Patent ID: 7969460

Claim:
An optical scanning device, comprising: a light source including multiple light-emitting elements, the multiple light-emitting elements being arranged in a linear manner; a collimator lens configured to collimate a light beam from the light source; a light-deflecting device configured to deflect a light beam having passed through the collimator lens to a medium to be scanned and configured to scan the medium to be scanned with the light beam; and a rear optical system arranged in an optical path between the collimator lens and the medium to be scanned, wherein the collimator lens is configured to deviate an image surface in a direction opposite to an image surface deviation on the medium to be scanned by a substantially same amount as the image surface deviation, the image surface deviation being caused by a change of an image height of the light source, and the change of the image height being caused by the rear optical system, and wherein a position of the collimator lens relative to a position of the light source along an optical axis of the collimator lens is fixed such that an adjustment of an image surface deviation in the collimator lens is conducted by an adjustment of a conic constant of a front surface of the collimator lens at a light source side or a back surface of the collimator lens at a light exit side.