Heating device

A heating device comprising:

• a heater that heats a heating object;
• a temperature detection unit that detects a temperature of the heating object;
• and
• a temperature regulator that controls the heater based on the temperature of the heating object detected by the temperature detection unit and a target temperature, such that the temperature of the heating object detected by the temperature detection unit reaches the target temperature,
• wherein the temperature detection unit includes a first temperature sensor and a second temperature sensor, and
• wherein the temperature regulator comprises
• an identification unit that identifies a plurality of transfer functions from temperature data detected by the first temperature sensor and the second temperature sensor, and electric power applied to the heater or manipulation quantity data corresponding to the electric power applied to the heater, the plurality of transfer functions including a first heat transfer function between the heater and the first temperature sensor, a second heat transfer function between the heater and the second temperature sensor, and a third heat transfer function between the first temperature sensor and the second temperature sensor, and
• the first heat transfer function includes first heat transfer function coefficients at one timing and first heat transfer function coefficients at another timing, the second heat transfer function includes second heat transfer function coefficients at one timing and second heat transfer function coefficients at another timing, the third heat transfer function includes third heat transfer function coefficients at one timing and third heat transfer function coefficients at another timing,
• a determination unit that detects:
• a first change between the first heat transfer function coefficients at one timing and the first heat transfer function coefficients at another timing,
• a second change between the second heat transfer function coefficients at one timing and the second heat transfer function coefficients at another timing,
• a third change between the third heat transfer function coefficients at one timing and the third heat transfer function coefficients at another timing,
• wherein the determination unit determines an abnormality has occurred in the heater, the first temperature sensor or the second temperature sensor based on the first change, the second change and the third change.