Abstract: A color separation optical system is disclosed which is effective in improving black color and black unevenness. Linearly polarized light impinging on a dichroic surface at an incident angle smaller than 45 degrees and then impinging on a polarization beam splitting surface at an incident angle larger than 45 degrees is referred to as first incident-angle light. A wavelength which is longer than a wavelength at the maximum transmittance of the dichroic surface for the first incident-angle light and at which the transmittance of the dichroic surface for the first incident-angle light is 10% is referred to as Wa, and a wavelength range shorter than Wa is referred to as W. The polarization beam splitting surface has a characteristic in which its transmittance for the first incident-angle light in the wavelength range W is 5% or lower.

Abstract: A multimedia player for providing two projection images is provided. The multimedia player for displaying two projection images includes: a first projection unit displaying a first projection image; and a second projection unit displaying a second projection image. The first projection unit includes: a first driving unit controlling an operation of the first projection unit and providing an image signal on the first projection image to be displayed; a first light source unit; a first light modulation device outputting the first projection image by modulating light provided from the light source in response to the image signal of the first projection image; and a first projection lens unit magnifying and projecting an image that is output from the first light modulation device. The structure of the first projection unit is the same as that of the second projection unit. The multimedia player further includes a screen sensing unit sensing a color of an area in which an image is to be displayed.

Abstract: A projector with a laser light source projects an image. In order to reduce the risk for a person to be exposed to harmful levels of laser light, the projector also projects a time-variant alerting image into an alerting region. Alerting region is arranged outside of the projection region. The alerting image is of a wave length visible to the human eye, and of an intensity of eye-safe level.

Abstract: A single-imager projection engine assembly includes a light source, a reflective polarization modulation imager, a reflective quarter wave composite plate, a projection lens system, and a PBS assembly which includes a first polarization beam splitting film and a second polarization beam splitting film in a V-notch pairing configuration. The first polarization beam splitting film reflects the illumination light in first polarization state to the reflective polarization modulation imager, while the second polarization beam splitting film and the reflective quarter wave composite plate in conjunction convert the illumination light in second polarization state passing through the first polarization beam splitting film to first polarization state and reflects the converted to the reflective polarization modulation imager. Combined illumination is modulated, polarization rotated and reflected by the reflective polarization modulation imager back to the PBS assembly for projection through the projection lens.

Abstract: A projector is provided, which includes a red substrate, a green substrate, a blue substrate, an X-cube, an electronic control element, a light guide element, a light valve element, and a projection lens. The red substrate, the green substrate, and the blue substrate respectively illuminate three surfaces of the X-cube, and the light is mixed in the X-cube and then exits from a light emitting surface. The electronic control element controls the red substrate, the green substrate, and the blue substrate. The light guide element is used for reflecting the light from the light emitting surface of the X-cube. The light valve element is used for reflecting the light from the light guide element back to the light guide element, and the light passes through the light guide element and then projected by the projection lens onto a projection plane area.

Abstract: One aspect of an LED package, which is covered by this disclosure, includes at least two LED emitters located on a substrate wherein each of the at least two LED emitters forms an emitting area. The emitting area is substantially equal to a reflective area of the LED package, and the LED package has an optical axis that is substantially non-parallel to an optical axis of each of the at least two LED emitters.

Abstract: A light engine combines light of first, second, and third color ranges using three pentagonal prism elements. Each prism has first and second diagonal surfaces. Each first diagonal surface has a first dichroic treatment and each second diagonal surface has a second dichroic treatment. The prisms are arranged with the first diagonal surface of the first prism juxtaposed with one diagonal surface of the third prism and with the second diagonal surface of the second prism juxtaposed with the other diagonal surface of the third prism. A first light beam of the first color is reflected at a right angle by the first diagonal surfaces, and a second light beam is reflected at a right angle by the second diagonal surfaces. A third light beam of the third color passes unreflected through the surfaces to produce a combined light beam or common output light path.

Abstract: A projection display device includes: a light source unit including light sources emitting light in a plurality of colors, condenser lenses and a color combining optical element; a total reflection prism that totally reflects a combined light flux from the color combining optical element so as to be guided to an image forming unit; and a projection lens. At least one of; an entry surface of the color combining optical element through which substantially parallel light fluxes from the condenser lenses enter, an exit surface of the color combining optical element through which the combined light flux exists, and an entry surface of the total reflection prism through which the combined light flux enters, is formed as a free curved surface where a shape of a section of the combined light flux is altered so as to be matched with a shape of an outline of the display area.

