Abstract: An illumination optical unit and a display apparatus having the same are provided. The display apparatus includes an illumination optical unit which generates and illuminates light; a display element which forms an image by the light illuminated from the illumination optical unit; and a projection optical unit which projects the image formed in the display element on a screen. The illumination optical unit includes a light source which includes a light emitting area, and a polarization converting unit which includes a plurality of polarization prisms which polarize and convert an entering light from the light source. The light source is disposed so that a long width of the light emitting area corresponds to a long width of the polarization prisms.

Abstract: Optical system for a projector, comprising: at least a first polarizing beam splitter for splitting a source illumination beam into a first illumination beam linearly polarized along a first direction and a second illumination beam polarized perpendicular to the first direction; at least one color wheel intersecting the polarized illumination beams in two different regions and producing a first color beam linearly polarized along the first direction and a perpendicularly polarized second color beam; and two imagers illuminated by the first and second polarized color beams respectively.

Abstract: An illumination apparatus includes: a polarization conversion element configured to align polarization directions of light emitted from a light source in one polarization direction; a color separation unit configured to separate the light whose polarization directions are aligned in the one polarization direction by the polarization conversion element; and a polarization adjustment element configured to adjust a polarization state of light in a predetermined wavelength band within a wavelength range of the light emitted from the light source. The polarization adjustment element is provided between the polarization conversion element and the color separation unit on an optical path of the light emitted from the light source.

Abstract: A multiple path stereoscopic projection system is disclosed. The system comprises a polarizing splitting element configured to receive image light energy and split the image light energy received into a primary path and a secondary path, a reflector in the secondary path, and a polarization modulator or polarization modulator arrangement positioned in the primary path and configured to modulate the primary path of light energy. A polarization modulator may be included within the secondary path, a retarder may be used, and optional devices that may be successfully employed in the system include elements to substantially optically superimpose light energy transmission between paths and cleanup polarizers. The projection system can enhance the brightness of stereoscopic images perceived by a viewer. Static polarizer dual projection implementations free of polarization modulators are also provided.

Abstract: An illumination source includes a number of light emitting diodes (LEDs) operating at a first wavelength. Light from the LEDs illuminates a phosphor material that generates light at a second wavelength. A reflective polarizer transmits light at the second wavelength in a first polarization state and reflects light at the second wavelength in a second polarization state orthogonal to the first polarization state. The light at the second wavelength reflected by the reflective polarizer is directed back towards the phosphor material without an increase in angular range. In some embodiments the LEDs, having a conformal layer of phosphor material, are attached directly to the first surface of a liquid cooled plate. A liquid coolant contacts a second surface of the plate.

Abstract: A display system includes a projection screen and a projector. The projection screen includes a retarder plate between a polarizer and a transparent screen. The projector projects an image through the polarizer and the retarder plate onto the transparent screen. The image is visible from a first side of the transparent screen but invisible from a second side of the transparent screen because any light passing twice through the retarder plate is blocked by the polarizer.

Abstract: An illumination apparatus includes: a first dichroic mirror; a second dichroic mirror which separates the combined light into a red component light R and the green component light G; and a polarization adjuster provided on an optical path of the combined light between the dichroic mirrors. The polarization adjuster adjusts a polarization direction of a yellow component light Ye in the combined light. A second dichroic mirror separates the combined light into the red component light R on which a part of or all of the yellow component light Ye is superimposed and the green component light G on which the rest of the yellow component light Ye is superimposed.

Abstract: There is provided a multilayered phase difference plate that serves as a half-wavelength phase difference plate in the range of 400 nm to 700 nm by bonding together a first phase difference plate and a second phase difference plate in a manner that their respective optical axes intersect each other. The multilayered phase difference plate obtains a high incident light polarization conversion efficiency because the respective plate thicknesses of the first and second phase difference plates are within a range such that phase difference deviation amounts become offset by each other.

