Patents by Inventor Hitoshi Taguchi

Hitoshi Taguchi 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: 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
  • 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: 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
  • Patent number: 9627112
    Abstract: A sintered ferrite magnet comprises a main phase of an M type Sr ferrite having a hexagonal crystal structure. An amount of Zn is 0.05 to 1.35 mass % in terms of ZnO and M1/M2 is 0.43 or less when an amount of a rare-earth element (R) is M1 in terms of mol and the amount of Zn is M2 in terms of mol.
    Type: Grant
    Filed: March 4, 2015
    Date of Patent: April 18, 2017
    Assignee: TDK CORPORATION
    Inventors: Yoshitaka Murakawa, Naoharu Tanigawa, Yoshihiko Minachi, Hitoshi Taguchi
  • Patent number: 9589713
    Abstract: A sintered ferrite magnet comprises a main phase of an M type Sr ferrite having a hexagonal crystal structure. An amount of Zn is 0.05 to 1.35 mass % in terms of ZnO, the sintered ferrite magnet does not substantially include a rare-earth element (R), and the following Formula (1) is satisfied, where a total amount of Sr, Ba and Ca is M3 in terms of mol, a total amount of Fe, Co, Mn, Zn, Cr and Al is M4 in terms of mol, and an amount of Si is M5 in terms of mol. 0.5?{M3?(M4/12)}/M5?4.8??(1).
    Type: Grant
    Filed: March 4, 2015
    Date of Patent: March 7, 2017
    Assignee: TDK CORPORATION
    Inventors: Yoshitaka Murakawa, Naoharu Tanigawa, Yoshihiko Minachi, Hitoshi Taguchi
  • Patent number: 9530548
    Abstract: Provided is a method for producing Sr ferrite particles for sintered magnets, the method includes: a mixing step of mixing an iron compound, a strontium compound, and an alkali metal compound which includes at least one of K and Na as a constituent element and which does not include Cl and S as the constituent element to prepare a mixture; and a calcining step of firing the mixture at 850° C. to 1100° C. to obtain Sr ferrite particles in which an average particle size of primary particles is 0.2 to 1.0 ?m. In the mixing step, the alkali metal compound is mixed in such a manner that a total amount of K and Na becomes 0.03 to 1.05% by mass in terms of K2O and Na2O with respect to a total amount of a powder of the iron compound and a powder of the strontium compound.
    Type: Grant
    Filed: June 7, 2013
    Date of Patent: December 27, 2016
    Assignee: TDK Corporation
    Inventor: Hitoshi Taguchi
  • Patent number: 9514871
    Abstract: Provided is a sintered ferrite magnet 10 that comprises Sr ferrite having a hexagonal crystal structure, wherein the total amount of Na and K is 0.004 to 0.31% by mass in terms of Na2O and K2O, an amount of Si is 0.3 to 0.94% by mass in terms of SiO2, and the following Expression (1) is satisfied. 1.3?(SrF+Ba+Ca+2Na+2K)/Si?5.7??(1) [In Expression (1), SrF represents an amount of Sr, on a molar basis, other than Sr which constitutes the Sr ferrite, and Ba, Ca, Na, and K represent amounts of respective elements on a molar basis.
    Type: Grant
    Filed: February 20, 2013
    Date of Patent: December 6, 2016
    Assignee: TDK Corporation
    Inventor: Hitoshi Taguchi
  • Patent number: 9460835
    Abstract: Provided is a sintered ferrite magnet 10 that contains Sr ferrite having a hexagonal crystal structure, wherein the total amount of Na and K is 0.01 to 0.09% by mass in terms of Na2O and K2O, an amount of Si is 0.1 to 0.29% by mass in terms of SiO2, and the following Expression (1) is satisfied. 2.5?(SrF+Ba+Ca+2Na+2K)/Si?5.4??(1) [In Expression (1), SrF represents an amount of Sr, on a molar basis, other than Sr which constitutes the Sr ferrite, and Ba, Ca, Na, and K represent amounts of respective elements on a molar basis.
