| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a developing device capable of maintaining a powder surface area of developer located downstream of a supply screw to be a lower limit value or more regardless magnitude of pulsation of a conveyance amount. <P>SOLUTION: A developing device 23 comprises: a developing section 6 having a developer carrier 27 and a rotatable developer supply member 28 for conveying developer while supplying the developer to the developer carrier 27; a developer agitating section 14 disposed at a different position from that of the developing section 6; developer conveying means 16 and 42 for conveying the developer from the developer agitating section 14 to the developing section 6 by air conveyance through inside of a developer conveying path 17; and powder surface area detecting means 49 for detecting a powder surface area of the developer accommodated in the developing section 6 in the lower vicinity of the developer supply member 28. The developing device 23 returns the developer circulated in the developing section 6 to the developer agitating section 14 through a developer discharging path 15. The developing device 23 further controls a conveyance amount of the developer to the developing section 6 by the developer conveying means 16 and 42 such that a fluctuation range of an output value of the powder surface area detecting means 49 exceeds a specified value. <P>COPYRIGHT: (C)2012,JPO&INPIT |