Abstract: An illuminating device includes a first light source unit emitting illumination beams with a first optical axis; a second light source unit; and two reflecting elements arranged on both sides of an optical path of the first light source unit. The reflecting element arranged on the side of the second light source unit reflects the illumination beams emitted from a substantially half region on one side in an aperture plane of the parabolic reflector of the second light source unit, towards the direction along the first optical axis. The reflecting element arranged opposite to the second light source unit reflects the illumination beams emitted from a substantially half region on the other side in the aperture plane of the parabolic reflector of the second light source unit, towards the direction along the first optical axis.

Abstract: Briefly, in accordance with one or more embodiments, beam position diversity or beam offset diversity in pupil space performs the complement to angular diversity by maintaining angular content of a beam while changing its position and/or polarization properties in pupil space over time.

Abstract: A projection optical system can achieve compactness and improve a state where polarized rays are separated by a polarized light separation section, without a separate optical system which makes the whole system telecentric, by using a reflective light valve. The projection optical system includes, in order, the reflective light valve, a projection lens and the polarized light separation section. The reflective light valve modulates incident illumination light in response to an input image signal and reflects and emits the modulated light. The projection lens transmits the illumination light incident to the reflective light valve and the modulated light emitted from the reflective light valve and is formed to be telecentric on the reduction side. The polarized light separation section separates the optical path of the illumination light incident to the projection lens from the optical path of the modulated light emitted from the projection lens.

Abstract: A wide color gamut projector having a plurality of dichroic prisms configured to split a light beam into six primary color components and direct each of the six primary color components to separate digital micromirror devices is disclosed. The projector further comprises a translucent rotatable drum having different polarization sections, wherein the light beam is capable of being passed orthogonally through a wall of the drum.

Abstract: A display apparatus (10) has at least one color channel providing a modulated light for each of a plurality of image frames (92). One or more laser sources that provide an illumination beam having a first polarization transmission axis. An imaging modulator (854, 85g, 85b) in the path of the illumination beam is actuable to direct the modulated light toward a projection lens. A laser blanking apparatus in the path of the modulated light is disposed to block transient light between image frames and has at least one analyzer (66) having a second polarization transmission axis that is orthogonal to the first polarization transmission axis and at least one light polarization modulator that is synchronously timed to rotate polarization of transient light during an interval between frames.

Abstract: An illumination apparatus includes a plate-like separation optical element having a dichroic surface and a PBS surface. The dichroic surface reflects green component light and transmits yellow component light. The PBS surface transmits P polarization component light and reflects S polarization component light. The separation optical element combines red component light entering from a certain direction and transmitted through the dichroic surface, with yellow component light entering from a different direction and reflected by the PBS surface, and leads a combined light towards a red liquid crystal panel. The separation optical element combines green component light entering from the certain direction and reflected by the dichroic surface, with yellow component light entering from the different direction and transmitted through the PBS surface, and leads a combined light towards a green liquid crystal panel.

Abstract: A polarization converting element includes: a main body that is made from a transparent member; an incident section that is provided to the main body, and upon which light generated from a light source is incident; an annular reflecting section that is formed on the periphery of the incident section; and a polarization splitting section that is formed opposite to the annular reflecting section on the emission side of light incident upon the incident section. One polarized light component of the incident light passes through the main body and is emitted from the polarization splitting section. Another polarized light component of the incident light is reflected towards the annular reflecting section by the polarization splitting section, and is emitted from the polarization splitting section after having again been reflected by the annular reflecting section and having been converted into light of a same polarization component as the light of the one polarized light component.

Abstract: A light source device includes: a light source which emits light; a first reflector which surrounds a part of the light source and reflects the light emitted from the light source in the direction of an optical axis; and a second reflector which surrounds at least a part of the light source different from the part surrounded by the first reflector and reflects the light emitted from the light source toward the first reflector, wherein the position of a convergence spot of the light reflected by the second reflector is displaced from the position of an emission spot of the light source at least in the direction of a plane perpendicular to the direction of the optical axis.

Abstract: An integrated microdisplay projection and imaging system includes: a focus-adjustable lens system, a planar polarization beam splitter, a reflective polarization modulation imager and an imaging sensor with a post polarizer in orthogonal polarization orientation to the planar polarization beam splitter, as well as a lighting module. Placed on two separate sides of the planar polarization beam splitter, the reflective polarization modulation imager and the imaging sensor have substantially equal-length optical passes through the planar polarization beam splitter to the focus-adjustable lens system, and thus the focus-adjustable lens system provides a unified means for adjusting focus with both the reflective polarization modulation imager and the imaging sensor, relative to an external object such a projection screen or an imaging object.

Abstract: An illuminator includes a light source that outputs light, a polarization separation device that separates the light outputted from the light source into polarization components of the first and second oscillation directions, the polarization components having mutually orthogonal polarizations, and a polarization conversion device that converts the polarization component of the second oscillation direction divided by the polarization separation device to the polarization component of the first oscillation direction. The polarization component of the first oscillation direction divided by the polarization separation device and the polarization component of the first oscillation direction converted by the polarization conversion device are incident on an incident surface of an illumination target from different directions from each other.

Abstract: A projector includes: a solid-state light emitting element that emits light; a projection image forming unit that includes an effective area in order to form a projection image; and a reflecting member disposed between the solid-state light emitting element and the projection image forming unit, wherein: the reflecting member reflects part of the light emitted from the solid-state light emitting element and thus redirects the part of the light to travel back to the solid-state light emitting element, the part of the light not entering the effective area.

Abstract: A projector includes an integrator illumination optical system. The integrator illumination optical system includes: a first lens array having a plurality of first small lenses, a second lens having a plurality of second small lenses, and a polarization converter including: polarization separating layers. The second small lenses of the second lens array are each arranged with its convex surface oriented to the light-irradiation side. A light shield section is provided on a portion on an incident-side surface of the polarization converter, the portion excluding a light-incident surface corresponding to the polarization separating layers. An extending portion is formed on one of the second lens array and the polarization converter in a manner extending toward the other one of the second lens array and the polarization converter, the second lens array and the polarization converter bonded and fixed to each other by bonding and fixing the extending portion to the other one.

Abstract: A projector includes a light-source unit, a color wheel, and a connecting portion. The light-source unit with a first support structure is configured for providing light beams. The color wheel includes a color filter, a rotating portion, a motor and a second support structure. The color filter is rotatable together with the rotating portion driven by the motor, which is fixed on the second support structure. The connecting portion is configured for connecting the first and second support structures together and aligning the light-source unit with the color wheel.

Abstract: A color separation device includes a first color separation member having a first polarization direction changing element and a second polarization direction changing element, and a first polarization separation element, and a second color separation member having a second polarization separation element. Linearly polarized light may be made incident on the first color separation member so as to separate the light into reflected light and transmitted light, both lights having different colors and one of the different colors corresponding to one of three colors, and one of the lights may be made incident on the second color separation member so as to separate the one of the lights into further reflected light and further transmitted light, both further reflected light and further transmitted light corresponding to the other two of the three colors, respectively.

Abstract: A color light combining system comprises a polarizing beam splitter that includes a reflective polarizer film, a first prism face that receives a first unpolarized color light, a second prism face that receives a second unpolarized color light, and a third prism face that provides a first combined light output that includes combined first color light polarized in a first direction and second color light polarized in a second direction. The polarizing beam splitter includes a reflector at a fourth prism face. A color-selective stacked retardation polarization filter faces the third prism face. The first color selective stacked retardation polarization filter provides a second combined light output that includes the first and second color lights that are combined and have the same polarization direction.

