The present invention relates to a heat exchanger for air conditioners having a plurality of a slit type grilles in each flat fin and making the air currents passing by the fin become turbulent flows and mixing the air currents together, to thereby improve the heat exchanging efficiency and reducing a cavitation zone formed in the back of each heat transfer pipe.

1. Field of the Invention
The present invention relates in general to a heat exchanger for an air conditioner and, more particularly, to a heat exchanger having a slit type grille in each flat fin and making the air currents passing by the fin, such as room air currents, become turbulent flows and mixing the above air currents together, thereby improving the heat exchanging efficiency and reducing the cavitation zone formed in the back of each heat transfer pipe.
2. Description of the Prior Art
With reference to FIG. 1, there is shown the construction of a conventional heat exchanger for an air conditioner. As shown in the above drawing, the conventional heat exchanger includes a plurality of regularly spaced flat fins 1. The fins 1 are vertically arranged such that they parallel each other. A plurality of heat transfer pipes 2 are angularly fitted into the fins 1 such that the pipes 2 are perpendicular to the fins 1. The air currents flow in the space defined between the fins 1 in the direction of the arrow in FIG. 1 and exchange heat with the fluid flowing in the heat transfer pipes 2.
A thermal fluid flowing about each flat fin 1 has the characteristic in that the thickness of the thermal boundary layer 3 on both heat transfer surfaces of the fin 1 is gradually increased in proportion to the square root of the distance from the air current inlet end of the fin 1 as shown in FIG. 2. In this regard, the heat transfer rate of the fin 1 is remarkably reduced in proportion to the distance from the air current inlet end. Therefore, the above heat exchanger has a lower heat transfer efficiency.
When lower velocity air currents flow in the direction of the arrow of FIG. 3, the thermal fluid flowing about each heat transfer pipe 2 has the characteristic in that the air currents separate from the outer surface of the pipe 2 at portions spaced apart from the stagnation point of the pipe 2 at points spaced apart by an angle 2.theta. in the range of 70.degree..about.80.degree. . Therefore, a cavitation zone 4 is formed in the back of the pipe 2 as shown in the cross-hatched region of FIG. 3. In the above cavitation zone 4, the heat transfer rate of the pipe 2 is remarkably reduced so that the heat transfer efficiency of the above heat exchanger become worse.
In order to overcome the above problems, Japanese U.N. Laid-open Publication No. Sho.55-110995 proposes an improved heat exchanger for air conditioners. As shown in FIG. 4, the above Japanese heat exchanger includes a plurality of heat transfer pipes 2 which are fitted into the regularly spaced flat fins 1 such that the pipes 2 are perpendicular to the fins 1. The above heat exchanger also includes a plurality of slit type grille which are formed beside the pipes 2 on each fin 1. Each slit type grille is formed by vertically slitting a given portion of the fin 1 several times and alternately bending the remaining strips in opposite directions, thereby forming a plurality bent strips 5a, 5b, 5c, 5d, 5e and 5f in the fin 1.
In other words, three strips 5a, 5c and 5e are bent to one side of the fin 1 such that the strips 5a, 5b and 5c are regularly spaced apart from each other. However, the other three strips 5b, 5d and 5f placed between the above strips 5a, 5c and 5e are bent to the other side of the fin 1.
The above heat exchanger having the plurality of slit type grilles on each flat fin 1 causes the heat exchanging fluid to become turbulent due to the above grilles, thereby reducing the thickness of the thermal boundary layers formed on the fins 1. As the above heat exchanger has thin thermal boundary layers formed on the fins 1 due to the slit type grilles, this heat exchanger somewhat improves the heat transfer efficiency in comparison with the conventional heat exchanger having the flat fins 1 with no slit type grilles. When the partial heat transfer capacities of the heat exchanger are measured, the upstream strips 5a and 5b create the thin thermal boundary layers, thus to improve the heat transfer efficiency. However, as the downstream strips 5c to 5f are included in the thermal boundary layers formed by the upstream strips 5a and 5b, the downstream strips 5c to 5f can not improve the heat transfer efficiency. In addition, the cavitation zone is still formed in the back of each heat transfer pipe 2. Furthermore, the air currents flowing in the space defined between the flat fins 1 are not mixed together but become laminar. Therefore, the above Japanese heat exchanger is not expected to improve the heat transfer efficiency which would be improved if the air currents are mixed together.


The present disclosure provides novel aqueous ink jet inks containing an aqueous vehicle, a colorant, a first organic co-solvent and a second organic co-solvent. Said ink jet inks demonstrate improved adhesion to print substrates.

This disclosure relates to novel aqueous ink-jet inks containing an aqueous vehicle, a colorant, a first organic co-solvent and a second organic co-solvent for improving ink adhesion to print substrates. Also disclosed is a printing method using these inks.
Inkjet recording is a printing method wherein droplets of ink are ejected through fine nozzles to form letters or figures on the surface of recording media. Inks used in such recording are subject to rigorous demands including, for example, good dispersion stability, ejection stability, and good fixation to media.
Aqueous dispersions of pigment particles are widely used in ink-jet printing. Because a pigment is typically not soluble in an aqueous vehicle, it is often required to use a dispersing agent, such as a polymeric dispersant or a surfactant, to produce a stable dispersion of the pigment in the aqueous vehicle. More recently, so-called "self-dispersible" or "self-dispersing" pigments (hereafter "SDP(s)") have been developed. As the name would imply, SDPs are dispersible in water without dispersants.
The main advantage of inkjet printers over laser printers includes low cost and simplicity. However, many commonly formulated inkjet ink do not dry adequately when printed on hydrophobic media that have not been specially treated to accept water-based inks, consequently resulting in poor image quality. Hydrophobic media include resin-coated papers such as those used for conventional printing, transparency films made of acetate and untreated vinyls. However, treatment of hydrophobic media to accept water-based inks causes increases to both printing costs and processing time.
U.S. Pat. No. 5,165,968 discloses water-based inks containing a small amount of lower alkyl alcohol(s) or benzyl alcohol to decrease dry time and improve smear resistance of printed image.
U.S. Pat. No. 6,277,183 discloses aqueous inkjet inks containing a long chain alcohol having at least 8 carbons to reduce mottle and halo of printed images.
U.S. Patent Application Publication No. 2003/0079649 discloses aqueous black inks containing one 1,2-diol, a mono- or di-hydric alcohol for printing on glossy media with increased dot size and reliability.
A need exists for an inkjet ink that can be printed on hydrophobic media to provide a high quality image without having to pre-treat the surface of the media or using a large amount of water-soluble solvents that can lead to degradation and/or delamination of pen components. The present disclosure satisfies this need by providing ink compositions having a desirable balance of organic co-solvents for both wetting the media and aiding the penetration of inks into the media for drying while maintaining the stability of the inks, good pen firing and material compatibility.

Aqueous ink-jet inks for improved adhesion to print substrates


A toe correction bushing including: an inner cylinder; a tubular damping mechanism which surrounds the inner cylinder; a retaining cylinder which surrounds the damping mechanism; an outer cylinder which surrounds the retaining cylinder; and an outer elastic body which connects the outer cylinder and the retaining cylinder. The retaining cylinder includes a bottom plate portion which extends inward in a radial direction from an end portion of the retaining cylinder on one side of an axial direction and a crimped portion which is located at an end portion on the other side of the axial direction and is crimped on the inside of the radial direction. The outer cylinder includes a facing surface which faces the one side of the axial direction and faces a part of a vehicle body. The facing surface is provided with a cushioning elastic body.

A toe correction bushing which is provided in a connection portion between a trailing arm and a vehicle body of an automobile and improves steering stability when turning is known. Patent Document 1 discloses a toe correction bushing including a toe correction mechanism which converts a load in a lateral direction of a vehicle when turning into a front and rear direction of the vehicle and improves steering stability of the vehicle and a liquid-sealed structure which is provided inside the bushing. The liquid-sealed structure functions as a damping mechanism which damps a vibration of a force converted into the front and rear direction of the vehicle.

Toe correction bushing and rear suspension device


A method for verifying a fingertip touch input to a digitizer, the method comprises detecting a pattern of signals obtained from conductive lines of a digitizer sensor, comparing the pattern to a pre-determined fingertip characteristic, and recognizing a fingertip touch input based on the comparison.

Touch technologies are commonly used as input devices for a variety of products. The usage of touch devices of various kinds is growing sharply due to the emergence of new mobile devices such as Personal Digital Assists (PDA), tablet PCs and wireless flat panel display (FPD) screen displays. These new devices are usually not connected to standard keyboards, mice or like input devices, which are deemed to limit their mobility. Instead there is a tendency to use touch input technologies of one kind or another. A stylus and/or fingertip may be used as a user interaction.
U.S. Pat. No. 6,690,156 entitled "Physical Object Location Apparatus and Method and a Platform using the same" and US Patent Publication No. 20040095333 entitled "Transparent Digitizer" both of which are assigned to N-trig Ltd., the contents of both which are incorporated herein by reference, describe an electro-magnetic method for locating physical objects on a FPD and a transparent digitizer that can be incorporated into an electronic device, typically over the active display screen. The digitizer sensor includes a matrix of vertical and horizontal conducting lines and sensors to sense an electric signal. Positioning the physical object at a specific location on the digitizer provokes a signal whose position of origin may be detected.
U.S. Patent Application Publication No. 20040155871 entitled "Touch Detection for a Digitizer" assigned to N-trig Ltd, which is incorporated herein by reference in its entirety, describes a digitizing tablet system capable of detecting position of both physical objects and fingertip touch using the same sensing conductive lines. Typically, the system includes a transparent sensor overlaid on a FPD. The digitizer's sensor includes a matrix of vertical and horizontal conducting lines to sense an electric signal. Touching the digitizer in a specific location provokes a signal whose position of origin may be detected.
U.S. Patent Application Publication No. 20060012580, entitled "Automatic switching for a dual mode digitizer" assigned to N-Trig, the contents of which is incorporated herein by reference, describes a method utilizing different types of user interactions, e.g. electromagnetic stylus and touch, in a digitizer system. A method for 'palm rejection' based on the size of the detected area of the touch, hence distinguishing between localized touch events and wide area touch events is described.

