Abstract: A liquid crystal display device having a pair of substrates, at least one of which is transparent. A liquid crystal layer held between the pair of substrates and an alignment layer formed on at least one of the pair of substrates. The pair of substrates are adhered together using a resin so that an interval is formed therebetween, and a portion formed with the resin has at least an opening for injecting liquid crystal into the interval formed between the pair of substrates and the opening is sealed with a photo-curable resin. The liquid crystal layer includes a photo-reactive liquid crystal compound, the molecular structure of which is converted by photo-irradiation, and a photo-absorbing organic compound having a photo-absorptivity larger than the photo-absorptivity of the photo-reactive liquid crystal compound at a designated wavelength, and containing at least one of alkyl substituent, alkenyl substituent, and alkoxyl substituent, respectively, in its molecule.

Abstract: A reflective liquid crystal display device of the present invention has the following construction. Only one polarization film is needed. The twist angle of the nematic liquid crystal layer is set in the range of 0° to 90°. The product of the birefringence of the nematic liquid crystal layer &Dgr;nLC and the thickness of the liquid crystal layer dLC, &Dgr;nLC·dLC, is in the range of 0.35 &mgr;m to 0.50 &mgr;m. The birefringence difference, &Dgr;R=RFilm−&Dgr;nLC·dLC is in the range of −0.20 &mgr;m to 0.00 &mgr;m.

Abstract: A twisted nematic color liquid crystal display. The liquid crystal display comprises parallel glass substrates covered by a transparent electrode and an alignment film, a twisted nematic liquid crystal between the glass substrates, a retardation layer and polarizers. Between the glass substrates, a liquid crystal unit which forms the liquid crystal has a twist angle about 70 to about 180 about degree while free of an externally applying voltage. A product of anisotropy of refractive index for the twisted nematic liquid crystal &Dgr;n and the thickness d thereof, that is, &Dgr;n·d, is set in a range between about 1100 Å to about 2000 Å. Without using a passive device such as an external color light source or color filter, a multi-color or full color display is formed by an active controlling method of birefringence of electric field via applying a voltage on the transparent electrode.

Abstract: A liquid crystal display device includes first and second substrates, a plurality of gate bus lines and data bus lines on the first substrate, the gate bus lines being perpendicular to the data bus lines, a plurality of pixels defined by the gate bus lines and the data bus lines, the pixels having a plularity of regions, at least a pair of electrodes in each region having a common direction, and a plurality of liquid crystal molecules between the substrates.

Abstract: A liquid crystal display device is disclosed, comprising a cholesteric liquid crystal layer which has an intrinsic helical pitch of approximately twice as large as a thickness of the liquid crystal layer and also has a bistable character capable of switching by an application of voltage, and further provided with at least one birefringent medium layer between a polarizer and a substrate. This construction of the liquid crystal display device results in a reduction of birefringent effects, whereby achieving a high contrast, satisfactory color purity, and other display characteristics such as a higher duty ratio operation and faster time response, suitable for displaying a large volume of information data.

Abstract: An ECB mode liquid crystal display device in which birefringence of liquid crystal is controlled by an applied voltage. The liquid crystal display device has: a drive liquid crystal cell having a pair of substrates disposed to face each other through a predetermined gap, each substrate having an electrode on one surface thereof, and a liquid crystal layer disposed between the pair of substrates. The birefringence of the liquid crystal layer of the drive liquid crystal cell is controlled by a voltage applied between electrodes, and an optical compensation unit is disposed between the drive liquid crystal cell and one of the pair of polarizers. The optical compensation unit includes a lamination of a left-twist liquid crystal layer of liquid crystal molecules having a chirality in a left-twist direction and a right-twist liquid crystal layer of liquid crystal molecules having a chirality in a right-twist direction.

