| 摘要 |
PURPOSE:To prevent a quality change and the coagulation of a toner, and to execute stable development by providing in a developing tank a toner scraping roll having a permanent magnet roll coupled magnetically to the permanent magnet roll of a developing roll. CONSTITUTION:A developing roll 2 opposed to a photosensitive drum 1 is formed by a non-magnetic sleeve 3 and a permanent magnet roll 4 which rotates in the direction as indicated with an arrow (y) in its inside. A toner 6 is replenished from a cartridge 10, fed to the developing roll 2 by a rotating body 8, its height is controlled by a doctor blade 7 and it moves in the direction as indicated with an arrow Z, develops the latent image of the photosensitive drum 1, and the remaining toner is carried in the direction as indicated with the arrow Z. A scraping roll 12 is constituted of a non-magnetic sleeve 13 and a permanent magnet 14, provided in the vicinity of the developing roll 2 and couples magnetically the permanent magnet 4 and 14. The remaining toner fed in between them goes to a chain shape, and when it advances further, it is separated and scattered and drops into a toner tank 5. In such a way, a mechanical force is not applied to the toner, and the coagulation and a quality change are prevented. |
