Abstract: A projection type color image display apparatus of the present invention includes: a light source section for generating white light beams; a first fly-eye lens array comprising a plurality of lenses for forming a plurality of secondary light source image spots of the light source section; a second fly-eye lens array comprising at least the same number of lenses as the first fly-eye lens array, provided near a position where the plurality of secondary light source image spots are formed by the first fly-eye lens array; a microlens array comprising a plurality of microlenses, wherein the light beams which have passed through the respective lenses of the second fly-eye lens array are superimposed on one another on the microlens array; a single image display device comprising a plurality of color pixels arranged in a predetermined arrangement for modulating the light beams from the microlenses; a color separator provided in a predetermined position in an optical path from the light source section to the microlen

Abstract: In a projection type color liquid crystal display apparatus, a polarization conversion section receives a luminous flux from a light source to convert the luminous flux into a unified luminous flux having a single linearly-polarized direction. A color separation section receives the unified luminous flux to selectively reflect a plurality of color components of the unified luminous flux individually at different angles. Convex lenses of a microlens array converge the reflected color components into different pixels of a liquid crystal element.

Abstract: A display panel is characterized by a pixel unit array comprising pixel units having a combination of two of, first, second and third three color pixels disposed in a first direction and a combination of two color pixels differing from the combination of the two color pixels disposed in a second direction differing from the first direction, so as to share a color pixel, the pixel units being two-dimensionally arranged at a predetermined pitch on a substrate, and a microlens array comprising a plurality of microlenses in which the pitch of the two color pixels in the first direction and the second direction is one pitch, the plurality of microlenses being two-dimensionally arranged on the pixel unit array on the substrate.

Abstract: The invention prevents deterioration of the image quality caused by dust adhering to the surface of a liquid crystal device. The invention is a liquid crystal device that includes an emergent-side substrate section, an incident-side substrate section disposed opposing the emergent-side substrate section, and a liquid crystal layer sandwiched between the emergent-side substrate section and the incident-side substrate section. The incident-side substrate section includes an incident-side substrate, an electrode that drives the liquid crystal layer formed on the incident-side substrate, and a micro-lens array disposed toward an incident side of the liquid crystal device relative to the incident-side substrate and having a plurality of micro-lenses that condense light beams onto a plurality of pixels. A thickness Ti of the incident side-substrate section along a direction of travel of a light beam is larger than a thickness To of the emergent side-substrate section along the direction of travel of the light beam.

Abstract: An image observing apparatus is arranged to observe outside information from the outside and a display image displayed on an image display device via an optical combiner and via an eyepiece lens superimposed. The outside information and the display image are imaged so as to be superimposed on a surface of a spatial modulator having a two-dimensional pixel structure. Part or all of the outside information and display image is selected on an area basis by the spatial modulator. The outside information and image information thus selected is observed through the eyepiece lens.

Abstract: A double-pass projection display system with separate polarizers and analyzers. One embodiment of the invention includes an input polarizer, a color separation/recombination device, and a number of image producing sections. The input polarizer receives unpolarized white light and polarizes this light. The color separation/recombination device receives the polarized white light and separates this light into a number of component color bands. The color separation/recombination device then supplies a component color band to each image producing sections. Each section includes a spatial light modulator and an output analyzer. The spatial light modulator modulates the color band that the image producing section receives from the color separation/recombination device. The output analyzer then (1) discards the light, in the modulated band, that has a first polarization state, and (2) directs the light, in the modulated band, that has a second polarization state to the color separation/recombination device.

Abstract: Binary optics are used in an illumination system to provide a method of imaging for a color projection display. In one embodiment a broad spectrum light source illuminates a multilevel optical phase element which disperses the broad spectrum light from the light source by diffraction. A display having a number of pixel elements, each capable of transmitting a predetermined spectral region, is positioned within the near field region of the multilevel optical phase element so as to receive the light dispersed by the multilevel phase element.

