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).

  • Publication number: 20140077685
    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: Application
    Filed: December 28, 2011
    Publication date: March 20, 2014
    Applicants: DEXERIALS CORPORATION, SONY CORPORATION
    Inventors: Takamasa Izawa, Tsuneo Kusunoki
  • Publication number: 20140036201
    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: Application
    Filed: May 14, 2012
    Publication date: February 6, 2014
    Applicant: DEXERIALS CORPORATION
    Inventors: Masaki Kanno, Takamasa Izawa, Tsuneo Kusunoki
  • Publication number: 20130292610
    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: Application
    Filed: January 18, 2012
    Publication date: November 7, 2013
    Applicant: DEXERIALS CORPORATION
    Inventors: Masaki Kanno, Takamasa Izawa, Tsuneo Kusunoki
  • Publication number: 20130154470
    Abstract: [Problems to Be Solved] 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. [Means to Solve the Problem] 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 composition formula (1). [Chemical Formula 1] [A(m-x)Eux][Si(9-y)Cy]OnN[12-2(n-m)/3]??Composition Formula (1) Note that, in the composition formula (1), the element A is a 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.
    Type: Application
    Filed: December 28, 2011
    Publication date: June 20, 2013
    Applicants: DEXERIALS CORPORATION, SONY CORPORATION
    Inventors: Takamasa Izawa, Tsuneo Kusunoki
  • Publication number: 20120326086
    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: March 21, 2012
    Publication date: December 27, 2012
    Applicant: SONY CORPORATION
    Inventors: Hiraku Akiho, Tsuneo Kusunoki, Takahiro Igarashi, Takamasa Izawa
  • Publication number: 20120218496
    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: December 28, 2011
    Publication date: August 30, 2012
    Applicant: SONY CHEMICAL & INFORMATION DEVICE CORPORATION
    Inventors: Takamasa Izawa, Hiraku Akiho, Tsuneo Kusunoki, Takahiro Igarashi, Masaki Kanno
  • Patent number: 8210701
    Abstract: Disclosed herein is a lighting device including a blue light-emitting element adapted to emit a blue light beam; and a green phosphor layer which is disposed apart from the blue light-emitting element and can function as a light diffusion layer, the green phosphor layer including a green phosphor adapted to emit green fluorescence when excited by the blue light beam, the green phosphor having a refractive index of 1.49 or more and a quantum efficiency of 79% or more.
    Type: Grant
    Filed: October 8, 2009
    Date of Patent: July 3, 2012
    Assignee: Sony Corporation
    Inventors: Takahiro Igarashi, Takamasa Izawa, Tsuneo Kusunoki
  • Publication number: 20110273864
    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: May 3, 2011
    Publication date: November 10, 2011
    Applicant: Sony Corporation
    Inventors: Takamasa Izawa, Tsuneo Kusunoki, Takahiro Igarashi
  • Publication number: 20110176084
    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: June 30, 2009
    Publication date: July 21, 2011
    Applicant: SONY CORPORATION
    Inventors: Hiraku Akiho, Tsuneo Kusunoki, Takahiro Igarashi, Takamasa Izawa
  • Publication number: 20100085727
    Abstract: Disclosed herein is a lighting device including a blue light-emitting element adapted to emit a blue light beam; and a green phosphor layer which is disposed apart from the blue light-emitting element and can function as a light diffusion layer, the green phosphor layer including a green phosphor adapted to emit green fluorescence when excited by the blue light beam, the green phosphor having a refractive index of 1.49 or more and a quantum efficiency of 79% or more.
    Type: Application
    Filed: October 8, 2009
    Publication date: April 8, 2010
    Applicant: SONY CORPORATION
    Inventors: Takahiro Igarashi, Takamasa Izawa, Tsuneo Kusunoki