| 摘要 |
<p>PURPOSE: To remove phase error components in a fixed cycle without being influenced by a speed error. CONSTITUTION: A first servo loop 30 constituting a phase control loop comprises a phase detector 32 which detects a phase error from a first reference signal and a reproduced control signal CTL, a learning compensator 20 which detects error signals repeatedly from the phase error signal, and an adder 26 which adds the phase error signal output from the learning compensator to a first reference speed signal. A second servo loop 40 constituting a speed control loop consists of a frequency converter 41 which converts an output of the adder 26 into a second reference signal, and a phase servo circuit 50 for comparing phases of the rotational frequency of a driving motor 12 with the second reference signal. Since speed error components are not, supplied at the first servo loop 30, phase error components in a fixed cycle due to the eccentricity of a capstan shaft 12a or the like can be removed without being influenced by the speed error components.</p> |
