A polymer electrolyte fuel cell consists of plural units, and the unit has an anode side separator, an anode diffusion layer, an anode catalytic layer, polymer electrolyte membrane, a cathode catalytic layer, a cathode diffusion layer, and a cathode side separator. The cathode catalytic layer further includes a catalyst in which platinum or platinum alloy is supported on a carbon supporting body having an average lattice space d002 of [002] surface of 0.338 to 0.355 nm and specific surface area of the supporting body of 80 to 250 m2/g, electrolyte containing ion exchange resin, and vapor grown carbon fiber. Furthermore, a water holding layer containing ion exchange resin, carbon particles, and vapor grown carbon fiber is arranged at an interface of the cathode diffusion layer and the cathode catalytic layer.

1. Technical Field
The present invention relates to a polymer electrolyte fuel cell, and in particular, relates to a technique for improving power generation efficiency in high-voltage operation.
2. Background Art
Recently, exhaustion of petroleum resources is a crucial issue, and environmental problems such as air pollution and global warming caused by consumption of fossil fuels have become serious. Under these circumstances, fuel cells have attracted much attention as a clean power source for electric motors in which carbon dioxide is not generated, and such fuel cells are being widely developed and used.
In the case in which such a fuel cell is used in a vehicle, a polymer electrolyte fuel cell in which a polymer electrolyte membrane is used is desirably used since high voltage and large current can be obtained. A membrane electrode assembly for the polymer electrolyte fuel cell is produced as follows: a catalyst such as platinum is carried by a catalyst carrier such as carbon black; a pair of electrode catalytic layers is made by unifying the catalyst and an ion conducting polymer binder; a polymer electrolyte membrane having ion conductivity is disposed between the electrode catalytic layers; and a gas-diffusion layer is formed on each of the electrode catalytic layers. Furthermore, a separator which also functions as a gas passage is formed on each of the gas-diffusion layers to yield a polymer electrolyte fuel cell.
In such a polymer electrolyte fuel cell, a reducing gas, such as hydrogen or methanol, is introduced at one electrode catalytic layer (fuel electrode) through the gas-diffusion layer of the fuel electrode side, and an oxidizing gas such as air or oxygen is introduced at the other electrode catalytic layer (oxygen electrode) through the gas-diffusion layer of the oxygen electrode side. In the fuel electrode, due to the existence of the catalyst in the electrode catalytic layer, protons (H+) and electrons are generated from the reducing gas, and protons migrate to the electrode catalytic layer of the oxygen electrode side through the polymer electrolyte membrane. In the oxygen electrode, due to the existence of the catalyst in the oxygen electrode, protons react with the oxidizing gas introduced at the oxygen electrode and electrons to produce water. Therefore, by electrically connecting the fuel electrode and the oxygen electrode with a lead, a circuit in which electrons generated in the fuel electrode migrate to the oxygen electrode is formed, and electric current is obtained.
At the cathode of the polymer electrolyte fuel cell, water is generated by reduction reaction of protons and oxygen which is an oxidizer. Therefore, in a high-voltage operation, water is generated faster than water vapor at the cathode can be exhausted, and as a result, a blockage (flooding) phenomenon of micropores of the electrode by condensation of water vapor may easily occur. If the flooding phenomenon occurs, the number of reaction sites is reduced, the reaction cannot be promoted efficiently, and it would be difficult to obtain reliable properties for a long period.
To solve such a problem, a technique in which graphitized carbon supporting a noble metal which is a catalyst component of the cathode is used, is disclosed (see Japanese Unexamined Patent Application Publication No. 2000-268828, 2000-357857, 2002-015745). In the technique, since the graphite is water-repellent, water is exhausted immediately, and the flooding can be restrained.
However, the number of functional groups on the surface of the supporting body and specific surface area are reduced by a heat treatment of graphitization, and as a result, the water holding property of graphite in the electrode is deteriorated. Therefore, under a low humidity operation, i.e., not more than 50% humidity, required water is in short supply, an activation over voltage of catalytic reaction is increased, and power generation efficiency is deteriorated.


To reduce power consumption in an apparatus for measuring a distance on the basis of a phase difference between light beams.

Conventionally, a distance measuring method referred to as "time of flight (ToF) method" has been frequently used in apparatuses and devices having a distance measuring function. This ToF method is a method in which an apparatus irradiates an object with irradiation light of a sine wave or rectangular wave and the apparatus receives reflected light from the object to measure a distance on the basis of a phase difference between the irradiation light and the reflected light. For example, there is proposed an apparatus that causes a plurality of light receiving elements arranged in array to receive reflected light and measures a distance by the ToF method (see, for example, Non-Patent Literature 1).

Distance measuring apparatus, electronic apparatus, and method of controlling distance measuring apparatus

Abstract: A distance measuring apparatus includes: a phase difference detecting section; and a distance measuring section. In the distance measuring apparatus, the phase difference detecting section detects a phase difference between light beams from a pair of external light sources. In addition, in the distance measuring apparatus, the distance measuring section acquires any one of a distance from one of the pair of external light sources and an interval between the pair of external light sources as known data and measures a distance from another of the pair of external light sources on a basis of the known data and the phase difference.

Sony Semiconductor Solutions Corporation


A method for providing an optical interface with at least one optical coupling structure for a packaged optical device is described. The at least one optical coupling structure may be, for example, wave-guides and/or microlenses. The packaged optical device includes an external alignment structure. The external alignment structure has a support means with at least one hole and at least one alignment feature. The method includes providing optical encapsulate material in the hole of the support means. Optical coupling structures, such as wave-guides or microlenses, may be provided into the encapsulation at a well-defined position relative to the at least one alignment feature of the external alignment structure. By providing the optical coupling structures directly in the material comprised in the encapsulation, a high degree of alignment accuracy is obtained.

