Abstract: An imaging apparatus has input optics for obtaining a multispectral image bearing light and a programmable spectral switching section. The programmable spectral switching section has a first lens for directing light toward a dichroic separator that separates the multispectral image bearing light into a plurality of discrete spectral bands, each directed to an optical switch. Each optical switch is selectively enabled to redirect its corresponding spectral band back through the first lens as switched spectral band light. A light path selector element directs switched spectral band light toward an image forming section that has a sensor lens for directing switched spectral band light toward an image sensor. The image sensor forms image data according switched spectral band light from each optical switch. A control logic processor communicates with optical switches and with the sensor, providing instructions for enablement of optical switches and obtaining sensor data.

Abstract: A cross dichroic prism color-synthesizes a plurality of color lights having entered therein separately and emits color-synthesized light to a projection lens. The cross dichroic prism includes a first dichroic film; and a second dichroic film intersecting the first dichroic film so as to pass through the first dichroic film. The cross dichroic prism is configured so that a color light having entered the cross dichroic prism and having become diffracted at a gap created in the first dichroic film over an area where the second dichroic film passes through the first dichroic film is not projected through the projection lens.

Abstract: A color separation prism assembly. The color separation prism assembly includes a polarizing beam splitter and a plurality of prism blocks. The polarizing beam splitter is coated with a polarizing beam splitter coating on a diagonal plane thereof. A first filter and a second filter, each corresponding to a specific color band, are respectively formed on two adjacent bounding surfaces of the polarizing beam splitter. A first prism block and a second prism block are connected to the polarizing beam splitter through the first filter and the second filter, respectively. The second prism block is a rectangular prism with a third filter formed on a base surface thereof. A third prism block is connected to the rectangular prism through the third filter. An angle formed by an inclined side of the rectangular prism and the base surface of the third filter is no more than 30°.

Abstract: The invention generally relates to an integrated head up displaying (HUD) device including a housing that houses an active-matrix image projecting system and its accompanying electronics, and an optical combiner (for providing a see-through image thereon) connected to the housing via a retractable arm attached at one end to the main body and holds the HUD optical panel at its other end. In particular, the telescopically retractable arm allows the assembly to extend or retract for a desirable combiner height. Further, the LED backlighting array is placed within a reflective light chamber which is lined with a safe, light-weight, low cost, specular, reflective sheet for high reflectivity. The non-conductive, reflective sheet also covers the LED printed circuit board.

Abstract: Exemplary embodiments of the invention provide a projector that can readily correct for chromatic aberration caused by, for example, a projecting lens without having to give a cross dichroic prism, for example, a special preliminary process. Illumination-light components modulated by corresponding liquid-crystal light valves are synthesized in a cross dichroic prism (27) to form image light. The image light enters a projecting lens (29) from which the image light is projected onto a screen, which is not shown in the drawings. In the cross dichroic prism (27) used to synthesize light components, a first prism element (P1) has a refractive index higher than that of remaining prism elements (P2, P3 and P4). This allows a width of a red projection-image component to be made larger than widths of projection-image components of remaining colors, whereby the chromatic aberration in the projecting lens can be readily corrected.

Abstract: A light filtering apparatus includes a first dispersion device, a spatial filter and a second dispersion device. The first dispersion device is arranged to cause spatial dispersion of an incident light beam as a function of its frequency. The spatial filter is arranged to filter the dispersed light beam so as to produce a spatially filtered resultant beam. The second dispersion device is arranged to recombine the dispersed and filtered light beam so as to produce an output light beam having a substantially similar spectrum at any position within the output beam cross-section.

