| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical scanner capable of reducing influences on optical characteristics accompanied by an environmental change or a change in the lapse of time in a scanning optical system using an imaging lens or an imaging mirror. SOLUTION: The image forming apparatus provided with the optical scanner comprises: a semiconductor laser element; a pre-deflection optical system; a polygon mirror; and a post-deflection optical system, wherein at least one imaging lens 61 for imaging the luminous flux scanned by the polygon mirror onto a photoreceptor drum is disposed on the post-deflection optical system, and at least one protrusion part 72 is disposed on a surface vertical to a sub-scanning directional axis formed by the effective area of the imaging lens 61, which allows an laser beam L to pass therethrough. A housing unit of the optical scanner comprises at least one positioning member 73 having a fitting groove which, while facing the protrusion part 72, is fitted by the protrusion part 72 and is engaged by ridge and groove connection in the main scanning direction for the housing unit. COPYRIGHT: (C)2009,JPO&INPIT
|
