| 摘要 |
PURPOSE:To stabilize the temperature control of a heating roller, by enclosing a material whose melting point is lower than the controlling temperature of the heating roller and higher than the lower limit temperature of the heating roller required when a toner image is fixed to a member to which the toner image is to be fixed, in the heating roller. CONSTITUTION:At the time of heating up, a heating roller 4 is heated by a heater 2 to the melting point of a material 5 enclosed in the heating roller 4 and set to a waiting state and the temperature of the roller 4 is maintained until all the material 5 melts. When the heating roller 4 is further heated, a temperature sensor 3 detects the temperature of the roller 4 and a control circuit maintains the heating roller 4 at a previously fixed heating roller controlling temperature. When the waiting state is shifted to the fixing state thereafter, the heat of the roller 4 is absorbed by a pressing roller 1 and member to which a toner image is fixed and, because of the insufficient capacity of the heater 2, the temperature 7 of the heating roller 4 drops. But the material 4 enclosed in the roller 4 generates heat of solidification and drop in temperature to a level lower than the melting point of the material 5 is prevented. Therefore, the heating roller temperature 7 can be controlled stably at the time of fixing. |
