| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To improve the image quality of an image by suppressing variation in the sectional beam diameter of a laser beam imaged on a photoreceptor drum, in an optical scanner of an over illumination type. <P>SOLUTION: In this optical scanner, an imaging optical system 60 includes an imaging lens 61 having at least one surface unsymmetrical to a first direction using, as a boundary point, the position where a luminous flux passes the optical axis of a system defined at a position having the shortest distance between each reflecting surface of a polygon mirror 50 and the photoreceptor drum 23. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
