Patents by Inventor Georges Lavaud

Georges Lavaud 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).

  • Dimming method and device for fluorescent lamps used for backlighting of liquid crystal screens
    Patent number: 5105127
    Abstract: A dimming device, with a brightness dimming ratio of 1 to 1000, for a fluorescent lamp used for the backlighting of a liquid crystal screen comprises a periodic signal generator for delivering rectangular pulses with an adjustable duty cycle. The pulses are synchronized with the image synchronizing signal of the liquid crystal screen. An alternating voltage generator provides power to the lamp only during the pulses. The decrease in tube efficiency for very short pulses allows the required dimming intensity to be achieved without image flickering.
    Type: Grant
    Filed: June 21, 1990
    Date of Patent: April 14, 1992
    Assignee: Thomson-CSF
    Inventors: Georges Lavaud, Jean P. Bouron