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).
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Patent number: 10991493Abstract: 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: GrantFiled: March 25, 2016Date of Patent: April 27, 2021Assignee: TDK CORPORATIONInventors: Wakako Okawa, Syota Goto, Yoshinori Fujikawa
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Patent number: 10984929Abstract: 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: GrantFiled: March 25, 2016Date of Patent: April 20, 2021Assignee: TDK CORPORATIONInventors: Wakako Okawa, Syota Goto, Yoshinori Fujikawa
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Patent number: 10726980Abstract: 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: GrantFiled: March 25, 2016Date of Patent: July 28, 2020Assignee: TDK CORPORATIONInventors: Wakako Okawa, Syota Goto, Yoshinori Fujikawa
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Patent number: 10256016Abstract: 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: GrantFiled: December 22, 2014Date of Patent: April 9, 2019Assignee: TDK CORPORATIONInventors: Yoshinori Fujikawa, Yuki Nagamine, Wakako Okawa, Chikara Ishizaka, Eiji Kato, Katsuo Sato
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Patent number: 10090087Abstract: 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: GrantFiled: December 22, 2014Date of Patent: October 2, 2018Assignee: TDK CORPORATIONInventors: Yoshinori Fujikawa, Yuki Nagamine, Wakako Okawa, Chikara Ishizaka, Eiji Kato, Katsuo Sato
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Patent number: 10083783Abstract: 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: GrantFiled: December 22, 2014Date of Patent: September 25, 2018Assignee: TDK CORPORATIONInventors: Yoshinori Fujikawa, Yuki Nagamine, Wakako Okawa, Chikara Ishizaka, Eiji Kato, Katsuo Sato
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Publication number: 20180114616Abstract: 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: ApplicationFiled: March 25, 2016Publication date: April 26, 2018Applicant: TDK CORPORATIONInventors: Wakako OKAWA, Syota GOTO, Yoshinori FUJIKAWA
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Publication number: 20180108463Abstract: 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: ApplicationFiled: March 25, 2016Publication date: April 19, 2018Applicant: TDK CORPORATIONInventors: Wakako OKAWA, Syota GOTO, Yoshinori FUJIKAWA
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Publication number: 20180082772Abstract: 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: ApplicationFiled: March 25, 2016Publication date: March 22, 2018Applicant: TDK CORPORATIONInventors: Wakako OKAWA, Syota GOTO, Yoshinori FUJIKAWA
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Publication number: 20150179317Abstract: 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: ApplicationFiled: December 22, 2014Publication date: June 25, 2015Inventors: Yoshinori FUJIKAWA, Yuki NAGAMINE, Wakako OKAWA, Chikara ISHIZAKA, Eiji KATO, Katsuo SATO
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Publication number: 20150179319Abstract: 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: ApplicationFiled: December 22, 2014Publication date: June 25, 2015Inventors: Yoshinori FUJIKAWA, Yuki NAGAMINE, Wakako OKAWA, Chikara ISHIZAKA, Eiji KATO, Katsuo SATO
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Publication number: 20150179318Abstract: 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: ApplicationFiled: December 22, 2014Publication date: June 25, 2015Inventors: Yoshinori FUJIKAWA, Yuki NAGAMINE, Wakako OKAWA, Chikara ISHIZAKA, Eiji KATO, Katsuo SATO
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Patent number: 8248728Abstract: 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: GrantFiled: February 1, 2010Date of Patent: August 21, 2012Assignee: TDK CorporationInventors: Atsushi Yamaguchi, Masaya Kato, Koichi Otani, Wakako Okawa
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Publication number: 20110188151Abstract: 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: ApplicationFiled: February 1, 2010Publication date: August 4, 2011Applicant: TDK CORPORATIONInventors: Atsushi YAMAGUCHI, Masaya KATO, Koichi OTANI, Wakako OKAWA
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Patent number: 7091484Abstract: 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: GrantFiled: November 12, 2004Date of Patent: August 15, 2006Assignee: TDK CorporationInventors: Katsuaki Yanagiuchi, Wakako Okawa
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Publication number: 20050103995Abstract: 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: ApplicationFiled: November 12, 2004Publication date: May 19, 2005Inventors: Katsuaki Yanagiuchi, Wakako Okawa