Optical disc apparatus
AssigneeHitachi Consumer Electronics Co., Ltd.
InventorSeiji Imagawa
Life of this patent
Estimating the term…
Abstract
An optical disc apparatus includes a focus controller including a first digital filter, tracking controller including a second filter, focus actuator driver, tracking actuator driver, defect detector for detecting a defect on an optical disc, and a system controller for controlling the focus controller, the tracking controller and the defect detector. The system controller holds an input and output of at least one of either the focus controller or the tracking controller on the basis of the output of the defect detector, and sets an initial value in a delay memory of the digital filter of the controller held upon awake of the hold state.
Claims13
An optical disc apparatus for performing data recording and/or reproducing operation by irradiating an optical disc with a laser beam, comprising:
- an objective lens configured to converge the laser beam directed to the optical disc to form an optical spot;
- a focus actuator configured to drive the objective lens toward a rotary shaft of the disc;
- a tracking actuator configured to drive the objective lens in a disc radius direction;
- a detector configured to convert light of the optical spot reflected by the optical disc to an electric signal;
- a focus error signal generating module configured to generate a focus error signal on a basis of an output of the detector;
- a tracking error signal generating module configured to generate a tracking error signal, on the basis of the output of the detector;
- a focus control module configured to include a first digital filter for generating a control signal to position the optical spot on a predetermined recording/reproducing surface, on the basis of an output of the focus error signal generating module;
- a tracking control module configured to include a second digital filter for generating a control signal to position the optical spot on a predetermined track, on the basis of an output of the tracking error signal generating module;
- a focus actuator driving module configured to drive the focus actuator on the basis of an output of the focus control module;
- a tracking actuator driving module configured to drive the tracking actuator on the basis of an output of the tracking control module;
- a defect detecting module configured to detect a defect on the optical disc;
- and
- a system controller configured to control the focus control module, the tracking control module and the defect detecting module;
- wherein the system controller is configured to hold an input or output of at least one of the focus control module and the tracking control module, and is configured to set an initial value in a delay memory of the digital filter provided in the held control module upon release of the hold state, on the basis of an output of the defect detecting module.
Dependencies are inferred from the claim text.