| 摘要 |
PURPOSE:To perform a track skipping operation accurately with a difficulty in generating an error, by providing a reverse deriction detecting means which detects the traverse of a bit train in the direction opposite to a direction corresponding to a track skipping signal to set a counting means to an initial value. CONSTITUTION:An H-level detection signal is generated from a reverse direction detecting circuit 26 when a tracking error control signal, which traverses a bit train in the opposite direction during the period from the generation of a track skipping signal at a time T1 in a track skipping control circuit 22 to the time when a pickup 13 becomes such speed at a time T2 that it is not affected by the waveform of the bit train is generated. A counter circuit 28 is reset by this detection signal, and a value attained by counting zero (v) level crossing points of the tracking error control signal after the time T2 is outputted as an extent of movement of the pickup 13 to the circuit 22. Thus, there is no deviation between the position, where the pickup 13 is stopped at the search operation end time, and an objective position, and an accurate search operation is possible. |
