| 摘要 |
<p>PURPOSE:To keep the optimum tracking state even in a variable speed reproduction mode, by providing a means that varies the tracking shift degree of a servo circuit in both forward and backward directions with each unit degree and detecting and deciding the increasing/decreasing direction of the reproduced signal level obtained before and after the change of the tracking shift degree. CONSTITUTION:The control signal (b) sent from a control track 4 is reproduced by a control head 12 and fed to a control microcomputer 15. The signal (b) is delayed by a unit degree and applied to a capstan servo circuit 14 to give a shift to the tracking. Then the tracking is shifted by a unit degree, and the reproduced signal level (f) obtained after the tracking change is compared with the reproduced signal level obtained before the tracking change through a comparator 11. When an increase is detected for the reproduced signal levels before and after the tracking change, the changing direction of the tracking is kept as it is. While the changing direction of the tracking is reversed when the reproduced signal level has a decrement.</p> |
