Patents by Inventor Wakako Okawa

Wakako Okawa 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: 10991493
    Abstract: A rare earth magnet includes main phase grains having an R2T14B type crystal structure. The main phase grains include Ga. A concentration ratio A (A=?Ga/?Ga) of the main phase grains is 1.20 or more, where ?Ga and ?Ga are respectively a highest concentration of Ga and a lowest concentration of Ga in one main phase grain.
    Type: Grant
    Filed: March 25, 2016
    Date of Patent: April 27, 2021
    Assignee: TDK CORPORATION
    Inventors: Wakako Okawa, Syota Goto, Yoshinori Fujikawa
  • Patent number: 10984929
    Abstract: A rare earth magnet includes main phase grains having an R2T14B type crystal structure. The main phase grains include C. A concentration ratio A1 (A1=?C/?C) of the main phase grains is 1.50 or more, where ?C and ?C are respectively a highest concentration of C and a lowest concentration of C in one main phase grain.
    Type: Grant
    Filed: March 25, 2016
    Date of Patent: April 20, 2021
    Assignee: TDK CORPORATION
    Inventors: Wakako Okawa, Syota Goto, Yoshinori Fujikawa
  • Patent number: 10726980
    Abstract: A rare earth magnet includes main phase grains having an R2T14B type crystal structure. The main phase grains include B. A concentration ratio A (A=?B/?B) of the main phase grains is 1.05 or more, where ?B and ?B are respectively a highest concentration of B and a lowest concentration of B in one main phase grain.
    Type: Grant
    Filed: March 25, 2016
    Date of Patent: July 28, 2020
    Assignee: TDK CORPORATION
    Inventors: Wakako Okawa, Syota Goto, Yoshinori Fujikawa
  • Patent number: 10256016
    Abstract: The present invention provides a rare earth based magnet in which the demagnetization rate at a high temperature can be inhibited even if the amount of heavy rare earth element(s) such as Dy and Tb is evidently decreased compared to the past or no such heavy rare earth element is used. The rare earth based magnet of the present invention is a sintered magnet which comprises R2T14B crystal grains as the main phases and the crystal boundary phases among the R2T14B crystal grains. The microstructure of the sintered body is controlled by including crystal boundary phases containing at least R, T and M in the crystal boundary phases, wherein the relative atomic ratios of R, T and M are as follows, i.e., 25 to 35% for R, 60 to 70% for T and 2 to 10% for M.
    Type: Grant
    Filed: December 22, 2014
    Date of Patent: April 9, 2019
    Assignee: TDK CORPORATION
    Inventors: Yoshinori Fujikawa, Yuki Nagamine, Wakako Okawa, Chikara Ishizaka, Eiji Kato, Katsuo Sato
  • Patent number: 10090087
    Abstract: The present invention provides a rare earth based magnet in which the demagnetization rate at a high temperature can be inhibited even if the amount of heavy rare earth element(s) such as Dy and Tb is evidently decreased compared to the past or no such heavy rare earth element is used. The rare earth based magnet of the present invention is a sintered magnet which comprises R2T14B crystal grains as the major phases and the crystal boundary phases among the R2T14B crystal grains. The microstructure of the sintered body is controlled by including crystal boundary phases containing at least R, T and M in the crystal boundary phases, wherein the relative atomic ratios of R, T and M are as follows, i.e., 60 to 80% for R, 15 to 35% for T and 1 to 20% for M.
    Type: Grant
    Filed: December 22, 2014
    Date of Patent: October 2, 2018
    Assignee: TDK CORPORATION
    Inventors: Yoshinori Fujikawa, Yuki Nagamine, Wakako Okawa, Chikara Ishizaka, Eiji Kato, Katsuo Sato
  • Patent number: 10083783
    Abstract: The present invention provides a rare earth based magnet in which the demagnetization rate at a high temperature can be inhibited even if the amount of heavy rare earth element(s) such as Dy and Tb is evidently decreased compared to the past or no such heavy rare earth element is used. The rare earth based magnet of the present invention is a sintered magnet which comprises R2T14B crystal grains as the main phases and the crystal boundary phases among R2T14B crystal grains. The microstructure of the sintered body is controlled by at least containing the first crystal boundary phases and the second crystal boundary phases, wherein the first crystal boundary phases contain at least R-T-M in the ranges of 20 to 40 atomic % for R, 60 to 75 atomic % for T and 1 to 10 atomic % for M, and the second crystal boundary phases contains at least R-T-M in the ranges of 50 to 70 atomic % for R, 10 to 30 atomic % for T and 1 to 20 atomic % for M.
