| 摘要 |
<p>PURPOSE:To perform accurate reel servo, by operating a value corresponding to the square of a period represented by a clock by counting the period of the edge of a signal corresponding to the rotation of a reel when measuring by a frequency with double the clock. CONSTITUTION:For example, when a reproduction mode at N-multiplied speed in a forward direction is set, switches 43 and 44 are switched to (a) sides. A frequency generator 8 detects the rotation of a take-up reel 3, and a generated pulse is amplified and waveform-arranged, then, inputted to an arithmetic circuit 15. Also, the clock 1/2-frequency divided is inputted to an edge detection circuit 21. The output of the circuit 21 is counted by the frequency of the clock by a counter circuit 23, and is inputted to an adder circuit 25. Similarly, a pulse corresponding to the rotation of a supplying reel 4 is processed by an edge detection circuit 22 and a counter circuit 24, and inputted to the circuit 25. The output of a D/A converter 42 and that of a back tension generation circuit 45 are supplied to motors 6 and 7, thereby, the accurate reel servo can be performed.</p> |
