Polygonal mirror, light scanning unit employing the polygonal mirror and image forming apparatus

摘要

PURPOSE: A polygonal mirror, an optical scanning device, and an image forming apparatus employing the same are provided to minimize performance reduction due to operational heat or high-speed rotation. CONSTITUTION: A polygonal mirror(11) is formed by injection molding a plastic material and has an inner mirror surface(11b) defining a central hole and a plurality of reflective surfaces(11a) prepared on the outer side. The outer surface of a holder frame contacts the inner mirror surface of the polygonal mirror and bonded with an adhesive. The reflective surfaces are formed by attaching a metal film, such as aluminum or silver, having superior reflectivity.