Patent ID: 7929007

Claim:
A color image forming apparatus comprising: a light source that emits a light beam corresponding to a target surface for scanning; a coupling lens that couples the light beam to specific beam shape; a light collection optical system that collects coupled light beam coupled by the coupling lens in at least a sub-scanning direction; an optical deflector that deflects collected light beam collected by the light collection optical system in at least a main scanning direction; a scanning optical system that focuses deflected light beam deflected by the optical deflector on the target surface; a fold mirror that guides focused light beam focused by the scanning optical system toward the target surface; a light receiving element that detects a synchronization light beam; and the synchronizing optical system that focuses a synchronization light beam on the light receiving element, wherein the light source, the coupling lens, the light collection optical system, the optical deflector, the scanning optical system, the light receiving element, and the synchronizing optical system are arranged in a first optical box, at least the fold mirror is arranged in a second optical box, and an optical path length from a deflecting surface of the optical deflector to the light receiving element is shorter than an optical path length from the deflecting surface of the optical deflector to a center of a scanned area of the target surface in the main scanning direction.