Patent · US Expired

Loudspeaking teleconferencing circuit

US4008376A · kind A · utility

48Cited by
8References
19Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 17, 1975
Grant dateFeb 15, 1977
Priority date
Expiry dateOct 17, 1995

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04M9/08
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

A loudspeaking teleconferencing circuit serving a plurality of remote conference room locations includes a plurality of speakerphone sets at each conference room location and a communication network connected to an incoming and an outgoing terminal at each location. The transmit channel of each set couples a microphone to the outgoing terminal; the receive channel of each set couples the incoming terminal to a loudspeaking device; and a control circuit selectively activates one of the set transmit and receive channels at a time responsive to speech energy present on the transmit and receive channels. Each set control circuit is operative independently of the control circuits of the other sets; and the outputs of all active transmit channels are combined and applied through the location outgoing terminal to the communication network. The communication path is adapted to transmit the conference room combined output from the conference room location outgoing terminal to only the other remote location incoming terminals.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.