| 摘要 |
PROBLEM TO BE SOLVED: To reduce a voltage fluctuation and a high frequency noise of an AC power source caused at the time of turning on/off a heat source by making the energizing control system of a heat source different between a copying mode and a standby mode. SOLUTION: This copying machine is provided with a zero cross detection circuit 4 detecting the zero cross point of AC voltage impressed on the heat source 3 having a fixing heater, and a control means 8 having a control circuit 6 incorporating an arithmetic processing means 5 and an electronic switching element 7 and energizing the heat source 3 for a specified time from the zero cross point in every half cycle of the AC voltage when power is supplied to the heat source 3. In the copying machine provided with a fixing device having the heat source 3 which is controlled to be energized so as to generate heat, the energizing control system of the heat source 3 is made different between the copying mode and the standby mode. In the copying mode, the on/off control of energizing the heat source 3 is performed according to the zero cross, and in the standby mode, soft start control that the heat source 3 is turned on while gradually increasing a phase angle in energizing the heat source 3 is performed. |
