| 摘要 |
PURPOSE:To achieve stabilization against environmental changes and perfectly operate the separation and discharging of a final support body by utilizing a piezoelectric type surface potential detector for the purpose of detecting the surface potential of a photoconductive photoreceptor. CONSTITUTION:A piezoelectric type surface potential detector 11 is disposed near a charger 29, and the detection output thereof is fed back to the control circuit 30 of a high voltage power source. When the surface potential changes, the detection voltage changes proportionally. On the other hand, the high voltage current through a photoconductive photosensitive drum 18 is fed back to a high voltage generating circuit 32 through a detecting resistance 31, and a detection signal generates across the resistance 31. These two detection signals are compared and amplified, whereby the regulation of high voltage is accomplished. the detector 11 is disposed with a pair of piezoelectric elements 37 in a case 36 having an opening part that makes the detection of surface potential possible, by directing the same to the outer side of the case, and has required circuits on a preset substrate 38. |