This patent is subject to a terminal disclaimer.

Fingertip touch recognition for a digitizer


A hot wedge, automatic seam welder is disclosed. The welder is comprised of a chassis having a base plate, a motor housing and a support arm extending from the motor housing. An S-shaped guide for guiding opposing sheets of material is between the base plate and the motor housing. Disposed downstream from the motor housing, depending from the support arm, is vertically-movable suspension for a driven upper pressure roller which is occludable with a driven lower pressure roller on the base plate. Also depending from the support arm is vertically-movable and adjustable suspension for the hot wedge. A horn-shaped shroud for guiding material over and under the wedge, and for shrouding the wedge when in its disengaged mode, is disposed upstream from the wedge. Guides for performing lap welds, fin welds and hem welds, as well as many variations thereupon, are also disclosed.

1. Field of the Invention
The present invention relates generally to apparatus for welding plastics, and more specifically to apparatus for forming seams in sheet materials having weldable plastic components.
2. Description of the Related Art
Apparatus for welding seams in plasticized sheet materials generally include several basic components: infeed guides; a heating element; pressure rollers; and, a drive system for moving either the sheet material or the welder with respect to the other.
Sheets of weldable material are commonly joined to one another with either of two primary seam configurations: the lap weld; or, the fin weld (the fin weld also being known as the "prayer" weld). A third primary seam type, used in binding a sheet's edge to itself, is the hem weld. Variations on, or specific applications of, these three primary seam configurations can be used to create a range of different structures adapted to particular purposes, including; taped reinforcements; taped, butt-welded joints; sleeves; tubes; and, flaps. And, weldable sheet materials can be mated with other materials and structures to yield features useful in the arts to which sheet materials are applied. Examples include hem tubes through which ropes, chains, cables and the like pass for supporting and suspending sheets; and, hem cords (i.e. hem tubes with tightly-bound, semi-rigid rods inside) for anchoring sheet edges to mating channels cut in support structures.
However, currently available seam welders are unable to produce all of the three primary seam types, or are otherwise lacking features which would make them equally practical for creating all three types in an industrial setting. For example, U.S. Pat. No. 4,950,352 issued to Greller in 1990 shows a welder with its pressure rollers oriented for unlimited material widths distal to the rollers with respect to the chassis; but, Greller's chosen roller suspension leaves limited space between the rollers and the chassis, making it impractical for use in lap welding very wide sheets of material. Further, Greller's 1990 welder, being a "hot-air" welder, would suffer limitations inherent to that genus, i.e. being useful only for sheet materials of limited thickness, and being generally noisy.
U.S. Pat. No. 4,855,004 issued to Chitjian in 1989 shows a power-driven, hand-guided, hot-air welder adapted for lap welding seams of wide sheets of material on roof decks, and the like. Lap seams are the primary intended product of the Chitjian welder; fin and hem welds appear technically possible, but less practical for the lack of appropriate infeed guides. Further, being hand-guided, drawbacks of the Chitjian welder include the non-uniformity in welds caused by slight drive speed and direction changes, and great dependence upon the skill of the operator, as well as the previously-mentioned problems with hot-air welders.
Ellenberger, et al, in U.S. Pat. No. 4,774,855 issued in 1988 shows another lap-seam welder adapted for hand-guiding over surfaces covered in weldable sheeting. This is a "hot-wedge" welder, employing a wedge-shaped, high-temperature, electrically-powered metal heating element. Hot-wedge welders such as that shown in the Ellenberger, et al 1988 patent are generally more versatile and reliable in their ability to weld materials of different thicknesses. However, the welder of the Ellenberger, et al 1988 patent is limited by its infeed guide structure in the types of welds it can perform; lap welds are primarily provided-for, while fin and hem welds may be technically feasible to a limited, albeit impractical, extent.
Taped reinforcements and taped, butt-welded joints are the product of the radiant-heat, tape welder disclosed in U.S. Pat. No. 4,913,772 issued to Taylor, et al in 1990. These are lap weld variants are difficult to perform with some other welders. However, the welder of Taylor, et al lacks the infeed guide structure to permit welds of the other primary types.
Greller, et al, in U.S. Pat. No. 5,091,038 issued in 1992, discloses a hot wedge welder with guides for performing lap and hem welds, and fin welds also appear possible. The Greller 1992 welder is "automatic," i.e. self-propelled, and can therefore be run along a sheet's edge under its own power at a precise speed for an accurate and consistent weld. However, the limitations of the chassis construction, and especially the dimension of the arm upon which the hot wedge is mounted on the Greller, et al 1992 apparatus, make lap welding therewith cumbersome, and practical in only limited applications. Specifically, only when both sheets to be lap welded can be laid out distal to the rollers and chassis can extremely wide sheets be lap welded together, because the space between the rollers and chassis is limited. Thus, the Greller 1992 welder cannot be used for lap welding or taped butt-welding wide sheets laid out on a roof deck, for example. Further, Greller, et al's 1992 apparatus appears to be exceedingly dangerous in that its hot wedge, which operates at temperatures of 1000.degree. F., or more, is not shielded to protect an operator from severe burns; and yet further, it projects menacingly from the apparatus when swung away from its welding position.
European Patent Application No. 79890022.1 filed by Winkler, et al in 1979 discloses a hot wedge welder illustrated as being capable of lap and fin welds, and which may have limited hem welding capability. The Winkler, et al welder employs an S-shaped chassis upon which opposed pressure rollers appear able to be mounted on either horizontal or vertical axes for either lap or fin welding, respectively. However, switching between roller orientations appears cumbersome, and would make precise centering of the hot wedge in the plane tangent to the point of roller occlusion difficult, wedge centering being quite important to the quality of the weld.
Methods and apparatus heretofore employed for constructing hem cords and for inserting ropes of cables in hem tubes are also inadequate. Most commonly, the hem is first constructed, and then a rope, cable or semi-rigid rod is threaded through the hem tube by hand. This task becomes exceedingly difficult when the hem tube is very long. And, even when a seam sealing machine's chassis includes a relieved area permitting a chain, rope or cable to be bound directly into the hem tube as the hem is being made, these machines are not adequate for making good quality hem cords because the hem tubes constructed therewith are characteristically too loose on the semi-rigid rod, allowing it to slip around more than is desirable.
Thus, it appears a need exists for a safe and reliable seam welder able to construct lap, fin and hem welds, as well as taped reinforcements, taped butt-welded joints, sleeves, tubes, hem cords and, flaps, while being minimally limited in the thickness of material it can weld. And, complexity and imprecision in switching among these different weld-types should be minimized, as well. Further, an ideal welder would be able to perform lap and taped butt-welds without limitations on the width of either sheet being welded. Yet further, accurate wedge centering to assure uniform heating of the sheets being welded would be desirable, as would precise speed control to assure that the weld is consistent along its length. And, means for producing a tight, continuous, unlimited-length hem cord would also be provided.


A body support system for providing support to a user is provided. In certain embodiments, a body support system comprises a single leg having a first end and a second end; a seat attached to the first end of the single leg; a base attached to the second end of the single leg, the base having a curved surface capable of securely engaging a ground surface at a range of angles; and a strap having a first end and a second end wherein the first end of the strap is attached to the single-legged body support system and wherein the second end of the strap is capable of attaching to a user.

The present invention generally relates to body support devices and more particularly, to single legged body support systems for use by fisherman and other outdoor enthusiasts.
Portable and collapsible seating devices have been heretofore proposed for the problem of providing a seating devices for the many occasions where outdoor seating is not available, such as during fishing, outdoor gatherings, and sporting events among others. For example, some activities, such as wade fishing may entail a fisherman standing outside for hours without being able to sit down and without a structure to lean on for support. This lack of seating or support structures can often result in undesirable fatigue and/or back pain among other problems.
Several solutions for such outdoor seating have heretofore been provided such as the portable and collapsible seat as described in U.S. Pat. No. 4,232,896, the single-legged chair as described as described in U.S. Pat. No. 4,930,839, the portable stool as described in U.S. Pat. No. 6,062,638, and the portable seat as described in U.S. Pat. No. 5,720,522. Unfortunately, all of the portable seat and/or support devices heretofore proposed suffer from one or more disadvantages including not being suitable for use during certain fishing activities such as wade fishing. In particular, many of the conventional seat/support devices are not capable of resisting the highly corrosive salt water environments inherent in many fishing locations. Further, many of the conventional devices are not buoyant and consequently, would sink in the water if released. Often, the conventional devices lack a strap to prevent the device from being separated from the user. Additionally, conventional devices suffer from a number of other disadvantages such as being incapable of simultaneously used as a storage device.
In some cases, it may be desirable for a person to drag a support device along with the person as the person moves about. Examples of activities with such a need are golf spectators who stay in a spot for a period of time before moving to the next golf hole or during fishing where a fisherman may fish in one spot for a period of time before moving on to another spot.
Other disadvantages of the prior art include a lack of comfort due in part to too small a seat size and lack of portability of the support device, including the inability to easily carry the device due to weight and/or physical configuration of the device.
Accordingly, it would be desirable to have a support device upon which users may lean that addresses one or more of the disadvantages of the prior art.


A non-intrusive flow detector consists of an optical sensor assembly that attaches non-obstructively and non-invasively to a fluid flow meter. The sensor monitors dial movement of a least flow dial or wheel and generates an electrical signal representative of a flow through the meter. Electrical circuitry having an adjustable timing circuit is used to selectively detect either excessive flow during a predetermined time period or the absence of flow after a predetermined time period. The electrical circuitry is adapted to connect to an existing alarm system and may be housed either near the meter in a separate enclosure or placed in an existing alarm panel.