Abstract: A common-aperture, multispectral device uses a folded beamsplitter to simultaneously image near infrared (NIR) and long wave infrared (LWIR) spectral bands. The folded-path optical design makes the sensor extremely compact and lightweight without compromising the F/# or field of view. The design is split into two channels; a NIR channel and a LWIR channel. A Zinc Sulfide environmental window provides the input to the device. The input first is split into the two channels via a Germanium (Ge) beam-splitter. For the NIR Channel, the input is focused directly onto a faceplate through a series of optics. For the LWIR Channel, the input is focused onto the Ge window via a folded design including a first Ge lens, a fold mirror, and then a second Ge lens. From the faceplate of the NIR channel and the Ge window of the LWIR channel, the input is then processed by respective focal planes.

Abstract: A LED light source is formed of a plurality of LEDs (light-emitting diodes). Primary optical axes of respective LEDs are set to be perpendicular to the plane surface (LED arranging plane surface). A first LED light source emits a light in red, a second LED light source emits a light in green, and a third LED light source emits a light in blue. An optical member has a first dichroic mirror portion and a second dichroic mirror portion alternately arranged, and the mirror potions inclined and arranged so as to form a saw-tooth appearance. Both the first dichroic mirror portion and the second dichroic mirror portion are designed to transmit the light in blue, and reflect lights in other colors.

Abstract: The present invention provides a projection type image display device capable of affording a bright display of a high saturation and capable of ensuring a high reliability of optical parts. The projection type image display device is provided with a color synthesizer for color-synthesizing modulated and polarized light of red light, green light, and blue light, outputted from an image display element. The color synthesizer has an optical characteristic such that the transmittance including reflection by a reflecting film in the interior of the color synthesizer becomes highest for the polarized light of blue light out of the modulated and polarized light of red light, that of green light, and that of blue light. The color synthesizer also has an optical characteristic such that the quantity of the polarized light of blue light outputted becomes largest out of the modulated and polarized light of red light, green light, and blue light.

Abstract: The invention relates to an illumination module for color display, preferably for use in data or video projectors as well as rear projection television sets, in which the light from at least three luminescent diodes (LEDs) or LED arrays of the base colors red, green and blue is collimated at a point provided for connection to a display unit and ranged on an optical axis of the illumination module. An LED or an LED array of a base color with a beam path (Lr) oriented in the direction of the display unit is arranged on the optical axis of the illumination module. For the purpose of color mixing, the LEDs and LED arrays of the other base colors are attached in such a way tat their beam paths (Lg, Lb) are laterally input in sequence under input angles (?, ?) of <90 degrees into the beam path (Lr) of the first base color.

Abstract: Various optical techniques are described for obtaining a specified light output from an LED source. One technique uses a parabolic reflector surrounding an LED or LED array to create a collimated beam, and the light exit opening of the parabolic reflector is defined by a reflective disc with an opening of the desired size. Any generated light that is outside of the opening is reflected back into the parabolic reflector and re-reflected until the light exits the opening. For mixing different light colors from different LEDs or energized phosphors, a mixing tunnel is used. The mixing tunnel includes angled dichroic mirrors or angled polarizer mirrors that selectively reflect and pass selected colors or polarizations of light to a single output port of the mixing tunnel. Efficient and compact ways to energize phosphors are also described. Other optical techniques are also described.

Abstract: A projector incorporating a prism and a plurality of light valves for modulating light that passes though the prism, wherein the color splitting-converging prism includes a dichroic coating having multiple layers of high and low index of refraction and ¼ wavelength thickness at each desired angle of incidence for reducing dichroic shift and thereby minimizing light loss.

Abstract: A display system includes at least one light emitting material having an absorption band carried on a support, wherein the support is a laminated article having a first ply and a second ply; and a projection assembly having an electromagnetic radiation source, the projection assembly configured to direct radiation of one or more selected wavelengths within the absorption band of the light emitting material toward the light emitting material to cause at least a portion of the light emitting material to emit light. The support can be an automotive transparency, a commercial window, a residential window, a commercial sign, an advertising display, and an insulating glass unit. The light emitting material is fluorescent materials, phosphorescent materials, and mixtures thereof.

