| 摘要 |
<p>PURPOSE:To quickly fast forward and rewind a tape by obtaining extents of rotations from certain points to another points of a tape supply reel and a take-up reel and detecting the middle point of the tape in accordance with these extents of rotation. CONSTITUTION:When the tape is rewound from the tape end, the diameter of winding of a supply reel 1 is about zero and that of a take-up reel 2 is maximum, and they are in the unbalanced state. When rewinding is started in this state, the extent of rotation of the supply reel 1 is larger than that of the take-up reel 2 and when the unbalanced winding diameter state is inverted between two reels and the diameters of winding of both reels are changed to each other, the integral extents of rotation from the start of rewinding of both reels coincide with each other. Since the tape top or the tape end does not exist until the extents of rotation of the supply reel 1 and the take-up reel 2 are equal to each other after the start of tape running, the tape can be transported at high speed then, and the tape speed can be accurately reduced a certain time before the extents of rotation of both reels coincide with each other.</p> |
