| 摘要 |
A developing device includes a casing having a sleeve chamber, an upper chamber and a lower chamber, a developing sleeve housed within the sleeve chamber with a portion of the outer peripheral surface spaced a distance from a photoreceptor drum to define a developing station, and a screw feeder operatively housed within each of the upper and lower chambers. A partition wall separates the upper and lower chambers from each other and has a port defined in a downstream end with respect to the direction of conveyance of the developing material within the lower chamber for placing the upper and lower chambers in communication with each other. A plurality of magnets are accommodated inside the developing sleeve so as to extend in a direction longitudinally of the developing sleeve while positioned circumferentially of the developing sleeve. A weak magnetic pole is disposed at a region confronting the screw feeder within the lower chamber and a strong magnetic pole is disposed at a region corresponding to the port in the partition wall member and longitudinally of the weak magnetic pole.
|
