US3577138A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Feedback type pulse amplitude modulation coding system
Assignee: Fujitsu Ltd
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Filing: 1966-12-13
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Granted: 1971-05-04
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Expires: 1986-12-13
Abstract
Abstract A pulse amplitude modulated signal is held in a first holding circuit and is supplied to a summing node via a switch. A reference signal from a reference signal source is also supplied to the summing node which provides a difference signal indicative of the difference in amplitude between the pulse amplitude modulated signal and the reference signal. An amplifier amplifies the difference signal and a comparator determines the polarity of the difference signal and provides a corresponding binary output signal. The comparator is also connected to the reference signal source in a first feedback path. A second holding circuit is connected in a second feedback path between the amplifier and the switch and the amplified difference signal is supplied to the summing node via the switch in selective alternation with the pulse signal.
Inventors
- 👤 Masao Kawashima
- 👤 Shunroku Sasaki
- 👤 Syoichi Kurita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:33
CPC Classifications
H; H03; H03M; H03M1/00; H03M1/06; H03M1/08
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
203 words
A coding system for converting a pulse amplitude modulated signal to a binary signal, comprising: first circuit means for providing a difference signal indicative of the difference in amplitude between a pulse amplitude modulated signal and a reference signal, said first circuit means including a source of said reference signal; input means connected to said first circuit means for supplying a pulse amplitude modulated signal to said first circuit means, said input means including first holding means for holding said pulse amplitude modulated signal; second circuit means connected to said first circuit means and to said input means and including second holding means for holding the difference signal provided by said first circuit means and for feeding back the held amplified difference signal to said first circuit means via said input means, said input means including switch means for selectively applying one of the held pulse amplitude modulated signal and the held amplified difference signal to said first circuit means in order to provide a coded binary signal; and output means connected to said first circuit means for determining the polarity of the difference signal provided by said first circuit means and for providing an indication of such polarity as a binary signal.
Claim 2
Dependent Claim
203 words
A coding system for converting a pulse amplitude modulated signal to a binary signal, comprising: first circuit means for providing a difference signal indicative of the difference in amplitude between a pulse amplitude modulated signal and a reference signal, said first circuit means including a source of said reference signal; input means connected to said first circuit means for supplying a pulse amplitude modulated signal to said first circuit means, said input means including first holding means for holding said pulse amplitude modulated signal; second circuit means connected to said first circuit means and to said input means and including second holding means for holding the difference signal provided by said first circuit means and for feeding back the held amplified difference signal to said first circuit means via said input means, said input means including switch means for selectively applying one of the held pulse amplitude modulated signal and the held amplified difference signal to said first circuit means in order to provide a coded binary signal; and output means connected to said first circuit means for determining the polarity of the difference signal provided by said first circuit means and for providing an indication of such polarity as a binary signal.
Claim 3
Dependent Claim
20 words
A coding system as claimed in claim 1, wherein the switch means of said input means includes electronic switch means.
Claim 4
Dependent Claim
66 words
A coding system as claimed in claim 1, wherein said first circuit means includes summing means having an input connected to the switch means of said input means, an input connected to the source of reference signal of said first circuit means and an output for providing said difference signal indicative to the difference in amplitude between said pulse amplitude modulated signal and said reference signal.
Claim 5
Dependent Claim
75 words
A coding system as claimed in claim 3, wherein said first circuit means further includes amplifier means connected to the output of said summing means and wherein said output means includes comparator means connected to said amplifier means for determining the polarity of the difference signal provided by said first circuit means and an output connected to said comparator means for providing an indication of the polarity of said difference signal as a binary signal.
Claim 6
Dependent Claim
65 words
A coding system as claimed in claim 4, wherein said first circuit means further includes first feedback means connecting said comparator means to the source of reference signal of said first circuit means and wherein saiD second circuit means includes second feedback means connecting said second holding means between the amplifier means of said first circuit means and the switch means of said input means.
Claim 7
Dependent Claim
52 words
A coding system as claimed in claim 5, wherein said output means further includes code converter means connected between the comparator means of said output means and the first feedback means of said first circuit means for converting the binary signal provided by said output means in accordance with a determined program.
Claim 8
Dependent Claim
68 words
A coding system as claimed in claim 5, wherein said second circuit means further includes full-wave rectifier means connected to the amplifier means of said first circuit means and ancillary summing means having an input connected to said rectifier means, an output connected to said second holding means and another input, said rectifier means and said ancillary summing means being connected in series in said second feedback means.
Claim 9
Dependent Claim
38 words
A coding system as claimed in claim 7, wherein said second circuit means further comprises ancillary voltage means connected to the other input of said ancillary summing means for applying an ancillary voltage to said ancillary summing means.
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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) | 1974-05-03 | 1974-11-02 | 1975-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-03 | 1978-11-02 | 1979-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-03 | 1982-11-02 | 1983-05-04 | $7700.00 | Window Closed / Lapsed |