OPTICAL SCANNER, IMAGE FORMING APPARATUS HAVING THE SAME, METHOD OF CORRECTING VARIATION IN SCANNING LINE OF THE SAME AND METHOD OF CORRECTING VARIATION IN SHADING

摘要

PPROBLEM TO BE SOLVED: To provide an optical scanner having small color shift and nonuniformity of density by a simple configuration and method without extremely enhancing the accuracy of plastic lenses. PSOLUTION: The optical scanner 21 has four optical scanning units 21Y, 21 M, 21C and 21K which are provided corresponding to a plurality of developing colors and have a plastic lens 1 and a plurality of turning back mirrors 5, respectively. Among them, the plastic lens 1 of the optical scanning unit 21Y and the plastic lens 1 of the optical scanning unit 21M are formed with one and the same cavity of an injection molding metallic mold, and are fixed on mounting bases 12 disposed on one and the same plane of an optical housing 6, being directed in plane symmetry interposing a virtual plane therebetween which includes the turning axis P of a polygon mirror 3 and is parallel to a main scanning direction S, respectively. PCOPYRIGHT: (C)2008,JPO&INPIT