Optical scanning unit and image forming apparatus

摘要

An optical scanning unit includes a light source that emits a light beam, a light deflector that deflects the light beam from the light source, and a scanning optical system that focuses the light beam deflected by the light deflector on a scanning surface. The light beam from the light source is at an angle in a secondary scanning direction with respect to a normal to a reflecting surface of the light deflector. At least one surface of the scanning optical system does not have a curvature in the secondary scanning direction, being tilted and decentered in the secondary scanning direction.