Patent ID: 9383676
Filing Date: 2016-07-05
CPC Classification: G03G

Claim Text:
1. An image forming apparatus comprising: an image forming unit comprising: a peripheral speed setting mechanism configured to set a peripheral speed ratio of the developing roller to the photosensitive member to at least a small peripheral speed ratio and a large peripheral speed ratio; a developing bias applying circuit configured to selectively apply a low developing bias or high developing bias to the developing roller; a charging bias applying circuit configured to selectively apply a low charging bias or high charging bias to the charger; and a controller configured to: wherein the low developing bias is set to have an absolute value smaller than the high developing bias and larger than zero, wherein the small peripheral speed ratio is set to be smaller than the large peripheral speed ratio and to be larger than zero, wherein the low charging bias is set to have an absolute value smaller than the high charging bias and larger than zero, and wherein the first preset time period is set to be shorter than a time period for which a high potential part reaches the developing roller, the high potential part being formed on a surface of the photosensitive member at a position facing the charger.