Abstract: In a reflection-type color liquid crystal display which can display a bright, high-saturation negative-type color display with a background in black or deep color, a pair of polarizing films 8 and 9 are disposed on both sides of a liquid crystal 20 which has a nematic liquid crystal 7 between a pair of substrates 1 and 4 having electrodes respectively, and a twisted retardation film 10 is disposed between the polarizing films 9 and the liquid crystal device 20. The intersecting angle between absorption axes of the pair of polarizing films 8 and 9 is set to be in the range of 60° to 120°, the &Dgr;nd value of the liquid crystal device 20 is set to be in the range of 1500 nm to 1800 nm, and the &Dgr;nd value of the twisted retardation film 10 is arranged to be in nearly the same range as the &Dgr;nd value of the liquid crystal device 20.

Abstract: The invention relates to a TN cell which contains a nematic liquid crystal having positive dielectric anisotropy and a twist angle of essentially 90.degree., between two substrates provided with electrode and alignment layers, where the product of the separation between the substrate plates d and the optical anisotropy d.multidot..DELTA.n [sic] of the liquid crystal is between 0.15 and 0.70 .mu.m, characterised in that the liquid crystal contains a doping component in order to improve the grey shade capacity, so that the cell has a value for the undisturbed quotient of the separation between the substrate plates d and the pitch of the liquid crystal p of 0.1.ltoreq.d/p.ltoreq.0.5.

Abstract: An optical system and projector includes a source of light, an output system having a collection angle for receiving light and passing such received light as an output, and a liquid crystal device including relatively low birefringence liquid crystal material for selectively scattering light through a controlled angle such that a major portion of the scattered light may be collected by said output system, or for transmitting light, the output system including an aperture for transmitting such scattered light and blocking unscattered light. A method of optimizing the angle of scattering of output light in a liquid crystal device which is operable to transmit light or to scatter light to match the entrance pupil of an optical system in order to maximize the amount of collected scattered light, includes selecting the birefringence of the liquid crystal material of about 0.16 or less, and placing the liquid crystal material and medium in physical relation to cause such light scattering or transmission.

Abstract: An optical display employs a liquid crystal cell with a d.DELTA.n/.lambda. of approximately 0.2-0.8, allowing the cell's optical transmissivity to be modulated by an applied electric field through a dominant non-polarization rotation effect. For visible wavelengths, d.DELTA.n is approximately 0.1-0.4 microns, with a preferred value of about 0.25 microns. Applications include a reflective projection display in which input light is polarized at a greater than 0.degree. and less than 90.degree. angle, preferably about 20.degree., to the input LC directors of a twisted nematic cell; a reflective direct view system in which a quarter-wave plate is substituted for a polarization analyzer; and both a reflective and a transmissive guest-host system in which optical absorption by dye molecules is the dominant modulation mechanism.

Abstract: A vertically-aligned liquid crystal display device includes a liquid crystal layer sandwiched between a pair of glass substrates, wherein a retardation of the liquid crystal layer is optimized in a range between 80 nm and 400 nm. Further, the use of retardation films adjacent to the liquid crystal layer and its optimization are also disclosed.

Abstract: A liquid crystal display apparatus includes a liquid crystal panel having a pair of substrates, a plurality of electrodes formed on at least one of the pair of substrates and a liquid crystal layer sandwiched between the pair of substrates, and a light source provided on the back surface of the liquid crystal panel. The light source has the luminous characteristic with the chromaticity of a warm color family, and the liquid crystal panel has a spectral transmission characteristic with the chromaticity of a cold color family, whereby the color of the light source can be compensated.

Abstract: A liquid crystal device comprises a liquid crystal cell having a liquid crystal material sandwiched between a pair of substrates, the liquid crystal material having a retardation less than 1 .mu.m, a polymer film comprised of an optically anisotropic substance disposed on one of the substrates opposite the liquid crystal material, a color polarizing plate disposed on the polymer film opposite the one substrate, and a polarizing plate disposed on the other of the substrates opposite the liquid crystal material. The liquid crystal material preferably comprises a super twisted nematic liquid crystal material, and the color polarizing plate preferably comprises a red, green or blue polarizing plate.

