Optimizing focus point for optical disc
An apparatus includes a first circuit and a second circuit. The first circuit may be configured to generate status signals and an error signal in response to accessing a storage medium. The error signal provides a first value based on an accuracy of accessing the storage medium. The second circuit may be configured to offset the first value of the error signal to a second value to increase the accuracy of accessing said storage medium. The status signals include one or more of a data signal and a differential signal. In a first mode, an offset signal is generated in response to the data signal. In a second mode, the offset signal is generated in response to the differential signal.
1. An apparatus comprising:
a first circuit configured to generate status signals and an error signal in response to accessing a storage medium, wherein said error signal provides a first value based on an accuracy of accessing said storage medium; and
a second circuit configured to offset said first value of said error signal to a second value to increase the accuracy of accessing said storage medium, wherein (i) said status signals comprise one or more of a data signal and a differential signal, (ii) in a first mode, an offset signal is generated in response to said data signal, and (iii) in a second mode the offset signal is generated in response to said differential signal.
2. The apparatus according to claim 1 , wherein said second circuit is configured to offset said first value of said error signal to said second value to increase the quality of a reading process when reading data from said storage medium.
3. The apparatus according to claim 1 , wherein said second circuit is configured to offset said first value of said error signal to said second value to increase the quality of a writing process when writing data to said storage medium.
4. The apparatus according to claim 1 , wherein said data signal is generated when reading data from an optical disc and said differential signal comprises a beam push-pull signal generated when writing or rewriting data to said optical disc.
5. The apparatus according to claim 1 , wherein said data signal comprises a radio frequency signal.
6. The apparatus according to claim 1 , wherein said first circuit comprises:
a data circuit configured to generate said status signals in response to a laser beam focused on a disc; and
an error circuit configured to generate said error signal, wherein said error signal provides said first value based on a focus point of said laser beam.
7. The apparatus according to claim 6 , further comprising:
a sensor configured to generate a plurality of sensory signals in response to said laser beam, wherein said data circuit generates said status signals in response to said plurality of sensory signals.
8. The apparatus according to claim 6 , further comprising:
a focus controller configured to control a lens in relation to said laser beam and allow said laser beam to focus on said disc.
9. An apparatus comprising:
means for generating a plurality of status signals and an error signal, wherein said error signal provides a first value based on an accuracy of an access of a storage medium; and
means for offsetting said first value of said error signal to a second value to increase the accuracy of accessing said storage medium, wherein (i) said status signals comprise one or more of a data signal and a differential signal, (ii) in a first mode, an offset signal is generated in response to said data signal, and (iii) in a second mode the offset signal is generated in response to said differential signal.
10. A method for increasing accuracy of accesses to a storage medium, comprising the steps of:
(A) generating status signals in response to accessing said storage medium;
(B) generating an error signal which provides a first value based on an accuracy of an access of said storage medium; and
(C) offsetting said first value of said error signal with an offset signal to a second value to increase the accuracy of accessing said storage medium, wherein (i) said status signals comprise one or more of a data signal and a differential signal, (ii) in a first mode, the offset signal is generated in response to said data signal, and (iii) in a second mode the offset signal is generated in response to said differential signal.
11. The method according to claim 10 , wherein step (C) further comprises the step of:
offsetting said first value of said error signal said second value to increase the quality of a reading process when reading data from said storage medium; and
offsetting said first value of said error signal to said second value to increase the quality of a writing process when writing or rewriting data to said storage medium.
12. The method according to claim 10 , wherein said storage medium comprises a disc and said method further comprises the steps of:
controlling a lens in relation to a laser beam to allow said laser beam to focus on said disc;
generating said status signals in response to said laser beam focused on said disc; and
generating said error signal such that said first value is based on a focus point of said laser beam.
13. The method according to claim 12 , further comprising the step of:
controlling said lens in relation to said laser beam to allow said laser beam to focus on said disc while at the same time controlling said laser beam to lock on a physical track on said disc.
14. The method according to claim 12 , wherein step (C) further comprises the steps of:
(D) applying a predetermined amount of constant offset to said error signal with said offset signal;
(E) measuring a peak-to-peak value of said data signal in response to applying said predetermined amount of constant offset; and
(F) adjusting said offset signal by a fixed predetermined amount.
15. The method of claim 14 , further comprising the steps of:
repeating steps (D), (E) and (F) a number of times to collect a number of (i) peak-to-peak values of said data signal and (ii) adjusted values of said offset signal.
16. The method according to claim 15 , further comprising the steps of:
finding a second-order curve using (i) said number of peak-to-peak values of one of said data signal and (ii) said adjusted values of the offset signal; and
finding said second value from said second order curve.
17. The method according to claim 16 , further comprising the step of:
controlling said lens in relation to said laser beam to allow said laser beam to focus on said disc without controlling said laser beam to lock on a physical track on said disc.
18. The method according to claim 17 , wherein step (C) further comprises the steps of:
(G) applying a predetermined amount of constant offset to said error signal with said offset signal;
(H) measuring a peak-to-peak value of said differential signal in revolutions in response to applying said predetermined amount of constant offset; and
(I) adjusting said offset signal by a fixed predetermined amount.
19. The method of claim 18 , further comprising the steps of:
repeating steps (G), (H) and (I) a number of times to collect a number of (i) peak-to-peak values of said differential signal and (ii) adjusted values of said offset signal.
20. The method according to claim 19 , further comprising the steps of:
finding a second-order curve using (i) said number of peak-to-peak values of said differential signal and (ii) said adjusted values of the offset signal; and
finding said second value from said second order curve.