| 摘要 |
PURPOSE:To obtain a suitable rotation control in accordance with the pickup position by counting the pickup movement and thereby controlling the number of revolutions of the disk motor. CONSTITUTION:When a power source is turned on, the pickup 13 is positioned at the innermost periphery of the recording area and an up/down counter 20 is in the reset state. When the pickup 13 starts moving in the FF direction, DMCK 2 of one pulse per each rotation of the disk motor is inputted to a NAND gate 17. When the pickup 13 is moved in the FF direction at a faster rate than that at normal movement, TECK is inputted by a switch circuit 22 to a NAND gate 18. In both cases, the up/down counter 20 counts up. When the pickup 13 is moved at a faster rate in the REV direction, the counter counts down. The count value corresponds to the position of the pickup 13 by 1:1 so as to be used as the position signal. The output of the up/down counter 20 is inputted as address to a ROM 24. The ROM 24 indicates the optimum number of revolutions of the disk motor 12 corresponding to the pickup position on the disk.
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