| 摘要 |
PROBLEM TO BE SOLVED: To obtain a stable output signal, even if a manufacturing lot of LD or the usage environment of an optical scanner varies. SOLUTION: A laser diode 1 which is a light source having an oscillation wavelength shorter than 450 nm emits a laser beam L. The laser beam L is focused on the face of a polygon mirror 4, deflected and reflected with the polygon mirror 4 and focused on the surface of a photoreceptor 6 at a substantially constant speed. A synchronize detection sensor 11 for beginning a writing with the laser beam L is provided on the beginning side of scanning except the effective exposure region of a photoreceptor 6. The synchronous detection 11 is composed of a photodiode 9, and an optical member, which shows reverse characteristic to the spectral sensitivity characteristics of the photodiode 9, is arranged in the optical path of the laser beam L, from the emission point on the laser diode 1 up the arrival on the photodiode 9. COPYRIGHT: (C)2007,JPO&INPIT |
