| 摘要 |
PURPOSE:To previously prevent a machine from burning by providing a control means detecting that the slop of temperature rise caused by a heating part is under a prescribed value, with a temperature detection signal, stopping the energization of a heating part and displaying abnormality. CONSTITUTION:When a main switch is turned on, a timer is resetted and a heater 14 is energized by a CPU 20. When a timer time (t) becomes (tb), CPU 20 judges whether or not the surface temperature of a fixing roller 11 reaches Tb. If not, the heater is judged to be disconnected, a heater energization signal is turned off, and the energization of the heater 14 is stopped, which is displayed in a display part. If the surface temperature of the fixing roller 11 reaches Tb, the CPU 20 judges whether or not the slop of the surface temperature rise of the fixing roller 11 (Tc-Tb)/(tc-tb) is larger than Ca based on a temperature detection signal from a thermister 15 when the timer time (t) becomes (tc). If not, the contact parts of heater terminals 29 and 30 with electrodes 25 and 26 are judged to be in contact failure, and the energization of the heater 14 is stopped, which is displayed in a display part. |