Abstract: As a compensator for use in an OCB mode liquid crystal display there is provided a compensating film capable of making color compensation and attaining such a viewing angle expansion as has not been attainable heretofore. A compensating film for a liquid crystal display, constituted by at least one layer of a compensating film to be used in an OCB mode liquid crystal display, the compensating film being formed by a discotic liquid crystalline material having a fixed orientation form of a discotic liquid crystal, the compensating film being disposed between a driving liquid crystal cell and a pair of upper and lower polarizing plates, and the orientation form being a hybrid orientation in which the angle between discotic liquid crystal directors near the upper interface of the film and the film plane and the angle between discotic liquid crystal directors near the lower interface of the film and film plane are different from each other.

Abstract: A vertically aligned type liquid crystal display includes a liquid crystal layer containing vertically aligned liquid crystal molecules and disposed between a plurality of pixel electrodes and a common electrode, wherein the orientation of the liquid crystal molecules is controlled by electric field, and wherein an refraction anisotropy .DELTA.n of the liquid crystal used in the liquid crystal layer and a cell gap d [.mu.m] which is a distance between the pixel electrodes and the common electrode are selected to satisfy .DELTA.n.multidot.d.ltoreq.-0.033*d+0.88. With this configuration, a sufficiently wide range of driving voltages and an improved response speed are achieved.

Abstract: A liquid crystal display device having a liquid crystal cell including: a pair of substrates at least one of which has light transparency; a chiral nematic liquid crystal layer having positive anisotropy of dielectric constant, disposed between the pair of substrates; and a voltage applying circuit for applying a voltage to the liquid crystal layer, wherein the liquid crystal layer contains a pleochroic dye, and liquid crystal molecules in the liquid crystal layer are twisted with respect to a helical axis perpendicular to surfaces of the pair of substrates, a twist angle of the liquid crystal molecules from one of the pair of substrates to the other of the pair of substrates is in a range selected from the group consisting of a range from 0.degree. to 50.degree., a range from 140.degree. to 250.degree., and a range of twist angles obtained by adding an integral multiple of n radian to the twist angles in the range from 0.degree. to 50.degree. and in the range from 140.degree. to 250.degree..

Abstract: A liquid crystal display is described in which the need for a conventional output polarizer is eliminated and the display comprises only a liquid crystal cell, a single input polarizer, a reflector placed behind the cell, and a retardation film placed between the reflector and the cell. A Jones matrix simulation approach is used in order to obtain the parameters corresponding to solution spaces for the above design and several combinations are disclosed that give good results.

Abstract: A liquid crystal display device including a liquid crystal composition layer having twistable liquid crystal molecules, a first substrate and a second substrate having the liquid crystal composition layer disposed therebetween, and a video signal line formed between a face of the first substrate and a face of the liquid crystal composition layer with at least one pixel electrode and at least one counter electrode being formed at each of pixels adjoining each other across the video signal line. The pixel electrode is fed with a selected video signal through the video signal line, and the counter electrode is fed with a counter voltage. The twisting extent of the liquid crystal molecules is controlled by an electric field which is generated between the pixel electrode and the counter electrode and which has a component substantially parallel to said first substrate.

Abstract: Supertwist liquid-crystal displays (SLCDs) with outstanding properties are obtained if the nematic liquid-crystal mixtures used therein comprise at least one compound selected from the formulae 1A and 1B ##STR1## and at least one compound of the formula 1C ##STR2## in which R.sup.a is alkyl, alkoxy, alkenyl or alkenyloxy having 1 to 12 carbon atoms,R.sup.b is alkyl or alkoxy having 1 to 5 carbon atoms,Z is --COO--, --CH.sub.2 CH.sub.2 -- or a single bond, andL.sup.a, L.sup.b, L.sup.c, L.sup.d, L.sup.e, L.sup.f, L.sup.g, and L.sup.h in each case independently of one another are H or F,with the proviso that the 1,4-phenylene rings carry not more than 2 fluorine atoms per ring,R.sup.3 is an alkenyl group having 2 to 7 carbon atoms,R.sup.4 is R.sup.a or R.sup.3 andc is 0 or 1.

