Patent ID: 8922863

Claim:
An optical scanning device which separately scans a plurality of scan target surfaces in a first direction with light, the optical scanning device comprising: a light source unit configured to emit a first light beam and a second light beam mutually different in polarization state; an optical deflector configured to rotate around an axis parallel to a second direction perpendicular to the first direction, and deflect the first light beam and the second light beam emitted from the light source unit; an imaging optical element provided on respective optical paths of the first light beam and the second light beam deflected by the optical deflector; a polarization adjustment element provided on the optical paths of the first light beam and the second light beam transmitted through the imaging optical element, and configured to correct respective changes in polarization state of the first light beam and the second light beam occurring during the transmission of the first light beam and the second light beam through the imaging optical element; and a polarization separation element provided on the optical paths of the first light beam and the second light beam emitted from the polarization adjustment element, and configured to separate the first light beam and the second light beam from each other.