Patent ID: 8768192

Claim:
A fixing apparatus comprising: an induction heating coil configured to heat a heat generating member including a conductive heating element; a boosting circuit configured to boost a DC voltage obtained by rectifying AC power; a switching element configured to input a DC voltage boosted by the boosting circuit and to supply a high-frequency current to the induction heating coil; a driving circuit configured to drive the switching element; a temperature detection unit configured to detect a temperature of the heat generating member; and a control unit configured to control power supplied to the induction heating coil by controlling a boosting ratio of the boosting circuit and a driving frequency of the switching element by the driving circuit so that the temperature detected by the temperature detection unit reaches a target temperature, wherein the control unit is configured to selectively execute a first control mode for controlling the power supplied to the induction heating coil by changing the driving frequency of the switching element within a range of frequencies equal to or higher than a predetermined frequency and a second control mode for controlling the power supplied to the induction heating coil by changing the boosting ratio of the boosting circuit within a range of ratios equal to or higher than a predetermined boosting ratio, and wherein the control unit is configured to select one of the first control mode and the second control mode based on the temperature detected by the temperature detection unit, the boosting ratio, and the driving frequency.