| 摘要 |
PROBLEM TO BE SOLVED: To prevent the picture quality of an image forming device equipped with a revolver developing unit from decreasing by suppressing a rear-end white void. SOLUTION: The nip between a photosensitive drum 100 and a developing roller of respective developing units of the revolver developing unit 400 is made narrow and in the nip area, a magnetic brush is closely formed. When the revolver developing unit 400 rotates and a developing roller comes close to the photosensitive drum 100, a developing bias is applied to the developing roller and the value of the developing bias at this time is set so that a revolution potential as the potential difference between the electrostatic charging potential of the photosensitive drum 100 and the developing bias is higher than a normal development condition without causing carrier sticking on the photosensitive drum 100. |
