Patent ID: 8130431

Claim:
An optical scanning apparatus, comprising: a light source that irradiates a laser beam; a rotating polygon mirror that deflects and scans a laser beam from the light source; and a light blocking member that is disposed facing a reflective face of the rotating polygon mirror, and blocks other light without blocking light in an effective scanning range of the laser beam; wherein an opposing face of the light blocking member that faces the reflective face of the rotating polygon mirror is inclined, wherein when a support member side where the rotating polygon mirror is rotatably attached and supported is defined as a lower side, and a side where the rotating polygon mirror is disposed relative to this support member is defined as an upper side, the opposing face of the light blocking member inclines downward from an upper edge of the opposing face nearest to the reflective face of the rotating polygon mirror so that the distance from the reflective face becomes wider downward.