| 摘要 |
PURPOSE:To make an electrostatic charge current constant without increasing the scale of constitution by supplying high-voltage power from the common secondary high-voltage output of a high-voltage transformer through a high resistance, and controlling the primary side of the high-voltage transformer according to a total load current. CONSTITUTION:A constant current flows from the common secondary winding of an inverter transformer 7 to a photosensitive drum electrifier 2 and a transfer electrifier 5 through the rectifying circuit of a rectifying diode D1, bleeder resistance R3, smoothing capacitor C1, etc., resistances R4 and R5 having high resistance values for making the current constant, etc., thereby supplying the high- voltage power. The total load currnet is detected in the form of a voltage by a resistance R1 between the reference side of the rectifying circuit and the ground, and an inverter driving circuit 8 on the primary side of the transformer 7 is brought under the feedback control of an LPF11, an error amplifier 9 making a comparison with a reference voltage, etc. Thus, the constitution which uses the common secondary winding while the need for a high-voltage transformer or secondary winding for every electrifier is eliminated, makes the electrostatic charge current constant without making the constitution large in scale nor complex. |
