Abstract: An optical system for reflective mode light valve full color display, and more particularly a compact and highly optically efficient trichroic prism assembly (TPA), and a polarizing beam splitter (PBS). This TPA and PBS combination is placed between the objective lens and the LCD panel or other kind of reflective light valves to form a compact projection system.

Abstract: A multiple display apparatus for displaying an image with projection of a plurality of images from a plurality of image projecting means 10p, 10q onto a screen is disclosed. The plurality of image projecting means 10p, 10q are disposed such that their images are projected substantially from one point onto the screen 20. Thus it is possible to realize superior display quality without pronounced display in any overlap part.

Abstract: A spatial light modulating device includes: an electrically-addressed type element for being addressed by electric signals representing information to be written, the electrically-addressed type element including an image display portion having a pixel structure, the electrically-addressed type element being inputted with write light; an optically-addressed type spatial light modulator including a thin film material portion and a pair of substrates, the thin film material portion being provided between the pair of substrates, the thin film material portion having an optical addressing layer and a light modulation layer which are provided one on the other, the optically-addressed type spatial light modulator being inputted with read light; and a compensation layer having a predetermined thickness and provided between the image display portion and the thin film material portion.

Abstract: A prism (1) has a first inner surface (114A) and a second inner surface (122) in its interior. The first inner surface (114A) performs total reflection of all rays (20) entering from the exterior, and is disposed apart from a variable mirror element (3) disposed in the exterior, such that the reflected rays are irradiated to the variable mirror element (3). The second inner surface (122) is disposed in proximity to the variable mirror element (3), and totally reflects a bundle of OFF rays from the variable mirror element (3), while allowing a bundle of ON rays from the variable mirror element (3) to pass therethrough.

Abstract: A full color image projection system is provided using two non-color-specific image sources and color-specific filters. The system is capable of projecting an image using one primary color from one image source and the other two primary colors from another image source. The system uses slower speed image sources than would be required with one source alternating between three colors, and exhibits higher resolution than would be obtained from a color-specific image source.

Abstract: A light source device, comprising a light guide block that is provided with an inner wall capable of reflecting light and is shaped as a hollow component to form a light guide, and a point light source array that is located opposite one end face of the light guide block and is capable of emitting light into the light guide.

Abstract: An illumination system for a projector having a color management system (CMS). The illumination system comprises a light source, a light-converging system for converging light beams coming from the light source, a P-S converter and a gobo. The P-S converter is used for receiving and polarizing the light beams and then transmitting the light beams into the CMS. The gobo is formed with a plurality of apertures and is provided between the light converging system and the P-S converter.

Abstract: The illumination device has a simple structure and a small size, can obtain a sufficient illumination light amount, and can improve illumination ability, with high reliability and high performance at low costs. A kaleidoscope is arranged such that its center axis substantially corresponds to the optical axis of a light bulb. The kaleidoscope includes a diffusive reflection surface in its rear side, and a laser beam is irradiated on the diffusive reflection surface from the opening side of the kaleidoscope, so that reflection light from the diffusive reflection surface is used as at illumination light source.

Abstract: An apparatus and method for illuminating a projection display which includes multiple light sources which are integrated through a multi-input ported light pipe disposed between the multiple lamps and the remainder of the projection display.

Abstract: A lens-less projection optical system of the reflection type is provided with four reflecting mirrors, which successively reflect a light flux transmitted through a picture-forming device. The light flux reflected by the fourth reflecting mirrors is projected on the screen. The second reflecting mirror is so situated that its reflecting surface shaped into a convexly curved surface is directed to the light flux reflected from the first reflecting mirror. The third reflecting mirror is so situated that its reflecting surface shaped into a convexly curved surface is directed to the light flux reflected form the second reflecting mirror. The fourth reflecting mirror is so situated that its reflecting surface shaped into a convexly curved surface is directed to the light flux reflected from the third reflecting mirror.

Abstract: An image projector, having a light source, an LCD panel into which a light emitted from the light source enters, and a projection lens into which the light emitted from the LCD panel enters. There exists, in an entrance pupil of the projection lens, a range in which light emitted from respective pixels of the LCD panel overlap with each other at least in a horizontal direction. The image projector forms part of an image display.

