| 摘要 |
PURPOSE:To speed up moving speed of information detection point during high speed reproduction by detecting relative moving speed in radial direction to the recording track of information detection point and controlling to obtain a speed signal of a prescribed value. CONSTITUTION:In ordinary reproduction, output of a phase compensating circuit 9 is supplied selectively to a driving circuit 10 and relative position in radial direction to recording track of information detection point is controlled. On the other hand, at the time of high speed reproduction, output of a compensating circuit 14 is outputted selectively by a change-over switch circuit 15, and a radial servo loop is formed. A tracking actuator 11 is driven to make output voltage of a speed detecting circuit 12 equal to reference voltage Vr, and the carriage is shifted. Consequently, controlling is so made that relative moving speed in radial direction to recording track of information detection point becomes equal to a speed corresponding to the reference voltage Vr. |
