Patents by Inventor Takamasa Izawa

Takamasa Izawa 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: 10358598
    Abstract: A compound is provided containing silicon, aluminum, strontium, europium, nitrogen, and oxygen is used that enables a red phosphor having strong luminous intensity and high luminance to be obtained, and that enables the color gamut of a white LED to be increased with the use of red phosphor. The red phosphor contains element A, europium, silicon, aluminum, oxygen, and nitrogen at the atom number ratio of the following formula: [Am?x)Eux]Si9AlyOnN [12+y?2(n?m)/3]. The element A in the formula is at least one of magnesium, calcium, strontium, and barium, and m, x, y, and n in the formula satisfy the relations 3<m<5, 0<x<1, 0<y<2, and 0<n<10.
    Type: Grant
    Filed: June 2, 2017
    Date of Patent: July 23, 2019
    Assignee: DEXERIALS CORPORATION
    Inventors: Hiraku Akiho, Tsuneo Kusunoki, Takahiro Igarashi, Takamasa Izawa
  • Patent number: 10047931
    Abstract: A method for manufacturing green-emitting phosphor particles including the steps of producing a powder containing europium and strontium from a solution containing a europium compound and a strontium compound, mixing the resulting powder and a powdered gallium compound, and performing firing.
    Type: Grant
    Filed: November 9, 2015
    Date of Patent: August 14, 2018
    Assignee: DEXERIALS CORPORATION
    Inventors: Takamasa Izawa, Tsuneo Kusunoki, Takahiro Igarashi
  • Publication number: 20170306225
    Abstract: A compound is provided containing silicon, aluminum, strontium, europium, nitrogen, and oxygen is used that enables a red phosphor having strong luminous intensity and high luminance to be obtained, and that enables the color gamut of a white LED to be increased with the use of red phosphor. The red phosphor contains element A, europium, silicon, aluminum, oxygen, and nitrogen at the atom number ratio of the following formula: [Am?x)Eux]Si9AlyOnN [12+y?2(n?m)/3]. The element A in the formula is at least one of magnesium, calcium, strontium, and barium, and m, x, y, and n in the formula satisfy the relations 3<m<5, 0<x<1, 0<y<2, and 0<n<10.
    Type: Application
    Filed: June 2, 2017
    Publication date: October 26, 2017
    Applicant: DEXERIALS CORPORATION
    Inventors: Hiraku AKIHO, Tsuneo KUSUNOKI, Takahiro IGARASHI, Takamasa IZAWA
  • Patent number: 9725648
    Abstract: A yellow phosphor is provided. The yellow phosphor includes a crystal formed of a compound that is represented by the following formula (1): Ln4?x(EuzM1?z)xSi12?yAlyO3+x+yN18?x?y(0.5?x?3, 0<z<0.3, 0<y?4) (1), wherein Ln includes at least one rare earth element, and M includes at least one selected from calcium (Ca), barium (Ba), strontium (Sr), and magnesium (Mg).
    Type: Grant
    Filed: December 10, 2014
    Date of Patent: August 8, 2017
    Assignee: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Takamasa Izawa, Dohoon Kim, Masahiko Yoshino, Takatoshi Seto
  • Patent number: 9695358
    Abstract: A compound is provided containing silicon, aluminum, strontium, europium, nitrogen, and oxygen is used that enables a red phosphor having strong luminous intensity and high luminance to be obtained, and that enables the color gamut of a white LED to be increased with the use of the red phosphor. The red phosphor contains an element A, europium, silicon, aluminum, oxygen, and nitrogen at the atom number ratio of the following formula: [A(m-x)Eux]Si9AlyOnN[12+y?2(n?m)/3]. The element A in the formula is at least one of magnesium, calcium, strontium, and barium, and m, x, y, and n in the formula satisfy the relations 3<m<5, 0<x<1, 0<y<2, and 0<n<10.
    Type: Grant
    Filed: December 11, 2015
    Date of Patent: July 4, 2017
    Assignee: DEXERIALS CORPORATION
    Inventors: Hiraku Akiho, Tsuneo Kusunoki, Takahiro Igarashi, Takamasa Izawa
  • Patent number: 9493701
    Abstract: A red phosphor of high efficiency and a method for producing it are provided. A white light source and an illumination device that allow illumination with the pure white color using the red phosphor are also provided. In addition, a liquid crystal display device using the red phosphor and exhibiting good color reproducing performance is provided. The red phosphor contains an element A, europium (Eu), silicon (Si), carbon (C), oxygen (O) and nitrogen (N) in the ratios of the numbers of atoms of the following compositional formula (1): [Chemical Formula 1] [A(m-x)Eux][Si(9-y)Cy]OnN[12-2(n-m)/3]?? compositional formula (1) where the element A is at least one of magnesium (Mg), calcium (Ca), strontium (Sr) and barium (Ba), and where m, x and n in the compositional formula (1) satisfy the relationships of 3<m<5, 0<x<1, 0<y<2 and 0<n<10 (FIG. 5A).
