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: 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 projection system includes a light source producing illumination light, an imager disposed to receive the illumination light, and a projection lens disposed to receive the illumination light from the imager. The imager includes an intrinsic polarizer. The intrinsic polarizer can be an intrinsic polarizer stack including a U.V. curable adhesive.

Abstract: A projection system includes a projection lens unit, a color combiner, and at least a first and a second image-forming devices for generating single color images. The single color images are combined in the color combiner to produce a colored image light beam. The colored image light beam passes from the color combiner to the projection lens system. A polarization control element is disposed between the color combiner and the first image-forming device. The polarization control element alters the polarization of light at either one of the first and second color, while not altering the polarization of light of the other of the first and second color. In some embodiments, the polarization control element is oriented to substantially prevent light at the second color from passing from the color combiner to the first image-forming device via a polarizing beamsplitter.

Abstract: Inhibiting formation of optical artifacts in a multi-layer film polarizer of an optical imaging assembly that includes a polarizing beam splitter. The beam splitter may include a multilayer reflective polarizing film having at least two materials, one of which may exhibit birefringence after uniaxial orientation; an adhesive disposed on the multilayer reflective polarizing film; and at least a first prism disposed on the adhesive. The adhesive may include a plasticizer for inhibiting formation of optical artifacts in the polarizing film.

Abstract: An optical imaging system including an illumination system, a Cartesian PBS, and a prism assembly. The illumination system provides a beam of light, the illumination system having an ƒ/# less than or equal to 2.5. The Cartesian polarizing beam splitter has a first tilt axis, oriented to receive the beam of light. A first polarized beam of light having one polarization direction is folded by the Cartesian polarizing beam splitter and a second polarized beam of light having a second polarization direction is transmitted by the Cartesian polarizing beam splitter. The Cartesian polarizing beam splitter nominally polarizes the beam of light with respect to the Cartesian beam splitter to yield the first polarized beam in the first polarization direction. The color separation and recombination prism is optically aligned to receive the first polarized beam. The prism has a second tilt axis, a plurality of color separating surfaces, and a plurality of exit surfaces.

Abstract: Single imager projection systems suffer from low light throughput, compared to three imager systems, because only one color band is illuminated at any one time. As a result, there is a need to increase the operating efficiency of the single imager projection system. The invention is directed to the incorporation of a high extinction ratio pre-polarizer, such as a compensated, multi-layer polarizer, in a single or dual imager projection system. This permits illumination with low f-number illumination light, and thus increases the efficiency of the projection system. The pre-polarizer may be incorporated within a polarization recovery unit to further enhance system efficiency.

Abstract: A projection system includes an image-forming device and a polarizing beamsplitter. Illumination light illuminates the image-forming device via the first polarizing beamsplitter. A retardation element is disposed between the image-forming device and the polarizing beamsplitter. A bias controller applies a bias to pixels of the image-forming device in the dark state so as to substantially maximize contrast in image light reflected from image-forming device. In some arrangements, the volume between the polarizing beamsplitter and the image-forming device is sealed, with the retarding element being disposed within the sealed volume and being attached to either the polarizing beamsplitter or the image-forming device.

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 projection system including an intrinsic polarizer is disclosed. The projection system includes a light source producing illumination light, an imager disposed to receive the illumination light, and a projection lens disposed to receive the illumination light from the imager. The imager includes an intrinsic polarizer. An intrinsic polarizer stack including a U.V. curable adhesive is also disclosed.

Abstract: A projection system including an intrinsic polarizer is disclosed. The projection system includes a light source producing illumination light, an imager disposed to receive the illumination light, and a projection lens disposed to receive the illumination light from the imager. The imager includes an intrinsic polarizer. An intrinsic polarizer stack including a U.V. curable adhesive is also disclosed.