An optoelectronic module typically comprises one or more optoelectronic components, such as light emitting diodes (LEDs), lasers, detectors, optical modulators, and one or more electronic chips, such as CMOS, BiCMOS, GaAs, or any other technology to used to fabricate integrated circuits. At least one of these electronic chips is connected electronically to at least one of the optoelectronic components. The connection may be made using wire bonding, flip-chipping, or any other suitable technique for achieving electrical connection.
Typically, in addition to an electrical connection, an optical interface is provided on the optoelectronic module, which provides an interface from the optoelectronic module to an external optical system. The external optical system can be a connector with optical fibers, an optical sensing system, or light emitting system.
The optoelectronic modules need to be packaged. A package for the optoelectronic modules needs to provide an optical interface for connecting to an external optical system, so that an optical signal to be obtained or received can be coupled out. The optical interface fulfills two functions. First, the optical interface facilitates a precision alignment from the optoelectronic module to the external optical system, with accuracy typically in the order of 1 to 10 μm depending on the application. For example, for multi-mode systems the accuracy is typically of the order of 10 μm and for single-mode systems the accuracy is typically in the order of 1 μm. Such accuracy is typically required, for example, in parallel optical interconnect systems.
The precision alignment may be achieved by using external alignment feature structures, such as alignment pins or ferrule accepting reference holes. The use of alignment pins is described in U.S. Patent Application Serial No. 2003/0219217. The use of ferrule accepting reference holes is described in U.S. Patent Application Serial No. 2003/0136968.
A second function of the optical interface is to facilitate guiding of light to and from the external optical system. Optical elements, such as lenses or wave-guides, integrated into the external alignment structure may be used to facilitate the guiding of light.
The optical packaging is employed to assemble the optical elements and the external alignment feature structure on the optoelectronic package with the desired accuracy. For example, micro lens arrays can be positioned in the package, as described in U.S. Pat. No. 6,736,553. As another example, wave-guides can be positioned in the package, as described in U.S. Pat. No. 6,674,948 and U.S. Pat. No. 6,722,788. Typically, the assembly of the package uses alignment features on the optoelectronic module, the optical element, and the external alignment feature structure.
When packaging, it is desirable that the optical element includes alignment features to assure a good positioning of the optical element on the optoelectronic package. This is not a simple task as the fabrication of the optical elements and the fabrication of alignment features on these optical elements typically use different technologies. Whereas the alignment features typically are made using thin-film techniques, the optical components typically are made using other techniques such as etching or molding. The use of these different techniques for fabricating the alignment features and the optical components usually results in some amount of misalignment.
In the assembly phase, the optical element is positioned on the optoelectronic module, again resulting in some misalignment, as well as longer fabrication times and a decreased yield. It is to be noted that in the optoelectronic module, not only the X and Y position, but also the vertical distance, i.e., the Z-alignment, between two objects determines the coupling efficiency. To achieve good Z-alignment, precision mechanical elements, such as spacers, are employed to define the height position of two objects. Using precision mechanical elements is expensive, involves additional handling, and is dependent on the availability of high-precision mechanical parts with the desired accuracy.
In LED packages and similar products, lenses are molded directly in the package, omitting the need for an intermediate optical element. In the same molding step, the alignment features to the external optical system can be defined (for example, to accept the ferrule of the connector). However, such directly molded optical structures on the optoelectronic module, in general, cannot produce accuracy better than 10 nm. Furthermore, this technique is limited to lenses only, and is not suitable for making alignment pins.
The molding process employs high-pressure and temperature to achieve good optical quality of the molded structure, which may not be compatible with the underlying optoelectronic module. Moreover, non-recoverable expenses of the molding process are relatively high, as designing the mold is an iterative and expensive process. Finally, this technique is not flexible, as it does not allow integrating the external alignment features into the package during molding. Furthermore, each design employs a new mold.
Most techniques used for fabricating refractive micro-optical components are based on well-known processes coming from microelectronics, such as standard lithographic techniques combined with a thermal reflow process and, if desired, pattern transfer to a substrate using dry etching or lithography using half-tone (e.g., greyscale), masks, and etching. Other direct-write techniques include laser writing (e.g., with a focused HeCd laser), e-beam or focused ion-beam writing, diamond turning, and micro-jet printing to name a few.
Replication of these structures in large quantities typically is achieved by injection molding, embossing, or casting. Another technique more recently introduced as a feasible fabrication technology, is laser ablation. This technique differs significantly from 'laser writing' mentioned above. In the first place, laser ablation does not require resist development as the material is physically removed during ablation. Secondly, while laser writing with a HeCd laser is limited to resists of merely a few microns thick, laser ablation allows machining of surfaces up to several hundreds of microns deep. Finally, it should be noted that pulsed laser ablation, in particular when an excimer or CO2 laser source is employed, involves a beam size that is much larger than the focused submicron spot of a continuous laser writing device, and typically amounts to several tens of microns or larger.
Laser ablation offers some advantages with respect to the previously mentioned fabrication techniques as laser ablation has a direct-write and contactless etching nature. Additionally, laser ablation has the potential to define microstructures and microoptics on a top surface of a heterogeneous optoelectronic module in a very late phase of the assembly process. Several techniques using laser ablation, in particular excimer laser ablation, for microoptics fabrication have been reported. In general, these techniques suffer from a variety of disadvantages, making laser ablation less attractive as prototyping technology.
In Appl. Opt. 36 (1997) p. 4660, Wang et al. suggest using complex mask patterns for fresnel lens fabrication. This method is not cost-effective when lenses with different focal lengths, diameters, or shapes need to be fabricated since every other lens requires different mask patterns. The application of greyscale masks, as suggested by Matz et al. in Appl. Phys. A 65 (1997) p. 349, suffers from the same disadvantage. Mihailov and Lazare in Appl. Opt. 32 (1993) p. 6211 report on the ablation of islands in a polymer substrate, followed by thermal reflow. Although the ablation process can be performed within seconds, reflow of the surface typically takes a few hours, making the technique less suitable for fast prototyping.
Another approach is based on irradiation of the polymer with UV (i.e., wherein no actual ablation is involved) and swelling of the irradiated zone due to diffusion of Styrene in a controlled way. Again, this last process step requires several hours to finish the microlenses. A similar process is based on irradiation of doped PMMA at subablative fluence only, as described by Beinhorn et al. in Appl. Phys. A 68 (1999) p. 709, where spontaneous swelling is the result of a balanced combination of photochemical reactions and surface tension, which means that the process is likely to be very material, dopant, and fluence sensitive.
Other work involves the use of scanning excimer laser ablation for correction of phase aberrations of glass lenses by ablation of a thin resin coating on the lens. However, experimental results report only on maximum ablation depths up to 5 μm. Examples with CO2 laser heating are also reported. None of the above-mentioned techniques combines fast processing with a sufficient machining accuracy and compatibility with heterogeneous assembly processing.
The use of connectors as external optical systems, for example in parallel optical interconnect systems, employs a flat optical interface to allow for a good physical contact between the connector and the optoelectronic module. Standard molding techniques cannot achieve the desired level of flatness, which can be, for instance, 0.1, 0.2, 0.5, 1, or 2 μm. Precision molding of micro lenses is shown in U.S. Pat. No. 6,597,020. These techniques allow for the production of optical elements and are suitable for producing the optical elements that could be assembled onto the optoelectronic module in a later step.
In U.S. Pat. No. 6,722,788, the problem of coupling light from/to an optoelectronic device in a package is described. The capability of out/in coupling of light is provided for using a complex system of connectors and couplers, which carry optical fibers and couple the fiber through the package towards the optoelectronic component, so that the fibers are well aligned with respect to the underlying optoelectronic component. A series of fibers is bundled in a fiber bundle array connector. A coupler holder piece, into which a light collimating or imaging coupler can fit, is fixed to a module connector. The module connector is the latching piece that usually sits permanently on the module, and onto which a fiber bundle array connector can fit. A fiber bundle array connector is then inserted into the module connector piece/coupler holder combination.
Light is shone through the far end of the fiber bundle so that light emits from the fiber array connector end. This light can be used for alignment purposes. The collimated coupler is inserted into the coupler holder and aligned so that the critical optical elements of the collimated coupler are aligned to the individual fibers in the fiber bundle/bundle array connector. Once the two pieces are aligned, the collimated coupler is permanently fixed in place in the coupler holder. This assures that any time the fiber bundle array is removed from and reconnected to the module connector that the individual fibers will still be aligned relative to the collimated coupler.
The assembly containing the collimated coupler, the coupler holder, and the module connector is then aligned relative to the chip assembly so that all of the optical elements in the collimated coupler are aligned relative to all of the optical devices in the chip assembly. This assures that efficient transfer of light between the optical devices and the collimated coupler occurs. The assembly containing the collimated coupler, the coupler holder, and the module connector is then brought into close proximity to the chip assembly and permanently affixed in place. This seals the optical devices, ensures that the alignment between the optical devices and the collimated coupler is maintained, and ensures that the spacing between the optical devices and the collimated coupler is small enough so that cross talk does not take place. This technique is very complex, expensive, and has reliability problems.
Therefore, there is a need for a technique of packaging optoelectronic modules using simple manufacturing techniques, and that results in better accuracy and process compatibility with the underlying optoelectronic module.

Method for providing an optical interface and devices according to such methods

Interuniversitair Microelektronica Centrum (IMEC)


Disclosed herein is a dishwasher including a spray unit fixed to one sidewall of a wash tub and a reflecting plate assembly to reflect wash water sprayed from the spray unit onto dishes and to linearly reciprocate in a spray direction of the wash water sprayed from the spray unit. The dishwasher further includes a drive unit to drive the reflecting plate assembly, and a cam unit to transmit driving force of the drive unit to the reflecting plate assembly. The drive unit includes a motor to generate rotational force, and a belt forming a closed loop and caused to make cyclic movement by the motor. The cam unit is engaged with the belt to transmit power of the belt to the reflecting plate assembly. The cam is alternately engaged with first and second portions of the belt to cause the reflecting plate assembly to reciprocate.

1. Field
Embodiments of the present disclosure relate to a dishwasher having a reflecting plate which linearly reciprocates in a washing tub and reflects wash water.
2. Description of the Related Art
A dishwasher is a home appliance that washes dishes by spraying high-pressure wash water onto dishes. The dishwasher includes a body having a wash tub arranged therein, a basket to accommodate dishes, a sump to collect and store wash water, a washing pump to pump wash water, a spray unit to spray wash water, and a connection flow passage to connect the washing pump to the spray unit.
The spray unit may come with various structures. For example, the spray unit may be rotatably arranged in the wash tub or disposed to linearly reciprocate in the wash tub.
In addition, the spray unit may be fixed at one point in the wash tub to spray wash water in an approximately horizontal direction, and may be provided with a reflecting plate to linearly reciprocate to divert the wash water sprayed from the spray unit onto dishes.


An electrowetting optical element comprising a first electrode layer stack and a second electrode layer stack, and a containment space formed between said first electrode layer stack and said second electrode layer stack, one or more pixel walls fixedly mounted on said second interface surface and extending between said first and second electrode stacks, for defining sides of said containment space. Said containment space at least contains a polar liquid and a non-polar liquid, the polar and non-polar liquids being immiscible with each other. Said hydrophobic interface surface has a higher hydrophobicity than the second interface surface. The electrowetting element is arranged for enabling powering of said first and second electrode layers for rearranging said polar liquid relative to said non-polar liquid. An end face of said one or more pixel walls opposite said first electrode layer stack faces said hydrophobic interface surface in a loose manner.

