Television system having common transmission line for power,video signals,and command signals

Claim 1

A COMMUNICATIONS SYSTEM COMPRISING IN COMBINATION: (A) A SUPPLY SECTION INCLUDING: (A) CONNECTION CABLE MEANS HAVING A PAIR OF ELECTRICALLY CONDUCTIVE ELEMENTS; (B) MEANS FOR SUPPLYING DC POWER TO SAID CONNECTION CABLE MEANS; (C) MEANS FOR SUPPLYING TELEVISION SIGNALS TO SAID CONNECTION CABLE MEANS; (B) A PLURALITY OF REMOTE STATIONS EACH INCLUDING: (A) A TELEVISION SET OPERABLE WITH SAID DC POWER TO PRESENT IN A FIRST MODE OF OPERATION BOTH VISUAL AND AUDIO INFORMATION IN RESPONSE TO SAID TELEVISION SIGNALS, SAID TELEVISION SET HAVING AUDIO TRANSDUCER MEANS AND AN AUDIO SIGNAL HANDLING NETWORK ADAPTED TO NORMALLY OPERATE IN SAID FIRST MODE TO DELIVER AN AUDIBLE SIGNAL THROUGH SAID AUDIO TRANSDUCER MEANS; AND (B) MEANS RESPONSIVE TO A PREDETERMINED CODED SIGNAL ON SAID CABLE MEANS FOR CONVERTING SAID AUTIO SIGNAL HANDLING NETWORK FROM SAID FIRST MODE OF OPERATION TO A SECOND MODE OF OPERATION IN WHICH SAID AUDIO SIGNAL HANDLING NETWORK RECEIVES AND AUDIBLY PRODUCES THROUGH SAID AUDIO TRANSDUCER MEANS COMMAND INFORMATION; AND (C) MEANS FOR RECEIVING COMMAND INFORMATION SIGNALS FROM SAID CONNECTION CABLE MEANS AND FEEDING COMMAND SIGNAL INFORMATION TO SAID AUDIO SIGNAL HANDLING NETWORK; (C) A MASTER STATION INCLUDING: (A) SECOND AUDIO TRANSDUCER MEANS; (B) CODE SIGNAL GENERATING MEANS FOR PRODUCING ANY ONE OF A PLURALITY OF PREDETERMINED CODE SIGNALS AND DELIVERING THE SAME TO SAID CONNECTION CABLE MEANS; AND, (C) MEANS FOR SUPPLYING SIGNALS GENERATED IN SAID SECOND AUDIO TRANSDUCER MEANS TO SAID CONNECTION CABLE MEANS AS COMMAND SIGNALS.