Patent ID: 7446918

Claim:
A light scanning device for scanning a scanned member by deflecting on a rotational multifaceted mirror a laser light irradiated from a scanning light source, the light scanning device comprising: a first optical system for forming the laser light irradiated from the light source into a parallel light flux; a second optical system for collecting the laser light formed into the parallel light flux toward a sub-scanning direction perpendicular to a main scanning direction, which is a direction to perform the scanning to form an image linearly on the rotational multifaceted mirror; and a third optical system having a function to render a scanning speed of the laser light deflected by the rotational multifaceted mirror on the scanned member to be a constant speed and form a spot-like image of the laser light deflected by the rotational multifaceted mirror on said scanned member, wherein the third optical system includes a correction lens whose incident side surface and outgoing side surface in a cross section in the sub-scanning direction perpendicular to the main scanning direction have respective curvature radii different from one another, and the correction lens is so configured as to be rotatable about a line passing through an intersection between an optical axis of the correction lens and a surface having a smaller curvature radius among the surfaces, and being parallel to the main scanning direction.