| 摘要 |
PROBLEM TO BE SOLVED: To prevent the overlapping of rush currents by deviating the power supply control starts of plural heaters and to suppress the increase of power by executing the time division control of the plural heaters. SOLUTION: A lower heater is turned on after a delay of a time tW1 from the time TS when an upper heater is turned on. The time tW1 is of the rush current attenuation time of the upper heater and changed according to the temp. of the upper heater, so that the time tW1 corresponding to the temp. is adopted. Since the lower heater is turned on after the rush current of the upper heater is obtained, the increase of the power caused by the overlapping of the rush currents is prevented. After that, the upper and lower heaters are alternately turned on to execute the time division control. Thus, the increase of the power is prevented. |
