Patent US3914538A successfully refreshed from Google Patents.
US3914538A
Expired / Lapsed
US
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Facsimile communication system
Assignee: Xerox Corp
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Filing: 1973-08-27
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Granted: 1975-10-21
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Expires: 1993-08-27
Abstract
Abstract A facsimile communication system is described wherein the transmission of data between a transmitting and receiving apparatus over a voice quality transmission medium is accomplished by providing spectrum compressing encoding of a video signal and by frequency modulation and vestigial sideband transmission of the frequency modulated video signal. In a principal mode of operation, the transmission of video data is preceded by receiver alerting, equalizing, synchronizing and scan pitch signals for respectively shifting the receiver from a standby to an operating status, for connecting distortions in the transmission medium, for causing line by line synchronization between sending and receiving units and for establishing the scanning pitch at the printing unit. A transceiving unit of the system when operating as a receiver in the principal mode generates reverse signalling information for acknowledging a ready to receive status at the initiation of communication and a printer ready status for enabling the transmission of video information. A high degree of reliability in interaction between the sending and receiving units is thereby imparted to the system and facilitates scanning and electrostatographic printing techniques. The transceiving system of the invention is further adapted for operating in optional modes including an automatic document feeding mode, an unattended sending mode and a printer polling mode. The communication system is further adapted to operate with existing facsimile systems which transmit at relatively lower document transmission rates, exhibit different signal formats and have different internal controlling.
Inventors
- 👤 Donald A Perreault
- 👤 Victor Lee Bedzyk
- 👤 Larry Richard Matthews
- 👤 Roy Wilben Rivers
- 👤 David Rollin Shuey
- 👤 John David Torpie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:05
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/32; H04N1/327; H04N1/00095; H04N1/333; H04N1/33307; H04N1/33315; H04N1/33323
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
184 words
In a facsimile communication system, including a transmitter and receiver, said transmitter being adapted for line scanning graphic information which is to be transmitted and formal a signal for transmission to said receiver at which the graphic material is reproduced, said transmitter including first means for generating a composite signal comprising components transmitted in sequence for conditioning said receiver prior to receipt of a video signal, said first means further including second means for generating a carrier signal having a demodulation amplitude indicative of the scan rate of said transmitter, third means for generating a plurality of equalizing signals of a preselected amplitude for providing a preselected reference indicative of the distortions in transmission, fourth means connected to said second and third means for generating a plurality of periodically recurring blanking signals, said blanking signals gating said second and third means between adjacent line scans of said transmitter whereby selected ones of said components correspond to the demodulated amplitude of said carrier signal indicative of the scan line pitch at said transmitter and selected other ones of said components correspond to said equalizing signals.
Claim 2
Dependent Claim
184 words
In a facsimile communication system, including a transmitter and receiver, said transmitter being adapted for line scanning graphic information which is to be transmitted and formal a signal for transmission to said receiver at which the graphic material is reproduced, said transmitter including first means for generating a composite signal comprising components transmitted in sequence for conditioning said receiver prior to receipt of a video signal, said first means further including second means for generating a carrier signal having a demodulation amplitude indicative of the scan rate of said transmitter, third means for generating a plurality of equalizing signals of a preselected amplitude for providing a preselected reference indicative of the distortions in transmission, fourth means connected to said second and third means for generating a plurality of periodically recurring blanking signals, said blanking signals gating said second and third means between adjacent line scans of said transmitter whereby selected ones of said components correspond to the demodulated amplitude of said carrier signal indicative of the scan line pitch at said transmitter and selected other ones of said components correspond to said equalizing signals.
Claim 3
Dependent Claim
52 words
The communication system of claim 1 wherein: said receiver includes means responsive to said first means for providing a reverse signal which is transmitted to said transmitter for indicating to said transmitter that said receiver is ready to receive in response to the composite signal from said first means of said transmitter.
Claim 4
Dependent Claim
96 words
A facsimile communication system having a transmitting station and a receiving station, wherein: said transmitting station is adapted for line scanning graphic information from a first document to transmit a video signal indicative thereof to said receiving station, said receiving station being adapted for receiving said video signal and for line scanning a second document to form thereon a graphic image in accordance with information contained in said video signal; and said transmitting station further including means for generating a command signal for transmission to said receiving station for terminating the operation of said receiving station.
Claim 5
Dependent Claim
96 words
A facsimile communication system having a transmitting station and a receiving station, wherein: said transmitting station is adapted for line scanning graphic information from a first document to transmit a video signal indicative thereof to said receiving station, said receiving station being adapted for receiving said video signal and for line scanning a second document to form thereon a graphic image in accordance with information contained in said video signal; and said transmitting station further including means for generating a command signal for transmission to said receiving station for terminating the operation of said receiving station.
Claim 6
Dependent Claim
25 words
The communication system of claim 3 wherein said transceiver includes means for initiating the generation of said command signal by an operator of the transceiver.
Claim 7
Dependent Claim
30 words
The communication system of claim 3 wherein said transceiving apparatus includes means for automatically sensing a predetermined condition and for generating said command signal upon the occurrence of said condition.
Claim 8
Dependent Claim
153 words
In a facsimile communication system having a transmitting and receiving stations, said transmitting station adapted for line scanning graphic information which is to be transmitted to said receiving station and for forming a video signal therefrom, the improvement comprising: means included in said transmitting station for automatically feeding each of the documents in a stack of documents to a scanning station for transmission of the markings thereon to said receiving station, and means included in said transmitting station for generating a command signal for transmission to said receiving station indicative of the transmission of a last of the documents in said stack and means in said transmitting station for generating a periodically recurring blanking signal between successive line scans, segments of said blanking signal forming synchronizing signals and said command signal indicative of the transmission of a last document in said stack, said command signal being delayed with respect to said synchronizing signal.
Claim 9
Dependent Claim
153 words
In a facsimile communication system having a transmitting and receiving stations, said transmitting station adapted for line scanning graphic information which is to be transmitted to said receiving station and for forming a video signal therefrom, the improvement comprising: means included in said transmitting station for automatically feeding each of the documents in a stack of documents to a scanning station for transmission of the markings thereon to said receiving station, and means included in said transmitting station for generating a command signal for transmission to said receiving station indicative of the transmission of a last of the documents in said stack and means in said transmitting station for generating a periodically recurring blanking signal between successive line scans, segments of said blanking signal forming synchronizing signals and said command signal indicative of the transmission of a last document in said stack, said command signal being delayed with respect to said synchronizing signal.
References Cited (Backward Citations)
US2290229A
Cited
US2567307A
Cited
US3006999A
Cited
US3112361A
Cited
US3609241A
Cited
US3632867A
Cited
US3705953A
Cited
US3662096A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-20 | 1979-04-21 | 1979-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-20 | 1983-04-21 | 1983-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-20 | 1987-04-21 | 1987-10-21 | $7700.00 | Window Closed / Lapsed |