| 摘要 |
PURPOSE:To enable stable positioning by providing a pressure control mechanism and a pressure sensor, thereby controlling pressure generated among a driving roller, an idler and a driving bar. CONSTITUTION:A pressure sensor 13 is firmly fixed to a lever member 9 rotatably supporting a shaft 7 of an idler 4. There is provided a pressure control mechanism comprising a piezoelectric element 12 for controlling pressure generated among a driving roller 3, the idler 4 and a driving bar 2 according to the pressure detected by the pressure sensor 13. Thus the sliding velocity can be controlled by the pressure control mechanism, so that stable positioning can be accomplished. |
