| 摘要 |
PURPOSE:To prevent the generation of the ghost image by the luminous flux imaging on the photosensitive medium surface to be scanned form the reflection surface of a rotary polyhedral mirror. CONSTITUTION:This optical scanner has a light source 1, the rotary polygonal mirror 3 having the plural reflection surfaces 10, an incident optical system 2 for making the luminous flux from the light source 1 incident on the reflection surfaces 10, an imaging optical system 4 for imaging the luminous flux reflected from the reflection surfaces 10 on the photosensitive medium surface 20 to be scanned and optical members 5, 6 which are disposed between the reflection surfaces 10 and the photosensitive medium surface 20 to be scanned and are set in light attenuation rate in such a manner that the intensity of the luminous flux imaging on the photosensitive medium surface 20 to be scanned is higher than the threshold value of the photosensitive intensity of at least the photosensitive medium surface 20 to be scanned. |
