Patents by Inventor Masayoshi Ichikawa

Masayoshi Ichikawa 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: 20220356074
    Abstract: A potassium hexafluoromanganate is represented by General Formula: K2MnF6, and a diffuse reflectance with respect to light having a wavelength of 310 nm is 20% or more.
    Type: Application
    Filed: August 4, 2020
    Publication date: November 10, 2022
    Applicant: DENKA COMPANY LIMITED
    Inventors: Masayoshi ICHIKAWA, Motoi TANAKA, Kazuhiro ITOH
  • Publication number: 20220348478
    Abstract: A potassium hexafluoromanganate is represented by General Formula: K2MnF6, and a diffuse reflectance with respect to light having a wavelength of 550 nm is 60% or more.
    Type: Application
    Filed: August 4, 2020
    Publication date: November 3, 2022
    Applicant: DENKA COMPANY LIMITED
    Inventors: Masayoshi ICHIKAWA, Motoi TANAKA, Kazuhiro ITOH
  • Patent number: 11114589
    Abstract: Provided is a fluoride phosphor that has a good external quantum efficiency and is suitable for stably producing white LEDs. The fluoride phosphor has a composition represented by a general formula (1) and a repose angle of 30° or more and 60° or less. general formula: A2M(1-n)F6:Mn4+n (1), wherein 0<n?0.1, the element A is one or more alkali metal elements including at least K, and the element M is a simple substance of Si, a simple substance of Ge, or a combination of Si and one or more elements selected from the group consisting of Ge, Sn, Ti, Zr, and Hf.
    Type: Grant
    Filed: June 12, 2018
    Date of Patent: September 7, 2021
    Assignee: Denka Company Limited
    Inventors: Masayoshi Ichikawa, Ryosuke Kondo, Hideyuki Emoto
  • Patent number: 10982139
    Abstract: Provided is a fluoride phosphor that has a good external quantum efficiency and is suitable for stably producing white LEDs. The fluoride phosphor having a composition represented by a general formula (1), a bulk density of 0.80 g/cm3 or more, and a mass median diameter (D50) of 30 ?m or less: general formula: A2M(1-n)F6:Mn4+n (1), wherein 0<n?0.1, the element A is one or more alkali metal elements including at least K, and the element M is a simple substance of Si, a simple substance of Ge, or a combination of Si and one or more elements selected from the group consisting of Ge, Sn, Ti, Zr, and Hf.
    Type: Grant
    Filed: June 12, 2018
    Date of Patent: April 20, 2021
    Assignee: Denka Company Limited
    Inventors: Masayoshi Ichikawa, Ryosuke Konda, Hideyuki Emoto
  • Patent number: 10947450
    Abstract: Provided is a fluoride phosphor that has a good external quantum efficiency and is suitable for stably producing white LEDs. The fluoride phosphor having a composition represented by a general formula (1), a bulk density of 0.80 g/cm3 or more, and a mass median diameter (D50) of 30 ?m or less: general formula: A2M(1-n)F6:Mn4+n (1), wherein 0<n?0.1, the element A is one or more alkali metal elements including at least K, and the element M is a simple substance of Si, a simple substance of Ge, or a combination of Si and one or more elements selected from the group consisting of Ge, Sn, Ti, Zr, and Hf.
    Type: Grant
    Filed: June 12, 2018
    Date of Patent: March 16, 2021
    Assignee: Denka Company Limited
    Inventors: Masayoshi Ichikawa, Ryosuke Konda, Hideyuki Emoto
  • Patent number: 10941339
    Abstract: The purpose of the present invention is to provide a fluoride phosphor (represented by the general formula A2SiF6:Mn) having high luminescence intensity and reliability, a high-luminance light-emitting device using this phosphor, and a production method for this phosphor. The production method for a fluoride phosphor represented by the general formula A2SiF6:Mn (where element A is an alkali metal element including at least potassium), wherein the fluoride phosphor production method comprises: a step of preparing an aqueous solution wherein element A and fluorine are dissolved in a solvent; and a step of adding, to the aqueous solution, solid silicon dioxide and a manganese compound that supplies manganese having a valence other than +7; wherein an added amount of the manganese compound is within a range such that an Mn content in the fluoride phosphor becomes at least 0.1 mass % and at most 1.
