Abstract: An optical modulation device is constituted by a polarizer; a first film forming a first state and a second state depending on an electric field applied thereto, the first state causing birefringence and the second state not causing birefringence respectively of polarized light from the polarizer, the first film having a thickness set for functioning as a halfwave plate in its first state; and a second film not causing birefringence of light having passed through the second state of the first film but causing birefringence of light having passed through the first state of the first film, the second film having a thickness set for functioning as quarter wave plate or a halfwave plate when the first film is set in its first state.

Abstract: A liquid crystal device comprises: a) a liquid crystal cell including a plurality of pixels aligned on a plurality of lines and rows, each of the pixels composed of a pair of electrodes and liquid crystals provided between the pair of electrodes; and b) an optical unit including high-refractive portions positioned corresponding to the pixels, and low-refractive portions positioned next to the high-refractive portions on a plane, the high-refractive portions and low-refractive portions having the refractive indexes the ratio between which satisfies the condition for total reflection of incident light.

Abstract: This specification discloses a plate-like polarizing element for converting light into polarized light having a plurality of units arranged along a common plane across the light, each of the units being provided with dividing means for dividing the light into reflected light and transmitted light whose planes of polarization are orthogonal to each other, varying means for varying the polarized state of at least one of the reflected light and the transmitted light to thereby make the planes of polarization of the two lights coincident with each other, and reflecting means for reflecting one of the reflected light and the transmitted light and directing it substantially in the same direction as the direction of travel of the other. The specification also discloses a polarizing conversion unit provided with such plate-like polarizing element, and a projector provided with such unit.

Abstract: A liquid crystal device is constituted by disposing a display layer between a pair of electrode plates. The display layer comprises a mesomorphic polymer and a low-molecular weight mesomorphic compound. The mesomorphic polymer may preferably be a main chain-type ferroelectric mesomorphic polymer having an ester linkage or a mesomorphic polymer derived from a polymerizable mesomorphic compound. The display layer may preferably comprise a ferroelectric mesomorphic polymer having a dielectric anisotropy .DELTA..epsilon. of -3.0 or below and a low-molecular weight mesomorphic compound incompatible with the mesomorphic polymer and having a positive dielectric anisotropy.

Abstract: A liquid crystal device comprising a liquid crystal cell including a plurality of pixels aligned on a plurality of lines and rows, each of the pixels composed of a pair of electrodes and liquid crystals provided between the pair of electrodes; and an optical unit including high-refractive portions positioned corresponding to the pixels, and low-refractive portions positioned next to the high-refractive portions on a plane, the high-refractive portions and the low-refractive portions having the refractive indexes the ratio between which satisfies the condition for total reflection of incident light. Another embodiment is a liquid crystal device comprising two liquid crystal cells wherein each of the cells exhibit monostable orientation.

Abstract: This specification discloses a polarization converting apparatus having means emitting non-polarized light, and polarizing means having a light incidence surface and a light emergence surface, the polarizing means receiving the non-polarized light by the light incidence surface and causing polarized light to emerge from the light emergence surface, the size and shape of the light incidence surface being similar to the size and cross-sectional shape of the non-polarized light. The specification also discloses an optical instrument having such apparatus.

Abstract: An image display apparatus has a radiation source, generator for generating an image by modulating a polarized light beam and directing device for directing a light beam from the radiation source toward the generator. The directing device has a conversion optical system for converting the beam from the radiation source into the polarized light beam. The conversion optical system has a polarizing beam splitter for splitting the beam from the radiation source into a first and second beams. In the conversion optical system, a 1/4 wavelength plate and a mirror are arranged so that the plane of polarization of the first beam is rotated to generate a third beam with the plane of polarization same as that of the second beam. The third beam is directed toward the generator through the polarizing beam splitter while the second beam is also directed toward the generator.

Abstract: This specification discloses a method of dividing a radiation beam into a first beam and a second beam differing in color from each other, modulating the first and second beams to thereby form first and second modulated beams indicative of images differing in color from each other, and projecting the images by the use of the first and second modulated beams. The radiation beam is divided into the first and second beams by a hologram.

Abstract: An optical modulation device is constituted by a polarizer; a first film forming a first state and a second state depending on an electric field applied thereto, the first state causing birefringence and the second state not causing birefringence respectively of polarized light from the polarizer, the first film having a thickness set for functioning as a halfwave plate in its first state; and a second film not causing birefringence of light having passed through the second state of the first film but causing birefringence of light having passed through the first state of the first film, the second film having a thickness set for functioning as quarter wave plate or a halfwave plate when the first film is set in its first state.

Abstract: An eccentric Fresnel lens is formed from a concentric Fresnel lens sheet or Fresnel lens sheet mold. The concentric Fresnel lens sheet or mold is cut to produce an eccentric Fresnel lens having a center offset from the optical axis of the concentric Fresnel lens.

