| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of obtaining a good image without causing image defects such as offset and fixation-tailing by a fixing device, and free from uneven halftone density due to uneven electrification. <P>SOLUTION: The output of a high voltage DC power source 101 is supplied as bias to a thermal fixation device. The output of the power source 101 is voltage-divided by resistances 103 and 104, and the voltage-divided output is supplied as a DC bias to an electrifier. A feedback signal by a difference between the voltage-divided output and a reference voltage is generated by a feedback circuit 107, and supplied to the power source 101, then, the voltage value of the voltage-divided output is controlled to a desired value. By having such the constitution, a bias voltage higher than the bias voltage supplied to the electrifier is supplied to the thermal fixation device, then, the image defects such as offset and fixation-tailing by the fixing device are prevented. Besides, the accurately controlled bias voltage can be supplied to the electrifier, then, the uneven halftone density due to the uneven electrification is prevented. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
