| 摘要 |
<p>An optical projector (10) for projecting colour images from a liquid crystal display (LCD) or cathode ray tube (CRT), including means (500) for electronically compensating for keystone (trapezoidal) deformation of images projected onto a screen in a response to detection of the angle of inclination of the projector with respect to the plane (table) on which the projector is located. Inclination adjusting legs, screws (110,120), are threaded in a bottom portion (12) of the projector housing for manual adjustment. The leg extension is detected by means of a worm or gear portion (211,212) provided on the legs and meshing with a gear wheel (220) made of transparant material having an optical code pattern (221) of light transmissive and opaque regions (code disk). The angular position of the code disk is detected by a photoelectric light barrier (240) having a plurality of light emitting and receiving elements on opposed sides of the code disk. Memory means (400) including a lookup table for converting the detected angular position of the code disk into angular inclination of the projector housing are provided. <IMAGE></p> |
