Patents by Inventor Walter Tews

Walter Tews 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: 8252203
    Abstract: A luminescent material is disclosed. The luminescent material may include a first compound having a host lattice comprising first ions and oxygen. A first portion of the first ions may be substituted by copper ions. In one embodiment, the host lattice may include silicon, the copper ions may be divalent copper ions and the first compound may have an Olivine crystal structure, ?-K0.2SO4 crystal structure, a trigonal Glaserite (K3Na(SO4)2) or monoclinic Merwinite crystal structure, a tetragonal Ackermanite crystal structure, a tetragonal crystal structure or an orthorhombic crystal structure. In another embodiment, the copper ions do not act as luminescent ions upon excitation with the ultraviolet or visible light.
    Type: Grant
    Filed: May 3, 2011
    Date of Patent: August 28, 2012
    Assignee: Seoul Semiconductor Co., Ltd.
    Inventors: Gundula Roth, Walter Tews, Chung Hoon Lee
  • Publication number: 20120205674
    Abstract: Exemplary embodiments of the present invention relate to a light emitting device including a light emitting diode and a surface-modified luminophore. The surface-modified luminophore includes a silicate luminophore and a fluorinated coating arranged on the silicate luminophore.
    Type: Application
    Filed: August 15, 2011
    Publication date: August 16, 2012
    Applicant: SEOUL SEMICONDUCTOR CO., LTD.
    Inventors: Chung Hoon Lee, Walter Tews, Gundula Roth, Detlef Starick
  • Publication number: 20120181481
    Abstract: Exemplary embodiments of the present invention relate to inorganic phosphors based on silicate compounds having improved stability under a resulting radiation load and resistance to atmospheric humidity, which are capable of converting higher-energy excitation radiation, i.e. ultraviolet (UV) or blue light, with high efficiency into a longer-wavelength radiation which may be in the visible spectral range. A calcium molar fraction x having a value between 0 and 0.05 is added to a silicate phosphor having the general formula Sr3-x-y-zCaxMIIySiO5:Euz.
    Type: Application
    Filed: March 29, 2012
    Publication date: July 19, 2012
    Applicants: LITEC-LP GMBH, SEOUL SEMICONDUCTOR CO., LTD.
    Inventors: Chung Hoon LEE, Walter TEWS, Gundula ROTH, Detlef STARICK
  • Publication number: 20120132939
    Abstract: Disclosed is a light emitting device employing non-stoichiometric tetragonal Alkaline Earth Silicate phosphors. The light emitting device comprises a light emitting diode emitting light of ultraviolet or visible light, and non-stoichiometric luminescent material disposed around the light emitting diode. The luminescent material adsorbs at least a portion of the light emitted from the light emitting diode and emits light having a different wavelength from the absorbed light. The non-stoichiometric luminescent material has tetragonal crystal structure, and contains more silicon in the crystal lattice than that in the crystal lattice of silicate phosphors having stoichiometric crystal structure. The luminescent material is represented as the formula (BauSrvCawCux)3-y(Zn,Mg,Mn)zSi1+bO5+2b:Eua. Light emitting devices having improved temperature and humidity stability can be provided by employing the non-stoichiometric tetragonal Alkaline Earth Silicate phosphors.
    Type: Application
    Filed: January 31, 2012
    Publication date: May 31, 2012
    Applicant: SEOUL SEMICONDUCTOR CO., LTD.
    Inventors: Chung Hoon LEE, Walter TEWS, Gundula ROTH, Stefan TEWS
  • Publication number: 20120126174
    Abstract: Disclosed are non stoichiometric Copper Alkaline Earth Silicate phosphors activated by divalent europium for using them as high temperature stable luminescent materials for ultraviolet or daylight excitation. The phosphors are represented as the formula (BauSryCawCux)3?y(Zn,Mg,Mn)zSi1+bO5+2b:Eua. The nonstoichiometric tetragonal silicate is prepared in a high temperature solid state reaction with a surplus of silica in the starting mixture. Furthermore, luminescent tetragonal Copper Alkaline Earth Silicates are provided for LED applications, which have a high color temperature range from about 2,000K to 8,000K or 10,000K showing a CRI with Ra=80˜95, when mixed with other luminescent materials.
    Type: Application
    Filed: January 31, 2012
    Publication date: May 24, 2012
    Applicant: SEOUL SEMICONDUCTOR CO., LTD.
