| 摘要 |
PROBLEM TO BE SOLVED: To suppress the time resolution reduction of an RF sum signal based on a phase difference between the reproducing signals of preceding sides and those of succeeding side in a pit advancing direction. SOLUTION: The preceding side reproducing signals (signal A+signal D) and succeeding side reproducing signals (signal B+signal C) from the 4-division photodetector of an optical pickup 10 are supplied to A/D12 and A/D14 respectively. The A/D12 executes sampling based on a first CLK, and the A/D14 executes sampling based on a second CLK. The first CLK and the second CLK are displaced each other in phase and the phase shift between the reproducing signals of preceding sides and those of succeeding side is compensated by the phase shift between their clock signals. The phase shift between the first CLK and the second CLK is adjusted so as to obtain the best reproducing signal quality regarding jitters, error rate, or the like. COPYRIGHT: (C)2007,JPO&INPIT
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