Patents by Inventor Shohei TAKAKU

Shohei TAKAKU 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: 20230383926
    Abstract: There is provided a wavelength conversion member including: a fluorescent body and a reflective film. The fluorescent body is configured to emit fluorescence by an excitation light and has an incident surface into which the excitation light comes and a rear surface which faces the incident surface. The reflective film is arranged on a side of the rear surface of the fluorescent body and includes a metal layer and ceramic particles dispersed in the metal layer. The ceramic particles are crystalline, and a melting point of the ceramic particles is higher than a melting point of a metal constructing the metal layer.
    Type: Application
    Filed: December 13, 2021
    Publication date: November 30, 2023
    Inventors: Yosuke YATSUYA, Toshiyuki SAKURAI, Shohei TAKAKU, Hiroki YAMAUCHI, Tomoo TANAKA, Hiroki TAKEUCHI, Shinji BAN
  • Patent number: 11796156
    Abstract: A fluorescent plate includes a fluorescent phase which emits fluorescence by excitation light, a light-transmitting phase which allows passage of the excitation light, and a plurality of voids surrounded by the fluorescent phase and the light-transmitting phase, wherein, in a cross section of the fluorescent plate including cross sections of the voids, an average ratio of a portion of the circumference of a void, which portion is in contact with the fluorescent phase to the entire circumference of the void, is higher than an area ratio of the area of the fluorescent phase present in the fluorescent plate to the total area of the fluorescent phase and the light-transmitting phase present in the fluorescent plate.
    Type: Grant
    Filed: June 3, 2021
    Date of Patent: October 24, 2023
    Assignee: NITERRA CO., LTD.
    Inventors: Shohei Takaku, Hiroki Yamauchi, Shinji Ban, Hiroki Takeuchi
  • Patent number: 11754259
    Abstract: A fluorescent plate including a fluorescent phase which emits fluorescence by excitation light, and a plurality of voids, wherein, in a cross section of the fluorescent plate including cross sections of the voids, voids having an equivalent circle diameter of 0.4 micrometers or greater and 50 micrometers or smaller have a standard deviation in equivalent circle diameter of 1.5 or less.
    Type: Grant
    Filed: June 3, 2021
    Date of Patent: September 12, 2023
    Assignee: NGK SPARK PLUG CO., LTD.
    Inventors: Shohei Takaku, Hiroki Yamauchi, Shinji Ban, Hiroki Takeuchi
  • Publication number: 20230220977
    Abstract: A fluorescent plate including a fluorescent phase which emits fluorescence by excitation light, and a plurality of voids, wherein, in a cross section of the fluorescent plate including cross sections of the voids, voids having an equivalent circle diameter of 0.4 micrometers or greater and 50 micrometers or smaller have a standard deviation in equivalent circle diameter of 1.5 or less.
    Type: Application
    Filed: June 3, 2021
    Publication date: July 13, 2023
    Inventors: Shohei TAKAKU, Hiroki YAMAUCHI, Shinji BAN, Hiroki TAKEUCHI
  • Publication number: 20230213171
    Abstract: A fluorescent plate includes a fluorescent phase which emits fluorescence by excitation light, and a plurality of voids. The plurality of voids include a plurality of particular voids having an equivalent circle diameter of 0.4 micrometers or greater and 50 micrometers or smaller. In a cross section of the fluorescent plate, the ratio of the number of the particular voids having a circularity greater than 0.6 and 1 or less to the total number of the plurality of particular voids is 50% or greater.
    Type: Application
    Filed: June 3, 2021
    Publication date: July 6, 2023
    Inventors: Hiroki YAMAUCHI, Shohei TAKAKU, Shinji BAN, Hiroki TAKEUCHI
  • Publication number: 20230213172
    Abstract: A fluorescent plate includes a fluorescent phase which emits fluorescence by excitation light, a light-transmitting phase which allows passage of the excitation light, and a plurality of voids surrounded by the fluorescent phase and the light-transmitting phase, wherein, in a cross section of the fluorescent plate including cross sections of the voids, an average ratio of a portion of the circumference of a void, which portion is in contact with the fluorescent phase to the entire circumference of the void, is higher than an area ratio of the area of the fluorescent phase present in the fluorescent plate to the total area of the fluorescent phase and the light-transmitting phase present in the fluorescent plate.