Leaks or other unusual events that cause extraordinary flow volumes in piping systems unnecessarily cost residential and commercial property owners money. In addition, leaking water can cause large amounts of damage to a home or commercial space. Water is typically expensive; high utility bills may result from excess or wasted usage. In addition, the growing scarcity of potable water motivates reducing or eliminating waste.
Water damage resulting from leaks can cost property owners or insurance companies additional expense. A detector that monitors fluid flow volume and alerts owners, authorities, insurance companies, or a central station when unusual volume is detected may reduce overall utility usage, as well as unnecessary damage and expenses caused by water leaks. Additionally, a small, easily installable, easily operable detector will encourage and facilitate use by property owners.
Many current flow meters that measure flow by automatically reading meters are bulky, are designed for technician use only, and do not alert owners to unusual flow volumes. Rather, they merely report actual consumption. Utility meters are often located inaccessibly. For this reason, and to reduce field personnel, utility companies, for instance, find advantage in automatically reading meters electronically, and transmitting the reading, such as by radio waves.
U.S. Pat. No. 7,042,368, issued May 9, 2006 to Patterson et al., discloses an automated meter reader to report utility consumption. A device and method of use are described having an optical transceiver that emits light toward a meter face, an optical receiver that accepts light reflected off the meter face, and an amplifier and gain control as part of a signal processing circuit. Patterson et al. do not disclose any means to continuously monitor for unusual flow rates. The meter reader is also obtrusive, blocking ordinary visual inspection of the meter during use. The detector is not designed for property owner use.
U.S. Pat. No. 5,214,587, issued May 25, 1993 to Green, also discloses a device for monitoring utility usage. A meter sensor assembly is attached to a meter and a user interface unit with LCD display processes the sensor signal into useful data. This device is less bulky and obtrusive than that of Patterson et al., but it is built to read only meters with rotating discs. Again, it reports consumption, but does not automatically alert a user or other party to unusual usage volumes.
Presently available flow detectors that do alert owners to unusual flow volumes are invasive to the meters and piping systems, bulky, and unwieldy for typical owners to install and operate. Whereas automatic meter readers are somewhat non-invasive, leak detectors typically use invasive means such as valve or pipe add-ons. Other detectors use non-centralized systems that do not detect flow starting at the meter where the piping system begins.
U.S. Pat. No. 6,317,051, issued Nov. 13, 2001 to Cohen, discloses an invasive flow monitoring device mounted in series with a water pipe, a controller, logic components, and a shut-off valve to shut off water flow when a predetermined condition is met. No meter is read, and actual modifications to existing piping systems must be made.
U.S. Pat. No. 5,228,329, issued Jul. 20, 1993 to Dennison, discloses a leak detector that uses a series of thermal fluid flow sensors. These sensors detect leaks indirectly by comparing variations in pipe temperatures caused by variations in flow rate. When leaks are detected, a chime and light emitting diode are activated.
It would be advantageous to provide a centralized flow detector to detect flow rates from the beginning throughout an entire piping system.
It would also be advantageous to provide a fluid flow detector that continuously monitors the dials on a meter for unusual flow volume.
It would further be advantageous to provide an easily installable, easily operable fluid flow detector to facilitate use by a property owner.
It would also be advantageous to provide a fluid flow detector with a sensor assembly mechanically adjustable in three planes.
It would further be advantageous to provide a fluid flow detector capable of alerting property owners, authorities, insurance companies, or central stations of unusual fluid flow rates.
It would also be advantageous to provide a non-invasive fluid flow detector that requires modification to neither existing piping systems nor existing meters.


A vacuum casting die simpler in configuration and improved in seal performance in vacuum casting using a slide core, provided with a pair of main dies, a sealing member for seamlessly and continuously sealing mating faces around the closed space formed between the main dies, and a slide core housed in the sealed space formed between the main dies sealed by the sealing member.

1. Field of Invention
The present invention is relates to a die used for vacuum casting.
2. Description of the Related Art
One of the reasons for variations in quality of die cast products and the resultant drop in reliability is gas contained in the die cast products. That is, molten metal injected and filled at a high speed and high pressure forms turbulence inside the injection sleeve and die cavity resulting in entrainment of air or vaporized release agent coated on the die.
To overcome this disadvantage, there is known the technology of casting using a die casting machine using the vacuum die casting method so as to suppress entrainment of gas in the die cast products and thereby reduce variations in quality due to the content of gas in the die cast products (for example, see U.S. Pat. No. 2,785,448).
In a die casting machine using the vacuum die casting method, the die cavity has to be able to be made greater in vacuum and the reduced pressure state maintained in order to cast a high strength and quality product. If the die cavity is not made high in vacuum, the cast product may contain gas. As a result, when applying annealing or other heat treatment to the product after casting, the product will easily suffer from distortion or deformation and it will be difficult to obtain a sufficient effect by the vacuum die casting method.
Japanese Unexamined Patent Publication (Kokai) No. 2002-239705 discloses technology for obtaining a better vacuum in the die cavity and maintaining the reduced pressure state by seamlessly and continuously sealing the mating faces around the cavity.
Summarizing the disadvantages to be solved by the invention, when a casting product has recesses or hollow parts which cannot be molded in the opening/closing direction of the die, it is necessary to insert a so-called slide core between the dies for casting. The slide core inserted between the dies before casting is pulled out in a direction along the mating faces of the dies after casting, then the casting product is taken out from the dies. When using a slide core for vacuum casting and moving the slide core, it is necessary to prevent the slide core from interfering with the seal member. Therefore, the seal structure around the slide core becomes complicated and the reliability of the seal performance easily falls.


A vertical Hall device includes: a substrate; a semiconductor region having a first conductive type and disposed in the substrate; and a magnetic field detection portion disposed in the semiconductor region. The magnetic field detection portion is capable of detecting a magnetic field parallel to a surface of the substrate in a case where a current flows through the magnetic field detection portion in a vertical direction of the substrate. The semiconductor region is a diffusion layer including a conductive impurity doped and diffused therein. The semiconductor region is made of diffusion layer so that the device has high design degree of freedom.

In general, a lateral Hall cell detects a magnetic field component perpendicular to a substrate surface (i.e., a chip surface). The lateral Hall cell is disclosed in, for example, "Integrated three-dimensional magnetic sensor" in Journal of Institute of Electrical Engineers of Japan, Vol. 109-C, No. 7, pages 483-490 (1989). However, it is difficult for the lateral Hall device to detect a magnetic field component parallel to the substrate surface.
To detect the magnetic field component parallel to the substrate surface, a vertical Hall device as a vertical type Hall device is provided. The vertical Hall device is disclosed in, for example, Japanese Patent Application Publication No. H01-251763. The vertical Hall cell can detect the magnetic field component in parallel to the chip surface.
However, an epitaxial substrate is necessitated to provide the vertical Hall device. Therefore, the design degree of freedom is limited to use the epitaxial substrate.

Magnetic sensor having vertical hall device and method for manufacturing the same


The present invention relates to processes for the enzymatic synthesis of nucleotide-6-deoxy-D-xylo-4-hexuloses starting from a nucleoside monophosphate (NMP). These processes comprise simultaneous incubation of the following substances in a buffer solution:. (a) substrates comprising a nucleoside monophosphate, phosphoenolpyruvate, adenosine triphosphate, and sucrose; and PA1 (b) enzymes comprising pyruvate kinase, nucleoside-monophosphate kinase, sucrose synthase and deoxythymidine-D-glucose 4,6dehydratase.

