DEVELOPING DEVICE

PURPOSE: To remove impurity from toner at a developing process by arranging an electrode structural body inside a developing area between a donor structural body and a surface and producing an air stream in a direction that the air stream is normally away from the developing area of at least the one part of the periphery of the donor structural body from the charge remaining surface. CONSTITUTION: This device includes a housing 44, the housing 44 partitions a chamber 76 housing developer for supplying inside, and a donor roller 40, an electrode wire 42, and a magnetic roller 46 are provided on the chamber 76 inside the housing 44. The wire 42 is physically vibrated by applying an AC bias having an adequate frequency, so that the impurity can be removed therefrom. The air stream 106 is produced in a specified direction by a frame 100, a manifold 102, and a vacuum pump 104. The air stream 106 partially passes on the surface of the donor roller 40 itself, so that the impurity and flocculation material are directly removed by replenishment toner on the roll 40.