    Type: Grant
    Filed: September 30, 2016
    Date of Patent: March 9, 2021
    Assignee: Denka Company Limited
    Inventors: Masayoshi Ichikawa, Hideyuki Emoto, Ryosuke Kondo
  • Patent number: 10759995
    Abstract: The present invention relates to a process for producing a composite-fluoride fluorescent material represented by the general formula A2MF6:Mn4+ (wherein A is at least one alkali metal element including K; M is one or more metallic elements including at least Si or Ge and selected from among Si, Ge, Sn, Ti, Zr, and Hf; F is fluorine; and Mn is manganese). With the production process, it is possible to obtain a fluorescent material which is high in absorptance, internal quantum efficiency, and external quantum efficiency and has excellent optical properties.
    Type: Grant
    Filed: February 17, 2016
    Date of Patent: September 1, 2020
    Assignee: DENKA COMPANY LIMITED
    Inventors: Masayoshi Ichikawa, Ryosuke Kondo, Hideyuki Emoto, Motoi Tanaka
  • Patent number: 10669476
    Abstract: The purpose of the present invention is to provide a potassium fluoromanganate for use as a raw material for a manganese-activated complex fluoride phosphor, from which a manganese-activated complex fluoride phosphor having good fluorescence properties and reliability can be produced. The potassium fluoromanganate of the present invention is characterized in that, in an orbital electron binding energy spectrum diagram for manganese obtained by X-ray photoelectron spectroscopy, a ratio (signal intensity value A/signal intensity value B) between a signal intensity value A obtained by subtracting a background value from a maximum signal intensity value for binding energy values within the range from 643.0 eV or more to 644.0 eV or less, and a signal intensity value B obtained by subtracting the background value from a maximum signal intensity value for binding energy values within the range from 645.0 eV or more to 646.0 eV or less, is greater than 0 and no greater than 0.9.
    Type: Grant
    Filed: September 29, 2017
    Date of Patent: June 2, 2020
    Assignee: DENKO COMPANY LIMITED
    Inventors: Hideyuki Emoto, Motonori Kino, Masayoshi Ichikawa
  • Publication number: 20200135983
    Abstract: Provided is a fluoride phosphor that has a good external quantum efficiency and is suitable for stably producing white LEDs. The fluoride phosphor has a composition represented by a general formula (1) and a repose angle of 30° or more and 60° or less. general formula: A2M(1-n)F6:Mn4+n (1), wherein 0<n?0.1, the element A is one or more alkali metal elements including at least K, and the element M is a simple substance of Si, a simple substance of Ge, or a combination of Si and one or more elements selected from the group consisting of Ge, Sn, Ti, Zr, and Hf.
    Type: Application
    Filed: June 12, 2018
    Publication date: April 30, 2020
    Applicant: Denka Company Limited
    Inventors: Masayoshi ICHIKAWA, Ryosuke KONDA, Hideyuki EMOTO
  • Publication number: 20200095501
    Abstract: Provided is a fluoride phosphor that has a good external quantum efficiency and is suitable for stably producing white LEDs. The fluoride phosphor having a composition represented by a general formula (1), a bulk density of 0.80 g/cm3 or more, and a mass median diameter (D50) of 30 ?m or less: general formula: A2M(1?n)F6:Mn4+n (1), wherein 0<n?0.1, the element A is one or more alkali metal elements including at least K, and the element M is a simple substance of Si, a simple substance of Ge, or a combination of Si and one or more elements selected from the group consisting of Ge, Sn, Ti, Zr, and Hf.
    Type: Application
    Filed: June 12, 2018
    Publication date: March 26, 2020
    Applicant: Denka Company Limited
    Inventors: Masayoshi ICHIKAWA, Ryosuke KONDA, Hideyuki EMOTO
  • Patent number: 10508235
    Abstract: Provided is a fluoride phosphor having a composition represented by the general formula (1): A2SiF6:Mn4+??(1) in which A represents at least one alkali metal comprising at least K. The fluoride phosphor has a ratio (A1/A2) of an area (A1) of a spectrum in a range of from 637 eV or more to less than 645 eV in XPS measurement to an area (A2) of a spectrum in a range of from 682.8 eV or more to less than 690 eV in XPS measurement, of 0.0008 to 0.0025.