    Type: Application
    Filed: June 3, 2021
    Publication date: July 6, 2023
    Inventors: Shohei TAKAKU, Hiroki YAMAUCHI, Shinji BAN, Hiroki TAKEUCHI
  • Patent number: 11560513
    Abstract: One aspect of the disclosure provides an optical wavelength conversion member including a polycrystalline ceramic sintered body containing, as main components, Al2O3 crystal grains and crystal grains represented by formula (Y,A)3B5O12:Ce. In the optical wavelength conversion member, a (Y,A)3B5O12:Ce crystal grain has a region wherein the A concentration of a peripheral portion of the (Y,A)3B5O12:Ce crystal grain is higher than that of an interior portion of the (Y,A)3B5O12:Ce crystal grain. Thus, the optical wavelength conversion member exhibits high fluorescence intensity (i.e., high emission intensity) and high heat resistance (i.e., low likelihood of temperature quenching). The optical wavelength conversion member has a structure wherein the element A concentration of a peripheral portion of a (Y,A)3B5O12:Ce crystal grain differs from that in an interior portion of the crystal grain.
    Type: Grant
    Filed: July 1, 2019
    Date of Patent: January 24, 2023
    Assignee: NGK SPARK PLUG CO., LTD.
    Inventors: Shohei Takaku, Yusuke Katsu, Tsuneyuki Ito, Toshiaki Kurahashi, Hideto Yamada
  • Patent number: 11287107
    Abstract: An optical wavelength conversion device includes an optical wavelength conversion member configured to convert the wavelength of incident light; a heat dissipation member which is more excellent in heat dissipation than the optical wavelength conversion member; and a joint portion which joins the optical wavelength conversion member and the heat dissipation member together. The optical wavelength conversion member includes a plate-shaped ceramic fluorescent body and a reflecting film disposed on a heat dissipation member-side surface of the ceramic fluorescent body. The joint portion has a thermal conductivity of 120 W/mK or more. The joint portion has a melting point of 240° C. or higher.
    Type: Grant
    Filed: October 31, 2018
    Date of Patent: March 29, 2022
    Assignee: NGK SPARK PLUG CO., LTD.
    Inventors: Shohei Takaku, Yosuke Yatsuya, Yusuke Katsu, Tomoo Tanaka
  • Patent number: 11214731
    Abstract: An optical wavelength conversion member (9) provided with a ceramic plate (11) which is configured from a polycrystalline body that is mainly composed of Al2O3 and a component represented by A3B5O12:Ce; and each of A and B in A3B5O12 represents at least one element selected from the element groups described below. In addition, a dielectric multilayer film (13) which transmits a specific wavelength and reflects another specific wavelength is formed on a light incident surface (11a) of the ceramic plate (11). The ceramic plate (11) has a porosity of 2% by volume or less, while having an average surface roughness (an arithmetic mean roughness Sa) of 0.5 ?m or less. A: Sc, Y and lanthanoids (excluding Ce) B: Al and Ga. Also disclosed is a light-emitting device including the optical wavelength conversion member.
    Type: Grant
    Filed: November 10, 2017
    Date of Patent: January 4, 2022
    Assignee: NGK SPARK PLUG CO., LTD.
    Inventors: Tsuneyuki Ito, Yusuke Katsu, Shohei Takaku
  • Publication number: 20210324266
    Abstract: In one aspect of the present disclosure, there is provided an optical wavelength conversion member including a polycrystalline ceramic sintered body containing, as main components, Al2O3 crystal grains and crystal grains represented by formula X3Al5O12:Ce. In the optical wavelength conversion member 9, atoms of element X are present also in an Al2O3 crystal grain adjacent to the interface between the Al2O3 crystal grain and an X3Al5O12:Ce crystal grain.
    Type: Application
    Filed: July 17, 2019
    Publication date: October 21, 2021
    Inventors: Shohei TAKAKU, Yusuke KATSU, Tsuneyuki ITO, Toshiaki KURAHASHI, Hideto YAMADA
  • Publication number: 20210246367
    Abstract: One aspect of the disclosure provides an optical wavelength conversion member including a polycrystalline ceramic sintered body containing, as main components, Al2O3 crystal grains and crystal grains represented by formula (Y,A)3B5O12:Ce. In the optical wavelength conversion member, a (Y,A)3B5O12:Ce crystal grain has a region wherein the A concentration of a peripheral portion of the (Y,A)3B5O12:Ce crystal grain is higher than that of an interior portion of the (Y,A)3B5O12:Ce crystal grain. Thus, the optical wavelength conversion member exhibits high fluorescence intensity (i.e., high emission intensity) and high heat resistance (i.e., low likelihood of temperature quenching). The optical wavelength conversion member has a structure wherein the element A concentration of a peripheral portion of a (Y,A)3B5O12:Ce crystal grain differs from that in an interior portion of the crystal grain.
