Patents by Inventor Robert C. True

Robert C. True has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Voice-switched telephone circuit with center idle state
    Patent number: 4700382
    Abstract: A voice-switched telephone circuit with center idle state improves bi-dirional gain control in loudspeaking telephones and thereby enhances the natural quality of interactive conversation. The voice-switched telephone includes: a transmit channel having a microphone and a three-state amplifier; a receiver channel having a three-state amplifier and a loudspeaker; and a hybrid circuit interconnecting the transmit and receive channels to a two-wire telephone line. The present invention is characterized by independent signal level detecting circuits for the transmit and receive channels. When the magnitude of the signal energy in the transmit channel exceeds a predetermined threshold, the transmit channel amplification is increased and the receive channel amplification is decreased by fixed equal amounts.
    Type: Grant
    Filed: March 3, 1986
    Date of Patent: October 13, 1987
    Assignee: American Telephone and Telegraph Company, AT&T Information Systems, Inc.
    Inventors: Donald R. Means, Robert C. True, Noble E. Wickliff