DEVELOPING DEVICE AND IMAGE FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a hybrid type developing device and an image forming apparatus in which a power supply has a simplified structure and density unevenness and fogging of a toner may be suppressed.

SOLUTION: A hybrid type developing device comprises: developing rollers 11 and 12 carrying a toner on outer peripheral faces thereof and disposed along a rotation direction of a photosensitive body 1 so as not to come in contact with the photosensitive body 1; and a developer carrying roller 10 carrying a developer including the toner and a carrier for supplying the toner to the developing rollers 11 and 12. Each of the developing rollers 11 and 12 has a dielectric layer on a surface thereof, and assuming that the dielectric layer of the developing roller 11 has a dielectric constant ε1 and a thickness d1 and that the dielectric layer of the developing roller 12 has a dielectric constant ε2 and a thickness d2, a relationship of d1/ε1>d2/ε2 is satisfied, and the developing rollers 11 and 12 are connected to one power circuit 16.

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