Abstract: Three colors of light beams from a light source travel via a first optical system to strike a reflecting surface of a rotating polygon mirror, or mirrors, at different angles without overlapping. The rotating polygon mirror or mirrors reflect the light beams for scanning. The reflected light beams enter a second optical system at different angles to illuminate an image display panel at different portions. On the image display panel, belt-like regions illuminated by the light beams of individual colors are formed in parallel with each other, and these illuminated regions are moved continuously by scanning. A formed color image is magnified and projected by a projection optical system. With such a projection type image display apparatus, a display having high resolution and light efficiency that is also small, thin and inexpensive is achieved.

Abstract: An image projection system includes an image generator, a screen and a focus and aim component. The focus and aim component receives modulated light from the image generator and focuses and deflects the light as a function of a position on the screen. The component consists of an array of lenslets with wedge. The wedge or prism refracts the light and the lens focuses the light. As a result, the optics are selectively tailored to provide a clear image over the entire field of view, even in systems compact in depth that would otherwise rely on a short focal length lens. Acute incidence angles at the periphery of the screen are handled by TIR Fresnel lens elements or by diffractive elements. The focus and aim capability is alternatively provided by holographic elements in a holographic array.

Abstract: A projection system is disclosed that utilizes a modulator, preferably in the form of an LCD matrix, to modulate light in accordance with a video image to be displayed. The light is supplied to the LCD matrix, reflected back off the matrix through a lens to a mirror, and then imaged through another lens. The mirror is placed in the path between the light source and the LCD matrix.

Abstract: Red, green and blue light beams from, a light source portion travel via a first optical system and enter a reflecting surface of a rotating polygon mirror at different angles so as not to overlap each other. The rotating polygon mirror makes these light beams perform scanning when reflecting these light beams. The light beams for the scanning enter a second optical system at different angles and are led to different positions on an image display panel. The second optical system forms an image that is rotated by 90° from that on the rotating polygon mirror on the image display panel. On the image display panel, belt-like regions illuminated by the light beams of individual colors are formed in parallel with each other, and these illuminated regions are moved continuously by the scanning. Each pixel of the image display panel is driven by a signal corresponding to a color of light entering this pixel. A formed color image is magnified and projected by a projection optical system.

Abstract: A projection device comprising at least one light source, at least one light-modulation panel preceding the light source, and polarization-separating means arranged between said light source and said light-modulation panel for separating light from the light source into first and second light beams having a first and a second direction of polarization, respectively. The projection device also comprises first and second integrator plates comprising lens elements which are arranged between said polarization-separating means and said light-modulation panel, and polarization-converting means arranged opposite the second integrator plate. Each lens element of the second integrator plate includes a first portion on which a first light beam is projected by the first integrator plate, and a juxtaposed, second portion, on which a second light beam is projected. The polarization-converting means are arranged at least opposite said first portions.

Abstract: An illumination system having a light-emitting unit and a reflecting mirror for condensing light is described. The illumination system includes a lens plate having a plurality of approximately identical lens elements. The lens plate is disposed away from the light-emitting unit and the plurality of lens elements are arranged two-dimensionally and approximately perpendicular to a main optical axis of a projection lens system and an object to be projected. The illumination system further includes first and second lenticules, and at least one convex lens disposed so as to refract a light path of the light flux formed by each of the plurality of lens elements such that the light flux illuminates a surface of the object to be projected after passing through the first and second lenticules.

Abstract: A projector is mainly composed of a polarized light beam illumination device, a collimating lens, polarized beam splitter, a reflection-type liquid crystal device, and a projection optical system. The polarized light beam illumination device includes a light source, a first optical element, and a second optical element. Light emitted from the light source is divided into a plurality of intermediate light beams by the first optical element, and then converted into polarized light beams having substantially one polarization direction by the second optical element. The polarized light beams enter the collimating lens, are transmitted by the polarized beam splitter, modulated by the reflection-type liquid crystal device, reflected by the polarized beam splitter, and then projected on a projection plane via the projection optical system.

