DEVELOPING DEVICE, PROCESS CARTRIDGE, AND IMAGE FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To uniformize an amount of charged toner on a developing roller. SOLUTION: The developing roller 25 is in contact with a photoreceptor 1. A toner electrifying roller 22 is provided upstream from a developing area where the developing roller 25 is in contact with the photoreceptor 1. A power source 27 is provided in order to apply a DC voltage to the toner 28, the DC voltage being equal to or higher than a discharge initiation voltage and having the same polarity as that of the toner 28. The control of a voltage applied to the toner electrifying roller 22 by the power source 27 is constant voltage control.