| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a light beam scanning optical system, an optical scanning device and an image forming device, reducing the time of optical beam scanning control in regions other than an image writing region on a reflection surface of a rotary polygon mirror without the light beam scanning control's relying on a light beam or of increasing the ratio of occupation of the image writing region on the reflection surface of the rotary polygon mirror. <P>SOLUTION: The light beam scanning optical system which writes image information on a photoconductor 3 while detecting the writing start position of the image information by deflecting and scanning the light beam L1a from a light source 110 emitting the light beam L1a by a polygon mirror 120 and by detecting the light beam L1b from the polygon mirror 120 by a BD part 130, and the optical scanning device 1 and the image forming device D include a light source 140 for BD emitting a light beam L2a besides the light source 110. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
