| 摘要 |
<p>PURPOSE:To attain the discrimination of tape speed at time of recording, by attaching a track which always goes to a Low level by the influence of cyclical noise, on a rectangular tracking error signal after passing through a Schmitt circuit, and performing the discrimination of the cycle of the tracking signal only when it goes to a High level. CONSTITUTION:A block 101 shows respective circuit to obtain the tracking error signal from a reproducing pilot signal, and a Schmitt circuit 902 generates a rectangular wave by dividing the tracking error signal into a High and a Low levels by a threshold value 1/2VCC. An output from the Schmitt circuit 902 is processed in software-wise, and it is inputted to the port of a microcomputer 103. In the microcomputer 103, the level of the cyclical noise is found, and the fluctuation of the tracking error signal due to the influence of the cyclical noise is simulated, and it is confirmed whether the tracking error signal after passing the Schmitt circuit is always at the Low level at any track. In this way, it is possible to discriminate exactly recording tape speed at time of reproduction, by performing a reliable and simplified arithmetic processing.</p> |
