Patent ID: 7012725

Claim:
A polygon mirror which is bonded to a connection member that connects the polygon mirror to a bearing to support the polygon mirror about an axis of rotation thereof, said polygon mirror comprising: a mirror body which is shaped as a regular polygon and includes circumferential surfaces, a top surface and a bottom surface, and which comprises a reflection surface formed on each of the circumferential surfaces; a machining reference surface which is provided on one of the top and bottom surfaces, and which is machined to have a mirror surface and is used as a reference surface for machining the reflection surface on each of the circumferential surfaces; and an assembling reference surface which is provided on one of the top and bottom surfaces and is parallel to the machining reference surface, and which is machined to have a rougher surface than the machining reference surface; wherein the assembling reference surface is used as a reference surface for bonding the polygon mirror to the connection member with an adhesive.