Abstract: A projector is provided which can handle high light intensities without dust or foreign matter penetrating the inside of the apparatus and thus deteriorating the quality of the image projected. The projector apparatus comprises a spatial light modulator (SLM) unit provided with a plurality of reflective SLMs and a prismatic light splitting/combining unit. The SLM unit is enclosed in a substantially sealed chamber. A heat path for cooling each SLM is provided, whereby the heat path connection is through the wall of the substantially sealed chamber. In this way, heat energy from the main heat source inside the sealed chamber is brought outside the sealed chamber for dissipation.

Abstract: An information display system having an output display for presenting information. Optical means are provided that deflect an illumination beam path into the field of view of the observer. Further, a subdividable output display is created that makes it possible to partly obtain information in a vehicle via a head-up display and partly via a traditional or back-projection display. Given seats arranged in rows, for example in airplanes or buses, back rests of preceding seats contain an output display and a communication interface to the seat of the viewer.

Abstract: A batched process for producing optical components for use in fiber-optic networks. The process involves creating optical substrate blocks with thin-film filters on at least one surface of the of the substrate blocks. Other surfaces on the blocks are finely polished such the several blocks may be fused together at the polished surfaces. By placing the blocks such that the thin-film filters on adjacent blocks are diagonally opposed and then fusing together adjacent blocks, the blocks connected in this manner can perform various optical functions. Some of the optical components that can be formed using this process include power taps, optical add/drop modules, multiplexers, and demultiplexers.

Abstract: A color wheel with a balancing groove comprises a carrier, having a central axis, a external surface, and a periphery, and rotates along the central axis; a set of filter plate sharing the same central axis with the carrier, wherein one or more annular groove is disposed on the external surface of the loading element, and a balancing substance is added into the annular groove to balance the color wheel.

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: An image projecting apparatus including a light source that emits a plurality of monochromatic lights of different wavelength, a condenser lens that concentrates the plurality of monochromatic lights, a color separating device that has a plurality of dichroic mirrors which while rotating selectively reflect or transmit the plurality of incident monochromatic lights. A square beam generator receives the input of two reflected monochromatic lights from the color separating device almost simultaneously, thereby forming two square beams. A panel unit receives the two square beams generated, thereby forming respectively corresponding monochromatic color stripes thereon. By selectively reflecting or transmitting the plurality of incident monochromatic lights with the plurality of dichroic mirror wheels, light utilization at a panel increases.

Abstract: An apparatus for manufacturing an optical device in which energy can be saved is provided. The apparatus for manufacturing an optical device performs mutual position adjustment of three liquid crystal panels, which are to be fixed to a cross dichroic prism. The apparatus includes an adjusting light source device having light-emitting diodes, each of which emits a colored light ray, which are used as light sources; a luminous flux detector to detect a luminous flux which is emitted from the adjusting light source device and which is combined in the cross dichroic prism; and a six-axis position adjusting unit to adjust the position of each of the liquid crystal panels based on the result obtained from the detection at the luminous flux detector. By using light-emitting diodes, energy can be saved, the cost for manufacturing the optical device can be reduced, and the adjusting light source device can be miniaturized.

Abstract: A color display apparatus for forming, on a display surface, a color image of superimposed color images, the display apparatus having a first color modulation channel for forming a first color two-dimensional image using a laser light source for providing a first color source beam, a linear spatial light modulator for modulating the first color source beam, and a scanning element for scanning the modulated light beam to form a first color two-dimensional image. A second color modulation channel forms a second color two-dimensional image using an incoherent light source for providing a second color source beam to an area spatial light modulator for modulating the second color source beam to form a second color two-dimensional image. A projection lens then projects a superimposed color image of the first color two-dimensional image and the second color two-dimensional image and any third color two-dimensional image.

Abstract: An optical pickup apparatus comprises two light sources having two wavelengths (&lgr;1<&lgr;2) and a converging optical system having an objective lens. The objective lens comprises a central region; a peripheral region provided at an outside of the central region on at least one optical surface of the objective lens; a diffractive ring-shaped zones which is blazed on a basis of a wavelength &lgr;0 (&lgr;1<&lgr;0<&lgr;2) and is formed on each of the central region and the peripheral region; and a phase difference suppressing structure to suppress a phase difference between a wavefront of a light flux passing the central region and a wavefront of a light flux passing the peripheral region when recording or reproducing information is conducted for the first optical information recording medium.

