Patent ID: 7084896

Claim:
A multi-beam scanning device, comprising: a light source that emits a plurality of light beams; a polygonal mirror that deflects the light beams emitted by said light source to scan an object; and an optical system that converges the deflected light beams on a plurality of objects to be scanned, the plurality of objects being arranged on a side, with respect to said polygonal mirror, in which said light beams scan, from a position closer to said polygonal mirror to a position farther from said polygonal mirror, said optical system including a plurality of optical path turning systems that turn optical paths of the deflected light beams, each of said optical path turning systems comprising a first reflection surface, the first reflection surface of each of said optical path turning systems being separate from the first reflection surface of every other optical path turning system, each of said first reflection surfaces being positioned along a direction in which the light beams are deflected by the polygonal mirror, optical path lengths of the optical paths being substantially the same, and all of said optical path turning systems including an even number of reflection surfaces, wherein the optical path turning system which is the farthest away from the polygonal mirror includes a prism having two reflection surfaces, said first reflection surface being one of the two reflection surfaces of said prism.