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Natural images which have been scanned into electronic image processing systems often have undesirable color casts which should (desirably) be removed. These casts may result from imperfections and errors within the image acquisition process. For example a scanned photograph may have been taken under lighting conditions which were inappropriate for the film type.
One method for determining how big a correction needs to be made for each picture is for an operator to add color to the image interactively until it looks "right." This method has the disadvantages of requiring a great deal of operator attention and judgement, and requiring a highly accurate color monitor.
One set of automatic methods involve assumptions about what colors various parts of the image should be. These methods assume, for instance, that bluish areas near the tops of pictures are sky, that the average color for a scene is gray, or that colors within a certain range are flesh. These methods are sensitive to image content; however, the assumption may simply be wrong for many images.
Another approach to determining the degree of color cast is to estimate the color of the illuminant of the original scene, as recorded in the image. In actual scenes, the human visual system tends to perceive the illuminant as neutral. Therefore, a color transform which maps the recorded color of the illuminant to neutral will tend to produce a balanced picture.
One method for making this estimate is for the system to detect specular highlights in the picture. Specular highlights in a natural scene tend to have the same color as the scene illuminant. This method has three disadvantages. First, not every scene contains specular highlights. Second, it only determines the color cast at bright luminances. Finally, because highlights tend to be the brightest objects in a scene, their color is particularly susceptible to being distorted by non-linearities in the capture process.
A method has been proposed by Lee (U.S. Pat. No. 4,685,071) which takes advantage of the fact that the reflected light from many objects contains both a specular and a diffuse component. Lee's method estimates the color of the scene illuminant by detecting the specular component and estimating its chromaticity.
Lee's method has the advantage that natural scenes do generally contain a number of differently colored objects having the proper reflectance properties. However the method contains a time-consuming pre-filtering step. In addition, the method either completely accepts or completely rejects any given candidate measure of scene illuminant, thereby giving an inordinate amount of importance to marginal subsets of the image. That is, measures that are highly likely to be accurate receive the same weight as measures that are less likely to be accurate. Finally the method does not account for distortions produced by the non-linearities of the photographic process. These non-linearities make measured colors a less reliable indicator of illuminant as those colors approach the edge of the input gamut. They also cause the measured illuminant chrominance to vary with luminance.
It is the object of the present invention to provide an improved method for detecting and correcting for scene illuminant based on the distribution of chrominances in an image. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
This invention relates to an information recording and/or reproducing apparatus and more particularly to an apparatus for recording and/or reproducing information signals with a pair of heads respectively shifter by a pair of shifting elements having residual displacement characteristics.
2. Description of the Prior Art
It is recent conventional practice in the field of magnetic recording to have magnetic recording or reproducing heads mounted on electric-to-mechanical conversion elements. The heads are made to record or reproduce a signal at desired points on a recording-bearing medium by driving electric-to-mechanical conversion elements so they shift the positions of the magnetic heads. Electric-to-mechanical conversion elements usable for this purpose include, for example, a bimorph-type piezo-electric ceramic element (hereinafter called a bimorph element). An element of this kind generally has a residual displacement characteristic.
FIG. 1 of the accompanying drawings shows the voltage impressed on a bimorph element and the displacement characteristic of the element in relation to the impressed voltage. As shown, even when a voltage which is the same as previously-impressed voltage is impressed on the bimorph element, the displacement of the element is different from the previous displacement due to the previous characteristic movement of the element. Such a residual displacement characteristic has caused problems in magnetic recording and/or reproducing apparatuses with an electric-to-mechanical conversion element such as a bimorph element.
FIGS. 2A-2C show th problems of these conventional apparatuses. In FIG. 2A, the apparatus includes a base plate 1, on which bimorph elements 2 and 3 are mounted, and magnetic heads 4 and 5 mounted on the bimorph elements 2 and 3. Displacement of the bimorph elements 2 and 3 shifts the magnetic heads 4 and 5 in the directions of arrows 6 and 7, respectively. Where the displacements of the bimorph elements 2 and 3 are equal to each other, heads 4 and 5 are in alignment with each other in the direction of arrow 11, which is perpendicular to the direction of displacement of the bimorph elements 2 and 3. For an apparatus arranged in this manner, let us assume that the magnetic heads 4 and 5 are repsectively shifted to an extent la by impressing voltages of opposite directions on the bimorph elements 2 and 3. The condition schematically shown in FIG. 2B results. In FIG. 2B, reference numerals 8 and 9 denote the tracing loci of heads 4 and 5 obtained when the record bearing medium is moved in the direction of arrow 11 under the above condition. In other words, recording tracks represented by the loci 8 and 9 are obtained if a recording operation is performed under the above condition. Where the same track is to be traced by both of the two heads, the position of either the base plate 1 or the record bearing medium need be adjusted in the direction of arrow 12, with the displacements of the bimorph elements arranged to be equal to each other. However, even when the voltage impressed on the two bimorph elements 2 and 3 in the condition of FIG. 2B are changed to zero, the displacement characteristic shown in FIG. 1 prevents these elements from coming back to their initial positions and causes element 2 to be shifted from a point A to a point A' and the other element 3 to be shifted from a point B to a point B'. The residual displacement characteristic thus causes the respective bimorph elements to deviate as much as lb in opposite directions from their initial positions, which are on a straight line 10 of FIG. 2B. FIG. 2C shows this deviation.
To remove the adverse effect of the above-stated residual displacement characteristic, attempts have been made to bring the position of the bimorph element to point 0 shown in FIG. 1 by applying an alternating voltage which gradually attenuates. However, this method necessitates provision of a gradually attenuating voltage and results in a complex circuit arrangement. Besides, this method takes an excessively long period of time to remove the adverse effect of the residual displacement characteristic. More specifically, a given length of time is necessary for equalizing the displacements of the two bimorph elements from the condition shown in FIG. 2B. This method is hardly effective for instantly equalizing the extents of displacement of the bimorph elements or those of the heads.
The residual displacement characteristic also presents problems in a magnetic video tape recording and/or reproducing apparatus of the rotating two-head helical scanning type (hereinafter called VTR). FIGS. 3A-3C show the problem caused a conventional VTR by the residual displacement characteristic of the electric-to-mechanical elements. FIG. 3A shows the structural arrangement of a rotary head drum of a VTR. The VTR is provided with a rotary drum 21; bimorph elements 22 and 23; and heads 24 and 25 mounted on the bimorph elements 22 and 23. Arrows 26 and 27 indicate the directions of shift of the heads 24 and 25. The heads 24 and 25 are arranged to rotate on the same plane if the extents of displacement of the bimorph elements 22 and 23 are equal. Further, the heads 24 and 25 have the same magnetization direction.
In FIG. 3B, arrow 33 indicates the travel direction of a magnetic tape 28. In normal recording, tape 28 travels at a predetermined speed in the direction of arrow 33. Recording tracks are formed on the tape 28 one after another by causing magnetic heads 24 and 25 to trace the tape. The center lines of the recording tracks are indicated by full lines 29. When the tape is brought to a stop, the direction of the tracing loci of the heads 24 and 25 is as shown by a one-dot-chain line 30. When reproducing at a tape speed four times as fast as the normal recording tape speed, the direction of the tracing loci of the heads 24 and 25 becomes that shown by a twodot-chain line 31.
During so-called high speed search or still picture reproduction carried out at a tape travel speed different from normal reproduction speed, a noiseless reproduced picture is obtained with the heads shifted in the direction of arrow 32 by controlling the bimorph elements. FIG. 3C is a timing chart showing the timing of impression voltages impressed on the bimorph elements 22 and 23 during a four-times increased-speed searching reproduction. In FIG. 3C, wave form (a) represents a signal related to the rotation of the drum 21. The magnetic tape is traced by the head 24 while this signal is at a low level, i.e., during periods indicated by reference symbol A in FIG. 3C, and is traced by another head 25 while this signal is at a high level, i.e., during periods indicated by symbol B. Further, in FIG. 3C, wave form (b) represents a voltage to be impressed on the bimorph element 22 for shifting the head 24; and a wave form (c) a voltage to be impressed on the other bimorph element 23 for shifting the other head 25. In these wave forms (b) and (c), downslope parts on the right-hand side represent voltage portions controlling the heads 24 and 25 while they are tracing the magnetic tape 28.
When an instruction is given at a time t1 of FIG. 3C, to bring the four-times increased speed search back to normal reproduction, for example, the extents of displacement of the bimorph elements 22 and 23 should be adjusted to equal each other to equalize the positions of the heads 24 and 25 in the directions of arrows 26 and 27 (hereinafter called the head height). In such an instance, however, if the two impressed voltages are adjusted to zero at ensuing zero points or at the point in time t1, the bimorph element 22 changes its position from the point A to another point A' and element 23 from the point B to another point B', as shown in FIG. 1. This hinders adjustment of the head height and results in the deviation 2lb as shown in FIG. 1. The conventional method for preventing this deviation by using an alternating attenuation signal as the impression voltage not only results in a complex circuit arrangement but also takes an excessively long period of time to remove the adverse effect of the residual displacement characteristic in question. In other words, bringing the two bimorph elements from the points A and B in FIG. 1 to the point 0 of FIG. 1 by the conventional method, requires a certain length of time. It has thus been impossible to instantaneously equalize the extents of displacement of the bimorph elements, i.e., the shifting extents of the heads. For example, in the case of FIG. 2A, the heads remain entirely useless while the operating mode of the apparatus is switched over from high speed searching reproduction to normal reproduction. Therefore, in that instance, no satisfactory reproduced picture is obtained. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
This invention relates to an improved apparatus for establishing and maintaining electric continuity within a drill string using an insulated electric conductor. The invention can be employed in wellbore telemetry operations and other operations wherein it is desired to transmit electric energy between the surface and a subsurface location in a well, including electric drilling operations.
2. Description of the Prior Art
In the drilling of oil wells, gas wells, and similar boreholes, it frequently is desirable to transmit electric energy between subsurface and surface locations. One application where electrical transmission has received considerable attention in recent years is found in wellbore telemetry systems designed to sense, transmit, and receive information indicative of a subsurface condition. This operation has become known in the art as "logging while drilling". A major problem associated with wellbore telemetry systems proposed in the past has been that of providing reliable means for transmitting an electric signal between the subsurface and surface locations. This problem can best be appreciated by considering the manner in which rotary drilling operations are normally performed. In rotary drilling, a borehole is advanced by rotating a drill string provided with a bit. Lengths of drill pipe, usually about 30 feet long, are individually added to the drill string as the borehole is advanced. In adapting an electrical telemetry system to rotary drilling equipment, it will thus be appreciated that the means for transmitting an electric signal between subsurface and surface locations must be such as to permit the connection of additional pipe lengths to the drill string.
An early approach to the problem involved the use of a continuous electrical cable which was adapted to be lowered inside the drill string and to make contact with a subsurface terminal. This technique, however, required withdrawing the cable each time an additional pipe section was connected to the drill string. Another approach involves the use of special drill pipe equipped with an electric conductor. Each pipe section is provided with connectors that mate with connectors of an adjacent pipe section and thereby provide an electrical circuit across the joint (See U.S. Pat. Nos. 3,518,608 and 3,518,609). Disadvantages of this system include the high cost of special pipe sections, the use of a large number of electric connectors (one at each joint), and the difficulty of maintaining insulation of the electric connectors at each joint.
Still another approach proposed for use in wellbore telemetry systems involves the use of cable sections mounted in each pipe section (see U.S. Pat. No. 2,748,358). The cable sections are connected together as pipe sections are added to the drill string. Each cable section is normally made slightly longer than its associated pipe section, with the result that a small amount of slack is present in the conductor string at all times. For long pipe strings and long conductor strings, the excess can be quite considerable and can present problems such as entanglement or restricting flow through the pipe string.
A more recent approach to wellbore telemetry involves the use of an insulated conductor maintained in a configuration to store conductor cable within the pipe string (see U.S. Pat. No. 3,825,078). In accordance with the preferred embodiment of this concept as disclosed in this patent, the conductor cable is arranged in a looped, overlapped configuration, the length of the overlap providing stored cable sections. The looped configuration of the cable permits the cable to be extended as the drill string is extended. This technique normally requires the use of guides and other apparatus within the drill string to maintain the cable in the looped configuration and to permit cable withdrawal from the drill string at the desired times. The looped cable arrangement presents certain problems. For long loop sections, extreme care must be exercised to prevent cable twisting and entanglement. Moreover, the arrangement somewhat restricts the type of cable that may be employed since it must be capable of being bent around relatively small guides.
Another application which requires the maintenance of electric continuity between the surface and subsurface in a drill string is found in electric drilling. Electric drilling apparatus usually involves a bit provided with a downhole electric motor and a cable for delivering power to the motor. An advantage of electric drilling over conventional rotary drilling is that the power is delivered at the bit and does not require rotation of the entire drill string. A problem associated with electric power systems, however, involves the electric cable for delivering power from a surface power source to the downhole electric motor. In the past, a continuous flexible pipe string having an internal electric cable has been used (see U.S. Pat. No. 3,285,629). This system requires coiling of the pipe string and internal cable at the surface and is not readily adaptable to conventional operations. | {
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The present invention relates to an apparatus and a method for predicting response performance of transaction processing, and a recording medium recording a program for making a computer implement the function of the apparatus.
Conventionally known is a performance prediction system which predicts performance of a computer system. For example, Japanese Patent Application Publication No. 2008-129876 discloses a system which predicts performance of a computer system based on the operation result of the computer system. The computer system includes front end servers, middle servers and backend servers. Each of the front end servers provides a user interface. Each of the middle servers executes predetermined processes via backend servers in response to requests from the front end servers, and returns the processing results to request sources. Each of the backend servers manages a database, and reads/writes data from/to the database in response to requests from the middle servers.
The performance prediction system stores, as the operation result of the middle servers, information of a number of servers, an average CPU utilization ratio, a BL performance function, an execution time per application, etc. The BL performance function calculates the CPU utilization ratio of middle servers from start frequencies of applications in the middle servers. The performance prediction system also stores a DB performance function. The DB performance function calculates, as the operation result of backend servers, a CPU utilization ratio of the backend servers from the total execution time of applications in the middle servers. In the event of addition of work-related matters, a required number of servers is calculated based on these operation results.
Particularly, on the basis of the start frequencies of applications corresponding to the added work-related matters, an increase in the CPU utilization ratio in the middle servers is calculated using the BL performance function. Based on the increase and the average CPU utilization ratio of the middle servers, a CPU utilization ratio after the addition of the work-related matters is predicted. Based on the predicted CPU utilization ratio, the required number of middle servers is calculated. As for the backend server, increases in the execution time of applications corresponding to the added work-related matters are calculated. On the basis of the increases, the execution time per application stored as the operation result of the middle servers, and so on, the total execution time of the applications after the addition of the work-related matters is calculated. On the basis of the total execution time and the DB performance function, the CPU utilization ratio in the backend servers is calculated, so that the required number of backend servers is calculated. | {
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Lamps are applied to various fields of daily life and industrial manufacture. These lamps which range from the simplest electric torch to the searchlight for industrial application provide human beings with weapons of conquering the darkness. However, the conventional hand-held lamps such as the electric torch are generally of the type of using dry battery or rechargeable battery. In general, for charging the hand-held rechargeable illuminating lamps, a fixed charging plug is disposed at the rear end of the lamp, which would make the structure of the lamp become bulky. In addition, sometimes, it is difficult for the fixed plug to be inserted into a socket disposed within a relatively small space, and thereby it is difficult to accomplish the charging operation.
Contents of the Utility Model
In view of the above problems of the prior art, an object of the utility model is to provide a hand-held chargeable optoelectronic illuminating lamp, which has compact structure and is convenient for charging operation.
According to the utility model, a hand-held chargeable optoelectronic illuminating lamp comprises: a hollow lamp body; a battery frame accommodated within the hollow lamp body, a plurality of rechargeable battery are mounted thereon; a light emitting unit, which is provided at front ends of the lamp body and the battery frame, for emitting visible light; a power supply plug, which is movably provided at a rear end of the lamp body and can fit with a socket of commercial power supply outside; and a handle, which is pivotally connected to the lamp body, and has an accommodating space therein, said handle may be in a first position and a second position relative to the lamp body, the handle is parallel to the lamp body and the power supply plug is contained in the accommodating space when the handle locates on the first position; the handle is perpendicular to the lamp body and the power supply plug is exposed out of the rear end of the lamp so as to implement charging operation when the handle locates on the second position.
In the illuminating lamp mentioned above, the light emitting unit comprises a light seat, a light source, a reflective mirror generally in a paraboloid shape, a front plate member and a front annular cap in order, wherein: said light seat is movably mounted at the front end of the battery frame; said light source is mounted on the light seat; said reflective mirror is disposed at the periphery of the light source so as to converge the light emitted from the light source; inner face of the front plate member is sealed with end face of the reflective mirror; and the annular cap is detachably fixed to the front end of the lamp body so as to encapsulate the light emitting unit.
In the illuminating lamp mentioned above, a driving circuit device is fixedly mounted at the rear end of the battery frame, and is provided with a plurality of state indicating lights for displaying work states of the illuminating lamp.
In the illuminating lamp mentioned above, two pins and two guiding slots are provided at the rear end of the lamp body; the power supply plug is pivotally connected with said two pins via two holes formed on the sidewall of the power supply plug; two conductive pins of the power supply plug pass through said two guiding slots and protrude out of the lamp body so that the power supply plug can insert into the socket of the commercial power.
In the illuminating lamp mentioned above, the handle is of cuboid shape; a hole for rotation is formed on each side of the front end of the handle; a hole for rotation is formed at the corresponding position of the lamp body; the handle is movably connected to the lamp body by passing a rotation lock through the holes of the handle and the holes of the lamp body.
In the illuminating lamp mentioned above, the inner surface of the rotation lock is provided with protruding fasteners which tightly fastens the inner surface of the sidewall of the lamp body so that the handle is fastened on the sidewall of the lamp body without separating from the lamp body while the handle is pivotally connected with the lamp body by the rotation lock.
In the illuminating lamp mentioned above, a switch button is provided at the centre of the battery frame so as to turn on and turn off the lamp.
In the illuminating lamp mentioned above, the rotation lock is formed with a rectangular hole; the position of the rectangular hole corresponds to the position of the switch button; a switch button covering member is provided on the rectangular hole; the inner surface of the switch button covering member passes through the rectangular hole of the rotation lock and thereby tightly engage with the switch button.
In the illuminating lamp mentioned above, a plurality of state indicating lights is provided on the driving circuit device.
In the illuminating lamp mentioned above, a hole is also provided on the front end of the lamp body; and an indicating light glass made of transparent material is fixed on the hole so that states of said state indicating lights would be observed through the indicating light glass.
The advantageous effects of the utility model are as follows: the novel hand-held chargeable optoelectronic illuminating lamp of the utility model provides the user with a convenient charging manner for the lamp by rotating the handle into the second position such that the handle is perpendicular to the lamp body and the power supply plug is exposed out of the rear end of the lamp body. For implement of charging the lamp, the user can directly insert the power supply plug of the lamp body into the socket of the commercial power. After the charging operation of the hand-held chargeable optoelectronic illuminating lamp is completed, the lamp can continuously illuminate for a relatively long time and can be applied to various fields such as police, fire protection, emergency lifesaving, discipline army and civil use as an important light source.
Hereinafter, the utility model will be further explained with reference to the drawings and the embodiments. | {
"pile_set_name": "USPTO Backgrounds"
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With the emergence of transgenic technologies, new ways to improve the agronomic performance of plants for food, feed, and processing applications have been devised. In addition, the ability to express foreign genes using transgenic technologies has opened up options for producing large quantities of commercially important products in plants.
New target genes of both plant and microbial origin are rapidly becoming available for the purpose of improving agronomic characteristics of crop species as well as plant properties. These advancements have already resulted in the development of plants with desirable traits such as resistance to diseases, insects, and herbicides, tolerance to heat and drought, reduced time to crop maturity, improved industrial processing, such as for the conversion of starch or biomass to fermentable sugars, and improved agronomic quality, such as high oil content and high protein content. | {
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The present disclosure relates generally to electron microscopes and more particularly to an electron microscope using radio frequencies and/or super-cooling.
It is known to employ transmission electron microscopes and scanning electron microscopes to obtain a magnified image of a specimen. Exemplary conventional electron microscopes are disclosed in U.S. Pat. No. 5,811,804 entitled “Electron microscope with Raman Spectroscopy” which issued to Van Blitterswijk et al. on Sep. 22, 1998. This patent is incorporated by reference herein. Another approach is disclosed in U.S. Pat. No. 7,154,091 entitled “Method and System for Ultrafast Photoelectron Microscope” which issued to Zewail et al. on Dec. 26, 2006, and is incorporated by reference herein. Such a device, however, employs a high repetition rate and only emits approximately one electron per each 10 nanosecond shot; even if the specimen event only lasts for 10 nanoseconds then a poor quality image will likely be created if the event is not precisely reproducible.
In many traditional electron microscopes for time-resolved studies, the imaging is carried out in pulse mode, which must compress electrons in a continuous transmission electron microscopic stream into short packets. In a sub-nanosecond arrangement, the density of electrons in packets reaches some 7-9 orders of magnitude higher than that in a steady stream. Such an implementation proves to be detrimental for traditional electron optics used in electron microscopes. Moreover, because of the strong coulombic dispersive forces and statistical fluctuations associated with the high-density electron packets, the coherence, spatial focusing, and ultimately the time resolution needed for freeze-frame imaging of atoms, are destroyed. This well-known space-charge problem has so far hindered any significant progress in using a high-density beam in a conventional microscope to form an atomically sharp image in a sub-nanosecond time scale.
Furthermore, experiments have been made with a dynamic transmission electron microscope. Such a device is disclosed in LaGrange, T. et al., “Single-Shot Dynamic Transmission Electron Microscopy,” Appl. Phys. Lett. 89, 044105 (2006). While this device provides a large quantity of electrons, it does so in a very slow 1 nanosecond pulse. Therefore, it is not fast enough to provide a clear freeze-framing image before the sample or reaction changes. Generally, to produce a clear image in time-resolved microscope, its time resolution must be better than the atomic reaction time scale, typically on 1 picosecond or less timescale.
In accordance with the present invention, an electron microscope is provided. In another aspect, an electron microscope employs a radio frequency which acts upon electrons used to assist in imaging a specimen. Furthermore, another aspect provides an electron beam microscope with a time resolution of less than 1 picosecond with more than 105 electrons in a single shot or image group. Yet another aspect employs a super-cooled component in an electron microscope. Moreover, a further aspect of an electron microscope uses a radio frequency wave to assist in bunching or increasing the density of a series of electrons. A method of operating an electron microscope is also set forth.
The electron microscope of the present invention is advantageous over traditional devices. For example, space-charge effects in a short-pulse electron beam are overcome by use of a radio frequency electron pulse compressor or cavity in an electron microscope beam column with a high-field photo gun, in one aspect. This serves to advantageously achieve much higher intensity images and time resolution than conventional time-resolved microscopes. Furthermore in an aspect, the present electron microscope is advantageously more flexible in terms of pulsed mode imaging, such that a probe size can be easily tuned from nanometer to micrometer, and it can be easily switched from a diffraction mode to a microscopy mode. Additionally, the present electron microscope allows for retrofitting radio frequency cavities onto previously assembled electron microscopes thereby significantly enhancing time-resolution but at less than half the cost of an entirely new microscope. Additional advantages and features can be found in the following description and appended figures. | {
"pile_set_name": "USPTO Backgrounds"
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It is known in the shingle art that shingles that are applied to a roof are generally applied in courses, running up the slope of a roof, toward the apex or ridge of the roof.
For example, in applying shingles to different sloped surfaces of a roof, wherein those sloped surfaces meet at an apex, the various courses of shingles on each side of the apex are increasingly disposed up each slope, until the apex or ridge of the roof is reached. At that point, it is desirable to provide a shingle that is a unitary structure that overlies a portion of each sloped surface of the roof, including the apex of the roof.
Sometimes, a piece of shingle is cut to be applied over the shingles on each sloped surface, and over the apex, in an inverted “V” manner. In bending such shingle, generally when it is of the manufactured asphalt shingle type, it is possible that, as the shingle is bent to have an included angle between surfaces thereof, to partially cover each surface of the roof as well as the apex of the roof, cracks can form.
In instances where the shingles are substantially rigid, such as resembling slate, tile, shakes or the like, it is often not practical to bend a shingle to cover the surfaces on each side of the apex of a roof. In some such cases molded plastic ridge cap pieces are applied to cover the gap at the roof edge. In other instances, a row of barrel-like tiles are applied over the apex of a roof. In still other instances, molded bent synthetic slate shingles are pre-shaped to a specific angle, to be applied over the ridge of a roof.
Examples of prior art techniques for covering a hip, ridge or rake portion of a roof exist in U.S. Pat. Nos. 5,295,340, 6,418,692, and 7,178,294. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of Invention
The present invention relates to agents having regulatory activity for the morphological transition of dimorphic fungi which can grow both as yeast form cells and as mycelial form cells.
2. Description of Related Art
Most fungi take the form, through their life cycle, of either a spherical single cell growing through budding (or cell division) (yeast form fungus) or a filamentous multicellular organism growing through apical growth (filamentous fungus). However, some yeasts can reversibly take yeast form (Y form) and mycelial form (M form). This phenomena in which such a reversible transition occurs due to a specific nutritional, physical or chemical factor is called as dimorphism. The dimorphic fungi generally belong to Subdivision Deuteromycotina. and typically include genus Candida. The dimorphic fungi such as genus Candida are indigenous microbes with respect to humans, which generally exist in human bodies or in a living environment. They are not pathogenic to healthy humans but become pathogenic to patients whose immunity is deteriorated by some cause, and such an infection is called as an opportunistic infection. By taking Candida albicans belonging to genus Candida as an example, it has been known, in fact, that a multiplicity of mycelial form cells are present in combination with yeast form cells in infectious foci of candidiasis, indicating that being mycelial form cells is one of the pathogenic factors of this fungi. This is supposedly because mycelia of the mycelium form cells readily adhere to animal tissues and advantageously serve to invade mechanically into the inside of host tissues, and in addition hardly suffer from mycophagy activities of phagocytes (Arai, T., et al., Sabouraudia 15, 171-177(1977)). | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates to an improvement in a stator of a dynamo-electric machine which is assembled by sequentially inserting premolded coil pieces into a stator core.
2. Description of the Related Art
In general, a stator of a dynamo-electric machine has a stator core 10 which is, as shown in FIG. 7, constituted by stacking a plurality of annular metal plates each having slots 10a and teeth 10b (a portion interposed between two teeth is called a "slot") alternately formed along the inner periphery thereof. The stator further has coils 12, each of which is formed by continuously winding a coil wire coated with enamel or the like around the tooth 10b of the stator core 10. The stator shown in FIG. 7 is formed by a winding method which is so-called concentrated winding. In this method, one coil 12 is provided for one tooth 10b. One or a plurality of bundled wires each having a diameter ranging from about 0.5 mm to about 1.0 mm are wound around a tooth 10b a predetermined number of times. Therefore, the slot 10a is designed to receive adjacent ends of two coils fitted to two teeth 10b interposing the slot 10a. When an electric current is allowed to pass through each coil 12, a magnetic flux is generated in a direction along which the magnetic flux penetrates the coil 12 through the teeth 10b serving as a magnetic path. As a result, a rotor (not shown) can be rotated. The dynamo-electric machine acts as a dynamo-electric generator by rotating the rotor with the aid of an external force.
Generally it takes a long time to wind the coil wire around each tooth 10b as described above. Additionally it is difficult to automate such winding operation. Japanese Utility-Model Publication No. 2524074 discloses a structure arranged such that coil pieces, which have been molded to have a predetermined shape using a mold or the like, are fitted with the teeth 10b. In this case, the slots 10a accommodate the coil pieces, each of which is formed by winding a coil wire predetermined number of times across the teeth 10b. Therefore, the operation for assembling the stator can easily be completed. Moreover, the operation for winding the coil wire can easily be automated.
When the slots 10a for accommodating the coil pieces are formed along the inner periphery of the stator core 10 as shown in FIG. 7, the width of the open portion (the upper portion) of each slot 10a is smaller than that of the bottom portion (the lower portion) of the slot 10a. That is, the slot 10a has a shape which is gradually widened toward the bottom portion thereof. Therefore, the cross sectional width of the coil piece which is inserted into the slot 10a must be equal to or smaller than the width of the open portion of the slot 10a so as to prevent interference with a leading end of the tooth 10b. As a result, there is undesirable space formed within the slot 10a after inserting the coil piece having the above described shape into the slot 10a. Thus, the required space factor in the slot 10a cannot be obtained, resulting in problems such as deteriorated performance of the dynamo-electric machine.
It might be considered feasible to form each of the teeth 10b into a trapezoidal shape so as to form the slot 10a into a rectangular shape, as shown in FIG. 8. In this case, the coil pieces 14 must be gradually widened so as to be fitted with the trapezoidal teeth 10b. However, the coil pieces 14, each of which is formed by winding the coil wire a plural number of times, are too rigid to be widened as described above. Thus, there arises a problem in that fitting operation while widening the coil pieces is very difficult.
Another method has been suggested which has the steps of fitting the coil pieces 14 with sectioned portions of the stator core 10, and combining the sectioned portions of the stator core 10 with one another by welding or the like. Using the above-mentioned method, however, may deteriorate rigidity of the stator itself and fail to keep the accuracy of the shape to a predetermined level or more. This may result in deterioration of the dynamo-electric machine. | {
"pile_set_name": "USPTO Backgrounds"
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1. Technical Field
The present invention relates to a video signal transmission apparatus, an identification information acquisition method for a video signal transmission system, and a computer readable medium storing an identification information acquisition program for a video signal transmission system.
2. Related Art
A serial data signal for a digital video so called a DVI (Digital Visual Interface) or HDMI (High Definition Multimedia Interface) requires high-speed signal which is equal to or higher than 1 Gbps. Therefore, such signal can be transmitted only up to about 10 m, when transmitted by an electric cable. Accordingly, when transmission of such signal for more than 10 m is required, the serial data signal needs to be converted into an optical signal and an optical fiber may be used to transfer such optical signal. In the case of using the optical fiber, an optical transmitter and an optical receiver, connected to both ends of the optical fiber, may be provided between a video source device such as a PC (including a video card) and a sink device such as a display.
The serial data signal includes a high-speed video signal, information of the display (hereinafter referred to as “EDID”), and a DDC (Display Data Channel) control system signal used to exchange an encryption key called an HDCP (High-bandwidth Digital Content Protection). Since this DDC control system signal is a DC signal or a low-speed signal of lower than 100 KHz, and is a bidirectional signal. The DDC control system signal may be transmitted through a metal cable such as a LAN (Local Area Network) cable.
Namely, when transmitting the serial data signal of digital video, different kinds of cables may be used to transmit the video signal and the DDC control system signal, respectively.
The HDCP is a type of digital copyright management technology that functions to prevent illegal copying by encrypting a digital type image or an output signal of video content.
Also, the DDC is a standard for exchanging various kinds of information between the display and the PC for realizing PnP (Plug and Play). According to the DDC, information representing permissible resolution of a display, color depth, a scanning frequency, and a model number of a product is exchanged between the PC (video source device) and the display (sink device). Through the exchange of the information, setting information of the display is transferred, and thus the setting is automatically performed to match the performance of the respective displays. | {
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This invention relates to a method for generating large numbers of fertilizable ova from the ovarian tissue of a mammal. More specifically, it relates to methods for the in vitro development and maturation of germ cells recovered from the ovarian tissue of a mammal into fertilizable oocytes. These oocytes may be fertilized in vitro to form embryos which can be implanted into surrogate mothers.
The two commonly employed methods for breeding animals are natural mating and artificial insemination. In addition, a small number of animals are bred by embryo transfer. In this technique, a female is impregnated either naturally or by artificial insemination and six to ten days thereafter her uterus is flushed and any viable embryos are recovered. The recovered embryos are then implanted into surrogate mothers. Often the female is superovulated by hormone treatments prior to impregnation to increase the yield of embryos. For example, in cows, superovulation can increase the number of viable embryos recovered from one to about five to fifteen.
With the widespread acceptance and use of artificial insemination for animal breeding, large quantities of sperm are commonly collected and banked for future use, in essence creating a limitless supply of sperm. Equally important, artificial insemination permits the genes from the most desirable animals to be made far more widely available than with natural mating techniques. For example, sperm collected from a single superior bull can be used to impregnate thousands of cows by artificial insemination. Heretofore, however, there has existed no practical method for collecting large numbers of fertilizable ova from females and, as a result, there is no efficient method comparable to artificial insemination for improving the quality of livestock by the widespread breeding of superior females. Embryo transfer which is designed to overcome this problem is inefficient and expensive and therefore not appropriate for widespread use.
The reason large numbers of fertilizable ova have heretofor not been available relates to the reproductive biology of females. Mature males are continuously producing large numbers of sperm. However, in female mammals, only certain cells in the ovaries are capable of maturing into ova. These germ cells, which usually number about 200,000 to 300,000 per ovary in most mammals, are present at birth, are held in the ovary, arrested in an early stage of meiosis and incapable of being fertilized and developing into normal young. Under normal circumstances, a number of these cells begin to develop within the ovary with a periodicity tuned to the animal's sexual cycle. At the appropriate time in the sex cycle, either one or a small number of these cells (depending on whether the animal is a litter bearer) will be released from the ovary, a process known as ovulation. The complex process by which an individual germ cell develops to the point at which ovulation occurs is known as folliculogenesis. Folliculogenesis involves several major steps and the coordinated activities of other cells of the ovary as well as pituitary and ovarian hormones. Following ovulation, the cell or cells (oocytes) released undergo another step in the process of meiosis in which the number of chromosomes in the cells is reduced by half, after which cells become fertilizable ova. This process usually occurs during the movement of the cells from the ovary to the oviduct where fertilization will take place.
To the knowledge and belief of the inventors, there currently exists no known method or process for the development and maturation of large numbers of germ cells into fertilizable ova either in vitro or in vivo. There is a clear need for such a process in order to eliminate the critical limiting factor in all known breeding techniques, the availability of fertilizable ova. Such a process would make possible the use of in vitro fertilization and embryo implantation on a large scale for efficiently reproducing commercially important animals or other important animals (such as endangered species). Perhaps more importantly, it would also make possible the use of these techniques for efficiently improving the quality of herds and of animals by selectively breeding desirable females. | {
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This invention relates generally to combination soap holding and dispensing means, and more particularly to such means adapted for use with bar soap.
While toilet soap in bar form is no doubt by far the most common type of soap employed in households, hotels, motels, etc., the use of soap in this form has certain longstanding disadvantages which have not as yet, to my knowledge, been successfully overcome. For one thing, it is virtually impossible for a bar of soap to be completely consumed because it eventually becomes so small as to be ineffectual for further use in the normal way. The majority of persons no doubt discard the bar when it becomes this small, which results in a significant loss of soap in the long run. This wastage represents a significant item of expense, especially in a large family where there are heavy daily demands for soap for use in showers and for other bathing purposes.
Another characteristic of bar soap resulting in loss through waste is its tendency to soften when kept in conventional soap trays or the like between periods of use. This softening reduces a bar of soap to a slushy, gelatinous consistency on its underside, even, in many cases, where it is supported in such a way as to permit the drainage of moisture from the bar and the circulation of air therearound. Not only is such softening wasteful of soap, but it renders a bar less attractive in appearance and gives it a mushy, unpleasant texture and feel.
Another problem with bar soap results from its slippery surface when wet which makes the bar hard to hold onto. As a result, wet soap is often dropped, which is annoying, especially when this occurs in a shower stall. It is not uncommon for one to drop a bar of soap several times while taking a shower, making it necessary to repeatedly bend over and pick it up, often where there is scarcely space enough to permit such bending. Sometimes the bar, when dropped, will split into two or more pieces, which obviously results in more soap wastage. This is annoying enough to a person in good physical condition, but when the person is handicapped in a way to make if difficult for him to retrieve a dropped bar of soap, the dropping becomes a serious problem instead of a mere annoyance. In some cases of disability, for example, where a person is seriously afflicted with arthritis in his hands, it's hard for the disabled individual to grip a bar of soap even before it becomes slippery, and virtually impossible to hold onto the bar after it gets wet. Also, a blind person dropping a bar of soap in a shower will obviously have more of a problem than a person with good eyesight who does the same thing.
