US5612938A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Correcting recorded marks and land lengths taken from an optical disk
Assignee: Eastman Kodak Co
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Filing: 1995-04-20
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Granted: 1997-03-18
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Expires: 2015-04-20
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 18:08
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)
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 |