US3700810A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Facsimile reverse signaling system
Assignee: Philips North America LLC
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Filing: 1970-03-26
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Granted: 1972-10-24
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Expires: 1990-03-26
Abstract
Abstract A facsimile transmission system utilizing telephone lines for its communication link is disclosed which is adapted to provide signals from the receiving unit to the transmitting unit to indicate failures of transmission to the transmitter. Provision is also made to simultaneously disable the echo suppressors present in long communication links so that two way communication is possible and to indicate to the transmitter that the receiver is ready to begin operation.
Inventors
- 👤 William E Richeson Jr
- 👤 Joel K Roach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:05
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/0035; H04N1/00405; H04N1/00488; H04L; H04L1/00; H04L1/12; H04N1/32; H04N1/32609; H04N1/32614; H04N1/32625; H04N1/32641; H04N1/32646; H04N1/32651; H04N1/32662
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
220 words
In a facsimile transmission system having a first unit adapted to scan an original document and send facsimile information representing the scanned document over a standard telephone line and a second unit adapted to receive the information sent and reproduce a copy of the original document, the improved method of effecting communication between said units comprising: transmitting over said telephone line from the second unit to the first unit a first signal adapted to disable any echo suppressor which may be present in the telephone line so as to allow two way communication between said first and second units and to notify the first unit that the second unit is ready to receive facsimile information; providing from the second unit to the first unit a second signal which provides the first unit with an indication of the continued receipt of facsimile information from the first unit, said first signal being provided for a first predetermined period of time and ceasing prior to the provision of said second signal; filtering subsequent to the lapse of said first predetermined period of time the input to the first unit so as to pass only said second signals; and filtering subsequent to the lapse of said first predetermined period of time the input to the second unit so as to reject said second signal.
Claim 2
Dependent Claim
220 words
In a facsimile transmission system having a first unit adapted to scan an original document and send facsimile information representing the scanned document over a standard telephone line and a second unit adapted to receive the information sent and reproduce a copy of the original document, the improved method of effecting communication between said units comprising: transmitting over said telephone line from the second unit to the first unit a first signal adapted to disable any echo suppressor which may be present in the telephone line so as to allow two way communication between said first and second units and to notify the first unit that the second unit is ready to receive facsimile information; providing from the second unit to the first unit a second signal which provides the first unit with an indication of the continued receipt of facsimile information from the first unit, said first signal being provided for a first predetermined period of time and ceasing prior to the provision of said second signal; filtering subsequent to the lapse of said first predetermined period of time the input to the first unit so as to pass only said second signals; and filtering subsequent to the lapse of said first predetermined period of time the input to the second unit so as to reject said second signal.
Claim 3
Dependent Claim
61 words
An improved facsimile system comprising: a transmitter adapted to simultaneously send video information and receive a confirmatory signal; a receiver adapted to simultaneously receive said video information and transmit said confirmatory signal; a narrow band pass filter in said transmitter adapted to pass said confirmatory signal; and a narrow band reject filter in said receiver adapted to reject said confirmatory signal.
Claim 4
Dependent Claim
61 words
An improved facsimile system comprising: a transmitter adapted to simultaneously send video information and receive a confirmatory signal; a receiver adapted to simultaneously receive said video information and transmit said confirmatory signal; a narrow band pass filter in said transmitter adapted to pass said confirmatory signal; and a narrow band reject filter in said receiver adapted to reject said confirmatory signal.
Claim 5
Dependent Claim
25 words
The facsimile system of claim 2 wherein transmission of said confirmatory signal is begun a predetermined time after said receiver is ready to receive information.
Claim 6
Dependent Claim
40 words
The facsimile system of claim 2 wherein the transmitter and receiver are coupled together by way of an ordinary telephone line further comprising: means for generating a lock-out signal effective to disable any echo suppressor present in the telephone line.
Claim 7
Dependent Claim
51 words
The facsimile system of claim 3 wherein the transmitter and receiver are coupled together by way of an ordinary telephone line further comprising: means for generating a lock-out signal prior to transmission of said confirmatory signal, which lock-out signal is effective to disable any echo suppressor present in said telephone line.
Claim 8
Dependent Claim
44 words
The facsimile system of claim 4 further comprising: a first carrier detector circuit associated with at least one of said transmitter and receiver and responsive to the cessation of said confirmatory signal for at least a first time interval to regenerate said lock-out signal.
Claim 9
Dependent Claim
57 words
The facsimile system of claim 6 further comprising a second carrier detector circuit associated with at least one of said transmitter and receiver and responsive to the cessation of said confirmatory signal for at least a second time interval greater than said first time interval to disable said receiver and to supply an indication to said transmitter.
Claim 10
Dependent Claim
73 words
An improved facsimile system comprising: a facsimile transmitter adapted to simultaneously send frequency modulated video signals lying within a predetermined frequency range, and receive a confirmatory signal having a frequency outside said predetermined frequency range; a receiver adapted to simultaneously receive said frequency modulated video signal, and transmit said confirmatory signal; and, means for initiating the transmission of said confirmatory signal a predetermined time after said receiver is ready to receive facsimile information.
Claim 11
Dependent Claim
73 words
An improved facsimile system comprising: a facsimile transmitter adapted to simultaneously send frequency modulated video signals lying within a predetermined frequency range, and receive a confirmatory signal having a frequency outside said predetermined frequency range; a receiver adapted to simultaneously receive said frequency modulated video signal, and transmit said confirmatory signal; and, means for initiating the transmission of said confirmatory signal a predetermined time after said receiver is ready to receive facsimile information.
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) | 1975-10-24 | 1976-04-24 | 1976-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-24 | 1980-04-24 | 1980-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-24 | 1984-04-24 | 1984-10-24 | $7700.00 | Window Closed / Lapsed |