Dispensers of liquid and powdered soaps, while useful to some extent under some circumstances, are not, for the most part, suitable substitutes for bar soap. For one thing, neither type of dispenser is very effective for use in a shower. A powdered soap dispenser mounted in a shower stall is obviously so unsuitable for use in that environment that no one, to my knowledge, has ever attempted such a thing. Neither, insofar as I am aware, has there been any serious attempt to install liquid soap dispensers in showers. While liquid soaps are available in pump-type dispensers, it is awkward and inconvenient to use such a dispenser in a shower as anyone who has ever attempted to do so has discovered. Furthermore, such usage results in soap wastage because the soap is dispensed in measured amounts from such dispensers, which do not necessarily coincide with the amounts actually required. Certain handicapped persons, for example those crippled by arthritis, moreover, would find the use of liquid soap dispensers in showers (or anywhere else) difficult, if not impossible, to manage.
Thus, while bar soap has been in widespread usage throughout the world for many decades, if not centuries, it has always been plagued by the above-mentioned, and other, shortcomings which no one has heretofore, to my knowledge, succeeded in eliminating. If these shortcomings could somehow be successfully overcome, bar soap would, I believe, be in even more universal demand than it is now, particularly among handicapped persons, and, additionally, could be used with significantly less waste, hence lower cost, than it now can. Also, this would ultimately result in a savings in energy because the energy going into the manufacture of presently wasted soap would not be dissipated in the form of the unused soap. | {
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1. Technical Field
This disclosure generally relates to a system comprising a touch sensor on polymer lens and methods for manufacturing such system.
2. Description of Related Art
Since touch screens provide an easy interface for human-machine interactions, they recently have found wide range of applications in consumer electronics, such as mobile phones, tablets, global positioning systems (GPS), medical devices, laptops, point-of-sale terminals, point-of-information kiosks, industrial control units, and visual display systems.
Among many types of touch screens, capacitive touch screens are getting more popular as compared to resistive touch screens due to their higher sensitivity to finger touch and good visibility for displays. The capacitive touch screens also allow users to perform functions not possible with resistive touch screens such as changing the orientation of images with thumb and forefinger since they can support multi touch capability. For a summary of touch screen technologies and their features, for example, see publications by: Alfred Poor “How It Works: The Technology of Touch Screens” Computerworld, Oct. 17, 2012; Geoff Walker “Fundamentals of Touch Technologies” 2013 SID Touch Gesture Motion Conference, October 2013; and Trevor Davis “Reducing Capacitive Touchscreen Cost in Mobile Phones” Embedded, Feb. 25, 2013. The entire content of these publications is incorporated herein by reference.
A capacitive touch screen system typically comprises a cover glass (or lens) with a screen printed decorative frame, and a touch sensor made from indium tin oxide (ITO) film deposited on another glass substrate. These two components are separately manufactured and assembled to form a single component by using an optically clear adhesive (OCA). Manufacturing of the currently available capacitive touch sensor involves in several process steps, including deposition of an ITO film on a glass surface by sputtering, then baking the ITO film above its melting point to create a conductive ITO layer, and finally etching the conductive ITO layer by photo or laser lithography to form a sensing circuit. Every manufacturing step adds to the cost of the final device, resulting from materials and elongated manufacturing time. Since every step may have risks for causing defects, losses or decreasing production yield further contribute to the overall cost. In addition, as the size of the capacitive touch screen increases, so does its weight since the typical touch screen comprises two layers of glass.
To reduce the cost and the weight of the touch screen, several different touch screen structures are being developed, such as sensor on-cell type touch screens, sensor in-cell type touch screens, glass lens/film sensor type touch screens, and sensor on glass lens or one glass solution (OGS) type touch screens. In these novel structures, main target is to reduce number of layers of glass incorporated into the system, thereby reducing the touch screen weight and costs.
However, there are still significant technical barriers for in-cell and on-cell type touch screens. For the on-cell type touch screens, the primary issue is the noise injected from the display module, such as liquid crystal display (LCD). As the touch sensor is structured to be closer and closer to the thin film transistor (TFT) switching elements of LCD, this noise substantially grows. In the case of in-cell type touch screen, the touch sensor is implemented within the TFT structure, which is complicated to manufacture, and therefore this type of touch screen is only used for a few high end applications today.
The glass lens/film type touch sensors are also manufactured by using two separate processes to prepare cover lenses and film sensors, and assembling these two components by using an optically clear adhesive.
The sensor on glass lens or one glass solution (OGS) approach may reduce the weight in overall device. This approach consolidates multilayer touch sensor system into a simpler structure and keeps supply chains intact for consumer electronics manufacturers. However, it still faces a number of technical challenges.
To be used as a glass lens, regular glass must be strengthened to prevent the breakage during the device use. The glass lens usually includes a silk screen printed decorative frame on its inner surface. This frame is used to hide the circuitry of the device. These two features of glass lens pose processing difficulties during the process scale up for commercialization. If the process scale up involves sputtering of an ITO layer on a large strengthened glass followed by patterning of the ITO layer, there may be substantial losses during cutting of the large strengthened glasses into small devices, decreasing the process yield. If the process involves small pieces of the strengthened glass, the productivity may dramatically drop.
Furthermore, the silk screen printed decorative frame usually has about 5 micrometers to 10 micrometers thickness. This frame prevents the ITO layer to form a uniform and continuous film during the ITO sputtering process across the glass and over the silk screen printed area. Any disruption in the conductive layer, at the frame to the glass transition regions, would cause device failures. This process may therefore be unsatisfactory. | {
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Personal communication systems (PCS), which include those based on CT-2, have handover between cells which is controlled by the system itself. When a handover is required in CT-2 based systems due to a mobile station (portable) being close to leaving a particular cell, the surrounding cells (cell neighbours)are instructed to perform a MUX1 SNIFF procedure. All of these cells which have a free radio will tune to the portable's channel and try to decode the PID (portable identity). If the PID can be detected, the base stations detecting it will measure the RSSI (Received Signal Strength Indication) and report this information to the system controller. The portable is then handed over to the first base station to respond which had an adequate RSSI. | {
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Because of its clean burning qualities and convenience, natural gas has become widely used in recent years. Many sources of natural gas are located in remote areas, great distances from any commercial markets for the gas. Sometimes a pipeline is available for transporting produced natural gas to a commercial market. When pipeline transportation is not feasible, produced natural gas is often processed into liquefied natural gas (which is called "LNG") for transport to market.
It has been recently proposed to transport natural gas at temperatures above -112.degree. C. (-170.degree. F.) and at pressures sufficient for the liquid to be at or below its bubble point temperature. For most natural gas compositions, the pressure of the natural gas at temperatures above -112.degree. C. will be between about 1,380 kPa (200 psia) and about 4,500 kPa (650 psia). This pressurized liquid natural gas is referred to as PLNG to distinguish it from LNG, which is transported at near atmospheric pressure and at a temperature of about -162.degree. C. (-260.degree. F.).
If PLNG is unloaded from a container by pumping the PLNG out and allowing the container pressure to decrease, the decompression of the PLNG can lower the temperature in the container below the permitted design temperature for the container. If the pressure in the container is maintained as the PLNG is removed to avoid such temperature reduction, the vapor remaining in the container will contain a significant mass percentage of the container's original cargo. Depending upon the pressure and temperature of storage and the composition of the PLNG, the vapors may constitute from about 10 to 20 percent of the mass of PLNG in the container before the liquid was removed. It is desirable to remove as much of this gas as is economically possible while keeping the container at approximately the same temperature as the PLNG before unloading. | {
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1. Field of the Invention
This invention relates to a process for separating contaminants from the exhaust gases generated from combustion of fossil fuels and from chemical processes, and more particularly, to the removal of nitrogen and sulfur oxides from a cold stream of gaseous combustion products such as the removal of nitrogen oxides and sulfur oxides from exhaust gases.
2. Description of the Prior Art
Gas recovery devices are well known and in particular, devices associated with power generation plants and coal, oil or gas/fired boilers and chemical processes for removing NO.sub.x and SO.sub.x from the exhaust gas and fugitive gas recovery streams. An example of conventional devices that not only recover heat from flue gases but also remove the contaminants is disclosed in U.S. Pat. No. 4,121,541 where flue gases from a power generating plant are purified and heat is recovered from the flue gases. Flue gases from the boiler initially enter a heat exchanger, where they are cooled and thereafter contacted with cooling water to remove waste heat. Pollutants contained in the flue gases are partially absorbed by cooling water. Thereafter, the purified flue gas is released with ambient cooling air and to the surrounding atmosphere. This system is characteristic of a wet flue gas scrubber used to remove contaminants in the form of sulfur dioxide, fluorine compounds, nitrogen oxides, etc.
U.S. Pat. No. 4,784,835 discloses a gas scrubber and heat exchanger for removing contaminants from sulfurous flue gases, where a glass fiber mat electrostatic filter retains particles within tile flue gases. Other known devices for removing contaminants from exhaust gases emitted from power plants are disclosed in U.S. Pat. Nos. 3,473,298; 4,681,744; and 4,799,941. With these devices, the exhaust gases are first chilled with direct water sprays and thereafter solid contaminants and water soluble substances are removed from the gases by the contacting water. In a spray chamber the water combines with water soluble gases, such as SO.sub.x, contained in the gases to form sulfurous and sulfuric acids which are collected with the water spray in a chamber. It is also known as disclosed in U.S. Pat. No. 3,881,004 to recover nitric acid by scrubbing a tail gas with acid or alkaline solution and nitric acids which minimize the discharge of nitrogen oxides to the atmosphere.
While heat recovery devices or economizers are well known, their efficiency needs to be improved because it has been determined that up to 16% of heat escapes uncovered from the stacks equipped with economizers. This in part can be attributed to admitting the exhaust gases at a relatively high exit temperature. Also, in the case of "mass transfer" heat recovery devices the primary function is to recover heat. Generally, the removal of the contaminants from tile flue gas stream is incidental. When scrubbing operations are combined with heat removal operations, the process becomes less efficient at heat transfer because a portion of the heat is lost in an effort to remove contaminants.
It is generally recognized that wet scrubbers are designed primarily to remove contaminants and are not efficient in recovering waste heat. Heat removal is considered incidental and adds to the expense of the pollution abatement operation. In many instances after wet scrubbing, flue gas must be reheated to rise up and out of the boiler chimneys. As a result, boilers equipped with gas scrubbing equipment are expensive to maintain and to operate. While it has been suggested by the prior art devices to remove contaminants in the form of NO.sub.x and SO.sub.x emissions from flue gases, the known devices are expensive to operate and waste a substantial amount of energy in the loss of heat that could be otherwise recovered from the flue gases in the process of removing the contaminants from the flue gases.
Therefore, there is need to provide apparatus for removing contaminants, specifically NO.sub.x and SO.sub.x emissions, from exhaust gases that allows for the efficient use of recovered waste heat, while at the same time reducing the content of the contaminants in the exhaust gases to the required levels as prescribed by air quality regulations. Improved emission equipment is therefore required that not only brings the content of the contaminants in the exhaust gases into compliance with regulated air quality standards, but also lowers the cost of the treatment process by recovering heat from the treated exhaust gases to lower the operating cost of the combustion or chemical processing unit generating the exhaust gases. | {
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1. Field of the Invention
This invention relates generally to vehicle components, and more particularly to an improved driver's side sun visor structured to allow the driver of the vehicle to observe a traffic light signal as when at a standstill therefor absent sunlight glare.
2. Description of Prior Art
Virtually all motor vehicles are equipped with at least a driver's side sun visor which is pivotally connected along an upper longitudinal margin thereof adjacent the windshield of the vehicle. In its pivoted downward in-use position, the sun visor generally blocks a portion of incoming sunlight entering the vehicle through the front windshield, while simultaneously reducing the area for viewing oncoming sky and sunlight and traffic signals.
In most instances, the presence of the sun visor in its downwardly in-use position does not obstruct any useful traffic visibility required by the driver. However, overhead traffic light signals, especially as the vehicle approaches or is stopped at an intersection, may become obscured from the driver's line of sight when the sun visor is in use.
In such situations, the driver must bend forwardly so as to facilitate line of sight with the traffic signal or pivot the visor into its upper stored position. In such situations, however, this may subject the driver's eyes to the very bright sunlight which the sun visor is otherwise blocking.
In extreme circumstances such as during morning and evening commuter traffic, this deficiency is quite acute, leaving the driver to either be temporarily "sun blind" to view a traffic signal or to simply hope for the best by observing movement of adjacent traffic.
A number of devices in prior art have attempted to address this problem by either modifying or adding to existing sun visors in a fashion which restricts or blocks the amount of sunlight which is able to be viewed by the driver passing through the windshield.
Cramer, in U.S. Pat. No. 4,362,330 teaches a see-through automobile sun visor which includes a plurality of spaced slots formed through the visor member which may be made viewable therethrough or blocked based upon the selective positioning of a separate movable slotted member. However, the complexity of this device, coupled with the range of selective adjustability, tends to render this invention somewhat impractical.
A sun visor for automobiles is disclosed in U.S. Pat. No. 4,512,605 invented by Aschermann which teaches a sun visor slidable along a guide rail between a stored and an in-use position without being swiveled around a bearing.
Takahashi discloses a sun visor for automobiles in U.S. Pat. No. 4,726,620 wherein a perforated sheet having at least a portion thereof a large number of fine holes therethrough which render the visor somewhat "see-through".
Takahashi has also invented another such invention as shown in U.S. Pat. No. 4,890,875 which includes a transparent sheet having a surface on which a translucent sheet is attached formed of reticulated patterns forming fine through-holes.
Masi, in U.S. Pat. No. 3,445,135, teaches a perforated sun visor as an accessory to a conventional sun visor structured to be connected along the bottom of the sun visor.
The present invention is considerably simpler in construction and mode of use and design for the express purpose of only allowing limited viewability of traffic signals in close proximity to the vehicle. Variations of the invention further limit the viewable light surrounding a traffic light so that the driver may, by side to side head and eye movement, be totally blocked from having to view bright sunlight which surrounds the field of vision of the traffic signal while still having immediate sight access to the stop signal by appropriate head and eye movement. | {
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Generally, in the fabrication of a complementary metal-oxide-semiconductor (CMOS) transistor, a selective area epitaxial (SAE) process is widely used to form source/drain regions. By using the selective area epitaxial process to provide stress, the channel mobility of the transistor is improved and the performance of the transistor is enhanced.
However, the efficacy of using the conventional selective area epitaxial process to increase the performance of the transistor is still unsatisfied. | {
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Glucocorticoids are steroid hormones, many of which are potent anti-inflammatory agents. Their physiological effects are not limited to their anti-inflammatory properties, however, nor are their effects restricted specifically to inflamed tissue. Protein, lipid and carbohydrate metabolism can be altered adversely and electrolyte balance can be disturbed particularly when large or repeated therapeutic doses of the anti-inflammatory glucocorticoids are administered.
Certain recently developed synthetic glucocorticoids show promise as therapeutic alternatives to the natural anti-inflammatory glucocorticoids such as cortisone, cortisol and corticosterone. The synthetic analogues, which include dexamethasone and betamethasone, exhibit reduced effects on electrolyte balance and tend therefore to elicit fewer adverse side effects. In many instances, they also exhibit greater potency as anti-inflammatory agents relative to their natural counterparts, presumably owing to their reduced binding affinity for the plasma protein known as corticosteroid binding globulin (CBG). It has been reported that natural glucocorticoids become biologically inactivated upon binding with CBG in the circulation whereas many synthetic glucocorticoids do not bind and thus remain active (see Mickelson et al., Biochemistry 1981, 20, 6211-6218 where binding affinities for some natural and synthetic glucocorticoids relative to CBG are tabled). The capacity of synthetic glucocorticoids to escape CBG-binding and thus to remain free and biologically active following administration is presumed to be at least partly responsible for their enhanced anti-inflammatory properties in vivo.
Apart from the numerous physiological effects exerted by glucocorticoids, their use in treating inflammation is further complicated by their ability to affect a broad range of tissues, whether inflamed or healthy. Because so many tissues are responsive to corticosteroids, they are rarely administered systemically unless inflammation is particularly severe or life threatening. | {
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The present invention relates to a golf club heads, and more particularly to such a golf club head which has means to lessen shocks when striking the ball.
The game of golf has become more and more popularly accepted by adult people. When playing the golf, different numbers of golf clubs may be used in different conditions. Conventional golf clubs are commonly made of wood. In recent years, a variety of materials including iron, carbon fibers, titanium, etc., have been developed for use in making club heads for golf clubs. In order to diminish material consumption and to reduce the weight, a club head for golf clubs is made having a recessed top chamber. However, a club head of this design con not efficiently absorb or lessen shocks when striking the ball.
It is one object of the present invention to provide a golf club head which effectively lessens shocks when striking the ball. It is another object of the present invention to provide a golf club head which produces a sound when striking the ball. To achieve these and other objects of the present invention, there is provided a golf club head which comprises a recessed top chamber, a face disposed at a front side of the recessed top chamber for striking the ball, the face having a plurality of scoring lines at an outer side, and a back wall disposed at a back side of the recessed top chamber opposite to the face, wherein a plurality of pores are provided at the face along the scoring lines and disposed in communication with the recessed top chamber; a circular through hole is provided at the center of the back wall and disposed in communication with the recessed top chamber for guiding air out of the recessed top chamber, the circular through hole having a diameter about within 1/6 to 1/4 of the width of the face. | {
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The present invention relates to a low-frequency sound reproducing speaker apparatus of Kelton type connected to a vehicle mounted acoustic system as a subwoofer.
In recent years, demand of a vehicle mounted acoustic system constructed by a constitution of mounting a subwoofer with an object of reproducing heavy low-frequency sound is increased in accordance with spreading or the like of a theater system for vehicle mounted use.
In a background art, there have been proposed various kinds of subwoofers constructed by a constitution of containing a woofer unit having a large aperture in a large-sized hermetically closed cabinet and in a case of vehicle mounted use, assigned to a trunk room of a vehicle as a large-sized hermetically closed cabinet.
However, according to the constitution, by occupying the trunk room by the subwoofer, a luggage room space is not present and accommodation performance of the vehicle is significantly deteriorated.
Hence, in the case of the subwoofer for vehicle mounted use, small-sized formation poses an important problem and there have been proposed a subwoofer constituted by Kelton type suitable for high quality reproducing of low-frequency sound even by a cabinet having a small capacity and integrated to an arm rest of a seat (refer to, for example, JP-A-5-276588 and JP-A-6-122347), a woofer mounted on a seat cushion (seat portion) of a rear seat (refer to, for example, JP-A-2004-330951) and the like. | {
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A computer system 100 illustrated in FIG. 1 represents a typical hardware setup for executing software that allows a user to perform tasks such as communicating with other computer users, accessing various computer resources, and viewing, creating, or otherwise manipulating electronic content—that is, any combination of text, images, movies, music or other sounds, animations, 3D virtual worlds, and links to other objects. The system includes various input/output (I/O) devices (mouse 103, keyboard 105, display 107) and a general purpose computer 100 having a central processor unit (CPU) 121, an I/O unit 117 and a memory 109 that stores data and various programs such as an operating system 111, and one or more application programs 113. The computer system 100 also typically includes non-volatile memory 110 (e.g., flash RAM, a hard disk drive, and/or a floppy disk or other removable storage media) and a communications card or device 123 (e.g., a modem or network adapter) for exchanging data with a network 127 via a communications link 125 (e.g., a telephone line).
The computer 100 of FIG. 1 also can be connected to various peripheral I/O devices. One of the more popular of such peripheral devices is a digital camera 108 that enables users to take pictures and save them in digital (electronic) format. The digital camera 108 enables users to take pictures (i.e., images), which are saved in memory (not shown) within the digital camera 108 in a digital (electronic) format. After taking and storing the images, the user can connect the digital camera 108 to a computer system 100 in order to upload the digital images to the computer's disk drive or other non-volatile memory 110. Once the digital images are uploaded to the computer system 100, the user can erase the digital images from the memory of the digital camera 108 so that the user can take and store additional images using the digital camera 108. Typically, the digital camera 108 is connected to the computer 100 only while the user is uploading images to the computer's disk drive or other non-volatile memory 110.
Users also can obtain digital images, for example, of film-based prints from a traditional camera, by sending an exposed film into a photo-finishing service, which develops the film to make prints and then scans (or otherwise digitizes) the prints or negatives to generate digital image files. The digital image files then can be transmitted back to the user by e-mail or on a CD-ROM, diskette, or other removable storage medium.
In any event, once the digital images are stored on the computer 100, a user can perform various operations on them. For example, an image viewer application can be used to view the images or a photo editor application can be used to touch-up or otherwise modify the images. In addition, an electronic messaging (e.g., e-mail) application can be used to transmit the digital images to other users.
In addition to viewing the digital images on the computer display 107, users often desire to have hard copies (physical prints) made of digital images. Such hard copies can be generated locally by the user using output devices such an inkjet printer or a dye sublimation printer. In addition, users can transmit digital images (e.g., either over a computer network or by using a physical storage medium such as a floppy disk) to a photo-finishing service, which can make hard copies of the digital images and send them (e.g., by U.S. Mail or courier service) back to the user.
FIGS. 2A-2F show a sequence of screen shots that a user might encounter when transmitting digital images to a photo-finishing service to have hard copies (prints) made of the images. In FIG. 2A, the user first encounters a contact information window 200 in which the user must enter several items of contact information such as first and last names 202, 204, address 206, city 208, state 210, country 210, phone 214, fax 216, and Email address 218. This information typically is required by the photo-finishing service for each order for purposes of billing and shipping.
After the user has entered the required information, the user presses the Next button 220 to arrive at the next screen—an image selection window 222 as shown in FIGS. 2B and 2C. In the image selection window 222, the user designates the specific images of which hard copies are to be made. The digital images either can be selected from among the images stored on the user's computer by clicking the “Select Image . . . ” button 230 or they can be acquired from a digital camera or scanner attached to the user's computer by clicking the “Acquire Image . . . ” button 232. Once selected, the images can be viewed and/or cropped by clicking on the “View/Crop” button 234. In addition, the user can designate the hard copy format and other parameters (e.g., size, number of copies, paper type) for each of the selected images by selecting or entering the desired options using drop-down list 224 and text box 226. The selected images and their associated parameters are shown in display area 228. Typically, each order for prints must meet a minimum order amount 223 (e.g., five dollars).
After the images and their respective hard copy parameters have been selected, the user clicks the Next button 236 and a shipping and payment information window 238 is presented. In this window 238, the user selects a desired shipping method from drop-down list 240 and specifies a method of payment and associated verification information in text boxes 242, 244, 246 and 248.
After this information has been provided, the user clicks the Next button 250 and is presented with an order confirmation window as shown in FIG. 2E. The order verification window 250 allows the user to view and confirm the order including the images selected and their respective parameters in display area 252, as well as the price of the order 254. If the user is satisfied with the order, the user clicks the Finish button 256 to complete the order.
Upon completing the order, the images are uploaded to the photo-finishing service as indicated by the upload window 258 in FIG. 2F. Once the images are uploaded, the photo-finishing service arranges to have prints made of the selected images and to have the prints mailed to the user and address specified in the contact information window 200 shown in FIG. 2A. If the user desires to have prints of the same (or different) images sent to another person (e.g., a family member or friend), the user typically must repeat the entire order generating process represented by FIGS. 2A-2F. Generally, repeating the ordering process to send prints to another person involves entering a considerable amount of redundant information and incurring separate charges, including multiple minimum order charges, on the user's credit card (or other financial instrument) as well as potentially requiring the image to be uploaded multiple times.
The present inventors recognized that it would be advantageous to provide users with a intuitive and robust environment in which a user can review a thumbnail associated with the image and upload image files so that they can be printed and/or distributed to multiple recipients while minimizing the user's time, effort, and expense in uploading the image files. | {
"pile_set_name": "USPTO Backgrounds"
} |
The semiconductor integrated circuit (IC) industry has experienced rapid growth. Technological advances in IC materials and design have produced generations of ICs. Each generation has smaller and more complex circuits than the previous generation.
In the course of IC evolution, functional density (i.e., the number of interconnected devices per chip area) has generally increased while geometric size (i.e., the smallest component (or line) that can be created using a fabrication process) has decreased. This scaling-down process generally provides benefits by increasing production efficiency and lowering associated costs.
Such scaling down has also increased the complexity of processing and manufacturing ICs and, for these advances to be realized, similar developments in IC processing and manufacturing are needed. For example, a three dimensional transistor, such as a semiconductor device with nanowires, has been introduced to replace planar transistors. These relatively new types of semiconductor IC devices face manufacturing challenges, and they have not been entirely satisfactory in all respects. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
The present invention relates to a method of subbing photographic supports, more particularly, to a method of subbing plastic film supports for photographic elements employing an aqueous subbing solution containing one or more copolymers of vinylidene chloride and a vinyl monomer having an alcohol group in its side chain to provide tenacious adhesion between a support and aqueous organic colloid layers.
2. Description of the Prior Art
The invention will hereinafter be exemplified using polyester film as an example, which is one representative plastic film.
Polyester film is superior to other supports in properties such as mechanical strength, dimensional stability, heat resistance, chemical resistance, transparency, etc., and has been applied to photographic, printing, drafting, magnetic materials and the like. In recent years, its application has been markedly expanding. In particular, its demand as a photographic film support has rapidly increased in recent years, occupying an important position in photographic film supports.
As is well known, however, it is generally difficult to tenaciously adhere a hydrophilic organic colloid layer such as a photographic emulsion layer to a polyester film support since polyesters are extremely hydrophobic due to their high crystallinity, chemical inertness, lack of a good solvent therefore due to high chemical resistance, and the absence of hydrophilic groups. In the past, there have been many attempts to overcome this problem. One such attempt is to impart good adhesiveness by subbing. For example, the adhesive property of a polyester film can be improved by subbing an unstretched or monoaxially stretched polyester film with an aqueous latex of an acrylate or vinylidene polymer before it is biaxially stretched and thermally treated. This method, however, has a cost disadvantage by reason of, for example, the lack of reusability of a biaxially stretched film prepared by this method.
In order to strengthen the adhesion between a subbing layer and a polyester film, it is also known to heat the film and the subbing layer to a fairly high temperature, or to heat them under pressure. These methods, however, are accompanied by the danger of thermal deterioration of the base.
In order to improve the adhesion between a subbing layer and a hydrophilic organic colloid layer, there has generally been practiced a subbing method using a copolymer of a polymerizable unsaturated carboxylic acid such as acrylic acid, itaconic acid and the like.
As copolymers in which such a polymerizable unsaturated carboxylic acid is used as a copolymerization component, there are, for example, copolymers of an unsaturated carboxylic acid (4 to 12 wt%), styrene or acrylonitrile (30 to 48 wt%) and an acrylate (48 to 70 wt%) as described in U.S. Pat. No. 2,794,742; copolymers consisting of an unsaturated fatty carboxylic acid and at least one ethylenically unsaturated monomer as described in U.S. Pat. No. 3,349,703; copolymers of an unsaturated carboxylic acid and vinylidene chloride as described in published German Patent Application No. 1,811,543; vinyl acetate-acrylate-unsaturated carboxylic acid copolymers as described in Japanese Patent Publication No. 29,995/69; and the like.
These subbing layers, however, have the following disadvantages due to their increased hydrophilicity owing to the acid component, i.e., the carboxylic acids contained therein: Such a subbing layer swells in water, particularly, in an aqueous alkaline solution, resulting in a weakening of its film strength. Consequently, the subbing layer, when applied to a photographic film, is liable to be peeled off in an alkaline developing solution. In addition, the carboxylic acid component in the subbing layer is liable to adversely affect light-sensitive emulsion layers coated thereon, impairing photographic properties such as sensitivity, in particular, under high temperature and high humidity conditions. | {
"pile_set_name": "USPTO Backgrounds"
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Conditioned air enters a passenger compartment of a vehicle through air outlet ducts in the front dashboard. The air outlet ducts have movable louvers to direct air to the left or right and also up or down to direct air where needed. Quite often, the louvers are used to direct cold air away from vehicle occupants so that the cold air does not impinge on the vehicle occupants. When conditioned air impinges on vehicle occupants, the occupants often feel quite cool and therefore uncomfortable. Occupants often experience chill bumps on the arms or other exposed portions of the body. While adjusting the louvers offers a bit of relief, cold air still impinges on the occupants causing many vehicle operators to turn the air conditioning off and then on again when they become uncomfortable. Accordingly, it will be appreciated that it would be highly desirable to have an air flow diverter that would prevent impingement of the cold air on the vehicle occupants. | {
"pile_set_name": "USPTO Backgrounds"
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Electronic commerce is hampered by privacy and security, as there is a requirement to ensure that the sender of an electronic transmission is in fact who they purport to be. Due to the non-physical nature of the medium, traditional methods of physically marking the media with a seal or signature, for various business and legal purposes, are not practical. Rather, some mark must be coded into the information itself in order to identify the source, authenticate the contents, and provide privacy against eavesdroppers.
Public key cryptography is the basis for a number of popular digital signature and key management schemes. These include Diffie-Hellman key agreement and the RSA, DSA, and ECDSA digital signature algorithms. Public key algorithms are typically combined with other cryptographic algorithms (e.g. DES) and security protocols (e.g. SSL) to provide a wide range of sophisticated and scalable security services such as authentication, confidentiality, and integrity.
Public key cryptography uses a pair of cryptographic keys—one private and one public. Public key cryptography provides an elegant architecture for authentication and authorization, on any kind of communication channel. The Private key is kept secret and used to create digital signatures and decrypt encrypted messages. The public key of the user can be published and used by others to confirm the validity of a digital signature or to encrypt a message to the owner of the corresponding private key.
A public-key certificate binds a public-key value to a set of information that identifies an entity (such as a person, organization, account or site) associated with use of the corresponding private key.
In order to permit one correspondent to communicate securely with another it is necessary that each is confident of the authenticity of the other and that the public key used by are of the correspondents to verify signatures or decrypt messages is in fact the public key of the other correspondent. This is typically achieved through the use of a certificate issued by a party trusted by both correspondents. The initiating correspondent requests the trusted party to sign the public key with the trusted parties own private key and thereby create a certificate.
The certificate may then be forwarded to the recipient correspondent who has the trusted parties public key. The recipient can therefore verify the initiating correspondent's public key and proceed with a communication.
The trusted party is usually a certifying authority or CA and the CA's public key will be embedded in or provided to the correspondents devices when they subscribe to the infrastructure organized by the CA. There is therefore a high degree of confidence that the CA's public key is accurate and genuine.
Usually a CA is responsible for several tasks. These may include, without restriction: Receiving certificate requests; Validating that the requesting entity has control of the private key matching the requested public key (proof of possession); Validating the conformance of the request with local policy, including restrictions on identifying information, attribute information and/or keying material; Modifying the request to create conformance with local policy; Validating the information in the request against external data sources; Determining if the request has been authenticated by the user or some other authority; Presenting the request for manual approval by an administrator or administrators; Signing or authenticating the certificate; Publishing the certificate to a central storage point or multiple storage points; and Returning the certificate to the requestor
The infrastructure organized under the CA is known as a public key infrastructure (PKI) and commonly defined as a set of hardware, software, people, policies and procedures needed to create, manage, store, distribute, revoke and destroy certificates and keys based on public key cryptography, in a distributed computing system. A PKI may include a certificate issuing and management system (CIMS) whereby includes the components of the PKI that are responsible for the issuance, revocation and overall management of the certificates and certificate status information. A CIMS includes a CA and may include Registration Authorities (RAs), and other subcomponents.
The advent of new technologies, such as 2.5G and 3G networks, which provide enough bandwidth to support audio and video content, and seamless global roaming for voice and data has given rise to a new class of mobile devices such as network-connected personal digital assistants (PDAs) and WAP-enabled mobile phones generally referred to as constrained devices. This trend effectively extends traditional personal computer application services to mobile devices, such that traditional e-commerce is performed on mobile devices, that is, mobile commerce. As in e-commerce there is still a need for the client to provide identification, authentication and authorization to the merchant, authentication being the act of verifying the claimed identity of the station or originator, while authentication involves the use of certificates via a certification authority.
However, there exists a problem with the current methods for obtaining mobile certificates from a certification authority due to bandwidth constraints, network latency, and the limitations of the resources of the mobile device such as processor power, speed and memory storage. Certificates are characteristically large pieces of data such that transmission times between the mobile device and the certification authority, or between a pair of mobile devices, may lead to substantial bandwidth usage during transactions and raise issues with data integrity.
It has previously been proposed to reduce the bandwidth in the exchange of such certificates by storing the certificates at a server and allocating an identifier to the stored location. The initiating client may then receive the URL, or other location indicator, of the certificate, which can then be forwarded to the other correspondent. The other correspondent may then retrieve the certificate and verify the information provided. This arrangement reduces the bandwidth needed compared with transmitting a full certificate but does not reduce the number of messages transmitted between the client and the RA or CA, and thus does not affect the significant network latency burden that results, especially when hundreds or thousands of certificate requests per minute may be handled by the CA.
Accordingly, it is an object of the present invention to obviate mitigate at least one of the above disadvantages. | {
"pile_set_name": "USPTO Backgrounds"
} |
Patent application WO 95/00497 published Jan. 5, 1995 under the Patent Cooperation Treaty (PCT) describes compounds which inhibit the enzyme, farnesyl-protein transferase (FTase) and the farnesylation of the oncogene protein Ras. Oncogenes frequently encode protein components of signal transduction pathways which lead to stimulation of cell growth and mitogenesis. Oncogene expression in cultured cells leads to cellular transformation, characterized by the ability of cells to grow in soft agar and the growth of cells as dense foci lacking the contact inhibition exhibited by non-transformed cells. Mutation and/or overexpression of certain oncogenes is frequently associated with human cancer.
To acquire transforming potential, the precursor of the Ras oncoprotein must undergo farnesylation of the cysteine residue located in a carboxyl-terminal tetrapeptide. Inhibitors of the enzyme that catalyzes this modification, farnesyl protein transferase, have therefore been suggested as anticancer agents for tumors in which Ras contributes to transformation. Mutated, oncogenic forms of Ras are frequently found in many human cancers, most notably in more than 50% of colon and pancreatic carcinomas (Kohl et al., Science, Vol. 260, 1834 to 1837, 1993).
In view of the current interest in inhibitors of farnesyl protein transferase, a welcome contribution to the art would be additional compounds useful for the inhibition of farnesyl protein transferase. Such a contribution is provided by this invention. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
This invention is directed to a mobile platform assembly such as, but not limited to, a skateboard, roller skate, etc. and including at least one but more practically a plurality of spherically configured wheels, each movably interconnected to the platform by a bearing assembly and a mounting assembly. Each bearing assembly is cooperatively disposed and structured with a corresponding mounting assembly to facilitate movement of a corresponding spherical wheel through a substantially universal, rotational range of motion relative to the platform.
2. Description of the Related Art
Numerous types of mobile support platforms have been known and utilized for years. The popularity of such structures has even risen to the level where the use thereof defines an “extreme” sport. As such, skateboards or other mobile platforms are utilized by skilled riders to perform a variety of difficult maneuvers. While not limited to skateboards, mobile platforms include various types of wheel structures adaptable for use in the performance of sporting maneuvers as well as recreation, exercising, and travel for relatively short distances. Mobile platforms of the type referred to include roller skates, rollerblades as well the aforementioned skateboards. In use, these types of platforms are manually propelled and are dimensioned and configured to support one or both of the individual's feet as the platform travels over a variety of different supporting surfaces.
As set forth above, skateboards in particular have become widely developed and generally comprise an elongated platform large enough for an individual to be supported in an upright or standing orientation. The wheel assembly associated therewith typically includes a front wheel structure and a rear wheel structure, wherein the portion of the platform extending between such front and rear wheel structures are sufficient to support the riding individual in the manner described.
