| 摘要 |
PURPOSE:To improve the optical characteristic of an optical scanning device in which a surface to be scanned is arranged through a correcting lens on the main scanning optical path of the scanning mirror by forming the reflecting surface of the scanning mirror on which projected light from a laser light source is made incident in a skew state by a curved surface having negative power in a main scanning direction. CONSTITUTION:The light incident surface 18 of the correcting lens 17 is formed by a rotation symmetry curved surface in which a rotary shaft 14 in parallel with the main scanning direction is displaced on a laser light source 7 side in a sub scanning direction from the center of the main scanning optical path, the light projecting surface 19 of the correcting lens 17 is formed by the rotation symmetry curved surface in which the rotary shaft 15 crossing at a right angle in the main scanning direction and the sub scanning direction is displaced to the sub scanning direction from the center of the main scanning optical path, the deformation of spot light obtained by the coma aberration of the correcting lens 17 can be reduced and also the projecting direction of stray light caused by the inside reflection of the correcting lens 17 is deflected; therefore, a countermeasure can be facilitated. |
