| 摘要 |
PURPOSE:To attain high resolution irrespective of a simple and miniature structure by consisting of an anamorphic signal lens whose one face is a spherical face and the other is a cylindrical face and a signal lens whose one face is a cylindrical face and the other is a toroidal face. CONSTITUTION:An abberation in a main scanning direction is nearly corrected by adjusting the curvature of the spherical face of a single lens 1 and the curvature in the main scanning direction of the toroidal face of a single lens 2 and the abberation is corrected by adjusting the distance between the single lens 1 and the single lens 2 and the distance from the single lens 2 to a scanned object 8. The face inclination of the reflecting face of a deflection device 7 is corrected with the cylindrical face of the single lens 1, the cylindrical face and the curvature in a sub-scanning direction of the toroidal face of the single lens 2 and at the same time, the image face curvature in the sub-scanning direction is corrected. Thus, irrespective of the simple structure with two lenses, the abberation of the image face curvature in the scanning direction can be corrected satisfactorily and the high resolution is attained. |
