| 摘要 |
PURPOSE:To set the surface to the nondeveloping potential, stop image formation, and prevent the consumption of excess toner until a device is stopped in emergency by turning a light writing light source on when an emergency stop signal is inputted, and radiating the light on the surface of an image carrier. CONSTITUTION:When developing units 25, 26, 27 of a developing unit 4 are set to the normal developing method, a document radiating light source 16 is turned off immediately after an emergency stop signal is inputted, a light writing light source is turned on, and this state is maintained until an emergency stop. The surface of a photoreceptor drum 1 is set to the developing potential by electrification, the portion radiated by the light from the light writing light source on the surface of the drum 1 is set to the nondeveloping potential because charges are released, this portion is not developed by a toner, and only the portion not radiated by the light is developed by the toner. The light writing light source is turned on when the emergency stop signal is inputted, the light is radiated to the surface of the drum 1, the surface of the drum 1 is set to the nondeveloping potential thereafter, the surface is not developed by the toner, and image formation is stopped before the developing units 25, 26, 27 are turned off. |
