated sensing air to the filling head output. The filling head source valve routs blow-down air to the filling head output in response to main air from a blow down valve. The blow down valve takes in the main air and outputs it to a switch the filling head source valve when actuated by a mechanical switch. The switch is of the same design as that of the start valve.
An overpressure valve mounted to the manifold exhausts the pilot air duct in response to the regulated sensing air having a pressure higher than normal. When the product fills the container to the point that the product nearly contacts the sensing tube, a back pressure is created that causes the overpressure sensor valve to trip.
Physically, the control unit includes a manifold within which are cut holes for valves and channels for ducts. A top plate houses the flow regulator and provides a mount for the overpressure sensor valve.
The start and blow down valve switches are improvements over those of the control units of the prior art. Each switch is a ball bearing captured by a collar. An external cam pushes the ball bearing into the collar, causing the ball bearing to push the start valve. Friction is reduced because the ball bearing rotates within the collar as the cam slides by. The improvement includes significantly fewer moving parts that substantially reduces both the initial manufacturing and the periodic maintenance costs.
Another improvement over the prior art is the means by which two of the ducts are routed to their respective valves. The pilot and filling head source valves fit into openings in the manifold. The appropriate duct exits at an aperture adjacent to the valve. A single machined plate has a depression that overlaps the aperture and the valve opening. An o-ring fits into a groove surrounding the depression and valve opening. The o-ring provides a seal between the plate and the manifold when installed.
Other objects of the present invention will become apparent in light of the following drawings and detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature and object of the present invention, reference is made to the accompanying drawings, wherein:
FIG. 1 is an front perspective view of the pneumatic control unit of the present invention;
FIG. 2 is a rear perspective view of the pneumatic control unit of the present invention;
FIG. 3 is a side view of an assembly of the control unit of the present invention and a filling head;
FIG. 4 is a schematic diagram of the control unit of the present invention;
FIG. 5 is an exploded view of the start switch mechanism of the control unit of FIG. 1; and
FIG. 6 is an exploded view of the pilot valve at the rear of the control unit of FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
The pneumatic control unit 10 of the present invention, shown in FIGS. 1-3 and schematically in FIG. 4, has three inlets for external air supplies. The main air inlet 12 accepts the main control air, typically at a pressure of about 60 psi. The sensing air inlet 14 accepts the sensing air, typically at a pressure of about 5 psi This pressure is chosen to be low to avoid bubbling the liquid 95 in the top of a container 97 being filled while being high enough to reliably build a back pressure when the liquid 95 fills the container 97 . The blow down air inlet 16 accepts the blow down air at a pressure typically in the range of about 20-40 psi. The purpose of the blow down air is to clean the filling head 96 as needed, so the pressure is set accordingly for the thickness of the filling liquid.
The air cylinder 20 for operating the filling head extends from the bottom of the control unit 10 . The air cylinder piston 90 extends downwardly under controlled air pressure to open the filling head 94 .
Refer now to FIG. 4 . The start switch 22 mechanically actuates a start valve 24 . The start valve 24 receives the main air and is normally closed, blocking the main air from the pilot air duct 46 . When actuated, the start valve 24 opens, permitting the main air into the pilot air duct 46 . The air in the pilot air duct 46 is referred to as the pilot air. The high pressure pilot air is routed into a no container safety valve 36 of well-known design. Essentially, when there is no container to fill, a mechanical switch 18 actuates the no container safety valve 36 , which exhausts the pilot air from the pilot air duct 46 , as at 37 , preventing it from causing the actuation of the air cylinder 20 . A flow restrictor 30 prevents an excess of main air pressure from exceeding the capacity of the no container safety valve 36 .
The pilot air is routed to a pilot valve 32 and to an overpressure sensor valve 34 . When the start switch 22 is actuated, the pilot air actuates the pilot valve 32 thereby permitting the main air into a cylinder air duct 33 , actuating the air cylinder 20 . Preferably, the pilot valve 32 has a compensating orifice which opens into a passageway into the pilot air chamber of the pilot valve 32 . When the pilot valve 32 is actuated, a portion of the main air passes through the compensating orifice into the pilot air chamber to help hold the pilot valve 32 actuated in order to compensate for any pilot system leaks. For example, some air is bled out of the pilot air duct 46 through a small bleed orifice in the overpressure sensor valve 34 , as described below. A drop in the pilot air pressure will deactuate the pilot valve 32 . Once closing begins, the air from the cylinder air duct 33 is exhausted through the pilot valve exhaust port 38 . In this way the pilot valve 32 reacts quickly to a drop in pilot pressure to stop the liquid filling operation.
The overpressure sensor valve 34 quickly triggers the shut off of the liquid filling operation in response to back pressure from the container 97 being filled. The sensing air is applied to a diaphragm and is allowed to escape through a bleed orifice 49 . When the pressure on the diaphragm increases such that the diaphragm flexes, the flexing diaphragm covers the bleed orifice 49 , causing a build up of pressure which triggers the valve 34 to open. When the overpressure sensor valve 34 opens, the pilot air is exhausted out through the valve 34 , as at 48 , causing the air cylinder piston 90 to retract, halting the liquid filling operation.
The sensing air inlet 14 provides the sensing air control signal to the overpressure sensor valve 34 . Optionally, the sensing air is routed through a sensing air shutoff valve 40 that is controlled by the main air to the cylinder 20 . By shutting off the sensing air when the fill is complete, bubbling of the filling liquid by the sensing air is avoided.
A flow regulator 42 permits accurate regulation of the pressure of the sensing air, providing a means to adjust the control unit 10 for the height of the liquid fill. If the flow regulator 42 is of a variable type, two or more control units 10 may be employed in a mass production filling machine by adjusting the sensing air to fill all containers to the same height.
The sensing air from the flow regulator 42 passes through a filling head source valve 44 to a filling head output 43 . The normal state of the filling head source valve 44 routs the sensing air to the filling head output 43 . The switched state of the filling head source valve 44 routs blow-down air to the filling head output 43 , as described below.
The filling head output 43 is connected, via a hose 96 , to a sensing tube 93 at the end of the filling head 92 . The sensing air easily passes out of the sensing tube opening 94 until the filling liquid 95 contacts or nearly contacts the opening 94 . When this occurs, a back pressure is created that causes the overpressure sensor valve 34 to trip, shutting off the filling operation.
The blow down operation clears the sensing tube 93 . A blow down switch 26 mechanically actuates the blow down valve 28 , allowing main air into a filling head source control duct 45 , which directs the filling head source valve 44 to rout the blow down air from the blow down air inlet 16 to the filling head output 43 . The blow down-operation is momentary, that is, it only operates as long as the blow down switch 26 is activated. When the blow down switch is not actuated, the main air is exhausted from the filling head source control duct 45 by the blow down valve 28 , as at 41 .
The majority of the control unit 10 is formed in a manifold 50 , preferably a block of aluminum. Holes are drilled and channels are cut in the manifold 50 to accommodate the valves and to form the passages between those valves, all in a manner well-known in the art.
A top plate 51 is mounted to the top of the manifold 50 . The top plate 51 provides a housing for the flow regulator 42 and a connection to the manifold 50 for the overpressure sensor valve 34 . The flow regulator control knob 52 extends vertically from the top of the top plate 51 . The sensing air shutoff valve 40 extends rearwardly from the top plate 51 . It receives its connection to the pilot air duct 33 by a hose 53 from the manifold 50 . The output 43 of the filling head source valve 44 is located on the bottom of the manifold 50 and is connected to the filling head 92 by a hose 96 .
The start valve 24 and blow down valve 28 are located on the same side of the manifold 50 . In the prior art, the start switch 22 and blow down switch 26 are rather complicated mechanisms. The appropriate valve is actuated by a leaf spring that is pushed by a pivoting arm. At the free end of the arm is a roller that is pushed by an external cam. The reason for the roller is so that friction is kept to a minimum as the external cam slides by. The various moving parts require regular maintenance to keep operating properly.
The present invention replaces each roller/arm mechanism with a simple ball bearing 57 inside a collar 58 . As can be seen in FIG. 5, the front surface 56 of the manifold 50 is covered by a front plate 59 . The front plate 59 includes a clearance hole 60 for the collar 58 . The collar 58 is a short tube with a flange 62 at the inner end. The inside diameter of the tube is slightly larger than the ball bearing 57 so that the ball bearing 57 slides easily within the tube. An internal lip 64 at the outer end of the collar 58 as an inside diameter slightly smaller than the ball bearing 57 so that the ball bearing 57 is retained in the collar 58 when installed. The plate 59 is typically removably secured by screws 65 sandwiching the collar 58 by the flange 62 between the manifold front surface 56 and the front plate 59 . The ball bearing 54 extends outwardly from the collar 58 at least the length of travel of the start valve 24 . As the control unit 10 moves past the start cam, the cam pushes the ball bearing 57 into the collar 58 , causing the ball bearing 57 to push the start valve 24 , initiating the fill operation. Friction is reduced between the start switch 22 and the cam because the ball bearing 57 rotates within the collar 58 as the cam slides by. The blow down 26 switch is implemented in the same way.
The ball bearing design is an improvement over the design of the prior art. The numerous moving parts, including the roller, the arm, and the leaf spring, are replace by a single moving part, the ball bearing 57 . The reduction in the number of parts substantially reduces both the initial manufacturing cost and the periodic maintenance cost of the control unit 10 .
The rear of the control unit 10 is shown in FIGS. 2 and 6. As can be seen, the filling head source valve 44 fits into a cylindrical opening 70 in the manifold 50 leaving the actuator 72 free. The filling head source control duct 45 exits at an aperture 74 in the rear wall 76 and must be routed to the filling head source valve 44 . The pilot valve 32 and the pilot air duct 46 have the same arrangement. In the prior art, a gasket with a groove fits over the rear wall of the manifold such that one end of the groove is positioned over the valve and the other end of the groove is positioned over the aperture. A metal plate is placed over the gasket and secured to the rear wall. The groove provides the connecting duct and the gasket prevents leaks. Since the rear of the control unit of the prior art has two valves and an air inlet, there are a number of components, including three plates, three gaskets, and a handful of screws, making the manifold relatively costly to manufacture and assemble.
The present invention replaces the piecemeal design of the prior art with the design of FIG. 6 . The multiple plates and gaskets are replaced by a single machined plate 78 and o-rings 80 . A depression 82 that overlaps both the aperture 74 and part of the valve opening 70 is machined in the surface 84 of the plate 78 . The shape of the depression 82 is unimportant, as long as it overlaps both the aperture 74 and the valve opening 70 . In the present embodiment, the depression 82 is cylindrical for ease in machining. A groove 86 surrounding the depression 82 and valve opening 70 is machined in the plate surface 84 . An o-ring 80 seats in the groove 86 and provides a seal between the plate 78 and the manifold rear wall 76 when the plate 78 is secured to the rear wall 76 , typically by screws 88 . In the present embodiment, the groove 86 is eccentric because of the dimensions of the plate 78 and manifold 50 . However, the shape of the groove 86 is unimportant as long as it provides a seat for the o-ring 80 as required. Since there are actually two valves and ducts that need to be connected, the control unit 10 of the present invention has two depressions 82 , two grooves 86 , and two 0 -rings 80 , one each for the pilot valve and the filling head source valve 44 .
Thus it has been shown and described a pneumatic control unit which satisfies the objects set forth above.
Since certain changes may be made in the present disclosure without departing from the scope of the present invention, it is intended that all matter described in the foregoing specification and shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense. | A pneumatic control head for controlling the supply of a product into a container via a filling head. A manifold has a pilot air duct. A start valve outputs main air to the pilot air duct when actuated by a mechanical switch. A pilot valve activates a cylinder using the main air in response to air pressure in the pilot air duct. A filling head source valve routs either sensing air or blow down air to a filling head output in response to the condition of a blow down valve actuated by a mechanical switch. An overpressure valve exhausts the pilot air duct in response to the sensing air having a pressure higher than normal. The switches each includes a ball bearing captured by a collar. An external cam pushes the ball bearing into the collar, causing the ball bearing to actuate the respective valve. Duct connections to valves are implemented by a single machined plate with a depression that overlaps the duct aperture and valve opening. An o-ring fits into a groove surrounding the depression and valve opening and provides a seal between the plate and the manifold. | 17,892 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to sealing ("stopping-off") ducts or pipes for example during repair of maintenance operations. The most common example of a duct or pipe on which this is done is a distribution duct for main gas supplies.
We are primarily concerned in this invention with the stopping-off of large ducts, say up to about 120 cm diameter, where the pressure to be resisted may be comparatively high, perhaps up to about 2 bar.
2. Description of the Prior Art
To stop-off systems which are working at that sort of pressure, primary sealing is achieved by a so-called iris-stop system. In this, an expansible disc is introduced into the duct through a hole in its wall and opened out to occupy most of its cross-section. A so-called primary bag is introduced into the duct at the upstream side of the disc. Once it is positioned inside the duct it is inflated and thereby forms a seal across the duct. The end of the bag remote from its point of inflation is supported by the disc. This therefore both prevents sliding of the bag along the duct under the high pressure encountered and reduces the general stresses on the primary bag.
A secondary bag is introduced into the duct downstream of the primary bag. The secondary bag acts as a further seal for gas seeping past the first bag. It is also desirable for the secondary bag to act as a safety device, maintaining the seal on the duct if the primary bag fails. The secondary bags currently in use do not perform this back-up safety function very well. Because it is a back-up system the secondary bag has to be designed to meet pressure differentials greater than those which were withstood by the primary system and to meet them in conditions where there has been a sudden collapse of the primary bag, which can result in a substantial shock effect. Because it has to meet anticipated higher pressures it will itself have to be inflated to substantial pressures if it is to seal effectively and so it will, even while the primary bag is still acting, be subjected to considerable stress.
In order to provide some support for the secondary bag, a support member (usually a steel tube) is inserted into the duct through the same hole as is used for insertion of the bag. The support member is placed downstream of the bag. The bag is normally inflated through its downstream end, and the pipe carrying the inflation fluid normally runs from the hole in the duct to the inflation point on the bag through the support member. This support member is much less effective than the iris disc supporting the primary bag, but it is a much simpler structure and does not require a separate insertion hole in the duct, while providing at least a degree of support for the secondary bag. The inflation fluid is in practice always compressed air or another gas, nitrogen is often used.
SUMMARY OF THE INVENTION
We have identified one problem with existing secondary bags as a danger that dislodgement of the bag along the duct by shock or pressure may, if it goes over too great a distance, unduly stress the bag in the region of its inflation connection which is mechanically fixed in relation to the duct because the inflation pipe is held by the support tube.
In particular, the bag usually has a sleeve-like neck at this connection for egress of the mouth of an inflation bladder. The neck tends not to move, and as the remainder of bag moves the bag material may be flexed and bent back at the point where the neck joins the remainder of the bag. Accordingly in the present invention the length of the neck, the dimensions of the inflation pipe, the dimensions of the support member and their dispositions in use are such that if the bag moves until its downstream end presses against the support member, the point where the neck meets the remainder of the bag is not substantially upstream of the upstream side of the support member. In this way, the material cannot be bent back at this point when the bag slips, greatly reducing the risk of bag failure. If the support member is a tube, and the inflation pipe runs within the tube to the connection on the bag, then this condition can become that when the inflation pipe runs in contact with the inside of the support tube at its downstream side, the point where the neck meets the rest of the bag is not substantially upstream of the outside of the tube at its upstream side. Roughly speaking, this means that the length of the neck including its connector for the inflation pipe should be less than the diameter of the tube.
Although a support tube is currently used in practice, other support members are possible.
Another problem which we have identified is that it is not easy to provide the prior art bags with sufficient frictional grip against the duct, to avoid slippage. Accordingly we have increased the length to width ratio of the bag. In the prior art the length over which the inflated bag contacted the duct was about 0.5 of the bag diameter. According to the present invention the length is at least 0.7, preferably between 0.75 and 1.0, more preferably between 0.8 and 0.9 of the bag diameter. This increased length gives an increased contact area and therefore an increased frictional grip for a given contact pressure.
In practice very long bags are not highly advantageous. As the contact length to diameter ratio increases past 1 the bags become less practical, with 1.5 representing the practical limit in the present state of the art. The very long bags have a number of problems. First, the longer the bag the longer the section of duct which needs to be excavated, and the greater the spacing between the iris disc and the secondary support member. Second, it becomes difficult to arrange the uninflated bag correctly in the duct before inflation. Third, the longer bag takes longer to inflate and deflate, especially if it has a large diameter. Last, the preferred bag materials are available in fixed widths, currently of about 1 meter, and it may require more expensive tailoring to make long bags.
Usually a bag and to some degree it associated apparatus are designed to be used in blocking off a duct of a predetermined diameter against a fluid flow in the duct at a predetermined pressure. In order to grip the duct with sufficient force, we find that the pressure differential between the inflation fluid in the bag and the fluid in the pipe should be about 5 p.s.i. (about 1/3 bar). Therefore the bag should be inflated to a pressure of about 21/3 bar if it is to block a duct against a fluid flow at 2 bar. However, since the bag is a secondary bag, it is not subjected to fluid pressure in the duct unless and until the primary system fails. Consequently the bag must be able to support the full differential pressure of 21/3 bar. This will be called the operating pressure in the following discussion.
Current safety requirements include that the bag should be able to withstand inflation to four times its operating pressure. Therefore the bag discussed above must be able to withstand 91/3 bar. If the bag is short, and has a small contact area, its frictional grip on the duct can be improved by inflating it to a higher pressure differential. However, in this case it becomes difficult to meet the safety requirements, as the maximum pressure to be withstood will increase by four times the increase the operating pressure. If the bag is made stronger, to meet this safety requirement then it will be bulkier when uninflated and thus require a bigger insertion hole in the side of the duct.
If a short bag is not inflated to a high pressure, but operated at a pressure giving reduced frictional grip on the duct, nothing adverse will happen for as long as the primary bag does not fail. If the primary bag fails, then the secondary bag is subjected to the full pressure of the fluid in the duct. It is also subjected initially to a shock. Further, the increase of applied pressure in the duct will tend to compress the inflation gas in the bag. At this moment the bag will tend to slip back, and also distort, pressing the downstream end against the support member. (This is the moment when the bag is stressed at the upstream end of the neck if it protrudes past the upstream side of the support member). All bags will tend to slip and distort at this moment, but if the bag's grip on the duct is insufficient it will move so far that the downstream end begins to wrap around the support member. This will pull away from the duct wall part of the duct-contacting surface of the bag. This surface consequently loses the support of the duct wall which it had previously enjoyed, and is therefore exposed to an increased risk of failure. Once again, this can be counter-acted by strengthening the bag, but this will tend to increase its uninflated bulk.
The features of the present invention discussed above are aimed at reducing stress, so that the bag can operate satisfactory and meet the safety requirements without being disadvantageously bulky. Current conventional secondary bags are manufactured in double envelope form mainly because the outer skin acts as an anti-scuffing layer in the event of bag slip. In order to obtain double strength from the two layer construction the tailoring must be exact or one layer will experience greater stress than the other. The general elongation of the nylon material is some 15% maximum and thus a small inner can be supported by the outer if sizing is not too far out. If, however, the inner is larger than the outer only the outer skin is stressed. If this fails then the inner skin of the same material will also fail.
As mentioned above, the part of the bag which is in contact with the duct is substantially relieved of stress by the duct. However, the end faces of the bag must be able to withstand the full operating pressure. Therefore we prefer to make the ends of the bag stronger than the duct-contacting portion, avoiding unnecessary bulk in the latter. In fact, the unsupported parts of the bag are not all stressed to the same degree. The tension in a surface restraining a given pressure depends on the radius of curvature of that surface, the smaller the radius the less the tension. If the bag has a generally cylindrical shape, then at the point where the bag surface leaves the duct wall the stress is relatively low. It is highest over the centre of the end faces. Thus it does not matter if the stronger end surfaces do not reach quite to the wall of the duct.
Preferably the secondary stopping-off bag is constructed as a hollow cylinder of fabric with end closures constructed of a double layer of fabric the warps of the respective layers in a given end closure being at an angle to each other, the end closure being secured to the cylinder by means of folded-over end flaps of the layer. The angle between the warps of the layers in the end closures is optimally 90°. The sleeve-like neck in one end closure of the bag for egress of the mouth of the inflation bladder is made as short as possible and preferably also of a double layer of fabric, each layer having end flaps to be folded over and be secured to the end closures. The flaps radiate from the sleeve with end flaps originating from one layer of the neck being angularly offset from and overlapping the flaps originating from the other.
A seam of the cylinder is axial and is aligned to lie within the convergence of the warps of the layers of the end closures; furthermore when a gas connector is fitted to the neck it should be aligned generally with a continuation of the direction of the seam.
To minimise strength loss during stitching of the fabric it is desirable to use so-called "delta" needles, which have a rounded point and a triangular-section tip portion.
The invention also includes the method of making a secondary bag.
BRIEF DESCRIPTION OF THE DRAWINGS
A particular embodiment of the invention, given by way of example, will now be described with reference to the accompanying drawings in which:
FIG. 1 shows the conventional layout of an iris-stop primary bag system and a secondary bag system in a duct, seen in cross-section;
FIG. 2 shows the secondary bag embodying the present invention in position in the duct;
FIGS. 3a, 3b, 3c, 3d and 3e show various stages in the formation of a neck piece of the present bag;
FIG. 4 shows an end closure of the bag;
FIG. 5 shows the cylinder of the bag;
FIG. 6 shows an assembly stage;
FIG. 7 shows a further assembly stage;
FIG. 8 shows a completed assembly;
FIG. 9 shows a partial cross-section through the assembly as positioned in a duct; and
FIG. 10 is a similar cross-section but of a modified embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1, a duct 1 of a mains gas pipe in which the gas flows from left to right is being temporarily stopped-off by a primary sealing bag 2 introduced by known means through a hole 3 formed in the wall of the duct. Downstream of the hole 3 a second hole 4 is formed, through which is introduced the support 5 of a spreadable iris-disc 6. The bag 2 having been guided to lie downstream of its insertion position by a skid 7, can be inflated to occupy the duct with its base resting against the iris-disc 6. Downstream of the iris-disc a further hole 9 is formed and a secondary bag (which here is a conventional secondary bag 11) is introduced through it and positioned in the duct upstream of it. A hollow support column 10 is also introduced through the hole 9 and positioned downstream of the secondary bag 11. The secondary bag is inflated through a gas connector 12 connected to a neck 13 of the bag. As can be seen the total length of the gas connector 12 and the neck 13 is greater than the cross-sectional width of the hollow column 10 so that when the bag 11 is inflated its rear end is substantially spaced out from the column. If, however, the primary bag were to fail the secondary bag might be forced back down the duct towards the position shown in dotted lines 11' at which it can be seen that its rear end closure is substantially flexed and stressed around the neck. The secondary bag 11 contacts the duct over a length which is about one half of the duct diameter.
FIG. 2 shows a bag 20 embodying the invention in use. The column 10 may be identical but the total length of the connector 12' and neck 13' is not greater than the cross-sectional dimension of the column. Thus in a normal position shown in full lines the rear end of the bag 20 is supported by the column. This secondary bag 20 contacts the duct over a length which is at least 0.7 times the duct diameter, preferably between 0.8 and 0.9 times the duct diameter. As compared with the conventional bag 11 the increased contact length makes the bag 20 less likely to slip along the duct. Even if it is somewhat dislodged by sudden pressure, to the position 20', there is substantially less flexion and stress in the region of the neck (slight overlapping past the column 10 is possible but only beyond each side of the column).
The bag 20 embodying the invention is made up as follows.
A neck portion of the bag is made up as seen in FIG. 3. Two parts 23 and 24 each having a plurality of tongues 25 and 26 at one of their edges are placed so that the tongues are in staggered relationship and are tacked together by a line of stitching 27, FIG. 3a. They are then brought around as shown in FIG. 3b and seamed along one edge as far as the line of the root of the tongues. This seam 28 results in the formation of the sleeve portion 29. This sleeve is pushed through a central aperture in a planar annulus 30 of fabric seen in FIG. 3d and the tongues 25, 26 are turned outwardly from the sleeve to be radiated upon the face of the annulus 30 and are then stitched down onto that by a circular row of stitching 31. The placing of a cylindrical former inside the sleeve portion 29 as this is being done, is helpful.
In the final step of the formation the sleeve portion 29 is pulled through so that the hem is now inside it, FIG. 3e.
The next step to be described is making end closures of the bag. Each end closure consists of two polygonal sheets of fabric of coincident outline laid upon each other so that the warp direction W1 of one of the sheets 32 lies at an angle which is preferably 90° to the warp direction W2 of the other sheet 31. The two layers thus formed are stitched together along radial lines of stitching 33 into the corners of the polygon. In the end closure seen in FIG. 4, which is that which is going to receive the neck assembly, both layers 31,32 have a central aperture 34 which is surrounded by a reinforcing annulus of fabric 35 which is stitched to the layers by a circle of stitching 36. In the end closure which is to form the other end of the bag (the one to be remote from the column 10) the fabric layers 31,32 are uninterrupted by any aperture.
After the two layers have been attached together in that way, the neck assembly is mounted on them by having the sleeve portion 29, in the condition seen in FIG. 3e, inserted through the aperture 34 from that face of the end closure which is to be innermost in use. The annulus 35 on the interrupted end closure face is on the layer which is to be outermost in use.
The tongues 25,26 are therefore entrapped between the reinforcing annulus 30 and the inner of the two layers of the end closure. The neck assembly is then stitched to the end closure by a ring of stitching 37, FIG. 6, through to the reinforcing annulus 35.
Meanwhile, a hollow cylinder has been prepared from a rectangular blank of fabric 38 having at each major edge extensions which are to form flaps 39. The ends of the blank are brought round together and are overlapped to form a seam 42 and are tacked together at 40, at their end portions only. The sleeve thus formed is next secured to the end closures. In a first step a continuous line of stitching 41 (FIG. 6) is formed parallel to the polygonal edges of the end closure and along the line joining the roots of the end flaps 39 of the cylinder. It is important to note that the securing of the cylinder to the end closures is done in such a way that the seam 42 of the cylinder occurs within the angle between the two warps W1,W2. That is it could either be to the corner marked F or to the corner marked G in FIG. 6, or perhaps between those corners. The same disposition of warps W1,W2 is followed when securing the other of the end closures.
In a second stage of securing of the end closures the end flaps 39 are folded over the end closure and are stitched down onto it by a line of stitching 43 parallel to the edges of the end flaps spaced slightly in from those edges. It is very important that the folded over end flaps 39 shall be at the same tension as the underlying layers 31,32 of fabric of the end closure, so that all layers of fabric secured between the lines 41 and 43 of stitching are in equal tension and equally share any stresses to be experienced.
In a final stage of assembly the bag so formed is turned inside-out by eversion through the gap left along the seam 42 between the tackings 40 and its bladder is inserted into it through the same gap. The inflation neck of the bladder is brought out through the sleeve 29 which is now projecting outside the bag as a whole and is there united by means of standard fitments both with the sleeve and with a gas connector 44 having an inlet 45 which is at right angles to the axis of the bag in the sleeve. It is important that this inlet is orientated generally toward the seam 42 in the cylindrical sleeve, that is to be directed to within the angle formed between the warps W1 and W2 of the end closure.
Finally, the seam 42 is closed either by bonding or stitching. The dimensions of the bag are, of course, chosen in accordance with expected pressures in the duct and the diameter of the duct to be stopped-off and the dimension of the projecting neck and gas connector are selected in relation to the column 10 as has already been noted in connection with FIG. 2.
The fabric used for most of the structural parts is a plain nylon fabric but for the reinforcing annuli such as 30, 35 and also for one of the two parts 23, 24 polyurethane coated nylon is used. The stitching is found to involve least loss of strength if it is performed with round pointed "delta needles", that is to say needles of which at least the tip of the end portion is of triangular section.
FIG. 9 shows the conformation of the bag in use, at the important region where it parts from the wall 1 of the duct. The construction is as previously described except that an additional row of stitching 46 is shown which may advantageously be applied. This method of assembling the single bag 38 to the double end wall 31, 32 is preferred because of its manufacturing advantage but it does leave a region where only a single layer of fabric is resisting, unsupported, the pressures in the bag. This single layer region can usually be tolerated, as the radius of curvature of the fabric is high here and so the stresses induced are relatively low.
An alternative method of construction is shown in FIG. 10 where inner panel 31' is extended at the region 48 to underlie the bag 38 and is secured by a row of stitching 47. This has the advantage of doubling the fabric at the critical area but it is a much more complex method of fabrication.
It is possible for the bag to be inflated not with gas but with liquid, which is advantageous because of the incompressability of the liquid (leading to lower pressure stress in the free standing normal mode of the secondary bag before failure of the primary bag) and because of its high mass leading to high mechanical inertia of the bag. | In an iris-stop arrangement for stopping-off a duct the secondary bag has a contact length with the duct of at least 0.7 times its diameter. The apparatus is such that the point where the inflation neck of the bag meets the remainder of the bag can adopt a position not substantially in front of the secondary bag support member. Thus the bag has improved functional grip on the duct and does not suffer severe flexing at the neck when it moves back to rest against the support member. Preferably the portion of the bag which contacts the duct in use is a single layer of fabric thick while the ends of the bag, which have to withstand the bag inflation pressure unsupported, are two layers thick. In this way the bag can have good performance characteristics while only needing a relatively small insertion hole in the side of the duct. | 22,138 |
FIELD OF THE INVENTION AND RELATED ART
[0001] The present invention relates to a developer supply container for supplying the developer receiving apparatus of such an electrophotographic image forming apparatus as a copying machine, a facsimile machine, a printer, etc., with developer.
[0002] In the field of such an image forming apparatus as an electrophotographic copying machine, a printer, etc., toner in the form of extremely minute particles has been used as developer, and it has been a common practice that as the toner in the main assembly of an image forming apparatus is depleted by consumption, a toner supply container is used to supply the image forming apparatus with toner. However, since the toner is in the form of extremely small particles, there has been the problem that during an operation for supplying an image forming apparatus with toner, toner scatters, contaminating an operator, and/or the adjacencies of the apparatus. Thus, various methods for preventing this problem have been proposed, and some of them have been put to practical use. According to some of these methods, a toner supply container is placed in the main assembly of an image forming apparatus, and the toner in the toner supply container is released into the main assembly little by little through the small hole with which the toner supply container is provided.
[0003] First, the toner supply container used with one of the above-mentioned methods for supplying the main assembly of an image forming apparatus will be briefly described.
[0004] For example, Japanese Laid-open Patent Application 7-199623 (which corresponds to U.S. Pat. No. 5,579,101) discloses the following method: The developing apparatus is provided with a shutter for keeping the toner reception hole thereof, and the toner supply container is provided with a pair of projections, which are positioned on the peripheral surface of the container proper of the developer supply container, being aligned in the direction parallel with the axial direction of the container, so that as the cylindrical toner supply container is rotated after it is mounted in the main assembly of the image forming apparatus, the shutter of the developing apparatus is pushed open by the pair of projections of the developer supply container, connecting the toner discharge hole of the toner supply container to the toner reception hole of the developing apparatus, allowing thereby the toner in the toner supply container to be supplied to the developing apparatus.
[0005] There has long been a strong desire for a structural arrangement for such a toner supply container as the above-described one, that substantially reduces the amount of the contamination of a toner supply container, and a developing apparatus, by the toner from the toner supply container, after the toner discharge from the toner supply container during the replenishment of the main assembly of an image forming apparatus with toner.
[0006] According to the methods disclosed in Japanese Laid-open Patent Applications 10-48938 and 10-55103 (which correspond to U.S. Pat. Nos. 5,630,198, 5,678,147, 5,761,585, 5,697,014, and 5,771,427), the toner supply container is provided with a shutter for the toner outlet of the toner supply container, and is placed next to the developing apparatus in the main assembly of an image forming apparatus. The toner supply container, and the developing apparatus of the image forming apparatus, are structured so that when the toner supply container is rotated in the main assembly of an image forming apparatus, the shutter is prevented from rotating. Therefore, as the developer supply container is rotated, the toner outlet of the toner supply container is opened, and at the same time, the shutter of the developing apparatus, which is engaged with the toner supply container, is also opened by the rotation of the toner supply container, creating a passage through which the toner is supplied from the toner supply container to the developing apparatus.
[0007] According to the method disclosed in Japanese Laid-open U. M. Application 63-86652, the toner supply container is provided with a pair of projections, which are located at the lengthwise ends of the peripheral surface of the toner supply container, one for one, whereas the shutter of the developing apparatus in the main assembly of the image forming apparatus is provided with a pair of holes, into which the pair of the projections of the toner supply container fits. Thus, as the toner supply container is rotated after the mounting of the toner supply container into the main assembly of an image forming apparatus, the pair of the projections of the toner supply container fit into the pair of holes of the shutter of the developing apparatus, opening or closing the shutter.
[0008] However, the toner supply container structured as disclosed in the above-mentioned Japanese Laid-open Patent Application 199623 has the following problem, because it is not provided with the mechanism for opening or closing the shutter of the toner supply container. More specifically, it is structured so that when removing it from the main assembly of an image forming apparatus, the opening of its toner outlet faces upward to prevent the toner from coming out. However, without the shutter, and the mechanism for moving the shutter for opening or closing the toner outlet, there is the possibility that the toner will come out of the toner supply container even though by only a small amount, if the toner supply container happens to be placed upside down after its removal. Therefore, this toner supply container is desired to be improved in terms of usability.
[0009] The toner supply container structured as disclosed in the above-mentioned Japanese Laid-open U. M. Application 63-86652 is problematic in that it is very complicated in design, because of the positional relation between the pair of projections which project from the lengthwise ends of the toner supply container which is rotationally moved, and the shutter of the developing apparatus, which is linearly moved; from the standpoint of design, it is very difficult to make such a structural arrangement that ensures that as the toner supply container is rotated, the pair of projections located at the lengthwise ends of the container fit into the pair of holes of the shutter. Further, there is the possibility that if the pair of projections are forced into the pair of holes, the shutter mechanism will be damaged. Moreover, the structural arrangement is made to ensure that not only is the shutter completely closed, but also, the pair of projections at the lengthwise ends of the container are disengaged from the pair of holes of the shutter is also problematic.
[0010] Further, in the case of the structural arrangement disclosed in the above-mentioned Japanese Laid-open Patent Application 10-55103, there is provided a member for covering the opening of the toner outlet of the toner supply container. Therefore, it is possible to prevent the problem that contamination is caused by the toner which comes out of the toner supply container after its removal from the main assembly of an image forming apparatus. However, the shutter of the developing apparatus is structured so that it is rotationally moved by the rotation of the toner supply container as soon as the toner supply container is rotated. Therefore, there is the problem that as soon as the toner supply container begins to be rotated, the shutter of the developing apparatus is opened, allowing the toner in the developing apparatus to adhere to (contaminate) the peripheral surface of the toner supply container.
[0011] As a result, when an operator removes the toner supply container from the main assembly of the image forming apparatus, the operator is contaminated by the toner adhering to the peripheral surface of the toner supply container. In addition, the developing apparatus is also contaminated by the toner when the opening of the toner outlet of the toner supply container is resealed. This contamination on the developing apparatus side occurs every time the toner supply container is replaced, allowing the toner to accumulate on the developing apparatus side. As a result, a problem occurs that is similar to the problem that occurs as the toner outlet of the toner supply container is opened; the peripheral surface of the toner supply container is contaminated in a manner similar to the manner in which the peripheral surface of the toner supply container is contaminated as the toner outlet of the toner supply container is opened.
SUMMARY OF THE INVENTION
[0012] The primary object of the present invention is to provide a developer supply container which does not suffer from the problem that as the developer supply container is rotated to open the developer outlet of the developer supply container, the developer supply container is contaminated by the developer.
[0013] Another object of the present invention is to provide a developer supply container which does not suffer from the problem that as the developer supply container is rotated to reseal the developer outlet of the developer supply container, the developer supply container is contaminated by the developer.
[0014] Another object of the present invention is to provide a developer supply container which is simple in structure, and yet, is capable of reliably opening or closing the shutter on the main assembly side.
[0015] These and other objects, features, and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a schematic sectional view of a typical electrophotographic image forming apparatus in which the toner supply container in one of the preferred embodiments of the present invention is mountable, showing the structure thereof.
[0017] FIGS. 2 ( a ) and 2 ( b ) are perspective and side views, respectively, of the toner supply container in the first embodiment of the present invention, and FIG. 2 ( c ) is an enlarged view of the portion A in FIG. 2 ( b ).
[0018] FIGS. 3 ( a ), 3 ( b ), and 3 ( c ) are perspective views of the toner receiving apparatus in the first embodiment of the present invention, showing the toner receiving apparatus with its toner inlet closed, open, and closed again, respectively.
[0019] FIGS. 4 ( a ) and 4 ( b ) are perspective views of the toner supply container in the first embodiment of the present invention, showing the state of the toner supply container immediately after the mounting of the container into the toner receiving apparatus, and after the rotation of the toner supply container by its handle after the mounting of the toner supply container into the toner receiving apparatus, respectively.
[0020] FIGS. 5 ( a )- 5 ( e ) are sectional views of the toner supply container, and the toner receiving apparatus in which the toner supply contain is present, during the toner discharge, FIG. 5 ( a ) showing the states of the toner supply container and toner receiving apparatus immediately after the mounting of the former into the latter, FIG. 5 ( a ′) being an enlarged view of the toner outlet and its adjacencies, FIG. 5 ( b ) showing the states of the toner supply container and toner receiving apparatus during the rotation of the toner supply container, FIG. 5 ( b ′) being an enlarged view of the toner outlet and its adjacencies, FIG. 5 ( c ) showing the states of the toner supply container and toner receiving apparatus during the toner discharge, FIG. 5 ( d ) showing the states of the container and apparatus after the completion of the toner discharge, and FIG. 5 ( e ) showing the states of the container and apparatus during the rotation of the container after the completion of the toner discharge.
[0021] FIG. 6 is a sectional view of the toner outlet of the toner supply container, and its adjacencies, in the first embodiment of the present invention, showing the state of the toner supply container, in which the bottom edge of the toner discharge hole 1 b of the toner supply container has not aligned with the top edge of the apparatus shutter 8 , that is, the shutter on the main assembly side of the image forming apparatus.
[0022] FIGS. 7 ( a ) and 7 ( b ) are perspective views of the toner supply container in the first embodiment of the present invention, as seen from diagonally above, and below, respectively, one of the lengthwise ends of the container, and FIG. 7 ( c ) is a sectional view of the container, at the plane indicated by an arrow mark G in FIG. 7 ( b ).
[0023] FIGS. 8 ( a )- 8 ( e ) are sectional views of the toner supply container, and the toner receiving apparatus in which the toner supply contain is present, during the toner discharge, FIG. 8 ( a ) showing the states of the toner supply container and toner receiving apparatus immediately after the mounting of the former into the latter, FIG. 8 ( b ) showing the states of the toner supply container and toner receiving apparatus during the rotation of the toner supply container, FIG. 8 ( c ) showing the states of the toner supply container and toner receiving apparatus during the toner discharge, FIG. 8 ( d ) showing the states of the container and apparatus after the completion of the toner discharge, and FIG. 8 ( e ) showing the states of the container and apparatus during the rotation of the container after the completion of the toner discharge.
[0024] FIG. 9 is a sectional view of the toner supply container in the first comparative example, showing the state of the toner supply container immediately after the mounting of the container into the toner receiving apparatus during the toner supplying operation.
[0025] FIGS. 10 ( a )- 10 ( e ) are sectional views of the toner supply container, and the toner receiving apparatus in which the toner supply contain is present, in the second comparative example, during the toner supplying operation, showing the states of the toner supply container and toner receiving apparatus immediately after the mounting of the former into the latter ( FIG. 10 ( a ), during the rotation of the toner supply container ( FIG. 10 ( b )), during the toner discharge ( FIG. 10 c )), after the completion of the toner discharge ( FIG. 10 d ), and during the rotation of the container after the completion of the toner discharge ( FIG. 10 ( e )), respectively.
[0026] FIG. 11 is a sectional view of the toner supply container in the third comparative example, showing the state of the toner supply container immediately after the mounting of the toner supply container into the toner receiving apparatus during the toner supplying operation.
[0027] FIGS. 12 ( a ) and 12 ( b ) are perspective and sectional views of another toner supply container in accordance with the present invention, and FIG. 12 ( c ) is an enlarged view of the portion of FIG. 12 ( b ) indicated by an arrow mark A in FIG. 12 ( b ).
[0028] FIG. 13 is a perspective view of a toner supply container (a) and a perspective view of a toner receiving device (b) according to a further embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] Hereinafter, the preferred embodiments of the present invention will be described in detail with reference to the appended drawings. The measurements, materials, and configurations of the structural components, the positional relationship among them, etc., in the preferred embodiments of the present invention, which will be described hereinafter, are to be modified, as necessary, according to the structure of the apparatus to which the present invention is applied, and/or the various conditions under which the apparatus is operated. In other words, they are not intended to limit the scope of the present invention, unless specifically noted.
[0030] First, referring to FIG. 1 , an electrophotographic copying machine, as an example of an electrophotographic image forming apparatus in which the toner supply container, as a developer supply container, is mounted, will be described with regard to its structure.
[0031] In FIG. 1 , designated by a referential number 100 is the main assembly of the electrophotographic copying machine (which hereinafter will be referred to as apparatus main assembly). Designated by a referential number 101 is an original, which is placed on a glass platen 102 . An optical image in accordance with the image formation data is formed on the electrophotographic photosensitive drum 104 by the combination of a plurality of mirrors M and a plurality of lenses Ln. Designated by referential numbers 105 - 108 are cassettes, from among which the cassette containing recording mediums (which hereinafter may be referred to simply as papers) P, which agree in size with the information inputted by an operator through the control panel, or are the most suitable to the size of the original 101 , is selected, based on the information regarding the sizes of the papers in the cassettes 105 - 108 . The recording medium does not need to be limited to paper. For example, an OHP sheet or the like may be used as necessary.
[0032] The papers P are conveyed one by one by separating and conveying apparatuses 105 A- 108 A, to a pair of registration rollers 110 by way of a paper conveyance path 109 . Then, each paper P is conveyed further by the pair of registration rollers 110 in synchronism with the rotation of the photosensitive drum 104 and the scanning timing of the optical portion 103 . Designated by referential numbers 111 and 112 are a transfer discharger for transferring the toner image formed on the photosensitive drum 104 , onto the paper P, and a separation discharger for separating the paper P from the photosensitive drum 104 after the transfer of the toner image onto the paper P, respectively.
[0033] Thereafter, the paper P is further conveyed by a paper conveying portion 113 to the fixation station 114 , in which the toner image on the paper P is fixed by heat and pressure. Then, when the copying machine is in the single-sided print mode, the paper P is moved through the reversing station, without being placed upside down, and is discharged into the delivery tray 117 by a pair of discharge rollers 116 . When the machine is in the two-sided print mode, the flapper 118 of the reversing station 115 is controlled so that the paper P is conveyed to the pair of registration rollers 110 by way of re-feeding conveyance paths 119 and 120 . Then, the paper P is made to move through the same paths as those through which the paper P is moved when the machine is in the single-sided print mode, and is discharged into the delivery tray 117 .
[0034] When the machine is in the multilayer print mode, the paper P is sent through the reversing station 115 so that it is stopped after it is partially extended outward from the main assembly by the pair of discharge rollers 116 . More specifically, it is stopped immediately after the trailing edge of the paper P is moved past the flapper 118 , while the paper P is remaining pinched by the pair of discharge roller 116 . Then, the flapper 118 is switched in position, and the pair of discharge rollers 116 are rotated in reverse so that the paper P is conveyed back into the main assembly. Thereafter, the paper P is conveyed to the registration rollers 110 through paper re-conveyance paths 119 and 120 . Then, it is moved through the same paths as those through it is moved when the machine is in the single-side print mode, and discharge into the delivery tray 117 .
[0035] In the main assembly 100 of the copying machine structured as described above, the development station 201 , cleaning station 202 , primary charging station (primary charger 203 ), etc., are disposed in the adjacencies of the peripheral surface of the drum 104 . The development station 201 is the station in which the electrostatic latent image formed on the peripheral surface of the drum 104 by the optical station 103 , based on the image formation data extracted from the original 101 , is developed with the use of toner. The toner supply container 1 for supplying this development station 201 with toner is to be removably mounted in the main assembly 100 of the copying machine by a user.
[0036] The development station 201 comprises a toner receiving apparatus 7 in which the toner supply container 1 is removably mounted, and a developing device 201 a . Further, the developing device 201 a comprises a development roller 201 b and a developer conveying member 201 c . After being supplied from the toner supply container 1 into the toner receiving apparatus 7 , the toner is sent by the conveying member 201 c to the development roller 201 b , by which the toner is supplied to the photosensitive drum 104 .
[0037] The cleaning station 202 is where the toner remaining on the peripheral surface of the photosensitive drum 104 is removed. The primary charger 203 is for charging the photosensitive drum 104 .
[0038] The main assembly 100 is provided with a cover for the replacement of a toner supply container, which constitutes a part of the external shell of the main assembly 100 , and which is opened in the direction indicated by an arrow mark X in FIG. 1 , when a user mounts the toner supply container 1 into the apparatus main assembly 100 or removes it therefrom.
Embodiment 1
[0039] Next, referring to FIGS. 12 ( a )- 12 ( c ), the toner supply container 1 as a developer supply container in this embodiment will be described regarding its structure.
[0040] The container proper 1 a of the toner supply container 1 , in which toner is stored, is a hollow and roughly cylindrical member. The cylindrical wall of the container proper 1 a is provided with a hole 1 b as an toner outlet, which is roughly in the form of a rectangle, the longer edges of which are parallel with the lengthwise direction of the container proper 1 a . The container proper 1 a is also provided with a toner filling hole 1 c , which is a part of one of the lengthwise end walls of the container proper 1 a , and which is sealed with an unshown sealing member or the like after the filling of the container proper 1 a with toner. The toner supply container 1 is also provided with a handle 2 , which is to be grasped by a user when the user is mounting the toner supply container 1 into the apparatus main assembly 100 or removing it therefrom. The handle 2 is anchored to the lengthwise ends of the toner supply container 1 . The configuration of the handle 2 does not need to be limited to the one in this embodiment. In other words, the handle 2 may be in any configuration as long as it can be used when a user is mounting or dismounting the toner supply container 1 , and also, as long as it is satisfactory in terms of the function of rotating the toner supply container 1 .
[0041] Referring to FIG. 2 ( a ), the hole 1 b is kept sealed by the shutter 3 , the curvature of which matches that of the peripheral wall of the toner supply container 1 . The shutter 3 is engaged with a pair of guiding members 1 d located at the length-wise ends of the hole 1 b , being allowed to slide along the peripheral surface of the container proper 1 a in the circumferential direction of the container proper 1 a.
[0042] The toner supply container 1 and its shutter 3 are structured so that when the toner supply container 1 is rotated after the mounting of the toner supply container 1 into the toner receiving apparatus 7 , the shutter 3 is prevented, by coming into contact with a predetermined portion of the toner receiving apparatus 7 , from rotating with the container proper 1 a , as will be described later in detail.
[0043] With the toner supply container 1 and its shutter 3 structured as described above, as the toner supply container 1 is rotated after it is mounted into the toner receiving apparatus 7 , the shutter 3 is moved relative to the container proper 1 a, exposing the hole 1 b.
[0044] On the other hand, when replacing the toner supply container 1 , the toner supply container 1 is to be rotated in the direction opposite to the direction in which the toner supply container 1 is rotated in order to expose the hole 1 b . As the toner supply container 1 is rotated in the reverse direction, the shutter 3 comes into contact with another predetermined portion of the toner receiving apparatus so that the rotation of the shutter 3 is regulated. As the toner supply container 1 is rotated further after its shutter comes into contact with the predetermined portion of the toner receiving apparatus 7 , the shutter 3 is moved, relative to the container proper 1 a , to the location at which the shutter 3 covers the hole 1 b , resealing the hole 1 b (toner supply container 1 ).
[0045] The toner supply container 1 is provided with a stirring member 4 , which is located in the container proper 1 a , and a stirring member driving gear 5 , which is located at the lengthwise end of the container proper 1 a , opposite to where the toner filling hole 1 c is located, and which is connected to the stirring member so that the stirring member rotates with the gear 5 . More specifically, the toner supply container 1 is structured so that after the toner supply container mounted in the main assembly of the image forming apparatus is readied for toner discharge, the driving force from the main assembly is transmitted to the stirring member 4 through the gear 5 in order to rotationally move the stirring member 4 relative to the container proper 1 a so that the toner within the toner supply container 1 is discharged from the toner supply container 1 through the hole 1 b.
[0046] The container proper 1 a is provided with a pair of projections 6 , as members for controlling the rotational movement of the apparatus shutter 8 , or the shutter on the main assembly side of the image forming apparatus, so that the apparatus shutter 8 is moved by the movement of the toner supply container 1 . The pair of projections 6 are configured and positioned so that as the toner supply container 1 is mounted into the toner receiving apparatus 7 , they engage with the apparatus shutter 8 .
[0047] More specifically, referring to FIG. 2 ( c ), each projection 6 has a portion 6 a and a portion 6 b . The portion 6 a is a hole unsealing portion for pushing down the apparatus shutter 8 . More specifically, as the toner supply container 1 is rotated, the surface D of the portion 6 a comes into contact with the apparatus shutter 8 , and pushes the apparatus shutter 8 , unsealing the hole 7 b of the toner receiving apparatus 7 , which will be described later. The portion 6 b , which is in the form of a claw, is a hole resealing portion. More specifically, as the toner supply container 1 is rotated in reverse to resealing the hole 7 b of the toner receiving apparatus 7 , the surface E of the portion 6 b comes into contact with the apparatus shutter 8 , and pushes it in the direction to pull up the apparatus shutter 8 .
[0048] There is provided a gap B of a predetermined size, between the above-described claw-like portion 6 b of the projection 6 , and the peripheral surface of the container proper 1 a . As force applies to the claw-like portion 6 b from the direction indicated by an arrow mark C, the claw-like portion 6 b elastically deforms toward the axial line of the container proper 1 a , and as the force is removed, it is restored to its original shape. In other words, the projection 6 is enabled to snap into, or out of, the corresponding hole of the apparatus shutter 8 . The direction in which the claw-like portion deforms is not limited to “toward the axial line of the container proper 1 a ”. For example, it may be the direction parallel with the axial line of the container proper 1 a.
[0049] The shutter movement regulating connective portions of the toner supply container 1 and toner receiving apparatus 7 may be structured as shown in FIGS. 12 ( a )- 12 ( b ). More specifically, the direction in which the protrusion, or the snap-fitting structure, of the claw-like portion 6 b , faces, may be opposite to the direction in which the protrusion of the claw-like portion 6 b faces in FIG. 2 . Such modification creates no problem in terms of the functionality of the claw-like portion 6 b of the projection 6 . When the projection 6 is structured as shown in FIGS. 12 ( a )- 12 ( b ), the portion of the apparatus shutter 8 , which engages with the claw-like portion 6 b , must be configured so that it accommodates the claw-like portion 6 b.
[0050] The shutter movement regulating connective portions may be different in structure from that in this embodiment and its modification described above. In other words, the connective portions may be modified in configuration, measurements, etc., as long as they can satisfy the requirement that they reliably push down the apparatus shutter 8 to unseal the toner receiving hole 7 b of the toner receiving apparatus 7 , and reliably pull up the apparatus shutter 8 to reseal the toner receiving hole 7 b.
[0051] Since the connective portions are structured to snap-fit, not only is the apparatus shutter 8 reliably pulled up to reseal the apparatus shutter 8 , but also, the apparatus shutter 8 can be easily disengaged from the pair of projections 6 after the resealing of the toner receiving hole 7 b by the apparatus shutter 8 .
[0052] It is desired that the projections 6 are formed, as integral parts of the container proper la, of resinous substance such as plastic by injection molding. However, it may be formed of material other than resinous substance, and formed by a method other than injection molding. Further, they may be made up of two or more pieces, which are joined. As described above, the claw-like portion 6 a of the projection 6 is required to have a proper amount of resiliency, since it is required to temporarily deform when engaging with the apparatus shutter 8 . Thus, low density polyethylene is the most desirable substance as the material for the claw-like portion 6 b . Next in order of preference are polypropylene, linear polyamide (for example, Nylon (commercial name)), high density polyethylene, or the like.
[0053] Next, referring to FIGS. 3 ( a )- 3 ( c ), the toner receiving apparatus 7 as a developer receiving apparatus in this embodiment will be described regarding its structure.
[0054] The toner receiving apparatus 7 is provided with a toner supply container cradle 7 a in which the toner supply container 1 is removably mounted, and a toner reception hole 7 b as a toner inlet through which the toner discharged from the toner supply container 1 is moved into the main assembly (unshown) of the image forming apparatus.
[0055] The toner receiving apparatus 7 is also provided with the shutter 8 for unsealing or resealing the toner reception hole 7 b . The apparatus shutter 8 is in the form of a semicylinder, the curvature of which matches that of the cylindrical wall of the toner supply container 1 , and that of the wall of the toner supply container cradle 7 a of the main assembly. The apparatus main shutter 8 is engaged with the pair of guiding members 7 c located at the lengthwise edges of the rectangular toner reception hole 7 b , on the underside of the semicylindrical top wall of the toner supply container cradle 7 a . With the provision of this structural arrangement, the apparatus shutter 8 is allowed to slide along the semicylindrical top wall of the toner supply container cradle 7 a along the curvature of the top wall, to open or close the toner reception hole 7 b.
[0056] When the toner supply container 1 is not in the toner supply container cradle 7 a of the toner receiving apparatus 7 , the apparatus shutter 8 is in the position, shown in FIG. 3 ( c ), in which the edge of the apparatus shutter 8 is in contact with the stopper 7 d of the toner receiving apparatus 7 , keeping thereby the toner supplying hole 7 b of the toner receiving apparatus 7 closed, and therefore, preventing the toner from moving back into the toner supply container cradle 7 a from inside the main assembly of the image forming apparatus.
[0057] The apparatus shutter 8 is also provided with a pair of projections 8 a which engage with the pair of projections 6 of the toner supply container 1 , during the operation for mounting the toner supply container 1 into the main assembly.
[0058] Next, referring to FIGS. 4 ( a ) and 4 ( b ) and FIGS. 5 ( a )- 5 ( c ), the operation for supplying the main assembly of the image forming apparatus with toner, with the use of the toner supply container 1 and toner receiving apparatus 7 in the first embodiment, will be described.
[0059] First, the toner supply container 1 is to be mounted into the toner receiving apparatus 7 from the direction indicated by an arrow mark F. When the toner supply container 1 is mounted, it is to be positioned so that the toner discharge hole 1 b covered with the shutter 3 , or the shutter on the toner supply container side, faces upward; in other words, the toner discharge hole 1 b is not in alignment with the toner reception hole 7 b sealed with the apparatus shutter 8 .
[0060] The toner supply container 1 is structured so that as soon as the bottom edge (leading edge in terms of direction in which the toner supply container 1 is moved to unseal toner discharge hole 1 b ) of the shutter 3 roughly aligns (inclusive of tolerance in measurements of toner supply container 1 and toner receiving apparatus 7 , and play) with the top edge of the toner reception hole 7 b , the shutter 3 is prevented by the stopper 7 d from moving with the container proper 1 a in the circumferential direction of the container proper 1 a (FIGS. 4 ( a ), 5 ( a ), and 5 ( a ′)).
[0061] Next, a user rotates the toner supply container 1 in the counterclockwise direction (first direction), as seen from the direction of the toner filling hole 1 c ( FIG. 5 ), by grasping the handle 2 . Initially, as the toner supply container 1 is rotated in the first direction, the shutter 3 of the toner supply container 1 rotates with the container proper 1 a of the toner supply container 1 . Then, it comes into contact with the aforementioned stopper 7 d of the toner receiving apparatus 7 , being prevented from rotating with the container proper 1 a.
[0062] Thus, as the toner supply container 1 is further rotated in the first direction, the bottom edge (leading edge portion in terms of direction in which toner supply container 1 is moved to unseal toner discharge hole 1 b ) of the toner discharge hole 1 b is exposed from the bottom side of the shutter 3 . Roughly at the same time as the bottom edge portion of the toner discharge hole 1 b is exposed from the bottom side of the shutter 3 , the bottom edge of the shutter 3 (leading edge portion in terms of direction in which toner supply container 1 is moved to unseal toner discharge hole 1 b ) roughly aligns with the top edge portion (trailing edge portion, no more than 2 mm wide from upstream edge, of apparatus shutter 8 in terms of direction in which toner supply container 1 is rotated) (FIGS. 5 ( b ) and 5 ( b ′)), and the claw-like portion 6 b of each projection 6 is elastically deformed, engaging thereby with the catch 8 a of the apparatus shutter 8 .
[0063] Then, as the toner supply container 1 is further rotated in the same direction, the apparatus shutter 8 is rotated with the toner supply container 1 by being pushed by portion 6 a of the projection 6 , while the top edge portion (trailing edge portion, no more than 2 mm wide from trailing edge, of shutter 8 in terms of rotational direction of toner supply container) is remaining overlapped with the bottom edge portion of the toner discharge hole 1 b (leading edge portion, no more than 2 mm wide from leading edge, of toner discharge hole 1 b in terms of rotational direction of toner supply container 1 ). As a result, the toner reception hole 7 b is exposed (unsealed), and therefore, the toner reception hole 7 b becomes connected with the toner discharge hole 1 b . Then, as the toner reception hole 7 b is entirely exposed, that is, the toner reception hole 7 b is fully connected with the toner discharge hole 1 b , the toner supply container 1 comes into contact with the stopper of the toner receiving apparatus 7 , being thereby prevented from being further rotated (FIGS. 4 ( b ) and 5 ( c )).
[0064] As the toner reception hole 7 b and toner discharge hole 1 b becomes fully connected, rotational driving force is transmitted to the stirring member 4 from the driving mechanism on the main assembly side of the image forming apparatus, through the coupling member 5 of the toner supply container 1 , which has coupled with the driving mechanism on the main assembly side. As a result, toner is supplied from the toner supply container 1 to the toner receiving apparatus 7 .
[0065] After the completion of the toner discharge from the toner supply container 1 , there is a certain amount of toner, across the bottom edge of the toner reception hole 7 b , which has accumulated thereon during the toner discharge ( FIG. 5 ( d )).
[0066] Next, the user rotates the toner supply container 1 in the clockwise direction ( FIG. 5 ) as the second rotational direction, as seen from the direction of the toner filling hole 1 c, in terms of the axial direction of the toner supply container 1 , by grasping the handle 2 , with the certain amount of toner still remaining across the bottom edge of the toner reception 7 b as described above. As the toner supply container 1 is reversely rotated, that is, in the clockwise direction, the apparatus shutter 8 is pulled upward by the pair of projections 6 of the container proper 1 a, because each of the pair of catch portions 8 a of the apparatus shutter 8 is remaining engaged with claw-like portion 6 a of the corresponding projection 6 of the toner supply container 1 . As a result, the apparatus shutter 8 is rotated with the toner supply container 1 , with the top edge portion of the apparatus shutter 8 (leading edge portion, no more than 2 mm wide, of shutter 8 in terms of direction in which toner supply container 1 is rotated to reseal toner reception hole 7 b ) remaining overlapped the bottom edge portion (trailing edge portion, no more than 2 mm wide from trailing edge, of toner discharge hole 1 b in terms of direction in which toner supply container 1 is rotated to reseal toner discharge hole 1 b ) of the toner discharge hole 1 b.
[0067] During this reverse rotation of the toner supply container 1 , the top edge portion of the apparatus shutter 8 (leading edge portion, not more than 2 mm wide from leading edge, of shutter 8 , in terms of direction in which toner supply container 1 is rotated to reseal toner reception hole 7 b ), and the bottom edge portion of the toner discharge hole 1 b (trailing edge portion, no more than 2 mm wide from trailing edge, of toner discharge hole 1 b , in terms of direction in which toner supply container 1 is rotated to reseal toner discharge hole 1 b ), passes, while remaining overlapped with each other, between the toner reception hole 7 b and toner discharge hole 1 b which are in connection with each other.
[0068] Also during this reverse rotation of the toner supply container 1 , the aforementioned certain amount of the toner having accumulated across the bottom edge portion of the toner reception hole 7 b is recovered into the toner receiving apparatus 7 through the toner reception hole 7 b , and also into the container proper 1 a through the toner discharge hole 1 b , as the toner supply container 1 is rotated to be resealed ( FIG. 5 ( e )), drastically reducing the amount by which the toner supply container 1 is contaminated by the aforementioned accumulated toner.
[0069] With the employment of the above-described structural arrangement, it is possible to prevent the hand(s) of a user from being contaminated when the user removes the toner supply container 1 from the main assembly of the image forming apparatus. Therefore, it is possible to improve the toner supply container 1 as well as the image forming apparatus, in terms of usability.
[0070] Further, as the toner supply container 1 is rotated to be resealed, the rotational movements of the apparatus shutter 8 and toner supply container shutter 3 are controlled by the pair of projections 6 of the toner supply container 1 in such a manner that the top edge portion of the apparatus shutter 8 (leading edge portion, no more than 2 mm wide from leading edge, of shutter 8 in terms of direction in which toner supply container 1 is rotated to reseal toner discharge hole 1 b ) comes into contact with the bottom surface of the stopper 7 d of the toner receiving apparatus 7 , preventing thereby the apparatus shutter 8 from rotating further with the toner supply container 1 . As a result, not only is the toner reception hole 7 b is completely closed by the apparatus shutter 8 , but also, the top edge portion of the toner discharge hole 1 b (leading edge portion, no more than 2 mm wide from leading edge, of toner discharge hole 1 b in terms of direction in which toner supply container 1 is rotated to reseal toner discharge hole 1 b ) begins to be covered by the shutter 3 roughly at the same time as the apparatus shutter 8 completely closes the toner reception hole 7 b.
[0071] As the toner supply container 1 is rotated further, the claw-like portion 6 b of each of the pair of projections 6 is disengaged from the corresponding catch 8 a of the apparatus shutter 8 , while elastically deforming in the direction to allow itself to be disengage from the catch 8 a , because the apparatus shutter 8 is prevented by the stopper 7 d from rotating further. In other words, the pair of projections 6 of the toner supply container 1 become disengaged from the pair of catches 8 a of the apparatus shutter 8 . Thereafter, the toner supply container 1 is to be further rotated, and during this rotation, the toner discharge hole 1 b is completely shut by the toner supply container shutter 3 , which is being prevented by the toner receiving apparatus 7 from rotating with the toner supply container 1 . As soon as the toner discharge hole 1 b is completely shut by the shutter 3 , the stopper (projection) on the peripheral surface of the container proper 1 a of the toner supply container 1 comes into contact with the toner receiving apparatus 7 , preventing the toner supply container 1 from being rotated further, in other words, restoring the toner supply container 1 to the state shown in FIG. 5 ( a ).
[0072] Lastly, the user pulls the toner supply container 1 out of the toner receiving apparatus 7 to complete the operation for supplying the main assembly of the image forming apparatus with toner, inclusive of the above-described sequence for resealing the toner supply container 1 (toner discharge hole 1 b ).
[0073] In this embodiment, the direction from which the toner supply container 1 is mounted into the toner receiving apparatus 7 is from above (direction indicated by arrow mark F in FIG. 4 ( a ). However, it does not need to be limited to this direction. For example, the toner supply container 1 and toner receiving apparatus 7 may be structured as disclosed in Japanese Laid-open Patent Applications 7-199623 or 7-44000, for example, so that the toner supply container 1 is mounted from the front side of the main assembly, more specifically, the toner supply container 1 is horizontally mounted into, or removed from, the toner receiving apparatus 7 , in the direction parallel with the lengthwise direction of the toner supply container 1 , as shown in FIG. 13 .
[0074] Also in this embodiment, the toner supply container 1 , and the main assembly of the image forming apparatus, are structured so that the toner discharge hole 1 b becomes connected to the toner reception hole 7 b as the toner supply container 1 is rotated enough to cause the toner discharge hole 1 b to face in the horizontal direction. However, they do not need to be structured in this manner.
[0075] Further, the direction in which the toner supply container 1 is rotated to be prepared for toner discharge does not need to be limited to the direction in which the toner supply container 1 is rotated in this embodiment. For example, the toner supply container 1 and the main assembly of the image forming apparatus may be structured so that the toner supply container 1 is to be mounted, with the toner discharge hole 1 b facing downward, and so that in order to unseal the toner supply container 1 , the toner supply container 1 is rotated in the direction opposite to the direction in which the toner supply container 1 in the above-described embodiment is rotated to unseal the toner supply container 1 , whereas in order to reseal the toner supply container 1 , the toner supply container 1 is rotated in the direction opposite to the direction in which the toner supply container 1 in the above-described embodiment is rotated to reseal the toner supply container 1 .
[0076] When the toner supply container 1 structured as described above was filled up with toner, was mounted into the toner receiving apparatus 7 , and was removed from the toner receiving apparatus 7 after the completion of toner discharge, there was virtually no confirmable contamination of the toner supply container 1 and toner receiving apparatus 7 by toner.
[0077] The above-described states of the toner supply container 1 and toner receiving apparatus 7 , in which the bottom edge portion of the toner discharge hole 1 b and the top edge portion of the apparatus shutter 8 overlap with each other in terms of the rotational direction of the apparatus shutter 8 , means the states of the toner supply container 1 and toner receiving apparatus 7 , in which the deviation (L) between the bottom edge of the toner discharge hole 1 b and the top edge of the apparatus shutter 8 , in terms of the rotational direction of the rotational direction of the toner supply container 1 is no more than roughly 5 mm. According to the levels of the contamination by toner, confirmed after the completion of the operation for supplying the main assembly of the image forming apparatus with toner, as long as the deviation (L) is no more than roughly 5 mm, the level of the contamination by toner is not problematic, that is, no worse than that when the deviation (L) was zero (state shown in FIG. 5 ).
[0078] In other words, this embodiment ensures that during the operation for supplying the main assembly of an image forming apparatus with toner, the shutter on the main assembly side, and the shutter on the toner supply container side, reliably and easily open or shut after the mounting of the toner supply container 1 into the toner receiving apparatus 7 , and also, minimizes the contamination of the toner supply container 1 by toner.
Embodiment 2
[0079] Next, referring to FIGS. 7 ( a )-( c ), the structure of the toner supply container 1 in the second embodiment of the present invention will be described.
[0080] In the above-described first embodiment of the present invention, the portion 6 a , as the portion for opening the apparatus shutter 8 , and the claw-like portion 6 b , as the portion for closing the apparatus shutter 8 , of the projection 6 as the shutter movement regulating portion of the container proper 1 a, are integral parts of the projection 6 . In this embodiment, the portion of the container proper 1 a for opening the apparatus shutter 8 , and the portion of the container proper 1 a for closing the apparatus shutter 8 , are made independent from each other, although they both project from the peripheral surface of the container proper 1 a of the toner supply container 1 .
[0081] More specifically, the toner supply container 1 is provided with a projection 9 as the portion for pushing down the apparatus shutter 8 to unseal the toner reception hole 7 b of the toner receiving apparatus 7 as the toner supply container 1 is rotated after the mounting of the toner supply container 1 into the toner receiving apparatus 7 to supply the apparatus main assembly with toner. The projection 9 projects from the peripheral surface of the container proper 1 a of the toner supply container 1 .
[0082] The toner supply container 1 is also provided with a shutter hooking projection 10 as the portion for hooking the apparatus shutter 8 to pull up the apparatus shutter 8 in order to reseal the toner reception hole 7 b . The hooking projection 10 projects from the peripheral surface of the container proper 1 a of the toner supply container 1 . It comprises the hooking portion 10 a and an elastic portion 10 b . The hooking portion 10 projects from the tip of the elastic portion 10 b in the radius direction of the container proper 1 a, beyond the peripheral surface of the container proper 1 a. The elastic portion 10 b elastically deforms toward the axial line of the container proper 1 a. In this embodiment, the combination of the pushing projections 9 as the container unsealing portions, and shutter hooking projection 10 , play the role of regulating the shutter movement, which is played by the pair of projections 6 of the toner supply container 1 in the first embodiment.
[0083] The structures of the other portions of the toner supply container 1 than the above-described portions, and the structure of the toner receiving apparatus 7 , are the same as those in the first embodiment, and therefore, will not be described.
[0084] Next, referring to FIGS. 8 ( a )-( e ), the operation for supplying the main assembly of the image forming apparatus with toner, with the use of the toner supply container 1 and toner receiving apparatus 7 in the second embodiment of the present invention, will be described.
[0085] First, the toner supply container 1 is to be mounted into the toner receiving apparatus 7 from the direction indicated by an arrow mark F. As the toner supply container 1 is inserted into the toner receiving apparatus 7 , the hooking portion 10 a of the hooking projection 10 is pressed against the upwardly facing surface of the apparatus shutter 8 , causing the elastic portion 10 b to be elastically deformed. As a result, the entirety of the hooking projection 10 is caused to retract into the recess of the cylindrical wall of the container proper 1 a ( FIG. 8 ( a )).
[0086] Next, a user rotates the toner supply container 1 in the counterclockwise direction, as seen from the direction of the toner filling hole 1 c, by grasping the handle 2 . As the toner supply container 1 is rotated, it is moved relative to the toner supply container shutter 3 , the movement of which is regulated by the toner receiving apparatus 7 .
[0087] As the toner supply container 1 is further rotated, the bottom edge of the toner discharge hole 1 b roughly aligns with the bottom edge of the shutter 3 ( FIG. 5 ( b ′)). Roughly at the same time as the bottom edge of the toner discharge hole 1 b aligns with the bottom edge of the shutter 3 , the pair of projections 9 of the toner supply container 1 come into contact with the edge of the apparatus shutter 8 , and the hooking projection 10 is freed from the pressure applied thereto by the upwardly facing surface of the apparatus shutter 8 in the radius direction of the container proper 1 a . As a result, the elastic portion 10 b of the hooking projection 10 resumes its original shape, causing the hooking portion 10 a of the hooking projection 10 to hook the apparatus shutter 8 by the edge of the apparatus shutter 8 ( FIG. 8 ( b )).
[0088] Then, as the toner supply container 1 is further rotated, the apparatus shutter 8 is moved (rotated) with the toner supply container 1 by being pushed by the projections 9 . As a result, the toner reception hole 7 b of the toner receiving apparatus 7 becomes connected with the toner discharge hole 1 b of the toner supply container 1 ( FIG. 8 ( c )). As the two holes 7 b and 1 b become connected with each other, it becomes possible for rotational driving force to be transmitted from the driving mechanism on the main assembly side of the image forming apparatus to the stirring member 4 through the gear 5 . Therefore it becomes possible for toner to be supplied from the toner supply container 1 to the toner receiving apparatus 7 .
[0089] After the operation for supplying the main assembly of the image forming apparatus with toner is completed, there is a certain amount of toner, across bottom edge of the toner reception hole 7 b , which has accumulated thereon during the toner discharge ( FIG. 8 ( d )).
[0090] Next, the user rotates the handle 2 in opposite direction, that is, the clockwise direction, as seen from the direction of the toner filling hole 1 c , in terms of the axial direction of the toner supply container 1 , with the certain amount of toner still remaining across the bottom edge of the toner reception 7 b as described above. As the handle 2 is reversely rotated, that is, in the clockwise direction, the apparatus shutter 8 is moved (rotated) with the toner supply container 1 , because each of the pair of hooking portions 10 a are remaining hooked on the edge of the apparatus shutter 8 . As a result, the toner reception hole 7 b is sealed. Also during this reverse rotation of the toner supply container 1 , the aforementioned certain amount of the toner having accumulated across the bottom edge portion of the toner reception hole 7 b is recovered into the main assembly of the image forming apparatus and/or the container proper 1 a ( FIG. 8 ( e )).
[0091] As the toner supply container 1 is further rotated, the hooking portion 10 b of the hooking projection 10 is made to elastically deform radially inward of the container proper 1 a, because the apparatus shutter 8 is regulated by the stopper 7 d , being therefore prevented from rotating further. As a result, not only is the hooking portion 10 a of the hooking projection 10 caused to disengage from the edge of the apparatus shutter 8 , but also, to come into contact with the surface of the apparatus shutter 8 , being thereby pressed by the surface of the apparatus shutter 8 so that it completely retracts into the recess of the cylindrical wall of the container proper 1 a. In other words, the toner supply container 1 becomes disengaged from the apparatus shutter 8 , being thereby allowed to rotate independently from the apparatus shutter 8 to be eventually restored to the state shown in FIG. 8 ( a ). Lastly, the user pulls the toner supply container 1 out of the toner receiving apparatus 7 to complete the operation (sequential steps) for supplying the main assembly of the image forming apparatus with toner.
[0092] When the toner supply container 1 structured as described above was filled up with toner, was mounted into the toner receiving apparatus 7 , and was removed from the toner receiving apparatus 7 after the completion of the toner discharge, there was virtually no confirmable contamination of the toner supply container 1 and toner receiving apparatus 7 by toner, as there was virtually none in the case of the toner supply container 1 in the first embodiment. In other words, this embodiment also ensures that during the operation for supplying the main assembly of an image forming apparatus with toner, the shutter on the main assembly side, and the shutter on the toner supply container side, reliably and easily open or shut after the mounting of the toner supply container 1 into the toner receiving apparatus 7 , and also, minimizes the contamination by toner, after the removal of the toner supply container 1 .
[0093] Next, the effects of the present invention will be further verified through the comparison of the toner supply container and toner receiving apparatus in the above-described embodiments of the present invention with those in the following comparative examples.
COMPARATIVE EXAMPLE 1
[0094] First, referring to FIG. 9 , the structure of the toner supply container in the first comparative example, and the toner supplying operation which employs the toner supply container in the first comparative example, will be described.
[0095] In the case of the toner supply container 1 in the first comparative example, a pair of pushing projections 9 for pushing the apparatus shutter 8 of the main assembly to unseal the toner reception hole 7 b during the toner supplying operation are located on the peripheral surface of the container proper 1 a of the toner supply container 1 (in other words, the toner supply container 1 is not provided with the projections 6 , with which the toner supply container 1 in the first embodiment is provided, nor the hooking projections 10 , with which the toner supply container 1 in the second embodiment is not provided). Also in the case of the toner supply container 1 in the first comparative example is not provided with a container shutter 3 such as those in the above-described first and second embodiments. Instead, the toner discharge hole 1 b is sealed with a heat seal or the like, which is to be removed after the mounting of the toner supply container 1 into the main assembly of the image forming apparatus, to unseal the toner discharge hole 1 b to carry out the toner supplying operation. The structures of the other portions of the toner supply container 1 than the above-described portion, and the structure of the toner receiving apparatus 7 , are roughly the same as those in the first embodiment.
[0096] The toner supply container 1 structured as described above was filled up with toner, and then, was mounted in the toner receiving apparatus 7 . Then, as it was rotated, the toner reception hole 7 b was opened by the pushing projections 9 , allowing the main assembly to be supplied with the toner from the toner supply container 1 . However, the toner reception hole 7 b could not be resealed with the apparatus shutter 8 . Therefore, the toner having accumulated across the bottom edge portion of the toner reception hole 7 b during the toner discharge was hardly recovered into the main assembly of the image forming apparatus and/or the container proper 1 a, resulting in the severe contamination of the surfaces of the toner supply container 1 and toner receiving apparatus 7 with toner; it was possible to confirm the presence of a substantial amount of toner on the surfaces of the toner supply container 1 and toner receiving apparatus 7 , after the removal of the toner supply container 1 from which toner had been discharged. Further, since the toner supply container 1 was not provided with a shutter, the contaminated portions of the toner supply container 1 were not covered.
[0097] In other words, the effectiveness of the shutter movement regulating portion (claw-like portion 6 b of connective projection 6 , hooking projection 10 , etc., in the above-described embodiments) in accordance with the present invention were confirmed.
COMPARATIVE EXAMPLE 2
[0098] Next, referring to FIGS. 10 ( a )- 10 ( e ), the structure of the toner supply container 1 in the second comparative example, and the toner supplying operation, which employs the toner supply container 1 in the second comparative example, will be described.
[0099] The toner supply container 1 in the second comparative example is similar in structure to the toner supply container 1 in first comparative example, except for the pair of projections 11 with which it is provided. The projection 11 is for pushing the apparatus shutter 8 to reseal the toner reception hole 7 b during the toner supplying operation. The projection 11 is positioned so that it will be on the downstream of the apparatus shutter 8 after the mounting of the toner supply container 1 into the toner receiving apparatus 7 . The structures of the other portions of the toner supply container 1 than the projections 11 , and the structure of the toner receiving apparatus 7 , were the same as those in the first comparative example.
[0100] The toner supply container 1 structured as described above was subjected to the same tests as those the toner supply container 1 in the first comparative example was subjected. The results were as follows.
[0101] The apparatus shutter 8 was rotated by the pushing projections 9 , and therefore, the toner reception hole 7 b of the toner receiving apparatus 7 was unsealed, as it was in the first comparative example (FIGS. 10 ( b )- 10 ( c ). However, there remained a deviation H between the other edge of the apparatus 8 , that is, the edge opposite from the pushing projection 9 , and the pushing projections 11 ( FIG. 10 ( d )). Therefore, as the toner supply container 1 was rotated in reverse after the toner discharge, the toner supply container 1 rotated alone until the pushing projections 11 came into contact with the edge of the apparatus shutter 8 ; in other words, the toner supply container 1 rotates alone by an angle proportional to the deviation H.
[0102] As a result, the peripheral surface of the container proper 1 a of the toner supply container 1 was contaminated across the area, the size of which is proportional to the deviation H, with the toner having had accumulated across the bottom edge portion of the toner reception hole 7 b during the toner reception ( FIG. 10 ( e )). When the toner supply container 1 and toner receiving apparatus 7 is in the state shown in FIG. 10 ( e ), the above-mentioned residual toner on the bottom edge portion of the toner reception hole 7 b can not be recovered into the container proper 1 a . Thus, it is highly possible that as the toner supply container 1 is further rotated in reverse to be restored to the state shown in FIG. 10 ( a ), that is, to reseal the toner reception hole 7 b , the residual toner, or the toner which failed to be recovered into the main assembly of the image forming apparatus, will enter the gap between the container proper 1 a and apparatus shutter 8 .
[0103] After the removal of the toner supply container 1 , it was confirmed that the external surfaces of the toner supply container 1 and toner receiving apparatus 7 had been contaminated with toner.
[0104] From the above-described results, it was possible to confirm the effectiveness of the shutter movement regulating portions (claw-like portion 6 b of connective projection 6 , hooking projection 10 , etc., in above-described embodiments) in accordance with the present invention.
COMPARATIVE EXAMPLE 3
[0105] Next, referring to FIG. 11 , the structure of the toner supply container 1 in the third comparative example, and the toner supplying operation which employs the toner supply container 1 in the third comparative example, will be described.
[0106] The toner supply container 1 in the third comparative example is provided with a container shutter 3 as are toner supply containers 1 in the first and second embodiments, in addition to the structural feature of the toner supply container 1 in the second comparative example. The structures of the other portions of the toner supply container 1 than the container shutter 3 , and the structure of the toner receiving apparatus 7 , are the same as those of the toner supply container 1 and toner receiving apparatus 7 in the second comparative example.
[0107] The toner supply container 1 structured as described above was subjected to the same tests as those to which the toner supply container 1 in the second comparative example was subjected, yielding the following results. That is, the contamination of the peripheral surface of the container proper 1 a by the residual toner having accumulated across the bottom edge portion of the toner reception hole 7 b during the toner reception, which occurred as it did in the second comparative example, was covered with the container shutter 3 .
[0108] However, the toner supply container 1 rotated alone, as it did in the second comparative example, until the pushing projections 11 came into contact with the edge of the apparatus shutter 8 . Therefore, the residual toner was not prevented from entering the gap between the container proper 1 a and the apparatus shutter 8 .
[0109] The removal of the toner supply container 1 revealed that the external surfaces of the toner supply container 1 and toner receiving apparatus 7 had been contaminated with toner. However, the contamination was less severe than that occurred in the second comparative example.
[0110] In other words, the above-described result also confirmed the effectiveness of the shutter movement regulating portions (claw-like portion 6 b of connective projection 6 , hooking projection 10 , etc., in above-described embodiments) in accordance with the present invention.
[0000] [Miscellaneous]
[0111] In the above-described embodiments, the container proper of the developer supply container is roughly cylindrical. However, the embodiments are not intended to limit the scope of the present invention in terms of the configuration of the container proper. In other words, the container proper may be different in configuration from those in the above-described embodiments, as long as it can store developer.
[0112] Also in the above-described embodiments, the image forming apparatus was a copying machine. However, the present invention is also applicable to various image forming apparatuses other than a copying machine, as long as they form an image with the use of developer. For example, the present invention is applicable to such an image forming apparatus as a printer, a facsimile machine, a multifunction image forming apparatus capable of two or more functions of these apparatuses. It also is applicable to an image forming apparatuses which comprises a transfer medium bearing member, such as a transfer medium conveyance belt, a transfer drum, etc., for holding a transfer medium in the form of a sheet or the like, and form an image on the transfer medium by sequentially laying multiple developer images different in color on the transfer medium. It also is applicable to an image forming apparatuses which comprise an intermediary transferring member, such as an intermediary transfer belt, an intermediary transfer drum, etc., and forms an image on the transfer medium by sequentially transferring multiple developer images different in color, onto the intermediary transfer member, and then, transferring all at once the multiple developer images having been transferred in layers on the intermediary transferring member, onto the transfer medium. The application of the present invention to these image forming apparatuses yields the same effects as those yielded by the image forming apparatus in the first and second embodiments.
[0113] Further, the application of the present invention to a given image forming apparatus is not limited by the number of the developing apparatuses employed by the image forming apparatus. In other words, not only is the present invention applicable to an image forming apparatus having only one developing apparatus, but also, an image forming apparatus employing a plurality of developing apparatuses which are different in the color of the developer they use; the present invention is applicable to various image forming apparatuses regardless of the number of developing apparatuses they employ. The effects of the present invention remain the same whether the present invention is applied to an image forming apparatus having a single developing apparatus, or an image forming apparatus having multiple developing apparatuses.
[0114] Further, the application of the present invention is not limited to such a developer supply container as the developer supply containers, in the first and second embodiments, which is removably mounted into the main assembly of an image forming apparatus. Further, the present invention is applicable to a developer supply container structured so that it can be removably mounted into the process cartridge (equivalent to toner receiving apparatus) removably mounted in the main assembly of an image forming apparatus.
[0115] Incidentally, the above-mentioned process cartridge means a cartridge in which the above-described electrophotographic photosensitive member 104 as an image bearing member, and a minimum of one processing device among the charging device 203 which acts on this photosensitive member 104 , developing device 201 a , and cleaner 203 , are integrally placed.
[0116] While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth, and this application is intended to cover such modifications or changes as may come within the purposes of the improvements or the scope of the following claims.
[0117] This application claims priority from Japanese Patent Applications Nos. 388832 and 328675 filed Nov. 19, 2003 and Nov. 12, 2004, respectively, which are hereby incorporated by reference. | A developer supply container detachably mountable to a developer receiving device having a receiving opening for receiving a developer, an apparatus shutter for opening and closing the receiving opening, the developer supply container including a container body for containing the developer, the container body including a discharge opening for discharging the developer; a container shutter for opening and closing the discharge opening by a rotational movement of the container body with the container shutter being prevented from moving by the developer receiving device; an interrelating portion for interrelating the rotational movement of the apparatus shutter with the container body such that apparatus shutter starts moving when a neighborhood of a leading, with respect to a moving direction thereof, end of the discharge opening exposed by the container shutter, is substantially aligned with a neighborhood of a trailing edge of the apparatus shutter. | 72,561 |
BACKGROUND OF THE INVENTION
The present invention relates to image display apparatus, such as a liquid crystal display.
An active matrix liquid crystal display which uses a thin film transistor (TFT) as a switching device is known today. In such an active matrix type liquid crystal display apparatus, a liquid crystal material is sealed between a TFT array substrate and a color filter substrate. A TFT array substrate contains scan signal lines and display signal lines in a matrix. Thin film transistors are disposed on intersections thereof, and a color filter substrate is spaced from the TFT array substrate by a specified interval. A display signal voltage is applied to the liquid crystal material under control of the thin film transistors. An electro optic effect on the liquid crystal causes a display.
Higher definition requires an increased number of pixels in the active matrix type liquid crystal display apparatus. This requires an increased number of display signal lines, scan signal lines and drivers along with increased storage. In addition, an electrode pitch for connecting the drive ICs and the TFT array substrate is narrowed, thus causing difficulty in connection thereof and lowering yield in connection work.
In order to solve these problems, many proposals have been made to reduce the number of drive ICs and increase a pitch between connection terminals by applying a potential to two or more adjacent pixels from one display signal line in time division. For example, such proposals are disclosed in Japanese Patent Laid-Open Nos. Hei 6 (1994)-138851, Hei 6 (1994)-148680, Hei 11 (1999)-2837, Hei 5 (1993)-265045, Hei 5 (1993)-188395 and Hei 5 (1993)-303114.
As object of the present invention is to provide a high definition, active matrix type liquid crystal display apparatus with reduced storage requirements.
Another object of the present invention is to provide a high definition, active matrix type liquid crystal display apparatus with simplified circuitry.
SUMMARY OF THE INVENTION
The invention resides in a process for supplying display signals from a storage device to a multiplicity of pixel electrodes in an image display apparatus. Display signals are serially stored into the storage device for a significant part of a line of the image display apparatus. After the display signals are stored for the part of the line into the storage device, the display signals are outputted while additional display signals for another part of the line are concurrently stored into the storage device. The outputting step is performed at a faster rate than the concurrent storing step.
According to one feature of the present invention, an image display apparatus comprises: a plurality of display signal lines for supplying display signals; a first pixel electrode and a second pixel electrode, to which the display signals are supplied from a common display signal line; a scan signal line for supplying scan signals to the first pixel electrode and the second pixel electrode; and a signal processing circuit for generating the display signals based on a first signal corresponding to the first pixel electrode and a second signal corresponding to the second pixel electrode and for supplying the display signals to the display signal lines. The signal processing circuit includes: a first storage area for storing the first signal; a second storage area for storing the second signal, the second storage area being larger than the first storage area in storage capacity; a distributing circuit for distributing the first signal to the first storage area and the second signal to the second storage area; and an output selecting circuit for selecting any of the first signal stored in the first storage area and the second signal stored in the second storage area and for outputting the selected signal.
The above image display apparatus of the present invention comprises the first storage area for storing the first signal, and the second storage area for storing the second signal, the second storage area being larger than the first storage area in storage capacity. Between the first signal and the second signal, which are stored in the first storage area and the second storage area respectively by the distributing circuit, the first signal stored in the first storage area relatively small in storage capacity is outputted prior to the second signal by an instruction of the output selecting circuit. After this output is ended, the second signal stored in the second storage area relatively large in storage capacity is outputted. Specifically, the first signal to be inputted to the first pixel electrode and the second signal to be inputted to the second pixel electrode are continuously supplied. Here, since the first signal is priorly outputted by the instruction of the output selecting circuit, the first storage area can save the storage capacity to be smaller than that of the second storage area. Specifically, according to the present invention, the capacity of circuit for storing display signals can be reduced.
Moreover, since the image display apparatus of the present invention has a structure, in which the display signals are supplied to two pixel electrodes of the first pixel electrode and the second pixel electrode, the number of display signal lines can be decreased in half or lower of the number of pixels arranged in one row.
In the image display apparatus of the present invention, with regard to the first and second signals inputted from the outside during a same horizontal cycle, the output selecting circuit can output the first signal stored in the first storage area prior to the second signal stored in the second storage area.
In the image display apparatus of the present invention, the signal processing circuit can store the first signal in the first storage area during a specified first horizontal cycle and can store the second signal in the second storage area, and can execute a control to output the first signal stored in the first storage area during the first horizontal cycle.
Moreover, in the image display apparatus of the present invention, during a second horizontal cycle following the first horizontal cycle, the signal processing circuit can execute the control to complete the output of the second signal stored in the second storage area during the first horizontal cycle.
Moreover, in the image display apparatus of the present invention, the signal processing circuit can execute a control to complete the output of the first signal from the first storage area and the output of the second signal from the second storage area during one horizontal cycle.
Furthermore, in the image display apparatus of the present invention, the first storage area and the second storage area desirably include First-in First-out functions for data input and output.
Moreover, at least one of the first storage area and the second storage area can be constituted of a plurality of storing circuit. Specifically, the first storage area and the second storage area are not limited to the case of having single structures.
Furthermore, the first storage area and the second storage area can be logically constituted and physically constituted as a logical storage apparatus of one system.
Moreover, the present invention can achieve the foregoing objects also by a novel image display apparatus to be described below. Specifically, the image display apparatus of the present invention comprises an image display device having a plurality of pixels arrayed in a matrix and having display signal lines and scan signal lines provided therein, the display signal lines being for supplying display signals to respective pixels and the scan signal lines being for supplying scan signals to the respective pixels, and signal processing circuit for generating the display signals based on signals inputted from an outside and for supplying the display signals to the display signal lines, wherein, in the image display device, a first pixel electrode and a second pixel electrode are connected to the display signal line common thereto, the first and second pixel electrodes existing in a same row, and the signal processing circuit includes a first storage area having a capacity for storing a first display signal to be inputted to the first pixel electrode in amount corresponding to a ½ horizontal cycle relating to the first display signal and a second storage area having a capacity for storing a second display signal to be inputted to the second pixel electrode in amount corresponding to one horizontal cycle relating to the second display signal.
In the image display apparatus of the present invention, the first storage area has a capacity for storing the display signals corresponding to the ½ horizontal cycle, and the second storage area has a capacity for storing the display signals corresponding to the one horizontal cycle. Specifically, though it has been heretofore required that each of the first storage area and the second storage area has the capacity for storing the display signals corresponding to one horizontal cycle, it is sufficient if one of the storage areas has the capacity for storing the display signals corresponding to ½ horizontal cycle. This is because the signal processing circuit executes the control as below. Specifically, when the first display signal is inputted during a specified horizontal cycle, and when the first storage area stores the first display signal in amount corresponding to the ½ horizontal cycle relating to the first display signal, the signal processing circuit executes a control to output the first display signal in storage order.
With regard to the second display signal, the signal processing circuit receives the second display signal during the specified one horizontal cycle, and after the second storage area stores the second display signal in amount corresponding to the one horizontal cycle relating to the second display signal, executes a control to output the second display signal in storage order.
For the image display device applied to the image display apparatus of the present invention, the following is desirable. Specifically, the present invention desirably uses the image display device including a plurality of display signal lines for supplying display signals, a plurality of scan signal lines for supplying scan signals, a first pixel electrode and a second pixel electrode, to which the display signals are supplied from a common display signal line, a first switching device having a gate electrode for controlling supply of the display signals, the first switching device being disposed between the common display signal line and the first pixel electrode; a second switching device disposed between the gate electrode of the first switching device and a specified scan signal line, and a third switching device for controlling supply of the display signals to the second pixel electrode, the third switching device being connected to the specified scan signal line.
This image display device can supply the display signals from the common and specified signal line to the first pixel electrode and the second pixel electrode. Accordingly, in the case where M rows of pixels exist, the number of signal lines, that is, the number of data drivers can be set at M/2.
Moreover, the image display device adopts a configuration, in which the second switching device is disposed between the specified scan signal line and the gate electrode of the first switching device, which is disposed between the first pixel electrode and the specified scan signal line. Specifically, two switching device are not arranged in series between the first pixel electrode and the specified display signal line. Accordingly, it is not necessary to enlarge the switching device represented by TFT. Meanwhile, the third switching device is connected to the second pixel electrode, and when the third switching device is turned on, the display signals from the signal line can be supplied to the second pixel electrode.
Note that description has been made here for the two pixel electrodes, that is, the first pixel electrode and the second pixel electrode. However, the above purpose of the present invention can be applied to an aspect where three or more pixel electrodes share one signal line. As a matter of course, the present invention also includes this aspect.