    Type: Application
    Filed: July 1, 2019
    Publication date: August 12, 2021
    Inventors: Shohei TAKAKU, Yusuke KATSU, Tsuneyuki ITO, Toshiaki KURAHASHI, Hideto YAMADA
  • Patent number: 11063186
    Abstract: A method for producing an optical wavelength conversion member (9) composed of a sintered body containing, as main components, Al2O3 and a component represented by formula A3B5O12:Ce; an optical wavelength conversion member; an optical wavelength conversion component including the optical wavelength conversion member; and a light-emitting device including the optical wavelength conversion member or the optical wavelength conversion component. The production method of the sintered body includes firing in a firing atmosphere having a pressure of 104 Pa or more and an oxygen concentration of 0.8 vol. % or more and less than 25 vol. %.
    Type: Grant
    Filed: October 24, 2017
    Date of Patent: July 13, 2021
    Assignee: NGK SPARK PLUG CO., LTD.
    Inventors: Yusuke Katsu, Shohei Takaku, Tsuneyuki Ito, Takeshi Mitsuoka, Jun Moteki
  • Publication number: 20210098657
    Abstract: An optical wavelength conversion member according to one aspect of the present disclosure includes a ceramic sintered body, wherein the ceramic sintered body has a fluorescent phase containing, as a main. component, fluorescent crystal grains that generate fluorescence in response to incident light, and a translucent phase containing translucent crystal grains as a main component. The optical wavelength conversion member includes a metal layer having light reflectivity and provided on a side of the ceramic sintered body opposite the side on which the light is incident, and a dielectric multilayer film including dielectric layers having different optical refractive indices and provided between the ceramic sintered body and the metal layer.
    Type: Application
    Filed: May 10, 2019
    Publication date: April 1, 2021
    Inventors: Tsuneyuki ITO, Shohei TAKAKU, Yuki SHIMURA, Shinji BAN, Yusuke KATSU
  • Patent number: 10910524
    Abstract: An optical wavelength conversion member and a light-emitting device including the optical wavelength conversion member. The light-emitting device (1) includes a container (3), a light-emitting element (5), and an optical wavelength conversion member (9). The optical wavelength conversion member (9) is composed of a polycrystalline ceramic sintered body containing, as main components, Al2O3 crystal grains and crystal grains of a component represented by formula A3B5O12:Ce. Specifically, A and B of the A3B5O12 individually represent at least one element selected from the following element groups: A: Sc, Y, and lanthanoids (except for Ce), and B: Al and Ga; the at least one element selected from the element groups is present in each crystal grain and the crystal grain boundary of the ceramic sintered body; and the element concentration of the crystal grain boundary is higher than the element concentration of the crystal grain.
    Type: Grant
    Filed: October 20, 2017
    Date of Patent: February 2, 2021
    Assignee: NGK SPARK PLUG CO.. LTD.
    Inventors: Jun Moteki, Shohei Takaku, Yusuke Katsu, Takeshi Mitsuoka, Tsuneyuki Ito
  • Publication number: 20210018160
    Abstract: Provided is an optical wavelength conversion device in which heat of an optical wavelength conversion member can be dissipated efficiently while the joint strength between the optical wavelength conversion member and a heat dissipation member is maintained. In the present disclosure, the optical wavelength conversion device includes an optical wavelength conversion member configured to convert the wavelength of incident light; a heat dissipation member which is more excellent in heat dissipation than the optical wavelength conversion member; and a joint portion which joins the optical wavelength conversion member and the heat dissipation member together. The optical wavelength conversion member includes a plate-shaped ceramic fluorescent body and a reflecting film disposed on a heat dissipation member-side surface of the ceramic fluorescent body. The joint portion has a thermal conductivity of 120 W/mK or more. The joint portion has a melting point of 240° C. or higher.
    Type: Application
    Filed: October 31, 2018
    Publication date: January 21, 2021
    Inventors: Shohei TAKAKU, Yosuke YATSUYA, Yusuke KATSU, Tomoo TANAKA
  • Publication number: 20200392401
    Abstract: An optical wavelength conversion member (9) provided with a ceramic plate (11) which is configured from a polycrystalline body that is mainly composed of Al2O3 and a component represented by A3B5O12:Ce; and each of A and B in A3B5O12 represents at least one element selected from the element groups described below. In addition, a dielectric multilayer film (13) which transmits a specific wavelength and reflects another specific wavelength is formed on a light incident surface (11a) of the ceramic plate (11). The ceramic plate (11) has a porosity of 2% by volume or less, while having an average surface roughness (an arithmetic mean roughness Sa) of 0.5 ?m or less. A: Sc, Y and lanthanoids (excluding Ce) B: Al and Ga. Also disclosed is a light-emitting device including the optical wavelength conversion member.