Abstract: An optical device includes a first input port, a first output port, a second output port, at least one filter, at least one reflector, a first reflection unit and a second reflection unit. The filter receives optical signals having wavelengths of &lgr;1 to &lgr;n from the first input port, selectively transmits the optical signal having a wavelength of &lgr;i, and reflects other optical signals, wherein 1≦i≦n. The first reflection unit reflects the optical signal having the wavelength of &lgr;i back to the filter, so that the optical signal having the wavelength of &lgr;i can pass through the filter and can be output from the first output port. The reflector reflects the optical signals having the wavelengths of &lgr;1 to &lgr;n except for &lgr;i from the filter.

Abstract: A rotating periodic color-regulating module of the image display device is disclosed to improve the usage of light. The rotating periodic color-regulating module comprises a color separating light guide and a color-regulating processor. By using a grating element installed in front of the color separating light guide, the incident light is interleaved into three parts of different wavelengths, red (R), green (G) and blue (B), propagating toward the corresponding color filters. Part of the light is reflected by the color filters, then reflected by the mirror around the grating element, and goes back to the color filters. The incident light is divided into three uniform beams of light, R, G and B, to the color-regulating processor. The color-regulating processor changes the outgoing position and order of the light beams periodically and rapidly for displaying image.

Abstract: The light which is input from an optical fiber to a first port is output to an optical path. The light which is input from the optical path to a half mirror is branched into two, and is output to the optical paths. The light which is output to the optical path reaches to and is reflected from a first reflecting mirror, and returns to the half mirror by an optical path. The light which is input to the half mirror by the optical path is branched into two, and is output to the optical paths. The light which is output to the optical path reaches to and is reflected from a second reflecting mirror, and returns to the half mirror by an optical path. The light which is input to the half mirror by the optical path is branched into two, and is output to the optical paths. The light which is output to the optical path is output from a second port to an optical fiber, and the light which is output to the optical path is output from a third port to an optical fiber.

Abstract: Wavelength lockers, which monitor the wavelength drift of a laser's beam due to aging, are tunable to adjust for manufacturing misalignments between its various optical components. Tuning is accomplished by adjusting the position of a collimating lens using a flexure. Adjusting the lens position changes the angle of incidence of a monitored beam relative to a fixed filter and detector and avoids the challenging manufacturing task of rotating the filter and detector to achieve the same result.

Abstract: An extreme ultraviolet (EUV) lithography system may include a spectral purity filter including diffractive gratings. The diffractive gratings may be formed in a silicon substrate using anisotropic etching techniques to produce smooth, flat facets defined by (111) crystallographic planes.

Abstract: A gobo is described wherein the superimposed layers are integrally bonded with a continuous and uniform layer of polymerized gluing material. Preferred bonding glues, their required characteristics, and a method for fabricating the integrally bonded gobo are disclosed.

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: A digital projection apparatus (10) for projection of a multicolor image uniformizes polychromatic light from a light source (12) and provides magnification to the uniformized illumination beam using a base condenser relay (80), providing a reduced numerical aperture for conditioning at a dichroic separator (27). For each monochromatic component color provided from the dichroic separator (27), a reducing relay (82) then demagnifies the illumination beam to provide source illumination to a spatial light modulator (30) at an increased numerical aperture. As a result, color shading across the field is minimized and brightness is optimized.

Abstract: This invention discloses a color separation prism assembly. The prism assembly includes three triangular-shaped prisms having identical shape and size. Each of the three triangular-shaped prisms has two triangular surfaces as interfacing surfaces bonded to two identical triangular surfaces of two other prisms. At least two triangular surfaces of the three triangular-shaped prisms are coated with color separation filtering films for reflecting a first color light and transmitting a second color light therethrough. At least two triangular surfaces of the three triangular-shaped prisms are coated with a total reflective coating constituting at least two total internal reflective (TIR) surfaces for reflecting a light projected thereon. Each of the TIR surfaces further comprising a phase-shift compensating coating coated thereon.

Abstract: A lens according to the present invention comprises a macro lens having radial light refraction varying from zero on the optical axis to a maximum refraction angle at the lens rim. A pattern of light-diffusing micro lenses, on at least one macro lens surface, vary in radial light-diffusion angle in proportion to the angle of refraction of the macro lens. In a second preferred embodiment the macro lens has light-diffusing micro lenses in the form of concentric, linear-lens rings about the optical axis, whereby the diffusion angle of each micro lens is radial only and is equal to the included angle of the radial chromatic aberration angle of the macro lens at the same point on the macro lens.

Abstract: An optical device has: a metal cooling device (500) disposed between a liquid crystal panel (441) and a light-incident side of a cross dichroic prism (443) and having a holding surface for holding polarization plates (521, 522) attached with a polarization films (521A and 522A) in a mutually spaced manner, the cooling device cooling the polarization films; a base (445) provided on the upper and lower sides of the cross dichroic prism (443) and having a cooling device attachment surface (449A) for the cooling device (500) to be attached; and a fixing member (600) provided on a light-incident side of the cross dichroic prism for locating and fixing the liquid crystal panel (441) on the light-incident side, the fixing member (600) being formed with a attachment surface (631) on which a pin (730) for mounting the liquid crystal panel (441) is formed.

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.

Abstract: A dichroic is positioned to separate color beams of polarized input light. The color beams are directed to microdisplays that contain correspondingly colored content in a kernel of a Light Management System (LMS). Adjustment of a voltage amplitude of the microdisplays is set to produce a maximum black state of the LMS. In one embodiment, a passive nematic liquid crystal device is utilized as a quarter waveplate. A thickness of a liquid crystal layer (d) is matched to a birefringence (&Dgr;n) of the nematic such that retardation d&Dgr;n=¼&lgr;.

Abstract: Partially polarized light produced by an integrator/polarization conversion system combination and two non-pixilated twisted nematic liquid crystal display cells (TN-LCD) or other light modulators are utilized. By adjusting the voltages on the TN-LCD cells, it is possible to adjust the relative amounts of the greatest two of the colors supplied, of the red, green and blue colors, used by the display without changing the light of the color in the least supply. Because all of the adjustments are done electronically through voltage controls, not mechanically, the “white” point correction system is both simple and reliable.

Abstract: Provided are a color combining optical element capable of forming a good projected image on a screen surface while permitting scaling-down of entire apparatus and a projection image display apparatus using it.

Abstract: Red, green and glue light beams from light source portions (301, 302, 303) are modulated respectively by light valve units (317, 319, 321) of a light valve portion (304) and enter a color combination optical system (305). The color combination optical system (305) includes three triangular prisms (325, 326, 327), each having a vertex angle of about 30 degrees, and is formed by joining the prisms together with dichroic mirror surfaces (328, 329) interposed therebetween. The respective light beams entering the planes of the prisms opposite to their vertex angles are combined in the color combination optical system (305) and emitted from an exit plane of the prism (327). The optical path lengths of the respective light beams between the incidence planes and the exit plane (332) are substantially equal to one another. Then, a projection lens (306) magnifies and projects the combined light beam onto a screen.

Abstract: In a projector, the precision of color synthesis is improved and the generation of vertical stripes in the projected image is suppressed by a dichroic prism used for color synthesis that employs at least the following aspects. (1) The dichroic prism is formed using triangular prisms, in which projections or grooves are provided that have two faces parallel to two pasted faces of the triangular prisms, the projections or grooves being integrally injection-molded on faces of the triangular prisms that are substantially perpendicular to the light beam (i.e., the faces through which no light beam passes); (2) the dichroic prism is positioned using marks on the pasted faces of the triangular prisms; or (3) the dichroic prism is formed by engaging triangular prisms in which recesses or projections are formed.

