Mechanism of contact charging photoconductor and insulator with DC-biased conductive roller

The contact charging method for electrophotography with a DC-biased conductive roller was investigated in order to clear its mechanism. From the examination both in vacuum and in air, the electrical discharge at the small gap between the conductive roller and the photoconductor surface is considered to contribute to the charging process in addition to the electron transfer at the point of contact. In the study, the charging mechanism in air that is due to the gaseous discharge is investigated with a simulative condenser model.