| 摘要 |
<p>PURPOSE:To reduce the starting time of tape and control the tension of the tape by stepwise controlling the voltages of reel driving motors according to tage speeds, numbers of rebolutions of reels, etc. CONSTITUTION:When the tape is started, the count value of a counter 29 with the output of a tape speed detector 27 via revolving post 10 as a gate time inputs to a CPU 26, from which the respectively constanct control voltages for fast feeding are applied to feed-and take-up reel motors 2, 15 through D/A convetters 32, 35 bias voltage regulating circuits 33, 36, driving circuits 23, 24, then the tape starts in a short time withour sag. Next, when it is likewise detected that the tape speed has reached a specified speeds, the control voltages inversely porportional tothe numbers of revolutions of the reels are applied for a constnat time to the motors 2, 15 through reel motor speed decectors 17, 18 rotating speed frequency conversion circuits 19, 20, counters 37, 38, CPU 26. When unevenness occurs in the tape speeds owing to changes in the tape quantities of the reels after a fixed time, the control voltages of the motors 2, 15 are likewise controlled stepwise, thus the tension being exerted upon the tape is satisfactorily controlled.</p> |