Electrowetting technology is based on modification of an energy balance between on one hand surface tension forces of liquids and wetting properties of a solid surface, and on the other hand electrostatic forces induced by an applied voltage over a capacitor arrangement comprising said boundary layer.
An electrowetting optical element or cell, further referred to as electrowetting element, according to the state of the art may from bottom to top be comprised of respectively a first electrode layer stack comprising a substrate, a first electrode layer, an electrically insulating hydrophobic layer or an insulating layer having a hydrophobic surface on a side opposite to the first electrode layer, for interfacing to a polar liquid and a non-polar liquid immiscible with each other, and a second electrode layer stack, comprising a second electrode which is electrically in contact with the polar liquid and a superstrate for supporting the second electrode layer. The second electrode layer has a hydrophobicity that is lower than the hydrophobic interface surface of the first electrode layer stack. This causes the non-polar liquid to be present near the hydrophobic surface of the first electrode stack and the polar liquid to be present near the less hydrophobic interface surface of the second electrode stack. Pixel walls attached to the first electrode layer stack and extending from the first electrode layer stack towards the second electrode layer stack, form a containment space between the first and second electrode stacks and the pixel walls. The pixel walls thus form a barrier for the non-polar liquid between the electrowetting cell and adjacent electrowetting cells.
An electrowetting element can thus form a picture element or pixel. A plurality of electrically controlled electrowetting elements can together form a display or part thereof comprising pixels, which can be used for displaying arbitrary images by appropriately controlling the electrowetting elements forming the display. Electrowetting elements can have arbitrary shapes determined by the shape of the pixel walls, such that displays can be manufactured for specific purposes.
An electrowetting element is mainly transparent, except for the non-polar liquid in each of the pixels formed by the pixel walls. The non-polar liquid is often non-transparent or has a low optical transmission coefficient. The transmission coefficient of the non-polar liquid typically depends on the application of the electrowetting element. In a colour display, an electrowetting element comprising coloured non-polar liquids may be used.
Electrowetting elements can be applied in a transmissive implementation, using for example backlighting to light-up the display screen. In another implementation the electrowetting elements may be applied in a reflective set-up, for example by providing a (specular or diffuse) reflective surface at one of the electrode layers.
The principles of operation of an electrowetting element are as follows. In an unpowered state, i.e. when no voltage is applied over the first and second electrode, the lowest energetic state of the system is where the non-polar liquid forms a boundary layer between the polar liquid and the hydrophobic surface of the insulating layer. This is because the polar liquid is repelled by the hydrophobic layer. The poor transmissibility of the non-polar liquid then forms an obstruction to light that penetrates the system.
When a voltage is applied over the electrodes, the lowest energetic state of the system becomes the situation wherein the (poorly conductive or insulating) non-polar liquid is pushed aside by the (conductive) polar liquid, and the polar liquid thereby being in direct contact with the insulating hydrophobic layer. Note that the voltage must be large enough for the electrostatic forces to overcome the repellent and surface tension forces that separate the polar liquid from the hydrophobic surface. In this situation, light that penetrates the system has rather unobstructed access to the insulating hydrophobic layer because of the well transmissibility of the polar liquid and the non-polar liquid being pushed aside. In the powered up state, when voltage is applied over the electrodes, the electrowetting element is thus transmissive. This working principle is used in electrowetting type displays and screens.
Electrowetting elements according to the state of the art exhibit poor adhesion of the pixel wall to the hydrophobic surface, causing the pixel walls to deteriorate, thereby destroying the electrowetting element and it's surrounding electrowetting elements which are defined by the pixel walls. This is due to the fact that the hydrophobic surface has a very low contact angle hysteresis and low surface tension which makes it extremely difficult to apply an uniform coating of photoresist from which the pixel walls are formed. Furthermore the adhesion of the photoresist to the hydrophobic surface is very poor, thus resulting in poor adhesion and deterioration of the pixel walls. This problem may already occur during manufacturing of the electrowetting elements, when pixel walls are created. As a result, the yield of commercial manufacturing processes is lowered and in addition the technical life of electrowetting displays is shortened.
In the art, adhesion of the pixel walls can be improved by performing a surface modification of the hydrophobic surface for making this surface less hydrophobic. After manufacturing of the pixels walls the surface is returned to a hydrophobic state by an annealing step. However the return to a hydrophobic state with minimal contact angle hysteresis is often not perfect causing imperfect spreading of the oil after switching to the unpowered state. Such a method thus leads to problems with the opening and closing of the pixels during switching operation.


An O-plate compensator comprising an organic liquid crystal polymer, and methods for fabricating the same, are disclosed. The compensator is a uniaxial birefringent thin film with its extraordinary axis oriented obliquely with respect to the surface of the film. (It is noted that the birefringent thin film could be weakly biaxial.) The oblique orientation of the liquid crystal director, which is parallel to the film's extraordinary axis, is achieved by casting an organic thin film onto a surface specially prepared for orienting liquid crystals, such as obliquely deposited SiO, mechanically rubbed alignment agents. The film can either be cast from a solution of the liquid crystal polymer or from a reactive liquid crystal monomer having a nematic phase. Any solvent that may be used during the fabrication process is evaporated off and the organic thin film is held at a temperature in its nematic phase. If a reactive monomer is used, the film is then photopolymerized. Alternative embodiments of an organic O-plate include the use of smectic-A and smectic-C materials. Fabrication techniques employing these materials arc described.

