| 摘要 |
PURPOSE:To reduce staining on a transfer paper and cleaning defect due to the stripping-off discharge by providing the controlling means for changing ON-OFF timing of the transferring current to flow to a transfer device corresponding to the residual toner in a developing device. CONSTITUTION:In the control part 38, the number of copies is integrated by integrating passing frequency of the,K.. transfer paper by integrating the output signal of the copying number sensor from the zero after replacing the toner cartridge basing on the input signal from the toner cartridge replacing sensor. Then, on judging whether the integrated value attains a prescribed number of copies or not, the ON timing of the transferring current made to flow to the transfer device is made earlier than the normal ON timing and at the same time, the OFF timing is made later than the normal OFF timing by controlling the high voltage power source 39, at the time of attaining the prescribed number of copies. Thus, the extent of the staining on the transfer paper can be reduced when the the number of copies exceeds the prescribed number, and the cleaning defect due to the stripping-off discharge between the transfer paper and the photorecetpor 11, that is liable to occur in the initial state remaining lots of the toner, can be reduced. |
