| 摘要 |
PURPOSE:To realize a high speed access without changing the seek speed of a carriage specially by reducing the quantity of the seek movement of the carriage alone, by shifting the carriage, on which an optical head is mounted, and a revolving system unit toward opposite directions. CONSTITUTION:A linear motor 25 is provided as a prime mover for driving the carriage 22, the optical head 21 is mounted on, to reciprocate linearly in the seek direction, and the linear motor 30 is provided as the prime mover for driving the revolving system unit 18 to reciprocate linearly in the seek direction through a cylindrical body 28. In order to drive the revolving system unit 18 in the opposite direction with the carriage 22, the polarity of a permanent magnet 32 is made to be of the reverse direction against the case of the permanent magnet 26. Thus, compared with the case of moving the carriage 22 alone, the seek movement of the carriage 22, shorter by the length the revolving system unit 18 moves, is enough, and the carriage can be made to operate a high speed access operation through about the same carriage drive speed as a customary one.
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