optical plattenlaufwerkvorrichtung, methods for measuring the inclination of an optical disk and method for correcting the inclination of an optical disk

摘要

Tilt (theta(r, phi)) is measured in a measuring location (P(r, phi) optical disc ( 2 ). A pivotable objective lens ( 34 ) is brought to a first focus measuring location such as to focus a light beam ( 32 ) in a first anchor point (P 1 (r-Deltar 1 , phi))having the same angular coordinate phi as said measuring location (P(r, phi)) and having a small radial distance Deltar 1 from said measuring location. The objective lens is brought to a second focus measuring location such as to focus the light beam in a second anchor point (P 2 (r+Deltar 2 , phi)) having the same angular coordinate phi as said measuring location and having a small radial distance Deltar 2 from said measuring location, wherein said first and second anchor pints are located on opposite sides of said measuring location. Tilt in said measuring location is calculated from the coordinates of said two focus measuring locations of said objective lens.