Developing device and image forming device

摘要

On surfaces of insulating layers 1b and 1c of a transportation member 1, a protective layer 1d having a volume resistivity of 10<10 >Omega.cm to 10<17 >Omega.cm is so laminated that a sum of thickness of the insulating layers 1b and 1c is less than intervals between adjacent ones of progressive wave generating electrodes 2. With this arrangement, it is ensured that a progressive wave electric field generated by the progressive wave generating electrodes 2 is exposed beyond a surface of the transportation member 1. Even if developer T and the transportation member 1 contact each other, a surface potential of the transportation member 1 is not changed. Moreover, firm adhering of the toner T to the surface of the transportation member 1 is prevented. It is therefore possible to certainly transport the developer T to a development position always stably.