| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical disk drive that calculates a tilt angle of an optical disk with a simple configuration and to provide a tilt angle detecting method. SOLUTION: An error phase differenceΔDP between a PPe signal and a DPD signal, changes according to a tilt amountθ, which is a tilt angle of an optical disk, the PPe signal being a push-pull signal generated by utilizing a fact that a difference in light quantity of two overlapped regions W changes according to displacement of radiation of an optical beam toward a desired track in the optical disk, and the DPD signal being a second signal generated by utilizing a fact that light quantity distribution is changed in the overlapped regions W according to the displacement of radiation. Based on the error phase differenceΔDP, the tilt angle as a tilt amountθis calculated. COPYRIGHT: (C)2009,JPO&INPIT
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