| 摘要 |
PURPOSE:To eliminate potential nonuniformity generated by transfer electrification, and to obtain an image with high definition, by supplying electrification which supplies a potential with polarity opposite to that of primary electrification and exposure on a photosensitive body prior to the application of the primary electrification. CONSTITUTION:A pre-exposure and pre-electrification means 20 to perform the cleaning of residual potential on the photosensitive body is provided at the front of an electrification means 2 which applies the primary electrification on the photosensitive body 1. The pre- exposure and pre-electrification means 20 consists of a pre-exposure device 22 and a pre- electrification device 24. Also, the pre-electrification device 24 is a device to add the potential with the same polarity as that of a transfer electrification means on the photosensitive body, and sets the potential of the surface of the photosensitive body at the polarity opposite to that of the primary electrification by the electrification means 2. Furthermore, it is necessary that the exposure by the pre-exposure device can erase the potential with the same polarity as that of the primary electrification left on the surface of the photosensitive body, and it is preferable that the exposure is performed simultaneously with the electrification by the pre-electrifier 24, or prior to that. In such way, it is possible to eliminate the potential nonuniformity on the photosensitive body after the transfer electrification, to supply uniform surface potential on the photosensitive body, and to obtain the image with high fidelity. |
