OPTICAL SCANNER

摘要

PROBLEM TO BE SOLVED: To obtain an optical scanner which can prevent deterioration in image quality by eliminating variation in synchronization detection signals without incurring a large scale/a heavy weight of a deflector. SOLUTION: The optical scanner comprises: a light source unit which radiates a plurality of luminous fluxes simultaneously; a polygon mirror 10 which deflects the plurality of luminous fluxes in a main scanning direction Y; scanning lenses which focus the luminous fluxes deflected with the polygon mirror 10 on a face to be scanned (photoreceptor drum); and a synchronization detection means for detecting the write-in position (write-in beginning and/or write-in terminating position) of an image. The synchronization detection means detects the write-in beginning position of the image in the main scanning direction Y by using one of the luminous fluxes Ba, Bb and Bc except the luminous flux Bd which is reflected at a position which is the remotest position from the center in the main scanning direction Y on the reflection face 11 of the polygon mirror 10. COPYRIGHT: (C)2009,JPO&INPIT