Abstract: An optical switching element, comprising a light transmitting element, a reflection substrate, and index variable material. The light transmitting element has a first light incident surface, a second light incident surface not parallel to the first light incident surface, and a light outgoing surface. The reflection substrate is arranged opposite to the second light incident surface and has a reflection surface with an angle that is not parallel to the second light incident surface, wherein a reflected light passes through the light transmitting element and the reflection substrate and then is reflected by the reflection surface. The index variable material is sandwiched between the light transmitting element and the reflection substrate and has an index of refraction varied according to an external signal.

Abstract: The invention relates to a projection display device comprising a illumination system having a light source and an optical bar for providing an illumination beam, an image display system comprising a display panel for modulating the illumination beam with image information and projecting the image on a screen, and a color filter provided on a wheel, rotatably mounted at its hub, for transmitting colored portions of the illumination beam for illuminating the display panel. In order to improve the efficiency of the projection display device, the color filter comprises adjacent spiral-shaped filter portions for simultaneously illuminating portions of the display panel by the colored portions of the illumination beam so that the portions of the display panel are consecutively illuminated by the colored portions of the illumination beam.

Abstract: A head mounted display may include a single liquid crystal display element. The display element may successively generate left and right image pairs. A beam slitter may be utilized to successively provide a first image to the left eye and a subsequent image to the right eye and so on so that a stereoscopic image may be produced from a single display element. As a result, the power consumption, cost, size and weight of the head mounted display may be reduced in some embodiments.

Abstract: A light engine for a single panel scrolling color projection display system employs a light guide to guide light from a source through unequal path lengths to an output lens. The light guide is characterized by little or no light loss or increase in etendue (angular extent) regardless of path length, resulting in a compact arrangement having high performance and low cost.

Abstract: A display device (1) comprising a light modulation panel (2), a first polarization layer (5), a first ¼&lgr; layer (6), a semi-transparent reflective layer (7), a lens (8), a second ¼&lgr; layer (11) and a second polarization layer (12). The first ¼&lgr; layer (6) is situated between the first polarization layer (5) and the semi-transparent reflective layer (7). The second polarization layer (12) is a reflective polarization layer. The display device may include a hologram.

Abstract: A chemical mixture of liquid crystal and a substance that lowers the clear/opaque transition temperature of the liquid crystal, thins the liquid crystal, and makes the liquid crystal more sensitive to heat generated in the lower layers of an integrated circuit chip during IC hot spot testing. The substance can be a solvent or a diluent comprising a ketone or an alcohol.

Abstract: An apparatus that includes a first panel that receives image information for a first color, a second panel that receives image information for a second color and a third color, a temporal modulator and polarizing unit that receives light that includes a first color light, a second color light, and a third color light, and passes either said first color light and said second color light or said first color light and said third color light, and a single beamsplitting and combining device for directing said first color light to said first panel and said second or third color light to said second panel.

Abstract: The present invention provides a display apparatus which can prevent the unevenness of the quantity of light in case of display giving priority to color reproducibility and can also correct the unevenness of the up rate to the brightness in display attaching importance to color reproducibility in case of display giving priority to brightness. In the display apparatus, light from a light source 1 is separated into three colors R, G and B by dichroic mirrors DM1, DM2, and liquid crystal display elements 8R, 8G and 8B corresponding to the color-separated three colors are illuminated with these lights, and the three color lights are modulated by these display elements to thereby form a color image, and the dichroic mirrors DM1 and DM2 include a dichroic mirror DM1 subjected to inclination correction movable in its inclined direction.

Abstract: The present invention provides a liquid crystal display device, which includes a liquid crystal panel as one of optical components for transmitting, absorbing or reflecting light. At least any one of the optical components is comprised of a sapphire substrate. The optical components further include a lens, and a polarizer having a polarizer film and a retaining plate for retaining the polarizer film, and the liquid crystal panel may include a transparent substrate. In this case, any one of the lens, the retaining plate and transparent substrates is comprised of a sapphire substrate, and thus, it is possible to provide a transmission type liquid crystal display device which transmits light from the light source through the lens, the polarizer and the liquid crystal panel so that light is projected.

Abstract: In a projection apparatus, an optical integrator is illuminated with light from a light source, one or more image display elements is irradiated with a plurality of beams from the integrator, and image light from the image display element or elements is projected by a projection optical system. The illuminating range of some of the plurality of beams is made smaller than the illuminating range of the other beams.

