Radial tilt compensating optical disk apparatus using tracking control loop gain

An optical disk apparatus for focusing first, second and third light beams on first, second and third tracks, respectively, of an optical disk by using a tracking control loop to perform at least one of recording and reproducing operations upon said optical disk, said first, second and third tracks being located at first, second and third radii, respectively, of said optical disk, comprising:

• a loop level calculating unit for calculating loop levels of said tracking control loop;
• and
• a control unit, connected to said loop level calculating unit, for generating a first correction amount relating to a coma aberration of said first optical beam and calculating a first loop gain of said tracking control loop in accordance with the loop levels of said tracking control loop to compensate for a radial tilt of said optical disk in accordance with said calculated first loop gain of said tracking control loop while said first light beam is being focused on said first track, generating a second correction amount relating to a coma aberration of said second optical beam and calculating second loop gain of said tracking control loop in accordance with the loop levels of said tracking control loop to compensate for a radial tilt of said optical disk in accordance with said calculated second loop gain of said tracking control loop while said second light beam is being focused on said second track, and generating a third correction amount relating to a coma aberration of said third optical beam by performing an interpolation method upon said first and second correction amounts using a radius relationship of said optical disk while said third light beam is being focused on said third track.

A method for controlling an optical disk apparatus for focusing a light beam on a track of an optical disk by using a tracking control loop to perform at least one of recording and reproducing operations upon said optical disk, comprising the steps of:

• calculating loop levels of said tracking control loop;
• calculating a loop gain of said tracking control loop in accordance with the loop levels of said tracking control loop;
• and
• compensating for a radial tilt of said optical disk in accordance with said calculated loop gain of said tracking control loop.

A method for controlling an optical disk apparatus for focusing first, second and third light beams on first, second and third tracks, respectively, of an optical disk by using a tracking control loop to perform at least one of recording and reproducing operations upon said optical disk, said first, second and third tracks being located at first, second and third radii, respectively, of said optical disk, comprising the steps of:

• calculating loop levels of said tracking control loop;
• generating a first correction amount relating to a coma aberration of said first optical beam;
• calculating a first loop gain of said tracking control loop in accordance with the loop levels of said tracking control loop to compensate for a radial tilt of said optical disk in accordance with said calculated first loop gain of said tracking control loop while said first light beam is being focused on said first track;
• generating a second correction amount relating to a coma aberration of said second optical beam;
• calculating a second loop gain of said tracking control loop in accordance with the loop levels of said tracking control loop to compensate for a radial tilt of said optical disk in accordance with said calculated second loop gain of said tracking control loop while said second light beam is being focused on said second track;
• and
• generating a third correction amount relating to a coma aberration of said third optical beam by performing an interpolation method upon said first and second correction amounts using a radius relationship of said optical disk while said third light beam is being focused on said third track.