Abstract: In a projection display apparatus, an air inlet is formed below an optical modulation device and a color synthesizing system, and a suction fan is placed across the optical modulation device and the color synthesizing system. Thereby the optical modulation device and the color synthesizing system are uniformly cooled by air on the suction side of the suction fan. A structure fixing the optical modulation device and the color synthesizing system is provided with a suction opening cooling the optical modulation device and the color synthesizing system, and this suction opening is covered with a dustproof filter, thereby achieving dust protection.

Abstract: In an illumination optical system and a liquid crystal projector apparatus using the same, two lens arrays each comprising linear convex lens arrays with their pitches shifted from each other are used for improving image quality such as not to generate shadows of the cementing ridge of a cross dichroic prism, and a polarization-converting optical system is appropriately disposed, so as to obtain uniform illumination effects efficiently. The vertical angle ridge 71 of four prisms constituting the cross dichroic prism 70 is disposed so as to be orthogonal to the optical axis, the polarization-converting optical system 3 is disposed such that a plane including the vertical angle ridge 71 and optical axis and the direction along which stripes of half-wavelength phase films 32 extend are orthogonal to each other, and the direction of shifting the lens columns of a plurality of linear convex lens arrays constituting the first and second lens arrays 21 and 22 is orthogonal to the plane.

Abstract: A projection-type liquid crystal display apparatus is provided for preventing a reduction in image quality due to deposited foreign substances such as dust, arc fluctuations of a light source and so on. An optical illumination system of a liquid crystal panel includes an integrator having a first lens array made up of a plurality of lens elements and a second lens array made up of lens element corresponding to the lens elements of the first lens array. A single ray bundle incident on the first lens array is split into a plurality of split ray bundles by the first lens array and pass through the corresponding lens elements of the second lens array and further through a collimator lens, dichroic mirrors and enter the liquid crystal panel. The liquid crystal panel is illuminated with the ray bundles sent from all the lens elements of the first lens array in a superimposing manner and the illuminance distribution is made even.

Abstract: In a color projection display system having a source of white light, an electro-optic light modulator for modulating the light in accordance with a display signal, a projection lens, and dichroic filters for separating the white light into color components prior to modulation, and for recombining the modulated color components prior to projection, the color uniformity of the display is improved by designing the filters to have different cut-off wavelengths of separation and recombination for at least one of the color components.

Abstract: An optical system is disclosed. The optical system includes a fluid. A container is filled with the fluid, and the container has at least one window for permitting subject light to enter the container. At least one optical element is disposed within the container for performing a predetermined optical function on the subject light. The fluid has a viscosity of no greater than 40 centistokes and the optical element has an index of refraction approximately the same as the fluid. The fluid provides increased transmission of blue light as a percentage of total light being transmitted.

Abstract: A liquid crystal panel displays an image, while a lens projects, as a virtual image, an image displayed by the liquid crystal panel. A control system controls either the liquid crystal panel or the lens so as to periodically effect a changing of the position of the virtual image, each changing occurring over a predetermined time period. The control can be accomplished by changing the position of the liquid crystal panel or of the lens along an optical axis at a speed of less than 0.1 mm/sec so as to avoid burdening the eye of the observer. The motion can be at a uniform speed through most of the range of the motion, while permitting a slowing down to a stop at each end of the range and then an acceleration to the uniform speed in the opposite direction. A rest period (i.e., a full stop for a period of time) can be provided at one or both ends of the motion range, either for each cycle of motion or after the occurrence of a plurality of such cycles.

Abstract: There is provided an image projector including (a) a light source, (b) a reflection mirror for reflecting flux of light emitted from the light source, (c) an image display unit for forming images, and (d) a relay system for transferring the flux of light to the image display unit, the relay system including a relay lens having a first convex surface through which the flux of light enters therein and a second convex surface through which the flux of light exits therefrom, a ratio of a radius of curvature of the first convex surface to a radius of a curvature of the second convex surface being determined in such a manner that aberration out of an optical axis of the relay lens is increased to thereby cause a converging point of the flux of light to displace from a calculated focal distance. For instance, the ratio is determined in the range of about 1:2 to about 1:3.