Abstract: An imaging system (200), such as a scanned laser projection system, includes one or more laser sources (201) configured to produce one or more light beams (204), and a light modulator (203) configured to produce images (206) from the light beams (204). Optional optical alignment devices (220) can be used to orient the light beams (204) into a combined light beam (205). A birefringent wedge (221) is disposed between at least one of the laser sources (201) and the light modulator (203). The birefringent wedge (221) is configured to receive light from the laser sources (201) and deliver two angularly separated and orthogonally polarized light beams (223) to the light modulator (203) so as to reduce speckle appearing when the images (206) are displayed on a display surface (207). An optional glass wedge (1004) can be used to correct optical path deviation (1001) introduced by the birefringent wedge (221).

Abstract: An imaging system (200), such as a scanned laser projection system, includes one or more laser sources (201) configured to produce one or more light beams (204), and a light modulator (203) configured to produce images (206) from the light beams (204). A polarization diversity element (221), which can be manufactured from a birefringent material or from a polymerized liquid crystal layer, is disposed within the imaging system (200). The polarization diversity element (221) is configured to alter the polarization of an incident beam to create a transmitted beam comprising diverse polarization patterns, thereby reducing speckle in projected images.

Abstract: An illumination apparatus includes a red light valve, a green light valve, a blue light valve, a polarization adjustment element, and a color combiner. The polarization adjustment element adjusts polarization of fourth color component light. The color combiner combines light emitted from the red light valve, the green light valve and the blue light valve. Superimposed component light which is any one of a red component light, a green component light and a blue component light enters the polarization adjustment element together with a fourth color component light. The polarization adjustment element transmits the superimposed component light without adjusting the polarization, and transmits the fourth color component light with adjusting the polarization.

Abstract: The present invention provides a polarization beam splitter including a multilayer film formed by laminating a first layer having a refractive index in a first range, a second layer having a refractive index in a second range which does not overlap the first range, and a third layer having a refractive index in a third range which does not overlap the first or second range in the order of the first layer, the second layer, the first layer, and the third layer in succession, wherein the transmittance of s-polarized light is 60% or more higher than the transmittance of p-polarized light in a first wavelength region, the transmittance of p-polarized light is equal to or higher than 70% in a second wavelength region different from the first wavelength region, and each of the first wavelength region and the second wavelength region has a bandwidth equal to or larger than 30 nm.

Abstract: A display apparatus includes: a light modulation section having a plurality of translucent window sections; a light emitting section having a light source adapted to emit light; a light guide section having a tubular reflecting surface having a function of guiding the light from the light source to the light modulation section; and a light separation section provided to the light modulation section and disposed in a vicinity of the light source in parallel to or in substantially parallel to a lateral cross-sectional surface of the tubular reflecting surface, and having a light separation surface having a function of separating the light from the light guide section into transmitted light transmitted toward the light modulation section and reflected light reflected toward the light guide section, wherein the tubular reflecting surface narrows from the light modulation section toward the light emitting section so as to guide the reflected light to the translucent window sections, denoting a lateral cross-sectio

Abstract: Disclosed is an optical unit for an image display device, the unit including: one or a plurality of light sources; one or a plurality of optical elements that control a spread of light; a combining element that combines the beams of light emitted from the light sources; and a scanning element, wherein the light from each of the light sources generates an elliptical beam spot on a screen and the spot has a major axis substantially perpendicular to a scanning direction, the result is that the unit is simple in structure, inexpensive, compact, lightweight, and capable of providing high-resolution image quality, thus providing the display device reduced dimensionally and in weight. Such an image display device using the optical unit is also disclosed.

Abstract: A projector includes: a light source which emits light; a light modulating device which modulates the light emitted from the light source according to image information; an image forming system which forms an image corresponding to the optical image formed by the light modulating device of modulated light which is modulated by the light modulation device at an image forming position; a polarized light emitting unit disposed at the image forming position of the image forming system to selectively convert the polarization direction of a part of entering light; and a projecting device which projects the light from the polarized light emitting unit.