Abstract: A projection display system includes a light source, wavelength-selective retarder device, first and second reflective light valves (LVs), a polarizing beam splitter (PBS), and a wavelength-selective filtering device. The wavelength-selective retarder device receives a uniformly polarized light from the light source and produces a first dark-state light having a first polarization state at a first set of wavelengths and a second dark-state light having a second polarization state at a second set of wavelengths. The first LV receives the first dark-state light and produces a first bright-state light by rotating the polarization from the first polarization state to the second polarization state. The second LV receives the second dark-state light and produces a second bright-state light by rotating the polarization from the second polarization state to the first polarization state.

Abstract: In an illuminating device in which a light from a light source is separated into three color lights differing in optical path from one another by a color separating system, and light modulating elements conforming to the respective color lights are illuminated with the color lights, at least one of the optical paths of the three color lights has therein a reflecting system having positive power for reflecting the color light passing therethrough.

Abstract: A projection type liquid crystal display unit includes (a) a first frame (13) having a first surface (15) formed with a first opening (13a), (b) a second frame (12) having a second surface formed with a second opening (12a), and (c) a liquid crystal display panel (11) sandwiched between the first and second frames (13, 12) such that an incident light passes through the second opening (12a), the liquid crystal display panel (11) and the first opening (13a) in this order. The first and second frames (13, 12) are both composed of resin, and the first surface (15) of the first frame (13) is roughened.

Abstract: The invention accurately sets a polarization direction of a polarization element, and prevents deterioration of the usage efficiency of the light and a reduction in image contrast. Field lenses are provided on a projection display device. A polarizer is placed on a flat surface of a field lens. The flat surface of the field lens is provided with a reference shape to place the polarizer at the end thereof. The reference shape may be one or more planes provided on the end of the field lens. In addition, the reference shape may be a straight line drawn on the flat surface of the field lens.

Abstract: A projection-type image displaying device includes liquid crystal elements for modulating light rays having wavelength regions different from each other, a color combining optical element for combining the light rays modulated by the liquid crystal display elements, and a projection type optical system for projecting light rays combined by the color combining optical element to display an image. Polarizing elements are disposed on an incidence side and an exit side of the liquid crystal display elements. Optically anisotropic elements for correcting the optical anisotropy of each of the liquid crystal elements are disposed between the polarizing elements. An air-reduced distance Linp between an entrance pupil of the projection optical system and display surfaces of the liquid crystal display element and diagonal length Ldisp across corners of the display surface of the liquid crystal display elements meet the predetermined condition.

Abstract: An apparatus is disclosed comprising a lamp which produces a first light which may be a white light; a first light valve, a second light valve, a first color separator, and a first aperture device. The first color separator receives the white light from the lamp, and separates the white light into a first color light and a first residual light. The first aperture device receives the first color light and the first aperture device can be controlled to modify a frequency of the first color light to the first light valve. The second light valve receives at least a portion of the first residual light. The first aperture device could also be controlled to substantially block at least a portion of the first color light.

Abstract: A display includes a light source and a filter positioned to receive light from the light source. An electronically controlled mirror can direct light through the filter in a first mode of operation and not through the filter in a second mode of operation. The display can be utilized in an avionics display system with night vision equipment. The electronically controlled mirror can be a reversible electrochemical mirror (REM).

Abstract: Active matrix domains are integrated and disposed on one and the same substrate. Then, directions of orientation are differentiated by 90° for one active matrix domain and the other active matrix domain. As a result, two images whose polarizing directions differ by 90° are formed when images formed in the two active matrix domains are combined. Then, one image is appropriated as an image for right eye and the other image as an image for left eye and the combined image is seen by wearing glasses equipped with polarizing filters whose polarizing directions are different by 90° for the right and left eyes. Then, the image for the right eye and that for the left eye may be seen independently and a stereoscopic image may be obtained.

Abstract: In a projection display apparatus, light from a light source is separated into a plurality of beams having different wavelength regions, a plurality of image display elements (123r, 123g, 123b) are inserted in the optical paths of the respective separated beams so as to be illuminated by the beams. A color combiner (XDP) is provided for combining the beams emerging from the plurality of image display elements. The beams combined by the color combiner are projected on a projection surface. A diffraction optical element (124) is inserted in at least one of a plurality of optical paths between the plurality of image display elements and the color combiner.

