Patent ID: 7573496
Filing Date: 2009-08-11
Classification: B41J,G02B

Abstract:
1. A scanning optical apparatus, comprising: a light source for outputting a beam light; a polygon mirror for reflecting said beam light outputted from said light source and then transforming said beam light into a scanning light on a prescribed scanning surface as rotating about a rotational axis along a sub scanning direction; and a lens system provided on a light pat of said beam light in between said polygon mirror and said scanning surface; said lens system comprising a curvature changing lens which monotonically changes, respectively, curvature of a cross section in said sub scanning direction of an incident surface and an outputting surface of said beam light with respect to a distance from a predetermined center position in a main scanning direction, as a scanning direction of said beam light, intersecting wit said sub scanning direction; said curvature of the incident surface of the curvature changing lens monotonically increases according to the distance in the main scanning direction from the predetermined center position of the curvature changing lens, and the curvature of the outputting surface of the curvature changing lens monotonically decreases with respect to the distance in the main curvature changing direction from the predetermined center position of the scanning lens.