Abstract: An optical system attaining a nearly double resolving power in spite of one projector and also eliminating a convergence device is provided. The system includes an 1:1 relay lens in place of a projector lens of a RGB split-combine projection system, and a quarter-wave plate for P-S polarization separation. In operation, once-modulated RGB composite light is divided into a P-polarized light and a S-polarized light by a PS separation wire grid. The S-polarized light is modulated by a luminance signal Y1 at a Y1 device. The P-polarized light is modulated by a luminance signal Y2 at a Y2 device. The lights modulated by the Y1/Y2 devices are combined with each other at a PS composite wire grid to project a synthetic light on a screen.

Abstract: The lighting unit includes the DMDs (80R), (80G), and (80B). The lighting unit also includes: the prisms (50) and (60) combining the light emitted from the DMDs (80R), (80G), and (80B); and the light modulating optical device (90G). The incident light including the green component light and the yellow component light enters the light modulating optical device (90G). The light modulating optical device (90G) transmits the green component light and changes a transmittance of the yellow component light depending on a change of a molecular state. Light having emitted from the light modulating optical device (90G) enters the DMD (80G), which corresponds to the incident light.

Abstract: A laser projection system comprising a laser source system configured to emit coherent light, an optical integrating system configured to uniformize coherent light it receives, a randomizing optical element configured to spatially move over time in order to temporally randomize the phase, angle or spatial location of coherent light it receives, an image forming system configured to interact with laser light that has been both uniformized by the optical integrating system and randomized by the randomizing optical element, thereby forming a laser light image, and a projection system configured to project the laser light image onto a viewing screen.

Abstract: LED modules (1R, 1G, 1B) for respectively emitting red, green and blue colors of light, illumination optical systems (2R, 2G, 2B) for guiding light from the LED modules, and a liquid crystal panel (7) for modulating the light from the LED modules guided by the illumination optical systems on the basis of an image signal are placed. The LED modules are provided with respective cooling units connected to the backside thereof through spreaders (11R, 11G, 11B) as thermal conductive members. Only the cooling device for the red LED module (1R) is formed by using a red Peltier device (12) as a thermoelectric element capable of controlling heating and absorbing heat. Efficient temperature control by appropriately using a Peltier device for cooling the plurality of solid light sources that emit colors of light different from each other becomes possible.

Abstract: Red, green, and blue laser light emitted from laser light sources 1-3 is transformed into substantially parallel beams by collimator lenses 4-6, collected by microlens arrays 7-9, and rendered uniform by rod integrators 10-12, whereupon it is used to illuminate spatial light modulation elements 16-18 and subjected to modulation. The modulated laser light exiting from the spatial light modulation elements 16-18 is recombined using a beam-combining prism 19 and subjected to pixel separation using a birefringent plate 20, which is rotationally driven by a birefringent plate rotary drive unit 26, after which it is projected upon a screen 22 using a projection optical system 21. The birefringent plate 20 spatially separates the modulated laser light using birefringence. When pixels are spatially separated by the birefringent plate, the pixel grid region is made smaller, the distribution of brightness on the screen is rendered uniform, and speckle noise is reduced.

Abstract: A composite optical element is provided. The composite optical element includes a plurality of optical elements, in which at least one of the optical elements is formed of an element modifying an optical path and the other optical elements are bonded to an incident surface and/or exit surface of the element modifying the optical path with a low refractive index material layer in between.

Abstract: An illumination system including a first light emitting chip, a chip package, a first dichroic film, and a second dichroic film is provided. The first light emitting chip emits a first light beam. The chip package includes a second light emitting chip and a third light emitting chip. The second light emitting chip emits a second light beam. The third light emitting chip emits a third light beam. The colors of the first, second, and third light beams are different from each other. The first dichroic film is disposed in the transmission paths of the first and second light beams. The second dichroic film is disposed in the transmission paths of the first, second, and third light beams. The first and second dichroic films are not parallel to and do not intersect each other. Besides, a projection apparatus employing the illumination system and another projection apparatus are provided.

