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US 4,722,593 AGranted
Liquid-crystal projector with light beam reduction lens array for improved brightness of image outer portions
AssigneeCasio Computer Co., Ltd.
InventorTatsuo Shimazaki
Life of this patent
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Abstract
A liquid-crystal projector reduces outer portions of a light beam corresponding to a projection image from a liquid-crystal display panel illuminated with light from a light source by a light beam width reduction lens array in order to increase the luminance of the outer beam portions. The projection image passing through the light beam width reduction lens array is compensated for attenuation in luminance of the outer beam portions, and is then projected onto a screen surface through a projection lens system.
Claims6
A liquid-crystal projector comprising:
- light source means;
- liquid-crystal display panel means which is illuminated with light emitted from said light source means and in which an image displayed thereon is enlarged and projected onto a screen surface;
- light beam width reduction lens means which reduces the widths of outer portions of the light beam corresponding to the image displayed on said liquid-crystal display panel means in order to increase an optical density of the outer portions of the light beam;
- and
- projection lens means, arranged along the optical axis of said liquid-crystal display panel means, said light beam width reduction lens means, and said screen, for enlarging the image passing through said light beam width reduction lens means and projecting it onto said screen surface.
2 more elements
Dependencies are inferred from the claim text.