| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce the drawing time of an ATF servo system by discriminating the polarity of ATF error signals using reproduced signals and thereby conducting tracking control. SOLUTION: H, J etc., ATF error signals of CH0, are used to conduct tracking control, and the polarities of these signals alternately reverse. Then, the level deviated to a maximum limit in the plus direction and that in the minus direction in the AFT error signals of CH1, for examples the levels of E and F, are compared to discriminate the polarity of the ATF error signal of CH1 at this time. For example, if the level at this time < that at the previous time, the AFT error signal of CH1 at this time corresponds to F and the polarity is minus. Depending on the results of the polarity discrimination, the polarity of the AFT error signal of CH0 is discriminated.</p> |
