| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing device in which toner scattering can be improved by enhancing the suck-in air flow to the developing device by improving a sealing property between a developing device lower case and a developing sleeve so as to be adaptable to an image forming device such as a high-speed copying machine. SOLUTION: The position of the P2 pole of a lower roller 15 is set at a position at which it is efficient to enhance the pumping effect of the lower roller 15, that means, in the vicinity of the R-shaped center of a lower case 16. The position is at the position at which an angle obtained by the P2 pole on the downstream side in the rotating direction of the developing sleeve is set as 90 deg. to a straight line connecting a photoreceptor 20 and the center of the developing sleeve. By this constitution, the sealing property between the developing device lower case 16 and the developing sleeve 15a by the developer stuck to the P2 pole of the lower roller 15 is improved. |