Abstract: Aspects of the present invention involve novel display screens comprising light diffusion and retro-reflectivity. In embodiments, a retro-reflective light diffusion screen can be used to generate a three-dimensional autostereoscopic display by generating a plurality of viewing windows wherein each viewing window depicts a unique perspective image view. In embodiments, the retro-reflective light diffusion screen comprises a transparent medium layer between the retro-reflector surface and the light diffuser layer to help reduce ghost images. In embodiments, the retro-reflective light diffusion screen comprises a lenticular layer positioned such that the light diffuser layer is between the lenticular layer and the retro-reflective surface and is also positioned so that the light diffuser layer is at a focal plane of the lenticular layer.

Abstract: A laminated half-wave plate includes: first and second wave plates having optical axes intersecting each other, wherein when phase differences of the first and second wave plates with respect to a wavelength ? are represented by ?1 and ?2, in-plane bearing angles formed by a polarization plane of a linearly-polarized beam incident on the laminated half-wave plate and the optical axes of the first and second wave plates are represented by ?1 and ?2, an angle formed by the polarization directions of the linearly-polarized beams incident on and emitted from the laminated half-wave plate is represented by ?, and an optical axis adjustment amount is represented by a, the following expressions are satisfied: ?1=180°+n×360°; ?2=180°+n×360° (where n in ?1 and ?2 is a non-negative integer); ?1=?/4+a; and ?2=3?/4?a.

Abstract: A single-imager micro projection engine includes a reflective polarization modulation imager, a projection lens system and a polarization conversion assembly integrating a light source with a planar polarization beam splitter and a reflective quarter wave composite plate in parallel. The polarization conversion assembly lets through first polarization portion of illumination light in first polarization state from the light source for illuminating a first half facing area on the reflective polarization modulation imager, while reflecting second portion in second polarization state perpendicular to first polarization state towards the reflective quarter wave composite plate. The reflective quarter wave composite plate reflects, while 90-degree polarization rotating from second polarization state to first, the received second portion back to the planar polarization beam splitter.

Abstract: An optical filter capable of removing an unnecessary component of incident light. The optical filter has a transparent body of a flat plate-like shape. A plurality of filtering layers, each that separate an unnecessary polarization component of incident light from a necessary polarization component, are formed within the transparent body in series and at uniform intervals with an angle inclination relative to the travel direction of incident light. A plurality of light-absorptive layers are formed within the transparent body in series and at uniform intervals between the filtering layers to absorb an unnecessary component reflected by the filtering layers.

Abstract: The present invention is directed to an illumination system. The illumination system comprises a plurality of modules such that each module comprises a plurality of light emitting diodes (LEDs) adapted to emit light. The illumination system further comprises a plurality of lens elements disposed subsequent to the LEDs. Further, a number of the lens elements corresponds to a number of LEDs; such that the plurality of lens elements is adapted to redirect the light emitted by the LEDs on a plurality lenses. The illumination system further comprises a plurality of imagers disposed subsequent to the plurality of lenses, such that each of the imagers forms an image from the light provided by each of the lenses, respectively. Further, the images formed by the plurality of imagers are combined by a device, such as an X-cube, to form a single image that is further provided to a light pipe of a display system.

Abstract: An optical element includes a mirror surface configured to transmit certain part of incident light and to reflect the other part of the incident light. The mirror surface has a first region and a second region. The first region includes a first polarization conversion layer configured to convert a polarization direction of incident light incident on the first region from one linear polarization into a different linear polarization. A region of the optical element from which light transmitted through the first region is emitted includes a second polarization conversion layer configured to convert a polarization direction of the light transmitted through the first region from the different linear polarization into the one linear polarization.

Abstract: An image display apparatus is provided with a laser light source, a spatial light modulation device for modulating the laser light emitted from the laser light source, a display surface for displaying the modulated light, an optical pixel aperture enlarging member for distributing the luminance of the laser light while introducing the laser light to apertures of pixels of the spatial light modulation device; and a display pixel aperture enlarging portion for optically enlarging the modulated light by the apertures of the pixels of the spatial light modulation device corresponding to pixels of an image to be displayed on the display surface.

