Patent ID: 8767280

Claim:
An optical scanning device comprising: a light source part that is provided in a resin-molded casing and emits a laser beam; a deflector that is arranged in the casing downstream of the light source part with respect to an emission direction of the laser beam and deflects and scans the laser beam, the deflector including, a rotary polygon mirror that reflects the laser beam, a driving source that is configured to rotate the rotary polygon mirror, and a substrate member that supports the rotary polygon mirror and the driving source and is fixed to the casing; and the casing including, a fixed wall that extends in a direction perpendicular to a mirror surface of the rotary polygon mirror, a first fixing part that is provided to the fixed wall and fixes the light source part, a second fixing part that is provided to the fixed wall and fixes the substrate member, and a reinforcing part that is provided to the fixed wall and extends toward the emission direction so as to continuously connect the first fixing part and the second fixing part.