Patents by Inventor Shellie K. Northrop

Shellie K. Northrop 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: 7535176
    Abstract: Blue-emitting phosphors for use with plasma display panels (PDP) or other vacuum ultraviolet-excited (VUV) devices are provided. These blue-emitting phosphors and mixtures thereof include at least a europium-activated calcium-substituted barium hexa-aluminate (CBAL) phosphor. Preferably, the CBAL phosphor has a composition which may be represented by the formula: Ba1.29-x-yCaxEuyAl12O19.29, wherein 0<x<0.25 and 0.01<y<0.20. These blue-emitting phosphors exhibit improved degradation characteristics, including reduced color shift and increased intensity maintenance, under conditions found in VUV-excited devices.
    Type: Grant
    Filed: May 13, 2004
    Date of Patent: May 19, 2009
    Assignee: Osram Sylvania Inc.
    Inventors: Gregory A. Marking, Chung-Nin Chau, Thomas M. Snyder, Shellie K. Northrop, Chen Wen Fan
  • Patent number: 7288216
    Abstract: An electroluminescent phosphor powder includes copper-activated zinc sulfide particles that have a size distribution with a D50 value of no more than 10 ?m, where no more than 25% of the particles have a size greater than about 15 ?m and/or a 24-hr brightness of at least 15 footlamberts. These particles are made by a method that includes first firing copper-doped zinc sulfide mixed with zinc oxide, sulfur and a chloride-containing flux, rapidly cooling the mixture to below 100° C., and then mulling and second firing the mixture to provide a powder. The powder can then be elutriated to provide the electroluminescent powder with a narrow particle size distribution (more than 90% between about 5 and 15 ?m). The elutriating step can be avoided (albeit with a slightly wider size distribution) by more tightly controlling the first firing temperature.
    Type: Grant
    Filed: March 30, 2005
    Date of Patent: October 30, 2007
    Assignee: Osram Sylvania Inc.
    Inventors: Xianzhong Chen, Shellie K. Northrop
  • Patent number: 6555021
    Abstract: A process for improving the half-life of ZnS:Cu,Cl electroluminescent phosphor wherein the improvement comprises firing a previously first fired material comprised of ZnS:Cu,Cl with a quantity of MgSO4.7H2O to form a second fired material. The quantity is from 0.015 to 0.15 mole of MgSO4.7H2O/mole of ZnS.
    Type: Grant
    Filed: September 1, 2001
    Date of Patent: April 29, 2003
    Assignee: Osram Sylvania Inc.
    Inventors: Butchi Reddy Vaddi, Shellie K. Northrop
  • Publication number: 20030068438
    Abstract: The half-life of coated electroluminescent phosphors is improved by annealing the coated phosphors in air for 30 minutes at 250° C.
    Type: Application
    Filed: September 29, 2001
    Publication date: April 10, 2003
    Inventors: Butchi Reddy Vaddi, Shellie K. Northrop
  • Publication number: 20030047715
    Abstract: A process for improving the half-life of ZnS:Cu,Cl electroluminescent phosphor wherein the improvement comprises firing a previously first fired material comprised of ZnS:Cu,Cl with a quantity of MgSO4.7H2O to form a second fired material. The quantity is from 0.015 to 0.15 mole of MgSO4.7H2O/mole of ZnS.
    Type: Application
    Filed: September 1, 2001
    Publication date: March 13, 2003
    Inventors: Butchi Reddy Vaddi, Shellie K. Northrop
  • Patent number: 6387299
    Abstract: An electroluminescent phosphor with an increased efficiency is created by blending a chloride flux, a copper source and a zinc sulfide to form a mixture and then heating the mixture for a period of time, cooling the mixture, and washing it with de-ionized water. The mixture is dried and milled to form cubic ZnS from hexagonal ZnS, forming a beginning uncoated ZnS:Cu,Cl electroluminescent phosphor. This beginning phosphor is added to other materials, including Ga2O3, forming a second step material (SSM). The SSM is placed into a first vessel, such as a plastic bottle, blended, sifted and then placed in a second inert reaction vessel that is then heated for a period of time. After cooling, the fired SSM is washed with de-ionized water, washed with acetic acid, again washed with de-ionized water to remove residual acid, washed with KCN and again with de-ionized water to remove residual KCN. The fired and washed SSM is then dried, filtered and sifted, producing a new phosphor with an increased efficiency.
