| 摘要 |
PROBLEM TO BE SOLVED: To prevent staining by satisfactorily electrifying toner in developer always steadily irrespective of use environment and use history in the case toner-concentration self-control function is provided. SOLUTION: The device 1 is equipped with a developing roller 2 which rotates holding the two-component developer 8 on it by means of a magnetic force, a developer regulation member 3 which regulates an amount of the developer held on the developing roller 2, a developer storage part 6 which stores the developer, and a toner storage part 7 which stores the toner. The device 1 is composed so that an amount of the toner added from the toner storage part 7 is controlled according to the volume of the developer in the developer storage part. Here, the volume of the developer storage part 6 is increased/ decreased according to a change in the electrifying capability of the developer magnetic particles, thereby controlling the amount of the toner added to the developer. |