Moreover, it is also desirable that the present invention use the image display device including: a first pixel electrode and a second pixel electrode disposed between an n-th (n: positive integer) scan signal line and an n+1-th scan signal line, to which display signals from a specified signal line are supplied; a first switching mechanism allowing the scan signals to pass therethrough when both of the n+1-th scan signal line and an n+m-th (m: integer except 0 and 1) scan signal line are selected; and a second switching mechanism allowing the scan signals to pass therethrough to the second pixel electrode when the n+1-th scan signal line is selected.
In this image display device, the first pixel electrode and the second pixel electrode share the specified signal line, and the display signals are supplied from the signal line. Moreover, in the image display device of the present invention, the first pixel electrode is supplied with the scan signals when both of the n+1-th scan signal line and the n+m-th (m: integer except 0 and 1) scan signal line are selected, and the second pixel electrode is supplied with the scan signals when the n+1-th scan signal line is selected. Accordingly, by selecting the number m, the storage capacity can be formed between each of the first and second pixel electrodes and an upstream scan signal line, which is not involved in the drive of the first and second pixel electrodes.
Moreover, the present invention provides a novel display signal supply apparatus to be described below for supplying display signals to an active matrix type image display device. Specifically, the display signal supply apparatus of the present invention comprises: a distributing circuit for distributing the display signals inputted thereto from an outside into a first signal and a second signal; a first storage area for storing the first signal obtained by distributing the display signals by the distributing circuit; a second storage area for storing the second signal obtained by distributing the display signals by the distributing circuit; and signal outputting circuit for instructing an output of the first signal from the first storage area prior to entire storage of the first signal in the first storage area.
In the display signal supply apparatus of the present invention, the signal outputting circuit can instruct an output of the second signal stored in the second storage area from the second storage area after the first signal in specified amount is outputted from the first storage area. Then, the distributing circuit distributes display signals for m pieces of pixels into the first signal for m/2 pieces of pixels and the second signal for the m/2 pieces of pixels, the signals being inputted circuit from the outside. Moreover, the signal outputting instructs the output of the priorly stored first signal from the first storage area when the first signal for m/4 pieces of pixels is stored in the first storage area, and instructs the output of the second signal stored in the second storage area from the second storage area after the first signal for the m/2 pieces of pixels is outputted from the first storage area.
When the first signal for the m/4 pieces of pixels is stored in the first storage area, the display signal supply apparatus of the present invention outputs the priorly stored first signal from the first storage area in storage order. Accordingly, it is not necessary for the first storage area to have the storage capacity for the m/2 pieces of pixels.
The display signal supply apparatus of the present invention can further comprise: a signal control circuit for receiving display signals and clock signals from the outside and for outputting the display signals and control signals; and a driver for receiving the display signals and the control signals, both being outputted from the signal control circuit, and for supplying the display signals to the image display device based on the control signals. In this case, the first storage area and the second storage area can be provided in the signal control circuit or in the driver.
The present invention provides a display signal supply method for an image display device to be described below.
Specifically, the present invention is a display signal supply method for an image display device, the image display device including a plurality of display signal lines for supplying display signals, a plurality of scan signal lines for supplying scan signals, a first pixel electrode disposed between the scan signal lines adjacent to each other and connected to a specified display signal line, and a second pixel electrode connected to the specified display signal line, the display signal supply method comprising the steps of: receiving display signals for m pieces of pixels; after a first display signal corresponding to the first pixel electrode is stored for m/4 pieces of pixels, while storing the first display signal subsequent thereto, outputting the first display signal priorly stored to the first pixel electrode; and after an output of the first display signal is completed, outputting a second display signal corresponding to the second pixel electrode to the second pixel electrode, the second display signal being stored for m/2 pieces of pixels.
In the display signal supply method for an image display device of the present invention, the storage of the first display signal and the second display signal can be started in different areas from the same time. Moreover, the storage and the output of the first display signal and the storage of the second display signal can be performed during one horizontal cycle.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings.
FIG. 1 is a view schematically showing a configuration of a liquid crystal display apparatus according to the present invention.
FIG. 2 is a view showing a circuit configuration of a display area 2 of an array substrate 1 according to a first embodiment.
FIG. 3 is a view showing an operation of the array substrate 1 of the liquid crystal display apparatus according to the first embodiment.
FIG. 4 is a view showing an operation of the array substrate 1 of the liquid crystal display apparatus according to the first embodiment.
FIG. 5 is a view showing an operation of the array substrate 1 of the liquid crystal display apparatus according to the first embodiment.
FIG. 6 is a view showing an operation of the array substrate 1 of the liquid crystal display apparatus according to the first embodiment.
FIG. 7 is a timing chart of scan signals of the liquid crystal display apparatus according to the first embodiment.
FIG. 8 is a timing chart of display signals of the liquid crystal display apparatus according to the first embodiment.
FIG. 9 is a view showing a configuration of a driver 32 of the liquid crystal display apparatus according to a second embodiment.
FIG. 10 is a timing chart of the display signals of the liquid crystal display apparatus according to the second embodiment.
FIG. 11 is a view showing a configuration of the driver 32 of the liquid crystal display apparatus according to a third embodiment.
FIG. 12 is a timing chart of the display signals of the liquid crystal display apparatus according to the third embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, description will be made for an image display apparatus of the present invention based on an embodiment regarding a liquid crystal display apparatus.
FIG. 1 is a schematic view showing a principal configuration of an array substrate 1 as an image display device according to this embodiment, FIG. 2 is a view showing a circuit configuration of a display area 2 , FIGS. 3 to 6 are views showing operations of display area 2 , FIG. 7 is a timing chart of scan signals, and FIG. 8 is a timing chart of display signals.
The liquid crystal display apparatus according to this embodiment has a feature in that two pixels adjacent to each other sandwiching one common display signal line share the display signal line to reduce the number of display signal lines in half. Moreover, the liquid crystal display apparatus according to this embodiment has a feature to supply the display signal by use of two FIFO-A 52 and FIFO-B 53 to be described later. As a matter of course, it is necessary for the liquid crystal display apparatus to include other elements such as a color filter substrate, which constitutes display area 2 and faces array substrate 1 each other, and a backlight unit. However, since these are not feature portions of the present invention, description thereof will be omitted.
As shown in FIG. 1 , array substrate 1 includes an X driver 3 as a drive circuit for supplying display signals to pixel electrodes arranged in display area 2 through display signal lines 30 , that is, for applying voltages thereto, and a Y driver 4 as a drive circuit for supplying scan signals controlling on/off of thin film transistors (TFT) through scan signal lines 40 . In display area 2 of the array substrate 1 , pixels in number of m′n are arrayed in a matrix. Here, m and n are any positive integers. X driver 3 is divided into five drivers 32 to 36 , each corresponding to a specified number of display signal lines 30 . Similarly, Y driver 4 is divided into five drivers 42 to 46 , each corresponding to a specified number of scan signal lines 40 . Note that the number five is only an example, and it is needless to say that other divisional numbers can be adopted.
X driver 3 and Y driver 4 are connected to a signal control circuit 5 . Signal control circuit 5 controls drives of X driver 3 and Y driver 4 upon receiving digital video data (hereinafter referred to as video data) as display signals, synchronization signals (Sync) and clock signals (Clock) from a side of a host, such as a personal computer. Signal control circuit 5 includes an input memory controller 51 , FIFO-A 52 as a first storage device, FIFO-B 53 as a second memory device, an output memory controller 54 , and XY timing generator 55 . FIFO-A 52 and FIFO-B 53 are memories, each having a First-in First-out function. As far as FIFO-A 52 and FIFO-B 53 are provided with this function, a concrete structure thereof does not become a problem. A signal processing circuit of the present invention is constituted of individuals or combinations of X driver 3 , Y driver 4 and signal control circuit 5 . Upon receiving the video data, input memory controller 51 controls as to which of FIFO-A 52 and FIFO-B 53 is to be a transfer destination of the received data and controls a transfer timing.
FIFO-A 52 and FIFO-B 53 store the video data transferred from input memory controller 51 one by one. The stored video data is outputted to output memory controller 54 based on the control of input memory controller 51 or output memory controller 54 .
Output memory controller 54 executes a control as to which video data stored in FIFO-A 52 of FIFO-B 53 is to be read out and supplied to X driver 3 . Output memory controller 54 also controls the timing when the video data is supplied to X driver 3 .
The supplied video data based on the operation of output memory controller 54 is transferred to X driver 3 through data bus 31 . While the video data is supplied to the respective drivers 32 to 36 constituting X driver 3 , one of drivers 32 to 36 to which the supplied video data is actually inputted is determined by an X timing pulse (X DIO) outputted from XY timing generator 55 to X driver 3 .
As described above, XY timing generator 55 generates the X timing pulse instructing which of drivers 32 to 36 is used for processing the video data transferred to data bus 31 . Moreover, the XY timing generator 55 supplies signals controlling on/off of the thin film transistors to Y driver 4 . The XY timing generator 55 generates a Y timing pulse (Y DIO) instructing which of drivers 42 to 46 of Y driver 4 is distributed with this on/off control signal. This Y timing pulse is supplied to Y driver 4 .
As described above, this embodiment is characterized in that the two memories of FIFO-A 52 and FIFO-B 53 are provided in signal control circuit 5 . Description will be made in detail later for specific contents of a video data supply method using these two memories.
FIG. 2 is a view showing a circuit structure in the display area 2 . Note that FIG. 2 only shows a part of the display area 2 and a circuit having the structure shown in FIG. 2 is continuously formed in the actual display area 2 . In FIG. 2 , with regard to pixel electrodes A 1 and B 1 adjacent to each other sandwiching a display signal line Dm, three TFTs, that is, a first TFT M 1 , a second TFT M 2 and a third TFT M 3 , are arranged in a manner as below.
First, with regard to first TFT M 1 , a source electrode thereof is connected to the display signal line Dm, and a drain electrode thereof is connected to pixel electrode A 1 . Moreover, a gate electrode of first TFT M 1 is connected to a source electrode of second TFT M 2 . Here, the TFT is a three-terminal switching device. In the liquid crystal display apparatus, there is an example where an electrode connected to the display signal line is referred to as the source electrode and an electrode connected to the pixel electrode is referred to as the drain electrode, and there is an example inverse thereto. Specifically, determination has not been uniquely made as to which of two electrodes except the gate electrode is to be referred to as the source electrode or the drain electrode. Accordingly, each of the two electrodes except the gate electrode will be referred to as a source/drain electrode hereinafter.
Next, with regard to second TFT M 2 , a source/drain electrode thereof is connected to the gate electrode of first TFT M 1 , and another source/drain electrode is connected to a scan signal line Gn+2.
Accordingly, the gate electrode of first TFT M 1 is connected to scan signal line Gn+2 through second TFT M 2 . Moreover, the gate electrode of second TFT M 2 is connected to scan signal line Gn+1. Hence, only during a period when two scan signal lines Gn+1 and Gn+2 adjacent to each other are simultaneously at a selected potential, first TFT M 1 is turned on, and a potential of display signal line Dm is supplied to pixel electrode A 1 . This suggests that second TFT M 2 controls on/off of first TFT M 1 .
With regard to third TFT M 3 , a source/drain electrode is connected to display signal line Dm, and another source/drain electrode is connected to pixel electrode B 1 . Moreover, a gate electrode of third TFT M 3 is connected to scan signal line Gn+1. Accordingly, when scan signal line Gn+1 is at the selected potential, third TFT M 3 is turned on, and the potential of the display signal line Dm is supplied to pixel electrode B 1 .
Description has been made above for the circuit configuration in display area 2 seen from first TFT M 1 to third TFT M 3 . Now, description will be made for the circuit configuration in display area 2 seen from pixel electrode A 1 and pixel electrode B 1 .
To pixel electrode A 1 and pixel electrode B 1 , the display signals are supplied from the common and single display signal line Dm. Specifically, the display signal line Dm can be said to be the display signal line Dm common to pixel electrode A 1 and pixel electrode B 1 . Hence, while the pixels are arrayed in an M′N matrix, the number of the display signal lines Dm will be M/2. To pixel electrode A 1 , first TFT M 1 and second TFT M 2 are connected, first TFT M 1 is connected to display signal line Dm and second TFT M 2 . The gate electrode of the second TFT M 2 is connected to scan signal line Gn+1 downstream of pixel electrode A 1 , and the drain electrode of second TFT M 2 is connected to scan signal line Gn+2 downstream of scan signal line Gn+1. Here, in order to supply the potential of display signal line Dm to pixel electrode A 1 , it is necessary to turn on first TFT M 1 . Moreover, the gate electrode of first TFT M 1 is connected to one source/drain electrode of second TFT M 2 , the gate electrode of second TFT M 2 is connected to scan signal line Gn+1 of its own, and the other source/drain electrode thereof is connected to scan signal line Gn+2 downstream of pixel electrode A 1 . Therefore, in order to turn on first TFT M 1 , it is necessary to turn on second TFT M 2 . In order to turn on second TFT M 2 , it is necessary that scan signal line Gn+1 be selected. During this selection period, when scan signal line Gn+2 is selected, first TFT M 1 is also turned on. Hence, first TFT M 1 and second TFT M 2 constitute a switching mechanism, which allows the scan signals to pass therethrough when both scan signal line Gn+1 and scan signal line Gn+2 are selected. Accordingly, pixel electrode A 1 is driven based on the scan signal from scan signal line Gn+1 and the scan signal from scan signal line Gn+2, and receives the potential from display signal line Dm.
To pixel electrode B 1 , third TFT M 3 is connected, and a gate electrode thereof is connected to scan signal line Gn+1. Hence, pixel electrode B 1 is supplied with the potential from display signal line Dm when scan signal line Gn+1 of its own is selected.
Description has been made above for pixel electrode A 1 and pixel electrode B 1 , however, pixel electrode A 2 and pixel electrode B 2 , pixel electrode C 1 and pixel electrode D 1 , pixel electrode C 2 and pixel electrode D 2 , and other pixel electrodes are configured similarly.
Next, description will be made for operations of pixel electrode A 1 to pixel electrode D 1 depending on selection and non-selection of scan signal lines Gn+1 to Gn+3 with reference to circuit diagrams of FIGS. 3 to 6 and the timing chart of the scan signals shown in FIG. 7 .
Dm( 1 ) and Dm( 2 ) shown in FIG. 7 are potentials of data signals supplied by display signal line Dm and show timings when the data signals are changed. These Dm( 1 ) and Dm( 2 ) include changes of polarities and gray-scales. Accordingly, if the changes are grasped as changes of the polarities, in the case of an operation by Dm( 1 ), the polarities of pixel electrode A 1 and pixel electrode B 1 become different from each other, and the polarities of pixel electrode A 1 and pixel electrode C 1 become the same. Meanwhile, in the case of an operation by Dm ( 2 ), the polarities of pixel electrode A 1 and pixel electrode B 1 become the same, and the polarities of pixel electrode A 1 and pixel electrode C 1 become different from each other.
Moreover, in FIG. 7 , diagrams of scan signal lines Gn to Gn+3 show the selection and the non-selection of scan signal lines Gn to Gn+3. Specifically, each portion where the diagram rises shows a state where the concerned scan signal line is selected, and each portion not corresponding to the above shows a state where the concerned scan signal line is not selected.
As shown in FIG. 3 and FIG. 7 , during a period (t 1 ) from a time when both scan signal line Gn+1 and scan signal line Gn+2 are selected to a time when scan signal line Gn+2 falls to the non-selection potential, first TFT M 1 to third TFT M 3 is turned on. Note that, in FIG. 3 , the selection of scan signal line Gn+1 and scan signal line Gn+2 is indicated by bold lines of the concerned diagrams. As shown in FIG. 3 , a potential Va 1 to be applied to pixel electrode A 1 from display signal line Dm is supplied to pixel electrode A 1 , pixel electrode B 1 and pixel electrode D 1 . Here, the potential Va 1 of pixel electrode A 1 is determined.
After scan signal lines Gn+2 falls to the non-selection potential, the potential supplied from display signal line Dm is changed to a potential Vb 1 to be applied to pixel electrode B 1 .
As shown in FIG. 7 , scan signal line Gn+1 is still set at the selection potential during period (t 2 ) after scan signal line Gn+2 falls to the non-selection potential, whereby, as shown in FIG. 4 , the potential Vb 1 is supplied to pixel electrode B 1 , and the potential of pixel electrode B 1 is determined. As described above, the potential of display signal line Dm is supplied to pixel electrode A 1 and pixel electrode B 1 in time division.
After scan signal line Gn+1 falls to the non-selection potential, the potential of display signal line Dm is changed to a potential Vc 1 to be applied to pixel electrode C 1 .
Moreover, as shown in FIG. 7 , when scan signal line Gn+2 rises again to the selection potential and scan signal line Gn+3 rises to the selection potential during a period (t 3 ) after scan signal line Gn+1 falls to the non-selection potential, as shown in FIG. 5 , the potential Vc 1 is supplied to pixel electrode C 1 , pixel electrode D 1 and pixel electrode F 1 . Here, the potential Vc 1 of pixel electrode C 1 is determined.
After scan signal line Gn+3 falls to the non-selection potential, the potential supplied from display signal line Dm is changed to a potential Vd 1 to be applied to pixel electrode D 1 .
As shown in FIG. 7 , scan signal line Gn+2 is still set at the selection potential during a period (t 4 ) after scan signal line Gn+3 falls to the non-selection potential, whereby, as shown in FIG. 6 , the potential Vd 1 is supplied to pixel electrode D 1 , and the potential of pixel electrode D 1 is determined.
The liquid crystal display apparatus of the first embodiment adopts the configuration of supplying a drive potential from one display signal line, for example, from display signal line Dm to two pixel electrodes A 1 and B 1 adjacent to each other sandwiching the display signal line. Accordingly, as compared with the conventional liquid crystal display apparatus, in which the pixels and the display signal lines correspond to each other one by one, the number of the display signal lines, that is, the number of data drivers can be reduced in half. Furthermore, in the liquid crystal display apparatus according to the first embodiment, the first TFT M 1 connected to pixel electrode A 1 and the second TFT M 2 connected to pixel electrode B 1 are directly connected to common display signal line Dm. Accordingly, unlike a circuit configuration disclosed in the gazette of Japanese Patent Laid-Open No. Hei 5 (1993)-265045, in which two TFTs are connected in series between the display signal line and the pixel electrode, it is not necessary to design the TFT to be large in order to secure a desired current. Specifically, according to the first embodiment, as compared with the liquid crystal display apparatus disclosed in the gazette of Japanese Patent Laid-Open No. Hei 5 (1993)-265045, the first TFT M 1 and the second TFT M 2 as the switching devices can be made to be small in dimension.
In the liquid crystal display apparatus according to the first embodiment, storage capacitors Cs are provided between the pixels and the scan signal lines upstream thereof. Specifically, as shown in FIG. 2 , storage capacitors Cs of pixel electrodes A 1 , B 1 , A 2 and B 2 are provided between the concerned pixel electrodes and the scan signal line Gn, and storage capacitors Cs of pixel electrode C 1 , D 1 , C 2 and D 2 are provided between the concerned pixel electrodes and scan signal line Gn+1. Scan signal line Gn is not involved in the drives of pixel electrodes A 1 , B 1 , A 2 and B 2 , and scan signal line Gn+1 is not involved in the drives of pixel electrodes C 1 , D 1 , C 2 and D 2 . Here, during the period when the potentials are supplied from display signal lines Dm and Dm+1 to pixel electrodes A 1 , B 1 , A 2 and B 2 and immediately after the period, the potential of scan signal line Gn is not varied. Accordingly, variations of the pixel potentials in pixel electrodes A 1 , B 1 , A 2 and B 2 are avoided, which implies that the pixel potentials can be controlled accurately. This becomes a greatly advantageous point on image quality, and a high-quality image can be thereby provided. This feature of the embodiment in that the storage capacitors Cs can be provided between the pixel electrodes and the scan signal line upstream thereof can be enjoyed even if two TFTs are connected in series between the display signal lines and the pixels.
Here, when the storage capacitors are disposed between the pixels and the scan signal line upstream thereof, the potential of the scan signal line upstream thereof will be varied during the period when the potentials are supplied from the display signal line to the concerned pixels, therefore, the potentials of the concerned pixels will be varied.
In order to avoid the variation of the pixel potentials, an aspect is not adopted, in which parts of the scan signal line are used as the storage capacitors, but independent storage capacitors may be formed. However, formation of the independent storage capacitors causes an aperture ratio of the pixels to be lowered. Moreover, in some cases, it may be also necessary to change or add a process for preparing the array substrate. Accordingly, the first embodiment can be said to be desirable from a viewpoint of the aperture ratio and the manufacturing process. As a matter of course, the present invention does not deny the formation of the independent storage capacitors Cs.
Incidentally, the liquid crystal display apparatus according to this embodiment is characterized in a supply method of video data inputted thereto to X driver 3 . Hereinafter, description will be made for this characteristic supply method of video data with reference to FIG. 8 .
FIG. 8 is a timing chart showing video data (Data) inputted to the liquid crystal display apparatus, storing states of the data in FIFO-A 52 and FIFO-B 53 , outputting states of the data from FIFO-A 52 and FIFO-B 53 , and the data supplied to X driver 3 in contrast to a horizontal cycle.
In FIG. 8 , “ 1 H” put to a row diagram denoted by Time denotes one horizontal cycle. Now, it is assumed that m pieces of pixels are arrayed in the horizontal direction of display area 2 . “m pixel” shown in the diagram of Time indicates that the m pieces of pixels are arrayed in the horizontal direction and that the display signals are supplied to the m pieces of pixels arrayed in the same row in the one horizontal cycle.
Now, when the first horizontal cycle is started, the video data is inputted to signal control circuit 5 from a host. Here, it is assumed that the video data for a row where pixel electrodes A 1 , B 1 , A 2 , B 2 are arrayed, and for a row where pixel electrodes C 1 , D 1 , C 2 , D 2 are arrayed in FIG. 2 is inputted.
The video data to the row where pixel electrodes A 1 , B 1 , A 2 , B 2 are arrayed is inputted during the first horizontal cycle, and the video data to the row where pixel electrodes C 1 , D 1 , C 2 , D 2 are arrayed is inputted during the next one horizontal cycle. This state is schematically shown in rows of “Data” of FIG. 8 . The video data inputted during the first horizontal cycle is supplied from the host in order of video data to be supplied to pixel electrode A 1 , video data to be supplied to pixel electrode B 1 , video data to be supplied to pixel electrode A 2 , and video data to be supplied to pixel electrode B 2 . When the video data to be supplied to pixel electrodes A 1 , A 2 , A 3 , A 4 is defined as A, and when the video data to be supplied to pixel electrodes B 1 , B 2 , B 3 , B 4 is defined as B, data for the m pieces of pixels in total, which is obtained by adding the video data A for m/2 pieces of pixels to video data B for m/2 pieces of pixels, is inputted to signal control circuit 5 during the first horizontal cycle.
The inputting operation is also executed in the next one horizontal cycle (hereinafter referred to as second horizontal cycle) similarly to the above. Specifically, the video data is supplied from the host in order of the video data to be supplied to pixel electrode C 1 , the video data to be supplied to pixel electrode D 1 , and the video data to be supplied to pixel electrode C 2 . Then, when the video data to be supplied to pixel electrodes C 1 , C 2 , C 3 , C 4 is defined as C, and when the video data to be supplied to pixel electrodes D 1 , D 2 , D 3 , D 4 is defined as D, data for the m pieces of pixels in total, which is obtained by adding video data C for m/2 pieces of pixels to video data D for m/2 pieces of pixels, is inputted to signal control circuit 5 during the second horizontal cycle.
The video data inputted to signal control circuit 5 is distributed to FIFO-A 52 and FIFO-B 53 by input memory controller 51 . In this embodiment, video data A and C are distributed to FIFO-A 52 , and video data B and D are distributed to FIFO-B 53 .
FIFO-A 52 has a capacity of storing data for m/4 pieces of pixels, and FIFO-B 53 has a capacity of storing data for m/2 pieces of pixels. The data for m/4 pieces of pixels has a volume corresponding to the ½ of the horizontal cycle of video data A (C), and the data for m/2 pieces of pixels has a volume corresponding to the one horizontal cycle of video data B (D). In diagrams of the storing state of the data in rows of “FIFO-A” and “FIFO-B”, Full (m/4 pixel) and Full (m/2 pixel) indicate the data storage capacities of FIFO-A 52 and FIFO-B 53 .
During the first horizontal cycle, video data A is stored in FIFO-A 52 , and video data B is stored in FIFO-B 53 . Storage amounts of video data A and video data B in FIFO-A 52 and FIFO-B 53 are linearly increased as shown in FIG. 8 .
In FIFO-A 52 , when FIFO-A 52 is filled with video data A sequentially inputted thereto, video data A is outputted from FIFO-A 52 by the First-in First-out function. A rate at which video data A is outputted from FIFO-A 52 is twice as rapid as a rate at which video data A is inputted to FIFO-A 52 . Accordingly, as shown in the row of “FIFO-A” of FIG. 8 , after FIFO-A 52 is filled with video data A, the data storage amount in FIFO-A 52 is linearly decreased. During this period, as shown in a row of “FIFO-A Output” of FIG. 8 , video data A is continuously outputted from FIFO-A 52 . Video data A is outputted from FIFO-A 52 at the sign of a supply start signal (Load Start in FIG. 8 ) generated in output memory controller 54 , and is held within X driver 3 by an instruction of a data strobe signal (Data Strobe in FIG. 8 ) generated in output memory controller 54 , then is outputted from display signal lines 30 as the pixel signals (Loading Data in FIG. 8 ).
In FIFO-B 53 , when FIFO-B 53 is filled with video data B sequentially inputted thereto, video data B is outputted from FIFO-B 53 by the First-in First-out function. Here, a point different from FIFO-A 52 is that an output start timing of video data B from FIFO-B 53 is delayed since the data storage capacity of FIFO-B 53 is larger than that of FIFO-A 52 . As shown in the row of “FIFO-B” of FIG. 8 , after video data B of an amount corresponding to that for m/2 pixels, that is, for one horizontal cycle, is stored in FIFO-B 53 , the output of video data B from FIFO-B 53 is started by the instruction of the supply start signal (Load Start). Then, the data storage amount in FIFO-B 53 is linearly decreased. During this period, as shown in the section of the “FIFO-B Output” of FIG. 8 , video data B is continuously outputted from FIFO-B 53 . Video data B outputted from FIFO-B 53 is held within X driver 3 at the sign of the data strobe signal (Data Strobe in FIG. 8 ), and then outputted as the pixel signals through display signal lines 30 .
During the second horizontal cycle, video data C is stored in FIFO-A 52 , and video data D is stored in FIFO-B 53 .
As shown in FIG. 8 , video data A is entirely outputted from FIFO-A 52 at a point of time when video data C is inputted to signal control circuit 5 . Accordingly, video data C is supplied to X driver 3 through a process similar to that of video data A in the first horizontal cycle.
At a point of time when video data D is inputted to signal control circuit 5 , video data B remains in FIFO-B 53 . Accordingly, there is a period when both video data B and video data D are stored in FIFO-B 53 . When video data B is entirely outputted from FIFO-B 53 , and when video data C is entirely outputted from FIFO-A 52 , video data D is outputted from FIFO-B 53 at the sign of the supply start signal (Load Start in FIG. 8 ). Supply of video data C and video data D to X driver 3 is executed similarly to the case of video data A and video data B.
Although description has been made above for video data A to D, similar operations are executed for other pixels E, F as described above, according to the first embodiment, even if the storage capacity of FIFO-A 52 is reduced in half of FIFO-B 53 , the supply of the display signals free from troubles can be realized by optimizing the timing of the data input from the outside and the timing of the data output thereto.
More specific contents of the timings will be described as below. Specifically, with regard to video data A and video data B, which have been inputted from the outside during the first horizontal cycle, video data A stored in FIFO-A 52 is outputted prior to video data B stored in FIFO-B 53 . Moreover, video data A is stored in FIFO-A 52 during the first horizontal cycle, video data B is stored in FIFO-B 53 , and video data A stored in FIFO-A 52 is outputted during the first horizontal cycle. Then, during the second horizontal cycle following the first horizontal cycle, the output of video data B stored in FIFO-B 53 during the first horizontal cycle is completed. In this case, the output of video data A from FIFO-A 52 and the output of video data B from FIFO-B 53 are completed during one horizontal cycle. Moreover, in the above first embodiment, description has been made for the example where two pixel electrodes are connected to common display signal line 30 , however, this embodiment can be applied to a display apparatus having a pixel structure where display signal line 30 common to three or more of the pixel electrodes is connected thereto while adjusting a balance of the storage capacities.
In the first embodiment, description has been made for the example where FIFO-A 52 and FIFO-B 53 are provided in signal control circuit 5 supplying the video data to X driver 3 . However, it is also possible to provide functions of two FIFOs, that is, FIFO-A 52 and FIFO-B 53 in X driver 3 . The second embodiment is where the functions of FIFO-A 52 and FIFO-B 53 are imparted into X driver 3 .
FIG. 9 is a view showing a configuration of driver 32 in the second embodiment. Note that, in the second embodiment, each of drivers 33 to 36 has a configuration similar to that of driver 32 .
As shown in FIG. 9 , driver 32 includes an input selector 321 , a FIFO-A 322 , a FIFO-B 323 , an output selector 325 , a data register 326 , a latch 327 , a level shifter 328 , a digital/analog (DA) converter 329 , and an amplifier 330 .
Input selector 321 controls as to which of FIFO-A 322 and FIFO-B 323 is to be a transfer destination of video data sent from signal control circuit 5 and controls a transfer timing.
FIFO-A 322 and FIFO-B 323 sequentially store the video data transferred from input selector 321 . The stored video data is outputted to data register 326 based on control of output selector 325 .
Output selector 325 reads out the video data stored in any of FIFO-A 322 and FIFO-B 323 , and supplies the read-out data to data register 326 . Output selector 325 also controls a supply timing of the video data to data register 326 .
The video data stored in data register 326 is transferred to latch 327 at the sign of a strobe signal sent from signal control circuit 5 . A voltage of the video data transferred to latch 327 is converted, for example, from 3.3 V to 8 V, by level shifter 328 , and then the video data is supplied to DA converter 329 . The video data subjected to conversion from digital signals to analog signals by DA converter 329 is amplified to a specified value by amplifier 330 , and then the video data (the analog signals) is outputted as display signals to the respective display signal lines 30 .
Assuming that, for example, ma/2 pieces of display signal lines 30 are connected to driver 32 shown in FIG. 9 , then driver 32 supplies the display signals corresponding to ma/2 pieces of pixels.
Similarly to the first embodiment, the video data is inputted to signal control circuit 5 from a host in order of reference codes A 1 , B 1 , A 2 , B 2 , A 3 , B 3 , and in the same order, is inputted to driver 32 . Hereinafter, description will be made for a supply method of video data in the second embodiment with reference to FIG. 10 .
FIG. 10 is a timing chart showing video data inputted to the liquid crystal display apparatus, storing states of the data in FIFO-A 322 and FIFO-B 323 , outputting states of the data from FIFO-A 322 and FIFO-B 323 , the data supplied from output selector 325 to data register 326 , and supply states of the video data in data register 326 in contrast to the horizontal cycle. Now, it is assumed that video data for a row where pixel electrodes A 1 , B 1 , A 2 , B 2 are arrayed is inputted. Moreover, in FIG. 10 , reference codes A 1 , B 1 , A 2 and B 2 denote the video data corresponding to the pixel electrodes having the same reference codes.
As shown in FIG. 10 , driver 32 receives video data A( 1 H) and B( 1 H) from signal control circuit 5 during the first horizontal cycle. During the second horizontal cycle, driver 32 receives video data A( 2 H) and B( 2 H). Note that in FIG. 10 , “ 1 H” of reference code A( 1 H) implies the first horizontal cycle, and “ 2 H” of reference code A( 2 H) implies the second horizontal cycle.
The video data inputted to driver 32 is distributed to FIFO-A 322 and FIFO-B 323 by input selector 321 . In this embodiment, video data A( 1 H), A( 2 H) are distributed to FIFO-A 322 , and video data B( 1 H), B( 2 H) are distributed to FIFO-B 323 . The number of pixels connected to driver 32 is ma per one row, FIFO-A 322 is provided with a capacity for storing data for ma/4 pieces of pixels, and FIFO-B 323 is provided with a capacity for storing data for ma/2 pieces of pixels.
During the first horizontal cycle, video data A( 1 H) is stored in FIFO-A 322 , and video data B( 1 H) is stored in FIFO-B 323 .
In FIFO-A 322 , when FIFO-A 322 is filled with video data A( 1 H) sequentially inputted thereto, video data A( 1 H) is outputted from FIFO-A 322 by the First-in First-out function. A rate at which video data A( 1 H) is outputted from FIFO-A 322 is twice as rapid as a rate at which video data A( 1 H) is inputted to FIFO-A 322 . Accordingly, as shown in the row of “FIFO-A” of FIG. 10 , after FIFO-A 322 is filled with video data A( 1 H), the data storage amount in FIFO-A 322 is linearly decreased. During this period, as shown in a row of “L_Out” of FIG. 10 , video data A( 1 H) is supplied from FIFO-A 322 through output selector 325 to data register 326 . Video data A( 1 H) is supplied to data register 326 at the sign of a supply start signal (Load Start in FIG. 10 ). After video data A( 1 H) is supplied to data register 326 for a specified period, video data A ( 1 H) stored in data register 326 is transferred to latch 327 at the sign of a data strobe signal (Data Strobe in FIG. 10 ).
In FIFO-B 323 , when FIFO-B 323 is filled with video data B( 1 H) inputted thereto, video data B( 1 H) is outputted from FIFO-B 323 by the First-in First-out function. Here, as shown in the row of “FIFO-B” of FIG. 10 , after video data B( 1 H) for the m/2 pieces of pixels is stored in FIFO-B 323 , the output of video data B( 1 H) from FIFO-B 323 is started by the instruction of the supply start signal (Load Start in FIG. 10 ). Thereafter, similarly to the case of FIFO-A 322 , video data B( 1 H) is transferred to latch 327 .
During the second horizontal cycle, video data A( 2 H) is stored in FIFO-A 322 , and video data B( 2 H) is stored in FIFO-B 323 .
As shown in FIG. 10 , video data A( 1 H) is entirely outputted from FIFO-A 322 at a point of time when video data A( 2 H) is inputted to driver 32 . Accordingly, video data A( 2 H) is supplied to latch 327 through a process similar to that of video data A( 1 H) in the first horizontal cycle.
At a point of time when video data B( 2 H) is inputted to driver 32 , video data B( 1 H) remains in FIFO-B 323 . Accordingly, there is a period when both of video data B( 1 H) and video data B( 2 H) are stored in FIFO-B 323 . When video data B( 1 H) is entirely outputted from FIFO-B 323 , and when video data A( 2 H) is entirely outputted from FIFO-A 322 , video data B( 2 H) is outputted from FIFO-B 323 at the sign of the supply start signal (Load Start in FIG. 10 ). Supply of video data A( 2 H) and video data B( 2 H) to latch 327 is executed similarly to the case of video data A( 1 H) and video data B( 1 H).
Description has been made above for video data A 1 , A 2 , B 1 and B 2 . In this embodiment, since driver 32 supplies the display signals to the pixels denoted by the codes A 1 to Ama/2 and B 1 to Bma/2, a similar operation is iterated in video data A 3 and B 3 and after. Moreover, also for drivers 33 to 36 , the similar operation to that for driver 32 is executed.
As described above, the present invention can be realized also within X driver 3 , while the invention can be realized in signal control circuit 5 as described in the first embodiment.
In the above-described second embodiment, the example has been shown, in which two FIFOs are provided within driver 32 . In the third embodiment, description will be made for a modification example of the second embodiment.
FIG. 11 is a view showing a configuration of driver 32 in the third embodiment.
In FIG. 11 , driver 32 includes an input selector 321 , a FIFO 422 , a first data register 423 , a second data register 424 , an output selector 325 , a latch 327 , a level shifter 328 , a DA converter 329 , and an amplifier 330 . As shown in FIG. 11 , in the third embodiment, first data register 423 constitutes a first storage area, and FIFO 422 and the second data register constitute a second storage area.
Input selector 321 controls as to which of FIFO 422 and first data register 423 is to be a transfer destination of video data sent from signal control circuit 5 and controls a transfer timing.
FIFO 422 sequentially stores the video data transferred from input selector 321 . The video data is stored in FIFO 422 until the storage capacity of FIFO 422 is filled therewith, and in response to an output request, the video data is outputted to second data register 424 from FIFO 422 in order of the transfer based on the First-in First-out function of FIFO 422 . The storage capacity of FIFO 422 is ma/4.
First data register 423 stores the video data transferred from input selector 321 . The video data stored in first data register 423 is transferred to output selector 325 based on the load signal sent from signal control circuit 5 . First data register 423 has a storage capacity for ma/2 pieces of pixels.
Second data register 424 stores the video data transferred from FIFO 422 . The video data stored in second data register 424 is transferred to output selector 325 based on the load signal sent from signal control circuit 5 . Second data register 424 also has a storage capacity for ma/2 pieces of pixels.
Output selector 325 makes selection as to which video data of first data register 423 and second data register 424 is to be supplied to latch 327 .
The video data transferred to latch 327 is stored once therein, and subjected to voltage conversion by level shifter 328 , then supplied to DA converter 329 . The video data subjected to conversion from digital signals to analog signals by DA converter 329 is amplified to a specified value by amplifier 330 , and then the video data is outputted as display signals to respective display signal lines 30 .
Next, description will be made briefly for a supply method of video data in the third embodiment with reference to FIG. 12 . FIG. 12 is a timing chart similar to that of FIG. 10 .
As shown in FIG. 12 , during the first horizontal cycle, driver 32 receives the video data A( 1 H) and B( 1 H) from signal control circuit 5 . During the next second horizontal cycle, driver 32 receives video data A( 2 H) and B( 2 H).
The video data inputted to the driver 32 is distributed to the FIFO 422 and the first data register 423 by the input selector 321 . The video data A( 1 H), A( 2 H), A( 3 H) . . . are sent to the first data register 423 , and the video data B( 1 H), B( 2 H), B( 3 H) . . . are sent to the FIFO 422 . Since the video data is distributed at this stage, the data transfer rate is reduced in half after passing through the input selector 321 .
Input lines of the first data register 423 are connected to the entire registers. The first data register 423 writes the video data to a register corresponding to pixel location when a pulse for selecting the inside, which is made of a write signal (Load_A), comes to the first data register 423 . Output lines of the first data register 423 exist by the number corresponding to the number of the entire bits. Therefore, the first data register 423 fetches the video data in order from the start pulse of Load_A. This state is shown in rows of “Data Register-A” and “Load_A”. Note that the video data A( 2 H) and A( 3 H) are processed similarly.
The video data B( 1 H) is first stored in the FIFO 422 . When the data for the ma/4 pieces of pixels is stored in the FIFO 422 , the data is fetched in the second data register 424 together with the start pulse of Load_B.
When the input of the video data A( 1 H) during the first horizontal cycle is ended, the fetch of the video data A( 1 H) in the first data register 423 is ended. At this point of time, the video data A( 1 H) in the first data register 423 becomes entirely effective. The period when the video data A( 1 H) becomes entirely effective is shown by A( 1 H) in a diagram of the row of DR_A of FIG. 12 . After a ½ horizontal cycle from the end of the fetch of the video data A( 1 H), the fetch of the video data B( 1 H) in the second data register 424 is ended. At this point of time, the video data B( 1 H) in the second data register 424 becomes entirely effective. The period when the video data B( 1 H) becomes entirely effective is shown by B( 1 H) in a diagram of the row of DR_B of FIG. 12 .
When the first data register 423 is effective, the output selector 325 selects DR_A, and when the second data register 424 is effective, the output selector 325 selects DR_B. In this case, in order to send the data to the next step, a data strobe signal (Data Strobe in FIG. 12 ) is outputted, and the video data A( 1 H) is latched in the latch 327 . The latched video data A( 1 H) is outputted (L_Out in FIG. 12 ). Thereafter, the video data is subjected to voltage conversion by the level shifter 328 . Then, the video data is subjected to conversion to analog signals by the DA converter 329 , and sent to the amplifier 330 . From the amplifier 330 , the video data is outputted as display signals for driving pixels to the display signal lines 30 . As described above, the first storage area and the second storage area of the present invention are not limited to the case of being constituted only of the FIFO 422 . The storage areas of the present invention can be realized by appropriately combining storing circuit such as the FIFO 422 and the data register.
As described above, according to the present invention, there can be provided the display signal supply method suitable to the active matrix type display apparatus of applying potentials to two or more adjacent pixels from one display signal line in time division.
Although the preferred embodiments of the present invention have been described in detail, it should be understood that various changes, substitutions and alternations can be made therein without departing from spirit and scope of the inventions as defined by the appended claims. | A process for supplying display signals from a storage device to a multiplicity of pixel electrodes in an image display apparatus. Display signals are serially stored into the storage device for a significant part of a line of the image display apparatus. After the display signals are stored for the part of the line into the storage device, the display signals are outputted while additional display signals for another part of the line are concurrently stored into the storage device. The outputting step is performed at a faster rate than the concurrent storing step. Consequently, the size of the storage device can be limited. | 61,933 |
RELATED APPLICATION
[0001] This application is a continuation of co-pending U.S. patent application Ser. No. 11/716,138, entitled “Low Pass Filter Semiconductor Structures For Use in Transducers For Measuring Low Dynamic Pressures In The Presence of High Static Pressures,” filed Mar. 9, 2007, which is a continuation of U.S. patent application Ser. No. 11/100,652, now U.S. Pat. No. 7,188,528, entitled “Low Pass Filter Semiconductor Structures For Use In Transducers For Measuring Low Dynamic Pressures In The Presence Of High Static Pressures,” filed Apr. 7, 2005, which is a continuation-in-part of U.S. patent application Ser. No. 10/830,796, now U.S. Pat. No. 7,107,853, entitled “Pressure Transducer for Measuring Low Dynamic Pressures in the Presence of High Static Pressures,” filed Apr. 23, 2004, all of which are hereby incorporated by reference as being set forth in its entirety herein.
FIELD OF THE INVENTION
[0002] The invention relates to pressure transducers for measuring low dynamic pressures in the presence of high static pressures, and more particularly to improved low pass filter structures employed with such transducers.
BACKGROUND
[0003] During the testing of jet engines and in many other environments, it is often desirable to measure both the static pressure and the dynamic pressure. The static pressure, in most instances, is usually very high and the dynamic pressure is much lower. The dynamic pressure is also associated with a distinct frequency which occurs at a relatively high rate, for example 5000 cycles/second or greater. In this manner, the dynamic pressure may typically be 20 times less than the static pressure. Hence, to measure static pressure, one requires a transducer with a relatively thick diaphragm so that it can stand the high static pressure. On other hand, such thick diaphragms have a poor response to low pressure. Therefore, to measure static pressure and dynamic pressure is extremely difficult unless one uses a thick diaphragm in conjunction with a thin diaphragm. However, if one uses a thin diaphragm, then this diaphragm will rupture upon application of the high static pressure which also contains the dynamic pressure. One can think of the dynamic pressure as a relatively high frequency fluctuation on top of a relatively high constant static pressure. Thus, as one can ascertain, using a thick diaphragm to measure dynamic and static pressure is not a viable solution.
[0004] U.S. Pat. No. 6,642,594 ('594 patent) entitled, “Single Chip Multiple Range Pressure Transducer Device”, which issued on Nov. 4, 2003 to A. D. Kurtz, the inventor herein and is assigned to Kulite Semiconductor Products, Inc., the assignee herein, discloses problems with transducers responsive to large pressures utilized to measure low pressures. Thus, pressure transducer adapted to measure relatively large pressures typically suffer relatively poor resolution or sensitivity when measuring relatively low pressures. This is because, as a span of the sensor increases, the resolution or sensitivity of that sensor at the low end of the span decreases. An example of various piezoresistive sensors are indicated in the aforementioned '594 patent wherein different transducers have thinned regions having the same thickness, but different planar dimensions. In this manner, the thinned regions will deflect a different amount upon application of a common pressure thereto, whereby when excited each of the circuits provides an output indicative of the common pressure of a different operating range.
[0005] As indicated above, during the testing of jet engines there is a very high static pressure which, for example, may be 100 psi. Present with the static pressure is a low dynamic pressure, which may exhibit frequencies in the range of 5000 Hz and above. As indicated, using a high pressure sensor to measure the static pressure will yield an extremely poor response to the dynamic pressure because of the small magnitude of dynamic pressure which can be, for example, about 5 psi. Therefore, it is desirable to use a relatively rugged pressure transducer having a thick diaphragm to measure static pressure and to utilize another transducer on the same chip having a thinned diaphragm to measure dynamic pressure. Because the thinned transducer is exposed to static pressure both on the top and bottom sides, the static pressure cancels out and does not, in any manner, cause the thinned diaphragm to deflect. As described herein, both static and a dynamic pressure may be applied to the rear side of the diaphragm by a reference tube of substantial length. This reference tube, as will be explained, is a helical structure and has a low resonant frequency. In this manner, when a small dynamic pressure is applied because of the low internal frequency of the tube, the sensor will respond to the static pressure only. The thinned diaphragm should be stopped for pressures in excess of 25 psi, or some higher number than the desired dynamic pressure. The long reference tube can be made by taking a tubular structure and wrapping it such that it looks like a coil or spring. One end would be inserted into the transducer and other end would be exposed to pressure. In this manner, one can implement a transducer for simultaneously measuring a low dynamic pressure in the presence of a high static pressure. Alternative transducer structures and methods for measuring low dynamic pressure in the presence of high static pressure are also desired.
SUMMARY
[0006] A semiconductor filter is provided to operate in conjunction with a differential pressure transducer. The filter receives both a high and relatively low frequency static pressure attendant with a high frequency low dynamic pressure at one end, and operates to filter the high frequency dynamic pressure to provide only the static pressure at the other filter end. A differential transducer receives both dynamic and static pressure at one input port and receives the filtered static pressure at the other port where the transducer provides an output solely indicative of dynamic pressure. The filter in one embodiment has a series of etched channels directed from an input end to an output end. The channels are etched pores of extremely small diameter and operate to attenuate or filter the dynamic pressure. In another embodiment, a spiral tubular groove is formed between a silicon wafer and a glass cover wafer. An input port of the groove receives both the static and dynamic pressure with an output port of the groove providing only static pressure. The groove filters attenuate dynamic pressure to enable the differential transducer to provide an output only indicative of dynamic pressure by cancellation of the static pressure.
BRIEF DESCRIPTION OF THE FIGURES
[0007] FIG. 1 is a partial cross sectional view of a pressure transducer for measuring low dynamic pressures in the presence of high static pressures.
[0008] FIG. 2 is a partial cross sectional view of a pressure transducer for measuring low dynamic pressures in the presence of high static pressures employing a semiconductor attenuator according to an embodiment of the present invention.
[0009] FIG. 3 is a series of top views showing alternate pore configurations useful for the semiconductor attenuator of FIG. 2 .
[0010] FIG. 4 is a partial cross sectional view of a pressure transducer responding to dynamic and static pressures employing a semiconductor helical structure operating as an attenuator.
[0011] FIG. 5A shows a top view of the semiconductor attenuator utilized in FIG. 4 ; and FIG. 5B shows a cross sectional view of the semiconductor attenuator utilized in FIG. 4 taken through line B-B of FIG. 5A .
DETAILED DESCRIPTION
[0012] Referring to FIG. 1 , there is shown a pressure transducer which basically consists of two leadless peizoresistive sensors 20 and 21 mounted on header pins in accordance with the methods disclosed in Kulite U.S. Pat. No. 5,955,771 entitled, “Sensors for Use in High Vibrational Applications and Methods for Fabricating the Same” which issued on Sep. 21, 1999 to A. D. Kurtz et al, the inventor herein and assigned to Kulite Semiconductor Products, Inc., the assignee herein. This patent is incorporated herein by reference.
[0013] Shown in FIG. 1 are two separate transducers 20 and 21 which are fabricated by the same process as according to the teachings of the above-noted co-pending application and patent. The difference between the two transducer or sensor structures is that the sensor structure on the left has a diaphragm 20 which is thicker than the diaphragm 21 of the sensor structure on the right. Both sensors receive on their top surfaces a pressure indicative of the static pressure (P s ) plus the dynamic pressure (P d ) (P s +P d ). As indicated, the static pressure (P s ) may be of a relatively high value and, for example, could be 100 psi or more. The dynamic pressure (P d ) appears as a ripple on top of the static pressure (P s ) and is characterized by a relatively high frequency on the order of magnitude of 5000 Hz and above and a low value of 5 psi or less. Both sensors receive the combination of the static plus the dynamic pressure shown in FIG. 1 . Sensor 20 , as indicated, has a thicker diaphragm and responds mainly to the static pressure to produce at the output pins ( 15 , 16 ) associated therewith, a voltage proportional to the static pressure. This voltage would indicate a static pressure of 100 psi or greater, whatever the case may be.
[0014] While the output of transducer 20 is also responsive to the dynamic pressure (P d ), the dynamic pressure (P d ) is an extremely small percentage of the total static pressure (P s ) and may, as indicated, be on the order of 5 psi or less. The thin diaphragm associated with the transducer 21 will respond only to the dynamic pressure (P d ), as will be explained. As seen in the Figure, transducer 21 has the static plus the dynamic pressure applied to the top surface and is indicated again by P s +P d . Coupled to the bottom surface of the diaphragm is a tube or reference tube of an exceedingly long length, designated by reference numeral 18 . The tube 18 is coupled to the bottom surface of the diaphragm. Essentially, the tube 18 receives at an inlet both the static and dynamic pressure, which is P s +P d .
[0015] The tube, as shown, is in helical form. It is well known that the resonant frequency f of such a tube, as, for example, an organ pipe, is given by f=c/(41), where c is the speed of sound, and 1 is the length of the tube. For instance, in air, where the speed of sound is approximately 1200 feet per second, a tube length of 2½ feet will give a resonant frequency of 120 Hz. Thus, tube 18 acts as a low pass filter and will only pass frequencies which are below 120 Hz. In this manner, the dynamic frequency, which is 5000 Hz or greater, will not pass through the tube 18 . Therefore, the underside of the diaphragm associated with transducer 21 only receives the status pressure (P s ). The static pressure (P s ) subtracted from the static pressure plus the dynamic pressure (P s +P d ) supplied to the top surface of the diaphragm such that the output of the differential unit 21 provides a pressure equal to the differential pressure (P d ). As seen, there is a stop member associated with diaphragm 21 . The stop member 25 assures that the diaphragm 21 will not deflect in a downward direction for pressures in excess of 25 psi, or some number higher than the desired dynamic pressure. The reference tube is fabricated by taking a tubular structure, which may be metal or some other material, and wrapping it such that it looks like a coil or a spring where one end is inserted into the transducer, as shown, and the other end is exposed to the static and dynamic pressure. Reference is made to U.S. Pat. No. 6,642,594 entitled, “Single Chip Multiple Range Pressure Transducer Device” issued on Nov. 4, 2003 to A. D. Kurtz, the inventor herein and assigned to the assignee herein, the entire disclosure of which is hereby incorporated by reference herein as well.
[0016] Therefore, the diaphragm associated with sensor 20 is intended for accurately measuring static pressure. The sensor unit 21 will measure dynamic pressure because of the differential operation of the sensor 21 and because of the tube. These dynamic pressures have relatively high frequencies measured primarily by the first assembly 21 , with the second assembly 20 measuring the steady state pressure, which is a large pressure. The fabrication of stops, such as 25 for transducers, is well known in the art. See, for example, U.S. Pat. No. 4,040,172 entitled, “Method of Manufacturing Integral Transducer Assemblies Employing Built-In Pressure Limiting” issued on Aug. 9, 1997 to A. D. Kurtz et al and is assigned to the assignee herein. See also U.S. Pat. No. 4,063,209 entitled, “Integral Transducer Assemblies Employing Built-In Pressure Limiting” issued on Dec. 13, 1997 to A. D. Kurtz et al. and assigned to the assignee herein. The entire disclosures of U.S. Pat. Nos. 4,040,172 and 4,063,209 are also incorporated by reference herein.
[0017] See also U.S. Pat. No. 6,595,066 issued on Jul. 22, 2003 to A. D. Kurtz et al. and is assigned to the assignee herein and entitled, “Stopped Leadless Differential Sensor”. This patent describes a leadless device which is similar to the devices utilized in FIG. 1 which has a stop apparatus associated therewith. The sensor depicted in the '066 patent also operates as a differential sensor with a Wheatstone bridge sensor array. The output provides a difference between a pressure applied to the top side of the sensor with respect to the force applied to the bottom side of the sensor. This sensor acts as the sensor 21 associated and seen in FIG. 1 . U.S. Pat. No. 6,595,066 is incorporated herein.
[0018] See also U.S. Pat. No. 6,588,281 issued on Jul. 8, 2003 entitled, “Double Stop Structure for a Pressure Transducer” issued to A. D. Kurtz et al. and assigned to the assignee herein. That patent shows a stop device in both first and second directions. As one can ascertain from FIG. 1 , a stop 25 is only required in the down direction. This is so, as the large pressure P s +P d , as applied to the top surface, could rupture the thin diaphragm if the pressure applied to the bottom surface momentarily is interrupted. In this manner, the diaphragm of the sensor 21 will impinge upon the stop 25 to prevent the fracture of the diaphragm. The interruption of the pressure applied to the bottom surface of the diaphragm could occur during pressure build-up or when the pressure source is first turned on or off. U.S. Pat. No. 6,588,281 is also incorporated herein.
[0019] Referring now to FIG. 2 , there is shown a transducer structure in which the helical tube 18 of FIG. 1 is eliminated. As the tube or organ pipe illustrated in FIG. 1 may be expensive and/or difficult to fabricate and incorporate, the semiconductor structure of FIG. 2 operates to emulate the characteristics of the helical tube, including for example, frequency response, without providing such a helical tube.
[0020] FIG. 2 utilizes the same reference numerals as FIG. 1 for corresponding parts. It is seen that there are again two sensor diaphragms 20 and 21 , each having piezoresistors located thereon and each receiving a pressure at a top surface which is the static plus dynamic pressure designated as P s +P d .
[0021] A reference tube 25 is shown which receives the pressure P s +P d at the inlet. Disposed between the back surface of transducer 21 and the input of the reference tube 25 is a silicon wafer 26 .
[0022] The wafer 26 has a plurality of holes or through channels, each having a diameter of less than about 0.001 inches and formed by etching or micromachining, for example. In this case, as indicated in FIG. 2 , the small diameter holes or apertures serve to attenuate any high frequency components of the pressure caused by viscosity of the gas flowing through the apertures. The pressure and attenuation provided is determined by the diameter of the holes, the number of holes, as well as by the cavity volume on the underside of the sensing diaphragm.
[0023] The hole diameter, number of holes on the silicon wafer 26 , and the cavity size are selected such that a desired filtering frequency can be obtained utilizing the formula:
[0000]
τ
=
32
γ
vVL
AD
2
c
2
[0000] where
τ=attenuation and γ represents the ratio of specific heats; for air γ=1.4; v represents the kinematic viscosity; for air v=14.5 m 2 /s or 0.0225 in 2 /s; V represents the volume of the cavity or wafer; L represents length of the pipe; A represents the total area of feeding pipes or apertures; D represents the diameter of feeding pipe or apertures; and c represents the speed of sound, which is about 1120 ft/s at room temperatures.
For example; to achieve a cut-off frequency of 100 Hz, or a time constant of 10 milli-seconds, the following parameters can be selected:
D=0.0002 inch A=0.000625 inch 2 assuming 25% pososity and a 0.050″ chip c=1120 ft/s=13400 inch/2 L=0.005 V=0.001 in 3 .
[0037] As one can see, attenuation is determined by the diameter of the hole as well as the number of holes. The wafer having the silicon holes acts as a single hole of considerably longer length. The fabrication of holes in silicon is well understood and can be accurately controlled. See for example, an article entitled “Porous Silicon/A New Material for MEMs” published in the IEEE 1996 by V. Lehmann of Siemens Ag Munchen, Germany, which describes a technique for the formation of pores or holes in silicon with high aspect ratios utilizing electrochemical etching of n-type silicon wafers in hydrofluoric acid.
[0038] The wafer as shown in FIG. 2 is an n-type silicon wafer. As the article indicates, porous silicon has been used for many years and may be formed on a silicon substrate during anodization in a hydrofluoric acid electrolyte. Pore formation is present for anodic densities below a critical current density. The pore geometry can be controlled, as can the pore cross section. The pore cross section can vary between a circle and a forearm star depending on the formation conditions. Subsequent to the electrochemical pore formation, the cross section of the pores can be made more circular by oxidation steps or can be made more square shaped by anisotropic chemical etching for example using aqueous HF.
[0039] Referring to FIG. 3 , there is shown a series of pore cross sections, all of which shapes can be formed during the etching process, and which shapes have been described in the above-identified article. While circular shapes may be preferred, the pores can be of a square or any other suitable configuration represented by shapes designated A through E in FIG. 3 .
[0040] While the above-identified article describes process steps which are standard techniques in microelectronic manufacturing, such techniques may be used to develop pore configurations in a silicon substrate which enable communication between the bottom surface of the substrate to the top surface of the substrate.
[0041] Based on the diameter of the pores and based on the width of the silicon wafer, one can therefore obtain the same frequency characteristics as are available by a helical tube. The bottom surface of wafer diaphragm 21 thus receives only the static pressure (P.sub.s), whereby the higher frequency dynamic pressure is completely suppressed by the semiconductor wafer 26 having pores of configurations A-E as shown in FIG. 3 .
[0042] The pore configurations A to E have various cross sections and will extend from the top surface of the wafer to the bottom surface of the wafer.
[0043] Referring now to FIG. 4 there is shown an alternate embodiment of a semiconductor arrangement that emulates the helical tube illustrated in FIG. 1 and that functions in a manner similar to the apertured wafer structure 26 illustrated in FIG. 2 . FIG. 4 illustrates transducer diaphragms 20 and 21 arranged in a housing whereby the static plus dynamic pressure (P s +P d ) is applied to the top surface. The reference tube 25 again receives the static and dynamic pressure, which now is applied to the bottom surface of a semiconductor wafer 28 . The semiconductor wafer 28 has an input aperture 30 which is directed into a coiled hollow helical structure fabricated on the surface of the semiconductor substrate. The helical structure has an output aperture 31 communicating with the underside of the diaphragm 21 .
[0044] Thus, the underside of the diaphragm 21 receives the static and dynamic pressure and because of the helical structure fabricated on the semiconductor wafer 28 , the dynamic pressure frequencies are again suppressed.
[0045] Referring to FIG. 5 , there is shown a top view of the wafer 28 . The wafer 28 as shown in a cross sectional view of FIG. 5 b has a bottom silicon wafer 33 with a glass cover wafer 32 . The silicon wafer is first processed to provide a helical structure 40 on a top surface. The helical structure 40 is fabricated at a given depth. The helical structure communicates with an aperture 30 as shown in FIG. 4 to enable the static plus the dynamic pressure to be applied to aperture 30 .
[0046] The pressure is then circulated within the helical structure as covered by the glass cover member 32 and at the output aperture 31 the pressure P s which is the static pressure now applied to the underside of the diaphragm.
[0047] It is understood that there are numerous ways of fabricating helical structures in semiconductor material. These can be fabricated by utilizing stacking layers whereby a spiral coil is fabricated between these layers and effectively constitutes a helical semiconductor structure which manifests itself in having the same diameter and length as the helical tube shown in FIG. 1 . In this case, the length of the spiral determines the frequency of operation according to the following formula
[0000]
f
=
c
4
L
1
-
(
4
v
D
2
c
4
L
)
2
[0000] where
c=speed of sound, about 1120 ft/s L=length of pipe or spiral; D=diameter of pipe or spiral; v=kinematic viscosity: for air, v is about 14.5 m 2 /s or 0.0225 in 2 /s.
In an exemplary configuration, a spiral of 0.005 inch diameter and 1 inch in length achieves a filtering frequency f of 100 Hz.
[0052] By varying lengths and diameters of the holes, as for example concerning the embodiment depicted in FIG. 2 , one can tailor the frequency attenuation to desired value. According to an aspect of the present invention, such frequency attenuation can be attained in an exceedingly small space. The structures as described herein can be mounted directly behind a deflecting diagram and beyond the header, as shown in FIG. 2 and FIG. 4 , for example.
[0053] It should be noted that after using standard micromachining techniques, a significant number of these structures could be made simultaneously within a relatively small size (of silicon, for example). The processing techniques, as indicated above, will enable such structures to be produced, and hence produce reliable semiconductor attenuators or semiconductor filters for use in static and dynamic pressure measurements.
[0054] While it is understood that the figures and descriptions herein illustrate a dual transducer structure, it is understood that a single transducer can be utilized, whereby static and dynamic pressure applied to one surface and static and dynamic pressure are applied to the bottom surface or the opposing surface via a semiconductor attenuator such as a semiconductor wafer having through pores from the top to the bottom surface. Alternately, a semiconductor helical arrangement having a hollow passageway from an input port which receives the static and dynamic pressure to an output port which will only allow the static pressure to pass due to the length and diameter of the helix can be employed.
[0055] It is therefore understood that the above-noted semiconductor structures may replace the mechanical helical design in a more efficient and compact structure while enabling a great number of applications to be provided. While the above noted exemplary embodiments are preferred, it is also understood that alternative embodiments can be employed according to the teachings of this invention.
[0056] For example, a single transducer such as that depicted by reference numeral 21 can be utilized to produce an output indicative of dynamic pressure and whereby the static pressure would be cancelled. These and alternate embodiments can be ascertained by one skilled in the art and are deemed to be encompassed with the spirit and scope of the claims appended hereto. | A semiconductor filter is provided to operate in conjunction with a differential pressure transducer. The filter receives a high and very low frequency static pressure attendant with a high frequency low dynamic pressure at one end, the filter operates to filter said high frequency dynamic pressure to provide only the static pressure at the other filter end. A differential transducer receives both dynamic and static pressure at one input port and receives said filtered static pressure at the other port where said transducer provides an output solely indicative of dynamic pressure. The filter in one embodiment has a series of etched channels directed from an input end to an output end. The channels are etched pores of extremely small diameter and operate to attenuate or filter the dynamic pressure. In another embodiment, a spiral tubular groove is found between a silicon wafer and a glass cover wafer, an input port of the groove receives both the static and dynamic pressure with an output port of the groove providing only static pressure. The groove filters attenuate dynamic pressure to enable the differential transducer to provide an output only indicative of dynamic pressure by cancellation of the static pressure. | 27,700 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to passive seatbelt systems and more particularly to passive seatbelt systems which automatically fasten a restrictive webbing about a passenger after the passenger has seated himself in the motor vehicle.
2. Prior Art
Seatbelt devices are designed to protect passengers in a motor vehicle by holding them with restrictive seatbelts during vehicular emergencies and preventing collision with dangerous objects within the motor vehicle to thereby greatly increase the safety of such passengers. However, because of the complexity, etc. fastening such seatbelts, the percentage of use is very low. For this reason, passive seatbelts which automatically fasten themselves about the passenger after the passenger has been seated, have been proposed. These passive seatbelt devices or systems consist of a restrictive seatbelt whose outer end is fastened on the door or roof side and is movable forward and backward. This outer end is connected to and moved by a motor connected to the vehicle's power supply and may be moved forward or backward to cause the seatbelt to approach or move away from the passenger seat.
Therefore, after the passenger seats himself, the seatbelt would automatically move rearward to fasten itself and to close the gap between the seatbelt and the seat.
However, in such present passive seatbelt systems, since the stopping point of the outer end of the seatbelt is a constant, it is not possible for the seatbelt device to fit passengers of different physiques and therefore the passenger's freedom is restricted after the seatbelt is fastened and the passenger is uncomfortable.
SUMMARY OF THE INVENTION
Accordingly, it is the general object of the present invention to provide a passive seatbelt system which automatically fastens the seatbelt appropriately about passengers of different physiques after the passengers enter the vehicle.
It is still another object of the present invention to provide a passive seatbelt system which guarantees the safety of the passenger by restricting them during vehicular emergencies but does not interfere with the passenger's freedom under normal vehicular operating conditions.
In keeping with the principles of the present invention, the objects are accomplished by a unique passive seatbelt system including a passenger restrictive seatbelt of which an inner end is attached to a roller mechanism fastened to a center of the motor vehicle and an outer end which is fastened to a moving plate, the moving plate is fastened to a roof side of the motor vehicle and constrained to forward and rearward motion, a narrow belt is attached to the moving plate at one end and to a winding roller located to the rear of the roof side for winding up the narrow belt, the narrow belt winding roller being arranged and configured such that it permits free unwinding to accomodate passengers of different physique except at times of a vehicular emergency wherein the unwinding of the narrow belt is stopped by an emergency locking retractor.
BRIEF DESCRIPTION OF THE DRAWINGS
The above mentioned features and objects of the present invention will become more apparent with reference to the following description taken in conjunction with the accompanying drawings wherein like reference numerals denote like elements, and in which:
FIG. 1 is a side view illustrating one embodiment of a passive seatbelt system in accordance with the teachings of the present invention;
FIG. 2 is a front view of the vehicle of FIG. 1;
FIG. 3 is an expanded view of a part of FIG. 1;
FIG. 4 is a cross sectional along the line IV--IV of FIG. 3;
FIG. 5 is a close-up of a thick tape;
FIG. 6 is a cross sectional along the line VI--VI of FIG. 1;
FIG. 7 is a cross sectional along the line VII--VII in FIG. 1;
FIG. 8 is a close-up of a front pillar showing a sprocket wheel;
FIG. 9 is a cross sectional along the line IX--IX of FIG. 8;
FIG. 10 is a side view showing a second embodiment of a passive seatbelt system in accordance with the teachings of the present invention;
FIG. 11 is an expanded view of part of FIG. 10;
FIG. 12 is a cross sectional view along the line XII--XII of FIG. 10; and
FIG. 13 is a cross sectional view along the line XIII--XIII of FIG. 10.
DETAILED DESCRIPTION OF THE INVENTION
Referring more particularly to the drawings, shown in FIG. 1 is a first embodiment of a passive seatbelt system in accordance with the teachings of the present invention. In FIGS. 1 and 2, the inner end 12 of the passenger restraining belt 10 is wound onto a self-winding roller 14 which is fastened to the vehicle floor 15. The winding roller 14 is fastened to the center of the vehicle facing left and right.
The outer end 16 of the belt 10 is fastened to a truck 18 which is fastened to the roof side member 20 and may be moved forward and backward. By this forward and backward motion, the belt 10 approaches and moves away from the passenger seat 22. Therefore, a passenger seated in the seat 22 may be automatically fastened in or released by the belt 10. The truck 18, as shown in FIGS. 3 and 4, includes a moving plate 20 and an extension 26 which protrudes toward the floor of the vehicle. The extension 26 is provided with a slot 28 onto which the other end of the belt 10 is secured. Also, the moving plate 24 has four axles 30 which are provided so as to be mutually parallel. On each of the axles 30, as shown in FIG. 4, is provided wheels 32 whose diameter at the center is smaller than the diameter at the edge. The wheels 32, as shown in FIG. 4, ride within a guide wheel 34 which is C-shaped in cross section and may be moved along the axis of the guide rail 34, that is forward and backward along the vehicle.
The guide rail 34 is fastened by several fastening screws 36 through the central part of the C-shaped cross section to the inside of roof side member 20 and the open part is arranged so as to face toward the inside of the vehicle.
The top of guide rail 34 is formed into a flange 38 and the flange 38 is attached by fastening screws 44 to flange 42 which is provided on slide rail 40. Accordingly, guide rail 34 and slide rail 40 are kept parallel. The central part of slide rail 40 is provided with a rectangular groove 46 along its axis and midway down the rectangular groove 46, slide grooves 48 widen the width of the groove 46. A thick tape 50, shown in FIG. 5, is provided in the slide grooves 48 and can slide along the long axis of the slide rail 40.
The thick tape 50, as shown in FIG. 5, is a rectangular cross section and many holes are provided in the thick tape 50 at uniform intervals. Also, the rectangular cross section of the thick tape 50 is a tight fit in the slide grooves 48 of the slide rail 40 when inserted such that while an extension force is naturally transmitted, a compression force can also be transmitted. Furthermore, it is desirable that the material of the tape 50 be made from a synthetic resin with an appropriate flexibility so that the tape 50 may be bent with a small radius of curvature. One end of the tape 50 is fastened by four rivets 52 to a sliding block 54.
Projection 56 of sliding block 54 disengageably engages with projection 58 of movable plate 24 which projects in the direction of the thick tape 50 from the rear. Furthermore, when sliding block 54 is moved toward the front of the vehicle by thick tape 50, the movable plate 24 which has the projection 58 is also caused to move toward the front of the vehicle. In contrast, movable plate 24 may move toward the rear of vehicle by itself. By this means, when a passenger wearing the belt 10 changes his driving position, the movable plate 24 unwinds the narrow belt 62 and moves toward the front of the vehicle thereby increasing the passenger's freedom. Also, if the passenger grabs the belt 10 causing the outer end 16 to move while the outer end 16 is being moved by the thick tape 50 or when the passenger's body is being moved around during an accident, truck 18 can separate from sliding block 54 to prevent damage to the parts of the mechanism.
The end of movable plate 24 at the rear of the motor vehicle has a slot 60 provided in it and one end of a narrow belt 62 is secured to this slot 60. The other end of the narrow belt 62 is wound on roller 68 of winding roller 66 which is held by a fastening bolt 64 to a roof side member 20 at the rear end of guide rail 34. The winding roller 66 is a winding roller of construction similar to winding roller or retractor 14 onto which the inner end 12 of belt 10 is wound. Furthermore, the winding roller 66 is provided with a well known emergency locking retractor for preventing extension of the belt 62 during a vehicular emergency. Under normal circumstances belt 62 is wound up by a spring-powered winder 70. Thus, movable plate 24 which is connected by belt 62 to winding rollers 66 is pulled toward the rear of the vehicle by the force of the spring winder 70. In a vehicular emergency, by movement of the inertia locking device, a pawl can engage ratchet wheel 71 which is fastened to roller 68 to prevent the belt 62 from unwinding. Accordingly, the outer end 16 of the passenger restrictive belt 10 is effectively fastened to the roof side member 20.
From the slide rail 40, as shown in FIG. 4, in a direction opposite to flange 42, that is toward the floor of the vehicle, is provided another flange 72 and the interior roof lining 74 is held by fastening screws 75 to the flange 72. The guide rail 40 is, as shown in FIGS. 6 and 7 held with fastening screws 44 to the inner side of the vehicular front pillar 79 and descends along this front pillar 79. The lower end of the slide rail 40 is, as shown in FIG. 8, fastened to a sprocket housing 82. The sprocket housing 82, as shown in FIG. 9, is fastened to the center pillar 79 by fastening screws 106. The holes 51 of the thick tape 50 engage with the sprocket wheel 84 and are guided through a groove receiver portion provided in the sprocket housing 82. The sprocket wheel 84 is rotated by a reversible motor 112 such that the thick tape 50, which is held by sprocket 84, is caused to move along its long axis. The motor 112 is arranged such that when the passenger door is opened, it turns counterclockwise in FIG. 8; and when the door is closed it turns clockwise. In each instance, the motor 112 turns a fixed predetermined number of revolutions.
In operation, initially in FIG. 1 the passenger is shown in the vehicle equipped with belt 10 in the operational position. Truck 18 has moved as far as possible to the rear of the vehicle along the guide rail 34 and the passenger is held in by the belt 10. Since the inner end 12 of the webbing 10 is held by winding roller or retractor 14 and the outer end 16 is coupled to movable plate 24 and narrow belt 62 and each of these move, the passenger may freely alter his seated position. When the movable plate 24 moves toward the front of the vehicle, projection 58 separates from projection 56 and thick tape 50 does not move.
When a vehicular emergency such as a collision occurs, the inertia locking devices within rollers 14 and 66 completely stop the unwinding of belt 10 and narrow belt 62. Accordingly whatever position truck 18 and belt 10 are in, the outer end 16 of belt 10 is held at that position to the roof side member 20 and the passenger is restrained and his safety is guaranteed.
Now, when the passenger begins to leave the vehicle and opens the door, motor 112, rotating in a counterclockwise direction in FIG. 1, turns sprocket wheel 84 to pull thick tape 50 and moves the tape 50 in the direction indicated by arrow A. The result is that sliding block 54 moves truck 18 along guide rail 34 toward the front of the vehicle. Therefore, the outer end 16 of the belt 10 moves substantially toward the front of the vehicle to a position shown by the dotted lines in the Figures. Next, when the passenger has reboarded the vehicle, after seating himself and closing the door, motor 112 reverses and exerts a compressive force on the thick tape 50 moving it in a direction opposite to that given by arrow A. As a result, sliding block 54 moves toward the winding rollers 66 and the winding rollers 66 exerts a force on the narrow belt 62 which is attached to truck 18 and moves it toward the rear of the vehicle. By this means, the belt fastened condition of FIG. 1 may be achieved.
From the above description, it is apparent that since the truck 18 follows the movement of the body of the passenger and its stopping point is fixed by the sliding block 56, the extent of the unwinding of the narrow belt 62 from the winding rollers 66 changes with the passenger's body movements and that no matter how far the narrow belt 62 has extended from the winding roller 66, as long as the inertia locking device can still operate, this system can still restrain the passenger in a vehicular emergency.
Referring now to FIGS. 10 through 13, shown therein is a second embodiment of a passive seatbelt system in accordance with the teachings of the present invention. This example differs from the previous example in that a wire 150 is used to transmit the pulling force of the motor 112 to the truck 18 instead of the wide tape 50. This wire 150 is naturally capable of transmitting a tensile force along its axis but also may transmit a compressive force. One end is, as shown in FIGS. 11 and 12, clamped to sliding block 54A, while the middle portion is inserted into a slide groove 48A of almost circular cross-section which is provided in slide rail 40 and the wire 150 moves in this slide groove 48A.
The other end of wire 150 is wound onto a wire capstan 152 which is fastened to roof side member 20 at the front end of guide rail 34. The wire capstan 152 has, as shown in FIG. 13, a dish-shaped base 154 which is fastend to roof side member 20 by fastening bolt 156 and axle 156 is provided in the center of the base 154. A worm wheel 160 is provided on the axle 158 and engages with worm 162 mounted on the base 154. The worm 162 is rotated by a motor 112 which is fastened by a bracket (not shown) to roof side member 20. Also, on the axle 158 is provided a circular pressure plate 164 and a pressure coil spring 170 is fitted between the circular pressure plate 164 and a ring 168 which is in turn secured by a C-ring 166. Furthermore, the pressure plate 164 is pressed against worm wheel 160 by a spring 170 and is thus caused by friction to turn with worm wheel 160.
A thin rotatable plate 174, containing a circumferential groove of U-shaped cross-section is fastened to pressure plate 164. The bottom of the circumferential groove 172 is fastened one side of capstan 176 and the space between groove 162 and the outer edge rotatable plate 174 is formed into a wire receiver 178 of tapered cross-section. Here a U-shaped wire guide 180 is formed in base 154. Wire groove 182, adjacent wire guide 180, matches the greatest diameter 178A of circular wire receiver 178 and wire receiver 178 communicates with slide groove 48A of slide rail 40. One end of wire 150 is fastend to capstan 176 at its smallest diameter 178B.
In this construction, capstan 176 is rotated by motor 112. Winding wire 150 on the point of smallest diameter 178B pulls sliding block 54 toward the front of the vehicle when motor 112 is normally operated. When motor 112 is reversed, wire 150 is unwound from the point of greatest diameter and compression of wire 150 causes sliding block 54 to move to the rear of the vehicle. The remainder of the elements of this second embodiment are similar to those described above and are given like reference numerals and the description of their operation and interconnection is omitted.
From the above description, it is apparent that with the present invention, it is possible to provide a passive seatbelt fastening device which can be used with passengers of different physiques and provide freedom of movement for the passengers.
It should be apprent to one skilled in the art that the above described embodiments are merely illustrative but a few of the many possible specific embodiments which represent the application of the principles of the present invention. Numerous and varied other arrangements can be readily devised by those skilled in the art without departing from the spirit and scope of the invention. | A passive seatbelt system including a passenger restrictive seatbelt of which an inner end is attached to a roller mechanism fastened to a center of the motor vehicle and an outer end which is fastened to a moving plate, the moving plate is fastened to a roof side of the motor vehicle and constrained to forward and rearward motion, a narrow belt is attached to the moving plate at one end and to a winding roller located to the rear of the roof side for winding up the narrow belt, the narrow belt and winding roller being arranged and configured such that it permits free unwinding to accommodate passengers of different physique except at times of a vehicular emergency wherein the unwinding of the narrow belt is stopped by an emergency locking retractor. | 16,679 |
RELATED APPLICATIONS
[0001] This Application is a regular utility application based on Provisional Patent Application Ser. No. 62/309,927 entitled “VEHICLE SAFETY RAILROAD CROSSING” by Frank J. Bartolotti filed Mar. 17, 2016, which is incorporated by reference herein in its entirety and claims any and all benefits to which it is entitled therefrom.
FIELD OF THE INVENTION
[0002] The present invention is a vehicle safety railroad crossing system comprising a system for preventing collisions between trains and motor vehicles at all railroad crossings. Designed to save both lives and property, the vehicle safety railroad crossing system functions to alert the train's engineer and brakeman of the vehicle ahead obstructing the tracks, and automatically apply the train's brakes to prevent a collision.
BACKGROUND OF THE INVENTION
[0003] The United States railroad system consists of over 750 railroads running on 140,000 miles of track. Every day trains travel across more than 212,000 highway/rail so-called grade crossings. A grade crossing is a location where a public highway, road, street, or private roadway, including associated sidewalks, and pathways, crosses railroad tracks at grade, i.e., at the same level as the street. There are also more than 38,000 locations were railroad tracks and roadways cross at different levels.
[0004] According to the Federal Railroad Administration (FRA), there are about 270 deaths a year at public and private grade crossings. These deaths include pedestrians, but are predominantly due to train-versus-vehicle collisions. Largely through the FRA's safety programs, the number of fatalities has gone down by 54 percent over the last two decades. According to the FRA, trespassing along railroad rights-of-way is the leading cause of rail-related pedestrian deaths in America. Nationally, more than 431 trespass fatalities occur each year, and nearly as many injuries, the vast majority of which are preventable. Whether in a vehicle at a rail-crossing or as a pedestrian walking in the railroad right-of way, the reality is that nearly every 180 minutes in America, someone is hit by a train. Combined, highway/rail-crossing and trespasser deaths account for 95 percent of all rail-related deaths and most of these deaths are avoidable. Being struck by a train almost always means death for the motorist, but that can often be only the beginning of a larger, cascading disaster as the locomotive and cars of the train, one after another, derail. Regardless of whether the train in question is carrying crude oil, chlorine, or passengers, the effects of that initial collision continue long after that impact. What is needed is some more-effective means of preventing such collisions from occurring in the first place. The present invention prevents trains from colliding with vehicles at all rail crossings equipped with a sensor scale triggered to brake the approaching train.
[0005] Several references in the prior art show train safety systems. U.S. Pat. Nos. 5,554,982, 5,699,986 and 5,864,304 all show various systems which try to alert a train engineer of a vehicle, person, or blockage on the railroad tracks and try to allow time for train stoppage before collision. However, none of these patents teaches the vehicle safety railroad crossing system of the present invention.
[0006] Here in the United States and World Wide there are three (3) basic types of railroad crossings. These three types are as follows:
[0007] A. The first type of crossing is a sign with no lights or no bells. The sign simply states “Railroad Crossing” or uses an abbreviation such as “RR Crossing” or similar.
[0008] B. The second type of crossing is a pole with a sign, as above, but also with a flashing red light and/or a ringing bell to signify that a train is approaching.
[0009] C. The third type of railroad crossing is the gate system where gates come down and block the crossing, along with flashing lights and ringing bells to alert on-comers that a train is approaching.
[0010] For all 3 types of crossings there must be some type of a ramp to get over the tracks. Otherwise the vehicle will always get stuck in the tracks. A solar panel can be used for power in areas where there is no electric power line available. This is useful in condition type A, mentioned above. It will be understood that in conditions B and C, an electrical hook up at the crossing to power the gates and bells is always necessary. At a point down the track about a half of a mile or more, the train reaches a certain point and trips a switch that powers the gates to go down and activates the bells and lights to signal to cars or trucks of the oncoming train. Theoretically, vehicles cannot enter the crossing once the gates are down. Sometimes, however, vehicles get stuck at the crossing while the gates are down. There is nothing in the prior art that detects a vehicle or other object located in the middle of an intersection on top of the tracks at a rail crossing and trips the brakes of the train before the train collides with the vehicle stuck in the railroad crossing.
SUMMARY OF INVENTION AND ADVANTAGES
[0011] The vehicle safety railroad crossing system of the present invention would equip the nation's railroad crossings with a unique technological innovation designed to save lives and property: a system that would sense the presence of a motor vehicle in the crossing as a train approaches, act to alert the train's engineer and brakeman, and automatically apply the train's brakes.
[0012] The beneficiaries of the vehicle safety railroad crossing system of the present invention, or those who would most benefit from its installation at railroad crossing, would not only be the owners and operators of the trains that travel the rails but also owners and operators of motor vehicles, i.e., the so-called automotive aftermarket. This automotive aftermarket might also include professional drivers, such as the operators of long-haul trucks, and tax and limousine services.
[0013] While the most obvious beneficiaries of the vehicle safety railroad crossing system would be motorists, the system itself would likely be installed at crossings by the railroad companies. As was noted previously, the U.S. railroad system consists of hundreds of railroads running on thousands of miles of track. It is an object and advantage of the present invention to enhance safety at the large number of U.S. grade and other rail crossings.
[0014] One object of the present invention is to provide an efficient and economical way to reduce traffic accidents caused by stalled vehicles stuck on a railroad track at a railroad crossing.
[0015] Another object and advantage of the present invention is to provide a fail-safe system whereby sensors located adjacent a railroad track at a railroad crossing that detect the presence of any large stationary object transmit a signal to a point distal to the railroad crossing such that an eminently approaching train will be braked and stopped by activation of an electronic or mechanical trip-switch.
[0016] Yet another object and advantage of the present invention is to provide a system that brakes and stops a train automatically, such as in the absence or unavailability of brakeman/operator intervention.
[0017] Yet a another object and advantage of the present invention is to provide a vehicle safety railroad crossing system that has a predetermined minimum vehicle weight requirement for activation.
[0018] Yet a another object and advantage of the present invention is to provide a vehicle safety railroad crossing system that has weight sensors built into the ramps leading up to and across the railroad tracks.
[0019] Yet a another object and advantage of the present invention is to provide a vehicle safety railroad crossing system in which the presence of transitory vehicles or other objects is distinguished and differentiated from the presence of stationary, non-moving vehicles or other objects resting upon the railroad tracks at the crossing that pose risk of being struck by an eminently passing train.
[0020] Yet a another object and advantage of the present invention is to provide a vehicle safety railroad crossing system which not only prevents damage to vehicles and trains, but also reduces the incidence of road and rail closures for repair, medical treatment of injured persons and collision investigations, which in turn reduced traffic congestion, commuter trains delays, etc.
[0021] Benefits and features of the invention are made more apparent with the following detailed description of a presently preferred embodiment thereof in connection with the accompanying drawings, wherein like reference numerals are applied to like elements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 (prior art) shows a representative typical railroad crossing 90 .
[0023] FIG. 2A is a representative top view of the vehicle safety railroad crossing system 100 of the present invention.
[0024] FIG. 2B is a representative section view of the vehicle safety railroad crossing system 100 shown in FIG. 2A taken at A-A.
[0025] FIG. 2C is representative top detail view D of the vehicle safety railroad crossing system 100 shown in FIG. 2A .
[0026] FIG. 3A is a representative side view of the vehicle safety railroad crossing system 100 of the present invention implemented in conjunction with a railroad crossing having moving gate arms 300 , looking in a direction parallel to the railroad tracks 70 .
[0027] FIG. 3B is a representative side view of the vehicle safety railroad crossing system 100 of the present invention implemented in conjunction with a railroad crossing having moving gate arms 300 , looking in a direction perpendicular to the railroad tracks 70 .
[0028] FIG. 3C is a representative perspective view of the vehicle safety railroad crossing system 100 of the present invention implemented in conjunction with a railroad crossing having lights 320 .
[0029] FIG. 3D is a representative perspective view of the vehicle safety railroad crossing system 100 of the present invention implemented in conjunction with a railroad crossing having conventional railroad crossing verbiage or symbols 350 .
[0030] FIG. 4 is a representative top view of the vehicle safety railroad crossing system 100 of the present invention illustrating a method of use of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0031] The description that follows is presented to enable one skilled in the art to make and use the present invention, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be apparent to those skilled in the art, and the general principals discussed below may be applied to other embodiments and applications without departing from the scope and spirit of the invention. Therefore, the invention is not intended to be limited to the embodiments disclosed, but the invention is to be given the largest possible scope which is consistent with the principals and features described herein.
[0032] FIG. 1 (prior art) shows a representative typical railroad crossing 90 . As is well known, the typical railroad crossing 90 consists of a road with 1 or more lanes 80 and a location or intersection 76 where a set of railroad tracks 70 cross the road 80 . In a typical railroad crossing 90 in which the railroad crossing is indicated by a system in which an audible, illuminated sign or moving gate arms (not shown), there is an electrical connection, such as wire enclosed in conduit, that communicates from the intersection 76 to a distal point 78 . When an eminently approaching train 88 passes the distal point 78 , an electrical or mechanical-type of trip switch 60 transmits an electrical signal to the railroad crossing lights, bells and optionally gate arms, thereby activating the railroad crossing 90 lights, alarm, bell and/or moving gate arms. When the railroad crossing 90 is activated, the operator of an approaching car or other motor vehicle 98 will be advised of the dangers of proceeding through the intersection 76 , or will actually be prevented from passing there through by moving gate arms.
[0033] FIG. 2A is a representative top view of the vehicle safety railroad crossing system 100 of the present invention. FIG. 2B is a representative section view of the vehicle safety railroad crossing system 100 shown in FIG. 2A taken at A-A. FIG. 2C is representative top detail view D of the vehicle safety railroad crossing system 100 shown in FIG. 2A . The vehicle safety railroad crossing system-enhanced railroad crossing 100 of the present invention comprises a set of railroad tracks 70 that in general run perpendicular or essentially perpendicular to a one or more lane street, road or highway 80 . It will be understood that the vehicle safety railroad crossing system-enhanced railroad crossing 100 of the present invention can be installed at intersections 100 in which the railroad tracks 70 run at an angle to the road 80 . In either case, ramp portions 102 are installed in the intersection 100 at both sides of the railroad tracks 70 such that as a vehicle 98 approaches the crossing area 104 of the intersection 100 , the ramp portions 102 raise the vehicle off the grade level 104 to allow the vehicle 98 to clear the elevated rails 72 .
[0034] In order to sense the presence of a stalled or otherwise stationary vehicle 98 at risk or in danger of being struck by a passing train 88 , weight sensors 110 are installed adjacent the rails 72 of the railroad track 70 underneath the ramp portions 102 on either one side or both sides of the railroad tracks 72 within the crossing area 104 of the intersection 100 . The weight sensors 110 are placed at a location underneath or within the ramp portions 102 adjacent the railroad tracks 72 . If a stalled or stationary vehicle 98 is detected by the weight sensor 110 , and the system 100 determines that the vehicle 98 is not moving, then a signal is sent to trip switch 120 . This notifies approaching train 88 a sufficient distance from the crossing area 104 intersection such that the approaching train 88 can stop before striking the vehicle 98 .
[0035] FIG. 3A is a representative side view of the vehicle safety railroad crossing system 100 of the present invention implemented in conjunction with a railroad crossing having moving gate arms 320 , looking in a direction parallel to the railroad tracks 70 . FIG. 3B is a representative side view of the vehicle safety railroad crossing system 100 of the present invention implemented in conjunction with a railroad crossing having moving gate arms 300 , looking in a direction perpendicular to the railroad tracks 70 . The improved railroad crossing system 100 of the present invention can be used in locations where a conventional railroad crossing with gate arms 300 is used. Such railroad crossings comprise a base portion 312 that supports a center mast 310 , with gate arms 300 and counterweights 302 , flashing lights 320 and a crossbuck sign 310 mounted thereon.
[0036] FIG. 3C is a representative perspective view of the vehicle safety railroad crossing system 100 of the present invention implemented in conjunction with a railroad crossing having only lights 320 .
[0037] FIG. 3D is a representative perspective view of the vehicle safety railroad crossing system 100 of the present invention implemented in conjunction with a railroad crossing having conventional railroad crossing verbiage or symbols 350 .
[0038] FIG. 4 is a representative top view of the vehicle safety railroad crossing system 100 of the present invention illustrating a method of use of the present invention. As described above, in the event a vehicle 98 stops or is unable to proceed out of the cross-walk 76 zone of danger, the vehicle weight is detected by scales or weight sensor 110 . The scales or sensors 110 trigger a switch 120 , such as by transmitting a signal along wire 122 or transmitted signal which is able to communicate with oncoming train 88 . Thus, the train will be notified and the brakes can automatically be activated, thus stopping the train 88 long before it collides with the vehicle 98 stopped in the intersection 76 .
[0039] Railroad Crossing Safety Feature for all 3 Types of Crossings
[0040] The present invention 100 is a retrofit assembly that is installed under the ramps 102 that lead over the railroad tracks 70 at virtually all railroad crossings. An installed weight sensor or scale 110 only gets activated when substantial weight up to 1,000 pounds or more stays on the tracks 72 at the crossing 100 for 30 seconds or more. The precise parameters including weight range and timing can be adjusted by the railroad companies or other users of the system 100 . The stopping feature must be wired with the gates and signal devices down the tracks about a mile or more. The distances between devices can be adjusted by the railroad companies or other users of the system. Thus, if a car or truck gets stuck on the crossing, the weight will activate the scale that will send a signal down the tracks to the trip switch. The trip switch will then apply the brakes to the trains and stop the train automatically.
[0041] Thus, the present invention requires a group of scales wired to a sensor wired to a trip switch. As suggested above, crossing type A would need to have solar panels installed to provide the electric to the scales, devices and switches. The scale would indicate that there is a vehicle on the tracks, which would then send a signal to the trip switch to stop the train. Even in an event where the motormen would be unable to stop the train, this system will work automatically.
[0042] The wiring, scales, sensor and distance to the trip switch can all be adjusted by the railroad companies operating the system to suit their conditions. This system can be used world wide and is cheaper to retrofit than building overpasses or underpasses.
[0043] The vehicle safety railroad crossing system would work on double gate crossings, crossings with bells and lights, and crossings with just signs. As a train travels down the track, a sensor is triggered and the gates go down, or crossing signals are activated. The vehicle safety railroad crossing system would affordably install scales under the ramps at each railroad crossing. The scales would detect weights up to and in excess of 1000 lbs which either linger on the tracks for more than 30 seconds (or another amount of time designated by the Railroad system), or are on the tracks as the train is approaching. When tripped, this system would send an alert signal to the approaching train that a vehicle is stopped on the tracks. The train's engineer and brakeman can then stop the train before a collision occurs, or the safety trigger alert could stop the train automatically when a signal is received, or if the brakeman fails to stop the train. The details are to be determined, however, the alert could be issued to any train within a 1 mile or more range. Electrical conduit would be used, and solar panels would serve to supply power to the scales, devices, and switches. It will be understood that the physical wiring, scales, sensors, and distance settings can all be installed, adjusted and maintained by the various railroad companies that use them. Among the benefits and advantages of the vehicle safety railroad crossing system, the most important is the increase in safety—for both motorists and trains—that it would provide. And the vehicle safety railroad crossing system would operate automatically to brake a train approaching an imminent collision. Less expensive than building overpasses and underpasses to avoid railroad crossings, the vehicle safety railroad crossing system should have a strong appeal for the nation's railroads—and provide far greater safety not only for the nation's motorists, but for its railroads as well.
[0044] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Although any methods and materials similar or equivalent to those described can be used in the practice or testing of the present invention, the preferred methods and materials are now described. All publications and patent documents referenced in the present invention are incorporated herein by reference.
