| 摘要 |
<p>PURPOSE:To suppress the runout of a track due to the dislocation of a track angle at a reproducing time and the lowering of an S/N in a reproducing signal and an error rate by decreasing the response sensitivity of servo control and to execute the effective servo control to correspond to the dislocation of the track angle when the dislocation of the track angle is generated. CONSTITUTION:An error fluctuating component to have prescribed relation with the rotational period of a rotary head is extracted from a detected tracking error by an error fluctuation extracting circuit 1. Then, when the error fluctuating component, which is extracted by a tracking angle dislocation discriminating circuit 2, goes over a specified value, such a condition is discriminated as the tracking angle dislocation and a tracking control changing signal is outputted. When the tracking control changing signal is received by a response sensitivity changing circuit 3, the response sensitivity of the servo control is changed and the response sensitivity of the servo control is decreased. Thus, the effective servo control can be executed in correspondence to the tracking angle dislocation.</p> |
