Developing device, process cartridge and image forming apparatus loaded therewith

摘要

A developing device of the present invention is operable with a two-ingredient type developer by mixing and agitating toner grains and carrier grains to thereby electrify the toner grains. At least the carrier grains are sealed in a space formed in the developing device until the developing device starts being used while the toner grains are introduced in the developing device at the start of use.