| 摘要 |
PURPOSE:To improve the optical characteristic of an optical scanner in which the reflection area of a scanning mirror on which the outgoing light of a laser beam source is made skew-incident is formed with a curved surface having a negative power in a main scanning direction and a plane to be scanned is arranged on the main scanning optical path of the scanning mirror via a correction lens. CONSTITUTION:The light incident plane 57 of the correction lens 45 is formed with a rotation symmetric curved surface in which an envelope is made a high- degree curve of even-numbered degree while displacing a rotary axis parallel with the main scanning direction from the center of the main scanning optical path to a sub-scanning direction, and the light emitting plane 59 of the correction lens 45 is formed with the rotation symmetric curved surface in which the envelope is made the high-degree curve of even-numbered degree while locating the rotary axis crossing orthogonally the main scanning direction and a sub-scanning direction in the center of the main scanning optical path, thereby, various kinds of optical aberration can be reduced, and also, the emitting direction of stray light is kept away from the main scanning optical path. |
