Patents by Inventor Prasanth Kumar Nammalwar

Prasanth Kumar Nammalwar 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: 11851595
    Abstract: A lighting apparatus includes a semiconductor light source in direct contact with a polymer composite comprising a color stable Mn4+ doped phosphor, wherein the lighting apparatus has a color shift of ?1.5 MacAdam ellipses after operating for at least 2,000 hour at a LED current density greater than 2 A/cm2, a LED wall-plug efficiency greater than 40%, and a board temperature greater than 25° C.
    Type: Grant
    Filed: July 13, 2021
    Date of Patent: December 26, 2023
    Assignee: CURRENT LIGHTING SOLUTIONS, LLC
    Inventors: James Edward Murphy, Anant Achyut Setlur, Florencio Garcia, Robert Joseph Lyons, Ashfaqul Islam Chowdhury, Nagaveni Karkada, Prasanth Kumar Nammalwar, William Winder Beers
  • Publication number: 20210340443
    Abstract: A lighting apparatus includes a semiconductor light source in direct contact with a polymer composite comprising a color stable Mn4+ doped phosphor, wherein the lighting apparatus has a color shift of ?1.5 MacAdam ellipses after operating for at least 2,000 hour at a LED current density greater than 2 A/cm2, a LED wall-plug efficiency greater than 40%, and a board temperature greater than 25° C.
    Type: Application
    Filed: July 13, 2021
    Publication date: November 4, 2021
    Inventors: James Edward MURPHY, Anant Achyut SETLUR, Florencio GARCIA, Robert Joseph LYONS, Ashfaqul Islam CHOWDHURY, Nagaveni KARKADA, Prasanth Kumar NAMMALWAR, William Winder BEERS
  • Patent number: 11149195
    Abstract: A process for coating a phosphor of formula I: Ax[MFy]:Mn4+ includes combining the phosphor of formula I in particulate form with a first solution including a compound of formula II: Ax[MFy] to form a suspension and combining a second solution with the suspension, the second solution including a precursor including an element selected from the group consisting of calcium, strontium, magnesium, yittrium, barium, scandium, lanthanum, and combinations thereof. A population of particles having a core including a phosphor of formula I and a manganese-free composite coating disposed on the core, and a lighting apparatus (10) including the population of particles are also presented.
    Type: Grant
    Filed: November 15, 2017
    Date of Patent: October 19, 2021
    Assignee: CURRENT LIGHTING SOLUTIONS, LLC
    Inventors: Digamber Gurudas Porob, Prasanth Kumar Nammalwar, Srinidhi Ramachandra, Matthew David Butts, James Edward Murphy
  • Patent number: 11098246
    Abstract: A lighting apparatus includes a semiconductor light source in direct contact with a polymer composite comprising a color stable Mn4+ doped phosphor, wherein the lighting apparatus has a color shift of ?1.5 MacAdam ellipses after operating for at least 2,000 hour at a LED current density greater than 2 A/cm2, a LED wall-plug efficiency greater than 40%, and a board temperature greater than 25° C.
    Type: Grant
    Filed: March 6, 2019
    Date of Patent: August 24, 2021
    Assignee: CURRENT LIGHTING SOLUTIONS, LLC
    Inventors: James Edward Murphy, Anant Achyut Setlur, Florencio Garcia, Robert Joseph Lyons, Ashfaqul Islam Chowdhury, Nagaveni Karkada, Prasanth Kumar Nammalwar, William Winder Beers
  • Patent number: 10920136
    Abstract: A process for synthesizing a manganese doped phosphor of formula I: Ax [MFy]:Mn4+ is presented. The process includes contacting a first solution with a second solution and a third solution in the presence of a plurality of inert particles. The first solution and the second solution include a composition of formula II: Ax[MnFy]. The third solution includes a source of M, where A is Li, Na, K, Rb, Cs, or combinations thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or combinations thereof; x is an absolute value of a charge of the [MFy] ion; and y is 5, 6 or 7.
