| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To obtain an optical scanning device that can effectively block unwanted light even when in installation error of an optical element occurs and that can form a high quality picture with simple constitution. <P>SOLUTION: The optical scanning device includes two scanning units each having an input optical system for making, in a sub-scan section, a light beam from a light source be incident at a finite angle on a deflection means, and an imaging optical system for imaging, on a surface to be scanned, the deflected light beam, the two scanning units being disposed opposed to each other with the deflecting means intervening therebetween, wherein one scanning unit out of the two scanning units has a first imaging optical element and a second imaging optical element while the other scanning unit has a third imaging optical element and a fourth imaging optical element, wherein the one scanning unit includes a light blocking member for blocking unwanted light reflected at the optical surface of the fourth imaging optical element, wherein the third imaging optical element is provided at a light path between the fourth imaging optical element and the light blocking member, and wherein the third imaging optical element has a positive refracting power in the sub-scan section through which unwanted light reflected at the optical surface of the fourth imaging optical element passes. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
