Television – Video display – Projection device
Patent
1996-05-29
1999-05-25
Casler, Brian L.
Television
Video display
Projection device
348756, 348757, 348779, 348780, H04N 997
Patent
active
059073730
ABSTRACT:
In a projection type image display device for combining an image by dichroic mirrors in a form of parallel plane plate, a projected image of high picture quality is presented by suppressing the astigmatism. In a projection type image display device comprising a light source for emitting blue light, green light, and red light, liquid crystal panels for modulating individual color lights, dichroic mirrors for combining the modulated lights, dichroic mirrors for combining the modulated lights, and a projection lens for projecting the combined light, the dichroic mirrors are disposed obliquely on a first plane including an optical axis linking the projection lens and liquid crystal panels, and a parallel plane plate for correcting astigmatism is disposed obliquely on a second plane orthogonal to the first plane. In particular, preferably, the thickness of the parallel plane plate for correcting the astigmatism should be greater than the thickness of the dichroic mirrors, and the light incident angle into the parallel plane plate for correcting the astigmatism should be smaller than the light incident angle to the dichroic mirrors.
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Casler Brian L.
Din Luanne P.
Matsushita Electric - Industrial Co., Ltd.
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