| 摘要 |
PROBLEM TO BE SOLVED: To reduce the fluctuations of an optical scanning position in a sub-scanning direction caused by the holding style of two lenses constituting the optical system of an optical scanner by allowing both of the two lenses to be a resin lens.SOLUTION: In the optical scanner, a housing 12 holding a single anamorphic lens 2 made of resin, forming a long line image in a main scanning direction, a light deflector 4 deflecting a luminous flux from a light source, and a single scanning lens 5 made of resin, condensing a deflected luminous flux deflected by the light deflector on a surface to be scanned includes a first holding surface 12A fixedly holding the end in the sub-scanning direction of the anamorphic lens 2 and a second holding surface 12B fixedly holding the end in the sub-scanning direction of the scanning lens 5. The first holding surface and the second holding surface hold the ends on the same side in the sub-scanning direction of the anamorphic lens 2 and the scanning lens 5, and the anamorphic lens 2 and the scanning lens 5 are expanded in the same direction in the sub-scanning direction due to temperature rise. |
