Patents by Inventor John Alfred Clarke

John Alfred Clarke 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: 6840646
    Abstract: A back lighting system for illuminating a display device comprises a light-emitting panel (1) and a light source (6) for coupling light into the light-emitting panel. The light source comprises a low-pressure discharge lamp (6; 7). The light source additionally comprises a plurality of LEDs (8, 8?, . . . ; 9, 9?, . . . ) for selectively setting the color temperature of the light emitted by the light source. Preferably, the LEDs increase the color temperature of the light emitted by the light source. Preferably, the light emitted by the back lighting system ranges from 6,000 to 10,500 K. Preferably, the LEDs are blue light emitting LEDs, each preferably having a luminous flux of at least 5 lm. The color point of an image to be displayed on a display screen of the display device is set by the back lighting system, thus enabling an optimum contrast to be achieved for the image to be displayed by the display device.
    Type: Grant
    Filed: February 15, 2002
    Date of Patent: January 11, 2005
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Hugo Johan Cornelissen, Horst Greiner, John Alfred Clarke
  • Publication number: 20020126478
    Abstract: A back lighting system for illuminating a display device comprises a light-emitting panel (1) and a light source (6) for coupling light into the light-emitting panel (1). The light source comprises a low-pressure discharge lamp (6; 7). According to the invention, the light source additionally comprises a plurality of LEDs (8, 8′, . . . ; 9, 9′, . . . ) for selectively setting the color temperature of the light emitted by the light source. Preferably, the LEDs (8, 8′, . . . ; 9, 9′, . . . ) increase the color temperature of the light emitted by the light source. Preferably, the light emitted by the back lighting system ranges from 6,000 to 10,500 K. Preferably, the LEDs (8, 8′, . . . ; 9, 9′, . . . ) are blue light emitting LEDs, each preferably having a luminous flux of at least 5 lm.
    Type: Application
    Filed: February 15, 2002
    Publication date: September 12, 2002
    Inventors: Hugo Johan Cornelissen, Horst Greiner, John Alfred Clarke