| 摘要 |
<p>A CLV control apparatus for an optical disk drive, which can suppress noise in the event of dropout of wobble signals due to dust, etc, and facilitates quick and stable disk rotation. The control circuit judges the operation state as a lock state when the frequency of the wobble signal obtained from an optical disk is withing a predetermined range, selects the wobble signal when the state is not judged as the lock state, selects and outputs the output signal from a PLL circuit for the wobble signal when the state is judged as the lock state, and executes the CLV control on the basis of this selection output signal. The lock state may be confirmed by counting a predetermined number of repeats of dropout of wobble signals or detecting a predetermined duration of dropout. A selector portion selects the wobble signal during the rotation of the disk and thereafter selects and outputs the signal from a PLL circuit portion.</p> |
