| 摘要 |
PURPOSE:To detect the rotation of an image carrier with high precision by positioning an encoder shaft coaxially with respect to a rotary shaft by means of the joining of the joining parts of the rotary shaft and the encoder shaft when the image carrier is mounted on a main body. CONSTITUTION:When the driving action of the main body is started, a belt 13 is driven, and a pulley 9 is rotated. When the pulley 9 is rotated forward, a roller one-way clutch 8 is locked and the pulley 9 and a drum shaft 3 are integrally coupled. Thus, the pulley 9 is positioned by the shaft 3, and is independent of an encoder supporting frame 12. Therefore, the rotary vibration of the pulley 9 does not influence on an encoder 19 via the frame 12. Even if the coupling of the pulley 9 and shaft 3 is not completely integrated and a deviation slightly occurs, a taper shaft 15 is driven by the shaft 3, so that the encoder 19 can be rotated in synchronization with the rotation of the image carrier 1 without giving an influence to the precision of a driving part. |
