| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing device where deterioration of the image density is prevented and a stable image density can always be obtained regardless of a pattern of a formed image even when developer with a weight mean grain diameter of <=7 μm is utilized. SOLUTION: This developing device is constituted so that when the weight mean grain diameter of toner in a toner container 6 is M, a proportion of the number of toner particles with a grain diameter of <=M/2 that is carried on a developing sleeve 3 to the number of toner particle carried on the developing sleeve 3 is A and a proportion of the number of toner particles with a grain diameter of <=M/2 in the toner container to the number of toner particles in the toner container is B, an agitating member 10 is rotationally driven so that the relation of 1.0<=A/B<=1.5 is satisfied. |
