Patent ID: 7853164

Claim:
An image forming apparatus comprising: a fixing unit that fixes a toner image transferred on a recording paper by heating; a plurality of input terminals each being connected to a corresponding alternating-current power supply unit from among a plurality of alternating-current power supply units; a plurality of heating units each generating a heat by an alternating-current power supplied from a corresponding alternating-current power supply unit through a corresponding input terminal and supplying the heat to the fixing unit; a plurality of power control units each controlling the alternating-current power to a corresponding heating unit; a plurality of detecting units each detecting a reference phase of waveform of the alternating-current power supplied from a corresponding alternating-current power supply unit to a corresponding heating unit through a corresponding input terminal; and a control unit that individually controls the power control units based on detected signals output from the detecting units, wherein the control unit controls the power control units based on a reference phase of an alternating-current power supply unit that supplies the alternating-current power to a heating unit having a largest power consumption from among the reference phases detected by the detecting units.