Abstract: An objective lens of an optical pickup device for both CD and DVD, in which a short-wave pass (SWP) filter is inserted in the objective lens, is capable of allowing the optical pickup device to have a light-weight, slim, simple, and miniaturized structure. The objective lens is divided into two lens portions with respect to a direction transverse to a beam transmitting path and provided with a short-wave pass (SWP) filter. The lens portions have planarized divisional surfaces facing each other, respectively. The objective lens reduces the space occupied by the SWP filter. Accordingly, the objective lens of the present invention alleviates a restriction in the design of an optical system caused thereby and an increased margin is secured.

Abstract: An immersed non-polarizing beamsplitter includes thin film groups and one or more additional thin films. Each of the thin film groups by itself fails to provide a non-polarizing reflection, but the combination of the thin film groups and the additional thin films provides a non-polarizing reflection. Each thin film group can consist of four layers, one of a higher refractive index material, two of an intermediate refractive index material, and one of a lower refractive index material, and at least one of the additional thin films is made of a material not used in the thin film groups. The additional thin films can precede, be between, or follow the thin film groups along the path of light through the beamsplitter. The order of the thin films in the groups can all be the same or can vary to improve performance of the non-polarizing beamsplitter.

Abstract: A projection apparatus is disclosed which uses a light modulation element of the reflection type and can demultiplex and multiplex light appropriately. The projection apparatus includes four PBSs including an incoming PBS, a RB-PBS, a G-PBS and an outgoing PBS to demultiplex illumination light emitted from a lamp into light components in wavelength bands of blue, red and green. The illumination light in the wavelength band of green is introduced to a position at which the highest contrast is obtained, and a third liquid crystal panel is disposed at the position. The illumination light in the wavelength band of red is introduced to another position at which the second highest contrast is obtained, and a second liquid crystal panel is disposed at the position. The illumination light in the wavelength band of blue is introduced to the remaining position, and a first liquid crystal panel is disposed at the position.

Abstract: A method and system for providing different images representing plural depths of field of an electronic device. The vision system has a beamsplitter for receiving an image of the device illuminated by the at least one light source, the beamsplitter providing one of the plurality of images of the device based in a wavelength of the light source; an aperture having a plurality of effective diameters based on the wavelength of light from the at least one light source, the aperture determining a depth of field of the image of the device; and an optical element for receiving the image of the device, the optical element magnifying the image by a predetermined magnification factor to produce a magnified image having the determined depth of field.

Abstract: A projection type image display apparatus includes a light axis moving unit for moving a direction of a light from a light source substantially in parallel periodically at a predetermined rate, a light separating unit for separating the light from the light axis moving unit into a plurality of color light components of predetermined wavelength bands, and a radiation unit for radiating the color light components from the light separating unit on an image display device, projecting an optical image corresponding to the image signal in enlarge form.

Abstract: A light focusing and dispersing apparatus of a light source module is disclosed. The light focusing and dispersing apparatus is particularly used in image scanners such as a single pass color scanner. The light focusing and dispersing apparatus concentrates light from a light source to form a light beam so as to upgrade the use efficiency of light energy. The light focusing and dispersing apparatus disperses the light beam from the light source to form red, green and blue light beams to illuminate a document to be scanned. The red, green and blue light beams reflected from the scanned document emit onto array of image sensors comprising red, green and blue light sensitive regions respectively.

Abstract: This time-division image projector is provided with: light source 1 that radiates white light; transmission color wheel 31, on which are mounted a plurality of color filters 31R, 31G, and 31B that each transmit only light of specific wavelength bands, for selectively transmitting only light of specific wavelength bands of the white light from light source 1; reflection element 33 for which the normal of the reflecting surface is arranged at an inclination with respect to light that is irradiated onto transmission color wheel 31 and that reflects light of specific wavelength bands that is transmitted by color filters 31R, 31G, and 31B in a different direction; optical modulation element 41 that is supplied, in time divisions, with a plurality of image signals that each correspond to light of the specific wavelength bands that is reflected by reflection element 33 and that modulates, in pixel units, the intensity of light of the specific wavelength bands that is transmitted by color filters 31R, 31G, and 31B ac

Abstract: A microscope has a light source that emits an illuminating light beam for illumination of a specimen, an apparatus for determining the light power level of the illuminating light beam and a beam splitter separating measuring light out of the illuminating light beam. The microscope permits determination of the light power level of the illuminating light beam with an apparatus for simultaneous color-selective detection of the measuring light.