Abstract: An apparatus is disclosed comprising a lamp which produces a first light which may be a white light; a first light valve, a second light valve, and a first aperture device, which may be a first electronically switchable filter. The first aperture device or the first electronically switchable filter function as selectively variable color separators. The first aperture device or the first electronically switchable filter each can be placed in a first state where the first light is separated into a first color light and a first residual light, and a second state where the first light is separated into a second color light and a second residual light. The first light valve receives the first light in the first state and the second light in the second state. The second light valve receives at least a portion of the first residual light in the first state or at least a portion of the second residual light in the second state.

Abstract: Provided are a color display driving principle obtained while taking into account a difference in eye sensitivity to the flickering of differently colored lights, a TFT liquid crystal display module structure that is adequate for this method, and a double-panel projection type display device. The count of the G (green) color data that can be written is increased compared with the count for the other primary colors, or the display period for green can be extended. The repetitive unit is set to R, G, B and G, so that a satisfactory refresh rate can be set for the important color G. Therefore, the overall refresh frequency and the power consumed by the display device can be reduced without deterioration of the display quality, and requests for the time response speeds by the display device can be reduced.

Abstract: An optical modulation device which can facilitate a reduction in size of a device and prevent overheating of the optical modulation device, and a projection display device utilizing the optical modulation device are provided. In the optical modulation device, sapphire glasses are affixed to the light-incident side and the light-emitting side surfaces of liquid crystal panels which respectively modulates light of three colors of red, green, and blue emitted from a light source according to image information. Therefore, heat generated on optical modulation devices can be discharged, so that overheating of the optical modulation devices can be prevented, and a reduction in size can be achieved. In addition, since the sapphire glass is difficult to scratch, it becomes easy-to-handle, thereby facilitating the management of the optical modulation devices.

Abstract: The optical system comprises three reflection liquid crystal panels, polarization spliters PBS-R, PBS-G PBS-B which polarize components of an incident light to be reflected by the respective reflection liquid crystal panels, color separation and composition elements. The polarization splitters further separate the polarization converted output light in either an outputting direction or a non-outputting direction corresponding to the polarization, and the color separation and composition elements are arranged as separate elements in terms of optical path and in such a manner that these elements are disposed adjacent to each other in terms of space.

Abstract: A display optical system has an illumination optical system for emitting illumination light, a plurality of reflection-type display devices, a projection optical system, and a plane-parallel mirror. The reflection-type display devices individually modulate the illumination light emitted from the illumination optical system and reflect the illumination light thus modulated as projection light. The projection optical system projects the projection light and has at least one optical element included therein arranged so as to be decentered with respect to the other optical elements included therein.

Abstract: To suppress light loss without deteriorating resolution of a projected image, light is first polarized and separated by a polarizing beam splitter. Green light is separated from a light flux emitted by the polarizing beam splitter by a dichroic mirror having a green light reflection property. A light flux containing blue and red light, which is transmitted by the dichroic mirror, is separated into red light and blue light by a dichroic prism. Resultant color light is modulated and reflected by reflection light valves, returned to the corresponding dichroic mirror or dichroic prism, and combined by the dichroic mirror and the dichroic prism. Resultant combined color light is projected via the polarizing beam splitter and a projection lens. The dichroic prism transmits s-polarized light having wavelengths less than a wavelength substantially within a wavelength band of green light and reflects s-polarized light having larger wavelengths.

Abstract: A color, high-throughput, ferroelectric liquid crystal-based light valve comprising a light input, a light output, a beam splitter, a color separator, reflective spatial light modulators, and a switchable half-wave plate. Light polarized parallel to a first direction is received through the light input. Light from the light input and reflected by the spatial light modulators is output from the light output. The reflective spatial light modulators are structured as a quarter-wave plates and each has a principal axis that switches through an angle &phgr;. The beam splitter has orthogonal directions of maximum transmissivity and maximum reflectivity, one of which is parallel to the first direction.

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: Optical systems for use with reflective LCDs (8,9,32,34,36) are provided. The systems include a polarization beam splitter (5) which can be composed of polarization beam splitting cubes (26) having sheet polarizers (30) and/or half wave plates (28) at their mating surfaces. By orienting the half wave plates (28) so that they convert S polarization to P polarization and P polarization to S polarization, the polarization beam splitter (5) can provide a high contrast ratio at a viewing screen between light from the “on” and “off” pixels of the reflective LCDs (8,9,32,34,36).

