| 摘要 |
PURPOSE:To effectively correct the adverse influence of deviation on a surface to be scanned and to make a highly accurate optical scan by providing a stop which limits the luminous flux from a light source part in a deflecting and scanning surface between an image formation system and a deflector. CONSTITUTION:The diverged luminous flux emitted by the light source part is collimated by a collimator lens 2a into parallel luminous flux for the deflection scanned surface and the luminous flux is made incident on the reflecting and reflecting surface 4a of the deflector as linear luminous flux through a cylindrical lens 2b which has refracting power only in a subscanning direction. The image formation optical system 2 consists of the collimator lens 2a and a cylindrical lens 2b. Then the stop 15 which limits the luminous flux from the light source part 1 in the deflecting and reflecting surface 9 is provided between the image formation optical system 2 and deflector 4. Consequently, even if the angle of projection of the luminous flux emitted by the light source part 1 deviates, the influence of the deviation is reduced and the highly accurate optical scan can be made without specially adjusting the light source part 1, image formation optical system 2, etc., nor requiring a member for adjustment. |
