Code signal generator

Claim 1

A CODE SIGNAL GENERATOR FOR USE IN SUBSCRIPTION TELEVISION SYSTEM, INCLUDING A SOURCE OF LINE-SYNCHRONIZING PULSES OCCURRING DURING LINE-RETRACE INTERVALS, FOR PRODUCING A CODE SIGNAL TO ESTABLISH SAID TELEVISION SYSTEM IN A SELECTED ONE OF SEVERAL POSSIBLE OPERATING STATES AS DETERMINED BY THE CODE PATTERN OF SAID CODE SIGNAL, SAID GENERATOR COMPRISING: A SOURCE OF AUDIO SIGNAL; A PLURALITY OF COUNTING MECHANISMS; MEANS COUPLED TO SAID SOURCE OF LINE-SYNCHRONIZING PULSES FOR DIFFERENTLY CYCLICALLY ACTUATING SAID COUNTING MECHANISM TO DEVELOP SEVERAL DIFFERENT SQUARE WAVE SHAPED CONTROL SIGNALS HAVING THE SAME COMMON FREQUENCY AND EACH HAVING PERIODICALLY RECURRING AMPLITUDE VARIATIONS EXHIBITING A UNIQUE PHASE CONDITION WITH RESPECT TO THE AMPLITUDE VARIATIONS OF THE OTHER CONTROL SIGNALS TO REPRESENT AN ASSIGNED ONE OF SAID SEVERAL OPERATING STATES OF SAID SYSTEM SO THAT THE CORRESPONDING AMPLITUDE VARIATIONS OF ALL OF SAID CONTROL SIGNALS OCCUR DURING DIFFERENT LINE-RETRACE INTERVALS; MEANS FOR SIMULTANEOUSLY UTILIZING SAID CONTROL SIGNAL TO PHASE INVERT SAID AUDIO SIGNAL TO DEVELOP SEVERAL DIFFERENTLY CODED AUDIO SIGNALS EACH OF WHICH IS CODED IN ACCORDANCE WITH A RESPECTIVE ONE OF SAID OPERATING STATES, IN THAT EACH EXHIBITS PHASE INVERSIONS OCCURING DURING DIFFERENT LINERETRACE INTERVALS, AND EACH OF WHICH CONTAINS A UNIDIRECTIONAL COMPONENTS HAVING A UNIQUE PREDETERMINED MAGNITUDE-POLARITY CONDITION; MEANS FOR SELECTING THE ONE OF SAID CODED AUDIO SIGNALS IN WHICH SAID UNIDIRECTIONAL COMPONENT IS OF A MAGNITUDE CLOSEST TO A PREDETERMINED REFERENCE MAGNITUDE BUT OF OPPOSITE POLARITY WITH RESPECT THERETO AND FOR PROVIDING A CONTROL EFFECT REPRESENTING THE SELECTED CODED AUDIO SIGNAL; AND MEANS FOR UTILIZING SAID CONTROL EFFECT TO DEVELOP A CODE SIGNAL HAVING A CODE PATTERN REPRESENTING THE OPERATING STATE ACCORDING TO WHICH THE SELECTED CODED AUDIO SIGNAL IS CODED.