Patents by Inventor Mary V. Hoffman

Mary V. Hoffman 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: 4847533
    Abstract: A low pressure mercury discharge fluorescent lamp is disclosed utilizing a particular phosphor blend deposited on a calcium haloapatite phosphor base layer to achieve white color lamp illumination efficiently with improved color rendition. The surface phosphor layer is a blended mixture of a first phosphor which is divalent europium barium and/or strontium magnesium aluminate having a hexagonal crystalline structure and which further includes coactivation by divalent manganese ion sufficient to produce substantial green color emission with a second phosphor which is trivalent europium activated rare earth oxide having a rare earth ion selected from yttrium, gadolinium and lutetium, including mixtures of these rare earth ions. The underlying calcium haloapatite layer also exhibits emission at approximately the same color point as achieved with the surface phosphor layer.
    Type: Grant
    Filed: November 30, 1987
    Date of Patent: July 11, 1989
    Assignee: General Electric Company
    Inventor: Mary V. Hoffman
  • Patent number: 4806824
    Abstract: A fluorescent lamp utilizing a dual layer phosphor coating is disclosed and with the base layer employing a calcium halophosphate phosphor which has been modified to provide efficient lumen output at a substantially reduced coating weight. The top phosphor layer in said coating comprises a blend of narrow bandwith emitting phosphors at various coating weights primarily to improve the color rendering capability of these lamps.
    Type: Grant
    Filed: March 2, 1988
    Date of Patent: February 21, 1989
    Assignee: General Electric Company
    Inventors: John Paynter, George R. Gillooly, Thomas F. Soules, Mary V. Hoffman
  • Patent number: 4751426
    Abstract: A fluorescent lamp utilizing a dual layer phosphor coating is disclosed wherein the base layer utilizes a first phosphor mixture and the top phosphor layer in said coating comprises a blend of narrow bandwith emitting phosphors to improve the color rendering capability of these lamps.
    Type: Grant
    Filed: November 10, 1986
    Date of Patent: June 14, 1988
    Assignee: General Electric Company
    Inventors: Mary V. Hoffman, Gustino J. Lanese
  • Patent number: 4645969
    Abstract: A skin tanning lamp construction of a fluorescent type utilizing a combination of two different phosphors to provide efficient artificial skin tanning along with improved color rendition. The particular phosphor combination can be utilized as a blended mixture having a sufficient level of a phosphor constituent to impart some visible radiation in the red color region to the composite lamp emission.
    Type: Grant
    Filed: August 1, 1980
    Date of Patent: February 24, 1987
    Assignee: General Electric Company
    Inventor: Mary V. Hoffman
  • Patent number: 4623816
    Abstract: A fluorescent lamp utilizing a dual phosphor layer coating is disclosed producing efficient white color illumination at a lower cost than conventional phosphor coatings of the same type. The base layer in the phosphor coating comprises a conventional calcium haloapatite phosphor whereas the top phosphor layer comprises a tri-phosphor blend including a lanthanum cerium orthophosphate phosphor activated with terbium ion as the green color component along with a modified europium-activated yttrium oxide phosphor as the red color component.
    Type: Grant
    Filed: April 22, 1985
    Date of Patent: November 18, 1986
    Assignee: General Electric Company
    Inventors: Mary V. Hoffman, John Paynter
  • Patent number: 4034257
    Abstract: Color correction is provided in a high-pressure mercury vapor discharge lamp with a particular combination of two different phosphor materials producing an efficient composite emission. A blend of said phospor materials can improve color rendition without effecting any significant reduction in the lamp lumen output.
    Type: Grant
    Filed: June 5, 1975
    Date of Patent: July 5, 1977
    Assignee: General Electric Company
    Inventor: Mary V. Hoffman