    Inventors: Chung Hoon Lee, Walter Tews, Gundula Roth, Stefan Tews
  • Patent number: 8173042
    Abstract: Exemplary embodiments of the present invention relate to inorganic phosphors based on silicate compounds having improved stability under a resulting radiation load and resistance to atmospheric humidity, which are capable of converting higher-energy excitation radiation, i.e. ultraviolet (UV) or blue light, with high efficiency into a longer-wavelength radiation which may be in the visible spectral range. A calcium molar fraction x having a value between 0 and 0.05 is added to a silicate phosphor having the general formula Sr3-x-y-zCaxMIIySiO5:Euz.
    Type: Grant
    Filed: September 10, 2010
    Date of Patent: May 8, 2012
    Assignees: Seoul Semiconductor Co., Ltd., LITEC-LP GmbH
    Inventors: Chung Hoon Lee, Walter Tews, Gundula Roth, Detlef Starick
  • Patent number: 8158028
    Abstract: This invention relates to luminescent materials for ultraviolet light or visible light excitation containing lead and/or copper doped chemical compounds. The luminescent material is composed of one or more than one compounds of aluminate type, silicate type, antimonate type, germanate/or germanate-silicate type, and/or phosphate type. Accordingly, the present invention is a good possibility to substitute earth alkaline ions by lead and copper for a shifting of the emission bands to longer or shorter wave length, respectively. Luminescent compounds containing copper and/or lead with improved luminescent properties and also with improved stability against water, humidity as well as other polar solvents are provided. The present invention is to provide lead and/or copper doped luminescent compounds, which has high color temperature range about 2,000K to 8,000K or 10,000K and CRI over 90.
    Type: Grant
    Filed: January 11, 2011
    Date of Patent: April 17, 2012
    Assignee: Seoul Semiconductor Co., Ltd.
    Inventors: Gundula Roth, Walter Tews, Chung Hoon Lee
  • Patent number: 8137589
    Abstract: Disclosed are non stoichiometric Copper Alkaline Earth Silicate phosphors activated by divalent europium for using them as high temperature stable luminescent materials for ultraviolet or daylight excitation. The phosphors are represented as the formula (BauSrvCawCux)3?y(Zn,Mg,Mn)zSi1+bO5+2b:Eua. The nonstoichiometric tetragonal silicate is prepared in a high temperature solid state reaction with a surplus of silica in the starting mixture. Furthermore, luminescent tetragonal Copper Alkaline Earth Silicates are provided for LED applications, which have a high color temperature range from about 2,000K to 8,000K or 10,000K showing a CRI with Ra=80˜95, when mixed with other luminescent materials.
    Type: Grant
    Filed: August 22, 2008
    Date of Patent: March 20, 2012
    Assignee: Seoul Semiconductor Co., Ltd.
    Inventors: Chung Hoon Lee, Walter Tews, Gundula Roth, Stefan Tews
  • Patent number: 8134165
    Abstract: Disclosed is a light emitting device employing non-stoichiometric tetragonal Alkaline Earth Silicate phosphors. The light emitting device comprises a light emitting diode emitting light of ultraviolet or visible light, and non-stoichiometric luminescent material disposed around the light emitting diode. The luminescent material adsorbs at least a portion of the light emitted from the light emitting diode and emits light having a different wavelength from the absorbed light. The non-stoichiometric luminescent material has tetragonal crystal structure, and contains more silicon in the crystal lattice than that in the crystal lattice of silicate phosphors having stoichiometric crystal structure. The luminescent material is represented as the formula (BauSrvCawCux)3?y(Zn,Mg,Mn)zSi1+bO5+2b:Eua. Light emitting devices having improved temperature and humidity stability can be provided by employing the non-stoichiometric tetragonal Alkaline Earth Silicate phosphors.
    Type: Grant
    Filed: August 14, 2008
    Date of Patent: March 13, 2012
    Assignee: Seoul Semiconductor Co., Ltd.
    Inventors: Chung Hoon Lee, Walter Tews, Gundula Roth, Stefan Tews
  • Publication number: 20120037933
    Abstract: The present invention provides a light emitting device comprising a first light emitting portion that emits white light at a color temperature of 6000K or more and a second light emitting portion that emits white light at a color temperature of 3000K or less, which include light emitting diode chips and phosphors and are independently driven. The present invention has an advantage in that a light emitting device can be diversely applied in a desired atmosphere and use by realizing white light with different light spectrums and color temperatures. Particularly, the present invention has the effect on health by adjusting the wavelength of light or the color temperature according to the circadian rhythm of humans.
