| 摘要 |
PURPOSE:To enable fixation of images without causing scorching and smoking of transfer papers by detecting temps. of the surface of an IR heater and the atmosphere in an image fixing device and controlling each temp. to a temp. capable of fixing a nonfixed image. CONSTITUTION:An image fixing device is provided with IR heaters 1, 1 and reflective mirrors 2, 2 facing to each other on both sides of a paper conveying route, and a heater surface temp. detecting means 3 is fixed so as to touch the surface of each heater 1, and an atmosphere temp. detecting means 4 is fixed in a position between the heaters 1, 1 and not disturbing conveyance of transfer papers. A fan 5 for ventilating the air in the fixing device is installed. The means 3, 4 are of a thermocouple and a thermistor, and the outputs are fed to noninverting inputs of hysteresis comparators 6, 7 to compare them with voltages VREFS and VREFA corresponding to heater surface reference temp. and atmosphere reference temp., and supplies of power to the heaters 1, 1 and a motor 10 for rotating the fan 5 are controlled. As a result, image fixation is carried out without scorching and smoking transfer papers. |
