| 摘要 |
<p>A rotation speed detection interval switching circuit (113) for switching a rotation speed detection interval of a spindle motor control circuit (103) is provided within the circuit (103) so as to switch the rotation speed detection interval of the circuit (103) according to a rotation speed of a spindle motor (102), whereby the rotation speed of the spindle motor (102) can be detected in a short time even despite a reduced rotation speed of the spindle motor (102).</p> |
