| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress a phenomenon without causing a side effect, the phenomenon that toner replenished from a toner replenishing port in an upper side to a developer agitation conveyance passage is supplied to a developer carrier in an insufficient agitated state with a developer in the developer agitation conveyance passage. <P>SOLUTION: A developing device is disclosed, in which a supply conveyance passage 60 having a supply screw 51 for supplying a developer to a developing roller 15 is separated by a partition wall 54 from an agitation conveyance passage 61 having an agitation screw 53 for agitating and conveying the developer in an opposite direction to the supply screw, and the developer is circulated and conveyed through an opening 62 that connects the most downstream part of the agitation conveyance passage to the most upstream part of the supply conveyance passage and through an opening 63 that connects the most downstream part of the supply conveyance passage to the most upstream part of the agitation conveyance passage. The toner is replenished through the toner replenishing port 55 above the upstream part of the agitation conveyance passage. A developer upper layer regulating member 57 regulating the delivery and reception of the developer upper layer is provided between the supply screw and the agitation screw in a region where the developer is delivered from the most downstream part of the agitation conveyance passage to the most upstream part of the supply conveyance passage. <P>COPYRIGHT: (C)2010,JPO&INPIT |
