| 摘要 |
PROBLEM TO BE SOLVED: To control rotation speed with extremely high precision by a simple structure. SOLUTION: Rotation speed corrective information stored in a storage circuit is a basic since wave data of one-rotation and one-cycle whose amplitude and phase difference are variable, formed by combining corrective information for correcting a precision error (FG ununiformity) in FG (rotation speed detector) 4 with corrective information for correcting errors in rotation speed corresponding to mechanical runout (capstan runout) for the diameter of a capstan. By setting a start address at a FG address circuit 6, and a gain at a gain circuit 9, the phase difference and amplitude of the basic sine wave data are set so as to be rotation speed corrective information suited to the characteristics of a capstan motor 1. The corrective information for correcting the capstan runout is coveted to corrective information for correcting errors in the rotation speed for combining. |