    Type: Application
    Filed: November 10, 2017
    Publication date: December 17, 2020
    Applicant: NGK SPARK PLUG CO., LTD.
    Inventors: Tsuneyuki ITO, Yusuke KATSU, Shohei TAKAKU
  • Patent number: 10727378
    Abstract: An optical wavelength conversion member and a light-emitting device including the optical wavelength conversion member. The optical wavelength conversion member (9) is formed of a ceramic sintered body having a fluorescent phase containing fluorescent crystal grains as a main component and a translucent phase containing translucent crystal grains as a main component. Crystal grains of the fluorescent phase have a composition represented by formula A3B5O12:Ce, where the element A is selected from Sc, Y, and lanthanoids (except for Ce), and the element B is selected from Al and Ga. In the optical wavelength conversion member (9), 0.3<a<34 and 300 ?m<y<1,050 ?m are satisfied, wherein a represents the area ratio of the translucent phase to the fluorescent phase in a cross section of the optical wavelength conversion member (9), and y represents the interfacial length of the fluorescent phase.
    Type: Grant
    Filed: October 20, 2017
    Date of Patent: July 28, 2020
    Assignee: NGK SPARK PLUG CO., LTD.
    Inventors: Shohei Takaku, Yusuke Katsu, Tsuneyuki Ito, Yuki Shimura, Takeshi Mitsuoka, Jun Moteki
  • Patent number: 10665761
    Abstract: An optical wavelength conversion member including a polycrystalline ceramic sintered body containing, as main components, Al2O3 crystal grains and crystal grains of a component represented by formula A3B5O12:Ce, wherein A is at least one element selected from Sc, Y and lanthanoids (except for Ce), and B is at least one element selected from Al and Ga. Further, the following relations are satisfied: 0%?X?25%, 9%?Y?45%, and 48%?Z?90%, wherein X represents a proportion corresponding to the ratio a/N, Y represents a proportion corresponding to the ratio b/N, and Z represents a proportion corresponding to the ratio c/N and a, b, c and N are as defined herein. Also disclosed is a light-emitting device including the optical wavelength conversion member.
    Type: Grant
    Filed: October 18, 2017
    Date of Patent: May 26, 2020
    Assignee: NGK SPARK PLUG CO., LTD.
    Inventors: Jun Moteki, Shohei Takaku, Yusuke Katsu, Takeshi Mitsuoka, Tsuneyuki Ito
  • Publication number: 20190259918
    Abstract: An optical wavelength conversion member and a light-emitting device including the optical wavelength conversion member. The optical wavelength conversion member (9) is formed of a ceramic sintered body having a fluorescent phase containing fluorescent crystal grains as a main component and a translucent phase containing translucent crystal grains as a main component. Crystal grains of the fluorescent phase have a composition represented by formula A3B5O12:Ce, where the element A is selected from Sc, Y, and lanthanoids (except for Ce), and the element B is selected from Al and Ga. In the optical wavelength conversion member (9), 0.3<a<34 and 300 ?m<y<1,050 ?m are satisfied, wherein a represents the area ratio of the translucent phase to the fluorescent phase in a cross section of the optical wavelength conversion member (9), and y represents the interfacial length of the fluorescent phase.
    Type: Application
    Filed: October 20, 2017
    Publication date: August 22, 2019
    Applicant: NGK SPARK PLUG CO., LTD.
    Inventors: Shohei TAKAKU, Yusuke KATSU, Tsuneyuki ITO, Yuki SHIMURA, Takeshi MITSUOKA, Jun MOTEKI
  • Publication number: 20190245119
    Abstract: A method for producing an optical wavelength conversion member (9) composed of a sintered body containing, as main components, Al2O3 and a component represented by formula A3B5O12:Ce; an optical wavelength conversion member; an optical wavelength conversion component including the optical wavelength conversion member; and a light-emitting device including the optical wavelength conversion member or the optical wavelength conversion component. The production method of the sintered body includes firing in a firing atmosphere having a pressure of 104 Pa or more and an oxygen concentration of 0.8 vol. % or more and less than 25 vol. %.
    Type: Application
    Filed: October 24, 2017
    Publication date: August 8, 2019
    Applicant: NGK SPARK PLUG CO., LTD.
    Inventors: Yusuke KATSU, Shohei TAKAKU, Tsuneyuki ITO, Takeshi MITSUOKA, Jun MOTEKI