| 摘要 |
PURPOSE:To reduce power supply capacity and to save energy consumption by interrupting or reducing power supply to a thermal fixing means at the start of a rotary polyhedral mirror scanning optical beams. CONSTITUTION:A fixing heater signal 63 is turned on after turning on a power supply. In response to a full wave/half wave control signal 76, temperature is controlled by an AC half wave only at the rise of the rotary polyhedral mirror. The variation of a resistance value of a thermistor 65 fitted to the periphery of a fixing roll is detected by bridge circuits 64-67 and a comparator 60, and when the output of the comparator 60 is H (a fixer is at a set temperature or less) and the signal 63 is H (half wave control), a TR 71 is turned on and TR 72 is turned off, so that an LED 75A lights up, only a thyristor 75C is actuated and the AC half wave is sent to a fixing heater 45. When the temperature of the fixer exceeds the set temperature, the output of the comparator 60 is turned to L, the TR 71 is turned off and the TR 72 is turned on, so that the LEDs 75A, 75B do not light up and power supply to the heater 45 is interrupted. Thus, energy can be saved. |
