| 摘要 |
<p>PURPOSE:To decrease the rotating speed of a rotary polygon mirror and the scanning speed of a laser beam on the exposure surface of a photosensitive body, etc., by providing plural laser light sources and providing a means which forms plural different main scanning lines simultaneously by performing a laser beam scan on the exposure surface only once. CONSTITUTION:Image electric signals at the same subscanning positions among signals stored in a memory 8 are transferred to the 1st - the 3rd modulating means 71-73 at the same time. Then the 1st - the 3rd laser light sources 11- 13 output laser light beams modulated according to the image electric signals. The laser light beams outputted from the 1st - the 3rd laser light sources 11- 13 are collimated by the 1st - the 3rd collimator lenses 21-23 and transmitted through a convex cylinder lens 24 and a concave cylinder lens 25. Then, the laser beams reach one of plural plane mirror surfaces 3E formed on flanks of the rotary polygon mirror 3.</p> |
