| 摘要 |
PURPOSE:To prevent local fatigue of a photoreceptor when it is not in use by providing an optical means having an optical lens and a reflecting mirror for guiding a light beam to the surface of the photoreceptor, and a shutter to open and close a beam passage on the optical path of said light beam. CONSTITUTION:On the optical path of the light beam which reaches a photoreceptor drum from a laser tube 1 as a light source, the shutter device for opening and closing the optical path is arranged. Namely, the shutter 13 is arranged at a downstream side near a beam expander 5. A prismatic cylinder shaped housing 14 is fixed with bolts to a copying machine body near the expander 5 and in the housing, a DC solenoid 15 is stored; a shutter rod 19 is supported horizontally and rotably to both side surfaces of the housing 14 in the forward part of advance direction of cylinder 16 of the solenoid and a shutter plate 20 interposed in the passing area of the light beam emitted from the expander 5 is fixed to the extended part of the shutter rod 19. |