Enzymatic syntheses of oligosaccharides (such as N-acetyllactosamine (LacNAc) and its derivatives), using glycosyltransferases (for example .beta.-1.fwdarw.4-galactosyltransferase (GaIT) EC 220.127.116.11!) and nucleoside phosphate glycosides (nucleotide-sugars) as glycosyl donors have been known for a long time (Wong, C.-H., et al., J. Am. Chem. Soc. 118, 8137-8145, 1991). Wong et al. developed LacNAc syntheses in which the nucleotide-sugar, the uridine diphosphate-glucose (UDP-Glc), is regenerated in situ. See Wong, C. -H., et al., J. Org. Chem. 47, 5416-5418 (1982) and Wong, C. -H., et al. J. Org. Chem. 57, 4343-4344, (1992). As a consequence of this, it is no longer necessary in these reactions to employ the relatively costly nucleotide-sugars in stoichiometric amounts.
The LacNAc cycle developed by Elling and Kula (DE P 42 21 595 C1; Elling, L., Grothus, M., Kula, M.-R., Glycobiol. 3, 349-355, (1993)) represents an improvement compared with cycles disclosed to date, because only three enzymes have to be employed for the synthesis of LacNAc, instead of the six enzymes used in prior art methods. See FIG. 1. Such synthesized disaccharides can be used as precursors for further reactions with different transferases, for example sialyltransferases or fucosyltransferases.
The demand for nucleotide-sugars as substrates has grown in past years due to the discovery and utilization of glycosyltransferases for the preparation of oligosaccharides. It was this development which resulted in a demand to prepare these costly nucleotide sugar substrates at minimum cost in order to more easily obtain defined glycosyl structures.
One target product of these enzymatic syntheses is, for example, the tetrasaccharide sialyl-LewisX or its derivatives (Ichikawa, Y., et al., J. Am. Chem. Soc. 114, 9283-9298 (1992)), whose importance in cell-cell recognition is the subject of intensive research. See DeFrees, S., et al., J. Am. Chem. Soc. 117, 66-79, (1995).
Sucrose synthase EC 18.104.22.168! is a glycosyltransferase which is widespread, especially in plants, and whose function as catalyst for the formation of nucleotide-sugars within plant metabolism has been reviewed in Avigad, G., Encyclopedia of Plant Physiology New Series Vol. 13A, Carbohydrates I, Intracellular Carbohydrates, Springer Verlag, Berlin, 217-347, (1982). This enzyme is suitable for synthesizing nucleotide-sugars, for example UDP-, dTDP-, ADP-, CDP- and GDP-Glc (Elling, L., Grothus, M., Kula, M.-R., Glycobiol. 3, 349-355, 1993). Purification of sucrose synthase from rice (Elling, L., Kula, M.-R., J. Biotechnol. 29, 277-286, 1993), and its use for in situ regeneration of UDP-Glc has been described by Elling et al. (DE P 42 21 595 C1; Elling, L., et al., Glycobiol. 3, 349-355, 1993). The rice enzyme is a homotetrameric protein with a molecular weight of 362 kDa. The enzyme has already been employed for the preparative synthesis dTDP-Glc starting from dTDP in an enzyme membrane reactor (EMR) (Zervosen, A., et al., Angew. Chem. 106, 592-593, (1994).
The increased availability of sucrose synthase in recent years has been made possible by purification studies such as those described by Elling (DE P 42 21 595 C1; Elling, L., et al., J. Biotechnol. 29, 277-286 (1993); Elling, L., et al., Glycobiol. 3, 349-355 (1993)). The enzyme itself has been known for several years, but insufficient amounts have been available to date to permit its protein chemical properties to be investigated.
Thus, only recently have the pH optimum, and the ions necessary for the reaction (ionic strength, presence of ions indispensable for the reaction) and the regulation of this enzyme (end product inhibition) become known (L. Elling, Glycobiology 5, 201-206, 1995). In addition while the enzyme is not commercially available, the isolation procedure for sucrose synthase is described in Elling, et al. Biotechnol 29:277-286 (1993), Elling, et al. Glycobiol. 3:349-355 (1993), and DE patent 42 21 595 C1, all of which are hereby incorporated by reference.
Preparative syntheses of nucleotide-sugars starting from a nucleoside monophosphate (NMP) have already been described (Heidlas J. E., Williams K. W., Whitesides G. M., Acc. Chem. Res., 25., 307-314, 1992). Heidlas discloses the conversion of NMP to nucleoside triphosphate (NTP) using myokinase and pyruvate kinase, which then reacted with the particular sugar 1-phosphate to give the nucleotide-sugar with catalysis by a specific pyrophosphorylase. In contrast to the nucleoside-specific pyrophosphorylases used in such processes, use of the enzyme sucrose synthase makes it possible to prepare variously activated glucose donors. Hence, it has now been found that sucrose synthase is able to accept both nucleotide diphospates (NDP) and deoxy nucleotide diphosphates (dNDP) as substrates. Thus, for example, dUDP-glucose can be prepared preparatively starting from sucrose as glycosyl donor and dUDP. Coupling kinase and sucrose synthase enzymatic reactions results in less costly production of nucleotide-sugars. Nucleoside monophosphates (NMP) can be used in such a coupled synthesis and can be obtained at distinctly lower cost than nucleoside diphosphates (NDP).
Some primary nucleotide-sugars are enzymatically converted in cells into other, so-called secondary nucleotide-sugars. Thus, for example, GDP-fucose is produced from GDP-mannose in three consecutive steps. Some recent findings in this area have been worked out by Chang et al. taking the example of porcine salivary glands (J. Biol. Chem., 263, 1693-1697, 1988). In this study, the authors describe the conversion of GDP-mannose first into GDP-4-keto-6-deoxymannose using a specific dehydratase, subsequently an epimerase and reductase activity to GDP-fucose. Direct preparation of fucose starting from mannose cannot take place in metabolism without the presence of the nucleotide group. These enzymes therefore rely on an activation, i.e. the nucleotide moiety. Based on the current state of research, it is likely that the formation of other secondary nucleotide-sugars takes place in a similar fashion. The nucleotide-sugars dUDP-and dTDP-6-deoxy-D-xylo-4-hexulose are formed via catalysis using dTDP-Glc-4,6-dehydratase EC 188.8.131.52! from dUDP-and dTDP-Glc (Zarkowsky, H., Glaser, L., J. Biol. Chem. 222, 4750-4756, 1969). dTDP-6-Deoxy-D-xylo-4-hexulose is an intermediate product in the biosynthetic pathway of the dTDP-L-rhamnose. Enzymatic synthesis and isolation of such a have been described (Marumo, K., Lindqvist, L., Verma, N., Weintraub, A., Reeves, P. R., Lindberg, A. A., Eur. J. Biochem. 204, 539-545, 1992). dUDP-Glc cannot be bought but has been synthesized in analytical amounts using the dTDP-Glc pyrophosphorylase from Pseudomonas aeruginosa (Melo, A., Glaser, L., J. Biol. Chem. 240, 398-405, 1965). It is possible by utilizing the synthetic potential of sucrose synthase to prepare dUDP-and dTDP-6-deoxy-D-xylo-4-hexulose starting from dUMP and dTDP respectively (FIG. 2) (Stein, A., Dissertation, Heinrich Heine University, Dusseldorf, 1995). However, in the process taught by Stein, et al. the separate enzymatic reactions required to produce such hexuloses are carried out in separate reaction vessels. In other words, (1) the coversion of NMP to NDP, (2) the transfer of the glucose moiety to dTDP or dUDP and (3) the dehydration of glucose all take place in separate vessels and one reaction must be complete before the next step is initiated.
Thus, the prior art does not disclose a method for the synthesis of nucleotide sugars whereby all the reagents and enzymes necessary to produce a nucleotide-sugar from a NMP, sugar and phosphate source may be incubated together. In particular, the prior art does not teach a method whereby sucrose synthase can be incubated along with enzymes which require dUDP-glucose as a substrate, such as a dehydratase.
It would therefore be useful to have a method for making nucleotide-sugars in which all reagents and enzymes could be incubated together in the same reaction vessel. In particular, it would be advantageous to have a method where sucrose synthase and a dUDP-glucose dehydratase could be used together to produce nucleotide-6-deoxy-D-xylo-4-hexulose.

Process for the synthesis of nucleotide-6-deoxy-D-xylo-4-hexuloses


The system includes a plate with a screw hole and a bone screw wherein the screw and plate cooperate such that the screw is inhibited from back out from the plate after inserted into bone. Described embodiments include a pawl, with and without ratchet, an interfering clip about the screw head, and a snap-fit engagement between the screw and screw hole. The screw hole is preferably provided with openings at at least one of two diametric sides which provide dynamic compression functionality and access under the screw for an instrument to facilitate screw release.

1. Field of the Invention
This invention relates broadly to orthopedic devices. More particularly, this invention relates to systems for engaging bone screws relative to bone plates.
2. State of the Art
For various fractures of bones of the body, compressive plating is a well known technique to impart the stabilization desirable for proper healing. In compressive plating, a rigid, typically metal plate is placed on the outer surface of the bone across the fracture, and screws extend through the plate and are secured into the bone on either side of the fracture in a manner which permits the rigid plate to offer support to the bone during healing. The screws include threads along a shaft adapted to engage cortical bone. Most commonly, the head portion of the screw is a standard screw head which provides a compressive force about a corresponding round screw hole of the plate as the fixator is threaded into the bone, thereby causing compression of the plate against the bone.
U.S. Pat. No. Re. 28,841 to Allgower describes a plate that is used with generally standard bone screws having heads with a convex undersurface. The plate includes oblong screw holes which each define at one end an upper ramped portion and a generally smaller radius of curvature about the ramped portion. In use, a hole is drilled into the bone through the screw hole adjacent the ramp and a screw is inserted into the drilled hole and rotated until the head of the screw contacts the ramp. Upon such engagement, there is displacement of the bone plate in a direction to move the ramped portion away from the screw and to cause the plate to apply pressure to maintain the bone parts together about the fracture in tight engagement. The holes in a such a plate are commonly referred to as dynamic compression holes (or DCH). However, micromotion between the bone and the portion of the screw within the bone can cause loosening of the entire assembly, diminishing the stability of the set fracture and a loss of compression across fracture.
More recently, threaded screws with heads which threadably engage in threads in the plate to lock the screws relative to the plate have been used. However, such systems do not provide the necessary control of compression between the plate and bone. Control over compressive forces is lost as soon as the threads of the head of the screw lock relative to the plate. Therefore, such a system provides sub-optimal stability for attachment of certain plates to bone. In addition, even such threaded engagement can loosen over time.
As a result, several systems have used secondary discrete locking elements to lock a bone screw to the plate. For example, U.S. Pat. No. 6,383,186 to Michelson teaches the use of a set screw which seats against the head of the bone screw to prevent backing out of the bone screw. U.S. Pat. No. 6,152,927 to Farris teaches a screw and washer assembly which provides compression against the head of the bone screw to lock the bone screw within the screw hole and prevent it from backing out. Both of these systems require that the surgeon work with separate and small locking elements at the time of the screw insertion, and such small elements may easily become lost in the surgical wound.
U.S. Pat. No. 5,549,612 to Yapp et al. teaches a system in which a screw can be locked relative to the plate with a cam permanently mounted in an aperture in the plate. The cam cannot provide any downward force against the screw head, thereby limiting potential fixation. As such, if the cam rotates just a small amount from a locking angle, the fixation provided by the cam may be lost. Moreover, the shape of the cam (as shown in FIGS. 4 and 4A of the patent) suggests that the cam applies an upward force against the screw head which disadvantageously counters the compressive force of the screw against the plate.

Bone fixation system and bone screws having anti-back out feature


When displaying decorative ornaments in vertical chains, that is, as ornament curtains, for example, in light fixtures, gaps or voids between the ornaments can detract from the overall visual appeal. Methods and apparatus of the present invention minimize the gaps and voids in an ornament display to provide a denser display of ornaments than the existing art. According to aspects of the invention, the denser ornament display is achieved by mounting ornament chains in gallery rings that suspend the ornament chains in staggered relationship either in multiple planes or within the same plane whereby the ornaments fill the gaps and voids in the visual field of the viewer. The invention also includes improved gallery rings and ornament chains that are adapted to be mounted to the improved gallery rings. Aspects of the invention may be used in many types of ornamental light fixtures, such as, chandeliers.

