| 摘要 |
PURPOSE:To exhibit a stable damper effect without the influence of temperature variation, change due to lapse of time, etc., by detecting the position of a driver made of a soft magnetic body electrically and feeding the detected information back to a drive control system negatively as a mechanical oscillation suppressing signal. CONSTITUTION:This controller suppresses the mechanical oscillation of an objective lens 4 for irradiating the recording surface of a recording medium with a light spot, and a driving winding 15 is supplied with the mixture signal of a tracking control signal and a sine-wave signal of specific frequency from the terminal T1 of a control part 20 to superpose alternating magnetic flux upon main magnetic flux for driving a soft magnetic body ring 10 as the driver. Detecting windings 16a and 16b, on the other hand, are connected to terminals T2 and T3 of the control part 20 and from the polarities and values of their detection signals, position information for suppressing the resonance of the soft magnetic body ring 10 is obtained and then fed back to a tracking control signal negatively as the suppressing signal. |
