| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent an S/N from being deteriorated and to prevent wow and flutter from being increased by providing a motor driving circuit rotating a rotary shaft at a prescribed rotational speed while controlling a current flowing through a stator coil based on the output of an error detecting part. SOLUTION: An error detecting part 22 detects the error of time intervals of edges of an FG component which is an output to be obtained by detecting a magnetic pole for rotation control and outputted from a wave shaping circuit 21. Then, it generates an error output indicating the error of a rotational speed out its output is outputted to a motor driving circuit 19, which rotates a rotational shaft 13 at a rotational speed corresponding to an operation mode by controlling a current flowing through respective phases of a stator coil 14 based on the output of a sensor detecting a magnetic pole for drive and the error output to be applied from the error detecting part 22. Besides, since the frequency characteristic of an amplifier circuit 18 is flat, the FG component and a noise component in each operation mode are amplified with an equal amplification factor. Thus, the S/N is prevented from being deteriorated even when the operation mode is changed and also wow and flutter is prevented from being increased.</p> |