    Type: Application
    Filed: October 24, 2011
    Publication date: February 16, 2012
    Applicant: SEOUL SEMICONDUCTOR CO., LTD.
    Inventors: Gundula ROTH, Walter TEWS, Chung-Hoon LEE
  • Publication number: 20120037850
    Abstract: A surface-modified silicate luminophore includes a silicate luminophore and a coating includes at least one of (a) a fluorinated coating including a fluorinated inorganic agent, a fluorinated organic agent, or a combination of fluorinated inorganic and organic agents, the fluorinated coating generating hydrophobic surface sites and (b) a combination of the fluorinated coating and at least one moisture barrier layer. The moisture barrier layer includes MgO, Al2O3, Y2O3, La2O3, Gd2O3, Lu2O3, and SiO2 or the corresponding precursors, and the coating is disposed on the surface of the silicate luminophore.
    Type: Application
    Filed: July 15, 2011
    Publication date: February 16, 2012
    Applicants: LITEC-LP GMBH, SEOUL SEMICONDUCTOR CO., LTD.
    Inventors: Chung Hoon LEE, Walter TEWS, Gundula ROTH, Detlef STARICK
  • Publication number: 20120001205
    Abstract: Exemplary embodiments of the present invention relate to light emitting devices including strontium oxyorthosilicate-type phosphors. The light emitting device includes a light emitting diode, which emits light in the UV or visible range, and phosphors disposed around the light emitting diode to absorb light emitted from the light emitting diode and emit light having a different wavelength from the absorbed light. The phosphors include an oxyorthosilicate phosphor having a general formula of Sr3-x-y-zCaxMIIySiO5: Euz with a calcium molar fraction in the range of 0<x?0.05.
    Type: Application
    Filed: December 20, 2010
    Publication date: January 5, 2012
    Applicant: SEOUL SEMICONDUCTOR CO., LTD.
    Inventors: Chung Hoon LEE, Walter TEWS, Gundula ROTH, Detlef STARICK
  • Patent number: 8089084
    Abstract: A light emitting device can be characterized as including a light emitting diode configured to emit light and a phosphor configured to change a wavelength of the light. The phosphor substantially covers at least a portion of the light emitting diode. The phosphor includes a compound having a host material. Divalent copper ions and oxygen are components of the host material.
    Type: Grant
    Filed: April 4, 2008
    Date of Patent: January 3, 2012
    Assignee: Seoul Semiconductor Co., Ltd.
    Inventors: Gundula Roth, Walter Tews, Chung Hoon Lee
  • Patent number: 8075802
    Abstract: This invention relates to luminescent materials for ultraviolet light or visible light excitation containing lead and/or copper doped chemical compounds. The luminescent material is composed of one or more than one compounds of aluminate type, silicate type, antimonate type, germanate/or germanate-silicate type, and/or phosphate type. Accordingly, the present invention is a good possibility to substitute earth alkaline ions by lead and copper for a shifting of the emission bands to longer or shorter wave length, respectively. Luminescent compounds containing copper and/or lead with improved luminescent properties and also with improved stability against water, humidity as well as other polar solvents are provided. The present invention is to provide lead and/or copper doped luminescent compounds, which has high color temperature range about 2,000K to 8,000K or 10,000K and CRI over 90.
    Type: Grant
    Filed: March 25, 2010
    Date of Patent: December 13, 2011
    Assignee: Seoul Semiconductor Co., Ltd.
    Inventors: Gundula Roth, Walter Tews, Chung Hoon Lee
  • Patent number: 8070983
    Abstract: This invention relates to luminescent materials for ultraviolet light or visible light excitation containing lead and/or copper doped chemical compounds. The luminescent material is composed of one or more than one compounds of aluminate type, silicate type, antimonate type, germanate/or germanate-silicate type, and/or phosphate type. Accordingly, the present invention is a good possibility to substitute earth alkaline ions by lead and copper for a shifting of the emission bands to longer or shorter wave length, respectively. Luminescent compounds containing copper and/or lead with improved luminescent properties and also with improved stability against water, humidity as well as other polar solvents are provided. The present invention is to provide lead and/or copper doped luminescent compounds, which has high color temperature range about 2,000K to 8,000K or 10,000K and CRI over 90.
    Type: Grant
    Filed: December 30, 2004
    Date of Patent: December 6, 2011
    Assignee: Seoul Semiconductor Co., Ltd.
