Patent ID: 7345965

Claim:
Method for direction-dependent track counting in an apparatus for reading from and/or writing to an optical recording medium having tracks, comprising the steps of illuminating the optical recording medium by a beam of light having two or more scanning beams such that the beam of light is reflected from the recording medium, and light intensities of the scanning beams reflected from the optical recording medium are originating from scanning locations that are laterally remote from one another, as seen in a track direction, imaging the light intensities reflected from these laterally remote scanning locations by an arrangement of optical components onto light-sensitive areas of a multiply divided photodetector, deriving at least two error signals by combination of output signals of the photodetector, which error signals in each case contain a track-error-dependent component which is caused by the laterally remote scanning locations, determining zero crossings of said at least two error signals, evaluating a phase difference between the at least two error signals, obtaining a relative lateral direction of movement of an objective lens of the apparatus relative to the tracks of the optical recording medium from said phase difference, and obtaining, in a direction-dependent way, a number of tracks crossed by the scanning beams based on said determined zero crossings of said error signals.