Patents by Inventor Wim Van Den Hoek

Wim Van Den Hoek 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).

  • Gas discharge lamp comprising an oxide emitter electrode
    Patent number: 6680574
    Abstract: A gas discharge lamp comprising an electrode including a carrier of an electrode metal, selected from the group formed by tungsten and tungsten-containing alloys, and a first coating of a first electron-emitting material, which material comprises an alkaline earth metal oxide, selected from the group formed by calcium oxide, strontium oxide and barium oxide, and a rare earth metal oxide, selected from the group formed by scandium oxide, yttrium oxide and europium oxide, in a quantity a that ranges from 0.1 to 10 wt. % by weight, is characterized by a longer service life, a higher resistance to poisoning and a robust manner of coping with a rapid succession of switching operations, as well as a short ignition stage.
    Type: Grant
    Filed: November 22, 2000
    Date of Patent: January 20, 2004
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Georg Gaertner, Wim Van Den Hoek