Image fixing device with heater responsive to thermal stress

摘要

A heater includes a base plate, and a resistor, extending in a longitudinal direction of the base plate, for generating heat when a power supply is applied thereto. A recess, such as a hole or groove, is formed in the base plate in a longitudinal portion of the resistor, to bias the base plate to break at the longitudinal portion and to open a circuit including the power supply and the resistor, to safely prevent overheating or smoking of the heater.