| 摘要 |
<p>PURPOSE:To prevent a damage to a tape due to an excess tension or unstable drive of the tape due to a deficient tension by controlling the tape winding tension to be always optimum and constant in the normal reproduction mode, the fast feed reproduction mode, the rewinding reproduction mode and the video recording mode. CONSTITUTION:A motor 23 is driven depending on the quantity of a tape winding tension detected by a tension sensor 3a at a supply reel side to rotate an energizing force variable gear 26 through gears 24, 25. Since a female thread provided in the inside of the gear 26 meshes with a male thread provided on a shaft 14, the gear 26 changes an amt. of compression of a press spring 28 through its own rotation. Since the change in the amt. of compression results in controlling a friction between a driving body 11 and a driven body 12, the tape tension sensor 3a at the supply reel side directly detects the tape winding tension. Thus, the tape winding tension is always kept optimum and constant.</p> |