Abstract: A writing apparatus (10) for forming images from digital data onto color motion picture film or other photosensitive medium (32), the apparatus employing a single spatial light modulator (30) and having an illumination system (14) comprising a dichroic prism (26) and a plurality of light sources (20). The dichroic prism (26) directs light from each light source (20) onto a common output axis, thereby providing an incident light beam for modulation by the spatial light modulator (30). The apparatus allows high-speed imaging optimized for photosensitive media (32). Additional sensor (12) and logic components allow writing apparatus (10) to adapt to different types of photosensitive media (32) without requiring any retooling or manual adjustment.

Abstract: An apparatus for processing an optical signal includes a tunable optical element and a reflective element. The tunable optical element receives an input signal at an incidence angle and separates the input signal into a first beam having a first optical path length and a second beam having a second optical path length. The difference between the first optical path length and the second optical path length is based at least in part upon the incidence angle of the input signal. The reflective element reflects the first beam and the second beam such that the first beam interferes with the second beam to produce a first output signal and a second output signal. The first output signal comprises a first subset of wavelength channels from the input signal and the second output signal comprises a second subset of wavelength channels from the input signal.

Abstract: The present invention provides a technique for improving the optical characteristics of a light-selective prism. By cutting a block along a plane perpendicular to a first direction, a plurality of first small blocks are obtained. A first selective film is formed on the cut face of the first small block, and the plurality of first small blocks are stuck together so as to obtain a first processed block in which the first selective film is located at the interface of adjacent two first small blocks. Next, by cutting the first processed block along a plane perpendicular to a second direction that is substantially perpendicular to the first direction, a plurality of second small blocks are obtained. A second selective film is formed on the cut face of the second small block, and the plurality of second small blocks are stuck together to obtain a second processed block in which the second selective film is located at the interface of adjacent two second small blocks.

Abstract: In a projection apparatus, a light beam emitted by a light source is guided to a modulation element for forming an image. The light beam emerged from the modulation element is projected onto a screen by a projection lens. An image of the light source is formed as a first light source image by a first optical system. The light beam from the modulation element illuminated with light emanating from the first light source image is imaged by a second optical system as a second light source image at a potion in the vicinity of an aperture of a stop of the projection lens. A peripheral portion of the first light source image is intercepted by another stop located at a potion conjugate with the stop of the projection lens.

Abstract: An OTDL device in accordance with the present invention is a method for and device for spatially resolving the wavelengths in an optical signal, i.e., channelizing or demultiplexing. The device is based on a tapped optical delay line.

Abstract: Kernels are designed in different configurations based on design properties of an enclosure or other requirements. A prism assembly having various types of filters, waveplates, beam splitters (e.g., path length matched beam splitters) and/or other optical components are provided to selectively direct light beams to each of red, green, and blue microdisplays that manipulate the light and then combine the manipulated lights into an output image. The prism assembly includes an input face, an output face, and other faces on which the microdisplays are attached in a number of different configurations. Requirements and exact placement of optical components varies depending on which microdisplay is attached to which face. The components of the prism assembly may be arranged in path length matched positions.

Abstract: A light filtering assembly for filtering an input beam of light having a plurality of desired wavelength components and a plurality of unwanted wavelength components so as to provide an output beam having only the desired wavelength components. The filtering assembly comprises an input section, a filtering section, and an output section. The input section divides the input beam into a plurality of polarized beamlets that travel along a corresponding plurality of spatially separated beam paths. The polarized beamlets comprise a plurality of desired beamlets corresponding to the desired wavelength components of the input beam and a plurality of unwanted beamlets corresponding to the unwanted wavelength components of the input beam. The filtering section is disposed in the paths of the beamlets so that the desired beamlets are passed and the unwanted beamlets are blocked.

Abstract: A writing apparatus (10) for forming images from digital data onto color motion picture film or other photosensitive medium (32), the apparatus employing a single spatial light modulator (30) and having an illumination system (14) comprising a dichroic prism (26) and a plurality of light sources (20). The dichroic prism (26) directs light from each light source (20) onto a common output axis, thereby providing an incident light beam for modulation by the spatial light modulator (30). The apparatus allows high-speed imaging optimized for photosensitive media (32). Additional sensor (12) and logic components allow writing apparatus (10) to adapt to different types of photosensitive media (32) without requiring any retooling or manual adjustment.

