| 摘要 |
PURPOSE:To prevent scattered toner from sticking to a lens, etc., by providing a shutter in order that it can cut a space which forms an optical path between a photosensitive body and a lens nearest to the photosensitive body in a write system. CONSTITUTION:A beam path passing through a cylindrical lens 10 is formed below the photosensitive body 1 in order to project a laser light beam and the toner is made to be scattered to the lens 10 from the beam path. In order to cut the beam path from the lens 10 to the photosensitive body 1, namely between the photosensitive body 1 and the lens 10 in a space 38 formed by device frames 41 so as to evade the scatter of toner, the shutter 39 is supported on the device frame 41 with an axis 40 to be freely turned. The shutter 39 is usually energized to obtain a turning force in a direction where the space 38 is cut inside and outside with a spring 42. When a cover is uncovered for exchanging and when vibration is generated the toner does not reach the lens 10 even if it falls, so that the lens 10 can be prevented from the dirt by the toner. |
