Patents Examined by Melissa Bonner
  • Patent number: 6086780
    Abstract: Methods for preparing homogeneous magnetic fluid compositions capable of forming ordered one dimensional structures or two dimensional lattices in response to externally applied magnetic fields are disclosed. The compositions are prepared using improved co-precipitation methods in which the steps of the procedure have been tuned to reduce sample heterogeneity. Fe.sub.3 O.sub.4 or MnFe.sub.2 O.sub.4 particles are coated with a surfactant and dispersed in a continuous carrier phase to form these homogeneous magnetic fluid compositions. The ability of these compositions to generate ordered structures can be tested by holding a magnet near a thin film of the compositions and observing the formation of colors in the region near the magnet. Methods for controlling the characteristic spacing of the ordered structures formed by the composition also are disclosed.
    Type: Grant
    Filed: October 22, 1997
    Date of Patent: July 11, 2000
    Inventors: Chin-Yih Rex Hong, Herng-Er Horng
  • Patent number: 5958295
    Abstract: A terbium-activated rare earth oxysulfide phosphor with an enhanced blue emission is disclosed. The phosphor includes a rare earth oxysulfide matrix of the nominal formula M.sub.2-x O.sub.2 S:xTb, where M is lanthanum, gadolinium, yttrium, scandium, lutetium, or mixtures of these metals, and x is 0.001-0.2. Copper is incorporated in the matrix to enhance the blue emission of the phosphor. A method of enhancing the blue emission is also disclosed.
    Type: Grant
    Filed: September 24, 1997
    Date of Patent: September 28, 1999
    Assignee: Osram Sylvania Inc.
    Inventor: Ramon L. Yale
  • Patent number: 5954992
    Abstract: The invention provides a hexagonal Z type magnetic oxide sintered material having a high resistivity and high density, and an impedance device using the same. The hexagonal Z type magnetic oxide sintered material contains a main oxide component containing M wherein M is at least one of Ba and Sr, Co, and Fe and an auxiliary oxide component containing Si, having a resistivity of at least 10.sup.6 .OMEGA.-cm, a sintered density of at least 4.6 g/cm.sup.3, and an initial magnetic permeability of 5 to 25. Pb may be contained in the auxiliary oxide component. Co may be partially replaced by Me wherein Me is at least one of Ni, Zn, and Cu.
    Type: Grant
    Filed: July 28, 1997
    Date of Patent: September 21, 1999
    Assignee: TDK Corporation
    Inventors: Masahiro Onizuka, Yutaka Saito
  • Patent number: 5954991
    Abstract: Methods for preparing homogeneous magnetic fluid compositions capable of forming ordered one dimensional structures or two dimensional lattices in response to externally applied magnetic fields are disclosed. The compositions are prepared using improved co-precipitation methods in which the steps of the procedure have been tuned to reduce sample heterogeneity. Fe.sub.3 O.sub.4 particles are coated with a surfactant and dispersed in a continuous carrier phase to form these homogeneous magnetic fluid compositions. The ability of these compositions to generate ordered structures can be tested by holding a magnet near a thin film of the compositions and observing the formation of colors in the region near the magnet. Methods for controlling the characteristic spacing of the ordered structures formed by the composition also are disclosed.
    Type: Grant
    Filed: April 4, 1997
    Date of Patent: September 21, 1999
    Inventors: Chin-Yih Rex Hong, Herng-Er Horng
  • Patent number: 5942148
    Abstract: A hot press method for the fabrication of doped or undoped gallium nitride compacts, and of other nitride compacts, employs as a starting material a powder mixture of the selected nitride and of a nitrogen rich salt. A preferred method for fabricating gallium nitride compacts employs ammonium carbonate powder as a starting material additive. In the course of the hot press operation, the endothermic volatilization of ammonium carbonate at a temperature below the disassociation temperature threshold of gallium nitride acts to cool the gallium nitride and also releases free nitrogen radicals that are available to replace any nitrogen lost by gallium nitride molecules through disassociation. The resulting compacts are substantially free of gallium metal, voids, or contaminants, and have a density exceeding 75% of theoretical maximum density.
