| 摘要 |
PROBLEM TO BE SOLVED: To maintain fluidity of a developer while suppressing the accumulation of an external additive in a developer during image formation with high image ratio after endurance against environment.SOLUTION: In an image forming apparatus 100 that supplies a toner from a replenishment toner bottle 34 and perform image formation with a developing device 4 by using the toner, the toner has at least two types of external additives added thereto, and when the addition amount of a first external additive T2, of the two types of external additives, is Wh (volume% based on toner) and the addition amount of a second external additive T1 is Wl (volume% based on toner), the value Wh+Wl in an initial toner T1 in a developer to be accommodated in advance in the developing device 4 is larger than the value Wh+Wl in a replenishment toner T2 in a developer accommodated in the replenishment toner bottle 34, and the fluidity of the replenishment toner T2 is higher than the fluidity of the initial toner T1. |
