| 摘要 |
<p>PURPOSE:To improve a rise characteristic by performing a tracking control in the manner of correcting the tracking error information by a reference information of a rotating phase, the value of which is varied in accordance with the rotating phase of a capstan motor. CONSTITUTION:By driving the capstan motor 22 in accordance with the result from an addition of the output signal of an adding circuit 44 to the information of a speed control circuit, the tracking control is roughly performed by taking a 2nd pilot signal SP2 as the reference. On the contrary, the component of a 1st pilot signal SP1 is extracted and subjected to envelope detection by a band-pass filter circuit, therefrom the signal level of signal SP1 is detected by a maximum value detecting circuit 32. Further, the output of this envelope detection and the output of an envelope detection at the time before one cycle accumulated in a specified memory means are compared by the circuit 32 to detect the increase/decrease of the level of the signal SP1, then the phase control information is outputted. By this procedure, the phase control information is added to the output of a subtracting circuit 42 by the circuit 44 to finely control the motor 22.</p> |