    Type: Grant
    Filed: December 22, 2014
    Date of Patent: September 25, 2018
    Assignee: TDK CORPORATION
    Inventors: Yoshinori Fujikawa, Yuki Nagamine, Wakako Okawa, Chikara Ishizaka, Eiji Kato, Katsuo Sato
  • Publication number: 20180114616
    Abstract: A rare earth magnet includes main phase grains having an R2T14B type crystal structure. The main phase grains include B. A concentration ratio A (A=?B/?B) of the main phase grains is 1.05 or more, where ?B and ?B are respectively a highest concentration of B and a lowest concentration of B in one main phase grain.
    Type: Application
    Filed: March 25, 2016
    Publication date: April 26, 2018
    Applicant: TDK CORPORATION
    Inventors: Wakako OKAWA, Syota GOTO, Yoshinori FUJIKAWA
  • Publication number: 20180108463
    Abstract: A rare earth magnet includes main phase grains having an R2T14B type crystal structure. The main phase grains include C. A concentration ratio A1 (A1=?C/?C) of the main phase grains is 1.50 or more, where ?C and ?C are respectively a highest concentration of C and a lowest concentration of C in one main phase grain.
    Type: Application
    Filed: March 25, 2016
    Publication date: April 19, 2018
    Applicant: TDK CORPORATION
    Inventors: Wakako OKAWA, Syota GOTO, Yoshinori FUJIKAWA
  • Publication number: 20180082772
    Abstract: A rare earth magnet includes main phase grains having an R2T14B type crystal structure. The main phase grains include Ga. A concentration ratio A (A=?Ga/?Ga) of the main phase grains is 1.20 or more, where ?Ga and ?Ga are respectively a highest concentration of Ga and a lowest concentration of Ga in one main phase grain.
    Type: Application
    Filed: March 25, 2016
    Publication date: March 22, 2018
    Applicant: TDK CORPORATION
    Inventors: Wakako OKAWA, Syota GOTO, Yoshinori FUJIKAWA
  • Publication number: 20150179317
    Abstract: The present invention provides a rare earth based magnet in which the demagnetization rate at a high temperature can be inhibited even if the amount of heavy rare earth element(s) such as Dy and Tb is evidently decreased compared to the past or no such heavy rare earth element is used. The rare earth based magnet of the present invention is a sintered magnet which comprises R2T14B crystal grains as the main phases and the crystal boundary phases among the R2T14B crystal grains. The microstructure of the sintered body is controlled by including crystal boundary phases containing at least R, T and M in the crystal boundary phases, wherein the relative atomic ratios of R, T and M are as follows, i.e., 25 to 35% for R, 60 to 70% for T and 2 to 10% for M.
    Type: Application
    Filed: December 22, 2014
    Publication date: June 25, 2015
    Inventors: Yoshinori FUJIKAWA, Yuki NAGAMINE, Wakako OKAWA, Chikara ISHIZAKA, Eiji KATO, Katsuo SATO
  • Publication number: 20150179319
    Abstract: The present invention provides a rare earth based magnet in which the demagnetization rate at a high temperature can be inhibited even if the amount of heavy rare earth element(s) such as Dy and Tb is evidently decreased compared to the past or no such heavy rare earth element is used. The rare earth based magnet of the present invention is a sintered magnet which comprises R2T14B crystal grains as the main phases and the crystal boundary phases among R2T14B crystal grains. The microstructure of the sintered body is controlled by at least containing the first crystal boundary phases and the second crystal boundary phases, wherein the first crystal boundary phases contain at least R-T-M in the ranges of 20 to 40 atomic % for R, 60 to 75 atomic % for T and 1 to 10 atomic % for M, and the second crystal boundary phases contains at least R-T-M in the ranges of 50 to 70 atomic % for R, 10 to 30 atomic % for T and 1 to 20 atomic % for M.
