CARRIER FOR DEVELOPER, TONER, DEVELOPER, DEVELOPING DEVICE, CONTAINER WITH DEVELOPER INSIDE, AND IMAGE FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide an electrophotographic developing device that achieves high image quality, while preventing the problems such as contamination of a carrier and inside the device by toner, embedment of an external additive, and low charge.SOLUTION: A developing device includes a developing roller, and one or more conveyance screws arranged parallel to the developing roller, accommodates a two-component developer comprising a toner and a carrier, and stirs the developer with the conveyance screws to circulate and convey the developer to the developing roller. The toner contains at least a binder resin and a colorant; the binder resin contains a crystalline resin; and the toner has the volume specific resistance in a range of 9.9 to 10.7 log&OHgr; cm. The carrier comprises core material particles having magnetism, and a coating layer that coats each of the surface of the core material particle; the coating layer contains 50 to 500 parts by weight of filler relative to 100 parts by weight of the resin; the carrier has the bulk density of 1.8 to 2.4 g/cmor less; and the conveyance screws are non-conductive.