Patents by Inventor Marinus G. A. Tak

Marinus G. A. Tak 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).

  • Bivalent europium-activated barium aluminate phosphor and low mercury vapor discharge lamp provided with a phosphor
    Patent number: 4590405
    Abstract: A luminescent screen provided with a luminescent layer (4) disposed on a support (1) and containing an alkaline earth metal aluminate activated by bivalent europium. The alkaline earth metal is barium which may be replaced up to 25 mol. % by strontium. The aluminate has a crystal structure, the X-ray powder diagram of which corresponds or substantially corresponds to the diagram given in Table I of the description, while the ratio of alkaline earth metal to aluminium in the aluminate has a value of 1:5 to 1:10. An advantageous use of such a luminescent screen is found in low-pressure mercury vapor discharge lamps.
    Type: Grant
    Filed: July 1, 1985
    Date of Patent: May 20, 1986
    Assignee: U.S. Philips Corporation
    Inventors: Gerardus P. F. Hoeks, Marinus G. A. Tak
  • Fluorescent discharge lamp having luminescent material of a specified grain size
    Patent number: 4166234
    Abstract: A low-pressure mercury vapor discharge lamp provided with a luminescent Eu-activated rare earth oxide, a luminescent aluminate with hexagonal crystal structure activated by Ce or by Ce and Tb, or a luminescent aluminate with hexagonal crystal structure activated by Eu or by Eu and Mn. Not more than 5% by weight of the luminescent material has a grain size smaller than 1 .mu.m and the maximum of the grain size distribution curve is located in the range from 2 to 8 .mu.m.
    Type: Grant
    Filed: February 28, 1978
    Date of Patent: August 28, 1979
    Assignee: U.S. Philips Corporation
    Inventors: Marinus G. A. Tak, Robert C. Peters
  • Luminescent aluminates and mercury vapor discharge lamp containing the same
    Patent number: 4150321
    Abstract: Luminescent aluminate with magnetoplumbite crystal structure, activated by cerium, by cerium and terbium or by cerium and manganese. The aluminate comprises at least one of the elements B, Si and P in a quantity of 0.001 to 0.20 mole per mole of aluminate which results in improved properties of luminescence. These aluminates are preferably used in low-pressure mercury vapor discharge lamps.
    Type: Grant
    Filed: January 13, 1978
    Date of Patent: April 17, 1979
    Assignee: U.S. Philips Corporation
    Inventors: Cornelis W. A. Schetters, Marinus G. A. Tak, Abraham Sonneveld