US4323932A
Expired / Lapsed
US
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Readback pulse compensator
Assignee: Unisys Corp
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Filing: 1979-07-30
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Granted: 1982-04-06
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Expires: 1999-07-30
Abstract
Abstract A system for compensating misalignment between information represented by transitions in a data bearing medium and a played back signal, the played back signal having consecutive opposite-polarity peaks corresponding to said data transitions, which system comprises a low-pass filter, which receives a signal from a non-linear element, preferably a pulse forming circuit, into which has been introduced the misaligned played back signal, and circuitry for converting the filtered signal to a series of pulses representative of the data transitions, which pulses have reduced misalignment with respect to the data transitions.
Inventors
- 👤 Jules A. Eibner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:51
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/22; G11B20/10; G11B20/10009
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
157 words
In a system for processing a first signal which has consecutive opposite-polarity peaks corresponding to information represented by transitions in a data bearing medium, and in which the said signal peaks are subject to misalignment with respect to the corresponding data transitions, the improvement which comprises: means for producing a second signal from said first signal, which second signal has peaks with substantially the same said misalignment but of the same polarity; means for subjecting the produced second signal to low-pass filtering; and means for deriving from said low-pass filtering means a third signal having peaks substantially in alignment with respective peaks of the same polarity in said second signal; whereby the misalignment between the peaks of the third signal and the data transitions is substantially less than the misalignment between the peaks of the first signal and the data transitions, reducing the misalignment between the data and the processed signal which is representative of said data.
Claim 2
Dependent Claim
157 words
In a system for processing a first signal which has consecutive opposite-polarity peaks corresponding to information represented by transitions in a data bearing medium, and in which the said signal peaks are subject to misalignment with respect to the corresponding data transitions, the improvement which comprises: means for producing a second signal from said first signal, which second signal has peaks with substantially the same said misalignment but of the same polarity; means for subjecting the produced second signal to low-pass filtering; and means for deriving from said low-pass filtering means a third signal having peaks substantially in alignment with respective peaks of the same polarity in said second signal; whereby the misalignment between the peaks of the third signal and the data transitions is substantially less than the misalignment between the peaks of the first signal and the data transitions, reducing the misalignment between the data and the processed signal which is representative of said data.
Claim 3
Dependent Claim
15 words
The system of claim 1 wherein the second signal producing means is a non-linear element.
Claim 4
Dependent Claim
12 words
The system of claim 1 wherein the non-linear element is a rectifier.
Claim 5
Dependent Claim
20 words
The system of claim 3 wherein the non-linear element comprises means for forming pulses in response to said first signal.
Claim 6
Dependent Claim
13 words
The system of claim 3 wherein the non-linear element is a full-wave rectifier.
Claim 7
Dependent Claim
14 words
The system of claim 1 wherein the low-pass filtering means is a Gaussian filter.
Claim 8
Dependent Claim
25 words
The system of claim 6 wherein the parameters of the filtering means are selected in accordance with the transition rate of the data bearing medium.
Claim 9
Dependent Claim
45 words
The system of claim 1 wherein the third signal deriving means comprises: means for differentiating said signal produced by lowpass filtering; means for detecting when said filtered differentiated signal crosses a selected threshold; and means for forming pulses in response to said threshold detecting means.
Claim 10
Dependent Claim
12 words
The system of claim 8 wherein the selected threshold is the zero-crossing.
Claim 11
Dependent Claim
20 words
The system of claim 9 wherein said threshold detecting means detects only those zero-crossings having slopes of the same polarity.
Claim 12
Dependent Claim
12 words
The system of claim 10 wherein only the positive-going zero-crossings are detected.
Claim 13
Dependent Claim
15 words
The system of claim 1 wherein the data bearing medium is a magnetic recording means.
Claim 14
Dependent Claim
48 words
The system of claim 1 wherein each of a plurality of first signals are produced from each of a plurality of data bearing media, and means for selectively, and alternately, connecting one of the plurality of first signals to said second signal producing means for a selected duration.
Claim 15
Dependent Claim
22 words
The system of claim 13 wherein said system has less of said second signal producing means than of said data bearing media.
Claim 16
Dependent Claim
12 words
The system of claim 14 having only one second signal producing means.
Claim 17
Dependent Claim
31 words
The system of claim 1 further comprising means for predistorting the data from which said first signal is derived, to compensate for misalignment of the data transitions with said first signal.
Claim 18
Dependent Claim
25 words
The system of claim 1 further comprising means for equalizing said third signal, to compensate for misalignment of the data transitions with said first signal.
Claim 19
Dependent Claim
151 words
In a method for processing a first signal which has consecutive opposite-polarity peaks corresponding to information represented by transitions in a data bearing medium, and in which the said signal peaks are subject to misalignment with respect to the corresponding data transitions, the improvement which comprises: producing a second signal from said first signal, which second signal has peaks with substantially the same said misalignment but of the same polarity; subjecting the produced second signal to low-pass filtering; and deriving from said filtered second signal a third signal having peaks substantially in alignment with respective peaks of the same polarity in said second signal; whereby the misalignment between the peaks of the third signal and the data transitions is substantially less than the misalignment between the peaks of the first signal and the data transitions, reducing the misalignment between the data and the processed signal which is representative of said data.
Claim 20
Dependent Claim
151 words
In a method for processing a first signal which has consecutive opposite-polarity peaks corresponding to information represented by transitions in a data bearing medium, and in which the said signal peaks are subject to misalignment with respect to the corresponding data transitions, the improvement which comprises: producing a second signal from said first signal, which second signal has peaks with substantially the same said misalignment but of the same polarity; subjecting the produced second signal to low-pass filtering; and deriving from said filtered second signal a third signal having peaks substantially in alignment with respective peaks of the same polarity in said second signal; whereby the misalignment between the peaks of the third signal and the data transitions is substantially less than the misalignment between the peaks of the first signal and the data transitions, reducing the misalignment between the data and the processed signal which is representative of said 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) | 1985-04-05 | 1985-10-05 | 1986-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-04-05 | 1989-10-05 | 1990-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-04-05 | 1993-10-05 | 1994-04-06 | $7700.00 | Window Closed / Lapsed |