Optical: systems and elements – Single channel simultaneously to or from plural channels
Patent
1997-12-11
1999-09-28
Ben, Loha
Optical: systems and elements
Single channel simultaneously to or from plural channels
359629, 359638, 359589, 348757, 348333, 349 8, G02B 2710, G03B 2141
Patent
active
059597780
ABSTRACT:
Apparatus is disclosed that provides a high-luminance projected image with no color shading or uneven contrast. Light from a light source undergoes color separation by passing through a color-separation optical system (e.g., a cross-dichroic mirror or cross-dichroic prism). The light from the light source can also be split into first and second polarized lights by passage through, e.g., a first polarized-light beamsplitter (PBS). Each color-separated light is modulated by a respective color-signal light valve and undergoes color combining by, e.g., a cross-dichroic prism. The second polarized light, if formed, is modulated by a luminance-signal light valve, undergoes color combining and polarized-light combining by, e.g., a second PBS, and is projected by a projection lens (that comprises an aperture stop). The PBSs, cross-dichroic mirrors, and cross-dichroic prisms are situated where principal rays (defined by the aperture stop) are parallel to the optical axis. The first PBS (if present) and color-separation optical system are preferably arranged between a front illumination lens group and a rear illumination lens group both comprising an illumination relay optical system telecentric on both front and rear sides thereof. Field lenses and relay lenses can be included that comprise a relay optical system forming a magnified image of the color-signal light valves at a position conjugate to the luminance-signal light valve with respect to the projection lens.
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Hattori Tetsuo
Kusano Masaaki
Manabe Yuji
Sekine Atsushi
Shimonura Hideaki
Ben Loha
Mitsubishi Denki & Kabushiki Kaisha
Nikon Corporation
Sparkman Klarquist
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