In the construction of ornamental lighting fixtures, such as chandeliers, it is common to incorporate vertical "curtains" of decorative ornaments. These curtains are typically are made from "chains" of ornaments, for example, chains of suspended octagonal crystals. The most widely used and cost effective crystal element used in the construction of crystal chandeliers is the 14-millimeter (mm) octagon. For example, the 14-mm octagon is the preferred ornament used for candle-to-candle swag chains in traditional chandeliers, vertical curtain chains for contemporary fixture designs, and in a variety of other common crystal configurations.
Spherical facetted beads are widely used components in the jewelry industry, and are sometimes used in the fixture industry. Spherical faceted beads are typically available in a variety of sizes, shapes, and colors. Historically, spherical faceted beads have had some limited use in the construction of chandeliers. More recently, the use of spherical faceted beads has increased; particularly, these beads are used to line the arms and scrolls of traditional chandeliers and in candle-to-candle swag chains. There have also been some attempts to use such jewelry beads to create crystal curtains.
The 14-mm crystal octagon ornaments became the preferred component for use in crystal curtain designs with the invention by Arnold Schonbek of the so called "bow tie connector," for example, as described in U.S. Pat. No. 3,629,571. The Schonbek bow tie connector provides the advantage of preventing ornament chains from twisting. By preventing twisting, the designer can create the visual effect of a continuous crystal surface, for example, by arranging octagons broad side out and adjacent to one another. Prior to the introduction of the Schonbek connector, interlocking wire loops were used to link ornamental crystals in chains. Not only did these interlocking wire loops vary in length, but wire loops also allowed the individual crystals to undesirably rotate and twist. As a result, when using wire lops, the orientation of ornaments one-to-another was often compromised. For example, the resulting crystal surface was typically interrupted by many openings and gaps due to the imprecision of the positioning of the ornaments, for example, the octagonal ornaments.
Even with the use and broad acceptance of the Schonbek connector, the resulting crystal curtains that used these connectors often lacked "density," that is, often lacked a uniform continuous ornament display. Among other things, this lack of density is primarily due to the gaps or discontinuities that could appear between adjacent ornaments. This lack of density that is typical of prior art ornament arrangements is clearly shown in FIG. 1.
As shown in FIG. 1, an arrangement 10 of octagonal crystals 12 connected by the connectors 14 disclosed in U.S. Pat. No. 3,629,571 typically resulted in undesirable gaps 16 between crystals 12. Among other things, these gaps 16 reduce the visually density of the display and introduce unsightly views into the interior of the chandelier.
An improvement in the appearance of lighting fixtures was realized in another innovation of Arnold Schonbek. As shown in FIG. 2A, Mr. Schonbek introduced a crystal support arrangement 20 including a specially designed metal support ring 22. Support ring 22 functions to raise every other octagon chain 24 and position the octagon crystals 26 in chains 24 in an interlocking arrangement with octagonal crystals 26 in adjacent crystal chains 28. A similar prior art interlocking arrangement 30 is shown in FIG. 2B having ring 32 and crystal chains 34 and 38. The arrangement shown in FIG. 2B is typical of the ornament mountings in chandeliers provided by A. Schonbek & Co. Inc. (now affiliated with Schonbek Worldwide Lighting Inc. of Plattsburgh, N.Y.) under the trade name "Mirabelle." As shown in FIGS. 2A and 2B, these crystal arrangements have the effect of significantly reducing the size of the gaps 25 and 35, respectively, between the octagonal crystals.
Though an improvement in the art, the arrangements shown in FIGS. 2A and 2B are still far from ideal. For example, undesirable gaps 25 and 35 are still provided between the chains 24 and 28 and chains 34 and 38, respectively. In addition, these arrangements shown in FIGS. 2A and 2B inherently required the exposure of horizontal structures, that is, the support rings 22 and 32, having no crystal ornaments. These structures typically are provided to have a height or thickness sufficient to raise every other chain into the interlocking position. In many ornamental fixture designs this banding (which is sometimes referred to as "vertical banding") introduced an unwelcome visual element.
One prior art ornament arrangement that reduces the required size of the vertical banding is shown in FIG. 3. In this prior art arrangement 40, interlocking of octagonal crystals can be provided by suspending the adjacent an intermediate crystal chain 48 between adjacent chains 44 from an appropriately longer wire hook 42 suspended from a gallery ring 43. However, arrangement 40 is also undesirable because it is characterized by especially unsightly gaps 45 at the top of the alternating chains 44, 48.
Another prior art improvement in the design of chandeliers having crystal curtains is provided with the development of the "pocket gallery", for example, as disclosed in U.S. Pat. No. 5,144,541. The pocket gallery, or the gallery plate having apertures or "pockets" for retaining ornaments, reduced or eliminated the disturbing appearance of vertical banding associated with a standing gallery ring while precisely positioning adjacent chains in relation to one another. However, the clean, metal-free appearance of the pocket gallery design is gained at the expense of a less dense curtain, since the individual octagons are typically arrayed along side one another, once again opening up square-shaped gaps, for example, similar to gaps 16 of FIG. 1.
Attempts have been made by artisans in the field to use facetted bead chains to create crystal curtains. However, these designs have generally been unsatisfactory for a number of reasons. For example, given their spherical shape, facetted beads are not a cost effective means of covering an ornamental surface. Furthermore, satisfactory methods for precisely positioning of such beads did not exist in the art.
Some attempts have been made to use square crystal chains, as shown in FIGS. 4A and 4B. FIG. 4A shows a front elevation view of an ornament arrangement 50 having a plurality of vertical ornament chains 52 comprising square ornaments 54. FIG. 4B is a plan view of a section of gallery plate 56 used in arrangement 50. Chains 52 are mounted in a gallery plate 56 having apertures 58 that retain ornaments 54 to suspend chains 52. Though arrangement 50 produces a dense crystal curtain, the disadvantage of arrangement 50 is that square crystals are not preferred; specifically, the faceting pattern of square crystals inherently reduces the prismatic effect of the appearance of the fixture.
Another prior art attempt to provide a dense, vertically hanging, crystal curtain is provided by the prior art arrangement shown in FIGS. 5A and 5B. FIG. 5A shows a front elevation view of an ornament arrangement 60 having a plurality of vertical ornament chains 62 comprising octagonal ornaments 64. FIG. 5B is a plan view of a section of gallery plate 66 used in arrangement 60. Prior art arrangement 60 increased the density of the crystal presentation with the addition of glass rods 68 suspended in apertures 68 in gallery plate 66 between adjacent octagon chains 64 suspended in apertures 69 in gallery plate 66. However, since the octagons 64 and glass rods 68 do not interlock, undesirable gaps 65 are left in the "curtain" of ornaments. Notwithstanding this disadvantage, in arrangement 60, the optical effect of the light in the glass rods 68 provides the desirable effect of drawing the eye of the viewer away from the fixture's internal components, for example, away from a chandelier's internal components. Thus, in this aspect, prior art arrangement 60 provides some improvement over arrangements that came before it.
However, clearly, these, and other, examples of prior art crystal mounting arrangements are characterized by undesirable gaps between ornaments. These gaps not only interrupt the desired uniform continuous display preferred in lighting fixtures, but these gaps may also undesirably expose internal components of the fixture, for example, internal structural components, that may be unsightly or simply interfere with the desired presentation intended by the designer of the fixture. These and other disadvantages of the prior art are overcome by aspects of the present invention.

Methods and apparatus for displaying decorative ornament curtains


A process and apparatus for planting aquatic plants underwater on the bottom of estuaries in propeller scars and for encouraging plant growth in propeller scars. Aquatic plant shoots are transplanted by positioning shoots in a sediment tube which is in turn placed in the propeller scar. When the sediment tube is placed in the propeller scar the sea grass shoots are held in position for an extended period of time to allow the sea grass shoots to take root on the estuary bottom. The sediment tubes may be preformed or they may be formed just prior to their placement in the estuary. A watercraft may be used to position the sediment tubes with and without sea grass shoots over an area of the propeller scar. With the process and apparatus of this invention, sea grass plants can be replanted on the bottom of an estuary and new plant growth encouraged in propeller scars. Further in accordance with another embodiment of this invention a tube or other obstruction without plant shoots is placed in a propeller scar in order to impede water flow through the propeller scar. When water flow through the propeller scar is impeded natural plant growth is encouraged.

