Patent ID: 7295359

Claim:
A light beam scanner comprising: a plurality of image carriers; a deflecting member configured to deflect plural light beams at constant angular velocity by rotation of a reflective surface of the deflecting member, the plural light beams being incident on the reflective surface at different incident angles in a secondary scanning direction perpendicular to a primary scanning direction that is parallel with axes of the image carriers, the plural light beams corresponding with respective images formed of respective color materials which are different in lightness from each other; a transformation member configured to deflect the plural light beams thus deflected by the deflecting member so that each of the plural light beams deflected by the transformation member scans a surface of an associated one of the image carriers at a constant velocity in the primary scanning direction; and separating members arranged to separate the plural light beams thus deflected by the transformation member from each other in respective directions toward the surfaces of the respective image carriers, wherein any one of the plural light beams, except a light beam incident on the deflecting member at a widest incident angle of the different incident angles in the secondary scanning direction, corresponds with an image formed of a color material which is lowest in lightness of the color materials.