| 摘要 |
<p>In an optical scanning apparatus, there are arranged a light source, a first optical system for converting a light beam emitted from the light source to a convergent light beam, a deflector for deflecting the convergent light beam from the first optical system, and a second optical system for image-forming the convergent light beam deflected by the deflector as a spot on a surface to be scanned. The symmetrical axis of the second optical system with respect to a main-scanning direction is disposed so as to have an inclination relative to a normal to the scanned surface in a main-scan cross section. As a result, aberrations of the optical scanning apparatus, especially degradation of f theta characteristics due to backward and forward movement of a mirror surface caused by the rotation of the polygon mirror, which occur in an optical scanning system wherein a convergent light beam is caused to enter the polygon mirror, are reduced. <IMAGE></p> |