This invention is concerned with a process and related apparatus whereby aquatic propeller scars may be repaired underwater for purposes of restoration. The restoration of all aspects of the environment has become extremely important in recent years. The three areas of restoration which are of primary import are reducing air pollution, restoring and cleaning up the land and cleaning up and restoring our waterways, the ocean and related estuaries. It is these related estuaries that are the primary thrust of the subject invention.
As a result of the decrease in water quality, millions of acres of aquatic plant life, which form an important part of the aquatic Eco system, have been destroyed. While the restoration of aquatic plant life is difficult, it is possible, for example see the process and apparatus of co pending application Ser. No. 09/104,681 filed Jun. 25, 1998 now U.S. Pat. No. 6,070,537 and application Ser. No. 09/573,724 filed May 18, 2000. While the process of this U.S. Pat. No. 6,070,537 is well suited to the planting of large underwater areas it is not particularly suited to the replanting of propeller scars. Propeller scars are areas that have been striped of aquatic plant life, as a result of the propeller of the moving boat inadvertently being allowed to come into contact with the estuary bottom, thereby leaving a semicircular trench on the bottom of estuary.
Because aquatic plant life is an important part of the complex aquatic environment, the restoration of the total estuary bottom is important including propeller scars.
The natural restoration of aquatic life, in propeller scars is an extremely slow process. While it is possible to manually plant shoots of aquatic plants, in propeller scars this process is extremely slow and expensive. Due to the cost of labor, the manual planting of sea grass plants has at best been marginally successful. Further due to the peculiar nature of propeller scars manual planting is often unsuccessful. Also because propeller scars are widely dispersed the cost of manually planting just one propeller scar in an estuary can be prohibitive. Likewise manual planting in some instances is of questionable success as the person doing the planting, in walking over the bottom of an estuary, does further damage by crushing other plants which may be growing in the area.
This invention is concerned with a process and apparatus whereby sea grass can be restored and quickly planted in an economical fashion in a propeller scar or the propeller scar can be filled in such a manner that the re-colonization of sea grass is encouraged.
As used in connection with this invention, the term aquatic plant life and sea grass includes many species of plant life such as halodule wrightii (shoal grass), thalassia (turtle grass), etc. The process and apparatus of this invention is particularly suited to the planting of thalossia sea grass in propeller scars and the re-colonization of sea grass in these propeller scars.
Aquatic plant life as it exists in estuaries is important in preventing water pollution as this plant life acts as a filter for many pollutants and hence, this plant life helps to maintain water quality. Therefore it is important that the maximum area be covered with aquatic plants including those areas that have been denuded of plant life by the contact of a marine propeller with the estuary bottom.
The restoration of aquatic life to the bottom of our estuaries is extremely important as this aquatic plant life plays a critical function in the total marine Eco system. A large number of important marine animals, both warm and cold blooded, rely totally or in part on aquatic plants as a breeding area, for cover, for food, etc. For example, the endangered manatee relies solely on sea grass as its food source and sea turtles rely on sea grass for part of their diet.
The primary object of this invention is a process whereby aquatic plant life may be and planted or restored in propeller scars which are located in the bottom of an estuary.
A further object of this invention is a process whereby a propeller scar can be filled in such a manner as to encourage the re-growth of sea grass.

Process and related apparatus for repairing aquatic propeller scars


A fishing reel supports at a front wall of a reel body, a spool, a rotary frame which has first and second arms, and a bail arm which is supported between the arms in a manner permitting it to be turned over between a position where the rotary frame rotates to wind a fishing line onto the spool and a position where the line is released. A control means is provided to turn over the bail arm from the line winding to the line releasing position, the control means having a control member positioned in proximity to an arm roller at the bail arm which retains the line at the line winding position, so that when an angler catches by his finger the line retained by the arm roller, he can operate the control member in association with the line catching action.

Generally, during casting of a spinning reel an angler turns the bail arm over in a swinging motion from the line winding to the line releasing position. In doing this he first catches, for example, by his right hand forefinger, the line retained by an arm roller at the bail arm which is in the line winding position. Then, while keeping his forefinger in this position, he uses, for example, his left hand to turn over the bail arm from the line winding to the line releasing position.
This very complicated operation makes turning the bail arm difficult and prevents quick casting.

Outer spool type spinning reel having improved bail arm control mechanism


The object of the present invention is to provide a simple, inexpensive method of surface treatment capable of improving the strength and smoothness of fishing tackle parts made of alloy steel containing chrome. The method of surface treatment for a fishing tackle part made of alloy steel containing chrome according to the present invention is characterized in that the surface of the fishing tackle part made of alloy steel containing chrome is nitrided to form a diffused layer of chromium nitride from the surface of said part inwards, and then said surface is covered with a layer of titanium nitride. Further, another embodiment of the method of surface treatment for a fishing tackle part made of alloy steel containing chrome according to the present invention is characterized in that the surface of the fishing tackle part made of alloy steel containing chrome is covered with a layer of titanium nitride, and then the surface of said layer of titanium nitride is nitrided to form a diffused layer of chromium nitride from the surface of said part inwards.

1. Field of the Invention
The present invention relates to a method of surface treatment for a fishing tackle part made of alloy steel containing chrome.
2. Description of the Related Art
Conventionally, line guides for fishing rods, particularly snake guides (S-shaped guides) have mainly been made of alloy steel containing chrome, such as stainless steel, because of its water and salt resistance. However, in the case of snake guides made of stainless steel, the stainless steel wire used must be quite thick to ensure that the guide itself is strong, adding unwanted weight to the rod. Recently, remarkable improvements have been made in the lightness of materials such as graphite used in fishing rods and rods are becoming lighter, but little improvement has been seen in the line guides attached to the rods, particularly snake guides, and there is room for improved lightness.
Other examples of metal fishing tackle parts include reels and reel seats. These are usually made of brass, stainless steel, aluminum based alloy, etc., but the surface strength of these materials is not yet adequate and there is room for improved resistance. Also, if the surface strength of other metal parts used in reels, such as screws, gears, axles, bearings, ratchets, etc., could be improved, the life of the reel itself would be extended.
Further examples of metal fishing tackle parts include the bobbin holders used in fly tying, where there is a problem with the smoothness of the tip of the metallic pipe through which the silk thread passes, which can cause the thread to break. To reduce this problem, ceramic pipe is being used instead. However, if the tip of the metallic pipe could be smoothened by a simple and inexpensive treatment, bobbin holders made from metallic pipe would be easier to work with.
Thus, the object of the present invention is to provide a simple, inexpensive method of surface treatment capable of improving the strength and smoothness of fishing tackle parts made of alloy steel containing chrome.

Method of surface treatment for a fishing tackle part made of alloy steel containing chrome


A process for the solution polymerization of olefins with improved on-stream time is provided. The solution polymerization process of the current invention comprises a method for the on-line removal of foulant material from one or more heat exchangers downstream of a polymerization reactor. Removal of foulant material is accomplished by deliberately applying a positive pressure differential across a heat exchanger. In the process of the current invention, reactor shut down is not required for the purpose of cleaning foulant material from a heat exchanger.

