摘要:
The present invention provides a unique polarizing beam splitter (PBS) that is suitable for use in projection systems and displays. The PBS contains at least one prism having at least one major surface and having a refractive index of at least about 1.6 and a birefringent film disposed on the major surface of the prism. The birefringent film is a multi-layer film having layers of at least a first material and a second material. After uniaxial stretching, the film exhibits a refractive index difference of less than about 0.15 units in the stretched direction.
摘要:
The present invention provides a unique polarizing beam splitter (PBS) that is suitable for use in projection systems and displays. The PBS contains at least one prism having at least one major surface and having a refractive index of at least about 1.6 and a birefringent film disposed on the major surface of the prism. The birefringent film is a multi-layer film having at layers of at least a first material and a second material. After uniaxial stretching, the film exhibits a refractive index difference of less than about 0.15 units in the stretched direction.
摘要:
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.
摘要:
An optical imaging system including a wide-angle Cartesian polarizing beam splitter, light valve illumination optics having an f/#≦2.5, and at least one reflective light valve. The Cartesian polarizing beam splitter (PBS) has a structural orientation defining fixed polarization axes. The use of a Cartesian PBS allows the development of systems using curved PBS that provide higher light output and/or replace or augment other optical components. By recognizing and advantageously applying properties of wide-angle Cartesian polarizers, the present invention discloses a high-efficiency optical imaging system capable of functioning at f/#'s equal to or below f/2.5 while maintaining a contrast ratio of at least 100 to 1, or, more preferably, 150 to 1 in a projection system configuration.
摘要:
An optical imaging system including a wide-angle Cartesian polarizing beam splitter, light valve illumination optics having an f/#≦2.5, and at least one reflective light valve. The Cartesian polarizing beam splitter (PBS) has a structural orientation defining fixed polarization axes. The use of a Cartesian PBS allows the development of systems using curved PBS that provide higher light output and/or replace or augment other optical components. By recognizing and advantageously applying properties of wide-angle Cartesian polarizers, the present invention discloses a high-efficiency optical imaging system capable of functioning at f/#'s equal to or below f/2.5 while maintaining a contrast ratio of at least 100 to 1, or, more preferably, 150 to 1 in a projection system configuration.
摘要:
Optical elements, color combiners using the optical elements, and image projectors using the color combiners are described. The optical elements can be configured as color combiners that receive different wavelength spectrums of light and produce a combined light output that includes the different wavelength spectrums of light. In one aspect, the received light inputs are unpolarized, and the combined light output is polarized in a desired state. The optical elements are configured to minimize the passage of light which may be damaging to wavelength-sensitive components in the light combiner. Image projectors using the color combiners can include imaging modules that operate by reflecting or transmitting polarized light.
摘要:
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. The surfaces of each polarizing beam splitter can be polished so that the light utilization efficiency is increased due to total internal reflection within the polarizing beam splitter. The light combiners can combine up to five unpolarized different color lights to produce an unpolarized polychromatic light output, which may be white light useful for a projection display. The light splitters can split unpolarized polychromatic light to produce up to five unpolarized different color light outputs.
摘要:
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.
摘要:
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.
摘要:
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.