| 摘要 |
PURPOSE:To prevent carriers from sticking on a nondevelopment part and to prevent toner from being scattered by separating a developing bias applied to a developing roller into an AC and a DC voltage and controlling them. CONSTITUTION:A voltage generated by superposing the DC and AC voltages is applied as the developing bias to developing rollers 31D, 32D, 33D and 34D and the DC voltage and AC voltage are controlled separately. Namely, an AC power source is provided for each of image forming units I-IV and the AC voltage AC is applied to the respective developing rollers 31D-34D through capacitors C. The DC voltage DC, on the other hand, is applied to the developing rollers 31D-34D from one DC power source through resistance R which are connected in parallel. Then, the AC voltage AC is turned on and off according to development signals supplied to the respective image forming units. |
