Patents by Inventor Wilem Jacobus Van Den Hoek

Wilem Jacobus 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: 6674240
    Abstract: A gas discharge lamp, in particular a low-pressure gas discharge lamp, comprising an electrode including a carrier of an electrode metal and a first electrode coating of an electron-emitting material, which material comprises a metal powder preparation of a powder of a reducing metal selected from the group formed by aluminum, silicon, titanium, zirconium, hafnium, tantalum, molybdenum, tungsten and the alloys thereof, which metal powder preparation is provided with a powder coating containing a noble metal selected from the group formed by rhenium, cobalt, nickel, ruthenium, palladium, rhodium, iridium and platinum, and the alloys thereof, and said material comprising at least one alkaline earth metal oxide selected from the group formed by calcium oxide, strontium oxide and barium oxide, is characterized by a uniform emission current and a long service life.
    Type: Grant
    Filed: November 20, 2000
    Date of Patent: January 6, 2004
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Georg Gärtner, Wilem Jacobus Van Den Hoek