Patents by Inventor Martin F. C. Willemsen

Martin F. C. Willemsen 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: 6590342
    Abstract: The electric lamp has a ceramic lamp vessel (1) having a filling of rare gas and metal halide. Current conductors (2, 3) which support electrodes (4, 5) inside the discharge vessel (1) enter the discharge vessel (1) in a gastight manner through a ceramic sealing compound (6). At least one of the current conductors (2, 3) has inside the lamp vessel (1) a first, halogen-resistant part (21, 31) which is selected from tungsten silicide, molybdenum aluminide, molybdenum boride, pentamolybdenum trisilicide and combinations of at least two of these intermetallic compounds. These compounds have a coefficient of thermal expansion which corresponds to that of the discharge vessel (1). It is thereby prevented that the discharge vessel starts leaking if the ceramic sealing compound (6) extends beyond the first part (21, 31).
    Type: Grant
    Filed: December 2, 1999
    Date of Patent: July 8, 2003
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Elisabeth Onnekes-Van Der Voort, Hendrik Dreuning, Franciscus H. Van Lierop, Peter A. Seinen, Martin F. C. Willemsen, Mark Bolech
  • Patent number: 5530317
    Abstract: The high-pressure metal halide discharge lamp has tungsten electrodes in a light-transmitting lamp vessel which is closed in a vacuumtight manner. The electrodes comprise an emitter which is distributed throughout their mass and is formed by a first oxide chosen from hafnium oxide and zirconium oxide and by a second oxide chosen from yttrium oxide, lanthanum oxide, cerium oxide and scandium oxide, and are substantially free from thorium oxide. The lamp retains its initial light output to a high degree throughout its life.
    Type: Grant
    Filed: October 7, 1994
    Date of Patent: June 25, 1996
    Assignee: U.S. Philips Corporation
    Inventors: Martin F. C. Willemsen, Paul D. Goodell, Willem Van Erk, Hui-Meng Chow