Optical scanning lens, optical scanning device and image forming apparatus

摘要

An optical scanning lens 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. The lens is formed by plastic molding of polyolefin resin, and the following condition is satisfied: 0<|Deltan(x)-min[Deltan(x)]|<34X10<-5>, where Deltan(x) denotes a refractive-index distribution existing inside the lens, in a range which the light flux passes through, in the lens, and min[Deltan(x)] denotes the minimum value of the Deltan(x).