Patent ID: 6407871
Filing Date: 2002-06-18
Classification: G02B,H04N

Abstract:
An optical device, for eliminating the stray light, provided at a stop of an illuminating system in an optical system of â€œdigital light processingâ€  (DLP) including the stop of an illuminating system, a â€œdigital micromirror deviceâ€  (DMD), a stop of a projection lens, and a screen, where the stray light is a chromatic halo at the peripheral area on the screen, wherein said optical device comprising:a reflecting mirror designed of an adjustable angle and installed near periphery of the stop of the illuminating system; wherein, the chromatic halo is generated by the light beam that is near the stop of the illuminating system and is reflected from the DMD into the stop of the projection lens, and then is projected on the screen, while said reflecting mirror is used to reflect the light beam at the periphery area so as to divert the original transmitting path of the light beam such that the light beam at the periphery area is reflected from the DMD and is uniformly transmitted into the stop of the projection lens so as to increase the contrast ratio of the illuminating system, to improve the quality of the output image, to enhance the efficiency of the DLP system, and to improve the luminance of the image projected on the screen.