Abstract: An STN liquid crystal element, formed to sandwich a nematic liquid crystal 6 twist-aligned at an angle ranging from 180 degrees to 270 degrees between a first substrate 1 having a first electrode and a second substrate 2 having a second electrode, is disclosed. A polarizing film is disposed outside the second substrate of the STN liquid crystal element through a retardation film or a twisted retardation film, a cholesteric liquid crystal polymer sheet is disposed outside the first substrate through a quarter-wave film, and a light absorbing film is disposed outside the cholesteric liquid crystal polymer sheet, to thereby form a liquid crystal display device which enables metallic color display.

Abstract: A liquid crystal display device includes first and second substrates spaced apart from each other with a liquid crystal therebetween. The liquid crystal display device adopts a cholesteric liquid crystal color filter. Each portion of the cholesteric liquid crystal color filter is designed to have an adjusted order parameter according to a wavelength of a corresponding color ray. Therefore, with the variously adjusted order parameters of the cholesteric liquid crystal color filter, an increase of the color shift due to a longer wavelength is prevented.

Abstract: A reflection type liquid crystal display device according to the present invention is constructed to include: a light modulation layer having a light scattering state changed when a voltage is applied between electrode faces; at least one kind of color separation layer arranged at the back of the liquid crystal; and a reflection layer arranged at the back of the color separation layer. The light modulation layer is a polymer network type polymer scattered liquid crystal layer or a phase conversion type liquid crystal layer, and the color separation mirror is a cholesteric liquid crystal polymer layer or a dielectric multi-layered thin film characterized to reflect a light within a predetermined wavelength range in the visible light region selectively. A reflection preventing layer and an ultraviolet ray cut-off layer are further arranged on the surfaces of the electrode faces.

Abstract: The invention teaches methods whereby the lighting efficiency of many lighted displays, including liquid Crystal Displays (LCDs) are increased by an order of magnitude through the use of chiral nematic liquid crystal materials incorporated into the light pipes of the displays. The light pipe technology also enables a practical embodiment of the stereoscopic display of Venolia. These methods are also applied to the fabrication of lighted signs for advertising and status indicators in hostile environments. The technology of the light pipes is also applied to the creation of a novel art medium.

Abstract: A reflective liquid crystal device comprises a polariser and a mirror between which are disposed several retarder. At least one of the retarders is a variable liquid crystal element whose optic axis is switchable so as to switch the device between a reflective sate and a non-reflective state. In the non-reflective state, the total retardance of the retarders between the polariser and the mirror is equal to an odd number of quarter wavelengths for a wavelength at or adjacent the middle of the visible spectrum.

Abstract: An LCD panel employing a novel scheme of systemic light recycling. A single polarization state of light is transmitted from the backlighting structure to section of the LCD panel where both spatial intensity and spectral filtering of the transmitted polarized light simultaneously occurs on a subpixel basis. At each subpixel location, spectral bands of light not transmitted to the display surface during spectral filtering, are reflected without absorption back along the projection axis into the backlighting structure. At a subcomponent level within the LCD panel, spectral components of transmitted polarized light not used at any particular subpixel structure location are effectively reflected either directly or indirectly back into the backlighting structure.

Abstract: The invention relates to a color filter layer of a cholesterically ordered material, in which the axis of the molecular helix is directed perpendicularly to said layer. According to the invention, the color filter layer comprises at least one dye which is able to absorb undesired colors caused by color shifts. A correct choice of the bandwidth of the primary colors of the color filter layer and the dyes significantly alleviates the problem of undesired color shift. The invention also relates to a liquid crystal color display device of the reflective type, which is provided with such a color filter layer.

