Patents by Inventor Eduardus Johannes Cottaar

Eduardus Johannes Cottaar 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).

  • Electric lamp having optical interference filter of alternating layers of SiO.sub.2 and Nb.sub.2 O.sub.5 --Ta.sub.2 O.sub.5
    Patent number: 6049169
    Abstract: Thin film interference filter consists of alternating first and second layers, the first layers being silica, the second layers being a mixture of tantala and niobia. The filter may be used on a high temperature lamp in an inert atmosphere if the niobia in the mixture is less than 40% by weight. For higher percentages a partial pressure of oxygen has been found to prevent blackening of the layers.
    Type: Grant
    Filed: April 8, 1998
    Date of Patent: April 11, 2000
    Assignee: Philips Electronics North America Corp.
    Inventors: Ray G. Gibson, Eduardus Johannes Cottaar, Wolfgang Doetter