| 摘要 |
PURPOSE:To reduce pulse components and to attain servo control free from delay in phase by superposing a signal obtained by smoothing a phase comparing signal to the original phase comparing signal to control a disc driving motor. CONSTITUTION:A phase comparator 19 compares the phase of a linear speed detecting signal of a disc with that of a reference signal and a time constant circuit 50 in a disc driving servo circuit 22 smoothes the phase difference signal. An adder 51 superposes the original phase difference signal to the smoothed output from the circuit 50, so that a servo controlling signal reducing the pulse components, preventing the generation of riging of the disc motor 3 and the delay in phase due to the superposition of the phase difference signal and securing a phase margine sufficiently to prevent oscillation or the like is obtained. |