This invention is concerned with the design of liquid crystal displays (LCDs) and, more particularly, with techniques for maximizing the field of view of such displays by maintaining a high contrast ratio and minimal variance in relative gray levels over a wide range of viewing angles. These goals are achieved through the fabrication and manufacture of LCDs using O-plate compensator technology.
2.1 LCD Technology Overview
Liquid crystals are useful for electronic displays because polarized light traveling through a liquid crystal layer is affected by the layer's birefringence, which can be changed by the application of a voltage across the layer. By using this effect, the transmission or reflection of light from an external source, including ambient light, can be controlled with much less power than is required for the luminescent materials used in other types of displays. As a result, liquid crystal displays are now commonly used in a wide variety of applications, such as, for example, digital watches, calculators, portable computers, and many other types of electronic equipment. These applications highlight some of the advantages of LCD technology including very long operational life in combination with very low weight and low power consumption.
The information content in many liquid crystal displays is presented in the form of multiple rows of numerals or characters, which are generated by segmented electrodes deposited in a pattern on the display. The electrode segments are connected by individual leads to electronic driving circuitry. By applying a voltage to the appropriate combination of segments, the electronic driving circuitry controls the light transmitted through the segments.
Graphic and television displays may be achieved by employing a matrix of pixels in the display which are connected by an X-Y sequential addressing scheme between two sets of perpendicular conductors. More advanced addressing schemes, applied predominantly to twisted nematic liquid crystal displays, use arrays of thin film transistors to control driving voltages at the individual pixels.
Contrast and stability of relative gray scale intensities are important attributes in determining the quality of a liquid crystal display. The primary factor limiting the contrast achievable in a liquid crystal display is the amount of light which leaks through the display in the dark state. In addition, the contrast ratio of the liquid crystal device also depends on the viewing angle. The contrast ratio in a typical liquid crystal display is a maximum only within a narrow viewing angle centered near normal incidence and drops off as the angle of view is increased. This loss of contrast ratio is caused by light leaking through the black state pixel elements at large viewing angles. In color liquid crystal displays, such leakage also causes severe color shifts for both saturated and gray scale colors.
The viewing zone of acceptable gray scale stability in a typical prior art twisted nematic liquid crystal display is severely limited because, in addition to color shifts caused by dark state leakage, the optical anisotropy of the liquid crystal molecules results in large variations in gray level transmission, i.e., a shift in the brightness-voltage curve, as a function of viewing angle. The variation is often severe enough that, at extreme vertical angles, some of the gray levels reverse their transmission levels. These limitations are particularly important for applications requiring a very high quality display, such as in avionics, where viewing of cockpit displays from both pilot and copilot seating positions is important. Such high information content displays require that the relative gray level transmission be as invariant as possible with respect to viewing angle. It would be a significant improvement in the art to provide a liquid crystal display capable of presenting a high quality, high contrast image over a wide field of view.
FIGS. 1A and 1B show a conventional normally white, twisted nematic liquid crystal display 100 including a polarizer 105, an analyzer 110 with a polarization axis perpendicular to that of the polarizer 105, a light source 130, and a viewer 135.
In the normally white configuration of FIGS. 1A and 1B, a "nonselect" area 115 (no applied voltage) appears light, while a "select" area 120 (those which are energized by an applied voltage) appear dark. In the select area 120 the liquid crystal molecules tend to tilt and rotate toward alignment with the applied electric field. If this alignment perfect, all the liquid crystal molecules in the cell would be oriented with their long axes normal to the cell's major surface. This configuration is known as homeotropic alignment.
Because the liquid crystals used for twisted nematic displays exhibit positive birefringence, this arrangement, known as the homeotropic configuration, would exhibit the optical symmetry of a positively birefringent C-plate. As is well known in the art, a C-plate is a uniaxial birefringent plate with its extraordinary axis (i.e., its optic or c-axis) perpendicular to the surface of the plate (parallel to the direction of normally incident light). In the select state the liquid crystal in a normally white display would thus appear isotropic to normally incident light, which would be blocked by the crossed polarizers.
One reason for the loss of contrast with increased viewing angle which occurs in a normally white display is that a homeotropic liquid crystal layer will not appear isotropic to off-normal light. Light propagating through the layer at off-normal angles appears in two modes due to the birefringence of the layer; a phase delay is introduced between those modes and increases with the incident angle of the light. This phase dependence on incidence angle introduces an ellipticity to the polarization state which is incompletely extinguished by the second polarizer, giving rise to light leakage. To correct for this effect, an optical compensating element must also have C-plate symmetry, but with negative birefringence (n.sub.e <n.sub.o). Such a compensator will introduce a phase delay opposite in sign to the phase delay caused by the liquid crystal layer, thereby restoring the original polarization state and allowing light passing through energized areas of the layer to be blocked more completely by the output polarizer. C-plate compensation, however, does not impact the variation of gray scale with viewing angle, which is addressed by the present invention.
FIG. 2 depicts the coordinate system which is used to describe the orientation of both liquid crystal and birefringent compensator optic axes. Light propagates toward the viewer 200 in the positive z direction 205 which, together with the x-axis 210 and the y-axis 215, form a right-handed coordinate system. Backlighting is provided, as indicated by the arrows 220, from the negative z direction. The polar tilt angle .THETA. 225 is defined as the angle between the liquid crystal's molecular optic axis c 230 and the x-y plane, measured from the x-y plane. The azimuthal or twist angle .PHI. 235 is measured from the x-axis to the projection 240 of the optic axis into the x-y plane.
2.2 Normally White Twisted Nematic LCDs
FIG. 3 is a cross sectional schematic view of a prior art twisted nematic, transmissive type normally white liquid crystal display. The display includes a polarizer layer 300 and an analyzer layer 305, between which is positioned a liquid crystal layer 310, consisting of a liquid crystal material in the nematic phase.
It is convenient in describing the orientation of various compensation elements of the display to refer to a normal axis perpendicular to the display, which is depicted by a dashed line 370. In the case of a normally white display, the polarizer 300 (with a polarization direction in the plane of the drawing 315) and the analyzer 305 (with a polarization direction into the plane of the drawing 320) are oriented with their polarization directions at 90.degree. to one another. (A polarizer 300 and an analyzer 305 both polarize electromagnetic fields. Typically, however, the term `polarizer` refers to a polarizer element that is closest the source of light while the term `analyzer` refers to a polarizer element that is closest the viewer of the LCD.) A first transparent electrode 325 and a second transparent electrode 330 are positioned on the glass plates 340 and 345 adjacent to opposite surfaces of the liquid crystal layer 310 so that a voltage can be applied, by means of a voltage source 335, across the liquid crystal layer. As is explained below, the inner surfaces of the glass plates 340 and 345, which are proximate to the liquid crystal layer 310, can be physically or chemically treated to affect the desired liquid crystal orientation, as by buffing.
As is well known in the LCD art (see, e.g., Kahn, "The Molecular Physics of Liquid-Crystal Devices," Physics Today, pp. 66-74, May 1982), when the inner surfaces of the plates 340 and 345 (the surfaces adjacent to the layer 310) are coated with a surface treatment for aligning the liquid crystal such as polyimide, buffed, and oriented with their buffed directions perpendicular, the director of the liquid crystal material, absent any applied electrical voltage, will tend to align with the buffed direction (known as the "rub direction") in the regions of the layer 310 proximate each of the plates 340 and 345. Furthermore, the orientation of the liquid crystal axis (i.e., the director) will twist smoothly with respect to the normal axis through an angle of 90.degree. along a path in the layer 310 from the first major surface adjacent to the plate 340 (i.e., at the 310/340 interface) to the second major surface adjacent to the plate 345 (i.e., at the 310/345 interface).
In the absence of an applied electric field the direction of polarization of incoming polarized light will be rotated by 90.degree. in traveling through the liquid crystal layer. When the glass plates and the liquid crystal layer are placed between crossed polarizers, such as the polarizer 300 and the analyzer 305, light polarized by the polarizer and traversing the display, as exemplified by the light ray 350, will thus be aligned with the polarization direction of the analyzer 320 and therefore will pass through the analyzer.
When a sufficient voltage is applied to the electrodes 325 and 330, however, the applied electric field causes the director of the liquid crystal material to tend to align parallel to the field. With the liquid crystal material in this state, light passed by the polarizer 300, as illustrated by the light ray 355, will be extinguished by the analyzer 305. Thus, an energized pair of electrodes will produce a dark region in the display, while light passing through regions of the display which are not subject to an applied field will produce illuminated regions. As is well known in the LCD display art, an appropriate pattern of electrodes, activated in selected combinations, can be utilized in this manner to display alphanumeric or graphic information. As explained further below, one or more compensator layers, such as the layers 360 and 365, may be included in the display to improve the quality of the display.
2.3 Normally White Twisted Nematic LCD Characteristics
FIG. 4 shows a calculated plot of liquid crystal director tilt as a function of position in a liquid crystal layer (where the cell gap has been normalized to unity) in a 90.degree. twisted nematic cell. Typical distributions for molecular tilt angles when no voltage is applied (curve 400), under a typical select state voltage (curve 405), and under the application of several intermediate voltages chosen to yield linearly spaced gray levels (curves 410, 415, 420, 425, 430, and 435) are shown.
FIG. 5 is a related plot for the same cell depicting the calculated twist angle of the liquid crystal molecules as a function of position in the cell. When there is no applied voltage, the twist is distributed evenly throughout the cell (straight line curve 500). Under a fully select state voltage, the twist is distributed as shown by the external, S-shaped curve 505. The twist distributions for gray levels are shown by the intermediate curves between the two curves 500 and 505.
As illustrated by FIGS. 4 and 5, when the fully selected voltage is applied nearly all of the twist experienced by the liquid crystal molecules, and a substantial portion of the tilt, occurs in the central region of the cell. Because of this phenomenon, the continuous variation of molecular orientation within the cell can be separated into three regions, each of which is characterized by its own optical symmetry. Thus, the central regions 440 (FIG. 4) and 510 (FIG. 5) can be considered as nominally homeotropic in the fully selected state, approximating the properties of a C-plate. The regions 445 and 450 (FIG. 4) and 515 and 520 (FIG. 5), near each surface of the cell, behave as A-plates, each with its extraordinary axis aligned with the rub direction of the proximate substrate. Because there is essentially no twist in the molecules in the regions 445, 450, 515, and 520, the molecules are essentially aligned with the respective rub directions on either side of the liquid crystal layer. In addition, because the twist angle of the molecules in the regions 445 and 515 tends to be perpendicular to the twist angle of the molecules in the regions 450 and 520, the effect of these two regions on light traveling through the cell tends to be canceled, leaving the middle C-plate region to exert the dominant influence.
2.3(a) C-Plate Compensation
As is well known in the art, a negative C-plate compensator is designed to correct for the angle dependent phase shift introduced by propagation through the central, approximately C-plate region of a LCD cell. Such a compensator is effective to the extent that the optical symmetry of the central region dominates the selected state of the liquid crystal cell, that is, the extent to which the molecules align with the applied field. This implies that negative C-plate compensation will work best when strong fields are used for the energized state as this makes the homeotropic approximation more nearly correct. The use of a C-plate has been demonstrated to significantly reduce the leakage of the dark state over an extended field of view, thus improving contrast and reducing color desaturation.
2.3(b) Gray Scale Stability
