| 摘要 |
<p>PURPOSE:To display the absolute position of a tape continuously with high precision through the rotation of a reel by using a means of detecting the tape position, an oscillator and a counter in combination. CONSTITUTION:Pulses, proportional to rotational frequencies of a take-up reel and a rewind reel shaft, obtained by detecting slits 2 and 2' of slit disks 1 and 1' fitted to the shafts by detectors 3 and 3' are applied to a counter C. Those pulses are counted at the oscillation frequency of an oscillator OSC, and the number of the pulses equivalent to the time required for one turn of the reel, namely, data corresponding to one rotation period is latched by a latch L3. The rotation periods of both the reels are applied to an arithmetic circuit A1 to perform prescribed arithmetic, thereby displaying on a display device 4 the absolute value of a tape continuously with high precision. Instead of using the slit disks for the detection of the tape position, another method is applicable.</p> |
