| 摘要 |
PROBLEM TO BE SOLVED: To enable reducing an AC voltage applied on the surface of a photoreceptor without reducing the electrified potential on the surface of the photoreceptor, to reduce an electrical load and a physical load applied on the photoreceptor and to prolong the durable life of the photoreceptor. SOLUTION: In the case of electrifying a part as a printing area on the photoreceptor drum 9, the AC voltage applied on the photoreceptor drum 9 is controlled to be equal to or exceeding a potential converging AC voltage, and in the case of electrifying a part as a non-printing area on the photoreceptor drum 9, the AC voltage is reduced and a DC voltage is increased, then, a constant electrified potential is secured. For example, in the case of controlling the electrified potential of the photoreceptor drum 9 to be -700 V the DC voltage applied on the photoreceptor drum 9 is increased to -1100 V, and the AC voltage applied on the photoreceptor drum 9 is reduced to 400 Vp-p (point P in Fig.). Thus, the AC voltage applied on the photoreceptor drum 9 is reduced while keeping the electrified potential of the photoreceptor drum constant. |
