Recording apparatus and control method

Abstract

A recording apparatus including: a light-illuminating/receiving-unit illuminating an optical-disc-recording-medium through a common object-lens with recording-light and ATS-light and receiving reflected-ATS-light; a rotation-driving-unit driving rotation of the medium; a tracking-mechanism driving the lens in a tracking-direction parallel to the radial direction; a tracking-error-signal-generation-unit generating a tracking-error-signal; and a tracking-servo-controller performing tracking-servo-control on the lens based on the tracking-error-signal, wherein the tracking-servo-controller includes: a servo-calculation-unit based on the tracking-error-signal in a feedback-loop as a tracking-servo-loop; and a feed-forward-controller calculating an estimated control-target-value of the tracking-servo-control based on an estimated illumination-spot-position value of the ATS-light obtained in a first-filter-process emulating a transfer-characteristic of the tracking-mechanism on an output of the servo-calculation-unit and a distance between the illumination-spot-positions and applies a control-signal generated in a second-filter-process on the estimated value for suppressing a transfer-characteristic-gain of the tracking-servo-loop to 0 dB or less in the entire band to the tracking-servo-loop.