HEATING DEVICE AND IMAGE FORMING APPARATUS USING HEATING DEVICE

PROBLEM TO BE SOLVED: To reduce heat damage of a heating device by a delay of heater shut-off action in the case that thermal runaway is produced at a heating member 22 in a state that mechanical movement members are not driven in a heating device 13 which has mechanical movement members 23, 30, a heating member 22, and a control means, while heating of a heated member S is carried out by the mechanical movement members and the heating member. SOLUTION: As a countermeasure constitution for thermal runaway of the heating device, an abnormality detecting temperature level is switched in a driving time and non-driving time of the mechanical action members of the heating device. By means that the abnormality detecting temperature level at the non-driving time of the mechanical action members is made lower than that of the driving time, earlier judgement of the thermal runaway of the heating member 22 becomes possible, a timelag due to heat conduction from the heating member 22 to a temperature detecting means 24 and heat response of the temperature detecting means is reduced, the heat damage to the heating device is reduced, and a safer heating device and image forming device are obtained. COPYRIGHT: (C)2005,JPO&NCIPI