    Type: Grant
    Filed: December 24, 1997
    Date of Patent: August 24, 1999
    Inventor: Kenneth G. Preston
  • Patent number: 5932134
    Abstract: The invention is directed to a composition containing from 45 to 99 weight percent of a permanent-magnetic and/or ferromagnetic metal-containing compound and from 1 to 55 weight percent of a polymer of formula IHO--?--CO--R.sub.1 --CO--X--Y--Z--!.sub.n --H (I)wherein R.sub.1 is phenyl, naphthyl, cyclohexyl, cyclohexenyl, or a C.sub.1 to C.sub.4 alkyl-substituted derivative thereof, and, if R.sub.1 is phenyl, the carboxy groups are in ortho, meta or para position to each other;X, Z are O or NR.sub.2, wherein R.sub.2 is H or C.sub.1 to C.sub.4 alkyl;Y is (CH.sub.2).sub.m or phenyl, cyclohexyl or cyclopentyl, and m is from 1 to 12; andn is an integer.Furthermore, the invention is directed to a process for producing said composition, a magnetic and a non-magnetic molded article made of said composition, the production of same and the use of said composition.
    Type: Grant
    Filed: April 7, 1997
    Date of Patent: August 3, 1999
    Assignee: A. Schulman GmbH
    Inventors: Hubert Christ, Hans-Peter Meyerhoff
  • Patent number: 5911815
    Abstract: Disclosed herein is an ink set comprising in combination at least two inks of different colors, wherein at least one ink comprises a cationic dye and an amphoteric compound, and another ink of a color different from said one ink comprises an anionic dye and a water-soluble anionic polymer or nonionic polymer in addition to the dye.
    Type: Grant
    Filed: November 25, 1996
    Date of Patent: June 15, 1999
    Assignee: Canon Kabushiki Kaisha
    Inventors: Mayumi Yamamoto, Yoshihisa Takizawa, Mikio Sanada, Eriko Saito
  • Patent number: 5906767
    Abstract: A magnetorheological fluid that includes magnetic-responsive particles, a carrier fluid and a phosphorus additive. The magnetorheological fluid does not include an organomolybdenum, a thiophosphorus additive or a thiocarbamate additive.
    Type: Grant
    Filed: October 28, 1997
    Date of Patent: May 25, 1999
    Assignee: Lord Corporation
    Inventors: Thomas J. Karol, Beth C. Munoz, Anthony J. Margida
  • Patent number: 5906771
    Abstract: A process is provided for manufacturing high-purity phosphors having utility in field emission displays. The high-purity phosphor is a host lattice infiltrated by a dopant that activates luminescent properties therein. The lattice and dopant are initially milled together to reduce their average particle size while simultaneously achieving complete mixing between the lattice and the dopant. The resulting mixture is maintained free of a flux or substantially any other treatment agent capable of contaminating the phosphor and placed in a heating vessel formed from a substantially impervious contaminant-free material. The mixture is heated to a high temperature effectuating thorough infiltration of the dopant into the lattice structure. The use of an impervious contaminant-free heating vessel and the exclusion of flux or other treatment agents from the mixture avoids undesirable contamination and undue particle size growth of the phosphor product during the manufacture thereof.
    Type: Grant
    Filed: November 19, 1997
    Date of Patent: May 25, 1999
    Assignee: Micron Technology, Inc.
    Inventors: Charles M. Watkins, Surjit S. Chadha
  • Patent number: 5904878
    Abstract: Orange azo fluorescent pigments and a process for a preparing same. Orange azo fluorescent pigments as a component of printing ink, coating, plastic compositions and articles of manufacture and used for controlling manufacturing operations.
    Type: Grant
    Filed: May 14, 1997
    Date of Patent: May 18, 1999
    Assignee: Sun Chemical Corporation
    Inventors: Paul A. Merchak, Russell J. Schwartz, Manuel Z. Gregorio
  • Patent number: 5902513
    Abstract: A magnetic fluid composition comprising fine magnetic particles in a solvent, wherein said solvent comprises a mixture of a base oil solvent and an ester.
    Type: Grant
    Filed: October 6, 1997
    Date of Patent: May 11, 1999
    Assignee: Taiho Industries Co., Ltd.
    Inventors: Kazuya Shimizu, Yuusuke Matsumura
  • Patent number: 5900188
    Abstract: A composition and method are provided for reducing the persistence of yttrium tantalate x-ray phosphors having the monoclinic M' structure. Persistence is reduced by incorporating a tungsten additive into the phosphor. The phosphor preferably contains at least about 4 ppm W. The method for incorporating the tungsten additive consists of adding a tungsten containing compound to the mixture of raw materials formulated to make the phosphor and firing the mixture at a temperature and for a time sufficient to form the phosphor.
    Type: Grant
    Filed: September 23, 1997
    Date of Patent: May 4, 1999
    Assignee: Osram Sylvania Inc.
