| 摘要 |
PROBLEM TO BE SOLVED: To output a highly reliable tracking cross signal without relation to a seek velocity. SOLUTION: In this track cross signal generating method, a track error signal(TE) or a miller(MI) signal on which a track cross element is superimposed are converted to a binary signal as an input signal with a hysteresis comparator 30 to output the track cross(TC) signal. Frequency of the TC signal is detected with a detecting means 58 and when the frequency becomes high, control is performed so that the hysteresis width of the hysteresis comparator 30 is narrowed with a hysteresis width setting means 57 and when the frequency becomes low, the hysteresis width is widened. As a result, when the seek speed is low, there is no noise by the RF element and when the seek speed is high, a highly reliable TC signal surely reflecting the track count can be outputted. Moreover, when the seek speed is high, the reliability of TC signal can further be improved by switching the TE signal to the MI signal.
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