Abstract: The present invention provides a projection image display technology capable of correcting astigmatism due to use of a polarized-beam splitter, thus ensuring high-resolution projection images. A wire-grid polarized-beam splitter (or the like) of a flat-plate-like structure is used as a polarized-beam splitter, and an astigmatism correction element, such as a cylindrical lens, is provided between the polarized-beam splitter and a projection lens unit.

Abstract: An optical prism assembly. The optical prism assembly includes an isosceles triangular prism and a plurality of prism blocks. The isosceles triangular prism comprises a base angle, between 30° and 45°. A first prism block and a second prism block are connected to two bounding surfaces of the isosceles triangular prism having equal lengths. A third prism block is connected between the first prism block and the second prism block. A first dichroic filter and a second dichroic filter are formed on the isosceles triangular prism and two adjacent bounding surfaces of each prism blocks, such that the isosceles triangular prism is combined with each prism block to form a first filter continuous plane and a second filter continuous plane.

Abstract: Color separation and synthesis systems, color separation systems and color synthesis systems, illumination optical systems, projection optical systems, and projection display devices using these systems include a wavelength-splitting element that reflects linearly polarized light of one wavelength and transmits light of another wavelength; a polarization-transforming element that changes the direction of polarization of linearly polarized light of one wavelength and that is arranged adjacent and at least nearly parallel to the wavelength-splitting element; and a polarization-sensitive beam splitter that reflects light having one direction of linear polarization and transmits light with another linear polarization.

Abstract: Optical multiplexers and demultiplexers are provided. In one implementation an apparatus is provided. The apparatus includes a first laser diode pair, a second laser diode pair, a polarization rotator coupled between the first and the second laser diode pairs, and an output port. The first and second laser diode pairs include a first laser diode, a polarization beam splitter, a first quarter waveplate, a filter; a second quarter waveplate, and a second laser diode. The first and second laser diode pairs are coupled to the polarization rotator at the polarization beam splitter of each laser diode pair. In one implementation the apparatus is operable to multiplex distinct light signals emitted from the first and second laser diodes. In another implementation, an apparatus is provided that is operable to demultiplex an input light beam having a plurality of distinct channels.

Abstract: A color prism capable of separating incident light into four color beams and synthesizing incident four-color beams, and a projection-type image display apparatus employing the color prism. The color prism includes: first through third triangular prisms each having two boundary surfaces which face the other two triangular prisms, and an outer surface which transmits or reflects incident light according to an incidence angle of the light; and first through third dichroic filters respectively interposed among the first through third triangular prisms and selectively transmits or reflects incident light according to wavelength so as to separate incident light into first through fourth light beams according to wavelength ranges and synthesize incident first through fourth light beams.

Abstract: An optical element including an anti-reflection (AR) coating is configured to reflect Extreme-Ultra-Violet (EUV) radiation only.

Abstract: This specification discloses a polarizing. element for dividing light into first and second polarized lights differing in polarized state from each other by a polarizing dividing surface, directing the first polarized light in a first direction, reflecting the second polarized light by a reflecting surface and directing it in the first direction, and varying the polarized state of at least one of the first and second polarized lights to thereby make the polarized states of the first and second polarized lights coincident with each other, characterized in that the polarizing dividing surface is disposed on one surface of a plane parallel plate and the reflecting surface is disposed on the other surface of the plane parallel plate, and the light enters obliquely from the one surface or the other surface. The specification also discloses a polarizing conversion unit provided with such polarizing element, and a projector provided with such polarizing conversion unit.

Abstract: A light pipe based projection engine includes a X-prism transmitting substantially light of a useful polarization in an output direction and reflecting substantially light of a non-useful polarization in a first orthogonal direction substantially orthogonal to the output direction. An initial reflector may reflect the non-said low, said medium, and said high bands of wavelengths in a second orthogonal direction substantially orthogonal to the output direction and the first orthogonal direction, and a final reflector may reflect the non-said low, said medium, and said high bands of wavelengths in the output direction. The non-said low, said medium, and said high bands of wavelengths may be rotated substantially to light of the useful polarization by the initial and final reflectors.