    Type: Grant
    Filed: August 27, 2018
    Date of Patent: December 17, 2019
    Assignee: DENKA COMPANY LIMITED
    Inventors: Shunsuke Mitani, Masayoshi Ichikawa
  • Publication number: 20190071602
    Abstract: Provided is a fluoride phosphor having a composition represented by the general formula (1): A2SiF6:Mn4+??(1) in which A represents at least one alkali metal comprising at least K. The fluoride phosphor has a ratio (A1/A2) of an area (A1) of a spectrum in a range of from 645 eV or more to less than 651 eV in XPS measurement to an area (A2) of a spectrum in a range of from 682.8 eV or more to less than 690 eV in XPS measurement, of 0.0005 to 0.0010.
    Type: Application
    Filed: August 24, 2018
    Publication date: March 7, 2019
    Inventors: Shunsuke MITANI, Masayoshi ICHIKAWA
  • Publication number: 20190062630
    Abstract: Provided is a fluoride phosphor having a composition represented by the general formula (1): A2SiF6:Mn4+??(1) in which A represents at least one alkali metal comprising at least K. The fluoride phosphor has a ratio (A1/A2) of an area (A1) of a spectrum in a range of from 637 eV or more to less than 645 eV in XPS measurement to an area (A2) of a spectrum in a range of from 682.8 eV or more to less than 690 eV in XPS measurement, of 0.0008 to 0.0025.
    Type: Application
    Filed: August 27, 2018
    Publication date: February 28, 2019
    Inventors: Shunsuke MITANI, Masayoshi ICHIKAWA
  • Publication number: 20180282620
    Abstract: The purpose of the present invention is to provide a fluoride phosphor (represented by the general formula A2SiF6:Mn) having high luminescence intensity and reliability, a high-luminance light-emitting device using this phosphor, and a production method for this phosphor. The production method for a fluoride phosphor represented by the general formula A2SiF6:Mn (where element A is an alkali metal element including at least potassium), wherein the fluoride phosphor production method comprises: a step of preparing an aqueous solution wherein element A and fluorine are dissolved in a solvent; and a step of adding, to the aqueous solution, solid silicon dioxide and a manganese compound that supplies manganese having a valence other than +7; wherein an added amount of the manganese compound is within a range such that an Mn content in the fluoride phosphor becomes at least 0.1 mass % and at most 1.
    Type: Application
    Filed: September 30, 2016
    Publication date: October 4, 2018
    Inventors: Masayoshi Ichikawa, Hideyuki Emoto, Ryosuke Kondo
  • Publication number: 20180094188
    Abstract: The purpose of the present invention is to provide a potassium fluoromanganate for use as a raw material for a manganese-activated complex fluoride phosphor, from which a manganese-activated complex fluoride phosphor having good fluorescence properties and reliability can be produced. The potassium fluoromanganate of the present invention is characterized in that, in an orbital electron binding energy spectrum diagram for manganese obtained by X-ray photoelectron spectroscopy, a ratio (signal intensity value A/signal intensity value B) between a signal intensity value A obtained by subtracting a background value from a maximum signal intensity value for binding energy values within the range from 643.0 eV or more to 644.0 eV or less, and a signal intensity value B obtained by subtracting the background value from a maximum signal intensity value for binding energy values within the range from 645.0 eV or more to 646.0 eV or less, is greater than 0 and no greater than 0.9.
    Type: Application
    Filed: September 29, 2017
    Publication date: April 5, 2018
    Inventors: Hideyuki Emoto, Motonori Kino, Masayoshi Ichikawa
  • Publication number: 20180086973
    Abstract: Provided is a phosphor that emits red light, is represented by the general formula, A2MF6:Mn, and exhibits little reduction in intensity even when exposed to a high-temperature, high-humidity atmosphere over a long period of time. Also provided is a light-emitting device using said phosphor. The present invention is a phosphor in which the main crystal phase thereof is represented by the general formula, A2MF6:Mn. The element A is an alkali metal element including at least K, and the element M is one or more tetravalent elements selected from the group consisting of Si, Ge, Sn, Ti, Zr, and Hf. The phosphor has a coating layer on the surface thereof. The coating layer is a hydrophobic organic substance having a hydrophobicity of 10% or more.
