DISCHARGE QUANTITY CONTROLLING METHOD OF DISCHARGER FOR ELECTROPHOTOGRAPHY OR ELECTROSTATIC RECORDING

摘要

PURPOSE:To prevent the decrease in image density at the continuous printing as low as possible by detecting only the electric current flowing in a photoreceptor and controlling the applying electricity quantity of an electric discharger based on said value. CONSTITUTION:The total output current IT from a constant current high voltage power source 1 is the sum of the current IB flowing in a back plate 3 and the current IM flowing in a drum 4. Thereupon, a circuit of floating the back plate 3 from GND is formed so that the current IB is not passed through resistances R1-R2 and only the current IM is passed. Based on this current IM, the feedback to an oscillation circuit is applied to perform controlling in such a manner that IM becomes always constant. Then, the decrease in image density at the continuous printing may be considerably prevented as compared to the case when the total output current IT is maintained constant.