| 摘要 |
PURPOSE:To eliminate faulty fixing and to prevent the curl of paper in a fixing device. CONSTITUTION:A thermistor 23 detects the surface temperature of a fixing roller 151 and outputs a temperature detection signal to a CPU 21 through an A/D converter 25. Based on the signal, the CPU 21 controls the heat generation of a heater 153 through a heater driving circuit 22. The paper is carried in a state where it is interposed between the fixing roller 151 and a backup roller 152. The calorific value of the heater 153 is decreased at the leading edge part and the trailing edge part of the paper. By restraining a water amount vaporized from the leading edge part and the trailing edge part of the paper, the curl of the paper is prevented. Since few toner images are formed at such parts, there is no trouble that the faulty fixing occurs because of the lowering of fixing temperature. |
