Birch, Stewart, Kolasch & Birch
Optical system for an LCD projector
 An optical system for an LCD projector comprising an illuminating device, an infrared filter, an optical system and a projecting lens comprises a 45.degree. horizontally inclined blue light tranmission filter, a 45.degree. horizontally inclined green light reflection mirror, a 45.degree. horizontally inclined red image reflection mirror, a 45.degree. horizontally inclined blue image transmission filter, three total reflection mirrors, three condensing lenses, three LCD panels, and separates red, green and blue light elements from the light having been transmitted through the infrared filter, then reemerging an image in respective colors by using the separated red, green and blue light elements in order to compose the reemerged image. The projector lens projects the composed image from the optical system on a screen as an enlarged image and the LCD projector according to this invention can provide a compensation of the red light radiation by red optical path considerably longer than those of the green and the blue optical paths, a considerably high luminance due to using the metal halide lamp, low manufacturing cost, an image of a good resolution power because of reducing the vignetting, also a compactness of its projection lens. 
Goldstar Co., Ltd.
H
H04N
inventional
Seung G.
Lee