| 摘要 |
PURPOSE:To permit adequate maintenance of a toner concn. even if a mode changes by changing the form of replenishing the toner when an ordinary copying mode changes to a mode for master plate making for a stencil printing machine. CONSTITUTION:An ordinary copying mode signal M1 is sent to a toner replenishment controller 51 and a signal S is sent thereto from a developing concn. detecting part 31 when a switching means 45 is set at the ordinary mode. A toner replenishment command instruction is then sent to a toner replenishment motor driving circuit 52 and a motor 53 for replenishing the toner to a developing device 3 is driven. On the other hand, a grid electrode 43 of an electric charger 2 is grounded by a means 45 only through a piece of varistor 44a. As a result, the initial charge potential on the surface of a photosensitive drum 1 is maintained lower than in the case in which ordinary copying is executed. The exposure of an exposing lamp 11 is so controlled cooperatively therewith by an exposure adjusting part 46 so as to attain an adequate value. |
