No title available

• US 3,126,513 A
• Filed:
• Issued:
• Status: Expired due to Term

• Current Assignee: N/A
• Original Assignee: N/A
• Time in Patent Office: Days
• US Class Current: 725/15
• CPC Class Codes: H04H 60/32 Arrangements for monitoring conditions of receiving stations, e.g. malfunction or breakdown of receiving stations
• CPC Class Codes: H04H 60/33 Arrangements for monitoring the users' behaviour or opinions
• CPC Class Codes: H04H 60/43 for identifying broadcast channels

Claims

1. AN INTERROGATING SYSTEM FOR INTERROGATING SELECTED ONES OF A PLURALITY OF TELEVISION RECEIVERS EACH ADAPTED TO RECEIVE AND REPRODUCE A PLURALITY OF DIFFERENT CHANNELS, EACH OF SAID CHANNELS HAVING A FREQUENCY DIFFERENT FROM THE OTHERS OF SAID CHANNELS, EACH OF SAID RECEIVERS RADIATING A PLURALITY OF DIFFERENT SPURIOUS SIGNALS, EACH OF SAID SPURIOUS SIGNALS HAVING A FREQUENCY DIFFERENT FROM THE OTHERS OF SAID SPURIOUS SIGNALS, THE FREQUENCY OF THE SPURIOUS SIGNAL RADIATED BY A RECEIVER CORRESPONDING TO THE FREQUENCY OF THE CHANNEL REPRODUCED BY SAID RECEIVER, SAID INTERROGATING SYSTEM COMPRISING, IN COMBINATION, A PLURALITY OF IDENTIFYING MEANS EACH POSITIONED IN OPERATIVE PROXIMITY WITH A DIFFERENT ONE OF SAID RECEIVERS FOR RECEIVING THE SPURIOUS SIGNALS AND FOR IDENTIFYING THE FREQUENCY OF THE SPURIOUS SIGNAL RADIATED BY THE PROXIMATE RECEIVER, EACH OF SAID IDENTIFYING MEANS COMPRISING A PLURALITY OF RF RESONANT CIRCUITS, EACH OF SAID RF RESONANT CIRCUITS BEING ADAPTED TO RESONATE AT A DIFFERENT FREQUENCY OF SAID SPURIOUS SIGNALS, A PLURALITY OF INDICATING CIRCUITS EACH ASSOCIATED WITH A DIFFERENT RF RESONANT CIRCUIT, EACH OF SAID INDICATING CIRCUITS BEING ADAPTED TO INDICATE ENERGIZATION THEREOF, AND ACTIVATING MEANS CONTROLLED BY SAID RF RESONANT CIRCUITS FOR PERMITTING THE ENERGIZATION OF THE INDICATING CIRCUIT ASSOCIATED WITH THE RF RESONANT CIRCUIT WHICH IS RESONATING;

INTERROGATING MEANS COUPLED TO THE INDICATING CIRCUITS OF SAID IDENTIFYING MEANS FOR ENERGIZING IN SELECTED ONES OF SAID IDENTIFYING MEANS THE INDICATING CIRCUIT ACTIVATED BY THE RESONATING RF RESONANT CIRCUIT OF EACH OF SAID SELECTED ONES OF SAID IDENTIFYING MEANS TO INDICATE THE FREQUENCY OF THE SPURIOUS SIGNAL RECEIVED BY SAID SELECTED ONES OF SAID IDENTIFYING MEANS THEREBY DETERMINING THE CHANNEL RECEIVED AND REPRODUCED BY EACH OF THE RECEIVERS PROXIMATE TO SAID SELECTED ONES OF SAID IDENTIFYING MEANS;

SWITCHBOARD MEANS CONNECTED TO SAID INDICATING CIRCUITS FOR SELECTING AND PERMITTING ENERGIZATION OF DETERMINED ONES OF SAID IDENTIFYING MEANS AND FOR INDICATING EACH OF THE RECEIVERS PROXIMATE TO SAID SELECTED ONES OF SAID IDENTIFYING MEANS AND THE CHANNEL RECEIVED AND REPRODUCED BY EACH OF SAID LAST-MENTIONED RECEIVERS;

ELECTRICALLY CONDUCTIVE WIRE MEANS CONNECTED FROM SAID SWITCHBOARD MEANS TO THE PROXIMITY OF EACH OF SAID RECEIVERS;

AND A LINE SWITCHING UNIT FOR EACH OF SAID PLURALITY OF RECEIVERS, EACH SAID LINE SWITCHING UNIT COMPRISING A PLURALITY OF SWITCHING BRANCHES CONNECTED BETWEEN SAID CONDUCTIVE WIRE MEANS AND A POINT AT GROUND POTENTIAL AND EACH BEING ADAPTED TO PROVIDE A CONDUCTIVE PATH TO GROUND WHICH IS ELECTRICALLY DISTINGUISHABLE FROM THE CONDUCTIVE PATH TO GROUND PROVIDED BY THE OTHERS OF SAID SWITCHING BRANCHES.