| 摘要 |
PURPOSE:To eliminate the defective transfer that arises at the rear end of transfer paper by changing the magnitude of the voltage or current to be impressed on a corona discharging means in such a way that the charge quantity of the corona discharge at the rear end of the transfer paper is made smaller than the charge quantity of the corona discharge at the part except the rear end of the transfer paper. CONSTITUTION:A selector switch SW is kept connected to a terminal A in the stage of starting a copying operation and the high output current from a power source 32 for transfer is impressed on a corona wire 30. On the other hand, the switch SW is connected to a terminal B by the signal from a control circuit 33 at the timing at which transfer paper P detaches from guiding plates 6, 6, and the low output current from a power source 31 for transfer is impressed on the wire 30. More specifically, the current impressed on the wire 30 in accordance with the rear end of the paper P and the part except the rear end thereof is controlled, by which the charge quantity of the corona discharge applied on the rear end of the paper P is made smaller than the charge quantity of the corona discharge applied on the part except the rear end. As a result, the charge quantity applied over the entire surface of the paper p is consequently maintained at the charge quantity enough to obtain satisfactorily stable transfer efficiency and the charge density on the paper P is made uniform over the entire surface of the paper P. |