Abstract: A beam combiner includes a first beam-input face, a beam-output face, and first and second reflectors. The first beam-input face receives first and second beams of electromagnetic energy respectively having a first and second wavelengths. The first reflector reflects the first received beam toward the beam-output face, and the second reflector passes the first beam from the first reflector and reflects the received second beam toward the beam-output face. In one alternative, the first beam-input face also receives a third beam of electromagnetic energy having a third wavelength, the beam combiner includes a third reflector that reflects the received third beam toward the beam-output face, and the first and second reflectors pass the third beam from the third reflector. In another alternative, the beam combiner includes a second beam-input face that receives a third beam directed toward the beam-output face, and the first and second reflectors pass the third beam.

Abstract: A projector has at least first and second micro-displays and at least first and second cross total internal reflection prisms respectively optically coupled to the at least first and second micro-displays. Each of the at least first and second cross total internal reflection prisms has first and second total internal reflection interfaces. A combiner is optically coupled to the at least first and second cross total internal reflection prisms.

Abstract: On a transparent substrate (1), a first alternating periodic layer (5) including low-refractive-index layers (2) and high-refractive-index layers (3), a second alternating periodic layer (6) including the low-refractive-index layers (2) or the high-refractive-index layers (3) and intermediate-refractive-index layers (4), and a third alternating periodic layer (7) including the low-refractive-index layers (2) and the high-refractive-index layers (3) are provided in this order. The refractive index of the intermediate-refractive-index layers (4) is higher than that of the low-refractive-index layers (2) and lower than that of the high-refractive-index layers (3). Furthermore, the intermediate-refractive-index layers (4) contain materials for the low-refractive-index layers (2) and the high-refractive-index layers (3).

Abstract: A light separator splits polychromatic light into longer and shorter wavelength spectral bands. The light separator is defined between opposing side surfaces that are reflective to incident light and further has an input side for accepting the polychromatic light and an output side for providing the separated spectral bands. A first light guiding channel narrows as it extends from the input to the output side and lies between a first dichroic surface for reflecting longer wavelengths and transmitting shorter wavelengths and a first outer surface reflective to incident light. A second light guiding channel narrows as it extends from the input to the output side and lies between a second dichroic surface for reflecting shorter wavelengths and transmitting longer wavelengths and a second outer surface reflective to incident light. A portion of the light separator is common to both first and second light guiding channels.

Abstract: The present invention relates to a color separating-combining optical system of a configuration having a separating optical system which separates light from a light source into a plurality of color spectrums; a combining optical system which combines light spectrums from a plurality of image display elements illuminated by the respective color spectrums; a filter which transmits a color spectrum of a specific wavelength band out of the plurality of color spectrums separated by the separating optical system; and a plurality of polarizing elements each disposed on the light entrance side of the plurality of image display elements, the polarizing elements being adapted to analyze the corresponding color spectrums incident to the respective image display elements. The color separating-combining optical system is further characterized in that the filter is placed apart from the polarizing element corresponding to the color spectrum transmitted by the filter.

Abstract: Beam splitter designs for interferometers provide a phase difference between the two resulting interference beams that are independent of the polarization status of the incident beam. The polarization independent phase coating is achieved by making the internal beam splitting coating of an unpolarized beam splitter to be symmetrical. A symmetrical coating will produce the phase matching condition, ?SR??SR?=?PR??PR?=0.

Abstract: A white beam with high color-rendering index is formed by uniting a collimated red beam and a collimated blue-green beam, the latter having as its source a blue LED with a green phosphor. The white beam is formed by a prism with an amber low-pass dichroic filter. The prism cross-section can be either a square or an equilateral triangle. The triangular prism can have one third of its mass reduced by stepped facets. Both types of prism can be elongated to accommodate multiple collimators. Switching between white, red, and blue-green allows application to police vehicles.