    Type: Application
    Filed: December 22, 2014
    Publication date: June 25, 2015
    Inventors: Yoshinori FUJIKAWA, Yuki NAGAMINE, Wakako OKAWA, Chikara ISHIZAKA, Eiji KATO, Katsuo SATO
  • Publication number: 20150179318
    Abstract: The present invention provides a rare earth based magnet in which the demagnetization rate at a high temperature can be inhibited even if the amount of heavy rare earth element(s) such as Dy and Tb is evidently decreased compared to the past or no such heavy rare earth element is used. The rare earth based magnet of the present invention is a sintered magnet which comprises R2T14B crystal grains as the major phases and the crystal boundary phases among the R2T14B crystal grains. The microstructure of the sintered body is controlled by including crystal boundary phases containing at least R, T and M in the crystal boundary phases, wherein the relative atomic ratios of R, T and M are as follows, i.e., 60 to 80% for R, 15 to 35% for T and 1 to 20% for M.
    Type: Application
    Filed: December 22, 2014
    Publication date: June 25, 2015
    Inventors: Yoshinori FUJIKAWA, Yuki NAGAMINE, Wakako OKAWA, Chikara ISHIZAKA, Eiji KATO, Katsuo SATO
  • Patent number: 8248728
    Abstract: A magnetic pole of a magnetic head includes a narrow and a wide portion, and is formed of a plating film. An electrode film forms the plating film, and is provided only under at least a part of the wide portion. A manufacturing method for the magnetic head includes: forming a plating-film-accommodating layer with an accommodating groove; forming the electrode film in part of the accommodating groove; and forming the plating film in the accommodating groove by plating using the electrode film. The accommodating groove includes a narrow and a wide groove portion for accommodating the narrow and wide portions, respectively. The electrode film is provided only in at least a part of the wide groove portion. In the step of forming the plating film, the plating film grows from the surface of the electrode film, and the narrow groove portion is filled with a part of the plating film.
    Type: Grant
    Filed: February 1, 2010
    Date of Patent: August 21, 2012
    Assignee: TDK Corporation
    Inventors: Atsushi Yamaguchi, Masaya Kato, Koichi Otani, Wakako Okawa
  • Publication number: 20110188151
    Abstract: A magnetic pole of a magnetic head includes a narrow and a wide portion, and is formed of a plating film. An electrode film forms the plating film, and is provided only under at least a part of the wide portion. A manufacturing method for the magnetic head includes: forming a plating-film-accommodating layer with an accommodating groove; forming the electrode film in part of the accommodating groove; and forming the plating film in the accommodating groove by plating using the electrode film. The accommodating groove includes a narrow and a wide groove portion for accommodating the narrow and wide portions, respectively. The electrode film is provided in at least a part of the wide groove portion. In the step of forming the plating film, the plating film grows from the surface of the electrode film, and the narrow groove portion is filled with a part of the plating film.
    Type: Application
    Filed: February 1, 2010
    Publication date: August 4, 2011
    Applicant: TDK CORPORATION
    Inventors: Atsushi YAMAGUCHI, Masaya KATO, Koichi OTANI, Wakako OKAWA
  • Patent number: 7091484
    Abstract: The method of measuring crystallographic orientations, crystal systems or the like of the surface of a specimen has steps of: irradiating the specimen with an ion beam; measuring the secondary electrons generated by the irradiation of the ion beam; repeating the irradiation of the ion beam and the measurement of the secondary electrons with each variation in an angle of incidence of the ion beam with respect to the specimen; and determining the crystalline state based on the variation in the amount of the secondary electrons corresponding to the variation of the angle of incidence.
    Type: Grant
    Filed: November 12, 2004
    Date of Patent: August 15, 2006
    Assignee: TDK Corporation
    Inventors: Katsuaki Yanagiuchi, Wakako Okawa
  • Publication number: 20050103995
    Abstract: The method of measuring crystallographic orientations, crystal systems or the like of the surface of a specimen has steps of: irradiating the specimen with an ion beam; measuring tho secondary electrons generated by the irradiation of the ion beam; repeating the irradiation of the ion beam and the measurement of the secondary electrons with each variation in an angle of incidence of the ion beam with respect to the specimen; and determining the crystalline state based on the variation in the amount of the secondary electrons corresponding to the variation of the angle of incidence.
    Type: Application
    Filed: November 12, 2004
    Publication date: May 19, 2005
    Inventors: Katsuaki Yanagiuchi, Wakako Okawa