| 摘要 |
PURPOSE:To prevent a failure caused by remaining toner at the time of stopping an action by providing a control part which inverts the relation of voltage level between a developing bias voltage and a blade bias voltage for a specified time before stopping the action. CONSTITUTION:For the specified time before stopping the supply of voltage, the relation of the voltage level between the developing bias voltage Va and the blade bias voltage Vb is inverted so as to invert the line of electric force F1 with which mono-component toner 4 is moved to a developing roller 7 to the line of electric force F2 in an opposite direction, and the quantity of toner which is moved to the developing roller 7 is reduced or made none at all. Since the developing roller 7 does not convey the toner 4 to the photosensitive drum 1 just before stopping the action, the toner 4 is prevented from remaining between the developing roller 7 and the photosensitive drum 1 at the time of stopping the action. |
