| 摘要 |
PURPOSE:To simplify structure for impressing the voltage of a reverse polarity on a developing device in order to prevent toner adhering to the part of a latent image carrier, which is not electrostatically charged, in an electrophotographic copying device where the latent image carrier to which an electrostatic charger, an exposing device and the developing device are successively arranged to be opposed is positioned on the carrying path of a printing medium to which a transfer device is arranged to be opposed. CONSTITUTION:An unnecessary development preventing mechanism 45 is provided, which connects the power source 37 of the transfer device 27 to the developing device 25 until the part of the surface of the latent image carrier 21, which is electrostatically charged by the discharge of the electrostatic charger 23, arrives at a position where it is opposed to the developing device 25. |
