| 摘要 |
PURPOSE:To realize developing without a faulty image regardless of the change of ambient environment or the like. CONSTITUTION:By an electrical conductive developer supply member 2, developer T is supplied to a developer carrier 1. By an electrical conductive layer thickness regulation member 3, the thin layer of the developer T is formed on the carrier 1 and the electrostatic charge thereof is executed. By a first surface potential sensor 11, the surface potential of the latent image part of an image on an electrostatic latent image holding body 10 is measured. By a second surface potential sensor 12, the surface potential of the carrier 1 on which the thin layer of the developer T is formed is measured. By a comparison and control part 13, a power source E3 connected to the carrier 1 is controlled so that a first differential value between the surface potential of the latent image part of the image on the holding body 10 and a voltage from the power source E3 becomes within a first regulation range with respect to a first regulation value and at least one of power sources E1 and E2 connected to the supply member 2 and the regulation member 3 is controlled so that a second differential value between the surface potential of the carrier 1 and the voltage from the power source E3 becomes within a second regulation range with respect to a second regulation value. |
