| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an image forming apparatus that can realize desirable constant voltage control corresponding to resistance unevenness in the circumferential direction of a transfer roller. <P>SOLUTION: An image forming apparatus comprises: voltage applying means 20 for applying bias voltage to a transfer roller 18; voltage controlling means 21 for performing constant voltage control for the voltage applying means 20; voltage detecting means 23 for detecting voltage of the transfer roller 18; current detecting means 22 for detecting electric current of the transfer roller 18; recording means 24 for recording a voltage value detected with the voltage detecting means 23 during rotation of the transfer roller 18; and storing means 25 for storing a plurality of predetermined upper limit values and a plurality of predetermined lower limit values. In the image forming apparatus during transfer operation, when the transfer current detected with the current detecting means 22 is larger than one selected upper limit value, the voltage applying means 20 is controlled so that the transfer current is equal to or less than the one upper limit value, whereas, when the detected transfer current is smaller than one selected lower limit value, the voltage applying means 20 is controlled so that the transfer current is equal to or more than the one lower limit value. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