Abstract: A stereoscopic digital image projecting system has a light source system energizable to provide polarized illumination having a first polarization state and a beam splitting system alternately generating first and second light beams having different polarization states from the polarized illumination. A combining system has a polarization beam combiner that combines the first and second light beams into a combined light beam. A spatial light modulator is used to modulate the combined light beam in a manner consistent with stereoscopic image data to form a first modulated image from illumination in the combined light beam having the first polarization state and to form a second modulated image from illumination in the combined light beam having the second polarization state. Projection optics are configured to project the first and second modulated images onto a display surface.

Abstract: A projection apparatus and a light guide module for use in the projection apparatus are provided. The projector apparatus comprises an illumination mechanism, at least one digital micromirror device (DMD), and a light guide module, wherein the light guide module includes a plurality of interfaces. The illumination mechanism provides a light beam which travels through the plurality of interfaces of the light guide module along a first axis without any rotation. The light beam orderly performs total internal reflections on each of the interfaces of the light guide module. Accordingly, the light beam travels to the at least one DMD, and then the light beam is reflected along a second axis.

Abstract: A total internal reflection prism comprises at least two subprisms. The at least two subprisms define an airgap of a uniform thickness following a one-dimensional curve.

Abstract: A projection type display apparatus includes: a reflective polarizing plate for each color light which transmits each of R light, G light and B light therethrough, allows each transmitted light to enter a corresponding reflective liquid crystal panel for each color light, and reflects image light of each color which has been subjected to light modulation in accordance with an image signal of each corresponding color light by the reflective liquid crystal panel for each color light; an absorption type polarizing plate for R and G lights and a reflection type polarizing plate for B light, each of which removes an unnecessary polarized component from the image light of each color reflected by the reflective polarizing plate for each color light; a color combination optical system which subjects the image light of each color transmitted through the transmission type polarizing plate for each color light to color combination.

Abstract: A laser projector includes a green laser, a two-wavelength laser, a PBS, a collimator lens, a two-axis galvanometer mirror, a group of lenses, and a screen. The green laser emits a green laser beam. The two-wavelength laser emits red and blue laser beams. The PBS is provided at the position where respective optical paths of laser beams emitted from respective lasers cross each other to cause these optical paths to coincide with each other.

Abstract: A laser illuminating device and an image display device are provided to enable a removal of speckle noises in a diffraction field and an image field, to uniformly illuminate an illumination plane, and to realize miniaturization. The laser illuminating device 100 includes a laser light source 3 and a first lens 1 including a plurality of microlenses 10, each having a predetermined numerical aperture in an in-plane direction, and each of the microlenses 10 being adapted to expand laser light emitted from the laser light source 3 to thereby superimpose the laser light transmitted through each of the microlenses 10. The laser illuminating device 100 also includes a second lens 2 having an effective diameter larger than an effective diameter of the first lens 1, and compensating for a divergence angle of the laser light expanded by each of the plurality of the microlenses 10.

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 stereoscopic image projection system using a circular polarization filter module is provided. Even though this system uses a single projector, it allows left and right images to have different polarization directions using the circular polarization filter module, thereby reducing crosstalk compared to an LCD-shutter-based system.

Abstract: Laser light beams are diffused and shaped by diffractive optical devices such that they are introduced to corresponding pixels of a liquid crystal layer over an entire area of a display region of a reflective liquid crystal panel. The diffused and shaped laser light beams are introduced to the reflective liquid crystal panel through a field lens and a polarizing beam splitter. Red, green and blue pixels are formed on the reflective liquid crystal panel, and a microlens array is formed on an incoming and outgoing side substrate while reflecting layers corresponding to the pixels are formed on a reflection side substrate. The laser light fluxes of the colors are distributed and condensed by the microlenses and introduced to the corresponding pixels and then reflected by the corresponding reflecting layers. Refractive optical devices may be used in place of the diffractive optical devices.

Abstract: A method for positioning a light modulation element of a projector. The projector including a first light modulation element unit having first through third light modulation elements and a second light modulation element unit having fourth through sixth light modulation elements. The projector further including a combining system for combining a first image light supplied from the first light modulation element unit and a second image light supplied from the second light modulation element unit and supplying the combined light, and positioning the first light modulation element unit and the second light modulation element unit such that color of combined light of color lights obtained from the first light modulation element, the second light modulation element, and the sixth light modulation element becomes a predetermined color.

