Patent ID: 7835677

Claim:
A developing device comprising: a two-component developer comprising a magnetic carrier and a toner; a developer bearing member comprising a nonmagnetic developing sleeve configured to bear the two-component developer on a surface thereof while rotating; a magnetic field generating unit fixed inside of the nonmagnetic developing sleeve; and a developer amount control member configured to control an amount of the two-component developer borne on the developer bearing member, wherein the magnetic carrier comprises a core material, and a coating layer coated on the core material and comprising a binder resin and conductive particles, and wherein the magnetic carrier satisfy a ratio D/h of 1.00<[D/h]≦1.95, where D denotes an average primary particle diameter of the conductive fine particles, and h denotes a thickness of the coating layer, and a ratio Ra/D of 1.0<[Ra/D]<10.0, where Ra denotes a surface roughness of the developing sleeve.