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US5612938A Expired / Lapsed US ⏱️ 0.0 years remaining

Correcting recorded marks and land lengths taken from an optical disk

Assignee: Eastman Kodak Co
•
Filing: 1995-04-20
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Granted: 1997-03-18
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Expires: 2015-04-20
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Abstract

Abstract Method for correcting the length of marks and lands representing information taken from an optical disk is disclosed. The method includes digitizing amplified analog data having marks and lands played back from an optical disk and providing a data synchronization clock by using a phase lock loop (PLL). The method further includes providing an adjustment to a threshold signal level based upon the difference in timing position in mark and land edge marks with reference to the data synchronization clock and changing the data mark and land lengths with reference to the adjusted threshold signal.

Inventors

  • 👤 Steven C. Dohmeier
  • 👤 Michael Meichle
  • 👤 Michael G. Fairchild

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 19:51
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/14; G11B20/1403; G11B20/10009; G11B7/00; G11B7/004; G11B7/005

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 151 words
A method for correcting the length of marks and lands representing information taken from an optical disk, comprising the steps of: a) digitizing amplified analog data having marks and lands played back from an optical disk; b) providing a data synchronization clock by using a phase lock loop (PLL); c) providing an adjustment to a threshold signal level based upon the difference in timing position in mark and land edges with reference to the data synchronization clock; d) providing mark and land length data with reference to the data synchronization clock and monitoring the phase relationship between the data synchronization clock and mark and land data to insure the polarity of the adjustment is correct; e) changing the data mark and land lengths with reference to the adjusted threshold signal; and f) preventing changing the data mark and land lengths if the monitoring step determines that a phase limit is exceeded.
Claim 2
Independent Claim 151 words
A method for correcting the length of marks and lands representing information taken from an optical disk, comprising the steps of: a) digitizing amplified analog data having marks and lands played back from an optical disk; b) providing a data synchronization clock by using a phase lock loop (PLL); c) providing an adjustment to a threshold signal level based upon the difference in timing position in mark and land edges with reference to the data synchronization clock; d) providing mark and land length data with reference to the data synchronization clock and monitoring the phase relationship between the data synchronization clock and mark and land data to insure the polarity of the adjustment is correct; e) changing the data mark and land lengths with reference to the adjusted threshold signal; and f) preventing changing the data mark and land lengths if the monitoring step determines that a phase limit is exceeded.
Claim 3
Dependent Claim 43 words
The method of claim 1 wherein the threshold adjustment is created by providing a mark and land length error signal using the PLL and synchronizing clock signals and supplying the error signal to a charge pump that in turn produces the variable threshold.
Claim 4
Dependent Claim 17 words
The method of claim 1 wherein the phase lock loop is responsive to digitized analog data signals.
Claim 5
Dependent Claim 18 words
The method of claim 1 wherein the phase lock loop is responsive to corrected mark and land data.

References Cited (Backward Citations)

US4734900A Cited
US5204848A Cited
US5502711A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2000-03-17 2000-09-16 2001-03-18 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2004-03-17 2004-09-16 2005-03-18 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2008-03-17 2008-09-16 2009-03-18 $7700.00 Window Closed / Lapsed

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