| 摘要 |
<p>PURPOSE:To alter characteristics softwarewise and to miniaturize a circuit structure by fetching an amplitude of a pilot signal directly with and A/D converter as a digital value, obtaining a tracking error amt. in a digital value and digital-processing a filter accordingly. CONSTITUTION:The pilot signal filtrated by a band pass filter 16 is detection- rectified by a rectifier 17 to be converted by an A/D converter 18 into the digital value. Then, a data corresponding to a difference between pilot signal amplitude voltages from both adjacent tracks to be reproduced by heads 2a and 2b is stored in memory 21. An output of the memory 21 is added to an output of a subtractor 11 which is difference between a cycle counter 4 and a reference value generator 10, and the output data of the memory 21 is controlled to be zero by a digital filter 22 in its integrating operation, so that a capstan motor 5a is rotated in order to make the heads 2a and 2b travel in the middle of a recorded track. By this method, the characteristics can softwarewise be altered, and hardware can be simplified.</p> |