Abstract: A projector apparatus comprises: a light modulation optical system which separates white light into a plurality of light components with respective wavelength bands, controls the intensity of each of the plurality of light components, and then composes the controlled plurality of light components; a projection lens for projecting the light composed in the light modulation optical system; a light source optical system for permitting the white light to exit therefrom, the light source optical system being disposed so that the optical axis of the light source optical system is displaced relative to the optical axis of the light modulation optical system; and a focusing lens which is disposed so that the optical axis of the focusing lens is coincident with the optical axis of the light modulation optical system, for focusing the light output from the light source optical system and inputting the focused light into the light modulation optical system.

Abstract: An image alignment system for rear projection in which a portion of the normally changing pixel pattern contains a pixel reference mark, which appears in each of the side-by-side pixel images projected onto a screen. A camera having a field of view large enough to encompass the pixel reference mark of each of the images on the screen captures the location of the pixel reference marks to enable a computer to determine the coordinates of the each of the pixel reference marks and generate a deviation signal represented of the visual misalignment of the side-by-side images. A drive member controllable by the deviation signal from the computer repositions one of the side-by-side images with respect to the other to thereby align the images to produce a single visually seamless image. The camera and computer can continually monitor both of the pixel reference marks to continually generate a deviation signal so that the side-by-side images can automatically be brought into a single visually seamless image.

Abstract: A color liquid crystal projector has an optical system for color splitting. The optical system includes a mirror for reflecting a first primary-color light and transmitting second and third primary-color lights in light from a light source; a first phase plate for transmitting the second primary-color light from the mirror with its polarization degree rotated through 90°, and for transmitting the third primary-color light; a first prism for transmitting the second primary-color light from the first phase plate into a second liquid crystal display panel, and reflecting the third primary-color light from the first phase plate into a third liquid crystal display panel; a second prism for entering the first primary-color light from the mirror into a first liquid crystal display panel; and a dichroic prism for combining the first, second and third primary-color lights reflected from the liquid crystal display panels.

Abstract: A spatial light modulator is constructed from a conductive silicon mirror substrate and a glass electrode substrate including sodium, anode-bonded together. The silicon mirror substrate has micromirrors arranged in a matrix, torsion bars coupling these micromirrors in the x-direction, and a frame coupled to both ends of the torsion bars. A glass electrode substrate has a central depression, a rim around the periphery thereof, pillars projecting from within the depression, and electrodes and wiring driving micromirrors formed within the depression in an inclining manner. Both ends of the torsion bars are bonded to the rim of the frame portion, and intermediate portions of the torsion bars are bonded to the pillars. Both ends of the torsion bars are cut away from the frame portion during dicing.

Abstract: A color projector for correcting chromatism by changing the sizes or positions of three display devices with respect to each color is provided. In the color projector, two or more display devices selected from the first through third display devices have different sizes of effective areas where an image is formed such that chromatism generated while lights of different colors synthesized by the synthesizing device pass the projection lens unit can be corrected. Also, the distances between two or more display devices selected from the first through third display devices and the projection lens unit are different from one another such that chromatism generated while lights of different colors synthesized by the synthesizing device pass the projection lens unit can be corrected.

Abstract: An image projection system is provided for generating an energy efficient output representative of a desired input image. The image projection system includes a light source positioning device for directing the light from a light source onto a spatial light modulator. An image source provides the desired image to the spatial light modulator and also image information to a light source position controller for coordinating the light source positioning device, such that the light from the light source impinges substantially only the area of the spatial light modulator which contains the desired image. In particular, the controller actuates the light source positioning device by using a predefined scan that corresponds to the desired image. The spatial light modulator modulates the light with the desired input image and generates an output representative of the desired image.