    Type: Grant
    Filed: July 11, 2014
    Date of Patent: November 15, 2016
    Assignee: Dexerials Corporation
    Inventors: Takamasa Izawa, Hiraku Akiho, Tsuneo Kusunoki, Takahiro Igarashi, Masaki Kanno
  • Patent number: 9318658
    Abstract: Provided is a process for producing a red phosphor, said process achieving enhanced productivity. Also provided are: a red phosphor having excellent luminescence characteristics; and a white light source, a lighting system, and a liquid crystal display device, using the red phosphor. This process comprises: mixing an A-containing compound, a nitrogen-free europium source, a silicon-containing compound, an aluminum-containing compound and a carbon-containing reducing agent so as to form a mixture wherein the atomic ratio among A, europium (Eu), silicon (Si), aluminum (Al) and carbon (C) is a value represented by compositional formula (1); firing the mixture; and pulverizing the fired mixture. (Am?xEux)Aly(Si1?zCz)90 nN[12+y?2(n?m)/3] (1) [wherein A is at least one element selected from among magnesium (Mg), calcium (Ca), strontium (Sr) and barium (Ba), and m, x, z and n satisfy the relationships: 3.
    Type: Grant
    Filed: May 14, 2012
    Date of Patent: April 19, 2016
    Assignee: DEXERIALS CORPORATION
    Inventors: Masaki Kanno, Takamasa Izawa, Tsuneo Kusunoki
  • Patent number: 9309457
    Abstract: A process for producing a coated phosphor, namely a phosphor coated with a coating material, which includes a mixing step of mixing a phosphor with a coating material in a solvent to form a mixed fluid and a separation step of separating the mixed fluid into a solid phase and a liquid phase, wherein the phosphor comprises barium (Ba), strontium (Sr), europium (Eu), silicon (Si) and oxygen (O) at an atomic ratio represented by compositional formula (1), and the mass ratio of the phosphor to the coating material is 40:260 to 200:260, [(Ba1-ySry)1-xEux]aSibOc (1) [wherein a, b, c, x and y satisfy the relationships: 2.7<a<3.3, 0.9<b<1.1, 4.5<c<5.5, 0<x<0.09 and 0.25<y<0.75].
    Type: Grant
    Filed: January 18, 2012
    Date of Patent: April 12, 2016
    Assignee: DEXERIALS CORPORATION
    Inventors: Masaki Kanno, Takamasa Izawa, Tsuneo Kusunoki
  • Publication number: 20160096990
    Abstract: A compound is provided containing silicon, aluminum, strontium, europium, nitrogen, and oxygen is used that enables a red phosphor having strong luminous intensity and high luminance to be obtained, and that enables the color gamut of a white LED to be increased with the use of the red phosphor. The red phosphor contains an element A, europium, silicon, aluminum, oxygen, and nitrogen at the atom number ratio of the following formula: [A(m-x)Eux]Si9AlyOnN[12+y?2(n?m)/3]. The element A in the formula is at least one of magnesium, calcium, strontium, and barium, and m, x, y, and n in the formula satisfy the relations 3<m<5, 0<x<1, 0<y<2, and 0<n<10.
    Type: Application
    Filed: December 11, 2015
    Publication date: April 7, 2016
    Applicant: DEXERIALS CORPORATION
    Inventors: Hiraku AKIHO, Tsuneo KUSUNOKI, Takahiro IGARASHI, Takamasa IZAWA
  • Publication number: 20160061418
    Abstract: A method for manufacturing green-emitting phosphor particles including the steps of producing a powder containing europium and strontium from a solution containing a europium compound and a strontium compound, mixing the resulting powder and a powdered gallium compound, and performing firing.
