| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus with a multistage developing system, which can reduce density unevenness caused by rotational deflection of an image carrier with high accuracy and which can sufficiently make use of advantages of the multistage developing system. <P>SOLUTION: Voltage control means 72 comprises a CPU, a DA converter, a developing bias high voltage power supply 70, and a delay circuit 74. A density unevenness correction signal is generated from a density sensor detection signal and a photoreceptor rotational position detection signal, and a developing bias applied to developing rollers with a multistage developing system is controlled based on the photoreceptor rotational position detection signal. A correction developing bias applied to a second developing roller 56 has a phase delayed more than the correction developing bias applied to a first developing roller 54. <P>COPYRIGHT: (C)2013,JPO&INPIT |
