| 摘要 |
PURPOSE:To eliminate deterioration in control precision due to the delay of the first transition of a feed motor device by detecting the timing of inversion of a specific jump direction to the opposite direction when jump operation is started, and starting a timer circuit with the detection output. CONSTITUTION:A high-frequency information signal RFS and a tracking error information signal TES are supplied to a direction component detecting circuit 23 to detect a moving direction component, and a direction (inversion) detecting circuit 24 detects the jump directin inversion with the detection signal to start the operation of the timer circuit 22. Therefore, jump operation in the opposite direction of the specific direction is carried on until the first transition T1 of the feed motor devece, but once the motor device starts, the jump operation is performed in the specific direction, so the direction inversion in said period is detected and the timer circuit 22 is started to start the motor device, thereby eliminating errors in the numbr of jumps due to the eccentricity of a disk originating from the delay of the first transition of the motor device. |
