Patents by Inventor Pat Keegan

Pat Keegan 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).

  • Modulated sound reading system
    Patent number: 4085296
    Abstract: A motion picture sound reading system employing a light emitting diode source which is modulated at a carrier frequency several times higher than the highest sound-track frequency for exciting the optical sound track and a carrier-demodulation signal processing system for deriving a high-quality audio signal from the photoelectrically detected optical sound track.
    Type: Grant
    Filed: December 19, 1975
    Date of Patent: April 18, 1978
    Assignee: International Audio Visual, Inc.
    Inventor: Pat Keegan