Being the scan glass lens which forms the scan optical system of the light scanning device which condenses

摘要

PPROBLEM TO BE SOLVED: To obtain a scanning lens that can prevent reverse mounting of the scanning lens asymmetrically shaped in the main scanning direction relative to the optical axis, without installing projections for preventing the reverse mounting in the scanning lens and the housing, and that can ensure surface accuracy of the scanning lens face, and also to obtain a scanning optical system, an optical scanner and an image forming apparatus using the lens. PSOLUTION: The scanning lens 10 constituting the scanning optical system of the optical scanner that converges a luminous flux deflected by an optical deflector on a surface to be scanned is composed of at least one lens and formed asymmetrically in the main scanning direction. The positioning reference 12, 14 in the main scanning direction is installed in a pair in the subscanning direction across the optical axis, and the shape of each positioning reference 12, 14 is made different in the width and length. The pair positioning reference 12, 14 each has nearly the same projection area. PCOPYRIGHT: (C)2006,JPO&NCIPI