Patent ID: 6330524
Filing Date: 2001-12-11
Classification: G02B

Abstract:
A scanning optical system for scanning and forming an image on a photosensitive member through an f.theta. lens for converging a beam light and for implementing f.theta. compensation by reflecting a beam light generated from a light source with a rotating polygon mirror, wherein:said f.theta. lens comprises a single lens designed by using an optional term containing an odd-numbered degree and an even-numbered degree for each of .SIGMA. A.sub.n.vertline.X.sup.n.vertline., .SIGMA. B.sub.m.vertline.X.sup.m.vertline., and .SIGMA. G.sub.j X.sup.2j in an aspherical formula representing a shape of each of an incident surface or an outgoing surface of the f.theta. lens, which is represented as follows: ##EQU8##Origin: a crossing point of f.theta. lens and light axis, Z-axis: light axis direction,X-axis: main scanning direction, Y-axis: sub-scanning directionwhere Cx, K, An, Cy, Bm, Ky, and Gj are each an optional coefficient; andu, v, and w are each an integer.