    Type: Grant
    Filed: August 2, 2000
    Date of Patent: May 14, 2002
    Assignee: Osram Sylvania Inc.
    Inventors: Butchi Reddy Vaddi, Shellie K. Northrop
  • Patent number: 5783106
    Abstract: The brightness of small size terbium activated gadolinium oxysulfide (Gd.sub.2-x Tb.sub.x O.sub.2 S) phosphor is increased by the incorporation of a lithium dopant. The lithium dopant is added to the phosphor by mixing lithium phosphate with the raw materials formulated to make the phosphor.
    Type: Grant
    Filed: September 23, 1997
    Date of Patent: July 21, 1998
    Assignee: Osram Sylvania Inc.
    Inventors: Vaddi Butchi Reddy, Shellie K. Northrop
  • Patent number: 5582768
    Abstract: Electroluminescent phosphors having substantially increased luminance and maintenance over that of prior art electroluminescent phosphors may be made by (1) doping an inorganic intercalation compound having an atomic structure interspersed with vacant spaces, with selected activator ions capable of luminescent emission, and (2) introducing organic monomers or other conductive material into the vacant spaces of the atomic structure of the doped inorganic intercalation compound. The organic monomers may be polymerized in situ to form conductive polymers therein.
    Type: Grant
    Filed: October 24, 1995
    Date of Patent: December 10, 1996
    Assignee: Osram Sylvania, Inc.
    Inventors: Vaddi B. Reddy, Ronald E. Karam, Shellie K. Northrop
  • Patent number: 5531928
    Abstract: Electroluminescent phosphors having substantially increased luminance and maintenance over that of prior art electroluminescent phosphors may be made by (1) doping an inorganic intercalation compound having an atomic structure interspersed with vacant spaces, with selected activator ions capable of luminescent emission, and (2) introducing organic monomers or other conductive material into the vacant spaces of the atomic structure of the doped inorganic intercalation compound. The organic monomers may be polymerized in situ to form conductive polymers therein.
    Type: Grant
    Filed: May 9, 1995
    Date of Patent: July 2, 1996
    Assignee: Osram Sylvania Inc.
    Inventors: Ronald E. Karam, Vaddi B. Reddy, Shellie K. Northrop, Yan Zhang
  • Patent number: 5489398
    Abstract: Electroluminescent phosphors having substantially increased luminance and maintenance over that of prior art electroluminescent phosphors may be made by (1) doping an inorganic intercalation compound having an atomic structure interspersed with vacant spaces, with selected activator ions capable of luminescent emission, and (2) introducing organic monomers or other conductive material into the vacant spaces of the atomic structure of the doped inorganic intercalation compound. The organic monomers may be polymerized in situ to form conductive polymers therein.
    Type: Grant
    Filed: December 6, 1993
    Date of Patent: February 6, 1996
    Assignee: Osram Sylvania Inc.
    Inventors: Vaddi B. Reddy, Ronald E. Karam, Shellie K. Northrop
  • Patent number: 5306441
    Abstract: Electroluminescent phosphors having substantially increased luminance and maintenance over that of prior art electroluminescent phosphors may be made by (1) doping an inorganic intercalation compound having an atomic structure interspersed with vacant spaces, with selected activator ions capable of luminescent emission, and (2) introducing organic monomers or other conductive material into the vacant spaces of the atomic structure of the doped inorganic intercalation compound. The organic monomers may be polymerized in situ to form conductive polymers therein.
    Type: Grant
    Filed: February 1, 1993
    Date of Patent: April 26, 1994
    Assignee: GTE Products Corporation
    Inventors: Vaddi B. Reddy, Ronald E. Karam, Shellie K. Northrop
  • Patent number: 5102633
    Abstract: A method for reducing impurity levels of calcium, magnesium and/or silicon in hexammine cobalt halide compounds involves the addition of ferric ions and, optionally, soluble fluorides to an aqueous hexammine cobalt (III) chloride solution having a pH of at least 9. Insoluble compounds of magnesium fluoride, calcium fluoride, and/or ferric hydroxide and silicon coprecipitates are removed from the solution by filtration.
    Type: Grant
    Filed: May 20, 1991
    Date of Patent: April 7, 1992
    Assignee: GTE Products Corporation
    Inventors: Eric F. Husted, Michael J. Miller, Shellie K. Northrop, David T. Smith