Patents by Inventor Madis Raukas

Madis Raukas 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: 8829777
    Abstract: There is herein described an LED light source comprising an LED and a ceramic wavelength converter positioned to receive at least a portion of the light emitted by said LED, said ceramic wavelength converter converting at least a portion of the light emitted by said LED into light of a different wavelength, said ceramic wavelength converter comprising a chlorosilicate phosphor and having a density at least about 90% of theoretical density. The chlorosilicate phosphor is preferably a green-emitting Ca8Mg(SiO4)4Cl2:Eu2+ phosphor.
    Type: Grant
    Filed: September 27, 2010
    Date of Patent: September 9, 2014
    Assignee: OSRAM Sylvania Inc.
    Inventors: George C. Wei, Steven Mackel, Madis Raukas, Frank Jermann, Tim Fiedler
  • Publication number: 20130313603
    Abstract: A wavelength converter for an LED is described that comprises a substrate of monocrystalline garnet having a cubic crystal structure, a first lattice parameter and an oriented crystal face. An epitaxial layer is formed directly on the oriented crystal face of the substrate. The layer is comprised of a monocrystalline garnet phosphor having a cubic crystal structure and a second lattice parameter that is different from the first lattice parameter wherein the difference between the first lattice parameter and the second lattice parameter results in a lattice mismatch within a range of ±15%. The strain induced in the phosphor layer by the lattice mismatch shifts the emission of the phosphor to longer wavelengths when a tensile strain is induced and to shorter wavelengths when a compressive strain is induced. Preferably, the wavelength converter is mounted on the light emitting surface of a blue LED to produce an LED light source.
    Type: Application
    Filed: January 31, 2012
    Publication date: November 28, 2013
    Applicant: OSRAM SYLVANIA INC.
    Inventors: Darshan Kundaliya, Madis Raukas, Adam M. Scotch, David Hamby, Kailash Mishra, Matthew Stough
  • Publication number: 20130250544
    Abstract: A wavelength-conversion plate is described herein. The wavelength conversion plate may include a converter of a first ceramic material and a reflector of a second ceramic material. The first ceramic material converts the primary light emitted by a light source such as a light emitting diode (LED) into a secondary light and the second ceramic material reflects the secondary light emitted by said converter. Preferably, the converter is inlaid into the reflector so that the reflector surrounds an outer edge of the converter. Such a configuration has an advantage of reducing unwanted side emissions from the converter.
    Type: Application
    Filed: March 22, 2012
    Publication date: September 26, 2013
    Inventors: Nathan Zink, Madis Raukas, Matthew A. Stough, Yi Zheng, Alan Lenef
  • Patent number: 8492182
    Abstract: A light-emitting semiconductor chip is provided, the semiconductor chip comprising a semiconductor body having a pixel region with at least two electrically isolated sub-regions, each sub-region comprising an active layer, which generates electromagnetic radiation of a first wavelength range during operation, a separately manufactured ceramic conversion die over a radiation emission area of at least one sub-region, said conversion die being configured to convert radiation of the first wavelength range into electromagnetic radiation of a second wavelength range, wherein a width of the conversion die does not exceed 100 ?m. Further, a method for the production of a light-emitting semiconductor chip and method for the production of a conversion die are provided.
    Type: Grant
    Filed: April 29, 2011
    Date of Patent: July 23, 2013
    Assignees: OSRAM Opto Semiconductors GmbH, OSRAM SYLVANIA Inc.
    Inventors: Norwin Von Malm, Madis Raukas, Darshan Kundaliya
  • Publication number: 20120273807
    Abstract: A light-emitting semiconductor chip is provided, the semiconductor chip comprising a semiconductor body having a pixel region with at least two electrically isolated sub-regions, each sub-region comprising an active layer, which generates electromagnetic radiation of a first wavelength range during operation, a separately manufactured ceramic conversion die over a radiation emission area of at least one sub-region, said conversion die being configured to convert radiation of the first wavelength range into electromagnetic radiation of a second wavelength range, wherein a width of the conversion die does not exceed 100 ?m. Further, a method for the production of a light-emitting semiconductor chip and method for the production of a conversion die are provided.
    Type: Application
    Filed: April 29, 2011
    Publication date: November 1, 2012
    Applicants: OSRAM SYLVANIA Inc., OSRAM Opto Semiconductors GmbH
    Inventors: Norwin Von Malm, Madis Raukas, Darshan Kundaliya
  • Publication number: 20120261688
    Abstract: A wavelength-converting structure for a wavelength-converted light emitting diode (LED) assembly. The wavelength-converting structure includes a thin film structure having a non-uniform top surface. The non-uniform top surface is configured increase extraction of light from the top surface of a wavelength-converting structure.
