HEATER AND HEATER ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide a heater capable of highly accurately measuring a resistance value of part of a heater element 40 to accurately estimate a resistance value of the entire heater element 40, and considerably reducing power consumption at a time of measuring the resistance value.SOLUTION: A heater comprises: a heater element 40 that includes a first heater 40a and a second heater 40b connected in series between a drive terminal 40c and a ground terminal 40d; a first power supply Bat selectively connected to the drive terminal 40c; a second power supply Bec selectively connected to a test terminal 40e provided between the first heater 40a and the second heater 40b; and a current detection circuit 31 connected in series to the heater element 40, the heater estimating a value of an electric resistance of the heater 40 on the basis of an output from the current detection circuit 31 at a time of connecting the test terminal 40e to the second power supply Bec and driving the heater element 40 on the basis of this estimated value.