Patent ID: 8849147

Claim:
An image forming apparatus comprising: a plurality of image supporting members provided for a plurality of colors; a plurality of chargers that are provided for the respective colors and that are configured to be impressed with charging biases so as to charge the respective image supporting members; a plurality of developing devices that are provided for the respective colors and that are configured to be impressed with developing biases so as to develop latent images formed on the respective image supporting members; a charging bias power supply including a plurality of high-voltage DC power supply circuits, which are provided for the respective colors, configured to output direct-current voltages and an AC power supply circuit, which is shared for the plurality of colors, configured to output an alternate-current voltage, the charging bias power supply applying the charging biases, which are generated by superposition of the alternate-current voltage outputted from the AC power supply circuit and the direct-current voltages outputted from the high-voltage DC power supply circuits, to the respective chargers; and a control circuit configured to perform stop processing to stop applications of the charging biases and the developing biases, wherein: the control circuit is configured to perform processing to attenuate each of the direct-current voltages outputted from the high-voltage DC power supply circuits and each of the developing biases applied to the developing devices step by step; and the control circuit is configured to stop the high-voltage DC power supply circuits from outputting the direct-current voltages in a state where all of the direct-current voltages outputted from the high-voltage DC power supply circuits provided for the colors, for which the AC power supply circuit is shared, have become a predetermined stop potential and thereafter are maintained at the predetermined stop potential and to thereafter stop the AC power supply circuit from outputting the alternate-current voltage.