| 摘要 |
PURPOSE:To improve the focusing property of a luminous flux and a spot shape on an object to be scanned without being accompanied with deterioration in the mass-producing property caused by a fact that the working accuracy of the toric surface becomes a high level by providing plural kinds of convex cylinder lenses whose refractive index or curvature is different. CONSTITUTION:In an optical path between a light source 1 and a deflector 4, a convex cylinder lens 3 having refracting power in the sub-scanning direction vertical to the main scanning direction in which a luminous flux is deflected by the deflector 4 is provided. In this state, by replacing this convex cylinder lens 3 with plural convex cylinder lenses whose refracting power is different from each other, an image forming position in the sub-scanning direction of the luminous flux is adjusted. In such a way, the variance of the image forming position of the luminous flux related to the sub-scanning direction caused by a working error of an anamorphic image forming optical system can be corrected by a simple means. |
