| 摘要 |
PURPOSE:To effectively prevent lowering in transferring rate caused by contamination, by providing a destaticizing means closely to a transfer member and destaticizing a transfer member at the time of non-transfer. CONSTITUTION:A bias voltage of polarity opposite (plus in this case) to the toner is applied to a transfer roller 2 and the surface potential of the roller 2 is maintained at Va during the period of tA-tB after a photosensitive body is driven. During the period tA-tB, the toner image on the surface of the photosensitive body is transferred to a transfer material and, at the same time, a bias voltage of polarity equal to that of the voltage applied to the roller 2 is applied to a destaticizing needle 5 provided in the vicinity of the transfer roller 2. During the period of tB-tC after the transfer material passes through the transferring area, the bias voltage to the roller 2 is turned off and, at the same time, another bias voltage V of the same polarity as that of the toner is applied to the destaticizing needle 5 so as to destaticize the transfer roller 2. Accordingly, not only the transfer of the toner on the surface of the photosensitive body to the transfer roller 2, but also the attraction of the floating toner to the transfer roller 2 can be prevented effectively. Therefore, the contamination of succeeding transfer materials and the lowering in image quality can be avoided.
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