| 摘要 |
PROBLEM TO BE SOLVED: To obtain an optical scanner in which performance deterioration such as occurrence of color shift is prevented even when asymmetric deformation of a scanning lens is caused at the positive and negative sides of an image height in a system in which luminous fluxes are deflected so as to be reversed in the scanning directions of the luminous fluxes on left and right sides of a deflector each other. SOLUTION: In the optical scanner, the luminous fluxes from a plurality of light sources are deflected to the left and the right sides with a single polygon mirror 5, and the deflected luminous fluxes are guided to a photoreceptor drum 50 with a first scanning lens 11, mirrors 21 to 28 and a second scanning lens 12. An SOS sensor 31A is arranged for detecting scanning start timing by receiving the luminous flux on the optical path By on the left upper side of the polygon mirror 5, an EOS sensor 32B is arranged for detecting the scanning end timing by receiving the luminous flux on the optical path Bm on the left lower side of the polygon mirror 5, and an SOS 34A is arranged for detecting the scanning start timing by receiving the luminous flux on an optical path Bk on the right upper side. COPYRIGHT: (C)2008,JPO&INPIT |
