发明名称 |
Optical overhead projector for electronic images |
摘要 |
A relatively small liquid-crystal display (LCD) device located well above the fresnel stage of an overhead projector produces large, sharp images with full color and motion. A focus-correcting lens moves with the overhead projector's optical head to maintain proper projection-focus and magnification. Spectrally-selective filters are interposed between the LCD device and fresnel stage to avoid LCD deterioration. A fan-actuated shutter or electrically-actuated shutter optionally provide still further protection. Optical collimation methods are employed to attain a large depth-of-field and image brightness.
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申请公布号 |
US5260730(A) |
申请公布日期 |
1993.11.09 |
申请号 |
US19930008503 |
申请日期 |
1993.01.25 |
申请人 |
NUMA CORPORATION |
发明人 |
WILLIAMS, RICHARD E.;CLOUGH, ERNEST F.;DANIEL, MARK L. |
分类号 |
G02F1/133;G02F1/13357;G03B21/132;(IPC1-7):G03B21/00 |
主分类号 |
G02F1/133 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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