Patent ID: 8446444
Filing Date: 2013-05-21
Classification: G02B

Abstract:
1. An optical scanning device that scans a scanning area on a scanning target surface with a light beam and writes image data in an image area within the scanning area, the optical scanning device comprising: a light source including a plurality of light-emitting units; a deflector that deflects a light beam emitted from the light source; a scanning optical system that focuses the light beam deflected by the deflector on the scanning target surface; a monitoring photoreceiver that receives a part of a light beam deflected by the deflector and directed toward an area within the scanning area outside the image area; and a detecting unit that individually detects emission powers of at least two light-emitting units based on an output signal of the monitoring photoreceiver in a single sweep of scanning, and wherein the monitoring photoreceiver includes a single light-receiving unit, and the detecting unit sets at least one of the light-emitting units as an offset light-emitting unit, causes at least two light-emitting units from among the light-emitting units other than the offset light-emitting unit to be turned on one by one together with the offset light-emitting unit in a single sweep of scanning, and individually detects emission powers of the at least two target light-emitting units based on an output signal of the monitoring photoreceiver when the at least two target light-emitting units are turned on one by one together with the offset light-emitting unit and an output signal of the monitoring photoreceiver when the offset light-emitting unit alone is turned on.