US3706842A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method to double transmission speed of telephone network facsimile
Assignee: Philips North America LLC
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Filing: 1971-02-01
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Granted: 1972-12-19
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Expires: 1991-02-01
Abstract
Abstract Material to be sent is scanned two lines at a time and the information in the two lines is transmitted simultaneously. The first line of each pair is encoded and transmitted by a frequency or phase modulated carrier. The second line of each pair is encoded and is used to amplitude modulate the frequency or phase modulated carrier of the first line.
Inventors
- 👤 Gene D Robertson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:08
CPC Classifications
H; H04; H04J; H04J9/00; H04N; H04N1/00; H04N1/00095
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
102 words
A method of rapidly and simultaneously transmitting two separate facsimile signals over a telephone network which comprises: optically scanning pairs of line simultaneously on an item to be sent, to obtain two separate facsimile signals, only frequency modulating an audio frequency carrier with a frequency modulating signal derived from one of the signals, converting the other of the two signals to a digital signal which is at a given potential more than 80 percent and less than 100 percent of the time, amplitude modulating the same carrier with said digital signal, transmitting the frequency and amplitude modulated carrier over the telephone network.
Claim 2
Independent Claim
102 words
A method of rapidly and simultaneously transmitting two separate facsimile signals over a telephone network which comprises: optically scanning pairs of line simultaneously on an item to be sent, to obtain two separate facsimile signals, only frequency modulating an audio frequency carrier with a frequency modulating signal derived from one of the signals, converting the other of the two signals to a digital signal which is at a given potential more than 80 percent and less than 100 percent of the time, amplitude modulating the same carrier with said digital signal, transmitting the frequency and amplitude modulated carrier over the telephone network.
Claim 3
Independent Claim
77 words
A method of rapidly and simultaneously transmitting two separate facsimile signals which comprises: only frequency modulating a carrier with a frequency modulating signal derived from one of the facsimile signals, converting the other facsimile signal to a binary signal which consists of pulses which occur at optical transitions from black to white and white to black, amplitude modulating the same carrier with said binary signal, and transmitting said amplitude and frequency modulated carrier over a telephone network.
Claim 4
Independent Claim
77 words
A method of rapidly and simultaneously transmitting two separate facsimile signals which comprises: only frequency modulating a carrier with a frequency modulating signal derived from one of the facsimile signals, converting the other facsimile signal to a binary signal which consists of pulses which occur at optical transitions from black to white and white to black, amplitude modulating the same carrier with said binary signal, and transmitting said amplitude and frequency modulated carrier over a telephone network.
Claim 5
Dependent Claim
18 words
The method of claim 2 in which the amplitude modulation of said carrier is positive during said pulses.
Claim 6
Dependent Claim
21 words
The method of claim 2 in which said two separate facsimile signals are obtained by optically scanning pairs of lines simultaneously.
Claim 7
Dependent Claim
16 words
The method of claim 2 in which said transmitting is done through a switched telephone network.
Claim 8
Dependent Claim
27 words
The method of claim 2 in which said binary signal is at a given potential more than 80 percent and less than 100 percent of the time.
Claim 9
Dependent Claim
98 words
A combination for facsimile usable with a switched telephone network comprising: a. scanning means for simultaneously scanning two lines of information on an information bearing medium and converting the infoRmation obtained by scanning to two electrical signals, b. means for frequency modulating a carrier with a frequency modulating signal derived from one of the facsimile signals, c. means for converting the other facsimile signal to a binary signal which consists of pulses which occur at optical transitions from black to white and white to black, and d. means for amplitude modulating the same carrier with said digital signal.
Claim 10
Dependent Claim
98 words
A combination for facsimile usable with a switched telephone network comprising: a. scanning means for simultaneously scanning two lines of information on an information bearing medium and converting the infoRmation obtained by scanning to two electrical signals, b. means for frequency modulating a carrier with a frequency modulating signal derived from one of the facsimile signals, c. means for converting the other facsimile signal to a binary signal which consists of pulses which occur at optical transitions from black to white and white to black, and d. means for amplitude modulating the same carrier with said digital signal.
Claim 11
Dependent Claim
25 words
The combination of claim 7 in which said means for amplitude modulating is polarized to cause positive modulation during said pulses of said binary signal.
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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) | 1975-12-19 | 1976-06-19 | 1976-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-19 | 1980-06-19 | 1980-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-19 | 1984-06-19 | 1984-12-19 | $7700.00 | Window Closed / Lapsed |