JP2006268961A5

JP2006268961A5 -

Info

Publication number: JP2006268961A5
Application number: JP2005085474A
Authority: JP
Filing date: 2005-03-24
Publication date: 2008-03-27

Claims

An optical disc apparatus that performs at least one of recording and reproduction of information by irradiating an optical disc with a light beam condensed by a condensing unit,
Disc tilt detection means for detecting a disc tilt value, which is an inclination of a recording surface of the optical disc, based on focus drive values at a plurality of radial positions of the optical disc;
A tilt drive value calculating means for calculating, as a tilt drive value, a drive value of a tilt variable means for changing the tilt of the light collecting means based on the disc tilt value;
A reference tilt drive value calculating means for calculating a drive value of the tilt varying means that provides good reproduction characteristics at a specific radial position as a tilt drive reference value;
A tilt drive value table generating means for generating a tilt drive value table storing the tilt drive values at the plurality of radial positions updated using the tilt drive reference value;
Comprising
In order to set the inclination of the condensing means at a desired radial position during information recording or reproducing operation to an optimum value according to the relative inclination between the recording surface of the optical disc and the light beam, the tilt driving value table is used. An optical disc apparatus for driving the tilt varying means by obtaining a tilt drive value at a corresponding radial position.

A light source for irradiating a light beam on an optical disc, a focusing means for focusing the light beam on the recording surface of the optical disc, the focus direction moving means for moving the focusing means along the optical axis of the light beam, An optical head having a photodetector for receiving reflected light from the recording surface;
A focus error detecting means for detecting a defocus of the light beam with respect to the recording surface;
Focus control means for driving the focus direction moving means based on the output of the focus error detecting means so as to focus the light beam on the information surface;
Tracking direction moving means for moving the light beam in a radial direction of the optical disc;
Rotating means for rotating the optical disc;
Disc tilt detecting means for detecting a disc tilt value, which is an inclination of the recording surface , based on output values of the focus control means at a plurality of different positions in the radial direction of the optical disc ;
Tilt varying means for varying the inclination of the light collecting means;
A tilt driving means for driving the tilt varying means;
Tilt drive value calculation means for calculating an input value to the tilt drive means as a tilt drive value based on the disk tilt value obtained by the disk tilt detection means ;
A tilt drive value table generating means for generating and storing the tilt drive value table storing said tilt drive value calculated on the basis of the disc tilt value in the radial direction of a plurality of different positions of the optical disc,
Reproduction signal measuring means for measuring a reproduction signal based on the output of the photodetector;
The acquired output values of the reproduced signal measurement means while changing the tilt of the focusing means by changing the input value to the tilt driving unit, said tilt output value of the reproduced signal measuring unit becomes a target value A reference tilt drive value calculation means for calculating an input value to the drive means as a tilt drive reference value;
In addition the tilt drive reference value us Keru substantially the same radial position as the difference amount between the tilt drive value to the tilt drive value obtained by the plurality of radial positions as the offset, based on the tilt drive value corrected by the offset wherein updating the tilt drive value table, the optimum value corresponding to the relative inclination of the recording surface and the light beam before Symbol optical disk tilt of the focusing means in a desired radial position or a reproducing operation during the recording operation Te to set, characterized in that inputting the tilt drive value of the radial position corresponding determined from the tilt drive value table updated before Symbol tilt drive means, and configured to drive the tilt changing means An optical disk device.

The tilt drive value table generating means stores the tilt drive values calculated based on the disc tilt values at a plurality of different positions in the radial direction of the optical disc, and calculates a radius from the tilt drive value at each radial position. The optical disc apparatus according to claim 2, wherein a calculation formula that approximates a relationship between a position and the tilt drive value is derived, and a tilt drive value table that stores the tilt drive value at predetermined intervals in the radial direction is generated and stored.