In addition, various types of roller skate designs have been popularized for sporting, recreational and entertainment uses. As conventionally designed and structured, roller skates normally include a plurality of two pairs of substantially disk shaped wheels each supported on either a leading and trailing axle, wherein the two axles are disposed generally adjacent a front and rear portion a skate base respectively. As such, sufficient stability is provided for the user to move and/or be transported over a variety of different surfaces while also performing a variety of different maneuvers. More recently developed shoe skates are commonly known as “blade” skates, “inline” skates and/or rollerblades, which normally comprise a plurality of disk shaped wheels disposed in a linearly aligned relation to one another as they collectively extend along the length of the sole or base portion of the shoe skate on which they are mounted.
While structures of the type set forth above have enjoyed extensive popularity over many years, they are at least generally recognized as being at least partially restrictive, at least to the extent of allowing the rider or user to perform movements incorporating a somewhat limited degree of maneuverability. To overcome such disadvantages, an additional wheel assembly or wheel structure has been incorporated in skates, skateboards and other mobile platforms wherein one or all of the wheels include a spherical configuration. Accordingly, while spherical wheels have been generally known, the attachment or movable interconnection of this type of wheel to the under portion of the support platform also presents problems and/or disadvantages.
Such disadvantages are typically related to a relatively limited range of motion of the spherical wheel(s) thereby restricting maneuverability of the mobile platform to which such one or more wheels are attached. More specifically, known and conventional interconnecting and/or mounting structures associated with spherical wheels frequently diminish the potential freedom of movement which an improved spherical wheel assembly and appropriate mounting assembly could accomplish. In addition, the use of spherical or ball-shaped wheels may also suffer from problems and disadvantages associated with stability and/or maintenance problems. Similar to the above recognized disadvantages, such reliability problems could also be the result of at least partially ineffective connecting or mounting structures used to movably interconnect the spherical or ball type wheels to the support platform.
Accordingly, there is a need in this area for a support platform assembly capable of supporting and/or transporting an individual over a variety of different surfaces. Such a preferred and proposed mobile platform assembly should overcome the problems and disadvantages recognized in known and conventional mobile platforms, of this type, by providing sufficient maneuverability while reliably and efficiently interconnecting the wheel assembly to the platform. Also, the adaptability of an appropriate wheel assembly to a variety of different types of support platforms including skateboards, roller skates, etc. should be such as to increase the performance of all such mobile support platforms. Finally, a proposed and preferred mobile support platform which incorporates a versatile and high performance wheel assembly should be designed and structured for commercial development at a reasonable cost and price so as to be available to a greater portion of the consuming public. | {
"pile_set_name": "USPTO Backgrounds"
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Iminodiacetic acid compounds are useful in various applications. Such compounds (particularly iminodiacetic acid and its salts) are, for example, widely used as raw materials for making pharmaceuticals, agricultural chemicals, and pesticides, and are particularly useful as raw materials for making N-(phosphonomethyl)glycine and its salts. N-(phosphonomethyl)glycine, known in the agricultural chemical industry as “glyphosate,” is described by Franz in U.S. Pat. No. 3,799,758. N-(phosphonomethyl)glycine and various salts thereof can be conveniently applied as a post-emergent herbicide in an aqueous formulation, and as a highly effective and commercially important broad-spectrum herbicide useful for killing or controlling the growth of a wide variety of plants, including germinating seeds, emerging seedlings, maturing and established woody and herbaceous vegetation, and aquatic plants. Widely known processes for making N-(phosphonomethyl)glycine and its salts from iminodiacetic acid compounds are disclosed in, for example, Franz, et al., Glyphosate: A Unique Global Herbicide (ACS Monograph 189, 1997) at pp. 233–62 (and references cited therein).
Many previously disclosed processes for making iminodiacetic acid compounds convert an intermediate amine compound having at least two identical groups. For example, in U.S. Pat. No. 5,627,125 (and references cited therein), Ebner et al. disclose making disodium iminodiacetate by dehydrogenating two hydroxyethyl groups of N,N-diethanolamine using a strong hydroxide base in the presence of a metallic catalyst. Micovic et al. (Journal of Serbian Chemical Society, 51, 435–39 (1986)), on the other hand, describe making iminodiacetonitrile (HN(CH2CN)2), and then hydrolyzing iminodiacetonitrile in acid to form iminodiacetic acid.
Iminodiacetic acid compounds also have been prepared using, for example, processes in which the two carboxymethyl groups are introduced simultaneously. Jasik et al. (Pol. Organika, 1–8 (1986)), for example, disclose making iminodiacetic acid and its salts by reacting ammonia with about two equivalents of chloroacetic acid.
Iminodiacetic acid compounds additionally have been made through unsymmetrical chemical intermediates. For example, Sano et al. (Japanese Patent No. 46040611) disclose making iminodiacetic acid and its disodium salt by hydrolyzing N-cyanomethylglycine. Sano et al. report making the N-cyanomethylglycine by reacting glycine with glycolonitrile. Nakao et al. (Japanese Patent No. 55007252) likewise disclose making iminodiacetic acid and its disodium salt by hydrolyzing N-cyanomethylglycine, but Nakao et al. report making the N-cyanomethylglycine by reacting glycine with formaldehyde and an alkali metal cyanide. Sodium glycinate, from which glycine can be obtained readily, may be prepared, for example, by dehydrogenating monoethanolamine. See, e., Franczyk et al., U.S. Pat. No. 5,739,390.
A process for making iminodiacetic acid or a salt thereof directly from monoethanolamine substrate is highly desirable. Because mono-, di-, and tri-ethanolamines are all obtained when ammonia is reacted with ethylene oxide in the major commercial production process, monoethanolamine is now more readily available due to the large quantities of diethanolamine utilized commercially to produce disodium iminodiacetate and other materials. Use of monoethanolamine in a process involving a single cyanomethylation to make disodium iminodiacetate would substantially reduce the amount of the highly toxic hydrogen cyanide needed compared to bis-cyanomethylation of ammonia to produce disodium iminodiacetate. Availability of a viable alternative to the current commercial routes could further offer flexibility in the use of existing manufacturing facilities.
Applicants are not aware of any reported processes that directly utilize monoethanolamine to make iminodiacetic acid or salts thereof. Cyanomethylation of monoethanolamine has been disclosed by Athey et al. in PCT application publication number WO 9721669 and Ulrich et al. in U.S. Pat. No. 1,972,465. Chemically, N-cyanomethyl substituted amines are generally unstable, which make their reactivity difficult to predict for new types of reactions or when reactive substituents are present. Athey et al. and Kern (U.S. Pat. No. 2,169,736) report that N-(2-hydroxyethyl)glycine may be formed by alkaline hydrolysis of N-cyanomethylethanolamine in an unreported yield without mentioning any stability problems. Applicants are not, however, aware of any previously reported processes which simultaneously or sequentially convert the cyanomethyl group and the hydroxyethyl group of N-cyanomethylated monoethanolamines to form iminodiacetic compounds. | {
"pile_set_name": "USPTO Backgrounds"
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The embodiments described herein relate generally to medical devices and methods for delivery catheters, and more particularly to delivery catheters configured for creating a passage in and/or through a target tissue for placement of a guidewire.
Many surgical procedures include delivering at least a portion of a device such as a catheter or the like to positions within a patient where access may be limited (e.g., by the anatomy or the like). For example, atrial fibrillation of a heart is typically treated by isolating portions of the atria. Such isolation of the atria can be done by open-heart surgery (e.g., a modified Maze procedure) or, most commonly, by a trans-venous catheter technique. In some known instances, the doctor cauterizes the left atrial muscle tissues using radiofrequency ablation techniques, with the ablation lesion targeting and/or circumscribing the pulmonary veins. Isolation of these anatomic portions of atria prevents the electrical propagation of the arrhythmia into the remainder of the atria. Generally, the operator (e.g., surgeon or interventionalist) places electrophysiologic catheters into the right heart. Under fluoroscopic guidance, a catheter is advanced adjacent to the atrial septum. In most cases, a puncture of the atrial septum (right to left) is made with a specialized needle catheter. A guidewire is then advanced into the left atrium.
The trans-septal catheter is removed and a guide catheter is delivered over the wire into the left atrium. An ablation catheter is then advanced into the left atrium under fluoroscopic guidance. Typically, electrophysiologists use additional imaging and mapping technology to improve safety and efficacy of the procedure, such as intracardiac ultrasound, cardiac computed tomography (CT), or non-contact mapping systems. Once the ablation/mapping catheters are in the left atrium, the operator delivers radiofrequency energy to the target sites. The operator moves the ablation catheter in a point-by-point fashion connecting the lesions, which in effect, electrically isolates the pulmonary veins from the rest of the atrium.
These known procedures typically take 3-6 hours to complete. The procedural success varies between operators and patient selection (success rate is between 50-85% for a single attempt), with some patients receiving subsequent ablation procedures to “touch up” the prior ablation site. The cost of these procedures is variable and increases substantially with duration of procedure and/or the addition of adjuvant imaging/mapping technology. Generally, current procedures are associated with a 5-6% risk of procedural complications, including a 0.5% risk of stroke due to instrumenting (i.e., placing one or more medical devices into) the left atrium. Other complications can include cardiac perforation, tamponade, pulmonary vein stenosis, and atrial-esophageal fistula. Despite attempts to simplify and streamline the procedure, the anatomic variations of the left atrium and pulmonary veins have limited the utility of alternative ablation techniques.
In some known instances, pericardial techniques for treating atrial fibrillation are employed; however, such known techniques also have various limitations. For example, most current pericardial ablation strategies include an operator blindly navigating recesses of the pericardial space with an ablation catheter. In some instances, reflections formed in the pericardial space, also described as “pericardial reflections”, can pose an obstacle to delivery of a single contiguous lesion using these techniques. Thus, the anatomy of the pericardial space limits the efficacy and technical ease of current pericardial/epicardial catheter-based procedures. For example, although the membranous reflections of the pericardial space are thin and relatively avascular, the angle, spatial limitations, and orientation of the surgical access point relative to the pericardial reflections does not facilitate simple puncture with a blunt catheter or a standard needle. Moreover, the large vessel and cardiac chambers adjacent to the pericardial reflections make the proposition of blind puncture with conventional catheters impractical.
Accordingly, there is a need in the pertinent art for devices, systems, and methods for efficiently and reliably locating and puncturing pericardial reflections, e.g., for delivery of a guidewire and/or catheter. | {
"pile_set_name": "USPTO Backgrounds"
} |
A. Field of the Invention
The present invention relates generally to two-way communication and control network systems, and, more particularly, to communication and control networks of the type disclosed in the above-identified related applications wherein a communication and control network provides communication between a variety of control devices such as circuit breakers, motor starters, protective relays, remote load controllers, lighting systems, and the like, to communicate with and be controlled by a central or master controller over a common network line. Specifically, the present invention is directed to certain aspects of a communication and control system which employs a multipurpose software based microcontroller which can be operated in a master mode in which the microcontroller interfaces an external host computer, or terminal, to the communication and control network through a hardware-based digital IC of the type disclosed in said above-identified related applications, said microcontroller also being operable in an expanded slave mode in which a controlled product connected to the microcontroller is interfaced to the common network line through the same or similar hardware-based digital IC.
B. Description of the Prior Art
In the communication and control system disclosed in the above-identified related applications control and monitoring is carried out over a network consisting of either the existing power lines or a dedicated twisted pair of lines. The hardware-based digital integrated circuit described in detail in the Verbanets application Ser. No. 625,747 identified above forms the basic building block for such a communication and control network. This digital IC is a twenty-eight pin semi-custom integrated circuit implemented by complementary metal oxide semiconductor (CMOS) technique which provides a simple, low cost interface to the communication and control network. This digital IC, which may also be referred to as an industrial communication (INCOM) integrated circuit, or chip, provides the network interface functions of address recognition, detection and storage of an on-off keyed carrier multi-bit message received from the network, carrier generation and transmission of an on-off keyed carrier message to the network in accordance with the information stored therein, generation and checking of a five bit BCH error checking code, and framing of the received and transmitted messages.
The digital IC, or INCOM chip, may be configured for one of three operating codes: stand alone slave, expanded-mode slave and expanded-mode master. Arbitration of the network is accomplished in a master-slave fashion. The stand alone slave mode is used by simple devices and provides control of a single output line and the return of two status bits from the slave device. The expanded-mode slave is used to interface microprocessor based equipment to the network and will support far more complex communications between the master and the expanded-mode slave. When the INCOM chip is operated in an expanded master mode, the INCOM device may be used as a direct interface to the master or central controller of the network. However, in many instances it is desirable that the network master use a conventional RS232C serial link or equivalent, to communicate with the stand alone slaves and enabled mode slaves on the network. The ASCII protocol normally used with such a serial link is, however, not compatible with the 33 bit message format employed by the INCOM network. Accordingly, this severely limits the types of computers or terminals which can be used as a master or central controller for the INCOM network.
When the INCOM chip is operated in the expanded slave mode it may be used as a direct interface to a microprocessor controlled product. However, in many instances the microprocessor associated with the controlled product may be quite busy and hence cannot be directly coupled to the network through the INCOM chip. This is particularly true of products such as motor starters and controllers in which many different variables, such as rotor winding temperature, bearing temperature, ground fault, overcurrent, locked rotor current, and underload and overload voltages may be monitored and/or controlled. Furthermore, even if the microprocessor associated with a controlled product is relatively inactive, it is in many instances desirable to provide an intermediate buffer interface between the INCOM chip and the controlled product so that a major design change or reprogramming of the microprocessor associated with the product is not required in order to utilize the INCOM network. | {
"pile_set_name": "USPTO Backgrounds"
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Washers are inserted between bolts, or screws, and building materials to ensure tightness, prevent leakage or relieve friction between the bolt and working piece. Often times the washers must be inserted in tight or hard to reach places, or the washer is simply awkward to handle with the bolt. Moreover, the screw or bolt must be aligned with the washer for proper installation.
Accordingly, it is an object of the present invention to provide a washer that is easy to handle and install. Another objective of the invention is to provide such a device that is convenient to use in tight work situations.
In order to accomplish the foregoing, a standard washer is integrally attached to an extension. The device is scored between the washer and extension so the extension may be bent with respect to the washer to detach the extension from the washer after the washer is installed. | {
"pile_set_name": "USPTO Backgrounds"
} |
Various methods are used to control users' access to systems, information, and network resources. In general, a typical access-control system performs two primary functions: an authentication function and an authorization function. For example, prior to providing a user access to a resource (e.g., a computing device, an application, or a website) an access-control system may first request authentication-factor information (e.g., a username, a password, a one-time-use password, etc.) from the user that the access-control system can use to positively identify the user. If the identity of the user can be established using the provided authentication-factor information, the access-control system may then determine whether the user has permission to access the resource and, if so, may allow the user to access the resource.
The level of security provided by an access-control system may be affected by the type and quantity of authentication factors that a user must have to be authenticated. Examples of authentication factors that a user may need to be authenticated may include knowledge factors that the user knows (e.g., a username, a password, or a personal identification number), possession factors that the user possesses (e.g., a smartcard or a hardware token or smartphone that generates one-time-use passwords), and inherence factors that are part of the user (e.g., a biometric characteristic of the user such as a fingerprint). To increase the level of security provided by its access-control systems, many enterprises implement access-control systems that authenticate users using an authentication method, commonly referred to as multi-factor (or two-factor) authentication, that uses two or more types of authentication factors (e.g., both knowledge factors and possession factors).
While multi-factor authentication generally provides greater levels of security, various issues may arise when typical multi-factor authentication methods are implemented. One of the biggest issues that may arise when typical multi-factor authentication methods are implemented is that, if a user loses a possession factor, the user may be unable to be authenticated. Moreover, the user may have limited options for recovering access to his or her accounts that required authentication. In general, standard techniques for resetting knowledge factors, such as resetting via email or other knowledge-factor based authentication techniques, cannot be used to reset possession factor since using these methods may defeat the purpose of requiring a possession factor in the first place. Some access-control systems may attempt to solve the problem of possession-factor loss by requiring that each user maintains multiple possession factors so that if one possession factor is lost, then one of the others can be used. Unfortunately, this solution may also fail when a user loses all possession factors. The instant disclosure, therefore, identifies and addresses a need for systems and methods for preventing loss of possession factors. | {
"pile_set_name": "USPTO Backgrounds"
} |
Benzoyl peroxide is commonly used in topical pharmaceutical formulations to treat dermatologic conditions such as acne vulgaris, commonly referred to as acne. Topically applied antibiotics have also been used in topical formulations to treat dermatologic conditions such as acne. Examples of antibiotics that have been used topically to treat acne include macrolide antibiotic such as erythromycin and lincomycin-type antibiotics such as clindamycin and lincomycin.
Combination products containing benzoyl peroxide and an antibiotic have been utilized and provide increased anti-acne efficacy compared to formulations containing either benzoyl peroxide or an antibiotic alone. Klein, U.S. Pat. No. 4,497,794, discloses a combination formulation containing benzoyl peroxide and erythromycin for the treatment of acne. Compositions prepared generally as described in Klein '794 are marketed under the tradename Benzamycin® (Dermik Laboratories, Berwyn, Pa.). Combinations of benzoyl peroxide and lincomycin family antibiotics such as clindamycin are disclosed in Klein, U.S. Pat. No. 5,767,098, Baroody, U.S. Pat. No. 5,733,886, and Stiefel, U.S. Pat. No. 5,466,446. Compositions prepared generally as described in Klein '098 are marketed under the tradename Benzaclin® (Dermik Laboratories) and as described in Stiefel are marketed under the tradename Duac® (Stiefel Laboratories, Inc., Coral Gables, Fla.).
One of the problems associated with topical therapy with compositions containing benzoyl peroxide, either alone or in combination with an antibiotic, is the localized irritation at the site of application. Benzoyl peroxide has been shown to have a concentration dependent irritation potential. See Mills et al, International Journal of Dermatology, 25(10):664-667 (1986) and Lassus, Current Medical Research and Opinion, 7(6):370-373 (1981). Each of the above products contains benzoyl peroxide at a concentration of 5% w/w, a concentration that is associated with irritation.
Benzoyl peroxide is practically insoluble in water. The irritation due to application of compositions containing benzoyl peroxide has been determined to be caused by the portion of the benzoyl peroxide that is in suspension, whereas dissolved benzoyl peroxide causes little or no skin irritation. See, Schwarz, U.S. Pat. No. 7,153,888; and De Villez, U.S. Pat. No. 4,923,900. Schwarz discloses a composition containing benzoyl peroxide wherein all of the benzoyl peroxide of the composition is in solution in an organic solvent. Because dissolution of benzoyl peroxide accelerates the degradation of benzoyl peroxide, Schwarz discloses that an antioxidant is included in the composition to improve the stability of the solution.
One disadvantage of Schwarz is that a high concentration of organic solvent is required in order to dissolve the benzoyl peroxide. High concentrations of organic solvents have a tendency to be irritating to skin, primarily due to the drying effect due to solubilization of skin lipids. In Tables 1 to 3, Schwarz discloses multiple examples of compositions containing various organic solvents and benzoyl peroxide. In each of the examples, the concentration of organic solvent is more than 10 times, and generally more than 15 times that of the benzoyl peroxide in the composition.
De Villez discloses a composition containing benzoyl peroxide, water, and a water-miscible organic solvent that is less volatile than water and in which the benzoyl peroxide is soluble. Prior to application on the skin, the benzoyl peroxide is in suspension in the composition. However, when applied to the skin, the water from the composition evaporates relatively rapidly compared to the organic solvent. The benzoyl peroxide of the composition is then dissolved in situ in the organic solvent, resulting in a solution of benzoyl peroxide after all of the water has evaporated.
In order for the De Villez composition to be transformed from a suspension to a solution, the composition must remain in residence on the skin surface for a sufficient time for the water in the composition to evaporate. During this time, the benzoyl peroxide is in suspension in the composition and the suspended particles are able to interact with the skin to cause irritation. Moreover, De Villez, like Schwarz, requires a relatively high concentration of an organic solvent, which may contribute to the irritation potential of such compositions. | {
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The present invention relates in general to ventilation of passenger vehicles, and, more specifically, to a pressure relief valve assembly for extracting air from a vehicular passenger compartment.
To obtain a quiet environment and to protect the interior passenger compartment of an automotive vehicle from outside elements, the compartment is substantially sealed from the atmosphere. During certain vehicle operating conditions, however, air pressure in the interior passenger compartment may exceed atmospheric pressure. This condition occurs routinely when a vehicle door is closed when entering or exiting the vehicle. If the interior is not vented to the atmosphere, the effort required to close the door may greatly increase, inconveniencing the operator of the vehicle. High internal pressures can also be created by operation of a blower in a climate control system or by the inrush of outside air when traveling at high speeds.
It is well known to provide a mechanism for equalizing the pressure between the interior compartment of an automobile and the atmosphere. Typically, a valve assembly is placed between the interior space and the outside of the vehicle in order to control an exhaust flow of air from the interior. One type of valve assembly known as a pressure relief valve or “air extractor” is typically connected, by way of one or more ducts, conduits, and/or vents, to the passenger compartment. The valve assembly allows air to be selectively expelled, discharged, or extracted from the vehicle passenger compartment, while substantially preventing air, gas, fumes, and/or other undesirable materials from entering into the passenger compartment. By eliminating and/or substantially reducing the pressure differentials, these pressure relief valve assemblies improve the performance of climate control systems, reduce door-closing efforts, minimize window frame deflection, and reduce noise within the passenger compartment of the vehicle.
A typical vehicle body air extractor is a passive valve that only permits air flow from a higher pressure vehicle interior to a lower pressure vehicle exterior. The aerodynamics of each particular vehicle affects the pressure appearing at various speeds at various locations along a vehicle exterior surface where the output of the air extractor valve may be mounted. The resulting pressures may limit the acceptable locations on the vehicle where the air extractor valve can be placed. In addition, heating, ventilation, air conditioning (HVAC) systems have required a sufficiently large main blower in order to produce sufficient air flow that will overcome air flow losses and exterior pressures to ensure a sufficient extraction of air from the vehicle interior space. However, as the main blower increases in size, an undesirable noise level may be produced by the blower.
In order to achieve a desired level for the door closing effort, a minimum size (i.e., flow area) has been required for the air extractor. An increase in air handling efficiency would be desirable since the overall size of the air extractor could be reduced. | {
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1. Field of the Invention
Embodiments of the present invention generally relate to optical transport networks and, more particularly, to a method and apparatus for providing a control plane across multiple optical network domains.
2. Description of the Related Art
Traditionally, transport networks are managed by centralized management systems, which receive connection requests, perform path selection, and establish connections through transport network elements. Recently, the intelligence for transport network functions, such as topology and resource discovery, automated connection provisioning, and failure recovery, are being moved into the network elements through the emergence of distributed transport control planes. Control plane standards that extend signaling protocols from packet networks are being developed. The Internet Engineering Task Force (IETF) has extended Internet Protocol (IP)-based protocols used in the Multi-Protocol Label Switching (MPLS) control plane to define Generalized Multi-Protocol Label Switching (GMPLS).
Standards development, however, has lagged vendor implementations, resulting in network operators deploying sub-networks running vendor-specific control planes that do not inter-work. In addition, company mergers and the associated network management integration complexities, scalability concerns, as well as other economic factors have led to transport networks that often consist of several control islands referred to as control domains (CDs). A control domain is a sub-network in which all network nodes run a common control plane. A given transport network may include several control domains, each of which implements different control plane signaling and routing protocols. Accordingly, there exists a need in the art for a method and apparatus for providing a control plane across multiple optical network domains. | {
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The invention is in the field of measuring devices, such as for measuring temperature or other parameters. A specific embodiment of the invention relates to a digital thermometer.
Prior art devices of this type typically rely on a temperature responsive element incorporated in a bridge circuit connected to a high precision voltage source. The bridge imbalance due to the temperature responsive arm is converted to a digital number by a suitable analog-to-digital converter. One disadvantage with devices of this type is that their accuracy depends on that of a high precision voltage source, which makes such devices expensive to make and difficult to maintain.
This invention is directed to an improvement in such devices which eliminates the need for a high precision voltage source. In accordance with the invention, dual slope analog-to-digital converter techniques are used in a novel way which provides an accurate measure of temperature or similar parameters without using the previously indispensable high precision voltage source.
In a specific embodiment of the invention, the input capacitor, integrator and detector of the prior art analog-to-digital converter in an autozeroing configuration is combined with a resistance bridge having a temperature responsive arm and a temperature insensitive arm. The bridge is powered by a low precision voltage source. The free side of the input capacitor is connected to the temperature insensitive bridge arm through a first switch, to the temperature responsive bridge arm through a second switch, and to the voltage source through a third switch. The other side of the input capacitor, i.e., the side which is normally connected to the integrator input, is connected to the detector output through a fourth switch in the common autozeroing configuration. By opening and closing the four switches in a sequence which reflects the invented technique, the undesirable effects of long-term changes in the voltage source level and in the offset and drift of the integrator and detector amplifiers are eliminated, and the difference between the two arms of the bridge is measured accurately, thus obtaining an accurate measure of the effect of temperature on the temperature responsive bridge arm.
Specifically, only the second and fourth switches are initially in a closed state, to thereby place on the input capacitor an initial charge which reflects: (a) the voltage level of the voltage source, (b) the resistance of the temperature responsive bridge arm, and (c) the offset and drift of the integrator and detector amplifiers. Then, a dual slope measurement cycle is started comprising a fixed time interval and a variable time interval. During the fixed time interval, only the first switch is maintained in a closed state, all other switches being open, to thereby apply to the integrator a measurement voltage which reflects: (a) the initial charge on the input capacitor, (b) the voltage level of the voltage source, and (c) the resistance of the temperature insensitive bridge arm. During the variable time interval, only the third switch is maintained in a closed state, all other switches being open, to thereby apply to the integrator a reference voltage whose polarity is opposite that of the measurement voltage and whose magnitude reflects the voltage level of the voltage source. The variable time interval ends when the output of the integrator crosses the reference voltage. The duration of this variable time interval is a measure of the difference between the resistances of the two bridge arms, and is therefore a measure of the temperature of interest. If the levels of the voltage source and of the drift and offset of the integrator and detector amplifiers remain reasonably constant during the dual slope measurement cycle, the absolute values of these levels or changes in these levels as between successive measurement cycles have no effect on accuracy. Since each measurement cycle is of the order of milliseconds, it is unlikely that the level of the voltage source or the level of the drift and offset of the amplifiers would change during a measurement cycle. The longer term changes, as between measurement cycles, do not affect accuracy. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates to motherboards, and more particularly to a motherboard with special traces formed thereon.
2. Description of Related Art
In order to facilitate connections of integrated circuits on a motherboard, copper traces are etched and formed on or in a Printed Circuit Board (PCB) of the motherboard. For a given multi layer PCB having a dielectric constant, metal traces each with a constant width, and a given thickness, the characteristic impedance of a trace is directly proportional to a length of the trace, and it is inversely proportional to a width of the trace. A trace with larger cross-section often endures higher current flowing therethrough. However, the width and thickness of the trace is limited in order not to influence other traces of the PCB.
There are signal traces as well as power/ground traces in or on the PCB of the motherboard. An impedance mismatch of the signal traces can detrimentally distort signals traveling via the signal traces. Thus, impedance matching of the signal traces is critical. However, regarding the power/ground traces of the motherboard, designers consider the maximum current power/ground traces can endure, since high current often flows through the power/ground traces. If current flowing through the power/ground traces exceeds a maximum safe current, the power/ground traces may burn and generate smoke, causing damage to the motherboard and detrimentally affecting the environment. Thus, computers that generate less smoke should their traces burn are preferred.
What is needed, therefore, is a motherboard with special traces for decreasing smoke generated by the traces if they should burn and protecting components connected to the traces of the motherboard from damage due to excess current. | {
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The rapidly growing market for portable electronics devices, e.g. cellular phones, laptop computers, and PDAs, is an integral facet of modern life. The multitude of portable devices represents one of the largest potential market opportunities for next generation packaging. These devices have unique attributes that have significant impacts on manufacturing integration, in that they must be generally small, lightweight, and rich in functionality and they must be produced in high volumes at relatively low cost.
As an extension of the semiconductor industry, the electronics packaging industry has witnessed ever-increasing commercial competitive pressures, along with growing consumer expectations and the diminishing opportunities for meaningful product differentiation in the marketplace.
Packaging, materials engineering, and development are at the very core of these next generation electronics insertion strategies outlined in road maps for development of next generation products. Future electronic systems may be more intelligent, have higher density, use less power, operate at higher speed, and may include mixed technology devices and assembly structures at lower cost than today.
Current packaging suppliers are struggling to accommodate the high-speed computer devices that are projected to exceed one TeraHertz (THz) in the near future. The current technologies, materials, equipment, and structures offer challenges to the basic assembly of these new devices while still not adequately addressing cooling and reliability concerns.
The envelope of technical capability of next level interconnect assemblies are not yet known, and no clear cost effective technology has yet been identified. Beyond the performance requirements of next generation devices, the industry now demands that cost be a primary product differentiator in an attempt to meet profit goals.
As a result, the road maps are driving electronics packaging to precision, ultra miniature form factors, which require automation in order to achieve acceptable yield. These challenges demand not only automation of manufacturing, but also the automation of data flow and information to the production manager and customer.
There have been many approaches to addressing the advanced packaging requirements of microprocessors and portable electronics with successive generations of semiconductors. Many industry road maps have identified significant gaps between the current semiconductor capability and the available supporting electronic packaging technologies. The limitations and issues with current technologies include increasing clock rates, EMI radiation, thermal loads, second level assembly reliability stresses, and cost.
As these package systems evolve to incorporate more components with varied environmental needs, the pressure to push the technological envelope becomes increasingly challenging. More significantly, with the ever-increasing complexity, the potential risk of error increases greatly during manufacture.
In view of the ever-increasing commercial competitive pressures, along with growing consumer expectations and the diminishing opportunities for meaningful product differentiation in the marketplace, it is critical that answers be found for these problems. Additionally, the need to reduce costs, reduce production time, improve efficiencies and performance, and meet competitive pressures, adds an even greater urgency to the critical necessity for finding answers to these problems.
Thus, a need remains for smaller footprints and more robust packages and methods for manufacture. Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art. | {
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Field
Aspects of the present disclosure relate to semiconductor devices, and more particularly to a capacitor structure for power delivery applications.
Background
The process flow for semiconductor fabrication of integrated circuits (ICs) may include front-end-of-line (FEOL), middle-of-line (MOL), and back-end-of-line (BEOL) processes. The front-end-of-line process may include wafer preparation, isolation, well formation, gate patterning, spacer, extension and source/drain implantation, silicide formation, and dual stress liner formation. The middle-of-line process may include gate contact formation. Middle-of-line layers may include, but are not limited to, middle-of-line contacts, vias or other layers within close proximity to the semiconductor device transistors or other like active devices. The back-end-of-line process may include a series of wafer processing steps for interconnecting the semiconductor devices created during the front-end-of-line and middle-of-line processes. Successful fabrication of modern semiconductor chip products involves an interplay between the materials and the processes employed.
For integrated circuits in wireless communications devices or other high-speed digital electronics, a power delivery network supplies power to the various components of the overall system. A power delivery network may include a voltage regulator module that regulates voltage for a component. Resonance in a power delivery network is undesirable. Suppressing resonance in a power delivery network may be performed using a capacitor. Surface mount technology (SMT) capacitors may reduce power delivery network resonance/noise in high power, system on chip devices, such as application processors and graphics processors. | {
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Wavelength division multiplexing is an approach for increasing the capacity of existing fiber optic networks. A WDM system employs plural optical signal channels, each channel being assigned a particular channel wavelength. In a WDM system optical signal channels are generated, multiplexed to form an optical signal comprised of the individual optical signal channels, transmitted over a single waveguide, and demultiplexed such that each channel wavelength is individually routed to a designated receiver.
A problem with many WDM systems is that they are not easily tested to determine optical transmission faults without first being connected to external data source/sink equipment such as client equipment. However, such connection makes it difficult to identify and localize transmission faults as being in the WDM system or the client equipment. | {
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1. Field of the Disclosure
The present disclosure relates to a pressure contact type connector, and particularly, to a pressure contact type connector in which a connection terminal is formed in a spiral shape.
2. Description of the Related Art
In recent years, as means for electrically connecting different substrates housed in an electronic device, use of a structure has increased, in which a pressure contact type connector including a connection terminal having elasticity is provided on one substrate, a contact portion is provided on the other substrate, and the substrates are disposed so that the contact portion and the pressure contact type connector come into pressure-contact with each other. In the pressure contact type connector, the connection terminal is formed in a spiral shape so as to have elasticity. As the pressure contact type connector in which the connection terminal is formed in a spiral shape, a pressure contact type connector disclosed in Japanese Unexamined Patent Application Publication No. 2010-118256 has been known.
Hereinafter, the pressure contact type connector disclosed in Japanese Unexamined Patent Application Publication No. 2010-118256 will be described with reference to FIGS. 13A and 13B. FIGS. 13A and 13B are views showing a structure of a connection terminal 902 of a pressure contact type connector 900, FIG. 13A is a plan view showing an outline of the connection terminal 902, and FIG. 13B is a sectional view showing a section taken along line Z-Z shown in FIG. 13A.
In the pressure contact type connector 900 disclosed in Japanese Unexamined Patent Application Publication No. 2010-118256, the spiral contactor (connector terminal) 902 is spirally formed from the base 902b toward the center of the tip, and includes a tip 902a at the center of the spiral. In addition, the spiral contactor 902 includes a groove 902d formed along a longitudinal direction of the spiral contactor 902 at the center in the width direction of the spiral contactor 902, the center is formed in a planar shape or a convex shape, and the spiral contactor 902 includes a protrusion 902aa on the upper surface of the tip 902a.
In recent years, as a pressure contact type connector, a pressure contact type connector having a mounting area of 2 mm×2 mm or less has been required. However, in the pressure contact type connector 900 disclosed in Japanese Unexamined Patent Application Publication No. 2010-118256, since the spiral contactor 902 is double-spirally formed, it is difficult to decrease a mounting area of the connector. In addition, even when the mounting area decreases by reducing the width of the spiral contactor 902, there is a concern that an elastic force sufficient for obtaining electrically stable connection cannot be obtained.
These and other drawbacks exist. | {
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A modem pass-through can be used to provide a modem connection for transporting modem data between a calling modem and an answering modem over a packet network. The modem pass-through emulates a PSTN network when transporting a G.711 Pulse Code Modulation (“PCM”) stream over the packet network. To emulate a PSTN network the modem pass-through provides the modem connection between the calling modem and the answering modem similar to the modem connection provided by the PSTN network.
The packet network can implement any well-known packet network protocol, such as, the Asynchronous Transfer Method (“ATM”), Frame Relay protocol (“FR”) or Internet Protocol (“IP”). The modem pass-through forwards the G.711 PCM stream using protocols developed for transmitting real-time audio over a packet network. One standard protocol for packetizing real-time audio for transporting Voice over IP (“VoIP”) is the Real-Time Transport Protocol (“RTP”) (Request for Comments (“RFC”) 1889, January 1996) available on the Internet Engineering Task Force (“IETF”) web site.
To transport VoIP, a packet transmitter in an originating packet network node encodes the analog voice signal received from the PSTN, stores the encoded data in the payload of one or more data packets and transmits the data packet over the packet network. Each data packet includes a destination address stored in a header included in the data packet.
Before the modem connection is provided, the calling modem and the answering modem must perform modem training. Modem training includes negotiating communication parameters such as, data transfer rate, data compression, error correction protocol and modulation. Modem training includes a series of training steps, in which the calling modem and the answering modem adjust to each other's characteristics and to the characteristics of the switched connection. These training steps include V.8/V.8bis, auto-mode, error correction and data compression. The steps and procedures are defined by the ITU V. series of modem specification and other modem specifications including MNP5 compression. ITU V. series modem specifications include V.8, V8bis, V.42, V.42bis, V.34, V.90, V.92, and V.32/V.32bis.
Once modem training is complete, the modem connection is provided by the modem pass-through between the calling modem and the answering modem. However, data can only be transported between the modems while the modem connection is provided by the modem pass-through.
Unlike a telephone network in which there is a dedicated connection between the calling modem and the answering modem, each data packet transmitted from a modem may travel on a different path from a source packet network gateway to a destination packet network gateway connected to the packet network. Some data packets may travel faster than others. Thus, data packets transmitted over the packet network may arrive out of order at the destination packet network gateway.
