| 摘要 |
PURPOSE:To prevent the transfer of a toner of a non-image part, and to execute color recording at a high speed and with a high picture quality by setting forcibly the polarity of the toner of an image part and the non-image part to the opposite polarity before the transfer. CONSTITUTION:The whole image exposure by a uniform light beam is executed in the irradiation range of an ion to a photosensitive body 1. When a corotron voltage of a pre-transfer electrifier 18 vibrates by width of VAC centering around a DC bias voltage VDC, a negative ion is radiated to a part of a higher potential than the DC bias VDC of the surface of the photosensitive body, and positive ion is radiated to a part of a lower potential. Accordingly, when this DC bias voltage VDC is set in advance between a potential 29 of an image part and a potential 22 of a non-image part, a toner of the image part, and a toner of the non-image part can be electrified to the negative polarity and the positive polarity, respectively. Thereafter, when the transfer is executed, while radiating the positive ion, in a transfer device 8, the toner which has adhered to the non-image part is not transferred to a recording form 12, and the picture quality can be improved.
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