| 摘要 |
A developer roller 3 includes an electrically conductive metal inner layer 4 and a semiconductive outer layer 5. The surface potential of the outer layer 5 is controlled by power supplies 6, 7 connected to the inner layer 4, so that particles of a single-component toner charged by friction can adhere to the outer layer surface 5. The outer layer 5 also has uniform irregularities on its surface, preferably of surface roughness of 2.5 to 4.5 mu m and formed by adding particles (eg. SiO2) to the semiconductive layer 5. <IMAGE> |
