Patent ID: 8247748

Claim:
An induction heating cooker comprising: a top plate made of a material capable of transmitting an infrared ray; a heating coil operable to perform induction heating of a cooking container placed on the top plate with a supplied high-frequency current; an inverter circuit operable to supply the high-frequency current to the heating coil; an infrared ray sensor including an amplifier and being operable to detect the infrared ray which is radiated from a bottom surface of the cooking container and passes through the top plate and to output a detection signal corresponding to a temperature of the bottom surface of the cooking container; an electric power integrating section operable to integrate an amount of heating electric power outputted from the inverter circuit; and a heating control section operable to control the high-frequency current outputted from the inverter circuit based on an output of the infrared ray sensor and an output of the electric power integrating section; wherein the infrared ray sensor has an amplification factor of the amplifier which is set in such a manner that magnitude of the detection signal is constant until the temperature of the bottom surface of the cooking container reaches a predetermined temperature and the magnitude of the detection signal increases exponentially after the temperature of the bottom surface of the cooking container exceeds the predetermined temperature; wherein the heating control section determines whether or not an integrated value from the electric power integrating section is less than a first predetermined amount of electric power, when an amount of increase in an output value of the infrared ray sensor on the basis of an output value of the infrared ray sensor at a start of heating with a first amount of heating electric power reaches a first predetermined value, when the integrated value from the electric power integrating section is less than the first predetermined amount of electric power, the heating control section shifts to a first heating control mode for limiting the amount of heating electric power to a second amount of heating electric power lower than the first amount of heating electric power, and when the integrated value from the electric power integrating section is equal to or more than the first predetermined amount of electric power, the heating control section shifts to a second heating control mode for heating with a third amount of heating electric power larger than the second amount of heating electric power.