Abstract: Method to display an image using four or more primaries having different spectral distributions that are distributed into three groups of primaries, wherein, in a visual color space, all primaries belonging to the same group have the same visual color and are metamehc. Each image being got from a combination of three primary images and each primary image being associated with each visual color of a group, the different primaries of each group are spatially or sequentially distributed over the primary image associated with this group, then allowing an efficient anti-copy protection based on metamerization of images, without any supplemental video processing.

Abstract: A light engine for use in a projector, comprising a motorized adjustable convergence mechanism for fine adjusting the relative positions of red, green and blue channel sub-assemblies. Motors are mounted on fixed elements of the sub-assemblies for driving movable elements thereof, including imaging devices thereof such as digital micromirror devices.

Abstract: A light engine for use in a projector, comprising an adjustable convergence mechanism for fine adjusting the relative positions of red, green and blue channel sub-assemblies. In one embodiment, motors are mounted on fixed elements of the sub-assemblies for driving movable elements thereof, including imaging devices thereof such as digital micromirror devices. In another embodiment, manual adjustment screws are provided in place of the motors, and wedge locking mechanisms are provided for driving and locking the position of the movable elements imaging devices mounted thereon.

Abstract: A projector including light valves respectively corresponding to red light, green light, and blue light. A color combining prism (e.g., cross dichroic prism) combines modulated light emitted from the light valves. A projection lens enlarges and projects the combined light from the color combining prism. An aberration correction lens corrects a chromatic aberration of magnification of the projection lens. A pressing member resiliently presses and fixes the aberration correction lens to the color combining prism at a light entrance surface for at least one of the red, green, and blue light.

Abstract: The invention discloses a projecting system. The projecting system includes two sets of lens. The first set of lens has a first focal length for focusing an incident ray of light to form a first image. The second set of lens has a second focal length for projecting the first image to form a second image. The two sets of lens are separated by a lens-apex distance relative to the light path between the two sets of lens. The second focal length is smaller than or equal to the lens-apex distance. A difference between the second focal length and the lens-apex distance is smaller than or equal to a half of the first focal length.

Abstract: Disclosed are a display apparatus and a light control method thereof, in which the display apparatus including a display panel, a light source unit, an illumination unit to illuminate the display panel with light emitted from the light source unit, and a projection unit to project the light from the display panel in a predetermined direction includes: a light sensor which is provided between the light source unit and the illumination unit; and a light controller which corrects brightness of light sensed by the light sensor on the basis of reflective characteristics of the display panel. With this configuration, the quantity of light is prevented from decreasing so as to prevent the brightness of an image from decreasing.

Abstract: A projector can form images of illumination system on respective optical paths at positions of corresponding liquid crystal display panels with respect to a light emission surface of a cross dichroic prism without relatively inverting the images and without increasing the number of lenses from the number of lenses included in a relay optical path structure in related art. Moreover, the projector can equalize the magnification of the images formed on the respective liquid crystal display panels by controlling relative image-forming conditions of the first and second optical paths in advance. Thus, deterioration of white balance and color unevenness of light projected by the projector can be reduced even when light emission distribution of a light source varies with elapse of time, for example.

Abstract: A video projector includes a reduced size spatial light modulator (400) that spatially modulates light from a light source (502) according to only a portion (e.g., ½) of a video frame at a time. A beam steerer (508, 600, 1600) steers spatially modulated light from the spatial light modulator to a correspond region (e.g., upper half, lower half) of a projection screen/surface (512) and one or more lenses (506, 510, 702, 802, 1002, 1008, 1100, 1300, 1502) insure that the spatially light modulator (400) is imaged onto the projection screen/surface (512).

Abstract: A beam alignment chamber extending in a length direction comprising a base having a front edge, and two side edges, first and second opposed side walls connected to the base, and extending along the length of the base, a front wall located at the front edge of the base having an output opening. The beam alignment chamber further comprises a plurality of arrays of light sources disposed to direct light beams through the first or second side walls, and a plurality of reflectors mounted on the base, each having independent yaw and pitch adjustments, each reflector being paired with a corresponding array of light sources, the base-mounted reflectors being disposed to direct the light beams along the length of the beam alignment chamber through the output opening forming an aligned two-dimensional array of parallel light beams.

