| 摘要 |
PURPOSE:To stabilize the copy quality, by detecting the surface potential of a photoconductive photoreceptor by means of an dynamic consenser type surface potential detector and carrying out the control to stabilize the surface potential. CONSTITUTION:A surface electrometer 11 is directly set to an electric charger 29 so that a coincidence is obtained between the aperture parts 29a and 5. A photoconductive photoreceptor 18 is charged with electricity after the corona is produced, and at the same time the detection signal of the electrometer 11 is taken out. At the same time, the surface potential at a nonirradiated part 39 of the receptor 18 is detected by another simple dynamic consenser type fault detecting surface potential detector 30. Thus a fault of the surface potential is detected via a comparing/amplifying circuit 35, etc., and an alarm is produced to outside via a fault alarm 40 to inform the occurrence of a fault. In such way, the copy quality is stabilized and furthermore the occurrence of a fault can be informed to outside. |
