| 摘要 |
PURPOSE:To correct speed deviation due to fluctuation of load without causing deterioration of jitter performance by performing servo control of the rotational speed of motor using an error amount signal which decreases gradually as the rotational speed of motor reaches a target speed and finally goes zero when the target speed is reached. CONSTITUTION:An error counter 23 counts up or down according to a speed error component detected at a speed error detecting section 22 and the sign thereof. Upon deviation of the count from a reference count set at a reference count storing section 24, a comparing section 25 controls a bias value modifying section 21 to modify a bias value being set in a bias value storing section 8. When the modification width of bias value and the reference value are varied according to the magnitude of speed deviation, the speed deviation can be corrected quickly without deteriorating the jitter performance. |
