| 摘要 |
PROBLEM TO BE SOLVED: To improve detection accuracy of abnormal heating without shortening a time interval for sequentially referring to each temperature sensor of a fixing device.SOLUTION: A fixing device allows a recording sheet to pass a heating area on an outer peripheral surface of a revolving endless heating belt to fix an unfixed image by heat using a resistance heating layer as a heating source, and detects abnormal heating of the resistance heating layer using a plurality of temperature sensors whose entire detection range covers an entire area of the heating area on the outer peripheral surface in the shaft direction. The fixing device refers to a temperature in the heating area of a detection range of one of the plurality of temperature sensors at every prescribed time to monitor the abnormal heating (S703), determines whether or not the abnormal heating is easy to be caused in the heating area of the detection range of each temperature sensor (S710), and controls a temperature reference operation so as to make the reference frequency of the temperature for a temperature sensor where the abnormal heating is determined to be easily caused higher than that for a temperature sensor where it is determined not to be easily caused for a prescribed period of time (S713). |
