| 摘要 |
PROBLEM TO BE SOLVED: To suppress the prolongation of time to attain a specified temperature even when the voltage of an AC commercial power source drops by detecting voltage applied to a heating body provided in a fixing roller and controlling the turn-on/off of the heating body. SOLUTION: When the value of a temperature detection part 13 for detecting the temperature of the fixing roller is high, a comparator 25 turns on a switch 23 so as to open the gate of a triac 28 to turn on the heating body 26. When the voltage of the AC commercial power source 30 becomes equal to or above a specified voltage value, a voltage detection part 31 is actuated and outputs its detection signal to the comparator 25. The comparator 25 is set to on/off control only the heating body 26. When the voltage is equal to or under the specified value, the detection part 31 is not actuated and the comparator 25 is set to select both the heating elements 26 and 27. The Comparator 25 turns on the switches 23 and 24 so as to open the gates of the triacs 28 and 29 to turn on the heating bodies 26 and 27.
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