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US 7,804,746 B2Granted
Land/groove track and pickup head movement direction detection
AssigneeMediatek Inc.
InventorsGwo-Huei Wu, Yuh Cheng, Chao-Ming Huang, Chih-Yuan Chen, Ching-Ning Chiu
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Abstract
A detector is scanned across an optical storage medium having groove tracks and land tracks, each track having a wobble structure, to detect light reflected from the optical storage medium. A wobble signal and a tracking error signal are generated based on an output of the detector, and the wobble signal is sampled according to the tracking error signal. A determination about whether the detector is at the groove track or the land track is made based on the tracking error signal and a comparison of sampled values of the wobble signal.
Claims36
A method comprising:
- receiving an optical storage medium having groove tracks and land tracks, each track having a wobble structure;
- scanning a detector across the optical storage medium to detect light reflected from the optical storage medium;
- generating a wobble signal and a tracking error signal based on outputs of the detector;
- sampling the wobble signal according to the tracking error signal;
- and
- determining whether the detector is at the groove track or the land track based on the tracking error signal and a comparison of sampled values of the wobble signal.
3 more elements
A method comprising:
- scanning a beam across an optical storage medium having land tracks and groove tracks, each track having a wobble structure;
- generating a wobble signal and an RF signal based on light reflected from the optical storage medium, the wobble signal having information about the wobble structure of a track scanned by the beam, the RF signal having information about data recorded in the track;
- selecting one of the wobble signal and the RF signal;
- and
- determining whether the beam is at a groove track or a land track based on a comparison of sampled values of the selected signal.
2 more elements
A method comprising:
- determining whether scanning is occurring at a groove track or a land track on a recording medium based on a comparison of sampled values of a wobble signal that is derived by scanning recurring deviations of a physical property of the groove track or the land track.
An apparatus comprising:
- a pickup head to scan an optical storage medium having groove tracks and land tracks, and detect recurring deviations in a physical property of the tracks;
- a wobble signal generator to generate a wobble signal that represents the recurring deviations and having an amplitude that varies depending on a position of the pickup head relative to the groove track or the land track;
- a tracking error signal generator to generate a tracking error signal, the tracking error signal and the wobble signal being based on outputs of the pickup head;
- and
- a land/groove track signal generator to generate a land/groove signal indicating whether the pickup head is scanning a groove track or a land track based on the tracking error signal and a comparison of sampled values of the wobble signal.
2 more elements
An apparatus comprising:
- a comparator to compare sampled values of a wobble signal that is derived by scanning recurring deviations of a physical property of a groove track or a land track on a recording medium;
- and
- a circuit to generate an output indicating whether scanning is occurring at the groove track or the land track based on an output of the comparator.
An apparatus comprising:
- a multiplexer to select one of a wobble signal and an RF signal, the wobble signal having information about a difference between two signals derived by scanning a groove track or a land track on a recording medium, each track having a physical property having recurring deviations, the RF signal having information about data recorded in the tracks;
- and
- a circuit to generate an output indicating whether scanning is occurring at the groove track or the land track based on a comparison of sampled values of the selected signal.
An apparatus comprising:
- a comparator to compare sampled values of a wobble signal that is derived by scanning recurring deviations of a physical property of a groove track or a land track on a recording medium;
- and
- a circuit to generate an output indicating a movement direction of a pickup head relative to the land track and the groove track based on an output of the comparator.
A method comprising:
- scanning a beam across an optical storage medium having land tracks and groove tracks, each track having a wobble structure;
- generating a wobble signal and an RF signal based on light reflected from the optical storage medium, the wobble signal having information about the wobble structure of a track scanned by the beam, the RF signal having information about data recorded in the track;
- when in a first situation, determining whether the beam is at a groove track or a land track based on the wobble signal;
- and
- when in a second situation, determining whether the beam is at a groove track or a land track based on the RF signal.
2 more elements
Dependencies are inferred from the claim text.