Patents by Inventor Donald W. Lewis

Donald W. Lewis 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).

  • System for encoding and decoding amplitude modulated signals
    Patent number: 4002825
    Abstract: A system for encoding or scrambling an amplitude modulated signal, such as the video component of a standard television signal, and for subsequently decoding or unscrambling the signal so as to restore the original message content. Encoding is achieved by shifting the phase of the carrier component relative to the phase of the side-bands by an amount sufficient to significantly distort the modulation envelope. Decoding is achieved by summing the received signal with a corrective signal having a frequency, amplitude, and phase which effectively cancels the phase-shifted carrier component and substitutes therefor a carrier component of phase and amplitude which will render intelligible the modulation envelope.
    Type: Grant
    Filed: July 25, 1973
    Date of Patent: January 11, 1977
    Assignee: Summit Systems, Inc.
    Inventor: Donald W. Lewis
  • Crayon display unit
    Patent number: D250927
    Type: Grant
    Filed: May 2, 1977
    Date of Patent: January 30, 1979
    Inventor: Donald W. Lewis