Patent ID: 6078419
Filing Date: 2000-06-20
Classification: B41J,G02B

Abstract:
An optical scanning apparatus comprising:a light source unit for emitting a light beam for optical scanning;an image-forming lens for producing a line image, elongated in a main-scanning direction, of the light beam from said light source unit;a beam deflector for causing the line image to be reflected by its deflecting and reflecting surface so as to produce a deflected light beam deflected at a constant angular velocity;a reflective optical system including a plurality of reflecting mirrors for reflecting the deflected light beam incident on said reflective optical system a plurality of times; whereinreflecting surfaces of the plurality of reflecting mirrors are tilted with respect to a system axis of said optical scanning apparatus;said reflective optical system includes an image-forming mirror for converging the deflected light beam to form a beam spot for scanning a scanned surface at a constant velocity wherein the number of reflections of the deflected light beam performed by said image-forming mirror is more than one; andsaid image-forming mirror has an anamorphic configuration obtained by rotating a curve drawn with a first radius on a main-scanning plane, around an axis residing on the main-scanning plane and parallel with the main-scanning direction, maintaining a second radius.