Abstract: An optical system and a projection system incorporating same are disclosed. The optical system includes first and second optical elements. The second optical element is polarization insensitive in the visible. The first optical element is capable of receiving light of a first polarization along a first direction and transmitting the received light along the first direction. The first optical element is also capable of receiving light of a second polarization orthogonal to the first polarization along the first direction and reflecting the received light along a second direction different from the first direction. When the optical system receives light of the first polarization along the second direction, the first optical element transmits the received light along the second direction. The transmitted light has the first polarization and a first set of color coordinates. The second optical element transmits at least a portion of the light transmitted by the first optical element.

Abstract: Some projection systems use a polarization beamsplitter (PBS) for coupling light to and from an image-forming device. The PBS is typically formed with a reflective polarizing layer disposed between glass covers. Stress birefringence in the glass cover lying between the reflective polarizing layer and the image-forming device can reduce the image contrast of the projection system. A quarter-wave retarding element positioned between the glass cover and the image-forming device is used to compensate for the birefringence, at least in part. This permits the PBS to use glass covers formed of a glass material having a higher stress optic coefficient than before, while still maintaining high image contrast.

Abstract: Inhibiting formation of optical artifacts in a multi-layer film polarizer of an optical imaging assembly that includes a polarizing beam splitter. The beam splitter may include a multilayer reflective polarizing film having at least two materials, one of which may exhibit birefringence after uniaxial orientation; an adhesive disposed on the multilayer reflective polarizing film; and at least a first prism disposed on the adhesive. The adhesive may include a plasticizer for inhibiting formation of optical artifacts in the polarizing film.

Abstract: Generally, the present invention relates to an apparatus for reducing astigmatism in a projection system that is particularly well suited to reducing astigmatism in LCD projection systems. A projection system includes a light source to generate light, conditioning optics to condition the light from the light source and an imaging core to impose on image on conditioned light from the conditioning optics to form image light. The imaging core includes a polarizing beamsplitter and at least one imager, and at least one element in the imaging core is adapted to reduce astigmatism in the image light. The astigmatism may arise in the polarizing beamsplitter. A projection lens system projects the astigmatism-reduced image light from the imaging core.

Abstract: An image display system including an illumination source configured to emit a light beam, a polarizing beam splitter, and an image-forming device. The polarizing beam splitter includes a reflective polarizer and an absorptive polarizer disposed adjacent to the reflective polarizer, where the absorptive polarizer is configured to receive a first portion of the light beam that has transmitted through the reflective polarizer. The image-forming device is disposed to receive a second portion of the light beam that has been reflected by the reflective polarizer.

Abstract: A projection engine uses a first polarizing beam splitter (PBS) that substantially reflects light incident along a first input direction in a first polarization state and substantially transmits light incident in the first input direction in a second polarization state orthogonal to the first polarization state. The first PBS demonstrates an angularly dependent reflectivity for light in the second polarization state that is asymmetric about the first input direction. At least two imager devices are positioned to receive light reflected and transmitted by the first PBS respectively. The imager devices modulate the incident light with an image. The image light from the imagers is combined and projected.

Abstract: Single imager projection systems suffer from low light throughput, compared to three imager systems, because only one color band is illuminated at any one time. As a result, there is a need to increase the operating efficiency of the single imager projection system. The invention is directed to the incorporation of a high extinction ratio pre-polarizer, such as a compensated, multi-layer polarizer, in a single or dual imager projection system. This permits illumination with low f-number illumination light, and thus increases the efficiency of the projection system. The pre-polarizer may be incorporated within a polarization recovery unit to further enhance system efficiency.

Abstract: A polarizing beam splitter (PBS) includes a multilayer reflective polarizing film, a pressure sensitive adhesive is disposed on the multilayer reflective polarizing film, a first rigid cover is disposed on the pressure sensitive adhesive. The PBS can be used in a variety of applications.

Abstract: LCD projection systems that use reflective LCD imager units commonly use one or more polarization beamsplitters to separate the light incident on the imager from the light reflected by one or more respective imagers. The polarizing beamsplitters can be mounted onto a color combiner using an index matching layer and optical adhesive.