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 correcting 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.
A facsimile communication system having a transmitting station and a receiving station, said transmitting station adapted for line scanning graphic information which is to be transmitted to said receiving station and forming a video signal for transmission, said receiving station adapted for receiving said video signal and for line scanning a record medium for forming thereon a graphic image in accordance with information contained in the video signal and conforming to the image at said transmitting station, said receiving station including means for transporting a surface upon which an image is to be reproduced in a direction which is substantially perpendicular to the direction of motion of a scanning means, said transmitted signal including a synchronizing signal component for periodically synchronizing a scanning means at the receiving station with a scanning means at the transmitting station, said transmitting station including means for modulating said synchronizing signal to have a demodulated amplitude for indicating the rate at which said surface is to be transported, said transporting means being responsive to said demodulated amplitude for transporting said surface at the indicated rate.
Claim 2
Dependent Claim
180 words
A facsimile communication system having a transmitting station and a receiving station, said transmitting station adapted for line scanning graphic information which is to be transmitted to said receiving station and forming a video signal for transmission, said receiving station adapted for receiving said video signal and for line scanning a record medium for forming thereon a graphic image in accordance with information contained in the video signal and conforming to the image at said transmitting station, said receiving station including means for transporting a surface upon which an image is to be reproduced in a direction which is substantially perpendicular to the direction of motion of a scanning means, said transmitted signal including a synchronizing signal component for periodically synchronizing a scanning means at the receiving station with a scanning means at the transmitting station, said transmitting station including means for modulating said synchronizing signal to have a demodulated amplitude for indicating the rate at which said surface is to be transported, said transporting means being responsive to said demodulated amplitude for transporting said surface at the indicated rate.