Abstract: A reflection type projector includes: a light source; a polarization beam splitter for transmitting or reflecting an input light according to a polarization component thereof; a dichroic beam splitter, having first and second dichroic reflection surfaces for transmitting or reflecting a ray of one polarized light emitted from the light source and split by the polarization beam splitter to thereby be split into three colors; first, second and third imaging units, respectively disposed at positions corresponding to light output surfaces of the dichroic beam splitter, for forming an image from the input light and reflecting the formed image; a fourth imaging unit for forming an image from a ray of the other polarized light emitted from the light source and split by the polarization beam splitter and reflecting the formed image; a color filter, disposed between the polarization beam splitter and the fourth imaging unit and capable of rotating, for determining the color of a ray proceeding toward the fourth imagin

Abstract: Apparatus are disclosed that provide a high-luminance projected image with no color shading or uneven contrast. Light from a light source undergoes color separation by passing through a color-separation optical system (e.g., a cross-dichroic mirror or cross-dichroic prism). The light from the light source can also be split into first and second polarized lights by passage through, e.g., a first polarized-light beamsplitter (PBS). Each color-separated light is modulated by a respective color-signal light valve and undergoes color combining by, e.g., a cross-dichroic prism. The second polarized light, if formed, is modulated by a luminance-signal light valve, undergoes color combining and polarized-light combining by, e.g., a second PBS, and is projected by a projection lens (that comprises an aperture stop). The PBSs, cross-dichroic mirrors, and cross-dichroic prisms are situated where principal rays (defined by the aperture stop) are parallel to the optical axis.

Abstract: A ferroelectric liquid crystal-based display device comprising a light source, a reflective spatial light modulator, a light output, a beam splitter, and a shutter. The beam splitter is located and aligned relative to the light source, the light output, and the spatial light modulator such that light generated by the light source is reflected or transmitted towards the spatial light modulator, and then light reflected by the spatial light modulator is reflected or transmitted towards the light output. The shutter has both and OPEN and a CLOSED state, and may include ferroelectric liquid crystal material. The shutter may be located and aligned relative to the lights source and the beam splitter such that when OPEN it transmits the light generated by the light source towards the beam splitter, and when CLOSED it prevents transmission of the light generated by the light source towards the beam splitter.

Abstract: A projection display apparatus has a reflective type display for displaying a two-dimensional image on a display surface, a projection optical system for projecting an enlargement image of the two-dimensional image displayed on the display surface onto a projection image surface, the projection optical system having a diaphragm and a decentering optical element disposed between the diaphragm and the reflective type display and decentered with respect to the diaphragm, and wherein the predetermined conditions are satisfied when an image center ray is defined by a line connecting a center position of the display surface and the center position of the projection image surface.

Abstract: A color projection display apparatus has a white light source, splitting means, a reflective color display device and projecting means. The splitting means splits a white luminous flux from the white light source into a plurality of luminous fluxes of different wavelength ranges, and from which luminous fluxes corresponding to the wavelength ranges exit in different directions. The reflective color display device modulates and reflects the luminous fluxes corresponding to the wavelength ranges which luminous fluxes exit from the splitting means and are incident from different directions. The projecting means projects the luminous fluxes modulated by the reflective color display device as image light. The luminous fluxes modulated and reflected by the reflective color display device are incident on the projecting means after being again transmitted by the splitting means.

Abstract: A color liquid crystal display projector having a light source with a radiating element and a liquid crystal display (LCD). The LCD includes an array of multiple picture elements or pixels that each has separate color component elements. A microlens array is positioned adjacent to the liquid crystal display to direct light from the light source into the picture elements. Illumination imaging components cooperate with the microlens array to image the radiating element toward the separate color component elements of the liquid crystal display. Multiple differently inclined dichroic mirrors split the light into light beams of different color components that are imaged onto the appropriate color component elements of the liquid crystal display.

