| 摘要 |
<p>PURPOSE:To make a circuit to be highly integrated and to improve the reliability and performance by making an ATF control system including a pilot signal process to be fully digital-processed. CONSTITUTION:A reproduced signal detected from a magnetic tape 1 is amplified by a preamplifier 3 and supplied to an LPF 4, and after the high range components such as a video, audio information, etc., unrequired for the tracking control are suppressed therein, the reproducing pilot signal is made to an appropriate level through an AGC amplifier 5 and supplied to a sample-and-hold circuit 6. This signal is held by the circuit 6 with a common multiple of signal frequencies f1-f4 by using a clock from a clock generating circuit 8. The held reproducing pilot signal is subjected to digital conversion by an A/D converter 7 and thinned out by data thinning-out circuits 9-19 so as to become 1/29, 1/25, 1/20 and 1/18 respectively. By this procedure, the reproducing pilot signals of four frequencies can be all converted to fH frequencies, therefore, any separate multiplying circuit for frequency conversion is unrequired, then the circuit is made small in scale.</p> |