Abstract: An image projector is supported by a vehicle to project a two-dimensional image on a projection surface, such as a portion of a windshield, an instrument panel, or a seat back, within the vehicle, for viewing by an occupant of the vehicle.

Abstract: Two set of filter chips on the upper and lower surfaces, each of which has a wavelength characteristic corresponding to each wavelength component of wavelength-multiplexed light, are mounted on a transparent substrate to make an optical filter element. When the wavelength-multiplexed light is inputted to the optical filter element via an optical fiber and when the same light components as those having the wavelengths demultiplexed by an optical fiber is also inputted, the demultiplexed light and the replaced wavelength-multiplexed light will be obtained at another optical fibers, respectively.

Abstract: An optical system and method comprising acquiring radiation in a plurality of spectral bands, each acquired by a discrete collector, receiving the acquired radiation in one or more of the spectral bands with one or more afocal zoom optics, each receiving radiation from a different collector, and aligning each point of fields of view of the collectors to a fraction of a pixel.

Abstract: A high-efficiency, compact color illuminating system and a projection type image display apparatus using the color illuminating system are provided. The color illuminating system includes a light source, a spiral lens disc that periodically scrolls light by rotational movement, and an optical unit that isolates light beams of different wavelengths from white light emitted from the light source and guides the isolated light beams to enter at least two effective regions of the spiral lens disc. The projection type image display apparatus includes the color illuminating system, an image forming unit that generates images using scrolling light from the spiral lens disc, and a projection lens unit that enlarges and projects the images formed by the image forming unit on a screen.

Abstract: A method for transmitting light in an image display system includes generating a beam of light from a light source. The beam of light is directed at a first segment of an electronically-switchable filter. A first portion of the beam of light is accepted by the first segment of the electronically-switchable filter, and a second portion of the beam of light is rejected by the first segment of the electronically-switchable filter. The first portion of the light beam is modulated to produce at least a portion of a displayed image. The second portion of the light beam is recycled to redirect the second portion of the light beam at a second segment of the electronically-switchable filter. The second portion of the light beam is accepted by the second segment of the electronically-switchable filter. The second portion of the light beam is modulated to produce at least a portion of the displayed image.

Abstract: Device for combining a scene image, produced by an imaging system, with an induced image, the imaging system including an eyepiece optics and at least a display screen producing the scene image, the eyepiece optics being located between the display screen and the eye of the observer, the device including an optical director projecting the induced image toward a diffusive surface, the diffusive surface being located between the display screen and the eyepiece optics, wherein the diffusive surface reflects the induced image back, toward the observer, through the eyepiece optics, and wherein the diffusive surface transmits the scene image from the display screen toward the observer, through the eyepiece optics.

Abstract: A color scrolling projection system is provided, including a light source, a color separator, a color scanner, a light valve, and a control circuit. The light source generates and emits light. The color separator separates incident light according to color. The color scanner includes a scrolling unit and a driving source for rotating the scrolling unit. The scrolling unit includes at least one lens cell and converts the rotation of the scrolling unit into the rectilinear motion of a lens array of the scrolling unit through which light passes. The light valve processes color bars according to an input image signal and forms a color image. The control circuit synchronizes the scrolling of the color with the electrical scanning of the light valve according to an image signal. The color bars are scrolled on the light valve due to a rotation of the scrolling unit.

Abstract: The invention is directed to downsized projector optics and projector both of which employ an LED light source attaining the enhanced efficiency of the quantity of the emitted light. The projector optics and the projector respectively include, in position, a polygon-based conical polyhedron prism of which reflection surfaces are opposed to the LED light source; a light tunnel, a PS converting element, a polarized beam splitter and a LCOS all of which are provided in the optical axis of the reflected light from the polygon-based conical polyhedron prism; and a projection lens placed in the optical axis of the transmitted light from the polarized beam splitter.