    Type: Application
    Filed: November 9, 2015
    Publication date: March 3, 2016
    Inventors: Takamasa IZAWA, Tsuneo KUSUNOKI, Takahiro IGARASHI
  • Patent number: 9243184
    Abstract: A compound is provided containing silicon, aluminum, strontium, europium, nitrogen, and oxygen is used that enables a red phosphor having strong luminous intensity and high luminance to be obtained, and that enables the color gamut of a white LED to be increased with the use of the red phosphor. The red phosphor contains an element A, curopium, silicon, aluminum, oxygen, and nitrogen at the atom number ratio of the following formula: [A(m-x)Eux]Si9AlyOnN[12+y-2(n-m)/3]. The element A in the formula is at least one of magnesium, calcium, strontium, and barium, and m, x, y, and n in the formula satisfy the relations 3<m<5, 0<x<1, 0<y<2, and 0<n<10.
    Type: Grant
    Filed: March 6, 2014
    Date of Patent: January 26, 2016
    Assignee: DEXERIALS CORPORATION
    Inventors: Hiraku Akiho, Tsuneo Kusunoki, Takahiro Igarashi, Takamasa Izawa
  • Patent number: 9181476
    Abstract: A method for manufacturing green-emitting phosphor particles including the steps of producing a powder containing europium and strontium from a solution containing a europium compound and a strontium compound, mixing the resulting powder and a powdered gallium compound, and performing firing.
    Type: Grant
    Filed: May 3, 2011
    Date of Patent: November 10, 2015
    Assignee: DEXERIALS CORPORATION
    Inventors: Takamasa Izawa, Tsuneo Kusunoki, Takahiro Igarashi
  • Publication number: 20150159085
    Abstract: A yellow phosphor is provided. The yellow phosphor includes a crystal formed of a compound that is represented by the following formula (1): Ln4?x(EuzM1?z)xSi12?yAlyO3+x+yN18?x?y(0.5?x?3, 0<y?4) (1), wherein Ln includes at least one selected from a Group IIIa element and a rare earth element, and M includes at least one selected from calcium (Ca), barium (Ba), strontium (Sr), and magnesium (Mg).
    Type: Application
    Filed: December 10, 2014
    Publication date: June 11, 2015
    Inventors: Takamasa IZAWA, Dohoon KIM, Masahiko YOSHINO, Takatoshi SETO
  • Patent number: 8961827
    Abstract: The present invention provides an efficient red fluorescent material and a method for producing the same, provides a white light source and an illuminating device each of which uses this red fluorescent material to achieve snow-white lighting, and furthermore provides a liquid crystal display having excellent color reproduction. The red fluorescent material contains an element (A), europium (Eu), silicon (Si), carbon (C), oxygen (O), and nitrogen (N), at an atomic ratio of the following in compositional formula (1). [A(m-x)Eux][Si(9-y)Cy]OnN[12-2(n-m)/3] Note that, in the compositional formula (1), element A is group 2 element including at least calcium (Ca) and strontium (Sr). Also, note that, in the composition formula (1), m, x, y, and n satisfy 3<m<5, 0<x<1, 0<y<9, and 0<n<10, respectively. Such red fluorescent material is able to improve quantum efficiency, compared with a red fluorescent material which does not contain calcium (Ca) but contains strontium (Sr) as the element A.
    Type: Grant
    Filed: December 28, 2011
    Date of Patent: February 24, 2015
    Assignee: Dexerials Corporation
    Inventors: Takamasa Izawa, Tsuneo Kusunoki
  • Patent number: 8884513
    Abstract: The present invention provides an efficient red fluorescent material and a method for producing the same, provides a white light source and an illuminating device each of which uses this red fluorescent material to achieve snow-white lighting, and furthermore provides a liquid crystal display having excellent color reproduction. The red fluorescent material contains an element A, europium, silicon, carbon, oxygen, and nitrogen, at an atomic ratio of the following composition formula (1), and, in a Photo Luminescence Excitation spectrum of the red fluorescent material, a relative value of a luminescence intensity of 550 nm excitation wavelength when a luminescence intensity of 400 nm excitation wavelength is defined as 1 is not more than 0.85 and not less than 0.55.
    Type: Grant
    Filed: December 28, 2011
    Date of Patent: November 11, 2014
    Assignee: Dexerials Corporation
    Inventors: Takamasa Izawa, Tsuneo Kusunoki
  • Publication number: 20140320787
    Abstract: A red phosphor of high efficiency and a method for producing it are provided. A white light source and an illumination device that allow illumination with the pure white color using the red phosphor are also provided. In addition, a liquid crystal display device using the red phosphor and exhibiting good color reproducing performance is provided. The red phosphor contains an element A, europium (Eu), silicon (Si), carbon (C), oxygen (O) and nitrogen (N) in the ratios of the numbers of atoms of the following compositional formula (1): [Chemical Formula 1] [A(m-x)EUx][Si(9-y)Cy]OnN[12-2(n-m)/3]??compositional formula (1) where the element A is at least one of magnesium (Mg), calcium (Ca), strontium (Sr) and barium (Ba), and where m, x and n in the compositional formula (1) satisfy the relationships of 3<m<5, 0<x<1, 0<y<2 and 0<n<10 (FIG. 5A).