    Type: Application
    Filed: April 13, 2011
    Publication date: October 18, 2012
    Inventors: Madis Raukas, Adam M. Scotch, Yi Zheng, Darshan Kundaliya
  • Patent number: 8282986
    Abstract: A method of applying a phosphor coating is described. The method comprises forming a suspension of a phosphor and a polymer binder dissolved in a solvent, the phosphor comprising at least one of a nitridosilicate or an oxonitridosilicate phosphor, the polymer binder being capable of decomposing thermally; applying the suspension to a substrate to form a coating; drying the coating; and baking the coating in an inert atmosphere to thermally decompose the polymer binder to form the phosphor coating, preferably at a temperature less than about 400° C. in a nitrogen atmosphere.
    Type: Grant
    Filed: May 17, 2007
    Date of Patent: October 9, 2012
    Assignee: OSRAM SYLVANIA, Inc.
    Inventors: Richard S. Speer, Madis Raukas
  • Patent number: 8242684
    Abstract: A wavelength-converting plate for a wavelength-converted light emitting diode (LED) assembly. The wavelength-converting plate includes microlenses deposited thereon. The microlenses may have an index of refraction different from the index of refraction of the wavelength-converting plate. The microlenses on the top surface of the plate increase lumen output in a direction normal to the top surface of a wavelength-converting plate.
    Type: Grant
    Filed: September 27, 2010
    Date of Patent: August 14, 2012
    Assignee: Osram Sylvania Inc.
    Inventors: Alan Piquette, Madis Raukas
  • Publication number: 20120074835
    Abstract: A wavelength-converting plate for a wavelength-converted light emitting diode (LED) assembly. The wavelength-converting plate includes multiple layers of microlenses deposited thereon. The microlenses may have an index of refraction different from an index of refraction of the wavelength-converting plate.
    Type: Application
    Filed: September 27, 2010
    Publication date: March 29, 2012
    Inventors: Alan Piquette, John Kelso, Nathan Zink, John Nappi, Yi Zheng, Madis Raukas
  • Publication number: 20120075834
    Abstract: There is herein described an LED light source comprising an LED and a ceramic wavelength converter positioned to receive at least a portion of the light emitted by said LED, said ceramic wavelength converter converting at least a portion of the light emitted by said LED into light of a different wavelength, said ceramic wavelength converter comprising a chlorosilicate phosphor and having a density at least about 90% of theoretical density. The chlorosilicate phosphor is preferably a green-emitting Ca8Mg(SiO4)4Cl2:Eu2+ phosphor.
    Type: Application
    Filed: September 27, 2010
    Publication date: March 29, 2012
    Inventors: George C. Wei, Steven Mackel, Madis Raukas, Frank Jermann, Tim Fiedler
  • Publication number: 20120074836
    Abstract: A wavelength-converting plate for a wavelength-converted light emitting diode (LED) assembly. The wavelength-converting plate includes microlenses deposited thereon. The microlenses may have an index of refraction different from the index of refraction of the wavelength-converting plate. The microlenses on the top surface of the plate increase lumen output in a direction normal to the top surface of a wavelength-converting plate.
    Type: Application
    Filed: September 27, 2010
    Publication date: March 29, 2012
    Inventors: Alan Piquette, Madis Raukas
  • Publication number: 20120018673
    Abstract: A material, comprising a garnet having the composition represented by the formula A3?xB5O12:Dx and a barium-containing oxide. In the garnet A3?xB5O12:Dx, A is selected from lutetium, yttrium, gadolinium, terbium, scandium, another rare earth metal or mixtures thereof. B is selected from aluminum, scandium, gallium, indium, boron or mixtures thereof. D is at least one dopant selected from chromium, manganese and rare earth metals, particularly cerium, praseodymium or gadolinium. The dopant is present with x is 0?x?2.
    Type: Application
    Filed: July 22, 2010
    Publication date: January 26, 2012
    Applicant: OSRAM Opto Semiconductors GmbH
    Inventors: Madis Raukas, Karl Krister Bergenek, George C. Wei, Nathan M. Zink, Stefan Lange
  • Patent number: 7935325
    Abstract: Rare earth-activated aluminum nitride powders are made using a solution-based approach to form a mixed hydroxide of aluminum and a rare earth metal, the mixed hydroxide is then converted into an ammonium metal fluoride, preferably a rare earth-substituted ammonium aluminum hexafluoride ((NH4)3Al1-xRExF6), and finally the rare earth-activated aluminum nitride is formed by ammonolysis of the ammonium metal fluoride at a high temperature. The use of a fluoride precursor in this process avoids sources of oxygen during the final ammonolysis step which is a major source of defects in the powder synthesis of nitrides. Also, because the aluminum nitride is formed from a mixed hydroxide co-precipitate, the distribution of the dopants in the powder is substantially homogeneous in each particle.
