| 摘要 |
<p>PURPOSE:To prevent occurrence of a false locking state, by providing a means which discriminates the kind of tracking signals in reproduced signals obtained from two heads, compares the kind with the kind of previously designated tracking signals, and confirms the coincidence. CONSTITUTION:Reproduced signals selectively inputted to a terminal 12 from heads A and B which are not shown in the figure are supplied to an equalizer circuit 15 and pilot extracting circuit 14. The synchronizing signal component and EVEN/ODD of the output of the circuit 15 are respectively discriminated by a synchronizing pattern detecting circuit 22 and synchronizing signal discriminating circuit 27. The discriminated results are compared with previously designated outputs of an EVEN/ODD selector 29 by means of a comparator circuit 28 and, when they coincide with each other, sampling pulses are generated. The output of the circuit 14 is outputted from a terminal 20 as tracking error signals when the sampling pulses are generated. Therefore, even when a false locking state is produced, the state is automatically shifted to a correct locking state by the tracking servo and correct data reproduction can be always carried out.</p> |