While the use of a C-plate compensator may be used to improve contrast, it does not improve gray scale stability. The problem of maintaining constant gray scale luminance differences over the field of view relates substantially to the brightness level changes for levels assigned between the select (black for a normally white display) and nonselect (white for a normally white display) states. This phenomenon is generally depicted using transmission, or brightness, versus voltage (BV) electro-optic response curves for a display to which eight gray levels are assigned, from level 0 (the select black state) to level 7 (the nonselect white state). Gray levels between 0 and 7 are chosen by assigning them a set of voltages spaced linearly in brightness along the BV curve between the select and nonselect voltages.
FIG. 6 is a plot of calculated BV (transmission versus drive voltage) curves for a normally white, 90.degree. twisted nematic display as the horizontal viewing angle varies from 0.degree. to 40.degree. in 10.degree. increments while the vertical viewing angle remains fixed at 0.degree.. (The change in the BV curves with horizontal angle is, to first order, independent of whether the horizontal deviation is to the left or right.) Note that the regions of each curve over which gray levels would be selected almost overlie one another for the various horizontal angles. This means that gray levels chosen to be linearly spaced at zero degrees would remain very nearly linear at even high horizontal viewing angles.
The gray scale stability problem appears most predominantly when the vertical viewing angle varies. This is illustrated in FIG. 7, which shows a series of BV curves for a normally white, 90.degree. twisted nematic display as the vertical viewing angle varies from -10.degree. to +30.degree. while the horizontal viewing angle remains fixed at 0.degree.. It can be observed that for angles below 0.degree. (measured from the normal) the BV curves shift to the right (higher voltage), and fall monotonically from their maximum but fail to reach zero.
For angles above normal, the curves shift to the left and develop a rebound after an initial minimum. These effects can be explained by considering the perspectives of viewers looking at the display from above, at, and below normal, as shown in FIG. 8. The critical feature to note is the relationship between the light traveling towards the viewer and the average liquid crystal director tilt at the center of a cell as voltage across the cell is increased.
For instance, as the voltage across a cell is increased, the average liquid crystal director in the center of the cell tilts from a parallel (with respect to the polarizer 300 and analyzer 305) orientation 815 toward a homeotropic one 825. For the viewer at normal incidence 800, retardation is highest at the nonselect state voltage and lowest at the select state voltage. When the retardation is nearly zero, the polarization state of the light is unchanged and it is blocked by the analyzer. Thus, the viewer sees a monotonic decrease in brightness to zero with increasing voltage.
Now consider the case of a positive vertical viewing direction (viewer above normal incidence 805). At some intermediate voltage the average director 820 points toward the viewer and the retardation is minimal. Here the viewer sees a brightness with voltage that initially decreases toward a minimum, at the point of minimal retardation, and then increases.
For the negative vertical viewing direction (viewer below normal incidence 810), the average director always presents a large anisotropy to a light ray, even at the highest voltage. The viewer therefore sees a monotonic decrease in brightness. Furthermore, the average liquid crystal director is always oriented at a larger angle with respect to the light ray for the below normal viewer 810 than it is for the normal incidence viewer 800. Therefore the anisotropy is greater and the brightness level is always higher in the negative vertical viewing direction than it is at normal incidence.
This dependency of an LCD's brightness versus viewing angle, has a profound impact on gray scale stability. In particular, the variation in gray level luminance versus vertical viewing angle can be extreme. (Note that a voltage chosen to yield a 50% gray level on the 0.degree. curve in FIG. 7 yields a dark state on the +30.degree. curve and approaches a fully white state at -10.degree..)
2.3(c) O-Plate Gray Scale Compensation
To eliminate reversal of gray levels and improve gray scale stability, a birefringent O-plate compensator can be used. The O-plate compensator principle, as described in U.S. patent application 223,251 utilizes a positive birefringent material with its principal optic axis oriented at a substantially oblique angle with respect to the plane of the display (hence the term "O-plate"). "Substantially oblique" implies an angle appreciably greater than 0.degree. and less than 90.degree.. O-plates have been utilized, for example, with angles relative to the plane of the display between 30.degree. and 60.degree., typically at 45.degree.. Moreover, O-plates with either uniaxial or biaxial materials can be used. O-plate compensators can be placed in a variety of locations between a LCD's polarizer layer and analyzer layer.
In general, O-plate compensators may also include A-plates and/or negative C-plates as well as O-plates. As is well known in the art, an A-plate is a birefringent layer with its extraordinary axis (i.e., its c-axis) oriented parallel to the surface of the layer. Its a-axis is thus oriented normal to the surface (parallel to the direction of normally incident light), leading to its designation as an A-plate. A-plates may be fabricated by the use of uniaxially stretched polymer films, such as polyvinyl alcohol, or other suitably oriented organic birefringent materials.
A C-plate is a uniaxial birefringent layer with its extraordinary axis oriented perpendicular to the surface of the layer (parallel to the direction of normally incident light). Negatively birefringent C-plates may be fabricated by the use of uniaxially compressed polymers (See, e.g., Clerc et al., U.S. Pat. No. 4,701,028), stretched polymer films, or by the use of physical vapor deposited inorganic thin films (See, e.g., Yeh et al., U.S. Pat. No. 5,196,953), for example.
Oblique deposition of a thin film by physical vapor deposition is known to produce a film having birefringent properties (see, e.g., Motohiro and Taga, "Thin Film Retardation Plate by Oblique Deposition," Appl. Opt., Vol. 28, No. 3, pp. 2466-2482, 1989). By further exploiting the tilted orientation of the symmetry axis, the Motohiro process can be refined or enhanced to fabricate O-plates. Such components are by their nature biaxial. Their growth characteristics generate a microscopic columnar structure. The angles of the columns are tipped toward the direction of the arrival of a vapor stream. A deposition angle (measured from normal) of 76.degree., for example, results in a column angle of approximately 45.degree.. The columns develop an elliptical cross section as the result of shadowing. This elliptical cross section gives rise to the biaxial character of the films. The birefringence, in magnitude and symmetry, is entirely attributable to the film microstructure and is referred to as form birefringence. These phenomena in thin films have been extensively studied and described by Macleod ("Structure-Related Optical Properties of Thin Films," J. Vac. Sci. Technol. A, Vol. 4, No. 3, pp. 418-422, 1986).
Uniaxial O-plate components can also be used to improve gray scale stability in twisted nematic liquid crystal displays. These may be fabricated by the use of suitably oriented organic birefringent materials. Those skilled in the art will recognize other means for fabricating both uniaxial and biaxial O-plates.
FIGS. 9 and 10 show one effect that an O-plate compensator layer can have on a normally white twisted nematic display. FIG. 9 shows the O-plate compensator layer's effect on the electro-optic response of the display at various horizontal viewing angles while FIG. 10 shows the O-plate compensator layer's effect on the display's vertical viewing angle. In this particular embodiment, one A-plate layer is positioned adjacent to the liquid crystal layer on both sides of the liquid crystal cell, and an O-plate layer is disposed between the polarizer layer and the A-plate/liquid crystal/A-plate layer stack. The variation in the BV curves versus both horizontal and vertical viewing angles are greatly reduced relative to the uncompensated case shown in FIGS. 6 and 7.
Elimination of gray scale reversal by the use of an O-plate compensator layer occurs in the following manner. In the positive vertical viewing direction, the retardation of the O-plate increases with viewing angle and tends to offset the decreasing retardation of the liquid crystal layer. When the viewer is looking down the axis of the average liquid crystal director, the presence of the O-plate prevents the layers between the two polarizers from appearing isotropic. Thus the rebound in the BV curve, shown in FIG. 7, is reduced and moved to higher voltages outside of the gray scale voltage range as shown in FIG. 10
In the negative vertical viewing direction, the combination of an O-plate and an A-plate with their optic axes nominally at right angles tends to exhibit birefringence characteristics similar to that of a negative birefringence retarder with its optic axis oriented perpendicular to the plane containing the axes of the O-plate and A-plate. The direction of this retarder axis is nominally parallel to the orientation of the average liquid crystal in the central region of the cell when it is driven at a voltage between select and nonselect states. Thus, the presence of an O-plate oriented in this manner tends to cancel the birefringence of the liquid crystal layer, pulling the BV curve down, or equivalently, moving it toward the direction of lower voltages (i.e., left). A similar effect occurs in the positive and negative horizontal viewing directions as well.
The overall effect of introducing an O-plate compensator in this manner is to eliminate large rebounds in the gray scale voltage region and reduce the left-to-right shift in the BV curves as the viewing angle is varied from negative to positive vertical angles.
The orientations of the compensator optic axes can be carefully chosen so that the combined retardation effects cancel each other in the normal incidence viewing direction as well as minimize rebounds in the horizontal viewing direction. Combinations of more than one O-plate can be used as long as their orientations satisfy these requirements. Furthermore, negative C-plates can, for certain configurations, increase the contrast ratio at large fields of view, occasionally with some decrease in gray scale stability.
2.3(d) O-Plate Technology
The liquid crystal layer, the compensator layer(s), the polarizer layer, and the analyzer layer may assume a variety of orientations relative to one another in a liquid crystal display. Some of the possible configurations which have been considered, and set out in U.S. patent application Ser. No. 223,251 are repeated in Table 1; where `A` represents an A-plate, `C` represents a C-plate, `O` represents an O-plate, `LC` represents the liquid crystal, and `O.times.O` represents crossed O-plates. Crossed O-plates are adjacent O-plates with their azimuthal angles .PHI. 235 nominally crossed, one oriented between 0.degree. and 90.degree.; and the second oriented between 90.degree. and 180.degree..
TABLE 1 ______________________________________ Liquid Crystal Display Elements .rarw. Toward Rear (Polarizer Side) Toward Front (Analyzer Side) .fwdarw. ______________________________________ O A LC A O LC O LC O A A O A LC O A LC A O A C LC OxO A LC A OxO A LC A LC OxO A A O A C LC A O LC O A A O C LC C O A O C LC C O A C A O LC O A C ______________________________________
The projections of the principal axes onto the plane of the display with respect to the liquid crystal director orientation can vary with the embodiment. In some cases, for example with two O-plates, the O-plate axis projections are at 45.degree. with respect to the average liquid crystal director orientation near the center of the liquid crystal cell, while in others, the O-plate axis projection is substantially parallel with that of the liquid crystal director.
Crossed O-plate (O.times.O) designs that are further compensated with A-plates provide additional design flexibility. The choice of A-plate value is not critical as such designs can be adjusted by varying the 11 relative orientations of the A-plates. Thus, it is possible to generate desired solutions with commercially available A-plate retardation values.
The flexibility which an O-plate compensation scheme offers the display designer allows tailoring of performance to specific display product requirements. It is possible, for example, with simple configuration and parameter modifications to achieve isocontrast optimized for left or right viewing, isocontrast optimized for extreme vertical angle viewing, or isocontrast optimized for viewing at both large left and right angles above normal viewing. It is also possible to adjust the configuration and parameters to improve both the contrast and gray scale stability over a specified field of view, or to further optimize one at the expense of the other. Furthermore, a negatively birefringent A-plate may be substituted for a positively birefringent A plate. In this case, the negatively birefringent A-plate would be oriented with its extraordinary axis perpendicular to the orientation appropriate for a positively birefringent A-plate. As would be understood by one skilled in the art of liquid crystal display design, additional changes would also be required in the other components of the compensator to optimize performance when a negative A-plate is used.
2.4 Summary
When viewed at an angle near the normal to its surface, a twisted nematic liquid crystal display provides high quality output, but at large viewing angles the image tends to degrade and exhibit poor contrast and gray scale nonuniformity. This occurs because the phase retardation effect of the liquid crystal material on light passing through it inherently varies with the inclination angle of the light, leading to a lower quality image at large viewing angles. By introducing one or more optical compensating elements in conjunction with the liquid crystal cell, however, it is possible to substantially correct for the undesirable angular effects and thereby maintain higher contrast and stable relative gray scale intensities at larger viewing angles than otherwise possible.
It is the goal of this invention to describe a positively birefringent O-plate compensator and method to manufacture the same, that makes possible a significant improvement in the gray scale properties and contrast ratios of liquid crystal displays over a wide range of viewing angles.