Abstract: A composition which includes the following compounds: ##STR1## wherein R.sup.1, which may be the same or different, is a hydrophilic group;R.sup.2, which may the same or different, is selected from the group consisting of electron donating groups, electron withdrawing groups, and electron neutral groups;R.sup.3 is a substituted or unsubstituted, positively charged heteroaromatic ring linked to the triazine backbone through a nitrogen atom in the R.sup.3 ring; andX.sup.- is a counterion.If R.sup.3 is an unsubstituted pyridine, the counterion X.sup.- may be selected from any counterion other than Cl.sup.- and OH.sup.-. Otherwise, the counterion X.sup.- may be selected from any counterion.The compound may be applied to a substrate to form a birefingent optical retardationdevice. The retardationdevice may be used in display devices such as computers and the like to correct the phase and polarization states of the display's emitted light and improve image quality at viewing angles away from the normal.

Abstract: A liquid crystal display device including a first substrate and a second substrate having a liquid crystal composition layer disposed therebetween, a black matrix formed on at least one of the first substrate and the second substrate, and a video signal line formed between a face of the first substrate and a face of the liquid crystal composition layer. At least one pixel electrode is formed at each of pixels adjoining each other through the video signal line and fed with a selected video signal through the video signal line, and at least one counter electrode is fed with a counter voltage. An optical transmissivity of the liquid crystal composition layer is controlled by an electric field component which is generated between the pixel electrode and the counter electrode. One of the counter electrodes of the individual pixels is positioned at opposite sides of the video signal line, and the black matrix is formed over the video signal line.

Abstract: An optical display employs a liquid crystal cell with a d.DELTA.n/.lambda. of approximately 0.2-0.8, allowing the cell's optical transmissivity to be modulated by an applied electric field through a dominant non-polarization rotation effect. For visible wavelengths, d.DELTA.n is approximately 0.1-0.4 microns, with a preferred value of about 0.25 microns. Applications include a reflective projection display in which input light is polarized at a greater than 0.degree. and less than 90.degree. angle, preferably about 20.degree., to the input LC directors of a twisted nematic cell; a reflective direct view system in which a quarter-wave plate is substituted for a polarization analyzer; and both a reflective and a transmissive guest-host system in which optical absorption by dye molecules is the dominant modulation mechanism.

Abstract: An electro-optical liquid crystal display with active-matrix addressing, in which the liquid-crystal layer has a homeotropic or tilted homeotropic alignment in the switched-off state and which contains a liquid-crystalline medium of negative dielectric anisotropy. The medium containsA) 30-70% by weight of two or more compounds of the formula I ##STR1## and B) 20-50% by weight of two or more compounds of the formula II ##STR2## in which R.sup.1, R.sup.2, ##STR3## and m are as defined in claim 1. The displays are particularly capable of operation based on the vertically-aligned cholesteric or nematic (VAC or VAN) effect.

Abstract: A liquid crystal display device including a liquid crystal composition layer having twistable liquid crystal molecules, a first substrate and a second substrate having the liquid crystal composition layer disposed therebetween, a video signal line formed on a face of the first substrate. At least one pixel electrode is fed with a video signal through the video signal line, and at least one counter electrode fed with a counter voltage, the pixel electrode and the counter electrode being opposed to each other. The twisting extent of the liquid crystal moles is controlled by an electric field component which is generated between the pixel electrode and the counter electrode. A spacing between the pixel electrode and the counter electrode arranged to oppose each other is larger than a width of at least one of the pixel electrode and the counter electrode and smaller than a spacing between the pixel electrode and the video signal line.

