| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing device capable of reducing a service cost by saving labor and time for maintenance by a service man by making a life of either developer carrier in common, and capable of satisfying gradation property and the gradation stability corresponding to a digital image and the graphic method of late years by eliminating difference of developing property for each developer carrier. SOLUTION: Relating to this image forming device 2 that is provided with plural developing sleeves (developer carriers) 20 and 30 arranged on the upstream side and the downstream side with regard to the rotary direction of the electrostatic latent image carrier, respective developing sleeves (developer carrier) 20 and 30 are constituted by forming non-magnetic member on periphery of the magnetic member inside and the coating member covering therefor, and the layer thickness control of the developer on the developing sleeve 30 on the down stream is performed by the developing sleeve 20 on the upstream, the weight ratio B/P of resin (B) and pigment member (P) consisting the coating member of the developing sleeve 30 surface on the downstream side is set larger than the weight ratio B/P of the resin (B) and the pigment member (P) consisting the coating member of developing sleeve 20 surface on the on the upstream side. |
