UNIDIRECTIONALLY LONG RESIN LENSE, MOLD AND METHOD FOR MOLDING THE SAME, RESIN LENS UNIT, SCANNING IMAGE FORMING OPTICAL SYSTEM, OPTICAL SCANNING APPARATUS AND IMAGE FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To effectively reduce or prevent the bending of a scanning line or variation of a spot diameter caused by the curving of the resin lens long in a main scanning direction and contained in the scanning image forming optical system of an optical scaning apparatus. SOLUTION: Molding is performed using a mold, of which the mold reference cross section (the interior of an LS mold) corresponding to the reference cross section LS of the lens is curved in the direction reverse to the curving of the lens, so that the reference cross section of the lens becomes a flat surface substantially as a result of the curving of the lens generated in its longitudinal direction accompanied by molding.