Patents by Inventor Kiyoshi Shimamura

Kiyoshi Shimamura 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: 9190483
    Abstract: An AlN single crystal Schottky barrier diode including: an AlN single crystal substrate having a defect density of 106 cm?2 or less and a thickness of 300 ?m or more; a first electrode formed on one surface of the AlN single crystal substrate; and a second electrode formed on one surface of the AlN single crystal substrate while being spaced apart from the first electrode, the AlN single crystal Schottky barrier diode being provided with: a rectifying property such that an on-off ratio at the time of applying 10 V and ?40 V is at least 103 even at a high temperature of 573 K; a high voltage resistance such that a voltage can be applied at least within a range of ?40 V to 10 V; and a low on-resistance characteristic such that a current begins to flow at no greater than 5 V.
    Type: Grant
    Filed: January 30, 2013
    Date of Patent: November 17, 2015
    Assignee: NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Yoshihiro Irokawa, Kiyoshi Shimamura, Encarnacion Antonia Garcia Villora
  • Patent number: 9159800
    Abstract: An AlN single crystal Schottky barrier diode including: an AlN single crystal substrate having a defect density of 106 cm?2 or less and a thickness of 300 ?m or more; a first electrode formed on one surface of the AlN single crystal substrate; and a second electrode formed on one surface of the AlN single crystal substrate while being spaced apart from the first electrode, the AlN single crystal Schottky barrier diode being provided with: a rectifying property such that an on-off ratio at the time of applying 10 V and ?40 V is at least 103 even at a high temperature of 573 K; a high voltage resistance such that a voltage can be applied at least within a range of ?40 V to 10 V; and a low on-resistance characteristic such that a current begins to flow at no greater than 5 V.
    Type: Grant
    Filed: January 30, 2013
    Date of Patent: October 13, 2015
    Assignee: NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Yoshihiro Irokawa, Kiyoshi Shimamura, Encarnacion Antonia Garcia Villora
  • Patent number: 9117974
    Abstract: A light emitting element that includes a Ga2O3 substrate; an AlxGa1-xN buffer layer (0?×?1) formed on the Ga2O3 substrate; an n-GaN layer formed on the AlxGa1-xN buffer layer; an p-GaN layer formed on a portion of the n-GaN layer; an n-electrode formed on a portion of the n-GaN layer; and an p-electrode formed on the p-GaN layer.
    Type: Grant
    Filed: June 27, 2014
    Date of Patent: August 25, 2015
    Assignee: KOHA CO., LTD.
    Inventors: Noboru Ichinose, Kiyoshi Shimamura, Yukio Kaneko, Encarnacion Antonia Garcia Villora, Kazuo Aoki
  • Patent number: 9112123
    Abstract: [Problem] To provide a light-emitting device which does not undergo the deterioration in luminous efficiency associated with the long-term use. [Solution] A light-emitting device (1) comprises a light-emitting element (10) which can emit blue light and a phosphor (2) which is composed of a single kind of single crystal and can emit yellow light upon the irradiation with the light emitted from the light-emitting element (10) which serves as excitation light. Thus, it becomes possible to prevent the deterioration in luminous efficiency associated with the deterioration in a binder or the like compared with a light-emitting device which utilizes multiple kinds of granular phosphors, because any binder for binding phosphors to each other is not required in the light-emitting device (1).
    Type: Grant
    Filed: October 28, 2011
    Date of Patent: August 18, 2015
    Assignee: NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Kazuo Aoki, Makoto Watanabe, Kiyoshi Shimamura, Villora Encarnacion Antonia Garcia
  • Patent number: 9051662
    Abstract: The present invention provides a single crystal for an optical isolator having a Faraday rotation angle exceeding that of TGG single crystal in a wavelength region of 1064 nm or longer or in a wavelength region of shorter than 1064 nm, and is capable of realizing enlargement of crystal size, a production process thereof, an optical isolator, and an optical processor that uses the optical isolator. The single crystal according to the present invention is composed of a terbium aluminum garnet single crystal, and mainly a portion of the aluminum is replaced with lutetium.
    Type: Grant
    Filed: April 20, 2012
    Date of Patent: June 9, 2015
    Assignees: FUJIKURA LTD., NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Kazuo Sanada, Kiyoshi Shimamura, Villora Encarnacion Antonia Garcia
  • Patent number: 9030739
    Abstract: The present invention provides a garnet single crystal comprising a terbium aluminum garnet single crystal, wherein a portion of the aluminum is substituted with scandium, and a portion of at least one of the aluminum and terbium is substituted with at least one type selected from the group consisting of thulium, ytterbium and yttrium.
    Type: Grant
    Filed: October 18, 2012
    Date of Patent: May 12, 2015
    Assignees: Fujikura Ltd., National Institute for Materials Science
    Inventors: Tsubasa Hatanaka, Akiharu Funaki, Kiyoshi Shimamura, Villora Encarnacion Antonia Garcia
  • Publication number: 20150083967
    Abstract: A phosphor (and a method for manufacturing the same, and a light-emitting device that uses this phosphor) includes single crystals including YAG crystals as a mother crystal, the quantum efficiency of the phosphor at 25° C. being 92% or higher at an excitation light wavelength of 460 nm.
