Patent ID: 6937372
Filing Date: 2005-08-30
Classification: G02B,G06K,H04N

Abstract:
1. A light beam deflecting apparatus provided with: a light source for emitting a light beam; modulation means for modulating the light beam emitting intensity of said light source; modulation signal generation means for outputting a modulation signal to said modulation means; a light beam deflecting device for deflecting the light beam emitted from said light source to conduct reciprocating scans; drive means for driving said light beam deflecting device; drive signal generation means for outputting a drive signal of a predetermined cycle period to said drive means; and measurement means for respectively measuring two times at which the light beam in reciprocating scan passes a specified position on a scanning line in forward and backward motions relative to a synchronization signal synchronized with the drive signal as a reference, the apparatus comprising: time lag data calculation means for calculating, based on the measured two passing times in the forward and backward scans, time lag data corresponding to the time lag of the reciprocating scans of the deflecting device relative to the synchronization signal as a reference; and timing data calculation means for calculating, based on the measured two passing times in the forward and backward scans and based on the calculated time lag data, timing data that is referenced to the synchronization signal and that corresponds to a modulation start time or a modulation end time for the light beam within a scanning cycle period; wherein the modulation signal generation means outputs a modulation signal to the modulation means, based on the calculated timing data.