| 摘要 |
PURPOSE:To attain good fixability in white-and-black recording as well as color recording by changing the fixing temperature in a heat fixing device in accordance with the color of image forming materials. CONSTITUTION:When a push button switch 7 for color copy is turned on, a control pat 6 sets the temperature of a heat roll 1 to a higher value. For example, the control pat 6 sets the fixing temperature to 190 deg.C (the temperature most suitable for fixing of a color toner) when the switch 7 is depressed, but the control part 6 sets the fixing temperature to 180 deg.C (the temperature most suitable for fixing of a black toner) when the switch 7 is not depressed. In this roll fixing device, the fixing temperature is set to 180 deg.C in case of white- and-black copy and is set to 190 deg.C by depression of the switch 7 in case of color copy. Thus, a good fixability is attained in case of white-and-black copy as well as color copy. |
