| 摘要 |
PROBLEM TO BE SOLVED: To satisfactorily control the temperature of a head roll using a heat generator sheet by a control means on the SELV side (the low voltage side like an operation panel). SOLUTION: An operational amplifier 161 compares a potential V (corresponding to the surface temperature of the heat roll) obtained by a thermistor 107 with a comparison potential Vr corresponding to the control signal from a CPU 71 inputted through photo-transistor couplers PC1,..., PCn and inputs the result to the CPU 71 through a photo-transistor coupler 171. The CPU 71 controls power supply to a fixing heater 16a through a photo-triac coupler 93 in accordance with this input. Since each of photo-transistor couplers and photo-triac couplers transmit this signal or the like independently of electric conduction, this control can be executed while the fixing heater 15a, a triac 95, and the thermistor 107 are arranged on the primary side and the CPU 71 is arranged on the SELV side. |
