| 摘要 |
<p>PURPOSE:To stabilize tracking, by providing a means which samples a tracking error, and a means which expands a sampling interval to a reproducing pilot signal interval different from a reference pilot signal frequency. CONSTITUTION:By expanding a sampling interval t2 by a sampling signal SP of the period t1 side of an original (tau), the interval side of a sampling hold output SH, where an ATF error descends than ever, is sampled extra, as shown in figure K. And a voltage obtained from a low-pass filter 31 becomes a voltage ED smaller than an EO, and a tracking position is shifted in a delayed direction. Therefore, when the optimum tracking position is shifted due to a step by the mounting error of a head, or dispersion in characteristics, a shift to the optimum tracking position can be obtained by adjusting the lengths of periods t1 and t3 of the sampling signal SP corresponding to the quantity of the shift, and also, noise can be reduced. In this way, it is possible to always perform reproduction at the optimum tracking position.</p> |
