Patent ID: 7538925

Claim:
An optical scanner comprising: a plurality of light source units, each light source unit outputting a corresponding light beam; a light deflector having a deflecting surface that deflects the light beams output from the light source units; and a scanning optical system that condenses each light beam deflected by the light deflector onto a corresponding scanning surface, wherein a direction in which the light beams scan the scanning surface is a main scanning direction, wherein the light beams output from the light source units make an angle in a sub-scanning direction with respect to a plane normal to the deflecting surface, wherein the sub-scanning direction is a direction perpendicular to the main scanning direction, wherein at least one surface of the scanning optical system is a surface that does not have a curvature in the sub-scanning direction and wherein a line describing the surface in the sub-scanning direction has a tilt which varies depending on a location of the line in the main scanning direction, and wherein the tilt of the line defines an angle which is measured with respect to the sub-scanning direction.