Solution polymerization processes are carried out at temperatures that are above the melting point of the product polymer. In a typical process, catalyst components, solvent, polymerizable monomers and hydrogen are fed under pressure to one or more stirred reactors. Catalyst components may be fed to the reactor as a solution or as a slurry and the temperature of the reactor is controlled by the rate of catalyst addition, the temperature of the catalyst feed stream and/or the use of heat transfer systems. Typical polymerizable monomers for solution phase polymerization processes include ethylene, styrene, propylene and various dienes.
For ethylene polymerization, reactor temperatures can range from about 130° C. to about 250° C. while pressures are generally in the range of from about 500 to about 4000 psi. Although catalyst residence times are generally short (e.g. minutes) due to the harsh reactor conditions, if desired, solution polymerization may be operated under a wide range of process conditions, which allow tailoring of the product polymer as well as rapid product swings.
In solution polymerization, product polymer is molten and remains dissolved in the solvent under reactor conditions, forming a polymer solution. After a selected hold-up time (i.e. catalyst residence time), the polymer solution leaves the reactor as an effluent stream and the polymerization reaction is quenched, typically with coordinating polar compounds, to prevent further polymerization. Once quenched, the polymer solution is fed to a flash devolatilization system for solvent removal. Flash devolatilization also removes un-reacted monomers from the polymer solution.
In a typical devolatilization process, the polymer solution (reactor effluent) is pre-heated in a heat exchanger and then passed into a chamber of reduced pressure. Boiling of solvent and un-reacted monomers occurs and the vapors are sent to a solvent and monomer recovery system and are recycled back to the reactor. Heating the polymer solution upstream of the devolatilization system increases the enthalpy of the product stream, providing high temperatures to the polymer melt after devolatilization. The high temperatures facilitate flow of the polymer melt by reducing its viscosity. The heat exchangers used are most commonly shell and tube type heat exchangers and can increase the temperature of the polymer solution to as high as about 280° C.
U.S. Pat. No. 4,547,473 describes a typical high temperature solution process for the homo- or co-polymerization of ethylene at temperatures in excess of 150° C. using a titanium based catalyst system. Solvent is removed using standard flash devolatilization as described in U.S. Pat. No. 5,708,133.
In PCT application, 98/02471 filed by Dow Chemicals, a solution polymerization process is described in which a two stage devolatilization system is used to remove solvent and un-reacted monomers from an EPDM (ethylene-propylene-diene monomer) polymer solution. In a preferred embodiment a dual reactor system is used in which the temperature of the second reactor is between 90° C. and 120° C. For flash devolatilization, the temperature of the reactor effluent is raised to between 210° C. and 250° C. by passage through a heat exchanger prior to entering the flash chamber, which is at lower pressure.
U.S. Pat. No. 5,691,445 assigned to Novacor Chemicals describes a polymer solution devolatilization process in which less than 150 ppm of residual volatiles is retained in the isolated polymer. In the process, the polymer solution leaves the reactor and travels through a pre-heat exchanger. The pre-heat exchanger heats the polymer solution to temperatures from about 200° C. to 270° C. to increase the vapor pressure of volatiles and to reduce the polymer solution viscosity. In a preferred embodiment, a super-critical fluid is added to the process at a point between the first and second devolatilization chambers to enhance polymer melt foaming.
Under certain conditions of temperature and pressure, the polymer solution can phase separate into two distinct liquid phases, one which is "lean" in dissolved polymer and one which is "rich" in dissolved polymer. Phase separation occurs at the lower critical solution temperature (LCST), also known as the "cloud point". Increasing the temperature, or decreasing the pressure at the cloud point leads to further phase separation. The cloud point is determined in part by the pressure, temperature, solution composition and the solvent used for polymerization.
It is generally undesirable to have phase separation occur within the polymerization reactor, and process conditions such as monomer concentration, temperature and pressure are controlled to avoid liquid-liquid phase separation. For example, the polymerization temperature may be kept between the crystallization boundary and the LCST of the polymer solution for a given pressure, solvent and monomer concentration. However, once the polymer solution leaves the reactor, it may be beneficial to promote liquid-liquid phase separation as it can facilitate separation of volatile components from the polymer product.
U.S. Pat. Nos. 3,553,156 and 3,726,843 assigned to du Pont de Nemours describes a process in which the reactor effluent, an elastomeric ethylene copolymer solution, is induced to undergo a liquid-liquid phase separation into "polymer rich" and "polymer lean" fractions through the release of pressure by use of a pressure let down valve. The two liquid phases are decanted from one another in a settlement chamber and the polymer rich phase is fed into a low-pressure separator to boil off residual solvent and un-reacted monomer. The polymer lean phase is recycled to the reactor. The process reduces substantially the energy lost by evaporation of volatiles (i.e. the heat of vaporization) in a devolatilization chamber by separating out the volatiles in a "polymer lean" liquid phase.
In U.S. Pat. No. 4,857,633 assigned to Exxon Research & Engineering, a high temperature solution process is described in which a low molecular weight hydrocarbon is added to a polymer solution to facilitate phase separation of a polymer solution under certain conditions of temperature and pressure.
U.S. Pat. No. 6,881,800 assigned to ExxonMobil, discloses a process and apparatus to separate a polymer solution into polymer rich and polymer lean liquid phases prior to devolatilization. The apparatus includes a pressure source, a polymerization reactor, a pressure let-down device, and a separator downstream of one another respectively. In the process, the high pressure source is used to maintain a single liquid phase in the polymerization reactor, while the pressure let-down device facilitates the formation of a two-phase liquid-liquid system having a polymer rich phase and a polymer lean phase. Separation of these phases is accomplished by way of a liquid phase separator that feeds the polymer rich phase to a chamber at lower pressure in order to flash off residual solvent and un-reacted monomer.
Similarly, U.S. Pat. No. 5,599,885 assigned to Mitsui Petrochemicals, describes a solution polymerization process in which phase separation downstream of the reactor is used to facilitate polymer isolation. The reactor effluent is separated into a lower phase, which is rich in polymer, and an upper phase, which is rich in solvent by increasing the temperature of the polymer solution within a "separation zone". The temperature is raised to more than 180° C. above the upper cloud point temperature of the polymer solution. Polymer is recovered from the lower phase, while the upper phase is in part recycled to the reactor.
In U.S. Pat. No. 4,444,922 an improved phase separation process is described. Temperatures and pressures are moderated to produce "spinodal decomposition" driven phase separation as opposed to "nucleation and growth" driven phase separation. Spinodal decomposition driven phase separation is a form of phase separation that promotes rapid partitioning and settling of the polymer lean and polymer rich phases. The process facilitates separation of the distinct liquid phases by way of a liquid-liquid separator or a decanter.
The use of heat exchangers in high temperature processes such as the solution polymerization processes described above or in other processes such as hydrocarbon refining may lead to fouling of the heat exchanger surface. Build up of foulant material will, over time, reduce efficiency of heat transfer across the heat exchange surface and increase the pressure drop across the heat exchanger by restricting flow. This can negatively impact production rates by reducing the throughput in a heat exchanger. As such, several methods for removing foulant material or deposits from a heat exchanger have been developed.
U.S. Pat. No. 4,773,357 describes a method, in which a water cannon is used to physically dislodge deposited foulant material from the tube sheet in a shell and tube type heat exchanger.
In U.S. Pat. No. 5,006,304 a heat exchanger is submerged in a liquid, such as water, and then treated to one or more pressure pulses that knock foulant material free from the heat exchanger tubes.
A two-step pressure pulse cleaning process using a combination of heated cleaning fluids has been described in U.S. Pat. No. 5,601,657.
Alternatively, European Patent 110,456 describes a blast cleaning method in which an abrasive material such as sand is passed through the tubes of a heat exchanger to physically collide with the deposits, thereby removing them from the surface of the tubes.
Examples in which a brushing device is used to physically scrape deposits free from heat exchanger tubes are described in U.S. Pat. Nos. 4,917,176 and 4,676,301.
The above methods require that the heat exchanger be taken "off line" for lengthy periods to effect a thorough cleaning. Partially in response to this limitation, chemical cleaning methods have also been developed. Typically a solvent, which can partially dissolve the foulant, is passed through the heat exchanger under an externally imposed pressure gradient. These chemical cleaning agents can be used to clean the tube-side or the shell-side of a standard shell and tube type heat exchanger. Due to their ease of use, chemical cleaning agents can reduce off-stream times and in some cases can be used to clean a heat exchanger without taking it off-line.
Examples of heat exchanger cleaning agents include aromatic solvent compositions as is described in U.S. Pat. No. 6,187,109 and polar organic solvents such as those described in U.S. Pat. No. 6,283,133.
Canadian Patent 1,142,470 discloses a method for using polyalkylene amines in a hydrocarbon stream for the in-line cleaning of heat exchanger tubes for use with hydrocarbon cracking equipment.
A method for using chemical agents for the "on-line" cleaning of a heat exchanger and its associated process equipment is described in U.S. Pat. No. 6,644,326. A high boiling aromatic solvent is passed through an apparatus for solution polymerization where it helps to dissolve foulant polymeric materials that have deposited on the heat exchanger surfaces.
In general however, the use of high boiling solvents, including aromatic reagents, are problematic for "on-line" cleaning of a solution phase polymerization plant. For example, in U.S. Pat. No. 5,599,885 assigned to Mitsui Petrochemicals, a solution polymerization process is provided in which the catalyst components are added to the polymerization reactor as a slurry in an aliphatic hydrocarbon diluent. The hydrocarbon diluent has a boiling point below 100° C. The use of more polar, more solubilizing, high boiling aromatic solvents, such as toluene, are specifically avoided, as they are difficult to remove from polymer product during devolatilization processes.
In light of the foregoing, there remains a need for a high temperature solution polymerization process in which a heat exchanger can be cleaned without requiring costly and time consuming reactor shut downs or the introduction of undesirable chemical agents such as high boiling, sometimes toxic aromatic solvents or reactive polar solvents.

High temperature process for solution polymerization


An electron gun structure includes a first non-axial-symmetrical lens portion which is arranged in the vicinity of an electron beam formation portion, and a second non-axial-symmetrical lens portion formed to a main lens portion, the first non-axial symmetrical lens portion has a lens action in the vertical direction that a focusing action relative to the electron beams becomes stronger as a quantity of deflection of the electron beams increases, and a lens action in the horizontal direction which substantially rarely acts on the electron beams, and a comprehensive lens system of the second non-axial-symmetrical lens portion and the main lens portion has a lens action in the vertical direction that a divergence action relative to the electron beams becomes stronger as a quantity of deflection of the electron beams increases, and a lens action in the horizontal direction which substantially rarely acts on the electron beams.

This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2000-225734, filed Jul. 26, 2000, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a cathode ray tube apparatus, and more particularly to a cathode ray tube having an electron gun structure for performing dynamic astigmatism-correction mounted thereon.
2. Description of the Related Art
In general, a color cathode ray tube apparatus is provided with an inline type electron gun structure for emitting triple electron beams, and a deflecting yoke for generating a deflection magnetic field for scanning on a phosphor screen in a horizontal direction and a vertical direction by deflecting the electron beams emitted from the electron gun structure. This deflecting yoke forms a non-uniform magnetic field by a pin cushion type horizontal deflection magnetic field and a barrel type vertical deflection magnetic field.
The electron beams having passed through such a non-uniform magnetic field are affected by deflection aberration, i.e., astigmatism included in the deflection magnetic field. Therefore, a beam spot of the electron beams which have reached a periphery part of the phosphor screen is over-focused in the vertical direction by deflection aberration, which results in blur in the vertical direction and lateral collapse wide in the horizontal direction. The deflection aberration which affects the electron beams becomes larger as a dimension of the tube is increased and a deflection angle becomes wider. Such distortion of the beam spot considerably deteriorates the resolution of the periphery part of the phosphor screen.
As means for solving deterioration of the resolution caused due to the deflection aberration, there is such an electron gun structure as disclosed in Jpn. Pat. Appln. KOKAI Publication No. 61-99249. This electron gun structure is provided with first to fifth grids and forms an electron beam generation portion, a non-axial-symmetrical lens, and a final main focus lens along a traveling direction of the electron beams. The non-axial-symmetrical lens is formed by providing three non-axial-symmetrical electron beam passage holes on each of opposed surfaces of electrodes adjacent to each other.
This electron gun structure reduces the influence of the deflection aberration of the deflection magnetic field given to the electron beams which are deflected around the phosphor screen and corrects the distortion of the beam spot by changing lens intensities of the non-axial-symmetrical lens and the final main lens in synchronization with a change in the deflection magnetic field.
In such an electron gun structure, however, when the electron beams are defected around the phosphor screen, the influence of the deflection aberration of the deflection magnetic field is extremely large. Further, even if the blur of the beam spot can be eliminated, the lateral collapse can not be sufficiently corrected.
Furthermore, as another means for solving deterioration of the resolution caused due to the deflection aberration, there is proposed such a dynamic focusing type electron gun structure as disclosed in Jpn. Pat. Appln. KOKAI Publication No. 64-38497.
This electron gun structure constitutes a final main focus lens by a dynamic focus electrode to which a dynamic focus voltage is applied, an anode electrode to which an anode voltage is applied, and an auxiliary electrode arranged between these electrodes. To the auxiliary electrode is supplied a voltage obtained by subjecting the anode voltage to resistance division by using a resistor arranged in the vicinity of the electron gun structure.
As a result, each non-axial-symmetrical lens is formed between the dynamic focus electrode and the auxiliary electrode and between the auxiliary electrode and the anode electrode. When the dynamic focus voltage is applied to the dynamic focus electrode according to deflect the electron beams in the periphery part of the phosphor screen, the final main focus lens including the non-axial-symmetrical lens generates the lens action for divergence only in the vertical direction without producing the lens action in the horizontal direction.
This electron gun structure corrects the distortion of the electron beam spot in the periphery part of the phosphor screen by such a lens action.
In such an electron gun structure, however, an alternating component of the dynamic focus voltage is superposed on the applied voltage of the auxiliary electrode by the electrostatic capacity between the electrodes constituting the final main focus lens by applying the dynamic focus voltage to the dynamic focus electrode. As a result, the non-axial-symmetrical lens formed between the dynamic focus electrode and the auxiliary electrode lacks the lens action, and an undesired lens action is generated to the non-axial-symmetrical lens formed between the auxiliary electrode and the anode electrode.
Therefore, the distortion of the beam spot can not be sufficiently corrected in the periphery part of the phosphor screen, and the excellent focusing characteristic can be hardly obtained in the entire phosphor screen area.
In order to obtain the excellent focusing characteristic in the entire phosphor screen area, the distortion of the beam spot must be corrected in the periphery area of the phosphor screen. Moreover, it is necessary to reduce a superposition ratio of the alternating component of the dynamic focus voltage to the auxiliary electrode and form the sufficient lens action to the lens for compensating the influence of the deflection aberration to the electron beams.
In view of the above-described problems, it is an object of the present invention to provide a cathode ray tube apparatus capable of forming a beam spot having an excellent shape across an entire phosphor screen area.
According to the present invention, there is provided a cathode ray tube apparatus comprising:
an electron gun structure having an electron beam formation portion for forming electron beams and a main lens portion for focusing the electron beams on a phosphor screen; and
a deflection yoke for generating a deflection magnetic field for scanning in a horizontal direction and a vertical direction on the phosphor screen by deflecting the electron beams emitted from the electron gun structure,
wherein the electron gun structure includes a first non-axial-symmetrical lens portion whose lens action changes in accordance with a quantity of deflection of the electron beams and which is arranged in the vicinity of the electron beam formation portion and a second non-axial-symmetrical lens portion whose lens action changes in accordance with a quantity of deflection of the electron beam and which is formed to the main lens portion;
the first non-axial-symmetrical lens portion has a lens action in the vertical direction by which a focusing action relative to the electron beams is strengthened as a quantity of deflection of the electron beams increases and a lens action in the horizontal direction which substantially rarely acts on the electron beams as compared with the lens action in the vertical direction; and
a comprehensive lens system of the second non-axial-symmetrical lens portion and the main lens portion has a lens action in the vertical direction by which a divergence action relative to the electron beams is strengthened as a quantity of deflection of the electron beams increases and a lens action in the horizontal direction which substantially rarely acts on the electron beams relatively.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.


