| 摘要 |
<p>PURPOSE:To set the run speed of a tape to a desired speed by measuring required times of both reels for single rotation and by exercising control based upon a fixed relational formula. CONSTITUTION:With the turning force of tape feed motor 4, take-up reel 2 is turned through the transfer mechanism to feed magnetic tape 1 from supply reel 3 to take-up reel 2. Coupling with reels 2 and 3, ring magnets 5 and 6 rotate and, in consequence, Hall elements 8 and 9 detect magnetic pulses respectively to supply microcomputer 12 with pulses alpha1 and alpha2 obtained by amplifying their detection outputs by amplifiers 10 and 11. On the basis of pulses alpha1 and alpha2, computer 12 performs the arithmetic and comparison of T1<2>+T2<2>-1/a<2> by using required times T1 and T2 of both the reels for single turning and reference number (a) for determining a desired feed speed. As a result, when the result is positive, the motor speed of reel 2 is increased and when negative, motor speed varying circuit 13 is controlled to exercise control over the speed of motor 4.</p> |