Abstract: The present invention proposes a reflective type liquid crystal projection system, which comprises an incident light source providing an S-polarization light beam or a P-polarization light beam as the incident light beam. A polarization of color-splitting device having a first polarization of color splitter and a second polarization of color splitter is used to split the incident light beam of three primary colors into two sets of light beams, which respectively penetrate through or are reflected. The two sets of light beams split by the first polarization of color splitter are reflected by two reflective mirrors, traverse two polarizing plates arranged between the reflective mirrors and the second polarization of color splitter, and are then incident on the second polarization of color splitter. At least a retarder is arranged between the reflective mirrors and the polarization of color-splitting device.

Abstract: A projection display apparatus (100) is formed by a light source (4) radiating white light w, a collimator lens (5) that converts condensed light flux from the light source (4) to collimated light flux, a cold mirror (6) for eliminating unwanted infrared light included in the white light w, an integrator that makes the intensity distribution of the illumination light on an object to be illuminated uniform, a reflective mirror (8) that reflects light flux from the integrator (7) at a prescribed angle, a polarizer (9) that polarizes separated light of each wavelength band, a spatial light modulation section (10), a coupling prism (11), and a projection lens (12).

Abstract: A display apparatus of the projection type is improved in that, when a lamp valve breaks or is to be replaced, glass fragments and so forth thereof are prevented from being scattered into the inside of an outer housing of a projector apparatus through a cooling air intake port in a portion of the outer casing below the lamp valve and a comparatively small number of cooling fans are used to reduce the size and the weight of the overall display apparatus while optical modulation elements, a light source element and so forth can be forcibly cooled in a high efficiency. Cooling air blasted from an air blasting fan is blasted through an air blasting duct to three spatial optical modulation elements, a PS conversion element and a discharge lamp to forcibly air-cool the elements. A lamp box in which the light source is accommodated and which is removably mounted in an outer housing has a cooling air intake port through which cooling air is taken in to the light source.

Abstract: A projector for producing a visually perceptible light image along predetermined vector coordinates, includes a light source for producing a beam of light along a light path; a deflector positioned to deflect the beam of light along the vector coordinates; a focusing lens for focusing the deflected light beam; and a projection reflector for reflecting the beam along the vector coordinates to thereby form the visually perceptible light image. A preferred light source comprises a laser, and a preferred reflecting surface has a substantially convex shape, preferably including a parabolic reflector.

Abstract: An overhead projector mounting system is provided that is configured to support a projector in a ceiling of a room. The system includes a housing having an opening through which an image generated by the projector is transmitted. Preferably, the system includes a mirror to reflect the image generated by the projector toward a viewing surface in the room.

Abstract: A projection display device for displaying electrically encoded images includes an L-type optical module, which includes first, second, and third polarization beam splitter mirrors and a first retarder film. The first and the third polarization beam splitter mirrors are aligned in a plane that is perpendicular to the second polarization beam splitter mirror. A first monochromatic polarized beam is directed to the first polarization beam splitter mirror, and a bi-chromatic polarized beam is directed to the third polarization splitter mirror. The first polarization beam splitter mirror directs the first monochromatic polarized beam to a first modulation unit, and a first modulated beam reflects from the first modulation unit to the second polarization beam splitter mirror via the first retarder film.

Abstract: A projecting image display device is disclosed which includes a display and a micro lens array, where the pixels of the display and the micro lens elements each have non symmetric properties in length and width directions. The micro lens concentrates color-separated light onto pixels of a display device so that light does not hit the black matrix. By providing a display having pixels which are not equal in length and width, pixels corresponding to red (R), green (G) and blue (B) can be arranged in a substantially square area, and by providing a micro lens array which has non symmetric properties in length and width, the color separated light can be concentrated onto the non square display pixels.

Abstract: An optical display system includes a source of white uncollimated light, a color separator for separating the white light into spectral components, a reflective ferroelectric light valve for spatially modulating the spectral components, and a polarizing beam splitter for directing vertically polarized light towards a display lens. The system further includes a corrective film disposed in an optical path between the white light source and the light valve. The film, which may be made of a ferroelectric material or other birefringent material, ensures that retardance of the light valve is approximately 180 degrees or some other desired angle over a spectrum of interest. In this manner, the light valve is achromatized by the film.

