Patents by Inventor Junnichi NAGAOKA

Junnichi NAGAOKA 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: 11810699
    Abstract: Provided is a ferrite sintered magnet including a ferrite phase having a magnetoplumbite-type crystal structure. x, y, and m satisfy the following Equations (1), (2), and (3) when composition of the ferrite sintered magnet is represented by R1-xAxFem-yCoy, where R denotes at least one kind of element selected from rare earth elements including Y and A denotes Ca or Ca and elements including at least one kind selected from Sr or Ba. The content of B in the ferrite sintered magnet is from 0.1% to 0.6% by mass in terms of B2O3. 0.2?x?0.8??(1) 0.1?y?0.
    Type: Grant
    Filed: December 22, 2017
    Date of Patent: November 7, 2023
    Assignee: TDK Corporation
    Inventors: Junnichi Nagaoka, Hitoshi Taguchi, Yuichi Sugawara, Jo Sato
  • Publication number: 20230290547
    Abstract: Provided is a ferrite sintered magnet including a ferrite phase having a magnetoplumbite-type crystal structure. x, y, and m satisfy the following Equations (1), (2), and (3) when composition of the ferrite sintered magnet is represented by R1-xAxFem-yCoy, where R denotes at least one kind of element selected from rare earth elements including Y and A denotes Ca or Ca and elements including at least one kind selected from Sr or Ba. The content of B in the ferrite sintered magnet is from 0.1% to 0.6% by mass in terms of B2O3. 0.2?x?0.8??(1) 0.1?y?0.
    Type: Application
    Filed: May 19, 2023
    Publication date: September 14, 2023
    Applicant: TDK Corporation
    Inventors: Junnichi NAGAOKA, Hitoshi TAGUCHI, Yuichi SUGAWARA, Jo SATO
  • Patent number: 11569013
    Abstract: This ferrite magnet has a magnetoplumbite structure and is characterized in that, when representing the composition ratios of the total of each metal element A, R, Fe and Me with expression (1) A1-xRx(Fe12-yMey)z, the Fe2+ content (m) in the ferrite magnet is greater than 0.1 mass % and less than 5.4 mass % (in expression (1), A is at least one element selected from Sr, Ba, Ca and Pb; R is at least one element selected from the rare-earth elements (including Y) and Bi, and includes at least La, and Me is Co, or Co and Zn). The invention makes it possible to achieve a ferrite magnet with increased Br.
    Type: Grant
    Filed: May 19, 2017
    Date of Patent: January 31, 2023
    Assignee: TDK CORPORATION
    Inventors: Junnichi Nagaoka, Hitoshi Taguchi
  • Patent number: 11450458
    Abstract: Provided is a ferrite sintered magnet including a main phase formed of ferrite having a hexagonal magnetoplumbite type crystalline structure, in which the main phase contains Fe and Co, and the ferrite sintered magnet contains CaB2O4. CaB2O4 is contained in a heterophase that is a crystalline phase different from the main phase, and an area ratio of CaB2O4 to the entire cross-sectional surface of a sintered magnet, is less than or equal to 2%.
    Type: Grant
    Filed: February 22, 2019
    Date of Patent: September 20, 2022
    Assignee: TDK Corporation
    Inventors: Junnichi Nagaoka, Hiroyuki Ono, Yuichi Sugawara
  • Patent number: 11417447
    Abstract: This ferrite magnet has a ferrite phase having a magnetoplumbite structure, and an orthoferrite phase, and is characterized in that the composition ratios of the total of each metal element A, R, Fe and Me is represented by expression (1) A1-xRx(Fe12-yMey)z, (in expression (1), A is at least one element selected from Sr, Ba, Ca and Pb; R is at least one element selected from the rare-earth elements (including Y) and Bi, and includes at least La, and Me is Co, or Co and Zn) and in that the content (m) of the orthoferrite phase is 0<m<28.0 in mol %. The invention makes it possible to achieve a ferrite magnet with increased Br.
    Type: Grant
    Filed: May 19, 2017
    Date of Patent: August 16, 2022
    Assignee: TDK CORPORATION
    Inventors: Junnichi Nagaoka, Hitoshi Taguchi
  • Patent number: 11205533
    Abstract: A ferrite sintered magnet contains a main phase formed of ferrite having a hexagonal magnetoplumbite type crystalline structure; a first subphase containing La, Ca, and Fe, in which an atomic ratio of La is higher than that of the main phase, and the atomic ratio of La is higher than an atomic ratio of Ca; and a second subphase containing La, Ca, Si, B, and Fe, in which an atomic ratio of Ca is higher than an atomic ratio of La, an atomic ratio of B is higher than an atomic ratio of Fe, and the atomic ratio of Fe is lower than that of the main phase. An area ratio of the second subphase on a cross-sectional surface of the ferrite sintered magnet is greater than or equal to 1%.