Abstract: A polarization converting device for converting a light from a light source into a polarized light comprises a first prism having a first slant plane for receiving the light from the light source and dividing it into first and second lights with their polarized planes orthogonal, a first emergent surface from which the first light exits, and a second emergent surface from which the second light exits, a second prism having an incident surface opposed to the second emergent surface of the first prism, a second slant plane for reflecting and deflecting the second light from the incident surface so as to direct it to an optical path almost parallel to that of the first light, and a third emergent surface from which the second light reflected from the second slant plane exits, and a transparent layer carried between the second emergent surface of the first prism and the incident surface of the second prism, the transparent layer having a smaller refractive index than the first prism.

Abstract: A polarization conversion unit is disclosed. In the unit, a definitely polarized light emitted from a light source is divided into a pair of lights differing in polarized state and are caused to be incident on the optical components including the polarizing beam splitter. The plane of polarization of one of the paired polarized light is rotated to be coincident with the plane of polarization of the other light by the optical components, so that the paired lights with the same plane of polarization are caused to be separately emitted. The optical component has a plano-convex lens which has a positive power and which is arranged at an exit side where the paired lights are separately emitted. The lens has a focal point at a position further than the position of the surface to be illuminated.

Abstract: A liquid crystal device is constituted by disposing a display layer between a pair of electrode plates. The display layer comprises a mesomorphic polymer and a low-molecular weight mesomorphic compound. The mesomorphic polymer may preferably be a main chain-type mesomorphic polymer having an ester linkage or a mesomorphic polymer derived from a polymerizable mesomorphic compound. The display layer may preferably comprise a mesomorphic polymer having a dielectric anisotropy .DELTA..epsilon. of -3.0 or below and a low-molecular weight mesomorphic compound incompatible with the mesomorphic polymer and having a positive dielectric anisotropy.

Abstract: A display apparatus using liquid crystal devices especially having a scattering mode and a projector in the display apparatus using the liquid crystal devices. The projector includes: an illuminating means for supplying illumination light; first and second modulating means for forming rays of image light by modulating the illumination light from the illuminating means; and a projecting means for projecting the rays of image light formed by the first and second modulating means. In this projector, a member for absorbing or reflecting the light traveling towards the second modulating means through the first modulating means is provides on at least any one of the light incident side and the light outgoing side of the second modulating means.

Abstract: A projector has means for supplying first and second radiation beams, first image generating means for modulating a plurality of portions of the first radiation beam individually and forming a deflected beam and a non-deflected beam to generate a first image, second image generating means for modulating a plurality of portions of the second radiation beam individually and forming a deflected beam and a non-deflected beam to generate a second image, and means for projecting the first and second images onto a predetermined plane by the use of one of the deflected beams and the non-deflected beams from the first and second image generating means, the first and second image generating means emitting the deflected beams so that most of the deflected beam from one of the generating means may substantially not enter the other generating means.

Abstract: An optical modulating device comprises a polarizer, an analyzer and liquid crystals positioned between the polarizer and the analyzer. The device controls the birefringence of the liquid crystals by applying an electric field to the liquid crystals so as to change the polarization of light of the device. The device further comprises a rotatable halfwave plate which is positioned between the liquid crystals and the analyzer or between the liquid crystals and the polarizer in such a manner that the optical axis of the halfwave plate will be rotated around the optical axis of light coming into the optical modulating device. The device varies the rotational angle of the halfwave plate in accordance with the temperature of the liquid crystals or the environment thereof.

Abstract: A screen is constituted of a sheet having a first lens array, and a second lens array formed in the interior of said sheet, wherein each lens of said second lens array is arranged in correspondence with each lens of said first lens array.

Abstract: A display apparatus comprises a projecting device for projecting an image, with the projecting device having a projection optical system having a limited pupil diameter and screen device arranged at a position where an image is substantially projected by the projecting device. The screen device has at least two sheets in each of which a number of prisms extending like a straight line or a curve are formed on the surface on the side opposite to the projecting device.

Abstract: An image display apparatus comprises an image projection system having a projecting optical system, and a screen for displaying an image by receiving the image light deflected by a mirror system. The screen has a plurality of sheets one of which contains a group of cylindrical lenses which act as light transmitting areas and light blocking areas arranged on an image light exit plane along the direction of arrangement of the cylindrical lenses. The screen arrangement is capable of blocking undesirable reflected light.

Abstract: A liquid crystal type video projector is disclosed which has a reflection type optical modulator for effective use of beams from a radiation source such as a lamp or the like. The projector further comprises means for modulating the plane of polarization of a polarized beam entering the radiation source and for reflecting the polarized beam, thereby causing a reflection beam and an optical arrangement. The optical arrangement includes a first polarizing beam splitter for separating the beam from the radiation source into P and S polarized components and for directing the S polarized component to the modulator and a converter for rotating the plane of polarization of the P polarized component and converting into another S polarized component for enhanced efficiency of beam utilization. It further includes a second polarizing beam splitter for reflecting the other S polarized component and directing the other S polarized component and directing to the modulator.