| 摘要 |
PURPOSE:To monitor the temperature control of a heat roll when a copying machine is stopped, by measuring the turning-on time of a heater by a timer when the temperature of the heat roll is controlled in accordance with a set temperature for unuse of the copying machine and providing a heater turning-off means which turns off forcibly the heater when a prescribed time is counted. CONSTITUTION:The heater turning-on time required for normal temperature keeping control of the heat roll at the time when the copying machine of power saving type is stopped is set to a prescribed time, and the occurrence of abnormality in the temperature control due to a temperature sensor 4 or the like is discriminated when the timer counts this prescribed time. Then, the heater is turned off forcibly independently of the control of a temperature controller which controls the heater in accordance with the detected value of the temperature sensor 4. Thus, the overheat accident at the copying machine stop time is prevented, and the set temperature is made lower than that for control to a copiable temperature to shorten the time-up time of the timer. |