    Type: Application
    Filed: April 18, 2013
    Publication date: March 26, 2015
    Inventors: Makoto Watanabe, Daisuke Inomata, Kazuo Aoki, Kiyoshi Shimamura, Encarnacion Antonia Garcia Villora
  • Publication number: 20150034961
    Abstract: An AlN single crystal Schottky barrier diode including: an AlN single crystal substrate having a defect density of 106 cm?2 or less and a thickness of 300 ?m or more; a first electrode formed on one surface of the AlN single crystal substrate; and a second electrode formed on one surface of the AlN single crystal substrate while being spaced apart from the first electrode, the AlN single crystal Schottky barrier diode being provided with: a rectifying property such that an on-off ratio at the time of applying 10 V and ?40 V is at least 103 even at a high temperature of 573 K; a high voltage resistance such that a voltage can be applied at least within a range of ?40 V to 10 V; and a low on-resistance characteristic such that a current begins to flow at no greater than 5 V.
    Type: Application
    Filed: January 30, 2013
    Publication date: February 5, 2015
    Inventors: Yoshihiro Irokawa, Kiyoshi Shimamura, Encarnacion Antonia Garcia Villora
  • Publication number: 20150009562
    Abstract: An optical material used in a UV-excited yellow light-emitting material and an optical isolator, capable of emitting yellow light stably and highly efficiently even if a large current is fed to obtain the high luminance emission. The optical material used for the UV-excited yellow light-emitting material (2) and the optical isolator (210) is an oxide containing Ce, which is a terbium cerium aluminum garnet type single crystal wherein a part of terbium of a terbium aluminum garnet type single crystal is substituted by cerium. The ratio of number of moles of cerium to the total number of moles of terbium and cerium, namely the composition ratio of cerium, preferably falls within the range from 0.01 mol % to 50 mol %. A part of aluminum may be substituted by scandium or further by any one of terbium, cerium, yttrium, lutetium, ytterbium, and thulium.
    Type: Application
    Filed: April 27, 2013
    Publication date: January 8, 2015
    Applicant: NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Kiyoshi Shimamura, Encarnacion Antonia Garcia Villora
  • Publication number: 20140361328
    Abstract: A UV photoexcited red light-emitting material comprising a fluoride single crystal represented by the chemical formula: M1?xRExF2+x?w, wherein M is at least one metal element belonging to Group 2 of the Periodic Table selected from the group consisting of Be, Mg, Ca, Sr, and Ba, RE is a rare earth element, and the relationships: 0<x?0.4 and 0?w?0.5 are satisfied.
    Type: Application
    Filed: April 25, 2013
    Publication date: December 11, 2014
    Inventors: Kiyoshi Shimamura, Encarnacion Antonia Garcia Villora
  • Publication number: 20140306237
    Abstract: A light emitting element that includes a Ga2O3 substrate; an AlxGa1?xN buffer layer (0?×?1) formed on the Ga2O3 substrate; an n-GaN layer formed on the AlxGa1?xN buffer layer; an p-GaN layer formed on a portion of the n-GaN layer; an n-electrode formed on a portion of the n-GaN layer; and an p-electrode formed on the p-GaN layer.
    Type: Application
    Filed: June 27, 2014
    Publication date: October 16, 2014
    Inventors: Noboru Ichinose, Kiyoshi Shimamura, Yukio Kaneko, Encarnacion Antonia Garcia Villora, Kazuo Aoki
  • Patent number: 8808656
    Abstract: A garnet-type single crystal is represented by a general formula, A3B2C3O12 (having a crystal structure with three sites A, B and C occupied by cations, wherein A represents an element occupying the site A, B represents an element occupying the site B, C represents an element occupying the site C, O represents an oxygen atom), and contains fluorine, in which the fluorine attains any one or both of substituting for the oxygen atom or compensating for oxygen defect.
    Type: Grant
    Filed: July 24, 2009
    Date of Patent: August 19, 2014
    Assignee: National Institute for Materials Science
    Inventors: Kiyoshi Shimamura, Encarnacion Antonia Garcia Villora, Yasuhiko Kuwano
  • Patent number: 8804240
    Abstract: The present invention is a garnet-type single crystal represented by the following general formula: (Tb3-xScx)(Sc2-yAly)Al3O12-z??(1) (wherein, x satisfies 0<x<0.1).
    Type: Grant
    Filed: January 25, 2013
    Date of Patent: August 12, 2014
    Assignees: Fujikura Ltd., National Institute for Materials Science
    Inventors: Akiharu Funaki, Tsubasa Hatanaka, Kiyoshi Shimamura, Villora Encarnacion Antonia Garcia
  • Patent number: 8791466
    Abstract: A light emitting element has a substrate of gallium oxides and a pn-junction formed on the substrate. The substrate is of gallium oxides represented by: (AlXInYGa(1-X-Y))2O3 where 0?x?1, 0?y?1 and 0?x+y?1. The pn-junction has first conductivity type substrate, and GaN system compound semiconductor thin film of second conductivity type opposite to the first conductivity type.