To compensate for these path differences, each packet network gateway includes a jitter buffer. The jitter buffer temporarily stores PCM data extracted from the payload of data packets received from the packet network. The PCM data is forwarded in-order after a playout delay to the modem. Temporarily storing received PCM data in a jitter buffer allows a smooth ordered playout of the extracted PCM data to the modem.
Each packet network gateway includes a separate clock source. The clock sources are not synchronized. The remote clock source determines the rate at which data packets are received by the local packet network gateway from the remote packet network gateway over the packet network. The local clock source determines the rate at which the packet network gateway reads the extracted PCM data from the jitter buffer. Thus, timing differences accumulate at both the local packet network gateway and the remote packet network gateway because the local clock source and the remote clock source are not synchronized. These timing differences result in a progressive accumulation of PCM data stored in the jitter buffer at one packet network gateway and a progressive depletion of PCM data stored in another jitter buffer at another packet network gateway. Eventually, the jitter buffer in a packet network gateway with either underflow or overflow. During these overflow/underflow periods, the jitter buffer provides incorrect data resulting in modem speed shifts and/or modem retrains. Modem retrains reduce data throughput through the packet network because no data packets are transmitted during the modem retrain.
In order to avoid modem retrains, a packet network gateway computes a playout delay time for its respective jitter buffer. Adaptive delay adjustment is implemented by continuously monitoring the playout delay time and periodically readjusting the playout delay in order to compensate for the difference between the local clock source and the remote clock source. However, even with adaptive delay adjustment to continuously adapt the playout delay, a clock slip is unavoidable resulting in modem retrains and/or speed shifts. These modem retrains and/or modem speed shifts result in decreased throughput on the modem connection and the inability to emulate a PSTN network over a packet network for modem transfer rates required by fast modems, such as V.90. | {
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Some of conventional electric power steering devices execute a steering wheel return control utilizing an electric motor for steering assist.
JP2007-320383A discloses an electric power steering device configured to calculate a steering wheel return correction current value on the basis of a steering angle and, when it is determined to execute a steering wheel return control, correct an assist base current value using the steering wheel return correction current value and execute the steering wheel return control. | {
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Mass data storage systems are used for many purposes, including storing user and system data for data processing, backup and transmission applications. A typical mass storage system includes numerous computer disk drives that cooperatively store data, for example, as a single logically contiguous storage space, often referred to as a volume or a logical unit. One or more such volumes/logical units may be configured in a storage system. The storage system therefore performs much like a single computer disk drive when viewed by a host computer system. For example, the host computer system can access data of the storage system much like it would access data of a single internal disk drive, in essence, without regard to the substantially transparent underlying control of the storage system.
A mass storage system may include one or more storage modules with each individual storage module comprising multiple disk drives coupled to one or more storage controllers. In one typical configuration, a storage module may be coupled through its storage controller(s) directly to a host system as a standalone storage module. Typical storage controllers include significant cache memory capacity to improve performance of the I/O operation. Write requests may be completed when the supplied data is written to the higher speed cache memory. At some later point, the data in cache memory may be flushed or posted to the persistent storage of the storage modules. In a standalone configuration, it is common to enhance reliability and performance by providing a redundant pair of storage controllers. The redundant pair of controllers enhances reliability in that an inactive storage controller may assume control when an active controller is sensed to have failed in some manner.
In another standard system configuration, a storage module may be part of a larger storage network or “cluster.” For a cluster-type architecture, multiple storage modules and corresponding storage controllers are typically coupled through a switched network communication medium, known as a “fabric,” to one or more host systems. This form of storage module system is often referred to as a Storage Area Network (SAN) architecture and the switching fabric is, concomitantly, referred to as a SAN switching fabric. In such a clustered configuration, it is common that all of the storage controllers exchange coherency information and other information for load balancing of I/O request processing and other control information. Such control information may be exchanged over the same network fabric that couples the storage controllers to the host systems (e.g., a “front end” connection) or over another fabric that couples the storage controllers to the storage modules (e.g., a “back-end” connection).
A network storage appliance (e.g., a storage server) is typically a discrete special-purpose computer that provides file services relating to the organization of information on the storage devices of a mass data storage system. The network storage appliance, or “filer,” includes integrated software (firmware) and an operating system that implements a file system to logically organize information, for example, as a hierarchical structure of directories and files on the storage devices (e.g., storage disks). Each “on-disk” file may be implemented as a set of disk blocks configured to store information, such as text; the directory, by comparison, may be implemented as a specially formatted file in which information about other files and directories are stored.
On-disk format representation of some file systems is block-based using, for example, four kilobyte (KB) blocks (“4K block”) and index nodes to describe the files. Index nodes, which are informally referred to as “inodes,” are data structures used to store information, such as metadata, about a file. Information contained in a typical inode may include, e.g., file ownership data, file access permission data, file size, file type, and on-disk location of the data for the file. The file system uses an identifier with an inode number, known as a “file handle,” to retrieve an inode from a disk. The file system also uses metadata files to store metadata describing the layout of its file system. An example of on-disk format structure of one standard file system is described in U.S. Pat. No. 5,819,292 to David Hitz et al., which is incorporated herein by reference in its entirety and for all purposes.
A “snapshot” of a file system captures the contents of the files and directories in the file system at a particular point in time. A conventional snapshot does not use disk space when it is initially created, is typically a virtual read-only file, and is designed so that many different snapshots can be created for the same file system. Unlike some file systems that create a clone of the file system by duplicating the entire inode file and all of the indirect blocks, conventional snapshots duplicate only the inode that describes the inode file. Such snapshots allow users of the file system to recover earlier versions of a file, for example, following an unintended deletion or modification of the file. In addition, the contents of a snapshot can be copied to another storage device or medium to provide a backup copy of the file system. A snapshot can also be copied to another file server and used as a replica. Some file systems include a copy-on-write snapshot mechanism. Snapshot block ownership in such systems is generally recorded by updating the block's entry in a blockmap file, which is a bitmap indicating which blocks are in-use and which are free for use. Additional information regarding snapshot files can be found, for example, in U.S. Pat. No. 6,289,356 B1, which is incorporated herein by reference in its entirety and for all purposes.
One problem with creating a conventional snapshot is the requirement for additional file system metadata and, thus, additional storage space in the active file system to keep track of which blocks the snapshot occupies. This is inefficient both in its use of storage space and in the time needed to create the snapshots. Another problem with conventional snapshots is that, once data has been captured in a snapshot, that data becomes “trapped” and, thus, modifications to trapped data are not allowed. This restriction is also applicable to any metadata holding that information in the flexible volume (flexvol). Both the virtual volume block numbers (VVBNS) and the physical volume block numbers (PVBNS) become trapped, which prevents a reduction in the footprint of the snapshot data. Consequently, it is no longer possible to modify the block numbers which were assigned previously to any files which are trapped in a snapshot in the flexvol. In addition, conventional filing systems do not allow space to be shared among unique data blocks or data to be shared across multiple flexible volumes. There is therefore a need for improved techniques for more quickly and efficiently capturing the contents of the files and directories in a file system at a particular point in time.
The present disclosure is susceptible to various modifications and alternative forms, and some representative embodiments have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the inventive aspects are not limited to the particular forms illustrated in the drawings. Rather, the disclosure is to cover all modifications, equivalents, combinations and subcombinations, and alternatives falling within the spirit and scope of the disclosure as defined by the appended claims. | {
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1. Field
The following description relates to a thin-film transistor (TFT) substrate, a method for manufacturing the TFT substrate and a display apparatus having the TFT substrate.
2. Discussion of the Background
A liquid crystal display apparatus generally includes a lower substrate, an upper substrate and a liquid crystal layer interposed between the lower substrate and the upper substrate. The lower substrate, such as a TFT substrate, may include a display area. The display area may include a first peripheral area, a second peripheral area, a third peripheral area, and a fourth peripheral area disposed on the display area.
A gate driving part outputting a gate signal to a gate line of the display area may be disposed in the first peripheral area. The first peripheral area may be disposed at a left side of the display area. A data driving part outputting a data signal to a data line of the display area may be disposed in the third peripheral area. The third peripheral area may be disposed at an upper side of the display area. In addition, a test pad to test an electrical short and/or an open electrical circuit of the data line may be formed between a sealing member and the display area in the fourth peripheral area. The fourth peripheral area may be facing the third peripheral area.
The test pad may be disposed between the sealing member and the display area in the fourth peripheral area. Some distance may be formed between the test pad and the sealing member to prevent or reduce the likelihood of the sealing member from being uncured due to an overlap of the test pad and the sealing member. Thus, a narrow bezel display apparatus may be hard to manufacture. | {
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The invention relates to an apparatus for driving an artificial heart, and more particularly to an artificial heart driving apparatus in which positive pressure and negative pressure are alternately applied to the artificial heart using a fluid such as air thereby to drive the same.
From the standpoint of safety, it is important for artificial hearts to be driven so that a pulsatory motion closely similar to pulsation of hearts in living bodies is imparted to blood. There are known a variety of artificial hearts, such as diaphragm type, sack type, piston type, which are usually driven by receiving the predetermined pressure from a fluid such as air. To drive those artififical hearts under the optimum conditions in accordance with the state of living bodies, it is essential to employ a driving apparatus which can generate correct pressure in accordance with the optimum conditions at proper timing. In other words, such a driving apparatus is preferable that is able to correctly and quickly set heart rate, positive pressure, negative pressure and duration or duty ratio of positive pressure and negative pressure applied to artificial hearts, etc. at the respective predetermined values.
In the prior artificial heart driving apparatus, mechanical pressure reducing valves or the like are used respectively in positive and negative pressure systems as means for attaining correct pressures. However, since outputs of both positive and negative pressure systems are interconnected to each other and hence negative pressure acts as a load for the positive pressure system, whereas positive pressure acts as a load for the negative pressure system, the foregoing artificial heart driving apparatus has a disadvantage such that adjustment of positive pressure varies a load for the positive pressure system and this results in changes of positive pressure, whereas adjustment of positive pressure varies a load for the negative pressure system and this results in changes of negative pressure. In the past, therefore, when adjusting pressures, the adjustment had to be carried out carefully even in the case of adjusting either one pressure in such a manner that a pair of two pressure reducing valves are operated at the same time while checking two levels of both pressures and one pressure is maintained at the predetermined value while updating a level of the other pressure. This results in the time-consuming pressure adjustment which also requires a great deal of skill. Moreover, the mechanical pressure reducing valves can not provide satisfactory performance, unless differential pressure between the inlet side and the outlet side is set to be relatively large. Thus, the pressure generated by a pressure source such as a compressor must be set as twice as that to be applied to artificial hearts. This leads to other disadvantages in that a large-sized pressure source is needed and levels of heating, noise, etc. are increased.
Meanwhile, the artificial heart driving apparatus of this kind is often used for a long period of time in succession. In such case, even if a part of the apparatus experiences trouble, the artificial heart can not be stopped in its driving. But when there occurs a trouble or anomaly, continued operation of the failed driving apparatus makes it impossible to drive the artificial heart under the best condition. Further, even in the case where no trouble or anomaly is observed from the outside, routine maintenance is necessary for internal parts of the apparatus. Accordingly, when carrying out maintenance, repairs, etc, up to now, another artificial heart driving apparatus is prepared and the previous driving apparatus is replaced by a new one by changing over a number of valves, cocks, etc. in the predetermined sequence in order that the artificial heart will never be stopped. But, when so many valves, cocks, etc. are changed over manually by operators, so it is impossible to absolutely eliminate a fear of switching those parts in wrong sequence. Also, at the time of exchanging the artificial heart driving apparatus, both apparatus are out of timing from each other in their drivings, whereby this exchange is accompanied with a highly possible danger.
In addition, the artificial heart driving apparatus of this kind must be equipped with a number of devices and units such as a compressor, vacuum pump, tank (accumulator), solenoid valve, control unit, etc., thus resulting in the large size. For example, artificial hearts are used as auxiliaries for the hearts of living bodies during a surgical operation, but the large-sized artificial heart driving apparatus can not be disposed near the operating table during an operation, because there are many doctors and operating equipment around the operating table. On the other hand, the artificial heart must be desirably varied in its heart rate, etc. in accordance with condition of the patient under an operation. Therefore, the prior artificial heart driving apparatus is placed at a position spaced from the operating table and then controlled by technical experts under instructions from the doctors. But, in order to drive the artificial heart under the optimum conditions, it is preferable that the driving apparatus is directly controlled by the doctors. Since the artificial heart driving apparatus in the past employs the mechanical pressure reducing valves or the like, it was difficult to realize such direct control and impossible to perform remote control.
There has been proposed another artificial heart driving apparatus in which solenoid valves to effect opening and closing control are respectively attached at the output end of a positive pressure system and the output end of a negative pressure system for switching positive and negative pressures to be applied to artificial hearts. In the apparatus of this kind, the solenoid valves are controlled by a control unit so that opening and closing are alternately switched at the predetermined timing in accordance with the preset heart rate. However, such artificial heart driving apparatus is disadvantageous in that occurrence of noise can not be avoided, because the solenoid valves are driven to be opened and closed alternately at all times. Sound-proofing covers or the like may be placed around the solenoid valves so as to suppress a level of noise, but this results in an increase of the size and cost and the apparatus becomes hard to move. | {
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This invention relates to a temperature sensing circuit using insulated gate field effect devices for sensing temperature.
In particular, this invention relates to a temperature sensing circuit comprising a first insulated gate field effect device, a second insulated gate field effect device, means for operating the first insulated gate field effect device in its subthreshold region so that the voltage across the first insulated gate field effect device varies with temperature, and means for comparing the voltages across the first and second insulated gate field effect devices.
Such temperature sensing circuits are described in, for example, GB-A-2096771 and a paper entitled "Integrated MOS temperature sensor" by R. C. Jaeger and D. V. Kerns published in the Conference Proceedings of the 1980 IEEE Region 3 Conference and Exhibit Apr. 13, 14, 15, 16, 1980 Nashville, Tenn.
In each of these prior documents, the first and second insulated gate field effect devices are each formed by an insulated gate field effect transistor (IGFET). The two IGFETs are arranged to be operated in their subthreshold region where the drain current Id varies logarithmically with the gate-to-source voltage Vgs in a manner such that the slope of the Id versus Vgs curve is constant over many decades and directly proportional to temperature. The two IGFETs are arranged to have different drain currents by, for example, appropriately scaling the channel width and length geometry of the IGFETs and/or by appropriately scaling load resistors connected in series with the IGFETs. The difference in the gate-source voltage .increment.Vgs of the two IGFETs may thus be used as a measure of absolute temperature. | {
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1. Technical Field
The present disclosure relates to a howling removing apparatus and a howling removing method each of which prevents the howling with use of an adaptive filter.
2. Description of the Related Art
In an environment where a microphone and a speaker are located at positions close to each other, a sound signal picked up by the microphone is amplified and output from the speaker, and the output sound signal thus amplified is transferred through a space and is picked up again by the microphone, whereby an acoustic closed loop is formed. As a result, the sound signal output from the speaker and input to the microphone again is amplified repeatedly, whereby howling occurs.
There is known a technology, in order to prevent the howling that occurs as described above, for calculating an adaptive filter by estimating spatial transfer characteristics in a course where the sound signal, which is output from the speaker, is transferred through the space and is input to the microphone with use of an adaptive algorithm. In accordance with this technology, the obtained adaptive filter and the sound signal output from the speaker are convoluted with each other, whereby a signal that simulates a speaker output transferred through the space is obtained. This simulation signal is subtracted from the sound signal picked up by the microphone, whereby it becomes possible to remove only the speaker output, which is transferred through the space and is input to the microphone to cause the howling, and as a result, such an occurrence of the howling can be prevented.
In the adaptive algorithm that updates the adaptive filter with use of an output of a system, which is changed from moment to moment, the adaptive filter sometimes oscillates depending on a state of the output. When the adaptive filter oscillates, a failed abnormal signal (for example, a noise signal always having maximum amplitude) is output irrespective of a magnitude of an input signal. Moreover, since there is always some value in the adaptive filter, an output signal does not become 0, and the abnormality signal continues to be output even if the input signal stops.
In order to prevent such oscillation of the adaptive filter, a fail-safe function is generally implemented in a system using the adaptive algorithm. For example, Japanese Patent No. 4428247 discloses; a method of calculating a sound pressure level of an input signal and a sound pressure level of an output signal, and initializing an adaptive filter when a difference therebetween exceeds a threshold value, thereby restoring an output to normal; and a method of initializing an adaptive filter when a difference between such an un-updated adaptive filter and such an updated adaptive filter, both of which represent a correction amount of the adaptive filter, exceeds a threshold value, thereby restoring an output to normal. | {
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In the case of driving a synchronous motor having coils of a plurality of phases, it is conventionally important to optimize so-called conduction timing of flowing a motor current with suitable timing to a motor rotor and applying a voltage to a coil terminal. To detect a reference for this conduction timing, there are various systems, such as a system of detecting a back electromotive voltage, a system of detecting a zero-cross current phase, and the like.
For example, in so-called sensorless driving of controlling and driving a motor without using a motor rotor position sensor, there is a system of, when bringing a motor coil into conduction, detecting a back electromotive voltage generated in the motor coil by rotation of the motor, from a motor coil terminal.
In addition, in a driving device shown in Japanese Patent Laying-Open No. 5-236789 (Patent Literature 1), a system of detecting a motor voltage phase at the time of motor current zero crossing, detecting a motor current phase based on this voltage phase, and calculating a voltage command or a frequency command such that this motor current phase is a desired current phase is shown.
FIG. 10 shows a configuration of a conventional typical motor control device.
Referring to FIG. 10, to drive a synchronous motor 100 having coils of a plurality of phases (three phases) in a stator and a permanent magnet in a rotor, an inverter device is formed of an inverter 150, a converter circuit 130, an AC power supply 160, a coil 170, a current sensor 180, and a controller 110. It is noted that, in this example, AC power supply 160 shall be 200V and 50 Hz.
Synchronous motor 100 is driven by inverter 150, and inverter 150 is supplied by converter circuit 130 with a DC voltage obtained by converting AC power supply 160 into a direct current.
Specifically, converter circuit 130 includes a diode full wave rectifying circuit 120 formed of diodes 122 to 128 and a smoothing capacitor 140 across buses, and the capacity of the smoothing capacitor is large enough to such a degree that a ripple in a DC voltage waveform can be suppressed.
An AC voltage of AC power supply 160 is converted by this converter circuit 130 into a DC voltage for supply to inverter 150.
Coil 170 is provided for the purpose of improving the power factor of the AC power supply supplied to converter circuit 130.
FIG. 11 is a drawing for explaining the relation between DC voltage waveform and U-phase motor current.
As shown in FIG. 11(a), when the capacity of smoothing capacitor 140 is large enough, the ripple in the DC voltage waveform is suppressed, and a constant DC voltage is supplied to inverter 150.
FIG. 11(b) is a drawing for explaining a U-phase motor current waveform detected by current sensor 180.
Since the ripple in the DC voltage waveform is suppressed and a constant DC voltage is supplied to inverter 150 as shown in FIG. 11(b), the U-phase motor current that drives synchronous motor 100 from inverter 150 is detected as a stable waveform of constant amplitude.
On the other hand, since a conventional configuration as described above is disadvantageous in that an improved input current waveform and a higher power factor are less likely to be achieved, Japanese Patent Laying-Open No. 2002-51589 (Patent Literature 2) proposes a system without using coil 170 but with a capacitor, having a small capacity of about 1/100 of the capacity of a conventional smoothing capacitor, provided across buses of an inverter to intentionally cause a ripple of a frequency twice that of the power supply to occur in a DC voltage, thereby achieving an improved input current waveform and a higher power factor with a simple system. | {
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For use in horizontally pivoted oven doors, hinges typically include a counterweight or recoil spring arrangement for supporting the weight of the door when opening, for instance in an equilibrium position, shortly before reaching the closing position of the door, and afterwards for holding the door closed. These arrangements avoid as far as possible large forces that would otherwise result from uncontrolled opening of the door.
Bench top toaster ovens are well suited for toasting and reheating tasks, but can also be used for baking and grilling. Being small in size such ovens are portable and can be accommodated in any kitchen, while also offering ease of use and cleaning. In toaster ovens there remains a need for a hinge which improves the course of motion when opening or closing a door, in particular within the end position ranges. However, the relatively complex hinge arrangements used on conventional ovens cannot be justified because the doors of toaster ovens are relatively lighter, and because they must achieve a substantially lower manufactured cost. In many toaster ovens a pair of tension-type coil springs is used to bias the door closed, and each spring, mounted as it is in the housing at either side of the door, requires significant space which compromises the ability to provide a more compact oven. It is an object of the present invention address the above need or more generally to provide an improved hinge for a horizontally pivoted door on a household appliance. | {
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The multi-zone feature of a wireless controller can allow multiple controllers to manage their wireless services separately with the same wireless access point infrastructure, while relieving the radio frequency interference that would come from having multiple wireless networks. Air time fairness may be based on the radio characteristics, but not multi-zones. | {
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Cerebral occlusions that lead to stroke require swift and effective therapy to reduce morbidity and mortality rates associated with the disease. Many current technologies for treating stroke are inadequate because emboli generated during the procedure may travel downstream from the original occlusion and cause ischemia. There is currently a need for a stroke treatment system that provides a swift and efficient treatment for occlusions while simultaneously controlling cerebral flow characteristics.
In the initial stages of stroke, a CT scan or MRI may be used to diagnose the cerebral occlusion, which commonly occurs in the middle cerebral arteries. Many current technologies position a catheter proximal to the occlusion, then deliver clot dissolving drugs to treat the lesion. A drawback associated with such technology is that delivering drugs may require a period of up to six hours to adequately treat the occlusion. Another drawback associated with lytic agents (i.e., clot dissolving agents) is that they often facilitate bleeding.
When removing thrombus using mechanical embolectomy devices, it is beneficial to engage the thrombus and remove it as cleanly as possible, to reduce the amount of emboli that are liberated. However, in the event that emboli are generated during mechanical disruption of the thrombus, it is imperative that they be subsequently removed from the vasculature.
Many current drug delivery and mechanical treatment methods are performed under antegrade flow conditions. Such treatment methods do not attempt to manipulate flow characteristics in the cerebral vasculature, e.g, the Circle of Willis and communicating vessels, such that emboli may be removed. Accordingly, there remains a need to provide effective thrombus and emboli removal from the cerebral vasculature while simultaneously controlling flow within that vasculature.
U.S. Pat. No. 6,161,547 to Barbut (Barbut '547) describes a technique for enhancing flow in the cerebral vasculature in treating patients with acute stroke or other cerebrovascular disease. The technique involves: (1) positioning a first tubular member in a vascular location suitable for receiving antegrade blood flow; (2) positioning a second tubular member in a contralateral artery of the occlusion (e.g., for an occlusion located in the left common carotid artery the second tubular member is placed in the right common carotid artery); and coupling the first tubular member to the second tubular member using a pump and filter.
The first tubular member receives antegrade blood flow and channels the blood to the pump and filter, where the blood then is reperfused via the second tubular member into the contralateral artery, thus increasing blood flow to the opposing hemisphere of the brain. The first and second tubular members may include balloons disposed adjacent to their distal ends.
The techniques described in the foregoing patent have several drawbacks. For example, if the first balloon of the first tubular member is deployed in the left common carotid artery, as shown in FIG. 7C, aspiration of blood from the vessel between the balloon and the occlusion may cause the vessel to collapse. On the other hand, if the balloon is not deployed, failure to stabilize the distal tip may result in damage to the vessel walls. In addition, failure to occlude the vessel may permit antegrade blood flow to diverted into that apparatus, rather than blood distal to the first tubular member.
The Barbut '547 patent further discloses that inflating the balloon of the second tubular member may assist in controlling the flow to the contralateral artery or provide more efficient administration of pharmacotherapy to the cerebral tissues. However, when that balloon is deployed, the contralateral artery may be starved of sufficient flow, since the only other flow in that artery is that aspirated through the first tubular member. On the other hand, if the balloon of the second tubular member is not inflated, no flow control is possible.
A method for removing cerebral occlusions is described in U.S. Pat. No. 6,165,199 to Barbut (Barbut '199). This patent describes a catheter having an aspiration port at its distal end that communicates with a vacuum at its proximal end. A perfusion port disposed in a lateral surface of the catheter may be used to enhance antegrade flow in collateral arteries. In use, the aspiration port is positioned proximal to an occlusion to provide a direct suction effect on the occlusion. The perfused flow in collateral arteries is intended to augment retrograde flow distal to the occlusion, such that the occlusion is dislodged via the pressure and directed toward the aspiration port. A chopping mechanism, e.g., an abrasive grinding surface or a rotatable blade, coupled to the aspiration port recognizes when the aspiration port is clogged. The chopping mechanism then engages to break up the occlusion and permit it to enter the aspiration port in smaller pieces.
The device described in the Barbut '199 patent has several disadvantages. First, the use of a vacuum to aspirate the occlusion requires an external pressure monitoring device. The application of too much vacuum pressure through the aspiration port may cause trauma, i.e., collapse, to the vessel wall. Also, because the system is intended to dislodge the occlusion using a pressure differential, a chopping mechanism is required to prevent the entire mass from clogging the aspiration port. The use of a chopping mechanism, however, may generate such a large quantity of emboli that it may be difficult to retrieve all of the emboli. In addition, emboli generated by the action of the chopping mechanism may accumulate alongside the catheter, between the aspiration port and the distal balloon. Once this occurs, it is unclear how the emboli will be removed.
Yet another drawback of the device described in the Barbut '199 patent is that high-pressure perfusion in collateral arteries may not augment retrograde flow distal to the occlusion as hypothesized. The patent indicates that high-pressure perfusion in collateral arteries via side ports in the catheter may be sufficient to cause an increase in pressure distal to the occlusion. Antegrade blood flow from the heart in unaffected arteries, e.g., other vertebral and/or carotid arteries, may make it difficult for the pressure differential induced in the contralateral arteries to be communicated back to the occluded artery in a retrograde fashion.
Other methods for treating ischemic brain stroke have involved cerebral retroperfusion techniques. U.S. Pat. No. 5,794,629 to Frazee describes a method that comprises at least partially occluding the first and second transverse venous sinuses and introducing a flow of the patient's arterial blood to a location distal to the partial venous occlusions. As described in that patent, the infusion of arterial blood into the venous sinuses provides a retrograde venous flow that traverses the capillary bed to oxygenate the ischemic tissues and at least partially resolve ischemic brain symptoms.
One drawback associated with the technique described in the Frazee patent is that the pressure in the transverse venous sinuses must be continuously monitored to ensure that cerebral edema is avoided. Because the veins are much less resilient than arteries, the application of sustained pressure on the venous side may cause brain swelling, while too little pressure may result in insufficient blood delivered to the arterial side.
In addition to the foregoing methods to augment cerebral perfusion, several methods are known for mechanically removing clots to treat cerebral occlusions. U.S. Pat. No. 5,895,398 to Wensel et al. describes a shape-memory coil affixed to an insertion mandrel. The coil is contracted to a reduced profile state within the lumen of a delivery catheter, and the catheter is used to cross a clot. Once the coil is disposed distal to the clot, the coil id deployed. The coil then is retracted proximally to engage and remove the clot.
A primary drawback associated with the Wensel device is that the deployed coil contacts the intima of the vessel, and may damage to the vessel wall when the coil is retracted to snare the occlusion. Additionally, the configuration of the coil is such that the device may not be easily retrieved once it has been deployed. For example, once the catheter has been withdrawn and the coil deployed distal to the occlusion, it will be difficult or impossible to exchange the coil for another of different dimensions.
U.S. Pat. No. 5,972,019 to Engelson et al. describes a deployable cage assembly that may be deployed distal to a clot. Like the Wensel device, the Engelson device is depicted as contacting the intima of the vessel, and presents the same risks as the Wensel device. In addition, because the distal end of the device comprises a relatively large profile, the risk of dislodging emboli while crossing the clot is enhanced, and maneuverability of the distal end of the device through tortuous vasculature may be reduced.
In view of these drawbacks of previously known clot removal apparatus and methods, it would be desirable to provide apparatus and methods for controlling hemodynamic properties at selected locations in the cerebral vasculature, e.g., the Circle of Willis and communicating vessels.
It also would be desirable to provide apparatus and methods for removal and recovery of thrombi and/or emboli above the carotid bifurcation.
It still further would be desirable to provide apparatus and methods that quickly and efficiently treat cerebral occlusions.
It still further would be desirable to provide apparatus and methods for selectively providing retrograde and/or antegrade flow to desired regions in the cerebral vasculature to effectively remove emboli. | {
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1. Field of the Invention
The present invention concerns mobile telephones and in particular a self-disabling device for disabling a portable terminal that has been stolen or used in an unauthorized manner.
2. Description of the Prior Art
In a GSM type mobile telephone system each user has a portable terminal or telephone which he can use to telephone any other telephone user. Each portable terminal is identified by a mobile equipment identifier number (IMEI) known to the network control station.
Each network user is supplied with a subscriber identifier module (SIM) when he takes out a subscription. He can use his portable terminal only after inserting his SIM card into his terminal. However, the SIM card is totally independent of the terminal and can be used in different terminals.
In the case of a terminal that has been stolen, the thief or someone receiving the stolen terminal can take out a subscription and obtain a SIM card and in this way obtain access to the network. For this reason the control station maintains an up-to-date database listing stolen terminals. To prevent a stolen terminal using the network, the IMEI of the terminal is requested during setting up of the session with the terminal, this identifier is checked against the database and communication with the terminal is barred if it proves to have been stolen. A procedure of this kind is time-consuming and greedy in terms of resources in that the verification procedure uses the communication channel of each terminal although very few terminals are stolen.
For this reason the main object of the invention is to provide a self-disabling device for disabling a portable terminal that is simple and effective and which does not make major use of resources assigned to the terminal.
Another object of the invention is to provide a self-disabling device for disabling a portable terminal which has been stolen in response to information contained in a short information message transmitted systematically to all terminals. | {
"pile_set_name": "USPTO Backgrounds"
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Image reproduction systems, such as printers and copiers, often include an image transfer device having an image transfer member, usually in the form of a belt or a drum, for receiving on its surface a marking substance, such as toner or ink, in image form and for subsequently transferring these images of marking substance in a transfer zone to a recording medium, such as paper. In an operative state, the image transfer member is urged against a counter member in the transfer zone while the recording medium passes therebetween. The transfer may take place by means of pressure, or heat, or heat and pressure each of them optionally being assisted by electrostatic forces and/or vibrational forces. Particularly in case the marking substance is a toner, the marking substance must be fixed onto the receiving material in order to render the images permanent. By applying an appropriate amount of pressure and heat in the transfer zone, transfer and fixing take place simultaneously. Otherwise a subsequent fixing step must be executed. For example, this may be done by feeding the recording medium, onto which the unfixed marking substance is already deposited, through a fixing zone where an increased temperature and pressure serve to fix the image permanently to the recording medium.
In such image transfer devices, contaminants, e.g., in the form of residual marking substance material and/or debris originating from the recording medium and/or other impurities may build up on the surface of the image transfer member. For instance, when the recording medium is paper or a like fibrous material, debris in the form of dust and fibers may build up on the image transfer member surface in the region of the transfer zone. If these contaminants remain on the image transfer member surface, the efficiency of the image transfer and the quality of the fixing, where applicable, may be affected. Hence, it is desirable to clean the surface of the image transfer member.
It is known to provide an endless cleaning member having a tacky substance on its surface and being positioned downstream of the transfer zone for removing contaminants from the image transfer member surface when being engaged in contact therewith. It is also known that over time, the tackiness of the cleaning member is reduced and hence the surface layer of the cleaning member needs to be rejuvenated. As disclosed in U.S. Pat. No. 4,705,388 (Huntjens et al./Océ-Nederland BV) or EP 0994861 (Douvdevani et al./Indigo N.V.), this may, for instance, be done by periodically developing a non-image pattern of a tacky substance, in casu toner, on an image transfer member to rejuvenate the surface layer of the cleaning member. In such a rejuvenation state, the image transfer member with the non-image toner pattern thereon passes the transfer zone while no recording medium is supplied and without urging the counter member against the image transfer member. The non-image toner pattern on the image transfer member is guided further towards the contact zone between the image transfer member and the cleaning member, i.e. the cleaning zone. When the image transfer member with the non-image toner pattern passes the cleaning zone, the non-image toner pattern is transferred to the cleaning member surface thereby rejuvenating it. The periodic rejuvenation of the tacky surface layer as described is found to lead to inconsistent cleaning characteristics caused by the reduction of the surface tackiness when proceeding in the operative state towards the next rejuvenation period. From this perspective, it seems beneficial to implement a high rejuvenation periodicity. However, contrary to the operative state, in the rejuvenation stage no prints or copies are generated and thus a high rejuvenation period is detrimental for the productivity of the image reproduction device. These conflicting requirements demand for a new approach for rejuvenating the tacky surface of the cleaning member. | {
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This invention relates to air-vapor mixers for internal combustion engines and is particularly directed to an improvement in the fuel valve of the air-vapor mixer wherein a combination action of the material composing the fuel valve and the configuration of the fuel valve itself improves engine performance.
Internal combustion engines fueled by propane, butane, a mixture of propane and butane, or natural gas utilize an air-vapor mixer in their fuel supply system to mix the fuel with air for combustion in the engine. It is advantageous for an internal combustion engine to operate on as lean a mixture as is possible without misfiring, especially at low and intermediate loads, because to do so results in higher fuel efficiency and a minimum output of pollutants such as hydrocarbons and carbon monoxide (CO). However, lean mixtures will not generally burn reliably under some engine conditions such as starting, idling and deceleration. Accordingly, it is desirable to enrich the charge under conditions where misfiring may occur but to lean the charge under other conditions, such as low and intermediate load level operating conditions, so that a nearly stoichiometric relationship of carbon and oxygen is achieved.
In response to this need, the fuel valve of the present invention is composed of an acetal copolymer resin marketed under the trademark Duracon by the Eiko Company in Japan. The simple linear chain structure(--OCH.sub.2 --).sub.n and the relative shortness of the carbon-oxygen bond impart properties of high crystallinity and relatively high density to acetal resins in the solid state. This material has the qualities of high stiffness, excellent dimensional stability, high tensile and impact strength, good abrasion resistance, and a low coefficient of friction. This combination of mechanical properties makes the Duracon acetal copolymer suitable as a replacement for metals in a variety of applications.
Besides dimensional stability, an important characteristic of Duracon in the fuel valve of the present invention is its high coefficient of linear thermal expansion over that of metals used in the body of the mixer, e.g. aluminum. The fuel valve, therefore, when cool and in its contracted state creates a larger effective size of the metering orifice in which it operates. When richer mixtures are required for cold starting and idling, the fuel valve, being in this contracted state, provides the larger effective orifice and, therefore, the richer mixture. As the internal combustion engine is heated from this cool state the fuel valve increases in size and, due to its high coefficient of expansion relative to the surrounding metal, thereby leans the mixture for operating conditions such as low and intermediate load levels.
The fuel valve is also provided with an incrementally decreasing perimeter that causes the diameter of the valve to vary in a step-by-step fashion along its operating length or axis. This stepped configuration provides close control of the carbon/oxygen relationship over the mid-range of engine operating speeds. Prior art valve cones with uniform conical surfaces unnecessarily enrichened the mixture with the result that the engine developed high power but at the cost of fuel economy.
It is, therefore, an important object of the present invention to provide an improved fuel valve for an air-vapor mixer which expands to lean the mixture when the engine warms up and effectively controls the mixture over the mid-range of operating speeds to achieve an optimal, nearly stoichiometric relationship of carbon and oxygen.
Another important object of this invention is to provide an improved fuel valve for an air-vapor mixer which has a significantly higher coefficient of thermal expansion than the material defining the metering orifice in which the valve operates, thereby decreasing the effective orifice size to lean the mixture as the internal combustion engine increases in temperature after starting.
Still another important object of this invention is to provide an improved fuel valve for an air-vapor mixer which enables a predetermined, optimal admixture of carbon and oxygen to be maintained over the mid-range of engine speeds, thereby increasing efficiency and minimizing exhaust pollutants.
