| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a developing device capable of achieving stable developing over a long period of time, and to provide an image forming apparatus. <P>SOLUTION: The developing device 1 using two-component developer composed of toner and carrier includes a replenishment carrier cartridge 8 for replenishing the carrier into the developer in the developing device body. The replenishment carrier cartridge 8 is configured to supply a plurality of kinds of replenishment carrier 9 having different physical properties. The developing device 1 includes: a replenishment-carrier remaining-amount detecting means 22 configured to detect the remaining amount of the carrier to be replenished 9; a toner density detecting means 23 configured to detect the density of the toner in the developer; an image density detecting means 24 configured to detect the density of the developed test image; a carrier determination means 21 configured to specify the kind of the carrier to be replenished from the replenishment carrier cartridge 8, on the basis of the detection results obtained by the replenishment-carrier remaining-amount detecting means 22, the toner density detecting means 23 and the image density detecting means 24, and also, on the basis of the deteriorated state of the developer obtained from the developing condition; and a display part 25 configured to display the specified result. <P>COPYRIGHT: (C)2011,JPO&INPIT |
