Patent ID: 8045249

Claim:
An optical scanning device comprising: a light source; a deflection device configured to deflect light beam from the light source; an image focus optical system configured to focus an image on a surface scanned by the light beam deflected by the deflection device; a polarization switching device provided between the light source and the deflection device and in which a refraction factor varies depending on application of an acting force; and a polarization separation device provided between the light source and the deflection device, wherein a plurality of surfaces are scanned by varying a timing with which the light beam is deflected while a light path for the light beam from the light source is switched, and wherein the polarization switching device comprises a pair of transparent substrates, an orientation film sandwiched between the transparent substrates on an inner side of the substrates, a liquid crystal layer comprising a chiral smectic C phase layer having homogeneous orientation by the orientation film, and an acting force application device which applies an acting force in a substantially perpendicular direction relative to the transparent substrates.