Abstract: A timepiece with a liquid crystal display panel 40 having at least either of a time display section 40a and a calendar display section 40b, and comprising a TN liquid crystal cell with about 90° twisted nematic liquid crystals sealed in-between a pair of transparent substrates having respective transparent electrodes, a first polarizing film disposed on the visible side of the TN liquid crystal cell, a second polarizing film, a retardation film for circularly polarized light, a cholestric liquid crystal polymer sheet, a translucent light absorbing member and a backlight disposed successively on a side of the TN liquid crystal cell, opposite from the visible side thereof. With such a constitution, time display and calendar display are rendered visible even at night by lighting up the backlight, and colored display in a metallic tone can be indicated.

Abstract: A full-color image capture system includes a color separation element and a single image sensor array. The color separation element can be operated in either a light reflective (mirror) mode in which selected intrinsic colors are reflected onto the image sensor array, or a light transmissive (filter) mode in which selected colors are transmitted to produce subtractive primary color images. The color separation element can be formed of holographic polymer dispersed liquid crystal materials that reflect light of selected intrinsic colors. The color separation element can include three holographic polymer dispersed liquid crystal material layers so that three different intrinsic colors can be selectively reflected or transmitted onto the image sensor to provide a full-color image.

Abstract: A backlight for a liquid crystal display apparatus of the present invention includes a light guide plate having a first side, a second side, and an end face, and a rod-like light source provided at the end face of the light guide plate, where light emitted from the light source enters the light guide plate through the end face, exits the light guide plate through the first side perpendicular to the end face, The backlight further comprise a polarization reflection film provided at the end face of the light guide plate.

Abstract: An object of the invention is to obtain brighter display in a liquid crystal display apparatus. Light of all the wavelengths in the visible range is converted into circularly polarized light by a first polarization condition converting member, converted into linearly polarized light by a second polarization condition converting member and is modulated by a liquid crystal display device. Then, transmission and block of the light is controlled by a polarizer. Specifically, one of the dextrorotatory circularly polarized light and the levorotatory circularly polarized light is reflected by a spectral member included in the first polarization condition converting member, converted into the other circularly polarized light by a reflecting member included in the first polarization condition converting member and supplied again to the spectral member. The other circularly polarized light is transmitted by the spectral member.

Abstract: A bistable liquid crystal display device includes a liquid crystal material which has a plurality of states, such as a stable state with a twist angle w.sub.0 and first and second metastable states with w.sub.0 180.degree. and w.sub.o -180.degree., respectively, wherein w.sub.0 is a twist angle along a direction of cell thickness of the liquid crystal material at an initial stable state. In order to properly drive the liquid crystal device, a first pulse voltage is applied to induce a transition from the stable state to a homeotropic state for the liquid crystal material, and a second voltage pulse is subsequently applied to relax the liquid crystal material from the homeotropic state selectively to either the first or second metastable state depending on the pulse shape. The liquid crystal material is composed such that a change of unstrained pitch thereof with temperature may suppress the change of switching behaviors with temperature, to thereby improve display characteristics of the liquid crystal device.

Abstract: This invention is to provide a diffusing film, a lighting unit, and a liquid crystal display element which can efficiently uses a light from a light source and which can obtain a beautiful image.A diffusing film comprising a powder which diffuses an incident light and which has an interference color of the same wave range with an absorption wave range, in uniformly and a diffusing film comprising two or more of a powder whose interference colors are complementary to each other, and a liquid crystal display element using the same.

Abstract: A switchable liquid crystal device, for instance for use as a reflective display, includes a cell containing a helical polymer network and a nematic liquid crystal. Electrodes are provided for applying a field across the cell so as to switch between different optical states. In a reflective state, the cell reflects incident light within a waveband which is relatively insensitive to temperature variations. The device is formed by filling the cell with the liquid crystal and polymer precursor material and then cross-linking or polymerising, for instance by photopolymerisation, the precursor material to form the helical polymer network.

