CHARGING DEVICE IN IMAGE FORMING APPARATUS

Japanese Patent JP3793754

B2

PROBLEM TO BE SOLVED: To provide a charging device compensating the temperature characteristic of a photoreceptor with simple configuration and always maintaining the electrified quantity of the photoreceptor at an appropriate value. SOLUTION: A charger 5 applying charge to the surface of a photoreceptor 6, a high voltage power source circuit 2 applying voltage to the charger 5 and feeding current to replenish the charge, a control circuit 4 producing a control signal VE to control the quantity of current fed to the charger 5 and imparting it to the high voltage power source circuit 2 and a temperature compensation circuit 3, compensating the temperature characteristic of the photoreceptor 6 by varying the control signal VE in the direction increasing the quantity of current fed to the charger 5 when the peripheral temperature is high and varying it in a direction decreasing the quantity of current fed to the charger 5 when the peripheral temperature is low are provided. The temperature compensation circuit 3 is a circuit containing a transistor Q and the temperature characteristic of the photoreceptor is compensated by using the temperature characteristic of voltage VBE between base emitters of the transistor Q.