Organic polymer O-plate compensator for improved gray scale performance in twisted nematic liquid crystal displays


The present invention was accomplished in order to provide a method for producing a sheet containing fine fibers, which enables production of a sheet containing fine fibers without producing wrinkles. The present invention provides a method for producing a sheet containing fine fibers comprising a coating step of coating a dispersion containing fine fibers having a fiber diameter of 1000 nm or smaller on a base material, and a drying step of drying the dispersion containing fine fibers coated on the base material to form a sheet containing fine fibers.

In recent years, as an alternative to oil resources and in connection with the growing environmental consciousness, applications of reproducible natural fibers attract attentions. Among natural fibers, cellulose fibers, especially those derived from wood (pulp), are widely used mainly for paper products. Most of cellulose fibers used for paper products have a fiber width of 10 to 50 μm. Paper (sheet) obtained from such cellulose fibers is opaque, and is widely used as paper for printing. If cellulose fibers are refined (microfibrillated) by a treatment in a refiner, kneader, sand grinder, or the like (beating or grinding), transparent papers (glassine paper etc.) are obtained from such fibers.
As an apparatus for producing a sheet containing fibers, Patent document 1 (Japanese Patent Unexamined Publication (KOHYO) No. 2012-516399) discloses an apparatus for making a nonwoven web, the apparatus comprising: a) a first source configured to dispense a first fluid flow stream comprising a fiber; b) a second source configured to dispense a second fluid flow stream also comprising a fiber; c) a mixing partition downstream from the first and second sources, the mixing partition positioned between the first and second flow streams, the mixing partition defining two or more openings in the mixing partition that permit fluid communication and mixing between the first and second flow streams; and d) a receiving region situated downstream from the first and second sources and designed to receive at least a combined flow stream and form a nonwoven web by collecting the combined flow stream, and Japanese Patent Unexamined Publication (KOHYO) No. 2012-516399 describes that the apparatus may further comprise a drying section proximal and downstream to the receiving region, and the drying section may comprise a drying can section, one or more IR heaters, one or more UV heaters, a through-air dryer, a transfer wire, a conveyor, or a combination thereof.
Patent document 2 (Japanese Patent Unexamined Publication (KOKAI) No. 2012-116905) discloses a method for producing a composite porous sheet using fine cellulose fibers and a polymer having a film-forming property, which is a method for producing a fine cellulose fiber composite porous sheet comprising a preparation step of mixing an aqueous suspension containing the fine cellulose fibers with an emulsion of the polymer having a film-forming property to produce a mixture, a papermaking step of forming a sheet containing moisture by dehydrating the mixture by filtration on a porous base material, a step of substituting an organic solvent for the moisture contained in the sheet, and a drying step of drying the organic solvent-substituted sheet by heating, and mentions cylinder dryer, yankee dryer, hot air drying, infrared heater, etc. as the drying means.
Patent documents 3 and 4 (Japanese Patent Unexamined Publication (KOKAI) No. 2007-23218 and Japanese Patent Unexamined Publication (KOKAI) No. 2007-23219) describe a fine fiber sheet obtained by separating a dry fine fiber layer from a base material, which dry fine fiber layer is formed on the base material by applying a slurry containing fine fibers on the base material and evaporating liquid components in the slurry, and describe that hot air drying, infrared drying, vacuum drying etc. are effective for the drying.
Patent document 5 (Japanese Patent Unexamined Publication (KOKAI) No. 2008-248441) describes a fiber sheet containing cellulose fine fibers treated with a hydrophobizing agent such as a sizing agent, oil and fat, wax, and hydrophobic resin. The fiber sheet described in Japanese Patent Unexamined Publication (KOKAI) No. 2008-248441 shows low hygroscopicity and thus reduced dimensional change due to moisture absorption, because it is constituted with cellulose fine fibers made hydrophobic.
Patent document 6 (Japanese Patent Unexamined Publication (KOKAI) No. 2013-71456) describes a porous sheet comprising a fine fiber web layer consisting of fine fibers having a diameter of 50 to 5000 nm, and a support layer, on one or both surfaces of which the fine fiber web layer is bonded. Further, it describes that the fine fiber web layer is formed by forming fine fibers consisting of a mixture of a polymer and an adhesive material through electrostatic spinning of a spinning solution consisting of a mixture of solutions of the polymer and the adhesive material, spraying a solution of the adhesive material on the fine fibers, and then bonding the fibers on the support layer to form the fine fiber web layer.

Method for producing sheet containing fine fibers


Described is a valve prosthesis comprising: an annular structure, and a plurality of valve leaflets, and a plurality of anchoring members attached around the annular structure, the anchoring members including: a web portion coupled to the annular structure and extending axially thereto, and two end portions at axially opposed sides of the web portion, the end portions having: an insertion condition for insertion of the prosthesis, wherein the end portions are aligned to the web portion and extend axially with respect to the annular structure; and an anchoring condition for anchoring the prosthesis, wherein the end portions extend at an angle to the web portion radially outwardly of the annular structure to provide anchoring of the prosthesis proximally and distally, respectively, of the annulus, and wherein one end portion forms an obtuse angle with the web portion.

Various valve pathologies, such as, in the case of cardiac valve pathologies, mitral valve pathologies (essentially stenosis or insufficiency), can be surgically treated either with "repair" techniques or with "replacement" techniques.
Some physicians consider repair techniques to provide a higher life expectancy and less morbidity as compared to replacement techniques. This may be related to the conservation of native valve structures, e.g., leaflets and chordae tendineae, in the repair process. Various valve pathologies may thus benefit from the availability of arrangements permitting valve replacement (such as, e.g., Mitral Valve Replacement or "MVR") while also conserving the native valve structures.


A system, method, and computer program product are provided for performing fast migration of a virtual resource from one node to another node. The method includes the steps of receiving a first request to migrate a resource from a first node to a second node, transmitting a second request to the second node to create a new instance of the resource, collecting a set of changes associated with the resource in a data structure, and transmitting the data structure that includes the set of changes to the second node. The second node generates the new instance of the resource based on a snapshot of the resource captured by the first node at a previous point in time and updates the new instance of the resource based on the set of changes such that the new instance of the resource on the second node matches the resource on the first node.

Modem systems that implement a plurality of virtual machines running on separate nodes may include functionality to copy a virtual resource such as a virtual storage device from one node to a different node. Migration of the resource thereby enables the resource to be utilized by a different virtual machine running on different hardware. However, such resources may be extremely large and the data that represents the resource may need to be transported over a network infrastructure. This data transfer may take hours or days to be copied from one node to another node. Thus, there is a need for addressing this issue and/or other issues associated with the prior art.

Efficient migration of virtual storage devices to a remote node using snapshots


A snowmobile is provided with airbag systems including airbag bodies expanding from a portion near a steering handle bar respectively, one of the airbag bodies expanding rearward of a handle bar and outward of both the ends of the handle bar, and the other airbag body expanding toward a front side of rider's knees. Another airbag system includes an airbag body expanding from an upper surface of an engine hood on the front portion of a vehicle body frame and blowing up toward a windshield of the engine hood. The respective airbag systems are detachable from the vehicle body, and hence, can be stored indoors.

1. Field of the Invention
The present invention relates to a snowmobile with an airbag system.
2. Related Art
Since the snowmobile is used in a cold snow zone or area, it is required for a rider to be heavily dressed or protects himself/herself with winter cloth and covers his/her head with a helmet or a cap. Thus, the rider of the snowmobile is protected from impact of collision to some extent in comparison with a driver on a four-wheel vehicle.
However, in accordance with recent improvement of performance of the snowmobile, it is desired to provide an airbag system as in the four-wheel vehicles in order to secure safety of the rider in case of collision of the snowmobile.
The following points are considered when providing an airbag system on a snowmobile.
First, the snowmobile travels not only on well maintained public roads, but also on sites which are not used as a road in a normal condition such as forest or rough terrain, and hence, the rider is required to make self-supporting efforts (such as weight shift) more than that in the case of the four-wheel vehicle. Accordingly, the airbag is required so that the vehicle can maintain its original shape as much as possible after the airbag has been expanded and blown up, and restoration to travel by its own ability can be achieved after the expanded airbag has been quickly handled, in comparison with the case of the four-wheel vehicle.
Next, the snowmobile is provided with no seatbelt because the weight shift is required for the rider for maneuvering the snowmobile, and it is itself difficult to fasten the seat belt to the snowmobile. It is therefore difficult and unreasonable to mount an airbag system on the premise of simultaneous usage of the seatbelt as in the four-wheel vehicle.
Third, the snowmobile travels on the snow and the airbag system is activated by the use of gunpowder, high-pressure gas and electricity. It is therefore necessary to consider that the snow, as a matter of course, snow-melted water or refreezing of the water does not give an adverse effect or damage on the airbag system.
Fourth, the snowmobile is generally left untouched for a long time in outdoors during seasons other than winter snow season, so that there arises a problem in functional durability or the maintenance of the airbag system unlike the case of the four-wheel vehicle in which the airbag is installed in the vehicle without being left untouched for a long time.

This patent is subject to a terminal disclaimer.


A liquid bait station for ants has separate nested inner and outer container sections with the inner container forming a liquid bait reservoir. The inner container section or reservoir has a lid that is closed whenever the outer container is closed, and access to the reservoir of liquid bait by the ants is indirect via one or more container access ports leading to a compartment inside the outer container and then via separate reservoir access ports leading from the compartment to the reservoir. In one embodiment, the reservoir lid comprises a raised portion in the inner surface of the outer container's own cover and the reservoir access ports are formed by depressions in that raised portion. In a second embodiment, the inner and outer container sections have separate lids, but at least one tang depending from the outer cover closes and holds down the inner lid whenever the outer cover is closed. The reservoir access ports can be holes in the inner lid. In a third embodiment, the ant bait station can be combined in a single integrated unit with a rodent bait station, provided there is a separate internal compartment and separate access for the rodents, and provided a partition completely isolates the ant compartment from the rodent compartment.