    Inventors: Gundula Roth, Walter Tews, Chung Hoon Lee
  • Patent number: 8071988
    Abstract: Disclosed herein is a light emitting device including one or more light emitting diodes to primarily emit light having different wavelengths in the wavelength range of ultraviolet rays and/or blue light, and a wavelength-conversion means to convert the primary light into secondary light in the visible light wavelength range. The light emitting device of the current invention has a high color temperature of 2000 to 8000 K or 10000 K and a high color rendering index of 90 or more, thus easily realizing desired emission on the color coordinate system. Therefore, the lighting emitting device is applicable to mobile phones, notebook computers, and keypads or backlight units for various electronic products, and, in particular, automobiles and exterior and interior lighting fixtures.
    Type: Grant
    Filed: May 3, 2005
    Date of Patent: December 6, 2011
    Assignee: Seoul Semiconductor Co., Ltd.
    Inventors: Chung-Hoon Lee, Gundula Roth, Walter Tews
  • Patent number: 8070984
    Abstract: A luminescent material is disclosed. The luminescent material may include a first compound having a host lattice comprising first ions and oxygen. A first portion of the first ions may be substituted by copper ions. In one embodiment, the host lattice may include silicon, the copper ions may be divalent copper ions and the first compound may have an Olivin crystal structure, a ?-K2SO4 crystal structure, a trigonal Glaserite (K3Na(SO4)2) or monoclinic Merwinite crystal structure, a tetragonal Ackermanite crystal structure, a tetragonal crystal structure or an orthorhombic crystal structure. In another embodiment, the copper ions do not act as luminescent ions upon excitation with the ultraviolet or visible light.
    Type: Grant
    Filed: November 30, 2007
    Date of Patent: December 6, 2011
    Assignee: Seoul Semiconductor Co., Ltd.
    Inventors: Gundula Roth, Walter Tews, Chung-Hoon Lee
  • Patent number: 8066909
    Abstract: A light emitting device is disclosed. The light emitting device may include a light emitting diode (LED) for emitting light and a phosphor adjacent to the LED. The phosphor may be excitable by light emitted by the LED and may include a first compound having a host lattice comprising first ions and oxygen. In one embodiment, the host lattice may include silicon, the copper ions may be divalent copper ions and the first compound may have an Olivin crystal structure, a ?-K2SO4 crystal structure, a trigonal Glaserite (K3Na(SO4)2) or monoclinic Merwinite crystal structure, a tetragonal Ackermanite crystal structure, a tetragonal crystal structure or an orthorhombic crystal structure. In another embodiment, the copper ions do not act as luminescent ions upon excitation with the light emitted by the LED.
    Type: Grant
    Filed: November 30, 2007
    Date of Patent: November 29, 2011
    Assignee: Seoul Semiconductor Co., Ltd.
    Inventors: Gundula Roth, Walter Tews, Chung-Hoon Lee
  • Publication number: 20110204291
    Abstract: A luminescent material is disclosed. The luminescent material may include a first compound having a host lattice comprising first ions and oxygen. A first portion of the first ions may be substituted by copper ions. In one embodiment, the host lattice may include silicon, the copper ions may be divalent copper ions and the first compound may have an Olivine crystal structure, ?-K.2SO4 crystal structure, a trigonal Glaserite (K3Na(SO4)2) or monoclinic Merwinite crystal structure, a tetragonal Ackermanite crystal structure, a tetragonal crystal structure or an orthorhombic crystal structure. In another embodiment, the copper ions do not act as luminescent ions upon excitation with the ultraviolet or visible light.
    Type: Application
    Filed: May 3, 2011
    Publication date: August 25, 2011
    Applicant: SEOUL SEMICONDUCTOR CO., LTD.
    Inventors: Gundula ROTH, Walter TEWS, Chung Hoon LEE
  • Publication number: 20110147662
    Abstract: Exemplary embodiments of the present invention relate to inorganic phosphors based on silicate compounds having improved stability under a resulting radiation load and resistance to atmospheric humidity, which are capable of converting higher-energy excitation radiation, i.e. ultraviolet (UV) or blue light, with high efficiency into a longer-wavelength radiation which may be in the visible spectral range. A calcium molar fraction x having a value between 0 and 0.05 is added to a silicate phosphor having the general formula Sr3-x-y-zCaxMIIySiO5:Euz.
    Type: Application
    Filed: September 10, 2010
    Publication date: June 23, 2011
    Applicants: SEOUL SEMICONDUCTOR CO., LTD., LITEC-LP GMBH
    Inventors: Chung Hoon LEE, Walter TEWS, Gundula ROTH, Detlef STARICK