| 摘要 |
PURPOSE:To permit formation of a developed image having a high image density by providing a magnetic member having one end part which generates napping of a developer and the other end part which does not generate the napping of the developer so as to face a developer carrying member apart therefrom. CONSTITUTION:The toner particles and magnetic particles which are not consumed for development are recovered in a container 21 and are subjected to circulation in the container 21. The magnetic particles taken in the toner from the toner layer in the upper part of the container 21 and receive the supply of the toner by as much as the toner is consumed. A magnetic brush by the magnetic particles 27 is formed between a magnetic pole 23d and a magnetic seal 31 to prevent the blowing out of the toner particles 28 at this time, but the magnetic particles are restrained by the magnetic lines 34 of force leaking out of the end part of the magnetic seal to the inside of the developing container and the napping is formed along the magnetic lines of force. The magnetic seal 31 is coated with a nonmagnetic material at the end part. Such a shape of the seal 31 as to decrease the leakage of the magnetic lines 34 of force into the developing container is determined by a finite element method. The stable supply of the toner particles is thereby executed and the developed image having the high image density is obtd. |
