Patent ID: 6819636
Filing Date: 2004-11-16
Classification: G11B

Abstract:
An optical disc device, comprising:an optical head comprising a light spot mover configured to cause a first light spot of a light beam directed onto an optical disc to move in a radial direction of the optical disc; a tracking error signal generator that generates a tracking error signal indicating relative positions of said first light spot and information tracks on the optical disc; a spot position signal generator that generates a spot position signal indicating a position of said first light spot in a radial direction on a light receiving element in said optical head; a tracking servo signal generator that generates a tracking drive signal for driving said light spot mover so that said first light spot follows said information tracks, based on said tracking error signal; a spot position servo signal generator that generates a spot position drive signal for driving said light spot mover so that a position of a second light spot of the light beam on said optical head is fixed, based on said spot position signal; a selector that selects one of said tracking drive signal and said spot position drive signal and supplies the selected drive signal to said light spot mover; and a discontinuation cancellation unit that implements processing, when switching between said tracking drive signal and said spot position drive signal, so that low-frequency components of said selected drive signal before switching and of said selected drive signal after switching do not become discontinuous, wherein said discontinuation cancellation unit diminishes a gain in said spot position servo signal generator, for a predetermined time period, when said selector switches said selected drive signal from said tracking drive signal to said spot position drive signal.