| 摘要 |
PURPOSE:To prevent a fixation part from being damaged in self-diagnostic, by permitting self-diagnostic when the surface temperature of a heat roll attains to predetermined temperature, e.g. the softening temperature of toner deposited thereupon. CONSTITUTION:The power source is turned on and a temperature signal corresponding to the surface temperature of the heat roll 7 is inputted from a temperature detecting element 11 to a microcomputer 2 whose flag 1 is set through an A/D converter; when the temperature is lower than the softening temperature of the toner sticking to the heat roll 7, a heater 8 is powered on by a power supply circuit 9, and the flag 2 is set when the temperature attains to the softening temperature. At this time, a copying machine state display part 5 is flashed and the self-diagnostic is permitted. The operations of respective diagnostic parts N1...Nn are checked and they are put in operation. When the flag 2 is not set, the surface temperature is low and a display part 4 for the number of copied sheets is flashed. |