[0045] While the principles of the invention have been made clear in illustrative embodiments, there will be immediately obvious to those skilled in the art many modifications of structure, arrangement, proportions, the elements, materials, and components used in the practice of the invention, and otherwise, which are particularly adapted to specific environments and operative requirements without departing from those principles. The appended claims are intended to cover and embrace any and all such modifications, with the limits only of the true purview, spirit and scope of the invention. | A vehicle safety railroad crossing system comprising a system for preventing collisions between trains and motor vehicles at railroad crossings. The vehicle safety railroad crossing system functions to alert the train's engineer and brakeman of the vehicle ahead obstructing the tracks, and automatically apply the train's brakes to prevent a collision. | 22,030 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 62/329,535, filed on Apr. 29, 2016, and U.S. Provisional Application No. 62/329,586, filed on Apr. 29, 2016. The entire disclosures of the applications referenced above are incorporated herein by reference.
FIELD
[0002] The present disclosure relates to co-fluids for use with carbon dioxide refrigerant in heating, ventilation, air conditioning and refrigeration (HVAC&R) systems.
BACKGROUND
[0003] This section provides background information related to the present disclosure which is not necessarily prior art.
[0004] Because carbon dioxide (R744) has a low global warming potential (GWP) of only 1 and no ozone-depleting potential at all (ODP of zero), it makes an excellent environmentally friendly refrigerant as compared to hydrofluorocarbons, hydrofluoroolefins, and other less environmentally sound refrigerants. However, the pressures required to liquefy carbon dioxide prove to be too high for use in conventional heating and cooling systems. To avoid high pressures in a refrigeration cycle, carbon dioxide can be used along with a so-called co-fluid or mixture of co-fluids.
[0005] In operation of an HVAC&R system using carbon dioxide and a co-fluid, carbon dioxide refrigerant is absorbed into and desorbed out of the co-fluid. For example, carbon dioxide is absorbed and the pressure lowered during compression and flow through a condenser or absorber. Subsequent flow through an expansion device and evaporator requires a desirable release (desorption) of a portion of the carbon dioxide refrigerant.
[0006] It has generally been observed that rates of absorption tend to be faster than rates of desorption in co-fluid systems using carbon dioxide as refrigerant. This rate inequality can potentially lead to problems in operating the heating and cooling system. There may not be enough time for proper heat flow to the evaporator needed for cooling. And there could be an accumulation of carbon dioxide in the co-fluid due to the rate difference, causing the system to be inefficient or even inoperable. There is a continuing need for co-fluids that provide a higher rate of desorption to improve operation in cooling systems.
SUMMARY
[0007] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
[0008] A carbon dioxide/co-fluid mixture is provided for use in a refrigeration cycle in which the carbon dioxide is alternately absorbed and desorbed from the co-fluid. The mixture includes from 50% to 99% by weight co-fluid and 1% to 50% by weight carbon dioxide. Suitable co-fluids are selected from the class of alkoxylated carboxylic amides, wherein the amides are cyclic or non-cyclic. It has been discovered that N-2,5,8,11-tetraoxadodecyl-2-pyrrolidinone and its homologs exhibit an advantageous property of a high rate of desorption at lower temperatures.
[0009] Pumps or compressors containing the co-fluid as a lubricant are provided for use in a system that includes in sequence a compressor, an absorber (or resorber), an expansion device (or expander), and a desorber. A method of operating a refrigeration system involves circulating the co-fluid and refrigerant around such a system.
[0010] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
[0011] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
[0012] FIG. 1 is a schematic representation of a climate-control system according to the principles of the present disclosure;
[0013] FIG. 2 is a schematic representation of an exemplary desorber that can be incorporated into the system of FIG. 1 ;
[0014] FIG. 3 is a schematic representation of another climate-control system according to the principles of the present disclosure;
[0015] FIG. 4 is a schematic representation of yet another climate-control system according to the principles of the present disclosure;
[0016] FIG. 5 is a schematic representation of a generator that can be incorporated into the system of FIG. 4 ;
[0017] FIG. 6 compares desorption rates among lubricants;
[0018] FIGS. 7-11 show comparative desorption rates of co-fluids;
[0019] FIG. 12 illustrates carbon dioxide desorption of co-fluids; and
[0020] FIG. 13 compares desorption rates to those of co-fluids.
[0021] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
DETAILED DESCRIPTION
[0022] Example embodiments will now be described more fully with reference to the accompanying drawings.
[0023] Co-fluids are provided for use in co-fluid systems where carbon dioxide is used as refrigerant. The co-fluid is an absorbent capable of absorbing and desorbing the carbon dioxide refrigerant. Use of the co-fluids eliminates the need for high system pressures otherwise required to change the phase of the refrigerant carbon dioxide.
[0024] Co-fluids are selected from those with the following generic formulae:
[0000]
[0000] where m is 1 to 10; R is alkyl, alkenyl, or aryl with 1 to 26 carbon atoms; R′ is H or optionally substituted C 1-6 alkyl; R″ is H, methyl, or ethyl; R′″ is H, methyl, or ethyl; and at least one of R″ and R′″ is H;
[0000]
[0000] where m is 1 to 10; p is 1 to 3; R is alkyl, alkenyl, or aryl with 1 to 26 carbon atoms; R′ is H or optionally substituted C 1-6 alkyl; R″ is H, methyl, or ethyl; R′″ is H, methyl, or ethyl; and at least one of R″ and R′″ is H;
[0000]
[0000] where x is 1 to 4; n is 1 to 10; R′ is H or optionally substituted C 1-6 alkyl-; R″ is H, methyl, or ethyl; R′″ is H, methyl, or ethyl; and at least one of R″ and R′″ is H;
[0000]
[0000] where y is 1 to 4; n is 1 to 10; p is 1 to 3; R′ is H or optionally substituted C 1-6 alkyl; R″ is H, methyl, or ethyl; R′″ is H, methyl, or ethyl; and at least one of R″ and R′″ is H;
[0000]
[0000] where z is 1 to 4; n is 1 to 10; R′ is H or optionally substituted C 1-6 alkyl; R″ is H, methyl, or ethyl; R′″ is H, methyl, or ethyl; and at least one of R″ and R′″ is H;
[0000]
[0000] where z is 1 to 4; n is 1 to 10; p is 1 to 3; R′ is H or optionally substituted C 1-6 alkyl; R″ is H, methyl, or ethyl; R′″ is H, methyl, or ethyl; and at least one of R″ and R′″ is H.
[0025] Although the invention is not to be limited by any scientific hypothesis or theory of operation, the compounds of formulae (I)-(VI) share chemical features that are believed to contribute to their general usefulness as co-fluids for use with carbon dioxide refrigerant. It is believed that the carboxylic amide (cyclic or open chain) and the polyoxyalkylene moiety combine to provide compositions that desorb carbon dioxide at a high rate, a rate that is higher than homologous compounds without those features, even though the homologous compounds are considered part of the described invention to the extent they have not yet been disclosed as co-fluids. Generally speaking, species with high desorption rates are preferred as co-fluids in carbon dioxide refrigeration systems, because of the operational advantages expected to flow from having high desorption.
[0026] The compounds of formulae (I)-(VI) are characterized by a “side chain” that has a polyoxyalkylene structure denoted by the repeat units of m or n in the formulae. If both of R″ and R′″ are hydrogen (H), the chain is polyoxyethylene; if one of them is methyl (the other being H), the chain is polyoxypropylene; if one of them is ethyl, the chain is polyoxybutylene. Because the repeat units m and n range from 1 to 10, it is also possible to provide so-called heteric polyoxyalkylene chains containing a combination of polyoxyethylene, polyoxypropylene, and polyoxybutylene. That is to say, the formulae should be interpreted as permitting up to 10 repeat units, where each repeat unit is independently based on ethylene-, propylene-, or butylene oxide.
[0027] The non-cyclic amide “alkoxylates” of formulae (I) and (II) are based on carboxylic amides with at least two and up to 27 carbon atoms (since R has 1 to 26 carbon atoms). The nature of the R group (size, level of branching, presence or not of unsaturation) is expected to affect the equivalent weight of and the viscosity of the co-fluid. These are design factors than can be taken into account.
[0028] In all formulae, the terminal hydroxyl of the polyoxyalkylene chain is in the alternative capped with an alkyl group (preferably methyl for ease of synthesis) that is optionally substituted. Although part of the invention, the hydroxyl compounds (R′ ═H) are less preferred in some embodiments because the hydroxyl could contribute to undesirable reactivity, high viscosity, or even corrosion. Capping takes the hydroxyl group out of play. Substitutions on R′ are allowed to the extent they do not spoil the operation of the compound as a co-fluid. In a particular embodiment, the alkyl group R′ is substituted with a carboxylic amide group as shown in the description below and in the examples. Thus, R′ in any of the above can be C 1-6 alkyl substituted with alkylcarbamido or alkenylcarbamido, represented by the following structures where R is alkyl or alkenyl:
[0000]
[0029] The compounds of formulae (I)-(VI) are formally alkoxylates of the carboxylic amide or -imide shown. The compounds of (I), (III), and (V) can be synthesized by direct alkoxylation of the amide/imide starting group, because the amide/imide group is reactive and can open the oxirane ring of the corresponding alkylene oxides. The compounds of (II), (IV), and (VI) on the other hand, can be made by alkoxylating the free hydroxyl group of a starting material that contains an alkylol moiety attached to the amide or imide. Depending on whether p in the formulae is 1, 2, or 3, the group is a methylol, ethylol, or propylol group.
[0030] Compounds with n (or m) from 1 to 10 can be made by reacting the starting material with n or m equivalents of oxide and reacting to a polydisperse mixture containing an average of n oxide units per amide group. Alternatively, they can be synthesized with a goal of producing a molecular weight distribution where the peak is at a species with n oxide units. Various fractions can be physically separated to provide other distributions of alkoxylation.
[0031] But especially for the lower molecular weight compounds, it can be simpler not to form the compounds by alkoxylation, but instead by reacting a pre-formed monodisperse compound containing n repeat units with the reactive amide nitrogen (or with the hydroxyl of an alkylol group added to the amide, for example by reaction with formaldehyde). This is illustrated by reacting a starting material N-methylolpyrrolidone (N-hydroxymethyl-2-pyrrolidone) with triethylene glycol monomethyl ether in a conventional Williamson ether synthesis.
[0032] In various embodiments, the co-fluids of formulae (I)-(VI) are further characterized by one or any combination of the following: the parameters x and y have a value of either 2 or 4; the parameter z has a value of 2 (meaning the structure is based on a succinimide derivative); the variables n and m are 1 to 4; R′ is methyl; R″ and R′″ are both H; R′ is C 1-3 alkyl substituted with alkylcarbamido. Particular embodiments include the following:
[0000]
[0033] In operation, the co-fluid acts as lubricant as well a carrier fluid for the refrigerant carbon dioxide. A compressor for use in the cooling circuits described herein contains any of the described co-fluids as a lubricant.
[0034] In operation, the co-fluids absorb (resorb) and desorb refrigerant carbon dioxide as they circulate around a refrigeration or cooling circuit. At various points in the circuit, a cooling composition comprises from 50% to 99% by weight co-fluid and 1% to 50% by weight carbon dioxide.
[0035] Preferred co-fluids have the chemical structures disclosed herein. In various embodiments, performance also relies on a co-fluid having advantageous physical properties as well. Naturally, preferred co-fluids readily absorb and desorb carbon dioxide used as refrigerant. An instantaneous rate (rate essentially at time zero) as well as amount desorbed at 1 minute and at 2 minutes are measured. The results can be used to screen potential candidates.
[0036] The co-fluid also needs to have suitable viscosity. In various embodiments, viscosity is in the range of 1 to 50 centistokes (cSt); 1 to 20 cSt; 3 to 20 cSt; 5 to 20 cSt; 1 to 10 cSt; 3 to 10 cSt. Some good candidates have a viscosity of fairly close to 10 cSt. The viscosity is advantageously in a range of 5 to 15 CSt, 8 to 12 cSt, or 9 to 11 cSt, in various embodiments. Too high a viscosity and fluid flow around the cooling circuit can be impeded. If the viscosity is too low, there could be leakage past seals in the system. A non-limiting illustration of use of the co-fluids follows.
Use of the Co Fluids in Refrigeration Methods
[0037] A representative refrigeration cycle based on carbon dioxide as refrigerant (“vapor”) operates as follows. A combination of vapor and liquid (co-fluid) is compressed in a compressor, raising the pressure and forcing some of the vapor into the liquid phase. Heat is rejected in a resorber (absorber) downstream of the compressor. This cools the mixture and causes more of the vapor to be absorbed. The remaining CO 2 vapor and co-fluid are further cooled in an internal heat exchanger. The cool, fully liquefied mixture is then passed through an expansion device, decreasing the pressure, dropping the temperature further, and releasing some of the CO 2 into the vapor phase. Heat is extracted from the refrigerated space into a desorber as the temperature of the mixture rises and further CO 2 escapes from the liquid phase. Finally, the fluids are further warmed in an internal heat exchanger, completing the cycle.
Binary-Cycle Climate-Control System
[0038] With reference to FIG. 1 , a binary-cycle climate-control system 10 is provided that may include a compressor 12 , a liquid-vapor separator 13 , an agitation vessel (e.g., a stirring and/or shaking vessel) 15 , an absorber (or resorber) 14 , an internal heat exchanger 16 , an expansion device 18 , and a desorber 20 . The compressor 12 can be any suitable type of compressor, such as a scroll, rotary or reciprocating compressor, for example. The compressor 12 may include a shell 22 , a compression mechanism 24 disposed within the shell 22 , and a motor 26 (e.g., a fixed-speed or variable-speed motor) that drives the compression mechanism 24 via a crankshaft 28 . The compressor 12 can be a fixed-capacity or variable-capacity compressor. The compressor 12 may compress a mixture of a refrigerant (e.g., carbon dioxide, hydrofluorocarbons, ammonia, bromide, etc.) and a co-fluid (e.g., oil, water, polyalkylene glycol, polyol ester, polyvinyl ether, etc.) and circulate the mixture throughout the system 10 . The co-fluid may be an absorbent capable of absorbing a refrigerant. Compressing the mixture of refrigerant and co-fluid raises the pressure and temperature of the mixture and causes some refrigerant to be absorbed into the co-fluid.
[0039] The liquid-vapor separator 13 may include an inlet 17 , a first outlet (e.g., a gas outlet) 19 , and a second outlet (e.g., a liquid outlet) 21 . The inlet 17 may be fluidly coupled with an outlet 34 of the compressor 12 such that the liquid-vapor separator 13 receives the compressed mixture of refrigerant and co-fluid (e.g., the compressed mixture of refrigerant vapor and liquid co-fluid containing some dissolved refrigerant gas) from the compressor 12 . The liquid co-fluid (which may contain some dissolved refrigerant gas) may settle to the bottom of the liquid-vapor separator 13 , and the undissolved refrigerant vapor may remain at the top (or rise to the top) of the liquid-vapor separator 13 (i.e., above the surface of the liquid co-fluid). The liquid co-fluid may exit the liquid-vapor separator 13 through the second outlet 21 (which may be located below the surface of the liquid in the separator 13 ), and the refrigerant vapor may exit the liquid-vapor separator 13 through the first outlet 19 (which may be located above the surface of the liquid in the separator 13 ).
[0040] The agitation vessel 15 may include a first inlet 23 , a second inlet 25 , a first outlet 27 , a second outlet 29 , and an agitator 31 . The first inlet 23 may be disposed at or generally near a top end of the vessel 15 and may be fluidly coupled with the second outlet 21 of the separator 13 such that liquid co-fluid from the separator 13 enters the vessel 15 through the first inlet 23 . The liquid co-fluid entering the separator 13 through the first inlet 23 may fall to the bottom of the vessel 15 . The second inlet 25 may be below the surface of the liquid co-fluid in the vessel 15 and may be fluidly coupled with the first outlet 19 of the separator 13 such that refrigerant vapor from the separator 13 enters the vessel 15 through the second inlet 25 . In this manner, the refrigerant vapor enters the vessel 15 below the surface of the liquid co-fluid, which causes some of the refrigerant vapor entering the vessel 15 to be absorbed (or dissolved) into the liquid co-fluid.
[0041] The agitator 31 can be or include an impeller (e.g., one or rotating paddles or blades) and/or a shaker, for example, disposed below the surface of the liquid co-fluid in the vessel 15 . The agitator 31 may be driven by a motor 33 and may stir or agitate the liquid co-fluid in the vessel 15 to further promote absorption of the refrigerant vapor into the liquid co-fluid.
[0042] The first outlet 27 of the vessel 15 may be disposed below the surface of the liquid co-fluid such that refrigerant vapor exits the vessel 15 through the first outlet 27 . The second outlet 29 of the vessel 15 may be disposed above the surface of the liquid co-fluid such that liquid co-fluid (with refrigerant vapor dissolved therein) exits the vessel 15 through the second outlet 29 . The first and second outlets 27 , 29 may both be in communication with a conduit 35 such that the liquid co-fluid from the first outlet 27 and refrigerant vapor from the second outlet 29 are combined and mix with each other (further promoting absorption of the refrigerant vapor into the liquid co-fluid) in the conduit 35 .
[0043] The absorber 14 may be a heat exchanger that may be fluidly coupled with the conduit 35 and may receive the compressed mixture of the refrigerant and co-fluid from the conduit 35 . In configurations of the system 10 that do not include the separator 13 and vessel 15 , the absorber 14 may receive the compressed mixture of the refrigerant and co-fluid directly from the compressor 12 . Within the absorber 14 , heat from the mixture of the refrigerant and co-fluid may be rejected to air or water for example, or some other medium. In the particular configuration shown in FIG. 1 , a fan 36 may force air across the absorber 14 to cool the mixture of the refrigerant and co-fluid within the absorber 14 . As the mixture of the refrigerant and co-fluid cools within the absorber 14 , more refrigerant is absorbed into the co-fluid.
[0044] The internal heat exchanger 16 may include a first coil 38 and a second coil 40 . The first and second coils 38 , 40 are in a heat transfer relationship with each other. The first coil 38 may be fluidly coupled with the outlet 32 of the absorber 14 such that the mixture of the refrigerant and co-fluid may flow from the outlet 32 of the absorber 14 to the first coil 38 . Heat from the mixture of the refrigerant and co-fluid flowing through the first coil 38 may be transferred to the mixture of the refrigerant and co-fluid flowing through the second coil 40 . More refrigerant may be absorbed into the co-fluid as the mixture flows through the first coil 38 .
[0045] The expansion device 18 may be an expansion valve (e.g., a thermal expansion valve or an electronic expansion valve) or a capillary tube, for example. The expansion device 18 may be in fluid communication with the first coil 38 and the desorber 20 . That is, the expansion device 18 may receive the mixture of the refrigerant and co-fluid that has exited downstream of the first coil 38 and upstream of the desorber 20 . As the mixture of the refrigerant and co-fluid flows through the expansion device 18 , the temperature and pressure of the mixture decreases.
[0046] The desorber 20 may be a heat exchanger that receives the mixture of the refrigerant and co-fluid from the expansion device 18 . Within the desorber 20 , the mixture of the refrigerant and co-fluid may absorb heat from air or water, for example. In the particular configuration shown in FIG. 1 , a fan 42 may force air from a space (i.e., a room or space to be cooled by the system 10 ) across the desorber 20 to cool the air. As the mixture of the refrigerant and co-fluid is heated within the desorber 20 , refrigerant is desorbed from the co-fluid. From an outlet 53 of the desorber 20 , the mixture of refrigerant and co-fluid may flow through the second coil 40 and back to the compressor 12 to complete the cycle.
[0047] One or more ultrasonic transducers (i.e., vibration transducers) 44 may be attached to the desorber 20 . As shown in FIG. 1 , the ultrasonic transducers 44 may be mounted to an exterior surface 46 of the desorber 20 . In some configurations, the ultrasonic transducers 44 are disposed inside of the desorber 20 and in contact with the mixture of refrigerant and co-fluid (as shown in FIG. 2 ). The ultrasonic transducers 44 can be any suitable type of transducer that produces vibrations (e.g., ultrasonic vibrations) in response to receipt of electrical current. For example, the ultrasonic transducers 44 could be piezoelectric transducers, capacitive transducers, or magnetorestrictive transducers. For example, the ultrasonic transducers 44 may have an output frequency in the range of about 20-150 kHz (kilohertz). The ultrasonic transducers 44 may (directly or indirectly) apply or transmit vibration to the mixture of refrigerant and co-fluid flowing through the desorber 20 to increase a rate of desorption of the refrigerant from the co-fluid.
[0048] The ultrasonic transducers 44 can have any suitable shape or design. For example, the ultrasonic transducers 44 may have a long and narrow shape, a flat disc shape, etc., and can be flexible or rigid. In configurations in which the ultrasonic transducers 44 are mounted to the exterior surface 46 of the desorber 20 , it may be beneficial for the desorber 20 to have a minimal wall thickness at the location at which the ultrasonic transducers 44 are mounted in order to minimize attenuation of the ultrasonic vibration. Furthermore, it may be beneficial to apply the ultrasonic vibration to the mixture of the refrigerant and co-fluid at a location at which the mixture of the refrigerant and co-fluid is static or at a location of reduced or minimal flow rate of the mixture of the refrigerant and co-fluid, because fluids flowing at high rates can be more difficult to excite with ultrasonic energy.
[0049] A control module (or controller) 48 may be in communication (e.g., wired or wireless communication) with the ultrasonic transducers 44 and may control operation of the ultrasonic transducers 44 . The control module 48 can control the frequency and amplitude of electrical current supplied to the ultrasonic transducers 44 (e.g., electrical current supplied to the ultrasonic transducers 44 by a battery and/or other electrical power source) to control the frequency and amplitude of the vibration that the ultrasonic transducers 44 produce. The control module 48 may also be in communication with and control operation of the motor 26 of the compressor 12 , the expansion device 18 , the motor 33 of the agitator 31 , the fans 36 , 42 , and/or other components or subsystems.
[0050] As described above, applying ultrasonic vibration to the mixture of refrigerant and co-fluid increases the desorption rate. The control module 48 may control operation of the ultrasonic transducers 44 to control the desorption rate. For example, the control module 48 may control the frequency, amplitude, runtime (e.g., pulse-width-modulation cycle time), etc. of the motor 33 , fans 36 , 42 , and/or the ultrasonic transducers 44 such that the desorption rate matches or nearly matches a rate of absorption of the refrigerant into the co-fluid that occurs upstream of the expansion device 18 (e.g., in the absorber 14 and vessel 15 ).
[0051] Without any excitation of the mixture of refrigeration and co-fluid, the absorption rate may be substantially greater than the desorption rate. The absorption rate may vary depending on a variety of operating parameters of the system 10 (e.g., pressure, compressor capacity, fan speed, thermal load on the system 10 , type of refrigerant, type of co-fluid, etc.). In some configurations, a first sensor 50 and a second sensor 52 may be in communication with the control module 48 and may measure parameters that are indicative of absorption rate and desorption rate. For example, the first sensor 50 can be a pressure or temperature sensor that measures the pressure or temperature of the mixture of refrigerant and co-fluid within the absorber 14 , and the second sensor 52 can be a pressure or temperature sensor that measures the pressure or temperature of the mixture of refrigerant and co-fluid within the desorber 20 . The pressures and/or temperatures measured by the sensors 50 , 52 may be indicative of absorption rate and desorption rate.
[0052] The sensors 50 , 52 may communicate the pressure or temperature data to the control module 48 , and the control module 48 may determine a concentration of refrigerant in the co-fluid based on the pressure or temperature data (e.g., using a lookup table or equations). The control module 48 can include an internal clock (or be in communication with an external clock) and can determine the absorption rate and desorption rate based on changes in the concentration of refrigerant in the co-fluid over a period of time. The control module 48 may control operation of the ultrasonic transducers 44 based on the absorption rate and/or the desorption rate. The control module 48 may also control operation of the compressor 12 , the fans 36 , 42 and/or the expansion device 18 based on the absorption and/or desorption rates and/or to control the absorption and/or desorption rates. In some configurations, the control module 48 may control the ultrasonic transducers 44 based on data from additional or alternative sensors and/or additional or alternative operating parameters.
[0053] Because the absorption rate of many refrigerants into many co-fluids is significantly faster than the desorption rate, the rate of desorption may substantially limit the capacity of the system 10 . Applying ultrasonic energy (e.g., via the ultrasonic transducers 44 ) to the mixture of refrigerant and co-fluid unexpectedly solves the problem of slow desorption rates. It can be shown that desorption rates may increase by about 100%-900% (depending on the refrigerant type and co-fluid type) by exciting the mixture of refrigerant and co-fluid with ultrasonic energy (e.g., using one or more ultrasonic transducers 44 ) as compared to stirring the mixture with a propeller at 400 revolutions per minute. This increase in the desorption rate surpassed reasonable expectations of success.
[0054] Referring now to FIG. 3 , another binary-cycle climate-control system 100 is provided that may include a compressor 112 , a pump 111 , a liquid-vapor separator 113 , an agitation vessel (e.g., a stirring and/or shaking vessel) 115 , an absorber 114 , an internal heat exchanger 116 , an expansion device 118 , a desorber 120 , a receiver 121 , one or more ultrasonic transducers 144 and a control module 148 . The structure and function of the compressor 112 , liquid-vapor separator 113 , agitation vessel 115 , absorber 114 , internal heat exchanger 116 , expansion device 118 , desorber 120 , ultrasonic transducers 144 and control module 148 may be similar or identical to that of the compressor 12 , liquid-vapor separator 13 , agitation vessel 15 , absorber 14 , internal heat exchanger 16 , expansion device 18 , desorber 20 , ultrasonic transducers 44 and control module 48 described above (apart from any exceptions described below). Therefore, similar features may not be described again in detail.
[0055] The receiver 121 may be fluidly coupled with the internal heat exchanger 116 (e.g., a second coil 140 of the internal heat exchanger 116 ), the compressor 112 , and the pump 111 . The receiver 121 may include an inlet 154 , a refrigerant outlet 156 , and a co-fluid outlet 158 . The inlet 154 may receive the mixture of refrigerant and co-fluid from the second coil 140 . Inside of the receiver 121 , gaseous refrigerant may be separated from liquid co-fluid. That is, the co-fluid accumulates in a lower portion 162 of the receiver 121 , and the refrigerant may accumulate in an upper portion 160 of the receiver 121 . The refrigerant may exit the receiver 121 through the refrigerant outlet 156 , and the co-fluid may exit the receiver 121 through the co-fluid outlet 158 . The refrigerant outlet 156 may be fluidly coupled with a suction fitting 164 of the compressor 112 such that refrigerant is drawn into the compressor 112 for compression therein. The co-fluid outlet 158 may be fluidly coupled with an inlet 166 of the pump 111 so that the co-fluid is drawn into the pump 111 . Outlets 168 , 170 of the compressor 112 and pump 111 , respectively, are fluidly coupled with an inlet 117 of the separator 113 via a conduit 172 or with an inlet of the absorber 114 such that refrigerant discharged from the compressor 112 and co-fluid discharged from the pump 111 can be recombine in the vessel 115 , in the absorber 114 and/or in the conduit 172 that feeds the separator 113 or the absorber 114 .
[0056] With reference to FIG. 4 , an absorption-cycle climate-control system 200 is provided that may include a vessel 212 (e.g., a generator), a condenser 214 , a first expansion device 216 , an evaporator 218 , an absorber 220 , an internal heat exchanger 222 , a second expansion device 224 , and a pump 226 . The vessel 212 may include an inlet 228 , a refrigerant outlet 230 , and a co-fluid outlet 232 . The inlet 228 may receive a mixture of refrigerant and co-fluid (i.e., with the refrigerant absorbed into the co-fluid).
[0057] The vessel 212 may be heated by any available heat source (e.g., a burner, boiler or waste heat from another system or machine)(not shown). In some configurations, the vessel 212 may absorb heat from a space to be cooled (e.g., the space to be cooled within a refrigerator, freezer, etc.). As heat is transferred to the mixture of refrigerant and co-fluid within the vessel 212 , the vapor refrigerant desorbs from the co-fluid so that the refrigerant can separate from the co-fluid. The refrigerant may exit the vessel 212 through the refrigerant outlet 230 , and the co-fluid may exit the vessel 212 through the co-fluid outlet 232 .
[0058] One or more ultrasonic transducers 244 may be attached to the vessel 212 . As shown in FIG. 4 , the ultrasonic transducers 244 may be mounted to an exterior surface 234 of the vessel 212 . In some configurations, the ultrasonic transducers 244 are disposed inside of the vessel 212 and in contact with the mixture of refrigerant and co-fluid (as shown in FIG. 5 ). The structure and function of the ultrasonic transducers 244 may be similar or identical to that of the ultrasonic transducers 44 described above. As described above, the ultrasonic transducers 244 produce ultrasonic vibration that is transmitted to the mixture of refrigerant and co-fluid to increase the desorption rate of the refrigerant from the co-fluid. In some configurations, ultrasonic vibration may be used to produce a desired amount of desorption without adding heat from another source. In some configurations, ultrasonic vibration and the addition of heat may further accelerate the desorption rate.
[0059] As described above, a control module 248 may be in communication with and control operation of the ultrasonic transducers 244 to increase the desorption rate to a desired level (e.g., to a level matching a rate of absorption). The structure and function of the control module 248 may be similar or identical to that of the control module 48 . The control module 248 may be in communication with sensors 250 , 252 and may control operation of the ultrasonic transducers 244 based on pressure and/or temperature data received from the sensors 250 , 252 . The sensor 250 may be disposed within the vessel 212 and may measure a pressure or temperature of the mixture of refrigerant and co-fluid therein. The sensor 252 may be disposed within the absorber 220 and may measure a pressure or temperature of the mixture of refrigerant and co-fluid therein. The control module 248 may also be in communication with and control operation of the pump 226 , the expansion devices 216 , 224 and/or fans 254 , 256 , 257 .
[0060] The condenser 214 is a heat exchanger that receives refrigerant from the refrigerant outlet 230 of the vessel 212 . Within the condenser 214 , heat from the refrigerant may be rejected to air or water for example, or some other medium. In the particular configuration shown in FIG. 4 , the fan 254 may force air across the condenser 214 to cool the refrigerant within the condenser 214 .
[0061] The expansion devices 216 , 224 may be expansion valves (e.g., thermal expansion valves or electronic expansion valves) or capillary tubes, for example. The first expansion device 216 may be in fluid communication with the condenser 214 and the evaporator 218 . The evaporator 218 may receive expanded refrigerant from the expansion device 216 . Within the evaporator 218 , the refrigerant may absorb heat from air or water, for example. In the particular configuration shown in FIG. 4 , the fan 256 may force air from a space (i.e., a room or space to be cooled by the system 200 ) across the evaporator 218 to cool the air.
[0062] The absorber 220 may include a refrigerant inlet 258 , a co-fluid inlet 260 , and an outlet 262 . The refrigerant inlet 258 may receive refrigerant from the evaporator 218 . The co-fluid inlet 260 may receive co-fluid from the second expansion device 224 . Refrigerant may absorb into the co-fluid within the absorber 220 . The fan 257 may force air across the absorber 220 to cool the mixture of refrigerant and co-fluid and facilitate absorption.
[0063] Like the internal heat exchanger 16 , the internal heat exchanger 222 may include a first coil 264 and a second coil 266 . The first coil 264 may receive co-fluid from the co-fluid outlet 232 of the vessel 212 . The co-fluid may flow from the first coil 264 through the second expansion device 224 and then into the absorber 220 through the co-fluid inlet 260 .
[0064] The mixture of refrigerant and co-fluid may exit the absorber 220 through the outlet 262 , and the pump 226 may pump the mixture through the second coil 266 . The mixture of refrigerant and co-fluid flowing through the second coil 266 may absorb heat from the co-fluid flowing through the first coil 264 . From the second coil 266 , the mixture of refrigerant and co-fluid may flow back into the vessel 212 through the inlet 228 .
[0065] It will be appreciated that the climate-control systems 10 , 100 , 200 can be used to perform a cooling function (e.g., refrigeration or air conditioning) or a heating function (e.g., heat pump).
EXAMPLES
Example 1—Comparison to Known Co Fluids
[0066] Several commercial lubricants were compared to a co-fluid of the current teachings. MinOil is mineral oil. POE is polyol ester. PAG is polyalkylene glycol. NMP is N-methylpyrrolidone. PVE is polyvinyl ether. Comparison of their desorption rates at 32° F. under the same initial pressure load, initial desorption pressure and agitation rate is plotted in FIG. 6 and compared with N-2,5,8,11-tetraoxadodecyl-2-pyrrolidone (abbreviated: Pyrr(EO)3Me) shown here:
[0000]
[0000] In FIG. 6 , each value represents the pressure increase in one minute's time and the values are an average of three trials.
[0067] Pyrr(EO)3Me also shows a rate inversion with temperature. Generally, desorption rates are expected to be faster at higher temperatures and slower at lower temperatures. But the plot in FIG. 7 shows that desorption is actually faster at the lower temperature.
Example 2—Comparison of Analog Compounds
[0068] A) Comparison of Aliphatic Side Chain and Polyoxyalkylene Side Chain
[0069] Pyrr(EO)3Me has a 12 atom chain attached to the nitrogen. A saturated analog, N-dodecyl-2-pyrrolidone (Abbreviated: NDDPy), also has a 12-atom chain. They have similar viscosities (NDDPy at 40° C.=9.29 cSt, Pyrr(EO)3Me at 40° C.=9.06 cSt) and are close in molecular weight. NDDPy had to be evaluated at a higher temperature due to it solidifying at 5° C. Pyrr(EO)3Me has a faster desorption rate, as shown in FIG. 8 .
[0000]
[0070] B) Comparison of Carboxylic Amide to Carboxylic Ester
[0071] Pyrr(EO3Me) was compared to a corresponding ester compound IsoV(EO)3Me. Although the comparison ester had a lower viscosity than Pyrr(EO)3Me (which would provide a faster desorption rate, all things equal), the Pyrr(EO)3Me had a faster desorption rate. Data are shown in FIG. 9 .
[0000]
[0072] C) Comparison to a Compound without the Cyclic Carboxylic Amide
[0073] Pyrr(EO)3Me was also compared with triethylene glycol dimethyl ether to show that a low viscosity, low molecular weight polyalkylene glycol would not have the same or better desorption rates. Data are shown in FIG. 10 , demonstrating Pyrr(EO)3Me has a faster desorption rate. The “dimethyl glycol ether” of FIG. 10 is triethylene glycol dimethyl ether.
[0000]
[0074] D) N-2,5,8,11-Tetraoxadodecyl-Caprolactam Shows the Same Temperature Rate Inversion as Pyrr(EO)3Me.
[0075] N-2,5,8,11-Tetraoxadodecyl-Caprolactam has a 7-membered lactam ring rather than the five-membered ring on Pyrr(EO)3Me. It shows a temperature rate inversion, with the data shown in FIG. 11 . The analog's structure is:
[0000]
[0076] E) Effect of Ethylene Oxide Chain Length on the Rate of Carbon Dioxide Desorption.
[0077] The graph in FIG. 12 shows instantaneous rates (rates at time zero) of desorption for a series of compounds with no, 1, 2, or 3 ethylene oxides added to N-hydroxymethyl-2-pyrrolidone, as shown here:
[0000]
[0078] F) Desorption Rates of Eight Atom Chain Co-Fluids Double Capped with 2-Pyrrolidone Rings.
[0079] The following two compounds were compared at 40° C. This temperature was chosen due to solidification of one of the compounds at 0° C.
[0000]
[0000] As with the single pyrrolidone capped material (methyl cap at the other end), the compound having both ethylene oxide and pyrrolidone functions desorbs carbon dioxide faster under comparable conditions. This can be seen in the graph in FIG. 13 .
Example 3—Synthesis of Co Fluids
Preparation of N-Hydroxymethyl-2-Pyrrolidone
[0080] (This preparation is a slight modification of U.S. Pat. No. 3,073,843)
[0081] To a 250 mL two necked round bottom flask, equipped with a thermometer, magnetic stirrer, and reflux condenser, was added 53.3 g (0.63 moles) 2-pyrrolidone, 19.1 g (0.64 moles) paraformaldehyde, and 0.2 g KOH all at once. The mixture was stirred and heated to 80-90° C. for ˜2.5 hours. Afterwards, 100 mL of hot toluene was added. The solution was then filtered and allowed to cool to room temperature. The resulting crystals were filtered and washed with cold toluene to give 64.5 g (89% yield) of 2-hydroxymethyl-2-pyrrolidone. H NMR and FTIR confirmed the structure.
Preparation of N-Hydroxymethyl-2-Caprolactam
[0082] (This preparation is essentially that of U.S. Pat. No. 4,769,454.)
[0083] To a 500 mL round bottom flask equipped with a magnetic stirrer, thermometer, and reflux condenser was added 113.2 g (1.00 mole) of caprolactam, The caprolactam was heated to liquid at which time 31 g (1.0 mole) of paraformaldehyde and 0.7 g of K 2 CO 3 were added at once. A slight exotherm raised the temperature to 97° C., however the reaction mixture was maintained between 70° C. and 95° C. for 2.5 hours. Afterwards, a seed crystal was added at 57° C. and the mixture held at 50° C. for 18 hours. White crystals resulted with a small amount of liquid. The liquid was decanted away from the white crystals to give 138 g (96% yield) of N-hydroxymethyl-2-caprolactam. H NMR and FTIR confirmed the structure.
Synthesis of N-2,5,8,11-Tetraoxadodecyl-2-Pyrrolidone
[0084] (See U.S. Pat. No. 3,853,910—hereby incorporated by reference—for hydroxymethyl-2-pyrrolidone ethers of alkyl, aryl, alkenyl, groups etc.)
[0085] To a 500 mL two-necked round bottom flask equipped with a magnetic stirrer, thermometer, and reflux condenser was added 58 g (0.50 moles) of N-hydroxymethyl-2-pyrrolidone and 246 g (1.5 moles) of triethylene glycol monomethyl ether at once. The mixture was cooled to ca. 10° C. and 21 mL of 12N HCl was added in 5 to 10 minutes while maintaining the temperature around 10° C. during the addition. Afterwards, the mixture was warmed to room temperature and was held at this temperature for 2 hours while stirring. Addition of 40 g of 25% NaOH to the mixture between 15° C. and 25° C., followed by stirring for 0.5 hours produced a mixture of NaCl and product. The salt was filtered off and the mixture subjected to vacuum distillation to remove water (27° C. at 0.12 Torr). More salt precipitated out and the distillation stopped and the salt filtered off. The resultant oil was distilled three times through a 6×¾ inch Vigreux Column under vacuum. The final cut distilled at 156° C. at 0.11 Torr to give 71.6 g (55% yield) of N-2,5,8,11-tetraoxadodecyl-2-pyrrolidone. H NMR and FTIR confirmed the structure.
Synthesis of N-2,5,8,11-Tetraoxadodecyl-Caprolactam
[0086] To a 500 mL two necked round bottom flask equipped with a magnetic stirrer, thermometer, and reflux condenser was added 71.6 g (0.50 moles) of N-hydroxymethyl-caprolactam and 246 g (1.5 moles) of triethylene glycol monomethyl ether at once. The mixture was cooled to ca. 4° C. and 21 mL of 12N HCl was added in ca. 15 minutes while maintaining the temperature around 10° C. during the addition. Afterwards, the mixture was warmed to room temperature and was held at this temperature for 2.5 hours while stirring. Addition of 40 g of 25% NaOH to the mixture between 15° C. and 25° C., followed by stirring for 0.5 hours produced a mixture of NaCl and product. The mixture was subjected to rotoevaporation to remove water. The resultant salt was filtered off and the mixture subjected to straight take over vacuum distillation collecting a top cut between 82° C. and 84° C. More salt precipitated out and the distillation stopped and the salt filtered off. The resultant oil was distilled through a 6×¾ inch Vigreux column under vacuum. The main cut distilled between 159° C. and 169° C. at 0.2 Torr to give 80.1 g (55% yield) of N-2,5,8,11-tetraoxadodecyl-2-caprolactam. H NMR and FTIR confirmed the structure.
Synthesis of 1,8-bis-(Pyrrolidon-1-yl)-3,6-dioxaoctane
[0087] To a single necked 500 mL round bottom flask was added 134 g (1.56 mole) gamma-Butyrolactone and 109.5 g (0.74 mole) 1,8-diamino-3,6-dioxaoctane at once. The flask was fitted with a magnetic stir bar, H-Trap and a condenser. At the top of the condenser a nitrogen source was attached via a Firestone Valve. A vacuum was pulled while heating the mixture to melt any resultant solids. This was followed by a vacuum then nitrogen purge three times. While under nitrogen, the mixture was heated and after 26 mL of water was collected in the H-Trap, the reaction mixture was cooled and subjected to straight take-over vacuum distillation. The material was distilled twice and the final product cut distilled between 196° C. and 214° C. at 0.11 Torr to give 124 g of product. H NMR and FTIR confirmed the structure.
Synthesis of 1,8-bis-(pyrrolidon-1-yl)octane
[0088] To a single necked 500 mL round bottom flask was added 134 g (1.56 mole) gamma-butyrolactone and 106 g (0.74 mole) 1,8-diaminooctane at once. The flask was fitted with a magnetic stir bar, Dean-Stark Trap and a condenser. At the top of the condenser a nitrogen source was attached via a Firestone Valve. A vacuum was pulled while heating the mixture to melt any resultant solids. This was followed by a vacuum then nitrogen purge four times. While under nitrogen, the mixture was heated and after 27 mL of water was collected in the Dean-Stark Trap, the reaction mixture was cooled and subjected to vacuum distillation. The material was distilled twice and the final product cut distilled between 200° C. and 208° C. at 0.2 Torr to give 166 g (81% yield) of product. H NMR and FTIR confirmed the structure.
Synthesis of 3,6,9-trioxadecyl isovalerate
[0089] To a 500 mL single necked round bottom flask equipped with a magnetic stir bar and a Dean-Stark Trap was added 53.7 g (0.526 mole) isovaleric Acid, 81.6 g (0.50 mole) triethylene glycol monomethyl ether, 0.3 g p-toluenesulfonic acid and 200 mL of toluene at once. The mixture was heated under reflux till 8.5 mL of water was collected. After cooling to room temperature, the toluene solution was washed with 200 mL of 5% aqueous NaOH, 200 mL of saturated salt solution and dried over sodium sulfate. The mixture was filtered and subjected to rotoevaporation. Straight take-over distillation gave 91.7 g (73% yield). The product cut was at 107° C. and 115° C. at 1.0 Torr. FTIR confirmed the structure.
Example 4—Measuring Carbon Dioxide Desorption Rate
[0090] A co-fluid (50 g) is added to a 300 mL Parr reactor and the reactor is evacuated to ca. 0.21 Torr while stirring and at the temperature being studied. The stirring is stopped, and the co-fluid allowed to settle for 1 minute. CO 2 is bled in to the reactor at the required pressure, which is 300 psia unless indicated otherwise. The CO 2 is introduced as quietly as possible, with minimal co-fluid agitation. Stirring is then started (400 rpms), time is marked 0 minutes and pressure rate recorded. Equilibrium is recorded generally after 15 minutes of stirring. Note that the equilibrium is reached prior to this.
[0091] Afterwards the stirring is stopped and the co-fluid allowed to settle for 1 minute. The pressure is then rapidly but “quietly” dropped to 50 psi. Stirring is resumed and the pressure rise (indicating release of CO 2 from the co-fluid) is recorded for a period of time. Instantaneous rates are determined by taking measurements for the first 20 seconds and fitting a straight line curve through the data.
[0092] All data points represent at least 3 experimental runs.
[0093] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure. | A carbon dioxide/co-fluid mixture is provided for use in a refrigeration cycle in which the carbon dioxide is alternately absorbed and desorbed from the co-fluid. Suitable co-fluids are selected from the class of alkoxylated carboxylic amides, wherein the amides are cyclic or non-cyclic. It has been discovered that N-2,5,8,11-tetraoxadodecyl-2-pyrrolidinone and its homologs exhibit an advantageous property of a high rate of desorption at lower temperatures. | 51,445 |
BACKGROUND OF THE INVENTION
This invention relates to a barometer for measuring gas pressure around a quartz oscillator using the quartz oscillator.
There is an urgent need in industrial applications to measure continuously gas pressure ranging from ambient pressure to 10 -3 Torr with a single sensor.
A quartz barometer which utilizes the phenomenon that the frequency at resonance of a quartz oscillator increases with a decreasing gas pressure surrounding the oscillator satisfies to some extent the industrial requirement described above. However, this barometer involves a critical problem in that the lower limit of measurement is about 10 Torr. Though a heat conduction vacuum gauge such as the Pirani gauge has a lower limit value of measurement of about 10 -4 to 10 -3 Torr, it is not free from the same problem as that of the quartz type barometer because its upper limit of measurement is about 10 Torr.
It has been shown recently that the resonance resistance of a quartz oscillator depends upon ambient gas pressure over an extremely wide range, and that a barometer which can continuously measure pressure ranging from ambient atmospheric pressure to 10 -3 Torr can be realized by utilizing this property. This is reported, for example, in "Development of Ultra-Miniature Vacuum Sensor Using Quartz Oscillator" in the magazine "Instrumentation", 1984, Vol. 27, No. 7.
However, in a quartz barometer having the prior art construction which utilizes the temperature depedence of the resistance of a quartz oscillator at resonance described above, a problem has been left unsolved in that precision measurement can not be readily effected because the resistance of the quartz oscillator at resonance varies markedly with temperature, particularly in the low pressure range of roughly 10 -3 to 10 -2 Torr.
SUMMARY OF THE INVENTION
To eliminate this problem, in a quartz barometer utilizing the temperature dependence of the resistance of a quartz oscillator at resonance, the present invention is directed to provide means which compensate for the temperature change of the resistance at resonance by connecting a temperature-dependent resistor in series with a quartz oscillator thereby enabling said quartz barometer to measure gas pressure much more accurately.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram showing the relation between the characteristic values (resistance at resonance, current at resonance, resonant frequency) of a quartz oscillator and ambient gas pressure;
FIG. 2 is a block diagram of a quartz barometer electronic circuit in accordance with the present invention;
FIG. 3 is a diagram showing the relation between the meter driving voltage and ambient pressure;
FIG. 4 is a diagram showing the temperature characteristics of the resistance of the quartz oscillator at resonance;
FIG. 5 is a circuit diagram showing one embodiment of the present invention; and
FIG. 6 is a diagram showing the temperature characterstics of the embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Hereinafter, the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a diagram showing the relation between gas pressure and the characteristic values (resistance at resonance, current at resonance and resonant frequency) of a quartz oscillator. The resonant frequency starts changing when pressure exceeds 10 Torr, but the sensitivity to pressure is virtually nil below 10 Torr. However, the resistance of a quartz oscillator at resonance is sensitive to pressure ranging from ambient atmospheric pressure to 10 -3 Torr. When this quartz oscillator is driven at a constant voltage, a resonance current-v-gas pressure curve can be obtained as represented by symbol i o in the diagram. It is sensitive to pressure ranging from ambient atmospheric pressure to 10 -3 Torr in the same say as the resistance at resonance described above. Therefore, it is easier to measure the current at resonance or the voltage at resonance than to measure the resistance at resonance.
FIG. 2 is a block diagram of a quartz barometer electronic circuit to which the present invention is directed. Its principal components are a PLL circuit, a display conversion circuit and a display. The PLL circuit consists of a variable frequency oscillator 1 which is controlled by a voltage or a current, an amplifier 2 which amplifies the current of a quartz oscillator 5 at resonance as a voltage, a phase comparator 3 which compares the phase of the output signal of the amplifier 2 with that of the output signal of the variable frequency oscillator 1 and produces a signal proportional to the phase difference, and a low-pass filter 4 which converts the pulse-like output signal of the phase comparator 3 to a d.c. voltage. The output voltage of the low-pass filter 4 controls the oscillation frequency of the variable frequency oscillator 1. The pressure-sensitive quartz oscillator 5 is connected to the output terminal of the variable frequency oscillator 1 and the input terminal of the amplifier 2.
The principle of operation of the PLL circuit is well known already, it is not described herein. The output signal of the variable frequency oscillator 1 is always controlled such that the phase difference between the output signal of the variable frequency oscillator 1, that is, the driving voltage of the quartz oscillator 5, and the output signal of the amplifier 2, that is, the current flowing through the quartz oscillator 5, is zero. Therefore the quartz oscillator 5 is always driven at its resonance frequency. This is a significant factor in practical application of a quartz barometer since the resonant frequency of the quartz oscillator varies with pressure as shown in FIG. 1.
Next, the display conversion circuit portion consists of a main amplifier 6 which further amplifies the signal from the amplifier 2, a rectifier 7 which changes the output signal of the main amplifier 6 to d.c. an inverter 8 which inverts the polarity of the output viltage of the rectifier 7, and a buffer 9 which biases the output voltage of the inverter 8. The bias level can be controlled by a variable resistor 9a. The display may be either digital or analog. In this embodiment, it consists of a meter 10; pressure is read from the deflection angle of said meter.
The pressure characteristics of the resonant current of the quartz oscillator are such that said current increases as ambient pressure decreases, as shown in FIG. 1. Therefore, if the current at resonance is amplified as a voltage and is changed to d.c. to drive the meter, the deflection angle of the meter will increase with decreasing pressure; consequently, the display will be the opposite of the detected pressure. This is obviously undesirable from the common sense point of view; therefore, the inverter 8 inverts the polarity of the d.c. voltage, and the buffer 9 then applies the bias voltage so that the meter dirving voltage shown in FIG. 3 can be obtained. In the embodiment shown in FIG. 3, the bias quantity is adjusted so that the meter driving voltage is 10 V at ambient atmospheric pressure. In this manner, a conventional pressure display can be effected in which the meter indicator angle of deflection increases as ambient atmospheric pressure increases and decreases as ambient atmospheric pressure decreses.
FIG. 4 shows the temperature characteristics of the resistance of the quartz oscillator at resonance. The degree of change of the resistance at resonance due to temperature is great in vacuum, and the resistance at resonance increases with as temperature increases. Since most of the resistance at resonance in the ambient atmosphere is frictional resistance, the resistance at resonance does not vary greatly with temperature. As a result, the prior art technique involves the problem that the effect of temperature increases markedly as gas pressure decreases, thereby introducing an error into the measured value.
The present invention provides means for minimizing the error just described.
FIG. 5 shows one embodiment of the present invention. Component 5 is a quartz osoillator, 11 is a thermistor and 12 is a resistor. In FIG. 6, a is the curve of the temperature characteristics of the resistance at resonance of the quartz oscillator at resonance, b is the curve of the temperature characteristics of the combined resistance of the thermistor and the resistor, and c is the curve of the temperature characteristics of the combined resistance of the quartz oscillator, the thermistor and the resistor. The resistance of the quartz oscillator at resonance has a positive temperature coefficient, whereas the resistance of the thermistor has a negative temperature coefficient. If they are connected in series, therefore, the combined resistance value becomes a curve which has a valley with respect to temperature. The resistor described above is a variable resistor so that the temperature range of the valley is that of room temperature (20°-30° C.).
The resistance of the thermistor is not affected by the gas pressure around it; hence, it can compensate for temperature without regard to pressure. In the prior art technique in which the thermistor does not compensate for temperature, the measured value of 1×10 -2 Torr at 25° C. varies to a maximum of 4×10 -2 Torr if the ambient temperature varies from 10° C. to 40° C. If the thermistor compensates for temperature, the measured value of 1×10 -2 Torr at 25° C. will fall within the range of a maximum of 2×10 -2 Torr. Thus, the measurement error due to temperature can be reduced by half. The practical temperature range in the environment of measurement is roughly 25°±5° C. Since the embodiment of the present invention can easily set the minimal point of the resistance value relative to the temperature to 25° C., measurement error due to varying temperature can be drastically reduced in practice.
As described above, the present invention can minimize the adverse effect of varying temperature upon the resistance of the quartz oscillator at resonance by extremely simple means, and can improve accuracy, particularly, in the low pressure range. Since the barometer of the present invention is simply constructed, any increase in the production costs will be minimal.
Though the embodiment described above uses the thermistor as a device to compensate for temperature characteristics of resistance of a quartz oscillator at resonance, devices other than the thermistor can be of course employed if they have a temperature coefficient opposite to that of the resonance of the quartz oscillator at resistance. | In a quartz barometer untilizing the temperature dependence of the resistance of a quartz oscillator at resonance, the present invention is directed to provide a circuit which compensates for the temperature change of the resistance at resonance by connecting a temperature-dependent resistor in series with a quartz oscillator thereby enabling said quartz barometer to measure gas pressure much more accurately. | 10,854 |
FIELD
The present invention relates to a process and a device for producing at least one three-dimensional object by solidifying a solidifiable material which comprises a filler and a binder. The process and the device are particularly suitable for medical applications, such as for producing implants, bone substitutes and in particular for producing dental products.
BACKGROUND ART
Known processes and devices for producing at least one three-dimensional object by solidifying a solidifiable material are sometimes referred to as rapid prototyping and manufacturing techniques, and sometimes they are more specifically referred to as stereolithography, laser sintering, fused deposition modelling, selective light modulation and the like, without being limited thereto. In the following, processes, devices and systems of this art are commonly referred to as “freeform fabrication”.
Sometimes and especially in situations affording three-dimensional objects of higher strength formed by freeform fabrication, the material to be solidified comprises a filler and a binder, and the resulting composite product being solidified may be further treated or not.
For example, WO 03/059184A2 describes a production of dental restorations and other custom objects by freeform fabrication methods and systems, involving a required deposition of a layer comprising photocurable material and ceramic material and selectively exposing the layer to radiation in a desired pattern.
However, previous freeform fabrication systems described in WO 03/059184A2 and in other documents dealing with composite materials to be solidified have found to be unsatisfactory. In particular the presence of a particulate of fibrous filler in admixture with a binder in the material to be solidified has been identified by the present inventors to encounter difficulties, if three-dimensional objects produced by freeform fabrication techniques shall be produced with a desirable accuracy and mechanical strength in a reliable manner.
SUMMARY
The present invention addresses this demand, and an object lies with the provision of a process and a device for producing a three-dimensional object by solidifying a material comprising a filler and a binder, which process or device is improved in terms of reliability.
In accordance with an embodiment the present invention provides a process for producing a three-dimensional object, comprising: providing a material to be solidified, the material comprising a filler and a binder; delivering electromagnetic radiation and/or synergistic stimulation in a pattern or an image to a building region for solidifying said material; wherein said delivering of electromagnetic radiation and/or synergistic stimulations performed selectively to a defined area or volume of said material to be solidified; and wherein an energy density of electromagnetic radiation and/or synergistic stimulation is varied within said pattern or image and/or between patterns or images of different building regions of said material.
In an alternative embodiment directed to a system where different first and second materials are to be solidified, there is provided a process for producing a three-dimensional object, comprising: providing a first material to be solidified for generating at least a part of a desired three-dimensional object structure, the material comprising a filler and a binder; providing a second material, different from said first material, to be solidified as another part of the desired three-dimensional object structure or as an auxiliary support structure; solidifying said first and second materials by means of electromagnetic radiation and/or synergistic stimulation delivered selectively to respectively defined areas or volumes of said first and second materials; wherein energy densities of electromagnetic radiation and/or synergistic stimulation are varied between said respectively defined areas or volumes of said first and second materials for solidification.
The present invention further provides a freeform fabrication system, comprising: a material to be solidified, the material comprising a filler and a binder; a electromagnetic radiation and/or synergistic stimulation delivery device capable of delivering electromagnetic radiation and/or synergistic stimulation in a pattern or an image to a building region for solidifying said material; wherein said electromagnetic radiation and/or synergistic stimulation delivery device is designed to selectively deliver electromagnetic radiation and/or synergistic stimulation to a defined area or volume of said material to be solidified; wherein an energy density of electromagnetic radiation and/or synergistic stimulation is varied within said pattern or image, and/or between patterns or images of different building regions of said material.
Likewise, in the alternative embodiment directed to different first and second materials to be solidified, there is provided a freeform fabrication system, comprising: a first material to be solidified for generating at least a part of a desired three-dimensional object structure, the material comprising a filler and a binder; a second material, different from said first material, to be solidified as another part of the desired three-dimensional object structure or as an auxiliary support structure; and a electromagnetic radiation and/or synergistic stimulation delivery device capable of delivering electromagnetic radiation and/or synergistic stimulation selectively to defined areas or volumes of said first and second materials, respectively;
wherein energy densities of electromagnetic radiation and/or synergistic stimulation is varied between said respectively defined areas or volumes of said first and second materials for solidification.
According to a further embodiment the present invention provides a freeform fabrication system, comprising: a material to be solidified, the material comprising a filler and a binder; an electromagnetic radiation and/or synergistic stimulation delivery device capable of delivering electromagnetic radiation and/or synergistic stimulation which allows an additive generation of a three-dimensional object by successive solidification of said material; wherein said electromagnetic radiation and/or synergistic stimulation delivery device is based on a mask exposure system or a projection system.
The present invention further provides a freeform three-dimensional object formed from a solidifiable material comprising a filler and a binder by electromagnetic radiation and/or synergistic stimulation according to any one of the above mentioned embodiments. By the processes and fabrication systems according to the present invention, a three-dimensional object having an improved combination of product characteristics is obtained, in particular a homogenous mechanical strength throughout the object (albeit being formed by an additive generative process) combined with a high dimensional accuracy both before and after post-treatment, in particular if the post-treatment is sintering.
Principles, advantages and preferred embodiments will be described in further detail below.
In accordance with the present invention, it has been found that solidification behaviour in parts of areas or volumes defining a building region is critically affected by a presence (and possibly a type) or absence of a particulate or fibrous filler substance depending on conditions of electromagnetic radiation and/or synergistic stimulation in certain areas or volumes being particularly relevant for a accurate solidification or differentiated solidification. Mechanisms affecting relevant process and product characteristics can be well adjusted according to the present invention by actively and selectively controlling energy density delivered by the electromagnetic radiation and/or synergistic stimulation (also known as “exposure energy density”, measured in a unit of J/m 2 or mJ/cm 2 or mW/dm 2 , in the following briefly denoted “energy density”). With the energy density being at least partially varied, it is possible to produce three-dimensional objects having well-balanced counter-acting properties such as homogeneous mechanical strength and high dimensional accuracy, i.e. avoiding local distortions that may be caused by a differential influence of particulate or fibrous filler on electromagnetic radiation and/or synergistic stimulation activity. In accordance with the present invention, variation of energy density means that at least in part(s) of an exposed pattern or image or at least in part(s) of different building regions, there is an active spatial modification of an energy density relative to an unmodified/unvaried exposure. This variation in turn means that within the totality of a building region or of different building regions of a three-dimensional object, there are parts having received less energy density for primary solidification than other parts. A variation of energy density can be imposed gradually, step-wise, selectively in a part of a defined pattern or image while the remaining part is kept unmodified/unvaried, or selectively in one or more building regions relative to other building region(s), or any combination thereof. Assuming a building region being defined by a selectively exposed area or volume with dimensions of X, Y and Z relative to the whole built volume of a three-dimensional object to be formed, variation of energy density may be imposed in the projected pattern or image in XY plane, in XZ plane, in YZ plane or otherwise structured plane or curved surface. Alternatively or in addition to this variation within a building region, variation between patterns or images of different building regions of the material to be solidified may be imposed. As noted, the active variation of energy density according to the present invention becomes particularly relevant owing to the presence and/or the spatial location and/or nature of the filler substance contained in the composite material together with the binder, under the action of electromagnetic and/or synergistic radiation. It is possible, according to the present invention, to counter-balance and to control critical phenomena of a particulate or fibrous filler provoked by electromagnetic radiation and/or synergistic stimulation at certain locations, including, but not limited to absorbance, reflection and/or scattering phenomena.
Owing to the above mentioned special circumstances based on the use of a composite material containing a particulate or fibrous filler in admixture with a binder to be solidified, variation of energy density of the electromagnetic radiation and/or synergistic stimulation may be controlled, for example by an appropriate control unit or by manual operation, depending on at least one of the following criteria, alone or in combination:
(i) Type and/or amount of filler contained in a material to be solidified:
For example, depending on whether or to which extent the filler absorbs, reflects, or scatters electromagnetic and/or synergistic radiation, energy density may be varied depending on the spatial location of the building region where solidification shall take place. For example, energy density may be increased at locations within a building region where absorption phenomena prevail over reflection or scattering phenomena. Conversely, energy density may be decreased at locations within the building region where reflection and/or scattering phenomena prevail over absorption phenomena. Whether absorption or reflection/scattering phenomena prevail may, inter alia, depend on the type of filler. Therefore, the active variation of energy density according to the present invention enables an adaptation to the use of a wide variety of different filler substances, including but not limited to ceramics, glass, solid polymer particles, metals, metal alloys as described in further detail below, and including modified forms such as making absorptive metal particles reflective by means of suitable coatings, e.g. by waxes, coupling agents, polymers and the like. The present invention also allows to take account of the size and/or the amount of a filler substance being present in a particulate (or powder) or fibrous form, as well as to respond to situations such as filler sedimentation during the fabrication process. Moreover, the present invention provides an advantage that a three-dimensional object can be more reliably produced by using two or more different materials to be solidified, among which at least one comprises a filler, yet with one fabrication system while making use of adapted varied energy density.
(ii) Type and/or amount of binder:
Likewise, in combination with the specific type and/or amount of filler substance, critical solidification criteria including absorption, reflection and/or scattering phenomena can be actively influenced depending on the type and/or amount of binder with respect to a certain location within a building region.
(iii) Hardening depth:
It has been found that owing to the presence of filler substance, and in particular with an increasing amount thereof, penetration depth (D p ) and minimum exposure dose required to cause gelation (E c ) may be substantially reduced in a given hardening depth direction, unless an active variation of energy density according to the present invention is performed. In a particular embodiment, energy density variation may be performed by, firstly, actively withdrawing energy density, e.g. by cooling or by interfering radiation, selectively at the surface where the electromagnetic radiation and/or synergistic stimulation impinges on the building region (for example a surface of a photopolymerizable or photocurable resin containing the filler substance) to thereby relatively enhance energy density towards the depth direction, secondly by shifting the focal plane of the exposure system to an area or plane away from the afore-mentioned surface, thirdly by appropriately superimposing electromagnetic radiation and/or synergistic stimulation fields to be concentrated at a certain desired hardening depth, and/or fourthly by applying an additional infrared electromagnetic radiation (i.e. heat) from the side opposite to the exposure direction of the electromagnetic radiation and/or synergistic stimulation intended for material solidification, in order to superimpose a temperature gradient with a higher temperature at increased hardening depths. By one or more of these or equivalent means, it is possible to counteract predominant hardening at the exposed surface region, and to more homogenize energy density in a desired hardening depth direction.
(iv) Presence or absence of underlying or overlying solidified and filler-containing material:
Depending on whether previously solidified filler-containing material has absorptive, or reflective and scattering characteristics, the local-specific presence or absence of such underlying/overlying filler-containing material can be taken into account by an appropriate variation. When absorptive, underlying/overlying portions may be rather overexposed by a relatively higher energy density, whereas when reflective and scattering, they may be rather underexposed by relatively lower energy density, respectively compared to other portions within the pattern or image or compared to other building regions where such underlying/overlying solidified filler-containing material is not present (e.g. at overhang portions or cavity portions of the object structure to be formed).
(v) Size of the defined area or volume of the material to be solidified in the building region:
In a given unmodified fabrication system, larger exposure areas or volumes tend to receive a larger amount of energy per unit area, relative to smaller or more delicate exposure areas or volumes. This tendency may be affected by the presence of filler in the exposed areas or volumes. Therefore, at least a partial area or volume of a building region having a larger size can be underexposed in terms of energy density relative to co-exposed smaller building regions.
(vi) Delivery of electromagnetic radiation and/or synergistic stimulation to area or volume regions as opposed to boundary regions of the three-dimensional object to be formed:
These distinct regions exhibit significantly different characteristics in terms of absorption, reflection and/or scattering performances, as well as in terms of shrinkage performances. Roughly, these characteristics are affected relatively isotropically within area or volume regions, but relatively anisotropically at boundary regions caused by the then present edges. An example may be explained in case of using a ceramic filler material having reflective and scattering characteristics: Given a certain amount of energy or energy density necessary to solidify the binder of the material in area or volume regions at a desired hardening depth, which hardening depth typically extends into a previously solidified material, a relatively lower amount of energy or energy density is delivered in the boundary regions, thereby counter-balancing size inaccuracies caused by reflection and scattering phenomena in such boundary regions. Hence, variation of energy density may be selectively controlled depending on whether area regions or boundary regions of a building region are exposed.
(vii) Viscosity and/or flowability of the material to be solidified:
The viscosity and/or flowability characteristics of the material to be solidified can be strongly affected by the presence of the filler substance in the material and may include, for example, liquid, fluid, thixotropic, semi-solid, paste, high-viscous, medium-viscous and low-viscous states. These states may vary depending on the status and point of time within the whole building process of a three-dimensional object, or may vary between different building areas or regions, or may vary between different first and second solidifyable materials used in a whole building process. For example, the actual viscosity and/or flowability existing in or at the building region, and/or in or at the object carrier, and/or in, at or near the solidifyable material carrier/provider may significantly differ, especially in or at a building region located between the object carrier (or the previously solidified material carried thereon) and the solidifyable material carrier/provider. The present invention allows for an effective adaptation to each of such varying states by a corresponding preset adaptation or an in-situ control of the energy density.
(viii) Pressure and/or strain occurring in the actual building region during solidification of the material:
Observations similar to those under (vii) apply to the conditions of strain and/or contact pressure in or at the building region. These characteristics may be significantly affected by the presence of a filler substance in the material to be solidified. In particular, a condition selected from pressure, strain and material flowability becomes relevant in or at a building region located between the object carrier (or the previously solidified material carried thereon) and the solidifyable material carrier/provider. That is, a movement of the object carrier and/or the solidifyable material carrier/provider, either in a mutually vertical and/or horizontal manner, for providing the filler-containing solidifyable material at least in a building region will have a relevant influence on at least one of the afore mentioned conditions of pressure, strain and material flowability in, at or near the solidifyable material carrier/provider and/or in or at the building region and/or in or at the object carrier. A pressure or a strain being too high or too low, or a material flowability being too high or too low respectively in, at or near the solidifyable material carrier/provider and/or in or at the building region and/or in or at the object carrier may impair the building process. Pre-setting and/or in-situ control of energy density depending on pressure and/or strain occurring in the actual building region during solidification of the filler-containing material thus provides an effective fine tuning of the freeform fabrication system.
In the performance of the present invention, a controlled variation of energy density for the aforementioned situations (i) to (viii) or for other situations can be determined and ascertained by theoretical considerations, or by practical experience. A practical testing or verification is preferred in cases where a fabrication system is adapted to the use of a yet unexperienced filler-containing material to be solidified. Hence, by testing one or more parameters discussed above, the effects of varied energy density and in particular a selective overexposure or underexposure in at least a part of an exposed pattern or image, or between patterns or images of different building regions, can be readily measured. This allows for a more accurate adjustment depending on the individual building parameters in the whole fabrication process, such as filler parameters, binder parameters, viscosity, flowability, desired selective hardening depth, and the respectively desired structure to be solidified as well as its surrounding structure.
The selective delivery of electromagnetic radiation and/or synergistic stimulation suitably includes an appropriate source capable of electromagnetic radiation and/or synergistic stimulation emission sufficient to solidify the material to be solidified. Solidification by electromagnetic radiation and/or synergistic stimulation according to the present invention may be understood as a process of solidification without photoreaction, such as gelation, fusion and/or sintering, but more preferably is understood as a process of gelation and/or solidification by photoreaction or by thermal setting reaction. Accordingly, the binder may be selected from the group consisting of inert binding agents; adhesives, which may gel and/or solidify without photoreaction or with photoreaction; and photopolymers or radiation sensitive resins, which may gel or solidify or cure by photoreaction and which normally include photopolymerization, cross-linking and/or network formation processes. Besides such a binder (first binder) being solidifyable or curable by the selective delivery of electromagnetic radiation and/or synergistic stimulation, a further binder (second binder) unaffected by such electromagnetic radiation and/or synergistic stimulation or affected by a electromagnetic radiation and/or synergistic stimulation but a modified one (e.g. at a different wavelength or intensity) may be used in addition.
The device for selective delivery of electromagnetic radiation and/or synergistic stimulation further preferably comprises a mask projector and/or a projection unit to deliver the electromagnetic radiation and/or synergistic stimulation selectively to the defined area or volume of material to be solidified. Electromagnetic radiation and/or synergistic stimulation can be delivered to the building region or parts thereof by means of further suitable components, including but not limited to optical elements, lenses, shutters, voxel matrix projectors, bitmap generators, mask projectors, mirrors and multi-mirror elements and the like. Examples of suitable radiation techniques to selectively deliver electromagnetic radiation and/or synergistic stimulation include, but are not limited to spatial light modulators (SLMs), projection units on the basis of Digital Light Processing (DLP®), DMD®, LCD, ILA®, LCOS, SXRD, etc., reflective and transmissive LCDs, LEDs or laser diodes emitted in lines or in a matrix, light valves, MEMs, laser systems, etc. Use of DLP mask projector is preferred.
Accordingly, in a particularly preferred embodiment of the present invention, there is independently provided a freeform fabrication system, which comprises: a material to be solidified, the material comprising a filler and a binder; a electromagnetic radiation and/or synergistic stimulation delivery device capable of delivering electromagnetic radiation and/or synergistic stimulation which allows an additive generation of a three-dimensional object by successive solidification of said material; and wherein said electromagnetic radiation and/or synergistic stimulation delivery device is based on a mask exposure system or a projection system. The above-mentioned devices having a mask unit and/or a projection unit are particularly suited for this embodiment by way of the selective delivering of electromagnetic radiation and/or synergistic stimulation. Such a freeform fabrication system is well suited and enables to perform the process according to the present invention in a rapid, efficient and reliable manner. Compared with other systems to produce three-dimensional objects, it produces objects actually having a high dimensional accuracy (relative to the nominal size desired); and it provides a high freedom in the desired design as well as in the selection of the materials both with respect to the filler and the binder matrix. Furthermore, this preferred freeform fabrication system provides a useful embodiment of its own: Independent from a variation of energy density, the energy density as such of the electromagnetic radiation and/or synergistic stimulation delivery device can be respectively set or controlled by a previous setting or by a control unit depending on at least one of the criteria:
(i) type, size and/or amount of filler contained in the material to be solidified;
(ii) type or amount of binder contained in the material to be solidified;
(iii) hardening depth;
(iv) presence or absence of underlying solidified, filler-containing material;
(v) size of the defined area or volume of said material to be solidified;
(vi) delivery of electromagnetic radiation and/or synergistic stimulation to area regions or to boundary regions of the three-dimensional object to be formed;
(vii) viscosity and/or flowability of the material to be solidified; and
(viii) pressure and/or strain occurring in the actual building region during solidification of the material.
Herein, the setting or the control parameters can be accomplished by a suitable pre-setting in advance of fabrication depending on the material to be used (in particular in case of (i) and (ii)) or depending on a desired built parameter ((in particular in case of (iii)), during a built program depending on the status or point of time of the whole procedure (in particular in any one case of (iii) to (vi)), or by in situ measurement and feedback-control (in particular in case of (viii) using e.g. a suitable sensor such as a flow measurement device, a pressure sensor or strain sensor). Suitable sensors are, for example, flowmeters, force sensors such as a piezoelectric device, a strain gauge, a differential pressure sensor, a touch sensor, a displacement sensor, or any other known or developed pressure or strain sensor.
The solidifiable material is subjected to selective delivery in a defined area or volume when placed in or on a suitable carrier or provider. Suitable examples for a solidifiable material carrier/provider to be used in the present invention include, but are not limited to a container or vat containing the solidifiable material, or a flexible and/or clear and/or resilient film/foil conveying the solidifiable material. When embodied as a film, the material may then be transferred by suitable film transfer techniques, before, during or after the solidification step. Larger volumes of solidifiable material may be stored and supplied from a reservoir or a solidifiable material cartridge to be conveyed to the solidifiable material provider.
Further, the growing and continuously or discontinuously built three-dimensional object may be carried on a suitable carrier or support. The object carrier/support is normally movably arranged in the fabrication system to allow a spatially controlled relationship with the material to be solidified. Alternatively or in combination therewith, the solidifiable material carrier/provider may be arranged movably in a spatially controlled relationship with the object carrier/support (and thus with previously solidified object). Various modifications are feasible when applying the principle of the present invention.
The source for delivery of electromagnetic radiation and/or synergistic stimulation and further optical elements as described above can be arranged relative to the material to be solidified as well as its provider and/or carrier in various suitable ways. For example, the arrangement may be such that electromagnetic radiation and/or synergistic stimulation is delivered from above the building region or the solidifiable material carrier/provider (in which case a carrier for carrying the produced three-dimensional object is usually placed below the building region or a solidifiable material carrier/provider), or one where electromagnetic radiation and/or synergistic stimulation is delivered from below the building region or a solidifiable material carrier/provider (in which case the carrier for carrying the produced three-dimensional object is usually placed above the building region or a solidifiable material carrier/provider). Again, various modifications are feasible.
A building region may be formed, for example, by a building plane/area or a building volume with desired dimensions in X, Y and Z directions (including, for example, XY plane and areas, XZ plane and areas, and YZ plane and areas as well as any X, Y, Z volumes). A building area may be flat, but is not necessarily flat. Further, building regions may be formed as layers, as cross-sections, as a matrix such as a point matrix, a line matrix and especially a voxel matrix, or in any other forms. A desired three-dimensional object can eventually be formed by an additive generative process involving successive solidification of the material in respective building regions.
According to the present invention, energy density can be delivered to the exposure pattern or image, and/or patterns or images of different building regions of the material to be solidified, in various ways or means. To make a variation of energy density efficient and controllable, the selective delivery of electromagnetic radiation and/or synergistic stimulation is preferably based on an imaging unit comprising a predetermined number of discrete imaging elements or pixels, and the variation of energy density is performed by controlling the discrete imaging elements or pixels in a selective manner. A preferred exposure system being advantageous for the varied energy density exposure is the use of a voxel matrix, which is defined according to the invention as a rastered arrangement of solidified voxels (volume pixels), wherein a voxel images an image point of a pixel matrix, and the hardening depth per voxel depends on the energy input per image point. The afore-mentioned exposure systems are particularly suitable for the freeform fabrication method of stereolithography.
According to the present invention, energy density of the electromagnetic radiation and/or synergistic stimulation can be varied by suitable ways or means. Particularly preferred ways or means include, alone or in combination, the following:
(a) Various exposure times within the dimensions of XY, XZ, YZ or in Z direction of one or more building regions. For example, this can also be accomplished by using selective shutters with appropriate timings, or selective mask exposures. (b) Number of multiple exposures of at least parts of a pattern or an image, or of a pattern or image of at least one among different building regions. For example, this can be performed by applying multiple mask exposures of a certain cross-sectional area or other building regions of the three-dimensional object to be formed, wherein parts of the respective multiple masks preferably overlap for overexposure of the selected area or region. (c) Gradation of energy density in one or more parts of the exposed pattern or image or between patterns or images of different building regions.
This can be most efficiently performed by allocating certain grey values or color values to corresponding parts of a pattern or image, or to one among the plurality of building regions. The parts allocated by grey or color values are correspondingly underexposed relative to full bright values, yet overexposed relative to black values. Grey value or color value allocation is most efficiently made pixel-wise in a pixel matrix or a voxel matrix system. Since gradation of energy density combines ease of processing with the achievement of high accuracy in the use of filler-containing materials to be solidified, this embodiment is preferably applied, alone or in combination with other variation means.
(d) Location of focal plane or focal point within the building region.
Normally, the focal plane or focal point, in particular in systems using a mask exposure or a projector unit for the selective delivery to a defined area or volume of the material to be solidified, coincides with the surface of the material to be solidified. However, modifying this normal arrangement such that the focal plane or focal point of the applied optical system is spaced apart from this surface, i.e. is actively changed to be located at a certain depth below this surface will—relative to an unmodified/unvaried normal system—underexpose the surface and overexpose corresponding depth regions in order to counter-balance higher energy absorption rates of the composite material and especially the filler substance in the surface region.
(e) Applying a second source or a second delivery of electromagnetic and/or synergistic radiation. For example, the second source or second delivery of electromagnetic radiation and/or synergistic stimulation may be accomplished by a dual or multiple illumination system including the use of two or more radiation sources having respectively same or different wavelengths. In this embodiment, the second or further illumination source may be directed selectively to those parts of a pattern or image, or to that building region among other building regions that need to be overexposed at a desired spatial location as explained above. Alternatively, a general infrared (IR) heating source may be used for the general delivery of a basic energy density, while a specific source for delivering electromagnetic radiation and/or synergistic stimulation active for solidifying the material is applied selectively to those parts within a pattern or image, or to that building region among other building regions that need to be exposed by additional energy density. The first and the second or further sources or deliveries of electromagnetic radiation and/or synergistic stimulation may be located on the same side or on different sides relatively to the building region(s). Further, the deliveries of first and second or further electromagnetic and/or synergistic radiations may be respectively oriented in the same direction or in different directions.
Any variations or combinations of the above variation embodiments are possible and feasible for a person skilled in the art.
The filler to be mixed with a binder for providing a material to be solidified according to the present invention typically is a solid or substantially solid substance and may include, without being limited to: a ceramic substance such as e.g. alumina, magnesia, zirconia, ceramic oxides of other transition metals such as titania, hafnium oxide, rare earth metal oxides, spinel type double metal oxide ceramics, or mixtures thereof; cermets; silicate, aluminosilicate, apatite, fluoroapatite, hydroxylapatite, phosphates such as tricalcium phosphate, calcium magnesium phosphate, calcium ammonium phosphate, mullite, spinels, and mixtures thereof; glass materials, such as silicate glass, borsilicate glass, quartz glass and mixtures thereof; metals and metal alloys such as stainless steel, titanium or titanium alloy, nickel alloy, copper or copper alloy such as brass (70% copper and 30% zinc), aluminium or aluminium alloy, iron or iron alloy and mixtures thereof; solid polymers or polymer blends such as polymerized acrylic resins and blends or copolymers thereof like polyurethane/polyacrylates, acrylonitril/butadien/styrene-polymerisates (ABS), epoxides and copolymers thereof, nylon and blends or copolymers thereof, polyamide elatomers and mixtures thereof, and other filler substances. In a preferred embodiment, which is particularly beneficial for dental applications in terms of achieving high mechanical strength at good homogeneity combined with high size accuracy (especially when the process includes post-treatment such as sintering and thereby a transformation from a first to a second circumferential size), the filler substance is a ceramic powder, preferably a powder comprising ceramic materials selected from alumina, zirconia, or a mixture thereof. A particularly preferred ceramic powder comprises a ceramic material selected from monoclinical or non-monoclinical zirconia, yttria-doped or -stabilized tetragonal monoclinical or non-monoclinical, single or non-single phased zirkonia (i.e. ZrO 2 containing 3-5 mol-% Y 2 O 3 ), especially 3YTZP.
The filler component may further comprise one or more kinds of additives, for example but not limited to dispersants, coloring agents such as pigments, post-treatment auxiliary additives such as sintering aids or stabilizers, etc.
The filler may co-fuse or co-sinter itself under the action of electromagnetic radiation and/or synergistic stimulation used for solidification (e.g. especially when polymer fillers are used). It is on the other hand preferred that the filler itself is inert with respect electromagnetic radiation and/or synergistic stimulation at a level which solidifies the binder admixed with the filler, but may nevertheless co-fuse or co-sinter in a post-treatment described later (e.g. when ceramics, glass or metals/metal alloys are used).
The filler may be in the form of particles, a powder, fibers, a net, a scaffold, and the like. The particularly preferred particulate form of the filler is a powder having a suitable particle size, preferably being spherical or essentially spherical in shape, and further preferably having a mean particle size in a range of about 0.001 μm to
100 μm, more preferably in a range of about 0.01 to 50 μm and particularly in a range of about 0.1 to 10 μm. As to the distribution of the absolute particle size of the filler, it may range from about 1 nm to 1000 μm or higher, more preferably from about 0.1 μm to 100 μm. The filler may have a monomodal, a bimodal or a trimodal size distribution, using the same or different filler materials.
The binder substance for the material to be solidified according to the present invention is suitably selected from substances which may themselves lead to solidification of the composite material upon exposure to electromagnetic and/or synergistic radiation. A thus selected binder may not necessarily solidify through photoreaction, but through other mechanisms such as gelation, or it may solidify by chemical reaction after activation through electromagnetic and/or synergistic radiation, possibly together with other co-reactants. Suitable examples of this type of binder are adhesives, including but not limited to waxes and modified waxes, thermally setting resins such as epoxides, and the like. The adhesive properties of adhesives can may be exerted not before solidification of the material to be solidified, and thereby allows partial structures such as layers, strands, dots or other structures or scaffolds, which contain a particulate or fibrous filler, to be successively attached together and to thereby build the three-dimensional object, even without performing a photocuring reaction.
According to a preferred embodiment, the binder contains at least one selected from photopolymers and thermally hardened resins, in particular a photopolymer which is hardened when subjected to electromagnetic radiation and/or synergistic stimulation of interest. Accordingly, a photopolymer to be used as a binder material may include, but is not limited to: acrylate and/or methacrylate containing compounds, for example mono-, di-, tri-, tetra-, pentaacrylate, such as alkyl- or alkoxy-(meth)acrylates, (meth)acrylic esters having short or long chain alkyl ester groups, e.g. alkyl glycol di(meth)acrylate; epoxy group containing compounds; vinyl group containing or vinyl ether group containing compounds; polysiloxanes; and the like, as well as mixtures thereof. Alternatively, a thermal hardening polymer substance such as an epoxy group containing compound may be used, which is preferably protected with an amine group that decomposes in response to light and/or heat.
The composite material to be solidified according to the present invention may contain further auxiliary agents, including but not limited to: photoinitiators, which may be selected depending on the desired wavelength of electromagnetic and/or synergistic radiation, such as 2-benzyl-2-dimethylamino-1(4-morpholino phenyl)butanone, 1,2,2′-dimethoxy-2-phenylacetophenol, bisimidazoles, benzophenones, α-aminoketones, xanthenes, fluorenes, fluorones, ferrocenes, and the like; co-initiators and/or activation agents such as thioxanthones (e.g. isopropyl thioxanthone1-chloro-4-propoxythioxanthone), 4-benzoyl-4′-methyldiphenyl sulfide, ethyl-p-dimethylaminobenzoate, N,N-dialkyl-toluidine or -aniline, benzophenones, diaryliodo compounds, borates, phosphites, and the like; rheology adjusting agents; viscosity adjusting agents; diluents; solvents; colorants such as dyes and/or color pigments; thixotropic agents; thickeners; stabilizers; coupling agents; welting agents; dispersants; lubricants; adhesives; pore forming agents; and the like, respectively alone or in combination.
The material to be solidified may be provided in a suitable form, including but not limited to liquid, fluid, thixotropic, semi-solid, paste, high-viscous, medium-viscous and low-viscous materials. Preferably but in no way limiting, it has viscosity in the range of about 0.1 Pa·s to 5×10 3 Pa·s, preferably about 0.2 to about 1×10 3 Pa·s, more preferably 1 Pa·s to 200 Pa·s, and in particular 10 Pa·s to 100 Pa·s, respectively measured at 25° C.
A suitable content of the filler substance in the whole material to be solidified lies in a range of about 0.5% by weight to 99.9% by weight, preferably about 1% by weight to about 99% by weight, and more preferably 10% by weight to 85% by weight, particularly above 50% by weight to 85% by weight, and still further preferred 70% by weight to 80% by weight.
After solidification, the three-dimensional object thus produced may be subjected to one or more post-treatments. Suitable post-treatments are selected from post-hardening, de-binding, fusing and sintering, alone or in combination. Post-hardening may be performed by a general exposure to an appropriate electromagnetic and/or synergistic radiation, such as microwave irradiation. A suitable de-binding process for removing or substantially removing binder or another component of the composite material other than the filler substance may be performed by suitable thermal treatment, for example in a range of at least 200° C., for example from 200° C. to 600° C., possibly under normal atmosphere, under inert gas atmosphere, and/or under vacuum. Fusing and/or sintering may be performed at a temperature adjusted to the respective filler substance used, suitably at temperatures below the melting point of the filler material. For example with metal or metal alloy fillers, sintering may be performed at a temperature between about 1,050° C. and 1,450° C., especially between about 1,150° C. and 1,300° C., and ceramic filler materials may be sintered at a temperature of between about 900° C. to about 1,850° C. depending on particle size distribution of the powder used initially as a filler and/or the desired density of the final sintered product, more specifically about 900° C. and 1,700° C. The temperature treatment scheme may include a controlled heat-up speed, for example in a range of 0.1 to 10° C./min, more preferably 0.2° C. to 2° C./min while holding the object for a longer period in the afore-mentioned temperature ranges, as well as an appropriate cooling speed as desired. After-treatments of de-binding and sintering may be performed individually in different steps, continuously or discontinuously one after another, or in any combination, while selecting appropriate temperatures and timings.
A preferred system according to the present invention comprises a freeform fabrication system using a mask exposure system or a projection system for the delivery of electromagnetic radiation and/or synergistic stimulation, whereupon after solidification, the obtained three-dimensional object is subjected to sintering in order to obtain the desired final three-dimensional size. After the additive or generative process including all solidification for obtaining a three-dimensional object having a first circumferential size in an untreated state, post-treatment may well lead to a second, normally smaller circumferential size, in particular in a sintered state. This embodiment is advantageously applied in particular when the material to be solidified comprises a ceramic filler besides the binder.
The present invention allows for obtaining a freeform three-dimensional object on the basis of the afore-defined composite material comprising filler and binder, such that the resulting object may have an excellent homogeneous mechanical strength. Accordingly, it may be possible to homogenize mechanical strength within the three-dimensional object formed by a freeform fabrication system with an intra-object standard deviation of maximally 10% or lower, preferably maximally 5% or lower, more preferably maximally 2% or lower, and even 1% or lower which is determined by measuring a mechanical strength property (typically flexural strength) at multiple points within the formed object, preferably at least 5 points and typically at 10 points, and determining the standard deviation with respect the mean value to the measured points. A particular characteristic of the present invention is that the afore-mentioned homogeneous mechanical strength is obtainable at a high level in a unique combination with an opposite trade-off property, namely dimensional accuracy. Thereby, it is possible to combine the afore-mentioned homogeneous mechanical strength at high level with a dimensional accuracy of maximally 5%, more preferably maximally 2%, still more preferably maximally 1% and in particular maximally 0.5% relative to the nominal dimensional size (such as length, width, diagonal or the like) of a model used for designing the three-dimensional object. Hence, it will be possible according to the present invention to make a compromise between trade-off properties caused by spatially distinct absorption/reflection/scattering phenomena based on the filler substance, and shrinkage and especially differential shrinkage phenomena predominantly caused by the binder, each phenomenon isotropically or anisotropically affecting counter-acting distortions or deformations within the solidified three-dimensional object. The advantageous properties and combinations of properties achieved by the present invention with the solidified three-dimensional object will be transformed into a final three-dimensional object after optional post-treatments such as post-hardening, de-binding, fusing and/or sintering.
Therefore, a finally sintered three-dimensional object may be realized according to the present invention, which may have an absolute dimensional accuracy, relative to the originally desired nominal circumferential size, of ±100 μm or below, more advantageously in the range of ±5 to 50 μm and even of ±5 μm or below. At the same time, it may be realized to obtain an extremely high sinter density, defined e.g. by a total porosity, which would include open and closed pores, of lower than 2%, preferably lower than 1% and particularly lower than 0.2% and even close to 0%. Compared with conventional techniques of producing three-dimensional bulk objects other than freeform fabrication, and especially compared with such conventional objects having been sintered which finally have to undergo a milling process and optionally a high-density pressurizing process, the freeform (i.e. additive/generative) 3D object fabrication system and thus the eventually sintered 3D objects according to the present invention can avoid such milling and high-density pressurizing process steps and therefore do not have structural drawbacks associated therewith such as surface defects and crack formations.
The freeform fabrication system has particular advantages when applying stereolithography systems, and accordingly the freeform three-dimensional object is preferably obtained by a stereolithography process. The freeform fabrication system may be performed in layers, in other cross-sectional building structures, in a voxel-based building structure, continuously or discontinuously, or any combination thereof. It is thus a particular advantage that a layer-wise formation is not necessarily required, which further improves fabrication freedom. The freeform fabrication and preferably stereolithography fabrication system is preferably applied to the fabrication of three-dimensional objects comprising, in the building direction of the material, multiple portions having respectively different sectional areas, and if desired it is preferably applied to a multitude of three-dimensional objects or any other complex building structure with respectively different building regions. This includes complex structures involving purposive three-dimensional object parts besides auxiliary support structures. It is a particular advantage of the present invention that different building structures, or a building structure besides auxiliary support structures, can thus be formed partially without a filler, or with another composite material containing a different type and/or amount of filler substance.
Due to the advantageous characteristics described above, the present invention is particularly suited for designing the freeform three-dimensional object as a medical product, such as an implant, an artificial tissue, a bone filler or a bone substitute, and in particular a dental product. Suitable dental products include, but are not limited to a filling, a restoration, a crown, a veneer, a prosthetic, an inlay, an onlay, tooth denture, attachments, artificial teeth, or the like. The dental product is typically a sintered material. The sintered material may be provided with an additional glaze, sintered ceramic and/or glass-ceramic layer.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described in more detail by referring to preferred embodiments, examples and figures, which are however for illustrative purposes only and shall not be understood in a limiting manner, wherein:
FIG. 1 schematically shows a principle of the present invention by referring to a particular embodiment of a freeform fabrication system where energy density of electromagnetic radiation and/or synergistic stimulation is varied within a pattern or image in XY plane;
FIG. 2 schematically shows a principle of the present invention by another particular embodiment of a freeform fabrication system where energy density of electromagnetic radiation and/or synergistic stimulation is varied in Z direction of an exposure pattern extending in XY plane;
FIG. 3 schematically shows a principle of the present invention in a particular embodiment employing variation of energy density depending on special locations within a building region, i.e. whether an overhanging structure, or a structure over-/underlying a previously solidified material, or above/under a hollow cavity shall be solidified;
FIG. 4 schematically shows a principle of the present invention using a freeform fabrication system on the basis of a transparent film that carries material to be solidified according to another embodiment, and wherein varied energy density is achieved by superimposing electromagnetic and/or synergistic radiations from different delivery sources;
FIGS. 5A and 5B schematically show a principle of the present invention according to another embodiment, wherein different building regions are formed by varied energy densities, respectively, involving building region(s) with a first, filler-containing material to be solidified and one or more other building region using a second, different material to be solidified, wherein the different building regions are associated with correspondingly different energy densities;
FIG. 6 schematically shows another embodiment of the present invention using a freeform fabrication system with a projection unit for selectively delivering electromagnetic radiation and/or synergistic stimulation, wherein energy density of is appropriately preset or adjusted depending on constitution and or characteristics of a material to be solidified containing a filler and a binder; and
FIG. 7 schematically shows still another embodiment of the present invention using a freeform fabrication system using a film transfer technique and using a mask exposure unit for selectively delivering electromagnetic radiation and/or synergistic stimulation, wherein similar to the embodiment of FIG. 6 energy density of is appropriately preset or adjusted depending on constitution and or characteristics of a material to be solidified containing a filler and a binder.
DETAILED DESCRIPTION
According to FIG. 1 , in a particular embodiment of a process and a system of freeform fabrication for producing a three-dimensional object based on stereolithography technique, there is used a container or vat 1 for providing a material 7 to be solidified, the material 7 comprising a particulate filler 6 such as yttria stabilized tetragonal zirkonia phase (3YTZP) and a binder 5 such as an acrylate resin. The material 7 to be solidified may contain further constituents as described above, such as a sintering aid in the filler substance and a photoinitiator in the binder, and optionally further auxiliary agents. FIG. 1 shows a process and a system at a certain moment during performance, where a part 9 of a desired three-dimensional object has already been produced and is carried on a three-dimensional object carrier/provider 10 , illustrated here in the form of a platform. A gap is formed between the surface of previously solidified partial object 9 and a bottom 2 of the container or vat 1 by an upward movement of three-dimensional object carrier/support 10 (indicated by an arrow at three-dimensional object carrier/support stem). By this upward movement, material yet to be solidified fills the gap, such that the material 7 to be solidified is provided in a desired building region 8 . The bottom 2 of vat or container 1 is transparent or transmissive to electromagnetic radiation and/or synergistic stimulation to be used for solidification, at least in a functional part of the bottom.