Abstract: A head up display system for a vehicle that includes a compact image source for projecting an image. The compact image source may be foldable up toward or into a cockpit ceiling of the vehicle, be positioned within a dashboard of the vehicle, or located at another suitable position. A combiner reflects the projected image with optical power toward an observer for observation. The combiner is positioned so that the observer, in a line of sight, may see a visual exterior view of an outside scene through the combiner and the projected image in the combiner. In a preferred embodiment, the image source includes an illumination system that includes a high power light emitting diode (LED) array assembly. A Fresnel lens array is operatively associated with the LED array assembly for receiving light produced by the LED and providing a nearly collimated light output. A spatial light modulator receives the nearly collimated light output.

Abstract: A multiband wavelength multiplexed optical device for bidirectional communication over one light path. The device may use dichroic filters or reflectors, or other mechanisms for wavelength or bandwidth separation or discrimination of sent or received light signals. It may have a multitude of light sources and detectors for sending and receiving light signals such as those for optical-based communications, controls and so forth. For instance, the optical device may be utilized in transceiver systems.

Abstract: Multi-directional optical elements are disclosed that include a body having a first side having a first curvature, a second side having a second curvature, a third side having a third curvature, and a fourth side having a fourth curvature. The second side is disposed generally opposite the first side along a first direction and a fourth side is disposed generally opposite the third side along a second direction, the second direction being different from the first direction. Also disclosed are optical systems utilizing such multi-directional optical elements.

Abstract: A solid-state imaging apparatus allowing miniaturization in a structure having a lens provided between a substrate and a color filter layer is provided. This solid-state imaging apparatus comprises a photodetection part formed on the substrate, the color filter layer formed on the substrate and the lens formed between the substrate and the color filter layer for concentrating light on the photodetection part. The lens has an upwardly projecting upper surface portion, while the upper end of the upper surface portion substantially comes into contact with the lower surface of the color filter layer.

Abstract: The invention relates to a device for holding a beam splitter element having an optically active beam splitter layer in an optical imaging device, the beam splitter element being connected to at least one support element that is fastened in the housing of the imaging device. The connection between the beam splitter element and said at least one support element is designed in such a way that the position of the beam splitter layer of the beam splitter element remains nearly constant relative to the housing independently of temperatures and of thermal stresses acting upon the beam splitter element.

Abstract: The wavelength division multiplexer includes a single optical substrate or a plurality of optical substrates integrated together, on which the first optical filter and the second optical filter are placed. The center wavelengths of three wavelength bands, ?1, ?2, and ?3, satisfy: 0.92??2/?1?1.08, and 0.20??3/?1?0.92 or 1.08??3/?1?5.00. The first optical filter combines or separates light of ?3 and two-wavelength multiplexed light of ?1 and ?2. The second optical filter combines or separates light of ?1 and light of ?2.

Abstract: A new heat sink apparatus and method that simplify the assembly of the heat sink and thermal stud. The new heat sink assembly uses a spring retainer that, in most cases, can use existing socket mounting screws. A spring clip (202) presses a thermal stud (204) against the back of an electrical device package (206). The present invention is especially useful for attaching a spatial light modulator to a printed circuit board (106) since it provides a simple, reliable heat sink without blocking the light path to and from the device. The preceding abstract is submitted with the understanding that it only will be used to assist in determining, from a cursory inspection, the nature and gist of the technical disclosure as described in 37 C.F.R. § 1.72(b). In no case should this abstract be used for interpreting the scope of any patent claims.

