Patents by Inventor Hirotaka Sakuma

Hirotaka Sakuma 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: 8115388
    Abstract: There is provided a plasma display panel device using phosphors to improve reliability and color reproductivity or color performance. A plasma display panel includes: a discharge gas for generating ultraviolet light as a result of electric discharge, and a phosphor layer containing a phosphor for emitting light as a result of excitation by the ultraviolet light, in which the phosphor contains an Eu activated silicate phosphor added with at least one element selected from Al, Ga, Y and Gd, represented by the following General Formula (1): M13-yM2Si2O8:Euy??(1) wherein M1 is at least one element selected from the group consisting of Ba, Ca, and Sr; M2 is at least one element selected from the group consisting of Mg and Zn; and y satisfies the condition of 0.001?y?0.2.
    Type: Grant
    Filed: October 8, 2008
    Date of Patent: February 14, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Hirotaka Sakuma, Hitoshi Oaku, Choichiro Okazaki, Shin Imamura, Masaaki Komatsu
  • Publication number: 20110175066
    Abstract: It is an object of the present invention to provide an organic light-emitting device which can emit white light by easily controlling dopant concentrations. The organic light-emitting device has a first electrode (112) and second electrode (111) which hold a light-emitting layer (113) in-between, wherein the light-emitting layer contains a host material (104), red-light-emitting dopant (105), green-light-emitting dopant (106) and blue-light-emitting dopant (107), the red-light-emitting dopant containing a first functional group for transferring the dopant toward the first electrode and the green-light-emitting dopant containing a second functional group for transferring the dopant toward the second electrode.
    Type: Application
    Filed: August 18, 2010
    Publication date: July 21, 2011
    Inventors: Hirotaka SAKUMA, Sukekazu ARATANI, Hiroshi SASAKI
  • Patent number: 7786659
    Abstract: Using Eu2+ as the luminescence center for a green-emitting phosphor, a plasma display panel and a PDP device using it are configured by using an Eu2+-activated silicate green-emitting phosphate (Ca1-xM1x)2-e.M2.Si2O7:Eue with improved decay characteristics. In the formula, M1 is at least one element selected from the group containing Sr and Ba; M2 is at least one element selected from the group containing Mg and Zn; and x indicates the mole fraction of the component M1 and e indicates the mole fraction of Eu respectively satisfy the following conditions: 0<x<1 and 0.001?e?0.2.
    Type: Grant
    Filed: June 17, 2008
    Date of Patent: August 31, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Hitoshi Oaku, Hirotaka Sakuma, Choichiro Okazaki
  • Publication number: 20090224668
    Abstract: There is provided a plasma display panel device using phosphors to improve reliability and color reproductivity or color performance. A plasma display panel includes: a discharge gas for generating ultraviolet light as a result of electric discharge, and a phosphor layer containing a phosphor for emitting light as a result of excitation by the ultraviolet light, in which the phosphor contains an Eu activated silicate phosphor added with at least one element selected from Al, Ga, Y and Gd, represented by the following General Formula (1): M13-yM2Si2O8:Euy (1) wherein M1 is at least one element selected from the group consisting of Ba, Ca, and Sr; M2 is at least one element selected from the group consisting of Mg and Zn; and y satisfies the condition of 0.001?y?0.2.
    Type: Application
    Filed: October 8, 2008
    Publication date: September 10, 2009
    Inventors: Hirotaka Sakuma, Hitoshi Oaku, Choichiro Okazaki, Shin Imamura, Masaaki Komatsu
  • Publication number: 20090058255
    Abstract: Using Eu2+ as the luminescence center for a green-emitting phosphor, a plasma display panel and a PDP device using it are configured by using an Eu2+-activated silicate green-emitting phosphate (Ca1-xM1x)2-e.M2.Si2O7:Eue with improved decay characteristics. In the formula, M1 is at least one element selected from the group containing Sr and Ba; M2 is at least one element selected from the group containing Mg and Zn; and x indicates the mole fraction of the component M1 and e indicates the mole fraction of Eu respectively satisfy the following conditions: 0<x<1 and 0.001?e?0.2.
    Type: Application
    Filed: June 17, 2008
    Publication date: March 5, 2009
    Inventors: Hitoshi OAKU, Hirotaka Sakuma, Choichiro Okazaki
  • Publication number: 20080067917
    Abstract: In order to improve luminescence life, color temperature, the linearity of luminous intensity, and colority that have not been solved by conventional methods, a thin panel display of electron beam excitation type includes a substrate including plural first electrodes parallel to each other, plural second electrodes parallel to each other that are orthogonal to the first electrodes, and electron emitters disposed in intersections of the first electrodes and the second electrodes, or near the intersections, and a faceplate on which phosphor layers are formed, in which, as the phosphor layers, blue emitting phosphor layers are used which contain CaMgSi2O6:Eu blue emitting phosphors that have 0.16° or less as full width at half maximum of an X-ray diffraction peak developing near a central peak of 29.8°.
    Type: Application
    Filed: July 11, 2007
    Publication date: March 20, 2008
    Inventors: Masaaki Komatsu, Hirotaka Sakuma, Shin Imamura
  • Publication number: 20080048547
    Abstract: A plasma display panel including a discharge gas for generating ultraviolet light as a result of electric discharge, and a phosphor layer containing a phosphor for emitting light upon excitation by ultraviolet light is provided. The phosphor contains a novel Eu-activated silicate phosphor represented by (CaxM11-x)3-e.M2.Si2O8: Eue. In the formula, M1 is at least one element selected from the group consisting of Sr and Ba; M2 is at least one element selected from the group consisting of Mg and Zn; x is the mole fraction of the component Ca satisfying the condition of 0<x?0.2, and e is the mole fraction of Eu satisfying the condition of 0.001?e?0.2.
    Type: Application
    Filed: July 26, 2007
    Publication date: February 28, 2008
    Inventors: Hitoshi Oaku, Hirotaka Sakuma, Choichiro Okazaki
  • Publication number: 20070210693
    Abstract: To improve luminescence life, linearity of emission luminescence, and colority of an electron beam excitation display of thin flat type. The electron beam excitation display of thin flat type has a rear plate provided with a plurality of first electrodes in parallel with one another, a plurality of second electrodes in parallel with one another and orthogonal to the first electrodes, and electron emitters placed at points of intersection or near the points of intersection of the first electrodes and the second electrodes and a faceplate formed with a phosphor layer. By using a blue-emitting phosphor formed by mixing a blue-emitting phosphor ZnS:Ag and a blue-emitting phosphor CaMgSi2O6:Eu for the phosphor layer, the electron beam excitation display of thin flat type improved in luminescence life, linearity of emission luminescence, and colority that have been left unsolved is provided.
    Type: Application
    Filed: February 9, 2007
    Publication date: September 13, 2007
    Inventors: Masaaki KOMATSU, Shin Imamura, Hirotaka Sakuma