Furthermore, it is an improtant object of this invention to provide a temperature compensating fuel valve as aforesaid which improves fuel economy and reduces exhaust pollutants while retaining high operational performance including richer mixtures for cold starting and idling.
Additionally, an important object of this invention is to provide a fuel valve as aforesaid with optimal mid-range control in which such control is achieved by a stepped valve surface, each step optimizing the carbon/oxygen admixture for a corresponding engine speed within the mid-range of operation. | {
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Dump trucks are commonly used to haul bulk materials such as aggregate, sand, gravel, dirt and the like. A pivotal dump body is located behind the cab for operation by a hoist between a down or level position for loading and travel, and a raised or tilted position wherein the load can be unloaded by dumping out the rear endgate.
Such endgates are typically connected to the dump bodies by top pivots and secured by bottom latches, which the driver can operate from the cab to either lock or release the endgate as desired. The top pivots are usually fixed so that the endgate can only open from the bottom, which in turn results in the load being dumped directly behind the truck.
The top pivot pins of some endgates are removable. This allows the endgate to be opened from the top, about the bottom latch, so that the load can be dumped further behind the truck. This can be very useful when, for example, it is not possible to back the truck up to the place where the load is to be used.
However, while such removable top pivot pins have been used heretofore, they have presented certain difficulties. The pins can easily become lost. They can bind and become difficult to remove and/or replace, particularly if there are torsional forces between the endgate and body--which there often are when several cubic yards of construction aggregate are being carried. Since the top pivots are located at the upper corners of the endgate, such forces can cause misalignment when the body is sprung or when the truck is not on level ground while dumping its load.
A need has thus arisen for a new and improved latch assembly which provides for the convenient, safe and secure latching of the tops of such endgates. | {
"pile_set_name": "USPTO Backgrounds"
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Vacuum pumps are known which use a source of compressed air (or other high-pressure fluid) in order to generate a negative pressure or vacuum in a surrounding space. Compressed-air driven ejectors operate by accelerating the high pressure air through a drive nozzle and ejecting it as an air jet at high speed across a gap between the drive nozzle and an outlet flow passage or nozzle. Fluid medium in the surrounding space between the drive nozzle and outlet nozzle is entrained into the high-speed flow of compressed air, and the jet flow of entrained medium and air originating from the compressed-air source is ejected through the outlet nozzle. As the fluid in the space between the drive and outlet nozzles is ejected in this way, a negative pressure or vacuum is created in the volume surrounding the air jet which this fluid or medium previously occupied.
For any given compressed-air source (which may also be called the drive fluid), the nozzles in the vacuum ejector may be tailored either to produce a high-volume flow, but not to obtain as high a negative pressure (i.e., the absolute pressure will not fall as low), or to obtain a higher negative pressure (i.e., the absolute pressure will be lower), but without achieving as high a volume flow rate. As such, any individual pair of a drive nozzle and outlet nozzle will be tailored either towards producing a high-volume flow rate or achieving a high negative pressure.
A high negative pressure is desirable in order to generate the maximum pressure differential with ambient pressure, and so generate the maximum suction forces which can be applied by the negative pressure, for example for lifting applications. At the same time, a high-volume flow rate is necessary in order to ensure that a volume to be evacuated can be emptied sufficiently quickly to allow for repetitive actuation of the associated vacuum device, or equally in order to convey a sufficient volume of material, in vacuum conveyer applications.
In order to achieve both a high ultimate vacuum level and a high overall volume flow rate, so-called multi-stage ejectors have been devised, which comprise three or more nozzles arranged in series within a housing, each adjacent pair of nozzles in the series defining a respective stage across which a negative pressure is generated in the gap between the adjacent two nozzles. Again, in general, any individual pair of nozzles in the series may be tailored either towards producing a high-volume flow rate or achieving a high negative pressure, for a given source of compressed air.
In such multi-stage ejectors, the earliest stages produce the highest levels of negative pressure, i.e., the lowest absolute pressures, whilst the subsequent stages provide successively lower negative pressure levels, i.e., higher absolute pressures, but increase the overall volume throughput of the ejector device. In order to apply the generated vacuum across the multiple stages to a desired vacuum device or volume to be evacuated, the successive stages are typically connected to a common collection chamber, whilst valves are provided to each successive stage, at least after the first, drive stage, so that the subsequent stages can be closed off from the collection chamber once the negative pressure in that chamber has been reduced below the negative pressure which the second and subsequent stages are able to generate.
The drive stage is so-called because it is the only stage connected to the source of pressurised fluid (compressed air), and so drives the flow of pressurised fluid through all of the subsequent stages and nozzles in the series, before the drive fluid and entrained fluid is ejected from the vacuum ejector.
In order to provide for the entrainment of fluid across each successive stage, the series of nozzles present a through-channel with gradually increasing sectional opening area, through which the stream of high-speed fluid is fed in order to entrain air or other medium in the surrounding volume into the high-speed jet flow. The nozzles between each stage form the outlet nozzle of one stage and the inlet nozzle of the next stage, and are configured to successively accelerate the flow of air and other medium in order to direct a high-speed jet of the fluid across each successive stage.
Although different pressurised fluids may be utilised as the drive fluid, multi-stage ejectors of the present type are typically driven by compressed air, and most usually are used to entrain air as the medium to be evacuated from the volume surrounding the jet flow through each gap in the series of nozzles, across the respective stages.
One design of multi-stage ejector which has found commercial success is to present the series of nozzles in a coaxial arrangement within a substantially cylindrical housing which incorporates a series of suction ports therein in communication with each stage of the ejector, the suction ports being provided with suitable valve members for selectively communicating each stage with a surrounding volume of air. So presented, the cylindrical body is formed as a so-called ejector cartridge, which, when installed inside a housing module, or within a suitably dimensioned bore hole, can be used to evacuate the surrounding chamber, which is in turn fluidly coupled to the vacuum device to which the negative pressure is to be applied.
Such a device is disclosed in PCT International Publication No. WO 99/49216 A1, in the name of PIAB AB, and is shown in FIGS. 14 and 15 of the present application.
As shown in FIG. 14, the ejector cartridge 1 comprises four jet-shaped nozzles 2, 3, 4 and 5 which define a through-channel 6 with gradually increasing cross-sectional opening area. The nozzles are arranged end-to-end in series with respective slots 7, 8 and 9 between them.
The nozzles 2, 3, 4 and 5 are formed in respective nozzle bodies, which are designed to be assembled together to form an integrated nozzle body 1. Through openings 10 are arranged in the wall of the nozzle body, to provide flow communication with an outer surrounding space.
Turning to FIG. 15, it can be seen how the ejector cartridge 1 may be mounted within a bore hole or housing, in which the outer surrounding space corresponds to a chamber V to be evacuated. Each of the through openings 10 is provided with a valve member 11 in order to selectively permit the flow of air or other fluid from the surrounding space V into the space or chamber between each adjacent pair of nozzles. As shown in FIG. 15, the ejector cartridge 1 has been mounted in a machine component 20, in which the bore hole has been drilled or otherwise formed. The ejector cartridge 1 extends from an inlet chamber i to an outlet chamber u, and is arranged to evacuate the three separate chambers constituting the outer surrounding space V, each of which is separated from the adjacent chamber by an O-ring 22. Although not shown, each of the chambers constituting the outer surrounding space V is connected to a common collection chamber or suction port, in order to apply the generated negative pressure to an associated vacuum-operated device, such as a suction cup.
Although such multi-stage ejector arrangements are beneficial in providing both a high-volume flow rate and a high level of negative pressure, there is necessarily still some degree of compromise in the design of each successive stage in the ejector, in order to obtain an overall desired performance characteristic for the multi-stage ejector as a whole. Accordingly, it has also been proposed to provide a further so-called booster nozzle, provided in parallel with the drive nozzle of the multi-stage ejector, where the booster nozzle is specifically designed to obtain the highest possible level of vacuum, but does not form part of the series of coaxially arranged nozzles which make up the multi-stage ejector. In this way, the booster nozzle can be configured to obtain the highest possible level of vacuum, whilst the parallel multi-stage ejector nozzle series can be arranged to obtain a high-volume throughput, which enables a high negative pressure (low absolute pressure) to be obtained within the volume to be evacuated within an acceptably short period of time.
Such an arrangement is disclosed in U.S. Pat. No. 4,395,202, as shown in FIG. 13 of the present application. In this arrangement, there is provided a set of ejector nozzles 12, 13, 14, 15 arranged successively for evacuation of associated chambers 5, 6, 7, which are in mutual communication with a vacuum collecting compartment 16 through respective ports 18, 19 and 20. Valves, 21, 22 and 23 are respectively provided to the ports 18, 19 and 20.
An additional pair of nozzles 24 and 25 is provided in parallel to the drive nozzle 12 of the multi-stage ejector, and is arranged in a separate booster chamber 4, connected to the collecting chamber 16 via a port 17. The booster stage is comprised of a pair of nozzles 24 and 25, with the inlet nozzle 24 being connected, together with the drive nozzle 12 of the multi-stage ejector, to the inlet chamber 3, which is supplied with compressed air. The pair of nozzles 24 and 25 across the booster stage serves to generate the highest possible vacuum (lowest negative pressure) in the booster chamber 4. The jet of compressed air which is generated by the nozzle 24 is ejected out of the booster stage through nozzle 25, into the same chamber 5 across which the drive nozzle 12 propels the drive jet of compressed air. In this way, the air expelled out of the booster stage is entrained into the drive jet flow to be expelled from the multi-stage ejector. Furthermore, the vacuum generated by the drive stage of the multi-stage ejector is applied to the exit of nozzle 25, so that the pressure differential across the booster stage is increased whereby the vacuum level which can be generated by the booster stage can be increased, i.e., the absolute pressure which can be obtained is reduced.
In operation of the vacuum ejector, the series of nozzles 12, 13, 14 and 15 of the multi-stage ejector is able to produce a high volume flow rate so as quickly to generate a vacuum to a low absolute pressure in the collecting chamber 16 within a short period of time by entraining fluid from each of the chambers 5, 6 and 7 and the collecting chamber 16 into the jet streams formed by each successive stage of the ejector. The booster stage functions in parallel to the multi-stage ejector, but typically produces a low volume flow rate, and so does not contribute significantly to the initial vacuum formation process. As the vacuum level in the collecting chamber 16 increases (i.e., as the absolute pressure falls), the associated valve members 23, 22 and 21 will close in turn, as the pressure in the vacuum, collecting chamber 16 drops below the pressure in the associated chamber 7, 6 or 5, respectively. Eventually, the pressure in the collection chamber 16 will fall below the lowest pressure that any of the stages of the multi-stage ejector is able to generate, so that all of the valves are closed, and all further evacuation will then be done by the booster stage, which provides suction to the collection chamber 16 via suction port 17.
Such multi-stage ejectors and ejector cartridges as described above have found commercial success in a number of different industries, and in particular in the manufacturing industry, where such vacuum ejectors may be connected to suction cups and used for picking and placing components during an assembly process.
As the demands for high vacuum levels (i.e. low absolute pressures) in processes such as de-gassing, de-humidifying, filling of hydraulic systems, forced filtration, etc., continue to increase, there is increasing demand for vacuum ejectors which are able to repeatedly provide a high level of negative pressure (i.e., a low absolute pressure) in order to carry out the above and other processes.
Coupled with this, there is an increasing drive towards smaller-sized ejectors, which are able to provide the desired evacuation capability at remote locations on the machinery (i.e., at the ends of mechanical arms, and significant distances from the ultimate source of compressed air) without negatively impacting on the overall dimensions of the machine. In particular, there is a desire for ejector devices having a small footprint, and so able to apply a vacuum to increasingly compact working areas. | {
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The present invention relates to snack products and more particularly to chip-type snack products.
The food products which are sold in the general category of snack items are many and varied, typically including such things as chips (e.g., potato chips and corn chips), puffs (e.g., corn puffs), etc. Snack items account for a large volume in the food industry. Generally, snack items are eaten apart from a regular meal and often different snack items are served at the same time. When snacks are served, normally at least one chip-type snack is included. One of the most popular chip-type snacks is the potato chip or fabricated potato chip.
The present invention relates to new method and apparatus for preparing fabricated chip-type snack. The present invention wil be described primarily with regard to preparation of potato chips; however, it should be recognized that various other types of fabricated chips (such as corn chips or wheat chips) may be prepared using the present invention.
It has been known in the past to prepare chip-type snacks by preparing a dough sheet and cutting sections from the dough sheet. The sections are then fried to form chips. A major difficulty has been confronted in controlling the movement of the sections through the deep fat fryer. A partial solution has been provided by operating a continuous belt in the upper portion of the fryer which assists in moving the sections through the fryer. Some sections, however, may clump together resulting in unfried or only partially fried chips. Other sections may remain in the fryer too long and become overly fried or burned. The present invention overcomes such problems by frying a continuous ribbon of chips which is moved positively through the system. | {
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This invention relates to apparatuses for automatically setting back or anticipating the temperature of a room controlled by a conventional heating system theremostat during preselected time periods, and in particular, relates to a combination temperature anticipator and night light apparatus which, by adjusting the proximity to the conventional thermostat, is capable of modifying the number of setback degrees desired.
The art abounds with numerous devices for modifying the temperature setting of a thermostat which is used to control the heating in a home or a place of business. In the face of the current energy crisis, it is extremely desirable to reduce the amount of heating supplied during nighttime hours when, either the occupants of the building are no longer there as in a business establishment, or during the sleeping hours in a home when persons are not moving about and are protected by various types of blankets. Generally, each of the apparatuses known in the prior art are expensive, require difficult installations, or special thermostats and controls to accomplish a temperature decrease during selected periods of time. Typical examples of setback controls known in the prior art may be found in U. S. Patents as follows:
______________________________________ Patent No. Issue Date Inventor ______________________________________ 3,352,490 November 14, 1967 Dalzell et al 3,834,618 September 10, 1974 Buck Walter 3,849,753 November 19, 1974 Nichols 3,934,217 January 20, 1976 Brcic 3,945,564 March 23, 1976 Smallegan 3,983,928 October 5, 1976 Barnes ______________________________________
The thermostats in use with conventional heating systems, whether for use in the home or factory, generally have a lower level in the range of 50 to 60 degrees Farenheit. However, when a factory or office building is closed for the evening and no work is being done, it is not economical and a serious waste of energy to maintain the temperature at 50 or 60 degrees when the outside temperature drops below the freezing point.
At this time, it would be extremely desirable to be able to maintain the building temperature above the freezing level to prevent water pipes and other vulnerable devices from becoming damaged. Thus, it would be most advantageous to be able to maintain the temperature at a level, for example, of 35 to 40 degrees Farenheit. Obviously, this can be accomplished by completely turning off the heating system during the evening hours, However, the possibility exists that the inside temperature may drop below the freezing point, which of course is undesirable.
The other alternative is to utilize a temperature anticipator or setback control device which is energized by a time control apparatus enabling the thermostat to read an air-flow temperature which is higher than that actually occurring in the room. This is especially advantageous over long shut-down periods such as a weekend for a factory or business, or vacation time when no one is left at home. | {
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In the rotary drilling of wells, and particularly oil and gas wells, a rotary table having an opening and kelly, which is an elongate member, flat faced in cross section, is slidable through a similarly-shaped kelly bushing secured to the rotary table and is secured to the upper end of the drill string therebelow for rotating the drill string rotary bit at its lower end during drilling. The kelly is used only during the actual drilling, and when not in use is stored in an out of the way position in what is referred to as a "rat hole." In the past, rat holes for storing the kelly have ranged from holes drilled into the ground to casing secured to a structural member of a drilling rig, for example, as illustrated in U.S. Pat. No. 3,371,728.
As the art of rotary drilling has progressed, and particularly in drilling for oil and gas in submerged offshore lands, both from fixed or floating vessels, it is highly desirable that a rat hole assembly be provided which is anchored to the drilling rig at its lower end, which rat hole is movable toward the rotary table for reception of the kelly for storing and moving to an out of the way position so that other operations may be performed without interference with the kelly, yet movable back toward the rotary for withdrawal when rotary drilling operations are to be commenced again, and which rat hole can be readily removed from the structural member when desired, for example, when moving from one location to another. | {
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The present invention relates to project modeling, and more specifically to using variable defect arrival rates and variable defect density rates when forecasting, estimating or otherwise managing software project status, timetables, and deliverables.
Software project management regards tracking the progress of a software project for management and control. Monitored and managed aspects of a software project include man-hours expended to date, the quantity of programmers on a project, and the scheduling of the project in relation to the other software development projects.
Embodiments are directed to new devices, systems, articles of manufacture, and processes for monitoring, managing, and enhancing software projects. | {
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Currently, automated and manual systems for classifying and mapping fire from overhead imagery do exist. The mapping of fires at the resolution that this invention achieves is currently done manually. This process requires a human analyst trained to identify fire from overhead imagery to scour the image looking for regions which appear to contain fire. Once areas that are believed to contain fire are noted, the analyst must create images and/or other files denoting their analysis. This process can be very time consuming, especially for images which cover large areas of land that the image analyst must observe. With this method, classification can only be completed by highly skilled analysts. In emergency situations or when there are many images which need to be analyzed, an analyst may be unable to accurately analyze all of the images on the timescale that the mission requires.
Other methods of automated fire classification from overhead EO/IR (Electro-Optical/Infra-Red) satellite imagery generally use lower resolution images. For example, the Moderate Resolution Imaging Spectroradiometer (MODIS) fire feed only achieves a one kilometer resolution. The low resolutions of the current automated classification systems are disadvantageous because individual fires may be much smaller than one kilometer. This means that a very large fire which actually does cover a one kilometer square has the possibility of appearing the same as a very small fire and vice versa. Accurate estimates of the area of the fire can be crucial information when used for combating the fire. The current methods have the possibility of masking the extent of the fire because of their low resolution.
The present invention also differs from the MODIS fire feed in the regions of the electromagnetic spectrum that it uses to identify fires. The MODIS sensors are capable of sensing electromagnetic radiation at 3.9 and 11 micrometers. From FIG. 1 we can see that these are in the mid-wave infrared (MWIR) and long-wave infrared (LWIR) regions of the spectrum. Radiation that we feel as heat typically comes from these regions of the spectrum. The present invention detects fires by only using information contained in the visible and near-infrared (NIR) and/or short-wave infrared (SWIR) regions of the spectrum. The fact that the NIR and SWIR bands are not true thermal bands makes the detection of fires much more difficult.
Some methods are limited by the size of the files that they create as an output of their mapping algorithm. Bandwidth can be an important factor when trying to stream important information to its destination. Some of the current methods create classification maps which can be proportional in size to the original image. To transmit these files can require a significant amount of bandwidth and time. The large file sizes can become especially restrictive when dealing with mobile wireless technologies such as those used by first responders. | {
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The present invention relates to a water-absorbent structure for various articles requiring a water-absorbing property such as a disposable diaper, a sanitary napkin and disposable wipes and also to a process for making the same.
U.S. Pat. No. 4,500,315 discloses a disposable superthin water-absorbent article. This article comprises a first layer, a second layer and an intermediate layer disposed between these first and second layers. The first layer comprises, in turn, a synthetic fibrous web and a plurality of super-absorbent polymer particles distributed in this web. The second layer is a wad formed by intertwined cellulose fibers or the like contributing to a liquid diffusibility. The intermediate layer also is formed by intertwined cellulose fibers or the like partially contacting with the polymer particles of the first layer. This article is compressed in its thickness direction so as to have a thickness less than half of the thickness before compressed and restores a thickness corresponding to at least 75% of its initial thickness before compressed as the article absorbs liquid such as bodily discharges.
Japanese Patent Application Publication No. 1990-74254A discloses an absorbent pad used in the absorbent article. This absorbent pad comprises a mixture of heat-weldable crimped fibers, fluff pulp and water-absorbent polymer particles. The crimped fibers are heat-welded together to form three-dimensional web formation presenting a mat-like appearance. The absorbent pad is obtained by compressing the fluff pulp and polymer particles in a wetted state together with the crimped fibers and then drying the assembly. The absorbent pad is free from a state of compression as the fluff pulp and the polymer particles absorb water sufficiently to become soft and thereupon the absorbent pad restores its initial mat-like state. After restoration of the initial mat-like state, the crimped fibers become easily deformable and, in consequence, the absorbent pad acquires a compressive elasticity.
In both the article disclosed in U.S. Pat. No. 4,500,315 and the absorbent pad disclosed in Japanese Patent Application Publication, the polymer particles are filled and held in interstices of the fibers. If it is desired to avoid falling off of the polymer particles from the absorbent article or pad, the fiber interstices must be as narrow as possible. As a result, the fiber interstices are choked up as the polymer particles absorb water and swell and a breathability of the absorbent article or pad may be remarkably deteriorated. | {
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This invention relates generally to stethoscope heads, particularly, to bell components that adapt the stethoscope head for use on infants or adults and in locations of smaller skin areas. In general, a head of a stethoscope is typically a dual head type consisting of a diaphragm on one side and a bell on the other. The diaphragm is suitable for detecting low frequency range sounds associated with diastolic and third heart sounds. The bell is suitable for detecting higher frequency range sounds such as those which signify murmurs. Typically, for the best detection of sounds, it is desirable to acoustically seal the rim of the bell with the skin of the patient's body above the site to be auscultated. For this reason, a bell suitable for use with an adult may not be suitable for use with an infant. Further, the region between the ribs is narrow, and therefore, an adult size bell might be too large to be used in such a location. One method of resolving this problem is using a stethoscope head with detachable diaphragm structures and bell components that adapt to the particular use required.
An example of a stethoscope with such an adaptable stethoscope head is known as the "Sprague". The Sprague stethoscope has a configuration which includes a chest piece with a drum and a stem, and removable diaphragm structures and bell components that attach to the drum. The diaphragm structures and bell components come in various sizes and are typically screwed onto the drum. While such configuration improves the detection of sounds, it is desirable to further acoustically seal the rim of the bell to the skin of the patient's body for the best detection of sounds. Moreover, the bell components may be made of plastic which is a poor conductor of sounds detected. Accordingly, what is needed is a stethoscope with a stethoscope head, in particular, bell components that provide excellent sound conductivity and a desirable acoustic seal with the skin of the patient's body. | {
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1. Field of the Invention
This invention relates to optical metrology used in the manufacturing of semiconductor devices, and more particularly to a zoned diffraction order sorting filter for spectrometers used in semiconductor optical metrology systems, and to a method for wavelength calibration of spectrometers with zoned order sorting filters.
2. Description of Related Art
One type of optical metrology involves directing an incident beam at a structure on a workpiece, measuring the resulting diffraction signal, and analyzing the measured diffraction signal to determine various characteristics of the structure. The workpiece can be a semiconductor wafer or substrate, a photomask, or a magnetic medium. In manufacturing of workpieces, periodic gratings are typically used for quality assurance. For example, one typical use involves fabricating a periodic grating in proximity to the operating structure of a semiconductor chip. The periodic grating is then illuminated with electromagnetic radiation, and the electromagnetic radiation that deflects off of the periodic grating are collected as a diffraction signal. The diffraction signal is then analyzed to determine whether the periodic grating, and by extension whether the operating structure of the semiconductor chip, has been fabricated according to specifications.
In one conventional system, the diffraction signal collected from illuminating the periodic grating (i.e. the measured diffraction signal) is compared to a library of simulated diffraction signals. Each simulated diffraction signal in the library is associated with a hypothetical profile, i.e. cross-section, of the periodic grating. When a match is made between the measured diffraction signal and one of the simulated diffraction signals in the library, the hypothetical profile associated with the simulated diffraction signal is presumed to represent the actual profile of the periodic grating. The hypothetical profiles, which are used to generate the simulated diffraction signals, are generated based on a profile model that characterizes the structure to be examined. Thus, in order to accurately determine the profile of the structure using optical metrology, a profile model that accurately characterizes the structure should be used.
With increased requirements for throughput, decreasing size of the test structures, smaller illuminated spot sizes, and lower cost of ownership, there is greater need to optimize designs of optical metrology systems to meet these design goals. Characteristics of the optical metrology system including sampling time, range of measurement capabilities, accuracy and repeatability of diffraction signal measurements are essential to meeting these ever-increasing requirements.
Spectrometers are used to measure diffraction signals over a wide range of wavelengths, from the near-infrared (NIR), over visible light (VIS), and ultraviolet (UV), to the deep ultraviolet (DUV) parts of the electromagnetic spectrum. A spectrometer typically employs a blazed diffraction grating to disperse an optical signal onto an array detector capable of measuring the intensity of different wavelengths present in the optical signal, i.e. the diffraction signal. A diffraction grating disperses the optical signal into a multitude of diffraction orders, of which typically only the first order is used to perform the actual diffraction signal measurement and matching against a diffraction signal library. However, when the wavelength range of the diffraction signal exceeds one octave, as is typically the case in semiconductor optical metrology systems, the diffraction orders generated by the grating start to overlap each other. Due to diffraction order overlap, in addition to measuring the intensity of the first diffraction order at a calibrated wavelength λ, the same array detector location, i.e. pixel, would also see and detect the second diffraction order intensity of wavelength λ/2. In the case of very large wavelength ranges, it may also see and detect the third diffraction order intensity of wavelength λ/3, etc. To prevent the detection of unwanted higher diffraction orders at any array detector pixel, an order sorting filter (OSF) may be employed. In the simplest embodiment, an OSF is a suitable optical long-pass or band-pass filter installed in front of the array detector, which prevents shorter wavelengths of the higher diffraction orders from reaching the detector. The OSF may comprise multiple zones spanning the length of the array detector, where each zone has different passband characteristics, or it may have continuously-changing passband characteristics. A zoned OSF is simpler and relatively inexpensive compared to the continuously-variable type, and is typically used for compact and fast spectrometers.
One of the drawbacks of a zoned OSF is the appearance of anomalies in measured diffraction signals at wavelengths in the vicinity of joints between OSF zones. In a zoned OSF filter, each zone is typically implemented as a thin-film stack filter on a common optically-transparent substrate. The inventors have realized that due to varying passband characteristics of the zones, the optical length traversed by the light beam through the thin-film stack filter of each zone also, in general, varies. The sharp change of traversed optical length at the zone joint may cause unwanted dispersion of light, such that light incident at the zone joint is spread sideways onto multiple pixels of the array detector. In addition to spreading onto multiple adjacent pixels, this dispersion may cause a sideways shift of the centroid of the image projected upon the detector. The inventors believe this image spreading and shifting to be the main cause of unwanted localized anomalies in the measured diffraction signals at the zone joints. Thus, to improve accuracy of measured diffraction signals, there exists a need to minimize unwanted dispersion at zone joints in an OSF, or otherwise correct measured diffraction signals affected by dispersion at OSF zone joints. | {
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During strenuous physical activity, the human body requires a significant amount of fluid replenishment to replace lost fluids, in order to prevent dehydration. It is preferable for a person to be able to consume a small amount of fluid frequently while continuing to perform the activity, rather than having to stop the activity periodically to consume a larger amount of fluid. Hydration packs such as those disclosed in U.S. Pat. Nos. 6,364,168 and 6,422,439 have been developed to allow frequent replenishment. They contain a flexible reservoir with up to several liters of fluid, and a flexible hose allowing the wearer to drink without interrupting their activity.
There are a large variety of devices known in the art for carrying standard bicycle water bottles. These are typically worn on a person's belt or attached to a standard backpack. There are also other types of reservoir carriers, such as the the Beverage Container Belt disclosed in U.S. Pat. No. 6,598,770. For longer periods of activity, a hydration pack is often preferred over these devices, due to its larger capacity. Hydration packs are commonly available that contain up to 3 liters of fluid, whereas bicycle water bottles typically contain no more than 1 liter.
The hydration pack may be worn by a person hiking in a remote area without a nearby potable water supply, requiring the reservoir to contain enough fluid for the entire hike. The hiker must ration the fluid to insure it does not run out prematurely. This is typically accomplished by controlling how often, as well as how much fluid is consumed, each time a drink is taken.
A disadvantage of hydration packs of the current art is a lack of any indication of the amount of fluid remaining in the reservoir. The pack is normally worn on a person's back, with the reservoir contained entirely inside of the pack, requiring the person to stop their activity, then remove and open up the pack in order to visually examine the liquid level. Although the weight of the pack will change as liquid is consumed, this is not a reliable gauge of remaining liquid, especially for an inexperienced user of the hydration pack.
Another disadvantage is an inability to indicate how much time the remaining fluid is expected to last, or to provide advance warning when it is about to run out.
There is a broad range of techniques for measuring fluid level. Many require mechanical devices such as floats installed in contact with the fluid. Others sense properties of the fluid using probes that are in direct contact with it, such as the impedance sensing technique disclosed in U.S. Pat. No. 5,565,851. Still others use techniques not requiring direct contact with the fluid, such as the optical technique disclosed in U.S. Pat. No. 4,840,137, and the capacitance measurement methods of U.S. Pat. Nos. 4,295,370 and 6,472,887.
The capacitance method is frequently employed, due to the possibility of using sensors that are not in contact with the fluid and therefore not subject to contamination by the fluid. The current art includes methods with sensors exhibiting a continuous capacitance change proportional to fluid level, as disclosed in U.S. Pat. No. 4,383,444; as well as methods with multiple sensors to detect for the presence of fluid at several discrete levels, as disclosed in U.S. Pat. No. 4,003,259.
A disadvantage of continuous capacitance methods of the current art is their inability to compensate for changes in ambient capacitance, such as changes in location of objects in proximity to the sensor, without requiring electrostatic shielding or other methods which increase the cost of the system.
A disadvantage of discrete capacitance methods of the current art is the inability to resolve more liquid levels than the number of electrodes in the system.
Another disadvantage of discrete capacitance methods is the necessity of filtering out variations in measured liquid level due to movement of the reservoir, such as is disclosed in “QProx QT114 Charge-Transfer QLevel Sensor IC” Data Sheet.
A technique known in the art as dithering may be used to increase resolution of an analog signal, as disclosed in U.S. Pat. No. 6,016,113. | {
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Masonry objects, that is, things comprised of stone or brick have long been used in natural and artificial gardens for esthetic and functional purposes. For instance, masonry walls are used to define boundaries and retain earth. Typically, good construction requires some sort of foundation, particularly when the ground alternately freezes and thaws. In any case, masonry structures are inherently heavy and need to have adequate structural support.
Simulated masonry articles in general are known. For instance, they are used when gardens are placed within a building, where the weight of masonry walls and other objects is undesirable from the standpoint of the structure. Similarly, it is desirable to have light weight objects when portability, easy placement or easy rearrangement of the units is an aim. In the past, simulated masonry articles have been made of such as painted wood, plaster, and plastic resins, etc. Simulated rocks, which are hollow and are made of molded plastic resin, have been known for decorative purposes, for use in exterior and interior locations.
Modular garden wall systems are known. For instance: U.S. Pat. No. 5,080,523 to Steiner describes a modular concrete wall system. U.S. Pat. No. 348,598 to Strickland shows curved concrete modules. U.S. Pat. No. 3,762,113 to O'Mullan shows molded plastic edging. U.S. Pat. No. 4,275,540 shows a modular plastic 4-high brick wall, with open rear sides which can be closed with a panel. The interlocking stepped ends of the modules are held together by pins, which optionally extend into the earth. Filler blocks are used to make vertical plane ends.
The modular garden wall systems in the prior art have various advantages and disadvantages. Some are obviously heavy. While they are stable, they are difficult to transport, move about, and store. On the other hand, simulated masonry which is so light that it does not stay in place can fail to achieve more than a simple cosmetic effect. Simulated masonry often fails to be good looking and sufficiently simulative of ordinary masonry. Other prior art designs are expensive to fabricate. Still others have means for connecting which does not combine well cost, simplicity, appearance of the joint, and ease of assembly or disassembly. Thus, there is a need for improvements. | {
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In general, the colorimetric values of a colored object change depending on temperatures, and this phenomenon is called thermochromism. The thermochromism poses a problem in a situation that requires high-precision colorimetry since it causes errors of colorimetric values according to the temperature of an object to be measured. However, many things are still unknown about the relationship between the thermochromism and colorimetry.
Color stabilization and color matching processing in a general printing apparatus will be described below. Conventionally, in order to control a printing apparatus represented by a printer apparatus to output desired colors, a color conversion lookup table (to be abbreviated as LUT hereinafter) is used. The color conversion LUT includes an LUT used in calibration required to maintain a printing apparatus in a constant state, and an LUT used in color matching represented by ICC profiles. In order to create these color conversion LUTS, for example, a printing apparatus outputs a plurality of color patches such as IT8.7/3 patches. The colors of these plurality of color patches are measured using a colorimeter such as a spectral colorimeter to obtain colorimetric values and to associate device values with device-independent values, thus creating a color conversion LUT. The created LUT absorbs a color appearance difference between devices or that due to variations of a printer engine, thus attaining color matching and color stabilization. Recently, using a color sensor incorporated in a printer, this LUT is generated in real time. In such printer, the built-in color sensor detects patches immediately after fixing, and feeds back their calorimetric values to LUT generation.
However, in a general printer, since the patches immediately after fixing have very high temperatures (about 70° C.), the colorimetric values of the patches change due to the thermochromism. For this reason, an LUT suited to an observation environment (room temperature) of the user cannot be precisely created.
Some media used in general printing contain a fluorescent whitening agent, which absorbs ultraviolet rays and emits fluorescence in the visible range (especially, in a blue-violet range) so as to increase the degree of whiteness. Since the fluorescent whitening effect by the fluorescent whitening agent increases/decreases depending on temperatures, the colorimetric values of printed materials output onto media including the fluorescent whitening agent also change depending on temperatures. Especially, spectral reflectance variations around the blue-violet range (440 nm) in the visible range are large.
Therefore, a technique for correcting calorimetric values in consideration of the temperature at the time of colorimetry in a printer apparatus is demanded, and the following methods are proposed.
In one method, spectral reflectance change amounts for respective wavelengths per unit temperature interval are calculated in advance for respective color samples, and the spectral reflectance at a desired temperature is predicted (for example, see patent reference 1).
In another method, change amounts of absorption coefficients and scattering coefficients in the Kubelka-Munk formula for respective wavelengths per unit temperature interval are calculated for respective color samples, and the spectral reflectance at a desired temperature is predicted (for example, see patent reference 2). [Patent Reference 1] Japanese Patent No. 3776492 [Patent Reference 2] Japanese Patent No. 3555706
However, in the method which is described in patent reference 1 and calculates spectral reflectance change amounts for respective wavelengths per unit temperature interval, spectral reflectances for all combinations of device values that can be output by a printing apparatus cannot be predicted.
In the method which is described in patent reference 2 and calculates change amounts of absorption coefficients and scattering coefficients for respective wavelengths per unit temperature interval for respective color samples, the spectral reflectance of a mixed color can be predicted according to the mixing ratio of color samples. However, since a printed material that has undergone general halftoning has an uneven colored surface, it is also difficult for this method to predict spectral reflectances for all combinations of device values that can be output by a printing apparatus.
Since neither of the two methods consider the influence of a fluorescent whitening agent contained in substrates of color samples (printing media), they cannot appropriately correct colorimetric values for printed materials using media containing the fluorescent whitening agent. | {
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The present invention relates to an optical writing apparatus that forms a latent electrostatic image on a photoreceptor by selectively activating a plurality of light-emitting elements in rows for light emission.
FIG. 15 is a schematic diagram of a known copier which forms a latent electrostatic image on the surface of a photoreceptor 2 using an optical writing head 1 in which light-emitting elements are arranged in rows. The photoreceptor 2 is a layer that surrounds the outer surface of a light-sensitive drum 3, which is coupled to a drive unit (not shown) in such a way that the drum is rotated in the direction indicated by arrow 4. Also disposed around the light-sensitive drum 3 are a charge corotron 7, the optical writing head 1, a light concentrating lens system 10, a developer 8, a transfer corotron 9, and a cleaning unit 6.
As the light-sensitive drum 3 is rotated in the direction of arrow 4, a uniform charge layer is formed on the surface of the photoreceptor 2 by means of the charge corotron 7 and the photoreceptor 2 is thereafter illuminated with light from the writing head 1 so as to form a latent electrostatic image. The lens system 10, which concentrates on the photoreceptor 2 light issuing from the plurality of light-emitting elements in the head 1, consists of an array of focusing rod-shaped lenses.