Within an area defined by XY or a corresponding volume extending in Z direction to thereby specifically define the desired building region 8 , electromagnetic radiation and/or synergistic stimulation is selectively delivered as indicated by parallel arrows from below the bottom 2 of vat 1 . Here, an exposed energy density is varied in boundary regions of a corresponding exposure pattern such that, based on a prevailing reflecting and scattering nature of a metal powder filler as filler substance 6 , exposure energy density E 1 in the boundary region is lower than energy density E 0 applied in the inner area region. Variation of energy density can be effected by allocating grey level to the boundary regions of a mask exposure system, relative to an ungraded, bright exposure level of the mask in the inner area region.
Conversely, modifying the fabrication system by using a prevailing absorbing filler substance, energy density variation can be modified in a different manner (not shown) such that higher energy density (E 1 ′) can be exposed in boundary regions, whereas relatively lower basic energy density (E 0 ′) can be exposed to the remaining inner area except the boundary margins.
In this manner, the freeform fabrication system can be adapted and adjusted to the use of a particular filler substance. Moreover, given a predetermined system, accuracy, shrinkage control and homogeneous mechanical strength can be significantly improved by the differential control with respect to boundary regions and large structural area regions, respectively.
FIGS. 2 and 3 show alternative embodiments or modifications of the fabrication system of FIG. 1 and further illustrate a principle of the present invention. While the relevant portion including the specifically selected and defined area or volume of the material to be solidified in a desired building region is illustrated both in FIG. 2 and FIG. 3 , other components and conditions may be the same as shown in FIG. 1 .
According to FIG. 2 , a variation of energy density is applied, where energy density is unusually increased from a surface where electromagnetic radiation and/or synergistic stimulation impinges on the material to be solidified towards a surface of previously solidified three-dimensional object 9 , i.e. in the Z irradiation direction within building region 8 formed in the gap. This is illustrated in FIG. 2 by a gradually increasing energy density from E 0 to E 1 . Thus, contrary to an unmodified system where a decrease of energy density from E 0 to E 1 would be enhanced by the presence of a filler substance, an unusual variation in energy density in building direction Z (i.e. throughout the exposed XY plane) is applied. This may be accomplished by shifting the focal plane of the exposure pattern or image away from solidification surface 2 (at the bottom plane 2 ) in Z direction, e.g. to a location at the previously solidified surface of object 9 (i.e. coinciding with the gap distance determined by the Z dimension of building region 8 ), or alternatively at a smaller or larger distance. Another means to accomplish this, alternatively or in addition, is superimposing another electromagnetic radiation and/or synergistic stimulation field emitted from the opposite side, possibly in a field directed towards the building region only (not shown). A sum of the electromagnetic radiation and/or synergistic stimulation fields thereby increases from E 0 to E 1 . For this purpose, an infrared (IR) radiation for emitting and delivering thermal energy from the upper side of FIG. 2 may be used for example. For example, an IR emitter may be incorporated into the three-dimensional object carrier/support 10 , and preferably being selectively controllable within the XY plane for selective super-exposure in a desired building region.
According to FIG. 3 , variation of energy density exposure is performed depending on which sectional part of the building region is concerned. Here, in the particular embodiment illustrated, a basic energy density E 0 is used in portion(s) of the exposure pattern allocated to the part of building region 8 where an over-/underlying previously solidified material 9 is present, whereas modified energy densities E 1 and E 2 are allocated to portions of building regions 8 {circle around (1)} and 8 {circle around (2)} referring to cavity portions or overhang portions, respectively.
Using a solidifying material comprising a reflecting and/or scattering filler substance, the system may be adjusted in a manner that E 0 is higher than each of E 1 and E 2 . Further, a condition of E 1 ≧E 2 may be set.
In further embodiments illustrated in FIGS. 4 and 5A and 5 B, variations of a freeform fabrication system and process based on film transfer imaging technology are used for applying a principle of the present invention. In these embodiments, a belt 30 , which may be provided in the form of an endless belt, is made of a transparent and/or flexible and/or resilient rubber/film/foil to provide thereon material 17 to be solidified. Material 17 to be solidified again contains filler substance 16 and a binder 15 and optionally further constituents as described above. The figures show certain stages within the entire fabrication process, where a part 19 of the final three-dimensional object had already been formed and placed on three-dimensional object carrier/support 20 embodied as a build platform. When a further layer of material shall be placed on top of object part 19 , it is moved by an upward movement of carrier/support 20 to get in contact with the material 17 yet to be solidified. Once a contact is reached, electromagnetic radiation and/or synergistic stimulation is delivered in a pattern or an image with an associated basic energy density E 0 within the defined area of a building region (in this case a further layer to be solidified).
According to the embodiment illustrated by FIG. 4 , energy density is varied by the super-exposure using an additional, second source of electromagnetic radiation and/or synergistic stimulation delivering or supplying further energy density E 1 in a desired part of the exposure pattern or image. Here, as a ceramic filler substance may be included into the material together with a binder substance, super-exposure with E 1 +E 0 is carried out in an inner area region of the layer to be formed, relative to basic energy density E 0 remaining in boundary regions, in order to counter-act inhomogeneities caused by scattering phenomena in boundary regions. First electromagnetic radiation and/or synergistic stimulation associated with E 0 and second electromagnetic radiation and/or synergistic stimulation associated with E 1 may have same or different wavelengths.
In another embodiment as illustrated by FIGS. 5A and 5B , a principle of the present invention is explained when different building regions or different layers are used, or alternatively when different first and second materials are used for one or more building regions. In a particularly exemplified step illustrated by FIG. 5A , a modified second material 18 having no filler substance or another filler substance, different from the compositions 15 , 16 or 17 of FIG. 4 described above, had been applied for forming a delicate structural portion, for example a modified structure or an auxiliary support structure, at a building region by exposure to electromagnetic radiation and/or synergistic stimulation associated with energy density E 3 only. After separation from belt 30 , this belt 30 or another belt carrying again the first material 17 to be solidified and containing filler 16 and binder 15 is supplied. Upon a further contact by redirecting partial object (structure 19 plus 19 ′) with a movement of its carrier/support 20 upwards and towards material 17 , basic energy density E 0 varied relative to E 3 is exposed for the next building region or next layer for forming another part of the three-dimensional object. Alternatively, instead of using different first and second materials 17 and 18 to be solidified, respectively, varied energy densities E 3 and E 0 may nevertheless be applied advantageously even with using the same materials to be solidified, the variation however being performed due to the quite different building region structure (delicate structure 19 ′ and overlying layer formed over the whole cross-section of object 19 ).
In the embodiments schematically illustrated by FIGS. 6 and 7 , it is not necessary but still possible to vary energy density as described in the previous embodiments within the pattern or image and/or between patterns or images of different building regions of the same or different materials. However, in these embodiments useful of its own, the energy density of the electromagnetic radiation and/or synergistic stimulation delivery device as such can be respectively set or controlled by a previous setting or by a suitable control unit depending on at least one of the criteria (i) to (viii) mentioned above.
The embodiment shown in FIG. 6 again uses a material 7 to be solidified which contains at least binder 5 and filler 6 and which is contained in a vat, container or trough 40 . The bottom of vat/container/trough 40 and a glass or plastic plate 41 used for its support is transparent to the type of electromagnetic radiation used. In this embodiment, electromagnetic radiation is projected from a projection unit 50 through a shutter 46 and via a reflector 45 to form a desired exposure image in or at the building region, to thereby solidify material 7 and to bind it to part 9 previously formed on the three-dimensional object carrier/support 10 , which is again embodied as a build platform. In this manner a desired three-dimensional object can be successively formed either continuously or discontinuously, for example layer-wise with intermediate layer separations or in a suitable voxel matrix. A control unit embodied by a computer unit 60 serves to control operations of the freeform fabrication system at suitable locations, e.g. the projection unit 50 for tuning energy density E, the shutter 45 for opening and closing the path of the electromagnetic radiation, and the three-dimensional object carrier/support 10 for its movement (e.g. upward as indicated by an arrow) for enabling delivery of fresh material to be solidified. Here, the energy density E of the projection and exposure unit can be manually preset and input by a suitable control module 61 in advance of the building process, for example depending on the material used and known before (i.e. according to any one or a combination of parameters (i) and (ii) described above, such as type, particle size or amount of filler; type or amount of binder). Alternatively or in addition, energy density E can be manually set and input into the control module 61 , or is adjusted in-situ during the built program and built process depending on any one or a combination of parameters (iii) to (viii) described above.
As a further possible option, a flowmeter or a viscosity meter (indicated by reference sign 55 ) may be provided if desired, allowing to measure in advance for a presetting operation, or to measure in situ during the building process either flowability or viscosity or both, in order to control the energy density E delivered by the projection unit 50 via control unit 60 .
As a still further possible option, the energy density E delivered by the projector may be varied, if desired, in the exposed area of the building region, in order to further counteract scattering, reflection and/or absorption phenomena by the filler 6 , as basically explained in the previous embodiments (i.e. by delivering spatially distinct energy densities E 0 , E 1 , etc.).
The embodiment shown in FIG. 7 illustrates a modification of the above embodiments for film transfer imaging techniques. Here, a embodiment of a freeform fabrication system according to the present invention uses a flexible and/or clear and/or resilient film/foil (respectively denoted by reference sign 75 ) conveying the material to be solidified 7 which again contains at least binder 5 and filler 6 . The film 75 , which is here transparent to the electromagnetic radiation of interest at least in the built area, is adapted to transport material 7 to be solidified, which is dispensed from a solidifying material reservoir 70 onto one side of the film, from a supply station to the built area, to be subjected to radiation action in the desired building region through delivery of a prescribed energy density E. Transport may be carried out by an active roller 76 2 under the control of control unit 60 , while other rollers 76 1 and 76 3 may be passive and merely roll up remaining ends of flexible film 75 . Further provided is a transparent glass or plastic plate 42 for providing support for flexible film 75 carrying the material 7 at the built area. This enhances the provision of a planar reference plane when desirable.
In this embodiment, the electromagnetic radiation and/or synergistic stimulation device is embodied by a mask exposure system comprising a bitmap generator and mask projector (commonly referred to by reference sign 80 ). By the mask exposure system (and optionally a further energy source not shown), energy density E is delivered selectively to the desired area of the building region in or at the reference plane. A control unit 60 is arranged to control the mask exposure system 80 for tuning energy density E, and may further control the whole system at suitable other locations, such as at the three-dimensional object carrier/support 10 for its movement (e.g. upward and downward as indicated by a double arrow) to enable steps of contacting fresh material 7 and of separation after solidification, at the opening of solidifying material reservoir 70 for the controlled dispensing of a fresh material film 7 , etc. Similar to the embodiment of FIG. 6 , the energy density E of the mask exposure system can be manually preset and input by a suitable control module 61 in advance of the building process, or alternatively or in addition, it can be adjusted in-situ during the built program and built process depending on any one or a combination of parameters (i) to (viii) described above.
In the present embodiment of FIG. 7 , the possibility is illustrated to adjust, if desired, energy density depending on pressure and/or strain occurring in the actual building region during solidification of the material. A pressure/strain sensor 56 is brought into contact with the flexible film 75 , optionally only during step of contacting part 9 with the flexible 75 carrying the material 7 , during solidification by means of radiation exposure, and/or during the step of separating the part 9 now bearing the additionally solidified material from the flexible film 75 .
Like in the embodiment of FIG. 6 , it is a still further possible option that the energy density E delivered by the mask exposure system may be varied, if desired, in the exposed area of the building region, as basically explained in the previous embodiments (i.e. by delivering spatially distinct energy densities E 0 , E 1 , etc.).
As a further modification of the embodiment of FIG. 6 it is possible to replace projector unit 50 and reflector 45 by a mask exposure system for the selective delivery of electromagnetic radiation and/or synergistic stimulation.
Further modifications of the embodiments of FIGS. 6 and 7 are conceivable. For example it is possible to replace projector unit 50 and reflector 45 by a mask exposure system in FIG. 6 , and vice versa to replace the mask exposure system 80 of FIG. 7 by another projection system, respectively for the selective delivery of electromagnetic radiation and/or synergistic stimulation.
The description of FIGS. 6 and 7 illustrate that when a freeform fabrication system based on a projection unit or a mask exposure unit is used, a fine tuning is reliably enabled depending on constitution and/or characteristics of a material to be solidified which contains a filler and a binder. The advantages according to the present invention are displayed independent whichever system used, e.g. a stereolithography system, a film transfer system or other freeform fabrication systems.
The embodiments described above can be combined, and they can be modified while still applying the principles of the present invention. It is further noted that the present embodiments have been described for illustrative purposes only, while various further modifications and variations are possible and can be applied by the person skilled in the art within the scope and gist of the present invention. | The present invention describes a process for producing a three-dimensional object, comprising: providing a material to be solidified, the material comprising a filler and a binder; delivering electromagnetic radiation and/or synergistic stimulation in a pattern or an image to a building region for solidifying said material; wherein said delivering of electromagnetic radiation and/or synergistic stimulation is performed selectively to a defined area or volume of said material to be solidified; and wherein an energy density of electromagnetic radiation and/or synergistic stimulation is varied within said pattern or image and/or between patterns or images of different building regions of said material. The present invention may be directed also to a system where different first and second materials are to be solidified. The present invention further provides a freeform fabrication system, and a freeform three-dimensional object having unique properties as well as products derived therefrom, such as sintered products. | 73,221 |
This application is a Continuation of application Ser. No. 08/287,567, filed Aug. 9, 1994 now abandoned.
FIELD OF THE INVENTION
This invention generally relates to semiconductor electronic devices, and more specifically to heterojunction bipolar transistors having improved current gain and reliability.
BACKGROUND OF THE INVENTION
Heterojunction bipolar transistors (HBTs) exhibit desirable features such as high current gain and an extremely high cut-off frequency for switching applications, and high power gain and power density for microwave amplifier applications. Even so, as with other types of semiconductor devices there is demand for ever higher operating frequencies or switching speeds from HBTs. Efforts to accomplish this increased performance invariably lead to a scaling down of transistor size. However, as the emitter in an HBT is scaled down, the current gain of the transistor is also dramatically reduced. This effect threatens to limit the level of integration and circuit complexity that can be realized with HBT technology, and has implications for the reliability of HBT power transistors as well.
The reduction in current gain is related to the ratio of the HBT's emitter perimeter-to-area ratio. A cross-sectional diagram of a typical npn HBT is shown in FIG. 1 (the base layer thickness relative it) the other layers is highly exaggerated). In operation, a flow of electrons is established from the emitter, through the base, and into the collector. This electron current is modulated by holes injected into the base from the base contacts. These holes recombine with some of the electrons from the emitter and therefore result in finite current gain. One limitation on current gain is the high density of carrier traps which exists at an exposed semiconductor surface. The trap density is typically large enough to create an electric field near the surface that extends some distance into the base layer. Electrons injected near the edge of the emitter mesa are drawn to the surface of the base layer by this electric field where they recombine in the abundance of traps present at the surface. Hence, the total minority carrier current from the emitter has a desirable component, i.e. the carriers that transit the base to the collector; and an undesirable component, i.e. the carriers that recombine at the surface of the base layer. Unfortunately, the desirable current scales with the area of the emitter, while the undesirable current scales with the perimeter. Consequently, as the emitter dimensions are reduced, the perimeter current becomes a larger percentage of the total emitter current. This results in a decrease of the current gain of the transistor.
Past efforts at solving the problem of surface recombination at the extrinsic base surface have included physical and chemical passivation treatments. Sputtered SiN, depleted AlGaAs passivation ledges, and sulfide-base coatings have been reported. See O. Nakajima, et al., "Emitter-Base Junction Size Effect on Current Gain H fc of AlGaAs/GaAs Heterojunction Bipolar Transistors", Japanese Journal of Applied Physics, Vol. 24, No. 8, pp. L596-L598, Aug. 1985; R. J. Malik, et al., "Submicron Scaling of AlGaAs/GaAs Self-aligned Thin Emitter Heterojunction Bipolar Transistors with Current Gain Independent of Emitter Area", Electronics Letters, Vol. 25, No. 17, pp. 1175-1177, Aug. 17, 1989; S. Tiwari, et al., "Surface Recombination in GaAlAs/GaAs Heterostructure Bipolar Transistors", Journal of Applied Physics, Vol. 64, No. 10, pp. 5009-5012, Nov. 15, 1988. However, these solutions have drawbacks such as process complexity and performance shortcomings that prevent them from offering a complete answer to the problem of extrinsic base surface recombination. For example, depleted AlGaAs passivation ledges, shown in FIG. 2, while effective in reducing the effects of surface states, require that the spacing between the base contact 10 and the active emitter 12 be large enough to accommodate a passivation ledge 14 extending between the active emitter 12 and the base contact 10. High frequency operation demands a lower base resistance and base-collector junction capacitance than is generally possible with such a technique. In addition, the passivation ledge structure does not lend itself to the self-aligned fabrication techniques necessary for economical volume production.
Another prior art approach to passivating the base surface is shown in FIG. 3 and is described in Malik, supra at 1176. It is a modification of the ledge passivation approach. The surface of the GaAs base layer 20 is completely covered by a thin AlGaAs emitter layer 22, in contrast to the ledge structure described above. As in the ledge approach the thin AlGaAs layer 22 extending between the emitter mesa 24 and the base contacts 26 is fully depleted. It serves to passivate the surface states at the surface of the base layer and therefore minimizes surface recombination. In this particular prior art structure, the base layer is primarily GaAs, but contains a small mole fraction of aluminum. The aluminum content is graded from 0% at the base-collector interface to 6% at the base-emitter interface. This sets up a quasi-electric field that helps to keep the minority carriers from migrating to the surface to recombine. However, a problem with this approach is that the base contacts are formed on the emitter layer. Metal from the contacts spikes through the emitter layer and into the base layer upon being alloyed. Since the base layer is typically very thin (approximately 600 Å), it is difficult to alloy the contacts such that metal 27 extends into the base layer 20 without also extending into the underlying collector layer 28. A structure that relies on such alloyed contacts suffers from process uncertainty and has been shown to be unreliable in production. The present invention is intended to address the reliability problems of this prior art structure and the process limitations of the ledge structure.
SUMMARY OF THE INVENTION
The invention includes a passivating layer of material in the base structure of an HBT that serves to cover the extrinsic base region of the transistor. The passivating layer is formed of a material having a wider bandgap than the base layer, and is heavily doped with the same doping type (n or p) as the base layer. This has advantages in that the base contacts of the device are made directly to the passivating layer and are not in direct contact with the base layer or the emitter layer. This eliminates the need for alloyed contacts and the concomitant reliability problems associated with spiking contacts. In addition, this is completely compatible with self-aligned production techniques, and can result in small self-aligned devices that have substantially the same current gain as very large devices not produced by self-alignment.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a cross-sectional view of a prior art heterojunction polar transistor;
FIG. 2 is a cross-sectional view of a prior an heterojunction bipolar transistor which incorporates ledge passivation;
FIG. 3 is a cross-sectional view of a prior an heterojunction bipolar transistor which uses a thin emitter layer to passivate the extrinsic base;
FIG. 4 is a cross-sectional view of a preferred embodiment of the invention;
FIG. 5a is an energy band diagram showing the conduction and valence bands of an extrinsic base region of a prior art unpassivated HBT;
FIG. 5b is an energy band diagram showing the conduction and valence bands of an extrinsic base region with a surface passivation consisting of a wide bandgap material;
FIG. 6 is an energy band diagram showing the emitter-base heterojunction;
FIG. 7 is a cross-sectional diagram of a preferred embodiment material structure from which a preferred embodiment of the invention may be fabricated:
FIGS. 8-13 are diagrams showing a preferred embodiment method of processing; and
FIGS. 14 and 15 are diagrams showing a second preferred embodiment method of processing.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In a first preferred embodiment shown in FIG. 4, a thin AlGaAs passivation layer 40 is included within the base structure 42 of an npn HBT adjacent to the emitter layer 46. Passivation layer 40 suppresses the recombination of electrons from the emitter at the surface of the base layer surrounding the emitter mesa 50. FIG. 5a shows the effect of surface states on the conduction and valence bands of an exposed base layer without a passivation layer. Electrons entering the base layer from the emitter are drawn to the surface of the base layer because of the electric field established by the presence of surface states. This is reflected in FIG. 5a by the band bending. FIG. 5b shows the band diagram of the preferred embodiment base layer with an overlying passivation layer. It is apparent from this diagram that electrons in the base layer will be inhibited from reaching the high density of carrier traps at the surface by the conduction band discontinuity between the base layer and the exposed surface. The discontinuity is a result of the interface between the wider bandgap passivation layer 40 and the narrower bandgap base layer 44. This is not true in FIG. 5a, where there is nothing between electrons in the base and the high density of carrier traps at the surface of the base.
The band diagrams of FIGS. 5a and 5b refer to the effect of the preferred embodiment passivation layer 40 over the portion of the base layer that lies between the base contact (48 in FIG. 4) and the emitter mesa 50. It is also important that the passivation layer 40 not interfere with the functioning of the emitter-base junction, which is critical to the operation of the transistor. It is an essential aspect of the functioning of an HBT that the emitter bandgap is larger than that of the base in order to create a barrier in the valence band at the interface between the emitter and base. This barrier prevents holes injected into the base from an external source from being injected into the emitter. A band diagram illustrating this point is shown in FIG. 6. In FIG. 6 a GaAs base and Ga 0 .52 In 0 .48 P emitter are separated by an Al 0 .17 Ga 0 .83 As passivation layer. Note that the valence band has the necessary offset and that the discontinuity in the conduction band may easily be overcome by electrons when the emitter-base junction is forward-biased. The choice of aluminum mole fraction is important in achieving the simultaneous goals of passivating the exposed, or extrinsic, base and of providing a functional emitter-base junction. The aluminum mole fraction that fulfills these requirements is typically in the range of approximately 4% to 30%, with approximately 17% being preferable.
The doping of the AlGaAs layer 40 is of the same type (n or p) as that of the GaAs base layer 44. The carrier concentration in the passivating layer varies according to the desired performance of the transistor, but will typically be within the range from approximately 5×10 18 cm -3 to approximately 1×10 20 cm -3 . For transistors requiring base doping below approximately 5×10 18 cm -3 , recombination is generally not a dominant problem, but for higher concentrations it is more critical. In order for the passivation to be effective, it is important that the entire thickness of the passivation layer not be depleted of carriers. Therefore, the choice of layer thickness depends directly upon the doping concentration in the passivation layer, which in turn is dependent upon the desired operating frequency of the transistor. For example, for L-band operation the preferred concentration is approximately 1.5×10 19 cm -3 ; for X-band operation the preferred concentration is approximately 4×10 19 cm -3 ; for K-band operation the preferred concentration is approximately 7×10 19 cm -3 . The surface depletion region depth varies in approximate proportion to the square root of the doping concentration. Thus, the depletion thickness ranges from approximately 85 Å to approximately 20 Å over the doping concentration range of 5×10 18 cm -3 to 1×10 20 cm - . To ensure that the passivation layer is not completely depleted, the layer thickness is typically chosen to be in the range of 50 to 300 Å, with the particular thickness being determined by the base doping. For an X-band transistor the passivation layer thickness is approximately 100 Å, and is roughly twice the thickness of the depletion region.
The first embodiment structure has numerous advantages over the prior art devices. For example, in the prior an device shown in FIG. 3, the emitter layer 30 extends from the emitter mesa out underneath the base contacts 26. The emitter layer is thin enough to be depleted, but it has been shown that such a structure establishes a leakage path between the emitter mesa and the base contacts. Electrons injected laterally into the depleted surface layer travel a very short distance before recombining at the base contacts 26. Typically, such a layer will allow leakage of several milliamps before the base-emitter junction becomes forward biased. This results in a reduction of current gain.
Additionally, in order for the base contacts 26 to make contact with the base layer 20, the contact must be alloyed. Aside from the difficulties involved in stopping the contact from spiking through the base layer and into the collector 28, the metal that enters the base in the alloying procedure creates an interface that introduces carrier traps. Metal that extends into the collector forms a Schottky diode between the base and collector. This increases the emitter-collector offset voltage, which is undesirable for power amplifier applications. Any disturbance of the semiconductor lattice in the base layer, whether it is an exposed surface, or a metal contact, creates a high density of mid-bandgap states that increases the amount of undesirable recombination in the base layer. So, while the prior an minimizes the carrier traps at the base layer surface by providing an overlying depleted emitter layer, it essentially counters that advantage by introducing traps at the base contact-to-base layer interface. It has been estimated that the surface passivation provides two or three orders of magnitude improvement on the recombination velocity in the base layer, but that the introduction of alloyed metal contacts to the base layer reduces that improvement to less than one order of magnitude.
The first preferred embodiment of the invention shown in FIG. 4 retains the advantages of surface passivation, while eliminating the need for alloyed contacts to the base. Forming the passivation layer of a material doped with the same type (n or p) of dopant as the base layer, rather than that of the emitter, allows the base contact to be made directly to the passivation layer. There is no need for alloying the base contact. This eliminates the leakage path between the emitter mesa and the base contact that plagues the prior art device, while retaining the full benefit of the reduction in base layer recombination.
In a second preferred embodiment of the invention, an Al 0 .35 Ga 0 .65 As emitter is used instead of the GaInP used in the first preferred embodiment. The 35% mole fraction of aluminum provides an emitter layer with a wider bandgap than the 17% aluminum passivation layer. Therefore, the band diagram of the second preferred embodiment structure is almost identical to that for the first preferred embodiment structure shown in FIG. 6. A difference between the two emitter materials is the processing involved in forming the emitter mesa shown in FIG. 4. It should be noted that the invention described with reference to these embodiments is completely compatible with self-aligned processes. This is in contrast to the prior art ledge passivation technique (FIG. 2) which requires a considerable space between the emitter mesa 12 and the base contacts 10, and other prior art techniques which suffer from high emitter-base leakage current if self-alignment is used.
A process to fabricate the first preferred embodiment may begin with the structure shown in FIG. 7 and fully described in Tables I and II. The commonly used etchants for GaAs and AlGaAs do not etch GaInP. Therefore, the processes described hereinbelow have been developed to take advantage of this selectivity. In the first approach, an emitter contact 120 of a suitable material (e.g. Ti/Pt/Au in respective thicknesses of 300/250/3000 Angstroms, for example) is deposited on GaAs layer 106, as shown in FIG. 8. The entire structure is then placed in the reaction chamber of a Reactive Ion Etching (RIE) apparatus. With BCl 3 +SF 6 , CCl 4 , or other commonly used chlorofluorocarbons as the reactant. GaAs layer 106 is anisotropically dry-etched from areas not covered by masking pattern 120. The etch is allowed to continue for approximately 1 minute after the GaInP layer 108 is exposed.
The GaInP is not etched because a residual layer of unknown composition 122, shown in FIG. 9, forms at the surface of GaInP layer 108. Thus, BCl 3 is an etchant that selectively etches GaAs, but not GaInP. Unfortunately, the residual layer 122 is not easily etched using the compositions known to wet etch GaInP, particularly HCl and HCl:H 3 PO 4 (3:1 by volume).
Thus, the BCl 3 apparently reacts with the GaInP to form a composition which is not readily etchable by either normal GaInP wet etchants or by the normal GaAs dry etchant. Therefore, in this embodiment the residual layer 122 is ion milled by placing the structure in an asher at approximately 300 Watts for approximately 10 minutes. O 2 and Ar 124 form the active species liar the milling, depicted in FIG. 10. One can also use a commercially available ion mill apparatus. Immediately alter ion milling, the structure is immersed in a solution containing HF and NH 4 F for approximately 1 minute. The structure is then immersed in a solution of H 2 SO 4 :H 2 O 2 :H 2 O (1:8:160 by volume) for 10 seconds. This prepares the GaInP for removal with an HCl solution. The structure is then immersed in static (unstirred) HCl for 5 seconds, and then immersed in a stirred HCl solution for approximately 1 minute intervals. After each interval two probes are placed on the etched surface to test for breakdown voltage. The process typically requires two 1 minute intervals to etch through the GaInP and results in a structure as shown in FIG. 11. Thus, this process combines the anisotropic, yet selective, reactive ion etching technique with the unselective ion milling and wet etch techniques. This allows the formation of an emitter having a smaller size than would be possible with a wet etch alone.
TABLE I______________________________________ Preferred ApproximateElement # Generic Name Material Thicknesses______________________________________106 Emitter Cop GaAs 2000 Å108 Emitter GaInP 700 Å110 Passivation layer AlGaAs 100 Å112 Base GaAs 800 Å114 Collector GaAs 7000 Å116 Subcollector GaAs 1 μm______________________________________
TABLE II______________________________________ Examples Approximate ofElement Generic Doping Preferred Alternative# Name Concentration Dopant Dopants______________________________________106 Emitter 1 × 10.sup.19 cm.sup.-3 Si Sn Cap108 Emitter 5 × 10.sup.17 cm.sup.-3 Si Sn110 Passivation 3 × 10.sup.19 cm.sup.-3 C Be layer112 Base 3 × 10.sup.19 cm.sup.-3 C Be114 Collector 3 × 10.sup.16 cm.sup.-3 Si Sn116 Subcollector 2 × 10.sup.18 cm.sup.-3 Si Sn______________________________________
Once the emitter mesa (50 in FIG. 4) is formed, base contacts 48 may be formed by spinning on and patterning a layer of photoresist (not shown) to define the location of the contacts on the base passivation layer 40. A metal composition such as Ti/Pt/Au, for example in thicknesses of approximately 500, 250, and 1500 Angstroms, respectively is deposited. The photoresist is then lifted off to leave the base contacts 48 as shown in FIG. 4. Unlike the prior art structure shown in FIG. 3, the first preferred embodiment structure of FIG. 4 does not require alloying of the base contacts 48. The passivation layer 40 is a part of the base structure, rather than the emitter as in the prior art.
After the base contacts are formed, the base mesa may be formed by removing layers 40, 42, 44, and the collector layer 52 to expose the subcollector layer 54. A solution of H 2 SO 4 :H 2 O 2 :H 2 O in the ratio of 1:8:160 (by volume), for example, may be used to remove the layers. Photoresist (not shown) is then deposited and patterned to define the collector contacts 56. AuGe/Ni/Au is then evaporated onto the water to thicknesses of, for example, 500/140/2000 Angstroms, respectively, to form the contact 56. The photoresist layer is then stripped, which lifts off all excess metallization. This results in the structure of FIG. 4. The structure is then heated to 430° C. for approximately 1 minute to alloy the collector contacts.
In a second preferred embodiment process, the structure of FIG. 8 is again etched using the RIE technique described above, but the etch is stopped before GaAs layer 106 is completely etched away. This leaves a thin layer 126 of GaAs, as shown in FIG. 11 (instead of forming the residual layer 122 of FIG. 9). This thin layer of GaAs is removed using a solution of H 2 SO 4 :H 2 O 2 :H 2 O (1:8:160 by volume). The H 2 SO 4 solution stops on the GaInP layer 108, leaving the structure shown in FIG. 13.
In another preferred embodiment process of the invention, the material structure is altered to include an Al x Ga 1-x As (where x is approximately 0.3) layer 128 between GaInP layer 108 and GaAs layer 106. The structure shown in FIG. 14. The AlGaAs layer serves as an etch stop in that the BCl 3 dry etch described in the abovementioned embodiments, when combined with SF 6 , for example, stops on AlGaAs. Hence, after deposition of a masking pattern 120, shown in FIG. 15, the dry BCl 3 etch is performed until GaAs layer 106 is removed. AlGaAs layer 128 is removed with a solution of H 2 SO 4 :H 2 O 2 :H 2 O (1:8:160 by volume) for example, in a timed etch. GaInP layer 108 is then removed with HCl:H 3 PO 4 (3:1 by volume) for example. Though 3:1 does not appreciably etch the AlGaAs base layer 110, the timing in this etch is monitored to avoid substantial undercutting. The structure shown in FIG. 15 results from this process.
Yet another preferred embodiment process is similar to the first except that an InGaAs layer is deposited (by MBE, MOCVD, or other suitable technique) on GaAs layer 106. The InGaAs layer facilitates the formation of an ohmic contact to the material structure. A transistor otherwise may be formed with the process described as the first preferred embodiment. In general, the transistor of FIG. 4 may be obtained with standard processing techniques after one of the above described processes is performed.
A few preferred embodiments have been described in detail hereinabove. It is to be understood that the scope of the invention also comprehends embodiments different from those described, yet within the scope of the claims.
Internal and external connections can be ohmic, capacitive, inductive, direct or indirect, via intervening circuits or otherwise. Implementation is contemplated in discrete components or fully integrated circuits in silicon, gallium arsenide, or other electronic materials families, as well as in optical-based or other technology-based forms and embodiments.
While this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the an upon reference to the description. For example, though AlGaAs was used as the wide bandgap passivation layer in the above embodiments, it may be appreciated that other materials having a bandgap wider than the layer being passivated in addition to having a lattice constant relatively close to the layer being passivated may be used. Also, though only GaInP and AlGaAs were mentioned above as emitter materials, it may be appreciated that other semiconductors producing an offset in the valence band between the emitter and base layers may be used. It is therefore intended that the appended claims encompass any such modifications or embodiments. | A bipolar transistor includes a passivating layer of material 40 in the base structure 42 that serves to cover the extrinsic base region of the transistor. The passivating layer 40 is formed of a material having a wider bandgap than the base layer 44, and is heavily doped with the same doping type (n or p) as the base layer. The invention is advantageous in that the base contacts 48 of the device are made directly to the passivating layer 40 and are not in direct contact with the base layer 44. This eliminates the need for alloyed contacts and the concomitant reliability problems associated with spiking contacts. In addition, the invention is completely compatible with self-aligned production techniques. | 25,399 |
TECHNICAL FIELD
[0001] The present invention relates to a water purifier, and more particularly to a water purifier provided with a sterilizing ability.
BACKGROUND ART
[0002] In recent years, there has been a raised interest in the quality of drinking and other water, and water purifiers have widely spread in households. To secure clean water, sterilization is as important as filtering, and accordingly there have been proposed water purifiers that incorporate a germicidal lamp.
LIST OF CITATIONS
Patent Literature
[0003] Patent Document 1: JP-A-H10-192893
SUMMARY OF INVENTION
Technical Problem
[0004] However, for water purifiers provided with a sterilizing ability to be realized in a form fit for general use as for use in households, there are many problems yet to be solved.
[0005] In view of the foregoing, an object of the present invention is to provide a water purifier that is provided with a sterilizing ability but is nevertheless fit for general use as for use in households.
Solution to Problem
[0006] To achieve the above object, according to the invention, a water purifier includes: an enclosure; a source water inlet through which source water is fed in from outside the enclosure; a purification section; an ultraviolet radiation sterilization section which has an ultraviolet light source; a purified water outlet through which purified water purified by the purification section and sterilized by the ultraviolet radiation sterilization section is fed out to outside the enclosure; a condition detection section; and a control section which controls generation of ultraviolet radiation from the ultraviolet light source according to the detection by the condition detection section (a first configuration).
[0007] In the water purifier of the first configuration described above, preferably, the condition detection section has an abnormality detection section which detects a condition in which ultraviolet radiation can leak from inside to outside the enclosure, and when the abnormality detection section detects the condition in which ultraviolet radiation can leak, the control section inhibits the ultraviolet light source from generating ultraviolet radiation (a second configuration).
[0008] In the water purifier of the second configuration described above, preferably, the enclosure has a lid for maintenance inside the water purifier, and the abnormality detection section detects whether or not the lid is in an improperly closed state (a third configuration).
[0009] In the water purifier of the second configuration described above, preferably, the abnormality detection section has a light leakage detection section which detects leakage of light from outside to inside the enclosure (a fourth configuration).
[0010] In the water purifier of the first configuration described above, preferably, the ultraviolet radiation sterilization section has a far-ultraviolet LED for letting ultraviolet radiation be transmitted through a quartz glass water passage (a fifth configuration).
[0011] In the water purifier of the fifth configuration described above, preferably, there is further provided a water passage transmitted radiation detection section which detects a flaw in transmission of far-ultraviolet radiation through the quartz glass water passage (a sixth configuration).
[0012] In the water purifier of the first configuration described above, preferably, the condition detection section has a running water detection section which detects a purified water outflow state in which purified water is flowing out through the purified water outlet; when the running water detection section detects the purified water outflow state, the control section makes the ultraviolet light source generate ultraviolet radiation, and when the running water detection section does not detect the purified water outflow state, the control section inhibits the ultraviolet light source from generating ultraviolet radiation (a seventh configuration).
[0013] In the water purifier of the first configuration described above, preferably, there is further provided a reservoir section in which purified water purified by the purification section is stored, the purified water outlet is configured to feed out the purified water stored in the reservoir section to outside the enclosure, and the ultraviolet radiation sterilization section has a far-ultraviolet LED and sterilizes the purified water before the purified water flows out through the purified water outlet (an eighth configuration).
[0014] In the water purifier of the eighth configuration described above, preferably, the far-ultraviolet LED is provided inside the reservoir section (a ninth configuration).
[0015] In the water purifier of the eighth configuration described above, preferably, the condition detection section has a stored water amount detection section which detects the amount of water stored in the reservoir section, and the control section controls the far-ultraviolet LED according to the detection by the stored water amount detection section (a tenth configuration).
[0016] In the water purifier of the eighth configuration described above, preferably, the control section inhibits the far-ultraviolet LED from generating ultraviolet radiation when the purified water in the reservoir section is discharged (an eleventh configuration).
[0017] In the water purifier of the first configuration described above, preferably, there is further provided a fluorescence derivation section which makes the ultraviolet radiation generated by the ultraviolet light source visible from outside the enclosure in a form of visible fluorescence having ultraviolet radiation eliminated therefrom (a twelfth configuration).
[0018] In the water purifier of the first configuration described above, preferably, the ultraviolet light source has a far-ultraviolet LED, and has a cooling section which cools down the far-ultraviolet LED with water inside the water purifier (a thirteenth configuration).
[0019] According to the invention, a water purifier includes: a water inlet; an ultraviolet radiation sterilization section which sterilizes water flowing in through the water inlet with a far-ultraviolet LED as a light source; a water outlet through which purified water sterilized by the ultraviolet radiation sterilization section is fed out, and a cooling section which cools down the far-ultraviolet LED with water flowing in through the water inlet (a fourteenth configuration).
[0020] In the water purifier of the fourteenth configuration described above, preferably, the cooling section cools down the far-ultraviolet LED with the very water flowing in through the water inlet and flowing out through the water outlet (fifteenth configuration).
[0021] In the water purifier of the fourteenth configuration described above, preferably, the cooling section has a water passage through which the water exposed to the ultraviolet radiation generated by the far-ultraviolet LED is passed to cool down the far-ultraviolet LED, the far-ultraviolet LED has an ultraviolet light emitting portion and a heat dissipating portion, and the water passage is arranged to run across the ultraviolet light emitting portion and the heat dissipating portion (a sixteenth configuration).
[0022] In the water purifier of the fourteenth configuration described above, preferably, there is further provided a drive section which drives the far-ultraviolet LED such that an ultraviolet radiation generation period and an ultraviolet radiation non-generation/cooling period alternate (a seventeenth configuration).
[0023] In the water purifier of the fourteenth configuration described above, preferably, there are further provided: a power supply section which is supplied with electric power from outside to drive the far-ultraviolet LED and which has a secondary battery charged with the supplied electric power; and a control section which normally supplies the far-ultraviolet LED with the electric power supplied from the outside and which, under a predetermined condition, even when electric power is being supplied from outside, supplies the far-ultraviolet LED with electric power from the secondary battery (an eighteenth configuration).
[0024] According to the invention, a water purifier includes: an ultraviolet radiation sterilization section which sterilizes water with a far-ultraviolet LED as a light source; a power supply section which is supplied with electric power from outside to drive the far-ultraviolet LED and which has a secondary battery charged with the supplied electric power; and a control section which normally supplies the far-ultraviolet LED with the electric power supplied from the outside and which, under a predetermined condition, even when electric power is being supplied from outside, supplies the far-ultraviolet LED with electric power from the secondary battery (a nineteenth configuration).
[0025] In the water purifier of the nineteenth configuration described above, preferably, there is further provided a water outlet through which water sterilized by the ultraviolet radiation sterilization section is fed out, and the control section supplies the far-ultraviolet LED with electric power from the secondary battery according to how water is flowing out through the water outlet (a twentieth configuration).
Advantageous Effects of the Invention
[0026] According to the present invention, it is possible to realize a water purifier that is provided with an ultraviolet radiation sterilizing ability but is nevertheless fit for general use as for use in households.
BRIEF DESCRIPTION OF DRAWINGS
[0027] [ FIG. 1 ] is a block diagram of a practical example of a water purifier system according to one embodiment of the invention;
[0028] [ FIG. 2 ] a flow chart showing the basic functions of the control section in FIG. 1 ;
[0029] [ FIG. 3 ] is a flow chart showing the details of the tests at step S 2 in FIG. 2 ;
[0030] [ FIG. 4 ] is a flow chart showing the details of the running water handling at step S 26 in FIG. 2 ;
[0031] [ FIG. 5 ] is a flow chart showing the details of the stored water handling at step S 23 in FIG. 2 ; and
[0032] [ FIG. 6 ] is a block diagram showing the detailed configuration of the sterilization device and the purified reservoir section in the embodiment in FIG. 1 .
DESCRIPTION OF EMBODIMENTS
[0033] FIG. 1 is a block diagram of a practical example of a water purifier system according to one embodiment of the present invention. A water purifier 2 has a source water inlet 7 connected to a water pipe branching off a main tap 6 of a household water pipe 4 leading from outside. In FIG. 1 , the reference sign 2 identifies the cabinet of the water purifier as well. Another water pipe branching off the main tap 6 is, as a bypass going around the water purifier 2 , directly connected to a switch valve 8 . The switch valve 8 is provided, for example, at a sink in a kitchen in a house, so that the served water can be switched between source water fed directly from the main tap 6 and purified water fed from the water purifier 2 . In FIG. 1 , the flow of water mentioned above is indicated by hollow arrows, and this applies in the following description. An operation to switch the switch valve 8 to serve water from the water purifier 2 can be made manually, and can also be made under the control of the water purifier 2 . Here, whenever the switch valve 8 is operated manually, information on how it is operated is conveyed to the water purifier 2 .
[0034] The source water fed into the water purifier 2 passes through a water pressure gauge 10 and a flowmeter 12 , and enters a filtering tub 14 . The filtering tub 14 filters out and removes comparatively large-sized impurities in water. The water that has passed through the filtering tub 14 then enters an absorption tub 16 , where molecular-level impurities are removed by absorption. The water that has passed through the absorption tub 16 then enters a sterilization tub 20 in a sterilization device 18 , where the water is treated to kill microbes.
[0035] In the sterilization tub 20 , a group of far-ultraviolet LEDs 22 is provided, and the water passage in the sterilization tub 20 is so configured as to pass through the group of far-ultraviolet LEDs 22 . The group of far-ultraviolet LEDs 22 can generate far-ultraviolet radiation in the UV-B or UV-C band. To permit far-ultraviolet radiation to be transmitted through it, the water passage through the group of far-ultraviolet LEDs 22 is formed of quartz glass. The group of far-ultraviolet LEDs 22 is driven by a drive circuit 26 controlled by a control section 24 .
[0036] The driving by the drive circuit 26 relies on comparatively low-frequency pulse-width modulation control (hereinafter “PWM control”), and one purpose of this is, as will be discussed later, to vary the amount of energy of far-ultraviolet radiation according to the amount of water to be sterilized. Another purpose of PWM control is to achieve increased light emission efficiency by preventing the far-ultraviolet LEDs from overheating as a result of continuous lighting. That is, PWM control is used to achieve the following operation: after the far-ultraviolet LEDs are turned on, before their temperature becomes so high as to degrade light emission efficiency, the far-ultraviolet LEDs are turned off, and their cooling-down is waited for before the far-ultraviolet LEDs are turned on again.
[0037] Moreover, according to the invention, as will be discussed later, the far-ultraviolet LEDs are cooled down with the water that is fed into the water purifier, and thus providing the periods for cooling down by exploiting the off periods of PWM control exerts a remarkable effect. While mercury lamps and xenon lamps are common as light sources of ultraviolet radiation, in this embodiment, far-ultraviolet LEDs are adopted to realize a water purifier that offers a powerful sterilizing effect, is compact, and is fit for use in households. Far-ultraviolet radiation is hazardous to the human body, and therefore, as will be discussed later, in this embodiment various safety measures are adopted. The control section 24 , which controls the drive circuit 26 , is constituted by a computer, and its functions are performed by a program stored in a memory section and a computation circuit.
[0038] Part of the enclosure of the sterilization tub 20 is formed into a fluorescence observation window 28 , which is formed of ordinary glass that does not transmit far-ultraviolet radiation itself but which is coated, on the inside, with a fluorescent substance that converts far-ultraviolet radiation to visible light. Through this fluorescence observation window 28 , visible fluorescence can be seen, and this permits one to check the light emission of the far-ultraviolet LEDs visually from outside the water purifier 2 . Moreover, the sterilization tub 20 is provided with a water passage transmitted radiation receiving section 30 , which receives the light emitted from the group of far-ultraviolet LEDs 22 and transmitted through the quartz glass water passage inside the sterilization tub 20 . The output of the water passage transmitted radiation receiving section 30 is conveyed to the control section 24 , and this permits one to check the light emission of the group of far-ultraviolet LEDs 22 without relying on visual checking. The water passage transmitted radiation receiving section 30 achieves its detection by use of a photo sensor that is sensitive to far-ultraviolet radiation, or by detecting fluorescence resulting from conversion of far-ultraviolet radiation with a fluorescent substance by use of a photosensor sensitive to longer-wavelength radiation. The water passage transmitted radiation receiving section 30 is used not only to check the light emission of the group of far-ultraviolet LEDs 22 but also to check for dirt inside the quartz glass water passage and hence to detect a lowering in the sterilizing effect.
[0039] As the group of far-ultraviolet LEDs 22 generates heat, its light emission efficiency lowers, and in the embodiment of the invention, a configuration is adopted in which, with the very water that circulates in the sterilization tub 20 , the group of far-ultraviolet LEDs 22 is water-cooled. A water temperature meter 32 monitors the temperature of the water circulating in the sterilization tub 20 to convey it to the control section 24 . When the water temperature becomes equal to or higher than a predetermined temperature, the control section 24 instructs a cooling water feeding section 34 to increase the amount of water flowing from the absorption tub 16 into the sterilization tub 20 so that water is introduced into an additional water cooling passage, provided in a separate circuit, through the group of far-ultraviolet LEDs 22 . The water passing through the additional water cooling passage is not sterilized for a sufficient length of time, and therefore it is not mixed with purified water but is discharged through a drain port 36 .
[0040] The purified water sterilized in the sterilization tub 20 can be used as running water through the switch valve 8 connected to a purified water outlet 37 , and can also be stored, with a reservoir valve 38 opened, in a purified water reservoir 40 so that it can be used when necessary with a water supply valve 42 opened, which is provided in a separate circuit. As compared with when purified water is supplied on a real-time basis through the switch valve 8 , when it is stored in the purified water reservoir 40 , it is possible to reduce the amount of water passed through the sterilization tub 20 and thus to reduce the energy intensity of the group of far-ultraviolet LEDs 22 . For purified water that has been stored in the purified water reservoir 40 for a long time, safety cannot be guaranteed. Therefore, when the storage time exceeds a predetermined length of time, a drain valve 44 can be opened so that the water in the purified water reservoir 40 is discharged and replaced with fresh purified water from the sterilization tub 20 . The reservoir valve 38 and the drain valve 44 are controlled automatically by the control section 24 , which monitors the water level in the purified water reservoir 40 and its change with time. The purified water reservoir 40 too is provided with a group of far-ultraviolet LEDs 46 so as to further sterilize the stored purified water. The group of far-ultraviolet LEDs 46 is controlled by the control section 24 . Although not shown, the purified water reservoir 40 too is provided with a fluorescence observation window and a transmitted radiation receiving section like those provided in the sterilization tub 20 , so that it is possible to check the light emission of the group of far-ultraviolet LEDs 46 both visually and by the control section 24 .
[0041] Maintenance work such as component replacement, cleaning, etc. with respect to the filtering tub 14 , the absorption tub 16 , the sterilization tub 20 , and the purified water reservoir 40 are done with a component replacement lid 50 opened. Since there is then a risk of exposure to far-ultraviolet radiation, the control section 24 monitors whether the component replacement lid 50 is in an open or closed state, and if it is in an open state, inhibits the group of far-ultraviolet LEDs 22 and the group of far-ultraviolet LEDs 46 from being lit. Here, an “open state” encompasses not only a clearly open state but any state posing a risk of leakage of ultraviolet radiation, for example an improperly closed state. Furthermore, whether or not, due to the component replacement lid 50 being incompletely closed or due to the enclosure of the water purifier 2 being broken somewhere, light is leaking from outside to inside is checked with a light tightness sensor 52 ; if leakage of light from outside to inside is detected, there is a risk of ultraviolet radiation leaking from inside to outside, and accordingly the control section 24 inhibits the group of far-ultraviolet LEDs 22 and the group of far-ultraviolet LEDs 46 from being lit.
[0042] The control section 24 inhibits the group of far-ultraviolet LEDs 22 from being lit also when the water purifier 2 is not in use and thus no water pressure is present at the water pressure gauge 10 or the flowmeter 12 does not detect a predetermined flow rate. Furthermore, the control section 24 inhibits the group of far-ultraviolet LEDs 46 from being lit when the purified water reservoir 40 is empty. In this way, unforeseeable accidents that may result from exposure to far-ultraviolet radiation are prevented. When an abnormal situation arises in which the group of far-ultraviolet LEDs 22 or the group of far-ultraviolet LEDs 46 should be inhibited from being lit as mentioned above, an alerting section 54 gives out an alert to outside the water purifier in the form of a light signal or a sound signal such as an alert sound or an announcement.
[0043] The different parts of the water purifier 2 described above are supplied with electric power from a power supply section 58 which is connected to a receptacle of AC power supply 56 . The power supply section 58 is provided with a secondary battery 60 , which is kept fully charged by trickle charge in preparation for water purification and sterilization at the time of a power outage or the like. Every time the switch valve 8 has been opened and closed a predetermined number of times, even when the supply of electric power from AC power supply is present, the power supply section 58 is switched, for a short period of time, into a state in which electric power is supplied from the secondary battery 60 . In this way, the secondary battery 60 is checked for a deterioration in its performance in order to prevent a situation in which the secondary battery 60 cannot perform sterilization in an emergency. In this embodiment, the light source of far-ultraviolet radiation for sterilization is LEDs, which operate with low electric power consumption, and this makes full battery operation possible.
[0044] FIG. 2 is a flow chart showing the basic functions of the control section 24 . The flow starts when, after the water purifier 2 is installed, the power supply section 56 is connected to a receptacle of AC power supply 54 , or, in the case of battery operation, the battery is attached. When started, the flow proceeds as follows. At step S 2 , tests are performed to check whether the water purifier 2 is installed properly. The details will be discussed later.
[0045] On completion of the tests at step S 2 , the flow proceeds to step S 4 , where, first, all the far-ultraviolet LEDs in the water purifier 2 are turned off. Specifically, the group of far-ultraviolet LEDs 22 in the sterilization tub 20 and the group of far-ultraviolet LEDs 46 in the purified water reservoir 40 are both turned off. Next, at step S 6 , whether or not the component replacement lid 50 is left in an open state is checked. If the check finds no abnormality, the flow proceeds to step S 8 , where whether or not the light tightness sensor 52 is detecting leakage of light is checked. If the check finds no abnormality, the flow proceeds to step S 10 , where it is checked whether or not the transmitted far-ultraviolet radiation as monitored by the water passage transmitted radiation receiving section 30 in the sterilization tub 20 and the transmitted far-ultraviolet radiation as monitored by a light receiving section (not shown) in the purified water reservoir 40 are both proper. If so, the flow proceeds to step S 12 . Here, the following should be noted. At step S 10 , if the far-ultraviolet LEDs are not on, no transmitted radiation is detected, in which case the check finds the condition proper. That is, the check at step S 10 is one intended for when the far-ultraviolet LEDs are on. This is true with similar steps in the following description.
[0046] By contrast, if the check at step S 6 finds the component replacement lid 50 in an open state, or if the check at step S 8 finds incomplete light tightness, or if the check at step S 10 finds any transmitted radiation improper, then in any case the flow proceeds to step S 14 , where a corresponding abnormality alert is given out. The flow then returns to step S 4 , where all the far-ultraviolet LEDs are turned off. Thereafter, unless the abnormality is corrected, steps S 4 through S 10 and S 14 are repeated. Here, the following should be noted. If an abnormality is detected at any of steps S 6 through S 10 when the far-ultraviolet LEDs are already off, step S 4 is redundant; even so, however, step S 4 is gone through for the purpose of turning all the far-ultraviolet LEDs off on detection of an abnormality in steps S 6 through S 10 , which check for abnormalities in various situations as described later.
[0047] At step S 12 , based on information at the water pressure gauge 10 , whether or not the water pressure being applied to the water purifier 2 is proper is checked. A state with a proper water pressure is one in which the main tap 6 is open and the water pressure from the water pipe 4 is applied to the water purifier 2 . If the water pressure is not proper, the flow returns to step S 6 . Thereafter, until the check at step S 12 finds the main tap 6 open, steps S 6 through S 12 are repeated.
[0048] If the main tap 6 is open, and thus the water pressure gauge 10 detects a water pressure being applied to the water purifier 2 , and thus the check at step S 12 finds the water pressure proper, the flow proceeds to S 16 , where whether or not the purified water reservoir 40 is empty is checked. If it is not empty, the flow proceeds to step S 18 , where the group of far-ultraviolet LEDs 46 in the purified water reservoir 40 is turned on, and the flow proceeds to step S 20 . By contrast, if the check at step S 16 finds the purified water reservoir 40 empty, the flow proceeds to step S 22 , where the group of far-ultraviolet LEDs 46 in purified water reservoir 40 is turned off, and the flow proceeds to step S 20 . In either case, if the group of far-ultraviolet LEDs 46 is already on or off, it is simply left as it is then.
[0049] At step S 20 , based on the output of the flowmeter 12 , it is checked whether or not water is flowing into the water purifier 2 at a flow rate equal to or higher than “level 1,” and if so, the flow proceeds to step S 24 . “Level 1” is the minimum-level flow rate at which the switch valve 8 can be regarded as open, and since, as mentioned later, the flow rate when the reservoir valve 38 is fully open is set to be smaller than “level 1,” even when the reservoir valve 38 is open, the flow does not proceed from step S 20 to step S 24 . Incidentally, the distinction of whether the flow of water monitored by the flowmeter 12 results from the switch valve 8 or the reservoir valve 38 being open can be made not only by checking the flow rate as at step S 20 but also by the control section 24 directly acquiring information on which of the switch valve 8 and the fluorescence observation window 28 is open. When this configuration is adopted, step S 20 should instead read “is the switch valve switched to be open for the water purifier and is there a flow of water?”
[0050] If the check at step S 20 finds a flow rate equal to or higher than level 1, the flow proceeds to step S 24 , where the group of far-ultraviolet LEDs 22 in the sterilization tub 20 is turned on, and the flow proceeds to running water handling at step S 26 . The running water handling involves, among others, controlling the amount of energy output from the group of far-ultraviolet LEDs 22 in accordance with the flow rate, and details will be discussed later. On completion of the running water handling at step S 26 , the flow returns to step S 6 to repeat the operations starting at step S 6 .
[0051] By contrast, if the check at step S 20 does not find a flow rate equal to or higher than level 1, it is regarded that no water is being served from the switch valve 8 , and the flow proceeds to step S 28 , where whether or not water has been stored in the purified water reservoir 40 for a long time is checked. If the check finds that, for example, the water level in the purified water reservoir 40 has not changed for one day or more, it is regarded that water has been stored for a long time. If the check does not find long-time storage of water, the flow proceeds to step S 30 , where it is checked whether or not the water level in the purified water reservoir 40 is equal to or lower than a predetermined level and the stored water is insufficient. If the check does not find insufficient storage of water, the flow returns to step S 6 to repeat the operations starting at step S 6 .
[0052] If the check at step S 28 finds long-time storage of water, or if the check at step S 30 finds insufficient storage of water, the flow proceeds to step S 32 , where the group of far-ultraviolet LEDs 22 in the sterilization tub 20 is turned on, and the flow proceeds to stored water handling at step S 34 . The stored water handling roughly involves, among others, refreshing or refilling of the stored water, and details will be discussed later. On completion of the running water handling at step S 34 , the flow returns to step S 6 to repeat the operations starting at step S 6 .
[0053] FIG. 3 is a flow chart showing the details of the tests at step S 2 in FIG. 2 . When started, the flow proceeds as follows. First, at step S 42 , all the far-ultraviolet LEDs are turned off, and the flow proceeds to step S 44 . Thereafter, while steps S 42 and S 44 are repeated, a manual operation is waited for to start the test-lighting of the far-ultraviolet LEDs. In this while, it is preferable to make an indication or an announcement prompting a manual operation. When a manual operation is made, the flow proceeds to step S 46 , where whether or not the component replacement lid 50 is left open is checked. If the check finds no abnormality, the flow proceeds to S 48 , where whether or not the light tightness sensor 52 is detecting leakage of light is checked. If the check also here finds no abnormality, the flow proceeds to Step S 50 , where all the far-ultraviolet LEDs are test-lit for five seconds.
[0054] The flow then proceeds to step S 52 , where it is checked whether the transmitted far-ultraviolet radiation as detected by the water passage transmitted radiation receiving section 30 in the sterilization tub 20 and the transmitted far-ultraviolet radiation as detected by a light receiving section (not shown) in the purified water reservoir 40 are both proper. Here, actually, it is still assumed that no water has been introduced into the water purifier 2 , and thus “whether proper or not” at step S 52 simply concerns whether the LEDs are on or off; thus, the check finds the condition proper so long as they are lit, irrespective of the level. It should be noted that, during the five seconds for which all the far-ultraviolet LEDs are lit, the light emission of the group of far-ultraviolet LEDs 22 and the group of far-ultraviolet LEDs 46 can also be confirmed visually through the fluorescence observation window. If the check at step S 52 finds the transmitted radiation proper, the flow proceeds to step S 54 .
[0055] By contrast, if an abnormality is detected at any of steps S 46 , 48 , and 52 , the flow proceeds to step S 56 , where an abnormality alert is given out, and the flow then returns to step S 42 , where all the far-ultraviolet LEDs 42 are turned off. Thereafter, unless an operation to turn on is made again at step S 44 , the flow repeats steps S 42 and S 44 . When, in response, the indicated abnormality is corrected and an operation to turn on is made, the checks are made again starting at step S 46 .
[0056] If the transmitted radiation is found proper and the flow proceeds to step S 54 , a guidance is given out prompting an operation to open the main tap 6 , and subsequently, at step S 58 , an operation is waited for to switch the switch valve 8 to make it open for the water purifier 2 . In this while, it is preferable to make an indication or an announcement prompting manually operating the switch valve 8 . If, at step S 58 , an operation to make the switch valve 8 open for purified water is detected, the flow proceeds to step S 60 , where whether or not the water pressure is proper is checked; if the water pressure is proper, then, at step S 62 , whether or not the flow rate is equal to or higher than level 1 is checked. Here, if the flow rate is equal to or higher than level 1, that means that the main tap 6 and the switch valve 8 have been opened properly, and thus the flow proceeds to step S 64 , where the group of far-ultraviolet LEDs 22 in the sterilization tub 20 is turned on. It is here assumed that, at this time, the five seconds' light emission of all the far-ultraviolet LEDs started at step S 50 has ended, and thus they are now all off.
[0057] Next, at step S 66 , while the group of far-ultraviolet LEDs 22 is on, it is checked whether or not the transmitted far-ultraviolet radiation as detected by the water passage transmitted radiation receiving section 30 in the sterilization tub 20 is proper. Here, the check is made with water introduced in the sterilization tub 20 , and thus “whether proper or not” concerns not simply whether or not the group of far-ultraviolet LEDs 22 is lit but also whether or not the level of the radiation that has been transmitted through the water passage filled with water is proper. If the check at step S 66 finds the water passage transmitted radiation proper, the flow proceeds to step S 54 . Also here, the light emission of the group of far-ultraviolet LEDs 22 can be confirmed visually through the fluorescence observation window 28 . The check at step S 66 not only serves to check whether or not the transmitted radiation is proper but also serves to check whether or not, when a flow rate equal to or higher than level 1 is detected, the group of far-ultraviolet LEDs 22 is automatically turned on.
[0058] If the check at step S 66 finds the transmitted radiation proper, the flow proceeds to step S 68 , where an operation is waited for to close the switch valve 8 , which has been open for the water purifier 2 . In this while, it is preferable to make an indication or an announcement prompting a manual operation. When a manual operation is made, the flow ends. By contrast, if the check at step S 66 finds the transmitted radiation in the sterilization tub 20 improper, the flow proceeds to step S 70 , where the group of far-ultraviolet LEDs 22 is turned off, then the flow proceeds to step S 72 , where a corresponding alert is given out, and then the flow returns to step S 54 . If the check at step S 60 finds the water pressure improper, or if the check at step S 52 finds the flow rate not equal to or higher than level 1, the flow proceeds to step S 72 , where a corresponding alert is given out, and then the flow returns to step S 54 . Thus, it is possible to remove the possible cause for any abnormality and then perform the tests starting at step S 54 again.
[0059] FIG. 4 is a flow chart showing the details of the running water handling at step S 26 in FIG. 2 . When started, the flow proceeds as follows. At step S 82 , whether or not the flow rate is equal to or lower than level 2 (assuming that level 2>level 1) is checked. The flow in FIG. 4 having been started means that the flow rate is higher than level 1, and therefore what is done at step S 82 is checking whether or not the flow rate is between levels 1 and 2. If so, the flow proceeds to step S 84 , where the light emission duty factor of the group of far-ultraviolet LEDs 22 which operates under the PWM control by the drive circuit 26 in FIG. 1 is reduced, and the flow proceeds to step S 86 . In the running water handling, the group of far-ultraviolet LEDs 22 is mainly controlled, and accordingly, in FIG. 4 , for simplicity's sake, the “sterilization tub far-ultraviolet LEDs (the group of far-ultraviolet LEDs 22 )” are referred to simply as the “far-ultraviolet LEDs” as at step S 84 . This applies to the subsequent steps in FIG. 4 .
[0060] By contrast, if the check at step S 82 finds the flow rate higher than level 2, the flow proceeds to step S 33 , where whether or not the flow rate is equal to or lower than level 3 (assuming that level 3>level 2) is checked. If so, the flow proceeds to step S 90 , where the light emission duty factor of the group of far-ultraviolet LEDs 22 is set to be medium, and the flow proceeds to step S 86 . By contrast, if the check at step S 88 finds the flow rate higher than level 3, the flow proceeds to step S 92 , where the light emission duty factor of the group of far-ultraviolet LEDs 22 is increased, and the flow proceeds to step S 86 . Thus, at steps S 82 , S 84 , and S 88 through S 92 , as the flow rate increases, the light emission duty factor of the group of far-ultraviolet LEDs 22 is increased and thereby the radiated energy is increased. Although in FIG. 4 , the duty factor is adjusted in three steps, it may be adjusted in more steps, or steplessly, that is, continuously.
[0061] At step S 86 , whether or not the water temperature in the sterilization tub 20 is equal to or higher than a predetermined temperature is checked; if it is equal to or higher than the predetermined temperature, the flow proceeds to step S 94 , where an instruction is issued to feed water for cooling, and then the flow proceeds to step S 96 . In response to the instruction at step S 94 , the cooling water feeding section 34 starts operation involving passing cooling water through the additional water cooling passage, provided in a separate circuit, through the group of far-ultraviolet LEDs 22 and discharging water after heat exchange through the discharge port 36 . If the feeding of cooling water has already being started, it is continued. By contrast, if the check at step S 86 does not find the water temperature equal to or higher than the predetermined temperature, the flow proceeds to step S 98 , where an instruction is issued not to feed water, and then the flow proceeds to step S 96 . In response to the instruction at step S 98 , the cooling water feeding section 34 stops feeding cooling water. If, at this point, no feeding of cooling water is being done, this state with no water being fed is maintained.
[0062] At step S 96 , whether the component replacement lid 50 is not left open is checked. If the check finds no abnormality, the flow proceeds to step S 100 , where whether or not the light tightness sensor 52 is detecting leakage of light is checked. If this check too finds no abnormality, the flow proceeds to step S 102 , where it is checked whether or not the transmitted far-ultraviolet radiation as detected by the water passage transmitted radiation receiving section 30 is proper. If the check finds the transmitted radiation proper, the flow proceeds to step S 104 .
[0063] At step S 104 , whether or not the flow rate is equal to or higher than level 1 is checked. If the flow rate is equal to or higher than level 1, it is considered that water continues being served with the switch valve 8 open, and thus the flow returns to step S 82 . Thereafter, unless the flow rate becomes equal to or lower than level 1, steps S 82 through S 104 are repeated so as to cope with variation in the flow rate, variation in the water temperature, and various abnormalities. By contrast, if the check at step S 104 finds the flow rate to have become equal to or lower than level 1, the flow proceeds to step S 106 , where the group of far-ultraviolet LEDs 22 is turned off, and then the flow ends.
[0064] If the check at step S 96 finds the component replacement lid 50 in an open state, or if the check at step S 100 finds incomplete light tightness, or if the check at step S 102 finds the transmitted far-ultraviolet radiation improper, then in any case the flow proceeds to step S 108 , where an alert of the corresponding abnormality is given out. Next, the flow proceeds to step S 110 , where, under the control of the control section 24 , the switch valve 8 is forcibly closed, and then the flow proceeds to step S 106 . At step S 106 , the group of far-ultraviolet LEDs 22 is turned off, and the flow ends.
[0065] FIG. 5 is a flow chart showing the details of the stored water handling at step S 34 in FIG. 2 . When started, the flow proceeds as follows. At step S 122 , it is checked whether or not the stored water handling has been started because of long-time storage of water. If the reason is long-time storage of water, the flow proceeds to step S 124 , where the group of far-ultraviolet LEDs 22 and the group of far-ultraviolet LEDs 46 are turned off. Next, at step S 126 , the drain valve 44 is opened to start draining the purified water reservoir 40 , and then step S 128 is repeated until the purified water reservoir 40 becomes empty.
[0066] If, at step S 128 , the purified water reservoir 40 is found to be empty, the flow proceeds to step S 130 , where the group of far-ultraviolet LEDs 22 and the group of far-ultraviolet LEDs 46 are turned on, and in addition the drain valve 44 is closed. The flow then proceeds to step S 132 , where whether or not the water level in the purified water reservoir 40 is equal to or higher than a predetermined level is checked. If the flow has proceeded from step S 130 to step S 132 , the water level is naturally equal to or lower than the predetermined level, and therefore the flow proceeds to step S 134 , where the light emission duty factor of the group of far-ultraviolet LEDs 22 is reduced. Next, at step S 136 , the reservoir valve 38 is fully opened, and the flow then proceeds to step S 138 . Here, when the reservoir valve 38 is fully opened, the flow rate at the flowmeter 12 is equal to or lower than level 1. Thus, even when the reservoir valve 38 is opened, the flow does not proceed from step S 20 in FIG. 2 to the running water handling.
[0067] By contrast, if the check at step S 132 finds the water level equal to or higher than the predetermined level, the flow proceeds to step S 140 , where the light emission duty factor of the group of far-ultraviolet LEDs 22 is set to be very low; then, at step S 136 , the reservoir valve 38 is half-opened, and then the flow proceeds to step S 138 . In this way, when the water level in the purified water reservoir 40 is equal to or higher than the predetermined level, the reservoir rate is reduced, and the energy from the group of far-ultraviolet LEDs 22 is minimized.
[0068] At step S 138 , whether or not the water temperature in the sterilization tub 20 is equal to or higher than a predetermined temperature is checked; if it is equal to or higher than the predetermined temperature, the flow proceeds to step S 144 , where an instruction is issued to feed cooling water, and then the flow proceeds to step S 148 . The details of the feeding of cooling water are as discussed above. Moreover, as mentioned above, if the feeding of cooling water has already been started, it is continued. By contrast, if the check at step S 138 does not find the water temperature equal to or higher than the predetermined temperature, the flow proceeds to step S 146 , where an instruction is issued not to feed water, and then the flow proceeds to step S 148 . Also as discussed above, if, at this point, no feeding of cooling water is being done, this state with no water being fed is maintained.
[0069] At step S 148 , whether or not the water level in the purified water reservoir 40 is full is checked. If it is not full, the flow returns to step S 132 ; thereafter, steps S 132 through S 148 are repeated so that water continues being stored in accordance with the water level and the water temperature. By contrast, if the check at step S 148 finds the water level in the purified water reservoir 40 full, the flow proceeds to step S 150 , where the reservoir valve 38 is closed and then at step S 152 , the group of far-ultraviolet LEDs 22 is turned off; the flow then ends. It should be noted that the group of far-ultraviolet LEDs 46 in the purified water reservoir 40 is kept on so long as water is stored in the purified water reservoir 40 .
[0070] FIG. 6 is a block diagram showing the detailed configuration of the sterilization device 18 and the purified water reservoir 40 in the embodiment shown in FIG. 1 . Common parts are identified by common reference signs, and no overlapping description will be repeated unless necessary. First, a description will be given of the detailed configuration of the sterilization device 18 . The sterilization tub 20 is specifically configured to include a quartz glass water passage 120 that leads from the absorption tub 16 , passes through the sterilization device 18 , and leads to the switch valve 8 or the reservoir valve 38 . The direction of the water flowing through the water passage is indicated by short arrows from place to place. This applies to other configurations described below. As shown in FIG. 6 , the group of far-ultraviolet LEDs 22 is disposed between folded parts of the quartz glass water passage 120 , and are so arranged that the water flowing through the quartz glass water passage 120 passes by the individual far-ultraviolet LEDs one after another and that the water simultaneously cools down the far-ultraviolet LEDs.
[0071] The group of far-ultraviolet LEDs 22 is arranged in an array on a metal heat-dissipating substrate 122 , and is, from outside, covered by a quartz glass package 124 . Here, the rear face of the heat-dissipating substrate 122 is exposed outside the quartz glass package 124 . This allows the quartz glass water passage 120 to remain in close contact with the rear face of the heat-dissipating substrate 122 , and thus enhances the effect of cooling down the rear side of the heat-dissipating substrate 122 by the water flowing through the quartz glass water passage 120 . The water passage transmitted radiation receiving section 30 receives ultraviolet radiation emitted from the group of far-ultraviolet LEDs 22 and transmitted through the quartz glass water passage 120 . This makes it possible to confirm the emission of ultraviolet radiation from the group of far-ultraviolet LEDs 22 , and to detect dirt or the like inside the quartz glass water passage 120 by detecting a lowering in the intensity of the transmitted radiation. The water temperature meter 32 is provided near the exit of the quartz glass water passage 120 , where the heat applied to the water accumulates.
[0072] The cooling water feeding section 34 has a water feed valve 126 and a cooling tub 128 which are controlled by the control section 24 . The cooling tub 128 serves to immerse, directly in the water that has entered it from the water feed valve 126 , and thereby cool the quartz glass package 124 of the group of far-ultraviolet LEDs 22 and the rear face of the heat-dissipating substrate 122 . The water that has been used for cooling is discharged through the drain port 36 . Thus, the water in the cooling water feeding section 34 , by making direct contact with the rear face of the heat-dissipating substrate 122 , exerts a more powerful cooling effect, and does not mix with the purified water passing through the quartz glass water passage 120 .
[0073] Like the group of far-ultraviolet LEDs 22 in the sterilization device 18 , the group of far-ultraviolet LEDs 46 in the purified water reservoir 40 is arranged in an array on a metal heat-dissipation substrate 130 , and a quartz glass package 132 here covers the group of far-ultraviolet LEDs 46 including the rear face of the heat-dissipation substrate 130 . Similarly configured is a group of far-ultraviolet LEDs covered by a lower quartz glass package 134 . Thus, in the purified water reservoir 40 , units, that is, groups, of far-ultraviolet LEDs, each unit having a structure entirely covered in a quartz glass package, are immersed directly in purified water, with those units stacked in horizontal layers. The purpose of covering the back face of the heat-dissipation substrate 130 with the quartz glass package 132 as described above is to prevent the stored purified water making direct contact with the heat-dissipation substrate 130 and thereby being contaminated; at the back face of the heat-dissipation substrate 130 , the quartz glass package 132 is extremely thin, and through this thin layer of the quartz glass package 132 , heat dissipates efficiently from the back face of the heat-dissipation substrate 130 to the stored water.
[0074] A water level meter 136 monitors the water level of the stored purified water and conveys it to the control section 24 . Based on the conveyed water level, the control section 24 instructs a drive circuit 48 to control the group of far-ultraviolet LEDs 46 . Specifically, when the water level is so low that only the group of far-ultraviolet LEDs covered by the lower quartz glass package 132 is submerged in purified water, then only lower unit, that is, group, of far-ultraviolet LEDs is turned on; when the water level is so high that also the upper unit, that is, group, of far-ultraviolet LEDs covered by the quartz glass package 132 is submerged in purified water, then both units, that is, groups, of the far-ultraviolet LEDs are turned on. This makes it possible to prevent, for example, the upper group of far-ultraviolet LEDs, which appears above the water surface when the water level is low, from being kept driven meaninglessly in an uncoolable condition. Although FIG. 6 shows units, that is, groups, of far-ultraviolet LEDs in two horizontal layers for simplicity's sake, a number of such layers may be provided and are turned on and off more finely according to the water level.
[0075] Through a fluorescence observation window 138 , which is omitted in FIG. 1 , the light emission of the group of far-ultraviolet LEDs 46 in the purified water reservoir 40 can be checked visually. A transmitted radiation receiving section 140 , which too is omitted in FIG. 1 , serves to receive and convey to the control section 24 the ultraviolet radiation emitted from the group of far-ultraviolet LEDs 46 configured as described above and transmitted through the purified water stored in the purified water reservoir 40 .
[0076] As described above, according to the present invention, to make a water purifier employing far-ultraviolet LEDs suitable for general use as for use in households, in such a water purifier, various safety measures are adopted to prevent unforeseeable accidents resulting from exposure to ultraviolet radiation. In addition, in the embodiment of the invention, with consideration given also to accidents that may occur if the water purifier 2 is disassembled and the group of far-ultraviolet LEDs 22 or 46 is taken out and misused (used for unintended uses), the group of far-ultraviolet LEDs 22 and 46 are so configured that, when separated from the water purifier 2 , they alone do not generate ultraviolet radiation. Specifically, the following configuration is adopted: a misuse prevention contact is provided among the contacts on the quartz glass package covering the far-ultraviolet LEDs, and a misuse prevention check circuit is provided within the quartz glass package; unless the misuse prevention check circuit recognizes an encryption key signal being fed from the water purifier 2 to the misuse prevention contact, the group of far-ultraviolet LEDs 22 and 46 do not emit ultraviolet radiation. Moreover, misuse prevention internal leads are provided in individual far-ultraviolet LEDs for connection to the heat-dissipating substrate 122 or 130 so that, when individual far-ultraviolet LEDs 22 or 46 are removed carelessly from the heat-dissipating substrate 122 or heat-dissipation substrate 130 , they are mechanically affected in such a way that the misuse prevention internal leads are broken and make the individual far-ultraviolet LEDs 22 or 46 unusable thereafter.
[0077] To follow is a summary of the various technical features disclosed in the present description.
[0078] The technology disclosed in the present description provides a water purifier that includes: a source water inlet through which source water is fed in from outside the enclosure; a purification section; an ultraviolet radiation sterilization section which has an ultraviolet light source; a purified water outlet through which purified water purified by the purification section and sterilized by the ultraviolet radiation sterilization section is fed out to outside the enclosure; a detection section which detects a condition in which ultraviolet radiation can leak from inside to outside the enclosure; and a control section which, when the detection section detects a condition in which ultraviolet radiation can leak, inhibits the ultraviolet light source from generating ultraviolet radiation. This makes it possible to provide a water purifier provided with an ultraviolet radiation sterilizing ability for general use as for use in households in a form free from a risk of exposure to ultraviolet radiation. According to a specific feature of the technology disclosed in the present description, as the light source in the ultraviolet radiation sterilization section, a far-ultraviolet LED is adopted. Far-ultraviolet radiation has a powerful sterilizing ability and is accordingly hazardous; thus its handling requires caution. However, with the above feature of the technology disclosed in the present description, far-ultraviolet radiation can be used suitably in water purifiers for general use as for use in households
[0079] According to a specific feature of the technology disclosed in the present description, a lid for maintenance inside the water purifier is provided in the enclosure, and the detection section detects whether or not the lid is in an improperly closed state. This makes it possible to prevent exposure to ultraviolet radiation when the lid is opened for maintenance or when it is closed incompletely. According to another specific feature of the technology disclosed in the present description, the detection section detects leakage of light from outside to inside the enclosure. This makes it possible to detect, conversely, a condition in which ultraviolet radiation is leaking from inside to outside the enclosure, and thus it is possible to prevent exposure to ultraviolet radiation resulting from unexpected breakage or failure of the water purifier.
[0080] According to another specific feature of the technology disclosed in the present description, while the water purifier is in use, the control section inhibits the ultraviolet light source from generating ultraviolet radiation. This makes it possible to prevent exposure to ultraviolet radiation when a condition in which ultraviolet radiation can leak arises in different modes of use of the water purifier as during ordinary use of the water purifier or during regular maintenance of the water purifier. According to another specific feature of the technology disclosed in the present description, the control section inhibits the ultraviolet light source from generating ultraviolet radiation when generation of ultraviolet radiation is attempted to test the water purifier. This makes it possible to prevent ultraviolet radiation exposure accidents when generation of ultraviolet radiation is attempted in a condition in which ultraviolet radiation can leak as when the water purifier is installed or when it is subjected to regular checks. There may be provided an alerting section that gives out an alert when the detection section detects a condition in which ultraviolet radiation can leak due to various causes in various situations; this suitably makes it possible to recognize the cause for the prohibition of ultraviolet radiation generation.
[0081] According to another feature of the technology disclosed in the present description, a water purifier is provided that includes: a source water inlet through which source water is fed in from outside an enclosure; a purification section; an ultraviolet radiation sterilization section which has a quartz glass water passage and a far-ultraviolet LED for letting far-ultraviolet radiation be transmitted through the quartz glass water passage; and a purified water outlet through which purified water purified by the purification section and sterilized by the ultraviolet radiation sterilization section is fed out to outside the enclosure. With this feature, owing to the use of an LED as the ultraviolet light source, it is possible to configure an ultraviolet radiation sterilization section that offers a powerful sterilizing effect, that is compact, and that operates with low electric power consumption, and thus it is possible to provide a water purifier having a sterilizing ability for general use as for use in households.
[0082] According to another specific feature of the technology disclosed in the present description, there is provided a detection section which detects a flaw in transmission of far-ultraviolet radiation through the quartz glass water passage. This makes it possible to recognize how far-ultraviolet radiation is being transmitted at a place where sterilization is actually taking place, and to be prepared for a lowering in the sterilizing effect due to such a flaw. According to a more detailed feature, there is provided a control section which, when the detection section detects a flaw in transmission of far-ultraviolet radiation, inhibits the ultraviolet light source from generating ultraviolet radiation. This makes it possible to prevent generation of far-ultraviolet radiation from being continued despite a lowering in the sterilizing effect. According to another more detailed feature, there is provided an alerting section which, when the detection section detects a flaw in transmission of far-ultraviolet radiation, gives out an alert calling attention to it. This makes it possible to recognize the cause for the flaw.
[0083] According to another feature of the technology disclosed in the present description, a water purifier is provided that includes: a source water inlet through which source water is fed in from outside an enclosure; a purification section; an ultraviolet radiation sterilization section which has an ultraviolet light source; a purified water outlet through which purified water purified by the purification section and sterilized by the ultraviolet radiation sterilization section is fed out to outside the enclosure; and a control section which controls generation of ultraviolet radiation by the ultraviolet light source according to the detection by a detection section which detects a purified water outflow state in which purified water is flowing out through the purified water outlet. This makes it possible to control generation of ultraviolet radiation in a way that suits how purified water is flowing out through the purified water outlet. For example, it is possible to adopt a configuration in which, when the detection section detects the purified water outflow state, the ultraviolet light source is permitted to generate ultraviolet radiation and, when the detection section does not detect the purified water outflow state, the ultraviolet light source is inhibited from generating ultraviolet radiation. A preferred example of the purification section is a filtering section combined with an absorbing section.
[0084] According to another feature of the technology disclosed in the present description, a water purifier is provided that includes: a source water inlet through which source water is fed in from outside an enclosure; a purification section; a reservoir section in which purified water purified by the purification section is stored; a purified water outlet through which the purified water stored in the reservoir section is fed out to outside the enclosure; and an ultraviolet radiation sterilization section which sterilizes the purified water before the purified water flows out through the purified water outlet. Providing the reservoir section in this way makes it possible to secure purified water through sterilization performed little by little for a sufficient length of time.
[0085] According to a specific feature of the technology disclosed in the present description, the far-ultraviolet LED is provided inside the reservoir section. This makes it possible to secure a sufficient length of sterilization time for a given part of the purified water. According to another specific feature of the technology disclosed in the present description, the far-ultraviolet LED is controlled according to the amount of water stored in the reservoir section. This makes it possible to control the far-ultraviolet LED rationally. According to yet another specific feature of the technology disclosed in the present description, there is provided a control section which, when the purified water in the reservoir section has been stored there for more than a predetermined length of time, discharges the purified water. This makes it possible to prevent inconveniences resulting from long-time storage of time. More specifically, when the purified water in the reservoir section is discharged, the far-ultraviolet LED is inhibited from generating ultraviolet radiation to prevent unnecessary generation of ultraviolet radiation. According to another feature of the technology disclosed in the present description, the reservoir section is configured to store purified water that has passed through the ultraviolet radiation sterilization section. In any case, it is preferable that the far-ultraviolet LED generate far-ultraviolet radiation when water is stored in the reservoir section.
[0086] According to another feature of the technology disclosed in the present description, a purified water is provided that includes: a source water inlet through which source water is fed in from outside the enclosure; a purification section; an ultraviolet radiation sterilization section which has a far-ultraviolet LED as a light source; a purified water outlet through which purified water purified by the purification section and sterilized by the ultraviolet radiation sterilization section is fed out to outside the enclosure; a control section which controls generation of ultraviolet radiation from the far-ultraviolet LED; and a fluorescence guide section which makes the ultraviolet radiation generated by the far-ultraviolet LED visible from outside the enclosure in a form of visible fluorescence having ultraviolet radiation eliminated therefrom. This makes it possible to visually confirm generation of ultraviolet radiation by the far-ultraviolet LED controlled by the control section, and serves as an appealing feature of the product that indicates that the water purifier has an ultraviolet radiation sterilizing ability.
[0087] The technology disclosed in the present description provides a water purifier that includes: a water inlet; an ultraviolet radiation sterilization section which sterilizes water flowing in through the water inlet with a far-ultraviolet LED as a light source; a water outlet through which purified water sterilized by the ultraviolet radiation sterilization section is fed out, and a cooling section which cools down the far-ultraviolet LED with water flowing in through the water inlet. As an LED generates heat, its light emission efficiency lowers. However, with the above feature of the technology disclosed in the present description, the far-ultraviolet LED can be cooled down with the water that flows in for purification. Thus, it is possible to produce purified water effectively without a lowering in the sterilizing effect.
[0088] According to a specific feature of the technology disclosed in the present description, the cooling section cools down the far-ultraviolet LED with the very water flowing in through the water inlet and flowing out through the water outlet. This makes it possible to realize a configuration that integrates together the sterilization of water by the far-ultraviolet LED and the cooling of the far-ultraviolet LED with that water. According to a more specific feature of the technology disclosed in the present description, the cooling section has a water passage through which the water exposed to the ultraviolet radiation generated by the far-ultraviolet LED is passed to cool down the far-ultraviolet LED. According to a further specific feature of the technology disclosed in the present description, the far-ultraviolet LED has an ultraviolet light emitting portion and a heat dissipating portion, and the water passage is arranged to run across the ultraviolet light emitting portion and the heat dissipating portion.
[0089] According to another specific feature of the technology disclosed in the present description, the cooling section has a cooling water passage through which cooling water is passed which flows in through the water inlet but does not mix with the purified water flowing out through the water outlet. With this feature, the necessary amount of water for cooling can be secured independently of the amount of sterilized purified water, and since the thus secured cooling water does not mix with the purified water, its insufficient sterilization does not matter.
[0090] According to a more specific feature of the technology disclosed in the present description, the cooling section cools down the far-ultraviolet LED with the very water flowing in through the water inlet and flowing out through the water outlet, and in addition has a water feeding section which, when the cooling is insufficient, introduces water from the water inlet into the cooling water passage. This makes it possible to perform cooling effectively first with the sterilized water itself and, when the cooling is insufficient, to additionally use the cooling ability of the cooling water passage. According to a further specific feature of the technology disclosed in the present description, whether or not water from the water inlet is introduced into the cooling water passage is determined according to the water temperature in the water outlet.
[0091] According to another feature of the technology disclosed in the present description, a water purifier is provided that includes: a reservoir section; an ultraviolet radiation sterilization section which sterilizes water stored in the reservoir section with a far-ultraviolet LED as a light source and which has a heat dissipation structure in which the far-ultraviolet LED is cooled down with the very water stored in the reservoir section. This makes it possible to realize a configuration that integrates together the sterilization of water by the far-ultraviolet LED structure immersed in water in the reservoir section and the cooling of the far-ultraviolet LED structure achieved by its immersion in water in the reservoir section.
[0092] According to a more specific feature of the technology disclosed in the present description, as the heat dissipation structure, a metal heat dissipating plate connected to the far-ultraviolet LED is adopted. According to a further specific feature of the technology disclosed in the present description, the metal heat dissipating plate is coated so as not to make direct contact with the water stored in the reservoir section. This makes it possible to prevent purified water from being contaminated as a result of the sterilization structure being immersed in water in the reservoir section. According to another specific feature related to the technology disclosed in the present description, the far-ultraviolet LED is controlled according to the water level of the water stored in the reservoir section. This makes it possible, for example, to prevent a part of the sterilization structure that appears above the water surface when the water level is low from being kept driven meaninglessly in an uncoolable condition.
[0093] According to another feature of the technology disclosed in the present description, a water purifier is provided that includes: an ultraviolet radiation sterilization section which sterilizes water with a far-ultraviolet LED as a light source; a cooling section which cools down the far-ultraviolet LED with water; and a drive section which drives the far-ultraviolet LED such that an ultraviolet radiation generation period and an ultraviolet radiation non-generation/cooling period alternate. This makes it possible to integrate together, in a water purifier that treats water, the provision of an ultraviolet radiation non-generation/cooling period of the far-ultraviolet LED and the cooling of the far-ultraviolet LED with water, and thus it is possible to effectively realize a water purifier that offers an sterilizing effect. According to a specific feature of the technology disclosed in the present description, there are further provided a water inlet and a water outlet through which purified water sterilized by the ultraviolet radiation sterilization section is fed out, and the cooling section cools down the far-ultraviolet LED with the very water flowing in through the water inlet and flowing out through the water outlet. This makes it possible to realize a specific configuration that makes the most of the features mentioned above. According to a more specific feature of the technology disclosed in the present description, the drive section for the far-ultraviolet LED varies the ultraviolet radiation energy generated by the far-ultraviolet LED, and uses the ultraviolet radiation generation period and the ultraviolet radiation non-generation/cooling period by varying their ratio.
[0094] According to another feature of the technology disclosed in the present description, a water purifier is provided that includes: a water inlet; an ultraviolet radiation sterilization section which sterilizes water flowing in through the water inlet with a far-ultraviolet LED as a light source; a water outlet through which purified water sterilized by the ultraviolet radiation sterilization section is fed out; and a control section which controls the ultraviolet radiation energy generated by the far-ultraviolet LED according to the flow rate at which water flows out through the water outlet. This makes it possible to perform sterilization according to the amount of purified water needed.
[0095] According to another feature of the technology disclosed in the present description, an ultraviolet radiation sterilization section which sterilizes water with a far-ultraviolet LED as a light source; a power supply section which is supplied with electric power from outside to drive the far-ultraviolet LED and which has a secondary battery charged with the supplied electric power; and a control section which normally supplies the far-ultraviolet LED with the electric power supplied from the outside and which, under a predetermined condition, even when electric power is being supplied from outside, supplies the far-ultraviolet LED with electric power from the secondary battery. This makes it possible to check the functioning of the secondary battery every time the predetermined condition is fulfilled, and thereby to prevent a situation in which the secondary battery does not function when the far-ultraviolet LED really needs to be supplied with electric power from the secondary battery in an emergency such as a power outage. According to a specific feature of the technology disclosed in the present description, there is further provided a water outlet through which water sterilized by the ultraviolet radiation sterilization section is fed out, and the control section supplies the far-ultraviolet LED with electric power from the secondary battery according to how water is flowing out through the water outlet. This is one rational example of the predetermined condition mentioned above.
INDUSTRIAL APPLICABILITY
[0096] According to the present invention, it is possible to realize a water purifier that is provided with a sterilizing ability but is nevertheless fit for general use as for use in households.
LIST OF REFERENCE SIGNS
[0000]
2 enclosure
7 source water inlet
14 , 16 purification section
22 ultraviolet light source
20 ultraviolet radiation sterilization section
37 purified water outlet
50 , 52 detection section
24 control section
22 far-ultraviolet LED
50 lid
52 light tightness sensor
54 alerting section
30 water passage transmitted radiation receiving section
12 purified water outflow state detection section
14 filtering section
16 absorption section
42 purified water outlet from reservoir section
22 , 46 ultraviolet radiation sterilization section
46 ultraviolet radiation sterilization section in reservoir section
44 purified water discharge section
28 fluorescence guide section
7 water inlet
22 far-ultraviolet LED
20 ultraviolet radiation sterilization section
37 water outlet
120 cooling section
120 water passage
22 ultraviolet light emitting portion
122 heat dissipating portion
128 cooling water passage
126 feeding section
24 control section
40 reservoir section
46 far-ultraviolet LED
130 heat dissipation structure
132 , 134 coat
26 , 48 drive section
60 secondary battery
58 power supply section | The disclosed water purifier comprises an outer wall, a RAW water inflow section that allows inflow of RAW water from outside said outer wall, a purifying section, an ultraviolet ray sterilizing section that has an ultraviolet ray source, a purified water outflow section that allows purified water that has been purified in said purifying section and sterilized in said ultraviolet ray sterilizing section to flow to the outside of said outer wall, a condition-detecting unit, and a control unit that controls generation of ultraviolet rays from said ultraviolet ray source according to the detection by said condition-detecting unit. | 75,992 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2011-267539, filed on Dec. 7, 2011, the entire contents of which are incorporated herein by reference.
FIELD
[0002] The embodiments discussed herein are related to an amplifier.
BACKGROUND
[0003] The number of frequency bands utilized in a mobile communication system has been increased. Recently, in the mobile communication system, a service is provided in multiple bands (multiband). More specifically, the service is provided in a 700 MHz band, an 800 MHz band, a 1.5 GHz band, a 1.7 GHz band, a 2.1 GHz band, and a 2.5 GHz band in the mobile communication system.
[0004] An amplifier used for a base station in the mobile communication system is requested to have a high efficiency performance. To satisfy the request of the high efficiency performance, the Doherty amplifier is adopted in many cases. The Doherty amplifier includes a carrier-amplifier and a peak-amplifier arranged in parallel. The carrier-amplifier regularly operates, and the peak-amplifier operates only at the time of a high output.
[0005] In the base station, an amplifier is prepared for each frequency band. However, the preparation of the amplifier for each frequency band is not preferable from viewpoints of a design, a cost, and an amount of resources. Therefore, a Doherty amplifier that can cope with the multiband by a single amplifier is desired.
[0006] A technique for achieving the high efficiency performance with respect to the multiband by switching, using a switch, an electrical length of an output power combining circuit of the Doherty amplifier in accordance with the frequency band is proposed (for example, see Japanese Laid-open Patent Publication No. 2006-345341).
