Method and apparatus for tracking error detection in optical disk driver
First Claim
1. A method of producing a tracking error signal as a difference signal of optical detection signals generated by more than two optical detectors positioned along a line diagonal to a track center, the method comprising:
- binarizing each of the outputs of the optical detectors;
phase locking to generate respective clock signals synchronized with each of the binarized outputs;
detecting a phase difference between the synchronized clock signals; and
low-pass filtering the detected phase difference to output the tracking error signal.
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Abstract
A method and apparatus for tracking error detection in an optical disk reproduction system. The tracking error detecting apparatus generates a tracking error signal as a difference signal of optical detection signals generated by more than two optical detectors positioned along a diagonal line from a track center and includes binarizers which binarize each output of the optical detectors, phase locked loops (PLLs) which generate respective clock signals synchronized with the outputs of each of the binarizers, a phase difference detector which detects a phase difference between the synchronized signals output from the PLLs, and low-pass filters which filter the output of the phase difference detector to output the result as the tracking error signal. The tracking error detecting apparatus generates a tracking error signal which is not dependent on the lengths of pits or marks recorded on an optical disk, enhancing the reliability of the tracking error signal.
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Citations
17 Claims
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1. A method of producing a tracking error signal as a difference signal of optical detection signals generated by more than two optical detectors positioned along a line diagonal to a track center, the method comprising:
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binarizing each of the outputs of the optical detectors;
phase locking to generate respective clock signals synchronized with each of the binarized outputs;
detecting a phase difference between the synchronized clock signals; and
low-pass filtering the detected phase difference to output the tracking error signal.
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2. A tracking error detecting apparatus for producing a tracking error signal as a difference signal of optical detection signals generated by more than two optical detectors positioned along a line diagonal line to a track center, the apparatus comprising:
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binarizers which binarize each of the optical detection signals;
phase locked loops which generate clock signals synchronized with each of the outputs of the binarizers;
a phase difference detector which detects a phase difference between the synchronized clock signals output from the phase locked loops; and
a low-pass filter which filters the output of the phase difference detector to output the result as the tracking error signal. - View Dependent Claims (3, 4, 5, 6, 7)
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8. A tracking error detecting apparatus for producing a tracking error signal as a difference signal of optical detection signals generated by two optical detectors disposed at the outside of the track center of a three-section optical detection unit, the apparatus comprising:
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binarizers which binarize each of the optical detection signals;
a phase difference detector which detects a phase difference between the binarized signals; and
a low-pass filter which filters the output of the phase difference detector to output the result as the tracking error signal. - View Dependent Claims (9)
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10. An apparatus for providing a tracking error signal for an optical disk recording track, comprising:
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first and second optical detectors which generate first and second electrical signals, respectively;
a circuit which binarizes the first and second electrical signals and phase locks each of the binarized signals to output first and second clock signals synchronized with the first and second binarized signals; and
a phase detector which compares a phase of the first synchronized clock signal with a phase of the second synchronized clock signal to generate the tracking error signal. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
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Specification