Disclosed herein is a heat reflecting sandwich plate made up of a first and a second transparent plates bonded together with a transparent resin film. The first transparent plate is coated on the inside thereof with a heat reflecting film which is a laminate composed of two metal oxide layers, with a noble metal layer intervening between them. The noble metal layer has a sheet resistance of 4-10 ohms/square. The first and second metal oxide layers have thicknesses controlled such that their ratio is in the range of 1.1 to 1.6. The heat reflecting sandwich plate produces reflected rays which have a chromaticness specified by -1.ltoreq.a.ltoreq.1 and -1.ltoreq.b.ltoreq.1, where a and b denote the chromaticness indices of Hunter's color specification system, and has a visible light reflectivity lower than 10%. Because of these characteristic properties, the heat reflecting sandwich plate has high strength and safety, exhibits outstanding heat reflecting performance, and assumes almost no color and looks good despite its comparatively high visible light transmittance.

1. Field of the Invention:
The present invention relates to a sandwich plate composed of a pair of transparent plates such as glass, synthetic resin or the like, and a transparent interlayer of synthetic resin, said sandwich plate being rendered capable of heat reflection. The heat reflecting sandwich plate is suitable as vehicle and building window glass.
2. Description of the Prior Art:
There has been known sandwich glass made up of a pair of glass sheets (made by, for example, float process) bonded together with an interlayer of transparent synthetic resin such as polyvinyl butyral. The sandwich glass of such multilayered structure has high strength and safety owing to the interlayer's ability to prevent the glass plates from shattering in the event of breakage.
A disadvantage of the sandwich glass used as vehicle and building window glass is that it transmits a large amount of solar radiant energy into the vehicle and building, causing the room temperature to rise unnecessarily, particularly in summer.
There is disclosed in U.S. Pat. No. 4,337,990 a heat reflecting glass prepared by forming a first metal oxide layer, a noble metal layer, and a second metal oxide layer consecutively on a glass sheet. The first and second metal oxide layers have almost the same thickness so that the three layers give rise to, by their light interference, a low reflectivity for light of wavelength 550 nm(nanometer) having a high visual sensitivity and yet give rise to a high transmittance for visible light.
The heat reflecting glass disclosed in the above-mentioned U.S. Patent gives a reflective spectrum which indicates the strong reflection in the longer (red) side and shorter (blue) side of the visible region. This spectral characteristic causes the heat reflecting glass to produce a dazzling reflected ray of purplish color for the incident rays on either sides. Because of this colored reflected rays, the heat reflecting glass as vehicle and building window glass is out of harmony with the exterior of the vehicle and building.


A method for the treatment of acne and/or the effects of ageing, by administering, to a subject in need thereof, a composition containing an effective amount of at least one HMG-Coenzyme A-reductase inhibitor in a carrier that is selected from the group consisting of dermatologically acceptable carriers, cosmetically acceptable carriers, and mixtures thereof, and the compositions for performing the method are provided.

FIELD OF THE INVENTION
The present invention relates to the use of an HMG-Coenzyme A-reductase inhibitor as an active anti-ageing agent, in or for the manufacture of a cosmetic and/or dermatological composition, its use in order to treat the effects of ageing and acne and to a topical composition containing the same in combination with an active agent possessing desquamating properties, acting in synergy.

Method for treatment of acne and/or the effects of ageing using HMG-coenzyme A-reductase inhibitor and compositions for performing the same


An apparatus for processing an input image including M image units is provided. Each of the M image units respectively includes N pixels. Each of the pixels respectively has an original gray scale. The apparatus includes a converting module, a gain generating module, and a contrast enhancing module. The converting module is used for generating M luminances. Based on the original gray scales of the N pixels in the ith image unit among the M image units, the converting module generates the ith luminance among the M luminances. A maximum luminance and a minimum luminance are generated based on the M luminances. The gain generating module generates a contrast gain and a minimum gray scale based on the maximum luminance and the minimum luminance. Based on the contrast gain and the minimum gray scale, the contrast enhancing module adjusts the original gray scales of the pixels in the input image.

1. Field of the Invention
The present invention relates to image processing methods and apparatuses and, in particular, to methods and apparatuses for image contrast stretching.
2. Description of the Prior Art
Image contrast stretching refers to extending the gray scales of an image to the maximum extent of a monitor. Taking a monitor capable of showing eight-bit gray scales as an example, the 256 gray scales are usually represented as gray scale 0 to gray scale 255. Generally, since image signals lose part of the gray scales due to signal degradation or noise disturbance or so on, the number of gray scales received at the monitor is usually smaller than 256. The object of image contrast stretching is to increase the distribution of gray scales of an image, and thereby enhance the contrast and quality of the image.
Please refer to FIG. 1, which illustrates the block diagram of an apparatus for image contrast stretching in prior arts. The apparatus 10 includes three blocks: a statistic module 11, a gain generating module 12, and a contrast enhancing module 13. The statistic module 11 further includes a first statistic unit 11A, a second statistic unit 11B, and a third statistic unit 11C.
A colored image includes red, green, and blue pixels. The first statistic unit 11A, the second statistic unit 11B, and the third statistic unit 11C are respectively used to statistically calculate the distribution of the gray scales of the red, green, and blue pixels in an input image. The statistic results are depicted as the histograms shown in FIG. 2. FIG. 2(A)˜2(C) respectively show the distributions of the gray scales of the red, green, and blue pixels in an image. In each histogram, the horizontal axis indicates gray scale values (ranging from 0 to 256), and the vertical axis indicates the number of pixels that have a corresponding gray scale value. By the histograms, we can get the distribution of gray scales of the input image.
According to the histograms, the first statistic unit 11A, the second statistic unit 11B, and the third statistic unit 11C can respectively find the maximum gray scales (Rmax, Gmax, Bmax) and the minimum gray scales (Rmin, Gmin, Bmin) corresponding to the red pixels, green pixels, and blue pixels. In some image processing methods in prior arts, the maximum gray scale is defined as the gray scale corresponding to the 0.5% area from the right of the histogram, while the minimum gray scale is defined as the gray scale corresponding to the 0.5% area from the left of the histogram.
Then, the gain generating module 12 selects the maximum one among the three maximum gray scales of the pixels as the maximum gray scale of the input image. Similarly, the minimum gray scale of the input image is the minimum one among the three minimum gray scales of the pixels. The traditional equation of image contrast stretching is:
                                          G            ″                    =                      255            ×                                          G                -                Min                                            Max                -                Min                                                    ,                            (                  Equation                                                              1                )
wherein G represents the original gray scale of some pixels, and G″ represents the stretched gray scale of the pixels.
Equation 1 can be rewritten into another form:G″=k×(G−Min)  (Equation 2)
wherein
                    k        =                              255                          Max              -              Min                                .                                    (                  Equation                                                              3                )                            The value k in Equation 3 is generally called a contrast stretching coefficient or contrast gain.
The gain generating module 12 first calculates the contrast gain (k) according to Equation 3 and sends the minimum gray scale (Min) and the contrast gain (k) to the contrast enhancing module 13. The contrast enhancing module 13 performs a contrast stretching calculation on each pixel of the input image according to Equation 2 and accordingly obtains the output image.
Taking the image shown in FIG. 3(A) as an example, the original maximum gray scale is 151, and the original minimum gray scale is 0 in this image. According to Equation 3, k is calculated to be 1.59, and the result of image contrast stretching is shown in FIG. 3(B). By comparison, we can find that the contrast of the image in FIG. 3(B) is much higher than that in FIG. 3(A).
The drawback of prior arts is that three statistic units are needed for calculating the individual distributions of the gray scales of the red pixels, green pixels, and blue pixels. Therefore the hardware resource is considerably consumed.

Method and apparatus for adjusting contrast of image