| 摘要 |
PROBLEM TO BE SOLVED: To conduct a fast and accurate jumping retrieval employing a simple constitution. SOLUTION: Optical beams 4 illuminate the recording surface of an optical disk 1 through an objective lens 3 of an optical pickup device 2. The lens 3 is moved by an objective lens accelerating device 6. An objective lens accelerating signal FCS+ is supplied to the device 6 from an acceleration signal generating device 7. A photodetector 8 of the device 2 detects the reflected light beams of the beams 4 and a defocus signal FE, which indicates that the focus of the lens 3 is deviated from the recording surface, is taken out. Moreover, three state signal F3ST from a microcomputer 11 is supplied to the device 7 and is superimposed to the signal FCS+. Furthermore, a focus position detection signal FZC is formed from the signal FE in a focus position detecting device 12 and is supplied to the microcomputer 11.
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