To accelerate the speed of sensing temperature, prevent overheating and discharge accidents or the like by bringing a pair of terminals for detecting a thermoelectromotive force into contact with different type metals for constituting a fusing roller or the like, and detecting the temperature from the thermoelectromotive force generated.
This using device comprises a circuit for detecting the temperature difference of both ends due to an electromotive force of a fusing roller, constituted by connecting or bringing two types of metals into contact with one another to decide whether or not an overheat fault occurs according to the temperature difference thereby to shut off a current to a resistor heater layer 10, when a fault is decided. A temperature control system has a fusing roller comprising the layer 10, a triac 11, a temperature fuse 13, a shut-off relay 15 or the like. In this case, a 100V commercial power source is connected to the layer 10, the temperature is regulated by the triac 11, the fuse 13 is operated when overheated so as to shut off the current of the commercial power source. Accordingly, the temperature difference of both the ends of the roller can be detected immediately and surely to prevent overheating.
ISHIKI AKIRA
TANAKA KENJI
SAITO TAKASHI