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: To reduce inconsistencies in an image to be displayed in a projector. At least one of a polarizer on the side of a light incident surface and a polarizer on the side of a light emitting surface is bonded on a sapphire glass plate. The sapphire glass plate may preferably be formed of single-crystal sapphire. In addition, the sapphire glass plate may preferably be held by a holding frame made of metal. The sapphire glass plate and the holding frame made of metal may preferably be bonded by an adhesive agent having superior heat conductivity.

Abstract: A reflective projector includes a light source, reflective liquid crystal panels, a dichroic prism for separating a light beam from the light source into light beams of predetermined colors by using interference and for synthesizing the light beams of predetermined colors into a light beam, and a projection lens. The reflective projector further includes a first polarizer provided between the light source and the reflective liquid crystal panels and a second polarizer provided between the reflective liquid crystal panels and the projection lens.

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: It is an object of the invention to provide a liquid crystal display apparatus capable of reducing the difference in temperature rise between liquid crystal panels and polarizers for respective colors, suppressing a temperature rise, and reducing noise caused by a fan. The liquid crystal display apparatus includes a hermetic container, and liquid crystal display sections for respective colors, namely, red, green and blue, each including a liquid crystal panel and polarizers. A cooling fan for blue sends cooling air to the liquid crystal display section for blue. A cooling fan for green and red sends cooling air to the liquid crystal display sections for green and red.

Abstract: The projection type display apparatus according to the present invention has a prism for separating incident light into a plurality of light components and combining the plurality of modulated color components. The prism is constituted by a plurality of prism assemblies, each including an optical member made of an optically transparent material having a photoelastic constant whose absolute value is not greater than +1.5×10−8 cm2/N with respect to the incident light. More preferably, these plurality of prism assemblies are arranged such that each of a plurality of the separated color components is totally reflected by any of the prism assemblies.

Abstract: A small-size liquid crystal capable of exhibiting good color balance and light utilization efficiency is formed of a layer of liquid crystal, two-dimensionally arranged pixel electrodes disposed so as to apply voltages to the liquid crystal and, together with the liquid crystal, form two-dimensionally arranged pixels each corresponding to one pixel electrode and designed to emit light of one of a plurality of colors, and an array of microlenses disposed to illuminate each pixel with a condensed light spot of illumination light of one of the plurality of colors. In the device, pixels of at least one of the plurality of colors are set to have a pixel size different from those of pixels of the other color(s).

Abstract: The invention provides a liquid crystal light valve that makes it possible to increase the life of a polarizer at a light-exiting-surface side of the liquid crystal light valve by reducing the burden thereon, and a projection display device that incorporates the liquid crystal light valve. In liquid crystal light valves that modulate incident light in accordance with image information, at least two corresponding polarizers are provided respectively at the light-exiting-surface sides of liquid crystal panels.

Abstract: A transmissive active matrix liquid crystal display device has a multievel optical phase element that sepaeates each color component of light into a plurality of diffraction orders. The multilevel optical phase element is aligned with a an active matrix array and directs light of different colors through different pixels of a liquid crystal material. The transmission of light through the liquid crystal material is controlled by an array of transistor circuits that actuate pixel electrodes.

Abstract: In an illumination optical system; a wavelength separating optical system; plural light modulation devices provided respectively so as to modulate the light in the plural wavelength regions according to a given image signal; a light synthesizing optical system for synthesizing the light modulated by the plural light modulation devices; a projection optical system for projecting the synthesized light emitted; and a reflecting mirror placed in the optical path. Light with a wavelength of approximately 425 nm is separated by the wavelength separating optical system and enters a corresponding light modulation device. The reflecting mirror has a reflectance of approximately 90% or more, for light in the wavelength region of approximately 435 nm or more, and a reflectance for light in the wavelength region of at least 425 nm±5 nm, that is lower than the reflectance for the light in the wavelength region of approximately 435 nm or more.

Abstract: An optical illumination system for a projection-type display unit is disclosed wherein multiple light sources are oriented so as to cause the optical axes of their emitted light beams to be non-parallel to one another and to overlap at a first lenticular lens array of an integrator section. The function of the integrator section is to make the light from the multiple light sources even, and to serve as a secondary light source in the projection-type display unit. The overlapping of the light beams on the first lenticular lens array of the integrator allows the optical illumination system to be more compact in three dimensions. It also allows the diameter of a polarization converter and a field lens to be made smaller. Thus, production costs are reduced without reducing the brightness of a projected image.