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: A display apparatus of the present invention includes: an illumination optical system for emitting illumination light; a reflective display panel divided into a plurality of pixels, illuminated by the illumination light from the illumination optical system, and selectively reflecting the incident illumination light pixel by pixel as projection light; a projection optical system for projecting image information the reflective display panel onto a projected surface by transmitting the projection light reflected at the reflective display panel; and a reflection angle converting optical system disposed ahead of the reflective display panel, changing the angle of incidence of the illumination light on the reflective display panel, and adjusting the sum of the angle of incidence of the illumination light on the reflective display panel and the angle of reflection of the projection light at the reflective display panel.

Abstract: A compact high resolution omnidirectional or panoramic viewer has several cameras with a common virtual optical center. The field of view of each of the cameras is arranged to form a continuous 360 degree view of an area when taken as a whole. The cameras are positioned so that they each view a different reflective surface of a polyhedron such as a pyramid. This results in each camera having a virtual optical center positioned within the pyramid. The cameras may be positioned so that their virtual optical centers are offset from each other. The offsets produce narrow blind regions that remove image distortions received from the edges of the pyramid's reflective surfaces. The reflective pyramids may be stacked base to base or nested within each other to produce a more compact panoramic viewer. Using two or more reflective pyramids in such close proximity permits using many cameras with the same virtual optical center.

Abstract: An illumination optical device has the following elements. A first optical block includes a first lens array having a plurality of cell lenses each being approximately similar in shape to a light modulation device. A second optical block includes a second lens array having a plurality of cell lenses corresponding to the respective cell lenses of the first lens array of the first optical block and each being approximately similar in shape to the light modulation device, and a first converging component for converging beams that have passed through the second lens array toward the light modulation device. A second converging component is disposed in the vicinity of the light modulation device and serves to image beams that are output from the second optical block at a predetermined position. The cell lenses of the first lens array have different aspherical surfaces.

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: A light source device for an image projector includes: two light sources for irradiating illumination light rays; a light distributor for receiving light rays from each of the two light sources, and sending out light rays of each of the two light sources parallel to an optical axis of the projector in a uniform distribution pattern from an entirety of an emerging surface of the light distributor. Each of the two light sources irradiates light rays in a direction inclined with respect to the light distributor so that light rays irradiated by each of the two light sources are incident onto the entire incident surface of the light distributor.

Abstract: There is disclosed an image projection apparatus which comprises separating a light beam from a light source into plural color lights by color separation means, respectively condensing the separated plural color lights, providing first deflection means in the vicinity of at least one of condensed positions to guide the color lights to optical modulation elements respectively corresponding thereto, and projecting image information, based on the optical modulation elements, onto a predetermined plane through a projection optical system.

Abstract: A color separating/light guiding optics comprises two independent dichroic mirrors, reflection mirrors and correcting lenses. A horizontal plane region occupied by these optical components is entirely involved in a horizontal plane region occupied by a light modulating/color compositing/image projecting optics. A red beam is guided along a detoured optical path extending across a dead space below a projection lens. Although the optical path length of the red beam becomes longer than those of the blue beam and the green beam, the detoured optical path provides a sufficient space for installing the correcting lenses. The substantial optical path lengths of three primary color beams can be equalized with each other by the provision of these correcting lenses.

Abstract: An image display apparatus includes an arc lamp as a white-light source, an ellipsoidal mirror for collecting a light beam from the arc lamp, a color filter for producing sequentially three primary colors of light from the white-light beam, a condenser lens for transmitting a light beam transmitted through the color filter, and a single spherical mirror or non-spherical mirror for reflecting the light beam transmitted through the condenser lens. The image display apparatus further includes a digital micromirror device. This device receives the light beam reflected from the reflecting mirror and produces on and off states by varying the tilt of a micromirror of each of a number of two-dimensionally arrayed pixels to vary the angle of reflection of the light beam reflected therefrom. From there, a projection lens enlarges and projects the light beam reflected from a pixel.

