| 摘要 |
PROBLEM TO BE SOLVED: To suppress influence of cross-talk light from an adjacent layer other than a read object layer being the recording layer of read object by a DPP signal generating circuit. SOLUTION: In a DPP signal generating circuit 50, by subtracting the push-pull differential signal SPD (SPD signal) of a sub-beam corrected so as to be able to suppress influence of cross-talk light for the push-pull signal SPP (SPP signal) of the sub beam from the push-pull signal MPP (MPP signal) of a main beam, a corrected differential push-pull signal DPP (corrected DPP signal) is obtained, and the corrected DPP signal is made a tracking error signal for an objective lens. COPYRIGHT: (C)2008,JPO&INPIT
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