    Type: Grant
    Filed: December 20, 2006
    Date of Patent: May 3, 2011
    Assignees: OSRAM SYLVANIA Inc., The Regents of the University of California
    Inventors: Bing Han, Jonathan H. Tao, Madis Raukas, Keith A. Klinedinst, Jan B. Talbot, Kailash A. Mishra
  • Patent number: 7800287
    Abstract: White-light efficiency from a light emitting diode is enhanced by recycling inwardly penetrating light outwardly by application of a multi-layer, thin film filter between the LED die and the phosphor layer. This procedure increases the package extraction efficiency.
    Type: Grant
    Filed: August 24, 2007
    Date of Patent: September 21, 2010
    Assignee: Osram Sylvania Inc.
    Inventors: Yi Zheng, Bruce Bateman, Matthew A. Stough, Madis Raukas
  • Publication number: 20090252667
    Abstract: Rare earth-activated aluminum nitride powders are made using a solution-based approach to form a mixed hydroxide of aluminum and a rare earth metal, the mixed hydroxide is then converted into an ammonium metal fluoride, preferably a rare earth-substituted ammonium aluminum hexafluoride ((NH4)3Al1-xRExF6), and finally the rare earth-activated aluminum nitride is formed by ammonolysis of the ammonium metal fluoride at a high temperature. The use of a fluoride precursor in this process avoids sources of oxygen during the final ammonolysis step which is a major source of defects in the powder synthesis of nitrides. Also, because the aluminum nitride is formed from a mixed hydroxide co-precipitate, the distribution of the dopants in the powder is substantially homogeneous in each particle.
    Type: Application
    Filed: December 20, 2006
    Publication date: October 8, 2009
    Applicant: OSRAM SYLVANIA, INC.
    Inventors: Bing Han, Jonathan H. Tao, Madis Raukas, Keith A. Klinedinst, Jan B. Talbot, Kailash A. Mishra
  • Patent number: 7420331
    Abstract: A ceramic discharge vessel is provided wherein the vessel comprises a hollow body for enclosing a discharge and the hollow body is made of a polycrystalline dysprosium oxide containing a luminescent dopant that emits one or more visible light wavelengths when stimulated by radiation generated by the discharge. Preferably, the polycrystalline dysprosium oxide has been doped with one or more of europium, cerium, or terbium in an amount from about 0.1 to about 10 percent by weight on an oxide basis.
    Type: Grant
    Filed: June 24, 2005
    Date of Patent: September 2, 2008
    Assignee: Osram Sylvania Inc.
    Inventors: George C. Wei, Walter P. Lapatovich, Joanne M. Browne, Kailash C. Mishra, Madis Raukas
  • Patent number: 7362049
    Abstract: A blue-enriched incandescent lamp having on the interior surface of its light transmissive glass envelope a coating in accordance with an aspect of the invention. The coating contains a phosphor that is energized by the ultraviolet/violet emission (<420 nm) from the hot filament causing it to emit radiation in the range of 420 to 490 nm. In a preferred embodiment of the invention, the coating contains a europium-activated barium magnesium aluminate phosphor and a blue pigment.
    Type: Grant
    Filed: December 28, 2004
    Date of Patent: April 22, 2008
    Assignee: Osram Sylvania Inc.
    Inventors: Madis Raukas, Kailash C. Mishra
  • Publication number: 20080054803
    Abstract: White-light efficiency from a light emitting diode is enhanced by recycling inwardly penetrating light outwardly by application of a multi-layer, thin film filter between the LED die and the phosphor layer. This procedure increases the package extraction efficiency.
    Type: Application
    Filed: August 24, 2007
    Publication date: March 6, 2008
    Applicant: OSRAM SYLVANIA INC.
    Inventors: Yi Zheng, Bruce Bateman, Matthew A. Stough, Madis Raukas
  • Publication number: 20070292609
    Abstract: A method of applying a phosphor coating is described. The method comprises forming a suspension of a phosphor and a polymer binder dissolved in a solvent, the phosphor comprising at least one of a nitridosilicate or an oxonitridosilicate phosphor, the polymer binder being capable of decomposing thermally; applying the suspension to a substrate to form a coating; drying the coating; and baking the coating in an inert atmosphere to thermally decompose the polymer binder to form the phosphor coating, preferably at a temperature less than about 400° C. in a nitrogen atmosphere.
    Type: Application
    Filed: May 17, 2007
    Publication date: December 20, 2007
    Applicant: OSRAM SYLVANIA INC.
    Inventors: Richard S. Speer, Madis Raukas
  • Publication number: 20070267960
    Abstract: A phosphor blend for use with an indium halide discharge lamp and a lamp made therewith is described. The phosphor blend comprising at least two phosphors selected from Ca8Mg(SiO4)4Cl2:Eu, SrSi2N2O2:Eu and Ca2Si5N8:Eu: The blend may also include a blue-emitting phosphor such as BaMgAl10O17:Eu.
    Type: Application
    Filed: May 17, 2007
    Publication date: November 22, 2007
    Applicant: OSRAM SYLVANIA INC.
    Inventors: Madis Raukas, Richard S. Speer, Philip E. Moskowitz