| 摘要 |
PURPOSE:To decrease scattering of a developer extending over a long period of time by a simple constitution, and to improve a picture quaility by providing a means for impressing a bias voltage of the same polarity as the developer, to an electrode plate placed in the vicinity of a photosensitive body, on the downstream side of a developing device. CONSTITUTION:When a negative bias voltage of the same polarity as a toner T1 is applied by a power source 14 to an L-shaped electrode plate 12 provided through an insulating material 13 on a post-electrifier 5 of the downstream side of a developing device, a negative toner T1 and a positive toner T2 among flaoting toners in a laminar flow are adsorbed by an image part of a photosensitive body 1, and the electrode 12, respectively. Thereafter, the surface of the electrode plate is filled with the toner T2, therefore, while paper is passing, when it is switched by a control means 15 and a positive voltage is applied instantaneously, the toner T2 flies to the photosensitive body and it is collected by a cleaning device. Accordingly, scattering of the developer is prevented extending over a long period of time by a simple constitution, a contamination in the device is prevented and a picture quality can be improved. |
