| 摘要 |
PROBLEM TO BE SOLVED: To prevent the wear or the pitting corrosion of a rectification brush for connecting an electrode embedded in the surface of a doner roll to a power source and a thin-film electrode brought into contact with the rectification brush from occurring. SOLUTION: Two sets of interdigital-shaped electrodes 92 and 94 are embedded in the surface of the doner roll. All the electrodes 92 of one set are simultaneously connected to the power source. The electrodes 94 of the other set are connected to the power source through a photoelectric switch mechanism 120. A photoelectric switch arrangement is provided with conductive foil electrodes 124 and 124' corresponding to the respective electrodes 94, a photoconductive coat 128 (128') brought into contact with all the electrodes and a light source 132' (132) irradiating the part of the coat corresponding to a developing area. Then, the part irradiated by the light source is conducted. Besides, a voltage is applied on the corresponding electrodes 94 and toner is separated from the doner roll in cooperation with the electrodes 92 corresponding to the electrodes 94. By removing the brush, the wear and the pitting corrosion are prevented from occurring. |
