| 摘要 |
PROBLEM TO BE SOLVED: To prevent a fixing roller from being damaged at the time of detecting a disconnection of a heater and at the time of consecutively turning on the heater by respectively arranging plural temperature detection means at specified spots of the fixing roller. SOLUTION: A 1st thermistor 5 is arranged to come into contact with the almost center part of the fixing roller 2 being a recording paper passing area W1. A 2nd thermistor 6 is arranged to come into contact with the inner face part of the end of a core bar body 2a being a recording paper passing area W2. The thermistors 5 and 6 are respectively connected to a CPU 8, and the CPU 8 controls triacs 10 and 12 based on the temperature data on the surface of the roller 2 so as to control to turn on/off the heaters 3 and 4. Even when either thermistor breaks down, the abnormal state such as the disconnection and the consecutive turning-on of the heaters 3 and 4 is prevented by the other thermistor. Therefore, an offset phenomenon and the damage of the fixing device A are prevented.
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