Abstract: The present invention provides a thin and light optical device for observing visual information with a large angle of visual field and a head-mount display (HMD) using the optical device. The optical device includes a refractor consisting of a refracting element with half-mirror coating and a circularly polarized light selecting semitransparent mirror, which are disposed in order from the incident side. The circularly polarized light selecting semitransparent mirror consists of a quarter-wave plate, a half-mirror and a polarizer or cholesteric liquid crystal, which are disposed in order from the incident side. A thin and high-magnification optical system is obtained by using the circularly polarized light selecting semitransparent mirror that first reflects incident light in a clockwise circularly polarized fashion and allows the counterclockwise circularly polarized light having made 1.5 round trips to pass therethrough without being reflected.

Abstract: An "intelligent" window combined with an additional structure for further controlling light incident on the "intelligent" window is disclosed.

Abstract: A broadband cholesteric polariser includes at least one pair of adjacent layers. The at least one pair includes a cholesteric layer and a compensating layer. The compensating layer has a refractive index perpendicular to the compensating layer greater than a refractive index oriented within the compensating layer.

Abstract: Process for broadening cholesteric reflection bands of photopolymerizable cholesteric liquid crystals, and optical elements produced by this process. The invention relates to a process for broadening the cholesteric reflection bands of photopolymerizable cholesteric liquid crystals, which comprises the following process steps:1) partial polymerization of a layer containing photopolymerizable cholesteric liquid crystals by exposure to actinic light for a defined brief period at a defined temperature,2) observance of a defined waiting time without exposure (dark phase) at a defined temperature,3) fixing of the resultant layer by exposure to actinic light at a defined temperature.

Abstract: An optical waveguide (5) for use in the in the visible range, the infrared range or the ultraviolet range. The waveguide has two cholesteric liquid crystal polymer layers (10) positioned parallel to each other, forming a gap between them. When electrically modulated to an `on` state, one or more of the cholesteric liquid crystal polymer layers become optically reflective, so that the waveguide becomes internally reflective, allowing a light beam (15) to be transmitted along the waveguide. The liquid crystal polymer is optically non-reflective when electrically modulated to an `off` state. The cholesteric liquid crystal polymer layers are each disposed on a substrate (30) having an electrically conductive layer (35) disposed between the substrate and the cholesteric liquid crystal polymer. A modulating means impresses an electrical signal upon the cholesteric liquid crystal polymer layers to convert them from the optically reflective state to the optically non-reflective state.

Abstract: A polarized-light converting elemental device which can produce an accurately unidirectionally and circularly polarized light with a minimized loss of light and a projection-type display device using said unidirectionally-polarized-light converting elemental device are provided. A polarized-light converting elemental device comprises a mirror glass portion consisting of an array of mirror glass blocks each having a first reflecting optical element and a second reflecting optical element and a cholesteric-liquid-crystal glass portion including a cholesteric liquid crystal layer for reflecting either clockwise circularly polarized component or anticlockwise circularly polarized component and transmitting the other. Natural light from the left side is split into two directions by the first reflecting optical element. Light reflected from the cholesteric liquid crystal is reflected by the second reflecting optical element to alter its rotation direction and then transmitted through the cholesteric liquid crystal.

Abstract: A liquid crystal display device includes cell wall structure and a chiral nematic liquid crystal material. The cell wall structure and the liquid crystal cooperate to form focal conic and twisted planar textures that are stable in the absence of a field. A device applies an electric field to the liquid crystal for transforming at least a portion of the material to at least one of the focal conic and twisted planar textures. The liquid crystal material has a pitch length effective to reflect radiation having a wavelength in both the visible and the infrared ranges of the electromagnetic spectrum at intensity that is sufficient for viewing by an observer. One liquid crystal material may be disposed in a single region or two liquid crystal materials may be used, each in separate regions. One aspect of the invention is directed to a photolithography method for patterning a substrate of the display. The display may also have multicolor capabilities by including at least two materials that reflect visible light.

