| 摘要 |
PURPOSE:To prevent the safety of the temperature sensor of a heat fixing device from degrading during a breakdown by stopping copying operation after discharging copying forms remaining in a passage when it is judged that the breaking of wire occurs to a fixing device temperature detection part. CONSTITUTION:If the breaking of the sensor 1 or sensor lead wire occurs during the operation of the copying machine, a microcomputer 20 outputs a control signal to a driving group 40 to inhibit forms from being fed from a form dish and if there is a form in the passage near the fixing device, the form is discharged by carrying on the copying operation and then the machine stops. When there is no form in the passage, the machine stops operating immediately. For this purpose, a heater 33 is turned on the off under control based upon the output of an AND circuit 4, but microcomputer control may be employed. The heater 33 is provided in a heat roller 31 contacting the presser roller 32 of a fixing part E. The sensor 1 uses a thermistor, etc., which decreases in resistance value according to a temperature rise. |