    Inventors: Gregory A. Marking, Vaddi Butchi Reddy, Kenneth T. Reilly
  • Patent number: 5900184
    Abstract: A magnetorheological fluid that includes a carrier component and a magnetizable particle component wherein the magnetizable particle component has a fractional packing density of at least 0.50 prior to formulation into the magnetorheological fluid. Use of this magnetorheological fluid can increase the force output of a magnetorheological device without increasing the viscosity of the fluid because the particle volume concentration in a working gap of the device increases when a magnetic field is applied.
    Type: Grant
    Filed: October 18, 1995
    Date of Patent: May 4, 1999
    Assignee: Lord Corporation
    Inventors: Keith D. Weiss, J. David Carlson, Donald A. Nixon
  • Patent number: 5897812
    Abstract: New oxide phosphors based on doped gallium oxides, alkaline earth gallates and germanates for electoluminescent display materials. Bright orange red electroluminescence has been obtained in amorphous and crystalline oxides Ga.sub.2 O.sub.3 :Eu for the first time. SrGa.sub.2 O.sub.4 and SrGa.sub.4 O.sub.9 doped with 1-8 mole % of Eu and Tb, CaGa.sub.2 O.sub.4, Ca.sub.3 Ga.sub.2 O.sub.8 and CaGa.sub.4 O.sub.7 doped with 1-4 mole % of Eu, Tb, Pr and Dy, BaGa.sub.2 O.sub.4 doped with 1-2 mole % of Eu and Tb, have been prepared using RF magnetron sputtering onto ceramic dielectric substrates and annealed at 600.degree. C.-950.degree. C. in air or Ar for 1-2 hours. Bright electroluminescent (EL) emission was obtained with wavelengths covering the visible spectrum from 400 to 700 nm, and infrared emission above 700 nm with spectral peaks characteristic of rare earth transitions. The films of CaGa.sub.2 O.sub.4 with 1 mole % Eu achieved 22 fL (75 cd/m.sup.2) at 60 Hz and had a maximum efficiency of 0.
    Type: Grant
    Filed: November 20, 1997
    Date of Patent: April 27, 1999
    Assignee: Adrian H. Kitai
    Inventors: Adrian H. Kitai, Tian Xiao, Guo Liu
  • Patent number: 5897696
    Abstract: A process for preparing a water-soluble, radio-opaque paint for marking acrylic resin dental stents includes the steps of preparing a solution comprising 50 ml of ethanol, 6.4 grams of glycerol; 4.0 ml of benzaldehyde; 1.0 ml of glacial acetic acid, and 0.15 grams of hydroxy propyl cellulose. A radio-opaque powder, such as 50 grams of barium sulfate powder having a mean particle diameter of about 10 .mu.m, is then added to the solution. The solution is then mixed to obtain the paint, wherein the paint has a uniform dispersion of the radio-opaque powder. This paint may be used on dental stents to locate and guide placement of dental implants. The method may include the steps of preparing a water-soluble, radio-opaque paint for marking dental stents comprising the steps of preparing a solution described above; adding a radio-opaque powder, such as 50 grams of barium sulfate powder; and mixing the solution to obtain the paint, wherein the paint has a uniform dispersion of the radio-opaque powder.
    Type: Grant
    Filed: February 14, 1997
    Date of Patent: April 27, 1999
    Assignees: Boston University, Illinois University
    Inventors: Russell A. Giordano, Kevin C. Kopp
  • Patent number: 5891815
    Abstract: Multiphase ceramic composites containing 47% to 52% by weight aluminum nitride, 23% to 27% by weight silica, 3% to 7% alumina and the balance boron nitride wherein the boron nitride is one phase in the composition and the reaction products of aluminum nitride, silica and alumina are the other phase in the composite. The boron nitride phase is uniformly distributed in the form of discrete particles throughout the reaction products of aluminum nitride, silica and alumina. A window transparent to electromagnetic radiation in a predetermined frequency spectrum is made by forming a homogeneous, finely-divided mixture of the foregoing composite and compacting the homogeneous, finely-divided mixture at an elevated temperature and pressure for a sufficient time to form reaction products of the aluminum nitride, silica and alumina. In preferred embodiments, the homogeneous, finely-divided mixture of aluminum nitride, silica, boron nitride and alumina is densified at a temperature of 1760.degree. C.
    Type: Grant
    Filed: December 21, 1988
    Date of Patent: April 6, 1999
    Assignee: Lockheed Martin Corporation
    Inventors: Gerald C. Dodds, Richard A. Tanzilli
  • Patent number: 5891361
    Abstract: Spherical particles of fluoride up-converter phosphors having a particle size of 1 micron and less can be made from their corresponding precursor hydroxycarbonate particles by heating the hydroxycarbonate particles in an oxygen-containing atmosphere to convert the hydroxycarbonate to the corresponding oxide but without changing the size and shape of the particles, and then heating the phosphor oxide particles to their corresponding fluoride particles by heating in SF.sub.6, at a temperature that will crack the SF.sub.6 but will not change the size or shape of the phosphor particles.
