| 摘要 |
PURPOSE:To execute stably special reproducing even in case when a surface stage of a disk is not good, by cutting off a tracking control loop or reducing the loop gain, in a period in which a kick pulse is applied. CONSTITUTION:An error signal is obtained by an error signal detecting circuit 20 from a signal detected from a disk 19, is made to pass through a phase compensating circuit 21 required for a control loop, the circuit is cut off by a muting circuit 22, and a kick pulse is added by an adding circuit 23. This adding signal makes a current flow to a driving coil 25 by a driving circuit 24, and moves a pickup. On the other hand, the kick pulse reverses and adds one of continuous pulses by a circuit 31, and the polarity is decided by an inverting and non-inverting circuit 32 in accordance with either a forward motion or a backward motion. Also, a mute pulse detects 28 an edge of rise of a front side pulse 26 of two pulses 26, 27, detects 29 of an edge of fall of a rear side pulse 27, inputs both of them to a latching circuit 30, generates a pulse and provides it to a muting circuit 22. |
