| 摘要 |
PURPOSE:To prevent the adhesion of toner or dust, etc., to a lens surface and to eliminate the need for cleaning and exchanging operation for the lens by installing a shutter which opens a light exit only at the time of producing an image on the light output surface of a scanning optical system. CONSTITUTION:Laser beam from the laser beam source of a laser optical system 1 is irradiated onto a photosensitive body 4 in a lower part through a lens 3 by a reflecting mirror 2 and the shutter 5 is arranged on the light output surface 31. Both end parts of the shutter 5 are supported by a supporting member 6 and usually blocked up by spring 7. In the image producing process, the shutter 5 is moved in a direction shown by an arrow A by applying a current to a solenoid 8, so that the light output surface 31 is opened. Therefore, occasions that the toner or the dust, etc., is made to adhere to the lens surface are reduced and the cleaning and exchanging operation for keeping the lens is not necessitated, so that the image of good quality can be obtained. |
