US3719934A
Expired / Lapsed
US
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System for processing signals having peaks indicating binary data
Assignee: Unisys Corp
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Filing: 1970-09-28
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Granted: 1973-03-06
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Expires: 1990-09-28
Abstract
Abstract A system for reading binary data recorded on a storage medium as magnetic tape in either of several coding techniques. Specifically, the system is capable of reading either phase encoded data or data recorded in the form of nonreturn-to-zero pulses in which one binary value is represented by a flux reversal in a bit cell and the other binary value is represented by the absence of a flux reversal in a bit cell (hereafter called modified NRZ). A positive threshold detector, a negative threshold detector, and a bipolar peak detector are utilized for recovering the NRZ data and part of the preamble of the phase encoded data. The bipolar peak detector is also employed in the recovery of the phase encoded data itself. To recover the NRZ data and the preamble of the phase encoded data, the output of the positive threshold detector and the bipolar peak detector are combined in one AND circuit and the output of the negative threshold detector and the inverse output of the bipolar peak detector are combined in another AND circuit. To recover the phase encoded data, an excursion indicating signal representing the peak-to-peak amplitude of the read head signal is produced by differentiating it and then separately integrating the two half cycles of the differentiated signal. The maximum amplitude of the differentiated signal is limited to suppress noise. The integrated signals are applied to a positive threshold detector and a negative threshold detector, respectively. The output of the positive threshold detector is combined with the output of the bipolar peak detector in one AND circuit and the output of the negative threshold detector is combined with the inverse of the output of the bipolar peak detector in another AND circuit to recover the phase encoded data. To check for errors in the phase encoded data, these outputs are switched and applied to two other AND circuits.
Inventors
- 👤 M Behr
- 👤 L Coon
- 👤 C Bickel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:54
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/10009
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
176 words
A binary data handling system comprising: a source of an oscillating signal representing phase encoded data read from a storage medium; means responsive to the oscillating signal for producing an excursion indication signal having a waveform that, during each time interval in which the oscillating signal is varying from a peak of one polarity to a successive peak of the other polarity, has a magnitude varying in accordance with the amplitude change in the oscillating signal during such time interval, and that, during at least a portion of intervening time intervals, has a predetermined constant value, the means for producing the excursion indicating signal comprising a differentiator and an integrator that integrates individually over the half cycles of the differentiated signal of one polarity; a threshold detector producing an output at a first level when the excursion indication signal is below a threshold level and at a second level when the excursion indication signal is above the threshold level; a utilization circuit; and means for coupling the output of the threshold detector to the utilization circuit.
Claim 2
Dependent Claim
176 words
A binary data handling system comprising: a source of an oscillating signal representing phase encoded data read from a storage medium; means responsive to the oscillating signal for producing an excursion indication signal having a waveform that, during each time interval in which the oscillating signal is varying from a peak of one polarity to a successive peak of the other polarity, has a magnitude varying in accordance with the amplitude change in the oscillating signal during such time interval, and that, during at least a portion of intervening time intervals, has a predetermined constant value, the means for producing the excursion indicating signal comprising a differentiator and an integrator that integrates individually over the half cycles of the differentiated signal of one polarity; a threshold detector producing an output at a first level when the excursion indication signal is below a threshold level and at a second level when the excursion indication signal is above the threshold level; a utilization circuit; and means for coupling the output of the threshold detector to the utilization circuit.
Claim 3
Dependent Claim
176 words
A binary data handling system comprising: a source of an oscillating signal representing phase encoded data read from a storage medium; means responsive to the oscillating signal for producing an excursion indication signal having a waveform that, during each time interval in which the oscillating signal is varying from a peak of one polarity to a successive peak of the other polarity, has a magnitude varying in accordance with the amplitude change in the oscillating signal during such time interval, and that, during at least a portion of intervening time intervals, has a predetermined constant value, the means for producing the excursion indicating signal comprising a differentiator and an integrator that integrates individually over the half cycles of the differentiated signal of one polarity; a threshold detector producing an output at a first level when the excursion indication signal is below a threshold level and at a second level when the excursion indication signal is above the threshold level; a utilization circuit; and means for coupling the output of the threshold detector to the utilization circuit.
Claim 4
Dependent Claim
176 words
A binary data handling system comprising: a source of an oscillating signal representing phase encoded data read from a storage medium; means responsive to the oscillating signal for producing an excursion indication signal having a waveform that, during each time interval in which the oscillating signal is varying from a peak of one polarity to a successive peak of the other polarity, has a magnitude varying in accordance with the amplitude change in the oscillating signal during such time interval, and that, during at least a portion of intervening time intervals, has a predetermined constant value, the means for producing the excursion indicating signal comprising a differentiator and an integrator that integrates individually over the half cycles of the differentiated signal of one polarity; a threshold detector producing an output at a first level when the excursion indication signal is below a threshold level and at a second level when the excursion indication signal is above the threshold level; a utilization circuit; and means for coupling the output of the threshold detector to the utilization circuit.
Claim 5
Dependent Claim
55 words
The system of claim 1, in which the amplitude of the differentiated signal is limited so as not to exceed substantially the amplitude of a signal at the output of the differentiator having the highest frequency component of the source required to produce a signal at the output of the integrator above the threshold level.