    Type: Application
    Filed: July 11, 2014
    Publication date: October 30, 2014
    Inventors: Takamasa Izawa, Hiraku Akiho, Tsuneo Kusunoki, Takahiro Igarashi, Masaki Kanno
  • Patent number: 8808578
    Abstract: A red phosphor of high efficiency and a method for producing it are provided. A white light source and an illumination device that allow illumination with the pure white color using the red phosphor are also provided. In addition, a liquid crystal display device using the red phosphor and exhibiting good color reproducing performance is provided. The red phosphor contains an element A, europium (Eu), silicon (Si), carbon (C), oxygen (O) and nitrogen (N) in the ratios of the numbers of atoms of the following compositional formula (1): [Chemical Formula 1] [A(m-x)Eux][Si(9-y)Cy]OnN[12-2(n-m)/3]??compositional formula (1) where the element A is at least one of magnesium (Mg), calcium (Ca), strontium (Sr) and barium (Ba), and where m, x and n in the compositional formula (1) satisfy the relationships of 3<m<5, 0<x<1, 0<y<2 and 0<n<10 (FIG. 5A).
    Type: Grant
    Filed: December 28, 2011
    Date of Patent: August 19, 2014
    Assignee: Dexerials Corporation
    Inventors: Takamasa Izawa, Hiraku Akiho, Tsuneo Kusunoki, Takahiro Igarashi, Masaki Kanno
  • Publication number: 20140183411
    Abstract: A compound is provided containing silicon, aluminum, strontium, europium, nitrogen, and oxygen is used that enables a red phosphor having strong luminous intensity and high luminance to be obtained, and that enables the color gamut of a white LED to be increased with the use of the red phosphor. The red phosphor contains an element A, curopium, silicon, aluminum, oxygen, and nitrogen at the atom number ratio of the following formula: [A(m-x)Eux]Si9AlyOnN[12+y-2(n-m)/3]. The element A in the formula is at least one of magnesium, calcium, strontium, and barium, and m, x, y, and n in the formula satisfy the relations 3<m<5, 0<x<1, 0<y<2, and 0<n<10.
    Type: Application
    Filed: March 6, 2014
    Publication date: July 3, 2014
    Applicant: Dexerials Corporation
    Inventors: Hiraku AKIHO, Tsuneo Kusunoki, Takahiro Igarashi, Takamasa Izawa
  • Patent number: 8703018
    Abstract: A compound is provided containing silicon, aluminum, strontium, europium, nitrogen, and oxygen is used that enables a red phosphor having strong luminous intensity and high luminance to be obtained, and that enables the color gamut of a white LED to be increased with the use of the red phosphor. The red phosphor contains an element A, europium, silicon, aluminum, oxygen, and nitrogen at the atom number ratio of the following formula: [A(m?x)Eux]Si9AlyOnN[12+y?2(n?m)/3]. The element A in the formula is at least one of magnesium, calcium, strontium, and barium, and m, x, y, and n in the formula satisfy the relations 3<m<5, 0<x<1, 0<y<2, and 0<n<10.
    Type: Grant
    Filed: March 21, 2012
    Date of Patent: April 22, 2014
    Assignee: Dexerials Corporation
    Inventors: Hiraku Akiho, Tsuneo Kusunoki, Takahiro Igarashi, Takamasa Izawa
  • Patent number: 8691113
    Abstract: A compound is provided containing silicon, aluminum, strontium, europium, nitrogen, and oxygen is used that enables a red phosphor having strong luminous intensity and high luminance to be obtained, and that enables the color gamut of a white LED to be increased with the use of the red phosphor. The red phosphor contains an element A, europium, silicon, aluminum, oxygen, and nitrogen at the atom number ratio of the following formula: [A(m?x)Eux]Si9AlyOnN[12+y?2(n?m)/3]. The element A in the formula is at least one of magnesium, calcium, strontium, and barium, and m, x, y, and n in the formula satisfy the relations 3<m<5, 0<x<1, 0<y<2, and 0<n<10.
    Type: Grant
    Filed: June 30, 2009
    Date of Patent: April 8, 2014
    Assignee: Dexerials Corporation
    Inventors: Hiraku Akiho, Tsuneo Kusunoki, Takahiro Igarashi, Takamasa Izawa