Abstract: An illumination system includes a first solid-state light-emitting element, a wavelength conversion device, a second solid-state light-emitting element and a third solid-state light-emitting element. The first solid-state light-emitting element is used for emitting a first color light in a first waveband region. The wavelength conversion device includes a wheel body and a wavelength conversion section. The wheel body includes a rotation shaft. The wavelength conversion section surrounds the rotation shaft and contains phosphor coating. By the phosphor coating, the first color light from the first solid-state light-emitting element is excited as a second color light in a second waveband region to be outputted. The second solid-state light-emitting element is used for emitting first color light. The third solid-state light-emitting element is used for emitting a third color light in a third waveband region.

Abstract: Provided is a projection optical system which includes a first optical part which projects an image; a second optical part having an image forming device, which forms an image using a light and emits the image to the first optical part; a third optical part having at least one light source which emits the light; and a deflector which guides the light emitted from the third optical part toward the second optical part, wherein an optical axis of the third optical part is angled toward an optical axis of the second optical part, and an optical axis of the first optical part and the optical axis of the second optical part are parallel to each other and separated from each other.

Abstract: A liquid crystal projection apparatus having an image synthesizing unit including a color synthesization prism having an upper surface, a lower surface facing the upper surface, and three light incident faces between the upper and lower surfaces; an upper prism pedestal provided on the upper surface of the color synthesization prism; a lower prism pedestal provided on the lower surface of the color synthesization prism; an upper liquid crystal panel holder provided on the upper prism pedestal and having first jointing sections, a lower liquid crystal panel holder provided on the lower prism pedestal and having second jointing sections; three liquid crystal panels; and three liquid crystal panel mounting members securely fixing thereon the three liquid crystal panels, the three mounting members arranged on the respective three incident faces of the color synthesization prism joining the first jointing sections located in association with the respective incident faces to corresponding second jointing sections l

Abstract: An illumination apparatus includes a fluorescence unit, laser light irradiation means, and a beam integration unit. The fluorescence unit has a plurality of phosphors, in which the colors of fluorescence generated due to excitation differ, arranged in different regions. The laser light irradiation means irradiates laser light onto the regions of each color of the fluorescence unit while changing the position at which the laser light strikes the fluorescence unit. The beam integration unit integrates fluorescence from each region of the fluorescence unit on a display panel.

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 multiple rate projector comprises at least three different color illuminations to illuminate a pre-determined light, respectively. A color control module is coupled to the at least three different color illuminations to switch the at least three different color illuminations on, respectively to allow turn-on times of two of the at least three different color illuminations are not overlapped, or the turn-on times of the two of the at least three different color illuminations are overlapped with half cycle, longer or short than half cycle of on cycle of each the at least three different color illuminations; and a two-dimension reflector reflects illumination from the at least three different color illuminations to a location.

Abstract: A near eye image display system includes an image projector, a beam combiner assembly, and an optical assembly, optically coupled between the image projector and the beam combiner assembly. The image projector projects a display image toward an optical pathway, the optical pathway intersecting a viewing axis, the viewing axis extending from the eye of a user to an ambient scene. The beam combiner assembly includes a plurality of beam combiners optically cascaded along the optical pathway, each of the beam combiners being disposed diagonally to the optical pathway and diagonally to the viewing axis. Each of the beam combiners is arranged such that for each two adjacent beam combiners, the first of the adjacent beam combiners is optically located between the second of the adjacent beam combiners and the image projector.

Abstract: A projector that projects video light corresponding to an image signal onto a display surface includes: a light source device that emits light; a housing that houses at least the light source device; a projection lens, that is, an optical element that transmits the video light projected onto the display surface and emits the video light toward the outside of the housing; a detecting unit that detects detection light supplied to the optical element; and a control unit that adjusts a light amount of the video light on the basis of a result of the detection by the detecting unit. The projector is set such that, when the optical element is in a normal setting state, the light amount density of the video light is equal to or lower than a predetermined value on an emission surface for emitting the video light of the optical element.

Abstract: At least one exemplary embodiment is directed to a projector which includes several optical elements, reflective devices and beam splitters, arranged to reduce back reflection effects. At least one exemplary embodiment includes a mirror, two beam splitters, three reflection devices, and two optical elements affecting polarization of incident light upon the optical elements.