Abstract: A light projector is disclosed that enables a bright display image to be presented with minimum waste of useable light. By arranging at least one light directing means, such as a mirror or a reflecting prism, on an optical path between a light source and a light modulator, and by supporting the light directing means using a support that enables the orientation of the light directing means to be rotatably adjusted, the position of a light spot which illuminates the modulator is made to be adjustable in position, thereby enabling the intensity of the light spot on the modulator to be maximized while minimizing vignetting of the light spot by the modulator.

Abstract: A projection optical unit comprises a frame, a projection lens, a dichroic prism for synthesizing red image light, green image light and blue image light, and three liquid crystal display panels for red, green and blue. A lens mounting portion on which the projection lens is mounted, a prism mounting portion on which the dichroic prism is mounted, and three mounting surfaces on which the three liquid crystal display panels are respectively mounted are formed in the frame. The projection lens, the dichroic prism, and the three liquid crystal display panels are mounted on the frame. The three liquid crystal display panels are mounted through a focus adjusting mechanism comprising a belleville spring and a screw. The two liquid crystal display panels for red and blue are further subjected to CG adjustment (adjustment for matching pixels of the liquid crystal display panels for read and blue with pixels of the liquid crystal display panel for green) by an eccentric screw.

Abstract: A display system having a non-absorbing and reflective color filtering array and a reflector to improve light utilization efficiency. One implementation of the color filtering array uses a surface plasmon filter having two symmetric metal-dielectric interfaces coupled with each other to produce a transmission optical wave at a surface plasmon resonance wavelength at one interface from a p-polarized input beam on the other interface. Another implementation of the color filtering array uses a metal-film interference filter having two dielectric layers and three metallic films.

Abstract: In a polarizing beam converter, a uniaxial anisotropic transparent medium is inserted and supported between isotropic transparent media; and an optical axis of said uniaxial anisotropic transparent medium is arranged almost perpendicular to an incident light beam or an incident face of the incident light beam at an interface between the isotropic transparent medium and the uniaxial anisotropic transparent medium. A half wavelength plate is placed with an inclined angle of 45.degree. relative to a polarization axis for either of a reflected light component or a transmitted light component at the interface. The retractive index of the isotropic medium, n.sub.p, and a refraction index n.sub.e greater than n.sub.0, of the uniaxial anisotropic transparent medium are substantially equal to one another. Further, at the interface of the isotropic medium and the uniaxial anisotropic transparent medium, an incident angle satisfying sin(.theta.).gtoreq.n.sub.0 /n.sub.p for satisfying a total reflection angle.

Abstract: A method is disclosed for displaying images represented by electronic image information, including the following steps: providing a light source; optically modulating light from the light source, the optical modulation utilizing a pixel pattern and a diffraction grating, the pixel pattern being modulated with the image information; providing a schlieren optical system for operating on the optically modulated light; and displaying an output of the schlieren optical system; the diffraction grating being provided with a grating spacing that differs from the pixel spacing of the pixel pattern by an odd multiple of half the grating spacing.

Abstract: A polarization device comprises: a light source; a first lens plate including a plurality of lenses in a planar configuration that divides light emitted from the light source into beams defined by apertures of the plurality of lenses; a second lens plate which is different from the first plate and includes a plurality of lenses in a planar configuration, the plurality of lenses of the first lens plate individually forming light spots at the plurality of lenses of the second lens plate; a polarization beam splitter array constituted of a plurality of polarization beam splitters provided continuously, that performs polarization splitting of light that has been emitted from the light spots of the plurality of lenses of the second lens plate and has entered therein to split the light into p-polarized light and s-polarized light, and emits the split light; and halfwave plates provided at an emission surface of the polarization beam splitter array that convert polarized light emitted from the polarization beam spli

Abstract: In an LCD projector, a color mixing optical system for mixing color beams transmitted through LCD elements includes an optical path length adjuster in three light paths from a light source to the LCD elements. The adjuster includes polarization beam splitters, phase plates, and light-beam reflectors. The numbers of reflections of the color beams in the optical paths from the light source to the projection lens are set only to odd values or only to even values. The adjusters are arranged and configured to equalize the respective optical path lengths to each other. With this configuration, the relative distribution of intensity of illumination is substantially equalized for the beams illuminating the respective LCD elements. Compounding the beams, there is attained a projected screen image with a satisfactory white balance and homogeneous chromaticity and luminance.

