| 摘要 |
PURPOSE:To prevent the consumption of excess toner until a device is stopped in emergency by feeding no image information to a latent image forming means when the power source of an image pickup means is stopped after an emergency stop signal is inputted, and stopping image formation. CONSTITUTION:When developing units 25, 26, 27 of a developing unit 4 are set to the normal developing method, at least either an image sensor 21 is turned off or a light writing light source is turned on immediately after an emergency stop signal is inputted. When the sensor 21 is turned off, no image signal is fed to a writing unit 3, and image formation is stopped. In the normal developing method, the surface of a photosensitive 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 on the surface of the drum 1, the surface of the drum 1 is set to the nondeveloping potential, the surface is not developed by the toner, and image formation is stopped. |
