| 摘要 |
PURPOSE:To stabilize image formation by generating an electric field which acts to lead positive or negative ions generated near a discharging electrode onto a photosensitive body and changing the intensity of the electric field, the peak value of an alternating voltage, and the frequency on a basis of the detected value of the surface potential of the photosensitive body. CONSTITUTION:A potential sensor 2 measures the potential of a latent image on the photosensitive body in the state, where a lamp for original exposure is extinguished, and the potential of a latent image corresponding to a white original, and these measured values are fed back to a control part 3 for the purpose of forming a latent image based on a preliminarily set potential curve on the photosensitive body. The control part 3 changes voltages applied to a discharger 13 and a secondary electrifier 15 on a basis of measured values to form the latent image having a prescribed potential on the photosensitive body 1. A control means is provided which detects the surface potential of the photosensitive body and changes one out of the intensity of the electric field generated by an electric field generating means, the peak-to-peak value of the alternating voltage applied across both electrodes, and the frequency of the alternating voltage at least on a basis of the detected value, thus stabilizing image formation. |
