Patent ID: 6018408
Filing Date: 2000-01-25
Classification: G02B,H04N

Abstract:
A laser projection display apparatus comprising:an optical separating device for separating a white light beam emitted from a first optical source into red, green, and blue monochromic light beams;an image signal processing unit for separating a received composite image signal into an image signal and horizontal and vertical synchronous signals;an optical modulator for modulating the monochromic beams according to the image signal output by the image signal processing unit;a galvanometer and a rotating polygonal mirror for vertically and horizontally projecting the modulated beams, respectively, on a screen;a second optical source for radiating light on the reflection planes of the rotating polygonal mirror; andan optical detector for detecting light emitted from the second optical source and reflected by the reflection planes of the rotating polygonal mirror, and transmitting the detection signal to the image signal processing unit, when a starting point of horizontal projection by the rotating polygonal mirror is made on a predetermined vertical line on the screen,wherein the image signal processing unit synchronizes the image signal with the detection signal of the optical detector and outputs the synchronized image signal to the optical modulator.