IMAGE FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To remove discharge products stuck to a photoreceptor which has a hard surface and to decrease charging current flowing in the course of charging. SOLUTION: An auxiliary charging roller 3 is disposed upstream of a main charging roller 2 but downstream of a primary transfer roller 14 along the direction (direction of the arrow R1) of the rotation of a photoreceptive drum 1. The auxiliary charging roller 3 is pressed against the surface of the photoreceptive drum 1 with a pressing force of 1 to 2kg, and rotated at 25% to 100% of the peripheral speed of the photoreceptive drum 1 in the counter direction (the direction of the arrow R3) with respect to the direction (the direction of the arrow R1) of the movement of the surface of the photoreceptive drum 1. The auxiliary charging roller 3 is a foam sponge rubber roller made conductive by dispersing zinc oxide (zinc oxide) and carbon (C), has a resistance value of 107to 109Ωand a hardness of 20 to 40 degrees(Asker C). COPYRIGHT: (C)2004,JPO