| 摘要 |
PURPOSE:To retrieve a target address in a short time even if the focus control is deviated during the high-speed movement of an optical system carrying base, by restarting the retrieval operation after stopping temporarily the movement of a reproducing means when the deviation of the focus control is detected. CONSTITUTION:If the lock of the focus control is deviated on the way of high- speed retrieval, the address of an ROM41 is switched through an address decoding circuit 40 so that the output of a D/A converter 23 becomes zero voltage. Since the speed of the optical system carrying base is controlled with a voltage obtained by subjecting the output of the ROM41 to D/A conversion, the movement of the optical system carrying base is stopped at the time when the focus lock is deviated. Thereafter, a microcomputer turns on the focus control again to operate the focus control, and the current reproducing address is read to preset again the difference between this address and a target position, and high-speed retrieval is performed. |