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: An optical modulation device which can facilitate a reduction in size of a device and prevent overheating of the optical modulation device, and a projection display device utilizing the optical modulation device are provided. In the optical modulation device, sapphire glasses are affixed to the light-incident side and the light-emitting side surfaces of liquid crystal panels which respectively modulates light of three colors of red, green, and blue emitted from a light source according to image information. Therefore, heat generated on optical modulation devices can be discharged, so that overheating of the optical modulation devices can be prevented, and a reduction in size can be achieved. In addition, since the sapphire glass is difficult to scratch, it becomes easy-to-handle, thereby facilitating the management of the optical modulation devices.

Abstract: An LCD projector of two-plate type is disclosed. The LCD projector comprises a light source, a color valve, a dichroic mirror, a polarization rotating device, a polarization beam splitter, a first reflective LCD panel, a second LCD panel and a projection lens. The first reflective LCD panel is used to modulate the green light with the green component of the image signal. The red light and the blue light are modulated in a time field sequential manner by the color valve and the second reflective LCD panel.

Abstract: A connection assembly (40) for operably coupling a plurality of independent imaging devices (41, 41′, 41″) to an optical subsystem (42). The connection assembly (40) includes a unitary flex circuit device (43) having an elongated arm portion (45), and a plurality independent finger portions (46, 46′, 46″) extending from a distal end of the arm portion (45). Each finger portion (46, 46′, 46″) defines a coupling region (47, 47′, 47″) adapted to operably couple a respective imaging device (41, 41′, 41″) to a respective finger portion (46, 46′, 46″) for support thereof. The finger portions (46, 46′, 46″) are further adapted to strategically couple each respective imaging device (41, 41′, 41″) to the optical subsystem (42) as a unit. The flex circuit device (30) includes a plurality of circuits (65) terminating at respective terminals (40) of a coupling region (47) thereof.

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: An optical modulation device which can facilitate a reduction in size of a device and prevent overheating of the optical modulation device, and a projection display device utilizing the optical modulation device are provided. In the optical modulation device, sapphire glasses are affixed to the light-incident side and the light-emitting side surfaces of liquid crystal panels which respectively modulates light of three colors of red, green, and blue emitted from a light source according to image information. Therefore, heat generated on optical modulation devices can be discharged, so that overheating of the optical modulation devices can be prevented, and a reduction in size can be achieved. In addition, since the sapphire glass is difficult to scratch, it becomes easy-to-handle, thereby facilitating the management of the optical modulation devices.

Abstract: A retardation film 30 and an upper polarized light separator 20 are provided on the upper side of a liquid crystal cell 10. A diffuser 40, a lower polarized light separator 50, a color filter 60, a PET film 70 and an Al deposited film 80 are provided on the lower side of the liquid crystal cell 10. As the upper polarized light separator 20 and the lower polarized light separator 50, a polarized light separator (reflective polarizer) is used, which reflects linearly-polarized light in one direction as linearly-polarized light in the one direction, and transmits linearly-polarized light in another direction perpendicular to the one direction as linearly-polarized light in the other direction. The light emitted from LED 120 is introduced into a light guide plate 130 between the upper polarized light separator 20 and the retardation film 30 through a light guide 110. Then the light is emitted from the lower side of the light guide plate 130 to the liquid crystal cell 10.

Abstract: The invention provides a projector capable of easily replacing and efficiently cooling a light source, and capable of facilitating a reduction in the size of the projector. An exhaust fan adjacent to a light source lamp is mounted to a replacement cover so as to be removed from the main body of the projector together with the replacement cover. For this reason, by only removing the replacement cover, the light source lamp can be easily attached and detached together with the replacement cover unit. In addition, since it is not necessary to separately secure a special space for sliding the replacement cover unit, other components except the exhaust fan can be disposed closely to the periphery of the unit, and the size of the projector can be further reduced. Furthermore, when the replacement cover is closed, the exhaust fan is positioned closer to the replacement cover unit, so that a light source device in the unit can be efficiently cooled.

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: 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: A red-reflecting film and a blue-reflecting film are formed in a substantially X shape on joint surfaces defined by the respective side faces of four columnar prisms or right-angle prisms. The red-reflecting film is continuously formed without separating at an intersection of the two reflecting films. The blue-reflecting film is, on the other hand, divided into two pieces by the red-reflecting film and an adhesive. It is preferable that that four columnar prisms are obtained from one block of sheet glass. This arrangement ensures an improvement in properties of a resulting light-selective prism.