Claim 6
Dependent Claim
119 words
A binary data handling system comprising: a source of an oscillating signal having peaks representing binary data; a differentiator for producing a differentiated signal having a waveform varying in accordance with the derivative of the oscillating signal; first and second integrators for integrating the differentiated first signal, to produce first and second signal waveforms; means for clearing the integrators; each integrator producing a waveform that on different, alternate half-cycles of the differentiated signal has a magnitude varying in accordance with the amplitude change of the oscillating signal during such half-cycles; the clearing means clearing each integrator on different, alternate half-cycles; and means for generating an indication each time that either the first or second signal exceeds a threshold level.
Claim 7
Dependent Claim
119 words
A binary data handling system comprising: a source of an oscillating signal having peaks representing binary data; a differentiator for producing a differentiated signal having a waveform varying in accordance with the derivative of the oscillating signal; first and second integrators for integrating the differentiated first signal, to produce first and second signal waveforms; means for clearing the integrators; each integrator producing a waveform that on different, alternate half-cycles of the differentiated signal has a magnitude varying in accordance with the amplitude change of the oscillating signal during such half-cycles; the clearing means clearing each integrator on different, alternate half-cycles; and means for generating an indication each time that either the first or second signal exceeds a threshold level.
Claim 8
Dependent Claim
77 words
The system of claim 3, and further comprising a limiter circuit connected across the output of the differentiator, the limiter circuit limiting the positive and negative amplitude of the differentiated signal so as not to exceed substantially the positive and negative amplitude of a signal at the output of the diFferentiator having a frequency of the highest frequency component of the source required to produce a signal at the outputs of the integrators above the threshold levels.
Claim 9
Dependent Claim
220 words
In a data handling system having a utilization circuit and a processing circuit including a bipolar peak detector, the processing circuit being adapted to respond to a conventionally encoded binary data signal to produce data pulses for application to the utilization circuit, the apparatus comprising: a source for producing encoded signals representative of data stored on a magnetic surface, the source being coupled to the processing circuit for processing conventionally encoded data signals; a differentiator having an input coupled to the source for producing a differentiated signal which has a positive half cycle and a negative half cycle; a first integrator for individually integrating the positive half cycles; a second integrator for individually integrating the negative half cycles; first and second coincidence detection means each having an input coupled to the bipolar peak detector, the first means for producing a pulse belonging to a first group in response to each coincidence of a threshold level at the first integrator and a positive peak indication of the bipolar peak detector, the second means for producing a pulse belonging to a second group in response to each coincidence of a threshold level at the second integrator and a negative peak indication of the bipolar peak detector; and means for coupling the pulses of the first and second groups to the utilization circuit.
Claim 10
Dependent Claim
220 words
In a data handling system having a utilization circuit and a processing circuit including a bipolar peak detector, the processing circuit being adapted to respond to a conventionally encoded binary data signal to produce data pulses for application to the utilization circuit, the apparatus comprising: a source for producing encoded signals representative of data stored on a magnetic surface, the source being coupled to the processing circuit for processing conventionally encoded data signals; a differentiator having an input coupled to the source for producing a differentiated signal which has a positive half cycle and a negative half cycle; a first integrator for individually integrating the positive half cycles; a second integrator for individually integrating the negative half cycles; first and second coincidence detection means each having an input coupled to the bipolar peak detector, the first means for producing a pulse belonging to a first group in response to each coincidence of a threshold level at the first integrator and a positive peak indication of the bipolar peak detector, the second means for producing a pulse belonging to a second group in response to each coincidence of a threshold level at the second integrator and a negative peak indication of the bipolar peak detector; and means for coupling the pulses of the first and second groups to the utilization circuit.
Claim 11
Dependent Claim
59 words
The apparatus of claim 5, in which: the amplitude of the output of the differentiator is limited in value substantially to the amplitude of a signal at the output of the differentiator having the frequency of the highest frequency component applied to the input of the differentiator required to provide the threshold levels at the outputs of the integrators.
Claim 12
Dependent Claim
33 words
The apparatus of claim 5, in which: control means are provided for causing the first and second means to be inoperative until a predetermined number of pulses are generated by the processing circuit.
Claim 13
Dependent Claim
151 words
A binary data handling system comprising: a source of an oscillating signal representing binary encoded data read from a storage medium; means responsive to the oscillating signal for producing an excursion indication signal having a waveform that, during each time interval in which the oscillating signal is varying from a peak of one polarity to a successive peak of the other polarity, has a magnitude varying in accordance with the amplitude change in the oscillating signal during such time interval, and that, during each intervening time interval has a predetermined constant value; a threshold detector producing an output indication at a first level when the excursion indication signal is below a threshold level and at a second level when the excursion indication signal is above the threshold level; a utilization circuit; and a gate connecting the output of the threshold detector to the utilization circuit under the control of clock pulses.
Claim 14
Dependent Claim
151 words
A binary data handling system comprising: a source of an oscillating signal representing binary encoded data read from a storage medium; means responsive to the oscillating signal for producing an excursion indication signal having a waveform that, during each time interval in which the oscillating signal is varying from a peak of one polarity to a successive peak of the other polarity, has a magnitude varying in accordance with the amplitude change in the oscillating signal during such time interval, and that, during each intervening time interval has a predetermined constant value; a threshold detector producing an output indication at a first level when the excursion indication signal is below a threshold level and at a second level when the excursion indication signal is above the threshold level; a utilization circuit; and a gate connecting the output of the threshold detector to the utilization circuit under the control of clock pulses.
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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) | 1976-03-05 | 1976-09-04 | 1977-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-05 | 1980-09-04 | 1981-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-05 | 1984-09-04 | 1985-03-06 | $7700.00 | Window Closed / Lapsed |