    Type: Grant
    Filed: October 18, 2016
    Date of Patent: February 16, 2021
    Assignee: CURRENT LIGHTING SOLUTIONS, LLC
    Inventors: Ravikumar Hanumantha, Prasanth Kumar Nammalwar, Digamber Gurudas Porob
  • Patent number: 10815423
    Abstract: A process for synthesizing a Mn4+ doped phosphor of formula I by electrolysis is presented. The process includes electrolyzing a reaction solution comprising a source of manganese, a source of M and a source of A. One aspect relates to a phosphor composition produced by the process. A lighting apparatus including the phosphor composition is also provided. Ax[MFy]:Mn4+ (I) where, A is Li, Na, K, Rb, Cs, or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; x is the absolute value of the charge of the [MFy] ion; and y is 5, 6 or 7.
    Type: Grant
    Filed: March 2, 2016
    Date of Patent: October 27, 2020
    Assignee: CURRENT LIGHTING SOLUTIONS, LLC
    Inventors: Digamber Gurudas Porob, Anant Achyut Setler, Prasanth Kumar Nammalwar, James Edward Murphy
  • Patent number: 10620324
    Abstract: A method and an apparatus for detecting photons are disclosed. The apparatus includes a scintillator single crystal and an avalanche photodiode coupled to the scintillator single crystal. The scintillator single crystal is at a temperature greater than about 175° C. and at a shock level in a range from about 20 Grms to about 30 Grms. The scintillator single crystal includes a praseodymium doped composition selected from (LaxY1-x)2Si2O7:Pr, ABCl3-yXy:Pr, A2(Li,Na)LaCl6-yXy:Pr, or any combinations thereof. As used herein A is cesium, rubidium, potassium, sodium, or a combination thereof, B is calcium, barium, strontium, magnesium, cadmium, zinc, or a combination thereof, and X is bromine, iodine, or a combination thereof. Further, (0<x<1), and (0<y<3).
    Type: Grant
    Filed: May 14, 2015
    Date of Patent: April 14, 2020
    Assignee: Baker Hughes Oilfield Operations, LLC
    Inventors: Srinidhi Ramachandra, Wusheng Xu, Alok Mani Srivastava, Gopi Chandran Ramachandran, Prasanth Kumar Nammalwar, Sergei Ivanovich Dolinsky, Helene Claire Climent
  • Publication number: 20190292448
    Abstract: A process for coating a phosphor of formula I: Ax[MFy]:Mn4+ includes combining the phosphor of formula I in particulate form with a first solution including a compound of formula II: Ax[MFy] to form a suspension and combining a second solution with the suspension, the second solution including a precursor including an element selected from the group consisting of calcium, strontium, magnesium, yittrium, barium, scandium, lanthanum, and combinations thereof. A population of particles having a core including a phosphor of formula I and a manganese-free composite coating disposed on the core, and a lighting apparatus (10) including the population of particles are also presented.
    Type: Application
    Filed: November 15, 2017
    Publication date: September 26, 2019
    Inventors: Digamber Gurudas POROB, Prasanth Kumar NAMMALWAR, Srinidhi RAMACHANDRA, Matthew David BUTTS, James Edward MURPHY
  • Publication number: 20190203116
    Abstract: A lighting apparatus includes a semiconductor light source in direct contact with a polymer composite comprising a color stable Mn4+ doped phosphor, wherein the lighting apparatus has a color shift of ?1.5 MacAdam ellipses after operating for at least 2,000 hour at a LED current density greater than 2 A/cm2, a LED wall-plug efficiency greater than 40%, and a board temperature greater than 25° C.
    Type: Application
    Filed: March 6, 2019
    Publication date: July 4, 2019
    Inventors: James Edward MURPHY, Anant Achyut SETLUR, Florencio GARCIA, Robert Joseph LYONS, Ashfaqul Islam CHOWDHURY, Nagaveni KARKADA, Prasanth Kumar NAMMALWAR, William Winder BEERS
  • Patent number: 10131835
    Abstract: A phosphor composition is derived from combining K2SiF6:Mn4+ in solid form with a saturated solution of a manganese-free complex fluoride including a composition of formula I: A3[MF6], where A is selected from Na, K, Rb, and combinations thereof and M is selected from Al, Ga, In, Sc, Y, Gd, and combinations thereof. The composition of formula I: A3[MF6] has a water solubility lower than a water solubility of K2SiF6. A lighting apparatus including the phosphor composition is also provided.