Abstract: A projection type display apparatus includes a color separation optical system separating light emitted from a light source into first, second and third color light; reflection type light valves provided each in correspondence to one of the first through third color light; polarization beam splitters provided each in correspondence to one of the first through third color light, which executes polarization separation causing the first through third color light to enter the reflection type light valves, and analyzing light exiting from the reflection type light valves after being modulated; a color composition optical system having a first, a second and a third prism, wherein the analyzed first through third color light undergo color composition; and a projection lens projecting the resulting light from the color composition, and lengths of optical paths wherein each of the first through third color light travels are equal to one another.

Abstract: A compact and efficient optical illumination system featuring planar multi-layered LED light source arrays concentrating their polarized or un-polarized output within a limited angular range. The optical system manipulates light emitted by a planar light emitters such as electrically-interconnected LED chips. Each light emitting region in the array is surrounded by reflecting sidewalls whose output is processed by elevated prismatic films, polarization converting films, or both. The optical interaction between light emitters, reflecting sidewalls, and the elevated prismatic films create overlapping virtual images between emitting regions that contribute to the greater optical uniformity. Practical illumination applications of such uniform light source arrays include compact LCD or DMD video image projectors, as well as general lighting, automotive lighting, and LCD backlighting.

Abstract: A light source device which employs a plurality of light emitting diodes for emitting different colors of light, and a projection display which incorporates the light source device provide for a good white balance and a high light utilization efficiency in consideration of light emission efficiencies inherent to the respective color light emitting diodes. An illumination beam from each of light emission boards is converted to one type of polarized light respectively by associated polarized light forming means, and resulting polarized light beams are combined by a polarizing beam splitter to produce an illumination beam for illuminating a two-dimensional image device which may comprise a digital mirror device (DMD). The light emitting diodes in the respective colors are arranged on respective light emission boards in a predetermined ratio of distribution to optimize the white balance.

Abstract: A multi-function combat laser is described that uses single or multiple laser sources (laser diodes) in a configuration such that when it is coupled with a dichroic substrate the laser sources outputs are coupled to produce a single desired output. The multi-function combat laser consolidates multiple laser functions for the dismounted soldier into a single package with shared power supplies, optics and laser sources.

Abstract: A sequential color display system using a white light source to create a full color image projected onto an image plane. A dynamic filter, typically a series of moving dichroic filters, generates a series of primary colored light beams that are swept across the surface of a spatial light modulator. Typically all three primary colors are produced simultaneously by the dynamic filter. The illuminated portion of the dynamic filter is imaged onto the modulator and controller provides appropriate image data for each portion of the modulator in synchronization with the sweep of the primary color bands across the modulator surface. The primary color bands are modulated by the spatial light modulator and the modulated light is focused by lens onto the image plane. The viewer integrates the light arriving at each portion of the image plane over a frame period to provide the perception of a full-color image.

Abstract: Disclosed is a compact, light, inexpensive reflection type liquid crystal projector optical unit or reflection type liquid crystal projector which provides high brightness without contrast deterioration caused by light leakage associated with black image display. The unit or projector uses, as a polarizer/analyzer for a reflection liquid crystal panel, a reflection polarizing plate which functions as a polarizing plate by its grating function only in a specific direction. It also uses an auxiliary polarizer and an absorption auxiliary analyzer. Their reflection axis or absorption axis is adjusted according to the characteristic of the reflection liquid crystal panel so as to minimize light leakage associated with black image display.

Abstract: Two polarization conversion element arrays are disclosed. Each polarization conversion element array is composed of a plurality of polarization conversion elements for converting light incident upon the polarization conversion element array to a linearly polarized light beam with a predetermined polarization direction. The plurality of polarization conversion elements are disposed opposite to each other with a predetermined space provided between at about the center of the light-outgoing surface of a lens array in the direction of arrangement. Of the light beams (s-polarized+p-polarized light beams) gathered by the lens array, light beam that is not incident upon the polarization conversion element and passes through the predetermined space is a light beam including a predetermined polarized light beam (s-polarized light beam) that is primarily made to leave the array 320a and an ineffective polarized light beam (p-polarized light beam).