Patent ID: 8922614

Claim:
A light scanning unit capable of scanning light beams to a scanning target surface, the light scanning unit comprising: a light source emitting the light beams according to an image signal; an incident optical system comprising a flux-limiting element limiting a flux of light beams emitted by the light source; an optical deflector deflecting the light beams emitted by the light source in a main scanning direction; and an image forming optical system comprising one or a plurality of scanning optical elements imaging the light beams deflected by the optical deflector on the scanning target surface, wherein at least one scanning optical element of the one or the plurality of scanning optical elements of the image forming optical system is eccentrically arranged from a central optical axis of the image forming optical system in a sub-scanning direction, and wherein the flux-limiting element is eccentrically arranged from a central optical axis of the incident optical system in a sub-scanning direction in order to compensate for a deterioration of beam spot diameter occurring due to the scanning optical elements eccentrically arranged in the image forming optical system.