    Type: Grant
    Filed: December 16, 2014
    Date of Patent: November 20, 2018
    Assignee: General Electric Company
    Inventors: Anant Achyut Setlur, Robert Joseph Lyons, Prasanth Kumar Nammalwar, James Edward Murphy, Florencio Garcia, Ravikumar Hanumantha
  • Publication number: 20180312751
    Abstract: A process for synthesizing a manganese doped phosphor of formula I: Ax [MFy]:Mn4+ is presented. The process includes contacting a first solution with a second solution and a third solution in the presence of a plurality of inert particles. The first solution and the second solution include a composition of formula II: Ax[MnFy]. The third solution includes a source of M, where A is Li, Na, K, Rb, Cs, or combinations thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or combinations thereof; x is an absolute value of a charge of the [MFy] ion; and y is 5, 6 or 7.
    Type: Application
    Filed: October 18, 2016
    Publication date: November 1, 2018
    Inventors: Ravikumar HANUMANTHA, Prasanth Kumar NAMMALWAR, Digamber Gurudas POROB
  • Publication number: 20180051207
    Abstract: A process for synthesizing a Mn4+ doped phosphor of formula I by electrolysis is presented. The process includes electrolyzing a reaction solution comprising a source of manganese, a source of M and a source of A. One aspect relates to a phosphor composition produced by the process. A lighting apparatus including the phosphor composition is also provided. Ax[MFy]:Mn4+ (I) where, A is Li, Na, K, Rb, Cs, or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; x is the absolute value of the charge of the [MFy] ion; and y is 5, 6 or 7.
    Type: Application
    Filed: March 2, 2016
    Publication date: February 22, 2018
    Inventors: Digamber Gurudas POROB, Anant Achyut SETLER, Prasanth Kumar NAMMALWAR, James Edward MURPHY
  • Patent number: 9698314
    Abstract: A process for synthesizing a color stable Mn4+ doped phosphor includes contacting a precursor of formula I, in gaseous form at an elevated temperature with a fluorine-containing oxidizing agent to form the color stable Mn4+ doped phosphor Ax[MFy]:Mn4+??I wherein A is Li, Na, K, Rb, Cs, NR4 or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; R is H, lower alkyl, or a combination thereof; x is the absolute value of the charge of the [MFy] ion; and y is 5, 6 or 7.
    Type: Grant
    Filed: March 13, 2014
    Date of Patent: July 4, 2017
    Assignee: General Electric Company
    Inventors: James Edward Murphy, Anant Achyut Setlur, Florencio Garcia, Robert Joseph Lyons, Ashfaqul Islam Chowdhury, Nagaveni Karkada, Prasanth Kumar Nammalwar
  • Publication number: 20170145304
    Abstract: A lighting apparatus includes a semiconductor light source in direct contact with a polymer composite comprising a color stable Mn4+ doped phosphor, wherein the lighting apparatus has a color shift of 1.5 MacAdam ellipses after operating for at least 2,000 hour at a LED current density greater than 2 A/cm2, a LED wall-plug efficiency greater than 40%, and a board temperature greater than 25° C.
    Type: Application
    Filed: January 10, 2017
    Publication date: May 25, 2017
    Inventors: James Edward Murphy, Anant Achyut Setlur, Florencio Garcia, Robert Joseph Lyons, Ashfaqul Islam Chowdhury, Nagaveni Karkada, Prasanth Kumar Nammalwar, William Winder Beers
  • Publication number: 20170097426
    Abstract: A method and an apparatus for detecting photons are disclosed. The apparatus includes a scintillator single crystal and an avalanche photodiode coupled to the scintillator single crystal. The scintillator single crystal is at a temperature greater than about 175° C. and at a shock level in a range from about 20 Grms to about 30 Grms. The scintillator single crystal includes a praseodymium doped composition selected from (LaxY1-x)2Si2O7:Pr, ABCl3-yXy:Pr, A2(Li, Na)LaCl6-yXy:Pr, or any combinations thereof. As used herein A is cesium, rubidium, potassium, sodium, or a combination thereof, B is calcium, barium, strontium, magnesium, cadmium, zinc, or a combination thereof, and X is bromine, iodine, or a combination thereof. Further, (0<x<1), and (0<y<3).
