Optical disc center error amplitude calibration
View Patent ↗A method for calibrating a center error signal in an optical disc system, comprising the steps of (i) measuring a peak-to-peak value of the center error signal, (ii) computing a nominal peak-to-peak value of the center error signal after locking to a particular track of an optical disc, (iii) computing the nominal peak-to-peak value of the center error signal for a run-out condition, and (iv) defining a calibration gain for the current value for the center error signal.
1. A method for calibrating a center error signal in an optical disc system, comprising the steps of:
(A) measuring a peak-to-peak value of said center error signal;
(B) computing a nominal peak-to-peak value of the center error signal after locking to a particular track of an optical disc;
(C) computing said nominal peak-to-peak value of the center error signal for a run-out condition; and
(D) generating a calibration gain for a current value of said center error signal based upon the peak-to-peak value and the nominal peak-to-peak value, wherein said calibration gain compensates for different disc reflections.
2. The method according to claim 1 , wherein said optical disc comprises a plurality of tracks.
3. The method according to claim 1 , wherein said run-out condition comprises a number of peaks of a tracking error signal.
4. The method according to claim 3 , wherein said tracking error signal is generated using differential phase detection.
5. The method according to claim 3 , wherein said tracking error is generated using differential push pull.
6. A computer readable medium comprising code executable on a computer, said code configured to execute the steps of claim 1 .
7. The computer readable medium according to claim 6 , wherein said computer readable medium comprises firmware.
8. The method according to claim 1 , wherein said method is implemented in hardware.
9. The method according to claim 1 , wherein said method is implemented partially in hardware and partially in firmware.
10. The method according to claim 1 , wherein said calibration gain is calculated within an initial number of rotations of said optical disc.
11. An apparatus for calibrating a center error signal in an optical disc system comprising:
means for measuring a peak-to-peak value of said center error signal;
means for computing a nominal peak-to-peak value of the center error signal after locking to a particular track of an optical disc;
means for computing said nominal peak-to-peak value of the center error signal for a run-out condition; and
means for defining a calibration gain for the current value for said center error signal based upon the peak-to-peak value and the nominal peak-to-peak value, wherein said calibration gain compensates for different disc reflections.
12. The apparatus according to claim 11 , wherein said apparatus is implemented in hardware.
13. The apparatus according to claim 11 , wherein said apparatus is implemented partially in hardware and partially in firmware.
14. The apparatus according to claim 11 , wherein said calibration gain is calculated within an initial number of rotations of said optical disc.
15. An apparatus comprising:
a sled motor configured to adjust a position of an optical housing in an optical disc system in response to a control signal;
a control circuit configured to generate said control signal in response to a calibrated center error signal, wherein said calibrated center error signal is generated in response to a plurality of photo-diode signals and the calibration of said calibrated center error signal is configured to compensate for different disc reflections; and
a photo-diode distribution portion configured to generate said photo-diode signals.
16. The apparatus according to claim 15 , wherein said control circuit comprises:
a center error creation circuit configured to generate a center error signal in response to said plurality of photo-diode signals;
a gain circuit configured to calibrate said center error signal.
17. The apparatus according to claim 16 , wherein said calibration of said center error signal occurs within an initial number of rotations of an optical disc.
18. The apparatus according to claim 16 , wherein said gain circuit is further configured to:
measure a peak-to-peak value of said center error signal;
compute a nominal peak-to-peak value of the center error signal after locking to a particular track of an optical disc;
compute said nominal peak-to-peak value of the center error signal for a run-out condition; and
generate a calibration gain for a current value of said center error signal based upon the peak-to-peak and nominal peak-to-peak values, wherein said calibration gain compensates for the different disc reflections.