Abstract: The present invention provides a position-control device for a light modulation device, capable of easily performing a position-control operation. A position-control device is provided with a reference projection lens built therein capable of being commonly used, the reference projection lens projecting light combined by a crossed dichroic prism and forming a projection image, and having a predetermined optical characteristic. If the position of the optical axis is aligned once when the reference projection lens was built in, it is not necessary to align the optical axes every time the positions of liquid crystal panels are controlled and the replacement of the liquid crystal panels and the crossed dichroic prism is only required, whereby the position-control operation can be easily performed.

Abstract: A miniature projector to allow the projection of images directly on a target surface, such as a viewer's retina, which is a compact and versatile device that further minimizes the potential for total immersion. The miniature projector can be selected for use in the monitor mode or full video and full color or monochrome operation. The miniature projector utilizes miniaturized 2D laser arrays integrated with nonlinear optical processes combining semiconductor technology with optics technology.

Abstract: There is provided a projection display apparatus using a polarization beam splitter having two splitting surfaces, which can simplify its structure and reduce its cost. The projection display apparatus includes the polarization beam splitter that has a first splitting surface for transmitting or reflecting a red light and a second splitting surface for transmitting or reflecting a green light and a blue light. A polarization state converter that is provided in the polarization beam splitter converts the polarization states of the green and blue lights and applies the converted green and blue lights to the polarization beam splitter.

Abstract: A system capable of changing the wavelength and intensity of an output light includes an input end, a first output end, a second output end, a first rotatable optical device, a second rotatable optical device, and a third optical device. The input end is used to receive a first optical signal and a second optical signal. When the angle of the first rotatable optical device is adjusted, the first optical signal is able to pass through and the second optical signal is reflected. The second rotatable optical device allows the first optical signal to be outputted from the first output end. When the angle of the second rotatable optical device is adjusted, the intensity of the first optical signal outputted from the first output end changes. The angle of the third rotatable optical device is adjusted with respect to the angle of the first rotatable optical device, so that the second optical signal can be outputted from the second output end.

Abstract: A display apparatus, includes a laser light source for emitting a light beam; a beam expander for expanding the light beam; a spatial light modulator; beam shaping optics for shaping the expanded laser beam to provide uniform illumination of the spatial light modulator, the beam shaping optics including a fly's eye integrator having an array of lenslets; and a moving diffuser located in the laser beam between the laser light source and the spatial light modulator.

Abstract: A night vision system 10 is provided for detecting objects at relatively low visible light levels. The system 10 includes an infrared light source 14. The system 10 further includes a thin sheet optical element 16 extending along a first axis 27 receiving light from the infrared light source 14 and reflecting the light generally in a first direction. Finally, the system 10 includes an infrared camera for receiving the light reflected off objects in the environment and generating a video signal responsive to the received light.

Abstract: The present invention has as its object to provide a projection type display apparatus which suffers little from the occurrence of the distortion of the surface of a dichroic mirror in a color combining optical system, and the occurrence of the deformation of a projected image by the angular deviation of the surface of the dichroic mirror and in which the correction of the chromatic aberration of magnification of a projection lens is stably possible during mass production. So, the color combining system of the present invention is provided with at least three prisms, two dichroic mirror layers for reflecting lights differing in wavelength area from each other, the two dichroic mirror layers being formed so as not to intersect with each other with one of the three prisms which is located most adjacent to the light exit side interposed therebetween, and at least one optical element having positive or negative refractive power.

Abstract: An apparatus which makes dark lines due to a central axis of a cross dichroic prism sufficiently inconspicuous. In a second lens array, minute lenses arranged on the same column include three different types of minute lenses having optical axes at different positions. Each row of the minute lenses consists of one of the three types of minute lenses. Partial light fluxes respectively passing through the minute lenses have optical axes at different positions relative to a center of a lighting area of a liquid-crystal light bulb, so as to illuminate different illumination areas.