Abstract: A projection type liquid crystal display according to the present invention comprises a dichroic prism for separating or synchronizing a light to provide fundamental colors for color display, and a unit for enlarging and projecting a transmitted light from the liquid panel. The liquid panel has one surface fixedly attached to a transparent member and the other surface integral with the dichroic prism directly or through at least one optical component. In the projection type liquid crystal display, the light which provides fundamental colors for color display and is separated or synchronized at the dichroic prism is incident on the light incidence surface of the liquid panel through the transparent member or the dichroic prism without contacting with the air in the space.

Abstract: Disclosed is a single plate projection type display apparatus which is capable of achieving a high luminance without an increase in an output of a light source. A first lens plate having a plurality of lenses divides a light from a light source into a plurality of light beams. A second lens plate having a plurality of lenses superposes the divided plurality of light beams on a light valve, thereby performing an illumination. A color separation optical system composed of dichroic mirrors which are perpendicular to an XY plane and form predetermined angles to each other, performs a color separation for the light beams from the second lens plate. The light valve modulates R, G and B light beams which are incident thereonto. The modulated lights are projected by a projection lens. The whole shape of the second lens plate is a rectangle.

Abstract: The invention relates to an image projection module (1) comprising, in this order, an illumination system (3) and an image display system (13) having at least one display panel (15) for modulating an illumination beam to be supplied by the illumination system (3) with image information. The illumination system (3) comprises an integrator system (19) having an exit surface which is located in an exit plane. First reflecting means (33; 43) are present in the exit plane of the integrator system (19) and the module (1) further comprises second, selectively reflecting means (39). An optical system (31) for at least partly imaging the exit surface via the second reflecting means on the first reflecting means is arranged between the first and the second reflecting means.

Abstract: In a reflection type liquid crystal projector, anti-reflection film optimized for the corresponding color (wavelength band) is formed on each of the light passing surfaces of a cross dichroic prism which are opposed to liquid crystal panels of respective colors and the reflectance of each anti-reflection film is made sufficiently small to thereby enhance the contrast of a colored image projected onto a screen by a projection lens.

Abstract: This invention relates to electromagnetic wave beam paths, formation of the beam, illumination of programmable electromagnetic wave field vector orientation rotating devices ("PEMFVORD") with an electromagnetic beam, and the technique of projection of the modulated beam. This invention also relates to a unique light path and method of forming the light into a rectangular beam to be used for optical projection systems and, more particularly, in a color and/or black and white liquid crystal device (LCD) projectors that produce high resolution, high brightness and/or three-dimensional images. This invention further relates to a device capable of receiving and displaying two-dimensional and three-dimensional images.

Abstract: An optical member used in a color composition system of an optical instrument, such as a projector, includesa prism member formed by joining a plurality of prisms, and a plurality of image forming units fixed to the prism member, wherein joint surfaces of the plurality of prisms reflect therefrom light of a predetermined wavelength range and pass therethrough the light other than that of the predetermined wavelength range, and wherein relative positions of the plurality of prisms are shifted along the joint surfaces to adjust optical path length of the light emitting from each of the image forming units and passing through the prism member, and thereafter the plurality of prisms are fixed.

Abstract: The present invention provides a light polarizing device comprising a light separating module and a retarder for converting an input trichrome unpolarized light having red, green and blue lights. The light separating module comprises a polarization beam splitter film and a dichroic film for separating the input trichrome unpolarized light into two trichrome polarized lights with different polarizations, each color light within the first trichrome polarized light and the second trichrome polarized light having a unique polarization. The retarder retards the first trichrome polarized light or the second trichrome polarized light so as to generate an output of trichrome polarized light with different polarizations. Furthermore, the light separating module is a stackable module that can be vertically stacked with other modules to form a light separating panel.