SUMMARY
[0007] According to an aspect of the invention, an amplifier includes a first amplification element configured to amplify a first signal in one of a first operation class and a second operation class, a second amplification element configured to amplify a second signal in one of a first operation class and a second operation class, a first transmission line through which the amplified first signal is transferred, and a coupler configured to couple the first signal transferred through the first transmission line and the amplified second signal so as to transfer the coupled signal to a second transmission line, wherein the first amplification element amplifies the first signal in the first operation class and the second amplification element amplifies the second signal in the second operation class, when the first signal and the second signal have a first frequency band, and wherein the first amplification element amplifies the first signal in the second operation class and the second amplification element amplifies the second signal in the first operation class, when the first signal and the second signal have a second frequency band.
[0008] The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims.
[0009] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF DRAWINGS
[0010] FIG. 1 illustrates a base station according to a first embodiment;
[0011] FIG. 2 illustrates another base station according to the first embodiment;
[0012] FIG. 3 illustrates a transmission unit according to the first embodiment;
[0013] FIG. 4 illustrates an amplifier according to the first embodiment;
[0014] FIG. 5 is a Smith chart illustrating an example of an impedance matching by input matching circuits;
[0015] FIG. 6 is a Smith chart illustrating an example of an impedance matching by output matching circuits;
[0016] FIG. 7 is a flowchart of an operation by the amplifier according to the first embodiment;
[0017] FIG. 8 illustrates a transmission unit according to a second embodiment;
[0018] FIG. 9 illustrates an amplifier according to the second embodiment; and
[0019] FIG. 10 is a flowchart of an operation by the amplifier according to the second embodiment.
DESCRIPTION OF EMBODIMENTS
[0020] Hereinafter, embodiments will be described based on the drawings. In all the drawings for describing the embodiments, the same reference sign is used for elements having the same function, and a repeated description thereof will be omitted.
First Embodiment
<Base Station 100 >
[0021] FIG. 1 illustrates a base station 100 according to an embodiment. The base station 100 includes amplification units 102 ( 102 1 to 102 6 ), modulation units 104 ( 104 1 to 104 6 ), control units 106 ( 106 1 to 106 6 ), and power units 108 ( 108 1 to 108 6 ). A base station may be configured by including units represented by the same suffix.
[0022] FIG. 1 illustrates a case in which the base station 100 includes six amplification units 102 1 to 102 6 . However, the number of the amplification units 102 is not limited to six, and one or two to five amplification units, or seven or more amplification units may be included. FIG. 1 illustrates a case in which the base station 100 includes six modulation units 104 1 to 104 6 . However, the number of the modulation units 104 is not limited to six, and one or two to five modulation units, or seven or more modulation units may be included. FIG. 1 illustrates a case in which the base station 100 includes six control units 106 1 to 106 6 . However, the number of the control units 106 is not limited to six, and one or two to five control units, or seven or more control units may be included. FIG. 1 illustrates a case in which the base station 100 includes six power units 108 1 to 108 6 . However, the number of the power units 108 is not limited to six, and one or two to five power units, or seven or more power units may be included.
[0023] For example, the amplification units 102 1 to 102 6 , the modulation units 104 1 to 104 6 , the control units 106 1 to 106 6 , and the power units 108 1 to 108 6 may have a card-like shape. The base station is configured by storing the respective units in a casing of the base station.
<Base Station 200 >
[0024] FIG. 2 illustrates a base station 200 according to the embodiment. The base station 200 includes Remote Radio Heads (RRHs) 202 ( 202 1 to 202 3 ) and a Base Band Unit (BBU) 208 . FIG. 2 illustrates a case in which the base station 200 includes three RRHs 202 1 to 202 3 . The number of the RRH 202 is not limited to three, and one or two, or four or more remote radio heads may be included.
[0025] The RRH 202 is a wireless unit of the base station. More specifically, the RRH 202 includes modulation units 206 ( 206 1 to 206 3 ) configured to perform modulation processing on transmission data. The RRH 202 also includes amplification units 204 ( 204 1 to 204 3 ) configured to amplify a signal on which the modulation processing is performed by the modulation unit 206 . The BBU 208 is configured to perform base band signal processing.
<Transmission Unit 300 >
[0026] FIG. 3 illustrates a transmission unit 300 according to the embodiment. The transmission unit 300 may be mainly included in the amplification unit 102 , the modulation unit 104 in the base station 100 illustrated in FIG. 1 and the RRH 202 in the base station 200 illustrated in FIG. 2 .
[0027] The transmission unit 300 includes modulation circuits 302 1 and 302 2 , digital-to-analog (D/A) converters 304 1 and 304 2 , preamplifiers 306 1 and 306 2 , an amplifier 308 , a filter 310 , an antenna 312 , and a phase conversion circuit 314 . The amplifier 308 is achieved by the Doherty amplifier.
[0028] The modulation circuits 302 1 and 302 2 are configured to modulate the transmission signal. The modulation circuit 302 1 sends out the modulated transmission signal to the D/A converter 304 1 . The modulation circuit 302 2 sends out the modulated transmission signal to the D/A converter 304 2 .
[0029] The D/A converters 304 1 and 304 2 are respectively connected to the modulation circuits 302 1 and 302 2 . The D/A converters 304 1 and 304 2 convert the modulated transmission signal from a digital signal to an analog signal. The D/A converter 304 1 sends out the signal converted into the analog signal to the preamplifier 306 1 . The D/A converter 304 2 sends out the signal converted into the analog signal to the preamplifier 306 2 .
[0030] The preamplifiers 306 1 and 306 2 are respectively connected to the D/A converters 304 1 and 304 2 . The preamplifiers 306 1 and 306 2 amplify the analog signals from the D/A converters 304 1 and 304 2 . The preamplifier 306 1 sends out the amplified analog signal to the amplifier 308 . The preamplifier 306 2 sends out the amplified analog signal to the phase conversion circuit 314 .
[0031] The phase conversion circuit 314 is connected to the preamplifier 306 2 . The phase conversion circuit 314 shifts a phase of the signal from the preamplifier 306 2 by 90 degrees. The phase conversion circuit 314 sends out the signal from the preamplifier 306 2 the phase of which is shifted by 90 degrees to the amplifier 308 . Specifically, the phase conversion circuit 314 delays the phase of the signal from the preamplifier 306 2 by 90 degrees. The phase of the signal from the preamplifier 306 2 is delayed by 90 degrees because the signal from a carrier-amplifier and the signal from a peak-amplifier are coupled to each other at a phase difference by 90 degrees in the Doherty amplifier.
[0032] The amplifier 308 is connected to the preamplifier 306 1 and the phase conversion circuit 314 . The amplifier 308 utilizes the signal from the preamplifier 306 1 and the signal from the phase conversion circuit 314 to amplify the power up to an average power level by the carrier-amplifier and operate the peak-amplifier from a point in the middle of the power elevation. The amplifier 308 synthesizes the signal amplified by the carrier-amplifier with the signal amplified by the peak-amplifier. With the amplification by the carrier-amplifier, it is possible to improve the amplification efficiency. With the operation by the peak-amplifier, it is also possible to obtain the maximum power. The amplifier 308 sends out the amplified signal obtained by utilizing the signal from the preamplifier 306 1 and the signal from the phase conversion circuit 314 to the filter 310 .
[0033] The filter 310 is connected to the amplifier 308 . The filter 310 performs a band limitation on the signal from the amplifier 308 and sends out the signal to the antenna 312 .
[0034] The antenna 312 is connected to the filter 310 . The antenna 312 wirelessly transmits the signal on which the filter 310 performs the band limitation.
<Amplifier 308 >
[0035] FIG. 4 illustrates the amplifier 308 according to the embodiment. The amplifier 308 operates corresponding to plural bands, that is, multiband. Specifically, the amplifier 308 operates corresponding to the 700 MHz band, the 800 MHz band, the 1.5 GHz band, the 1.7 GHz band, the 2.1 GHz band, and the 2.5 GHz band.
[0036] A case will be described in which the amplifier 308 according to the embodiment operates corresponding to the 700 MHz band and the 2.1 GHz band among the plural bands. The present embodiment can also similarly be applied to a case in which the amplifier 308 operates corresponding to other frequencies without a limitation on the case in which the amplifier 308 operates corresponding to 700 MHz band and the 2.1 GHz band.
[0037] The amplifier 308 includes input matching circuits 402 1 and 402 2 , amplification elements 404 1 and 404 2 , the output matching circuits 406 1 and 406 2 , and transmission lines 408 and 410 . For example, the amplification elements 404 1 and 404 2 may be a semiconductor device such as an LD-MOS (Lateral Double-Diffused MOS), a GaAs-FET, an HEMT, or an HBT.
[0038] In the amplifier 308 , between a bias voltage operating in Class AB and a bias voltage operating in Class C, voltages applied to the amplification elements 404 1 and 404 2 are switched. More specifically, in a case where the input signal is a signal in the 700 MHz band, the bias voltage to operate in Class AB is applied to the amplification element 404 1 , and the bias voltage to operate in Class C is applied to the amplification element 404 2 . Since the amplification element 404 1 receives the bias voltage to operate in Class AB, the amplification element 404 1 functions as the carrier-amplifier of the Doherty amplifier. Since the amplification element 404 2 receives the bias voltage to operate in Class C, the amplification element 404 2 functions as the peak-amplifier of the Doherty amplifier. The input signals are the signals from the preamplifier 306 1 and the phase conversion circuit 314 .
[0039] Further, in a case where the input signal is a signal in the 2.1 GHz band, the bias voltage to operate in Class C is applied to the amplification element 404 1 , and the bias voltage to operate in Class AB is applied to the amplification element 404 2 . Since the amplification element 404 1 receives the bias voltage to operate in Class C, the amplification element 404 1 functions as the peak-amplifier of the Doherty amplifier. Since the amplification element 404 2 receives the bias voltage to operate in Class AB, the amplification element 404 2 functions as the carrier-amplifier.
[0040] By switching the bias voltages to be applied to the amplification elements 404 1 and 404 2 , the amplification elements 404 1 and 404 2 can switch the functions between the function as the carrier-amplifier and the function as the peak-amplifier of the Doherty amplifier.
[0041] The input matching circuit 402 1 is connected to the preamplifier 306 1 . The input matching circuit 402 1 converts an impedance of the signal from the preamplifier 306 1 to be matched with an input impedance of the amplification element 404 1 . The input matching circuit 402 1 sends out the impedance-converted signal to the amplification element 404 1 .
[0042] The amplification element 404 1 is connected to the input matching circuit 402 1 . The amplification element 404 1 is an amplification element configured to amplify the signal. The amplification element 404 1 is biased to Class AB or Class C. That is, the amplification element 404 1 receives, as the bias voltage, the voltage that is applied for operating the amplification element 404 1 in Class AB or the voltage that is applied for operating the amplification element 404 1 in Class C. Since the amplification element 404 1 receives the voltage to an extent where the operation class is changed, the amplification element 404 1 can be operated as the Class AB amplifier or the Class C amplifier. The amplification element 404 1 sends out the amplified signal to the output matching circuit 406 1 .
[0043] The output matching circuit 406 1 is connected to the amplification element 404 1 . The output matching circuit 406 1 including the transmission line 408 converts a load impedance of the signal from the amplification element 404 1 .
[0044] The input matching circuit 402 2 is connected to the phase conversion circuit 314 . The input matching circuit 402 2 converts the impedance of the signal from the phase conversion circuit 314 to be matched with the input impedance of the amplification element 404 2 . The input matching circuit 402 2 sends out the impedance-converted signal to the amplification element 404 2 .
[0045] The amplification element 404 2 is connected to the input matching circuit 402 2 . The amplification element 404 2 is an amplification element configured to amplify the signal. The amplification element 404 2 is biased to Class AB or Class C. That is, the amplification element 404 2 receives, as the bias voltage, the voltage that is applied for operating the amplification element 404 2 in Class AB or the voltage that is applied for operating the amplification element 404 2 in Class C. Since the amplification element 404 2 receives the voltage to an extent where the operation class is changed, the amplification element 404 2 can be operated as the Class AB amplifier or the Class C amplifier. The amplification element 404 2 sends out the amplified signal to the output matching circuit 406 2 .
[0046] The output matching circuit 406 2 is connected to the amplification element 404 2 . The output matching circuit 406 2 converts a load impedance of the signal from the amplification element 404 2 .
[0047] The transmission line 408 is connected to the output matching circuit 406 1 . The transmission line 408 is a transmission line configured to carry out the impedance conversion of the signal from the output matching circuit 406 1 . More specifically, in the transmission line 408 , an impedance conversion is carried out based on an electrical length of λ/4 with respect to a frequency of the signal that is input to the amplifier 308 . The signal input to the amplifier 308 is the signal from the preamplifier 306 1 . Herein, the electrical length regulates the length of the transmission line while a wavelength (λ) in the transmission line is set as a reference. With the regulation while the wavelength in the transmission line is set as a reference, it is possible to take a line constant into account. The line constant includes a specific inductive capacity of a dielectric or the like. By carrying out the impedance conversion of the signal from the output matching circuit 406 1 based on the electrical length of λ/4 with respect to the frequency of the signal that is input to the amplifier 308 , it is possible to ensure the matching with the signal from the output matching circuit 406 2 .
[0048] The transmission line 410 is connected to the transmission line 408 and the output matching circuit 406 2 . In the transmission line 410 , the impedance conversion is carried out on the signal obtained by synthesizing the signal from the transmission line 408 with the signal from the output matching circuit 406 2 . A point where the signal from the transmission line 408 is coupled to the signal from the output matching circuit 406 2 is set as a coupling part A. The signal from the transmission line 408 is synthesized with the signal from the output matching circuit 406 2 at the coupling part A. More specifically, in the transmission line 410 , the impedance conversion is carried out based on the electrical length of λ/4 with respect to the frequency of the signal that is input to the amplifier 308 . By carrying out the impedance conversion based on the electrical length of λ/4 with respect to the frequency of the signal that is input to the amplifier 308 , it is possible to ensure the matching with the filter 310 .
<Input Matching Circuits 402 1 and 402 2 >
[0049] Under the condition for matching the impedance between the devices, an impedance point at which the efficiency is optimized may be different from an impedance point at which the electric power is maximized in some cases. Depending on the frequency of the input signal, also, an impedance point at which the efficiency is optimized may be different from an impedance point at which the electric power is maximized in some cases.
[0050] An amplifier that operates corresponding to plural frequency bands will be described. For example, the amplifier can be used for input signals in two frequency bands. In the above-mentioned amplifier, it may be difficult, in some cases, to obtain a matching circuit that can ensure the impedance matching so that the efficiency is optimized in both frequency bands of a frequency band f 1 and a frequency band f 2 . Herein, the frequency band f 1 may be the 700 MHz band, and the frequency band f 2 may be the 2.1 GHz band. According to the present embodiment, the amplifier is designed so that the matching can be ensured to optimize the efficiency in the frequency band f 1 and the matching can be ensured to maximize the electric power in the frequency band f 2 . The impedance matching point at which the efficiency is optimized may be different from the impedance matching point at which the electric power is maximized. In the amplifier 308 , since the two types of impedance points can be selected, it is possible to increase the impedance points that can be selected at the time of designing.
[0051] FIG. 5 is a Smith chart illustrating an example of an impedance matching by the input matching circuits 402 1 and 402 2 .
[0052] In FIG. 5 , “Pf 1 AB” is a point representing the impedance where the electric power is maximized when the input signal in the frequency band f 1 is amplified by the amplification element that receives the bias voltage to operate in Class AB. “Pf 1 C” is a point representing the impedance where the electric power is maximized when the input signal in the frequency band f 1 is amplified by the amplification element that receives the bias voltage to operate in Class C. “γf 1 AB” is a point representing the impedance where the efficiency is optimized when the input signal in the frequency band f 1 is amplified by the amplification element that receives the bias voltage to operate in Class AB. “γf 1 C” is a point representing the impedance where the efficiency is optimized when the input signal in the frequency band f 1 is amplified by the amplification element that receives the bias voltage to operate in Class C.
[0053] Further, “Pf 2 AB” is a point representing the impedance where the electric power is maximized when the input signal in the frequency band f 2 is amplified by the amplification element that receives the bias voltage to operate in Class AB. “Pf 2 C” is a point representing the impedance where the electric power is maximized when the input signal in the frequency band f 2 is amplified by the amplification element that receives the bias voltage to operate in Class C. “γf 2 AB” is a point representing the impedance where the efficiency is optimized when the input signal in the frequency band f 2 is amplified by the amplification element that receives the bias voltage to operate in Class AB. “γf 2 C” is a point representing the impedance where the efficiency is optimized when the input signal in the frequency band f 2 is amplified by the amplification element that receives the bias voltage to operate in Class C.
[0054] In the example illustrated in FIG. 5 , “Pf 1 AB” as the impedance matching point at which the electric power is maximized in the frequency band f 1 or “γf 1 AB” as the impedance matching point at which the efficiency is optimized in the frequency band f 1 can be set in the input matching circuit 402 1 . Furthermore, in accordance with the impedance matching point set in the input matching circuit 402 1 , it is possible to set the impedance matching point in the input matching circuit 402 2 . More specifically, “γf 1 C” as the impedance matching point at which the efficiency is optimized in the frequency band f 1 or “Pf 1 C” as the impedance matching point at which the electric power is maximized in the frequency band f 1 can be set in the input matching circuit 402 2 .
[0055] Further, “Pf 2 AB” as the impedance matching point at which the electric power is maximized in the frequency band f 2 or “γf 2 AB” as the impedance matching point at which the efficiency is optimized in the frequency band f 2 can be set in the input matching circuit 402 1 . Furthermore, in accordance with the impedance matching point set in the input matching circuit 402 1 , it is possible to set the impedance matching point in the input matching circuit 402 2 . More specifically, “γf 2 C” as the impedance matching point at which the efficiency is optimized in the frequency band f 2 or “Pf 2 C” as the impedance matching point at which the electric power is maximized in the frequency band f 2 can be set in the input matching circuit 402 2 . Accordingly, when the multiband of the amplifier is to be achieved, it is possible to improve the degree of freedom in the design of the matching circuit.
<Output Matching Circuits 406 1 and 406 2 >
[0056] With regard to the output matching circuits 406 1 and 406 2 , similarly as in the input matching circuits 402 1 and 402 2 , under the condition for matching the impedance between the devices, an impedance point at which the efficiency is optimized may be different from an impedance point at which the electric power is maximized in some cases. Depending on the frequency of the input signal, also, an impedance point at which the efficiency is optimized is different from an impedance point at which the electric power is maximized.
[0057] For example, in the amplifier that operates corresponding to the plural frequency bands, in both the frequency of the frequency band f 1 and the frequency band f 2 , it may be difficult to achieve a matching circuit that can ensure the impedance matching so that the efficiency is optimized in some cases. In this case, the design is made such that the matching can be ensured to optimize the efficiency in the frequency band f 1 and the matching can be ensured to maximize the electric power in the frequency band f 2 . The impedance matching point at which the efficiency is optimized may be different from the impedance matching point at which the electric power is maximized. In the amplifier 308 , since the two types of impedance points can be selected, it is possible to increase the impedance points that can be selected at the time of designing.
[0058] FIG. 6 is a Smith chart illustrating an example of an impedance matching by the output matching circuits 406 1 and 406 2 .
[0059] In FIG. 6 , “Pf 1 AB” is a point representing the impedance where the electric power is maximized when the input signal in the frequency band f 1 is amplified by the amplification element that receives the bias voltage to operate in Class AB. “Pf 1 C” is a point representing the impedance where the electric power is maximized when the input signal in the frequency band f 1 is amplified by the amplification element that receives the bias voltage to operate in Class C. “γf 1 AB” is a point representing the impedance where the efficiency is optimized when the input signal in the frequency band f 1 is amplified by the amplification element that receives the bias voltage to operate in Class AB. “γf 1 C” is a point representing the impedance where the efficiency is optimized when the input signal in the frequency band f 1 is amplified by the amplification element that receives the bias voltage to operate in Class C.
[0060] Further, “Pf 2 AB” is a point representing the impedance where the electric power is maximized when the input signal in the frequency band f 2 is amplified by the amplification element that receives the bias voltage to operate in Class AB. “Pf 2 C” is a point representing the impedance where the electric power is maximized when the input signal in the frequency band f 2 is amplified by the amplification element that receives the bias voltage to operate in Class C. “γf 2 AB” is a point representing the impedance where the efficiency is optimized when the input signal in the frequency band f 2 is amplified by the amplification element that receives the bias voltage to operate in Class AB. “γf 2 C” is a point representing the impedance where the efficiency is optimized when the input signal in the frequency band f 2 is amplified by the amplification element that receives the bias voltage to operate in Class C.
[0061] In the example illustrated in FIG. 6 , “Pf 1 AB” as the impedance matching point at which the electric power is maximized in the frequency band f 1 or “γf 1 AB” as the impedance matching point at which the efficiency is optimized in the frequency band f 1 can be set in the output matching circuit 406 1 . Furthermore, in accordance with the impedance matching point set in the output matching circuit 406 1 , it is possible to set the impedance matching point in the output matching circuit 406 2 . More specifically, “γf 1 C” as the impedance matching point at which the efficiency is optimized in the frequency band f 1 or “Pf 1 C” as the impedance matching point at which the electric power is maximized in the frequency band f 1 can be set in the output matching circuit 406 2 .
[0062] Further, “Pf 2 AB” as the impedance matching point at which the electric power is maximized in the frequency band f 2 or “γf 2 AB” as the impedance matching point at which the efficiency is optimized in the frequency band f 2 can be set in the output matching circuit 406 1 . Furthermore, in accordance with the impedance matching point set in the output matching circuit 406 1 , it is possible to set the impedance matching point in the output matching circuit 406 2 . More specifically, “γf 2 C” as the impedance matching point at which the efficiency is optimized in the frequency band f 2 or “Pf 2 C” as the impedance matching point at which the electric power is maximized in the frequency band f 2 can be set in the output matching circuit 406 2 . Accordingly, when the multiband of the amplifier is to be achieved, it is possible to improve the degree of freedom in the design of the matching circuit.
<Operation by the Amplifier 308 >
[0063] FIG. 7 is a flowchart of an operation by the amplifier 308 according to the embodiment. Herein, a case where the switching is conducted so that the signal in the 700 MHz band is amplified and a case where the switching is conducted so that the signal in the 2.1 GHz band is amplified will be described.
[0000] <Case where Switching is Conducted so that Signal in 700 MHz band is Amplified>
[0064] The switching is conducted to cause the amplifier 308 that has been set to amplify the signal in the 2.1 GHz band to amplify the signal in the 700 MHz band.
[0065] The matching condition is set in the amplifier 308 (step S 702 ). More specifically, in the input matching circuit 402 1 , the impedance matching point at which the efficiency is optimized at 700 MHz is set. Also, in the output matching circuit 406 1 , the impedance matching point at which the efficiency is optimized at 700 MHz is set.
[0066] On the other hand, in the input matching circuit 402 2 , the impedance matching point at which the electric power is maximized at 700 MHz is set. Also, in the output matching circuit 406 2 , the impedance matching point at which the electric power is maximized at 700 MHz is set.
[0067] The bias voltage is applied to the amplifier 308 (step S 704 ). More specifically, the amplification element 404 1 receives the bias voltage to operate in Class AB. On the other hand, the amplification element 404 2 receives the bias voltage to operate in Class C.
[0000] <Case where Switching is Conducted so that Signal in 2.1 GHz Band is Amplified>
[0068] The switching is conducted to cause the amplifier 308 that has been set to amplify the signal in the 700 MHz band to amplify the signal in the 2.1 GHz band.
[0069] The matching condition is set in the amplifier 308 (step S 702 ). More specifically, in the input matching circuit 402 1 , the impedance matching point at which the electric power is maximized at 2.1 GHz is set. Also, in the output matching circuit 406 1 , the impedance matching point at which the electric power is maximized at 2.1 GHz is set.
[0070] On the other hand, in the input matching circuit 402 2 , the impedance matching point at which the efficiency is optimized at 2.1 GHz is set. Also, in the output matching circuit 406 2 , the impedance matching point at which the efficiency is optimized at 2.1 GHz is set.
[0071] The bias voltage is applied to the amplifier 308 (step S 704 ). More specifically, the amplification element 404 1 receives the bias voltage to operate in Class C. On the other hand, the amplification element 404 2 receives the bias voltage to operate in Class AB.
[0072] According to the present embodiment, when the multiband of the Doherty amplifier is to be achieved, it is possible to improve the degree of freedom in the design of the matching circuit. That is, it is possible to select the impedance matching point to be set from the plural impedance matching points. Since the impedance matching point can be selected from the plural impedance matching points, it is possible to easily achieve the multiband of the Doherty amplifier. Also, without switching the transmission lines or the like, it is possible to achieve the multiband of the Doherty amplifier.
[0073] Further, in the amplifier that operates corresponding to the 700 MHz band and the 2.1 GHz band, as described above, the transmission lines 408 and 410 can be achieved by the lines of λ/4.
[0074] In the Doherty amplifier, the signal from the carrier-amplifier and the signal from the peak-amplifier are to be coupled to each other at a phase difference of 90 degrees. In the amplifier 308 illustrated in FIG. 4 , the signal from the carrier-amplifier and the signal from the peak-amplifier can be coupled to each other at the phase difference of 90 degrees by the transmission line 408 .
[0075] Further, at the time of the operation by the peak-amplifier, since the carrier-amplifier and the peak-amplifier are operated in parallel, the impedance conversion is to be conducted on the signal obtained by synthesizing the signal from the peak-amplifier with the signal from the carrier-amplifier. In the amplifier 308 illustrated in FIG. 4 , the impedance conversion is conducted by the transmission line 410 on the signal obtained by synthesizing the signal from the peak-amplifier with the signal from the carrier-amplifier.
[0076] For example, the transmission lines 408 and 410 can be replaced by lines of 90 degrees (λ/4). However, since the line has a frequency characteristic, a case of a certain frequency corresponds to the phase of 90 degrees.
[0077] According to the present embodiment, the amplifier 308 is set to correspond to the 700 MHz band and the 2.1 GHz band that is three times as high as 700 MHz. With the settings for corresponding to the 700 MHz band and the 2.1 GHz band, the transmission lines 408 and 410 can be used in common with the λ/4 line at the low frequency, that is, 700 MHz. Since the transmission lines can be used in common with the λ/4 line at 700 MHz, it is possible to avoid the switching of the line on the output side.
Second Embodiment
<Base Station>
[0078] The base station 100 and the base station 200 according to a second embodiment are similar to those in FIG. 1 and FIG. 2 .
<Transmission Unit 300 >
[0079] FIG. 8 illustrates the transmission unit 300 according to the second embodiment. The transmission unit 300 according to the second embodiment is different from the transmission unit described with reference to FIG. 3 in that the transmission unit 300 according to the second embodiment includes a phase conversion circuit 316 .
[0080] The phase conversion circuit 316 is connected to the preamplifier 306 1 . The phase conversion circuit 316 shifts the phase of the signal from the preamplifier 306 1 . The phase conversion circuit 316 sends out the signal from the preamplifier 306 1 the phase of which is shifted to the amplifier 308 . More specifically, the phase conversion circuit 316 delays the phase of the signal from the preamplifier 306 1 .
[0081] Further, the phase conversion circuit 314 adds 90 degrees and more to shift the phase of the signal from the preamplifier 306 2 . The phase conversion circuit 314 sends out the signal from the preamplifier 306 2 the phase of which is shifted by being added with 90 degrees and more to the amplifier 308 . More specifically, the phase conversion circuit 316 shifts the phase of the signal from the preamplifier 306 1 by 90 degrees and further delays the phase. <Amplifier 308 >
[0082] FIG. 9 illustrates the amplifier 308 according to the embodiment. The amplifier 308 according to the second embodiment is different from the amplifier 308 described with reference to FIG. 4 in that the amplifier 308 according to the second embodiment includes phase compensation lines 412 and 414 .
[0083] A signal from the phase conversion circuit 316 is input to the input matching circuit 402 1 .
[0084] The phase compensation line 412 is connected to the output matching circuit 406 1 . The phase compensation line 412 is a transmission line configured to compensate for a shift of the phase generated by the amplification element 404 1 .
[0085] Specifically, in a case where the signal in the 700 MHz band is amplified, the phase compensation line 412 compensates the signal from the output matching circuit 406 1 by a phase θ 1 . The phase θ 1 is a shift of the phase supposed to be generated by the amplification element 404 1 when the signal in the 700 MHz band is amplified. The signal the phase of which is compensated by the phase compensation line 412 is input to the transmission line 408 .
[0086] Further, in a case where the signal in the 2.1 GHz band is amplified, the phase compensation line 412 compensates the signal from the output matching circuit 406 1 by a phase θ 3 . The phase θ 3 is a shift of the phase supposed to be generated by the amplification element 404 1 when the signal in the 2.1 GHz band is amplified. The signal the phase of which is compensated by the phase compensation line 412 is input to the transmission line 408 .
[0087] The phase compensation line 414 is connected to the output matching circuit 406 2 . The phase compensation line 414 is a transmission line configured to compensate for a shift of the phase generated by the amplification element 404 2 .
[0088] Specifically, in a case where the signal in the 700 MHz band is amplified, the phase compensation line 414 compensates the signal from the output matching circuit 406 2 by a phase θ 2 . The phase θ 2 is a shift of the phase supposed to be generated by the amplification element 404 2 when the signal in the 700 MHz band is amplified. The signal the phase of which is compensated by the phase compensation line 414 is synthesized with the signal from the transmission line 408 at the coupling part A to be input to the transmission line 410 .
[0089] Further, in a case where the signal in the 2.1 GHz band is amplified, the phase compensation line 414 compensates the signal from the output matching circuit 406 2 by a phase θ 4 . The phase θ 4 is a shift of the phase supposed to be generated by the amplification element 404 2 when the signal in the 2.1 GHz band is amplified. The signal the phase of which is compensated by the phase compensation line 414 is synthesized with the signal from the transmission line 408 at the coupling part A to be input to the transmission line 410 .
[0090] In the Doherty amplifier, the signal from the carrier-amplifier and the signal from the peak-amplifier are to be coupled to each other at a phase difference of 90 degrees. However, since the bias conditions and the matching conditions vary between the carrier-amplifier and the peak-amplifier, the signal that is output from the carrier-amplifier and the signal that is output from the peak-amplifier do not have a same passing phase. Accordingly, on the output side of the output matching circuits 406 1 and 406 2 , the phase compensation lines 412 and 414 are respectively provided, so that the lines configured to compensate the passing phase are inserted.
[0091] However, if the frequency for achieving the multiband is changed, the phase shift amounts are not the same. To compensate for the phase shift amounts supposed to fluctuate in response to the change in the frequency, the phase shift amounts are individually set in the carrier-amplifier and the peak-amplifier.
[0092] More specifically, in a case where the signal in the 700 MHz band is amplified, the phase conversion circuit 316 sets an amount of shifting the phase of the signal from the preamplifier 306 1 as Δθ 1 , and the phase conversion circuit 314 sets an amount of shifting the phase of the signal from the preamplifier 306 2 as Δθ 2 .
[0093] Further, in a case where the signal in the 2.1 GHz band is amplified, the phase conversion circuit 316 sets an amount of shifting the phase of the signal from the preamplifier 306 1 as Δθ 3 , and the phase conversion circuit 314 sets an amount of shifting the phase of the signal from the preamplifier 306 2 as Δθ 4 .
[0094] With this configuration, for achieving the multiband, even in a case where the frequency of the input signal is changed, it is possible to compensate for the phase shift amount that fluctuates when the frequency is changed.
<Operation by the Amplifier 308 >
[0095] FIG. 10 is a flowchart of an operation by the amplifier 308 according to the embodiment. Herein, a case will be described where the switching is conducted so that the signal in the 700 MHz band is amplified and a case will be described where the switching is conducted so that the signal in the 2.1 GHz band is amplified.
[0000] <Case where Switching is Conducted so that Signal in 700 MHz Band is Amplified>
[0096] The switching is conducted to cause the amplifier 308 that has been set to amplify the signal in the 2.1 GHz band to amplify the signal in the 700 MHz band.
[0097] The matching condition is set in the amplifier 308 (step S 1002 ). Specifically, in the input matching circuit 402 1 , the impedance matching point at which the efficiency is optimized at 700 MHz is set. Also, in the output matching circuit 406 1 , the impedance matching point at which the efficiency is optimized at 700 MHz is set.
[0098] On the other hand, in the input matching circuit 402 2 , the impedance matching point at which the electric power is maximized at 700 MHz is set. Also, in the output matching circuit 406 2 , the impedance matching point at which the electric power is maximized at 700 MHz is set.
[0099] The phase is set (step S 1004 ). More specifically, Δθ 1 is set as the phase shift amount in the phase conversion circuit 316 , and Δθ 2 is set as the phase shift amount in the phase conversion circuit 314 . Also, the phase compensation line 412 is set to compensate the phase of the signal from the output matching circuit 406 1 by the phase θ 1 . Also, the phase compensation line 414 is set to compensate the phase of the signal from the output matching circuit 406 2 by the phase θ 2 .
[0100] The bias voltage is applied to the amplifier 308 (step S 1006 ). More specifically, the amplification element 404 1 receives the bias voltage to operate in Class AB. On the other hand, the amplification element 404 2 receives the bias voltage to operate in Class C.
[0000] <Case where Switching is Conducted so that Signal in 2.1 GHz Band is Amplified>
[0101] The switching is conducted to cause the amplifier 308 that has been set to amplify the signal in the 700 MHz band to amplify the signal in the 2.1 GHz band.
[0102] The matching condition is set in the amplifier 308 (step S 1002 ). More specifically, in the input matching circuit 402 1 , the impedance matching point at which the electric power is maximized at 2.1 GHz is set. Also, in the output matching circuit 406 1 , the impedance matching point at which the electric power is maximized at 2.1 GHz is set.
[0103] On the other hand, in the input matching circuit 402 2 , the impedance matching point at which the efficiency is optimized at 2.1 GHz is set. Also, in the output matching circuit 406 2 , the impedance matching point at which the efficiency is optimized at 2.1 GHz is set.
[0104] The phase is set (step S 1004 ). More specifically, Δθ 3 is set as the phase shift amount in the phase conversion circuit 316 , and Δθ 4 is set as the phase shift amount in the phase conversion circuit 314 . Also, the phase compensation line 412 is set to compensate the phase of the signal from the output matching circuit 406 1 by the phase θ 3 . The phase compensation line 414 is set to compensate the phase of the signal from the output matching circuit 406 2 by the phase θ 4 .
[0105] The bias voltage is applied to the amplifier 308 (step S 1006 ). More specifically, the amplification element 404 1 receives the bias voltage to operate in Class C. On the other hand, the amplification element 404 2 receives the bias voltage to operate in Class AB.
[0106] According to the present embodiment, when the multiband of the Doherty amplifier is to be achieved, it is possible to improve the degree of freedom in the design of the matching circuit. That is, it is possible to select the impedance matching point to be set from the plural impedance matching points. Since the impedance matching point can be selected from the plural impedance matching points, it is possible to easily achieve the multiband of the Doherty amplifier. Also, without switching the transmission lines or the like, it is possible to achieve the multiband of the Doherty amplifier.
[0107] Further, in the amplifier that operates corresponding to the 700 MHz band and the 2.1 GHz band, as described above, the transmission lines 408 and 410 can be achieved by the lines of λ/4.
[0108] In the Doherty amplifier, the signal from the carrier-amplifier and the signal from the peak-amplifier are to be coupled to each other at a phase difference of 90 degrees. In the amplifier 308 illustrated in FIG. 9 , the signal from the carrier-amplifier and the signal from the peak-amplifier can be coupled to each other at the phase difference of 90 degrees by the transmission line 408 .
[0109] Further, at the time of the operation by the peak-amplifier, since the carrier-amplifier and the peak-amplifier are operated in parallel, the impedance conversion is to be conducted on the signal obtained by synthesizing the signal from the peak-amplifier with the signal from the carrier-amplifier. In the amplifier 308 illustrated in FIG. 9 , the impedance conversion is conducted by the transmission line 410 on the signal obtained by synthesizing the signal from the peak-amplifier with the signal from the carrier-amplifier.
[0110] For example, the transmission lines 408 and 410 can be replaced by lines of 90 degrees (λ/4). However, since the line has a frequency characteristic, a case of a certain frequency corresponds to the phase of 90 degrees.
[0111] According to the present embodiment, the amplifier 308 is set to correspond to the 700 MHz band and the 2.1 GHz band that is three times as high as 700 MHz. With the setting for corresponding to the 700 MHz band and the 2.1 GHz band, the transmission lines 408 and 410 can be used in common with the λ/4 line at the low frequency, that is, 700 MHz. Since the transmission lines can be used in common with the λ/4 line at 700 MHz, it is possible to avoid the switching of the line on the output side.
[0112] Further, according to the present embodiment, since the shift of the passing phases between the signal from the carrier-amplifier and the signal from the peak-amplifier can be compensated for, the shifts of the synthesis points between the signal from the carrier-amplifier and the signal from the peak-amplifier can be reduced. Since the shifts of the synthesis points between the signal from the carrier-amplifier and the signal from the peak-amplifier can be reduced, it is possible to improve the amplification characteristic at a time when the maximum power is obtained, in particular.
[0113] Further, without carrying out the physical switching of the lines or the like when the frequency bands are switched, it is possible to adjust the shift of the phase generated by the frequency characteristic that is different for each amplification element by controlling the phase of the input signal.
[0114] According to the above-mentioned embodiment, the operation classes of the amplification elements 404 1 and 404 2 may be switched between Class AB and Class B and may also be switched between Class A and Class B. Also, the operation classes of the amplification elements 404 1 and 404 2 may be switched between Class AB and Class C and may also be switched between Class A and Class C.
[0115] All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention. | An amplifier includes a first amplification element configured to amplify a first signal in one of first and second operation classes, a second amplification element configured to amplify a second signal in one of first and second operation classes, a first transmission line through which the amplified first signal is transferred, and a coupler configured to couple the transferred first signal and the amplified second signal, wherein the first amplification element amplifies the first signal in the first operation class and the second amplification element amplifies the second signal in the second operation class, when the first signal and the second signal have a first frequency band, and wherein the first amplification element amplifies the first signal in the second operation class and the second amplification element amplifies the second signal in the first operation class, when the first signal and the second signal have a second frequency band. | 51,782 |
FIELD OF THE INVENTION
The instant invention pertains to those numerous instances wherein it is desired to operate a solenoid coil or other device which experiences the same benefits in steady state conditions at reduced power. The goal is to reduce energy consumption by controlling the net wattage of the solenoid coil. Use of an alternating or direct current power supply for inputting power to the solenoid coil is achieved by the instant invention. The preferred embodiment is shown with respect to the coils powered by DC. However, the inventive concepts will apply equally well to AC powered coils.
BACKGROUND OF THE INVENTION
The problem is not new. The power to initially actuate a solenoid coil is much higher than that necessary to maintain the solenoid in the latched position. The magnetic circuit is different in these two conditions.
Some devices employ a power circuit having a pulsed square wave or rectified sine wave output. These devices lower the net RMS voltage and power to approximately 20% but they experience significant DC ripple which can cause the plunger within the solenoid to drop out. They also suffer from potential reliability problems because they are polarity sensitive. The input voltage tolerance to these devices is +/-10% and the DC ripple can be as much as 20% peak to peak. The input voltage tolerance is narrow because these devices do not have any output voltage sensing apparatus.
SUMMARY OF THE INVENTION
The instant invention reduces power consumption of the solenoid coil by 80 to 90%. Coil life is extended by virtue of lower power consumption by the coil. A rectifying bridge is employed in the preferred embodiment so that either AC or DC power sources may be used. The bridge is not polarity sensitive so the orientation of the positive and negative power leads in the case of the DC power source does not matter.
A power circuit for controlling the amount of power delivered to a solenoid coil is disclosed in the preferred embodiment. The initial voltage applied to the coil may be chosen to be higher than the steady state rating, for example 24 volts applied to a 12 volt coil, to ensure quick and reliable pull in. Thereafter the voltage is reduced to prevent heating etc. A current mode pulse width modulated controller is employed to control the flow of current through a power branch of the circuit. A rectifying bridge enables use of the power circuit with either AC or DC power sources. The power circuit includes a novel startup current source for initially energizing the pulse width modulation controller. Two feedback circuits, one representing a compensated current through a power branch of the power circuit and one representing the output voltage of the power circuit are processed by the pulse width modulation controller (PWMC). The PWMC outputs pulses of varying duration at a constant frequency to a field effect transistor in the power branch of the power circuit. The opening of the field effect transistor interrupts the flow of current in the power branch of the circuit. The shorter the duration of the pulses the less time the field effect transistor in the power branch of the power circuit is closed and the less power is delivered to the output of the power circuit for a given input voltage. The longer the duration of the pulses the more time the field effect transistor in the power branch is closed and more power is delivered to the output of the power circuit.
Two inductors are used. A coupling capacitor is interposed between the first inductor and the second inductor. Control of the output voltage and output current of the circuit are effected by two feedback circuits (in the preferred embodiment voltages) inputted to the current mode pulse width modulation controller. The power branch of the circuit containing the field effect transistor is at a node located between the first inductor and the current coupling capacitor. The voltage and current at this node are constantly changing in value due to the operation of the field effect transistor in the power branch of the power circuit.
Accordingly, it is an object of the present invention to provide a circuit to control the output power in the steady state energized condition thereof to 10 to 20% of the rated wattage of the coil.
It is a further object of the present invention to provide a power circuit capable of delivering high output power to the solenoid coil during initial energization thereof.
It is a further object of the present invention to provide a power circuit capable of delivering high output power to the solenoid coil for 0.3-0.5 seconds after initial energization thereof.
It is a further object of the present invention to use the energy stored in the magnetic fields of two inductors to supply output power to the solenoid coil.
It is a further object of the present invention to provide a pulse width modulation controller to gate a field effect transistor allowing different amounts of current to flow through the power branch of the circuit containing the field effect transistor.
It is a further object of the present invention to provide a branch of the circuit in parallel with the output of the circuit which branch contains a resistor and a capacitor for operating a junction field effect transistor. The junction field effect transistor is in series with a resistor which is in parallel with another resistor to develop a feedback voltage representative of the voltage output of the power circuit.
It is a further object of the present invention to provide a current sensing circuit, (or first feedback voltage sensing circuit) for sensing the current (inferred by a voltage measurement) in the power branch of the circuit containing the field effect transistor.
It is a further object of the present invention to provide a current sensing circuit, (or first feedback voltage sensing circuit) for sensing the current (inferred by a voltage measurement) in the solenoid.
It is a further object of the present invention to provide a compensated current sensing circuit for use by the current mode pulse width modulation controller.
It is a further object of the present invention to provide a voltage sensing circuit which senses the solenoid voltage. The voltage sensing circuit includes two parallel resistors. During normal low power output of the power circuit, the second feedback voltage is sensed across one of the resistors to ground. When the solenoid coil is first being energized, the second feedback voltage is sensed across two resistors in parallel to ground. The second resistor is in the circuit by means of a closed, junction field effect transistor which is in series with the second resistor. The normally closed junction field effect transistor is no longer gated, or closed, when the voltage applied to its gate reaches approximately 3.0 VDC. The voltage applied to the gate of the junction field effect transistor is sensed across a capacitor to ground in a resistor-capacitor branch of the circuit measured across the output of the power circuit. The time constant of the circuit together with the ramping of the voltage across the output of the power circuit provides a 0.3 to 0.5 second delay before the junction field effect transistor opens (is not gated). This 0.3 to 0.5 second delay has been found to be a sufficient delay for initially energizing the solenoid coil (load) rated at 24 volts, 15 watts. Other time consultants can be used to provide longer or shorter energizing power to other solenoid coils as will become apparent from the present teachings.
It is a further object of the present invention to provide a startup current means for supplying power to the pulse width modulation controller.
It is a further object of the present invention to include a resistor and a capacitor as part of the current sensing circuit. The capacitor provides a smooth voltage which is input to the pulse width modulation controller together with a clocked compensated signal.
It is a further object of the present invention to provide a startup current source for initially powering the current mode pulse with modulation controller which includes a metal oxide semiconductor field effect transistor, an amplifier (voltage regulator), a transistor, resistors and diode which allow 10 VDC power to pass to the PWMC.
It is a further object of the present invention to provide a power circuit for energizing a solenoid coil which is operable with DC voltage sources and is not polarity sensitive.
It is a further object of the present invention to provide a power circuit for powering a solenoid coil which is operable with AC power sources in the range of 40-140 VAC at either 50 or 60 hz or DC power sources in the range of 10.8-140 VDC.
It is a further object of the present invention to eliminate AC buzz of solenoid coils.
It is a further object of the instant invention to provide a power circuit that has no DC ripple on the output of the power circuit.
It is a further object of the present invention to provide a power circuit which eliminates AC solenoid coil buzz and AC coil burn out.
The objects of the invention will be better understood when taken in conjunction with the Brief Description of the Drawings, the Detailed Description of the Invention and the Claims that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing of the power circuit;
FIG. 2 is a schematic drawing of the startup current source.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, current mode pulse width modulation controller 1 is an integrated circuit, a Unitrode UC 3843AD. The pulse width modulation controller has a first input which senses the voltage across resistor 24. Resistor 24 is a 0.22 Ω resistor. Resistor 25 is a 49.9 Ω resistor. Capacitor 34 is a 220 pF capacitor yielding a very short time constant. Reference numeral 37 is a 5 VDC reference output by the pulse width modulation controller 1. Resistor 31 is a 10 kΩ resistor and capacitor 32 is a 0.001 μF capacitor. Together, resistor 31 and capacitor 32 set the clock input 39 of the pulse width modulation controller at 100 kHz.
Reference numeral 39 is a clock input to the PWMC 1. Input 39 reaches approximately 3 VDC and then resets at 1 VDC. Capacitor 32 discharges when clock input 39 resets.
The cycling of the clock applies and removes voltage from the base 46 of the transistor 45. Capacitor 44 is a 0.1 μF capacitor which stabilizes the 5 VDC reference voltage at output 37. Transistor 45 conducts more current when voltage is applied to the base 46 thereof Resistor 56 is a 3.01 kΩ resistor. A sawtooth wave is generated at the clock 39 which follows the charging of capacitor 32. Current flows to the junction of the resistor 25 and capacitor 34 via transistor 45.
The currents flowing through resistors 25 and 56 are summed into a voltage across capacitor 34. The current flowing through resistor 56 is a slope compensation current and is summed with the current through resistor 25.
Zener diode 29 and capacitor 30, a 10 μF capacitor, regulate and stabilize respectively, the input voltage applied to power input 10 of the PWMC.
Reference numeral 38 indicates a ground on the PWMC. Reference numeral 10 is the power input to the PWMC which is connected to resistors 8 and 33. Reference numeral 14 is the second (voltage) input of the PWMC. A feedback voltage is applied to second input 14. Capacitor 41 is a 0.1μF capacitor in series with 42, a 5.11 kΩ resistor. Capacitor 41 and resistor 42 provide high frequency compensation of the voltage feedback from the output of the power circuit. Reference numeral 40 is the compensating input to the PWMC.
It will be apparent to those skilled in the art that the PWMC is being employed as a current mode PWMC. Reference numeral 11 is the output of the PWMC which is buffered by resistor 13, a 10 Ω resistor. The output 11 of the PWMC controls the field effect transistor 12.
A supply voltage input is applied at the terminals denoted by reference numeral 15 in FIG. 1. A metal oxide varistor 4 is applied across the input terminals for surge protection. Fuse 3 provides overpower protection. Rectifying bridge 5 converts alternating current to direct current. The input voltage may be in the range of 10 to 140 VDC or 40 to 140 VAC at either 50 or 60 Hz. A 10 μF power supply filtering capacitor 7 is used to stabilize the input voltage. One side of the bridge is connected to a ground 2. Node 2 is either a common voltage or ground. A common voltage may be impressed on the node 2 shown in FIG. 1.
Inductor 9 is a 100 μH inductor. This inductor is known as a boost to those skilled in the art. Capacitor 26 is an AC current coupling capacitor between the inductor 9 and the output. The voltage at the node between inductor 20 and capacitor 26 is switching due to the field effect transistor 12 switching the current in the power branch 59 of the power circuit. Inductor 20 is a 100 μH inductor. Inductor 20 once energized, supplies power to the output of the power circuit when field effect transistor 12 closes and current flows through the power branch 59 of the power circuit. When the current mode PWMC outputs a voltage to the field effect transistor 12 it closes for the duration of the pulse width. The pulse width is operating at 100 kHz and the duration of the pulses vary. The amount of current that flows through the power branch 59 of the power circuit beginning at the node connecting inductor 9 and capacitor 26 and terminating at node 2 and passing through resistor 24 is a function of the input voltage at the output of the rectifying bridge 5, the time that the inductor 9 has charged and the amount of charge held in the field of inductor 9, the discharge of capacitor 26 (a 2.2 μF current coupling capacitor), and the amount of time that field effect transistor 12 is closed, and the resistance of the field effect transistor 12, as is known in the art.
The startup current source 6 necessary to power 1 and associated circuitry is shown in FIG. 2. Resistor 8 (FIG. 1) is a 220 Ω resistor and it drops a voltage as current flows out of the current source 6. Current source 6 is used during the startup of the circuit. Once power is established to the inductor 9 and the capacitor 26 for a sufficient amount of time, diode 28 passes current through resistor 33 to power PWMC 1 and its circuitry. This reduces the power dissipation in 6 which may otherwise be considerable if the maximum input voltage is applied to 15. Resistor 33 is a 49.9 Ω resistor.
Referring to FIG. 2, reference numeral 48 indicates incoming voltage (and current) applied to the current source 6 from bridge rectifier 5. Reference numeral 47 illustrates ground or common. Resistors 49 and 50 are 100 kΩ resistors. Metal oxide semiconductor field effect transistor (MOSFET) 51 is in series with incoming power on line 48. Reference numeral 52 is a transistor. Reference numeral 54 is a 10 volt zener diode. Reference numeral 55 is a 10 kΩ resistor and reference numeral 53 is a voltage regulator (amplifier). Metal oxide semiconductor field effect transistor 51 is a variable linear impedance. The larger the voltage on the gate of MOSFET 51 the more current flows from the drain to the source. The drain is the side of the MOSFET 51 near the input power source 48 and the source is the other side. Transistor 52 shunts voltage across gate resistor 55 and zener diode 55 establishes the feedback for zener diode 53 to the source when sufficient voltage is applied to the source of MOSFET 51. Zener diode 54 permits current to flow when the output 60 of the current source 6 exceeds 10 VDC either due to current flow through 51 or resistors 33 and 8. MOSFET 51 is a variable impedance and drops voltage when, for example, 24 VDC is applied to input power source 48. The drop across MOSFET 51 will be 14 VDC in this example. Linear regulator 53 acts as a variable impedance. The current of the circuit of FIG. 2 is reduced after the start of current flow in diode 28 and resistor 33. The circuit of FIG. 2, just described, is a linear regulator.
Referring again to FIG. 1 and in particular referring to the right most or output portion of the figure, resistor 17 is a 48.7 kΩ resistor and resistor 18 is a 14.7 kΩ resistor. Reference numeral 27 indicates a diode through which power passes to the output 16 of the circuit. The output voltage across terminals 16 changes as a function of the feedback voltage. The feedback voltage is the voltage across resistor 18. The maximum power output of the circuit on terminals 16 is nominally 24 VDC at 1.5 A and the normal power output of the circuit is nominally 10.8 VDC at approximately 0.28 A. Load 70 is a solenoid coil which includes a plunger.
Reference numeral 19 is a 5.11 kΩ resistor in series with a junction field effect transistor 23. The transistor 23 is normally closed and opens when its base voltage is approximately 3.0 VDC. It takes approximately 0.3 to 0.5 seconds after initial energization of the power circuit to charge capacitor 22 to approximately 3 VDC. It will be understood by those skilled in the art that the voltage at the output of diode 27 is a dynamic voltage from the standpoint that it does not instantaneously reach 24 VDC upon initial energization of the power circuit. Rather, the voltage ramps up to approximately 24 VDC upon initial energization of the power circuit. The higher power output is necessary to initially energize the solenoid coil. Because the voltage on 22 is the integral of current through resistor 21 which in turn is proportional to the voltage at 16, the voltage on 22 may be thought of as a measure of, or proportional to, the current passed through the solenoid at initial energization. The charging of capacitor 22 may be thought of as a time delay.
The junction field effect transistor 23 is controlled by the RC circuit made up of resistor 21 and capacitor 22. Resistor 21 is a 2 MΩ resistor and capacitor 22 is a 0.47 μF capacitor. This RC branch of the circuit is across the output of the power circuit.
The voltage across resistor 18 changes depending whether or not resistor 18 is in parallel with resistor 19. When resistors 18 and 19 are in parallel the voltage across them will decrease and the voltage sensed at the second input 14 to the PWMC 1 will also decrease.
The output 11 of the PWMC is dependent upon the voltage applied to the first input 36 and second input 14 of the PWMC. The voltage applied to the first input 36 is the voltage across capacitor 34 which is created by the currents flowing through resistors 25 and 56. Ignoring resistor 56, the current flowing through the resistor 25 will charge capacitor 34 to the voltage across resistor 24. The current flowing through resistor 56 will add additional charge to capacitor 34. The current through resistor 56 is from the slope compensating network. The slope compensating network is comprised of resistor 56 and transistor 45. Resistor 31 and capacitor 32 are the RC components for the PWMC clock. This slope compensating network combines a voltage which is representative of the primary current through resistor 24. The Unitrode current mode pulse width modulation controller 1 processes the feedback voltage from the output circuit which is impressed on the second input 14 to the controller together with the compensated current input which is impressed on the first input 36 to form pulses of sufficient duration to maintain the desired voltage across resistor 18 which in turn maintains the desired voltage at 16.
Output 11 clocks pulses of varying widths at 100 kHz. The maximum pulse width is typically 97%. When the pulse widths are at their maximum the power circuit is in a current limiting mode meaning that the amount of power being transferred to the output circuit through the current coupling capacitor 26 and diode 27 is limited. The circuit is thus protected against shorts to ground (or other problems) on the output side. The maximum current through the solenoid is also limited. The maximum pulse widths occur when the voltage applied to the first input 36 exceeds 1 VDC. The PWMC acts to control the current through the resistor 24 and thus the corresponding solenoid current, by forcing it to follow the error between voltage applied to second input 14 and an internal voltage (2.5 VDC) of the PWMC.
The output across terminals 16 is filtered by capacitor 35 which is a 47 μF capacitor.
Simplistically described, it will be recognized that upon initial excitation of the circuit by application of voltage at 15, that the output voltage 16 will quickly ramp up to a maximum of 24 volts at which time the voltage at 14 which is determined by the resistor divider comprised of resistor 17 in series with the parallel combination of resistors 18 and 19 causes the PWMC 1 to begin to limit and maintain the output voltage at terminal 16 to approximately 24 volts.
Simultaneously the current through current sense resistor 24 begins to charge capacitor 34, and the voltage at 16 causes current to flow through resistor 21 to charge capacitor 22. Current through the solenoid coil will increase as determined by its electrical characteristics toward a steady state value which would otherwise be limited only by the coil's resistance.
The electrical characteristics affecting the rate at which the solenoid's current increases include the series resistance, inductance and stray capacitance of the coil. The inductance is affected by the position of the plunger and current in the coil and all of the parameters are normally affected by temperature. Without other control, the pull in time of the solenoid will vary depending on temperature, and the mechanical condition (dirt, wear, etc.) of the solenoid.
When the current in resistor 24 reaches a value which corresponds to the solenoid coil minimum plunger pull current out of terminal 16, the pulse width at 11 is caused to be changed to limit the terminal 16 current to that value. This effectively causes the buildup of magnetic field in the solenoid to occur at a predictable and steady rate which is mostly insensitive to the previously mentioned variables. This limitation allows fairly accurate determination of the total magnetic field in the solenoid, and thus a related knowledge of the position of the solenoid plunger. In other words this provides a method of determining when the plunger is assured of being fully pulled in by either elapsed time or by the integral of the current through resistor 21, without undue effects of the variables mentioned above. In addition, it provides some control on the speed at which the plunger is pulled in, as that speed is somewhat proportional to coil current.
At a time thereafter which is determined by the integral of the current through 21, the values of resistor 21 and capacitor 22, transistor 23 is turned off. The turn off of 23 removes the effect of resistor 19, causing a rapid increase of the voltage at 14, thus causing PWMC 1 to limit the voltage at 16 to a new and lower value. This lower value is selected to be high enough to reliably maintain the solenoid in an energized state while not being so high as to cause unwanted or excessive heating and other effects as previously described.
The values of resistor 21 and capacitor 22 may be chosen to create a simple time delay, causing 23 to turnoff a known time after the appearance of a certain voltage at 16, or may be chosen to represent the integral of the current through resistor 21 which in turn is a measure of the current flowing in the solenoid, which in turn is a measure of the magnetic field and thus the position of the plunger of the solenoid.
It is possible to first limit the solenoid current and then afterward to reduce the current to a hold in value by one of the described methods, or to simply use the current limit as a failure safety feature and merely use either a time delay or a measure of the of coil current to reduce the hold in current as desired to meet particular requirements when utilizing the present invention.
From the teachings herein, one of ordinary skill in the art will be able to adjust the values of the various components for optimum performance, for example, R24 and C34 to control the maximum current and the response timing of the current limitation, capacitor 41 and resistor 42 for the response timing of the output voltage on 16, resistor 21 and capacitor 22 to control either timing or measure of solenoid parameters as discussed above, as well as the values of resistors 17, 18, and 19 to control the pull in and hold in currents of the solenoid. Such adjustments may be made to allow optimization of the invention for use in particular applications where one parameter may be more desirable than another.
It will be recognized by those skilled in the art that the present invention has been disclosed by way of example only and the invention shall not be limited to the embodiment disclosed. Further, those skilled in the art will recognize that many changes may be made to the present invention without departing from the scope of the appended claims. | A power circuit for controlling the amount of power delivered to a solenoid coil is disclosed. A current mode pulse width modulation controller is employed to interrupt the flow of current through a power branch of the circuit. A rectifying bridge enables use of the power circuit with either AC or DC power sources. The power circuit includes a startup current source for initially energizing the pulse width modulation controller. Two feedback voltages, one representing the compensated current through the power branch of the circuit and one representing the output voltage of the power circuit are used by the pulse width modulation controller to output pulses of varying duration at constant frequency to a field effect transistor. The opening of the field effect transistor interrupts the flow of current in the power branch of the circuit. | 25,488 |
RELATED APPLICATIONS
[0001] This application is a divisional of copending application Ser. No. 09/059,796, filed April 13, which is a divisional of application Ser. No. 08/788,786, filed Jan. 23, 1997, now U.S. Pat. No. 6,235,043, which is a continuation of application Ser. No. 08/188,244, filed on Jan. 26, 1994 (now abandoned).
FIELD OF THE INVENTION
[0002] This invention relates to improvements in the surgical treatment of bone conditions of the human and other animal bone systems and, more particularly, to an inflatable balloon-like device for use in treating such bone conditions. Osteoporosis, avascular necrosis and bone cancer are diseases of bone that predispose the bone to fracture or collapse. There are 2 million fractures each year in the United States, of which about 1.3 million are caused by osteoporosis. Avascular necrosis and bone cancers are more rare but can cause bone problems that are currently poorly addressed.
BACKGROUND OF THE INVENTION
[0003] In U.S. Pat. Nos. 4,969,888 and 5,108,404, an apparatus and method are disclosed for the fixation of fractures or other conditions of human and other animal bone systems, both osteoporotic and non-osteoporotic. The apparatus and method are especially suitable for use in the fixation of, but not limited to, vertebral body compression fractures, Colles fractures and fractures of the proximal humerus.
[0004] The method disclosed in these two patents includes a series of steps which a surgeon or health care provider can perform to form a cavity in pathological bone (including but not limited to osteoporotic bone, osteoporotic fractured metaphyseal and epiphyseal bone, osteoporotic vertebral bodies, fractured osteoporotic vertebral bodies, fractures of vertebral bodies due to tumors especially round cell tumors, avascular necrosis of the epiphyses of long bones, especially avascular necrosis of the proximal femur, distal femur and proximal humerus and defects arising from endocrine conditions).
[0005] The method further includes an incision in the skin (usually one incision, but a second small incision may also be required if a suction egress is used) followed by the placement of a guide pin which is passed through the soft tissue down to and into the bone.
[0006] The method further includes drilling the bone to be treated to form a cavity or passage in the bone, following which an inflatable balloon-like device is inserted into the cavity or passage and inflated. The inflation of the inflatable device causes a compacting of the cancellous bone and bone marrow against the inner surface of the cortical wall of the bone to further enlarge the cavity or passage. The inflatable device is then deflated and then is completely removed from the bone. A smaller inflatable device (a starter balloon) can be used initially, if needed, to initiate the compacting of the bone marrow and to commence the formation of the cavity or passage in the cancellous bone and marrow. After this has occurred, a larger, inflatable device is inserted into the cavity or passage to further compact the bone marrow in all directions.
[0007] A flowable biocompatible filling material, such as methylmethacrylate cement or a synthetic bone substitute, is then directed into the cavity or passage and allowed to set to a hardened condition to provide structural support for the bone. Following this latter step, the insertion instruments are removed from the body and the incision in the skin is covered with a bandage.
[0008] While the apparatus and method of the above patents provide an adequate protocol for the fixation of bone, it has been found that the compacting of the bone marrow and/or the trabecular bone and/or cancellous bone against the inner surface of the cortical wall of the bone to be treated can be significantly improved with the use of inflatable devices that incorporate additional engineering features not heretofore described and not properly controlled with prior inflatable devices in such patents. A need has therefore arisen for improvements in the shape, construction and size of inflatable devices for use with the foregoing apparatus and method, and the present invention satisfies such need.
[0009] Prior Techniques for the Manufacture of Balloons for In-Patient Use
[0010] A review of the prior art relating to the manufacture of balloons shows that a fair amount of background information has been amassed in the formation of guiding catheters which are introduced into cardiovascular systems of patients through the brachial or femoral arteries. However, there is a scarcity of disclosures relating to inflatable devices used in bone, and none for compacting bone marrow in vertebral bodies and long bones.
[0011] In a dilatation catheter, the catheter is advanced into a patient until a balloon is properly positioned across a lesion to be treated. The balloon is inflated with a radiopaque liquid at pressures above four atmospheres to compress the plaque of the lesion to thereby dilate the lumen of the artery. The balloon can then be deflated, then removed from the artery so that the blood flow can be restored through the dilated artery.
[0012] A discussion of such catheter usage technique is found and clearly disclosed in U.S. Pat. No. 5,163,989. Other details of angioplasty catheter procedures, and details of balloons used in such procedures can be found in U.S. Pat. Nos. 4,323,071, 4,332,254, 4,439,185, 4,168,224, 4,516,672, 4,538,622, 4,554,929, and 4,616,652.
[0013] Extrusions have also been made to form prism shaped balloons using molds which require very accurate machining of the interior surface thereof to form acceptable balloons for angioplastic catheters. However, this technique of extrusion forms parting lines in the balloon product which parting lines are limiting in the sense of providing a weak wall for the balloon itself.
[0014] U.S. Pat. No. 5,163,989 discloses a mold and technique for molding dilatation catheters in which the balloon of the catheter is free of parting lines. The technique involves inflating a plastic member of tubular shape so as to press it against the inner molding surface which is heated. Inflatable devices are molded into the desired size and shape, then cooled and deflated to remove it from the mold. The patent states that, while the balloon of the present invention is especially suitable for forming prism-like balloons, it can also be used for forming balloons of a wide variety of sizes and shapes.
[0015] A particular improvement in the catheter art with respect to this patent, namely U.S. Pat. No. 54,706,670, is the use of a coaxial catheter with inner and outer tubing formed and reinforced by continuous helical filaments. Such filaments cross each other causing the shaft of the balloon to become shorter in length while the moving portion of the shank becomes longer in length. By suitably balancing the lengths and the angle of the weave of the balloon and moving portions of the filaments, changes in length can be made to offset each other. Thus, the position of the inner and outer tubing can be adjusted as needed to keep the balloon in a desired position in the blood vessel.
[0016] Other disclosures relating to the insertion of inflatable devices for treating the skeleton of patients include the following:
[0017] U.S. Pat. No. 4,313,434 relates to the fixation of a long bone by inserting a deflated flexible bladder into a medullary cavity, inflating the balloon bladder, sealing the interior of the long bone until healing has occurred, then removing the bladder and filling the opening through which the bladder emerges from the long bone.
[0018] U.S. Pat. No. 5,102,413 discloses the way in which an inflatable bladder is used to anchor a metal rod for the fixation of a fractured long bone.
[0019] Other references which disclose the use of balloons and cement for anchoring of a prosthesis include U.S. Pat. Nos. 5,147,366, 4,892,550, 4,697,584, 4,562,598, and 4,399,814.
[0020] A Dutch patent, NL 901858, discloses a means for fracture repair with a cement-impregnated bag which is inflated into a preformed cavity and allowed to harden.
[0021] It can be concluded from the foregoing review of the prior art that there is little or no substantive information on inflatable devices used to create cavities in bone. It does not teach the shape of the balloon which creates a cavity that best supports the bone when appropriately filled. It does not teach how to prevent balloons from being spherical when inflated, when this is desired. Current medical balloons can compress bone but are too small and generally have the wrong configuration and are generally not strong enough to accomplish adequate cavity formation in either the vertebral bodies or long bones of the body.
[0022] U.S. Pat. Nos. 4,969,888 and 5,108,404 disclose a checker-shaped balloon for compressing cancellous bone, but does not provide information on how this balloon remains in its shape when inflated.
[0023] Thus, the need continues for an improved inflatable device for use with pathological bones and the treatment thereof.
SUMMARY OF THE INVENTION
[0024] The present invention is directed to a balloon-like inflatable device or balloon for use in carrying out the apparatus and method of the above-mentioned U.S. Pat. Nos. 4,969,888 and 5,108,404. Such inflatable devices, hereinafter sometimes referred to as balloons, have shapes for compressing cancellous bone and marrow (also known as medullary bone or trabecular bone) against the inner cortex of bones whether the bones are fractured or not.
[0025] In particular, the present invention is directed to a balloon for use in treating a bone predisposed to fracture or to collapse. The balloon comprises an inflatable, non-expandable balloon body for insertion into said bone. The body has a predetermined shape and size when substantially inflated sufficient to compress at least a portion of the inner cancellous bone to create a cavity in the cancellous bone and to restore the original position of the outer cortical bone, if fractured or collapsed. The balloon body is restrained to create said predetermined shape and size so that the fully inflated balloon body is prevented from applying substantial pressure to the inner surface of the outer cortical bone if said bone is unfractured or uncollapsed.
[0026] In addition to the shape of the inflatable device itself, another aspect of importance is the construction of the wall or walls of the balloon such that proper inflation the balloon body is achieved to provide for optimum compression of all the bone marrow. The material of the balloon is also desirably chosen so as to be able to fold the balloon so that it can be inserted quickly and easily into a bone using a guide pin and a cannula, yet can also withstand high pressures when inflated. The balloon can also include optional ridges or indentations which are left in the cavity after the balloon has been removed, to enhance the stability of the filler. Also, the inflatable device can be made to have an optional, built-in suction catheter. This is used to remove any fat or fluid extruded from the bone during balloon inflation in the bone. Also, the balloon body can be protected from puncture by the cortical bone or canula by being covered while inside the canula with an optional protective sleeve of suitable material, such as Kevlar or PET or other polymer or substance that can protect the balloon. The main purpose of the inflatable device, therefore, is the forming or enlarging of a cavity or passage in a bone, especially in, but not limited to, vertebral bodies.
[0027] The primary object of the present invention is to provide an improved balloon-like inflatable device for use in carrying out a surgical protocol of cavity formation in bones to enhance the efficiency of the protocol, to minimize the time prior to performing the surgery for which the protocol is designed and to improve the clinical outcome. These balloons approximate the inner shape of the bone they are inside of in order to maximally compress cancellous bone. They have additional design elements to achieve specific clinical goals. Preferably, they are made of inelastic material and kept in their defined configurations when inflated, by various restraints, including (but not limited to) use of inelastic materials in the balloon body, seams in the balloon body created by bonding or fusing separate pieces of material together, or by fusing or bonding together opposing sides of the balloon body, woven material bonded inside or outside the balloon body, strings or bands placed at selected points in the balloon body, and stacking balloons of similar or different sizes or shapes on top of each other by gluing or by heat fusing them together. Optional ridges or indentations created by the foregoing structures, or added on by bonding additional material, increases stability of the filler. Optional suction devices, preferably placed so that if at least one hole is in the lowest point of the cavity being formed, will allow the cavity to be cleaned before filling.
[0028] Among the various embodiments of the present invention are the following:
[0029] 1. A doughnut (or torus) shaped balloon with an optional built-in suction catheter to remove fat and other products extruded during balloon expansion.
[0030] 2. A balloon with a spherical outer shape surrounded by a ring-shaped balloon segment for body cavity formation.
[0031] 3. A balloon which is kidney bean shaped in configuration. Such a balloon can be constructed in a single layer, or several layers stacked on top of each other.
[0032] 4. A spherically shaped balloon approximating the size of the head of the femur (i.e. the proximal femoral epiphysis). Such a balloon can also be a hemisphere.
[0033] 5. A balloon in the shape of a humpbacked banana or a modified pyramid shape approximating the configuration of the distal end of the radius (i.e. the distal radial epiphysis and metaphysis).
[0034] 6. A balloon in the shape of a cylindrical ellipse to approximate the configuration of either the medial half or the lateral half of the proximal tibial epiphysis. Such a balloon can also be constructed to approximate the configuration of both halves of the proximal tibial epiphysis.
[0035] 7. A balloon in the shape of sphere on a base to approximate the shape of the proximal humeral epiphysis and metaphysis with a plug to compress cancellous bone into the diaphysis, sealing it off.
[0036] 8. A balloon device with optional suction device.
[0037] 9. Protective sheaths to act as puncture guard members optionally covering each balloon inside its catheter.
[0038] The present invention, therefore, provides improved, inflatable devices for creating or enlarging a cavity or passage in a bone wherein the devices are inserted into the bone. The configuration of each device is defined by the surrounding cortical bone and adjacent internal structures, and is designed to occupy about 70-90% of the volume of the inside of the bone, although balloons that are as small as about 40% and as large as about 99% are workable for fractures. In certain cases, usually avascular necrosis, the balloon size may be as small as 10 % of the cancellous bone volume of the area of bone being treated, due to the localized nature of the fracture or collapse. The fully expanded size and shape of the balloon is limited by additional material in selected portions of the balloon body whose extra thickness creates a restraint as well as by either internal or external restraints formed in the device including, but not limited to, mesh work, a winding or spooling of material laminated to portions of the balloon body, continuous or non-continuous strings across the inside held in place at specific locations by glue inside or by threading them through to the outside and seams in the balloon body created by bonding two pieces of body together or by bonding opposing sides of a body through glue or heat. Spherical portions of balloons may be restrained by using inelastic materials in the construction of the balloon body, or may be additionally restrained as just described. The material of the balloon is preferably a non-elastic material, such as polyethylene tetraphthalate (PET), Kevlar or other patented medical balloon materials. It can also be made of semi-elastic materials, such as silicone or elastic material such as latex, if appropriate restraints are incorporated. The restraints can be made of a flexible, inelastic high tensile strength material including, but not limited, to those described in U.S. Pat. No. 4,706,670. The thickness of the balloon wall is typically in the range of 2/1000 ths to 25/1000 ths of an inch, or other thicknesses that can withstand pressures of up to 250-400 psi.
[0039] A primary goal of percutaneous vertebral body augmentation of the present invention is to provide a balloon which can create a cavity inside the vertebral body whose configuration is optimal for supporting the bone. Another important goal is to move the top of the vertebral body back into place to retain height where possible, however, both of these objectives must be achieved without fracturing the cortical wall of the vertebral body. This feature could push vertebral bone toward the spinal cord, a condition which is not to be desired.
[0040] The present invention satisfies these goals through the design of inflatable devices to be described. Inflating such a device compresses the calcium-containing soft cancellous bone into a thin shell that lines the inside of the hard cortical bone creating a large cavity.
[0041] At the same time, the biological components (red blood cells, bone progenitor cells) within the soft bone are pressed out and removed by rinsing during the procedure. The body recreates the shape of the inside of an unfractured vertebral body, but optimally stops at approximately 70 to 90% of the inner volume. The balloons of the present invention are inelastic, so maximally inflating them can only recreate the predetermined shape and size. However, conventional balloons become spherical when inflated. Spherical shapes will not allow the hardened bone cement to support the spine adequately, because they make single points of contact on each vertebral body surface (the equivalent of a circle inside a square, or a sphere inside a cylinder). The balloons of the present invention recreate the flat surfaces of the vertebral body by including restraints that keep the balloon in the desired shape. This maximizes the contacts between the vertebral body surfaces and the bone cement, which strengthens the spine. In addition, the volume of bone cement that fills these cavities creates a thick mantle of cement (4 mm or greater), which is required for appropriate compressive strength. Another useful feature, although not required, are ridges in the balloons which leave their imprint in the lining of compressed cancellous bone. The resulting bone cement “fingers” provide enhanced stability.
[0042] The balloons which optimally compress cancellous bone in vertebral bodies are the balloons listed as balloon types 1, 2 and 3 above. These balloons are configured to approximate the shape of the vertebral body. Since the balloon is chosen to occupy 70 to 90% of the inner volume, it will not exert undue pressure on the sides of the vertebral body, thus the vertebral body will not expand beyond its normal size (fractured or unfractured). However, since the balloon has the height of an unfractured vertebral body, it can move the top, which has collapsed, back to its original position.
[0043] One aspect of the invention provides a device for insertion into a vertebral body to apply a force capable of compacting cancellous bone and moving fractured cortical bone. The device includes a catheter extending along an axis and having a distal end sized and configured for insertion through a cannula into the vertebral body. The catheter carries near its distal end an inflatable body having a wall sized and configured for passage within the cannula into the vertebral body when the inflatable body is in a collapsed condition. The wall is further sized and configured to apply the in response to expansion of the inflatable body within the vertebral body. The wall includes, when inflated, opposed side surfaces extending along an elongated longitudinal axis that is substantially aligned with the axis of the catheter. The inflatable body has a height of approximately 0.5 cm to 3.5 cm, an anterior to posterior dimension of approximately 0.5 cm to 3.5 cm, and a side to side dimension of approximately 0.5 cm to 5.0 cm.
[0044] In a representative embodiment, the inflatable body comprises a balloon and the cannula is a percutaneious cannula.
[0045] In another aspect of the invention, the wall includes changes in wall thickness which restrain the opposed sided surfaces from expanding beyond a substantially flat condition.
[0046] According to another aspect of the invention, the wall includes an internal restraint which restrains the opposed side surfaces from expanding beyond a substantially flat condition. The internal restraint may include a mesh material, a string material, a woven material, a seam, or an essentially non-elastic material.
[0047] In yet another aspect of the invention, the wall includes an external restraint which restrains the opposed side surfaces from expanding beyond a substantially flat condition. The internal restraint may include a mesh material, a string material, a woven material, a seam, or an essentially non-elastic material.
[0048] A primary goal of percutaneous proximal humeral augmentation is to create a cavity inside the proximal humerus whose configuration is optimal for supporting the proximal humerus. Another important goal is to help realign the humeral head with the shaft of the humerus when they are separated by a fracture. Both of these goals must be achieved by exerting pressure primarily on the cancellous bone, and not the cortical bone. Undue pressure against the cortical bone could conceivably cause a worsening of a shoulder fracture by causing cortical bone fractures.
[0049] The present invention satisfies these goals through the design of the inflatable devices to be described. Inflating such a device compresses the cancellous bone against the cortical walls of the epiphysis and metaphysis of the proximal humerus thereby creating a cavity. In some cases, depending on the fracture location, the balloon or inflatable device may be used to extend the cavity into the proximal part of the humeral diaphysis.
[0050] Due to the design of the “sphere on a stand” balloon (described as number 7 above), the cavity made by this balloon recreates or approximates the shape of the inside cortical wall of the proximal humerus. The approximate volume of the cavity made by the “spherical on a stand balloon” is 70 to 90% that of the proximal humeral epiphysis and metaphysis, primarily, but not necessarily exclusive of, part of the diaphysis. The shape approximates the shape of the humeral head. The “base” is designed to compress the trabecular bone into a “plug” of bone in the distal metaphysis or proximal diaphysis. This plug of bone will prevent the flow of injectable material into the shaft of the humerus, improving the clinical outcome. The sphere can also be used without a base.
[0051] A primary goal of percutaneous distal radius augmentation is to create a cavity inside the distal radius whose configuration is optimal for supporting the distal radius. Another important goal is to help fine tune fracture realignment after the fracture has been partially realigned by finger traps. Both of these goals must be achieved by exerting pressure primarily on the cancellous bone and not on the cortical bone. Excessive pressure against the cortical bone could conceivably cause cortical bone fractures, thus worsening the condition.
[0052] The present invention satisfies these goals through the design,of inflatable devices either already described or to be described.
[0053] The design of the “humpbacked banana”, or modified pyramid design (as described as number 5 above), approximates the shape of the distal radius and therefore, the cavity made by this balloon approximates the shape of the distal radius as well. The approximate volume of the cavity to be made by this humpbacked banana shaped balloon is 70 to 90% that of the distal radial epiphysis and metaphysis primarily of, but not necessarily exclusive of, some part of the distal radial diaphysis. Inflating such a device compresses the cancellous bone against the cortical walls of the epiphysis and metaphysis of the distal radius in order to create a cavity. In some cases, depending on the fracture location, the osseous balloon or inflatable device may be used to extend the cavity into the distal part of the radial diaphysis.
[0054] A primary goal of percutaneous femoral head (or humeral head) augmentation is to create a cavity inside the femoral head (or humeral head) whose configuration is optimal for supporting the femoral head. Another important goal is to help compress avascular (or aseptic) necrotic bone or support avascular necrotic bone is the femoral head. This goal may include the realignment of avascular bone back into the position it previously occupied in the femoral head in order to improve the spherical shape of the femoral head. These goals must be achieved by exerting pressure primarily on the cancellous bone inside the femoral head.
[0055] The present invention satisfied these goals through the design of inflatable devices either already described or to be described.
[0056] The design of the spherical osseous balloon (described as balloon type 4 above) approximates the shape of the femoral head and therefore creates a cavity which approximates the shape of the femoral head as well. (It should be noted that the spherical shape of this inflatable device also approximates the shape of the humeral head and would, in fact, be appropriate for cavity formation in this osseous location as well.) Inflating such a device compresses the cancellous bone of the femoral head against its inner cortical walls in order to create a cavity. In some cases, depending upon the extent of the avascular necrosis, a smaller or larger cavity inside the femoral head will be formed. In some cases, if the area of avascular necrosis is small, a small balloon will be utilized which might create a cavity only 10 to 15% of the total volume of the femoral head. If larger areas of the femoral head are involved with the avascular necrosis, then a larger balloon would be utilized which might create a much larger cavity, approaching 80 to 90% of the volume of the femoral head.
[0057] The hemispherical balloon approximates the shape of the top half of the femoral (and humeral) head, and provides a means for compacting cancellous bone in an area of avascular necrosis or small fracture without disturbing the rest of the head. This makes it easier to do a future total joint replacement if required.
[0058] A primary goal of percutaneous proximal tibial augmentation is to create a cavity inside the proximal tibia whose configuration is optimal for supporting either the medial or lateral tibial plateaus. Another important goal is to help realign the fracture fragments of tibial plateau fractures, particularly those features with fragments depressed below (or inferior to) their usual location. Both of these objectives must be achieved by exerting pressure on primarily the cancellous bone and not the cortical bone. Pressure on the cortical bone could conceivably cause worsening of the tibial plateau fracture.
[0059] The present invention satisfies these goals through the design of the inflatable devices to be described. Inflating such a device compresses the cancellous bone against the cortical walls of the medial or lateral tibial plateau in order to create a cavity.
[0060] Due to the design of the “elliptical cylinder” balloon (described as balloon type 6 above) the cavity made by this balloon recreates or approximates the shape of the cortical walls of either the medial or lateral tibial plateaus. The approximate volume of the cavity to be made by the appropriate elliptical cylindrical balloon is 50 to 90% of the proximal epiphyseal bone of either the medial half or the lateral half of the tibial.
[0061] Other objects of the present invention will become apparent as the following specification progresses, reference being had to the accompanying drawings for an illustration of the invention.
DESCRIPTION OF THE DRAWINGS
[0062] [0062]FIG. 1 is a perspective view of a first embodiment of the balloon of the present invention, the embodiment being in the shape of a stacked doughnut assembly.
[0063] [0063]FIG. 2 is a vertical section through the balloon of FIG. 1 showing the way in which the doughnut portions of the balloon of FIG. 1, fit into a cavity of a vertebral body.
[0064] [0064]FIG. 3 is a schematic view of another embodiment of the balloon of the present invention showing three stacked balloons and string-like restraints for limiting the expansion of the balloon in directions of inflation.
[0065] [0065]FIG. 4 is a top plan view of a spherical balloon having a cylindrical ring surrounding the balloon.
[0066] [0066]FIG. 5 is a vertical section through the spherical balloon and ring of FIG. 4.
[0067] [0067]FIG. 6 shows an oblong-shaped balloon with a catheter extending into the central portion of the balloon.
[0068] [0068]FIG. 6A is a perspective view of the way in which a catheter is arranged relative to the inner tubes for inflating the balloon of FIG. 6.
[0069] [0069]FIG. 7 is a suction tube and a contrast injection tube for carrying out the inflation of the balloon and removal of debris caused by expansion from the balloon itself.
[0070] [0070]FIG. 8 is a vertical section through a balloon after it has been deflated and as it is being inserted into the vertebral body of a human.
[0071] [0071]FIGS. 9 and 9A are side elevational views of a cannula showing how the protective sleeve or guard member expands when leaving the cannula.
[0072] [0072]FIG. 9B is a vertical section through a vertebral bone into which an access hole has been drilled.
[0073] [0073]FIG. 10 is a perspective view of another embodiment of the balloon of the present invention formed in the shape of a kidney bean.
[0074] [0074]FIG. 11 is a perspective view of the vertebral bone showing the kidney shaped balloon of FIG. 10 inserted in the bone and expanded.
[0075] [0075]FIG. 12 is a top view of a kidney shaped balloon formed of several compartments by a heating element or branding tool.
[0076] [0076]FIG. 13 is a cross-sectional view taken along line 13 - 13 of FIG. 12 but with two kidney shaped balloons that have been stacked.
[0077] [0077]FIG. 14 is a view similar to FIG. 11 but showing the stacked kidney shaped balloon of FIG. 13 in the vertebral bone.
[0078] [0078]FIG. 15 is a top view of a kidney balloon showing outer tufts holding inner strings in place interconnecting the top and bottom walls of the balloon.
[0079] [0079]FIG. 16 is a cross sectional view taken along lines 16 - 16 of FIG. 15.
[0080] [0080]FIG. 17A is a dorsal view of a humpback banana balloon in a right distal radius.
[0081] [0081]FIG. 17B is a cross sectional view of FIG. 17A taken along line 17 B- 17 B of FIG. 17A.
[0082] [0082]FIG. 18 is a spherical balloon with a base in a proximal humerus viewed from the front (anterior) of the left proximal humerus.
[0083] [0083]FIG. 19A is the front (anterior) view of the proximal tibia with the elliptical cylinder balloon introduced beneath the medial tibial plateau.
[0084] [0084]FIG. 19B is a three quarter view of the balloon of FIG. 19A.
[0085] [0085]FIG. 19C is a side elevational view of the balloon of FIG. 19A.
[0086] [0086]FIG. 19D is a top plan view of the balloon of FIG. 19A.
[0087] [0087]FIG. 20 is a spherically shaped balloon for treating avascular necrosis of the head of the femur (or humerus) as seen from the front (anterior) of the left hip.
[0088] [0088]FIG. 20A is a side view of a hemispherically shaped balloon for treating avascular necrosis of the head of the femur (or humerus).
DETAILED DESCRIPTION
[0089] Ballons For Vertebral Bodies
[0090] A first embodiment of the balloon (FIG. 1) of the present invention is broadly denoted by the numeral 10 and includes a balloon body 11 having a pair of hollow, inflatable, non-expandable parts 12 and 14 of flexible material, such as PET or Kevlar. Parts 12 and 14 have a suction tube 16 therebetween for drawing fats and other debris by suction into tube 16 for transfer to a remote disposal location. Catheter 16 has one or more suction holes so that suction may be applied to the open end of tube 16 from a suction source (not shown).
[0091] The parts 12 and 14 are connected together by an adhesive which can be of any suitable type. Parts 12 and 14 are doughnut-shaped as shown in FIG. 1 and have tubes 18 and 20 which communicate with and extend away from the parts 12 and 14 , respectively, to a source of inflating liquid under pressure (not shown). The liquid can be any sterile biocompatible solution. The liquid inflates the balloon 10 , particularly parts 12 and 14 thereof after the balloon has been inserted in a collapsed condition (FIG. 8) into a bone to be treated, such as a vertebral bone 22 in FIG. 2. The above-mentioned U.S. Pat. Nos. 4,969,888 and 5,108,404 disclose the use of a guide pin and cannula for inserting the balloon into bone to be treated when the balloon is deflated and has been inserted into a tube and driven by the catheter into the cortical bone where the balloon is inflated.
[0092] [0092]FIG. 8 shows a deflated balloon 10 being inserted through a cannula 26 into bone. The balloon in cannula 26 is deflated and is forced through the cannula by exerting manual force on the catheter 21 which extends into a passage 28 extending into the interior of the bone. The catheter is slightly flexible but is sufficiently rigid to allow the balloon to be forced into the interior of the bone where the balloon is then inflated by directing fluid into tube 88 whose outlet ends are coupled to respective parts 12 and 14 .
[0093] In use, balloon 10 is initially deflated and, after the bone to be filled with the balloon has been prepared to receive the balloon with drilling, the deflated balloon is forced into the bone in a collapsed condition through cannula 26 . The bone is shown in FIG. 2. The balloon is oriented preferably in the bone such that it allows minimum pressure to be exerted on the bone marrow and/or cancellous bone if there is no fracture or collapse of the bone. Such pressure will compress the bone marrow and/or cancellous bone against the inner wall of the cortical bone, thereby compacting the bone marrow of the bone to be treated and to further enlarge the cavity in which the bone marrow is to be replaced by a biocompatible, flowable bone material.
[0094] The balloon is then inflated to compact the bone marrow and/or cancellous bone in the cavity and, after compaction of the bone marrow and/or cancellous bone, the balloon is deflated and removed from the cavity. While inflation of the balloon and compaction occurs, fats and other debris are sucked out of the space between and around parts 12 and 14 by applying a suction force to catheter tube 16 . Following this, and following the compaction of the bone marrow, the balloon is deflated and pulled out of the cavity by applying a manual pulling force to the catheter tube 21 .
[0095] The second embodiment of the inflatable device of the present invention is broadly denoted by the numeral 60 and is shown in FIGS. 4 and 5. Balloon 60 includes a central spherical part 62 which is hollow and which receives an inflating liquid under pressure through a tube 64 . The spherical part is provided with a spherical outer surface 66 and has an outer periphery which is surrounded substantially by a ring shaped part 68 having tube segments 70 for inflation of part 68 . A pair of passages 69 interconnect parts 62 and 68 . A suction tube segment 72 draws liquid and debris from the bone cavity being formed by the balloon 60 .
[0096] Provision can be made for a balloon sleeve 71 for balloon 60 and for all balloons disclosed herein. A balloon sleeve 71 (FIG. 9) is shiftably mounted in an outer tube 71 a and can be used to insert the balloon 60 when deflated into a cortical bone. The sleeve 71 has resilient fingers 71 b which bear against the interior of the entrance opening 71 c of the vertebral bone 22 (FIG. 9A) to prevent tearing of the balloon. Upon removal of the balloon sleeve, liquid under pressure will be directed into tube 64 which will inflate parts 62 and 68 so as to compact the bone marrow within the cortical bone. Following this, balloon 60 is deflated and removed from the bone cavity.
[0097] [0097]FIGS. 6 and 6A show several views of a modified doughnut shape balloon 80 of the type shown in FIGS. 1 and 2, except the doughnut shapes of balloon 80 are not stitched onto one another. In FIG. 6, balloon 80 has a pear-shaped outer convex surface 82 which is made up of a first hollow part 84 and a second hollow part 85 . A tube 88 is provided for directing liquid into the two parts along branches 90 and 92 to inflate the parts after the parts have been inserted into the medullary cavity of a bone. A catheter tube 16 is inserted into the space 96 between two parts of the balloon 80 . An adhesive bonds the two parts 84 and 85 together at the interface thereof.
[0098] [0098]FIG. 6A shows the way in which the catheter tube 16 is inserted into the space or opening 96 between the two parts of the balloon 80 .
[0099] [0099]FIG. 7 shows tube 88 of which, after directing inflating liquid into the balloon 80 , can inject contrast material into the balloon 80 so that x-rays can be taken of the balloon with the inflating material therewithin to determine the proper placement of the balloon. Tube 16 is also shown in FIG. 6, it being attached in some suitable manner to the outer side wall surface of tube 88 .
[0100] Still another embodiment of the invention is shown in FIG. 3 which is similar to FIG. 1 except that it is round and not a doughnut and includes an inflatable device 109 having three balloon units 110 , 112 and 114 which are inflatable and which have string-like restraints 117 which limit the expansion of the balloon units in a direction transverse to the longitudinal axes of the balloon units. The restraints are made of the same or similar material as that of the balloon so that they have some resilience but substantially no expansion capability.
[0101] A tube system 115 is provided to direct liquid under pressure into balloon units 110 , 112 and 114 so that liquid can be used to inflate the balloon units when placed inside the bone in a deflated state. Following the proper inflation and compaction of the bone marrow, the balloon can be removed by deflating it and pulling it outwardly of the bone being treated. The restraints keep the opposed sides 77 and 79 substantially flat and parallel with each other.
[0102] In FIG. 10, another embodiment of the inflatable balloon is shown. The device is a kidney shaped balloon body 130 having a pair of opposed kidney shaped side walls 132 which are adapted to be collapsed and to cooperate with a continuous end wall 134 so that the balloon 130 can be forced into a bone 136 shown in FIG. 11. A tube 138 is used to direct inflating liquid into the balloon to inflate the balloon and cause it to assume the dimensions and location shown vertebral body 136 in FIG. 11. Device 130 will compress the cancellous bone if there is no fracture or collapse of the cancellous bone. The restraints for this action are due to the side and end walls of the balloon.
[0103] [0103]FIG. 12 shows a balloon 140 which is also kidney shaped and has a tube 142 for directing an inflatable liquid into the tube for inflating the balloon. The balloon is initially a single chamber bladder but the bladder can be branded along curved lines or strips 141 to form attachment lines 144 which take the shape of side-by-side compartments 146 which are kidney shaped as shown in FIG. 13. The branding causes a welding of the two sides of the bladder to occur since the material is standard medical balloon material, which is similar to plastic and can be formed by heat.
[0104] [0104]FIG. 14 is a perspective view of a vertebral body 147 containing the balloon of FIG. 12, showing a double stacked balloon 140 when it is inserted in vertebral bone 147 .
[0105] [0105]FIG. 15 is a view similar to FIG. 10 except that tufts 155 , which are string-like restraints, extend between and are connected to the side walls 152 of inflatable device 150 and limit the expansion of the side walls with respect to each other, thus rendering the side walls generally parallel with each other. Tube 88 is used to fill the kidney shaped balloon with an inflating liquid in the manner described above.
[0106] The dimensions for the vertebral body balloon will vary across a broad range. The heights (H, FIG. 11) of the vertebral body balloon for both lumbar and thoracic vertebral bodies typically range from 0.5 cm to 3.5 cm. The anterior to posterior (A, FIG. 11) vertebral body balloon dimensions for both lumbar and thoracic vertebral bodies range from 0.5 cm to 3.5 cm. The side to side (L, FIG. 11) vertebral body dimensions for thoracic vertebral bodies will range from 0.5 cm to 3.5 cm. The side to side vertebral body dimensions for lumbar vertebral bodies will range from 0.5 cm to 5.0 cm.
