| 摘要 |
PURPOSE:To perform high-speed copying or the like without increasing the rated power consumption by detecting the temperature of the surface of a fixing device, which heats a powdery material on a base material to fuse and fix it, or its fluctuating factor to control the quantity of the base material which passes the fixing device in a unit time. CONSTITUTION:The image of a back and forth moved original 2 is developed by a developing device 5 and is transferred to a transfer paper 7 and is allowed to pass fixing rolls 13 and 14. A power source voltage is supplied to a transformer 21 for a voltage detecting circuit and a transformer 22 for a control circuit. The output voltage of the transformer 21 is compared with a voltage between both ends of a variable resistance 25, and a voltage detector A outputs a voltage detection signal. The output of the transformer 22 is supplied to a going motor control circuit 31 and a control circuit 32 through a DC stabilizing circuit 30. The variable resistance 25 is so set that the power source voltage is detected when it becomes 95% of a rated voltage, and a fixing heater 15 of the roll 13 is controlled to turn on and off by a load 34 connected to the circuit 32. Thus, high-speed copying is possible till the power source voltage is reduced to 95%, and the copying speed is made lower for <=95% reduction, and constant fixing is performed. |
