IMAGE FORMING APPARATUS

To sufficiently obtain a toner adhesion inhibition effect even if the amount of electrification of toner is increased or decreased.SOLUTION: An image forming apparatus comprises: a photoreceptor; electrifying means that electrifies a surface of the photoreceptor; exposure means that exposes the electrified surface of the photoreceptor; developing means that develops a latent image formed on the surface of the photoreceptor with toner; an electrification power supply that is connected with the electrifying means to apply electrification voltage to the electrifying means; and control means that controls the electrification voltage to be applied from the electrification power supply to the electrifying means. The exposure means has a conductive member that is connected with the electrification power supply and has conductivity. The control means applies, from the electrification power supply to the conductive member, voltage Vs having the same polarity as potential Vd of a portion of the surface of the photoreceptor facing the exposure means. When the amount of electrification of the toner is a first amount of electrification, the image forming apparatus determines the voltage Vs to be applied to the conductive member to be a first value larger than the potential Vd, and when the amount of electrification of the toner is a second amount of electrification smaller than the first amount of electrification, determines the voltage Vs to be a second value larger than the potential Vd and larger than the first value.SELECTED DRAWING: Figure 5 【課題】トナーの帯電量が増減しても、トナーの付着抑制効果を十分に得る。【解決手段】感光体と、感光体の表面を帯電する帯電手段と、帯電された感光体の表面を露光する露光手段と、感光体の表面に形成された潜像をトナーにより現像する現像手段と、帯電手段に接続され、帯電手段に帯電電圧を印加するための帯電電源と、帯電電源から帯電手段に印加する帯電電圧を制御する制御手段と、を備え、露光手段は、帯電電源に接続された、導電性を有する導電部材を有し、制御手段は、感光体の表面の露光手段と対向する部位の電位Ｖｄと同じ極性の電圧Ｖｓを帯電電源から導電部材に印加し、導電部材に印加する電圧Ｖｓを、トナーの帯電量が第一の帯電量であるときは電位Ｖｄより大きい第一の値に決定し、トナーの帯電量が第一の帯電量より小さい第二の帯電量であるときは電位Ｖｄより大きく、第一の値より大きい第二の値に決定する。【選択図】 図５