IMAGE FORMING APPARATUS

To provide a developing device capable of suppressing excessive electrification to toner, while maintaining an electric charge supply capacity to the toner sufficient for development.SOLUTION: An image forming apparatus includes an image carrier for forming an electrostatic latent image, a developer storage container for storing a developer, a developer carrier, a regulation member for regulating the layer thickness of the developer carried by the developer carrier, an interval holding member for holding an interval between the image carrier and the developer carrier, and a control device for controlling a power supply for applying a voltage to the developer carrier. The developer carrier includes at least a substrate and a surface layer. The surface layer includes an electron-donating part for mainly giving an electric charge to the developer, when giving and receiving the electric charge by friction between the developer and the surface layer and an electron acceptor for mainly receiving the electric charge from the developer. The control device applies an AC voltage different from that when an image is formed to the developer carrier, when the image is not formed and when the developer carrier is driven.SELECTED DRAWING: Figure 4 【課題】現像に十分なトナーへの電荷供与能力を維持しつつ、トナーへの過度な帯電を抑えることが可能な現像装置を提供する。【解決手段】静電潜像を形成する像担持体と、現像剤を収容する現像剤収容器と、現像剤担持体と、現像剤担持体が担持する前記現像剤の層厚を規制する規制部材と、像担持体と現像剤担持体との間隔を保持する間隔保持部材と、現像剤担持体に電圧を印加する電源を制御する制御装置と、を有し、現像剤担持体は少なくとも基体と表面層を有し、表面層は、現像剤と表面層とが摩擦することで電荷を授受する際に、現像剤へ電荷を主に与える電子供与部と、現像剤から電荷を主に受け取る電子受容部とを有し、制御装置は、非画像形成時かつ現像剤担持体の駆動時に、現像剤担持体に画像形成時と異なる交流電圧を印加する、画像形成装置を用いる。【選択図】図４