In U.S. Pat. No. 3,017,717, Caubre describes a container for an open bottle of ant poison that is accessible to ants but that cannot be opened by a child. The container is a box with a hinged side wall. A steel pin extends through a bore in a top wall of the box and into an elongate recess in a lug attached to the inside of the hinged side wall, thereby locking the box closed. Since the pin does not protrude from the bore, it cannot be removed by hand, but must instead be drawn out by a magnet in order to unlock the box. Small holes in an end wall of the box give ants ready access to the open bottle of poisonous bait inside the box. Presumably, the poison should be sufficiently viscous to avoid leakage from the bottle through the ant access holes if up-ended by a child.
In U.S. Pat. No. 5,033,229, Demarest et al. describe a liquid bait station for roaches. The bait station has a base structure that includes a central well area with an absorbent pad and a plurality of insect access openings in side walls surrounding the well area. The bait station also has a funnel-shaped reservoir seated in the base structure and tapering to a narrow opening at its bottom for controllably releasing liquid bait onto the absorbent pad in the central well area. The larger upper end of the funnel-shaped reservoir has a cover.
In U.S. Pat. No. 5,548,922, Wefler describes an insect liquid bait station that includes a base having a floor and a peripheral dike that together define a reservoir for a slow-kill liquid insecticide. A porous pad sits in the pooled liquid on the floor of the reservoir. A cover is mounted in liquid-tight relation on the base. The cover has an inclined ramp leading down to a central stage area with access portals through which the target insects can enter and feed on the poisonous liquid on the porous pad. The tight mounting of the cover to the base and the use of a porous pad immediately beneath the access ports resist spillage of the liquid bait.
In U.S. Pat. No. 794,323, Small describes a poison vault for rodents which is constructed so that the poison bait is accessible to mice and rats, but not to fowl and larger animals, and also so that the rodents cannot carry away any large pieces of the bait. The vault includes an outer box with a hinged top. The outer box has round openings at an upper portion of each side and end wall, large enough to admit rats and mice, and at a height from the bottom so that the rodents must stand on their hind feet to pass through the opening. The vault also includes an inner box with side and end walls secured to the bottom of the outer box (but no lid) and separated from the outer walls to create a space between the inner and outer walls into which the rodents must first enter before passing through similar openings in the walls of the inner box. Because the rodents must stand on their hind feet to traverse the openings, they are unable to carry large pieces of bait with their feet and must leave the pieces behind or consume them while in the box. The hinged top of the outer box may be provided with a hook that engages a pin to securely close the box.
U.S. Pat. Nos. 4,026,064; 4,550,525; 5,040,327; 5,272,832; and 5,448,852 disclose other rodent bait stations. In general, these consist of a protective box provided with access holes, interior rooms or trays containing solid bait, and passageways from the holes to the rooms or trays. Bolts, ties or other means may be used to provide tamper resistant closure of these boxes. J.T. Eaton & Co., Inc. of Twinsbury, Ohio provides several models of rodent bait stations that use bait holding rods or racks in interior rooms, where the bait is in the form of blocks that can be slid onto the rod.
U.S. Pat. No. 1,964,611 to Watson discloses a combined rodent and insect exterminator station with separate compartments for solid rodent bait and liquid insect bait within an enclosed structure. The structure has openings that allow entry of rodents but that keep out chickens. The insect bait appears not to be sufficiently isolated from the rodent feeding compartments, so that mice or rats would have to traverse or pass by the insect bait area to reach the rodent bait. Rodents would be unlikely to feed in the presence of large numbers of ants.
An object of the invention is to provide a liquid bait station for ants or other crawling insects constructed to resist spillage of bait within the bait station.
Another object of the invention is to provide a liquid bait station with improved access to liquid bait by the target crawling insects.
Still another object of the invention is to provide a liquid bait station which is tamper resistant.
Another object of the invention is to provide a combined bait station with liquid bait for ants and solid bait for rodents, wherein rodents will feel comfortable feeding even when ants are also feeding in their own bait.

Liquid bait station for ants and combined ant/rodent station


A hybrid work machine includes: an engine; a generator motor; a storage battery; a motor; a transformer; a target engine speed calculation unit configured to calculate a target engine speed based on at least an engine load and an output state of the generator motor; a generation control unit configured to output a generator requesting minimum engine speed; an engine controlling target engine speed calculation unit configured to calculate and output an engine controlling target engine speed based on the target engine speed and the generator requesting minimum engine speed; an engine control unit configured to control an engine speed based on the engine controlling target engine speed; and an assist control unit configured to set the target engine speed to the generator controlling target engine speed and control engine assist based on the generator controlling target engine speed and the generator motor speed.

There is a hybrid work machine configured to operate a work unit or the like by driving a generator motor with an engine and driving a motor with power generated by the generator motor. For example, Patent Literature 1 discloses a technology in which a hydraulic pump and a generator motor are driven by an engine, and a battery is charged by generation action of the generator motor, and further an engine is assisted by driving the generator motor with battery power. Further, Patent Literature 1 discloses the technology in which output of the generator is restricted until an engine rotation speed reaches a setting speed at the time of accelerating the engine so as to assist acceleration by reducing an engine load.
Furthermore, Patent Literature 2 discloses a technology in which whether to cause a generator motor to execute engine torque assist action or not to execute engine torque assist action is determined. In the case of determining to cause the generator motor to execute the engine torque assist action, the generator motor is caused to execute the engine torque assist action, and in the case of determining not to cause the generator motor to execute the engine torque assist action, the generator motor is caused to execute generation action in accordance with a requested generation amount.


The invention relates to a surgical instrument and a method for treating female urinary incontinence. A tape or mesh is permanently implanted into the body as a support for the urethra. In one embodiment, portions of the tape comprise tissue growth factors and adhesive bonding means for attaching portions of the tape to the pubic bone. In a further embodiment, portions of the tape comprise attachment means for fastening portions of the tape to fascia within the pelvic cavity. In both embodiments the tape is implanted with a single incision through the vaginal wall.

Women account for more than 11 million of incontinence cases. Moreover, a majority of women with incontinence suffer from stress urinary incontinence (SUI). Women with SUI involuntarily lose urine during normal daily activities and movements, such as laughing, coughing, sneezing and regular exercise.
SUI may be caused by a functional defect of the tissue or ligaments connecting the vaginal wall with the pelvic muscles and pubic bone. Common causes include repetitive straining of the pelvic muscles, childbirth, loss of pelvic muscle tone, and estrogen loss. Such a defect results in an improperly functioning urethra. Unlike other types of incontinence, SUI is not a problem of the bladder.
Normally, the urethra, when properly supported by strong pelvic floor muscles and healthy connective tissue, maintains a tight seal to prevent involuntary loss of urine. When a woman suffers from the most common form of SUI, however, weakened muscle and pelvic tissues are unable to adequately support the urethra in its correct position. As a result, during normal movements when pressure is exerted on the bladder from the diaphragm, the urethra cannot retain its seal, permitting urine to escape. Because SUI is both embarrassing and unpredictable, many women with SUI avoid an active lifestyle, shying away from social situations.
U.S. Pat. No. 5,899,909 discloses a surgical instrument comprising a shank having a handle at one end and connecting means at the other end to receive, one at a time, two curved needle-like elements which are connected at one end to one end of a tape intended to be implanted into the body. In practice, the tape is passed into the body via the vagina first at one end and then at the other end at one side and the other, respectively, of the urethra to form a loop around the urethra, located between the urethra and vaginal wall. The tape is extended over the pubis and through the abdominal wall and is tightened. The tape ends are cut at the abdominal wall, and the tape is left implanted in the body. U.S. Pat. No. 5,899,909 is hereby incorporated by reference in its entirety herein.
This invention simplifies the apparatus and method of the instrument and method prior art and provides for a safe and effective method of placing a tape mesh in a sling relationship with the urethra.

Surgical instrument and method for treating female urinary incontinence


Described are techniques used in connection with management and processing of configuration data and performance data about a data storage system. The data is collected by one or more agents and forwarded to store components. The store components are responsible for maintaining persistent data objects in a repository. A server may process user requests issued from one or more consoles by retrieving data from the repository and displaying information based thereon on the consoles. The data collected by the agents may be in accordance with a first object model or data representation different from another object model or data representation of the repository. The store components update the repository using data collected by the agents.

1. Technical Field
This application generally relates to a computer system, and more particularly to techniques used in data management.
2. Description of Related Art
Computer systems may include different resources used by one or more host processors. Resources and host processors in a computer system may be interconnected by one or more communication connections. These resources may include, for example, data storage systems, such as the Symmetrix™ family of data storage systems manufactured by EMC Corporation. These data storage systems may be coupled to one or more host processors and provide storage services to each host processor. An example data storage system may include one or more data storage devices, such as those of the Symmetrix™ family, that are connected together and may be used to provide common data storage for one or more host processors in a computer system.
A host processor may perform a variety of data processing tasks and operations using the data storage system. For example, a host processor may perform basic system I/O operations in connection with data requests such as data read and write operations.
Host processor systems may store and retrieve data using a storage device containing a plurality of host interface units, disk drives, and disk interface units. Such storage devices are provided, for example, by EMC Corporation of Hopkinton, Mass. and disclosed in U.S. Pat. No. 5,206,939 to Yanai et al., U.S. Pat. No. 5,778,394 to Galtzur et al., U.S. Pat. No. 5,845,147 to Vishlitzky et al., and U.S. Pat. No. 5,857,208 to Ofek. The host systems access the storage device through a plurality of channels provided therewith. Host systems provide data and access control information through the channels to the storage device and storage device provides data to the host systems also through the channels. The host systems do not address the disk drives of the storage device directly, but rather, access what appears to the host systems as a plurality of logical disk units. The logical disk units may or may nor correspond to the actual disk drives. Allowing multiple host systems to access the single storage device unit allows the host systems to share data stored therein.
It may be desirable to monitor data storage systems for a variety of different reasons, such as, for example, to obtain configuration data and/or performance data. Performance data may include, for example, data regarding system device usage and throughput, system load. System configuration information may be obtained, for example, at a predefined interval, or in connection with a system configuration modification, such as a logical or physical device reconfiguration. Monitoring and related operations for data storage system management may be automated. It may be desirable to have an automated monitoring system that efficiently provides updated configuration data and other information about a data storage system.


An animal training apparatus is comprised of a leash connector attached to a chest portion of a harness. The harness is arranged for preventing the leash connector from shifting to the back of the animal. The harness is preferably comprised of a chest strap for positioning across the chest of the animal between the tops of the front legs, a withers strap for positioning across the withers of the animal behind the neck and between the shoulders, and a girth strap for positioning across the girth of the animal behind the front legs on the underside. The leash connector is attached to an intermediate position on the chest strap for applying a rotating force to the animal when the animal moves forwards of the handler and pulls on the leash connector. The animal is prevented by the rotational force from pulling further.

