| 摘要 |
A laser scanning apparatus permits laser light to converge satisfactorily all over a scanned region despite having a post-deflector optical system composed of a comparatively small number of optical elements. The post-deflector optical system has a transmissive and a reflective surface, each a free-form surface, and the laser light coming from a deflector and transmitted through the transmissive surface is reflected from the reflective surface so as to be transmitted through the transmissive surface again. The laser light is made incident on the reflective surface obliquely with respect to the sub scanning direction so that, when the laser light is transmitted through the transmissive surface for the first and second times, it is incident thereon in different areas thereon in the sub scanning direction. The transmissive and reflective surfaces may be formed on a single optical element.
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