| 摘要 |
PROBLEM TO BE SOLVED: To prevent thermal damage of a temperature detecting element detecting temperature rise at the paper non-passing part of a heating body and peeling from the heating body to obtain stable operation by forming a device so that the disposing structure of 1st and 2nd temperature detecting elements may differ. SOLUTION: A 1st thermistor 19 is attached to an opposite side to a surface where the resistance heating element 8 of a heater 2 is printed with a heat resistant adhesive. A 2nd thermistor 21 is disposed in non-contact with the heater 2 in a window formed in a stay 1, and its periphery is covered with heat resistant resin 22 such as a polyimide tape. The 1st thermistor 19 accurately detects the variation of a calorific value caused by a necessary power difference and the variation of power source voltage caused by switching at the time of paper passing time/paper non-passing time and controlling the heating device at desired temperature. Since the 2nd thermistor 21 does not directly participate in the temperature control of the heating device, it does not require detecting accuracy and responsiveness as high as the 1st thermistor 19, and there is no possibility that the 2nd thermistor 21 is thermally damaged due to the temperature rise at the paper non-passing part.
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