[0107] The eventual selection of the appropriate balloon for, for instance, a given vertebral body is based upon several factors. The anterior-posterior (A-P) balloon dimension for a given vertebral body is selected from the CT scan or plain film x-ray views of the vertebral body. The A-P dimension is measured from the internal cortical wall of the anterior cortex to the internal cortical wall of the posterior cortex of the vertebral body. In general, the appropriate A-P balloon dimension is 5 to 7 millimeters less than this measurement.
[0108] The appropriate side to side balloon dimensions for a given vertebral body is selected from the CT scan or from a plain film x-ray view of the vertebral body to be treated. The side to side distance is measured from the internal cortical walls of the side of the vertebral bone. In general, the appropriate side to side balloon dimension is 5 to 7 millimeters less than this measurement by the addition of the lumbar vertebral body tends to be much wider than side to side dimension then their A-P dimension. In thoracic vertebral bodies, the side to side dimension and their A-P dimensions are almost equal.
[0109] The height dimensions of the appropriate vertebral body balloon for a given vertebral body is chosen by the CT scan or x-ray views of the vertebral bodies above and below the vertebral body to be treated. The height of the vertebral bodies above and below the vertebral body to be treated are measured and averaged. This average is used to determine the appropriate height dimension of the chosen vertebral body balloon.
[0110] Ballons for Long Bones
[0111] Long bones which can be treated with the use of balloons of the present invention include distal radius (larger arm bone at the wrist), proximal tibial plateau (leg bone just below the knee), proximal humerus (upper end of the arm at the shoulder), and proximal femoral head (leg bone in the hip).
[0112] Distal Radius Balloon
[0113] For the distal radius, a balloon 160 is shown in the distal radius 152 and the balloon has a shape which approximates a pyramid but more closely can be considered the shape of a humpbacked banana in that it substantially fills the interior of the space of the distal radius to force cancellous bone 154 lightly against the inner surface 156 of cortical bone 158 .
[0114] The balloon 160 has a lower, conical portion 159 which extends downwardly into the hollow space of the distal radius 152 , and this conical portion 159 increases in cross section as a central distal portion 161 is approached. The cross section of the balloon 160 is shown at a central location (FIG. 17B) and this location is near the widest location of the balloon. The upper end of the balloon, denoted by the numeral 162 , converges to the catheter 88 for directing a liquid into the balloon for inflating the same to force the cancellous bone against the inner surface of the cortical bone. The shape of the balloon 160 is determined and restrained by tufts formed by string restraints 165 . These restraints are optional and provide additional strength to the balloon body 160 , but are not required to achieve the desired configuration. The balloon is placed into and taken out of the distal radius in the same manner as that described above with respect to the vertebral bone.
[0115] The dimensions of the distal radius balloon vary as follows:
[0116] The proximal end of the balloon (i.e. the part nearest the elbow) is cylindrical in shape and will vary from 0.5.times.0.5 cm to 1.8.times.1.8 cm.
[0117] The length of the distal radius balloon will vary from 1.0 cm to 12.0 cm.
[0118] The widest medial to lateral dimension of the distal radius balloon, which occurs at or near the distal radio-ulnar joint, will measure from 1.0 cm to 2.5 cm.
[0119] The distal anterior-posterior dimension of the distal radius balloon will vary from 0.5 to 3.0 cm.
[0120] Proximal Humerus Fracture Balloon
[0121] The selection of the appropriate balloon size to treat a given fracture of the distal radius will depend on the radiological size of the distal radius and the location of the fracture.
[0122] In the case of the proximal humerus 169 , a balloon 166 shown in FIG. 18 is spherical and has a base design. It compacts the cancellous bone 168 in a proximal humerus 169 . A mesh 170 , embedded or laminated and/or winding, may be used to form a neck 172 on the balloon 166 , and second mesh 170 a may be used to conform the bottom of the base 172 a to the shape of the inner cortical wall at the start of the shaft. These restraints provide additional strength to the balloon body, but the configuration can be achieved through molding of the balloon body. This is so that the cancellous bone will be as shown in the compacted region surrounding the balloon 166 as shown in FIG. 18. The cortical bone 173 is relatively wide at the base 174 and is thin-walled at the upper end 175 . The balloon 166 has a feed tube 177 into which liquid under pressure is forced into the balloon to inflate it to lightly compact the cancellous bone in the proximal humerus. The balloon is inserted into and taken out of the proximal humerus in the same manner as that described above with respect to the vertebral bone.
[0123] The dimensions of the proximal humerus fracture balloon vary as follows:
[0124] The spherical end of the balloon will vary from 1.0.times.1.0 cm to 3.0.times.3.0 cm.
[0125] The neck of the proximal humeral fracture balloon will vary from 0.8.times.0.8 cm to 3.0.times.3.0 cm.
[0126] The width of the base portion or distal portion of the proximal numeral fracture balloon will vary from 0.5.times.0.5 cm to 2.5.times.2.5 cm.
[0127] The length of the balloon will vary from 4.0 cm to 14.0 cm.
[0128] The selection of the appropriate balloon to treat a given proximal humeral fracture depends on the radiologic size of the proximal humerus and the location of the fracture.
[0129] Proximal Tibial Plauteau Fracture Balloon
[0130] The tibial fracture is shown in FIG. 19A in which a balloon 180 is placed in one side 182 of a tibia 183 . The balloon, when inflated, compacts the cancellous bone in the layer 184 surrounding the balloon 180 . A cross section of the balloon is shown in FIG. 19C wherein the balloon has a pair of opposed sides 185 and 187 which are interconnected by restraints 188 which can be in the form of strings or flexible members of any suitable construction. The main purpose of the restraints is to make the sides 185 and 187 substantially parallel with each other and non-spherical. A tube 190 is coupled to the balloon 180 to direct liquid into and out of the balloon. The ends of the restraints are shown in FIGS. 19B and 19D and denoted by the numeral 191 . The balloon is inserted into and taken out of the tibia in the same manner as that described above with respect to the vertebral bone. FIG. 19B shows a substantially circular configuration for the balloon; whereas, FIG. 19D shows a substantially elliptical version of the balloon.
[0131] The dimensions of the proximal tibial plateau fracture balloon vary as follows:
[0132] The thickness or height of the balloon will vary from 0.5 cm to 5.0 cm.
[0133] The anterior/posterior (front to back) dimension will vary from 1.0 cm to 6.0 cm.
[0134] The side to side (medial to lateral) dimension will vary from 1.0 cm to 6.0 cm.
[0135] The selection of the appropriate balloon to treat a given tibial plateau fracture will depend on the radiological size of the proximal tibial and the location of the fracture.
[0136] Femoral Head Balloon
[0137] In the case of the femoral head, a balloon 200 is shown as having been inserted inside the cortical bone 202 of the femoral head which is thin at the outer end 204 of the femur and which can increase in thickness at the lower end 206 of the femur. The cortical bone surrounds the cancellous bone 207 and this bone is compacted by the inflation of balloon 200 . The tube for directing liquid for inflation purposes into the balloon is denoted by the numeral 209 . It extends along the femoral neck and is directed into the femoral head which is generally spherical in configuration. FIG. 20A shows that the balloon, denoted by the numeral 200 a , can be hemispherical as well as spherical, as shown in FIG. 20. The balloon 200 is inserted into and taken out of the femoral head in the same manner as that described with respect to the vertebral bone. The hemispherical shape is maintained in this example by bonding overlapping portions of the bottom, creating pleats 200 b as shown in FIG. 20A.
[0138] The dimensions of the femoral head balloon vary as follows:
[0139] The diameter of the femoral head balloon will vary from 1.0 cm to up to 4.5 cm. The appropriate size of the femoral head balloon to be chosen depends on the radiological or CT scan size of the head of the femur and the location and size of the avascular necrotic bone. The dimensions of the hemispherical balloon are the same as the those of the spherical balloon, except that approximately one half is provided. | A balloon for use in compressing cancellous bone and marrow (also known as medullary bone or trabecular bone) against the inner cortex of bones whether the bones are fractured or not. The balloon comprises an inflatable, non-expandable balloon body for insertion into said bone. The body has a shape and size to compress at least a portion of the cancellous bone to form a cavity in the cancellous bone and to restore the original position of the outer cortical bone, if fractured or collapsed. The balloon is prevented from applying excessive pressure to the outer cortical bone. The wall or walls of the balloon are such that proper inflation the balloon body is achieved to provide for optimum compression of all the bone marrow. The balloon is able to be folded so that it can be inserted quickly into a bone. The balloon can be made to have a suction catheter. The main purpose of the balloon is the forming or enlarging of a cavity or passage in a bone, especially in, but not limited to, vertebral bodies. | 53,261 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a detector of quantity of electricity for detecting a value of amplitude of quantity of electricity of AC voltage, AC current and the like, particularly to improvement of frequency characteristics thereof.
2. Description of Related Art
FIG. 1 is a figure explaining a principle of a conventional digital processing apparatus of a quantity of AC electricity disclosed in Japanese Patent Application No. 62-333434, the value of amplitude being determined by using three data which have been sampled with electrical angle 90° of AC current being sampling cycle T. In the figure, assuming that a sampling value 1 of an appropriate time is i(O), a sampling value 2 preceding one cycle (T) being i(T), a sampling value 3 preceding two cycles (2T) being i(2T), sampling values 1˜3 are squared, by square operating means 5˜7 respectively, and only the result of the square operating means 6 is doubled by a double operating means 29.
The results obtained at aforesaid square operating means 5 and 7 are added to the result of aforesaid double operating means 29 by an adder means 11 so as to obtain the sum. The sum is divided by 2 by a divide operating means 30 and the square root is calculated by a square root operating means 13 to obtain, at a terminal 14, the output Fn thereof, being the value of amplitude of AC current.
Next, explanation will be given on the operation. For the convenience sake of the explanation, the quantity of AC electricity is assumed to be AC current, maximum value I, instantaneous magnitude i, fundamental blade frequency fo, and the sampling cycle T whose cycle is made to be 1/4 of the fundamental blade frequency fo. And in order to distinguish data at a sampling time, assuming that nT (where n =0, 1, 2, . . . , and n=0 being this time) is suffix, the sampling value of the appropriate time are expressed to be i(O), the sampling value preceding one cycle from the appropriate time to be i(T), and the sampling value preceding two cycles from the appropriate time to be i(2T). . . respectively.
When output Fn is expressed in any formula, the following first formula is obtained. ##EQU1##
The sampling cycle T is fixed to 1/4 cycle relative to where the fundamental frequency of the AC current, that is, a time period which corresponds to electrical angle 90°, however, where the frequency of the sampling time is f, the sampling cycle T is expressed as in the second formula. ##EQU2##
For example, the frequency of the AC current is f=fo =50 Hz, the sampling cycle T=90° is established.
Generally, as an electric power system is operated by rated frequency fo, in formula (1), Fn=I is obtained, thereby the amplitude value of the current can be calculated, which, for example, is used for such as an AC excess current protection relay and a control apparatus. But, for the protection relay for detecting accidents being happened in the electric power system and for the control apparatus for detecting the quantity of electricity for controlling an operation apparatus, there are many cases where the frequency of the electric power system has changed from fo. But, even if there is some dislocation of frequency of the electric power system, there is a need to determine the value of amplitude accurately. Generally, in order to cope with the change of ±5% of the frequency, it is necessary to lessen errors as much as possible.
Now, assuming that the frequency f=52.5 Hz (increase of 5% of 50 Hz), formula T=94.5° is obtained. When it is substituted in formula (1), the following formula is established:
Fn=I{1-0.0062cos(2θ-189°)}.sup.1/2 ( 3).
Such result is obtained as that the constant value is degenerated by the amplitude waveform of double cycle. Since cos(2θ-189°) can be changed from +1.0 to -1.0, the formula (3) becomes as
Fn=0.997I˜1.003I (4),
thereby, the error of -0.3% to 0.3% is created compared with that of the operation of the amplitude value at the time when the rated frequency is 50 Hz.
Because the conventional detector of quantity of electricity is so constructed as above, there is a problem that the calculation of error of amplitude value is relatively larger in the case where the frequency varies to the extent of about ±5%.
SUMMARY OF THE INVENTION
The present invention has been devised to solve such a problem as mentioned above.
The primary object of the invention is to provide a detector of quantity of electricity which is capable of lessen the detected error of the amplitude value of quantity of AC electricity on the basis of four sampling values of quality of AC electricity.
The above and further objects and features of the invention will more fully be apparent from the following detailed description with accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a drawing showing a conception of detecting principle of the conventional detector of quantity of electricity.
FIG. 2 is a block diagram showing a construction of the detector of quantity of electricity.
FIG. 3 is a drawing showing a conception of detecting principle of the detector of quantity of electricity of the present invention, and
FIG. 4 is a graph which compares the detected accuracy of the conventional detector of quantity of electricity with the one that of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An explanation will now be given on an embodiment of the present invention referring to the drawings.
FIG. 2 is a block diagram showing a hardware construction of the detector of quantity of electricity 28 for executing aforesaid calculation of amplication value. In the figure, reference numeral 15 is a potential transformer, 16 being a current transformer, 17 and 18 being input transformers for converting the values of voltage and current of the electric power system so that they can be processed easily, and reference numerals 19 and 20 being filters for removing frequency at more than a half of the sampling frequency out of such high frequency as included in the voltage and current, as well known. Numerals 21 and 22 are sample-and-hold circuits for holding the sampling value until the next sampling cycle. Numeral 23 is a multiplexer for sequentially switching the outputs of the sample-and-hold circuits so as to transmit them to an analog-digital converter 24. Numeral 25 is a microprocessor for executing calculation by using the program being previously stored in a memory 26, the result thereof being outputted to an output circuit 27.
FIG. 3 is a conceptual diagram showing a principle of detecting the quantity of electricity by the detector of quantity of electricity 28. The sampling values 1˜4, at the time t-nt (n=0, 1, 2, 3) which is separated cycles being required for obtaining the predetermined sampling number n according to the time t, are assumed to be i(O), i(T), i(2T), and i(3T), and the sampling values 1˜4 are squared by the square calculating means 5˜8, respectively, only the result of the square calculating means 6 and 7 being tripled by triple calculating means 9 and 10.
The result being obtained by aforesaid square calculating means 5 and 8, are added to the result of aforesaid triple calculating means 9 and 10 by the adding means 11 so as to obtain the sum. Then the sum is divided by 4 by a division calculating means 12 so as to obtain the square root by a square root calculating means 13. The result is obtained to be as the output Fn at a terminal 14.
The above operation is expressed in such formula (5) as follows: ##EQU3## At the sampling time, in the case where the frequency f=52.5 Hz (increase of 5% of 50 Hz), such formula as T=94.5° is obtained. When this is substituted into the formula (5), the following formula (6) is obtained:
Fn=I[1-cos.sup.3 (94.5°)·cos(2θ-3×94.5°)].sup.1/2 =I[1+4.83×10.sup.-4 cos(2θ-283.5°)].sup.1/2(6)
This formula expresses that the amplitude relative to I is to be as 4.83×10 -4 and the amplitude wave form of double frequency is degenerated. Since cos(2θ-283.5°) can be changed from +1.0 to -1.0, the following formula is established:
Fn=0.99976I˜1.00024I (7)
When this is compared with the calculation of amplitude value at 50 Hz of the rated frequency, the error is to be such minimum value as -0.024% to +0.024%.
The result of calculation of the amplitude value Fn obtained here (not shown) is compared with the predetermined value (also called setting value) by a comparison calculating means so as to compare which is larger, thereby detecting accidents to the electric power system by the digital protection relay. And according to the obtained Fn, the control apparatus (not shown) is used for such as on-off control of a static capacitor and the like.
In addition, the above explanation has made on such arrangement as that the output of the adding means 11 is processed by the division calculating means 12 and the square root calculating means 13, however, aforesaid square calculating means 13 is dispensable, if the preset values of the digital protection relay and the control apparatus are set at the values which have been obtained by squaring the predetermined value (setting value). And, if the preset value is set at the value which has been obtained by squaring the predetermined value (setting value) and then quadrupling, aforesaid division calculating means 12 and aforesaid square root calculating means 13 become dispensable.
In addition, in aforesaid embodiment, the outputs of the square calculating means 6 and 7 are adapted to be tripled by triple calculating means 9 and 10 respectively, however, such change of the well-known operation law as to calculate the sum of the square calculating means 6 and 7 and then triple the sum, is not restricted in any way.
Next will be explained the change status of Fn being the result of calculation of the amplitude value in the case where the frequency is varied.
When the ratio of the frequency f after the change to the rated frequency fo is expressed as the formula m=f/fo, formula (8) is obtained from formulas (2) and (5).
Fn=I[1-cos.sup.3 (T)·cos(2θ-3T)].sup.1/2 =I[1-cos.sup.3 (90° m)·cos(2θ-3×90° m)].sup.1/2(8)
When m in the formula (8) is varied and displayed, which is shown in the portion of oblique lines in FIG. 4, and in the vicinity of m=1 (f=fo), the change of the size of the portion is scarcely to be seen, thereby it can be clear that the error of the calculated result of the amplitude value becomes minimum.
In the same way, formula (9) is obtained by expressing the conventional formula (1) with such formula of m as described above, and dotted lines in FIG. 4 show that the calculation processing of the present invention obviously has less error.
Fn=I[1-cos.sup.2 (90° m)·cos(2θ-2×90° m)].sup.1/2 (9)
In addition, since the sampling value used in the calculation of amplitude value is realized with four sampling values including that at the predetermined time, the result can be obtained with the time period corresponding to 90°×4=360°, thereby the present invention can realize to obtain the result at a high speed practically the same as that in the conventional apparatus, and also generally the same quantity of memory necessary for calculation processing can be realized.
Furthermore, explanation has been given on the embodiment above mentioned in order to calculate the amplitude value of the AC current. The AC current at that time is the same as a phase current and a line-to-line current of the electric power system, or a symmetrical component obtained from aforesaid phase current and line-to-line current, that is, a positive phase current, a negative current or a zero phase current.
Moreover, the AC voltage can also has the same effect by applying it in the same way.
As this invention may be embodied in several forms without departing from the spirit of essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within the meets and bounds of the claims, or equivalence of such meets and bounds thereof are therefore intended to be embraced by the claims. | A detector of quantity of electricity of the invention for detecting an amplitude value from the quantity of AC electricity, comprising sampling means for sampling the quantity of AC electricity at a cycle T which is 1/4 of the rated cycle of quantity of AC electricity, and operating means for operating the amplitude value on the basis of the sampling values, operates with the following formula:
y(o).sup.2 +3·{y(T).sup.2 +y(2T).sup.2 }+y(3T).sup.2
where, y(t-nT) is expressed as y(nT). | 12,738 |
FIELD OF THE INVENTION
[0001] The present invention relates to methods and systems for using extrapolation analysis or techniques to express an approximate self-consistent solution or a change in a self-consistent solution based on a change in the value of one or more external parameters. The self-consistent solution may be used in a model of a system or nano-scale system having at least two probes or electrodes, and the model may be based on an electronic structure calculation comprising a self-consistent determination of an effective one-electron potential energy function and/or an effective one-electron Hamiltonian.
BACKGROUND OF THE INVENTION
[0002] Most common examples of methods within the field of atomic scale modelling, where the modelling is based on electronic structure calculations that require a self-consistent determination of an effective one-electron potential energy function are Density Functional Theory (DFT) and Hartree-Fock (HF) theory. Many applications of DFT are studies of how a system responds when an external parameter is varied. In such studies, it is necessary to perform a self-consistent calculation for each value of the external parameter, and this can be very time consuming. An important application is the calculation of the current-voltage (I-U) characteristics of a nano-scale device. An example of such a calculation is given in Stokbro, Computational Materials Science 27, 151 (2003), where the I-U characteristics of a Di-Thiol-Phenyl (DTP) molecule coupled with gold surfaces is calculated. The system is illustrated in FIG. 2 , and the calculation follows the steps outlined in flowcharts 2 and 3 shown in FIGS. 5 and 6 . The calculation is very computationally demanding, due to the self-consistent loop for each voltage.
[0003] It is an objective of the present invention is to provide an efficient and reasonable accurate method for determining a change in a self-consistent solution caused by a variation of one or more external parameters.
SUMMARY OF THE INVENTION
[0004] According to the present invention there is provided a method of using extrapolation analysis or technique to express an approximate self-consistent solution or a change in a self-consistent solution based on a change in the value of one or more external parameters, said self-consistent solution being used in a model of a system having at least two probes or electrodes, which model is based on an electronic structure calculation comprising a self-consistent determination of an effective one-electron potential energy function and/or an effective one-electron Hamiltonian, the method comprising:
[0000] determining a first self-consistent solution to a selected function for a first value of a first external parameter by use of self-consistent loop calculation;
[0005] determining a second self-consistent solution to the selected function for a second value of the first selected external parameter by use of self-consistent loop calculation, said second value of the first selected external parameter being different to the first value of the first selected external parameter; and
[0006] expressing an approximate self-consistent solution or a change in the self-consistent solution for the selected function for at least one selected value of the first selected external parameter by use of extrapolation based on at least the determined first and second self-consistent solutions and the first and second values of the first selected external parameter. Here, the approximate self-consistent solution or change in the self-consistent solution may be expressed by use of linear extrapolation.
[0007] According to an embodiment of the invention the method may further comprise that a third self-consistent solution to the selected function is determined for a third value of the first selected external parameter by use of self-consistent loop calculation, said third value of the first selected external parameter being different to the first and second values of the first selected external parameter. Here, the approximate self-consistent solution or change in the self-consistent solution for the selected function for at least one selected value of the first selected external parameter may be expressed by use of extrapolation based on at least the determined first, second and third self-consistent solutions and the first, second and third values of the first selected external parameter. Here, it is preferred that the approximate self-consistent solution or change in the self-consistent solution is expressed by use of second order extrapolation.
[0008] It is preferred that the system being modelled is a nano-scale device or a system comprising a nano-scale device. It is also preferred that the modelling of the system comprises providing one or more of the external parameters as inputs to said probes or electrodes.
[0009] According to an embodiment of the invention the system being modelled is a two-probe system and the external parameter is a voltage bias, U, across said two probes or electrodes, said two-probe system being modelled as having two substantially semi-infinite probes or electrodes being coupled to each other via an interaction region.
[0010] It is also within an embodiment of the invention that the system being modelled is a three-probe system with three probes or electrodes and the external parameters are a first selected parameter and a second selected parameter being of the same type as the first selected parameter. Here, the system being modelled may be a three-probe system with three probes or electrodes and the external parameters are a first voltage bias, U 1 , across a first and a second of said electrodes and a second voltage bias, U 2 , across a third and the first of said electrodes, said three-probe system being modelled as having three substantially semi-infinite electrodes being coupled to each other via an interaction region.
[0011] When the system being modelled is a three-probe system, the method of the invention may further comprise:
[0000] determining a fourth self-consistent solution to the selected function for a first value of the second selected external parameter by use of self-consistent loop calculation,
[0012] determining a fifth self-consistent solution to the selected function for a second value of the second selected external parameter by use of self-consistent loop calculation, said second value of the second selected external parameter being different to the first value of the second selected external parameter; and
[0013] wherein said expressing of the approximate self-consistent solution or change in the self-consistent solution for the selected function is expressed for the selected value of the first selected external parameter and a selected value of the second selected external parameter by use of extrapolation based on at least the determined first and second self-consistent solutions together with the first and second values of the first selected external parameter, and further based on at least the determined fourth and fifth self-consistent solutions together with the first and second values of the second selected external parameter. Here, the approximate self-consistent solution or change in the self-consistent solution may be expressed by use of linear extrapolation.
[0014] The above described method of the invention provided for the three-probe system may further comprise that a sixth self-consistent solution to the selected function is determined for a third value of the second selected external parameter by use of self-consistent loop calculation, said third value of the second selected external parameter being different to the first and second values of the second selected external parameter; and that said expressing of the approximate self-consistent solution or change in the self-consistent solution for the selected function is expressed for the selected value of the first selected external parameter and the selected value of the second selected external parameter by use of extrapolation based on at least the determined first, second and third self-consistent solutions together with the first, second and third values of the first selected external parameter, and further based on at least the determined fourth, fifth and sixth self-consistent solutions together with the first, second and third values of the second selected external parameter. Here, the approximate self-consistent solution or change in the self-consistent solution may be expressed by use of second order extrapolation.
[0015] For the methods of the invention provided for the three-probe system, the first value of the second selected external parameter may be equal to the first value of the first selected external parameter.
[0016] According to the present invention it is preferred that the selected function is selected from the functions represented by: the effective one-electron potential energy function, the effective one-electron Hamiltonian, and the electron density. Here, it is again preferred that the selected function is the effective one-electron potential energy function or the effective one-electron Hamiltonian and the self-consistent loop calculation is based on the Density Functional Theory, DFT, or the Hartree-Fock Theory, HF.
[0017] According to an embodiment of the invention, the self-consistent loop calculation may be based on a loop calculation including the steps of:
[0000] a) selecting a value of the electron density for a selected region of the model of the system,
[0000] b) determining the effective one-electron potential energy function for the selected electron density and for a selected value of the external parameter,
[0000] c) calculating a value for the electron density corresponding to the determined effective one-electron potential energy function,
[0000] d) comparing the selected value of the electron density with the calculated value of the electron density, and if the selected value and the calculated value of electron density are equal within a given numerical accuracy, then
[0000] e) defining the solution to the effective one-electron potential energy function as the self-consistent solution to the effective one-electron potential energy function, and if not, then
[0018] f) selecting a new value of the electron density and repeat steps b)-f) until the selected value and the calculated value of electron density are equal within said given numerical accuracy. Here, the self-consistent solution to the effective one-electron potential energy function may be determined for the probe or electrode regions of the system.
[0019] For embodiments where the self-consistent solution to the effective one-electron potential energy function is determined for the probe or electrode regions of the system, it is also preferred that Green's functions are constructed or determined for each of the probe or electrode regions based on the corresponding determined self-consistent solution to the effective one-electron potential energy function.
[0020] It is within an embodiment of the method of the invention that the selected function is the effective one-electron Hamiltonian for an interaction region of the system, and the determination of a second self-consistent solution to the effective one-electron Hamiltonian of the interaction region of the system comprises the step of calculating a corresponding self-consistent solution to the effective one-electron potential energy function for the interaction region at a given value of the first selected external parameter. Here, the determination of a second self-consistent solution to the effective one-electron Hamiltonian may be based on a loop calculation including the steps of:
[0000] aa) selecting a value of the electron density for the interaction region of the system,
[0000] bb) determining the effective one-electron potential energy function for the selected electron density for a given value of the selected external parameter,
[0000] cc) determining a solution to the effective one-electron Hamiltonian for the interaction region based on the in step bb) determined effective one-electron potential energy function,
[0000] dd) determining a solution to Green's function for the interaction region based on the in step cc) determined solution to the effective one-electron Hamiltonian,
[0000] ee) calculating a value for the electron density corresponding to the determined Green's function for the interaction region,
[0000] ff) comparing the selected value of the electron density with the calculated value of the electron density, and if the selected value and the calculated value of electron density are equal within a given numerical accuracy, then
[0000] gg) defining the solution to the effective one-electron Hamiltonian as the self-consistent solution to the effective one-electron Hamiltonian, and if not, then
[0000] hh) selecting a new value of the electron density and repeat steps bb)-hh) until the selected value and the calculated value of electron density are equal within said given numerical accuracy.
[0021] According to an embodiment of the invention the selected function may be the effective one-electron Hamiltonian being represented by a Hamiltonian matrix with each element of said matrix being a function having an approximate self-consistent solution or a change in the self-consistent solution being expressed by use of a corresponding extrapolation expression,
[0022] The method of the present invention also covers an embodiment wherein the selected function is the effective one-electron Hamiltonian and the external parameter is a voltage bias across two probes of the system, an wherein a first and a second self-consistent solution is determined for the effective one-electron Hamiltonian for selected first and second values, respectively, of the external voltage bias, whereby an extrapolation expression is obtained to an approximate self-consistent solution for the effective one-electron Hamiltonian when the external voltage bias is changed, said method further comprising: determining the electrical current between the two probes of the system for a number of different values of the applied voltage bias using the obtained extrapolation expression, which expresses the approximate self-consistent solution or change in the self-consistent solution for the effective one-electron Hamiltonian. Here, the obtained extrapolation expression may be a linear expression. The electrical current may be determined for a given range of the external voltage bias and for a given voltage step in the external voltage bias, and the electrical current may be determined using the following loop:
[0000] aaa) determining the current for the lowest voltage within the given range of the external voltage bias,
[0000] bbb) increasing the voltage bias by the given voltage step,
[0000] ccc) determining the current for the new increased voltage bias,
[0000] ddd) repeating steps bbb) and ccc) until the new increased voltage bias is larger than the highest voltage of the given range of the voltage bias.
[0023] It is also within an embodiment of the invention that the system being modelled is a two probe system and that the selected function is the effective one-electron Hamiltonian and the external parameter is a voltage bias across two probes of the system, said method comprising:
[0024] dividing a determined voltage range for the external voltage bias in at least a first and a second voltage range,
[0025] determining for the first and second voltage ranges a maximum and a minimum self-consistent solution to the effective one-electron Hamiltonian corresponding to the maximum and minimum values of said voltage ranges,
[0026] obtaining a first extrapolation expression to the approximate self-consistent solution for the effective one-electron Hamiltonian when the external voltage bias is changed, said first extrapolation expression being based on the determined maximum and minimum self-consistent solutions for the first voltage range and the maximum and minimum voltage values of the first voltage range,
[0027] obtaining a second extrapolation expression to the approximate self-consistent solution for the effective one-electron Hamiltonian when the external voltage bias is changed, said second extrapolation expression being based on the determined maximum and minimum self-consistent solutions for the second voltage range and the maximum and minimum voltage values of the second voltage range,
[0028] determining the electrical current between the two probes of the system for a number of different values of the applied voltage bias within the voltage range given by the minimum and maximum voltage of the first voltage range using the obtained first extrapolation expression, and
[0029] determining the electrical current between the two probes of the system for a number of different values of the applied voltage bias within the voltage range given by the minimum and maximum voltage of the second voltage range using the obtained second extrapolation expression. Here, the obtained first and second extrapolation expressions may be first and second linear expressions, respectively. It is also within an embodiment of the method of the invention that the determined voltage range is divided in at least three voltage ranges, and that the method further comprises:
[0030] determining for the third voltage range a maximum and a minimum self-consistent solution to the effective one-electron Hamiltonian corresponding to the maximum and minimum values of the third voltage range,
[0031] obtaining a third extrapolation expression to the approximate self-consistent solution for the effective one-electron Hamiltonian when the external voltage bias is changed, said third extrapolation expression being based on the determined maximum and minimum self-consistent solutions for the third voltage range and the maximum and minimum voltage values of the third voltage range, and
[0032] determining the electrical current between the two probes of the system for a number of different values of the applied voltage bias within the voltage range given by the minimum and maximum voltage of the third voltage range using the obtained third linear extrapolation. Also here, the obtained third extrapolation expression may be a third linear extrapolation expression.
[0033] The method of the present invention also covers an embodiment where the system being modelled is a two-probe system and wherein the selected function is the effective one-electron Hamiltonian and the external parameter is a voltage bias across two probes of the system, an wherein a first and a second self-consistent solution is determined for the effective one-electron Hamiltonian for selected first and second values, respectively, of the external voltage bias, with said second value being higher than the selected first value of the voltage bias, whereby a first extrapolation expression is obtained to an approximate self-consistent solution for the effective one-electron Hamiltonian when the external voltage bias is changed, said method further comprising:
[0034] aaaa) selecting a voltage range having a minimum value and a maximum value for the external voltage bias in order to determine the electrical current between the two probes of the system for a number of different values of the applied voltage bias within said range,
[0000] bbbb) determining a maximum self-consistent solution to the effective one-electron Hamiltonian for the selected maximum value of the external voltage bias by use of self-consistent loop calculation,
[0000] cccc) determining the electrical current between the two probes of the system for the maximum value of the voltage bias based on the corresponding determined maximum self-consistent solution,
[0000] dddd) determining the electrical current between the two probes of the system for the selected maximum value of the voltage bias based on the obtained first extrapolation expression,
[0000] eeee) comparing the current values determined in steps cccc) and dddd), and if they are equal within a given numerical accuracy, then
[0035] ffff) determining the electrical current between the two probes of the system for a number of different values of the applied voltage bias within the voltage range given by the selected first voltage value and the maximum voltage value using an extrapolation expression for an approximate self-consistent solution for the effective one-electron Hamiltonian when the external voltage bias is changed. Here, the obtained first extrapolation expression may be a first linear extrapolation expression, and linear extrapolation may be used in step ffff) for expressing the approximate self-consistent solution for the effective one-electron Hamiltonian when the external voltage bias is changed. It is within a preferred embodiment that a maximum extrapolation expression is obtained to the approximate self-consistent solution for the effective one-electron Hamiltonian, said maximum extrapolation expression being based on the determined first and maximum self-consistent solutions and the first voltage bias and the maximum value of the voltage bias, and wherein said maximum extrapolation expression is used when determining the current in step ffff). The maximum extrapolation expression may be a maximum linear extrapolation expression. It is also preferred that when in step eeee) the current values determined in steps cccc) and dddd), are not equal within the given numerical accuracy, then the method further comprises:
[0000] gggg) selecting a new maximum value of the external voltage bias between the first value and the previous maximum value,
[0000] hhhh) repeating steps bbbb) to hhhh) until the in steps cccc) and dddd) determined current values are equal within said given numerical accuracy. According to an embodiment of the invention, the method may further comprise the steps:
[0000] iiii) determining a minimum self-consistent solution to the effective one-electron Hamiltonian for the selected minimum value of the external voltage bias by use of self-consistent loop calculation,
[0000] jjjj) determining the electrical current between the two probes of the system for the minimum value of the voltage bias based on the corresponding determined minimum self-consistent solution,
[0000] kkkk) determining the electrical current between the two probes of the system for the selected minimum value of the voltage bias based on the obtained first extrapolation expression,
[0000] llll) comparing the current values determined in steps jjjj) and kkkk), and if they are equal within a given numerical accuracy, then
[0036] mmmm) determining the electrical current between the two probes of the system for a number of different values of the applied voltage bias within the voltage range given by the selected first voltage value and the minimum voltage value using an extrapolation expression for an approximate self-consistent solution for the effective one-electron Hamiltonian when the external voltage bias is changed. Here, linear extrapolation may be used in step mmmm) for expressing the approximate self-consistent solution for the effective one-electron Hamiltonian when the external voltage bias is changed. Also here, it is within a preferred embodiment that a minimum extrapolation expression is obtained to the approximate self-consistent solution for the effective one-electron Hamiltonian, where the minimum extrapolation expression is based on the determined first and minimum self-consistent solutions and the first voltage bias and the minimum value of the voltage bias, and wherein the minimum extrapolation expression is used when determining the current in step mmmm). Here, the minimum extrapolation expression may be a minimum linear extrapolation expression. Also here it is preferred that when in step llll) the current values determined in steps jjjj) and kkkk), are not equal within the given numerical accuracy, then the method further comprises:
[0000] nnnn) selecting a new minimum value of the external voltage bias between the first value and the previous minimum value,
[0000] oooo) repeating steps iiii) to oooo) until the in steps jjjj) and kkkk) determined current values are equal within said given numerical accuracy.
[0037] According to the present invention there is also provided a computer system for using extrapolation analysis to express an approximate self-consistent solution or a change in a self-consistent solution based on a change in the value of one or more external parameters, said self-consistent solution being used in a model of a nano-scale system having at least two probes or electrodes, which model is based on an electronic structure calculation comprising a self-consistent determination of an effective one-electron potential energy function and/or an effective one-electron Hamiltonian, said computer system comprising:
[0000] means for determining a first self-consistent solution to a selected function for a first value of a first external parameter by use of self-consistent loop calculation;
[0038] means for determining a second self-consistent solution to the selected function for a second value of the first selected external parameter by use of self-consistent loop calculation, said second value of the first selected external parameter being different to the first value of the first selected external parameter; and
[0039] means for expressing an approximate self-consistent solution or a change in the self-consistent solution for the selected function for at least one selected value of the first selected external parameter by use of extrapolation based on at least the determined first and second self-consistent solutions and the first and second values of the first selected external parameter. Here, the means for expressing the approximate self-consistent solution or change in the self-consistent solution may be adapted for expressing such solution by use of linear extrapolation.
[0040] According to an embodiment of the invention the computer system may further comprise: means for determining a third self-consistent solution to the selected function for a third value of the first selected external parameter by use of self-consistent loop calculation, said third value of the first selected external parameter being different to the first and second values of the first selected external parameter. Here, the means for expressing the approximate self-consistent solution or change in the self-consistent solution for the selected function for at least one selected value of the first selected external parameter may be adapted for expressing such solution by use of extrapolation based on at least the determined first, second and third self-consistent solutions and the first, second and third values of the first selected external parameter. Here, it is preferred that the means for expressing the approximate self-consistent solution or change in the self-consistent solution is adapted for expressing such solution by use of second order extrapolation.
[0041] For the computer system of the invention it is within an embodiment that the nano-scale system is a two-probe system and the external parameter is a voltage bias, U, across said two probes or electrodes, said two-probe system being modelled as having two substantially semi-infinite probes or electrodes being coupled to each other via an interaction region.
[0042] The computer system of the invention also covers an embodiment wherein the nano-scale system is a three-probe system with three probes or electrodes and the external parameters are a first selected parameter and a second selected parameter being of the same type as the first selected parameter. Here it is preferred that the nano-scale system is a three-probe system with three probes or electrodes and the external parameters are a first voltage bias, U 1 , across a first and a second of said electrodes and a second voltage bias, U 2 , across a third and the first of said electrodes, said three-probe system being modelled as having three substantially semi-infinite electrodes being coupled to each other via an interaction region.
[0043] Also here, when the nano-scale system being modelled is a three-probe system, the computer system of the invention may further comprise:
[0000] means for determining a fourth self-consistent solution to the selected function for a first value of the second selected external parameter by use of self-consistent loop calculation;
[0044] means for determining a fifth self-consistent solution to the selected function for a second value of the second selected external parameter by use of self-consistent loop calculation, said second value of the second selected external parameter being different to the first value of the second selected external parameter; and
[0045] wherein said means for expressing of the approximate self-consistent solution or change in the self-consistent solution for the selected function is adapted to express the approximate self-consistent solution for the selected value of the first selected external parameter and a selected value of the second selected external parameter by use of extrapolation based on the determined first and second self-consistent solutions together with the first and second values of the first selected external parameter, and further based on the determined fourth and fifth self-consistent solutions together with the first and second values of the second selected external parameter. Here, the means for expressing the approximate self-consistent solution or change in the self-consistent solution may be adapted for expressing such solution by use of linear extrapolation.
[0046] The above described computer system for modelling a three-probe system may further comprise:
[0047] means for determining a sixth self-consistent solution to the selected function for a third value of the second selected external parameter by use of self-consistent loop calculation, said third value of the second selected external parameter being different to the first and second values of the second selected external parameter. Here, the means for expressing the approximate self-consistent solution or change in the self-consistent solution for the selected function may be adapted to express the approximate self-consistent solution for the selected value of the first selected external parameter and the selected value of the second selected external parameter by use of extrapolation based on at least the determined first, second and third self-consistent solutions together with the first, second and third values of the first selected external parameter, and further based on at least the determined fourth, fifth and sixth self-consistent solutions together with the first, second and third values of the second selected external parameter. Here, the means for expressing the approximate self-consistent solution or change in the self-consistent solution may be adapted for expressing such solution by use of second order extrapolation.
[0048] For the system of the invention provided for the three-probe system, the first value of the second selected external parameter may be equal to the first value of the first selected external parameter.
[0049] Also for the computer system of the present invention it is preferred that the selected function is selected from the functions represented by: the effective one-electron potential energy function, the effective one-electron Hamiltonian, and the electron density. Here, it is again preferred that the selected function is the effective one-electron potential energy function or the effective one-electron Hamiltonian and the self-consistent loop calculation is based on the Density Functional Theory, DFT, or the Hartree-Fock Theory, HF.
[0050] According to an embodiment of the invention, the computer may further comprise means for performing a self-consistent loop calculation based on a loop calculation including the steps of:
[0000] a) selecting a value of the electron density for a selected region of the model of the nano-scale system,
[0000] b) determining the effective one-electron potential energy function for the selected electron density and for a selected value of the external parameter,
[0000] c) calculating a value for the electron density corresponding to the determined effective one-electron potential energy function,
[0000] d) comparing the selected value of the electron density with the calculated value of the electron density, and if the selected value and the calculated value of electron density are equal within a given numerical accuracy, then
[0000] e) defining the solution to the effective one-electron potential energy function as the self-consistent solution to the effective one-electron potential energy function, and if not, then
[0051] f) selecting a new value of the electron density and repeat steps b)-f) until the selected value and the calculated value of electron density are equal within said given numerical accuracy. Here, the means for performing the self-consistent loop calculation may be adapted to determine the self-consistent solution to the effective one-electron potential energy function for the probe or electrode regions of the system.
[0052] For embodiments wherein the means for performing the self-consistent loop calculation may be adapted to determine the self-consistent solution to the effective one-electron potential energy function for the probe or electrode regions of the system, it is also preferred that the computer system further comprises means for determining Green's functions for each of the probe or electrode regions based on the corresponding determined self-consistent solution to the effective one-electron potential energy function.
[0053] For the computer system of the invention it is also within an embodiment that the selected function is the effective one-electron Hamiltonian for an interaction region of the system, and the means for determining a second self-consistent solution to the effective one-electron Hamiltonian of the interaction region of the system is adapted to perform said determination by including the step of calculating a corresponding self-consistent solution to the effective one-electron potential energy function for the interaction region at a given value of the first selected external parameter. Here, the means for determination of a second self-consistent solution to the effective one-electron Hamiltonian is adapted to perform said determination based on a loop calculation including the steps of:
[0000] aa) selecting a value of the electron density for the interaction region of the system,
[0000] bb) determining the effective one-electron potential energy function for the selected electron density for a given value of the selected external parameter,
[0000] cc) determining a solution to the effective one-electron Hamiltonian for the interaction region based on the in step b) determined effective one-electron potential energy function,
[0000] dd) determining a solution to Green's function for the interaction region based on the in step c) determined solution to the effective one-electron Hamiltonian,
[0000] ee) calculating a value for the electron density corresponding to the determined Green's function for the interaction region,
[0000] ff) comparing the selected value of the electron density with the calculated value of the electron density, and if the selected value and the calculated value of electron density are equal within a given numerical accuracy, then
[0000] gg) defining the solution to the effective one-electron Hamiltonian as the self-consistent solution to the effective one-electron Hamiltonian, and if not, then
[0000] hh) selecting a new value of the electron density and repeat steps bb)-hh) until the selected value and the calculated value of electron density are equal within said given numerical accuracy.
[0054] Also the computer system of the invention covers an embodiment wherein the selected function is the effective one-electron Hamiltonian and the external parameter is a voltage bias across two probes of the system, wherein the means for determining a first and a second self-consistent solution is adapted to perform said determination for the effective one-electron Hamiltonian for selected first and second values, respectively, of the external voltage bias, and wherein the means for expressing an approximate self-consistent solution by use of extrapolation analysis is adapted to obtain an extrapolation expression to an approximate self-consistent solution for the effective one-electron Hamiltonian when the external voltage bias is changed, said computer system further comprising: means for determining the electrical current between the two probes of the system for a number of different values of the applied voltage bias using the obtained extrapolation expression, which expresses the approximate self-consistent solution or change in the self-consistent solution for the effective one-electron Hamiltonian. Here, the obtained extrapolation expression may be a linear extrapolation expression. The means for determining the electrical current may be adapted to determine the electrical current for a given range of the external voltage bias and for a given voltage step in the external voltage bias, and the means for determining the electrical current may be adapted to perform said determination using the following loop:
[0000] aaa) determining the current for the lowest voltage within the given range of the external voltage bias,
[0000] bbb) increasing the voltage bias by the given voltage step,
[0000] ccc) determining the current for the new increased voltage bias,
[0000] ddd) repeating steps bbb) and ccc) until the new increased voltage bias is larger than the highest voltage of the given range of the voltage bias.
[0055] It is also within an embodiment of the computer system of the invention that the system being modelled is a two-probe system and that the selected function is the effective one-electron Hamiltonian and the external parameter is a voltage bias across two probes of the system, and wherein the computer system further comprises:
[0056] means for dividing a determined voltage range of the external voltage bias in at least a first and a second voltage range,
[0057] means for determining for the first and second voltage ranges a maximum and a minimum self-consistent solution to the effective one-electron Hamiltonian corresponding to the maximum and minimum values of said voltage ranges,
[0058] means for obtaining a first extrapolation expression to the approximate self-consistent solution for the effective one-electron Hamiltonian when the external voltage bias is changed, said first extrapolation expression being based on the determined maximum and minimum self-consistent solutions for the first voltage range and the maximum and minimum voltage values of the first voltage range,
[0059] means for obtaining a second extrapolation expression to the approximate self-consistent solution for the effective one-electron Hamiltonian when the external voltage bias is changed, said second extrapolation expression being based on the determined maximum and minimum self-consistent solutions for the second voltage range and the maximum and minimum voltage values of the second voltage range,
[0060] means for determining the electrical current between the two probes of the system for a number of different values of the applied voltage bias within the voltage range given by the minimum and maximum voltage of the first voltage range using the obtained first extrapolation expression, and
[0061] means for determining the electrical current between the two probes of the system for a number of different values of the applied voltage bias within the voltage range given by the minimum and maximum voltage of the second voltage range using the obtained second extrapolation expression. Here, the obtained first and second extrapolation expressions may be first and second linear extrapolation expressions, respectively.
[0062] Other objects, features and advantages of the present invention will be more readily apparent from the detailed description of the preferred embodiments set forth below, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0063] FIG. 1 is a flowchart (flowchart 1 ) illustrating the computational steps in a self-consistent loop of the Density Functional Theory.
[0064] FIG. 2 illustrates a Benzene-Di-Thiol molecule coupled with two Gold (111) surfaces, here the gold surfaces are coupled to an external voltage source, and the electrodes have different chemical potentials μ L and μ R .
[0065] FIG. 3 shows the self-consistent electron density of a carbon nano-tube coupled with a gold surface, where, when being outside the interaction region, the electron density is given by the bulk density of the electrodes.
[0066] FIG. 4 a shows equivalent real axis (R) and complex contours (C) that can be used for the integral of Green's function G 1 (z).
[0067] FIG. 4 b shows the variation of the spectral density
( 1 π Im G I ( z ) )
along contour C (dashed) of FIG. 4 a and along the real axis R (solid) of FIG. 4 a.
[0068] FIG. 5 is a flowchart (flowchart 2 ) showing steps required to calculate a self-consistent effective potential energy function of a two-probe system with applied voltage U using the Green's function approach, and where from the self-consistent effective one-electron potential energy function the electrical current/can be calculated.
[0069] FIG. 6 is a flowchart (flowchart 3 ) showing steps required for a self-consistent calculation of the I-U characteristics of a two-probe system.
[0070] FIG. 7 a shows the self-consistent effective one-electron potential energy function of the system illustrated in FIG. 2 and calculated for different values of the applied voltage.
[0071] FIG. 7 b shows the self-consistent effective one-electron potential energy function rescaled with the applied voltage.
[0072] FIG. 8 is a flowchart (flowchart 4 ) showing steps involved when using a linear extrapolation expression according to an embodiment of the invention to calculate the current-voltage characteristics, I-U.
[0073] FIG. 9 is a flowchart (flowchart 5 ) showing how an interpolation formula or linear extrapolation expression according to an embodiment of the invention can be used to calculate the I-U characteristics.
[0074] FIG. 10 shows the result of a calculation of the I(U) characteristics of the system illustrated in FIG. 2 , with the line denoted “SCF” showing the result obtained with a full self-consistent calculation, while the line denoted “1. order” is showing the result obtained using the scheme illustrated in FIG. 8 , and the line denoted “2. order” is a second order approximation.
[0075] FIG. 11 is a flowchart (flowchart 6 ) illustrating the use of an adaptive grid algorithm according to an embodiment of the invention for calculating the current voltage characteristics, I-U.
[0076] FIG. 12 is a flowchart (flowchart 7 ) being a recursive flowchart used by flowchart 6 of FIG. 11 .
[0077] FIG. 13 is a flowchart (flowchart 8 ) being a recursive flowchart used by flowchart 6 of FIG. 11 .
DETAILED DESCRIPTION OF THE INVENTION
[0000] Background Theory
[0078] The purpose of atomic-scale modelling is to calculate the properties of molecules and materials from a description of the individual atoms in the systems. An atom consists of an ion core with charge Z, and an equal number of electrons that compensate this charge. We will use {right arrow over (R)} μ , Z μ for the position and charge of the ions, where μ=1 . . . N label the ions, and N is the number of ions. The positions of the electrons are given by {right arrow over (r)} i , i=1 . . . n, and n is the number of electrons.
[0079] Usually it is a good approximation to treat the ions as classical particles. The potential energy of the ions, V({right arrow over (R)} 1 , . . . , {right arrow over (R)} N ), depends on the energy of the electronic system, E 0 , through
V ( R → 1 , … , R → N ) = E 0 + 1 2 ∑ μ , μ ′ = 1 N Z μ Z μ ′ ⅇ 2 R μ - R → μ ′ , Eq . 1
where e is the electron charge. The electrons must be described as quantum particles, and the calculation of the electron energy requires that we solve the many-body Schrödinger wave equation
H ^ Ψ ( r → 1 , … , r → n ) = E 0 Ψ ( r → 1 , … , r → n ) , Eq . 2 H ^ = - ∑ i = 1 n ℏ 2 2 m ∇ → i 2 - ∑ i = 1 n ∑ μ = 1 N Z μ ⅇ 2 r → i - R → μ + 1 2 ∑ i , j = 1 n ⅇ 2 r → i - r → j . Eq . 3
[0080] In Eq. 2, Ĥ is the many-body Hamiltonian and Ψ the many-body wavefunction of the electrons. The “hat” over the many-body Hamiltonian, Ĥ, symbolizes that the quantity is a quantum mechanical operator. The first term in Eq. 3 is the kinetic energy of the electrons, with =h/2π where h is Planck's constant, m the electron mass and {right arrow over (∇)} i the gradient with respect to {right arrow over (r)} i . The second term is the electrostatic electron-ion attraction, and the last term is the electrostatic electron-electron repulsion.
[0081] The last term couples different electrons, and gives rise to a correlated motion between the electrons. Due to this complication an exact solution of the many-body Schrödinger equation is only possible for systems with a single electron. Thus, approximations are required that can reduce the many-body Schrödinger equation into a practical solvable model. A number of successful approaches have used an effective one-electron Hamiltonian to describe the electronic structure, and included the electron-electron interaction via an effective one-electron potential energy function in the one-electron Hamiltonian.
[0000] Density Functional Method for Electronic Structure Calculations
[0082] The invention can be used with electronic structure methods, which describe the electrons with an effective one-electron Hamiltonian. DFT and HF theory are examples of such methods. In these methods the electrons are described as non-interacting particles moving in an effective one-electron potential setup by the other electrons. The effective one-electron potential depends on the average position of the other electrons, and needs to be determined self consistently.
H ^ 1 el = - ℏ 2 2 m ∇ → 2 + V eff [ n ] ( r → ) . Eq . 4
[0083] In Eq. 4 the term
term - ℏ 2 2 m ∇ → 2
describes the kinetic energy, V eff [n]({right arrow over (r)}) the effective one-electron potential energy function and Ĥ 1el is the one-electron Hamiltonian. The effective one-electron potential energy function depends on the electron density n. The kinetic energy is given by a simple differential operator, and therefore independent of the density. This means that the effective one-electron potential energy function and the Hamiltonian has the same variation as function of the density, and when we are interested in determining the self-consistent change of the effective one-electron potential energy function it is equivalent to specifying the self-consistent change of the Hamiltonian. Furthermore, for the self-consistent solution there is a one to one relation between the electron density and the effective one-electron potential energy function, thus specifying the self-consistent electron density, Hamiltonian or effective one-electron potential are equivalent.
[0084] In DFT the effective one-electron potential energy function is given by
V eff [n]=V ion +V xc [n]+V H [n]. Eq. 5
[0085] The first term is the ion potential energy function which is given by the electrostatic potential energy from the ion cores
V ion ( r → ) = ∑ μ = 1 N Z μ ⅇ 2 r → i - R → μ , Eq . 6
and therefore independent of n. The second term is the exchange-correlation potential energy function
V xc ( {right arrow over (r)} )= f ( n ( {right arrow over (r)} ),{right arrow over (∇)} n ( {right arrow over (r)} ),{right arrow over (∇)} 2 n ( {right arrow over (r)} )), Eq. 7
which is a local function of the density and its gradients. The third term is the Hartree potential energy function, which is the electrostatic potential energy from the electron density and it can be calculated from the Poisson's equation
{right arrow over (V)} 2 V H ( {right arrow over (r)} )=−4π en ( {right arrow over (r)} ). Eq. 8
[0086] Poisson's equation is a second-order differential equation and a boundary condition is required in order to fix the solution. For isolated systems the boundary condition is that the potential energy function asymptotically goes to zero, and in periodic systems the boundary condition is that the potential energy function is periodic. For such boundary conditions the solution of the Poisson's equation is straight-forward, and V H can be obtained from standard numerical software packages. For systems with an external voltage U, we solve the Hartree potential in separate parts of the system. This situation is discussed in more detail on page 26.
[0087] Thus from the density, we can obtain the effective one-electron potential energy function and thereby the Hamiltonian. The next step is to calculate the electron density from the Hamiltonian. It can be obtained by summing all occupied one-electron eigenstates.
H ^ 1 el ψ α ( r → ) = ɛ α ψ α ( r → ) , Eq . 9 n ( r → ) = ∑ α ∈ occ ψ α ( r → ) 2 . Eq . 10
[0088] For systems with a single chemical potential the occupied eigenstates are the states with an energy below the chemical potential. For systems with an applied external voltage U there are two chemical potentials and the situation more complicated. This situation is described on page 25.
[0089] The flowchart in FIG. 1 illustrates the self-consistent loop required to solve the equations. The system is defined by the position of the atoms R μ (ionic coordinates), and external parameters like applied voltage U, temperature T, and pressure P, 102 . Initially we make an arbitrary guess of the electron density of the system, 104 . From the density we can construct the effective one-electron potential energy function using Eq. 5, 106 . The effective one-electron potential energy function defines the Hamiltonian through Eq. 4, 108 . From the Hamiltonian we can calculate the electron density of the system by summing all occupied one-electron eigenstates as shown in Eq. 9, 10. If the new density is equal (within a specified numerical accuracy) to the density used to construct the effective one-electron potential energy function, 112 , the self-consistent solution is obtained, 114 , and we stop, 116 . If the input and output electron densities are different, we make a new improved guess based on the previously calculated electron densities. In the simplest version the new guess is obtained from a linear mixing of the two electron densities, with a mixing parameters, 110 .
[0000] Application of DFT to Closed and Periodic Systems
[0090] We will first show how Eq. 9 is most commonly solved for periodic and closed systems. A closed system is a system with a finite number of atoms. A periodic system is a system with an infinite number of atoms arranged in a periodic structure. For these systems, Eq. 9 is usually transformed into a matrix eigenvalue problem that can be solved with standard linear algebra packages. The transformation is obtained by writing the wave functions, ψ α , as a linear combination of basis functions,
ψ α ( r → ) = ∑ i a i α φ i ( r → ) .
Many different choices exist for the basis functions, φ i , some of the most common are plane-waves or atom-based functions with shapes resembling the atomic wave functions. Using the basis functions, Eq. 9 is transformed into
∑ j H _ ij a j α = ɛ α ∑ j S _ ij a j α , Eq . 11 H _ ij = 〈 φ i H 1 el φ j 〉 , Eq . 12 S _ ij = 〈 φ i | φ j 〉 , Eq . 13 n ( r → ) = ∑ i , j ∑ ɛ α < μ ( a j α ) * a i α φ i * ( r → ) φ j ( r → ) . Eq . 14
[0091] The symbol H denotes the Hamiltonian matrix, and S the overlap matrix. The “bar” above the letters indicates that the quantities are matrixes.
[0092] For a molecular system the Hamiltonian matrix is finite and it can be diagonalized with standard linear algebra packages. For a periodic structure it is only necessary to model the part of the system, which when repeated, generates the entire structure. Thus, again the Hamiltonian matrix will be finite and the solution will be straight forward.
[0000] Application of DFT to Open Systems with an Applied Voltage
[0093] The application area of the invention is to systems where two (or more) semi-infinite electrodes are coupling with a nano-scale interaction region. We call such systems two-probe systems. The nano-scale interaction region can exchange particles with the electrodes and the two-probe systems are therefore open quantum mechanical systems. The left and right electrodes are electron reservoirs with definite chemical potentials, μ L and μ R . The difference between the chemical potentials,
μ L −μ R =eU, Eq. 15
defines the voltage bias, U, applied to the system. For open systems the Hamiltonian matrix is infinite and the simple diagonalization technique in Eq. 11 for obtaining the one-electron eigenstates cannot be applied. Instead we will determine the electron density using the non-equilibrium Green's function formalism described in the following sections. Examples of two-probe systems are illustrated in FIGS. 2 and 3 . The system in FIG. 2 consists of two semi-infinite gold electrodes coupling with a Phenyl Di-Thiol molecule. The interaction region 22 consists of the molecule and the first two layers of the electrodes. Regions 21 , 23 show the left and right electrode regions. Regions 24 , 26 show the occupation of the one-electron levels within the electrodes; due to the applied voltage the chemical potential of the right electrode 26 is higher than for the left electrode 24 .
[0094] FIG. 3 shows a semi-infinite carbon nano-tube coupling with a semi-infinite gold wire. The interaction region 32 is given by the nano-tube apex and the first layers of the gold wire. The left electrode 31 consists of a semi-infinite gold wire, and the right electrode 33 consists of a semi-infinite carbon nano-tube. The electron densities in the left electrode region 34 and in the right electrode region 36 are obtained from self-consistent bulk calculations. These densities seamlessly match the self-consistently calculated two probe density of the interaction region 35 .
[0000] The Screening Approximation
[0095] The first step is to transform the open system into three subsystems that can be solved independently. FIG. 3 a shows a carbon nano-tube coupled with a gold wire. The gold wire and the carbon nano-tube are metallic. Because of the metallic nature of the semi-infinite electrodes, the perturbation due to the interaction region only propagates a few Ångstrøm into the electrodes. This is illustrated in FIG. 3 b , which shows the electron density. We see that when we move a few atomic distances away from the nano-tube to gold contact point, the electron density is periodic and resembles the bulk electron density. Thus, we can divide the electron density and the effective one-electron potential energy function into an interaction region and electrode regions, where the value in the electrode region is similar to the electrode bulk value. This is called the screening approximation.
[0096] Since the effective one-electron potential energy function is a local operator, the Hamiltonian operator can also be separated into electrode and interaction region. Thus, if we expand the Hamiltonian operator in a basis set with finite range, the Hamiltonian matrix can be separated into
H _ = ( H _ LL H _ LI 0 H _ IL H _ II H _ IR 0 H _ RI H _ RR ) , Eq . 16
where H LL , H II , and H RR denotes the Hamiltonian matrix of the left electrode, interaction region, and right electrode, respectively, and H LI and H IR are the matrix elements involving the interaction region and the electrodes. Note that the size of the interaction region is such that there are no couplings between the left and right electrode, i.e. H LR =H RL =0.
Calculating the Electron Density Using Green's Functions
[0097] We will now show how the electron density is obtained within the Green's function formalism. For this purpose we introduce the spectral-density, {circumflex over (D)}(ε), and the electron density operator {circumflex over (N)}. The spectral density is the energy resolved electron density, and the total electron density is obtained by integrating the spectral density over all energies
D ^ ( ɛ ) = δ ( ɛ - H ^ ) , Eq . 17 N ^ = ∫ - ∞ μ D ^ ( ɛ ) ⅆ ɛ . Eq . 18
[0098] In Eq. 17, the function δ(x) is Dirac's delta function. The (retarded) Green's function is defined by
Ĝ (ε)=[ε− Ĥ+iδ + ] −1 , Eq. 19
where δ + is an infinitesimal positive number and i is the complex base. The Green's function is related to the spectral density through
D ^ ( ɛ ) = 1 π Im G ^ ( ɛ ) , Eq . 20
where Im Ĝ is the imaginary part of Ĝ. Expanding the operators in basis functions, we transform Eq. 19 into a matrix equation
G (ε)=[(ε+ iδ + ) S − H ] −1 , Eq. 21
[0099] From the Green's function we can obtain the spectral density matrix
D _ ( ɛ ) = 1 π Im G _ ( ɛ ) , Eq . 22
and thus the electron density
n ( r → ) = ∑ i , j N _ ij φ i ( r → ) φ j ( r → ) , Eq . 23 N _ = ∫ - ∞ μ D _ ( ɛ ) ⅆ ɛ . Eq . 24
[0100] The calculation of the electron density is now reduced to the matrix inversion in Eq. 21, and the energy integral in Eq. 24. However, we have an open system and the matrix in Eq. 21 is therefore infinite. Due to the screening approximation we only need to calculate the electron density in the interaction region since in the electrode regions we can use the bulk electron density. From Eq. 24 we see that since our basis functions are localized, we only need to calculate the Green's function matrix of the interaction region and a few layers of the electrodes.
[0000] Including the Electrode Region through a Self Energy Term
[0101] In this section we will show how the Green's function matrix of the interaction region, G II , can be calculated by inverting a matrix with the same size. To obtain this result we will use perturbation theory in the coupling elements {tilde over ( H )} LI (ε)= H LI −ε S LI and {tilde over ( H )} RI (ε)= H RI −ε S RI . The unperturbed Green's functions, G 0 , is calculated by setting {tilde over ( H )} LI ={tilde over ( H )} RI =0 and using that in this case Eq. 21 is block diagonal
G LL 0 (ε)=[(ε+iδ + ) S LL − H LL ] −1 , Eq. 25
G II 0 (ε)=[(ε+ iδ + ) S II − H II ] −1 , Eq. 26
G RR 0 (ε)=[(ε+ iδ + ) S RR − H RR ] −1 . Eq. 27
[0102] Putting back the perturbation {tilde over ( H )} LI and {tilde over ( H )} RI we find the Green's function from the Dyson's equation
G II (ε)= G II 0 (ε)+ G II 0 (ε)[ Σ II L (ε)+ Σ II R (ε)] G II (ε), Eq. 28
Σ II L (ε)={tilde over ( H )} IL (ε) G LL 0 (ε){tilde over ( H )} LI (ε), Eq. 29
Σ II R (ε)={tilde over ( H )} IR (ε) G RR 0 (ε){tilde over ( H )} RI (ε), Eq. 30
where the terms Σ II L (ε) and Σ II R (ε) are called the selfenergies of the electrodes. Rearranging the terms in the Dyson's equation, we arrive at
G II (ε)=[(ε+ iδ + ) S II − H II − Σ II R (ε)] −1 . Eq. 31
Calculation of the Electrode Green's Function
[0103] In order to determine the self energies we need to calculate the unperturbed Green's function, G LL 0 , of the electrodes. Since, the Hamiltonian of the electrodes is semi-infinite, the Green's function cannot be obtained by simple matrix inversion. However, in cases where the electrode Hamiltonian is periodic, there exist very efficient algorithms for calculating the electrodes Green's function. Below we will describe one of them. We will write the electrode Hamiltonian as periodic blocks, H L 1 L 1 = H L 2 L 2 = . . . , where the size of each block is such that only neighbouring blocks interact, i.e.
H _ LL = ( ⋰ H _ L 3 L 3 H _ L 3 L 2 H _ L 2 L 3 H _ L 2 L 2 H _ L 2 L 1 H _ L 1 L 2 H _ L 1 L 1 ) . Eq . 32
[0104] The Hamiltonian of each block, H L 1 L 1 and the coupling matrix, H L 1 L 2 , are obtained from a bulk calculation of the electrode system. Using recursion, we build up a series of approximations for the Green's function
G _ L 1 L 1 0 [ 0 ] ( ɛ ) = [ ( ɛ + i δ + ) S _ L 1 L 1 - H _ L 1 L 1 ] - 1 , Eq . 33 G _ L 1 L 1 0 [ 1 ] ( ɛ ) = [ ( ɛ + i δ + ) S _ L 1 L 1 - H _ L 1 L 1 - H _ L 1 L 2 G _ L 2 L 2 0 [ 0 ] H _ L 2 L 1 ] - 1 , Eq . 34 G _ L 1 L 1 0 [ 2 ] ( ɛ ) = [ ( ɛ + i δ + ) S _ L 1 L 1 - H _ L 1 L 1 - H _ L 1 L 2 G _ L 2 L 2 0 [ 1 ] H _ L 2 L 1 ] - 1 , Eq . 35 ⋮ Eq . 36
[0105] In Eq. 33, 34, 35 the quantity G L 1 L 2 0[n] (ε) is the n'order approximation to the Green's function. The error, [ G L 1 L 1 0 (ε)− G L 1 L 1 0[n] (ε)] decreases as 1/n where n is the number of steps. Due to this poor convergence usually more than 1000 steps are required to obtain reasonable accuracy with this algorithm. The Green's function can be obtained in fewer steps by using a variant of the method described in Lopez-Sancho, J. Phys. F 14, 1205 (1984). With this variant of the algorithm only a few steps are needed to calculate the electrode Green's function, and the computational resources required for this part is usually negligible compared to the resources required for the calculation of G II .
[0000] Integration of the Spectral Density Using a Complex Contour
[0106] We now have all the ingredients required in Eq. 31 to obtain G II and thereby the electron density matrix,
N _ ij = 1 π ∫ - ∞ μ Im G _ ij ( ɛ ) ⅆ ɛ . Eq . 37
[0107] The Green's function is a rapidly varying function along the real axis, and for realistic systems often an accurate determination of the integral requires more than 5000 energy points along the real axis. To find a more efficient method we use that the Green's function is an analytical function, and we can do the integral along a contour in the complex plane. In the complex plane the Green's function is very smooth. This is illustrated in FIG. 4 . In FIG. 4 a we show two equivalent lines of integrations, the contour C and the real axis line R. FIG. 4 b shows the variation of the spectral density along C (dashed) and along R (solid). The function varies much more rapidly along R, and substantially more points are needed along R than along C to obtain the same accuracy. Typically, the use of contour integration reduces the number of integration points by a factor 100.
[0000] The Electron Density for a Two Probe System with External Voltage Bias
[0108] We have so far used that the system has a single chemical potential, i.e. μ L =μ R . However, if we apply an external voltage, U, the two electrodes will have different chemical potentials linked through Eq. 15. FIG. 2 illustrates the system set up. The energy axis can be divided into two regions, the energy range below both chemical potentials we call the equilibrium region, and the energy range between the two chemical potentials we call the non-equilibrium region or voltage window. We will divide the electron density matrix into two parts,
N ij = N ij eq + N ij neq , Eq. 38
where N ij eq is the electron density matrix of the electrons with energies in the equilibrium region, and N ij neq the electron density matrix of the electrons with energies in the non-equilibrium region. We may say that N ij neq is the additional density due to the external voltage U.
[0109] N ij eq can be calculated with the approach described in the previous sections, thus
N _ ij eq = 1 π ∫ - ∞ μ L Im G _ ij ( ɛ ) ⅆ ɛ , Eq . 39
where we have assumed that μ L <μ R .
[0110] In the non-equilibrium region electrons are only injected from the right reservoir. Thus we need to divide the spectral density matrix into electron states originating from the left or right electrode, and only add the right electrode electron density. This division of the electron density is accomplished in non-equilibrium Green's function theory, and we may write
N _ II neg = 1 π ∫ μ L μ R G _ II ( ɛ ) Im ∑ II R ( ɛ ) G _ II † ( ɛ ) ⅆ ɛ . Eq . 40
[0111] The foundation of this equation can be found in Haug and A. P. Jauho, Quantum kinetics in transport and optics of semiconductors , (Springer-Verlag, Berlin, 1996) or Brandbyge Phys. Rev. B 65, 165401 (2002). Thus, we now have a description for how to calculate the electron density of the two probe system, including the situation with an external voltage applied to the system.
[0000] Calculating the Effective One-Electron Potential Energy Function in a Two-Probe System
[0112] In the previous sections we showed how to calculate the electron density from the Hamiltonian using the Green's function approach. To complete the self-consistent cycle we need to calculate the Hamiltonian from the electron density, which means calculating the effective one-electron potential energy function, V eff [n]. Within DFT the effective one-electron potential energy function is given by Eq. 5. For the two-probe system we need to solve Poisson's equation, Eq. 8, for the interaction region and the electrode regions separately. The Hartree potential energy function of the electrodes is obtained with the same approach as used for periodic systems, in this case the repeated structure is the electrode cell used to defined H L 1 L 1 in Eq. 32 and the corresponding cell for the right electrode H R 1 R 1 . These electrode Hartree potential energy functions now supply boundary conditions for the Hartree potential energy function of the interaction region. However, the electrodes are bulk systems and this means that we can add an arbitrary constant to their Hartree potential energy function and still obtain a valid solution. To fix this arbitrary constant we relate each electrode Hartree potential energy function to the chemical potential of the electrode, and use Eq. 15 to relate the left and right chemical potential. Thus, we now have fixed the Hartree potentials in the electrodes and they define the boundary condition of the Poisson's equation in the central region along the z direction. In the x and y direction we will use periodic boundary conditions. With these boundary conditions the Hartree potential energy function of the interaction region can be obtained by a multigrid approach, as described in Taylor, Phys. Rev. B 63, 245407 (2001).
[0000] Electron Transport Coefficients and Currents Obtained from the Green's Function
[0113] After finishing the self-consistent cycle we can calculate the transport properties of the system. The non-linear current through the contact, I, is obtained as
I ( U ) = G 0 ∫ μ L μ L + U Tr [ Im ∑ II L ( ɛ ) G _ II ( ɛ ) Im ∑ II R ( ɛ ) G _ II † ( ɛ ) ] , Eq . 41
where
G 0 = 2 ⅇ 2 h
is the conduction quantum. The foundation of this equation is described in H. Haug, Quantum kinetics in transport and optics of semiconductors , (Springer-Verlag, Berlin, 1996).
The Self-Consistent Algorithm for the Two-Probe System
[0114] FIG. 5 shows required steps for a two-probe calculation of the electrical current from the left to the right electrode through a nano-scale device due to an applied voltage between the left and right electrode as described in Eq. 15. Initially we define the system by specifying the ionic positions, and the external parameters like the applied voltage and temperature, 202 . Next we use the screening approximation to separate the system geometry into interaction and electrode regions, 204 . The electron density and the effective one-electron potential energy function should approach their bulk value in the electrode region. Usually this will be the case around atoms in the third layer of a metallic surface, and it is therefore sufficient to include the first two layers of metallic surfaces within the interaction region. We calculate the self-consistent effective one-electron potential energy function for the isolated electrode regions using the flowchart in FIG. 1, 206 . From the self-consistent effective one-electron potential energy function we construct the electrode Greens functions, using Eq. 4, 12, 33-36, and the electrode selfenergies using Eq. 29, 30, 208 . These initial calculations are now used as input to the two-probe calculation. Thus, we have calculated the self-consistent density of the electrode regions and only need to calculate the self-consistent density of the interaction region. Starting with an initial guess of the electron density for the interaction region, 210 , we perform a self-consistent loop similar to the flowchart in FIG. 1 . First we calculate the effective one-electron potential energy function of the interaction region using Eq. 5-8, 212 . From the effective one-electron potential energy function we can obtain the Hamiltonian using Eq. 4, 12 and the Green's function through Eq. 31, 214 . From the Green's function we can calculate the electron density using Eq. 23, 38, 39, 40, and thereby close the self-consistent cycle, 218 . If the new electron density is different (within a specified numerical accuracy) from the electron density used to construct the effective one-electron potential energy function, 220 , we make a new improved guess based on the previously calculated densities. In the simplest version the new guess is obtained from a linear mixing of the two densities, with a mixing parameter β, 216 . If the input and output densities are equal, we have obtained the self-consistent value of the electron density and thereby also the effective one-electron potential energy function, Hamiltonian and Green's function, 222 . From this Green's function we can calculate the current using Eq. 41, 224 . After the calculation of the current the algorithm stops, 226 .
[0115] The procedure has been implemented in the TranSIESTA and McDCAL software. Further description of these softwares and the implementation details can be found in Brandbyge Phys. Rev. B 65, 165401 (2002), and Taylor Phys. Rev. B 63, 245407 (2001). To obtain the current-voltage characteristics, I-U curve, of a nano-scale device, we need to perform a self-consistent calculation for each voltage U. This is illustrated in the flowchart of FIG. 6 . Input system geometry and the voltage interval U 0 , U 1 and step size ΔU, 302 . Set starting voltage to U 0 , 304 . Follow the steps in flowchart 2 of FIG. 5 to perform a self-consistent calculation of the effective one-electron potential energy function at voltage U, and use the self-consistent potential energy function to calculate the current, 306 . Increase the voltage with the step size, 308 , if the new voltage is within the specified voltage interval, then perform a new self-consistent calculation, 310 , else stop, 312 .
[0000] Example: Calculation of the I-U Characteristics of DTP Coupled with Gold Surfaces
[0116] We will now present results for the calculation of the I-U characteristics of the geometry illustrated in FIG. 2 using the TranSIESTA software. The calculation follows flowchart 3 of FIG. 6 , and the points in FIG. 9 show the result of the calculation. A similar I-U characteristic was obtained in Stokbro Computational Materials Science 27, 151 (2003).
[0117] In FIG. 7 we show the change in the self-consistent effective one-electron potential energy function due to the applied voltage. The value of the effective one-electron potential energy function is shown along a line starting in the left electrode, going through the center of the two sulphur atoms of the DTB molecule and ending in the right electrode. In the right electrode the effective one-electron potential energy function is shifted down due to the applied voltage. The main feature is that the effective one-electron potential energy function is flat in the electrode regions, and the main voltage drop is taken place within the molecular region.
[0118] The curves in FIG. 7 a all have similar shapes. In FIG. 7 b we have rescaled the curves with the applied voltage, and we observe that the rescaled effective one-electron potential energy functions are nearly identical. This observation forms a basis for the invention as it shows that the self-consistent change in the effective one-electron potential energy function has a simple variation with the applied voltage.
[0000] Linear Interpolation Using Two Voltage Points
[0119] In one version of the algorithm, the effective one-electron potential energy function is calculated at zero voltage, U 0 and for a small finite voltage, U Δ . These data are now used to extrapolate to a general voltage. The effective one-electron potential energy function for the general voltage, U, is obtained by simple linear extrapolation
V int eff [ U ] := V SCF eff [ U 0 ] + U + U 0 U Δ - U 0 ( V SCF eff [ U Δ ] - V SCF eff [ U 0 ] ) . Eq . 42
[0120] The Hamiltonian is related to the effective one-electron potential energy function by
H ^ = - ℏ 2 m ∇ ^ 2 + V eff . Eq . 43
[0121] This means that the same scaling relation applies to the Hamiltonian. Thus, the Hamiltonian at a general voltage can be approximated by
H ^ int [ U ] := H ^ SCF [ U 0 ] + U - U 0 U Δ - U 0 ( H ^ SCF [ U Δ ] - H ^ SCF [ U 0 ] ) , Eq . 44
where Ĥ SCF [U 0 ] and Ĥ SCF [U Δ ] are the self-consistent Hamiltonian at U 0 and U Δ .
[0122] In most electronic structure methods the Hamiltonian is expanded in a basis set {φ i }, and represented by the matrix
H ij = φ i |Ĥ|φ j . Eq. 45
[0123] In this case the linear interpolation formula is applied to the Hamiltonian matrix elements.
[0124] From the Hamiltonian we can calculate all properties of the system, including the electrical current due to the applied voltage. The electrical current is obtained by first calculating the Green's function using Eq. 31 and from the Green's function calculate the current using Eq. 41. We may combine Eq. 44, 31 and 41 and write it as a mapping, M, that takes H SCF [U 0 ], H SCF [U Δ ], U, and returns the current, I, at voltage U. We write the mapping as
I ( U ):= M ( U, H SCF [U 0 ], H SCF [U Δ ]), Eq. 46
[0125] The calculation of the I-U characteristics using the interpolation formula is summarized by flowchart 4 in FIG. 8 . Input system geometry and the voltage interval U 1 , U 2 , step size ΔU, and voltages U 0 U Δ where we will calculate the self-consistent Hamiltonians that are used for the interpolation, 402 . Use flowchart 2 of FIG. 5 to calculate the self-consistent effective one-electron potential energy function and Hamiltonian for voltage U 0 , 404 . Self-consistent calculation for voltage U Δ , 406 . Use flowchart 5 of FIG. 9 to calculate the I-U curve for the voltage interval U 1 ,U 2 using Eq. 46 with the self-consistent results at U 0 and U Δ to obtain an approximation for the current, 408 . Stop, 410 . The calculation of the I-U curve follows flowchart 5 of FIG. 9 . Input voltage interval U 1 , U 2 , step size ΔU and the self-consistent Hamiltonian for two voltages, U 0 and U, 502 . Set starting voltage to U:=U 1 , 504 . Use Eq. 46 with the self-consistent results at U 0 and U Δ to obtain an approximation for the current at U, 506 . Increase the voltage with the step size, 508 , if the new voltage is within the specified voltage interval, then continue calculating the I-U curve, 510 , else stop, 512 .
[0126] Typical parameters for the calculation will be to select U 0 =0 Volt and U Δ =0.4 Volt. It is most computationally efficient to choose a relative low value of the voltage, since the self-consistent calculation is more computationally demanding at a high voltage due to the calculation of the non-equilibrium density, Eq. 40, which involves an integral where the number of points is proportional to the size of the voltage.
[0127] Typical values for the range of the voltage in the I-U curve will be U 1 =−2.0 Volt and U 2 =2.0 Volt. At higher voltages the electric field will be very high for a small nano-scale device, and such voltages are difficult to measure experimentally due to electrical breakdown of the device.
[0128] In FIG. 10 we compare the result of calculating the current using the formula in Eq. 46 with the full self-consistent solution. The line denoted “1. order” shows the result obtained with Eq. 46, while the line denoted “SCF” shows the result obtained with the self-consistent calculation. We see that the results obtained with Eq. 46 are in excellent agreement with the full self-consistent calculation for V<2.0 Volt, even though only calculations at V=0.0 Volt and V=0.4 Volt were used for the calculation.
[0000] Adaptive Grid Method for Calculating the I-U Characteristics.
[0129] In the previous section we used a two point interpolation formula to extrapolate the Hamiltonian to a general voltage using the self-consistent Hamiltonian at two voltages U 0 and U Δ . We will now propose a systematic method to improve this scheme. The method is based on performing additional self-consistent calculations at selected voltage points, and using the self-consistent Hamiltonian at these voltage points to make improved interpolation formulas. With this method a series of I-U curves are produced that converges towards the self-consistently calculated I-U characteristics.
[0130] The target is to calculate the I-U characteristics in the interval [U 1 ,U 2 ]. Flowchart 6 in FIG. 11 shows the steps involved in the calculation. The initial steps are similar to flowchart 4 of FIG. 8 ; however, in this new algorithm we will improve the approximation by performing additional self-consistent calculations, where the new voltage points may be selected by the algorithm shown in flowcharts 7 and 8 of FIGS. 12 and 13 . Input system geometry and the voltage interval U 1 , U 2 , step size ΔU, and interpolation voltages U 0 ,U Δ , 602 .
[0131] Use flowchart 2 of FIG. 5 to calculate the self-consistent effective one-electron potential energy function and Hamiltonian for voltage U 0 , 604 . Self-consistent calculation for voltage U Δ , 606 . Use flowchart 8 of FIG. 13 to calculate the I-U curve for the voltage interval U 1 ,U 0 using Eq. 46 with the self-consistent results at U 0 and U Δ to obtain an approximation for the current, 608 . Use flowchart 7 of FIG. 12 to calculate the I-U curve for the voltage interval U 0 ,U 2 using Eq. 46 with the self-consistent results at U 0 and U Δ to obtain an approximation for the current, 610 . Stop 612 .
[0132] Flowcharts 7 and 8 of FIGS. 12 and 13 show the algorithms for subdivision of the interval. The interval is subdivided until interpolated and self-consistent calculated currents agree within a specified accuracy, which we denote δ. Flowchart 7 and 8 are similar except that flowchart 7 assumes the self-consistent Hamiltonian is known for the lowest voltage U A of the voltage interval where we request the I-U curve, while flowchart 8 assumes the self-consistent Hamiltonian is known for the highest voltage U B of the voltage interval. For flowchart 7 , the input to the recursion step is the voltage interval U A , U B , and the self-consistent Hamiltonian at the endpoint U A and at an arbitrary voltage point U C , 702 . Next we perform a self-consistent calculation at the highest voltage U B of the voltage interval, 704 . We calculate the current from the interpolation formula, Eq. 46 and from the self-consistent Hamiltonian Eq. 31, 41, 706 . If the interpolated current differs by more than δ from the self-consistent current, 708 , we will further subdivide into intervals {U A ,U M } and {U M ,U B }, where U M :=(U A +U B )/2, 714 . The algorithm is recursively called with the interval {U A ,U M }, 716 . For the interval {U M ,U B } we know the Hamiltonian at the last voltage point instead of for the first voltage point, and we use the slightly modified algorithm shown in flowchart 8 , 718 . The procedure is continued until the self-consistently calculated current for the new grid point agrees with the interpolated value within the prescribed accuracy δ. When the prescribed accuracy is obtained we can safely use Eq. 46 to calculate the I-U characteristics of the subinterval {U A ,U B }, 710 . The recursive algorithm stops, 712 .
[0133] The algorithm in flowchart 8 of FIG. 13 is a slight modification of the algorithm in flowchart 7 of FIG. 12 , the only difference being that the input self-consistent Hamiltonian is calculated at U B instead of U A . Here we just mention the differences in flowchart 8 when compared to flowchart 7 . Input H SCF [U B ] instead of H SCF [U A ], 802 . Perform self-consistent calculation at U A instead of at U B , 804 . Calculate the current at U A , 806 , compare currents calculated at U A , 808 . The remainder of the algorithm is similar to the algorithm flowchart 7 .
[0134] We note that in general this procedure will result in grid points unevenly distributed over the voltage window. The grid points will be most dense in the regions where the linear interpolation formula gives a poor description of the variation of the self-consistent potential energy function. Thus the algorithm results in an adaptive formation of the grid points.
[0000] Using Higher Order Approximations
[0135] For the methods described in the previous section the approximate solution was systematically improved by performing additional self-consistent calculations. When more than two self-consistent calculations are performed it is possible to use higher order interpolation formulas. For instance, self-consistent calculations at U 0 , U 1 , and U 2 , can be combined to obtain a second order extrapolation formula
V int eff [ U ] := V SCF eff [ U 0 ] + ( U - U 0 ) b + ( U - U 0 ) 2 c Eq . 46 b c = ( V SCF eff [ U 1 ] - U 1 - U 0 U 2 - U 0 V SCF eff [ U 2 ] ) / ( U 2 U 2 - U 1 U 1 ) Eq . 46 c b = V SCF eff [ U 1 ] / ( U 1 - U 0 ) - c ( U 1 - U 0 ) Eq . 46 d
for the effective potential, V int eff [U]. Similar second order extrapolation formulas can be used for the Hamiltonian,
H [ U ] := H [ U 0 ] + ( U - U 0 ) b + ( U - U 0 ) 2 c Eq . 46 e c = ( H [ U 1 ] - U 1 - U 0 U 2 - U 0 H [ U 2 ] ) / ( U 2 U 2 - U 1 U 1 ) Eq . 46 f b = H [ U 1 ] / ( U 1 - U 0 ) - c ( U 1 - U 0 ) Eq . 46 g
[0136] The line denoted “2. order” in FIG. 10 shows the result using a second order extrapolation formula obtained from self consistent calculations at 0.0 Volts, 0.4 Volts and 1.0 volts. The above can easily be generalized such that for n biases a (n−1) order extrapolation formula is used.
[0000] Generalization to Multi-Probe Systems
[0137] The algorithm can be generalized to multi-probe systems, i.e. systems where there are more than two electrodes. Lets assume that we will include one additional electrode, then we can relate the chemical potential of this electrode, μ 3 , to the chemical potential of the left electrode through the applied voltage between the electrodes, U L3
μ L −μ 3 =e U L3 . Eq. 47
[0138] We can now generalize Eq. 44 to a two-dimensional interpolation formula in the variables U L3 and U LR , where the latter is the voltage difference between the left and the right electrode. It is convenient to choose U 0 L3 =U 0 LR =U 0 =0, since then we can use the same self-consistent Hamiltonian for the U 0 value in the interpolation formula. In this case
H ^ int [ U L 3 , U LR ] := H ^ SCF [ U 0 ] + U L 3 - U 0 U Δ L 3 - U 0 ( H ^ SCF [ U Δ L 3 ] - H ^ SCF [ U 0 ] ) + U LR - U 0 U Δ LR - U 0 ( H ^ SCF [ U Δ LR ] - H ^ SCF [ U 0 ] ) Eq . 48
where U Δ L3 , U Δ LR are a small voltage increase in the left electrode-electrode 3 and left electrode-right electrode voltages, respectively. The self-consistent Hamiltonians Ĥ SCF [U Δ L3 ] are calculated for U L3 =U Δ L3 , U LR =0, and Ĥ SCF [U Δ LR ] are calculated for U LR =U Δ LR ,U L3 =0.
Generalization to Use Electronic or Ionic Temperature
[0139] So far we have implicitly assumed that the electronic temperature is zero, since all integrals are written with fixed integration boundaries at the chemical potentials. To include a finite electronic temperature we must change the integrals in Eq. 18, 24, 37, 39, 40, 41 such that
∫ μ → ∫ ∞ f [ ( ɛ - μ ) / kT ] , Eq . 49
where T is the temperature, k the Boltzmanns constant, and f is the Fermi function
f [ x ] = 1 ⅇ x + 1 . Eq . 50
[0140] We can readily generalize this to use different electronic temperatures for the left and right electrode, by using different values of T in the Fermi function for the left and right electrode.
[0141] Those skilled in the art will appreciate that the invention is not limited by what has been particularly shown and described herein as numerous modifications and variations may be made to the preferred embodiment without departing from the spirit and scope of the invention. | The invention relates to a method an computer system for using extrapolation analysis to express an approximate self-consistent solution or a change in a self-consistent solution based on a change in the value of one or more external parameters, said self-consistent solution being used in a model of a system having at least two probes or electrodes, which model is based on an electronic structure calculation comprising a self-consistent determination of an effective one-electron potential energy function and/or an effective one-electron Hamiltonian. The method of the invention comprises the steps of: determining a first self-consistent solution to a selected function for a first value of a first external parameter by use of self-consistent loop calculation; determining a second self-consistent solution to the selected function for a second value of the first selected external parameter by use of self-consistent loop calculation, said second value of the first selected external parameter being different to the first value of the first selected external parameter; and expressing an approximate self-consistent solution or a change in the self-consistent solution for the selected function for at least one selected value of the first selected external parameter by use of extrapolation based on at least the determined first and second self-consistent solutions and the first and second values of the first selected external parameter. | 97,997 |
FIELD
[0001] This disclosure relates generally to vehicles and more particularly to two, three and four-wheeled vehicles.
BACKGROUND
[0002] The three wheeler market kit/conversion industry is predominantly focused on vehicles having one front-wheel and two rear-wheels (1F2R), with a rapidly emerging focus on vehicles with two front-wheels and one rear-wheel (2F1R) for customs and production vehicle manufacturers. The market segment for conversions is nascent and includes a variety of potentially competing platforms, such as delta trikes; ‘ride-on’ reverse trikes, and open cockpit, ‘side-by-side’ reverse trikes. Current designs of three-wheeled motorcycles focus more on the 1F2R designs. The “delta trike” is a popular design that exemplifies this layout. However, the one-front-two rear design is inherently unstable and exhibits poor handling characteristics. However, none of the conventional designs are even robustly stable. The need for a stable design for a 1F2R or 2F1R vehicle has been recognized and long felt for over 80 years, and has been characterized by failure by many others to design a stable 1F2R or 1F2R vehicle using other designs.
BRIEF DESCRIPTION
[0003] The above-mentioned shortcomings, disadvantages and problems are addressed herein, which will be understood by reading and studying the following specification.
[0004] In one aspect, a motorized tricycle includes a lean mechanism and an active system that is operably coupled to the lean mechanism that receives an signal indicative of an interaction with human, that is operable to detect a lean of the body of the human and that is operable to receive a sensed movement on the seat via multisensory devices, and to generate and send a signal to the lean mechanism from the signal, the lean and the sensed movement.
[0005] The disclosure herein is applicable to, and can be implemented on, two front wheels and one rear wheel (2F1R) ‘reverse tricycle’ vehicles, one front wheel and two rear wheels (1F2R) ‘tricycle’ vehicles, one front wheel and one rear wheel (1F1R) ‘motorcycle’ vehicles and two front wheel and two rear wheel (2F2R) ‘quad’ vehicles. Apparatus, systems, and methods of varying scope are described herein. In addition to the aspects and advantages described in this summary, further aspects and advantages will become apparent by reference to the drawings and by reading the detailed description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is an isometric drawing of a three-wheeled two-front-one-rear tricycle with retractable cockpit canopy system, according to an implementation.
[0007] FIG. 2 is a block diagram of a three-wheeled two-front-one-rear vehicle, according to an implementation.
[0008] FIG. 3 is a block diagram of forces acting on a three-wheeled two-front-one-rear vehicle, in some implementations in which the forces acting on the center of gravity are in line to that of the central axis of the vehicle.
[0009] FIG. 4 is a block diagram of forces acting on a three-wheeled two-front-one-rear vehicle, in some implementations in which the vehicle is turning.
[0010] FIG. 5 is a block diagram of forces acting on a three-wheeled two-front-one-rear vehicle, in some implementations in which the vehicle is at rest, but leaning.
[0011] FIG. 6 is a block diagram of forces acting on vehicle that is three-wheeled two-front-one-rear, in some implementations in which the vehicle is turning.
[0012] FIG. 7 is an isometric drawing of the front of the tube frame under the body with wheels, according to an implementation.
[0013] FIG. 8 is a front view of the isometric drawing of the modular chassis with articulating suspension, according to an implementation.
[0014] FIG. 9 is a block diagram of the modular chassis with articulating suspension, according to an implementation.
[0015] FIG. 10 is a top view of the isometric drawing of the modular chassis with articulating suspension, according to an implementation.
[0016] FIG. 11 is an inset of the front axle of FIG. 10 , according to an implementation.
[0017] FIG. 12 is a bottom view of the isometric drawing of the modular chassis with articulating suspension, according to an implementation.
[0018] FIG. 13 is an inset of the front axle of FIG. 12 , according to an implementation.
[0019] FIG. 14 is a horizontal top view of the isometric drawing of modular chassis with articulating suspension, according to an implementation.
[0020] FIG. 15 is a side view of the isometric drawing of the modular chassis with articulating suspension, according to an implementation.
[0021] FIG. 16 is an inset of the front axle of FIG. 17 , according to an implementation.
[0022] FIG. 17 is a front view of the isometric drawing of the modular chassis with articulating suspension set, according to an implementation.
[0023] FIG. 18 is an inset of the front axle of FIG. 17 , according to an implementation.
[0024] FIG. 19 is an isometric drawing of the tube frame under the body, according to an implementation.
[0025] FIG. 20 is an inset of the front axle of FIG. 19 , according to an implementation.
[0026] FIG. 21 is a side view of the front portion of the isometric drawing of the tube from under the body, according to an implementation.
[0027] FIG. 22 is an inset of the axle in FIG. 21 , according to an implementation.
[0028] FIG. 23 is a front view of the isometric drawing of the tube frame under the body, according to an implementation.
[0029] FIG. 24 is a detailed isometric drawing of the front axle and front portion of the tube frame, according to an implementation.
[0030] FIG. 25 is an inset of the front axle of FIG. 24 , according to an implementation.
