Patent ID: 7034859
Filing Date: 2006-04-25
Classification: G02B

Abstract:
1. An optical scanning device, comprising: light source means; deflecting means for deflecting a light beam emitted from said light source means; and a scanning optical system for scanning a surface to be scanned, with the light beam deflected by said deflecting means; wherein said scanning optical system includes a scanning optical element disposed so that, with respect to a sub-scan direction, a principal ray of the deflected light beam passes a portion other than an optical axis of the scanning optical system, wherein said scanning optical element has a sagittal aspherical amount changing surface in which an aspherical amount of a sagittal changes along a main scan direction of said scanning optical element, and wherein, within an effective scan range upon the surface to be scanned, the position in the sub-scan direction upon which the deflected light beam impinges is made even.