Abstract: A projection color liquid crystal display apparatus includes a light source, and a light separator to which light emitted from the light source is inputted. The light separator separates the light inputted thereto into color lights of the three primary colors of red, green and blue, converts each of the color lights into one of p-polarized light and s-polarized light and outputs the polarized lights. In a light path of the light outputted from the light separator, a liquid crystal display element having a plurality of pixels arranged corresponding to the individual color lights obtained by the color separation of the light separator and a projection lens for projecting the light outputted from the liquid crystal display element to a screen are disposed.

Abstract: The present invention is directed to a liquid crystal projector comprising a light source for emitting white light, a separation mechanism for separating the white light into light beams with a plurality of colors at different angles, a liquid crystal panel for giving the light beams optical modulation, a lens mechanism for converging the light beams so that the light beams are incident upon respective pixels of the liquid crystal panel, a mechanism for magnifying and projecting the light beams emergent from the liquid crystal panel, and a moving mechanism for moving an incident position of the light beams on the liquid crystal panel an amount of an integer times a pitch between the pixels.

Abstract: An analyzing-synthesizing optical system has the structure in which for each of the three primary colors of R, G, and B, there are provided a light valve for modulating incident light and a polarization beam splitter for guiding specific polarized light to this light valve and extracting only modulated light coming from the light valve to output it, wherein these light valves and polarization beam splitters are fixed as integrated with a synthesizing optical system comprising a cross dichroic prism and wherein optical path lengths of optical paths of the respective colors are adjusted to be almost equal to each other. A projection image display apparatus comprises the analyzing-synthesizing optical unit.

Abstract: In a display panel, a first substrate is opposed to a second substrate and interposing a liquid crystal/resin composite layer. If the display panel is a transmission type display, a film for absorbing light is formed on a black matrix and between pixel electrodes. If the display panel is a reflection type display, a film for absorbing light is formed between reflection electrodes. Further, a counterelectrode is made from a multi-layer film of dielectric films and a transparent electrically conductive film for preventing reflection. The film for absorbing light includes pigments which can absorb light modulated by the liquid crystal/resin composite layer. By using the display panel, a projection display system of high contrast and high brightness can be constructed.

Abstract: A projection display for preventing reflected light beams produced during optical modulation or light compositing from reinjecting into the modulating liquid crystal panel, as well as to convert projected light or light impinged into a light compositing system into a linearly polarized light beam, thereby projecting high-contrast, high-intensity images with minimal reflection errors.

Abstract: This invention is to provide a projecting apparatus which focuses a plurality of color light components through a lens, illuminates reflection optical modulation elements arranged in units of color light components through a first deflection unit provided near a position where the color light components are focused, guides a light beam from at least one optical modulation element to a projection optical system through a second deflection unit, and superposes and projects pieces of image information based on the optical modulation elements on a predetermined surface through the projection optical system, wherein the second deflection unit is arranged near the stop of the projection optical system to divide the aperture of the stop into a plurality of areas, the first deflection unit is arranged near the stop of the projection optical system, and the optical modulation elements are illuminated with light beams tilted in a direction of division of the stop aperture and in a direction perpendicular to the directi

Abstract: Methods and apparatus for enhancing the performance of reflective LCD systems. The high-contrast color-splitting prism system utilizes a "double-pass" prism assembly. Polarized light enters the prism assembly, is color-split and is emitted as separate colors to reflective imagers which reflect each color in accord with a desired image. The reflected light is passed, once again, through the prism assembly where the separate colors converge and the convergent light is emitted to a projection lens for display of the image on a screen. At least one zero-incidence waveplate compensator is positioned between one reflective imager and the prism assembly. The waveplate compensator effectively decreases the unwanted polarized light entering the prism assembly for the second pass-through, thereby increases the polarization purity of the light that is emitted from the prism assembly to the projection lens to yield a high-contrast projection image.

