Patent ID: 7903517
Filing Date: 2011-03-08
Classification: G11B

Abstract:
1. An optical disk drive for determining a disk type of an optical disk comprising a substantially circular track, the optical disk drive comprising: an optical source for generating an incident beam, an optical arrangement comprising an objective lens for focusing the incident beam into a spot on the optical disk, for positioning the spot at a radial position along the disk and for tracking the track, wherein the disk type of the optical disk at least be either a first disk type or a second disk type, wherein the first disk type is associated with a first disk standard corresponding to a first laser color of the incident beam and a first numerical aperture of the objective lens relating to a first spot size of the spot, the second disk type is associated with a second disk standard corresponding to a second laser color of the incident beam and a second numerical aperture of the objective lens relating to a second spot size of the spot, and the second spot size is different from the first spot size; a sensor for sensing a reflected beam produced by the optical disk upon receiving the incident beam and for producing a sensor output signal comprising a radial error signal, and a signal analyzer arranged to: wherein, upon detecting the presence of the wobble signal, the signal analyzer is arranged to: check whether the wobble signal comprises a frequency within a selected frequency range associated with a selected disk type, the selected disk type being selected from the group consisting of the first disk type and the second disk type, and if the check is positive, classify the optical disk as being of the selected disk type, if the check is negative, further check whether the wobble signal comprises a frequency within a further frequency range associated with a further disk type, the further disk type being selected from the group consisting of the first disk type and the second disk type, the further disk type being different from the selected disk type, and if the further check is positive, classify the optical disk as being of the further disk type, and wherein, after classification of the optical disk as being of either the first or the second type, the optical disk drive is arranged to be subsequently operated with: the optical source generating the incident beam with either the first laser color, upon classification of the optical disk as being of the first type, or the second laser color upon classification of the optical disk as being of the second type, and the optical arrangement focusing the incident beam into a reading spot on the optical disk, positioning the reading spot at a radial position along the disk and tracking the track with the reading spot.