    Type: Grant
    Filed: February 22, 2019
    Date of Patent: December 21, 2021
    Assignee: TDK Corporation
    Inventors: Junnichi Nagaoka, Hiroyuki Ono, Yuichi Sugawara
  • Publication number: 20190318856
    Abstract: Provided is a ferrite sintered magnet including a ferrite phase having a magnetoplumbite-type crystal structure. x, y, and m satisfy the following Equations (1), (2), and (3) when composition of the ferrite sintered magnet is represented by R1-xAxFem-yCoy, where R denotes at least one kind of element selected from rare earth elements including Y and A denotes Ca or Ca and elements including at least one kind selected from Sr or Ba. The content of B in the ferrite sintered magnet is from 0.1% to 0.6% by mass in terms of B2O3. 0.2?x?0.8??(1) 0.1?y?0.
    Type: Application
    Filed: December 22, 2017
    Publication date: October 17, 2019
    Applicant: TDK Corporation
    Inventors: Junnichi NAGAOKA, Hitoshi TAGUCHI, Yuichi SUGAWARA, Jo SATO
  • Publication number: 20190267168
    Abstract: Provided is a ferrite sintered magnet including a main phase formed of ferrite having a hexagonal magnetoplumbite type crystalline structure, in which the main phase contains Fe and Co, and the ferrite sintered magnet contains CaB2O4. CaB2O4 is contained in a heterophase that is a crystalline phase different from the main phase, and an area ratio of CaB2O4 to the entire cross-sectional surface of a sintered magnet, is less than or equal to 2%.
    Type: Application
    Filed: March 29, 2019
    Publication date: August 29, 2019
    Applicant: TDK Corporation
    Inventors: Junnichi NAGAOKA, Hiroyuki ONO, Yuichi SUGAWARA
  • Publication number: 20190267167
    Abstract: A ferrite sintered magnet contains a main phase formed of ferrite having a hexagonal magnetoplumbite type crystalline structure; a first subphase containing La, Ca, and Fe, in which an atomic ratio of La is higher than that of the main phase, and the atomic ratio of La is higher than an atomic ratio of Ca; and a second subphase containing La, Ca, Si, B, and Fe, in which an atomic ratio of Ca is higher than an atomic ratio of La, an atomic ratio of B is higher than an atomic ratio of Fe, and the atomic ratio of Fe is lower than that of the main phase. An area ratio of the second subphase on a cross-sectional surface of the ferrite sintered magnet is greater than or equal to 1%.
    Type: Application
    Filed: February 22, 2019
    Publication date: August 29, 2019
    Applicant: TDK Corporation
    Inventors: Junnichi NAGAOKA, Hiroyuki ONO, Yuichi SUGAWARA
  • Publication number: 20190206594
    Abstract: This ferrite magnet has a ferrite phase having a magnetoplumbite structure, and an orthoferrite phase, and is characterized in that the composition ratios of the total of each metal element A, R, Fe and Me is represented by expression (1) A1-xRx(Fe12-yMey)z, (in expression (1), A is at least one element selected from Sr, Ba, Ca and Pb; R is at least one element selected from the rare-earth elements (including Y) and Bi, and includes at least La, and Me is Co, or Co and Zn) and in that the content (m) of the orthoferrite phase is 0<m<28.0 in mol %. The invention makes it possible to achieve a ferrite magnet with increased Br.
    Type: Application
    Filed: May 19, 2017
    Publication date: July 4, 2019
    Applicant: TDK CORPORATION
    Inventors: Junnichi NAGAOKA, Hitoshi TAGUCHI
  • Publication number: 20190122792
    Abstract: This ferrite magnet has a magnetoplumbite structure and is characterized in that, when representing the composition ratios of the total of each metal element A, R, Fe and Me with expression (1) A1-xRx(Fe12-yMey)z, the Fe2+ content (m) in the ferrite magnet is greater than 0.1 mass % and less than 5.4 mass % (in expression (1), A is at least one element selected from Sr, Ba, Ca and Pb; R is at least one element selected from the rare-earth elements (including Y) and Bi, and includes at least La, and Me is Co, or Co and Zn). The invention makes it possible to achieve a ferrite magnet with increased Br.
    Type: Application
    Filed: May 19, 2017
    Publication date: April 25, 2019
    Applicant: TDK CORPORATION
    Inventors: Junnichi NAGAOKA, Hitoshi TAGUCHI