Patent ID: 6937374
Filing Date: 2005-08-30
Classification: G02B

Abstract:
1. A scanning optical system that emits at least two beams to a plurality of surfaces to be scanned, comprising: a polygonal mirror that is rotated about a rotation axis thereof to deflect the at least two beams simultaneously to scan in a main scanning direction, the at least two beams incident on said polygonal mirror along a plurality of optical paths arranged symmetrically with respect to a plane perpendicular to said rotation axis; and an imaging optical system that converges the at least two beams deflected by said polygonal mirror on the plurality of surfaces to be scanned, said imaging optical system including at least two lenses, each of said at least two lenses converging an incident beam, in an auxiliary scanning direction which is perpendicular to the main scanning direction, on a corresponding surface to be scanned, the at least two beams deflected by said polygonal mirror passing through said at least two lenses, said at least two lenses having the same shapes and being arranged symmetrically with respect to the plane, an orientation of one of said at least two lenses being oriented oppositely by 180° rotation, in the auxiliary scanning direction, to the other one of said at least two lenses.