The latent electrostatic image on the photoreceptor 2 is subsequently rendered visible by passage under a developer 8. The resulting toner image on the photoreceptor 2 is transferred to a copy sheet 11 by means of a transfer corotron 9, the sheet 11 being discharged after the toner pattern is fixed by a fixing unit (not shown). The photoreceptor 2 is cleaned of any residual electrostatic image by a cleaning unit 6 and conditioned for another cycle.
The internal structure of the writing head 1 which is used in the manner described above is shown in FIGS. 16 and 17. FIG. 16 is a cross-section of the head, and FIG. 17 is a plan view showing the essential part of the head.
As shown in FIG. 16, a transparent partition 12 is provided on top of an evacuated air-tight case 13 which contains anode electrodes 14. As shown in FIG. 17, each of the anode electrodes 14 is in the form of a tongue which is coated at one end with a phosphor 15 on its top surface. In the following description of the present invention, this phosphor is referred to as a light-emitting element 15.
Cathodes 16 comprising a plurality of filaments are provided beneath the transparent partition 12. When the cathodes 16 are heated by an electric current flowing therethrough, thermions are emitted. If the cathodes 16 are connected to ground and the anode electrodes 14 are supplied with a positive voltage, the emitted thermions will flow toward the anode electrodes 14 and strike the light-emitting elements 15, causing light emission.
As shown in FIG. 17, the anode electrodes 14 are arranged parallel to one another and spaced at equal distances in such a manner that they are partially interleaved with each other. The anode electrodes 14 are electrically insulated from one another and are connected to a drive circuit (not shown) that provides for selective application of a predetermined positive voltage to individual anode electrodes. According to this system, the light-emitting elements 15 are selectively excited for light emission, thereby forming a latent electrostatic image on the surface of the photoreceptor 2. As a result of light emission from one element 15, a single dot of a latent electrostatic image is formed on the surface of the photoreceptor 2. This dot provides a minimum unit of the latent electrostatic image, namely, one pixel of a developed image.
Japanese Unexamined Patent Application Publications Nos.38967/1983, 49148/1984 and 46740/1984 address other various optical writing head configurations.
The known optical writing head 1, discussed above, has various problems. First, the linear arrangement of light-emitting elements 15 requires a certain distance d to be provided between adjacent elements 15, as shown in FIG. 17. The distance d is necessary to ensure reliable electrical insulation between adjacent anode electrodes 14 carrying light-emitting elements 15, and as an inevitable result, a non-light-emitting portion is formed between adjacent light-emitting elements 15. If the optical writing head 1 having such non-light-emitting portions is used to form a latent electrostatic image on the surface of photoreceptor 2, residual charges will be incompletely neutralized in that part of the photoreceptor which faces the non-light-emitting portions. This can be the cause of deterioration of a developed image when the light-emitting elements 15 are seen in the principal scanning direction, or in the direction in which the elements are aligned.
Furthermore, if a mismatch occurs between the speed of rotation of the photoreceptor 2 and the timing of light emission from elements 15, part of the photoreceptor 2 will fail to be illuminated with an adequate amount of light, thus causing deterioration of a developed image when the light-emitting elements 15 are seen in the auxiliary scanning direction, or in the direction in which the elements move, as indicated by arrow 4 in FIG. 5.
Another problem with the previously known optical writing head 1 is that in order to ensure that the individual light-emitting elements 15 can be turned on and off independently of one another, the drive circuit requires as many drive elements and associated drive circuits as light-emitting elements 15. This disadvantageously increases the overall cost of the equipment. | {
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A liquid crystal display comprises pixel units designed in a matrix form, and a driving circuit for driving these pixel units. The deflection of liquid crystal molecules is achieved by means of change in the electric field in the liquid crystal cell, thereby achieving the display effect.
TFT-LCD is an active semiconductor device. Its display principle is to convert incident light emitted from the backlight into linearly polarized light by means of a first polarizer, which polarized light passes through a liquid crystal cell formed by attaching two layers of glass and injecting liquid crystal therebetween, and is emitted via a second polarizer. The liquid crystal has an optical birefringence property and would generate optical retardation for different incident light or different vibration directions, thereby changing the polarization state of the incident light. Since the liquid crystal molecules are arranged in different manners under different electric field intensities, the amounts of optical retardation generated are different, the polarization states of the incident light arriving at the second polarizer are different, and the intensities of the exit light are also different, such that the brightness of the exit light is adjusted by different liquid crystal electric field intensities and display of different gray scales is formed.
Typically, a pillar-shaped spacer (PS) is provided between the array substrate and the color film substrate in a liquid crystal display panel. The current design of PS is classified into PS on TFT and PS on Gate in terms of the position of PS, wherein the PS on Gate is further divided into PS on Gate with pillow-shaped spacer and PS on Gate without pillow-shaped spacer; and is generally classified into main PS and sub PS in terms of the height of PS, wherein the height of the main PS is relatively high and plays the role of static support in cell alignment of the array substrate and the color film substrate to ensure that the cell gap between the array substrate and the color film substrate reaches a design value, and the height of the sub PS is lower than that of the main PS and used for maintaining the cell gap when the liquid crystal cell is subjected to a vertical pressure and the main PS is heavily compressed.
The brightness of the dark state (L0 gray scale) is an important indicator of a TFT-LCD product. If the brightness of the dark state is high, it affects the contrast of the product, and in severe cases the picture cannot be normally viewed. Thus, to reduce light leakage in the dark state is a major issue of design of the TFT-LCD product.
In addition to the layout design and circuit design of the TFT-LCD, a further important cause for light leakage in the dark state is additional optical retardation resulting from deformation of glass when the liquid crystal screen is subjected to an external force (which may be an interference caused by design mismatch or imprecise manufacture of the mechanism, forming a local external force; and may be an external force applied on the liquid crystal screen), which changes the polarization state of the incident light passing through the liquid crystal cell in a normal state, thereby causing light leakage. In particular, for a notebook computer and a TPC product, this undesirable phenomenon becomes more common and obvious since they often need to be locally applied with an external force in use (for example, during the opening and closing process of the notebook computer).
According to the theory of photoelasticity, even if glass is an isotropic material, an anisotropic phenomenon would also take place therein under the effect of external force, that is, the refractive indexes under different stress states are not the same. The refractive index of a photoelastic material at a certain point is directly related to the stress state of this point. For a liquid crystal display, the stress is mainly caused by the frictional force between the PS and the array substrate, the magnitude of which is directly proportional to the friction coefficients and the contact area of the PS and the array substrate. The increase in stress results in birefringence of glass and the resulting optical retardation is directly proportional to the magnitude of stress and the thickness of glass.
In the prior art, in order to reduce the light leakage caused by the additional optical retardation of glass, an effective improvement method is to reduce the thickness of glass. However, too thin glass cannot be used directly on the high-generation TFT-LCD production line. Using thinning technology would further cause problems including complex process, rising cost and pressure in environmental protection.
In addition, since the designed density of the main PSs is relatively low, when they are subjected to an external force, a great internal stress is generated at local points inside the glass, resulting in obvious light leakage. In contrast, since the designed density of the sub PSs is very high and present in almost every pixel, when an external force is applied, the substrate bears the force uniformly and disperses the stress, not causing light leakage and whitening. Experiments prove that the light leakage and whitening are mainly caused by an internal stress of glass resulting from the friction between the main PSs and the array substrate under the effect of external force. When a TFT-LCD product is subjected to an external force, the glass is deformed to generate an internal stress and thereby produce additional optical retardation, resulting in light leakage in the dark state. In severe cases, the whole screen is whitened so that the picture cannot be normally viewed.
In conclusion, in the prior art, the friction between the pillar-shaped spacer and the array substrate of the display panel is increased under the effect of internal stress, thereby the amount of additional optical retardation is increased, resulting in the phenomenon of light leakage in the display panel in the dark state. | {
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1. Field of the Invention
The invention relates to a flat weighbridge with a load platform supported via supporting devices by two one-armed or two two-armed levers arranged at least partly beneath the load platform.
2. Prior Art
The levers of such weighers are mostly unilaterally spread apart in a fork-like manner and are connected each at two places, via joints, with the casing. Likewise, the load platform is supported by each lever at two places in each case via flexible intermediate elements. Depending on construction requirements, both levers are one-armed or both are two-armed. A bridge construction of this type is well adapted to the generally rectangular form of load platform, but it presents the disadvantage that, due to the support of the load platform at four places, the position thereof is statically over-determined. Besides, the corner load adjustment must be carried out separately for all four corners, which requires at least three places of adjustment. | {
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The present invention relates to an apparatus and method for automatically wave soldering workpieces such as printed circuit boards.
A usual automatic wave soldering apparatus includes a pair of endless chain conveyors driven to advance a printed circuit board at a constant speed from the entrance to exit ends of the apparatus. With the printed circuit board held by gripping fingers, the board is first carried to a fluxer where a foam or spray of flux is applied to the underside of the board. The printed circuit board is then carried over preheaters where the temperature of each board is elevated to approximately 110xc2x0 C. to 130xc2x0 C. so as to evaporate excess flux solvent, activate the flux and minimize thermal shock to the printed circuit board. After the printed circuit board is brought to such a preheat temperature, the board passes over a solder reservoir to receive solder. The board is finally transported to a cool down zone where the solder is cooled to solidify.
Typically, two solder waves are established in the solder reservoir. One of the two solder waves is a turbulent wave, and the other is a non-turbulent wave. The turbulent wave allows the solder to reach component terminations and other hard to reach areas to be soldered, but bridges and icicles of solder remain on the underside of a printed circuit board and can cause a short circuit or damage to sensitive electrical components. Such bridges and icicles can be removed in the subsequent non-turbulent wave.
Various attempts have been made to promote turbulence. For example, Japanese patent publication No. 62-46270 discloses a plurality of vanes disposed in a solder nozzle and interconnected by a rod. The rod and thus, the vanes are rotated or reciprocated by means of a motor to cause molten solder to flow in a turbulence wave. Japanese patent publication No. 62-35857 discloses a cylindrical body disposed in the upper end of a solder nozzle. A multiplicity of openings are defined in the cylindrical body. While the cylindrical body is rotated by a motor, molten solder is forced through the openings to thereby promote turbulence in a solder wave. A disadvantage with these designs is that the rotational speed of the motor fluctuates due to heat degenerated in a solder reservoir in which the motor is disposed. The heat also reduces the service life of the motor. Another problem is that the vanes and other movable turbulent means tend to cause molten solder to spatter. Such spattering creates bridges, particularly between closely adjacent conductors.
Japanese laid-open patent publication NO. 58-178593 discloses two waves established in two respective solder nozzles without the use of vanes and other movable turbulent means. The solder waves are both smooth or laminar waves. It has been found that such laminar waves are unable to cause molten solder to fill through holes through which leads of electronic components extend.
Accordingly, it is an object of the present invention to provide an automatic wave soldering apparatus and method which promote turbulence in a solder wave without the use of a motor or similar means and which allow molten solder to fill through holes and reach component terminations and other hard to reach areas to be soldered, regardless of orientations of selected areas of electronic components to be soldered.
According to one aspect of the present invention, there is provided an apparatus for wave soldering a printed circuit board, which comprises a solder reservoir for holding a supply of molten solder, a solder nozzle disposed in the solder reservoir to establish a solder wave, and means for promoting turbulence in the solder wave and for increasing flow velocity of the molten solder. The turbulent means is disposed in the solder nozzle to thereby provide at least one upwardly inclined outlet through which the molten solder emerges at an angle relative to the direction of movement of the printed circuit board.
In a preferred embodiment, the turbulent means includes a trapezoidal element secured within the solder nozzle. The trapezoidal element has horizontal top and bottom sides. This bottom side acts as a step to cause molten solder to flow in a turbulent wave. The trapezoidal element is fixed in position and thus, will not cause molten solder to spatter. Also, this arrangement eliminates the need for a motor to create turbulence. The solder nozzle is composed of a pair of upstream and downstream vertical walls, and a pair of opposite side walls connected to the vertical walls. Preferably, the downstream vertical wall has an inclined upper end. The inclined upper end of the vertical wall and the trapezoidal element collectively reduce the sectional area of the solder nozzle to thereby increase the flow velocity of the molten solder.
In a preferred embodiment, the turbulent means includes a baffle disposed between the upstream and downstream vertical walls to form an upwardly inclined upstream outlet between the baffle and the upstream vertical wall and an upwardly inclined downstream outlet between the baffle and the downstream vertical wall, and a pair of valves disposed on opposite sides of the baffle and adapted to selectively open and close the upstream and downstream outlets. The upwardly inclined upstream outlet is inclined at an acute angle against the direction of movement of the printed circuit board, whereas the upwardly inclined downstream outlet is inclined at an acute angle in the direction of movement of the printed circuit board. This arrangement allows molten solder to reach all areas to be soldered, regardless of the orientations of electrical components on a printed circuit board.
According to another aspect of the present invention, there is provided a method of wave soldering a printed circuit board, which comprises selectively establishing at least either one of a turbulent wave which flows counter to the direction of movement of the printed circuit board, and a turbulent wave which flows in the direction of movement of the printed circuit board, establishing a substantially non-turbulent solder wave, and passing the printed circuit board along a predetermined path to allow the printed circuit board to successively engage at least a selected one of the turbulent waves and the non-turbulent wave. | {
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Hiding data in imagery or audio is a technique well known to artisans in the field, and is termed “steganography.” There are a number of diverse approaches to, and applications of, steganography. A brief survey follows:
British patent publication 2,196,167 to Thorn EMI discloses a system in which an audio recording is electronically mixed with a marking signal indicative of the owner of the recording, where the combination is perceptually identical to the original. U.S. Pat. Nos. 4,963,998 and 5,079,648 disclose variants of this system.
U.S. Pat. No. 5,319,735 to Bolt, Berenak & Newman rests on the same principles as the earlier Thorn EMI publication, but additionally addresses psycho-acoustic masking issues.
U.S. Pat. Nos. 4,425,642, 4,425,661, 5,404,377 and 5,473,631 to Moses disclose various systems for imperceptibly embedding data into audio signals—the latter two patents particularly focusing on neural network implementations and perceptual coding details.
U.S. Pat. No. 4,943,973 to AT&T discloses a system employing spread spectrum techniques for adding a low level noise signal to other data to convey auxiliary data therewith. The patent is particularly illustrated in the context of transmitting network control signals along with digitized voice signals.
U.S. Pat. No. 5,161,210 to U.S. Philips discloses a system in which additional low-level quantization levels are defined on an audio signal to convey, e.g., a copy inhibit code, therewith.
U.S. Pat. No. 4,972,471 to Gross discloses a system intended to assist in the automated monitoring of audio (e.g. radio) signals for copyrighted materials by reference to identification signals subliminally embedded therein.
U.S. Pat. No. 5,243,423 to DeJean discloses a video steganography system which encodes digital data (e.g. program syndication verification, copyright marking, media research, closed captioning, or like data) onto randomly selected video lines. DeJean relies on television sync pulses to trigger a stored pseudo random sequence which is XORed with the digital data and combined with the video.
European application EP 581,317 discloses a system for redundantly marking images with multi-bit identification codes. Each “1” (“0”) bit of the code is manifested as a slight increase (decrease) in pixel values around a plurality of spaced apart “signature points.” Decoding proceeds by computing a difference between a suspect image and the original, unencoded image, and checking for pixel perturbations around the signature points.
PCT application WO 95/14289 describes the present applicant's prior work in this field.
Komatsu et al., describe an image marking technique in their paper “A Proposal on Digital Watermark in Document Image Communication and Its Application to Realizing a Signature,” Electronics and Communications in Japan, Part 1, Vol. 73, No. 5, 1990, pp. 22-33. The work is somewhat difficult to follow but apparently results in a simple yes/no determination of whether the watermark is present in a suspect image (e.g. a 1 bit encoded message).
There is a large body of work regarding the embedding of digital information into video signals. Many perform the embedding in the non-visual portion of the signal such as in the vertical and horizontal blanking intervals, but others embed the information “in-band” (i.e. in the visible video signal itself). Examples include U.S. Pat. Nos. 4,528,588, 4,595,950, and 5,319,453; European application Ser. No. 441,702; and Matsui et. al, “Video-Steganography: How to Secretly Embed a Signature in a Picture,” IMA Intellectual Property Project Proceedings, January 1994, Vol. 1, Issue 1, pp. 187-205.
There are various consortium research efforts underway in Europe on copyright marking of video and multimedia. A survey of techniques is found in “Access Control and Copyright Protection for Images (ACCOPI), WorkPackage 8: Watermarking,” Jun. 30, 1995, 46 pages. A new project, termed TALISMAN, appears to extend certain of the ACCOPI work. Zhao and Koch, researchers active in these projects, provide a Web-based electronic media marking service known as Syscop.
Aura reviews many issues of steganography in his paper “Invisible Communication,” Helskinki University of Technology, Digital Systems Laboratory, Nov. 5, 1995.
Sandford II, et al. review the operation of their May, 1994, image steganography program (BMPEMBED) in “The Data Embedding Method,” SPIE Vol. 2615, Oct. 23, 1995, pp. 226-259.
A British company, Highwater FBI, Ltd., has introduced a software product which is said to imperceptibly embed identifying information into photographs and other graphical images. This technology is the subject of European patent applications 9400971.9 (filed Jan. 19, 1994), 9504221.2 (filed Mar. 2, 1995), and 9513790.7 (filed Jul. 3, 1995), the first of which has been laid open as PCT publication WO 95/20291.
Walter Bender at M.I.T. has done a variety of work in the field, as illustrate by his paper “Techniques for Data Hiding,” Massachusetts Institute of Technology, Media Laboratory, January 1995.
Dice, Inc. of Palo Alto has developed an audio marking technology marketed under the name Argent. While a U.S. Patent Application is understood to be pending, it has not yet been issued.
Tirkel et al, at Monash University, have published a variety of papers on “electronic watermarking” including, e.g., “Electronic Water Mark,” DICTA-93, Macquarie University, Sydney, Australia, December, 1993, pp. 666-673, and “A Digital Watermark,” IEEE International Conference on Image Processing, Nov. 13-16, 1994, pp. 86-90.
Cox et al, of the NEC Technical Research Institute, discuss various data embedding techniques in their published NEC technical report entitled “Secure Spread Spectrum Watermarking for Multimedia,” December, 1995.
Möller et al. discuss an experimental system for imperceptibly embedding auxiliary data on an ISDN circuit in “Rechnergestutzte Steganographie: Wie sie Funktioniert und warum folglich jede Reglementierung von Verschlusselung unsinnig ist,” DuD, Datenschutz und Datensicherung, 18/6 (1994) 318-326. The system randomly picks ISDN signal samples to modify, and suspends the auxiliary data transmission for signal samples which fall below a threshold.
There are a variety of shareware programs available on the internet (e.g. “Stego” and “White Noise Storm”) which generally operate by swapping bits from a to-be-concealed message stream into the least significant bits of an image or audio signal. White Noise Storm effects a randomization of the data to enhance its concealment. | {
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The present invention relates to a process for producing doped III-N bulk crystals from a gas/vapor phase, as well as to a process for producing free-standing doped III-N substrates which are obtained from the doped III-N bulk crystals. Here, the term N denotes nitrogen and III denotes at least one element of group III of the periodic system, selected from aluminum, gallium and indium (in the following sometimes abbreviated by (Al,Ga,In)). The invention further relates to doped III-N bulk crystals and free-standing doped III-N substrates obtained by such process. These free-standing doped III-N substrates are well-suited for the manufacture of optic and optoelectronic devices.
Conventionally in the commercial use, devices for (Al,Ga,In) N-based light emitting or laser diodes essentially had been grown on foreign substrates such as Al2O3 (sapphire) or SiC.
The disadvantages caused by the use of the foreign substrates with respect to crystal quality and correspondingly lifetime and efficiency of the devices may be coped with only by growing on free-standing III-N-, such as e.g. (Al,Ga)N-substrates. The latter, however, are hardly available in sufficient quality up to now. The reason for this essentially resides in difficulties of conventional bulk growing technologies owing to the extremely high steady-state vapor pressure of nitrogen above III-N compounds at typical growth temperatures.
The growth of bulk material under high pressure had been described by Porowski (MRS Internet J. Nitride Semicond. Res 4S1, 1999, G1.3). This process leads to a qualitatively valuable GaN bulk material, but has the disadvantage that, up to now, only small GaN substrates having an area of maximally 100 mm can be produced. In addition, the manufacturing process, in comparison with other processes, requires a lot of time and, due to the extremely high growth pressures, is technologically laborious.
Another method resides in the growth of III-N material on a foreign substrate from the gaseous/vapor phase with a subsequent separation from the foreign substrate.
For producing thick, free-standing layers of III-N, such as GaN, it is e.g. known from the publication “Large Free-Standing GaN Substrates by Hydride Vapor Phase Epitaxy and Laser-Induced Liftoff” by Michael Kelly et al. (Jpn. J. Appl. Phys. Vol. 38, 1999, pp. L217-L219) to separate, from a sapphire substrate, a thick GaN layer previously grown on the sapphire (Al2O3) substrate by means of hydride vapor phase epitaxy (HVPE). In this connection, it is described to irradiate the GaN-coated sapphire substrate by means of a laser, whereby the GaN layer is thermally decomposed locally at the interface to the sapphire substrate and thereby released from the sapphire substrate. Alternative releasing methods consist of wet chemical etching (for example of GaAs; K. Motoki et al., Jap. J. Appl. Phys. Vol. 40, 2001, pp. L140-L143, dry-chemical etching (for example of SiC; Yu. Melnik et al., Mat. Res. Soc. Symp. Proc. Vol. 482, 1998, pp. 269-274), or mechanical lapping (for example of sapphire; H.-M. Kim et al., Mat. Res. Soc. Symp. Proc. Vol. 639, 2001, pp. G6.51.1-G6.51.6) of the substrate.
The disadvantage of the described methods resides, on the one hand, in the relatively high costs owing to laborious technologies for the substrate release, and on the other hand in the basic difficulty to produce III-N material having a homogeneously low defect density.
The growth of thick III-N bulk crystals (boules) on III-N substrate by means of vapor phase epitaxy with subsequent individualization of the bulk crystal by a sawing process offers an alternative to the aforementioned processes.
Such a process has been described by Vaudo et al. (U.S. Pat. No. 6,596,079). As a preferred growing method the HVPE was chosen; as preferred boule crystal length, values of >1 mm, 4 mm or 10 mm had been mentioned. Vaudo et al. further described, inter alia, how to obtain III-N substrates from the bulk crystal by means of wire sawing or other treatment steps, for example chemical-mechanical polishing, reactive ion beam etching or photo-electrochemical etching. In an international patent application of Vaudo et al. (WO 01/68955 A1), III-N bulk crystals and substrates produced by means of the described technology are further mentioned.
Melnik et al. describe a process for growing GaN- (U.S. Pat. No. 6,616,757) or AlGaN-bulk crystals (US 2005 0212001 A1) having crystal lengths greater than 1 cm. There, the process consists of the basic steps: growth of a single-crystalline (Al)GaN layer on a substrate, removal of the substrate, and growth of the (Al)GaN bulk crystal on the single-crystalline (Al)GaN layer. As the preferred method, a HVPE process with a specific reactor structure is mentioned. In addition, Melnik et al. describe, in a US application (US 2005 0164044 A1) or in U.S. Pat. No. 6,936,357, GaN or AlGaN bulk crystals having various properties, such as, for example, sizes, dislocation densities or full widths at half maximum (half widths) of X-ray diffraction curves.
Besides the crystallinity, the electrical properties of semiconductor crystals must also be adapted to the needs of the respective uses. The properties of semiconductor crystals, in particular the electrical properties, can be controlled by the incorporation of foreign atoms, so-called dopants. By the concentration of dopants in a crystal, the concentration of charge carriers and thus the specific electric resistivity can be controlled. For opto-electronic devices, conducting substrates are used in order to allow a contact of the devices through the back-side of the substrate. In the case of GaN or AlGaN substrates, typically an n-doping is chosen, i.e., the incorporation of foreign atoms which generate mobile electrons. For example, a usual dopant for (Al)GaN is silicon. A p-doping is also possible, i.e., the incorporation of foreign atoms which generate holes, i.e., defect electrons. For example, a usual dopant for (Al)GaN is magnesium. Another possibility is represented by the incorporation of foreign atoms which act as low-energy defect sites and thus bond mobile charge carriers and thereby reduce the conductivity of the crystal. For (Al)GaN, this is, for example, possible by iron.
In vapor phase epitaxy, the dopants are typically provided in the form of gaseous compounds. For example, silane, SiH4, can be used for silicon, bis(cyclopentadienyl)magnesium, Mg(C5H5)2, for magnesium, and bis(cyclopentadienyl)iron, Fe(C5H5)2, for iron.
For example, Manabe et al. (U.S. Pat. No. 6,472,690) describe the n-doping of GaN by feeding a silicon-containing gas. Usikov et al. (Mat. Res. Soc. Proc. Vol. 743, L3.41.1) describe the n-doping by feeding silane with the HVPE. There is no mention about the homogeneity.
Vaudo et al. (US publication 2005/0009310 A1) describe semi-insulating GaN crystals having a doping with low acceptors. In the description, metal-organic compounds are mentioned as dopants.
For HVPE growth, chlorine-containing compounds such as dichlorosilane, SiCl2H2, may also be used. Usui et al. (JP 3279528 B) describe doping with SiHxCl(4-x).
The generation of the chloride compound of the dopants in the HVPE process may be carried out, analogous to the generation of GaCl, in situ by the reaction of the elemental dopant with HCl. Thus, the gaseous doping substances may be generated in the reactor via additional gas pipelines in connection with corresponding additional crucibles with the respective elemental starting materials. This process is, for example, described by Fomin et al. (phys. stat. sol. (a) Vol. 188, pp. 433). Hong et al. (U.S. Pat. No. 6,177,292) mention this procedure, in order to produce an n-doped GaN layer on a polished GaN substrate. Nikolaev et al. (U.S. Pat. No. 6,555,452; corresponding to US 2002/28565 A) describe the p-doping by the inclusion of a metallic dopant such as Mg or Zn into an additional source region separated from the III-starting material. This process requires a complex enlargement of gas feedings and sources within the reactor. | {
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The present invention is related to resolvers, and in particular to resolvers employing multiplexed signal sampling.
Resolvers are used in a variety of applications to provide position feedback. For example, resolvers are oftentimes associated with actuators to provide feedback regarding the state of the actuator (e.g., open, partially open, closed). A typical resolver includes an excitation coil and first and second secondary coils positioned 90° out of phase with one another. An excitation signal supplied to the excitation coil generates corresponding output signals in the first and second secondary coils. By comparing the phase of the excitation signal to the phase of the output signals, the orientation or position of the excitation coil can be determined.
Typically, a resolver monitors the excitation signal and the corresponding output signals simultaneously to determine position. However, in some applications, a multiplexer is used to sample the respective signals successively as opposed to simultaneously. For these applications, the resolver position is only determinable within a 90° range. If the resolver position rotates more than 90°, the position cannot be determined without knowledge of the quadrant in which the position is located. For example, a first quadrant may represent angles from 0-90°, the second quadrant represents angles from 90-180°, the third quadrant represents angles from 180-270°, and the third quadrant represents angles from 270-360°. In these applications, the magnitude alone is insufficient to determine position. | {
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The present invention relates to an imaging device, a method of controlling an imaging device, and the like.
An imaging device (camera) may be provided with a blur correction function (image stabilization function) in order to prevent a deterioration in captured image due to shake (motion) of the imaging device (camera) during the imaging (capture) operation. The blur correction technique may be roughly classified into the following three techniques.
The first technique is an optical blur correction technique that detects the motion (vibrations) of the imaging device using a motion sensor (e.g., angular velocity sensor or acceleration sensor), and corrects blurring by driving an optical system (e.g., lens or variable apex angle prism) corresponding to the detected motion amount (see JP-A-61-240780 and JP-A-61-223819, for example).
The second technique provides only a shake detection motion sensor in the imaging device to record shake information, and corrects blurring by performing a blur correction process during viewing using the shake information (see JP-A-6-276512, JP-A-6-343159, and JP-A-7-226905, for example).
The third technique acquires (calculates) blur information from the captured image, and performs a blur correction process using the blur information when reading the image. For example, the non-blurred image is restored from the deteriorated image by digital processing (e.g., inverse filter, Wiener filter, or Richardson-Lucy method).
A technique that improves the frequency characteristics of the point spread function during the imaging operation, and then performs a blur correction process has also been known. For example, JP-T-2009-532928 and JP-T-2009-522825 improve the frequency characteristics of the point spread function during the imaging operation by quickly and repetitively opening and closing (hereinafter referred to as “fluttering”) the shutter at a given timing to implement a more accurate blur correction process. JP-A-61-240780 improves the frequency characteristics of the point spread function during the imaging operation by utilizing a coded aperture as the aperture of the imaging device to implement a more accurate blur correction process. | {
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Atrial fibrillation (“AF”) is a cardiac arrhythmia wherein the atria beat chaotically, thereby providing generally poor conduction of blood into the ventricles of the heart and hence reducing the flow of blood throughout the body. AF has been shown to lead to long-term health problems such as increased risk of thrombolytic stroke. AF can also cause reduced cardiac efficiency, irregular ventricular rhythm and unpleasant symptoms such as palpitations and shortness of breath. In some cases, AF can trigger ventricular fibrillation (VF) wherein the ventricles of the heart beat chaotically thereby providing little or no blood flow to the brain and other organs. VF, if not terminated, is usually fatal.
Hence, it is highly desirable to terminate AF should it arise and revert the atria to a normal rhythm. The current, most common therapy for atrial fibrillation is the administration of anti-arrhythmic drugs that control atrial and ventricular rates during AF. However, these drugs can actually be proarrhythmic, causing the arrhythmia to worsen. At best, anti-arrhythmic drugs appear to provide short-term therapy. Another technique for terminating AF is to administer an electrical cardioversion shock to the atria of the heart. The cardioversion shock, if successful, terminates the chaotic pulsing of the atria and causes the atria to resume a normal beating pattern. Patients prone to AF may have an ICD implanted therein capable of detecting AF and automatically administering one or more cardioversion shocks to terminate AF. Typically, about two joules of energy is administered within each cardioversion shock at an initial voltage of between 100 to 500 volts (V). The duration of the pulse is usually between 5-15 milliseconds (ms) and is a descending voltage capacitive discharge waveform. State of the art ICDs are also capable of detecting a wide variety of other heart arrhythmias, such as VF, and for administering appropriate therapy as well. For VF, the ICD administers a much stronger cardioversion shock (referred to as a defibrillation shock) directly to the ventricles of the heart. The defibrillation shock typically has at least ten to twelve joules of electrical energy. Note that, herein, “cardioversion” generally refers to the delivery of any electrical shock intended to synchronize action potentials of myocardial cells within the heart to terminate arrhythmias. Defibrillation, herein, refers to a type of cardioversion specifically intended to terminate fibrillation.
Although atrial cardioversion shocks have been found to be effective for terminating AF within many patients, the shocks can be quite painful. One reason is that the patient is typically conscious and alert at the time the shock is administered. In contrast, the much stronger ventricular defibrillation shocks for terminating VF are typically not administered until the patient has lost consciousness and hence the patient may feel only residual chest pain upon being revived. Because AF is not usually immediately life-threatening, painful cardioversion shocks for its treatment are often perceived by patients as being worse than the condition itself and therefore not tolerated. Indeed, anxiety arising from the fear of receiving a painful cardioversion shock may be sufficient to raise the heart rate sufficiently to trigger the shock. As some patients have hundreds of AF episodes per year, techniques for reducing the pain associated with cardioversion shocks are highly desirable. It is also desirable to reduce pain associated with ventricular defibrillation shocks. Although patients receiving ventricular defibrillation shocks are usually unconscious when the shock is delivered, in some cases, such shocks are erroneously delivered while the patient is conscious due to false-positive VF detection, resulting in considerable patient pain.
One method for reducing pain arising from cardioversion shocks involves altering the stimulation waveform of the shock to, for example, reduce or smooth initial voltage peaks. See, for example, U.S. Pat. No. 5,830,236, to Mouchawar et al., entitled “System for Delivering Low Pain Therapeutic Electrical Waveforms to the Heart” and U.S. Pat. No. 5,906,633, also to Mouchawar et al., entitled “System for Delivering Rounded Low Pain Therapeutic Electrical Waveforms to the Heart.” Shock smoothing is illustrated by way of FIGS. 1 and 2. FIG. 1 illustrates a conventional cardioversion shock waveform 1 (shown in V) along with a resulting cardiac membrane response 2. Herein, the cardiac membrane response is shown in arbitrary response units for the purposes of comparison. The shock waveform is biphasic, with a peak voltage of the initial (positive) phase at about 100 V and with a peak voltage of the second (negative) phase at about 33 V. The peak of the resulting cardiac membrane response occurs at about 4 ms and is at about 50 response units. Peak voltage of the initial phase is typically regarded as the primary determinant of shock pain; whereas the peak cardiac membrane response is typically regarded as the primary indicator of shock effectiveness. Hence, with the conventional shock waveform of FIG. 1, the effectiveness of the shock is only about 50 cardiac response units; the resulting pain is associated with 100 V.
FIG. 2, in contrast, illustrates a smoothed cardioversion waveform 3 along with a resulting cardiac membrane response 4, shown in the same arbitrary response units of FIG. 1 for comparison purposes. The shock waveform of FIG. 2 is smoothed so as to reduce the peak voltage of the initial phase to about 70 V. The peak voltage of the second (negative) phase remains at about 33 V. The peak of the resulting cardiac membrane response is still about 45 response units. Hence, with the smoothed shock waveform of FIG. 2, the cardioversion shock is almost as effective as with the non-smoothed waveform of FIG. 1; whereas the resulting pain is significantly lower, i.e. the resulting pain is associated with a peak voltage of only about 70 V rather than with a peak voltage of 100 V.
One way to generate the smoothed waveform of FIG. 2 is to start with a higher initial capacitor voltage (about 160 V) than the non-smoothed waveform of FIG. 1 and then use resistive loss to lower the voltage as needed. The capacitor voltage is shown by way of phantom line 5, which decreases exponentially. The capacitor voltage at each point in time must be at least as great as the output pulse being generated at that same point in time. During times when the capacitor voltage is greater than the corresponding output shock voltage, the additional energy is dissipated as heat. Thus, pain reduction is achieved at the expense of consuming somewhat greater energy per shock.
Note that the shock waveforms of FIGS. 1 and 2 both provide a fairly substantial peak voltage for the second (negative) phase as compared to that of the initial phase. For the non-smoothed waveform of FIG. 1, the peak voltage of the second phase is at least about one third that of the initial phase. For the smoothed waveform of FIG. 2, the peak voltage of the second phase is at least about four tenths that of the initial phase. Conventionally, it is believed that the second phase must have a fairly large peak voltage is comparison with that of the initial phase to achieve a suitable defibrillation threshold. In addition, conventionally, it is believed that long duration shock phases are disadvantageous. For example, in the case of FIG. 1, the peak cardiac membrane response is achieved at about 4 ms, although the voltage remains relatively high until the 6 ms point, at which it is finally truncated. Truncation of the first phase of a conventional shock waveform is performed, in large part, to reduce the amount of shock energy delivered after the peak membrane response. In this regard, the smoothed waveform of FIG. 2 has the advantage of achieving peak membrane response just at the end of the initial phase with the voltage of the initial (positive) phase then decreasing promptly before commencement of the second (negative) phase.
Note also that the graphs of FIGS. 1 and 2, and all other graphs provided herein, include stylized representations of the parameters being illustrated. This is done so as to more clearly illustrate pertinent features of those parameters. The graphs should not be construed as illustrating actual clinically-detected parameters.
Thus, smoothed waveforms of the type shown in FIG. 2 can be effective in reducing the resulting pain. It would be desirable, however, to achieve an even greater amount of pain reduction without reducing shock effectiveness. It is to that end that certain aspects of the invention are directed. Moreover, it would also be desirable to provide a relatively simple circuit capable of generating improved shock waveforms and other aspects of the invention are directed to that end.