    Type: Application
    Filed: January 19, 2016
    Publication date: March 29, 2018
    Inventors: Ryosuke KONDO, Masayoshi ICHIKAWA, Hideyuki EMOTO, Motoi TANAKA
  • Publication number: 20180016494
    Abstract: The present invention relates to a process for producing a composite-fluoride fluorescent material represented by the general formula A2MF6:Mn4+ (wherein A is at least one alkali metal element including K; M is one or more metallic elements including at least Si or Ge and selected from among Si, Ge, Sn, Ti, Zr, and Hf; F is fluorine; and Mn is manganese). With the production process, it is possible to obtain a fluorescent material which is high in absorptance, internal quantum efficiency, and external quantum efficiency and has excellent optical properties.
    Type: Application
    Filed: February 17, 2016
    Publication date: January 18, 2018
    Inventors: Masayoshi Ichikawa, Ryosuke Kondo, Hideyuki Emoto, Motoi Tanaka
  • Patent number: 9850131
    Abstract: Provided is a method for producing a phosphor, using a nitride raw material, that gives a high-reliability (Sr,Ca)AlSiN3-based nitride phosphor at a productivity higher than before. The method comprises a mixing step of mixing raw materials and a calcining step of calcining the mixture obtained in the mixing step and, in producing the phosphor having a crystalline structure substantially identical with that of (Sr,Ca)AlSiN3 crystal as the host crystal, a strontium nitride containing SrN, Sr2N, or the mixture thereof as the main crystalline phase, as determined by crystalline phase analysis by powder X-ray diffractometry, and having a nitrogen content of 5 to 12 mass % is used as part of the raw materials.
    Type: Grant
    Filed: February 22, 2013
    Date of Patent: December 26, 2017
    Assignee: DENKA COMPANY LIMITED
    Inventors: Ryozo Nonogaki, Masayoshi Ichikawa, Tomohiro Nomiyama, Yusuke Takeda
  • Patent number: 9676999
    Abstract: The present invention relates to an Mn4+-activated complex fluoride phosphor with improved moisture resistance due to modification of the particle surface, and a light emitting element and light emitting device having excellent color rendering properties and stability due to the use of this phosphor. The phosphor of the present invention is characterized in that it is represented by the general formula: A2MF6:Mn4+, wherein element A is an alkali metal element comprising at least K, element M is one or more metal elements chosen from among Si, Ge, Sn, Ti, Zr and Hf, F is fluorine, and Mn is manganese, wherein the phosphor comprises Ca in a concentration range of at least 20 ppm and at most 10,000 ppm or Cl in a concentration range of at least 20 ppm and at most 300 ppm.
    Type: Grant
    Filed: February 25, 2015
    Date of Patent: June 13, 2017
    Assignee: DENKA COMPANY LIMITED
    Inventors: Hideyuki Emoto, Shinichi Yanagi, Masayoshi Ichikawa, Kazuhiro Ito
  • Patent number: 9680066
    Abstract: The present invention relates to an Mn4+-activated complex fluoride phosphor with improved moisture resistance due to modification of the particle surface, and a light emitting element and light emitting device having excellent color rendering properties and stability due to the use of this phosphor. The phosphor of the present invention is characterized in that it is represented by the general formula: A2MF6:Mn4+, wherein element A is an alkali metal element comprising at least K, element M is one or more metal elements chosen from among Si, Ge, Sn, Ti, Zr and Hf, F is fluorine, and Mn is manganese, wherein the phosphor comprises a Ca-containing compound on a particle surface.
    Type: Grant
    Filed: February 25, 2015
    Date of Patent: June 13, 2017
    Assignee: DENKA COMPANY LIMITED
    Inventors: Hideyuki Emoto, Shinichi Yanagi, Masayoshi Ichikawa, Kazuhiro Ito