Abstract: A liquid crystal display includes a first substrate having a transparent electrode formed on its surface and a non-aperture portion in its predetermined region, a second substrate separated from and opposed to the first substrate, a member having a color filter function and a transparent electrode formed on the second substrate, a liquid crystal layer sandwiched a between the first and second substrates, and a backlight optical system arranged on the side of the second substrate away from the first substrate. The member having a color filter function is patterned in accordance with the display unit controlled by the two transparent electrodes. This member is a color reflecting layer stack constituted by a stack of a first planar-oriented cholesteric liquid crystal layer having a first chiral pitch and a second planar-oriented cholesteric liquid crystal layer having a second chiral pitch different from the first chiral pitch.

Abstract: A liquid crystal display having a liquid crystal mixture of cholesteric and nematic liquid crystal materials and a method of manufacturing the display. A polymer-liquid crystal mixture, obtained by mixing a mixture of cholesteric and nematic liquid crystals with a polymer compound, is sealed in a plurality of cells between two substrates having respective electrodes. Various mixtures are used in different cells so that different colors can be displayed.

Abstract: A liquid crystal display includes a thin film transistor and a storage capacitor. The thin film transistor includes an active layer formed over a substrate, source and drain regions formed of a impurity-doped semiconductor layer on both sides of the active layer, a gate electrode, and a gate insulating layer formed between the gate electrode and the active layer. The storage capacitor includes a first storage electrode formed over the substrate, a dielectric layer formed over the first storage electrode, and a second storage electrode formed over the dielectric layer. One of the first and second storage electrodes is connected to one of the source and drain regions, and the gate insulating layer and the dielectric layer are formed in different steps or layers.

Abstract: Electro-optical glazing structures having total-reflection and semi-transparent and totally-transparent modes of operation which are electrically-switchable for use in dynamically controlling electromagnetic radiation flow in diverse applications.

Abstract: A cholesteric liquid crystal display device with improved display images is provided. The device includes a transparent front plate (16) with a front conductive film (18) spaced apart from a back conductive film (22) by a gap filled with cholesteric liquid crystal material (24) which can be switched between a transparent state and a reflective state through application of an electric field. The front conductive film (18) is coated with an opaque mask which defines openings (36) for transmitting light. In the reflective state, ambient light entering the device (10) is reflected by the cholesteric liquid crystal (24) through openings (36) in the opaque mask (12) to form a bright image. In the transparent state, ambient light entering the device (10) passes through the cholesteric liquid crystal (24), front film (18) and back film (22) and is substantially absorbed by an underlying opaque layer (14) which is preferably color-matched to the internal mask (12) to form an single color, image-free display area.

Abstract: Display device (1) comprising an illumination system (3) having a radiation source (17; 31, 35) for supplying a radiation beam. The display device (1) also comprises a diffusing display panel (5). This panel (5) consists of an optically active diffusing medium (7) which is switchable between a transparent, polarization-maintaining state and a diffusing, depolarizing state for the radiation beam. The medium (7) is present between a first polarizer (9) having a first state of polarization and a second polarizer (11) having a second, complementary state of polarization. At least the first polarizer (9) is a reflecting polarizer and polarization-converting means (10) are arranged at a side of the first polarizer (9) facing away from the display panel (5).

Abstract: An illumination system (3) comprises an optical waveguide (9) of an optically transparent material having an exit surface (19) and four end faces (13, 14, 15, 16). The light from a light source (11) is coupled into the optical waveguide (9) via at least one of the end faces (13). The illumination system, for an LCD, further has a reflective polarizer (21) in combination with a diffuser (23) for polarizing the light supplied by the light source (11). The reflective polarizer (21) is integrated with the optical waveguide and constitutes the surface (25) of the optical waveguide (9) which is located opposite the exit surface (19). The diffuser (23) is present on a surface of the polarizer (21) remote from the optical waveguide (9).

Abstract: A new liquid crystalline light modulating cell and material are characterized by liquid crystalline light modulating material of liquid crystal and polymer, the liquid crystal being a chiral nematic liquid crystal having positive dielectric anisotropy and including chiral material in an amount effective to form focal conic and twisted planar textures, the polymer being distributed in phase separated domains in the liquid crystal cell in an amount that stabilizes the focal conic and twisted planar textures in the absence of a field and permits the liquid crystal to change textures upon the application of a field. In one embodiment, the material is light scattering in a field-OFF condition and optically clear in a field-ON condition, while in another embodiment, the material is optically clear in a field-OFF condition and light scattering in a field-ON condition.