[0031] FIG. 26 is a front view of the isometric drawing of the front axle of the tube from under the body, according to an implementation.
[0032] FIG. 27 is an isometric drawing of the modular chassis with articulating suspension and fail-safe apparatus, according to an implementation.
[0033] FIG. 28 is an inset of the front axle of FIG. 27 , according to an implementation.
[0034] FIG. 29 is a top view of the isometric drawing of the modular chassis with articulating suspension and fail-safe apparatus, according to an implementation.
[0035] FIG. 30 is a side view of the isometric drawing of the modular chassis with articulating suspension and fail-safe apparatus, according to an implementation.
[0036] FIG. 31 is an apparatus of the modular chassis with articulating suspension and fail-safe apparatus, according to an implementation.
[0037] FIG. 32 is a top view of the modular chassis with articulating suspension and fail-safe apparatus, according to an implementation.
[0038] FIG. 33 is a schematic of an input power filter, according to an implementation.
[0039] FIG. 34 is a model of an accelerating vehicle, according to some implementation.
[0040] FIG. 35 is a block diagram of a LMC that uses a layered hierarchy, according to some implementation.
[0041] FIG. 36 is a block diagram of a single voltage system in some implementations in which the battery voltage is also the motor voltage.
[0042] FIG. 37 is a block diagram of a voltage conversion system, according to an implementation in which a primary battery voltage is converted to a higher secondary voltage for motor operation.
[0043] FIG. 38 is a schematic of an electrical circuit, according to an implementation.
[0044] FIG. 39 is a schematic of a decoupling capacitor, according to an implementation.
[0045] FIG. 40 is a schematic of a decoupling capacitor, according to an implementation.
[0046] FIG. 41 is a schematic of a decoupling capacitor, according to an implementation.
[0047] FIG. 42 is a schematic of an input circuit for motor current monitoring, according to an implementation.
[0048] FIG. 43 is a schematic of switches on the motor drive board, according to an implementation.
[0049] FIG. 44 is a schematic of current monitors for the switches on the motor drive board, according to an implementation.
[0050] FIG. 45 is a schematic of 3 phase motor controller, according to an implementation.
[0051] FIG. 46 is a schematic of motor current monitors, according to an implementation.
[0052] FIG. 47 is a block diagram of a control computer in which different methods can be practiced.
DETAILED DESCRIPTION
System Level Overview
[0053] FIG. 1 is an isometric drawing of a three-wheeled two-front-one-rear tricycle 100 with retractable cockpit canopy system 102 , according to an implementation. The vehicle is a versatile platform allowing multiple configurations and customizations to target varying consumer preferences. Entirely unique to the three-wheeled two-front-one-rear tricycle 100 is a retractable cockpit canopy system 102 , enabling the vehicle to be ridden in the full open/top off configuration, and either with or without doors 104 . The retractable cockpit canopy system 102 offers protection from foul weather opening up year-round use and making this attractive to everyone from workday commuters to recreational riders. Commuters can enjoy using the single occupancy HOV lane with the comfort of climate control. Entirely unique to the three-wheeled two-front-one-rear tricycle 100 is an interactive lean control (ILC) system described in greater detail below in FIG. 2-47 that provides stability in situations where conventional vehicles would roll-over.
[0054] In some implementations, the three-wheeled two-front-one-rear tricycle 100 employs motorcycle type handlebars, with common motorcycle type controls (clutch, brake and throttle). Switches are mounted on each hand grip for initiating lean control. The right hand switch leans the three-wheeled two-front-one-rear tricycle 100 to the right and the left hand switch leans the three-wheeled two-front-one-rear tricycle 100 to the left. The switches may be a simple on/off type or may be used to initiate a pre-programmed lean profile (speed proportional, soft start, etc.) Alternatively, an additional axis of motion at each hand grip may be employed to initiate lean control, so that lean is initiated by bending the hand grip downward. This control may be a simple on/off type or may be proportional, the angle of the hand grip being proportional to the angle of the commanded lean.
[0055] The three-wheeled two-front-one-rear tricycle 100 employs an automobile type steering wheel. Switches are mounted at locations corresponding to the thumb when the driver's hands are placed at the common 10 o'clock and 2 o'clock positions. Alternatively, a trigger type switch may be employed mounted at locations corresponding to the forefinger when the driver's hands are placed at the common 10 o'clock and 2 o'clock positions. Alternatively, an additional axis of motion (yaw) at each hand location may be employed to initiate lean commands. These controls may have any of the characteristics noted in the motorcycle type section. Other implementations of the three-wheeled two-front-one-rear tricycle 100 that have a saddle seat and handlebars fall into the general category of motorcycle. An important distinction of the three-wheeled two-front-one-rear tricycle 100 that have a saddle seat and handlebars is that the three-wheeled two-front-one-rear tricycle 100 can include a saddle because of the interactive lean control (ILC) system.
[0056] In some implementations, the three-wheeled two-front-one-rear tricycle 100 employs a two axis joystick for acceleration/deceleration and turning. Two switches are mounted on the joystick for thumb operation. Alternatively, an additional axis of motion (yaw) may be employed to initiate lean commands. These controls may have any of the characteristics noted in the motorcycle type section. While the three-wheeled two-front-one-rear tricycle 100 is not limited to any particular three-wheeled two-front-one-rear tricycle 100 and retractable cockpit canopy system 102 for sake of clarity a simplified three-wheeled two-front-one-rear tricycle 100 and retractable cockpit canopy system 102 are described.
[0057] The three-wheeled two-front-one-rear tricycle 100 provides active control in a counter-steering leaning trike at performance speeds with human-rated safety system design and an intuitive/purest motorcyclist control. Other vehicles are included in the auto-cycle classification that are anticipated to face increased regulatory compliance, i.e. the polaris slingshot, Campagna T-Rex, Elio Motors.
Apparatus Implementations
[0058] In the previous section, a system level overview of the operation of an implementation was described. In this section, the particular apparatus of such an implementation are described by reference to a series of diagrams.
[0059] FIG. 2 is a block diagram of a vehicle 200 that is three-wheeled two-front-one-rear, according to an implementation. The vehicle 200 includes the following elements: a three-wheeled architecture 202 , a sliding canopy 204 , a lean mechanism controller 206 , and software 208 . For purposes of this description the term a lean mechanism controller 206 refers to all elements mechanical, electrical, electronic (including software). These include the lean mechanism controller 206 as well as other electronically controlled or assisted driving elements such as braking, steering and suspension, electrical distribution systems, batteries, motors, mechanical linkages and gearings, hydraulics and associated pumps and valves, etc., sensors, computers and software.
[0060] In order for the lean mechanism controller 206 to control the tilt of the vehicle some means of determining the tilt of the vehicle is required. This may be accomplished through any of the following means.
[0061] The Mechanical Position Sensor measures the mechanical motion of the lean actuator. This motion may be linear or rotational depending on the type of actuator used.
[0062] With a Linear Lean Actuator the tilt angle of the wheels can be determined by measuring the length of the linear actuator. This may be done by employing linear potentiometers, string potentiometers, or a linear variable differential transformer (LVDT).
[0063] With a Rotary Lean Actuator the tilt angle of the wheels may be determined by measuring the rotational angle of the rotary actuator. This may be done by employing rotary potentiometers, resolvers, synchros, optical or electrically commutating encoders, or magnetic angle sensors. This measurement may be taken on the actuator shaft or at the wheel itself.
[0064] The tilt angle may be inferred from knowledge of the state of the actuator motor, specifically the number of rotations of the motor from some known position, and the turning ratio of the gearing in the actuator. One or more known positions can be detected with the use of limit switches or mechanical stops. Motor rotation may be measured using any of the rotational position sensors noted above. Alternatively, in the case of stepper motors, the number of rotations of the motor is known from the number of steps commanded by the control computer. Alternatively, in the case of brushless DC (BLDC) motors, the number of rotations of the motor is known from the angular feedback required for any BLDC motor. This feedback is in the form of reverse EMF, Hall effect sensors, or any of the rotary sensors noted above.
[0065] The tilt angle may be measured by employing inertial sensors such as gyroscopes and accelerators, in some implementations, based on micro-electro-mechanical systems (MEMS) technologies. In an implementation of this element the tilt angle would be measured by at least two of the above methods, one with high precision for the operation of the lean actuator control loop and others with less resolution as a means of ensuring the accuracy of the control loop sensor.
[0066] The TC employs Inertial Measurement Unit (IMU) sensors deployed in at least four locations. These locations include the vicinity of each of the three wheels and at the CG. At each location is a set of at least three identical IMU sensors. Each IMU measures acceleration in three axes, angular rate in three axes, and magnetic field in at least one axis. Each IMU may be one or multiple sensors acting together. The data from the IMUs is used to determine all the forces acting on the vehicle 200 at any moment. This allows for precise calculation of the lateral resultant force needed to calculate the tilt angle. IMU data also allows for the determination of magnetic heading, road incline and smoothness, braking and acceleration forces, aerodynamic forces, skid and hydroplaning and automatic CG calculation (see below). The data from each IMU is compared against the other IMUs in the set and made available to the lean mechanism controller 206 (LMC) software. In the event that the data from all sensors in the set do not match within the manufacturer's tolerance a fault is registered in the LMC software and displayed to the driver, and the faulty sensor is disabled. The sensor sets at the four locations are compared against each other. In the event that the data from all sensor sets do not match within expected characteristic parameters a fault is registered in the LMC software and displayed to the driver, and the faulty sensor set is disabled.
[0067] LMC is an umbrella term for the set of distinct and distributed electronics and software control functions that form the vehicle 200 driver interface. These include everything from low level signal processing to environment modeling and adaptive control. For purposes of this description “electronics” includes any electronic device used to manipulate electrical power and sensor signals at the analog level, and any means of communicating between sensors or processing functions. “Software” includes any mathematical of symbolic digital process whether encoded in as machine executable instructions or as reconfigurable digital logic circuits.
[0068] The lean mechanism controller 206 operates autonomously at all times to ensure adequate safety margins while the vehicle 200 is moving, but the driving experience is greatly enhanced when the driver has the ability to initiate lean action, especially when entering and exiting a turn. The vehicle 200 employs a variety of manual controls, described as follows.
[0069] The vehicle 200 employs sensors in the driver seat to detect when the driver leans to the left or right, as a motorcycle rider would lean to control the tilt of a motorcycle. The seat contains load cells to measure the differential in weight between the left and right side of the seat. Alternatively, the seat may pivot about the roll axis when the driver leans right or left and this pivot action is measured by any of the means noted earlier for measuring rotational movement. The seat control may be a simple on/off type, or may be used to initiate a preprogrammed lean profile (speed proportional, soft start, etc.,) or may be proportional, the angle of the seat being proportional to the angle of the commanded lean.
[0070] The vehicle 200 detects the driver leaning left or right directly using a video camera. The control is proportional, the commanded lean angle being proportional to the lean of the driver's body. Alternatively, the driver's body motion may be detected by employing an RGB camera and IR laser depth sensor (Kinect® device). Alternatively, the driver's body motion may be detected by an IMU sensor located on the driver's body, typically in a communications headset. The lean mechanism controller 206 and the software 208 in vehicle 200 provide a bionic electromechanical system that senses and enhances the Humans/Riders intuitive lean movements/motions while comparing with multiple electronic sensing and Kinematic systems for redundant safety, adaptive intelligence and optimized/extreme corning performance. The ILC system coupled with independent steering, hardware and science make the vehicle 200 an extreme exotic SuperTrike that rides like a bike. The ILC is interactive and bionically moves with the driver. The most significant aspects are that the ILC cause leaning that is independent of steering inputs, allowing countersteer. In some implementations, the ILC includes forward looking sensors and video analysis for virtually autonomous ride and lean control. The ILC is an autonomous equilibrium system that simulates the intuitive motorcycle rider's actions.
[0071] FIG. 3 is a block diagram of forces acting on a vehicle 200 that is three-wheeled two-front-one-rear, in some implementations in which the forces acting on the CG 302 are in line to that of the central axis 304 of the vehicle 200 . In a vehicle 200 , maximum stability is achieved when the forces acting on the vehicle center of CG 302 , such as the force due to gravity, FG 306 are in line with the central axis 304 of the vehicle 200 .
[0072] FIG. 4 is a block diagram of forces acting on a vehicle 200 that is three-wheeled two-front-one-rear, in some implementations in which the vehicle 200 is turning. Consider a vehicle 200 at rest: The force due to gravity, FG 306 , acts on the CG 302 and is in line with the central axis 304 of the vehicle. There are no lateral forces present. Now, consider the case where the vehicle is turning right: In this case, a second force, the FC 402 (centrifugal force), acts laterally on the CG 302 . Here the direction of the resultant force, FR 404 , is no longer in line with the central axis 304 of the vehicle, deviating by the angle θ 406 . This causes a counter clockwise torque to develop about the CG 302 which tends to tip the vehicle to the left. (For a left hand turn a clockwise torque will tend to tip the vehicle 200 to the right.)
[0073] FIG. 5 is a block diagram of forces acting on a vehicle 200 that is three-wheeled two-front-one-rear, in some implementations in which the vehicle 200 is at rest, but leaning. Now, consider the vehicle 200 again at rest, but leaning at an angle, φ 406 : Here the CG 302 has moved to the right and the force of gravity, FG 306 , is no longer in line with the central axis 304 . This causes a clockwise torque to develop about the CG 302 tending to tip the vehicle 200 to the right. (A lean to the left will create a counter clockwise torque that will tend to tip the vehicle to the left.)
[0074] FIG. 6 is a block diagram of forces acting on a vehicle 200 that is three-wheeled two-front-one-rear, in some implementations in which the vehicle 200 is turning. Finally, consider the vehicle 200 making a right hand turn which creates a resultant force, FR 404 , acting through the CG 302 at an angle θ (not shown), while the vehicle 200 is tilted at the angle φ=θ. It can be shown that the counter clockwise torque produced by the centrifugal force, FC 402 , of the turn is exactly canceled by the clockwise torque produced by the lean. The resultant force acting through the CG 302 is once again in line with the central axis 304 of the vehicle 200 and the vehicle 200 is stable.
[0075] The function of the Lean mechanism controller 206 is to ensure that the vehicle 200 remains stable by tilting the vehicle in response to lateral forces so that the resultant force acts through the CG in line with the central axis. While developed particularly for turning forces, the lean mechanism controller 206 is also effective in countering the destabilizing effects of wind or unlevel terrain.
[0076] The vehicle 200 is tilted by means of a Lean Actuator. The Lean Actuator may be a single actuator connected to both front wheels through a mechanical linkage, or it may be independent actuators mounted to each wheel. Each Lean Actuator may be of two types, either rotary or linear. These are described below.
[0077] The Linear Lean Actuator includes of a linear actuator connected at one to the frame of the vehicle 200 and at the other end to one or both front wheels so that the plane of the wheel rotates as the linear actuator extends and retracts. The linear actuator may be electrical or hydraulic.
[0078] The Hydraulic Linear Lean Actuator is a system including of a single or double acting hydraulic cylinder, pump and valves to control the direction of the cylinder piston. The pump may be driven by an electric motor, or may be driven via a power take off (PTO) either coupled directly to the vehicle 200 engine or by an accessory pulley and fan belt or chain.
[0079] The Electric Linear Lean Actuator includes of mechanical linear actuator driven by a motor. The mechanical linear actuator may be of several common types, including Acme screw, ball screw, or roller (planetary) screw. The motor may be electric, of any common type including brushed DC, brushless BC, stepper, AC inductance, reluctance or axial rotor (pancake). Alternatively the actuator may be driven via a PTO as described above in conjunction with a mechanical or magnetic clutch and reversible motion transmission. Alternatively, the actuator may be driven by the rotation of the wheels, through a suitable clutch and reversible motion transmission system. Typically the motor speed will be reduced (and torque correspondingly increased) through a gearing system before driving the linear actuator screw. This gearing may be of any common type, including spur or helical worm gears, planetary gears or strain wave gearing. Alternatively, the Electric Linear Lean Actuator may employ a rack and pinion, driven by a motor of any type described above. The rack may be straight or curved to accommodate the geometry of the mechanical system.
[0080] Alternatively, a linear motor may be used where the motor itself becomes the linear actuator. The linear motor may be of any common type including induction or synchronous types.
[0081] The Rotary Lean Actuator includes of a rotary actuator connected at one to the frame of the vehicle 200 and at the other end to one or both front wheels so that the plane of the wheel rotates as the rotary actuator turns. The rotary actuator may be electrical or hydraulic.
[0082] The Hydraulic Rotary Lean Actuator is a system including of a rotary hydraulic motor, pump and valves to control the direction of the rotation. The pump may be driven by an electric motor, or may be driven via a power take off (PTO) as described above.
[0083] The Electric Rotary Lean Actuator includes of a rotating mechanical actuator driven by a motor. The mechanical actuator is a speed reducing gear box of any common type, including spur or helical worm gears, planetary gears or strain wave gearing. The motor may be electric, of any common type including brushed DC, brushless BC, stepper, AC inductance, reluctance or axial rotor (pancake). Alternatively the actuator may be driven via a PTO as described above in conjunction with a mechanical or magnetic clutch and reversible motion transmission. Alternatively, the actuator may be driven by the rotation of the wheels, through a suitable clutch and reversible motion transmission system. The mechanical linkage between the rotary actuator and the wheel(s) may be direct coupling (the wheel mounted on the shaft of the actuator), or through any common type of mechanical linkage, including sprocket and chain.
[0084] In addition to tilting the vehicle through the use of the Lean Actuator, an electronic suspension system on the front wheels may be employed, either separately of in conjunction with the Lean Actuator, to provide a tilt by raising the vehicle 200 body at one wheel and lowering it on the other. In particular, the Lean Actuator may be used for the majority of the tilt angle, in response to centrifugal force, while the electronic suspension applied smaller deviations about the tilt angle in response to road or engine vibration.
[0085] In addition, independent lean actuators on each front wheel may be employed to apply a camber to the wheels (both wheels leaning outward or inward) during straight ahead driving to provide stability in certain road or weather conditions. This can only be achieved while the vehicle is moving
[0086] In an implementation of the Lean mechanism controller 206 one or more electric motors are employed to drive the lean actuator. Electrical power for the motor(s) is derived from one or more vehicle storage batteries making use of any of the following electrical distribution topologies. For purposes of the following the term “battery” may refer to a single battery or a parallel or serial combination of batteries, of any rechargeable type, including lead acid or lithium ion batteries. In any case, a battery is not necessarily required if the vehicle is equipped with a high current alternator, or other generator type, however in an implementation of this element the battery supplies the relatively large lean actuator motor currents for the short duration of each turning maneuver and is continuously recharged by the alternator.
[0087] FIG. 7 is an isometric drawing of the front of the tube frame under the body with wheels 700 , according to an implementation. The tube frame 702 under the body provides an added level of safety and protection for increased peace of mind compared to completely exposed riders of two wheeled motorcycles.
[0088] FIG. 8 is a front view of the isometric drawing of the modular chassis, according to an implementation.
[0089] FIG. 9 is a block diagram of the modular chassis with articulating suspension, according to an implementation. The modular chassis is capable of mating up to other OEM motorcycles as a kit conversion and/or a rear chassis extension enabling various drive train configurations in single or double rear wheel drivetrains with numerous power options from electric, alternative fuel, and combustible engines. The modular chassis may be tubular, moncoque, or space-frame
[0090] FIG. 10 is a top view of the isometric drawing of the modular chassis with articulating suspension, according to an implementation. The modular chassis may be tubular, moncoque, or space-frame.
[0091] FIG. 11 is an inset of the front axle of FIG. 12 , according to an implementation. The modular chassis may be tubular, moncoque, or space-frame.
[0092] FIG. 12 is a bottom view of the isometric drawing of the modular chassis with articulating suspension, according to an implementation. The modular chassis may be tubular, moncoque, or space-frame.
[0093] FIG. 13 is an inset of the front axle of FIG. 14 , according to an implementation. The modular chassis may be tubular, moncoque, or space-frame.
[0094] FIG. 14 is a horizontal top view of the isometric drawing of modular chassis with articulating suspension, according to an implementation. The modular chassis may be tubular, moncoque, or space-frame.
[0095] FIG. 15 is a side view of the isometric drawing of the modular chassis with articulating suspension, according to an implementation. The modular chassis may be tubular, moncoque, or space-frame. The suspension set may also be traditional fixed independent suspension.
[0096] FIG. 16 is an inset of the front axle of FIG. 17 , according to an implementation. The suspension includes an axle spindle, a spring, an upper A-Arm, a lower A-Arm. Both the Upper and Lower A-Arms may be H-Arms, strut, trailing and or leading arm type suspension configuration.
[0097] FIG. 17 is a front view of the isometric drawing of the modular chassis with articulating suspension set, according to an implementation. The suspension set may also be traditional fixed independent suspension.
[0098] FIG. 18 is an inset of the front axle of FIG. 17 , according to an implementation. This suspension system may be fixed like conventional automobile or articulate to provide lean-in turns, counter-balancing, and lateral G-forces. This system may be incorporated into the front, rear, or both front and rear of a motorcycle and autocycle.
[0099] FIG. 19 is an isometric drawing of the tube frame under the body, according to an implementation.
[0100] FIG. 20 is an inset of the front axle of FIG. 19 , according to an implementation.
[0101] FIG. 21 is a side view of the front portion of the isometric drawing of the tube from under the body, according to an implementation.
[0102] FIG. 22 is an inset of the axle in FIG. 21 , according to an implementation.
[0103] FIG. 23 is a front view of the isometric drawing of the tube frame under the body, according to an implementation.
[0104] FIG. 24 is a detailed isometric drawing of the front axle with tilting independent suspension system on a modular chassis, according to an implementation. This system is typical of reverse trike 2F1R or quad 2F2R configurations. The suspension system shown is leaning to the right.
[0105] FIG. 25 is an inset of the front axle of FIG. 24 , according to an implementation. The front axle with tilting independent suspension includes an actuator, lower tower frame mount, a pivot point for the lower tower frame mounter, a pivoting shock tower, and a tower link. The shock tower serves as the shock mount linking the high misalignment long travel A-Arm independent suspension assembly. The shock tower pivots from the lower frame mount. The optional tower link may connect the pivoting shock towers to provide tandem articulation of both left and right independent suspension. One actuator may be linked to the tower link or either tower to control the entire suspension actuation. Alternatively, this member is removed when two actuators are used for independent lean control.
[0106] FIG. 26 is a front view of the isometric drawing of the front axle of the tube from under the body, according to an implementation.
[0107] In regards to FIG. 27-32 , an independent secondary fail-safe tilt brake and dampening system is shown. The independent secondary fail-safe tilt brake and dampening system may be a solenoid and gear power off system as illustrated in FIG. 27-32 . Alternatively the independent secondary fail-safe tilt brake and dampening system may be a linear friction, electromagnetic, caliper or rotary brake and dampening system. The independent secondary fail-safe tilt brake and dampening system may serve both as an independent a secondary safety system and a parallel dampening system that additionally manages and mitigates impact and fatigue of primary control system hardware.
[0108] FIG. 27 is an isometric drawing of the modular chassis with articulating suspension and fail-safe apparatus, according to an implementation.
[0109] FIG. 28 is an inset of the front axle of FIG. 27 , according to an implementation.
[0110] FIG. 29 is a top view of the isometric drawing of the modular chassis with articulating suspension and fail-safe apparatus, according to an implementation.
[0111] FIG. 30 is a side view of the isometric drawing of the modular chassis with articulating suspension and fail-safe apparatus, according to an implementation.
[0112] FIG. 31 is an apparatus of the modular chassis with articulating suspension and fail-safe apparatus, according to an implementation.
[0113] FIG. 32 is a top view of the modular chassis with articulating suspension and fail-safe apparatus, according to an implementation.
[0114] FIG. 33 is a schematic of an input power filter 3300 , according to an implementation. The input power filter 3300 includes two 12V battery terminals The terminals include a positive terminal, BATT+ 3302 , and negative terminal, BATT− 3304 . The input power filter 3300 also includes a bidirectional transient voltage suppression (TVS) diode 3306 which prevents noise on the main battery bus 3308 from propagating into the electric circuits. Connector 3310 connects the power from either the battery or another external power source to the rest circuit. A fuse 3312 is included on the input power filter 3300 to protect from a catastrophic failure. The input power filter 3300 also includes a pi type low pass filter 3314 , which prevents motor noise from interfering with the electric circuit. LED1 3316 and LED2 3318 are light emitting diodes which indicate whether power is present on the circuit.
[0115] FIG. 34 is a model of an accelerating vehicle, according to some implementation. The vehicle is moving from left to right driven by the force, F. This force causes a counterclockwise torque to act about the CG, tending to pull the front of the vehicle up and push the rear of the vehicle down. The force F1 adds to the force of gravity and causes an increase in acceleration to be measured by IMU1. F2 subtracts from the force of gravity and causes a decrease in acceleration to be measured by IMU2. Force is related to torque by the relation T=F1xR1=F2xR2, where F and R are vectors and x is the cross product. Knowing F1 and F2 we can calculate R1 and R2 (R1+R2 being a known value) and fix the position of the CG between the front and rear of the vehicle. Similarly by measuring the centrifugal forces at the two front wheels we can fix the location of the CG between the left and right sides of the vehicle. This allows the vehicle 200 to calculate in real time any change to the CG from, for instance, various drivers and cargo. With this capability the Lean mechanism controller 206 is better able to calculate safety margins for braking and turning maneuvers.
[0116] FIG. 35 is a block diagram of a LMC that uses a layered hierarchy, according to some implementation.
[0117] The lowest layer is the Sensor Layer. This layer includes of electronic and electro-mechanical sensors and the additional signal processing circuitry that is required to convert the sensor measurements into serial digital data.
[0118] The next level is the Verification Layer. This layer determines the veracity of the sensor data by comparing redundant sensor measurements. Once the data is verified, additional processing is employed to extract the data required for the various elements of the higher layers. For instance, the output of an IMU sensor may be correlated with engine vibration data to remove the engine vibration from the acceleration data. Data is sampled and averaged at different rates depending on the end disclosure for the data. For instance, wheel rotation may be sampled at a very high rate to detect wheel slipping, but at a much lower rate to provide vehicle speed information to the HUD.
[0119] The next level is the Processing Layer. This layer utilizes the data from the Verification Layer to perform high level processing functions, such as driving the Lean Actuator, controlling the HUD, adjusting the sound quality and volume of the audio system, generating operating status and caution and warning alarms, etc.
[0120] The highest level is the Modeling Layer. This layer creates a virtual model of the entire environment of vehicle 200 , analogous to the driver's sensory experience. This model includes knowledge of the operation of all elements of the vehicle 200 as well as knowledge of the immediate environment around the vehicle from both real time information (from cameras, radar, etc.) and stored information from previous trips (by this vehicle 200 or any other vehicle 200 ), augmented by available disclosures such as GPS, traffic and weather reporting, etc.
[0121] The knowledge accumulated in the Modeling Layer is passed back down to the Processing Layer to augment the sensor based processing to adapt intelligently to environmental conditions. Examples of this behavior may include warning the driver of imminent traffic problems, tuning down the Lean Actuator in high wind conditions or adjusting the suspension for an upcoming section of rough road.
[0122] The vehicle 200 employs a variety of sensors to monitor the environment in and around the vehicle. This allows the LMC to create and maintain a computer model analogous to what the driver experiences. In this way the LMC can adapt various control parameters to changing requirements. These sensors are described below.
[0123] The vehicle 200 MEMS sensors have already been noted above as providing inputs to the calculation of the tilt angle and automatic CG calculation. These sensors include the IMU, with triaxial angular rate and acceleration measurement. In addition to providing inputs for the calculation of the tilt angle, these sensors provide information on road incline and banking, road surface smoothness, engine vibration, and aerodynamic effects such as wind gusting.
[0124] Each wheel of the vehicle 200 is equipped with a rotational speed sensor. These may be in the form of magnetic proximity encoders, resolvers, or magnetic rotation sensors. Knowing the rotational speed of each wheel allows the vehicle 200 to detect wheel lock for anti-lock braking, and wheel slip for active traction control on wet or icy road surfaces. In addition wheel speed is used for calculating vehicle speed, acceleration and deceleration, also inputs to the tilt angle calculation.
[0125] The vehicle 200 employs magnetic sensors to detect the geomagnetic field of the Earth in order to determine compass heading. This is used in conjunction with the GPS and map system to create a model of the location and direction of the vehicle on the road. Corrections to the magnetic heading are applied from a look up table based on the latitude and longitude coordinates from the GPS in order to provide compass headings.
[0126] The vehicle 200 employs various video cameras to aid in driving and navigation. A forward looking camera is used to adjust the adaptive headlight system, allowing individual lighting elements to be dimmed to protect the drivers of nearby vehicles from glare, while maintaining the brightest lighting for driver of the vehicle 200 . The forward looking camera is also used in conjunction with the GPS and map systems to anticipate upcoming turns and curves in the road. The vehicle 200 employs a rear facing camera to provide maximum rearward visibility while driving, and to facilitate parking. The rear facing camera is one element of the Heads Up Display (HUD). Both the forward facing and rear facing cameras are used in conjunction with the Radar System for detecting potentially dangerous traffic and obstacles. The video cameras may be sensitive to either visible or infrared light.
[0127] The vehicle 200 has the capability of transferring sensor data to and from remote third party servers (commonly referred to as “the cloud”) via wireless cellular telephony. This capability has at least two disclosures, described below. The cloud data is configurable and can include anything from location or speed information to a complete record of all vehicle 200 sensors, including video. This data includes inputs from all sensors noted above, as well as common engine functions such as tachometer, fuel consumption, battery voltage, coolant temperatures and oil pressure. This allows the driver a complete record of trips, and most usefully, racing track information. Use of the cloud also allows the vehicle 200 to download sensor and route information in real time from previous trips, and from other vehicle 200 owners.
[0128] The vehicle 200 has the ability to store sensor information recorded while driving. This data can be recorded locally in the memory of the LMC, or uploaded to the cloud. Utilizing this data in conjunction with the GPS and map system allows the vehicle 200 to create a detailed model of a particular route. In one instance this allows a driver to improve his track performance in real time lap to lap, as the LMC adapts control parameters and safety margins to take advantage of foreknowledge of the track geometry and conditions. In another instance this allows the commuter to improve fuel efficiency as the LMC adapts to a daily traffic routine with foreknowledge of typical traffic patterns and road speeds. In another instance this allows the LMC to adapt to the driving habits of a particular operator of vehicle 200 , adjusting control parameters and safety margins based on the driving habits (acceleration/deceleration, turning speed, reaction time, etc.) of the driver. In another instance this allows the LMC to detect an impairment of the driver (or a malfunction of the vehicle 200 itself), if the driver is having difficulty maintaining the typical driving pattern learned from previously driving the same route. The LMC can then adjust control parameters and increase safety margins to compensate, and even shut down if required.
[0129] FIG. 36 is a block diagram of a single voltage system 3600 in some implementations in which the battery voltage is also the motor voltage. The battery is discharged into the motor through a control computer and is recharged from an alternator powered by the vehicle engine. The battery voltage can be any practical value. In an implementation the battery voltage is 12V, 24V or 48V. In this system the battery acts as a reservoir supplying the lean actuator motor with short bursts of high current for turning, and is recharged continuously at a lower current.
[0130] FIG. 37 is a block diagram of a voltage conversion system 3700 , according to an implementation in which a primary battery voltage is converted to a higher secondary voltage for motor operation. In an implementation of system 3100 the secondary voltage would be 90VDC to 300VDC, or 200VAC to 240VAC, either 50 Hz or 60 Hz. The higher voltage makes it possible to use a smaller motor and smaller gauge wiring. In this system the battery acts as a reservoir supplying the lean actuator motor with short bursts of high current for turning, and is recharged continuously at a lower current.
[0131] In a dual battery system, the primary voltage (typically 12V) is converted to a higher voltage (typically 48VDC to 96VDC) for charging the secondary battery. The primary batter is optional in this system but is shown for completeness. The primary voltage alternator is used for continuous charging of the secondary battery through the voltage converter. The secondary battery supplies large amounts of current in short bursts to the motor during turns.
[0132] The vehicle 200 is equipped with a WIFI Ethernet capability for communicating with other nearby vehicles that are equipped with WIFI Ethernet capability. This allows the formation of traveling convoys of vehicle 200 for travel to cycling events or other purposes. By sharing sensor information from vehicle to vehicle speeds and spacing can be matched precisely, with one vehicle 200 being the “master” and the others being “slaves” as a form of convoy cruise control. In addition, road conditions from vehicles at the front of the convoy can be communicated to vehicles further back allowing the further back vehicles some foreknowledge or curves, rough road, sudden traffic stops, etc. The WIFI also allows owners of vehicle 200 to communicate using audio, and allows the transfer of the forward looking video from the leading vehicles to the HUD of vehicles further back.
[0133] FIG. 38 is a schematic of an electrical circuit, according to an implementation.
[0134] FIG. 39 is a schematic of a decoupling capacitor 3900 , according to an implementation. The decoupling capacitor 3900 provides instantaneous current to nearby circuitry. The instantaneous current prevents the inductance of the circuit board and wiring from creating noise in the circuitry. Every integrated circuit component on the board has one or more of these nearby its supply voltage pin.
[0135] FIG. 40 is a schematic of a decoupling capacitor 4000 , according to an implementation. The decoupling capacitor 4000 provides instantaneous current to nearby circuitry. The instantaneous current prevents the inductance of the circuit board and wiring from creating noise in the circuitry. Every integrated circuit component on the board has one or more of these nearby its supply voltage pin.
[0136] FIG. 41 is a schematic of a decoupling capacitor 4100 , according to an implementation. The decoupling capacitor 4100 provides instantaneous current to nearby circuitry. The instantaneous current prevents the inductance of the circuit board and wiring from creating noise in the circuitry. Every integrated circuit component on the board has one or more of these nearby its supply voltage pin.
[0137] FIG. 42 is a schematic of an input circuit 4200 for motor current monitoring, according to an implementation. The input circuit 4200 includes two current sense resistors, 4202 and 4204 for AUX1 motor 4206 and AUX2 motor 4208 . The input circuit of the single voltage system 3600 also includes two low pass filters, 4210 and 4212 , on each circuit.
[0138] FIG. 43 is a schematic of switches 4300 on the motor drive board, according to an implementation. The switches 4300 include an optocoupler 3702 which receives PWM signals from a control computer. The PWM signals control the single ended motor loads 4304 and 4306 . The switches 4300 also includes MOSFET switches 4308 and 4310 . With one terminal of a brushed motor connected to 12V through the circuit of FIG. 42 and the other terminal connected to the drain 4312 of Q 1 or Q 2 , driving a positive voltage into the gate 4314 of the MOSFET switches 4308 and 4310 closes the switch and current flows through the motor.
[0139] FIG. 44 is a schematic of current monitors 4400 for the switches on the motor drive board, according to an implementation. The filtered current sense voltage is applied to the VIN+ and VIN− inputs of U 9 , where it is amplified by a gain of 20. The CMPOUT signal (pin 6 ) is a warning signal that indicates that the motor current has exceeded a threshold set by the ratio of resistors R 18 and R 19 . An identical circuit exists for the AUX2 motor.
[0140] FIG. 45 is a schematic of 3 phase motor controller 4500 , according to an implementation. FIG. 45 —U 11 and U 12 are optocouplers. They receive the PWM signals for motor phases A, B and C from the control computer. The purpose of an optocoupler is to transmit a signal across an electrical boundary using a light emitting diode and photo sensitive receiver. This keeps switching noise from the motor windings from interfering with the voltages on the control computer. U 11 receives the PWM signals for phase A and phase B, U 12 receives the PWM signal for phase C, and the motor disable signal. U 13 is the PWM generator. It takes the three PWM signals and the disable signal from U 11 and U 12 and converts them into drive voltages for the three phase H-Bridge (Q 3 thru Q 8 ). An H-bridge is a common way of applying voltage to loads such as motors. Each of the three phases of the motor (A, B, C) is connected to one pair of MOSFET transistor switches. Phase A is connected to Q 3 ,Q 4 ; Phase B is connected to Q 5 ,Q 6 ; Phase C is connected to Q 7 , Q 8 . Turning on one (and only one) transistor in each pair allows each motor phase to be connected to either 12V or 0V. The different motor phases are exciting in the proper sequence to make the motor turn. This is a standard technique for driving brushless DC motors. The three low side transistors, Q 4 , Q 6 , and Q 8 , are each turned on by applying a voltage (˜10V) to the gate pin (pin 1 ). This voltage comes from U 13 , following the PWM inputs from the control computer. The diodes D 2 -D 4 and the capacitors C 21 -C 23 , form a bootstrapping circuit for U 13 . The purpose of this circuit is to create a gate voltage for the three high side transistors, Q 3 , Q 5 , and Q 7 . Since these transistors are on the high side of the motor winding, the output of each (the source, pin 3 ) is at 12V when the switch is on. In order to drive the gate 10V higher than the source and gate voltage of ˜22 volts is required. The bootstrap circuit creates this voltage in the following way: When Q 4 is closed, the pin AHS is pulled to 0V. This charges the capacitor C 23 through the diode D 2 to ˜10V. When Q 4 is opened and Q 3 is closed, the pin AHS is pulled to 12V and the voltage at pin AHB is now 10V+12V=22V. This voltage is made available in U 13 to drive the gates of the high side transistors. Phases B and C work likewise. The diodes D 9 thru D 14 are Schottky type high speed diodes. Their purpose is to supply a path to ground for the large negative voltages that occur when a (highly inductive) motor phase is switched off. They protect the low side transistors. The resistor R 31 is the current sense resistor for Phase A. With a value of 0.001 ohm, it generates a voltage of 0.001 times the current through Phase A, or 0.1V for 100 amps. The resistors R 34 , R 35 and the capacitor C 24 form a low pass filter to remove some of the high frequency switching noise from the current sense voltage. Phases B and C have identical circuits.
[0141] FIG. 46 is a schematic of motor current monitors 4600 , according to an implementation. Continuing with Phase A, the filtered voltage across R 31 in FIG. 46 is applied between the VIN+ and VIN− inputs of U 6 . U 6 is a current sense amplifier and multiplies the current sense voltage by a factor of 20, so a 100 amp motor current (0.1V current sense voltage) will result in a 2V output. This output signal (CURRENT_A) is sent to the control computer board to be used in the control computer. Pin 6 is a comparator output that sends an over current warning signal in the event that the motor current is too high. The threshold for this warning current is set by the ratio of the resistors R 11 and R 16 . Phase B and C have identical circuits.
Hardware and Operating Environment
[0142] The description of FIG. 47 provides an overview of electrical hardware and suitable computing environments in conjunction with which some implementations can be implemented. Implementations are described in terms of a computer executing computer-executable instructions. However, some implementations can be implemented entirely in computer hardware in which the computer-executable instructions are implemented in read-only memory. Some implementations can also be implemented in client/server computing environments where remote devices that perform tasks are linked through a communications network. Program modules can be located in both local and remote memory storage devices in a distributed computing environment.
[0143] FIG. 47 is a block diagram of a control computer 4700 in which different implementations can be practiced. The control computer 4700 includes a processor (such as a Pentium III processor from Intel Corp. in this example) which includes dynamic and static ram and non-volatile program read-only-memory (not shown), operating memory 4704 (SDRAM in this example), communication ports 4706 (e.g., RS-232 port 4708 COM1/2 or Ethernet port 4710 ), and a data acquisition circuit 4712 with analog inputs 4714 and outputs and digital inputs and outputs 4716 .
[0144] In some implementations of the control computer 4700 , the data acquisition circuit 4712 is also coupled to counter timer ports 4740 and watchdog timer ports 4742 . In some implementations of the control computer 4700 , an RS-232 port 4744 is coupled through a universal asynchronous receiver/transmitter (UART) 4746 to a bridge 4726 .
[0145] In some implementations of the control computer 4700 , the Ethernet port 4710 is coupled to the bus 4728 through an Ethernet controller 4750 .
[0146] With proper digital amplifiers and analog signal conditioners, the control computer 4700 can be programmed to drive coolant control gate valves, either in a predetermined sequence, or interactively modify coolant flow by opening and closing (or modulating) coolant control valve positions, in response to engine or coolant temperatures. The engine temperatures (or coolant temperatures) can be monitored by thermal sensors, the output of which, after passing through appropriate signal conditioners, can be read by the analog to digital converters that are part of the data acquisition circuit 4712 . Thus the coolant or engine temperatures can be made available as information/data upon which the coolant application program can operate as part of decision-making software that acts to modulate coolant valve position in order to maintain the proper coolant and engine temperature.
CONCLUSION
[0147] A tilting two-front-one-rear vehicle is described. A technical effect of the coordinated tilting of a vehicle during turns. Although specific implementations are illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement which is calculated to achieve the same purpose may be substituted for the specific implementations shown. This disclosure is intended to cover any adaptations or variations. For example, although described in tricycle terms, one of ordinary skill in the art will appreciate that implementations can be made in automobiles or any other vehicle that provides the required function.
[0148] In particular, one of skill in the art will readily appreciate that the names of the methods and apparatus are not intended to limit implementations. Furthermore, additional methods and apparatus can be added to the components, functions can be rearranged among the components, and new components to correspond to future enhancements and physical devices used in implementations can be introduced without departing from the scope of implementations. One of skill in the art will readily recognize that implementations are applicable to future sensor devices, different tricycles, and new microprocessors.
[0149] The terminology used in this disclosure meant to include all transportation and vehicle environments and alternate technologies which provide the same functionality as described herein. | Systems, methods and apparatus are provided through which in some implementations a motorized tricycle includes a lean mechanism and an active system that is operably coupled to the lean mechanism that receives an signal indicative of an interaction with human, that is operable to detect a lean of the body of the human and that is operable to receive a sensed movement on the seat via multisensory devices, and to generate and send a signal to the lean mechanism from the signal, the lean and the sensed movement. | 60,169 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to Provisional Serial No. 60/046,006, filed May 9, 1997, under 35 U.S.C. Section 119(e).
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
This invention was supported in part by the National Science Foundation under Grant No. ECD-8907068. The United States Government has certain rights in this invention.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed generally to high density magnetic recording sequence detectors, and, more particularly, to correlation-sensitive sequence detectors.
2. Description of the Background
In recent years, there has been a major shift in the design of signal detectors in magnetic recording. Traditional peak detectors (PD), such as those described in Nakagawa et al., “A Study of Detection Methods of NRZ Recording”, IEEE Trans. Magn., vol. 16, pp. 1041-110, Jan. 1980, have been replaced by Viterbi-like detectors in the form of partial response maximum likelihood (PRML) schemes or hybrids between tree/trellis detectors and decision feedback equalizers (DFE), such as FDTS/DF, MDFE and RAM-RSE. These methods were derived under the assumption that additive white Gausian noise (AWGN) is present in the system. The resulting trellis/tree branch metrics are then computed as Euclidian distances.
It has long been observed that the noise in magnetic recording systems is neither white nor stationary. The nonstationarity of the media noise results from its signal dependent nature. Combating media noise and its signal dependence has thus far been confined to modifying the Euclidian branch metric to account for these effects. Zeng, et al., “Modified Viterbi Algorithm for Jitter-Dominated 1-D 2 Channel,” IEEE Trans. Magn., Vol. MAG-28, pp. 2895-97, Sept. 1992, and Lee et al., “Performance Analysis of the Modified maximum Likelihood Sequence Detector in the Presence of Data-Dependent Noise,” Proceedings 26th Asilomar Conference, pp. 961-64, Oct. 1992 have derived a branch metric computation method for combating the signal-dependent character of media noise. These references ignore the correlation between noise samples. The effectiveness of this method has been demonstrated on real data in Zayad et al., “Comparison of Equalization and Detection for Very High-Density Magnetic Recording,” IEEE INTERMAG Conference, New Orleans, April 1997.
These methods do not take into consideration the correlation between noise samples in the readback signal. These correlations arise due to noise coloring by front-end equalizers, media noise, media nonlinearities, and magnetoresistive (MR) head nonlinearities. This noise coloring causes significant performance degradation at high recording densities. Thus, there is a need for an adaptive correlation-sensitive maximum likelihood sequence detector which derives the maximum likelihood sequence detector (MLSD) without making the usual simplifying assumption that the noise samples are independent random variables.
SUMMARY OF THE INVENTION
In high density magnetic recording, noise samples corresponding to adjacent signal samples are heavily correlated as a result of front-end equalizers, media noise, and signal nonlinearities combined with nonlinear filters to cancel them. This correlation deteriorates significantly the performance of detectors at high densities.
The trellis/tree branch metric computation of the present invention is correlation-sensitive, being both signal-dependent and sensitive to correlations between noise samples. This method is termed the correlation-sensitive maximum likelihood sequence detector (CS-MLSD), or simply correlation-sensitive sequence detector (CS-SD).
Because the noise statistics are non-stationary, the noise sensitive branch metrics are adaptively computed by estimating the noise covariance matrices from the read-back data. These covariance matrices are different for each branch of the tree/trellis due to the signal dependent structure of the media noise. Because the channel characteristics in magnetic recording vary from track to track, these matrices are tracked on-the-fly, recursively using past samples and previously made detector decisions.
The present invention represents a substantial advance over prior sequence detectors. Because the present invention takes into account the correlation between noise samples in the readback signal, the detected data sequence is detected with a higher degree of accuracy. Those advantages and benefits of the present invention, and others, will become apparent from the Detailed Description of the Invention hereinbelow.
BRIEF DESCRIPTION OF THE DRAWINGS
For the present invention to be clearly understood and readily practiced, the present invention will be described in conjunction with the following figures wherein:
FIG. 1 is an illustration of a magnetic recording system;
FIG. 2 is an illustration of a CS-MLSD detector circuit of a preferred embodiment of the present invention;
FIG. 3 is an illustration of a sample signal waveform, its samples, and written symbols;
FIG. 3A is an illustration of a branch metric computation module;
FIG. 3B is an illustration of an implementation of a portion of the branch metric computation module of FIG. 3A;
FIG. 4 is an illustration of one cell of a PR4 trellis;
FIG. 5 is an illustration of a detected path in a PR4 trellis;
FIG. 6 is a block diagram of a preferred embodiment of a method for signal detection;
FIG. 7 is an illustration of PR4 detection results at a 4.4 a/symbol;
FIG. 8 is an illustration of EPR4 detection results at a 4.4 a/symbol;
FIG. 9 is an illustration of PR4 detection results at a 3.5 a/symbol;
FIG. 10 is an illustration of EPR4 detection results at a 3.5 a/symbol;
FIG. 11 is an illustration of S(AWG)NR margins needed for error rate of 10 −5 with EPR4 detectors;
FIG. 12 is an illustration of PR4 detection results at a 2.9 a/symbol; and
FIG. 13 is an illustration of EPR 4 detection results at a 2.9 a/symbol.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a magnetic recording system 10 . A data source 12 supplies data to a write signal processing circuit 14 . The signal processing circuit 14 converts the input data into signals with a format suitable for storage on a magnetic medium 16 . The medium 16 is typically a rotating disk, a “floppy” disk, or a tape with magnetic coatings. A write head 18 stores the signals on the medium 16 as a series of variations in the magnetic flux of the medium 16 . The write head 18 is controlled by a write control circuit 20 , which supplies signals to the write head 18 to control its position with respect to the medium 16 .
A read head 22 retrieves the variations in the magnetic flux that are stored on the medium 16 . A read control circuit 24 supplies signals to the read head 22 to control its position with respect to the medium 16 . The read head 22 provides a stream of data to a detector circuit 26 . The detector circuit 26 detects the data from the data stream and outputs the data. The detector 26 must be able to detect the data in the presence of intersymbol interference (“ISI”) noise. Prior art detector circuits have employed the maximum likelihood sequence (“MLS”) estimation algorithm or peak detection techniques. The MLS algorithm analyzes a sequence of consecutive data and determines the output data based on the sequence. Peak detection techniques identify analog peaks in a sequence of data and determine the output data based on the peaks.
A block diagram of a CS-MLSD detector circuit 28 is shown in FIG. 2 . The CS-MLSD detector circuit 28 is a part of the detector circuit 26 of FIG. 1 . The detector circuit 28 has a feedback circuit 32 which feeds back into a Viterbi-like detector 30 . The outputs of the detector 30 are decisions and delayed signal samples, which are used by the feedback circuit 32 . A noise statistics tracker circuit 34 uses the delayed samples and detector decisions to update the noise statistics, i.e., to update the noise covariance matrices. A metric computation update circuit 36 uses the updated statistics to calculate the branch metrics needed in the Viterbi-like algorithm. The algorithm does not require replacing current detectors. It simply adds two new blocks in the feedback loop to adaptively estimate the branch metrics used in the Viterbi-like detector 30 .
The Viterbi-like detector 30 typically has a delay associated with it. Until the detector circuit 28 is initialized, signals of known values may be input and delayed signals are not output until the detector circuit 28 is initialized. In other types of detectors, the detector may be initialized by having the necessary values set.
The correlation-sensitive maximum likelihood sequence detector (CS-MLSD) 28 is described hereinbelow. Assume that N>1 channel bits (symbols), a 1 , a 2 , . . . , a N , are written on a magnetic medium. The symbols a i , i=1, . . . , N, are drawn from an alphabet of four symbols, a i , ε {+, ⊕, −, ⊖}. The symbols ‘+’ and ‘−’ denote a positive and a negative transition, respectively. The symbol ‘⊕’ denotes a written zero (no transition) whose nearest preceding non-zero symbol is a ‘+’ while ‘⊖’ denotes a written zero whose nearest preceding transition is a negative one, i.e., ‘−’. This notation is used because a simple treatment of transitions as ‘1’s and no transitions as ‘0’s is blind to signal asymmetries (MR head asymmetries and base line drifts), which is inappropriate for the present problem. In FIG. 3 a sample waveform is illustrated. The signal asymmetries and base line shifts are exaggerated in FIG. 3 . FIG. 3 also shows the written symbols a 1 , . . . , a 18 , as well as the samples r 1 , . . . , r 18 of the read-back waveform, sampled at the rate of one sample per symbol interval.
When the written sequence of symbols a i , i=1, . . . , N, is read, the readback waveform is passed through a pulse-shaping equalizer and sampled one sample per symbol, resulting in the sequence of samples r i , i=1, . . . , N. Due to the noise in the system, the samples r i are realizations of random variables. The maximum likelihood detector determines the sequence of symbols a i that has been written, by maximizing the likelihood function, i.e.: { a ^ 1 , … , a ^ N } = arg [ max all a i f ( r 1 , … , r N a 1 , … , a N ) ] . ( 1 )
In (1), the likelihood function f (r 1 , . . . , r N |a 1 , . . . , a N ) is the joint probability density function (pdf) of the signal samples r 1 , . . . , r N , conditioned on the written symbols a, . . . , a N . The maximization in (1) is done over all possible combinations of symbols in the sequence {a 1 , . . . , a N }.
Due to the signal dependent nature of media noise in magnetic recording, the functional form of joint conditional pdf f (r 1 , . . . , r N |a 1 ,. . . , a N ) in (1) is different for different symbol sequences a 1 , . . . , a N . Rather than making this distinction with more complex but cluttered notation, the notation is kept to a minimum by using simply the same symbol f to denote these different functions.
By Bayes rule, the joint conditional pdf (likelihood function) is factored into a product of conditional pdfs: f ( r 1 , … , r N a i , … , a N ) = ∏ i = 1 N f ( r i r i + 1 , … , r N , a 1 , … , a N ) . ( 2 )
To proceed and obtain more concrete results, the nature of the noise and of the intersymbol interference in magnetic recording is exploited.
Finite correlation length. The conditional pdfs in Equation (2) are assumed to be independent of future samples after some length L≧0. L is the correlation length of the noise. This independence leads to:
f ( r i |r i+1 , . . . , r N , a 1 , . . . , a N )= f ( r i |r i+1 , . . . , r i+L , a 1 , . . . , a N ). (3)
Finite intersymbol interference. The conditional pdf is assumed to be independent of symbols that are not in the K-neighborhood of r i , . . . , r i+L . The value of K≧1 is determined by the length of the intersymbol interference (ISI). For example, for PR4, K=2, while for EPR4, K=3. K 1 ≧0 is defined as the length of the leading (anticausal) ISI and K t ≧0 is defined as the length of the trailing (causal) ISI, such that K=K l +K t +1. With this notation the conditional pdf in (3) can be written as:
f ( r i |r i+1 , . . . , r i+L , a 1 , . . . , a N )= f ( r i |r i+1 , . . . r i+L a i−K t ). (4)
Substituting (4) into (2) and applying Bayes rule, the factored form of the likelihood function (conditional pdf) is obtained: ( 5 ) f ( r 1 , … , r N | a i , … , a N ) = ∏ i = 1 N f ( r i r i + 1 , … , r N , a 1 , … , a N ) = ∏ i = 1 N f ( r i , r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) f ( r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) .
The factored form of equation (5) is suitable for applying Viterbi-like dynamic programming detection techniques. Equation (5) assumes anticausal factorization, i.e., it is derived by taking into account the effect of the samples r i+1 , . . . , r i+L , on r i . If only the causal effects are taken into account, the causal equivalent of (5) can be derived as f (r 1 , . . . r N ,|a 1 , . . . , a N )= ∏ i = 1 N f ( r i , r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) f ( r i + 1 , … , r i + L - 1 a i - K l , … , a i + L + K t )
The causal and anticausal factorization could be combined to find the geometric mean of the two to form a causal-anticausal factorization. Since this only complicates derivations and does not provide further insight, only the anticausal Equation (5) is considered.
Maximizing the likelihood function in (5) is equivalent to minimizing its negative logarithm. Thus, the maximum likelihood detector is now: ( 6 ) { a ^ 1 , … , a ^ N } = arg [ min all a i log ∏ i = 1 N f ( r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) f ( r i , r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) ] = arg [ min all a i ∑ i = 1 N log f ( r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) f ( r i , r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) ] = arg [ min all a i ∑ i = 1 N M i ( r i , r i + 1 , … , r i + L , a i - K l , … , a i + L + K t ) ]
M i represents the branch metric of the trellis/tree in the Viterbi-like algorithm. The metric is a function of the observed samples r i , r i+1 , . . . , r i+L . It is also dependent on the postulated sequence of written symbols a i −K 1 ,. . . , a i +L+K t , which ensures the signal-dependence of the detector. As a consequence, the branch metrics for every branch in the tree/trellis is based on its corresponding signal/noise statistics.
Specific expressions for the branch metrics that result under different assumptions on the noise statistics are next considered.
Euclidian branch metric. In the simplest case, the noise samples are realizations of independent identically distributed Gaussian random variables with zero mean and variance σ 2 . This is a white Gaussian noise assumption. This implies that the correlation distance is L=0 and that the noise pdf s have the same form for all noise samples. The total ISI length is assumed to be K=K l +K t +1, where K l and K t are the leading and trailing ISI lengths, respectively. The conditional signal pdfs are factored as f ( r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) f ( r i , r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) = 2 πσ 2 exp [ ( r i - m i ) 2 2 σ 2 ] ( 7 )
Here the mean signal m i is dependent on the written sequence of symbols. For example, for a PR4 channel, m i ε{−1,0,1}. The branch/tree metric is then the conventional Euclidian distance metric:
M i =N i 2 =(r i −m i ) 2 (8)
Variance dependent branch metric. It is again assumed that the noise samples are samples of independent Gaussian variables, but that their variance depends on the written sequence of symbols. The noise correlation length is still L=0, but the variance of the noise samples is no longer constant for all samples. The variance is σ 2i , where the index i denotes the dependence on the written symbol sequence. As for the Euclidian metric, it is assumed that the total ISI length is K=K l +K t +1. The conditional signal pdf is factored to give: f ( r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) f ( r i , r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) = 2 πσ i 2 exp [ ( r i - m i ) 2 2 σ i 2 ] ( 9 )
The corresponding branch metric is: M i = log σ i 2 + N i 2 σ i 2 = log σ i 2 + ( r i - m i ) 2 σ i 2 ( 10 )
Correlation-sensitive branch metric. In the most general case, the correlation length is L>0. The leading and trailing ISI lengths are K l and K t , respectively. The noise is now considered to be both correlated and signal-dependent. Joint Gaussian noise pdfs are assumed. This assumption is well justified in magnetic recording because the experimental evidence shows that the dominant media noise modes have Gaussian-like histograms. The conditional pdfs do not factor out in this general case, so the general form for the pdf is: f ( r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) f ( r i , r i + 1 , … , r i + L a i - K l , … , a i + L + K t ) = ( 2 π ) L + 1 det C i ( 2 π ) L det c i exp [ N _ i T C i - 1 N _ i ] exp [ n _ i T c i - 1 n _ i ] ( 11 )
The (L+1)×(L+1) matrix C i is the covariance matrix of the data samples r i , r i+1 , . . . , r i+L , when a sequence of symbols a i−Kl , . . . a i+L+Kt is written. The matrix c i in the denominator of (11) is the L×L lower principal submatrix of C i =[c i ]. The (L+1)-dimensional vector N i is the vector of differences between the observed samples and their expected values when the sequence of symbols a i−Kl , . . . , a i+L+Kt is written, i.e.:
N i =[( r i −m i )( r i+1 −m i+1 ) . . . ( r i+L −m i+L )] T (12)
The vector n i collects the last L elements of N i , n i =[(r i+1 −m i+1 ) . . . (r i+L −m i+L )] T .
With this notation, the general correlation-sensitive metric is: M i = log det C i det c i + N _ i T C i - 1 N _ i - n _ i T c i - 1 n _ i ( 13 )
In the derivations of the branch metrics (8), (10) and (13), no assumptions were made on the exact Viterbi-type architecture, that is, the metrics can be applied to any Viterbi-type algorithm such as PRML, FDTS/DF, RAM-RSE, or, MDFE.
FIG. 3A illustrates a block diagram of a branch metric computation circuit 48 that computes the metric M i for a branch of a trellis, as in Equation (13). Each branch of the trellis requires a circuit 48 to compute the metric M i .
A logarithmic circuit 50 computes the first term of the right hand side of (13) ( i . e . log det C i det c i )
and a quadratic circuit 52 computes the second terms of the right hand side of (13) (i.e. N i T C i −1 N i − n i T c i −1 n i ). The arrows through the circuits 50 and 52 represent the adaptive nature of the Virterbi-like detector 30 . A sum circuit 53 computes the sum of the outputs of the circuits 50 and 52 .
As stated above, the covariance matrix is given as: C i = [ α i c _ i c _ i T c i ] . ( 14 )
Using standard techniques of signal processing, it can be shown that: det C i det c i = α i - c _ i T c i - 1 c _ i . ( 15 )
This ratio of determinants is referred to as σ i 2 , i.e.: σ i 2 = det C i det c i = α i - c _ i T c i - 1 c _ i . ( 16 )
It can be shown by using standard techniques of signal processing that the sum of the last two terms of (13), i.e. the output of the circuit 52 , is: Y i = N _ i T C i - 1 N _ i - n _ i T c i - 1 n _ i ( 17 ) = ( w _ i T N _ i ) 2 σ i 2 , ( 18 )
Where the vector w i is (L+1)-dimensional and is given by: w _ i T = [ 1 w i ( 2 ) w i ( 3 ) … ( w i ( L + 1 ) ] ) T ( 19 ) = [ 1 - c i - 1 c _ i ] . ( 20 )
Equations (17), (18) and (16) (the circuit 52 ) can be implemented as a tapped-delay line as illustrated in FIG. 3 B. The circuit 52 has L delay circuits 54 . The tapped-delay line implementation shown in FIGS. 3A and 3B is also referred to as a moving-average, feed-forward, or finite-impulse response filter. The circuit 48 can be implemented using any type of filter as appropriate.
The adaptation of the vector of weights w i and the quantity σ i 2 as new decisions are made is essentially an implementation of the recursive least squares algorithm. Alternatively, the adaptation may be made using the least mean squares algorithm.
The quantities m i that are subtracted from the output of the delay circuits 54 are the target response values, or mean signal values of (12). The arrows across multipliers 56 and across square devices 58 indicate the adaptive nature, i.e., the data dependent nature, of the circuit 52 . The weights w i and the value σ i 2 can be adapted using three methods. First, w i and σ i 2 can be obtained directly from Equations (20) and (16), respectively, once an estimate of the signal-dependent covariance matrix C i is available. Second, w i and σ i 2 can be calculated by performing a Cholesky factorization on the inverse of the covariance matrix C i . For example, in the L i D i −1 L i T Cholesky factorization, w i is the first column of the Cholesky factor L i and σ i 2 is the first element of the diagonal matrix D i . Third, w i and σ i 2 can be computed directly from the data using a recursive least squares-type algorithm. In the first two methods, an estimate of the covariance matrix is obtained by a recursive least squares algorithm.
Computing the branch metrics in (10) or (13) requires knowledge of the signal statistics. These statistics are the mean signal values m i in (12) as well as the covariance matrices C i in (13). In magnetic recording systems, these statistics will generally vary from track to track. For example, the statistics that apply to a track at a certain radius will differ from those for another track at a different radius due to different linear track velocities at those radii. Also, the signal and noise statistics will be different if a head is flying slightly off-track or if it is flying directly over the track. The head skew angle is another factor that contributes to different statistics from track to track. These factors suggest that the system that implements the metric in (13) needs to be flexible to these changes. Storing the statistics for each track separately is very difficult because of the memory span required to accomplish this. A reasonable alternative is to use adaptive filtering techniques to track the needed statistics.
Tracking the mean signal values m i is generally done so that these values fall on prespecified targets. An adaptive front-end equalizer is employed to force the signal sample values to their targets. This is certainly the case with partial response targets used in algorithms like PR4, EPR4, or EEPR4 where the target is prespecified to one of the class-4 partial responses. For example, in a PR4 system, the signal samples, if there is no noise in the system, fall on one of the three target values 1, 0, or −1. Typically this is done with an LMS-class (least mean-squares) algorithm that ensures that the mean of the signal samples is close to these target values. In decision feedback equalization (DFE) based detectors or hybrids between fixed delay tree search and DFE, such as FDTS/DF or MDFE, the target response need not be prespecified. Instead, the target values are chosen on-the-fly by simultaneously updating the coefficients of the front-end and feed-back equalizers with an LMS-type algorithm.
When there are severe nonlinearities in the system (also referred to as nonlinear distortion or nonlinear ISI), a linear equalizer will generally not be able to place the signal samples right on target. Instead, the means of the signal samples will fall at a different value. For example, in a PR4 system, the response to a sequence of written symbols . . . , −,+, ⊕, . . . might result in mean sample target values . . . , 0, 1, 0.9, . . . , while a sequence of written symbols . . . , +, −, ⊖, . . . might result in a sequence of mean sample values . . . , 0.95, −1.05, 0, . . . Clearly, in this example, what should be a target value of 1 becomes either 1, 0.9, or 0.95 depending on the written sequence. Because mean values and not noisy samples are being considered, this deviation is due to nonlinearities in the system. There are two fixes for this problem. The first is to employ a nonlinear filter (neural network or Volterra series filter) that is capable of overcoming these nonlinear distortions. Although recently very popular, such a method introduces further correlation between noise samples due to the nonlinear character of the filter. The second fix is to track the nonlinearities in a feedback loop and use the tracked value in the metric computation. For example, let the response to a written symbol sequence . . . , ⊖, +, ⊕, . . . be consistently . . . , 0, 1, 0.9, . . . Then, rather than using the value 1 in the metric computation for the third target, this behavior can be tracked and the value m i =0.9 can be used.
In the remainder of this discussion, for simplicity, it is assumed that the front-end equalizer is placing the signal samples right on the desired target values and that there is no need for further mean corrections. The focus is shifted to tracking the noise covariance matrices needed in the computation of the branch metrics (13).
Assume that the sequence of samples r i , r i+l . . . , r i+L is observed. Based on these and all other neighboring samples, after an appropriate delay of the Viterbi trellis, a decision is made that the most likely estimate for the sequence of symbols a i−K l , . . . , a i+L+K t is â i−K l , . . . , â i+L+K t . Here L is the noise correlation length and K=K l +K t +1 is the ISI length. Let the current estimate for the (L+1)×(L+1) covariance matrix corresponding to the sequence of symbols â i−K t , . . . , â i+L+K t be Ĉ(â i−K t , . . . , â i+L+K t ).
This symbol is abbreviated with the shorter notation, Ĉ(â). If the estimate is unbiased, the expected value of the estimate is:
EĈ ( â )= E[ N i N i T ] (21)
where N i is the vector of differences between the observed samples and their expected values, as defined in (12).
Note that once the samples r i , r i+1 , . . . , r i+L are observed, and once it is decided that most likely they resulted from a series of written symbols â i−K l , . . . , â i+L+K t , the sequence of target (mean) values m i , m i+1 , . . . , m i+L is known that correspond to these samples. They are used to compute the vector N i , with which the empirical rank-one covariance matrix N i , N T i is formed. In the absence of prior information, this rank-one matrix is an estimate for the covariance matrix for the detected symbols. In a recursive adaptive scheme, this rank-one data covariance estimate is used to update the current estimate of the covariance matrix Ĉ(â). A simple way to achieve this is provided by the recursive least-squares (RLS) algorithm. The RLS computes the next covariance matrix estimate Ĉ′(â) as:
Ĉ ′( â )=β( t ) Ĉ ( â )+[1−β( t )] N i N i T (22)
Here, β(t), 0<β(t)<1, is a forgetting factor. The dependence on t signifies that β is a function of time. Equation (22) can be viewed as a weighted averaging algorithm, where the data sample covariance N i N i T is weighted by the factor [1−β(t)], while the previous estimate is weighted by β(t). The choice of β(t) should reflect the nonstationarity degree of the noise. For example, if the nonstationarity is small, β(t) should be close to 1, while it should drop as the nonstationarity level increases. The forgetting factor is typically taken time-dependent to account for the start-up conditions of the RLS algorithm in (22). As more data is processed, a steady-state is expected to be achieved and β(t) is made to approach a constant value. Initially, β(t) is close to zero, to reflect the lack of a good prior estimate Ĉ(â), and to rely more on the data estimate. With time, β(t) is increased and settles around a value close to 1.
The impact of the initial conditions in (22) decays exponentially fast. Hence, the algorithm (22) can be started with an arbitrary initial guess for the covariance matrix Ĉ(â), with the only constraint being that the matrix be positive semidefinite, e.g, a zero matrix or an identity matrix.
The one-dimensional equivalent of equation (22) is
{circumflex over (σ)} new 2 =β{circumflex over (σ)} old 2 +[1 −β]N i 2 . (23)
This equation can be used in conjunction with the metric in (10).
It is important to point out that, due to the signal-dependent character of the media noise, there will be a different covariance matrix to track for each branch in the tree-trellis of the Viterebi-like detector. Practical considerations of memory requirements, however, limit the dimensions of the matrices to be tracked. Fortunately, simple 2×2 matrices are enough to show substantial improvement in error rate performance.
The following example illustrates how the algorithm in (22) works. Assume a PR4 target response with a simple trellis structure as shown in FIG. 4 Notice that for PR4, the symbols can be equated to the trellis states, as is illustrated in FIG. 4 The number next to each branch in FIG. 4 represents the target value (mean sample value) for the corresponding path between states. The target values in PR4 can be one of three values −1, 0, or 1.
In this example a noise correlation length of L=1 is assumed. It is also assumed that the leading and trailing ISI lengths are K l =0 and K t =1, respectively, to give the total ISI length K=K l +K t +1=2 for the PR4 response. Because L=1, signal covariance matrices of size (L+1)×(L+1)=2×2 need to be tracked. The number of these matrices equals the number of different combinations of two consecutive branches in the trellis. A simple count in FIG. 4 reveals that this number is 16, because there are 4 nodes in the trellis and 2 branches entering and leaving each node.
Assume that, using the branch metric in (13), the Viterbi-like detector decides that the most likely written symbols a i , a i+1 , a i+2 , equal {â i , â i+1 , â i+2 }={⊖, +, −}. This is illustrated in FIG. 5, where the corresponding path through the trellis is highlighted. The noisy signal samples corresponding to the trellis branches are r i =0.9 and r i+1 =−0.2, which deviate slightly from their ideal partial response target values of 1 and 0, respectively.
Suppose that, prior to making the decision {â i , â i+1 , â i+2 }={⊖, +, −}, the estimate for the covariance matrix associated with this sequence of three symbols is C ^ ( ⊖ , + , - ) = [ 0.5 - 0.2 - 0.2 0.8 ] ( 24 )
Let the forgetting factor be B=0.95. To update the covariance matrix the vector is first formed:
N =[( r i −1)( r i+1 −0)] T =[−0.1−0.2] T (25)
The rank-one sample covariance matrix N N T is used to find the covariance matrix update: C ^ ′ ( ⊖ , + , - ) = β C ^ ( ⊖ , + , - ) + ( 1 - β ) N _ N _ T = [ 0.4755 - 0.189 - 0.189 0.7620 ] ( 26 )
The matrix Ĉ′(⊖, +, −) becomes our estimate for the covariance matrix corresponding to this particular symbol sequence (trellis path) and is used to compute the metrics (13) in the subsequent steps of the Viterbi-like algorithm.
FIG. 6 illustrates a flowchart of a method of detecting a sequence of adjacent signal samples stored on a high density magnetic recording device. Viterbi sequence detection is performed using a signal sample at step 38 . The sequence detection produces decisions which are output at step 40 . The signal sample is delayed at step 42 . The past samples and detector decisions are used to update the noise statistics at step 44 . Branch metrics, which are used in the sequence detection step 38 , are calculated at step 46 .
It can be understood by those skilled in the art that the method of FIG. 6 can be performed on a computer. The steps may be coded on the computer as a series of instructions, which, when executed, cause the computer to detect a sequence of adjacent signal samples stored on a high density magnetic recording device. The computer may be, for example, a personal computer, a workstation, or a mainframe computer. The computer may also have a storage device, such as a disk array, for storage of the series of instructions.
Simulation results using two partial response detection algorithms, namely PR4 and EPR4 are now presented. To create realistic waveforms, corrupted by media noise, an efficient stochastic zig-zag model, the TZ-ZT model was used. These waveforms are then passed through the detectors. A Lindholm inductive head is used for both writing and reading. Table 1 presents the recording parameters of the model. These recording parameters are chosen so that with a moderately low symbol density per PW50, a low number of transition widths a per symbol transition separation results. Namely, at 3 symbols/PW50 a transition separation of only 2.9a is present. The transition profile was modeled by an error function, where the transition width a denotes the distance from the transition center to the point where the magnetization equals M r /2.
TABLE 1
Recording parameters used in simulations.
Parameter
Symbol
Value
media remanence
M r
450kA/m
media coercivity
H c
160kA/m
media thickness
δ
0.02 μm
media cross-track correlation width
s
200Å
head-media separation
d
15 nm
head field gradient factor
Q
0.8
had gap length
g
0.135 μm
track width
TW
2 μm
transition width parameter
α
0.019 μm
percolation length
L = 1.4α
0.0266 μm
50% pulse width
PW50
0.167 μm
Table 1: Recording Parameters Used in Simulations
The symbols utilizing the (0,4) run length limited code are written. No error correction is applied, so the obtained error rates are not bit error rates, but (raw) symbol error rates.
Both the PR4 and EPR4 detectors were tested using the following three different metric computation methods: the Euclidian metric (8), the variance dependent metric (10), also referred to as the C1 metric, and the 2×2 correlation sensitive metric (13), named the C2 metric for short. For a PR4 target response, the total ISI length is K=K l +K t +1=2, where the leading and trailing ISI lengths are K l =0 and K t =1, respectively. The noise correlation length for the Euclidian and the C1 metrics is L=0, and for the C2 metric the noise correlation length is L=1. These three PR4 detectors are referred to as PR4(Euc), PR4(C1), and PR4(C2).
Similarly to the PR4 detectors, three EPR4 detectors were tested, EPR4(Euc), EPR4(C1) and EPR4(C2). The only difference between the PR4 detectors and the EPR4 detectors are the target response and the ISI length, which for the EPR4 target response equals K=K l +K t +1=3, with K l =1 and K t =1.
The signal obtained by the TZ-ZT model is already corrupted with media noise. To this signal white Gaussian noise was added to simulate the head and electronics noise in a real system. The power of the additive white Gaussian noise is quoted as the signal to additive white Gaussian noise ratio, S(AWG)NR, which is obtained as: S ( AWG ) NR = 10 log A iso 2 σ n 2 ( 27 )
where A iso is the mean (media noise free) amplitude of an isolated pulse and σ 2 n is the variance of the additive white Gaussian noise. The noise distorted signal is first passed through a low-pass filter to clean out the noise outside the Nyquist band- The signal is then sampled at a rate of one sample per symbol and subsequently passed through a partial response shaping filter, either PR4 or EPR4. The partial response shaping filter is implemented as an adaptive FIR filter whose tap weights are adjusted using the LMS algorithm. Note that both filters add correlation to the noise. For the C1 and C2 metrics in (10) and (13), the RLS algorithms (22) and (23) are used to estimate the noise variances and covariance matrices for the branch metric computations. In both cases, the forgetting factor is set to β=0.95.
All six detection algorithms were tested at three different recording densities.
Symbol separation of 4.4a. This recording density corresponds to a symbol density of 2 symbols/PW50, see Table 1. FIG. 7 shows the symbol error rate performance of the PR4 detectors for different additive noise SNRs. The media noise is embedded in the system, which is why the x-axis on the graph is labeled as S(AWG)NR instead of simply SNR. At this density, the PR4(Euc) and PR4(C1) detectors perform just about the same and the PR4(C2) detector outperforms them both by about 3 dB. The reason for this is that the PR4 shaping filter averages noise samples from different symbols, which masks the signal dependent nature of the media noise. This is why there is not much to gain by using PR4(C1) instead of PR4(Euc). The PR4(C2) detector performs better because it partially removes the effects of noise correlation introduced by the PR4 shaping filter. FIG. 8 shows how the EPR4 detectors perform at this same density (symbol separation 4.4a). The PR4(C2) has the best performance and PR4(Euc) has the worst. The difference in performance at the error rate of 10 −5 is only about 0.5 dB between PR4(Euc) and PR4(C2). This is because the media noise power at this density is low and the signal is well matched to the target so the EPR4 shaping filter does not introduce unnecessary noise correlation.
Symbol separation of 3.5a. This recording density corresponds to a symbol density of 2.5 symbols/PW50. FIG. 9 shows the performance of the PR4 detectors at this density. FIG. 9 is similar to FIG. 7, except that the error rates have increased. This is again due to a mismatch between the original signal and the PR4 target response, which is why the PR4 shaping filter introduces correlation in the noise. PR4(C2) still outperforms the two other algorithms, showing the value of exploiting the correlation across signal samples.
FIG. 10 shows the error rates obtained when using the EPR4 detectors. Due to a higher density, the media noise is higher than in the previous example with symbol separations of 4.4a. This is why the graph in FIG. 10 has moved to the right by 2 dB in comparison to the graph in FIG. 8 . While the required S(AWG)NR increased, the margin between the EPR4(Euc) and EPR4(C2) also increased from about 0.5 dB to about 1 dB, suggesting that the correlation-sensitive metric is more resilient to density increase. This is illustrated in FIG. 11 where the S(AWG)NR required for an error rate of 10 −5 is plotted versus the linear density for the three EPR4 detectors. From FIG. 11 it can be seen that, for example, with an S(AWG)NR of 15 dB, the EPR(Euc) detector operates at a linear density of about 2.2 symbols/PW50 and the EPR4(C2) detector operates at 2.4 symbols/PW50, thus achieving a gain of about 10% of linear density.
Symbol separation of 2.9a. This recording density corresponds to a symbol density of 3 symbols/PW50. Due to a very low number of symbols per a, this is the density where the detectors significantly lose performance due to the percolation of magnetic domains, also referred to as nonlinear amplitude loss or partial signal erasure. FIGS. 12 and 13 show the performance of the PR4 and EPR4 families of detectors at this density. The detectors with the C2 metric outperform the other two metrics. The error rates are quite high in all cases. This is because at the symbol separations of 2.9a, nonlinear effects, such as partial erasure due to percolation of domains, start to dominate. These effects can only be undone with a nonlinear pulse shaping filter, which have not been employed here.
The experimental evidence shows that the correlation sensitive sequence detector outperforms the correlation insensitive detectors. It has also been demonstrated that the performance margin between the correlation sensitive and the correlation insensitive detectors grows with the recording density. In other words, the performance of the correlation insensitive detector deteriorates faster than the performance of the correlation sensitive detector. Quantitatively, this margin depends on the amount of correlation in the noise passed through the system. Qualitatively, the higher the correlation between the noise samples, the greater will be the margin between the CS-SD and its correlation insensitive counter part.
While the present invention has been described in conjunction with preferred embodiments thereof, many modifications and variations will be apparent to those of ordinary skill in the art. For example, the present invention may be used to detect a sequence that exploits the correlation between adjacent signal samples for adaptively detecting a sequence of symbols through a communications channel. The foregoing description and the following claims are intended to cover all such modifications and variations. | The present invention is directed to a method of determining branch metric values for branches of a trellis for a Viterbi-like detector. The method includes the step of selecting a branch metric function for each of the branches at a certain time index. The method also includes the step of applying the selected function to a plurality of time variant signal samples to determine the metric values. | 50,733 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Cross reference is made to:
U.S. patent application Ser. No. 12/050,575, filed Mar. 18, 2008, entitled “OPEN CABLE APPLICATION PLATFORM SET-TOP BOX (STB) PERSONAL PROFILES AND COMMUNICATIONS APPLICATIONS,” ;
U.S. patent application Ser. No. 12/050,605, filed Mar. 18, 2008, entitled “OPEN CABLE APPLICATION PLATFORM SET-TOP BOX (STB) PERSONAL PROFILES AND COMMUNICATIONS APPLICATIONS,” ; and
U.S. patent application Ser. No. 12/050,677, filed Mar. 18, 2008, entitled “OPEN CABLE APPLICATION PLATFORM SET-TOP BOX (STB) PERSONAL PROFILES AND COMMUNICATIONS APPLICATIONS,” , all of which are incorporated herein by this reference in their entirety.
FIELD OF THE INVENTION
The invention relates generally to set-top boxes and more particularly to one or more profiles associated with a set-top box. Additional aspects of the invention relate to the interoperability of STB's, one or more profiles and one or more applications associated with the open cable application platform.
BACKGROUND OF THE INVENTION
Multiple Service Operators (MSOs), e.g., cable companies, are working to transform their value proposition from one dominated by basic subscriptions and equipment leases to a customer service driven value model. One of the reasons for this is the recent ruling by the Federal Communications Commission (FCC), which has been upheld in court, that MSOs adopt the Open Cable Application Platform (OCAP) and that Set-Top Boxes (STBs) be open to other uses. With larger pipes, more powerful STBs, and improved customer service applications residing in those STBs, the MSO can begin to dominate the other Local inter-Exchange Carriers (LECs). This enhanced customer service value equation is viewed to be one key to continued MSO growth, increased revenue and increased margins. OCAP is a new paradigm that will allow MSOs to create, or have made, and deploy, a whole suite of new interactive communications services that can drive new revenue streams with higher margins for the MSOs. The OCAP middleware, written in the Java® language, will facilitate “write once, use anywhere” application software to provide new features and services created by third party developers.
The OpenCable™ Platform specification can be found at http://www.opencable.com/ocap/, “OpenCable Application Platform Specification (OCAP) 1.1,” which is incorporated herein by reference in its entirety.
OCAP is an operating system layer designed for consumer electronics, such as STBs, that connect to a cable television system. Generally, the cable company controls what OCAP programs can be run on the STB. OCAP programs can be used for interactive services such as eCommerce, online banking, program guides and digital video recording. Cable companies have required OCAP as part of the CableCard 2.0 specification, and they indicate that two way communications by third party devices on their networks will require them to support OCAP.
More specifically, OCAP is a Java® language-based software/middleware portion of the OpenCable initiative. OCAP is based on the Globally Executable MHP (GEM)-standard, as defined by CableLabs. Because OCAP is based on GEM, OCAP shares many similarities with the Multimedia Home Platform (MHP) standard defined by the Digital Video Broadcasting (DVB)-project. The MHP was developed by the DVB Project as the world's first open standard for interactive television. It is a Java® language-based environment which defines a generic interface between interactive digital applications and the terminals on which those applications execute. MHP was designed to run on DVB platforms but there was a demand to extend the interoperability it offers to other digital television platforms. This demand gave rise to GEM, or Globally Executable MHP, a framework which allows other organizations to define specifications based on MHP.
One such specification is OCAP which has been adopted by the US cable industry. In OCAP the various DVB technologies and specifications that are not used in the US cable environment are removed and replaced by their functional equivalents, as specified in GEM. On the terrestrial broadcast side, CableLabs and the Advanced Television Systems Committee (ATSC) have worked together to define a common GEM-based specification, Advanced Communications Application Platform (ACAP), which will ensure maximum compatibility between cable and over-the-air broadcast receivers.
Packet Cable 2.0 is a specification based on the wireless Third Generation Partnership Program (3GPP) Internet protocol Multimedia Subsystem (IMS), which uses Session Initiated Protocol (SIP) for session control. By using SIP, MSOs can create the foundation of a service delivery platform on top of their existing DOCSIS (Data Over Cable Service Interface Specification) or cable modem service. Two of the SIP features that are particularly important to this invention are extensibility and interoperability. These SIP features are important because new messages and attributes can be easily defined and communications between previously incompatible endpoints are facilitated.
Another development that sets the stage for the disclosed inventions is the processing power, multimedia codecs and storage capabilities of the STBs. Many of the more advanced STBs have Digital Video Recorders (DVRs) based on hard disk drives or flash memory that provide many gigabytes of available storage. They also have advanced audio/video codecs designed to handle the requirements of High Definition Television (HDTV). Processors such as the Broadcom BCM7118 announced in January 2007, provide over 1000 Dhrystone mega-instructions per second (DMIPS) worth of processing power to support OCAP, new customer applications, and DOCSIS 2.0 and DSG advanced mode. The Broadcom chip, and other general purpose and application-specific integrated circuit (ASIC) processors used for STBs, provide powerful security capabilities such as the emerging Polycipher Downloadable Conditional Access Security (DCAS) system. DCAS eliminates the need for a CableCard and supports multiple conditional access systems and retail products.
SUMMARY OF THE INVENTION
These technologies provide the platform for a greatly enhanced, multimedia, customer communication experience. Specifically, one exemplary aspect of this invention is advanced multimedia communications via OCAP using customer specific profiles resident in the STB. Telephony application servers have already been proposed by CableLabs and others. Phone and STB association can be done in the MSO network. Similarly, personalized information for the display of financial data, home security information and the like, is also known.
However, an exemplary aspect of this invention utilizes storage of personalized information and communication preferences in the STB in a structured format or via cookies. The combination of feature rich telephony applications with the personalized data stored in STBs facilitates feature rich communications sessions. Providing advanced multimedia communications applications using personalized data resident in STBs could allow the MSOs to provide, for example, many previously unavailable services, and therefore provide considerable new business potential.
The types of personal information that can be stored in STBs may include, but are not limited to, communication preferences, payment preferences, vendor preferences, priority preferences, personal information, etc. Examples of communications preferences could include when to be reached or not reached, numbers to reach, calendar synchronization, etc., and in general any information related to communications. Examples of payment preferences could include credit card information, direct deposit/debit information, what financial instrument was used for the most recent transaction with a specific company, and in general any information related to transactions. Examples of vendor preferences could include favorite delivery pizza, most commonly ordered items, etc. Examples of priority preferences could include conditions like don't interrupt me watching the Chicago Bears beat the Green Bay Packers unless it is my boss calling, and in general any preference that can be used to assist with priority determinations. Examples of personal information could include clothing or shoe size, favorite colors, name, address, etc., and in general any information about an individual(s). Other such personal information categories and variations stored in STBs as can be imagined by one schooled in this art are also within the scope of this invention disclosure.
Screen menus, pushed URLs, and adaptations specific to various devices connected to STBs (such as different size screens, different capability devices, etc.) can be rendered as part of this process of enhanced communications. Similarly contextual favorites or preferences can be provided depending on what content is being displayed or interacted with.
When one combines the integration of a profile, such as, for example, personal information in STBs, with applications resident in a variety of places on the MSO's network, these new value added services are enabled.
A few simple examples of what is possible could include, but are not limited to, enhanced web enabled service transactions, mobile requests for goods or services using the profiles and communication capabilities of the STB/MSO network, display of or sharing of information among two or more individuals, etc.
For example, the user can initiate a service transaction on the STB itself. The exemplary menu based request will use the stored service information entry to key a web service request. If the request should trigger a human response (like communication with a retention agent when service cancellation is requested), then the STB information can key to the customer phone for an outbound call to confirm the cancellation request and allow the agent to describe a retention offer.
Another example could be a user delayed at work wanting to order a pizza to be ready shortly after their arrival at their home. The user can access personal information in their remote STB about their preferred vendor, most recent order and previous method of payment. They can place a new pizza order based on this stored information rather than having to key or speak all this information while driving. The user benefits from an enhanced user experience, the accuracy of the order is improved, and they can have the food arrive closely timed with their own arrival at home.
Another example is when a user has relocated to a new city or state; they may not have had the time to develop favorite vendors for pizza or other goods and services. In such a case, the MSO can push a list of preferred partners to the new user that the new user can edit or modify based on their own personal experiences and preferences.
The exemplary embodiments discussed herein just hint at the power of the proposed enhancement to this new communications paradigm. There are many other potential examples and applications to serve them that are possible.
For example, it is generally recognized that an intelligent agent is a software agent that assists users and will act on their behalf, in performing non-repetitive computer-related tasks. An agent in this sense of the word is like an insurance agent or a travel agent. While the working of software agents used for operator assistance or data mining (sometimes referred to as bots) is often based on fixed pre-programmed rules, “intelligent” in this context is often taken to imply the ability to adapt and learn. The term “personal” indicates that a particular intelligent agent is acting on behalf of an individual or a small collective group of users such as a household, business entity, etc.
OCAP provides another venue for an intelligent personal agent but offers several advantages compared with previous attempts at this type of application. One is the fact that STBs are already equipped to handle two-way, full-motion, High Definition (HD) video, as well as any other communication media. Another advantage is the integration of the personal profile information with the Intelligent Personal Agent application. Another is the improved security discussed herein. The extensibility and the interoperability that the Session Initiation Protocol (SIP) adds to Packet Cable 2.0 allows the full gamut of communications modalities and devices to be leveraged.
Another exemplary aspect of the invention is the use of personalized information and personal preferences contained in a STB in combination with an intelligent personal agent application and improved security to provide, for example, a greatly enhanced user agent experience.
The fact that sensitive information about the user can be stored within their own STB reduces security concerns associated with having too much web presence. The disclosure or query of the personal information can be established on a trust basis which also helps with security and privacy. The push of security information such as DCAS makes the environment significantly safer. One could also envision if there are multiple users within one household, that they can each have a profile that is login protected for personal privacy. Parents would be able to set certain conditions/limits for children using the intelligent personal agent application that would also add to the safety and age appropriate use of the application.
The two-way, full-motion, HD video without many of the quality issues associated with the Internet is a significant enhancement to current intelligent personal agents. It could provide an opportunity for video messages to be personalized for the party which is initiating the contact.
The personal information stored in the STB can convey many exemplary benefits such as communication preferences, alternate contact modalities, payment preferences, priority preferences, trusted contacts, personal information, as well as multimedia messaging, etc. The integration of the personal information with the intelligent personal agent also enhances the user experience.
There are several examples of what this idea can provide the user that current intelligent agents are not able to do. One is the ability to greet calling parties with a fall motion video greeting unique to that calling party. Another is the ability to handle more complicated transactions. For example, the user wants to buy a particular item at a particular price from one of several preferred vendors. Offers from preferred business partners can be pushed to the MSO's users and the content can be filtered, compared with conditions set by the user for a purchase, and the intelligent personal agent can either complete the transaction or call the user on a mobile device to seek approval and then transact business. While there are shopping agents, mobility applications and contactless payment devices, this intelligent agent can provide a user experience unequaled in the current art. Another possible variation is for the intelligent personal agent to coordinate multiple parties within a household. Let's say an invitation arrives inviting a family over to dinner at the calling party's house. The intelligent agents can interact with personal information and scheduler software for all of the members of the family to make certain that the invite has considered each members previous commitments prior to replying and either accepting or modifying the proposed dinner invitation. There are numerous other variations that are possible with this intelligent personal agent not possible within the existing art.
Social network services focus on the building and verifying of online social networks for communities of people who share interests and activities, or who are interested in exploring the interests and activities of others, and that necessitates the use of software.
Most social network services are primarily web based and provide a collection of various ways for users to interact, such as chat, messaging, email, video, voice chat, file sharing, blogging, discussion groups, and so on.
The main types of social networking services are those that contain directories of some categories (such as former classmates), means to connect with friends (usually with self-description pages), and recommender systems linked to trust. Popular methods now combine many of these, with MySpace™, Bebo™ and Facebook™ services being the most widely used.
OCAP combined with personal profile information provides another venue for a social network, but offers several advantages compared with previous attempts at this type of application. One is the fact that, as discussed, STBs are equipped to handle two-way, full-motion, High Definition (HD) video. Another is the improved security discussed above. The extensibility and the interoperability that SIP adds to Packet Cable 2.0 allows the full gamut of communications modalities and devices to be leveraged. One exemplary embodiment of the social network proposed here can be one-to-one, one-to-many and many-to-one, and can cover both personal and professional interest areas.
Another exemplary aspect of this invention is the use of personalized information and personal preferences contained in a STB combined with two-way, full-motion, HD video and improved security to provide a greatly enhanced social networking experience.
The two-way, full-motion, HD video without many of the quality issues associated with the Internet is a significant enhancement to the current social networking offerings. It would provide an experience that is much more like a face-to-face interaction.
The personal information stored in the STB can convey all of the benefits listed above such as communication preferences, alternate contact modalities, payment preferences, priority preferences, trusted contacts, personal information, etc. The integration of the personal information combined with the social networking application(s) also enhances the user experience. In addition to the normal uses of a social networking application such as on-line dating, discussion groups, virtual communities, and the like, one can imagine extensions to the use of this application. One such extension would be the addition of personal reviews of restaurants, movies, books, music, and the like. Other users of the social network could determine over time which reviewers tend to rate goods and services consistently with their interests and/or from a perspective that they enjoy their reviews, and could preview the ratings provided about items of interest by those reviewers. One could also see reviews when previewing related media. The reviewers and the users that tend to agree or become popular could go on to form their own social network based on their experience with each other's recommendations or interactions. With the extensibility of Packet Cable 2.0, a user could also provide a review of a movie that they had just viewed in a theater via their cell phone while their thoughts are fresh.
Many small businesses start out as part-time home businesses. In addition, some people run a small business focusing on rental properties, or the like, in parallel with their normal employment. Some fairly sizable businesses are run at locations served by MSO DOCSIS services. OCAP provides an opportunity to integrate business profile information into STBs similar to how personal information is integrated in a STB, as discussed in above. Further, business application software, such as the Quicken® Home and Business program or the Quicken® Rental Property Manager program can be advantageously integrated together with business information profiles in the STB.
There are many other instances where OCAP can provide an enhanced user experience to business users. Via OCAP, and with a business profile, actual inventory levels can be compared with desired levels stored as business information in the STB. Since preferred vendor and preferred payment information can also be stored, when inventory runs below a certain level, it can be automatically ordered, or alternatively, OCAP can provide a pop-up or call a specified phone number such as a mobile phone to confirm that the inventory reorder should be processed.
Another example would be management of a rental vacation property. Not only could the landlord view bookings and the like, but the ability to extend a rental stay could be offered to the guest via the TV/STB when such an opening is available. Further, an offer to return at a future date could also be made via OCAP. In this way, the renter feels that they are getting increased attention without significant intrusion, and the landlord is more likely to be able to keep the rental property at maximum capacity.
While the internet provides some of these types of features, OCAP allows for, as an example, a richer feature set, improved convenience and the ability to leverage previously incompatible devices in a seamless way. Specifically, the ability to reorder inventory when the small business owner is mobile, and the ability to provide all of the information regarding the transaction such as vendor, inventory type and quantity, preferred payment options, and the like, without the small business owner having to key in such information, is useful. Similarly, renting vacation properties is typically done via the internet. However, not everyone takes a PC or web-enabled device everywhere with them. Offering the ability to extend a stay, rebook a future vacation, or offer incentives to good repeat guests can all be done via OCAP and displayed on a TV or forwarded as an audio message to the rental property phone.
