Image projection system with multiple arc lamps and flyseye lens array light homogenizer directing polychromatic light on a liquid crystal display

摘要

A projector ( 12 N) of this invention employs a 380 mm diagonal, amorphous silicon LCD ( 80 ) for receiving light rays from a light source ( 70 ), which achieves a small source size by employing four lamps ( 160 ) with small arc gaps ( 166 ) and a "pinwheel" mirror ( 164 ) that overlaps light rays from each of the arc lamps into a single collimated light bundle. The small source size produces a small cone angle ( 130 ) of light through the LCD. A lens ( 78 ) directs the narrow cone of light though the LCD at an optimal angle for achieving a 1,500:1 contrast ratio. Only a 4x magnification ratio is required to achieve a 170 cm (67 inch) diagonal projected image, which ratio enables projecting SXGA or greater resolution images with a five element projection lens ( 86 ). The LCD achieves an operational life of at least 50,000 hours before projected images display color degradation.