| 摘要 |
PURPOSE:To obtain a stable transfer picture irrespective of a kind of an original, by providing a means for detecting the potential of a latent image, a pre- transfer corona discharge means, and a means for controlling impressed voltage. CONSTITUTION:First of all, exposure is performed to a photoreceptor by a preexposure means 20. For instance, +7.0KV is impressed to a primary corona discharger 2, and the surface of a photoreceptor is electrostatic charged uniformly. Subsequently, corona destaticization is executed by a secondary corona discharger 3 to which -8.0KV is impressed, performing optical image exposure of an original to the surface of the photoreceptor, the surface of the receptor is irradiated uniformly by the whole face exposure source using a fluorescent lamp, and formation of an electrostatic latent image is completed. The electrostatic latent image formed in this way is converted to a developed picture by a jumping development, a transfer material is superposed, and transfer corona is performed by a transfer corona discharger 7. Thereafter, back charge of transfer paper is destaticized by a separate corona discharger 9, and a copy which is separated and fixated by a fixation device is offered. On the other hand, after the transfer is ended, a residual toner on the surface of the photoreceptor is removed by a cleaning means 12, and on its way, surface potential formed on a photosensitive drum is detected successively by a potential detecting sensor 15, is amplified by an amplifier 16, also is sent to an operation controlling circuit of a control means 17, and in conformity with its detected signal, intensity of a pretransfer corona is calculated. Subsequently, a control signal based on this calculation is sent to a high voltage power source 18 of the pre-transfer corona, and by its signal, a proper value is impressed to the pre-transfer corona discharger. |
