| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an image forming apparatus that can suppress both unevenness in density due to a change in a developing gap and a difference in density between edge parts of a solid image for a long period, when a blank pulse bias can be applied as a developing bias, irrespective of the process speed.SOLUTION: An image forming apparatus includes an image carrier, a developing device, a voltage application device, a driving mechanism, and a control unit. The developing device is arranged opposite to the image carrier, and includes a toner carrier carrying a toner on the surface thereof. The voltage application means can apply, to the toner carrier, a blank pulse bias including pulse parts applying an AC voltage having a rectangular waveform and blank parts not applying the AC voltage, as a developing bias. The control unit controls the driving mechanism and voltage application device to apply a continuous pulse bias having eliminated the blank parts as a developing bias during a full-speed mode, and apply the blank pulse bias as a developing bias during a reduced speed mode.</p> |