Abstract: A transflective Liquid Crystal Display (LCD) system is described, wherein the half silvered mirror is replaced by Chiral Liquid Crystal (CLC) reflectors/filters, which increase the reflected and transmitted brightness from over two times to as much as ten times. These principles are also applied to create an improved efficiency full color transflective LCD and a number of high brightness, limited color, displays.

Abstract: An illumination system includes a polarized light source which emits circularly polarized light of a particular handedness and a cholesteric filter having a region arranged to transmit circularly polarized light falling within a first wavelength band and to reflect other wavelengths of circularly polarized light. A reflector redirects the reflected light back towards the cholesteric filter. The cholesteric filter can include a first layer having portions which reflect red, green and blue light while transmitting other colors, and a second layer identical to the first layer but out of alignment therewith so that each region of the filter transmits only one color of light, the other colors being reflected.

Abstract: Flat-panel picture display device comprising a picture display panel for modulating the state of polarization of polarized light coupled into said panel in conformity with a picture to be displayed. The light is polarized by means of a reflective polarizer which is integrated or not integrated with the picture display panel. At least a part of the picture display panel functions as an optical waveguide, notably for the beam component b.sub.2 having the state of polarization which is not suitable for modulation. An analyzer is present at a first surface of the picture display panel. The polarizing means in the form of a reflective polarizer are present at a second surface of the picture display panel, which surface is located opposite the first surface.

Abstract: A variable index distributed mirror is disclosed used for high resolution reflective displays that are thin and have high resolution, reflectivity and contrast; wide viewing angle; low power consumption; and low voltage operation. The mirror is electrically switchable or variable between substantially transparent and reflective states. The mirror has alternating layers of a first material having a fixed refractive index, and a second material having a variable refractive index. The second material may be a nematic liquid crystal. The alternating layers are located between a pair of electrodes. The variable refractive index approximately equals the fixed refractive index in the transparent state and differs from the fixed refractive index in the reflective state. The variable refractive index varies in response to a signal applied across the electrodes. The mirror is tuned to a particular color to form a monochrome display.

Abstract: A colored reflective liquid crystal display employs a liquid crystal light valve switchable between a light scattering and a transmissive state. Positioned on the non-viewing side of the light valve is a reflector which reflects light of selected wavelengths and transmits the other wavelengths.

Abstract: A new liquid crystalline light modulating cell and material are characterized by liquid crystalline light modulating material of liquid crystal and polymer, the liquid crystal being a chiral nematic liquid crystal having positive dielectric anisotropy and including chiral material in an amount effective to form focal conic and twisted planar textures, the polymer being distributed in phase separated domains in the liquid crystal cell in an amount that stabilizes the focal conic and twisted planar textures in the absence of a field and permits the liquid crystal to change textures upon the application of a field. In one embodiment, the material is light scattering in a field-OFF condition and optically clear in a field-ON condition, while in another embodiment, the material is optically clear in a field-OFF condition and light scattering in a field-ON condition.

Abstract: An improvement in a light modulating chiral nematic liquid crystal adapted to form focal conic and twisted planar textures and a liquid crystal device employing such a material, the improvement wherein the liquid crystal material includes a plurality of essentially distinct regions within which the liquid crystal has different pitch lengths, whereby the liquid crystal can be made to reflect different wavelengths of light in different regions. The regions are created by including in the chiral nematic liquid crystal composition, a chiral material adapted to change its chirality upon photo-irradiation, in an amount effective to change the pitch length of the liquid crystal composition upon photo-irradiation. By exposing different regions of the material to increasing amounts of photo-irradiation, the pitch length of each region can be selectively tuned to reflect light of a different wavelength.