| 摘要 |
PURPOSE:To obtain the donor drum which is easy to manufacture and has excellent workability. CONSTITUTION:A donor drum 1 is rotatably carried by a shaft 22 between left and right side plates 20, 21. This drum 1 has torus grooves 1a respectively near both left and right side ends. The portion between said torus grooves 1a, 1a is the image-forming effective region 1b for actually carrying doner and the portions closer to the drum end side than each of the torus grooves 1a are guide faces 1c. Fine undulation treatment is applied to the image-forming effective region 1b by electroforming after finishing by grinding to high accuracy. The guide faces 1c are finished by grinding to high accuracy, after which they are subjected to hardening treatment such as hard alumite treatment or hard chromium treatment. |
