Patents by Inventor Johannes J. M. Buck

Johannes J. M. Buck 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).

  • Electrodeless low-pressure mercury vapour discharge lamp employing a high frequency magnetic field having a layer of aluminum oxide particles
    Patent number: 6051922
    Abstract: An electrodeless low-pressure mercury vapor discharge lamp includes a discharge vessel that gas-tightly encloses a discharge-space that is provided with a fill of mercury and a noble gas. The discharge vessel has a light-transmitting enveloping part and further has a sunken part in which a coil for generating a high-frequency magnetic field is arranged. At least a portion of a surface of the discharge vessel turned towards the discharge space is provided with a luminescent layer. At least a portion of the luminescent layer bears a protective layer of aluminum oxide particles with a covering weight of 10 to 500 .mu.g/cm.sup.2. The protective layer provides for a lower mercury consumption and/or a reduction in the change of colour point during lamp life.
    Type: Grant
    Filed: February 3, 1997
    Date of Patent: April 18, 2000
    Assignee: U.S. Philips Corporation
    Inventors: Jakob Schlejen, Johannes J. M. Buck, Christianus J. Roozekrans