    Type: Grant
    Filed: May 2, 1997
    Date of Patent: April 6, 1999
    Assignee: Sarnoff Corporation
    Inventor: James Kane
  • Patent number: 5888417
    Abstract: A rare earth bonded magnet formed by bonding a rare earth magnet powder with a binding resin contains the rare earth magnet powder, and a thermoplastic resin serving as the binding resin in an amount within a range of from 1 to 5 wt. %, and preferably further contains an oxidation inhibitor. As the rare earth magnet powder, for example, at least one of an Sm--Co alloy, an R--Fe--B alloy (where, R represents at least a kind of rare earth elements including Y) and an Sm--Fe--N alloy can be appropriately used. As the thermoplastic resin, for example, polyamide, a liquid crystal polymer, or a PPS is appropriately employed. As the oxidation inhibitor, a chelating agent is appropriately applicable. In such a rare earth bonded magnet, the thermoplastic resin covers the outer surface of the rare earth magnet powder 2, and is present so as to prevent particles of the magnet powder from coming into contact with each other. Such a rare earth bonded magnet should preferably have a void ratio of no more than 2 vol. %.
    Type: Grant
    Filed: October 16, 1996
    Date of Patent: March 30, 1999
    Assignee: Seiko Epson Corporation
    Inventors: Koji Akioka, Hayato Shirai, Ken Ikuma
  • Patent number: 5885915
    Abstract: The subject-matter of the invention is a glass composition, which is suitable for use in electric lamps, comprising SiO.sub.2, Al.sub.2 O.sub.3, Na.sub.2 O, K.sub.2 O, Li.sub.2 O, SrO, B.sub.2 O.sub.3, and optionally CaO, MgO, TiO.sub.2, P.sub.2 O.sub.5, Sb.sub.2 O.sub.3, Fe.sub.2 O.sub.3, MnO.sub.2, ZnO and/or CeO.sub.2. It is characterized in that its SiO.sub.2 content is 65-73 mass %, Al.sub.2 O.sub.3 content is 0.5 to 2.5 mass %, Na.sub.2 O content is 5 to 9 mass %, K.sub.2 O content is 8 to 12 mass %, Li.sub.2 O content is 0.4 to 1.5 mass %, SrO content is 0.5 to 5 mass %, B.sub.2 O.sub.3 content is 2.1 to 5 mass %. Furthermore in addition to the components listed, it optionally also comprises maximum 2.5 mass % CaO, maximum 3.8 mass % MgO, maximum 1 mass % TiO.sub.2, maximum 0.8 mass % P.sub.2 O.sub.5, maximum 0.5 mass % Sb.sub.2 O.sub.3, maximum 0.25 mass % Fe.sub.2 O.sub.3, maximum 0.25 mass % MnO.sub.2, maximum 5 mass % ZnO, and/or maximum 0.8 mass % CeO.sub.
    Type: Grant
    Filed: July 24, 1997
    Date of Patent: March 23, 1999
    Assignee: General Electric Company
    Inventors: Zoltan Laszlo Bako, Zoltan Kamill Suha, Zsuzsanna Klara Varga
  • Patent number: RE36513
    Abstract: This invention is directed broadly to transparent glasses exhibiting excellent transmission far into the infrared region of the electromagnetic radiation spectrum, those glasses consisting essentially, expressed in terms of mole percent, of 40-80% Ga.sub.2 S.sub.3, 0-35% RS.sub.x, wherein R is at least one network forming cation selected from the group consisting of aluminum, antimony, arsenic, germanium, and indium, 1-50% Ln.sub.2 S.sub.3, wherein Ln is at least one cation selected from the group consisting of a rare earth metal cation and yttrium, 1-45% MS.sub.x, wherein M is at least one modifying metal cation selected from the group consisting of barium, cadmium, calcium, lead, lithium, mercury, potassium, silver, sodium, strontium, thallium, and tin, and 0-10% total chloride and/or fluoride. Glass compositions consisting essentially, expressed in terms of mole percent, of 5-30% Ga.sub.2 S.sub.3, 0-10% R.sub.2 S.sub.
    Type: Grant
    Filed: December 17, 1996
    Date of Patent: January 18, 2000
    Assignee: Corning Inc.
    Inventors: Bruce G. Aitken, Mark A. Newhouse