Patent ID: 8374531

Claim:
A developer bearer for conveying a developer to a developing station under an influence of an electric field created by an electric flux line, said developer bearer comprising: an outer electrode and an inner electrode configured to receive voltages different from each other and collectively create the electric flux line, said outer electrode and said inner electrode being arranged on different layers in a normal line direction of the developer bearer, wherein the outer electrode is located at an outer side of the developer bearer and configured to include at least two electrode portions separated at a prescribed interval on a same circumference of the developer bearer, the inner electrode opposing at least two intervals between the at least two electrode portions of the outer electrode, and at least two electric fields are created side by side outside an outer circumferential surface of the developer bearer by a neighboring pair of the at least two electrode portions, said at least two electric fields having different intensities from each other; and an insulation layer sandwiched between the outer electrode and the inner electrode in the normal line direction and configured to insulate the outer electrode and the inner electrode.