Patent ID: 7697873
Filing Date: 2010-04-13
Classification: G03G

Abstract:
1. A development apparatus, comprising: a developer supporting member which supports developer containing toner and magnetic carrier on a surface of the developer supporting member to convey the developer, wherein the developer supporting member comprises a rotatable sleeve in which a magnet body is fixedly arranged; a toner supporting member which is disposed facing the developer supporting member to receive the toner transferred from the developer supporting member onto a surface of the toner supporting member, to convey the toner to a development area, wherein the developer forms a magnetic brush on the developer supporting member so as to rub the toner supporting member, the toner having passed through the development area is collected onto the developer supporting member by the developer rubbing the toner supporting member, and the surface of the toner supporting member travels in a direction opposite a traveling direction of the surface of the developer supporting member at an opposing portion between the toner supporting member and the developer supporting member; and an electric field forming mechanism which is adapted to form an alternating electric field between the developer supporting member and the toner supporting member, wherein a strength of an electric field in a direction in which the toner is collected from the toner supporting member onto the developer supporting member is in a range from 2.5×10 M (g/m Dss (m) is a smallest spacial distance between the developer supporting member and the toner supporting member; ρ (g/m ρt (g/m ρc (g/m TC is a mass ratio of the toner in the developer.