Abstract: A liquid crystal projection system includes a light source module, a light management module, an image signal module and a projection lens. The light source module provides an illumination light beam of first polarization state. The light management module includes a color separator for separating the illumination light beam into a first color light beam and a bichromatic light beam, first and second reflectors for respectively reflecting the first color light beam and the bichromatic light beam, a phase plate for converting the polarization of the bichromatic light beam, a first PBS for receiving the first color light beam, a second PBS for receiving the bichromatic light beam, and a dichroic prism for separating the bichromatic light beam into second and third color light beams. The image signal module includes three image modulation units for transforming the polarizations of the first, second and third color light beams and modulating them into image light beams carrying corresponding image signals.

Abstract: A projector includes: a first optical device, and a first color combining optical device; a second optical device, and a second color combining optical device; a combining optical device adapted to combine emission light emitted respectively from the first optical device and the second optical device; a first polarization conversion device disposed between the first optical device and the combining optical device, and adapted to align a polarization direction of the emission light from the first optical device into a first polarization direction; and a second polarization conversion device disposed between the second optical device and the combining optical device, and adapted to align a polarization direction of the emission light from the second optical device into a second polarization direction.

Abstract: A polarization element includes: a substrate; a plurality of convex line sections disposed on one surface of the substrate so as to form substantial stripes in a plan view; and a multilayer thin line provided to each of the convex line sections and extending along an extending direction of the convex line sections, wherein the multilayer thin line has a lower layer thin line disposed on the convex line section, and an upper layer thin line stacked on the lower layer thin line, the lower layer thin line and the upper layer thin line each have a first thin line disposed on one side surface out of both side surfaces in a direction along a shorter dimension of the convex line section, and a second thin line disposed on the other side surface, materials of the first thin line belonging to the lower layer thin line and the first thin line belonging to the upper layer thin line are different from each other, and materials of the second thin line belonging to the lower layer thin line and the second thin line belongi

Abstract: A folded projection display system includes a wire-grid polarizer placed immediately behind the system's imaging screen. The display system includes an image projector that projects an image beam containing light of a predetermined linear polarization toward the imaging screen. The wire-grid polarizer reflects the light in the image beam away from the screen. The reflected image beam then encounters a ¼-wavelength achromatic retarder that converts the linear polarization to circular polarization. The image beam next hits a mirror that reflects the light back through the ¼-wavelength achromatic retarder, which converts the circular polarization back to linear polarization, with the polarization director rotated 90 degrees from the original polarization direction. The wire-grid polarizer then allows the light to pass through to the image screen.

Abstract: A virtual image display device is provided which displays a two-dimensional image for viewing a virtual image in a magnified form by a virtual optical system. The virtual image display device includes an optical waveguide (13) to guide, by internal total reflection, parallel pencil groups meeting a condition of internal total reflection, a first reflection volume hologram grating (14) to diffract and reflect the parallel pencil groups incident upon the optical waveguide from outside and traveling in different directions as they are so as to meet the condition of internal total reflection inside the optical waveguide and a second reflection volume hologram grating (15) to project the parallel pencil groups guided by internal total reflection inside the optical waveguide as they are from the optical waveguide by diffraction and reflection thereof so as to depart from the condition of internal total reflection inside the optical waveguide.

Abstract: A multipurpose projector 100 is provided with a fiber bundle 6 including a plurality of cores fixedly arranged on an input plane and an output plane, laser beam sources 1r, 1g and 1b for emitting laser beams having directivities, an optical guide unit 2 to 5 for modulating the laser beams emitted from the laser beam sources 1r, 1g and 1b and guiding the modulated laser beams to the input plane of the fiber bundle 6, a projection lens 8 for enlarging and projecting the laser beams emerging from the output plane of the fiber bundle 6 to a display space 12, and a projection angle adjusting mechanism 7 disposed on the side of the output plane of the fiber bundle 6 for adjusting projection angles of the laser beams projected from the projection lens 8. Thus, the projector can have its projection space freely operated and enlarged to extend its application not only to image display, but also to illumination and decoration with colored light.