The use of business information and business preferences contained in a STB integrated with other PC or STB-based business software can provide full compatibility with previously incompatible endpoints and improved security to provide a greatly enhanced business experience.
The fact that sensitive information about business(es) can be stored within their own STBs improves security concerns associated with web-based attacks. The disclosure or query of the business information can be established on a trust basis, which also helps with security and privacy. The push of security information, such as DCAS, also makes the environment significantly safer. One could also envision, if there are multiple users within one entity, that they can each have a profile that is login protected for privacy. In addition, one or more members of the entity can also have a business profile in the STB.
The two-way, full-motion, HD video, without many of the quality issues associated with the Internet, is also a significant enhancement to businesses. It provides, for example, an opportunity for video messages to be personalized to the guest or customer when the business owner is unavailable.
The business information stored in the STB can also convey the benefits of personal information listed above, such as communication preferences, alternate contact modalities, payment preferences, priority preferences, trusted contacts, inventory levels, business events/calendar, as well as multimedia messaging, etc. The integration of the business information combined with existing business software enhances the business owners' ability to conduct their businesses.
There are several examples of what this idea can provide to the business user that current PC based software does not allow. One is the ability to greet guests and customers with a full motion video greeting unique to each party. Another is the ability to handle more complicated transactions. For example, a vacation rental guest decides that they really like the property that they rented, but would like to consider other such properties for a future vacation prior to the end of their current vacation. Offers from the landlord can be extended to preferred guests while on their current vacation for reduced rate stays at this or other properties, to retain the guest's business. All of this can be displayed to the TV at the property, or if the TV is not used, sent via an audio message to the phone in the rental. There are numerous other variations that are possible with this business application and profile that are not possible within the existing art.
Aspects of the invention thus relate to one or more profiles on a STB.
Aspects of the invention further relate to the use of personalized information and personal preferences associated with a STB combined with an intelligent personal agent application and improved security to provide an enhanced user experience.
Aspects of the invention also relate to use of a personalized profile of communications preferences and personal information resident in STBs combined with communications applications also resident in STB's to enable enhanced communications and customer service in an OCAP/IMS network(s).
Aspects further relate to having business information and preferences stored in STBs, an OCAP business application combined with existing business software and enhanced security within an OCAP/IMS network(s).
Aspects also relate to use of a personalized profile of communications preferences and personal information resident in a STB combined with two-way, full-motion, high definition video and enhanced security to implement a social networking application within an OCAP/IMS network(s).
Aspects also relate to utilizing a master profile to regulate creation and use of subordinate profile(s).
Aspects also relate to integration and cooperation between a profile associated with a STB and one or more applications associated with other electronic devices.
Aspects of the invention can also be used to support enhanced e-commerce in association with a STB.
Aspects still further relate to business management in conjunction with one or more business profiles on a STB.
Aspects also relate to setup and use of an automated agent performing certain tasks in association with a profile associated with a STB.
Additional aspects relate to a set-top box with an operating system layer supporting cable network interconnectability and providing an application platform on which one or more customer service applications can be run.
Aspects still further relate to use of social networking applications and integration with a profile associated with a STB.
These and other needs are addressed by the various embodiments and configurations of the present invention.
The present invention can provide a number of advantages depending on the particular configuration.
These and other advantages will be apparent from the disclosure of the invention(s) contained herein.
The phrases “at least one”, “one or more”, and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B, or C” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together.
The term “a” or “an” entity refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. It is also to be noted that the terms “comprising”, “including”, and “having” can be used interchangeably.
The term “automatic” and variations thereof, as used herein, refers to any process or operation done without material human input when the process or operation is performed. However, a process or operation can be automatic even if performance of the process or operation uses human input, whether material or immaterial, received before performance of the process or operation. Human input is deemed to be material if such input influences how the process or operation will be performed. Human input that consents to the performance of the process or operation is not deemed to be “material”.
The term “computer-readable medium” as used herein refers to any tangible storage and/or transmission medium that participate in providing instructions to a processor for execution. Such a medium may take many forms, including but not limited to, non-volatile media, volatile media, and transmission media. Non-volatile media includes, for example, NVRAM, or magnetic or optical disks. Volatile media includes dynamic memory, such as main memory. Common forms of computer-readable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, or any other magnetic medium, magneto-optical medium, a CD-ROM, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, a RAM, a PROM, and EPROM, a FLASH-EPROM, a solid state medium like a memory card, any other memory chip or cartridge, a carrier wave as described hereinafter, or any other medium from which a computer can read. A digital file attachment to e-mail or other self-contained information archive or set of archives is considered a distribution medium equivalent to a tangible storage medium. When the computer-readable media is configured as a database, it is to be understood that the database may be any type of database, such as relational, hierarchical, object-oriented, and/or the like. Accordingly, the invention is considered to include a tangible storage medium or distribution medium and prior art-recognized equivalents and successor media, in which the software implementations of the present invention are stored.
The terms “determine”, “calculate” and “compute,” and variations thereof, as used herein, are used interchangeably and include any type of methodology, process, mathematical operation or technique.
The term “module” as used herein refers to any known or later developed hardware, software, firmware, artificial intelligence, fuzzy logic, or combination of hardware and software that is capable of performing the functionality associated with that element. Also, while the invention is described in terms of exemplary embodiments, it should be appreciated that individual aspects of the invention can be separately claimed.
The preceding is a simplified summary of the invention to provide an understanding of some aspects of the invention. This summary is neither an extensive nor exhaustive overview of the invention and its various embodiments. It is intended neither to identify key or critical elements of the invention nor to delineate the scope of the invention but to present selected concepts of the invention in a simplified form as an introduction to the more detailed description presented below. As will be appreciated, other embodiments of the invention are possible utilizing, alone or in combination, one or more of the features set forth above or described in detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an exemplary content system according to this invention;
FIG. 2 illustrates an exemplary set-top box according to this invention;
FIG. 3 illustrates an exemplary profile according to this invention;
FIG. 4 is a flowchart outlining an exemplary method for creating or editing a profile according to this invention;
FIG. 5 is a flowchart outlining an exemplary method for performing a service transaction according to this invention;
FIG. 6 is a flowchart illustrating the exemplary interaction between a set-top box and a service provider according to this invention;
FIG. 7 illustrates an exemplary flowchart for intelligent agent performance according to this invention;
FIG. 8 is a flowchart illustrating an exemplary method for utilization of a business profile according to this invention;
FIG. 9 is a flowchart outlining an exemplary method for social network interaction according to this invention;
FIG. 10 is a flowchart outlining an exemplary method for initiating a transaction in greater detail according to this invention;
FIG. 11 is a flowchart outlining an exemplary method for storing transaction information in greater detail according to this invention; and
FIG. 12 is a flowchart outlining an exemplary method for social network interaction in greater detail according to this invention.
DETAILED DESCRIPTION
FIG. 1 illustrates an exemplary content system 100 . The system 100 comprises one or more trusted entities 200 , one or more content/service providers 300 , such as a cable company, and a set-top box 500 , all interconnected by one or more links 5 and networks 10 . The set-top box 500 is connected to one or more of a stereo 700 , PC 800 , TV 900 , or in general any electronic device as represented by box 600 . Associated with the set-top box 500 are one or more profiles 400 , as will be discussed in detail hereinafter.
In general, the set-top box 500 is capable of receiving content, such as video content, as well as providing services such as access to the internet, telephony service, and the like. As will be discussed hereinafter, the set-top box is also capable of providing services such that, for example, the user located at one of the attached devices utilizes the set-top box 500 to assist with the ordering, consumption and/or management of the service.
Typically, the content/service provider 300 provides content, such a video content, to a user via the set-top box 500 . An exemplary embodiment of the present invention expands on this concept and in conjunction with profile 400 provides enhanced content capabilities through the set-top box 500 .
Furthermore, and in accordance with an optional exemplary embodiment, trusted relationships can be established between the content/service provider 300 and one or more trusted entities 200 . For example, the content/service provider 300 , such as a cable company, can negotiate trusted relationships with various service providing entities. Upon the completion of various checks and assurances from the service providing entities, the various entities could be listed as a trusted entity 200 , at which point service requests made via set-top box 500 , in conjunction with profile 400 , would be handled in a different manner.
The association of the profile 400 with the set-top box 500 allows, for example, a richer communications environment to be provided to a user. For example, a customer at their home calls into a customer service number. Instead of the call being rerouted from center to center based on information the customer inputs via the phone, the call can use a common customer routing center. The routing center, which could be one of the trusted entities 200 , can use the phone number to look-up a key set-top box entry for the customer, and the center can then electronically retrieving the stored service information entry via the set-top box 500 , from the profile 400 . The information retrieved from the profile 400 can be combined with the caller's requested service, routed to the appropriate agent with the information retrieved from the customer STB (relieving the need to interrogate other databases or the user and making for more efficient contact centers), and additional information for the customer can be displayed on, for example, the TV 900 or PC 800 associated with the set-top box 500 .
In another example, the customer can initiate a service transaction on the set-top box itself. For example, a menu based request can use stored service information in the profile 400 to key a web service request. If the question triggers a human response, like that from a retention agent when service cancellation is requested, the set-top box information can key to the customer phone for an outbound call to confirm the cancellation request and allow for a retention offer to be made.
Therefore, in accordance with one exemplary embodiment, the profile 400 can be used, for example, to assist with contacts to a contact center and can be utilized in conjunction with the set-top box to provide a service to, for example, other retailers, service outfits, and trusted or other entities. The set-top box can also store customer service records specific to, for example, an individual or a business. The same method used to assist with a customer service contact as discussed above could similarly be used to access records or other information stored in the profile 400 to assist with business services, business management, online banking, or the like.
For example, the same mechanisms can be used to push structured information and menu information for the requested transaction, inquiry, or service request, thereby providing a richer customer service experience. This richer experience combined with the ease of retrieval of customer service information, personal information and/or business information from the profile 400 provides, for example, a significantly richer customer contact capability than that which can be offered by traditional centers. This in turn gives an opportunity for new large business service opportunities for the contact/service provider 300 .
In accordance with an exemplary embodiment, the profile 400 used in conjunction with one or more applications on the set-top box 500 provides a richer experience for a user of the set-top box for interacting with one or more content/service providers, trusted entities, other entities, or in general any entity that may be able to provide a richer customer experience based on the information available to them via the profile 400 .
FIG. 2 illustrates in greater detail an exemplary set-top box 500 . The exemplary set top box includes one or more of a DVR 510 , codec 515 , hard drive 520 , one or more customer service applications 525 , a binding hardware/software module 530 , a menu module 535 , a business application integration module 540 , a social network applications module 545 , a processor 550 , a memory 555 , an I/O interface 560 , a SIP functionality/integration module 565 , a security module 570 , one or more communications applications 575 and an intelligent agent module 580 .
The DVR 510 can be used to store video information, as is conventionally known, and can also be used as a storage device for one or more applications on the set-top box. For example, the DVR 510 can used as back up for non-active applications, while active applications can be run on, for example, the hard drive 520 in conjunction with one or more of the processor 550 , memory 555 and I/O interface 560 .
The set-top box can also include one or more codecs 515 that provide, for example, one or more of coding and decoding of video information, audio information, high-definition video information, multimedia information, or in general any audio or video format received by or sent from the set-top box 500 .
The set-top box 500 also includes one or more customer service applications 525 . These customer service applications can cooperate with the profile 400 to provide various functionalities to a user at one or more of a TV 900 , PC 800 , stereo 700 , or in general any electric device 600 connected to the set-top box 500 . As discussed above, these customer service applications can include, but are not limited to, ordering, online banking, call center assistance applications, profile management applications, or in general any application that is capable of operating on or in conjunction with the set-top box 500 . As will be appreciated, the application need not run exclusively on the set-top box 500 , but could operate in conjunction with one or more applications, on, for example, a connected electronic device such as PC 800 .
The hardware/software binding module 530 allows the set-top box 500 to be associated with one or more other electronic devices, such as a telephone, soft phone, or in general any device that is capable of being bound to the set-top box 500 . For example, if a user activates a customer service application on the set-top box 500 to cancel the particular service with a trusted entity 200 , upon the intelligent agent module (discussed hereinafter) determining that a cancellation service request has been initiated, the intelligent agent module can request the hardware/software binding module to initiate a call so that the user can communicate directly with the trusted entity customer service agent regarding the cancellation request. This binding can be done, for example, with the cooperation of the SIP functionality/integration module 565 , in that SIP provides a convenient mechanism to established, tear down, or redirect communications. More specifically, stored within the profile can be information specifying phone information associated with the user of the set-top box. SIP protocols can be initiated from the STB to specify that the phone associated with the user is to place a call to a specific customer service agent. A message indicating that a phone call has been initiated can then be displayed on one or more of the phone and a device associated with the STB 500 .
The menu module 535 provides an interface, such as a graphical user interface, which can be displayed on one or more of the TV 900 , PC 800 , or in general any display device that allows manipulation of, for example, one or more of the features of the set-top box 500 and one or more profiles. For example, a user can utilize the menu module 535 to edit one or more profiles 400 stored on the set top box. Additionally the menu module 535 can used in conjunction with various customer service applications 525 residing on the set top box to provide necessary menus to the user associated with the particular customer service application that was requested. For example, in an on-line banking environment, where their customer service application provides to the user the ability to manage their bank accounts, the customer service application can serve various menus in conjunction with the menu module 535 that allow the various actions associated with the customer service application to be performed. Menu module 535 can also cooperate with one or more of the content/service provider 300 , trusted entities 200 , or other entities on the network 10 , to provide menus to a user of the set-top box 500 in conjunction with one or more of the services, products, or features provided by that particular entity.
For example, if the set-top box 500 is in communication with a real estate agent connected to network 10 , the real estate agent could push a series of menus to the menu module 535 that allow the user of the set-top box 500 to access various listings of that agent. With these menus, the user could set up, for example, virtual viewings of the listing in high-definition video formation. The SIP functionality 565 could also be used to spawn a call that is bound to the real estate viewing application in conjunction with the hardware/software binding module 530 . Personal preferences of the user could also be layered on top of the menus pushed to the STB to account for their own personal preferences, such as skin-type display characteristics.
The business application integration module 540 allows one or more business applications stored on, for example, PC 800 , to be utilized in conjunction with the set-top box 500 and profile 400 . In addition to the stand-alone business application(s) stored on the set-top box, the business application integration module 540 allows for integration and sharing of information stored in, for example, the profile 400 with one or more business applications, such as financial management applications, run on the PC 800 . To provide a layer of security for these communications, the business application integration module 540 can cooperate with the security module 570 to regulate the type of information that can be shared by the set-top box 500 , the profile 400 and the other financial management applications. For example, the profile 400 can be associated with a number of rules governing who has access to one or more portions of information, who can spawn customer service applications, who can authorize use of funds, or in general any rule that governs, regulates, restricts or allows access to one or more of information within the profile, applications on the set top box, or communications for the set-top box 500 to an entity connected to network 10 .
The social network application module 545 in a similar manner cooperates with the profile 400 and set-top box 500 to allow the use of personalized information and personal preferences as contained in the profile 400 to provide a richer social networking environment. For example, social networking applications used in conjunction with the set-top box 500 allow the user to experience two-way, full-motion high-definition video content as well as enhanced security. For example, storing personalized information and personal preferences in the profile 400 can provide a layer of security above that which is typically associated with a web presence. The disclosure, query or access to information in the profile 400 can be based on one or more of a trust relationship with one or more trusted entities, analysis by the intelligent agent, or rules associated with a profile, or a master profile. The push of security information such as DCAS makes the environment associated with the use of the profile 400 significantly safer. As discussed above, social networking applications can be established on a hierarchical basis where, for example, parents would be able to set certain conditions, limits or thresholds for children using a social networking applications to add safety and age appropriate rules governing use of the applications, as well as access to information within the profile and restrictions on access to the various types of service applications available to that particular user.
The set-top box environment also provides the ability to utilize two-way, full-motion video, in addition to high-definition video, and does not suffer from the drawbacks associated with typical internet-based applications, such as latency, dropped frames, and the like. The social network application module 545 is thus capable of providing interaction with one or more other participants that is more like a face-to-face interaction.
As with the other modules, the social network application module can benefit from the various information stored on the profile 400 and features of the set-top box 500 such as communications, preferences, alternate contact modalities, payment preferences, priority preferences, trusted contact information, personal information, business information, or the like. The ability to integrate the personal information stored in the profile 400 with one or more social networking applications associated with the social network application module 545 provides the ability to enhance a user's experience.
In general, any application stored in a social network applications module 545 can be used for social networking. These applications can include any type of communications modality such as video, text, image sharing, or the like, in either a one-directional, two-way or multiparty format. For example, multimedia versions of social networking applications can also be used that combine one or more of the above with such functionality, as, for example, blogging, real-time white-boarding, chatting, video conferencing, or in general, any multimedia application between one or more parties.
The SIP functionality/integration module 565 allows one or more SIP-based communications to be used in conjunction with the set-top box 500 and profile 400 . These SIP-based communications could be run in parallel with various applications run on the set-top box 500 and, as discussed above, can be bound to one or more other devices such a telephone, PDA, home phone, business phone, or in general any SIP-enabled device. In addition to being able to run in parallel with one or more applications on the set-top box 500 , upon execution of a specific customer service application initiated in the set-top box, a SIP communication could be established and, once active, the corresponding communication on the set-top box could optionally be terminated.
Security module 570 can provide varying levels of security for the information within the profile 400 . Furthermore, as previously discussed, a hierarchical security platform can be established with, for example, a master profile that regulates dependent profiles, such as those that would be established by parents for their children. Extending this basic concept to a business environment, business managers could also set up various rules in conjunction with the security module 570 regulating the control, access to, and usability by employees of information stored in the profile 400 .
In general, since any information can be stored in the profile 400 , various rules, policies, profiles, and the like, can be established that govern not only access to, but dissemination of the information within the profile. For example, access to the various types of information in the profile can be regulated based on who is trying to access the information, what type of information is being accessed, what the accessed information is going to be used for, and the like and can be analyzed by the security module 570 to determine whether that access or dissemination should be allowed. For example, the security module 570 can cooperate with the intelligent agent module 580 to assist with analysis of any security risks that may be associated with providing access to the information within the profile 400 .
Communications applications module 575 enables various types of communications application to be used with the set-top box 500 . These communications include, for example, audio communications, video communications, chat communications, telephony-type communications, or in general any communication between the set-top box and, another entity on the network, with one or more of the devices associated with and connected to the set-top box, to another entity on the network, or communications associated with a bound device, such a bound IP soft phone.
Intelligent agent module 580 is a software agent that assists users with various functions and is capable of acting on their behalf in an automated or semi-automated manner. Intelligent agent module 580 is thus capable of cooperating with one or more of the other modules in the set-top box, or devices connected to the set top box, and based on information and/or rules within the profile 400 , to perform various actions. The actions can be triggered by one or more triggering events that may be based on information received by the set-top box, or information sent to an entity on the network 10 . For example, upon receiving a new program schedule, the intelligent agent could parse the various shows that are scheduled to be shown within the next week, and knowing, based on information within the profile 400 , if their user is a fan of a particular actor, automatically docket the recording of the movie featuring the actor.
As another example, the intelligent agent module 580 can monitor the various interactions between the set-top box and entities on the network 10 . If, for example, a parent has established restrictions on social networking applications associated with a child, and the intelligent agent module 580 detects that the child is attempting to access one of these social networking applications on the prohibited list, the intelligent agent module can spawn a communication to the parent indicating such an attempt. For example, the intelligent agent module can cooperate with an email or call spawning module and, for example, send a text message to the parent indicating that the child was trying to access a prohibited social networking application at a given date and time. This can be enabled with cooperation of the SIP functionality module 565 and the text message sent to a SIP enabled endpoint. At the same time, a communication could be established between the SIP endpoint and the set-top box, and if the SIP endpoint is video enabled, real-time communications could be established between the parent and child to discuss their activities.
FIG. 3 outlines an exemplary profile 400 . The exemplary profile 400 comprises one or more of business, personal, and entity information 410 , communications preferences 420 , personal preferences 430 , payment information 440 , vendor information 450 , priority information 460 , contextual preferences and sub-profiles 470 , alternate contact modalities 480 and one or more trusted contacts 490 .
As discussed, one ore more of the personal, business and entity information can include any information that a user would like to store. For example, examples of personal information include name, address, credit card information, banking information, movie preferences, communications preferences, restaurant preferences, vendor preferences, billing preferences, and the like. Examples of business information includes, for example, preferred vendors, banking information, communications preferences, ordering or inventory information, employee information, payment information, accounting information, business management information, or in general any information related to a business. Entities can also include information about items such as groups of individuals, groups of businesses, or in general any entity that may not be personal or business in nature. Interfaces that can be provided that provide access to the information stored within the profile, and this information can be edited, updated or deleted as appropriate. The editing, updating or deleting of this information can be performed via an interface on the set-top box, or via any interface connected to the set-top box. This access to the information within the profile can be password protected, and the information can be transferred via or in accordance with well known encryption techniques and standards.
The communications preferences 420 provide to the user the ability to store various types of communications preferences or modalities that can effect not only the type of communication to use to access the user, e.g., video, chat, IM, telephone, or the like, but that can also be used in conjunction with presence information and/or communication routing.
The personal preferences 430 are a set of rules related to a particular user's personal preferences. These personal preferences can relate to any functionality of the set-top box, display characteristics of the STB, operation of the STB, or the like, and can be related to any one or more of menu options, communications preferences, contact preferences, set-top box management, or the like.
Vendor information 450 stores various information that can be used for payment of goods and/or services ordered through or in conjunction with the set-top box. This payment information can have a higher security level than other types of information within the profile 400 , such that, for example, a password is required before the purchase for goods and services can be made. Additionally, the payment information could be limited to use by the contact/service provider 300 .
Vendor information 450 can include such information as preferred vendors, vendors who should not be used, historical purchase information, account information, reference information associated with a particular vendor, or in general any information associated with a vendor. When new vendors are utilized, and in conjunction with the intelligent agent module 580 , new information can be added to the vendor information 450 and stored in the profile 400 .
In addition, also in conjunction with the intelligent agent module 580 , the vendor information 450 can be dynamic such that as, for example, a user accesses a particular vendors website, account information can be populated into the vendor information 450 such as order placed, remaining balance, special offerings, or in general any information associated with that particular vendor.
Priority information 460 includes any information, such as rules, that can be used to assist with prioritizing certain activities, applications, or in general, any functionality associated with the set-top box 500 . This priority information 460 could also be used in conjunction with the intelligent agent module 580 to assist with determining prioritization of certain activities.
The contextual preferences and sub-profiles 470 establishes preferences based on context that could also be categorized as sub-profiles depended upon, for example, a particular application being run on the set-top box 500 . As with the other types of information, the contextual preferences 470 can be used in conjunction with the intelligent agent module 580 to provide dynamic application behavior.
The alternate contact modalities 480 outline various contact modalities for a particular user. These alternate contact modalities 480 can be used with the communication preference information, personal preference information and/or priority information to assist with completion of an incoming communication to an endpoint. For example, based on information in the alternate contact modalities profile, one or more of the binding module and SIP functionality module can be utilized to complete an incoming communication to an endpoint where the user is located.
Trusted contacts 490 include information regarding one or more entities that are trusted. For example, an entity can be trusted if it is approved by the content/service provider 300 . Additionally, an entity can be trusted if, for example, the user has had previous interactions with the entity and has identified them it as being trusted.
Optionally, the intelligent module 580 can also be used to analyze transactions with a particular entity, and upon, for example, a threshold number of transactions being completed in a satisfactory manner, the entity can be identified as “trusted.”
The trusted entities need not be limited to businesses that sell goods and/or services, but can also include entities such as schools, other individuals, or in general any one or any entity that is identified as being trusted. For example, in a social networking environment, parents can establish rules that can identify certain chat groups or other users that are trusted. In conjunction with the intelligent module, for example, a child can request a parent to approve a specific entity as trusted, and communications with that entity are restricted until it is approved by that parent.
Trusted status can also be achieved by, for example, the intelligent agent module 580 analyzing an entity's, user's or merchant's feedback. Upon a merchant having reached a threshold level of feedback, the agent can identify the merchant as “trusted” which could then, optionally, forward the “trusted” identification to an additional entity, such as a parent, for final approval.
FIG. 4 outlines an exemplary method for profile management. In particular, control begins in step S 100 and continues to step S 110 . In step S 110 , an interface is provided that allows for one or more of creation and editing of a profile. Next, in step S 120 , an option is provided for editing or creating a new profile. Then, in step S 130 , and optionally based on password verification, creation, editing or updating of the profile is allowed. Control then continues to step S 140 .
In step S 140 , the profile is saved. Next, in step S 150 , a determination is made whether to edit or create another profile. If editing or creation of another profile is desired, control jumps back to step S 120 , with control otherwise ending in step S 160 .
FIG. 5 outlines an exemplary method for a service transaction. In particular, control begins in step S 200 and continues to step S 210 . In step S 210 , a service transaction is initiated on or in association with the set-top box. As will be appreciated, the original request for initiation of a service transaction can come from one or more of the attached or associated devices such as a TV, personal computer, or the like. As previously discussed, this service transaction could also be initiated from an associated device, such as a SIP enabled communications device.
In step S 220 , a web service request is triggered by, for example, a menu based request that has stored information that can be derived from, for example, the stored profile. Next, in step S 230 , a determination is made whether another device, such as a communication device, should be bound to the service transaction. If another device should be bound to the service transaction, control jumps to step S 240 where the communication device is bound, and for example, a call is spawned from that device.
Otherwise, control continues to step S 250 , where profile information is used to assist with completion of the web service request. Control then continues to step S 260 where the control sequence ends.
FIG. 6 outlines an exemplary exchange between the set-top box and a service provider. This exemplary exchange could be utilized upon the initiation of a service request from a user associated with a set-top box to a goods and/or services provider. In particular, control begins in step S 300 and continues to step S 305 . In step S 305 , a service request is initiated. As will be appreciated, this could also be a request for goods or in general a request for anything. Next, in step S 310 , the service request is received. Then, in step S 320 , a check is made to determine that the service availability is present. Control then continues to step S 330 , where the profile information stored on the set-top box is requested based on, for example, information in the service request. Next, in step S 315 , the requested information is retrieved. Next, in step S 325 , the requested information can be filtered based on one or more of preferences, personal preferences, contextual preferences, sub-profiles, analysis by one or more of a security agent or intelligent agent, or in general any filtering criteria. The filtered information is then forwarded to the service provided in step S 335 . Next, in step S 340 , the profile information is received. Then, in step S 350 , the service request is initiated. Control then continues to step S 360 .
In step S 360 , the coordination of the supply of goods and/or services can optionally be coordinated with, for example, an outside party, such as a trusted entity. Then, in step S 370 , the service is provided to the user, with control then continuing to step S 345 where the control sequence ends.
FIG. 7 outlines an exemplary method for analyzing incoming information and the use of an intelligent agent. In particular, control begins in step S 400 and continues to step S 410 . In step S 410 , one or more types of information, such as information incoming to the set-top box, information from the set-top box, and information received from a user, can be analyzed. Next, in step S 420 , a determination is made whether to invoke the intelligent agent based on this analysis. This analysis can be based on, for example, logic in the form of one or more of neural networks, expert systems, key word searching, or the like. If the intelligent agent is to be invoked, control jumps to step S 440 with control otherwise continuing to step S 430 where the control sequence ends.
In step S 440 , the intelligent agent is activated. Inputs to assist the intelligent agent with determining an appropriate action can include one or more of profile information, security information, and rules, and can also be based on queries that are spawned to, for example, an end user. Control then continues to step S 450 .
In step S 450 , the information that triggered the spawning of the intelligent agent is analyzed, and utilization of profile information, security information, rules, query responses and the like is taken into consideration for an appropriate action. Next, in step S 460 , the action is performed, with control continuing to step S 470 where the control sequence ends.
FIG. 8 outlines an exemplary method for business profile interaction according to this invention. In particular, control begins in step S 500 and continues to step S 510 . In step S 510 , a determination is made whether a business profile is being used. If a business profile is being used, control jumps to step S 530 , with control otherwise continuing to step S 520 where the control sequence ends.
In step S 530 , a determination is made whether one or more of a business profile and rule is requesting access to a business application. If the determination result is yes, control jumps to step S 540 , with control otherwise continuing back to step S 520 where the control sequence ends.
In step S 540 , the business profile and/or rule information is integrated with one or more business applications. Next, in step S 550 , information can optionally be exchanged between the profile and business applications. Then, in step S 560 , the profile can optionally be updated with information received from the one or more business applications. In a similar manner, information from the profile can be used to update the one or more business applications with selected information. Control then continues to step S 570 where the control sequence ends.
FIG. 9 illustrates an exemplary method of social networking utilizing the set-top box and profile(s) associated therewith. In particular, control begins in step S 600 and continues to step S 610 . In step S 610 , one or more social networking applications are initiated with their corresponding interfaces. Initiation of the various social networking applications can be limited by information in the profile, security information, and/or rules. For example, as discussed above, parental controls may be input into the rule set, thereby restricting the type of social networking application that can be available to certain users. This type of restrictive rule can be placed in the master profile, with a hierarchical rule set that governs all subordinate profiles. Next, in step S 620 , interactions with one or more social networking applications can be monitored for compliance with security information, the rules, and, for example, information in the profile. The various types of interactions include two-way video, high definition video, interactive media, enhanced blogging, text messaging, chat, or in general, any communication modality. Control then continues to step S 630 .
In step S 630 , the disclosure of sensitive information is regulated by the intelligent agent with reliance on the rules, security information, and type of profile. For example, as previously discussed, if this is a child's profile, a parent can apply various rules and security information that regulates the disclosure of sensitive information, with, in step S 640 , a determination being made, upon violation of one or more of the security information and rules, of whether an alert should be sent. If an alert should be sent, control continues to step S 650 where an alert is prepared and sent. Otherwise, control jumps to step S 660 .
In step S 660 , an option is provided to manage or update the profile. If managing or updating is required, control continues to step S 670 , with control otherwise jumping to step S 680 where the control sequence ends.
In step S 670 , updating and/or management of the profile is allowed. This updating or management can be user-centric, for example, if a user wants to add another social networking application to a trusted category, update personal information, update payment information, or in general update any information associated with the profile. In addition, the profile can also be managed by a superior profile holder, such as a parent, as appropriate.
FIG. 10 illustrates an exemplary method for initiating a transaction in greater detail. In particular, control begins in step S 700 and continues to step S 705 . In step S 705 , one or more communications devices or other electronic devices are associated with the STB. For example, a phone number or other identifier can be stored in the profile with an indication that the device associated with that identifier or phone number is associated with the STB. This activity could be user centric, in association with the service provider, or in general, through any process. Next, in step S 710 , a transaction is initiated. Depending on whether a personal agent or a service provider agent is being used for the particular instance of the invention, control continues to either step S 712 or step S 715 , respectively.
In step S 715 , a desired transaction is selected. This desired transaction can be selected from a list of available transactions, or, for example, a user can navigate via a web-based service to find merchants, service providers, or the like, with which they would like to initiate a transaction. Next, in step S 720 , the service agent looks up the STB and retrieves information, such as payment information, from the profile. Then, in step S 725 , the service agent forwards the transaction information and payment information to the business providing the requested service. Control then continues to step S 730 .
In a similar manner, in step S 712 , a desired transaction is selected in cooperation with a personal agent. As with the transaction request to a service provider, the selection of the desired transaction can be either from one or more of canned transactions, or navigated to, based on, for example, web navigation. Next, in step S 714 , the personal agent forwards the transaction information and payment information to the business providing the requested service. The transaction information can include such information as the name of the person placing the order, address, phone number, order options, and in general any information associated with an order. Control then continues to step S 730 .
In step S 730 , a determination is made whether the transaction information is to be stored. If the transaction information is to be stored, control continues to step S 735 with control returning to step S 740 .
In step S 740 , a determination is made whether another transaction is desired. If another transaction is desired, control jumps to step S 750 , with control otherwise ending at step S 745 .
In step S 750 , a determination is made whether a previous transaction should be reused. If it is to be reused, control continues to step S 755 with the selection and retrieval of the previous transaction, with control continuing in step S 760 to either step S 725 or step S 714 as appropriate.
If a previous transaction is not to be reused, control continues to step S 765 where control returns to either step S 715 of step S 712 , as appropriate.
FIG. 11 illustrates in greater detail storing information regarding the transaction of step S 735 . In particular, control begins in step S 800 and continues to step S 810 . In step S 810 , the stored transaction information trigger is detected. For example, upon completion of a transaction, the user can be queried as to whether they would like to store the transaction. Next, in step S 820 , information regarding the transaction can be stored in one or more of the STB, service provider network, and communications device, depending on, for example, whether a personal agent or service agent is being used and whether the device from which the transaction request was sent is able to store the transaction information. Then, in step S 830 , a determination is made whether the information should be stored on the communications device. If the information is to be stored on the communications device, control continues to step S 835 . Otherwise, control jumps to step S 845 .
In step S 835 , an agent sends a configuration request to the phone. Next, in step S 840 , the menu item is populated on the phone with control continuing to step S 845 .
In step S 845 , a determination is made whether the transaction information should be stored on the service provider network. If the transaction information is to be stored on the service provider network, control continues to step S 850 , with control otherwise continuing to step S 860 .
In step S 860 , a determination is made whether to store the transaction information on the set-top box, e.g., in a profile. If the transaction information is to be stored on the set-top box, control continues to step S 865 . Otherwise, control jumps to step S 875 .
In step S 865 , an agent sends a configuration request to the set top box. Next, in step S 870 , the menu item is populated on the menuing service, with control continuing to step S 875 .
In step S 875 , the menu item is made available for subsequent transactions. Control then continues to step S 880 where the control sequence ends.
FIG. 12 illustrates in greater detail a social networking application associated with an exemplary embodiment of the present invention. In particular, control begins in step S 900 and continues to step S 910 . In step S 910 , one or more buddy lists of one or more buddies are created. Next, in step S 920 , one or more of rules, rights, and preferences are associated with the one or more buddies. Then, in step S 930 , the status of one or more buddies can optionally be populated on the user's device. In a similar manner, the status of the user can be pushed to other users' devices and their status provided thereon. Control then continues to step S 940 .
In step S 940 , one or more of audio, video and multi-media content can optionally be rendered on other buddies' devices. Snapshots or screen captures or audio sub-clips can also be provided to the other buddies. Next, in step S 950 , information can be exchanged among the buddies via one or more of text messaging, chat, or any other known methods of exchanging information between devices. Control then continues to step S 960 where the control sequence ends.
Below are examples of transactions, the setup of these transaction and options for performing the transaction according to exemplary embodiments of this invention.
In accordance with a first exemplary scenario, a user is assumed to either have a cell phone provided by a service provider or to have a cell phone number that is associated with the phone specially stored as a contact in their profile. In the latter case, an agent in the STB shares the cell phone data with a server in the service provider so that calls from that cell phone can be associated with that user and their specific STB. A user inputs their personal data and financial preferences (including credit card information and preferences, and bank account information and preferences) into their secure profile stored on the STB. At some later time when they make a transaction (like ordering a pizza from a local pizza delivery shop), the personal agent on the STB prompts the user to indicate if they would like this transaction to be stored as a preference for future use. If the user indicates that they would like to store the transaction, then at a still later time, when the user is returning home (where the STB is) and desires to make the same transaction (ordering a pizza), the user can use their cell phone and call the personal agent phone number associated with the STB. The call to the personal agent results in a voice menu being presented to the user from which the user can select the desired transaction orally, for example with the assistance of an agent or an IVR-type system. This request is then sent from the STB with secure payment information to the business providing the requested service for the transaction.
In another exemplary scenario, a user is assumed either to have a cell phone provided by the service provider or to have the cell phone number that is associated with the phone specially stored as a contact in their profile. In the latter case, an agent in the STB shares the cell phone data with a server in the SP so that calls from that cell phone can be associated with that user and their specific STB. The user inputs their personal data and financial preferences (including credit card information and preferences, and bank account information and preferences) into their secure profile stored on the STB. At some later time, when they make a transaction (like ordering a pizza from a local pizza delivery shop), the personal agent on the STB prompts the user to indicate if they would like this transaction to be stored as a preference for future use. If the user indicates that they would like to store the transaction, then at a still later time, when the user is returning home (where the STB is) and desires to make the same transaction (ordering a pizza), the user uses their cell phone and calls a service provider agent service phone number that is associated with a set of servers in the service provider network. The call to the service agent results in the user being presented with a voice menu from which the user can select the desired transaction either orally or based on keyed-in responses. The service agent then uses the association of the cell phone with the user to determine the STB for the user, and then uses this information to launch a secure fetch of the payment information and to send the transaction request to the business providing the requested service for the transaction.
In yet another scenario, a user is assumed either to have a cell phone or some other type of communication device provided by the service provider or to have the cell phone number of the device specially stored as a contact in their profile. In the later case, an agent in the STB shares the cell phone data with a server in the service provider system so that calls from that cell phone can be associated with that user and their specific STB. The user inputs their personal data and financial preferences (including credit card information and preferences, and bank account information and preferences) into their secure profile stored on the STB. At some later time, when the user makes a transaction (like ordering a pizza from a local pizza delivery shop), the personal agent on the STB prompts the user to indicate if they would like this transaction to be stored as a preference to be used in the future. If the user indicates that they would like to store this transaction, the agent sends a configuration request to the user's cell phone so that a menu item associated with the preference is created on the cell phone and made easily accessible in the future. At a still later time, when the user is returning home (where the STB is) and desires to make the same transaction (ordering a pizza), the user uses their cell phone menu button to indicate the request to a set of servers in the service provider network. The request launches a secure fetch of the payment information and sends the transaction request to the business providing the requested service for the transaction.
For another exemplary scenario, a user is assumed either to have a cell phone provided by the service provider or to have the cell phone number of the cell phone specially stored as a contact in their profile. In the latter case, an agent in the STB shares the cell phone data with a server in the service provider network so that calls from that cell phone can be associated with that user and their specific STB. The user inputs their personal data and financial preferences (including credit card information and preferences, and bank account information and preferences) into their secure profile stored on the STB. At a later time, when the user makes a transaction (like ordering a pizza from a local pizza delivery shop), the personal agent on the STB prompts the user to indicate if they would like this transaction to be stored as a preference for future use. If the user indicates that they would like to store the transaction, the agent sends a configuration request to a server in the SP network that provides service menuing to the cell phone. At a still later time when the user is returning home (where the STB is) and desires to make the same transaction (ordering a pizza), the user uses their cell phone to access their menuing preferences stored in the SP network. They select the menu button for the desired transaction, which indicates the request to a set of servers in the SP network. The request launches a secure fetch of the payment information and sends the transaction request to the business providing the requested service for the transaction.
Below are examples of social networking applications based on exemplary embodiments described herein.
In a first exemplary scenario, a user is assumed either to have a cell phone provided by the service provider or to have the cell phone number of the cell phone specially stored as a contact in their profile. In the latter case, an agent in the STB shares the cell phone data with a server in the SP so that calls from that cell phone can be associated with that user and their specific STB. The user inputs their personal data and financial preferences (including credit card information and preferences, and bank account information and preferences) into their secure profile stored on the STB. At a later time, the user indicates, either in their preferences, via a web transaction, or via a cell phone menu, that a group of other SP users are “buddies” of the user. Any user can have a number of buddy groups, and other users can be members of multiple buddy groups for the same user or for different users. A specific buddy group makes up an instance of a social network for the user.
Using methods well known in the art, the presence of each user in the buddy group can be exposed in real-time to the whole group. (Watching a television program, or currently mobile, busy, or off-line, are examples of buddy states). The STB social network agent provides an interface to indicate the buddy state to a network server and to provide the ability to render the state of the user's buddies over the top of a program that the user is viewing. The agent is capable of rendering video and/or audio of both the viewer and the program being viewed to the network server. The network server can in turn render the video and audio in an appropriate format to the other buddies in the users' currently selected group while respecting any copy restriction flags in the program material sent to it. The social network agent in the STB, and an appropriate client in the cell phone then make it possible for the buddies to share their thoughts, feelings, and reactions to the program being watched. Their interaction can be stored on the network server to be accessible to the other buddy list members. Optionally, the conversation can be tagged and made available for search and access by other members of the social network service being provided by the enterprise. Some service providers may give to active buddy groups privileged access to desired material in order to generate interest in the material by other groups.
A number of variations and modifications of the invention can be used. It would be possible to provide for some features of the invention without providing others.
The exemplary systems and methods of this invention have been described in relation to STB's and profile(s). However, to avoid unnecessarily obscuring the present invention, the description omits a number of known structures and devices. This omission is not to be construed as a limitation of the scope of the claimed invention. Specific details are set forth to provide an understanding of the present invention. It should however be appreciated that the present invention may be practiced in a variety of ways beyond the specific detail set forth herein.
Furthermore, while the exemplary embodiments illustrated herein show various components of the system collocated, certain components of the system can be located remotely, at distant portions of a distributed network 10 , such as a LAN, cable network, and/or the Internet, or within a dedicated system. Thus, it should be appreciated, that the components of the system can be combined in to one or more devices, such as a STB, or collocated on a particular node of a distributed network, such as an analog and/or digital communications network, a packet-switch network, a circuit-switched network or a cable network.
It will be appreciated from the preceding description, and for reasons of computational efficiency, that the components of the system can be arranged at any location within a distributed network of components without affecting the operation of the system. For example, the various components can be located in a switch such as a PBX and media server, gateway, a cable provider, in one or more communications devices, at one or more users' premises, or some combination thereof. Similarly, one or more functional portions of the system could be distributed between a communications device(s), such as a STB, and an associated computing device. The one or more functional portions of the system could be also be installed in a TV or TV tuner card, such as those installed in a computer.
Furthermore, it should be appreciated that the various links, such as link 5 , connecting the elements can be wired or wireless links, or any combination thereof, or any other known or later developed element(s) that is capable of supplying and/or communicating data to and from the connected elements. These wired or wireless links can also be secure links and may be capable of communicating encrypted information. Transmission media used as links, for example, can be any suitable carrier for electrical signals, including coaxial cables, copper wire and fiber optics, and may take the form of acoustic or light waves, such as those generated during radio-wave and infra-red data communications.
Also, while the flowcharts have been discussed and illustrated in relation to a particular sequence of events, it should be appreciated that changes, additions, and omissions to this sequence can occur without materially affecting the operation of the invention.
In yet another embodiment, the systems and methods of this invention can be implemented in conjunction with a special purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit element(s), an ASIC or other integrated circuit, a digital signal processor, a hard-wired electronic or logic circuit such as discrete element circuit, a programmable logic device or gate array such as PLD, PLA, FPGA, PAL, special purpose computer, any comparable means, or the like. In general, any device(s) or means capable of implementing the methodology illustrated herein can be used to implement the various aspects of this invention. Exemplary hardware that can be used for the present invention includes computers, handheld devices, telephones (e.g., cellular, Internet enabled, digital, analog, hybrids, and others), and other hardware known in the art. Some of these devices include processors (e.g., a single or multiple microprocessors), memory, nonvolatile storage, input devices, and output devices. Furthermore, alternative software implementations including, but not limited to, distributed processing or component/object distributed processing, parallel processing, or virtual machine processing can also be constructed to implement the methods described herein.
In yet another embodiment, the disclosed methods may be readily implemented in conjunction with software using object or object-oriented software development environments that provide portable source code that can be used on a variety of computer or workstation platforms. Alternatively, the disclosed system may be implemented partially or fully in hardware using standard logic circuits or VLSI design. Whether software or hardware is used to implement the systems in accordance with this invention is dependent on the speed and/or efficiency requirements of the system, the particular function, and the particular software or hardware systems or microprocessor or microcomputer systems being utilized.
In yet another embodiment, the disclosed methods may be partially implemented in software that can be stored on a storage medium, executed on programmed general-purpose computer with the cooperation of a controller and memory, a special purpose computer, a microprocessor, or the like. In these instances, the systems and methods of this invention can be implemented as program embedded on personal computer such as an applet, JAVA® or CGI script, as a resource residing on a server or computer workstation, as a routine embedded in a dedicated measurement system, system component, or the like. The system can also be implemented by physically incorporating the system and/or method into a software and/or hardware system.
Although the present invention describes components and functions implemented in the embodiments with reference to particular standards and protocols, the invention is not limited to such standards and protocols. Other similar standards and protocols not mentioned herein are in existence and are considered to be included in the present invention. Moreover, the standards and protocols mentioned herein and other similar standards and protocols not mentioned herein are periodically superseded by faster or more effective equivalents having essentially the same functions. Such replacement standards and protocols having the same functions are considered equivalents included in the present invention.
The present invention, in various embodiments, configurations, and aspects, includes components, methods, processes, systems and/or apparatus substantially as depicted and described herein, including various embodiments, subcombinations, and subsets thereof. Those of skill in the art will understand how to make and use the present invention after understanding the present disclosure. The present invention, in various embodiments, configurations, and aspects, includes providing devices and processes in the absence of items not depicted and/or described herein or in various embodiments, configurations, or aspects hereof, including in the absence of such items as may have been used in previous devices or processes, e.g., for improving performance, achieving ease and\or reducing cost of implementation.
The foregoing discussion of the invention has been presented for purposes of illustration and description. The foregoing is not intended to limit the invention to the form or forms disclosed herein. In the foregoing Detailed Description for example, various features of the invention are grouped together in one or more embodiments, configurations, or aspects for the purpose of streamlining the disclosure. The features of the embodiments, configurations, or aspects of the invention may be combined in alternate embodiments, configurations, or aspects other than those discussed above. This method of disclosure is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment, configuration, or aspect. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate preferred embodiment of the invention.
Moreover, though the description of the invention has included description of one or more embodiments, configurations, or aspects and certain variations and modifications, other variations, combinations, and modifications are within the scope of the invention, e.g., as may be within the skill and knowledge of those in the art, after understanding the present disclosure. It is intended to obtain rights which include alternative embodiments, configurations, or aspects to the extent permitted, including alternate, interchangeable and/or equivalent structures, functions, ranges or steps to those claimed, whether or not such alternate, interchangeable and/or equivalent structures, functions, ranges or steps are disclosed herein, and without intending to publicly dedicate any patentable subject matter. | Utilization of stored of personalized information and communication preferences in a profile in a STB in a structured format or via cookies allows at least a combination of feature rich telephony applications, with the personalized data stored in STBs facilitating feature rich communications sessions. Providing advanced multimedia communications applications using personalized data resident in STBs could allow an entity to provide, for example, many previously unavailable services, and therefore provide considerable new business potential. The personal information stored in the STB can convey many exemplary benefits, such as communication preferences, alternate contact modalities, payment preferences, priority preferences, trusted contacts, personal information, as well as multimedia messaging, etc. The integration of the personal information with the intelligent personal agent also enhances the user experience. | 93,961 |
BACKGROUND OF THE INVENTION
The present invention relates to an electrode structure for nitride III-V compound semiconductor devices and, more particularly, to a Schottky electrode structure having high adhesion strength and good temperature characteristics.
A conventional hetero-junction field effect transistor (hereinafter referred to as “HFET”) made of nitride semiconductor is generally of such a construction as shown in FIG. 9 . As is shown in FIG. 9, the HFET includes a sapphire substrate 101 , a low temperature grown GaN (gallium nitride) buffer layer 102 having a layer thickness of 20 nm, and a GaN buffer layer 103 having a layer thickness of 2 μm and a carrier density of 5×10 16 cm −3 , the latter two layers being sequentially placed on the substrate. Sequentially stacked on the buffer layer 103 are an AlGaN (aluminum gallium nitride) spacer layer 104 having a layer thickness of 20 nm, an AlGaN donor layer 105 having a layer thickness of 20 nm and a carrier density of 1×10 18 cm −3 , and a GaN contact layer 106 having a layer thickness of 10 nm and a carrier density of 2×10 18 cm −3 .
Source/drain electrodes 107 , 107 using an ohmic contact, and a gate electrode 108 using the Schottky junction are formed on the GaN contact layer 106 .
Generally, metals having a large work function, such as nickel (Ni) (Y.-F. Wu et al, IEEE Electron Device Lett. 18 [1997] 290), platinum Pt (W. Kruppa et al, Electronics Lett. 31 [1995] 1951), and gold Au (U.S. Pat. No. 5,192,987), have been used as Schottky electrode materials for gate electrodes. These metals are ohmic electrode materials relative to p-type semiconductors and are, therefore, used as Schottky electrode materials relative to n-type semiconductors.
However, these metals will show relatively weak adhesion to the semiconductor and, at temperatures of 400 ° C. or more, the metals will give rise to the problem of increased current leaks, with the result that the HFET is very much deteriorated in its characteristics.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide an electrode structure for nitride III-V compound semiconductor devices, the electrode structure including a Schottky electrode having a high adhesion to a semiconductor and good temperature characteristics.
In order to solve the above object, present inventors made an extensive research and, as a result, it was found that the electrode structure described below would be effective as a solution. This finding led to the present invention.
That is, in nitride III-V compound semiconductor devices, it was found that a nitride o f a metal having a nitride forming negative free energy could provide a Schottky electrode showing a high adhesion to semiconductors and good temperature characteristics. The reason for this is that the formation of the metallic nitride on a nitride semiconductor leads to the formation of a chemical bond through nitrogen atoms, resulting in a stronger bond than prior art semiconductor/metal interfaces.
Therefore, an electrode structure for nitride III-V compound semiconductor devices in accordance with the present invention is characterized in that a metallic nitride is used as an electrode material, a metallic material of the metallic nitride having a negative nitride formation free energy.
The metallic nitride should show a metallic conductivity in order to play a role of an electrode.
As examples of metals having a negative nitride formation free energy and at the same time forming a metallic nitride showing a metallic conductivity, mention may be made of metals included in the IVa, Va, and VIa groups. Such metals are exemplified by titanium (Ti) and zirconium (Zr) belonging to the IVa group, vanadium (V), niobium (Nb) and tantalum (Ta) belonging to the Va group, and chromium (Cr), molybdenum (Mo), and tungsten (W) belonging to the VIa group. Hafnium (Hf) is an exception and use of this material is undesirable because its nitride formation free energy is positive. As Table 1 given below tells, the tabulated data of metals shown indicates that all of the metals show a negative nitride formation free energy. The larger the formation free energy in the negative direction, the better. The reason for this is that the resulting metallic nitride is more stable and, in particular, Zr, Ti, Ta, and Nb having a formation free energy of not more than −50 kcal/mol are preferred.
TABLE 1
Nitride
Formation
Melting
Melting
Free
Point
Nitride
Point
Energy − *
Metal
(° C.)
Form
(° C.)
(kcal/mol)
Ti
1668
Tin
2950
−74
Zr
1852
ZnN
2980
−87
Hf
2230
HfN
3000
81
V
1887
VN
2050
−35
Nb
2468
NbN
2300
−51
Ta
2996
TaN
3087
−54
Cr
1907
CrN
1500
−24
Mo
2617
Mo 2 N
—
−12
W
3407
W 2 N
—
−11
*“Structure and Properties of Inorganic Solids” by F. S. Galasso (1970), Pergamon Press Inc.
The metal material for these metallic nitrides may be a single metal or a composite metal comprised of two or more kinds of metals. These metals have a high melting point and, accordingly, nitrides of the metals have a high melting point and are thermally stable, being thus able to exhibit good temperature characteristics.
From the standpoint of thermal stability, it is desirable that the melting points of the metals and metallic nitrides be as high as possible, while some correlation can be observed between the melting points of metals and the melting points of metallic nitrides through the formation free energy. That is, in case that even if the melting point of a metal is relatively low, but if its formation free energy is large, the melting point of a nitride of the metal tends to rise. Therefore, from the standpoint of thermal stability, Zr, Ti, Ta, Nb are preferred.
For depositing such a metallic nitride, various methods, such as molecular beam epitaxy using a nitrogen radical and a reactive sputtering method, can be employed.
A suitable thickness range of the metallic nitride layer formed in this way is not less than 10 nm but not more than 200 nm. If the thickness of the metallic nitride is less than 10 nm, the metallic nitride layer does not form a continuous layer, and this poses a problem that no satisfactory reproducibility could be obtained with respect to the characteristics of the metallic nitride layer. On the other hand, the thickness of the metallic nitride which is more than 200 nm will cause a problem of deterioration of the electrical characteristics and crystallinity of a GaN semiconductor layer due to the stress of the metallic nitride layer.
Further, in order to facilitate bonding of lead wire onto the metallic nitride layer, a layer comprised of Au or an Au alloy may be placed on the metallic nitride layer. The Au alloy is not particularly limited; as long as it is superior to Au in hardness, the alloy is acceptable. As a method of depositing Au or an Au alloy, vacuum deposition and sputtering may be mentioned, but are not limitative. By depositing Au or an Au alloy on the metallic nitride, it is possible to reduce the contact resistance of a contact portion between the electrode and the lead wire and hence generation of heat from the contact portion to thereby further improve the characteristics of the electrode.
Thus, a schottky electrode having high film adhesivity and a good temperature characteristic can be obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 is a schematic sectional view of a nitride III-V compound semiconductor device having a first embodiment of the electrode structure of the present invention;
FIG. 2 is an I-V characteristic diagram of a ZrN film of the semiconductor device;
FIGS. 3A, 3 B, and 3 C are I-V characteristic diagrams of the semiconductor device after annealing at temperatures of 500° C., 643° C., 800° C., respectively.
FIGS. 4A and 4B are, respectively, an I-V characteristic diagram of a comparative example in relation to a second embodiment after deposition of a Ti film and before annealing, and an I-V characteristic diagram of the second embodiment after deposition of a TiN film and before annealing;
FIGS. 5A and 5B are, respectively, an I-V characteristic diagram of the comparative example after the annealing preceded by the Ti film deposition, and an I-V characteristic diagram of the second embodiment after the annealing preceded by the TiN film deposition;
FIGS. 6A and 6B are, respectively, an I-V characteristic diagram of a metal/semiconductor interface structure of the comparative example after the Ti film deposition but before the annealing, and a metal/semiconductor interface structure after annealing the Ti film deposited structure;
FIGS. 7A and 7B are, respectively, a diagram showing a metal/semiconductor interface structure of the second embodiment after the TiN film deposition but before the annealing, and a diagram showing a metal/semiconductor interface structure after the annealing preceded by the TiN film deposition;
FIG. 8 is a schematic sectional view of a nitride III-V compound semiconductor device having a third embodiment of the electrode structure of the present invention; and
FIG. 9 is a schematic sectional view of the conventional HFET.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the invention will now be described in detail with reference to the accompanying drawings.
First Embodiment
FIG. 1 schematically shows the construction of a semiconductor device having an electrode structure according to a first embodiment of the invention. The semiconductor device has a (0001) sapphire substrate 1 , a low temperature grown AlN (aluminum nitride) buffer layer 2 formed on the substrate 1 and having a thickness of 20 nm, an n-type GaN layer 3 formed on the buffer layer 2 and having a carrier density of 2×10 18 cm −3 and a layer thickness of 1 μm, and ZrN (zirconium nitride) electrodes 4 formed on the n-type GaN layer 3 .
In the electrode structure of the present embodiment, the ZrN electrodes 4 were formed by the reactive sputtering process. This process was carried out in the following way.
First, with zirconium (Zr) used as a target, the flow rate of argon gas and the flow rate of nitrogen gas were set to 30 sccm and 12 sccm respectively, and sputtering was carried out at the power of 70 W. Thus, a ZrN electrode 4 comprised of a ZrN film having a thickness of 100 nm was formed on the n-type GaN layer 3 .
FIG. 2 shows I-V characteristics of the GaN layer 3 after deposition of the ZrN film. As shown in FIG. 2, according to the electrode arrangement of the present embodiment, it is possible to obtain a satisfactory Schottky characteristic of a turn-on voltage on the order of 1.5 V.
FIGS. 3A, 3 B, and 3 C show I-V characteristics at annealing temperatures of 500° C., 643 ° C., and 800° C., respectively. As shown in FIGS. 3A, 3 B, and 3 C., no change was observed among the I-V characteristics at annealing temperatures 500° C., 643° C., and 800° C. (annealing time: 6 minutes each). That is, experiments have proved that the ZrN electrode structure exhibits a thermally stable Schottky characteristic.
Second Embodiment
Next, a second embodiment of the invention will be described. A semiconductor device having an electrode structure of the second embodiment is different from the semiconductor device having the electrode structure of the above described first embodiment only in that the zirconium nitride electrode 4 shown in FIG. 1 was replaced by a titanium nitride (TiN) electrode.
FIG. 4B shows I-V characteristics of the n-type GaN layer 3 of the semiconductor device having a nitride titanium electrode of this second embodiment. The I-V characteristics were measured in the condition of the device prior to annealing, and good Schottky characteristic was witnessed, which showed a turn-on voltage of the order of 1.2 V. FIG. 5B shows I-V characteristic measured after annealing was carried out at 500° C. for 10 minutes. After annealing the n-type GaN layer 3 also showed good Schottky characteristic such that the turn-on voltage was of the order of 1.2 V, which was almost same as the I-V characteristic before annealing.
Whilst, as a comparative example in relation to the foregoing example, in FIG. 4A is shown the I-V characteristic of an n-type GaN layer 3 of a semiconductor device including a titanium (Ti) electrode in place of the titanium nitride (TIN) electrode, and in FIG. 5A is shown the I-V characteristic after annealing at 500° C. for 10 minutes.
Where Ti is deposited on the n-type GaN layer in place of TiN, a characteristic having a slight deviation from an ohmic characteristic was observed in the condition after film deposition, as shown in FIG. 4A, but as FIG. 5A shows, a perfect ohmic characteristic was obtained by annealing.
In contrast, according to the present embodiment, as already mentioned, after film or layer deposition, and even after annealing, nearly same good Schottky characteristics were achieved.
The reason for this is explained hereinbelow.
If Ti is deposited on the n-type GaN layer 3 to form a Ti electrode 61 , as shown in FIG. 6A corresponding to the comparative example, and then annealing process is carried out, an intermediate layer (GatiN) 62 is formed at the interface between the n-type GaN layer 3 and the Ti 61 , as shown in FIG. 6B, in which the composition continuously changes like GaN/GaTiN/TiN/Ti. By virtue of the presence of the intermediate layer (GaTiN) 62 , the ohmic characteristic is obtained.
In contrast to the comparative example, when TiN is deposited on the n-type GaN layer 3 as shown in FIG. 7A to form a TiN electrode 63 according to the second embodiment, a steep interface between GaN and TiN is maintained even after the annealing process, as shown in FIG. 7 B. By virtue of the presence of the steep GaN/TiN interface, good Schottky characteristics are obtained.
Third Embodiment
Next, the electrode structure of the third embodiment of the invention is described with reference to FIG. 8 . The electrode structure of the third embodiment is different from the electrode structure of the first embodiment in that the third embodiment has a layer 5 made of an alloy of gold (Au) on the ZrN film 4 . After deposition of the ZrN film 4 on the n-type GaN layer 3 to the thickness of 100 nm, in succession a gold (Au) alloy (AuCr in the present case) is deposited thereon by sputtering process to form the AuCr layer 5 . By depositing an Au alloy on a metallic nitride (zirconium nitride in the present case), the contact resistance of the electrode and lead wire can be reduced. Thus, it is possible to minimize heat generation at the contact portion therebetween, resulting in further improvement on the characteristics of the electrode. While a gold alloy (AuCr) is deposited on zirconium nitride in the present embodiment, gold (Au) may be deposited on the zirconium nitride. Further, other gold alloys may be used.
In the first, second and third embodiments, for component metals of the metallic nitride, titanium (Ti) and zirconium (Zr) are used, but where other metals belonging to the IVa, Va, and/or VIa groups, such as niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), vanadium (V), and tungsten (W), are used, same effect as in first, second and third embodiments can be obtained.
Test Results
Schottky electrodes were formed using metallic nitrides shown in Table 1 (see the “SUMMARY OF THE INVENTION” column), except Mo and W, and acceleration tests on leak current under reverse bias were carried out. The acceleration tests were conducted under the conditions of 800° C. and 1,000 hours of duration time. Percentages of change in leak current at reverse bias voltage of 50 V are shown in Table 2 below. For the purpose of comparison, percentages of change in the case of Pt and Ni are also shown in Table 2.
TABLE 2
Electrode Material
Change (%)
TiN
0.5
ZrN
0.5
VN
0.9
NbN
0.5
TaN
0.4
CrN
0.9
Pt
400
Ni
800
Percentages of change in leak current of metallic nitrides were all below 1%, and good thermal stability was witnessed. Whilst, in the case of Pt and Ni, the amount of change was very noticeable, showing they are thermally unstable electrode materials.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | In an electrode structure for a nitride III-V compound semiconductor device, a metallic nitride is used as an electrode material. A metallic material of the metallic nitride has a negative nitride formation free energy, and comprises at least one metal selected from a group consisting of IVa-group metals such as titanium and zirconium, Va-group metals such as vanadium, niobium, and tantalum, and VIa-group metals such as chromium, molybdenum, and tungsten. | 21,140 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to devices and method for treating a patient with compression, and in particular, to techniques employing separate shells.
[0003] 2. Description of Related Art Edema is a medical condition that requires careful treatment. Lymphedema, a type of edema, is a swelling of a body part, often the result of the abnormal accumulation in the affected area of protein-rich edema fluid (primarily lymph fluids). Lymphedema is classified as either primary or secondary. Primary lymphedema is the result of lymphatic dysplasia. It may be present at birth but more often develops later in life without obvious cause. Secondary lymphedema is much more common and is the result of surgery or is a side effect of radiation therapy for cancer. Secondary forms may also occur after injury, scarring, trauma, or infection of the lymphatic system. Lymphedema treatment options offered in the United States include surgery, medication, pneumatic compression pump therapy, Manual Lymph Drainage (MLD), and Complete Decongestive Therapy (CDT).
[0004] Surgery and medication have their place, but their success is not guaranteed and comes with risks. The pneumatic compression pump is a mechanical device that “milks” the lymph fluid out of the swollen extremity. The problems with pneumatic pumps are numerous and any results achieved are usually very temporary.
[0005] Lymphedema physical therapy treatment would not be possible without compression therapy employing bandages and elastic compression garments. Elastic compression garments are easily used and sold under the trade names: Solaris, JoviPak, CircAid, Biacare, and Reid Sleeve. Another compression therapy involves bandaging with short stretch bandages and is a highly skilled procedure designed to take advantage of natural pumping pressures.
[0006] Lymph is propelled through the various lymph vessels by muscular activity, breathing, etc. Bandaging/garments improve the efficiency of the muscle and joint pump and also prevents the re-accumulation of evacuated lymph fluid. These techniques will also break up deposits of accumulated scar and connective tissue.
[0007] The nature of compression varies greatly when a comparison is made between short stretch bandages and elastic compression garments. Both are necessary complements to a program of Complete Decongestive Therapy (CDT) when utilized by competent and well-trained therapists. The distinction lies in the working and resting forces generated by these two forms of compression. Elastic compression garments are designed to provide a pressure gradient favoring proximal fluid flow and are comfortable and convenient. However, they tend to produce constant resting pressure without enhanced working pressure. Short stretch compression bandages supports a limb without constant “squeezing” (i.e. will exhibit low resting pressure), but when a limb is exercised produces relatively high working pressure.
[0008] No effective homecare device exists to maintain/reduce lymphedema/edema consistent with the principles of CDT (Complete Decongestive Therapy). Therefore, patients are saddled with the responsibility of life-long lymphedema control, but the task is arduous, tedious and time consuming. When self-applied compression is performed with less than sufficient skill, it can also be painful, counter-therapeutic or even damage the limbs' health.
[0009] Aftermarket compression products have tried alternative solutions to replace multilayered compression bandages. Treatment at joints is most problematical for these products. Even at the limb segments (between joints) the solutions offered utilize unsatisfactory materials and tensioning techniques to generate pressure. As a result these products lack continuous working pressure (cast-like containment) longitudinally as well as structure to prevent buckling and bulging of tissues.
[0010] See also U.S. Pat. Nos. 4,676,233; 5,152,302; 6,526,592; 6,785,905; 7,135,005; and 6,991,612; as well as US Patent Application Publication Nos. 2005/0066412; 2006/0135902; and 2008/0228117.
SUMMARY OF THE INVENTION
[0011] In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided a compression device for treating edema. The device includes a plurality of curved shells, each having an internal pad. The device also includes a ligature network routed across the plurality of shells. The network includes a plurality of tensioners. The tensioners are mounted on at least some of the plurality of shells and are operable to separately adjust tension in different portions of the ligature network.
[0012] In accordance with another aspect of the invention, a compression device is provided for treating edema. The device includes a plurality of curved shells, each having an internal pad. The device also includes a ligature network routed across the shells. The ligature network includes a plurality of tensioners mounted on at least some of said plurality of shells. At least at least a portion of the ligature network is releasably mounted and repositionable on the shells to allow spatial adjustment of compression forces produced by said compression device
[0013] In accordance with yet another aspect of the invention, a method is provided for treating edema with a ligature network and a plurality of padded shells. The method includes the step of routing the ligature network across the plurality of shells. Also, with a body part embraced by the padded shells, the method performs the step of separately adjusting tension in different portions of the ligature network to affect the balance of compression forces at spaced positions along the plurality of padded shells.
[0014] In accordance with still yet another aspect of the invention, a method is provided for treating edema with a ligature network and a plurality of padded shells. The method includes the step of adjusting routing of the ligature network across the plurality of shells to provide tailored compression forces at spaced positions along the plurality of padded shells. Also, with a body part embraced by the padded shells, the method performs the step of adjusting tension in the ligature network to adjust compression forces along the plurality of padded shells.
[0015] By employing devices and methods of the foregoing type an improved technique is achieved for treating edema. For example, lymphedema limb areas need not be immobilized and the present device does not function as a cast or an immobilizer. Areas of joint articulation can sustain movement without abrasion or discomfort. The natural muscle and joint pumps will be allowed to activate a natural fluid pumping effect. Allowing movement within a compression device tends to reverse lymphostatic fibrosis.
[0016] A disclosed embodiment is presented for treating the hand, although treatment of other body parts is described. The embodiment for treating the hand employs a pair of padded shells, one placed on the palm and one on the dorsum.
[0017] These padded shells each have a heat-treatable, plastic panel that is relatively stiff, so that the shells can apply transaxial pressure without squeezing the hand laterally. This arrangement cancels out high lateral pressures, and accentuates high dorsal and palmar pressures.
[0018] These panels are fashioned to accommodate the specific body part being treated. For example, an outline of a hand may be applied to plastic panels and used to trim them accordingly, although the final panel outline need not follow the exact outline of the hand. Typically, the panel will be notched to allow articulation of the thumb.
[0019] The panels may be heated to soften and bend them into a curve that accommodates the curves of the hand or other body part under treatment.
[0020] Lymphedema is a staged condition according to disease severity (stages 1, 2, 3). As such it requires modifications in the approach according to the quantity of swelling and tissue integrity. The above noted shells apply the external force, but inner-padding materials must be tailored to modify the force according to the disease severity, desired gradient of pressure, limb girth and abnormal contours if any.
[0021] With this in mind, the inside of the disclosed panels will be fitted with pads; for example, multiple layers of foam material. In one case the layer on the plastic panel is a closed cell foam that readily accommodates transaxial force, while the layer contacting skin tissue is an open cell foam that conforms more closely to the curves of the hand and increases comfort. In some cases one or more of the layers will not be one continuous piece, but will be formed from multiple disjoint segments that are fashioned to tailor the pressure being applied to the body part under treatment.
[0022] Proper treatment requires that skin integrity be preserved to combat any localized immune deficiency. To address this requirement the shells' pads ought to be hypoallergenic, customized to the patient, and hygienic. Moreover, any inner layer in contact with the skin should be exchanged regularly.
[0023] Lymphedema treatment requires that a gradient of pressure be exerted regardless of the contour of the swollen limb. Pressure applied to hypothetical conical shapes will respond according to the “law of Laplace” (P=Tc/R), however swollen limbs are not always conical. To address this anatomical requirement “zones” of pressure are created and padding modified suitably to direct fluid from distal areas towards proximal areas. Limbs that have received treatment in the clinic (e.g., with CDT) become more normally shaped (from columnar to conical again) and readily responsive to the above compression device.
[0024] In order to achieve an appropriate pressure, a disclosed embodiment employs a ligature network that is formed from a number of cords that are routed across the padded shells. Specifically, these cords are routed through guides strategically placed at various locations on the opposing shells. A disclosed network has two circuits that are independently tightened by two tensioners. The disclosed tensioners are cord winders placed in strategic locations on one or more of the shells.
[0025] In this embodiment, the guides and winders are easily repositioned to modify the routing of the cords in the ligature network. Specifically, the guides and winders are attached to the outside of the shells by hook and loop fasteners.
[0026] Devices of this type may be used as an adjunct to, or a follow-up after, professional therapy. Also, after the initial fitting of the device, a user will be able to readily remove the device and later place it back on the body part under treatment without the need for professional assistance. In addition, since the tension in the ligature network is readily adjusted, a user can easily adjust tension throughout the day as needed.
[0027] Devices according to the foregoing principles can achieve high working pressure, and low resting pressure throughout. Such devices are adaptable to the edema reduction process by allowing movement, and normal activity. In the disclosed embodiment, tension is easily adjusted so a user is able to regularly conduct subtle re-tensioning.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The above brief description as well as other objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of illustrative embodiments in accordance with the present invention when taken in conjunction with the accompanying drawings, wherein:
[0029] FIG. 1 is a top view of a compression device in accordance with principles of the present invention;
[0030] FIG. 2 is a bottom view of the compression device of FIG. 1 ;
[0031] FIG. 3 is a side view of the compression device of FIGS. 1 and 2 ;
[0032] FIG. 4 is a sectional view of a fragment of one of the padded shells of the device of FIGS. 1 and 2 ;
[0033] FIG. 5 is a side view of one of the tensioners of FIG. 1 ;
[0034] FIG. 6 is a perspective view of one of the guides of FIGS. 1 and 2 ;
[0035] FIG. 7 is a perspective view of the curved guide of FIG. 2 ;
[0036] FIG. 8 is a fragmentary, perspective view of a tensioner in a ligature network that is an alternate to that shown in FIGS. 1 and 2 ;
[0037] FIG. 9 is an inside view of a padded shell that is an alternate to that shown in FIG. 2 ;
[0038] FIG. 10 is a perspective view of a compression device that is an alternate to that shown in FIGS. 1-3 ;
[0039] FIG. 11 is an end view of the device of FIG. 10 ; and
[0040] FIG. 12 is an end view of a device that is an alternate to that of FIG. 11 .
DETAILED DESCRIPTION
[0041] Referring to FIGS. 1-7 , the illustrated compression device has a palmar shell 10 and a dorsal shell 12 , each designed for right hand H. Each of the shells 10 and 12 have a heat-deformable plastic panel 14 ( FIG. 4 ). Various types of thermoplastics will operate satisfactorily as a panel, and the Aquaplast® moldable sheets from Patterson Medical (1.6 to 3.2 mm thick, perforated) will operate satisfactorily. Panel 14 ought to be relatively stiff in order to transmit compression forces normal to its surface. In this embodiment the opposite faces of panel 14 have a coterminous covering 16 and 18 in the form of a sheet of hook and loop material (loop material prominent) on a breathable plastic substrate.
[0042] FIG. 1 shows the outline of padded shell 12 , it being understood that the right and left edges are rolled about 45°, except at the extension 12 A provided for thumb T. One can establish the outline of shell 12 by tracing the outline of the hand (hand H of FIG. 2 ) on panel 14 and trimming appropriately. The trimmed panel 14 will have additional material for the rolling of the right and left panel edges and will make accommodations for the extended thumb region 12 A.
[0043] Thereafter, panel 14 can be heated by, for example, immersion in hot water. When heated, the right and left edges of panel 14 can be rolled as noted above, while the central region can be given an appropriate curve to accommodate the natural curves of hand H. The outline and curvature of panel 14 may be refined based on the judgment and experience gathered by a properly trained therapist. Also, after an initial shaping, panel 14 can be placed against hand H to determine what areas need correction before possibly trimming and reshaping the panel again.
[0044] FIG. 2 shows the outline of padded shell 10 with the right and left edges again rolled about 45°, except in the vicinity of notch 10 A provided for thumb T. Panel 14 of shell 10 can be trimmed and curved in a manner similar to that described in connection with shell 12 .
[0045] The faces of panels 14 of shells 10 and 12 that face the skin are fitted with an internal pad, shown in FIG. 4 as a pair of resilient layers 20 and 22 . Layers 20 and 22 will be trimmed to be coterminous with their associated shells 10 and 12 .
[0046] Distal layer 20 may be formed of a closed cell foam material of the type typically used in compression therapy for lymphedema patients. Such lymphedema grade foams are available under the trade names Jobst Foam or Komprex Foam. Foams of this type are resilient but still tend to transmit compression forces substantially perpendicular to shell panel 14 . Layer 20 will be secured onto hook and loop material 18 , using, if necessary, an additional hook and loop sheet (hooks prominent).
[0047] It is desirable that proximal layer 22 be more compliant than layer 20 to add to the wearer's comfort. Also, a softer material will tend to feather the compression forces near the edges of the device, thereby avoiding the tendency to apply undesired lateral compression. Open cell foam material has been found satisfactory for this purpose, although other types of resilient materials can be used as well. An acceptable open cell foam material is available from Canal Rubber Supply Co. of New York (light to medium density).
[0048] In this embodiment layer 22 is ½ inch thick (1.3 cm). In other embodiments the layer thickness may be varied, although typically remaining within a range of ¼ to ¾ inch (0.6 to 1.9 cm) thick, with the thickness chosen to accommodate the needs of the patient.
[0049] Padded shells 10 and 12 are pressed together with a ligature network employing nylon cords arranged in a pair of circuits 24 and 26 . Circuit 24 terminates at network tensioner 28 , while circuit 26 terminates at network tensioner 30 . In this embodiment tensioners 28 and 30 are identical, but need not be so. Circuit 24 has cord segment 24 A running atop shell 12 through plastic tube 36 A, which tube is designed to decrease cord friction. Cord segment 24 A traverses the edge of shell 12 and crosses over to run atop shell 10 , as shown by cord segment 24 B.
[0050] Cord segment 24 B is threaded through network guide 32 A, which is releasably secured atop shell 10 . Guide 32 A is shown in FIG. 6 as a slab 32 A- 1 supporting sleeve 32 A- 2 , which has through bore 32 A- 3 for receiving previously mentioned cord segment 24 B. A sheet of hook and loop fastening material 32 A- 4 glued on the underside of slab 32 A- 1 is designed to releasably attach guide 32 A to mating sheet 16 ( FIG. 4 ) on shell 10 . Guide 32 A is identical to guides 32 B, 32 C, 32 D and 32 E shown in FIGS. 1 and 2 (these guides sometimes being referred to as annular implements).
[0051] Cord segment 24 B traverses the edge of shell 10 and passes between forefinger I and middle finger M before running atop shell 12 , as shown by cord segment 24 C. Cord segment 24 C is threaded through guides 32 B and 32 C, which are mounted atop shell 12 . Cord segment 24 B traverses the edge of shell 12 and passes between ring finger A and pinky finger S before running atop shell 10 , as shown by cord segment 24 D. Cord segment 24 D is threaded through guide 32 D, which is releasably secured atop shell 10 . Cord segment 24 D traverses the edge of shell 10 to run atop shell 12 , as shown by cord segment 24 E. Cord segment 24 E passes through friction reducing tube 36 B.
[0052] Referring now to circuit 26 , cord segment 26 A runs atop shell 12 and traverses the edge of shell 12 before running atop shell 10 as shown by cord segment 26 B. Cord segment 26 B is threaded through guide 32 E, which is releasably secured atop shell 10 . Cord segment 26 B traverses the edge of shell 10 before running atop shell 12 , as shown by cord segment 26 C, which passes through friction reducing tube 36 C. Cord segment 26 C traverses the edge of shell 12 before running atop shell 10 , as shown by cord segment 26 D. Cord segment 26 D runs through a channel in network guide 34 , which is releasably secured atop shell 10 .
[0053] In FIG. 7 guide 34 is shown with a platform 34 A having a curved outside edge (approximately a quarter circle curve) and an inside edge leading to a curved wall 34 B (approximately a quarter circle curve). A similarly curved shelf 34 C projecting from atop wall 34 B forms a curved channel 34 D to guide previously mentioned cord segment 26 D. Hook and loop fastener 34 E glued on the underside of platform 34 A will releasably attach guide 34 to hook and loop fastening material 16 atop shell 10 .
[0054] Tensioner 28 is shown in FIG. 5 having a dial 28 A rotatably mounted on body 28 B, which sits atop base 28 C. Cord segment 24 A is shown passing through hole 28 D in body 28 B. It will be appreciated that cord segment 24 E passes through another hole (not shown) on the other side of body 28 B. Tensioner 28 operates as a manually operable winder. Specifically, dial 28 A can be rotated clockwise (counterclockwise) to wind (unwind) cord segments 24 A relative to a reel (not shown) inside winder body 28 B. Cord segment 24 E will not be wound although winding may be implemented in other embodiments. Winders of this type can be obtained from Boa Technology, Inc. of Steamboat Springs, Colo.
[0055] A sheet of hook and loop material 28 E is glued to the underside of winder base 28 C to act as a fastening device that will releasably attach the winder 28 by mating to hook and loop material 16 atop shell 12 ( FIG. 1 ).
[0056] Referring to FIG. 8 , a different type of manually operable winder (tensioner) is illustrated. Components corresponding to those previously described in connection with FIG. 5 have the same reference numeral but increased by 100 . The winder 128 has mounted atop base 128 C a body 128 B containing a winding reel (not shown) that is driven by dial 128 A. Rotation of dial 128 A will wind or unwind band 124 A, which will be part of a ligature network similar to that previously described. However, in this embodiment, winder 128 only works with one end of band 124 A, whose opposite end may either be anchored at another location or connected to another winder. Moreover, band 124 A is not routed in a closed circuit in this embodiment.
[0057] An alternate guide 132 A is shown as a cloth strip stitched into a loop that holds annular implement 133 . Band 124 A is shown routed through implement 133 . Cloth loop 132 A may be attached atop a padded shell by hook and loop fastening means, snaps, mechanical clips, etc.
[0058] Referring to FIG. 9 , palmar shell 10 ′ is designed for left hand H′ and is substantially the mirror image of shell 10 of FIG. 2 . As before, shell 10 ′ has a heat deformable plastic core 14 with the same covering 16 and 18 as mentioned previously. In this embodiment, the layer 20 previously mentioned in FIG. 4 has been replaced with three disjoint segments 120 A, 1208 and 120 C (also referred to as discrete panels). While three segments are shown, in other embodiments a greater or lesser number may be employed instead.
[0059] Segment 120 A is an elongated slab with rounded ends designed to engage the knuckles of hand H′. Segment 120 B has a teardrop shaped outline and is designed to engage the fleshy part of the palm at the base of thumb T′. Segment 120 C is shaped to treat most of the remaining area of the palm of hand H′ and has an outline that is roughly a triangle with rounded corners. Segment 120 C is given some flexibility to bend along one of its edges by a pair of grooves 38 .
[0060] It will be appreciated that the chosen outline, placement, thickness, and materials of segments 120 A- 120 C will be tailored by the therapist that sets up the device, these choices being made to accommodate and best treat hand H′. Also, each of the discrete segments 120 A- 120 C may be formed from the same material as layer 20 of FIG. 4 , but in some cases each of the segments may use a different material with different characteristics adapted to accommodate the hand H′ under treatment.
[0061] Panel segments 120 A- 120 C may be overlaid (face to face) with a full panel (not shown) having an outline substantially the same as that of core panel 14 and made of material similar to panel 22 of FIG. 4 . In other embodiments the roles may be reversed with the layer adjacent to the skin tissue being segmented, and the other layer being continuous.
[0062] Referring to FIG. 10 , the illustrated compression device is designed to treat a different body part, namely forearm F instead of hand H. Components in this Figure corresponding to those of the embodiment of FIGS. 1-7 have the same reference numerals but increased by 200 . Padded shell 212 is shown on the extension side of forearm F and padded shell 210 is shown on the volar side of the forearm. Shells 210 and 212 are roughly semicylindrical and are layered in substantially the same manner as shown in FIG. 4 .
[0063] Mounted on shell 212 are winders 230 and 228 , which each have independently adjustable circuits 224 and 226 , respectively. Winder 228 is shown connected to cord segments 224 A and 224 E of circuit 224 . Winder 230 is shown connected to cord segments 226 A and 226 E of circuit 226 .
[0064] Circuit 224 extends along cord segment 224 E on shell 212 , crossing over to shell 210 to form cord segment 224 D, which passes through guide 232 D before returning to shell 212 to form the cord segment 224 C, passing through guide 232 C. Cord segment 224 C will pass through another guide (not shown) before taking a looping turn on a guide (not shown) on shell 210 , eventually returning as cord segment 224 A. It will be appreciated that circuit 224 has topographically the same routing as circuit 24 of FIGS. 1 and 2 .
[0065] Circuit 226 is topographically the same as circuit 26 of FIGS. 1 and 2 . Specifically, cord segment 226 A crosses from shell 212 to shell 210 where cord segment 226 B passes through guide 232 E on shell 210 before returning to shell 212 to form cord segment 226 C. Cord segment 226 C will make a looping turn on a guide (not shown) on shell 210 before returning as cord segment 226 E. It will be appreciated that circuit 226 has topographically the same routing as circuit 26 of FIGS. 1 and 2 .
[0066] A third winder 40 on shell 212 connects to a third independently adjustable circuit 42 at cord segments 42 A and 42 E. Circuit 42 cooperates with a pair of guides at the proximal corner of shell 212 , one such guide being shown as guide 44 B. Guide 44 A is mounted along the edge of shell 210 and a corresponding guide (not shown) is mounted at the opposite edge of shell 210 at the same longitudinal position.
[0067] Cord segment 42 A extends across shell 212 , crossing over to shell 210 where cord segment 42 B passes through guide 44 A before returning to shell 212 to form cord segment 42 C, which passes through guide 44 B and the complementary guide on the other side of shell 212 . It will be appreciated that cord segment 42 C crosses over to shell 210 and loops back in a manner similar to that shown for cord segment 42 B.
[0068] As before, winders 228 , 230 and 40 are releasably secured to shell 212 to allow a therapist to adjust the position of each. Similarly positionable are the guides (e.g., illustrated guides 232 C- 232 E and 44 A- 44 B).
[0069] As shown in FIG. 11 , previously mentioned padded shells 210 and 212 have gaps at approximately the three o'clock and nine o′clock positions. In other embodiments such as shown in FIG. 12 three shells 46 , 48 , and 50 may be arranged with gaps at approximately the two o'clock, six o'clock and 10 o'clock positions (i.e., shell 46 on the extension side and shells 48 and 50 primarily on the volar side).
[0070] While the devices of FIGS. 10-12 are mentioned for treating a forearm, they can equally be applied to different body parts such as the upper arm, calf, or thigh.
[0071] To facilitate an understanding of the principles associated with the foregoing apparatus, its operation will be briefly described in connection with the embodiment of FIGS. 1-7 .
[0072] Heat deformable panel 14 is trimmed to size based on the size and proportions of hand H. To customize padded shell 12 , hand H may be placed atop panel 14 , palm up, and the outline of the hand may be traced with a pencil or other writing instrument. Panel 14 will then be trimmed to extend longitudinally from the end of the wrist to the base of the fingers. Panel 14 will also be trimmed to extend from the right to the left edge of the hand H with a little excess to allow the panel to curl slightly around the edge of the hand. Panel 14 will be allowed to extend outwardly slightly outwardly along extension 12 A to cover a portion of the thumb knuckle. This extension will be useful in applying pressure in this region without restricting the mobility of thumb T.
[0073] To customize padded shell 10 , hand H may be placed atop panel 14 , palm down, and the outline of the hand may be traced with a pencil or other writing instrument. Panel 14 will be trimmed as before except that previously mentioned thumb extension 12 A will be replaced with a thumb notch 10 A. This notch will be useful in allowing articulation of thumb T. In fact, the wrist, thumb T and all the fingers of hand H can be moved so the user will retain most of the function of hand H. This ability to move the wrist and fingers and thereby exercise the hand will enhance the natural ability of the body to reduce edema by means of the natural pumping action produced when exercising the fingers and wrist.
[0074] Panels 14 of shells 10 and 12 can be further shaped by immersion in hot water to soften the panels. The panels may be curved in a general way to accommodate the shape of hand H. Special attention may be given to the right and left edges of panel 14 to roll these edges slightly around the hand H. For thumb extension 12 A, panel 14 may be bowed about the thumb axis to provide a proper fit.
[0075] The foregoing trimming and shaping may be performed after a session with a therapist who examines and measures hand H. The therapist may either personally perform the trimming and shaping, but in some cases the information gathered by the therapist will be sent to a specialized lab along with a general description of the characteristics of hand H, so that the lab can customize the panel 14 . In any event, this trimming and shaping will be based upon a therapist's experience and judgment.
[0076] Pads 20 and 22 ( FIG. 4 ) may be provided as a kit having a variety of padding materials. The materials will offer a selection of different thicknesses, softness, etc. As noted above, the padding materials can include commercially available, closed cell foams that are designed for the treatment of lymphedema. The padding materials can also include softer, open cell foams of various types. In some cases the padding will be some other type of non-foam, synthetic material.
[0077] As noted previously, the padding may be cut into discrete segments as shown in FIG. 9 . Again, the selection and arrangement of padding materials will be based on the therapist's experience and judgment.
[0078] Pad 20 may be secured in place by taking advantage of a natural propensity to adhere to hook and loop material 18 . Where such a propensity does not exist, a mating sheet of a hook and loop material may be glued to pad 20 . Likewise, hook and loop material may be used to connect pads 20 and 22 together. The advantage of using hook and loop material is that the therapist can experiment with a variety of combinations of pads and pad shapes. This ability to modify will be important when initially establishing the most desirable combination and also afterward when the arrangement needs to be modified as the patient's condition changes.
[0079] Also, while hook and loop fastening material will work satisfactorily, in some embodiments other fastening means may be employed, including releasable adhesives that allow repositioning and replacement of pads.
[0080] Next, a therapist will make judgments about the zones where pressure ought to be applied. In the embodiment of FIGS. 1-7 , two compression zones are achieved by using two tensioners 28 and 30 and two independent circuits 24 and 26 . A therapist can determine the course of circuits 24 and 26 by positioning guides 34 and 32 A- 32 E. In the disclosed embodiment, circuit 24 is arranged with four crossovers between shells 10 and 12 , which determine the compression forces between the shells.
[0081] For circuit 24 , the compression affects primarily the knuckles at the base of the fingers. Specifically, the crossover between courses 24 A and 24 B applies pressure on the proximal and outer side of the knuckle for forefinger I. The crossover between courses 24 B and 24 C applies pressure on the distal side of the knuckles for fingers I and M, at the gap between those fingers. The crossover between courses 24 C and 24 D applies pressure on the distal side of the knuckles for fingers A and S, at the gap between those fingers. The crossover between courses 24 D and 24 E applies pressure on the distal and outer side of the knuckles for finger S.
[0082] For circuit 26 , compression affects the portion of the hand H spaced proximally from the knuckles. Specifically, the crossover between courses 26 A and 26 B applies pressure on the pinky side of the hand about midway between the fingers and wrist. The crossover between courses 26 B and 26 C applies pressure on the pinky side of the hand at a position that is fairly close to the wrist. The crossover between courses 26 C and 26 D applies pressure on the thumb side of the hand between the thumb T and wrist. The crossover between courses 26 D and 26 E applies pressure on the thumb side of the hand about midway between thumb, T and forefinger I.
[0083] It will be appreciated that therapist can adjust the routing of courses 24 and 26 to change the manner in which pressure is applied to hand H. Also, since panels 14 of shells 10 and 12 are relatively stiff, the forces applied by the shells are substantially perpendicular to the palmar and dorsal surfaces of hand H, so that the hand is not squeezed laterally.
[0084] Winders 28 and 30 can be independently adjusted to establish the compression forces and their respective regions. By tightening (loosening) circuit 24 compression forces can be increased (reduced) around the knuckles at the base of the fingers. By tightening (loosening) circuit 26 compression forces can be increased (reduced) around the portion of hand H between the wrist and the knuckles at the base of the fingers. Normal forces will be transmitted primarily by pad 20 . Pad 22 will usually be a softer material to increase comfort and to provide feathering of compression forces near the edges of shells 10 and 12 .
[0085] Initially, the compression forces will be the established at the time the therapist first places the device on hand H. However, the patient will be taught how to independently place the device on hand H without professional assistance. Thereafter, the patient can wear the device during the time periods recommended by the therapist. In some cases, a patient may be asked to wear a compression glove under the device in order to assist in reducing edema, but this choice will depend upon the specific condition of this patient.
[0086] To don the device, one will start with winders 28 and 30 arranged to fully slacken circuits 24 and 26 . A patient can then slip the fingers between shells 10 and 12 on the proximal edge of the shells. When hand H is positioned as shown in FIGS. 1-3 , winders 28 and 23 can be adjusted to produce the tension in circuits 24 and 26 recommended by a therapist.
[0087] During the course of a day, a patient may find it necessary to increase or decrease the compression forces. Since winders 28 and 30 are easily adjusted, these compression forces can be easily changed. Also, the patient can be given a supply of replacement pads in order to replace pad 22 when it becomes soiled.
[0088] Also, the device is easily removed by using winders 28 and 30 to remove all tension on circuits 24 and 26 . Thereafter, hand H is withdrawn in a direction opposite to the direction used to don the device. Accordingly, the patient can temporarily remove the device for routine activities such as bathing.
[0089] When the device is worn, the compression forces will tend to reduce the edema. The compression forces will tend to urge edematous fluids in a proximal direction. Also, the patient's fingers and thumb will remain highly mobile. Thus, the patient can perform most daily activities. Accordingly, the fingers and thumb will be routinely exercising, which will produce a natural pumping effect that tends to reduce edema. In addition, the device is relatively open so that air can reach the hand H, which will enhance comfort and avoid elevated temperatures.
[0090] The patient will still need to periodically visit a therapist to check the progress and to perform different types of CDT. At these visits the therapist can inspect the condition of the body part. If necessary, therapist can change pads 20 and 22 to a different type of pad.
[0091] The advantages of this device are: time savings and ease of application, comfort, safety, and therapeutic efficacy. Using appropriate materials and an effective tensioning system, this device offers a high working, low resting pressure environment similar to that which his offered to lymphedema patients during CDT using short stretch (non-elastic) bandaging materials. Furthermore compression is achieved while avoiding trauma to the lymphatic, hemodynamic and neurological system, by using customizable thermoplastics and padding to areas like the hand, forearm, upper arm, calf, thigh and other body parts.
[0092] It will be appreciated that various modifications may be implemented with respect to the above described embodiments. In some cases a variety of shells may be manufactured in sizes and shapes designed to accommodate the affected body part of most patients. In some embodiments shells may be provided with a large number of molded eyes or lacing hooks, so that the therapist can effectively route a tensioning cord through almost any desired route by selecting different eyes or hooks. In still other embodiments, the winders may be mounted in fixed positions, in which case the ligature network is adjusted by changing the routing of the cords connected to the tensioner. In some cases the ligature network will be formed of a single cord but will be segregated into different independent sections by tying some intermediate point on the cord to an anchor, so that tension is not transferred from one section to the other. While a double layer pad is disclosed, in some embodiments the pad may be a single layer or may employ more than two layers.
[0093] Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. | A compression device can treat edema with a number of curved shells, each having an internal pad. A ligature network employing tensioners is routed across the shells for compressing them. Tensioners on at least some of the shells can separately adjust tension in different portions of the ligature network. The ligature network is (a) releasably mounted on the shells, and (b) repositionable to allow spatial adjustment of compression forces produced by the compression device. By adjusting the routing of the ligature network across the shells, tailored compression forces are provided. With a body part embraced by the padded shells, tension is separately adjusted in different portions of the ligature network to provide different compression forces at spaced positions along the plurality of padded shells. | 39,876 |
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