Patents by Inventor Richard S. Grinnell

Richard S. Grinnell 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).

  • Patent number: 6173059
    Abstract: A telephone system includes two or more cardioid microphones held together and directed outwardly from a central point. Mixing circuitry and control circuitry combines and analyzes signals from the microphones and selects the signal from one of the microphones or from one of one or more predetermined combinations of microphone signals in order to track a speaker as the speaker moves about a room or as various speakers situated about the room speak then fall silent. Visual indicators, in the form of light emitting diodes (LEDs) are evenly spaced around the perimeter of a circle concentric with the microphone array. Mixing circuitry produces ten combination signals, A+B, A+C, B+C, A+B+C, A−B, B−C, A−C, A−0.5(B+C), B−0.5(A+C), and C−0.5(B+A), with the “listening beam” formed by combinations, such as A−0.
    Type: Grant
    Filed: April 24, 1998
    Date of Patent: January 9, 2001
    Assignee: Gentner Communications Corporation
    Inventors: Jixiong Huang, Richard S. Grinnell