US Patent 7247841 Light scanning apparatus

Provided is a light scanning apparatus, including a light source, a light source controller to control an on/off operation of the light source, a light deflector deflecting light emitted from the light source, an image formation optical system to direct light deflected by the light deflector on a scan area of a to-be-scanned surface, a synchronous signal detector to receive the light emitted from the light source and to detect a synchronous signal for light scanning, and a light path changer changing a path of light emitted from the light source and incident upon the light deflector.