Patent ID: 6400391
Filing Date: 2002-06-04
Classification: B41J,G02B,Y10S

Abstract:
An optical scanning lens which is used in a scanning and image forming optical system which gathers a light flux deflected by a light deflector in the vicinity of a surface to be scanned, wherein:said lens is formed by plastic molding of polyolefin resin; and the following condition is satisfied 0n(x)âˆ’min[&Dgr;n(x)]|<34Ã—10âˆ’5â€ƒâ€ƒ(A) where&Dgr;n(x) denotes a refractive-index distribution existing inside said lens, in a range which the light flux passes through, in said lens, and min[&Dgr;n(x)] denotes the minimum value of said &Dgr;n(x); &Dgr;n(x) is expressed as an average value along the optical-axis direction of the optical scanning lens in a section parallel to the optical axis and the sub-scanning direction; and &Dgr;n(x) is expressed as a one-dimensional relative refractive index with respect to the sub-scanning direction.