Another method for reducing pain arising from cardioversion shocks is to deliver a pre-pulse pain inhibition (PPI) pulse prior to the main shock. See, for example, U.S. Pat. No. 6,091,989 to Swerdlow et al., entitled “Method and Apparatus for Reduction of Pain from Electric Shock Therapies.” With PPI techniques, a relatively weak stimulus (the PPI pulse) is applied to the patient shortly before a main cardioversion shock. The human pain perception system responds to the weak stimulus in such manner that the pain associated with the subsequent main cardioversion shock is reduced or otherwise inhibited. PPI techniques typically employ either a single relatively long, low-voltage PPI pulse or a single relatively short, high-voltage PPI pulse. The long, low-voltage PPI pulse is usually delivered at about 12-20 V. The shorter, high-voltage PPI pulse is usually delivered at the voltage of the subsequent main cardioversion shock. Each has its respective advantages and disadvantages.
Conventional low-voltage and high-voltage PPI pulses are illustrated by way of the timing diagrams of FIG. 3, which show a low-voltage PPI pulse 6 followed by a high-voltage main cardioversion shock 7 and which also show a much shorter high-voltage PPI pulse 8 followed also by a main shock 9. All waveforms of FIG. 3 are monophasic, though biphasic waveforms may instead be employed. None of the waveforms has been smoothed. The exemplary low-voltage PPI pulse and its subsequent main shock are of substantially equal duration (typically about 1-10 ms) but the PPI pulse has an initial peak voltage of only about 20 V whereas the main shock has an initial peak voltage of about 100 V. The exemplary high-voltage PPI pulse is much shorter than its subsequent main shock (e.g., as short as 0.1 ms as opposed to 1-10 ms) but is of equal voltage (again about 100 V). In each case, the PPI pulse is provided to reduce the pain perceived by the patient during the subsequent main cardioversion shock. The time scale of FIG. 3 is arbitrary but, typically, PPI pulses are delivered 30-500 ms prior to the main cardioversion shock.
A significant advantage of generating a short, high-voltage PPI pulse at the same voltage as the main shock is that only a single shocking capacitor is required, precharged to the main shock voltage. To instead deliver a PPI pulse at a low-voltage followed by a main shock at a much higher voltage, two shocking capacitors are usually required—one precharged to the low-voltage and the other precharged to the high-voltage. However, high-voltage PPI pulses can be painful in and of themselves thus reducing their effectiveness in overall pain reduction. Hence, low-voltage PPI pulses are typically preferred despite the need for an extra shocking capacitor. In this regard, note that capacitors used for generating conventional pacing pulses ordinarily cannot be employed to also generate low-voltage PPI pulses, which typically require a somewhat higher voltage than the pacing pulses.
One technique for delivering high-voltage PPI pulses that are not painful in and of themselves is to utilize extremely short duration “sliver” pulses, which are typically only about 25-50 microseconds (□s) in duration. The sliver pulses are nevertheless sufficient to provide pain inhibition. Preferably, the high-voltage PPI sliver pulses are delivered between electrodes implanted within the heart, such as between a right ventricular (RV) coil and a superior vena cava (SVC) coil, so that high-voltage can be used without risk of significant pain arising from the PPI pulse itself. In particular, pain is reduced by generating the PPI pulse away from the device can or housing. Pulses instead generated using the device can as a return electrode may stimulate sensitive skin nerves and sensitive alpha motor neurons in the pectorals. The subsequent main cardioversion shock is preferably delivered using widely spaced electrodes, such as between the SVC coil and the housing of the implanted device, to ensure maximum likelihood of success. Sliver pulses are discussed in U.S. patent application Ser. No. 10/428,222 of Kroll et al., entitled “System and Method for Generating Pain Inhibition Pulses Using an Implantable Cardiac Stimulation Device”, filed Apr. 30, 2003, which is incorporated by reference herein.
Still further improvements were set forth in U.S. patent application Ser. Nos. 10/855,654 and 11/005,976, cited above. These improvements, which are also described herein-below, pertain to the use of relatively low-voltage PPI pulses with chevron-shaped waveforms and relatively high-voltage main shocks having plateau-shaped waveforms. By employing plateau-shaped waveforms for the main shocks, a greater cardiac membrane response can be achieved at an equivalent peak voltage as compared to conventional shock waveforms. As peak voltage is a significant contributor to pain caused by cardioversion shocks, the use of a plateau-shaped waveform helps achieve pain reduction without significant loss of shock effectiveness. Moreover, by employing chevron-shaped PPI pulses in combination with plateau-shaped main shocks, a relatively simple shocking circuit having a single high-voltage shocking capacitor may be used, thus eliminating the need for both low-voltage PPI capacitors and higher voltage main shock capacitors.
Although the aforementioned techniques are effective, there are still further opportunities for pain reduction. The plateau-based techniques summarized above primarily operate to reduce pain by reducing the peak voltage of the shock. For relatively short duration waveforms, this is typically sufficient. However, for longer duration waveforms—particularly waveforms having a first phase longer than 10 ms—it appears that pain receptors refire. That is, pain receptors initially triggered at the beginning of the first phase of the shock appear to refire before the first phase is complete. This results in somewhat greater perceived pain than would otherwise be expected when using a plateau-shaped waveform. The present invention is primarily directed to techniques for addressing this issue to achieve a still further reduction in pain. | {
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1. Field of the Invention
The present invention is directed to channel access methods that provide Quality of Service (“QoS”) for shared communications, more specifically to channel access methods that provide Quality of Service on IEEE 802.11 wireless networks.
2. Description of the Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
The abbreviations and acronyms used in this application are well known to those skilled in the art and can be readily located in the IEEE 802.11 standard, or in the IEEE 802.11E QoS baseline proposal. See Michael Fischer, QoS Baseline Proposal, IEEE 802.11 Standards Committee, Document IEEE 802.11-00/360 (Nov. 7, 2000); also QoS Baseline Proposal Revision 1, Document IEEE 802.11-00/360R1 (Nov. 7, 2000) and QoS Baseline Proposal Revision 2, Document IEEE 802.11-00/360R2 (Nov. 9, 2000), the contents of which are hereby incorporated by reference. Some of the abbreviations and acronyms used in this application are:
ACKAcknowledgement;APAccess Point;BSSBasic Service Set;BSSIDBasic Service Set Identification;CCAClear Channel Assessment;CFPContention-Free Period;CF-PollableContention-free PollableCPContention Period;CWContention Window;DCFDistributed Coordination Function;DIFSDistributed (coordination function) Interframe Space;CWContention Window;DTIMDelivery Traffic Indication Message;EAPEnhanced Access Point;IFSInterframe Space;MACMedium Access ControlNAVNetwork Allocation Vector;PCFPoint Coordination Function;P-CFBPoint-controlled Contention-free Bursts;PIFSPoint (coordination function) Interframe Space;QoSQuality of Service;SBMSubnet Bandwidth Manager;SIFSShort Interframe Space;STAStation;V-DCFVirtual Distributed Coordination Function;WSTAWireless (enhanced) Station.
In the description that follows, an “outbound” transmission is a transmission from an AP and an “inbound” transmission is directed to an AP. FIG. 2 illustrates the relationship between a SIFS, PIFS and DIFS as used herein and as defined in the 802.11 specification. As can be observed from FIG. 2, a SIFS is always a shorter interval than a PIFS, and a PIFS is always a shorter interval than a DIFS.
The IEEE 802.11E QoS working group has adopted a baseline proposal (hereinafter “baseline proposal”) for channel access methods that provide QoS on 802.11 wireless LANs. The baseline proposal defines three QoS levels—a “prioritised” DCF-based solution and “prioritised” and “parameterised” PCF-based solutions. It is generally agreed that a single unified approach is better from a user perspective; however, no single approach, as it is currently defined, is applicable to all environments. A PCF approach is more deterministic and efficient in single-BSS environments; however, it is difficult to implement a CFP scheduling algorithm in environments with BSS overlap. The present invention is directed to an integrated DCF/PCF channel access model that uses V-DCF for lightly and moderately loaded channels, and dynamically uses unscheduled “Point-controlled Contention-free Bursts”, to arbitrate channel contention, as the network load increases.
The baseline “prioritised” solutions are intended for stations that simply send and receive prioritised frames. The baseline “parameterised” solution is intended for WSTAs that use a signaling protocol to establish bandwidth requirements and delay constraints. This invention, the Point-controlled Contention Arbitration model, or PCCA model, requires all WSTAs to implement sufficient channel access and interface functions to support optional parameterised services. QoS features can be added to an AP implementation on an incremental basis.
The baseline proposal discloses a virtual DCF protocol (“V-DCF). By design, the V-DCF, or level 1 in the baseline proposal, cannot provide integrated services such as “Controlled Load” and “Guaranteed Bandwidth”. Two fundamental requirements are lacking for controlled load service. 1) The total traffic at a given QoS priority must be limited (i.e. by admission control), and 2) higher priority traffic cannot be affected by lower priority traffic. The V-DCF level cannot support admission control because it lacks even a simple signaling protocol. The V-DCF access method, with contention offset and CWmin values per category, only statistically increases the probability of channel access for higher-priority packets. A tiered channel access method can be used to isolate a high-priority traffic category but only if the idle sense time, required for any lower-priority traffic category, is greater than the sum of the idle sense time plus the maximum CW value for the high-priority category. However, the tiered method doesn't scale well for large high-priority populations. “Guaranteed Bandwidth” service has the same requirements as controlled load and also requires a deterministic channel access method.
Presently, 802.11 networks use two protocols, the DCF and PCF. The DCF works great under low load situations. The PCF works optimal under high load conditions. The DCF works better in networks where BSSs overlap, the PCF is ideally suited for networks where BSSs are carefully planned not to overlap. The DCF has a relatively low implementation complexity, the PCF is reputed to be more complex to implement. The DCF does not allow explicit access control, the PCF does. The DCF efficiency drops considerably in densely populated BSSs, the PCF has no scaling problem.
Due to the inability of the PCF to work well under overlapping BSS conditions and the high implementation complexity, the PCF has not yet been widely adopted in current 802.11 implementations. The demand for better medium efficiency and a versatile QoS platform, however, increased interest in this optional access mechanism of the 802.11 MAC.
The hybrid nature of the 802.11 MAC has caused proposals to focus either on the DCF or the PCF. However, by only looking at the PCF and not considering the DCF overlooks the fact that the 802.11 MAC always spends some time under the DCF access mechanism rules and that the DCF is also an integral part of a PCF based system. The system always has to spend at least a small part of its time under the DCF. The PCF has the fundamental characteristic that a station can't access the medium unless explicitly polled. However, to be polled, the station must first make itself known to the Point Coordinator, which requires medium access. Therefore, a PCF based solution must support both contention-free and contention periods. A contention period is required for bursty traffic, adjacent BSSes, probe requests, association and re-association requests, etc.
FIG. 1 shows an example of a sample rate for a real-time application in a WSTA and the associated polling sequences for that WSTA. The lower portion 12 of FIG. 1 shows the WSTA sample rate. The upper graph 14 shows the polling sequences. The polling sequence starts with a DTIM beacon 16. The contention-free period 18 starts immediately after the DTIM beacon 16. During the contention-free period 18, the point controller initiates polling sequences 20. After the polling sequences 20 is shown an idle time period 22. The idle time period 22 is then followed by an additional polling sequences 20 and idle time periods 22. Following the contention-free period 18 is the contention period 24. After the contention period 24, another DTIM beacon 16 starts a new sequence of a contention-free period 18 and a contention period 24.
In FIG. 1, the DTIM beacon rate is slower than the sampling rate. Idle time 22 is introduced if the CFP is extended so that the same WSTA can be polled more than once per CFP. Latency is introduced if the channel is overloaded in the contention period.
Delay sensitive applications, such as VoIP, require short DTIM intervals (i.e. 30 milliseconds) to minimize CF polling latency. A fast DTIM beacon rate wastes bandwidth because of the beaconing overhead and because contention-based transmissions cannot span the TBTT (per the baseline proposal). A fast DTIM beacon rate also requires power-save WSTAs to wake up more often, for example to receive multicast frames and buffered unicast frames.
In installations with multiple QoS applications with different service rates, the DTIM beacon rate cannot match the sampling rate for each application. Actually, it is difficult to match the sampling rate for any application. It is not efficient to arbitrarily poll WSTAs in every CFP. Therefore, some sort of signaling protocol is necessary to suppress unnecessary polls. In addition, a need exists for a protocol that can divorce the service rate, for active parameterised stations from the beacon rate. Periodic polling is not optimal for intermittent traffic. VoIP traffic can be intermittent due to silence suppression.
Depending on the ‘load of the medium’, the system may spend more or less time in the CFP. In a heavily loaded system, the system may spend the larger part in the CFP while a mildly loaded system may spend the larger part in the CP. The balance between the two access mechanisms is a function of the medium load. As a consequence, both access mechanisms must provide the same QoS capabilities. The transition between one access mechanism and the other must be a smooth one. This is especially a challenge in average loaded systems where the DCF efficiency is starting to breakdown while the PCF efficiency is not yet optimal. For the upper layer protocol (or application) the performance profile of the service should be linear over all medium conditions and this is something that should be considered when proposing a PCF based system. Therefore, when proposing PCF enhancements, one also to consider the interaction between the PCF and the DCF and the dynamics of the system as a whole under various medium load conditions.
PCF combines the ability of full medium control with optimal medium efficiency, without suffering from scalability problems. However, there are two issues that limit the use of the current PCF for QoS systems. Section 9.3.4 and specifically clause 9.3.4.1 of the IEEE 802.11 standard imposes strict rules upon the order in which stations are addressed or polled. This is undesirable in a QoS system. Secondly, there is no mechanism, other than the More-Data bit, that allows a station to communicate its queue states to the PC.
The entity in the PC that actually calculates the order in which stations are addressed is in literature often referred to as the ‘scheduler’. The rules for the handling of the polling list limit the freedom of the scheduler and may conflict with QoS requirements. The original intent to poll stations in order of ascending AID value is not clear from the standard and in fact the whole concept of a polling list may become obsolete due to the introduction of a mechanism for communicating To-DS queue state(s). Therefore, the rules as defined in section 9.3.4 are neglected for this method.
In order to make accurate scheduling decisions, the scheduler in the PC needs to have knowledge about the queues in the associated stations. The More-Data bit is a Boolean that could be used for this but only allows communication of a truth-value on the queue state; for a good scheduler implementation this is not enough. Preferably, the scheduler needs to know the length and priority of the next frame in the queue of each station.
Scheduling problems arise with CFPs in networks with overlapping BSSes in the same ESS or multiple ESSes. A CFP is not completely contention-free unless all stations in any neighboring BSS, that are in range of any active stations in the BSS, set their NAV for CFPMaxDuration for the CFP. Therefore, the total “reservation area” for a CFP can be very large compared to the coverage area of the point controller for the BSS.
The baseline proposal defines a “proxy beacon” mechanism where WSTAs in a BSS repeat AP beacons to extend the area for propagating beacon information to hidden nodes. The baseline proposal does not define which WSTAs should send proxy beacons and it does not define the scheduling mechanism for proxy beacons. Also, it is not clear whether a hidden node in a neighboring BSS, that receives proxy CFP beacons, should set its NAV for CFPMaxDuration for the TBTT of the associated hidden CFP. If hidden nodes do not set their NAV for proxy beacons, then CFPs are not contention-free.
If hidden nodes set their NAV for CFPMaxDuration for a hidden CFP (due to proxy beacons or some other mechanism) then two difficult problems must be considered. First, as noted above, spatial reuse is severely inhibited as compared to DCF. The baseline proposal attempts to solve the “spatial reuse” problem by classifying WSTAs as belonging to overlap and non-overlap sets per BSS. However, that approach does not work for all applications because it assumes that a WSTA is relatively stable compared to its transmission rate and it uses the flow error rate as an overlap indicator. Second, if a hidden CFP ends early, then bandwidth is wasted because hidden nodes may not be able to determine that the hidden CFP has ended. It has been suggested that WSTAs that transmit proxy beacons could also transmit “proxy CF-End” messages or CF-End messages could be transmitted on the distribution system. The first solution is “chatty” and the second solution is not generally applicable because the distribution system may introduce latency (i.e. if it includes wireless links or IP tunnel links).
It should also be noted that in the PCF/CFP model, where the NAV is set for long CFPs, use of sophisticated techniques that increase spatial reuse by varying the transmit power and/or antenna direction per unicast transmission sequence is inhibited.
One suggested PCF enhancement that can ease the overlapping BSS problem and alleviate the scheduling problem is the Contention Free Burst. A paper entitled “Suggested 802.11 PCF Enhancements and Contention Free Bursts”, IEEE 802.11-00/113 (May 10, 2000), written by Maarten Hoeben and Menzo Wentink, hereby incorporated by reference, describes bi-directional contention-free bursts that include point controller polling.
The Contention Free Bursts concept breaks up a Contention Free Period into smaller Contention Free Bursts. This is useful for two reasons: First, it allows the PC to relinquish medium control to other BSSs in the same area. Second, in the case of average loaded systems, the PC can temporarily give-up medium control (to possibly another BSS) and defer control until new frames are available for transmission.
Normally, a CFP starts with the transmission of a Beacon. A SIFS after the Beacon, the first CFB is started. Within the CFB, the PCF transfer procedures apply as defined in section 9.3.3 of the IEEE 802.11 standard. CFBs have a maximum duration of CFBMaxDuration. The duration remaining in the CFB is encoded in the Duration/ID field of every From-DS frame sent by the PC. The CFB may be foreshortened but never lasts longer than CFBMaxDuration. The end of a CFB is signaled through a duration of 0.
Between two CFBs the PC performs a random backoff, selected from a range of 0 to CW-1 slots. The random backoff mechanism allows PCs to contend for the medium to start a new CFB. In the current definition of the CFP, all stations (including other access points) set their NAV based on the Duration Remaining field in the CF-Parameter set and reset the NAV upon receiving a CF-End. This prevents access points and stations from accessing the medium during observed medium idleness during the CFP (possibly caused by the transmission of a frame by a hidden node). PCs may use the backoff mechanism to contend for the medium and start a CFP or continue their own CFP with a new CFB. In a sense the CFB concept works like a superimposed DCF over the PCF. PCs coordinate their bursts by using the backoff-mechanism, deferring and restarting the backoffs whenever a PC starts a CFB or ends the CFB. The CFBs are protected through the NAV-alike duration field in the redefined in Duration/ID field, CPs use the information as received in the ToDS frames from other CPs to update their CF-Nav and defer backoff and start of a new CFB.
Note that only PCs contend for medium control; stations (and legacy access points) do not attempt to access the medium during the periods of medium silence caused by the backoff periods because they adhere to the Contention Free Periods of (at least one of) the BSSs. A CFB is furthermore protected from interference of legacy implementations due to the SIFS/PIFS interframe spaces, and a Duration/ID field that is interpreted as a very long NAV.
Another concern is that PCF and DCF applications do not always coexist well. The PCF model only supports “polled” inbound transmissions during a CFP. As a result long PCF-based CFPs can starve DCF-based stations. The problem is exacerbated when CFPs in overlapping BSSes must be scheduled to avoid CFP contention. PCF polling is appropriate for isochronous applications, but DCF is more appropriate for asynchronous data. It should not be assumed that PCF polling is used for all high-priority inbound transmissions; however, the current baseline model inherently prioritizes PCF over DCF. As an example, consider inbound asynchronous high-priority network control transmissions. Such transmissions can be delayed extensively by lower priority PCF transmissions.
The current 802.11 standard specifies that an AP must buffer all outbound multicast frames and deliver them immediately following a DTIM beacon if “strict ordering” is not enabled, then. Therefore, short DTIM intervals are necessary to support multicast applications that cannot tolerate delays. In addition, outbound multicast transmissions are more susceptible to problems associated with inter-BSS contention and hidden nodes because multicast frames are not retransmitted (i.e. after a collision with a hidden node) and the DCF channel reservation mechanisms cannot be used for multicast frames.
The baseline proposal removes the restriction that buffered multicast/broadcast frames must be sent immediately following a DTIM beacon. The baseline proposal requires that QoS WSTAs must respond to +CF-Polls. Therefore, it is strongly recommended that QoS stations should also associate as CF-Pollable (i.e. not requesting to be polled). If QoS power-save WSTAs do not use the PS-Poll mechanism for the delivery of outbound buffered messages, an AP can more easily schedule outbound transmissions for PS WSTAs. Note that CF-Pollable stations do not send PS-Poll frames to solicit outbound transmissions. Instead, a CF-Pollable station must stay awake, after it receives a DTIM beacon with its AID bit set on, until either it receives a unicast frame with the more bit set off, or a TIM with its AID bit set off. Therefore, it is generally assumed, but not required, that QoS WSTAs with active flows will operate in active mode because a point controller cannot successfully poll a WSTA that is in power-save mode.
The baseline proposal defines “awake-time epochs” that can, optionally, be used to set an awake-time window for periodic polling and/or outbound data transmissions. However, awake-time epochs introduce complexity for P-CFB polling and PCF polling. If power management must be supported, it would be simpler to schedule P-CFB polls for power-save parameterised WSTAs, if such WSTAs used automatic power-save intervals. Such a power-save WSTA can remain in power-save mode for, at most, the duration of its “automatic power-save interval”, following an inbound transmission, where the duration is selected to match the WSTAs inbound transmission rate. The point controller can simply adjust the duration of the poll timer, for a WSTA, so that it is greater than the sleep-time window duration. The point controller can then poll a WSTA and/or deliver outbound buffered data for a WSTA when the poll timer expires.
Therefore, for the reasons set forth above, there is a need for a contention-based channel access method for supporting parameterised QoS applications. Furthermore, the channel access method must coexist well with PCF and DCF applications. | {
"pile_set_name": "USPTO Backgrounds"
} |
Spinal fusion is a surgical procedure used to join two or more vertebrae. The procedure is primarily used to eliminate pain, which can be caused by a number of conditions, such as degenerative disc disease, vertebral fracture, spondylolisthesis and other diseases that cause instability of the spine.
In most spinal fusion procedures, spinal fixation rods are attached to vertebral implants, which are first secured to adjacent vertebrae. The vertebral implants generally include a bone anchor seat, a collet disposed inside the anchor seat, and a bone anchor with a head portion attached to the collet. The spinal fixation rod is inserted through the collet and fixed in place by a locking cap that attaches to the collet.
The placement of a spinal fixation rod within a vertebral implant typically required a large opening in a patient's body to provide a surgeon with the visibility required at the surgical site. Recently, minimally invasive surgeries have become more common and desirable as they reduce complications during surgery and recovery time after surgery. Minimally invasive spinal fusion surgery presents a number of unique challenges including: retention of the spinal fixation rod within the surgical instrument during the insertion process; manipulation of the spinal fixation rod while it is inside the patient; and proper alignment and positioning of the spinal fixation rod relative to the vertebral implants. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
Generally, the present disclosure relates to sophisticated integrated circuits including transistor elements comprising gate structures formed on the basis of a high-k gate dielectric material and a metal-containing electrode material.
2. Description of the Related Art
The fabrication of advanced integrated circuits, such as CPUs, storage devices, ASICs (application specific integrated circuits) and the like, requires the formation of a large number of circuit elements on a given chip area according to a specified circuit layout, wherein field effect transistors represent one important type of circuit element that substantially determines performance of the integrated circuits. Generally, a plurality of process technologies are currently practiced, wherein, for many types of complex circuitry, including field effect transistors, CMOS technology is currently one of the most promising approaches due to the superior characteristics in view of operating speed and/or power consumption and/or cost efficiency. During the fabrication of complex integrated circuits using, for instance, CMOS technology, millions of transistors, i.e., N-channel transistors and P-channel transistors, are formed on a substrate including a crystalline semiconductor layer. A field effect transistor, irrespective of whether an N-channel transistor or a P-channel transistor is considered, comprises so-called PN junctions that are formed by an interface of highly doped regions, referred to as drain and source regions, with a slightly doped or non-doped region, such as a channel region, disposed adjacent to the highly doped regions. In a field effect transistor, the conductivity of the channel region, i.e., the drive current capability of the conductive channel, is controlled by a gate electrode formed adjacent to the channel region and separated therefrom by a thin insulating layer. The conductivity of the channel region, upon formation of a conductive channel due to the application of an appropriate control voltage to the gate electrode, depends on, among other things, the dopant concentration, the mobility of the charge carriers and, for a given extension of the channel region in the transistor width direction, on the distance between the source and drain regions, which is also referred to as channel length. Hence, the conductivity of the channel region substantially affects the performance of MOS transistors. Thus, as the speed of creating the channel, which depends on the conductivity of the gate electrode, and the channel resistivity substantially determine the transistor characteristics, the scaling of the channel length, and associated therewith the reduction of channel resistivity, is a dominant design criterion for accomplishing an increase in the operating speed of the integrated circuits.
Presently, the vast majority of integrated circuits are based on silicon due to the substantially unlimited availability, the well-understood characteristics of silicon and related materials and processes and the experience gathered during the last 50 years. Therefore, silicon will likely remain the material of choice in the near future for circuits designed for mass products. One reason for the importance of silicon in fabricating semiconductor devices has been the superior characteristics of a silicon/silicon dioxide interface that allows reliable electrical insulation of different regions from each other. The silicon/silicon dioxide interface is stable at high temperatures and, thus, allows the performance of subsequent high temperature processes as are required, for example, for anneal cycles to activate dopants and to cure crystal damage without sacrificing the electrical characteristics of the interface.
For the reasons pointed out above, in field effect transistors, silicon dioxide is preferably used as a base material of the gate insulation layer that separates the gate electrode, frequently comprised of polysilicon or metal-containing materials, from the silicon channel region. In steadily improving device performance of field effect transistors, the length of the channel region has been continuously reduced to improve switching speed and drive current capability. Since the transistor performance in terms of switching speed and drive current is controlled by the voltage supplied to the gate electrode to invert the surface of the channel region to a sufficiently high charge density for providing the desired drive current for a given supply voltage, a certain degree of capacitive coupling, provided by the capacitor formed by the gate electrode, the channel region and the silicon dioxide disposed therebetween, has to be ensured. It turns out that decreasing the channel length requires an increased capacitive coupling to avoid the so-called short channel behavior during transistor operation. The short channel behavior may lead to an increased leakage current and to a pronounced dependence of the threshold voltage on the channel length. Aggressively scaled transistor devices with a relatively low supply voltage, and thus reduced threshold voltage, may suffer from an exponential increase of the leakage current, while also requiring enhanced capacitive coupling of the gate electrode to the channel region. Thus, the thickness of the silicon dioxide layer has to be correspondingly decreased to provide the required capacitance between the gate and the channel region. For example, a channel length of approximately 0.08 nm may require a gate dielectric made of silicon dioxide as thin as approximately 1.2 nm. Although, generally, usage of high speed transistor elements having an extremely short channel may be substantially restricted to high speed signal paths, whereas transistor elements with a longer channel may be used for less critical signal paths, such as storage transistor elements, the relatively high leakage current caused by direct tunneling of charge carriers through an ultra-thin silicon dioxide gate insulation layer may reach values for an oxide thickness in the range of 1-2 nm that may not be compatible with thermal design power requirements for performance driven circuits.
Therefore, replacing silicon dioxide based dielectrics as the material for gate insulation layers has been considered, particularly for extremely thin silicon dioxide based gate layers. Possible alternative materials include materials that exhibit a significantly higher permittivity so that a physically greater thickness of a correspondingly formed gate insulation layer provides a capacitive coupling that would be obtained by an extremely thin silicon dioxide layer.
Additionally, transistor performance may be increased by providing an appropriate conductive material for the gate electrode so as to replace the usually used polysilicon material, since polysilicon may suffer from charge carrier depletion at the vicinity of the interface to the gate dielectric, thereby reducing the effective capacitance between the channel region and the gate electrode. Thus, a gate stack has been suggested in which a high-k dielectric material provides enhanced capacitance based on the same thickness as a silicon dioxide based layer, while additionally maintaining leakage currents at an acceptable level. On the other hand, the non-polysilicon material, such as titanium nitride and the like, in combination with other metals, may be formed so as to connect to the high-k dielectric material, thereby substantially avoiding the presence of a depletion zone. Since the threshold voltage of the transistors, which represents the voltage at which a conductive channel forms in the channel region, is significantly determined by the work function of the metal-containing gate material, an appropriate adjustment of the effective work function with respect to the conductivity type of the transistor under consideration has to be guaranteed.
Providing different metal species for adjusting the work function of the gate electrode structures for P-channel transistors and N-channel transistors at an early manufacturing stage may, however, be associated with a plurality of difficulties, which may stem from the fact that a complex patterning sequence may be required during the formation of the sophisticated high-k metal gate stack, which may result in a significant variability of the resulting work function and thus threshold of the completed transistor structures. For instance, during a corresponding manufacturing sequence, the high-k material may be exposed to oxygen, which may result in an increase of layer thickness and thus a reduction of the capacitive coupling. Moreover, a shift of the work function may be observed when forming appropriate work function metals in an early manufacturing stage, which is believed to be caused by a moderately high oxygen affinity of the metal species, in particular during high temperature processes which may typically be required for completing the transistor structures, for instance, for forming drain and source regions and the like.
For this reason, in some approaches, the initial gate electrode stack may be provided with a high degree of compatibility with conventional polysilicon-based process strategies and the actual electrode metal, possibly in combination with a high-k dielectric material, and the final adjustment of the work function of the transistors may be accomplished in a very advanced manufacturing stage, i.e., after completing the basic transistor structure. In a corresponding replacement gate approach, the high-k dielectric material, if provided in this stage, may be covered by an appropriate metal-containing material, such as titanium nitride and the like, followed by a standard polysilicon or amorphous silicon material, which may then be patterned on the basis of well-established advanced lithography and etch techniques. Consequently, during the process sequence for patterning the gate electrode structure, the sensitive high-k dielectric material may be protected by the metal-containing material, possibly in combination with sophisticated sidewall spacer structures, thereby substantially avoiding any undue material modification during the further processing. After patterning the gate electrode structure, conventional and well-established process techniques for forming the drain and source regions having the desired complex dopant profile are typically performed. After any high temperature processes, the further processing may be continued, for instance, by forming a metal silicide, followed by the deposition of an interlayer dielectric material, such as silicon nitride, in combination with silicon dioxide and the like. In this manufacturing stage, a top surface of the gate electrode structures embedded in the interlayer dielectric material has to be exposed, which is accomplished by chemical mechanical polishing (CMP). The polysilicon material exposed during the CMP process is then removed and thereafter an appropriate masking regime may be applied in order to selectively fill in an appropriate metal for any type of transistors.
Although, in general, this approach may provide advantages in view of reducing process-related non-uniformities in the threshold voltages of the transistors since the high-k dielectric material, if provided in an early manufacturing stage, may be reliably encapsulated during the entire process sequence without requiring an adjustment of the work function and thus the threshold voltage at an early manufacturing stage, the complex process sequence for exposing and then removing the placeholder material and providing appropriate work function materials for the different types of transistors may also result in a significant degree of variability of the transistor characteristics, which may thus result in offsetting at least some of the advantages obtained by the common processing of the gate electrode structures until the basic transistor configuration is completed.
For example, an efficient removal of the polysilicon material may have a significant influence on the overall characteristics of the replacement gate, i.e., on the provision of appropriate work function metals for the N-channel transistor and P-channel transistor and the subsequent deposition of the actual metal-containing electrode material. For this purpose, typically, a dielectric cap layer in the form of a silicon nitride material may be maintained throughout the entire manufacturing process for forming the gate electrode structures and the basic transistor configuration, which may also act as a silicidation mask during the critical process step for forming metal silicide regions in the drain and source areas in order to suppress the formation of a metal silicide in the polysilicon material since any residues of the silicide material may not be efficiently removed. On the other hand, the cap layer has to be removed by the CMP process, which may result in process non-uniformities, as will be explained with reference to FIGS. 1a-1e.
FIG. 1a schematically illustrates a cross-sectional view of a semiconductor device 100 in an early manufacturing stage in which a first semiconductor region 102A and a second semiconductor region 102B are formed in a semiconductor layer 102, which in turn is formed above a substrate 101. The substrate 101 typically represents a silicon-based carrier material above which is formed the semiconductor layer 102, for instance in the form of a silicon-based crystalline material. Moreover, in the manufacturing stage shown, a first gate electrode structure 110A is formed above the first semiconductor region 102A and a second gate electrode structure 110B is formed above the second semiconductor region 102B. Moreover, the regions 102A, 102B and the gate electrode structures 110A, 110B are covered by a spacer layer 103, such as a silicon nitride material. The gate electrode structures 110A, 110B may comprise a sophisticated layer stack, for instance comprising a sophisticated gate dielectric material 111 comprising any high-k dielectric material as specified above, in combination with a titanium nitride cap layer 114. Furthermore, a silicon material 112 is typically formed above the cap layer 114, followed by a dielectric cap layer 113 in the form of a silicon nitride material.
The semiconductor device 100 as illustrated in FIG. 1a may be formed on the basis of the following well-established process techniques. First the semiconductor regions 102A, 102B may be formed by providing appropriate isolation structures in the semiconductor layer 102, for instance in the form of shallow trench isolations and the like, which, for convenience, are not shown in FIG. 1a. For this purpose, any appropriate process techniques may be applied. Thereafter, the complex gate material stack may be formed by oxidation and deposition techniques using any appropriate process recipes for obtaining the desired materials and the corresponding layer thickness values, such as for the gate dielectric material 111 and the cap layer 114. Thereafter, the silicon material 112 may be deposited on the basis of well-established low pressure chemical vapor deposition (CVD) techniques, followed by the deposition of the silicon nitride cap material 113. Furthermore, if required, any additional materials, such as hard mask materials and anti-reflective coating (ARC) materials, may be formed in accordance with requirements for the subsequent lithography and patterning strategies. Consequently, the gate electrode structures 110A, 110B are obtained with a desired critical length, i.e., in FIG. 1a, the horizontal extension of the material 112, which may be approximately 50 nm and less in sophisticated applications. Thereafter, the spacer layer 103 in the form of a silicon nitride material is deposited by using thermally activated CVD techniques or plasma-enhanced deposition recipes so as to obtain a desired layer thickness and material characteristics as required for the further processing. That is, the spacer layer 103 may be used for appropriately covering the sidewalls of the gate electrode structures 110A, 110B and in particular the sidewalls of the sensitive materials 111 and 114 during the further processing. Moreover, the spacer layer 103 may be used for providing sidewall spacers, which may additionally provide a corresponding lateral offset during the incorporation of dopant species for forming drain and source extension regions during the further processing of the device 100. In addition, corresponding sidewall spacer elements may be used as an etch and growth mask for incorporating a strain-inducing semiconductor material, for instance into the semiconductor region 102A, in order to create a desired strain component therein. It is well established that strain in the channel region of a field effect transistor may have a significant influence on the mobility of the charge carriers and may, therefore, result in a pronounced modification of drive current capability and thus performance of the transistor. For example, the generation of a compressive strain component in the channel region of P-channel transistors formed on the basis of a standard crystallographic configuration of a silicon layer may result in superior performance, which may be accomplished by incorporating a silicon/germanium alloy into the silicon material, which may result in a corresponding strained state, which may thus create a corresponding strain in the adjacent channel region. The incorporation of the silicon/germanium alloy is typically accomplished by forming cavities in the semiconductor region corresponding to the P-channel transistor, for instance the semiconductor region 102A, and subsequently refilling the cavities by using a selective epitaxial growth technique while substantially suppressing a material deposition on the semiconductor region 102B and the corresponding gate electrode structure 110B when representing an N-channel transistor.
FIG. 1b schematically illustrates the semiconductor device 100 in a further advanced manufacturing stage. As illustrated, a spacer element 103A is formed on sidewalls of the gate electrode structure 110A and may represent a remaining portion of the spacer layer 103, which is substantially completely preserved above the semiconductor region 102B and the gate electrode structure 110B. Moreover, the thickness of the silicon nitride cap layer 113 may be significantly reduced, as indicated by reference sign 113A. Additionally, a silicon/germanium alloy 104 is formed in the semiconductor region 102A with a lateral offset from the gate electrode structure 110A, i.e., from the material 112, that may be based on a thickness of the sidewall spacer 103A.
