Abstract: An imaging light source module that includes a plurality of light guides, a plurality of light emitting sources, and an intermediate image surface is disclosed. Each of the plurality of light guides has an entrance face, an exit face, and at least one side wall, and all of the light guides are capable of delivering light along associated light distribution axes intersecting a common reference point. Each of the plurality of light emitting sources delivers light only to a single light guide of the plurality of light guides. The intermediate image surface comprises a plurality of pixels, where each pixel receives light from the exit face of a single associated light guide of the plurality of light guides.

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: Light reflectors and flood lighting systems for illumination and lighting. Each light reflector may include a housing having a plurality of facets, each of the plurality of facets having a shape that is a portion of separate ellipses sharing a common focus. First and second surfaces are defined by first and second planes intersecting along a line within a volume of the body. A light source is positioned near the first surface, at the common focus, and is angularly oriented thereto such that light emitted by the light source is directed into the housing, reflected by at least one of the plurality of facets, and exits the light reflector out of either the first plane or the second plane. The body of the light reflector may include a free-form surface that is generated as the best fit to the plurality of facets.

Abstract: Optical elements, color combiners using the optical elements, and image projectors using the color combiners are described. The optical element includes light recycling stacks, a polarizing beam splitter, and a color-selective stacked retardation polarizing filter. The polarizing beam splitter includes a first reflective polarizer aligned to a first polarization direction. Each light recycling stack includes a second reflective polarizer aligned to the first polarization direction, and a retarder aligned at 45 degrees to the first polarization direction. The color combiner includes partially reflective light sources coupled to the optical element. Un-polarized light having different colors can enter the color combiner through the light recycling stacks, and combined light of a desired polarization state can exit the color combiner. Light having an undesired polarization state can be recycled to the desired polarization state within the color combiner, so that light utilization efficiency is increased.

Abstract: An imaging light source module that includes a plurality of light guides, a plurality of light emitting sources, and an intermediate image surface is disclosed. Each of the plurality of light guides has an entrance face, an exit face, and at least one side wall, and all of the light guides are capable of delivering light along associated light distribution axes intersecting a common reference point. Each of the plurality of light emitting sources delivers light only to a single light guide of the plurality of light guides. The intermediate image surface comprises a plurality of pixels, where each pixel receives light from the exit face of a single associated light guide of the plurality of light guides.

Abstract: Light combiners and light splitters, and methods of using light combiners and light splitters are described. In particular, the description relates to light combiners and splitters that combine and split, respectively, light of different wavelength spectrums using polarizing beam splitters. The polarizing beam splitters include a reflective polarizer to efficiently split incident light into transmitted and reflected beams having different polarization directions. Reflectors and quarter-wave retarders are positioned facing selected prism faces of the polarizing beam splitters, to affect the polarization state of light passing through the prism faces. The reflectors can be dichroic filters adapted to reflect light that is outside a selected wavelength range, so that light of different wavelength spectrums can be affected at different prism faces.

Abstract: Light combiners and light splitters, and methods of using light combiners and light splitters are described. In particular, the description relates to light combiners and splitters that combine and split, respectively, light of different wavelength spectrums using polarizing beam splitters. The light combiners include arrangements of four polarizing beam splitters, such that three different wavelength spectrums of light can be directed into three of the polarizing beam splitters, and a combined light can be received from the fourth polarizing beam splitter. The light splitters can be the same configuration as the light combiners, but the direction of light travel is reversed to split, rather than combine, light. Polychromatic light can be directed into one of the polarizing beam splitters, and light having three different wavelength spectrums can be received from the other three polarizing beam splitters.

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: A projection engine is disclosed, in which white light from a uniform telecentric source is collimated, polarized, and split into red and cyan beams. The collimated red light passes through a red focuser, which has an off-axis, front-surface mirror that has an aspheric and/or conic profile, and a spherical lens. The collimated cyan light passes through a similar cyan focuser, after which it is split into blue and green beams. The mirror reflective surface has an aspherical shape to minimize aberrations at the edge of the field of view in the illumination optical path. The collimator is at the front focal plane of each focuser, making the emergent converging beam telecentric, and a pixelated panel is at the rear focal plane of each focuser. The reflected light beams from the red, green and blue pixelated panels are superimposed on a pixel-by-pixel basis and are directed to a projection lens.

