| 摘要 |
PURPOSE:To simplify an optical adjustment by installing a semiconductor laser so that the short axial direction of elliptical laser light which is made incident to an optical scanner becomes a revolving shaft of the optical scanner, passing laser light for optical scanning through a cylindrical lens, and leading it to a surface to be scanned. CONSTITUTION:Laser light from a semiconductor laser 9 is converted to parallel light with high light utilizing efficiency by a coupling lens whose N.A. is large, has a laser light sectional shape of an elliptical shape on a rotary polyhedral mirror 2, and the short axial direction of the light becomes a direction parallel to a revolving shaft of the rotary polyhedral mirror 2. Therefore, a joint surface of the semiconductor laser 9 and the revolving shaft of the rotary polyhedral mirror 2 are placed so as to be parallel to each other. The laser light scanned by the rotary polyhedral mirror 2 is made incident to an image forming lens 7, but as for this lens 7, an Ftheta lens of a focal distance (f) is used, and a cylindrical lens 8 is placed in front of a photosensitive drum 1 functioning as a scanning surface. |
