The fixation expedient which becomes fixed development expedient

摘要

PROBLEM TO BE SOLVED: To provide a inexpensive and compact image forming apparatus, where when one high voltage transformer in a high-voltage power source provided in the apparatus outputs a plurality of high voltages and concurrently voltages having different polarities, the high-voltage transformer superimposes the voltages, having different polarities and outputs a target voltage.;SOLUTION: A positive DC high voltage is supplied to a transfer roller 5 as a transfer voltage by a transformer 474 for transfer power source with a transfer power source drive circuit 402 on, and a negative DC high voltage is supplied to the transfer roller 5 as a transfer cleaning voltage by a transformer 414 for charging bias power source with a charging bias drive circuit 404 on. When the transfer voltage and the transfer cleaning voltage are concurrently output at the same time, the transfer voltage and the transfer cleaning voltage are superimposed and the resultant voltage is output to the transfer roller 5 as a target voltage.;COPYRIGHT: (C)2007,JPO&INPIT