| 摘要 |
PURPOSE:To fix the charging potential independently of the temperature by detecting the temperature of a photosensitive drum by a drum temperature detecting means and controlling the impressed voltage of a main charger based on the detection output by a control means. CONSTITUTION:This device is provided with a thermistor 20 to detect the temperature of a photosensitive drum 1, and the resistance value of the thermistor 20 is detected as the drum temperature by a drum temperature detecting circuit 22. The detection output of the circuit 22 is inputted to a reference voltage setting circuit 23, and the circuit 23 outputs a reference voltage corresponding to the detection output of the circuit 22. A differential amplifier 25 amplifies the difference between an input voltage corresponding to the surface potential of the drum 1 detected by a surface potential sensor 21 and a surface potential detecting circuit 24 and the reference voltage set by the circuit 23 and controls the impressed voltage of a main charger 2 through a high voltage power output adjusting circuit 26. Thus, the main charger 2 uniformly electrifies the photosensitive drum 1. |
