High-voltage power unit for corona discharge of copying machine or the like

Abstract

Abstract PURPOSE:To prevent picture quality from deteriorating even when environmental conditions such as temperature varies by detecting the DC component of a current which flows from an electrostatic charger to a photosensitive body and controlling a high-voltage generating circuit so that the value of the DC component is constant. CONSTITUTION:A latch circuit 6 is provided which operates according to an oscillation frequency generated by an oscillation circuit 5 and when this latch circuit 6 performs latching operation, the DC component which flows from the electrostatic charger 2 to the photosensitive body 1 is detected by a detecting circuit 7 and sent to a comparing circuit 8. The comparing circuit 8 compares the input current with a reference voltage and outputs the difference to the a control circuit 9. The control circuit 9 controls a high-voltage generating circuit 4 according to the current inputted from the comparing circuit 8 so that the DC component flowing to the photosensitive body 1 is constant.

Inventors

• 👤 Akira Matsuura
• 👤 亮 松浦

Bibliographic Details