Abstract: A projection-type display apparatus includes a light source, a uniform illumination optical system, a color separating system for separating a white light beam emitted from the uniform illumination optical system into three color beams, three liquid crystal panels for respectively modulating each of the separated color beams, a light guide system located on an optical path of the color beam having the longest optical path among the separated color beams, a dichroic prism for synthesizing the beams modulated through the liquid crystal panels, and a projection lens for projecting the synthesized and modulated beam onto a screen. The uniform illumination optical system is provided with a uniform illumination optical device for converting the white light beam emitted from the light source into a uniform beam.

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 projection type display apparatus which allows a reduction in size and which enables images to be clearly projected. In a projection type display apparatus 1 in which an image displayed by an image display device 53 is projected onto a screen by using light from a light source 3, the light from the light source 3 is transmitted through an optical element as illuminating light and guided along a first optical axis OP1 before it is reflected by a first reflecting mirror; and the illuminating light is reflected by a second reflecting mirror and guided toward the image display device 53 along a second optical axis OP2. The first optical axis OP1 and the second optical axis OP2 are arranged at different positions and parallel to each other. Arranged in the first optical axis OP1 is an optical element for concentrating the intensity distribution of the illuminating light, and the optical element is formed by two-dimensionally arranging a plurality of unit lenses.

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 rear projection monitor includes a projection optical system, a screen, and a guide optical system. The projection optical system projects an original image. The original image is projected on the screen from the rear side to display an enlarged image of the original image. The guide optical system guides light emitted from the projection optical system to the screen. The guide optical system has a movable reflecting surface, and functions to adjust the position of the image on the screen by changing the incident angle of light emitted from the projection optical system to the reflecting surface.

Abstract: In an image display system capable of displaying an M.times.N number of pixels based on optical projection, a light source emits a white light, the white light being reflected on a total mirror at a predetermined angle. An optical filter splits the white light reflected from the total mirror into a trinity of primary light beams, i.e., a red, green and blue light beam. Each of a trinity of arrays of M.times.N actuated mirrors generates an optical pixel signal by reflecting the primary light beams impinging thereon, each of the actuated mirrors in the arrays being capable of changing the optical path of the primary light beams reflected therefrom, wherein a driver circuit controls each actuated mirror based on an input image signal. A projection stopper partially transmits the optical pixel signal and a projection screen displays the optical pixel signals passing through the projection stopper.

Abstract: A video display system includes a laser beam that is reflected from a vertical scan rotating mirror, then from a horizontal scan rotating mirror and then toward a viewing surface. The rotational angles of the mirrors and the intensity of the laser are controlled by a controller that is driven by a video signal. Rotation of the horizontal mirror scans the laser beam across the viewing surface while the laser intensity is modulated to form pixels on the viewing surface. The vertical scan mirror then directs the beam to the next horizontal scan line. The resolution and aspect ratio of the image are adjusted by changing the rotation rate of the mirrors and by changing the rate at which the laser is modulated.

Abstract: An output light from an light source lamp unit 8 in a projection-type display apparatus illuminates liquid-crystal light valves 925R, 925G and 925B for three colors via an integrator optical system 923. A superimposing lens 930 that is a component of the integrator optical system 923 as a uniform illumination optical system is arranged such that the mounting position of the superimposing lens 930 is fine-adjustable in a direction orthogonal to an optical axis 1a. By fine-adjusting the mounting position of the superimposing lens 930, the position of an illumination area B is adjusted such that the illumination area includes the image forming area A of the liquid-crystal light valve. It is not necessary to assure a wide margin around the image forming area A to cover the offset of the position of the illumination area B. As a result, the utilization of illumination light is heightened and a bright projected image results.

Abstract: A projection-type display apparatus includes a light source, a uniform illumination optical system, a color separating system for separating a white light beam emitted from the uniform illumination optical system into three color beams, three liquid crystal panels for respectively modulating each of the separated color beams, a light guide system located on an optical path of the color beam having the longest optical path among the separated color beams, a dichroic prism for synthesizing the beams modulated through the liquid crystal panels, and a projection lens for projecting the synthesized and modulated beam onto a screen. The uniform illumination optical system Is provided with a uniform illumination optical device for converting the white light beam emitted from the light source into a uniform rectangular beam.