| 摘要 |
PROBLEM TO BE SOLVED: To provide a disk drive unit capable of normally performing the pull-in operation for focus servo control when a sampling frequency in performing focus servo control and tracking servo control are performed is high. SOLUTION: When focus search operation is performed, a reference clock for PWM frequency-divided by a frequency-divider 22 is selected by a switch 23, while a lamp wave signal from a lamp circuit 27 is selected by a switch 28. Therefore, its sampling period can be made longer by using a frequency-divided clock than that when focus servo control operation is performed, and stable focus search can be performed. COPYRIGHT: (C)2004,JPO&NCIPI
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