Abstract: An optical display employs a liquid crystal cell with a d.DELTA.n/.lambda. of approximately 0.2-0.8, allowing the cell's optical transmissivity to be modulated by an applied electric field through a dominant non-polarization rotation effect. For visible wavelengths, d.DELTA.n is approximately 0.1-0.4 microns, with a preferred value of about 0.25 microns. Applications include a reflective projection display in which input light is polarized at a greater than 0.degree. and less than 90.degree. angle, preferably about 20.degree., to the input LC directors of a twisted nematic cell; a reflective direct view system in which a quarter-wave plate is substituted for a polarization analyzer; and both a reflective and a transmissive guest-host system in which optical absorption by dye molecules is the dominant modulation mechanism.

Abstract: The invention provides a reflective liquid crystal display which consists of just an input polarizer, the liquid crystal cell and a rear reflector which can be placed inside or outside of the liquid crystal cell. There is no rear polarizer and no retardation film compensation. The invention is capable of producing a high contrast, low chromatic dispersion display. Depending on the twist angle chosen for the liquid crystal cell, the display can be used in direct view or in a projection type display. The display can also be driven in an active matrix mode or in a passive matrix multiplexed drive mode. A full numerical simulation which takes into account the liquid crystal director deformation under the application of an electric field was used to optimize such displays.

Abstract: A liquid crystal (LC) cell having LC phase gratings is disclosed. The LC cell includes alternating strips of a first single domain LC material having a twist angle with a magnitude and a positive sign, and a second single domain LC material having a twist angle with the same magnitude and a negative sign. The magnitude of the twist angle is approximately from 45 to 70 degrees. The first and second LC materials are twisted nematic LC materials or ferro-electric LC materials. The liquid crystal phase gratings operate preferably in a normally-black condition with low operating voltages of below 3 V and high optical diffraction efficiencies. The LC cell is used in reflective or transmissive spatial light modulators of displays.

Abstract: A twisted nematic liquid crystal device has a liquid crystal layer between a pair of alignment layers. Glass plates with electrodes are disposed on opposite sides of the layers. The alignment layers have their alignment directions disposed mutually perpendicular and at .+-.45.degree. with respect to adjacent linear polarizers. The pretilt angle of liquid crystal molecules in a surface region of the layer adjacent the alignment layer is different to that of liquid crystal molecules in a surface region of the layer adjacent the alignment layer.

Abstract: A twisted nematic liquid crystal (TNLC) cell used in reflective spatial light modulators (SLMs) of displays is disclosed. The TNLC cell includes front and rear substrates, and a TNLC material having a thickness d and a left-handed or right-handed twist angle .phi.. The TNLC material is sandwiched between the front and rear substrates, and the twist angle .phi. is approximately from 46.degree. to 62.degree.. A direction of directors of the TNLC material located nearest the front substrate forms an initial angle .beta. with a direction of linearly polarized light incident thereon. The initial angle .beta. is approximately from -6.degree. to 60.degree.. A birefringence .DELTA.n of the TNLC material times the thickness d is between approximately 0.7.lambda. to 1.25.lambda., where .lambda. is a wavelength of light incident on the front substrate.

Abstract: A TN-mode, normally-white format liquid crystal display device having high contrast and exceptional display characteristics. The angle of gradation inversion is increased and a straight-on contrast of more than 100 is obtained by setting the twist angle to 78.degree.-90.degree., preferably 84.degree.-90.degree., .DELTA..sub.n d to 0.3-0.4 .mu.m, preferably 0.35-0.38 .mu.m, and .DELTA..sub..epsilon. to at least 6.2.