Abstract: A beam alignment chamber comprising: a base, first and second side walls connected to the base, and a front wall located at the front edge of the base having an output opening. The beam alignment chamber further including a plurality of light sources disposed to direct light beams through the first or second side walls, a plurality of reflectors mounted on the base, each having independent yaw and pitch adjustments, each being disposed to direct the light beams from a corresponding light sources along the length of the beam alignment chamber through the output opening forming an aligned array of parallel light beams, and one or more optical elements positioned in the optical path of the aligned array of light beams disposed to correct the beam divergence with respect to at least one axis.

Abstract: A micro projection device includes a light-emitting unit, a first lens unit, a reflective unit, a second lens unit, a prism unit, an image display unit and a projection unit. The light-emitting unit has three light-emitting modules. Each light-emitting module has a heat-dissipating element, a light-emitting element and a light-guiding element combined with the heat-dissipating element for receiving light beams generated by the light-emitting element. The first lens unit has three first lens sets respectively disposed beside the three light-emitting modules. The reflective unit is disposed beside the first lens unit. The second lens unit is disposed beside the reflective unit. The prism unit is disposed beside the second lens unit. The image display unit has a reflective image display panel disposed beside one side of the prism unit. The projection unit has a projection lens disposed beside another side of the prism unit.

Abstract: A projector apparatus utilizing wedge-type lens for projecting an image onto a surface, comprising a light source module for generating a single first light path; an illumination lens set for inputting the first light path and outputting a second light path; a reflection-type image generator for generating said image; a prism set for inputting said second light path and outputting the second light path onto the reflection-type image generator, wherein the reflection-type image generator reflects the second light path and forming a third light path carrying said image; an image projection lens set disposed on the third light path for projecting said image onto the surface, wherein the illumination lens set including a wedge-type lens working with the prism set for providing a suitable angle of incidence and angle of emission to the reflection-type image generator, the wedge-type lens lowers the required height difference, between the light axles of the illumination lens and the reflection-type image generator,

Abstract: A method includes generating a plurality of beams that each illuminate a separate portion of a spatial light modulator. The spatial light modulator has a first dimension of a first length and a second dimension of a second length. Each of the beams spans a portion of the first length of the first dimension and a portion of the second length of the second dimension. The method also includes scrolling the plurality of beams along the second dimension of the spatial light modulator while maintaining at least a first gap between each of the plurality of beams.

Abstract: A projection apparatus includes a first, a second and a third light sources, a first reflective element, a first and a second dichroic mirrors, a light-homogenizing element, a light valve and a projection lens. The first reflective element is configured to reflect the first light beam, and the first dichroic mirror is configured to reflect the second light beam and to transmit the first light beam transmitted from the first reflective element. The second dichroic mirror is configured to reflect the first and the second light beams transmitted from the first dichroic mirror and to transmit the third light beam. The light-homogenizing element is used for homogenizing the combined light beam, and the light valve is used for modulating the combined light beam to form an image beam. The projection lens is used for receiving and then projecting the image beam.

Abstract: A coupling lens for coupling first light having a first wavelength from a first light source with a second light having a second wavelength from a second light source disposed adjacent to the first light source in substantially the same direction includes a first surface disposed to face the first and second light sources, the first surface including a first region transmitting the first light and having a first region curvature and a second region transmitting the second light and having a second region curvature, and a second surface opposite to the first surface and having a second-surface curvature. A position of a center of the first region curvature differs from a position of a center of the second region curvature. A center of the second surface curvature and the center of the first region curvature are disposed on an optical axis of the first or second light source.

Abstract: A projector using coherent light as a light source includes: one or more coherent light sources emitting coherent light beams; a beam scanner which changes a direction of the coherent light beam; and a beam splitter which splits a beam into multiple segments and changes a phase of light of each split segment, the beam splitter being located in an optical path between the beam scanner and the coherent light source. This projector reduces speckle noises. The beam splitter includes a pair of transparent substrates; a plurality of parallel electrodes disposed on each surface of the pair of transparent substrates, the pair of the parallel electrodes being disposed in a perpendicular direction to each other. Voltages are applied to the respective electrodes at predetermined time intervals so as to produce different potentials in a liquid crystal sandwiched by the transparent substrates.