| 摘要 |
<p>PURPOSE:To stabilize the tracking servo by using the relation of position between each track and ATF (Automatic Track Finding) so as to judge automatically a true synchronous signal and a false synchronous signal thereby controlling the synchronizing detection. CONSTITUTION:A CY output of a 6-block timer 7-23 is inputted to an AND gate 7-20 and after 6 blocks from the initial sampling signal SP1, an ATF window-off signal is outputted to the output of an OR gate 7-21 to inhibit the synchronizing detection. In this case, the final SP2 during the 6 blocks from the initial sampling signal SP1 is regarded to be correct and the sample/hold value in this case is applied actually to a capstan servo. Moreover, in setting the 6-block timer 7-23 to optional (16-12) blocks, the value subject to sample/ hold by the last sampling signal SP2 in the designated period becomes a reference voltage to control the capstan. Thus, correct tracking is obtained without malfunction.</p> |
