BEAM LIGHT SCANNING APPARATUS AND IMAGE FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a beam light scanning apparatus wherein the position of beam light on a face to be scanned can be always controlled at an appropriate position and high quality of image can be always kept thereby. SOLUTION: In a digital copying machine using a multi-beam optical system, passing position of each beam light scanned by a polygon mirror is detected by means of a beam light detector 38 arranged in the neighborhood of the surface of a photosensitized body drum 15 and the amt. of controlling optical path for controlling is operated in such a way that the relative position of each beam light on the photosensitized body drum 15 is at an appropriate position based on this detected result and in accordance with this operated amt. of controlling optical path, galvanomirrors 33a-33d for changing the relative position on the surface of the photosensitized body drum of each beam light are driven to control each beam light at an ideal position. In addition, a clock pulse is generated by synchronizing the beam light passing timing detected by the beam light detector 38 and laser oscillators 31a-31d are modulated by driving in synchronizing the clock pulse to form an image.