DONOR ROLL WITH ELECTRODE EQUIPPED WITH STURDY COMMUTATOR CONTACT

摘要

PROBLEM TO BE SOLVED: To provide a scavengeless developing device containing a donor roll with an electrode having an over-molded tough commutator contact. SOLUTION: The donor roll 40 with the electrode partially attached into a development unit mixing chamber and forming a development zone together with an image carrier member and for moving a charged toner particle from the mixing chamber to the development zone is provided. The donor roll 40 contains a shaft core 153 and a dielectric layer 154 injection molded covering the shaft core 153. Further, the donor roll 40 contains the electrodes 42 formed in the surface of the dielectric layer 154 and prolonging in the axial direction and a tough commutator contact pad 320 formed from a conductive commutator washer device over-molded in the dielectric layer 154. The commutator pad 320 is dressed and in contact with the electrodes respectively prolonging in the radial direction.