    Type: Application
    Filed: May 14, 2015
    Publication date: April 6, 2017
    Inventors: Srinidhi RAMACHANDRA, Wusheng XU, Alok Mani SRIVASTAVA, Gopi Chandran RAMACHANDRAN, Prasanth Kumar NAMMALWAR, Sergei Ivanovich DOLINSKY, Helene Claire CLIMENT
  • Patent number: 9611237
    Abstract: A phosphor material is presented that includes a blend of a first phosphor, a second phosphor and a third phosphor. The first phosphor includes a composition having a general formula of RE2?yM1+yA2?yScySin?wGewO12+?:Ce3+ wherein RE is selected from a lanthanide ion or Y3+, where M is selected from Mg, Ca, Sr or Ba, A is selected from Mg or Zn and where 0?y?2, 2.5?n?3.5, 0?w?1, and ?1.5???1.5. The second phosphor includes a complex fluoride doped with manganese (Mn4+), and the third phosphor include a phosphor composition having an emission peak in a range from about 520 nanometers to about 680 nanometers. A lighting apparatus including such a phosphor material is also presented. The light apparatus includes a light source in addition to the phosphor material.
    Type: Grant
    Filed: September 20, 2012
    Date of Patent: April 4, 2017
    Assignee: GENERAL ELECTRIC COMPANY
    Inventors: Prasanth Kumar Nammalwar, Digamber Gurudas Porob, Anant Achyut Setlur, Satya Kishore Manepalli
  • Patent number: 9580648
    Abstract: A color stable Mn4+ doped phosphor of formula I, Ax[MFy]:Mn4+??I wherein A is Li, Na, K, Rb, Cs, or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; x is the absolute value of the charge of the [MFy] ion; y is 5, 6 or 7; and wherein % intensity loss of the phosphor after exposure to light flux of at least 80 w/cm2 at a temperature of at least 50° C. for at least 21 hours is ?4%.
    Type: Grant
    Filed: May 23, 2014
    Date of Patent: February 28, 2017
    Assignee: General Electric Company
    Inventors: James Edward Murphy, Anant Achyut Setlur, Florencio Garcia, Robert Joseph Lyons, Ashfaqul Islam Chowdhury, Nagaveni Karkada, Prasanth Kumar Nammalwar
  • Publication number: 20160376499
    Abstract: A phosphor composition is derived from combining K2SiF6:Mn4+ in solid form with a saturated solution of a manganese-free complex fluoride including a composition of formula I:A3[MF6], where A is selected from Na, K, Rb, and combinations thereof and M is selected from Al, Ga, In, Sc, Y, Gd, and combinations thereof. The composition of formula I:A3[MF6] has a water solubility lower than a water solubility of K2SiF6. A lighting apparatus including the phosphor composition is also provided.
    Type: Application
    Filed: December 16, 2014
    Publication date: December 29, 2016
    Inventors: Anant Achyut Setlur, Robert Joseph Lyons, Prasanth Kumar Nammalwar, James Edward Murphy, Florencio Garcia, Ravikumar Hanumantha
  • Patent number: 8906724
    Abstract: A process for synthesizing a color stable Mn4+ doped phosphor includes contacting a precursor of formula I, in gaseous form at an elevated temperature with a fluorine-containing oxidizing agent to form the color stable Mn4+ doped phosphor Ax[MFy]:Mn4+??I wherein A is Li, Na, K, Rb, Cs, or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; x is the absolute value of the charge of the [MFy] ion; and y is 5, 6 or 7.
    Type: Grant
    Filed: June 23, 2014
    Date of Patent: December 9, 2014
    Assignee: General Electric Company
    Inventors: James Edward Murphy, Anant Achyut Setlur, Florencio Garcia, Robert Joseph Lyons, Ashfaqul Islam Chowdhury, Nagaveni Karkada, Prasanth Kumar Nammalwar
  • Publication number: 20140327026
    Abstract: A process for synthesizing a color stable Mn4+ doped phosphor includes contacting a precursor of formula I, in gaseous form at an elevated temperature with a fluorine-containing oxidizing agent to form the color stable Mn4+ doped phosphor Ax[MFy]:Mn4+ wherein A is Li, Na, K, Rb, Cs, or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; x is the absolute value of the charge of the [MFy] ion; and y is 5, 6 or 7.
    Type: Application
    Filed: June 23, 2014
    Publication date: November 6, 2014
    Inventors: James Edward Murphy, Anant Achyut Setlur, Florencio Garcia, Robert Joseph Lyons, Ashfaqul Islam Chowdhury, Nagaveni Karkada, Prasanth Kumar Nammalwar