Patent ID: 7945181

Claim:
A fixing device comprising: a fixing unit that fixes a toner image transferred onto a recording medium by a heating target unit heated by a plurality of heating units each of which is grouped as a first heating unit to which power is selectively supplied or a second heating unit to which power is supplied in priority to the first heating unit; a detecting unit that is provided to each of the heating units, and detects a temperature of the heating target unit heated by the heating units; and a supply control unit that supplies power to a heating unit grouped as the second heating unit and selectively supplies power to a heating unit grouped as the first heating unit, among the heating units that heat the heating target unit of which detected temperature is lower than a target temperature, wherein the supply control unit selectively supplies power to the heating units grouped as the first heating unit based on any one of a first supply condition about comparative relationship of differences between the detected temperature and the target temperature, a second supply condition about comparative relationship of periods during which power is not supplied to the heating units, and a third supply condition about comparative relationship of power supply periods based on the detected temperature.