Patent ID: 6677974
Filing Date: 2004-01-13
Classification: G06K,H04N

Abstract:
A light beam scanning apparatus for scanning a light beam across an image bearer on which a latent image is formed, said light beam scanning apparatus comprising:a light emitter for emitting a light beam in accordance with the latent image to be formed on the image bearer; an optical system for guiding the light beam emitted by the light emitter to the image bearer and for scanning the light beam across the image bearer in a main scanning direction thereof one line at a time, based on a synchronization signal; and a synchronization signal detector for detecting a synchronization signal, said synchronization signal detector including a photoelectric conversion element that detects the light beam scanned by the optical system in units of one cycle and converts the detected light beam into an analog signal, said synchronization signal detector digitizing the analog signal obtained by the photoelectric conversion element based on a reference signal supplied from an external circuit, and thereby obtaining a digital signal that serves as the synchronization signal, wherein said image bearer rotates at a predetermined outer peripheral speed of a predetermined value; and said synchronization signal detector performs digitizing processing based on said reference signal supplied from the external circuit in accordance with an accumulative number of rotations the image bearer makes.