| 摘要 |
PURPOSE:To prevent the occurrence of a defective fixing and a high temperature offset even if working and stopping are repeated through the use of the heater of high capacity of heating-up and cooling-down by setting a fixing temperature based on the temperature of the heating member before the control of the fixing temperature is started and a change in the temperature at the time of completing the supply of prescribed power to the heating member. CONSTITUTION:When an image forming signal is inputted, the energization of a heat generating zone is started and the energization of a heating element 6 is controlled so as to maintain a prescribed fixing control temperature with the detection temperature of a temperature detecting element. In other words, the detection temperature T1 of the temperature detecting element 4 just before an action has been started, is classified into three levels. When the detection temperature T1 is <50 deg.C, it is judged that a device is in cooled state and the higher fixing temperature of 190 deg.C is selected and when the temperature T1 is >=50 deg.C and <=70 deg.C, 180 deg.C is selected and when the temperature T1 is >=70 deg.C, it is judged that the device is in warmed up state and 170 deg.C is selected. A c ontrol temperature Tc is set in this manner, so that both of the defective fixing and a hot offset can be prevented. |
