| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of quickly and accurately detecting the step out of a stepping motor for speed up and stabilization of seek operation. SOLUTION: A drive circuit 3 applies a pulse width modulation (PWM) system of control signal 10 where its Hi period is changed to supply the stepping motor 2 with a specified drive current without recouse to its rotational speed. A Hi period detector 5 detects the duty ratio in the Hi period of the control signal. A microcomputer 4 compares the step to serve as a reference with the duty ratio in the step, and judges that the stepping motor is stepping out in case that these magnitude corelation does not correspond to the set speed, and switches it into a lower speed of speed profile. COPYRIGHT: (C)2007,JPO&INPIT |
