| 摘要 |
PURPOSE: To prevent the occurrence of image sweep due to a developing unit by isolating toner from a donor roll by an AC electric field based upon a self- interval adjusting type electrode structure and generating controlled clouds. CONSTITUTION: An electrode structure 48 consisting of two tungsten wires is raid in parallel with the axial line of the donor roll, an interval between the two tungsten wires is self-adjusted and adapted to the donor roll by average static electricity following AC voltage. When a discharge area is developed by red toner at first, the donor roll is biased to intermediate potential on a photoinductive discharge curve and the discharge area is developed by black toner under the biased state, only a high potential image is developed by the red toner and a low potential image is developed by both the red toner and black toner. Clouds are generated by isolating toner from the black toner developed image by an AC magnetic field generated by the electrode structure 48 adjacent to the donor roll to execute no-sweep development. |
