| 摘要 |
<p>PROBLEM TO BE SOLVED: To perform high-temperature heating accurately according to a conveyance state of recording paper by a fixing unit, so as to prevent excessive temperature rise when abnormality occurs in conveyance of recording paper to the fixing unit even if a control unit is not controllable.SOLUTION: A fixing temperature monitoring device 10 includes: a temperature detection unit 13 for a heating roller 51; a heater control unit 12; a control unit 11; a temperature setting resistor 141; a comparator 142 that outputs a heater energization stop signal when the temperature of the heating roller is higher than a second monitoring temperature; a timer 153; a reset time setting resistor 151; and a reset IC 152 that outputs an instruction of disconnection of a resistor R5 to a switch SW1 of the temperature setting resistor 141 when the timer 153 measures the lapse of a predetermined time at the time of input of a reset voltage. When the control unit 11 outputs an instruction of connection of a resistor R5 to the switch SW1 to output a voltage for a second monitoring temperature, outputs an instruction of switching connection of a resistor R2 to a switch SW2 of the reset time setting resistor 151.</p> |
