| 摘要 |
PURPOSE:To adjust the tension of a film to an optimum value by calculating the amount of transfer control of a movable-roller group with respect to a guide- roller group in accordance with the amount of variation of the pass of a film and shifting the movable-roller group on the basis of the control amount. CONSTITUTION:Each speed at the inlet side and the outlet side in a movable- roller group 2 is detected by detectors 14 and 15 respectively, and the difference of speed is calculated by an arithmetic apparatus 16, and the amount of variation of the pass of film is calculated from said difference of speed. The amount of transfer control for the movable-roller group 2 with respect to a guide-roller group 1 is calculated from the above-described variation amount, in order to adjust the tension of the film to an optimum value. Said calculation value is input into a control apparatus 17, and a driving mechanism 4 is driving-controlled on the basis of the amount of transfer control, and the movable-roller group 2 is all at once brought close to or separated from the guide-roller group 1 through the driving mechanism 4, and the tension of the film 3 is adjusted to the optimum value according to the amount of variation of the pass of film in the movable-roller group 2. |
