| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a developing device capable of suppressing ioccurrence of image irregularity due to the variation of developing gap, and to provide an image forming apparatus with the developing device. <P>SOLUTION: The developing device includes a developing roller 72 and a voltage applying means 80 to apply a developing bias voltage to the developing roller 72. The voltage applying means 80 includes a first period to apply the AC voltage of a rectangular waveform and a second period not to apply the AC voltage, and the duty ratio of the AC voltage is ≥50% in a direction to develop an electrostatic latent image with toner, the AC voltage in the first period has two or more cycles in the periodicity. The developing bias voltage to return the toner to the developing roller is applied as the AC voltage to be applied just before shifting from the first period to the second period. <P>COPYRIGHT: (C)2008,JPO&INPIT |
