Servo control using digital signal processing for optical disk drive
DC CAFC
First Claim
Patent Images
1. A digital servo for an optical disk drive, comprising:
- an analog-to-digital converter for converting low-pass filtered and gain-adjusted versions of photodetector output signals into digital signals; and
a digital signal processor configured to receive the digital signals, the digital signal processor being further configured to determine a focus error signal (FES) and a tracking error signal (TES) from the digital signals, the digital signal processor being further configured to process TES and FES through servo algorithms to produce tracking and focus control signals.
11 Assignments
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1 Petition
Reexamination
Accused Products
Abstract
A servo processor for an optical disk drive is provided that includes: an analog-to-digital converter for converting versions of photodetector output signals into digital signals; and a digital signal processor configured to receive the digital signals, the digital signal processor being further configured to determine a focus error signal (FES) and a tracking error signal (TES) from the digital signals, the digital signal processor being further configured to process TES and FES through servo algorithms to produce tracking and focus control signals.
177 Citations
39 Claims
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1. A digital servo for an optical disk drive, comprising:
- an analog-to-digital converter for converting low-pass filtered and gain-adjusted versions of photodetector output signals into digital signals; and
a digital signal processor configured to receive the digital signals, the digital signal processor being further configured to determine a focus error signal (FES) and a tracking error signal (TES) from the digital signals, the digital signal processor being further configured to process TES and FES through servo algorithms to produce tracking and focus control signals. - View Dependent Claims (2, 3, 4, 17, 25, 30, 31)
- an analog-to-digital converter for converting low-pass filtered and gain-adjusted versions of photodetector output signals into digital signals; and
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5. A digital servo method for an optical disk drive, comprising:
- receiving at an integrated circuit low-pass filtered and gain-adjusted versions of photodetector output signals resulting from an illumination of an optical disk;
within the integrated circuit, digitizing versions of the photodetector signals to produce digital signals;
in a digital signal processor, processing the digital signals into either a tracking error signal (TES) or a focus error signal (FES); and
in the digital signal processor, processing TES or FES through a servo algorithm to produce a control signal, the control signal being adapted to drive an actuator such that either TES or FES is minimized. - View Dependent Claims (6, 7, 8, 18, 19, 20, 26, 27, 28, 32, 33, 34)
- receiving at an integrated circuit low-pass filtered and gain-adjusted versions of photodetector output signals resulting from an illumination of an optical disk;
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9. A digital servo for an optical disk drive, comprising:
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an analog-to-digital converter configured to convert low-pass filtered and gain-adjusted versions of photodetector output signals into at least one digital signal; and a digital signal processor configured to determine at least one of tracking error and focus error from the at least one digital signal and to determine, through at least one servo algorithm, at least one of a tracking control signal from the tracking error and a focus control signal from the focus error. - View Dependent Claims (10, 11, 12, 21, 29, 35, 36)
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13. A digital servo method for an optical disk drive, comprising:
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receiving low-pass filtered and gain-adjusted versions of photodetector output signals resulting from an illumination of an optical disk; digitizing versions of the photodetector signals to produce digital signals; and determining, through servo algorithms in a digital signal processor, at least one of a tracking control signal based on a tracking error determined from the digital signals and a focus control signal based on a focus error determined from the digital signals. - View Dependent Claims (14, 15, 16, 22, 23, 24, 37, 38, 39)
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Specification
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Litigation Data
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Current AssigneeRPX Corporation
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Original AssigneeOD Servo Technologies LLC
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InventorsKadlec, Ron J
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Primary Examiner(s)Dinh, Tan X
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Application NumberUS12/952,135Publication NumberTime in Patent Office869 DaysField of Search369 301- 3018, 369/44.28, 369/44.27, 369/44.29, 369/44.35US Class Current369/30.12CPC Class CodesG11B 20/10046 filtering or equalising, e....G11B 20/18 Error detection or correcti...G11B 27/105 of operating discsG11B 27/3027 used signal is digitally codedG11B 7/08505 Methods for track change, s...G11B 7/08529 Methods and circuits to con...G11B 7/08541 involving track counting to...G11B 7/0901 for track following only G1...G11B 7/0908 for focusing only G11B7/092...G11B 7/0917 Focus-error methods other t...G11B 7/094 Methods and circuits for se...G11B 7/0941 Methods and circuits for se...G11B 7/0945 Methods for initialising se...
