| 摘要 |
PURPOSE:To obtain images which are nearly constant for a long period by detecting the resistance of a developer by an electrode installed opposite a conveyor roller according to the in-use state and then applying an optimum bias voltage corresponding to a detected resistance. CONSTITUTION:An electrode for measurement is arranged opposite a developer conveyor roll and the electric resistance of the developer passing between them is measured. A control plate 8 which limits the extent of rotation of the developer is used as the measuring electrode. The voltage developed across a resistance 10 is compared with a differential voltage from that of a reference voltage source 12 through an amplifier 11 to control the voltage of a bias power source 13. |
