| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a developing device capable of performing accurate toner concentration control at all times. <P>SOLUTION: A developing sleeve 25 is rotated reversely to a photoreceptor drum 1 and a developer 31 which is left on the developing sleeve 25 after development and peeled from the developing sleeve 25 is collected in a collection region R3a. An optical sensor 41 detects the toner concentration of the collected developer 31 and toner is supplied to the developer 31 from a toner supply chamber R4; and the resulting developer is carried toward an agitation chamber R2 and a magnetic permeability sensor 51 detects the toner concentration again. Then the developer 31 is supplied to a development chamber R1 via the agitation chamber R2 to carry out development. The amount of toner supply is controlled on the basis of detection results of toner concentration by the optical sensor 41 and magnetic permeability sensor 51. <P>COPYRIGHT: (C)2007,JPO&INPIT |