Abstract: This invention refers to a liquid crystal device that provides a color display by utilizing a colorization phenomenon caused by double refraction birefringence of a liquid crystal, wherein the color tone that appears when no voltage or a non-selected voltage is applied is white or a non-color close thereto, and at least two colors are displayed when a voltage is applied, and electronic equipment in which this liquid crystal device is installed.A liquid crystal device which is capable of displaying colors without using color filters and which is also capable of displaying white or a non-color close thereto is implemented by optimizing the value of .DELTA.n.multidot.d of the liquid crystal and the relationship between the value of .DELTA.n.multidot.d of the liquid crystal and the value of retardation (R) of an optically anisotropic substance such as a retardation film.In other words, the liquid crystal cell and the optically anisotropic substance should be such as to satisfy the following relationships:.DELTA.

Abstract: In a liquid crystal display device the number of grey levels is increased by means of a compensation foil comprising a layer having a cholesteric ordering with a helix pattern, in which the pitch of the helix is smaller than (0.26-0.31..DELTA.n) .mu.m, in which .DELTA.n is the optical anisotropy of the anisotropic layer. Moreover, the viewing angle dependence will be more symmetrical by patterning the cholesteric ordering.

Abstract: A color liquid crystal display apparatus comprises an ECB (Electrically Controlled Birifringence) type liquid crystal display device, which has a plurality of dots arranged in a matrix form and displays a plurality of colors in accordance with applied voltages dot by dot, and a driving circuit. The driving circuit includes an image memory, a display controller, a conversion table, a D/A converter and drivers. The display controller reads image data stored in the image memory. This image data defines a display color of a pixel consisting of a plurality of dots and a gradation. The conversion table converts image data to voltage data defining voltages to be applied to a plurality of dots of the liquid crystal display device in order to display the color and gradation defined by the image data. The D/A converter converts this voltage data to an analog voltage and the drivers apply this analog voltage to each dot of the liquid crystal display device.

Abstract: The liquid crystal display panel comprising a twisted nematic liquid crystal inserted between a pair of substrates having alignment films, respectively. The liquid crystal twists from one substrate to the other substrate at a predetermined twist angle which is greater than zero degrees but smaller than 90 degrees. A polarizer and an analyzer are arranged crosswise. The alignment films are divided into minute regions so that the liquid crystal molecules in one of the regions align in one direction and the liquid crystal molecules in the other region align in another direction. The product (.DELTA.nd) of the anisotropy of the refractive index (.DELTA.n) and the layer thickness (d) of the liquid crystal is smaller than approximately 0.5 .mu.m and ensures a linearly polarized light incident onto the liquid crystal rotates approximately 90 degrees before the light emerges from the liquid crystal.

Abstract: A birefringence control type color liquid crystal display device includes a liquid crystal cell having first and second substrates; first and second electrodes formed on opposing surfaces of the first and second substrates; a first aligning film formed on the first electrode and subjected to an aligning treatment in a first direction; a second aligning film formed on the second electrode and the second substrate and subjected to an aligning treatment in a second direction intersecting the first direction at 90 degrees; and a liquid crystal sealed between the first and second aligning films and twisted at 90 degrees.

Abstract: The present invention provides a liquid crystal display device including a pair of electrode substrates and a display medium sandwiched between the electrode substrates and including a polymeric wall and liquid crystal regions at least partly surrounded by the polymeric wall. In this liquid crystal display device, the polymeric wall is tightly attached to both the electrode substrates. Furthermore, the invention also provides a method for producing a liquid crystal display device including a pair of electrode substrates, at least one of which is transparent, and a display medium including a polymeric wall and liquid crystal regions at least partly surrounded by the polymeric wall and sandwiched between the electrode substrates.

Abstract: A sub-twisted nematic liquid crystal display (SBTN-LCD) device (30) having a liquid crystal layer (34) characterized as a polarization rotator below an optical threshold voltage, a half-wavelength plate at approximately a saturation voltage, and a transparent layer above the saturation voltage. The twist angle of the liquid crystal layer is between 46.degree.-89.degree., preferably about 55.degree.. The product of the birefringence of the liquid crystal and the thickness of the liquid crystal layer (.DELTA.nd) is in the range of 0.35-0.70 .mu.m, and preferably about 0.52 .mu.m for the 55.degree. twist. One polarizing layer (42) is applied to the liquid crystal device with the polarization direction either parallel or perpendicular to the immediately neighboring liquid crystal director. Further, the performance of the SBTN-LCD is dependent upon the parameters of the liquid crystal material, such as the elastic constants.