The semiconductor device 100 as illustrated in FIG. 1b may typically be formed on the basis of the following processes. After providing the spacer layer 103, the region 102B and the gate electrode structure 110B are masked, for instance by a resist material, and the exposed portion of the spacer layer 103 is etched so as to form the spacer elements 103A, which may be accomplished on the basis of any well-established anisotropic etch recipe. Thereafter, an appropriate etch chemistry is selected in order to etch into the semiconductor region 102A, thereby forming corresponding cavities, the offset of which may be defined on the basis of the spacer elements 103A and the characteristics of the corresponding etch recipe. It should be appreciated that, during the etch process, a certain amount of the silicon nitride cap layer 113 may be removed. Thereafter, the remaining resist material is removed and the device 100 is treated on the basis of appropriate cleaning recipes using wet chemical chemistries in order to prepare exposed surface portions for the subsequent selective epitaxial deposition of the silicon/germanium alloy. Thereafter, the silicon/germanium alloy 104 is deposited by applying well-established deposition recipes in order to refill and, if desired, overfill the previously formed cavities. During the selective epitaxial growth process, the silicon nitride cap layer 113A in combination with the spacer element 103A act as a mask, while the region 102B and the gate electrode structure 110B are still reliably covered by the spacer layer 103. As explained above, the spacer element 103A may also act as an offset spacer during a subsequent implantation process and consequently a corresponding spacer element is also to be formed on sidewalls of the gate electrode structure 110B. Consequently, the semiconductor region 102A and the gate electrode structure 110A are masked by resist material while the spacer layer 103 is exposed to an anisotropic etch ambient in order to form corresponding spacer elements, as is also described above for the spacer element 103A.
FIG. 1c schematically illustrates a cross-sectional view of the semiconductor device 100 in an advanced manufacturing stage. As illustrated, transistors 150A, 150B are formed in and above the active regions 102A, 102B in combination with the gate electrode structures 110A, 110B. The transistors 150A, 150B comprise drain and source regions 152 in combination with metal silicide regions 154. The drain and source regions 152 laterally enclose a channel region 153, which, in the transistor 150A, may have a certain compressive strain due to the presence of the silicon/germanium material 104. Furthermore, a spacer structure 151 may be formed on sidewalls of the gate electrode structures 110A, 110B, i.e., on the spacers 103A and spacer elements 103B that have been formed in accordance with the above-specified process sequence. It should be appreciated that, typically, the dielectric cap layer 113 of the gate electrode structure 110B may have a greater thickness compared to the dielectric cap layer 113A due to the difference in process history.
The transistors 150A, 150B may be formed on the basis of any appropriate process technique, for instance by incorporating appropriate dopant species in combination with providing the spacer structure 151, thereby obtaining the desired lateral and vertical dopant profile of the drain and source regions 152. After activating the dopant species and preparing exposed surface areas of the device 100 for the subsequent deposition of a refractory metal, such as nickel, platinum and the like, the metal silicide regions 154 are formed by well-established process techniques, wherein the dielectric cap layers 113A, 113 may act as a mask material in order to avoid the formation of a metal silicide in the polysilicon material 112. Next, an interlayer dielectric material 160 is formed, for instance, by depositing a first dielectric layer 161, such as a silicon nitride material and the like, which may act as an etch stop material for patterning a further dielectric material 162, possibly in combination with any additional dielectric materials still to be formed when forming contact openings in the interlayer dielectric material 160. In some cases, the material 161 may be provided in the form of a highly stressed material in order to create a desired type of strain in the channel region 153 of at least one of the transistors 150A, 150B. In sophisticated applications, the material 161 is provided with different types of internal stress above the transistors 150A, 150B in order to individually enhance performance of these devices. For this purpose, any appropriate manufacturing strategies are applied in order to deposit the desired material having the internal stress level and removing portions thereof from above one of the transistors 150A, 150B, for which the corresponding internal stress level may result in a deterioration of transistor performance.
FIG. 1d schematically illustrates the semiconductor device 100 during a polishing process 105, which may be applied so as to planarize the surface of the interlayer dielectric material 160 and to remove a portion thereof so as to finally expose the material 112. Generally, a polishing process, for instance in the form of a chemical mechanical polishing (CMP) process, may rely on the physical interaction of abrasive particles supplied by a slurry material and/or being present in a polishing pad, which may contact the material 160 on the basis of well-defined process parameters, such as relative speed between the material 160 and the polishing pad, the down force and the like. Furthermore, frequently, a chemical reaction may be concurrently initiated at the surface to be polished on the basis of appropriate chemical agents contained in the slurry material. Consequently, although CMP represents a very effective process for removing materials and concurrently providing a substantially planar surface topography, the removal of different materials, such as silicon dioxide, silicon nitride, possibly in differently stressed states, may represent a very complex process step, wherein a pronounced material removal between the gate electrode structures 110A, 110B is to be avoided as a metal-containing material will be deposited in the subsequent manufacturing stage. It turns out that, during the polishing process 105, in particular the removal of the cap layers 113A, 113 (FIG. 1c) may result in significant process non-uniformities, such as material residues of the cap layer which may still be present in a surface 112S of the polysilicon material 112. For example, typically, the cap layer 113 (FIG. 1c) may have an increased thickness, which may require a certain degree of over-polish time, which on the other hand may result in the generation and incorporation of any residues 160R in the material 112 of the gate electrode structure 110A, since the material 112 may be exposed earlier due to the reduced thickness of the dielectric cap layer 113A (FIG. 1c). Furthermore, the additional polish time may result in unwanted removal of material of the gate electrode structure 110A, thereby possibly unduly reducing the height thereof, which may also result in process and device irregularities upon finishing the semiconductor device 100. Furthermore, at any transition areas (not shown) of gate electrode structures of P-channel transistors and N-channel transistors, very sophisticated polish conditions occur, since here typically the layers 161 may have an increased thickness due to the previous patterning when differently stressed materials are to be used, while also the different thickness of the cap layers 113, 113S (FIG. 1c) may contribute to a very challenging process situation during the polishing process 105.
FIG. 1e schematically illustrates the semiconductor device 100 when exposed to an etch process 106 that is performed on the basis of an appropriate etch chemistry in order to remove the material 112 (FIG. 1d) selectively to the interlayer dielectric material 160 and the cap layer 114. For instance, very selective etch chemistries are available so as to efficiently remove polysilicon material substantially without unduly damaging the cap layer 114 and the underlying high-k dielectric material, while also substantially maintaining the dielectric materials. However, due to the presence of non-removed portions or any other polishing-related residues as described above with reference to FIG. 1d, the polysilicon material may not be completely removed so that corresponding residues 112R may still be present after the etch process 106. However, applying any pronounced over-etch times may not be a desirable option in view of integrity of the layers 114 and 111.
Consequently, during the further processing, i.e., during the deposition of metal-containing material layers for adjusting the work function of the gate electrode structures 110A, 110B and for providing a metal-containing electrode material, the polysilicon residues 112R significantly contribute to yield losses due to severe failures of the gate electrode structures or due to a pronounced variability in transistor characteristics.
The present disclosure is directed to various methods that may avoid, or at least reduce, the effects of one or more of the problems identified above. | {
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The present invention relates to error correction for flash memory.
Continuous improvements in price/performance for flash electrically-erasable programmable read-only memory have enabled flash memory to become the long term storage of choice for many applications. A flash memory is typically made from an array of floating-gate metal-oxide-silicon field effect transistors arranged as memory cells in typical row and column fashion with circuitry for accessing individual cells and placing the memory transistors of those cells in different memory conditions. Such memory transistors may be programmed by storing a charge on the floating gate. This charge remains when power is removed from the array. This charge (a “zero” or programmed condition) or its absence (a “one” or erased condition) may be detected when the device is read. Flash memory arrays are especially useful in portable computers where low power consumption is mandatory, space is at a premium and weight is important.
Two common flash memory architectures are NAND-type structure (NAND-flash) and NOR-type structure (NOR-flash). The NAND-flash serially arranges its memory cells while the NOR-flash arranges memory cells in parallel. An advantage of the NAND-type structure is faster sequential accessing than the NOR-type structure. In addition, the NAND-type structure supports faster write and erase operations and permits fabrication of higher density memory chips or smaller and less expensive chips of the same density.
During fabrication, flash memory devices may contain defective areas, and more defects may appear during the device lifetime, thereby limiting their usage. To manage these defects and to achieve efficient and reliable operation, digital systems typically use techniques to control errors and to ensure reliable data reproduction. For example, if hardware error occurs in a block of the array, that block of the array can be removed from operation. Blocks of flash memory are relatively expensive compared to other forms of storage, so this technique of having redundant/spare storage blocks is undesirable. Moreover, since only a limited number of spare blocks of flash memory are available in an array, this error correction approach eventually restricts the ability of the device to function.
A typical device (for example a Samsung K9F1208U0M 64M×8 flash memory) includes 16 extra bytes per 512-byte page. Manufacturers typically recommend error protection capability to detect 2-bit errors or to correct single bit errors on each device page (4096 bits). NAND-flash devices typically ship with an additional 16-byte area for each 512-byte page, for a total of 528 bytes. Some NAND-flash manufacturers rely on external ECC in order to support an extended number of write cycles per page/block. In the past, certain standards for NAND-flash file systems have been set, which include limited data protection. One such standard is the SmartMedia™ standard, mainly targeted for removable flash memory cards. This standard includes single-bit error correcting code that can also detect (but not correct) 2-bit errors per 256 bytes. The SmartMedia™ standard allocates 6 bytes for ECC related information per page. In addition, 2 bytes are used to duplicate logical block address information already included elsewhere. Therefore, a total of 8 bytes are allocated for this information. The SmartMedia™ standard sets aside bytes 0–511 for data storage and the following as an extra storage area: byte 516 for data status, byte 517 for block status, bytes 518–519 for block address field 1, bytes 520–522 for ECC field 2, bytes 523–524 for block address field 2, and bytes 525–527 for ECC field 1. The SmartMedia™ standard proposes the use of a Hamming-like code using 6 parity bytes (actually 22×2 bits). This code is capable of detecting up 2-bit errors and of correcting a single bit error per 256 bytes. However, the SmartMedia™ specification does not provide error detection and correction for the extra storage area.
U.S. Pat. No. 6,438,706 to Brown entitled “On Chip Error Correction For Devices In A Solid State Drive” provides an error correction arrangement for a flash memory with a plurality of redundant array circuits, a circuit for sensing when a hardware error has occurred in a block of the flash array, and a circuit for replacing an array circuit with a redundant array circuit in response to detection of a hardware error. However, this approach does not correct for one, two or three bits of errors.
As high-speed digital systems employing flash memory become more widely used and integral to day-to-day activities, individuals likely will depend more upon the efficient and reliable reproduction of the data stored in the flash memory of these digital systems. | {
"pile_set_name": "USPTO Backgrounds"
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Various systems and methods of data recognition are known to those skilled in the art, including portable systems for optically sensing and decoding data. Examples of such systems may be seen in U.S. Pat. No. 4,143,417 titled "Portable Data-Gathering Apparatus Formed by Modular Components Having Operate-Standby Modes" by Wald et al.; U.S. Pat. No. 4,521,678 titled "Battery-Powered Optical Bar Code Reader and Voltage Regulator Therefor" by Winter; U.S. Pat. No. 4,160,156 titled "Method and Apparatus for Reading Bar Coded Data Wherein the Light Source is Periodically Energized" by Sherer; and U.S. Pat. No. 5,189,291 titled "Bar Code Reader Operable as Remote Scanner or with Fixed Terminal" by Siemiatkowski. Portable systems have been used for data collection in a broad range of operations, including inventory control in retail stores and in the tracking of packages or cargo in the delivery industry. Portable optical reading units are typically battery powered or attached to a terminal station which supplies a power source.
Codes have been produced, and printed on products or containers, to increase the accuracy of such data collection systems. One such code is a "bar code" which may be read by passing an optical sensing unit over the bar code on the product or by passing the product over the optical sensing unit. A bar code typically consists of a pattern of black and white bars of varying widths, with the encoded information determined by the sequence of these varying width bars. Bars are scanned by the optical sensing unit and the widths of the bars are then translated into a specific identifying sequence for that particular item.
An optical sensing unit typically requires a source of radiation to illuminate the bar coded data which normally places a significant drain on the battery. As the applications of these portable optical sensing units continue to expand, users of such units continue to demand more capabilities, lighter weight, lower cost, and extended usage time from these units. Hence, the amount of power used by the radiation source, accompanying sensing, decoding, and other data processing circuits, data transmission circuits, and the display of decoded or user interface data continue to be a major obstacle in expanding applications. | {
"pile_set_name": "USPTO Backgrounds"
} |
Various solutions, such as culture media, buffers, reagents, and other biological materials are used extensively in research and development. Often, the solutions are used in creating vaccines, producing and purifying proteins, and developing other biologics. Many solutions include precise compositions, are frequently required to be pure and sterile, and may be highly regulated. As such, manufacturing of these solutions is expensive and often requires specialized equipment.
Due to the cost of creating, operating, and maintaining the systems used in the manufacture of many solutions, companies frequently purchase the solutions from a manufacturer in their final form. Typically, manufacturers produce master batches of the solution in large quantities, then transfer the solution from the master batches into smaller individual containers for shipping. Dynamic forces experienced during shipping may compromise the integrity of currently available mixing containers, such as mixing bags. As such, the solution is usually shipped in individual transportation containers.
During shipping, or storage of the solution after shipping, the solution may settle in the transportation containers. The settled solution requires mixing prior to use, and may settle in a manner that cannot be mixed, thus resulting in a loss of material. The transportation containers are usually non-mixing, such that, prior to use, the solution must be transferred from the transportation container into a mixing container at an end-user facility. Transferring the solution from the transportation container to the mixing container increases a risk of contamination, as well as preparation time prior to use and loss of material. Additionally, the use of multiple containers for a single solution increases an overall cost of the solution.
A mixing system, mixing container, and mixing method that show one or more improvements in comparison to the prior art would be desirable in the art. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
The invention relates to tunable high-frequency devices based on superconductive materials.
2. Discussion of Background
A device for the processing of electromagnetic waves may be formed by an element made of a superconductive material as well as a dielectric element associated with this superconductive element.
Since the thickness of an element made of superconductive material is smaller than the length of penetration .lambda..sub.L of the magnetic field, the device has an additional inductance, known as a kinetic inductance, due to the superconductive element, and this kinetic inductance gets added to the ordinary magnetic inductance.
This inductance takes account of the kinetic energy of the superconductive electrons. For very thin layers, it is proportional to the square of the depth of penetration .lambda..sub.L of the magnetic field and hence inversely proportional to the Cooper pairs density.
For a determined Cooper pairs density, the kinetic inductance is fixed.
The invention provides for means enabling the modification, at will, of the additional kinetic inductance. For this purpose, these means are such that they enable the modification of the Cooper pairs density.
This Cooper pairs density may be changed by:
the variation of the temperature; PA0 the application of a polarization current; PA0 the application of a magnetic field; PA0 the illumination of the superconductor by a radiation. | {
"pile_set_name": "USPTO Backgrounds"
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Users are frequently requested to be authenticated while accessing internet from terminal devices. Main reasons for the authentication are to protect user privacy and personal assets and to maintain a high level of cyber security. As a result, the execution of many operations, such as making an online payment, downloading from a certain database, or using a personal account, usually requires confirmation of the user's identity.
Present online authentication technologies often rely on terminal device binding. For example, the identity of the user is tied to a terminal device connected to the network by logging into a personal account on the terminal device and the terminal device is verified by installed digital certificates. As shown here, the user's identity is verified through the ownership of the terminal device.
However, such practice had low flexibility in situations when the ownership alters. For example, when the user buys a new computer, he/she cannot perform all operations mentioned above on this new device until digital certificates are installed, and the installation can be inconvenient and burdensome. | {
"pile_set_name": "USPTO Backgrounds"
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Examples of passive lift devices mounted to the torso of a person configured to support the weight of the arm can be found in U.S. Pat. No. 9,205,017 B2 and U.S. Patent Application Publication No. 2014/0158839 A1. Such devices are seen to be limited because they are not able to automatically cut or substantially reduce their assistance when the user intends to rest his/her upper arm at his/her sides, or pick a tool from his/her tool belt. Such devices do not provide a sustained range of position where support torque automatically reduces to zero. Except for a few points of position, these devices will always be applying lifting forces to a user's upper arm, potentially inhibiting motion and creating discomfort during non-working postures when assist is not desired.
In general, passive support devices that are configured to assist a person supporting the weight of a tool are known in the art. Typical passive devices are configured to compensate for gravity under a range of positions using a combination of structural elements, springs, cables and pulleys. The configuration of these devices provides for gravity compensation within a limited range of motion. Additionally, these devices do not allow for a substantially zero torque to be provided. Examples of passive lift assist devices can be found in U.S. Pat. Nos. 6,821,259 B2 and 7,325,777. Such devices are seen to be fairly limited in terms of functionality, as their base must be repositioned every time a user moves to a new location. Examples of a passive lift assist device mounted to the torso of a person to support the weight of a tool include U.S. Pat. No. 7,618,016 B2 and U.S. Patent Application Publication No. US 2015/001269 A1. Such devices are seen to be fairly limited because of a bulky frame that does not accurately follow the motions of the user. | {
"pile_set_name": "USPTO Backgrounds"
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In the field of clinical analysis, a method utilizing coupling enzymes of glucokinase (GK) and glucose-6-phosphate dehydrogenase (G6PDH), i.e., a so-called GK/G6PDH coupling enzyme system, has heretofore been employed in determination of glucose or CPK.
This method is based on the following principle: ##STR1##
The symbols used in the above formulae are defined as follows:
CP: creatine phosphate PA0 C: creatine PA0 ADP: adenosine-5'-diphosphate PA0 ATP: adenosine-5'-triphosphate PA0 G6P: glucose-6-phosphate PA0 NAD(P): oxidized form nicotinamide adenine dinucleotide (phosphate) PA0 NAD(P)H: reduced form nicotinamide adenine dinucleotide (phosphate) PA0 6-PGA: 6-phosphogluconate
The above-described reactions (1), (2) and (3) are catalyzed by CPK, GK and G6PDH, respectively. Thus, the CPK measurement follows the equations (1), (2) and (3), and the lucose measurement, the equations (2) and (3).
Conventional glucose or CPK-measuring compositions utilizing the HK/G6PDH coupling enzyme system are of low stability when stored at room temperature in the form of solution and their service lives as reagents at room temperature (18.degree.-35.degree. C.) after dissolving are very short, as described in Methods in Enzymatic Analysis, 2nd English Edition, ed. by Hans Ulrich Bergmeyer (published by Verlag Chemie International), pages 789-793 and 1196-1205 (1974). Thus, an improved measuring composition using heat stable GK has been developed, as described in Japanese Patent Application (OPI) No. 169598/81 (corresponding to U.S. patent application Ser. No. 267,245, now U.S. Pat. No. 4,438,199, and also to EPC Patent Publication No. 43181) (the term "OPI" as used herein means a "published unexamined Japanese patent application").
The above-proposed composition is improved in storage stability at room temperature compared with conventional compositions. Its stability, however, is not sufficiently satisfactory because of instability of coupling enzyme and SH-containing compound contained in the composition. Furthermore, to keep the stability over long periods of time, it is necessary to add a relatively large amount of enzyme. Use of such a large amount of enzyme does not cause any serious problem. However, as the amount of enzyme to be used is decreased, the problem of a drop in rate of reaction and, in its turn, an increase in the time required for the measurement arises. Although this problem is not noticeable in measuring the individual activity of GK and G6PDH, it becomes seriously noticeable when the composition is used in determination of glucose or CPK. This is one of the causes preventing practical use of the composition.
Addition of potassium chloride (KCZ) in the assay mixture or purification medium of GK is described in Methods in Enzymology, published by Academic Press Inc., Vol. 9, pages 381-388 (1966). It is also described that although KCl possesses an action to stabilize GK, while not exerting influences on the rate of reaction (Vm). | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
The present invention relates to a recording material detecting apparatus applied to an image forming apparatus such as a printer or a photocopier, and more specifically, it relates to a reference member for correcting the output from a detecting device.
2. Description of the Related Art
There are many types of sheet materials used as recording materials for image forming apparatuses, for example, so-called plain copying paper (plain paper), transparent film for projectors, white film for obtaining a high-quality image, and so forth. In addition, there are various thicknesses of sheets of plain paper, for example, 60 g/m2 and 200 g/m2 in basis weight.
In order to form an excellent image on any type of sheet material, the image forming condition needs to be changed according to the type of sheet material to be used. For example, in an electrophotographic image forming apparatus, during transferring, an optimum bias needs to be applied according to the resistance value of the sheet material. More specifically, a low bias needs to be applied to plain paper, which has a low resistance value, and a high bias needs to be applied to gloss film, which has a high resistance. In addition, fusing needs to be performed at an optimum temperature according to the heat capacity of the sheet material. More specifically, fusing needs to be performed at a low temperature in the case of plain paper, which has a low heat capacity, and fusing needs to be performed at a high temperature in the case of gloss film, which has a high heat capacity. In order to obtain an excellent image regardless of the type of sheet material, the type of sheet material needs to be detected. In general, an optical sensor is used for such detection.
An optical sensor reads the surface of a sheet material conveyed to the sensor. The accuracy of reading differs from sensor to sensor, and varies due to the accuracy of mounting location, long-term deterioration, and so forth. In order to correct these variations, the sensor reads a reference portion. On the basis of the result, the output from the sensor is corrected. This reading is preferably performed under the same condition as the reading of the sheet material conveyed to the sensor, that is to say, in substantially the same plane as the sheet material (conveying plane). Therefore, the reference portion is preferably placed in substantially the same plane as the sheet material.
However, in this case, the sheet material being conveyed can contaminate and damage the surface of the reference portion.
In order to solve the problem of contamination and damage of a reference portion in an optical sensor, Japanese Patent Laid-Open No. 4-208935 discloses an apparatus in which a reference portion is supported by a movable supporting member and is retracted to a position apart from the conveying surface by a driving unit. That is to say, a supporting member is driven by a driving unit so that a reference portion is retracted to a position apart from the conveying surface, and thereafter a sheet material is conveyed to the conveying surface.
However, in the case of the above-described known apparatus, since a driving unit is used for moving a reference portion, a motor or the like is necessary. Therefore, the cost is increased and the apparatus structure is more complicated. | {
"pile_set_name": "USPTO Backgrounds"
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The present application relates generally to an improved data processing apparatus and method and more specifically to mechanisms for providing and utilizing range check based lookup table structures in a data processing system.
Division, reciprocal, square root, approximations, and other arithmetic operations are used in critical applications and impact the performance of a data processing unit. This is especially true of integer divisions which are relevant in the JAVA. C++, and Oracle programming languages. Integer division is typically used for fast hashing in many current software routines.
A predominant and fast divide algorithm currently available is SRT based division (named for its creators, Sweeney, Robertson, and Tocher). SRT division is a popular method for division in many microprocessor implementations. SRT division is similar to non-restoring division, but SRT division uses a lookup table based on the dividend and the divisor to determine each quotient digit. The SRT division algorithm is an adequate algorithm for fast division operations, but requires a very large lookup table (LUT), and thus a large chip area, which constrains or limits the speed of the chip design. For high frequency processors, such as the IBM z-Series and POWER series chip designs, available from International Business Machines Corporation of Armonk, N.Y., a standard SRT algorithm is not a suitable solution because the time required to access the large LUT results in a hardware solution that does not meet the specified target cycle time for the processor | {
"pile_set_name": "USPTO Backgrounds"
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This specification relates to providing information about topics.
While the Internet has experienced explosive growth, the basic way we browse information online has remained largely unchanged. In particular, the web is still a predominantly page and site-centric environment with information about the same topic often scattered across a large number of different websites. | {
"pile_set_name": "USPTO Backgrounds"
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This invention is directed to the formation of one or more channels into the wall of a patient's heart and particularly to the intraoperative formation of such channels in the heart wall. These channels may be used to increase blood flow to heart tissue experiencing ischemic conditions and for the delivery of therapeutic or diagnostic agents to various locations.
The formation of channels to increase the blood to flow to a patient's heart tissue is called myocardial revascularization. The first clinical trials of the revascularization process was made by Mirhoseini et al. See for example the discussions in Lasers in General Surgery (Williams & Wilkins; 1989), pp 216-223. Other early disclosures of this procedure is found in an article by Okada et al. in Kobe J. Med. Sci 32, 151-161, October 1986 and U.S. Pat. No. 4,658,817 (Hardy). These early references describe intraoperative revascularization procedures which require an opening in the chest wall and include formation of the channels through the epicardium.
Copending application Ser. No. 08/361,787, filed on Dec. 20, 1994 (Aita et al.), now U.S. Pat. No. 5,554,152 which is incorporated herein in its entirety, describes an intraoperative system for myocardial revascularization which is introduced through the chest wall. While the intra-operative system for performing revascularization, developed by Aita et al., was a substantial advance, one of the difficulties in developing intraoperative channel forming devices was to provide an intraoperative device which was flexible enough to be manually positioned within the patient's chest cavity and yet be constructed of sufficient strength to maintain its integrity and to preclude loss of the distal tip of the optical device, particularly within the patient's heart, during the procedure. Another difficulty with prior channel forming devices is the difficulty in forming channels on the posterior side of the patient's heart. The present invention minimizes the difficulties of the prior channel forming devices. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
The present invention relates to an apparatus for processing a signal and method thereof. Although the present invention is suitable for a wide scope of applications, it is particularly suitable for encoding/decoding band extension information of an audio signal.
2. Discussion of the Related Art
Generally, information for decoding an audio signal is transmitted by a frame unit and information belonging to each frame is repeatedly transmitted according to a predetermined rule. Although information is separately transmitted per frame, there may exist correlation between information of a previous frame and information of a current frame like frame type information.
However, in the related art, when correlation exists between information of a previous frame and information of a current frame, if information on each frame is transmitted per frame irrespective of the correlation, the number of bits is unnecessarily incremented. | {
"pile_set_name": "USPTO Backgrounds"
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The field of the present invention is wheel assemblies. More specifically, the field of the present invention relates to wheel assemblies for video and motion picture camera dollies.
In the motion picture or video filming procedures, cameras are often supported on dollies so that the camera positions, angles and elevations may be smoothly and easily changed without interruption. For use on a relatively smooth surface, the camera dolly may be equipped with pneumatic wheels. On the other hand, if the dolly is to be moved over rough terrain or irregular ground, it is common practice to lay a track over such terrain or surface to provide a smooth rolling surface for the dolly.
However, running the dolly on the track or rails has heretofore required that the pneumatic dolly tires be removed from the dolly and replaced with track wheels specifically configured to roll on the track but not suitable for operation on pavement or other smooth surface. This required changeover from the pneumatic tires to track wheels has been time consuming. In addition, it requires a grip, technician or mechanic to make the pneumatic to track wheel exchange. Correspondingly, one or more tools to make the changeover are also required. In addition, in many, if not all dollies, the changeover from pneumatic (ground) tires to track wheels (and vice versa) exposes certain dolly components, i.e. bearings and axles, at least momentarily, to contamination from dirt and debris. Moreover, whichever set of tires or wheels is not being used on the dolly must be stored and transported with the dolly, thereby requiring additional space and adding weight. Further, the dolly braking system must be considered in the changeover between ground and track wheels. | {
"pile_set_name": "USPTO Backgrounds"
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The present invention concerns a polymer layer for a sensor, wherein the polymer layer has nanoparticles embedded therein which impart to the polymer layer recognizing properties as well as transducer properties, a sensor comprising such layer, and the use of the sensor for detecting and/or quantifying a target analyte.
Various sensors for determining substances of interest in a qualitative and quantitative manner have been described to date. In particular, in the fields of environmental and food technology, medicine, and biotechnology the development of precise analytical means and methods is of great interest. For example, enzyme-based sensors with electrochemical or optical transduction are widely used to determine analytes in the blood and in other body liquids.
Generally, classical sensors consist of a multilayer structure. For example, U.S. Pat. No. 6,107,083 describes an optical enzyme-based sensor with a multilayer structure which comprises, in the sequence of layers: (a) an oxygen-sensitive layer containing a luminescent dye in a light-transmissive, oxygen-permeable matrix, (b) an enzymatic layer containing an oxidative enzyme in a hydratable and oxygen-permeable matrix, and (c) a rapidly hydrating gas-permeable cover layer disposed over the enzymatic layer.
Major drawbacks of such multilayer-structured sensors are the complex buildup of the sensors involving problems with the coating compatibility of the multiple layers, the limited density of functional elements available on a planar surface, and the difficulty in controlling precisely the thickness of each layer in order to maintain reproducible diffusion processes. These processes are accompanied by unsatisfactory sensor responses and reduced signal yields.
In U.S. Pat. No. 6,238,930 B1 a different approach for a layer structure for the determination of a substance has been made by forming a micellar recognition system from two non-miscible phases, a surface-active substance and a recognition component, and by incorporating this system into a layer. The substance of interest is then detected by the interaction with the recognition component and a transducing step both occurring in the layer. The construction of the layer structure according to U.S. Pat. No. 6,238,930 B1 is complex and due to the requirement of forming appropriate micelles, the flexibility and field of application of such systems is limited. Compared to the classical multilayer-structured sensors no significant simplification could be achieved. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of Invention
This invention relates generally to sleep shades adapted to cover the wearer""s eyes and having properties for inhibiting the passage of light throughout the shield to the eyes of the wearer.
2. Discussion of Prior Art
Adequate sleep is essential to well being, for without sleep one is deprived of the natural benefits that it provides. Yet the modern era has created an artificial environment for large segments of the population that demands to sleep under natural or artificial light. The human sensory system is not at idle during sleep, but stays alert to protect the sleeper. While the amount of ambient light striking on the eyes is vastly reduced when the eyelids are closed, nevertheless, the eyes remain responsive to ambient light. A common situation is that of a passenger of an airplane who has no choice but to sleep under lighted conditions.
Unfortunately, sleeping habits and state of minds vary, more so in a closed social crowd such as that of an airplane. Some travelers sleep with their sun-glasses worn so as not to be seen with their eyelids closed. It is also common prevention to sleep or to fall to a state of semi-consciousness to be afraid to miss a meal or a snack service. It is the human perception of these habits which often make them want to maintain some degree of consciousness. This of course interferes with the ultimate desire to sleep for a prolonged period of time.
In accordance with the present invention is to provide a sleep shield adapted to facilitate the sleep state of a wearer with ascetically appealing means to effectively exclude ambient light from the eyes of the wearer.
And more particularly, an object of this invention is to provide a sleep shield of the above type which is made of opaque layers of soft fabric forming a substrata unit and an outer layer of clear flexible plastic sheeting attached thereto, and cooperate in a fashion to allow the insertion, retention, displaying and withdrawal of graphic art. The resulting sleep shield inhibits the visual aspect of various sleeping habits by providing the sleep shield with a number of more appealing displays of the eye section of the face and more ascetically acceptable. Various graphic art accessories can also be provided for the sleep shield to otherwise facilitate the sleeping period of time. The shield can be attached to the head of the user using one or more ties, elastic bands, straps and buckles as well known in the art.
The graphic accessories or inserts can also be printed with indicia illustrating such as plain color, open or closed eyes, eyebrows, spectacles, sunglasses, gender, and race of the user, or simple statements such as xe2x80x9cdo no disturbxe2x80x9d or xe2x80x9cwake me for meal service.xe2x80x9d The resulting sleep should provide better peace of mind of the user thus enhancing every aspect of the sleeping period of item, resulting in a more relaxed sleep.
These and other features and advantages of the invention will become more apparent with a discussion of preferred embodiments in reference to the associated drawings. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
This invention relates generally to electrical connectors, and more specifically to the design of a female receptacle adapted to cooperate with a coaxial-type jack pin and which is especially suited for use with printed circuit boards.
2. Description of the Prior Art
Coaxial jack-type connectors have long been used in the electrical industry as a means for establishing electrical connections between cooperating systems. Early telephone switchboards commonly used coaxial jacks on the ends of patch cords and which were adapted to cooperate with female receptacles on a switchboard. In these systems, however, the female receptacle was generally screw mounted on a panel and discrete wiring was used to connect the female receptacle to its associated electrical circuits.
In the past three decades, great strides have been made in the miniaturization of electronic and electrical assemblies. This is attributed to the advent of printed circuit board technology and the wide spread application of semiconductor devices including discrete transistor components and integrated circuits. It is still common practice to utilize plug-in type connectors in a wide variety of electrical and electronic gear. For example, television and high fidelity sound equipment often includes ear phone jacks, but little progress has been made since the early days of the telephone switchboard. More specifically, the female receptacle used to accept the male pin of a coaxial jack is a separate, cabinet mounted device which is electrically connected to the internal circuitry, which may be on printed circuit boards, by means of discrete wiring rather than printed conductors. Thus, a real need exists for a female plug-in jack receptacle which may be mounted directly on a printed circuit board with the electrical connections therefore being preprinted on a insulating substrate. | {
"pile_set_name": "USPTO Backgrounds"
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In the current technology of integrated circuits, the dimensions of the devices in the integrated circuits are smaller than one-micron meters. In the manufacture of ultra large-scale integrated (ULSI) circuits, the channel's length of transistors is below 0.5 micron meters. The short channel effect often arises in the manufacture of the ULSI circuit. One approach of reducing the short channel effect is a self-aligned silicide (Salicide) of the active region in a transistor. The salicide process can reduce the contact resistance of the ULSI devices and improve the operation speed of the devices. In IEDM Tech. Dig. in the page 73 on 1996, P. Fornara et al. described the application of the salicide process to the short-channel transistors. In this paper, the authors discussed the formation of TiSi.sub.2 or CoSi.sub.2 on spacers and produced simulating structures of metal films on the spacers. The well-known salicide process is now one of the most efficient ways of obtaining self-aligned low resistive contacts in CMOS and BiCMOS technology. The silicide layers are not formed on spacers of devices and has different topographical results which depend on the materials of the silicide layers.
Salicide processes are used to reduce the contact resistance of the ULSI MOS devices but the devices show worse electrostatic-shielding-devices (ESD) performance than the nob-salicide devices. On page 893 of IEDM Tech. Dig. on 1996, A. Amerasekera et al. discussed the relationship between the salicide thickness on devices and the current gain of the devices. In this paper, the authors concluded that the thicker salicide of the device could degrade the ESD performance of the device and found a phenomena that junction depths and salicide thickness in a 0.25 micron meters CMOS process affect the current gain of a self-biased lateral NPN transistor. The relationship between the current gain and the ESD performance is discussed in this paper. According to this paper, the salicide process can prevent the short-channel effect of the ULSI MOS devices but can degrade the ESD performance of the devices. Devices with lower current gain are found to have lower ESD performance. Current gain is observed to be strongly influenced by the effective drain/source diffusion depth below the silicide which is determined by the implant energy as well as the amount of active diffusion consumed in silicidation.
Therefore, using the salicide process to manufacture the ULSI devices but not influence the ESD performance of the devices is an important topic. | {
"pile_set_name": "USPTO Backgrounds"
} |
In this day and age of do-it-yourselfers, a need has arisen for the average person unskilled in the art of drapery fabrication, to be able to easily and economically construct their own draperies.
This chart will provide these means. It's a simple step by step method of pinch pleating draperies without the complicated process of measuring and figuring of where the pleats should be placed and how far apart they should be.
Past experience has shown that consumers have their biggest problem in drapery pleating when there is an existing drapery rod already in place. This means the draperies have to be pleated to the precise width to fit the drapery rod. By using this chart, this is now easily accomplished.
Pleating devices now available are large, expensive and are designed for commercial use. Only one skilled in the art with plenty of money to spend would have a use for this type of device. Reference is made to U.S. Pat. No. 3-464-600. These conditions virtually eliminate the average person from being able to purchase such a device.
The chart is small enough to be rolled up for easy shipping and storage. It can be used in any home on the average kitchen table or floor, virtually eliminates all the complex figuring involved in drapery making, and is inexpensive to manufacture, therefore, making it very economical for the consumer to purchase. | {
"pile_set_name": "USPTO Backgrounds"
} |
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