Patent ID: 6391511
Filing Date: 2002-05-21
Classification: G03G

Abstract:
A developing apparatus comprising:a developer container for holding a developer; a developer carrying member for carrying a positively chargeable developer held in the developer container and transporting the developer to a developing zone; and a developer layer-thickness regulating member for regulating the thickness of a positively chargeable developer layer to be formed on the developer carrying member; wherein; said developer comprises a positively chargeable toner having a weight-average particle diameter of 5 to 10 &mgr;m, said developer carrying member has at least a substrate and a resin coat layer formed of a resin composition on the surface of the substrate; said resin composition containing at least (I) a binder resin having a structure selected from the group consisting of an â€”NH2 group, an &boxH;NH group and an â€”NHâ€” linkage, (II) a conductive fine powder, (III) spherical particles having a number-average particle diameter of from 0.3 &mgr;m to 30 &mgr;m and (IV) a quaternary ammonium salt compound which is positively chargeable to iron powder, represented by the following general formula: â€ƒwherein R1, R2, R3 and R4 each represent a member selected from the group consisting of an alkyl group, an aryl group, and an aralkyl group, and may be the same or different from one another, and Xâˆ’ represents an anion.