| 摘要 |
PURPOSE: To provide a contact-type charging device, capable of preventing surface fogging with simple constitution and an electrohotographic printing using the same. CONSTITUTION: In this contact type charging device having a charging roller 21 coming into contact with a photoreceptor 20 and a power source circuit 23 for applying DC constant voltage to the roller 21, a power source circuit 23 is equipped with a resistor 24 and applies voltage to the roller 21 via the resistor 24. Then, the circuit 23 is equipped with a rectifying circuit 25, and the resistor 24 is arranged nearer to the roller 21 side than the circuit 25. Thus, a current flowing into the roller 21 is changed according to impedance between the photoreceptor 20 and the roller 21 and an outputted voltage value is changed, so that the surface fogging caused by the change of electrification potential due to environmental change and the film thickness of the photoreceptor is prevented.
|
