| 摘要 |
PROBLEM TO BE SOLVED: To provide a wobble clock extraction method for quickly generating a wobble clock synchronized with the meandering of a recording track, an optical disk device, and a PLL circuit. SOLUTION: The wobble clock extraction method includes a reproduction step, a driving step, a predicting step, and a clock extraction step. In the reproduction step, a recording track formed spirally in an optical disk is irradiated with an optical beam, and a reproduction signal is generated based on a reflected light. This reproduction signal contains a wobble signal indicating the meandering of the recording track. In the driving step, the optical disk is rotary-driven so that the frequency of the wobble signal is close to a predetermined frequency value. In the prediction step, the discontinuous change of the wobble signal is predicted to calculate a predicted value after the change. In the clock extraction step, based on the predicted value, a wobble clock synchronized with the wobble signal is generated. COPYRIGHT: (C)2008,JPO&INPIT
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