| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical disk unit which discriminates the kind of an optical disk of a different track pitch by accurately and speedily measuring a track pitch. SOLUTION: During focus servo execution, a light spot generated by laser beams irradiated from an optical pickup during a single rotation of an optical disk is moved (S202) by a prescribed distance in the radial direction of the optical disk. A binary signal (track cross signal) of a tracking error signal obtained during the movement of the optical disk is counted (S204 to S206) in consideration of a phase relation with an off track signal. Thus, the track pitch is calculated (S207), the track pitch can accurately be measured without regard to the eccentricity of the optical disk, and discriminates the kind of the optical disk of the different track pitch (S208). COPYRIGHT: (C)2004,JPO
|
