| 摘要 |
PURPOSE:To obtain a clear image stably by a frictional electrostatic charging method which uses a single-component developer (only toner) by providing a uniform conductive coating layer on the internal surface of an external coating layer, and fixing a mandrel and the external coating layer in one body. CONSTITUTION:The external coating layer 20 has its surface volume instrinsic resistance value adjusted to 10<8>-10<12>OMEGA.cm so that a toner is charged electrostatically and attracted and supplied to an electrostatic latent image on the surface of a photosensitive drum uniformly and efficiently and the amount of electrostatic charging of the toner is controlled within a specific range. The conductive coating layer 22 uses a conductive coating agent, such as low viscosity urethane, etc., which has an about 10<-1>-10<6>OMEGA.cm volume intrinsic resistance value and excellent adhesive strength to the external coating layer, and is formed as a uniform thickness thin layer at room temperatures or be baked to set. A conductive adhesive layer 30, on the other hand, uses a conductive adhesive, such as relatively high viscosity epoxy, which has nearly the same volume intrinsic resistance value and also has good adhesive strength to the mandrel 10 and conductive coating layer 22, and formed to proper thickness by being adhered at room or high temperatures. |
