| 摘要 |
PURPOSE: To eliminate a deviation in the control of a potential by electrification due to the deviation in the measurement of a current flowing to an electrifying roller, mainly caused by the degradation of the surface of the electrifying roller. CONSTITUTION: The electrifier is provided with at least the electrifying roller 1, a high-voltage power source for the electrifying roller 5 impressing at least two or more kinds of different voltages to the electrifying roller, a current measuring device 3 measuring the current flowing from the high-voltage power source for the electrifying roller 5 to the electrifying roller 1, a controller 4 executing a calculation based on the result of the measurement of the current, to decide/control the output voltage of the power source 5 and a discharge lamp 6. When the voltage previously set by the controller 4 is impressed to the electrifying roller 1 and a photoreceptor 13 whose electrostatic charge is removed by the discharge lamp 6 is electrified, the current measuring device 3 measures at least the current during one rotation or more of the electrifying roller 1, in the current flowing from the power source 5 to the electrifying roller 1. Then, the controller 4 calculates the time average value of the current measured by the current measuring device 3 and changes the level of the voltage impressed to the roller 1, based on the time average value of the current. |
