Patent US3887942A successfully refreshed from Google Patents.
US3887942A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tape speed compensation system
Assignee: CENTURY DATA SYSTEMS Inc A DIV
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Filing: 1972-04-13
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Granted: 1975-06-03
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Expires: 1992-04-13
Abstract
Abstract The margin of reliability of magnetically recorded data is sharply affected by speed variations of the moving media. A phase locked oscillator can be used to vary the initiation and termination of a window to bracket data information in accordance with tape speed changes.
Inventors
- 👤 Noah Horowitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:53
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/14; G11B20/1403; G11B20/1407; G11B20/1419
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
167 words
An apparatus for compensating for variations in the speed of a moving medium upon which digital data is recorded comprising: means for varying the time position of the opening of a sample window as a function of the recording medium variations comprising a phased locked oscillator which generates a feedback voltage proportional to the instantaneous phase difference between the input frequency and the phase locked oscilator frequency; means for varying the time position of the closing of the sample window as a function of recording medium speed variations comprising a one shot multivibrator having a width which is controlled by the feedback voltage generated by said phase locked oscillator; means for centering the time position of the data edge between said opening and closing of the sample window and means for adjusting the opening and closing of the sample window so as to maintain the data edge centered with, respect to the opening and closing of the sample window as the speed of the recording medium varies.
Claim 2
Independent Claim
167 words
An apparatus for compensating for variations in the speed of a moving medium upon which digital data is recorded comprising: means for varying the time position of the opening of a sample window as a function of the recording medium variations comprising a phased locked oscillator which generates a feedback voltage proportional to the instantaneous phase difference between the input frequency and the phase locked oscilator frequency; means for varying the time position of the closing of the sample window as a function of recording medium speed variations comprising a one shot multivibrator having a width which is controlled by the feedback voltage generated by said phase locked oscillator; means for centering the time position of the data edge between said opening and closing of the sample window and means for adjusting the opening and closing of the sample window so as to maintain the data edge centered with, respect to the opening and closing of the sample window as the speed of the recording medium varies.
Claim 3
Independent Claim
167 words
An apparatus for compensating for variations in the speed of a moving medium upon which digital data is recorded comprising: means for varying the time position of the opening of a sample window as a function of the recording medium variations comprising a phased locked oscillator which generates a feedback voltage proportional to the instantaneous phase difference between the input frequency and the phase locked oscilator frequency; means for varying the time position of the closing of the sample window as a function of recording medium speed variations comprising a one shot multivibrator having a width which is controlled by the feedback voltage generated by said phase locked oscillator; means for centering the time position of the data edge between said opening and closing of the sample window and means for adjusting the opening and closing of the sample window so as to maintain the data edge centered with, respect to the opening and closing of the sample window as the speed of the recording medium varies.
Claim 4
Independent Claim
167 words
An apparatus for compensating for variations in the speed of a moving medium upon which digital data is recorded comprising: means for varying the time position of the opening of a sample window as a function of the recording medium variations comprising a phased locked oscillator which generates a feedback voltage proportional to the instantaneous phase difference between the input frequency and the phase locked oscilator frequency; means for varying the time position of the closing of the sample window as a function of recording medium speed variations comprising a one shot multivibrator having a width which is controlled by the feedback voltage generated by said phase locked oscillator; means for centering the time position of the data edge between said opening and closing of the sample window and means for adjusting the opening and closing of the sample window so as to maintain the data edge centered with, respect to the opening and closing of the sample window as the speed of the recording medium varies.
Claim 5
Dependent Claim
20 words
The apparatus recited in claim 1 wherein is included logic means for deriving a clock pulse from the incoming data.
Claim 6
Dependent Claim
26 words
The apparatus recited in claim 2 wherein is included logic means for shifting the time position of the clock pulse in accordance with a recorded preamble.
Claim 7
Dependent Claim
26 words
The apparatus recited in claim 3 wherein is included logic means for decoding the recorded data irrespective of the direction which the recording medium is traveling.
References Cited (Backward Citations)
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US3560947A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |