Patent ID: 8705157

Claim:
An optical scanning device comprising: a first light source unit configured to emit a first laser beam; a second light source unit configured to emit a second laser beam; a deflector disposed to face the first and second light source units in a predetermined direction, the deflector being configured to reflect and deflect the first laser beam emitted by the first light source unit and the second laser beam emitted by the second light source unit in a main scanning direction; a first reflecting mirror configured to reflect the first laser beam deflected by the deflector toward a first scanned surface; a second reflecting mirror configured to reflect the second laser beam deflected by the deflector toward a second scanned surface; and a casing configured to accommodate the first light source unit, the second light source unit, the deflector, the first reflecting mirror, and the second reflecting mirror, the casing comprising: a supporting wall configured to support the deflector; a first reflecting mirror supporting portion formed in a pillar shape to extend from the supporting wall, the first reflecting mirror supporting portion being configured to support the first reflecting mirror; a second reflecting mirror supporting portion formed in a pillar shape to extend from the supporting wall at a side opposed to the first reflecting mirror supporting portion across the deflector in a direction perpendicular to the predetermined direction, the second reflecting mirror supporting portion being configured to support the second reflecting mirror; and a reinforcing wall disposed in a position separated from the first and second light source units in the predetermined direction, the position being between the deflector and the first and second light source units, the reinforcing wall extending from the supporting wall and linearly extending in the direction perpendicular to the predetermined direction throughout a whole distance between the first reflecting mirror supporting portion and the second reflecting mirror supporting portion, the reinforcing wall comprising a first through-hole configured such that the first laser beam emitted by the first light source unit toward the deflector and the second laser beam emitted by the second light source unit toward the deflector pass therethrough.