| 摘要 |
<p>PURPOSE:To enable the speed and tension of media to be readily and accurately controlled by electrically detecting the speed and tension of media such as tapes, films, etc. and performing electric controlling based on the electric signals. CONSTITUTION:When a photo sensor 21 positions at nearly the central part of the length of the radiation type blades of a tension pole 7, the pulse signal like (a) is obtained. In addition, when the tape speed is low, the pulse of a low frequency like (a) is obtained and when the tape speed is high, the pulse signal of a high frequency like (b) is obtained. Hence, the tape speed may be readily detected. When the winding diameter of the tape 3 on a supply reel disc is large, the output signal like (d) is obtained and when the winding diameter is small, the output signal like (e) may be obtained. Hence, the tension may be readily detected. The speed and tension of the medium may be readily and accurately controlled by the electric signals obtained in this way.</p> |