Abstract: A liquid crystal electro-optical device comprising: a pair of insulating substrates; an electrode and an alignment film formed in this order on each of the insulating substrates; a liquid crystal layer interposed between the pair of insulating substrates, wherein the alignment film is a film capable of aligning the liquid crystal molecules in the liquid crystal layer perpendicularly with respect to the insulating substrates, and wherein the thickness of the liquid crystal layer is 45 to 70% of the twist pitch of the liquid crystal molecules.

Abstract: A normally white twisted birefringent liquid crystal display having first and second retardation films having retardation values of about 80-200 nm on opposite sides of a liquid crystal layer for the purpose of expanding the viewing angles of the display. Also, the viewing zone of this normally white display can be shifted vertically by rotating the optical axes of the retardation films so as to position the viewing zone away from an inversion area.

Abstract: The invention relates to a TN cell which contains a nematic liquid crystal having positive dielectric anisotropy and a twist angle of essentially 90.degree., between two substrates provided with electrode and alignment layers, where the product of the separation between the substrate plates d and the optical anisotropy d.multidot..DELTA.n ?sic! of the liquid crystal is between 0.15 and 0.70 .mu.m, characterized in that the liquid crystal contains a doping component in order to improve the grey shade capacity, so that the cell has a value for the undisturbed quotient of the separation between the substrate plates d and the pitch of the liquid crystal p of 0.1.ltoreq.d/p.ltoreq.0.5.

Abstract: The liquid crystal display device of the present invention comprises a liquid crystal layer of a nematic liquid crystal having positive dielectric anisotropy and including a chiral material, the liquid crystal layer being interposed between a pair of substrates with transparent electrodes each having an aligning layer which are arranged substantially in parallel to provide a twist angle of 160.degree.-300.degree., a driving means to apply a voltage across the electrodes attached to the substrates which interpose the liquid crystal layer, a pair of polarizing plates arranged outside the liquid crystal layer, and at least one birefringent plate provided between the liquid crystal layer and the polarizing plate at at least one side of the liquid crystal layer, wherein the product .DELTA.n.sub.1 .multidot.d, of the anisotropy of refractive index .DELTA.n, of liquid crystal molecules in the liquid crystal layer and the thickness d, of the liquid crystal layer is in a range of 0.4-1.5 .mu.

Abstract: In a projection display device based on one or more (twisted nematic) LCDs (4), simple temperature compensation is possible by optimizing the d.&Dgr;n value (n) at the maximal operating temperature. The associated transmission/voltage characteristics at different temperatures then extend substantially parallel so that it is possible to compensate for temperature changes by means of a simple voltage compensation.

Abstract: A reflection-type liquid crystal (LC) device having a twisted nematic (TN) LC layer that lets linearly-polarized incident light enter and become circularly-polarized at a reflecting surface, and then linearly polarizes it, after reflecting, with a plane of polarization that has been rotated 90.degree. from the incident light at an light output surface. The TN LC layer allows linearly-polarized incident light to enter at an angle to the molecular plane of light input of the twisted nematic LC, and to linearly polarize the light after reflection. The plane of polarization is rotated 90.degree. from the incident light at the light output surface. The TN LC layer also allows circularly-polarized incident light to enter and become linearly-polarized light at the reflecting surface. Circularly-polarized light after reflection may be rotated opposite the incident circularly-polarized light at the light output surface to provide for reverse on/off states.

Abstract: A color display is formed by stacking two or more birefringent elements that are tuned to provide different spectral characteristics, and operating each of the elements independently.