Patent ID: 7149018

Claim:
An optical scanning device comprising a first optical system and a second optical system that are provided in one housing frame, each of the first optical system and the second optical system comprising: two light sources, one optical deflector for scanning light beams from the two light sources with mutually different deflection faces of the optical deflector, two first imaging optical systems that are arranged between the optical deflector and the two respective light sources, that guide the light beams from the two light sources to the deflection faces of the optical deflector, and that form linear images on the deflection faces, and two second imaging optical systems that are arranged between the optical deflector and two respective surfaces to be scanned, that guide the light beams from the optical deflector to the two surfaces to be scanned, and that form images on the two surfaces to be scanned, wherein the optical scanning device simultaneously exposes, by scanning, the four surfaces to be scanned, and wherein the optical deflector provided in the first optical system and the optical deflector provided in the second optical system rotate in mutually opposite directions.