Multiplex communication system for transmitting television and facsimile signals

Claim 2

An electrical communication system for transmitting a principal signal having periodically repeating idle intervals, and a continuous additional signal through a communication channel having a frequency bandwidth only for said principal signal, said system comprising a source of sampling pulses having a repetition frequency equal to an integral multiple greater than one of the repetition frequency of said idle intervals, means for sampling, quantizing and storing in digital form said additional signal in response to said sampling pulses; means for reading out the stored quantized signal within said idle intervals in said principal signal in response to a second pulse train appearing within said idle interval, the number of pulses in said second pulse train in each of said idle intervals being equal in number to the number of pulses in said first pulse train appearing within a repetition period of said idle intervals; and means for adding the read out pulses in timed relationship to said principal signal.

Claim 3

The communication system of claim 1, further comprising means for pulse-width modulating said additional signal in response to said read out pulses.

Claim 4

In combination with the electrical communication system of claim 1, a signal receiving apparatus comprising means for reproducing said principal signal having said periodic idle intervals, means for separating from said principal signal said additional signal contained therein in a time-compressed fashion in said idle intervals, and means for time-expanding said separated additional signal to reproduce said additional signal.

Claim 5

The combination of claim 3, in which said receiving apparatus further comprises means coupled to said separating means for pulse-width demodulating said time-compressed signals.

Claim 6

The electrical communication system of claim 3, in which said time-expanding means is a shift register.

Claim 7

The communication system of claim 1, in which said principal signal is a television signal and at said additional signal a facsimile signal.

Claim 8

The communication system of claim 6, in which the repetition rate of said sampling pulses is an integral multiple of the repetition frequency of the blanking signal of said television signal.

Claim 9

The communication system of claim 1, in which said storing means is a shift register.

Claim 10

An electrical communication system for transmitting a television signal and a facsimile signal through a communication channel having a frequency bandwidth only for said television signal, said system comprising a shift register for digitally storing said facsimile signal in response to first shift pulses having a repetition frequency of an integral multiple greater than one of the repetition frequency of the blanking signal of said television signal, said digital storing of said facsimile signal resulting in the simultaneous sampling and quantizing of said facsimile signal, means for reading out the stored pulses from said shift register within the blanking period of said television signal in response to second shift pulses, the number of said second shift pulseS included within one blanking period of said television signal being equal to the number of said first shift pulses included within one repetition period of said blanking signal, means for adding the read out pulses to said television signal, and means for transmitting said facsimile signal superimposed on said television signal.

Claim 11

An electrical communication system for transmitting a television signal and a facsimile signal through a communication channel having a frequency bandwidth only for said television signal, said system comprising a shift register for digitally storing said facsimile signal in response to first shift pulses having a repetition frequency of an integral multiple greater than one of the repetition frequency of the blanking signal of said television signal, said digital storing of said facsimile signal resulting in the simultaneous sampling and quantizing of said facsimile signal, means for reading out the stored pulses from said shift register within the blanking period of said television signal in response to second shift pulses, the number of said second shift pulseS included within one blanking period of said television signal being equal to the number of said first shift pulses included within one repetition period of said blanking signal, means for adding the read out pulses to said television signal, and means for transmitting said facsimile signal superimposed on said television signal.

Claim 12

In combination with the communication system of claim 9, a signal receiving apparatus comprising means for reproducing said television signal containing time-compressed pulses produced from said facsimile signal in the blanking period of said television signal, means for separating said time-compressed pulses from said television signal, a second shift register, means for storing said time-compressed pulses in said second shift register during said blanking period in response to third shift pulses, means for reading out the stored pulses from said second shift register in response to fourth shift pulses, the number of said fourth shift pulses included within one repetition period of said blanking signal being equal to the number of said third shift pulses included within one of said blanking periods, means for reproducing said facsimile signal from the read out signals, and means for producing a facsimile picture in response to said reproduced facsimile signal.