×

TELEMETRY SYSTEMS

  • US 3,587,077 A
  • Filed: 08/21/1968
  • Issued: 06/22/1971
  • Est. Priority Date: 08/23/1967
  • Status: Expired due to Term
First Claim
Patent Images

1. An Audience Survey System comprising a central control and remote signalling units connected with household wave signal receivers tuned to programs, a transmitter at the central control, means for activating the transmitter during a first part of every time slot in a repetitive cycle of time slots to transmit an interrogation signal composed of a carrier modulated to identify in each time slot a respective one of the remote signalling units, means at each remote signalling unit to receive the interrogation signals and to respond thereto with a reply signal during a second part of the respective time slot when that signalling unit corresponds with the modulated identification conveyed by the interrogation signal, a transmitter at each of the remote signalling units,

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×