Patents by Inventor Trevor Dragwidge

Trevor Dragwidge 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).

  • Telephones with talker sidetone
    Patent number: 5946391
    Abstract: A telephone, particularly a portable handset operable in a digital radio telephone system, has a sidetone gain circuit 28 which applies one of two levels of gain G1 G2 dependent on whether a detector 30 detects a high magnitude of input signal 14 corresponding to speech or a low level of input signal 14 corresponding to an idle condition. With varying magnitude of input signal 14, the gain switches between G1 and G2 dependent on two thresholds T1 and T2 of the input signal, the relationship including hysteresis to prevent unduly rapid switching.
    Type: Grant
    Filed: November 22, 1996
    Date of Patent: August 31, 1999
    Assignee: Nokia Mobile Phones Limited
    Inventors: Trevor Dragwidge, Richard George, Adrian Kennard, Richard Williams