| 摘要 |
PURPOSE:To control the temperature of a heat roller precisely with a simple constitution and to control the density of toner efficiently by detecting the change of magnetic characteristics following temperature change through a temperature sensitive magnetic thin layer fitted to a fixing heat roller to control a heating body. CONSTITUTION:A temperature sensitive magnetic thin layer 7 is formed on the surface of the heat roller 5 forming the heat fixing roller 3 together with a pressing rubber roller 4 and the change of the magnetic characteristics which follows the temperature change of the roller 3 is detected by a sensor 14. The heating body 6 built in the roller 5 is controlled through a control circuit 13 on the basis of the detected output of the sensor 14, so that the temperature of the roller 5 is controlled precisely with simple constitution and the density of toner forming a picture is efficiently controlled. |