    Type: Grant
    Filed: May 24, 2013
    Date of Patent: July 29, 2014
    Assignee: Koha Co., Ltd.
    Inventors: Noboru Ichinose, Kiyoshi Shimamura, Yukio Kaneko, Encarnacion Antonia Garcia Villora, Kazuo Aoki
  • Patent number: 8778225
    Abstract: An object of the invention is to provide an iodide single crystal material that provides a scintillator material for the next-generation TOF-PET, and a production process for high-quality iodide single crystal materials. The iodide single crystal material of the invention having the same crystal structure as LuI3 and activated by a luminescence center RE where RE is at least one element selected from the group consisting of Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb is characterized in that a part or the whole of lutetium (Lu) in said iodide single crystal material is substituted by Y and/or Gd.
    Type: Grant
    Filed: August 4, 2009
    Date of Patent: July 15, 2014
    Assignee: Sakai Chemical Industry Co., Ltd.
    Inventors: Kiyoshi Shimamura, Encarnacion Antonia Garcia Villora, Kenji Kitamura
  • Patent number: 8747553
    Abstract: A method of growing a p-type thin film of ?-Ga2O3 includes preparing a substrate including a ?-Ga2O3 single crystal, and growing a p-type thin film of ?-Ga2O3 on the substrate. The p-type thin film is grown in a manner that Ga in the thin film is replaced by a p-type dopant selected from H, Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Mn, Fe, Co, Ni, Pd, Cu, Ag, Au, Zn, Cd, Hg, Tl, and Pb.
    Type: Grant
    Filed: August 13, 2012
    Date of Patent: June 10, 2014
    Assignee: Waseda University
    Inventors: Noboru Ichinose, Kiyoshi Shimamura, Kazuo Aoki, Encarnacion Antonia Garcia Villora
  • Patent number: 8674399
    Abstract: A light-emitting element includes a ?-Ga2O3 substrate, a GaN-based semiconductor layer formed on the ?-Ga2O3 substrate, and a double-hetero light-emitting layer formed on the GaN-based semiconductor layer.
    Type: Grant
    Filed: June 22, 2011
    Date of Patent: March 18, 2014
    Assignee: Koha Co., Ltd.
    Inventors: Noboru Ichinose, Kiyoshi Shimamura, Kazuo Aoki, Encarnacion Antonia Garcia Villora
  • Publication number: 20130308187
    Abstract: The object(s) of the invention is to provide a Faraday rotator, an optical isolator, and optical processing equipment, which has a transmittance higher than that of TGG, is capable of upsizing, and has a higher performance index in the visible wavelength region in general, and on wavelengths of up to 400 nm in particular. The Faraday rotator is characterized by containing as a main component a fluoride represented by the following general formula (1) or (2): RE1F3-x??(1) LiRE2F4-x??(2) where 0?x<0.1, and RE1 or RE2 is at least one element selected from the group of rare earth elements.
    Type: Application
    Filed: March 23, 2012
    Publication date: November 21, 2013
    Applicant: NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Kiyoshi Shimamura, Encarnacion Antonia Garcia Villora
  • Publication number: 20130256730
    Abstract: [Problem] To provide a light-emitting device which does not undergo the deterioration in luminous efficiency associated with the long-term use. [Solution] A light-emitting device (1) comprises a light-emitting element (10) which can emit blue light and a phosphor (2) which is composed of a single kind of single crystal and can emit yellow light upon the irradiation with the light emitted from the light-emitting element (10) which serves as excitation light. Thus, it becomes possible to prevent the deterioration in luminous efficiency associated with the deterioration in a binder or the like compared with a light-emitting device which utilizes multiple kinds of granular phosphors, because any binder for binding phosphors to each other is not required in the light-emitting device (1).
    Type: Application
    Filed: October 28, 2011
    Publication date: October 3, 2013
    Applicants: National Institute for Materials Science, KOHA Co., Ltd.
    Inventors: Kazuo Aoki, Makoto Watanabe, Kiyoshi Shimamura, Villora Encarnacion Antonia Garcia
  • Publication number: 20130248902
    Abstract: A light emitting element has a substrate of gallium oxides and a pn-junction formed on the substrate. The substrate is of gallium oxides represented by: (AlXInYGa(1-X-Y))2O3 where 0?x?1, 0?y?1 and 0?x+y?1. The pn-junction has first conductivity type substrate, and GaN system compound semiconductor thin film of second conductivity type opposite to the first conductivity type.
    Type: Application
    Filed: May 24, 2013
    Publication date: September 26, 2013
    Applicant: KOHA CO., LTD.
    Inventors: Noboru Ichinose, Kiyoshi Shimamura, Yukio Kaneko, Encarnacion Antonia Garcia Villora, Kazuo Aoki