1. Field of the Invention
The invention broadly relates to animal harnesses and leashes.
2. Prior Art
An animal leash is typically connected to a collar worn around the neck of an animal. The collar is free to rotate around the neck. An animal, such as a dog, which has not been trained, instinctively wishes to roam away from its handler. When the dog tries to walk or run away and pulls the leash taut, the collar is automatically rotated so that the leash is positioned at the back of the neck. As the dog pulls the leash taut, it feels pressure on the front of its neck. Many types of animals have an opposition reflex which makes them instinctively move toward the part of their bodies which feel pressure. Since the dog feels pressure at the front part of the collar when the leash is rotated to the back, the collar encourages the dog to pull away from its handler with even greater force. As another example, the opposition reflex of a horse causes it to turn towards the side where the rider's leg applies pressure.
In addition to collars, there are also animal harnesses that wrap around the torso. A typical harness has a leash attachment at the back of the animal, but a back-mounted leash cannot be used to give the animal cues for learning commands such as sit, down, and come. The back-mounted leash also signals the animal to pull on the leash. Some prior art harnesses discourage pulling behavior by providing devices that rub, chafe, or hobble the animal's front legs, but these devices cause stress and discomfort.


A fin field effect transistor is provided. The FinFET device includes a base substrate; an isolation layer on the base substrate; first fins in the isolation layer and on the base substrate. The first fins is made of a material having a thermal conductivity greater than a material of the base substrate.

As semiconductor technologies develop, semiconductor devices are developed toward a direction with a higher device density and a higher integration level. A transistor is one of the most fundamental devices and is widely used. With developments of the semiconductor technologies, a length of a gate in a planar transistor decreases. Correspondingly, a controlling ability of a conventional planar transistor on channel currents becomes weaker, causing short channel effects and serious leakage current problems. The semiconductor device has a poor performance.
To better alleviate the short channel effects and suppress the leakage currents, fin field effect transistors (FinFETs) are widely used. A FinFET is a multi-gate device, and usually includes: fins on a semiconductor substrate; a dielectric layer on the semiconductor substrate covering a portion of sidewalls of the fins and with a top surface lower than top surfaces of the fins; gate structures on the top surface of the dielectric layer, on tops of the fins, and on the sidewalls of the fins; and sources and drains in the fins on two sides of the gate structures.
However, as the device density increases and critical dimensions decrease, it is more difficulty for forming the FinFETs, and the formed FinFETs have poor performances and low reliabilities.

Semiconductor Manufacturing International (Shanghai) Corporation

Semiconductor Manufacturing International (Beijing) Corporation


A visual display includes a dimming mode. The dimming mode is provided via analog and digital dimming mode signals. The dimming mode signals can be provided via a digital-to-analog converter. The display can be an OLED or LCD display used in avionic and projection applications.

Displays are utilized in diverse applications for which visual information is presented. Displays include conference room projectors, optical equipment, operator displays, computer displays, dashboard displays, cockpit displays, entertainment displays, etc. In general, it is desirous to provide large gray scale capability to displays. Gray scale capability refers to the range from darkness to lightness for each pixel or element on a display. More gray scale capability (e.g., more bits of gray scale) are particularly important in avionic display systems, projection displays and other high-definition viewing applications.
In conventional display systems, such as, liquid crystal display (LCD) systems, the brightness of each pixel or element is controlled by a transistor. The display includes a matrix of transistors, such as, thin film transistors (TFTs) arranged in rows and columns. Alternatively, the display can include other light controlling or light emitting devices arranged in a matrix.
A column line is coupled to the drain or source associated with each transistor in each column. A row line is coupled to each gate associated with the transistors in each row. A row of transistors is activated by providing a gate control signal to the row line. The gate control signal turns on each transistor in the row. Each transistor in the row provides an analog voltage associated with its column line to cause the pixel or element to emit a particular amount of light.
Generally, a column driver circuit provides the analog voltage to the column lines so that the appropriate amount of light is emitted by each pixel or element. In conventional systems, the column driver circuit can typically provide approximately 8 or 16 levels of voltage at the column line (approximately 8 or 16 gray scale levels).
Conventional displays such as flat-panel displays, liquid crystal displays (LCDs) and projection light sources are not readily dimmable. Certain conventional displays have provided dimming modes by adjusting the amount of light emitted by a spacial light modulator by adjusting the light source. For conventional projection applications spacial light modulators can be of the type manufactured by Texas Instruments, such as, digital micromirror displays and digital light processors.
According to one type of conventional projection display, a conference room projector, the projector includes an arc lamp as its background or projection light source. The arc lamp is difficult to effectively dim. The power provided to the arc lamp is decreased to dim the display. However, reducing the power to the arc lamp can severely shorten the operational life of the arc lamp.
Further, conventional dimming schemes have not achieved a wide dimming range. Reducing the available gray scale range for the display when it is in the dimming mode is not an acceptable option for display customers.
There is a need for a display system or projection system including a dimming mode for some applications, such as avionics. Further still, there is a need for a display system or projection system including a dimming mode with does not compromise gray scale capabilities or lamp lifetime. Yet even further still, there is a need for a projection system or display system having a dimming mode which does not jeopardize the lifetime of background light sources.

Display driver supporting a dimming mode


A firing mechanism for a breech-loaded weapon to assure safety and provide reliability of operation. A receiver is formed from a central portion that has a receptor whereby the mechanism can be assembled to the rear end of a weapon barrel, there being a pair of yoke legs extending rearward from this central portion. Each of the yoke legs have slideways to receive a closely dimensioned breech block. The breech block is moved in a reciprocating motion, when desired, by action of a lever. A shaft attached to this lever causes operation of linkage members which, in turn, move the breech block from a fully caged position within the yoke arm slideways to a shell-loading position. During this motion a hammer assembly is moved to a cocked position and an ejector removes any spent shell from the weapon. A trigger release extension pin in the breech block is aligned with a trigger release pin in the receiver only when the breech block is fully caged in the receiver thereby preventing firing until this fully caged position is achieved. Provision is made for the disassembly of components of the mechanism without the use of tools, thereby facilitating "field stripping" of the mechanism.

In recent years, the popularity of the 0.50 BMG cartridge has risen among hobbyists, the para-military, as well as in various branches of the armed forces. What is needed is a firing mechanism for a breech-loaded weapon that can be adapted to heavy caliber rifles and/or shoulder-fired cannon chambered for the 0.50 BMG, the 14.5 mm Russian cartridge, the 20 mm Vulcan round and similar large cartridges. A recoil dampening device for large caliber weapons that would allow a shouldered-fired configuration for a weapon chambered for the 0.50 BMG, the 14.5 mm Russian cartridge, the 20 mm Vulcan round and similar large cartridges is shown and described in my co-pending application, Ser. No. 08/031,961, filed on Mar. 16, 1993, which is hereby incorporated by reference.
Due to the popularity of the 0.50 BMG cartridge among hobbyists, the para-military, as well as various branches of the armed forces, it is also desirable to have a fully caged firing mechanism that has a high degree of safety, i.e. one not capable of firing a cartridge prior to the cartridge being chambered and the mechanism fully closed and locked, and that can be readily field stripped, cleaned and reassembled by hand without the use of tools.
U.S. Pat. No. 458,505, issued to Emil Ritter Von Skoda on Aug. 25, 1891, discloses a sliding breech-block firing mechanism such as was commonly used on artillery. Von Skoda's firing mechanism slides within guide grooves and is designed to bring the firing pin to a cocked position through the movements of the breech block. However, in Von Skoda's firing mechanism, the sear that releases firing pin is in constant engagement with the trigger release thus presenting the possibility of chambering a round and sliding the breech-chamber closed without actually cocking the firing pin. Because Von Skoda's firing mechanism slides within guide grooves, it is not likely that the Von Skoda firing mechanism could easily, or safely, be adapted to a shoulder-fired rifle chambered for the 0.50 BMG, the 14.5 Russian cartridge or the 20 mm Vulcan round. What is needed is a breech-block that can be fully caged in mortise-tenon manner and that prevents engagement of the sear by the trigger release prior to the point where the breech-block is closed.
The following references are also noted as relating to breech-loading mechanisms; U.S. Pat. No. 466,567 issued to Koerner on Jan. 5, 1892; U.S. Pat. No. 512,743 issued to Parkhurst on Jan. 16, 1894; U.S. Pat. No. 1,040,001 issued to Olsson on Oct. 1, 1912; U.S. Pat. No. 1,707,444 issued to McCann on Apr. 2, 1929; U.S. Pat. No. 2,802,400 issued to Edmund on Aug. 13, 1957; U.S. Pat. No. 2,821,885 issued to Burk on Feb. 4, 1958; U.S. Pat. No. 3,687,001 issued to Brint on Aug. 29, 1972; and U.S. Pat. No. 5,042,361.
Accordingly, it is an object of this invention to provide a firing mechanism for breech-loaded weapons wherein the firing mechanism is fully caged, self-contained within the breech block, and automatically cocked upon cycling the action.
It is also an object of the present invention to provide a firing mechanism that moves within the breech-block in a mortise and tenon configuration.
A further object of the present invention is to provide a breech-loaded firing mechanism in which the sear assembly is not engaged by the trigger release until the breech is closed by firing mechanism and the firing mechanism is fully caged.
Still another object of the present invention is to provide a firing mechanism that is machined with very close tolerances and interlocking components that allow the firing mechanism to be completely stripped, cleaned and reassembled by hand without the use of tools.
These and other objects and advantages over the prior art will become apparent to those skilled in the art upon reading the detailed description together with the drawings as described as follows.

Firing mechanism for breech-loading weapons