Abstract: A liquid crystal projector has three liquid crystal panels for modulating first color light, second color light, and third color light respectively. A light synthetic device synthesizes each color light modulated by the liquid crystal panels. A projection lens projects the light synthesized by the light synthetic device. Setting members set the liquid crystal panels to the light synthetic device and wedge-type spacer members adjust the position of the liquid crystal panels in their planar direction and the direction perpendicular to the planar direction.The liquid crystal panels are secured to the light synthetic device through the setting members and spacer members.

Abstract: A liquid crystal projector having a high contrast ratio has an optical system including, for each color, a liquid crystal display device, a drive device for driving the liquid crystal display device and a polarization device, and a light source. The liquid crystal display device has active devices connected to reflective electrodes. Driving voltages applied to pixels have different polarities in every row. The liquid crystal layer is aligned at an angle from 75.degree. to 105.degree. to the direction of an electric field between electrodes. An optical rotator is provided between the liquid crystal display device and the polarization device.

Abstract: A projection image display device includes, a light source, an image display panel having a number of pixels and a vertical scanning function, an optical system for dividing light from the light source into a plurality of lights of different wave ranges and directing and overlapping the divided plural lights onto an area from different directions, a light-collector for collecting each of the plural divided lights directed onto the area by the optical system into apertures of pixels of the image display panel corresponding to the wave range of the light, a projector for projecting an image displayed on the image display panel, and a color-changer for mutually changing, at every vertical scanning of the image display panel, the directions in which the optical system directs the plural divided lights of the different wave ranges, so as to mutually change the wave ranges of light directed to the pixels of the image display panel sequentially.

Abstract: Apparatus is disclosed that provides a high-luminance projected image with no color shading or uneven contrast. Light from a light source undergoes color separation by passing through a color-separation optical system (e.g., a cross-dichroic mirror or cross-dichroic prism). The light from the light source can also be split into first and second polarized lights by passage through, e.g., a first polarized-light beamsplitter (PBS). Each color-separated light is modulated by a respective color-signal light valve and undergoes color combining by, e.g., a cross-dichroic prism. The second polarized light, if formed, is modulated by a luminance-signal light valve, undergoes color combining and polarized-light combining by, e.g., a second PBS, and is projected by a projection lens (that comprises an aperture stop). The PBSs, cross-dichroic mirrors, and cross-dichroic prisms are situated where principal rays (defined by the aperture stop) are parallel to the optical axis.

Abstract: Color and/or polarization beam splitters are used in a multi-color light valve projection systems. The color and/or polarization beam splitters each include first and second prisms with a thin-film stack located therebetween. The prisms are made of glass which has an index of refraction between 1.65 and 1.85. The color and polarization beam splitters operate at an angle of incidence of 45 degrees. By operating at 45 degrees, the color and/or polarization beam splitters can be assembled in a compact and parallel manner and thereby reduce the size of the color and/or polarization beam splitter while increasing the contrast of the light valve projection system. The high index of refraction glass also produces a smaller optical path for a given physical path. The disadvantages associated with index of refraction oil prisms are also eliminated.

Abstract: In the optical apparatus, the projection lens has a first lens group and a second lens group, the color synthesizing optical system has a transparent plate, dichroic mirrors and a plane mirror, the second lens group is disposed between the color synthesizing optical system and the polarization beam splitters, and the plane including the normal line of the plane of the transparent plate, the color synthesizing planes of the dichroic mirrors and the optical axis of the projection lens is perpendicular to the plane including the normal line of the polarizing and splitting planes of the polarization beam splitters and the optical axis of the projection lens.

Abstract: This optical filtering device includes a dichroic separator on the path of a light beam to be processed. According to the invention, it also includes a holographic filtering device situated in series with the separator on the path of the same beam. The holographic device can be oriented so as to adjust the angle of incidence of the beam and hence adjust its range of filtering wavelengths.

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.

Abstract: A projection-type display device having a single light source which produces light. A first dichroic mirror group receives the light and separates it into colored light. A transmissive light valve system modulates the colored light and a second dichroic mirror group synthesizes the modulated colored light. A projection system projects the synthesized colored light onto a screen.