| 摘要 |
PURPOSE:To prevent the rotation of a spindle motor from varying by detecting the defect of an encoder pulse signal, forming a complementary pulse for complementing it, and combining it therewith. CONSTITUTION:A controller of a spindle motor SM is composed of a control unit 20, a reference signal generator 2, an incremental/decremental counter 23, a D/a converter 26, a motor driver 29, etc. The control unit 20 determines whether an encoder pulse signal SE is defective or not on the basis of the time interval of the change of the signal SE, and outputs a complementary pulse signal SC at the time of defect. As a result, the encoder pulse signal SE is corrected on the basis of the complementary pulse signal SC. |