Abstract: A GaN-based semiconductor laser (1) emits first laser light of a single polarization and having a first wavelength. An optical resonator (30) includes a solid-state laser medium which is excited by incidence of the laser light and which oscillates second laser light having a second wavelength different from the first wavelength. A polarization switch (6) switches over at least one of polarization directions of the first laser light and the second laser light to thereby change the wavelength of laser light to be emitted from the optical resonator (30) or the intensity ratio between a plurality of laser light to be emitted from the optical resonator (30). With the above arrangement, a plurality of laser light can be used effectively.

Abstract: A projection system includes a projector that emits imaging light, a polarization screen that selectively reflects, of the imaging light, only light in a specified state of polarization, and a reflecting element placed on an optical path between the projector and the polarization screen to reflect the imaging light. The projector emits imaging light containing circularly polarized light whose state of polarization varies according to the wave range of the light, and the first and the second reflective layers in the reflecting element have polarization characteristics and reflection wave ranges corresponding to the state of polarization and the wave range of the circularly polarized light contained in the imaging light in such a manner that the state of polarization of the circularly polarized light, after being reflected from the first and the second reflective layers, is uniform irrespective of the wave range of the light.

Abstract: A projector includes: an illuminating device including a light source device, a first lens array that comprises first regions located at four corners in the first lens array when viewed along a system optical axis and second regions located between the two first regions, and a second lens array; a light modulating device; a projection optical system; a light control device; and a mode selection device. The light control device blocks part of the plural partial light beams by causing first and second light shields to integrally operate, when the brightness priority mode is selected. The light control device always blocks part of the partial light beams with the first light shields and blocks part of the partial light beams by causing the second light shields to operate independently from the first light shields.

Abstract: An optical apparatus includes a frame, having optical components, mounted on a casing by means of an auxiliary member. The casing is provided with a groove in which the frame is inserted and a mount section to which a first part of the auxiliary member is fixed. The frame is provided with a frame-side positioning section engaged with a second part of the auxiliary member when the frame is inserted in the groove and then set at a predetermined angle of rotation. The auxiliary member is provided with the first part fixed to the mount section of the casing and the second part engaged with a frame-side positioning section. The first and the second part of the auxiliary member are formed in positions separate from each other while the second part is engaged with the frame-side positioning section under the elastic force of the auxiliary member.

Abstract: An optical system is provided. The optical system comprises a first polarizing beamsplitter (PBS), a first reflecting image-forming device, and a first quarter-wave retarding element. An optical system is also provided that comprises an image-forming device, a reflective polarizing layer, at least a first birefringent element disposed on an optical path between the image-forming device and the polarizing layer, and a quarter-wave retarding element. Further provided is an optical system comprising a color combiner unit, at least two polarizing beamsplitters (PBSs), and a first quarter-wave retarding element. The present application also provides methods of compensating for birefringence in an image projection system.

Abstract: A projector includes first and second optical systems each having a light modulation device that modulates light emitted from a light source device, in accordance with image information input, and forms an optical image. A combining optical system combines the optical images respectively formed by the first and second optical systems. A projection optical system projects the combined optical image. The first or the second optical system includes a transparent parallel plate between the light modulation device and the combining optical system in a rotatable manner, and a tilt angle adjustment mechanism that rotates the transparent parallel plate with respect to a first axis perpendicular to a normal line of an entrance surface of the light modulation device and a second axis perpendicular to the normal line and the first axis to adjust a tilt angle of the transparent parallel plate with respect to the normal line.

Abstract: An output light from an a 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.