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

Abstract: A 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 illumination system, useful for generating illumination light in an image-projection system, has at least a first image-forming panel. A first array of light emitting elements, for example light emitting diodes (LEDs), generates a first light beam associated with a first wavelength range. A second array of light emitting elements generates a second light beam associated with a second wavelength range. The second array of light emitting elements comprises at least a first light emitting element generating light in the second wavelength range and a second light emitting element generating light in the first wavelength range. The center wavelength of the second light emitting element may be closer in value to the center wavelength of a light emitting element in the first array than to the center wavelength of the first light emitting element.

Abstract: An optical system and a projection system incorporating same are disclosed. The optical system includes a light source that is capable of emitting light. The emitted light includes one or more substantially collimated discrete light beams. The optical system further includes a lenslet array for receiving and transmitting the emitted light. Each discrete light beam in the emitted light has an intensity full width at half maximum (FWHM) at the lenslet array that covers at least a portion of a plurality of lenslets in the lenslet array. The optical system further includes an optical element for receiving the transmitted light from an input face of the optical element. The optical element homogenizes the received light and transmits the homogenized light from an output face of the optical element.

Abstract: In an image projection system, there are at least two light illumination units producing illumination light beams of respective first and second primary colors. A first beamsplitter is disposed to split at least a portion of the first illumination light beam into sub-beams, one of which is directed to a first image-forming panel. The other sub-beam is combined with at least some of the second illumination light beam to form a light beam of mixed light that illuminates the image-forming panel. In some embodiments, the first beamsplitter is a polarizing beamsplitter.

Abstract: A color-splitting optical element is disclosed that includes a first prism having a first transmissive curved outer side, a second transmissive curved outer side and an inner side. The color-splitting optical element also includes a second prism having a first transmissive curved outer side, a second side and an inner side. A dichroic element is disposed between the inner side of the first prism and the inner side of the second prism. The first transmissive curved outer side of the first prism is disposed generally opposite the first transmissive curved outer side of the second prism along a first direction and the second transmissive curved outer side of the first prism is disposed generally opposite the second side of the second prism along a second direction. Also disclosed are optical systems utilizing such color-splitting optical elements.

Abstract: An illumination system, used for illuminating a target area, includes a plurality of light generating elements and a plurality of light collection units disposed to collect light from respective light generating elements. Imaging lens units are disposed to relay images of respective light collection units to the target area, light from different light generating elements overlapping at the target area. In some embodiments, the illumination system also includes color combining elements to combine light from differently colored light generating elements. The illumination system may be used in a projection system, with the light from the illumination system incident on an image-forming device placed at the target area.

Abstract: A projection engine is disclosed, in which white light from a uniform telecentric source is collimated, polarized, and split into red and cyan beams. The collimated red light passes through a red focuser, which has an off-axis, front-surface mirror that has an aspheric and/or conic profile, and a spherical lens. The collimated cyan light passes through a similar cyan focuser, after which it is split into blue and green beams. The mirror reflective surface has an aspherical shape to minimize aberrations at the edge of the field of view in the illumination optical path. The collimator is at the front focal plane of each focuser, making the emergent converging beam telecentric, and a pixelated panel is at the rear focal plane of each focuser. The reflected light beams from the red, green and blue pixelated panels are superimposed on a pixel-by-pixel basis and are directed to a projection lens.

Abstract: An optical display system includes a light source, for generating light in first, second and third color bands, and a projection core. The projection core includes a crossed color combiner and first, second and third display panels disposed to direct first, second and third image light into the color combiner. The display panels are arranged for forming images in the light in the first, second and third color bands respectively. An optical relay system relays illumination to the first, second and third imager panels. A first dichroic separator is disposed in the light beam between the light source and the projection core, and separates light in the first color band from light in the second and third color bands. The lengths of optical paths from the first dichroic separator to each of the three display panels are all substantially equal.

Abstract: High pressure mercury arc lamps are commonly used as the illumination source in many projection systems. Such lamps may be deficient in either output power or spectrum, and so it is desirable to combine the light from the lamp with light from a second light generator. The second light generator may be another mercury lamp or a solid state source, such as one or more light emitting diodes. Different ways of combining light from two light generators are described. The second light source may be an arrangement of a number of red LEDs that supplements the red light produced by the mercury light. A tunnel integrator may be used to homogenize the combined light beam and to reduce the angular separation between the light beams from the two light generators.