    Type: Grant
    Filed: February 20, 2013
    Date of Patent: October 4, 2016
    Assignee: TDK CORPORATION
    Inventor: Hitoshi Taguchi
  • Publication number: 20150325350
    Abstract: Provided is a sintered ferrite magnet 10 that comprises Sr ferrite having a hexagonal crystal structure, wherein the total amount of Na and K is 0.004 to 0.31% by mass in terms of Na2O and K2O, an amount of Si is 0.3 to 0.94% by mass in terms of SiO2, and the following Expression (1) is satisfied. 1.3?(SrF+Ba+Ca+2Na+2K)/Si?5.7??(1) [In Expression (1), SrF represents an amount of Sr, on a molar basis, other than Sr which constitutes the Sr ferrite, and Ba, Ca, Na, and K represent amounts of respective elements on a molar basis.
    Type: Application
    Filed: February 20, 2013
    Publication date: November 12, 2015
    Inventor: Hitoshi TAGUCHI
  • Publication number: 20150255197
    Abstract: A sintered ferrite magnet comprises a main phase of an M type Sr ferrite having a hexagonal crystal structure. An amount of Zn is 0.05 to 1.35 mass % in terms of ZnO, the sintered ferrite magnet does not substantially include a rare-earth element (R), and the following Formula (1) is satisfied, where a total amount of Sr, Ba and Ca is M3 in terms of mol, a total amount of Fe, Co, Mn, Zn, Cr and Al is M4 in terms of mol, and an amount of Si is M5 in terms of mol. 0.5?{M3?(M4/12)}/M5?4.
    Type: Application
    Filed: March 4, 2015
    Publication date: September 10, 2015
    Inventors: Yoshitaka MURAKAWA, Naoharu TANIGAWA, Yoshihiko MINACHI, Hitoshi TAGUCHI
  • Publication number: 20150255198
    Abstract: A sintered ferrite magnet comprises a main phase of an M type Sr ferrite having a hexagonal crystal structure. An amount of Zn is 0.05 to 1.35 mass % in terms of ZnO and M1/M2 is 0.43 or less when an amount of a rare-earth element (R) is M1 in terms of mol and the amount of Zn is M2 in terms of mol.
    Type: Application
    Filed: March 4, 2015
    Publication date: September 10, 2015
    Inventors: Yoshitaka MURAKAWA, Naoharu TANIGAWA, Yoshihiko MINACHI, Hitoshi TAGUCHI
  • Publication number: 20150125700
    Abstract: Provided is a method for producing Sr ferrite particles for sintered magnets, the method includes: a mixing step of mixing an iron compound, a strontium compound, and an alkali metal compound which includes at least one of K and Na as a constituent element and which does not include Cl and S as the constituent element to prepare a mixture; and a calcining step of firing the mixture at 850° C. to 1100° C. to obtain Sr ferrite particles in which an average particle size of primary particles is 0.2 to 1.0 ?m. In the mixing step, the alkali metal compound is mixed in such a manner that a total amount of K and Na becomes 0.03 to 1.05% by mass in terms of K2O and Na2O with respect to a total amount of a powder of the iron compound and a powder of the strontium compound.
    Type: Application
    Filed: June 7, 2013
    Publication date: May 7, 2015
    Applicant: TDK Corporation
    Inventor: Hitoshi Taguchi
  • Publication number: 20150053883
    Abstract: Provided is a sintered ferrite magnet 10 that contains Sr ferrite having a hexagonal crystal structure, wherein the total amount of Na and K is 0.01 to 0.09% by mass in terms of Na2O and K2O, an amount of Si is 0.1 to 0.29% by mass in terms of SiO2, and the following Expression (1) is satisfied. 2.5?(SrF+Ba+Ca+2Na+2K)/Si?5.4??(1) [In Expression (1), SrF represents an amount of Sr, on a molar basis, other than Sr which constitutes the Sr ferrite, and Ba, Ca, Na, and K represent amounts of respective elements on a molar basis.
    Type: Application
    Filed: February 20, 2013
    Publication date: February 26, 2015
    Inventor: Hitoshi Taguchi
  • Publication number: 20070023970
    Abstract: There is provided a method for producing a La—Co based ferrite magnet by using a polyhydric alcohol as a dispersant, the method capable of suppressing the composition deviation.
    Type: Application
    Filed: June 5, 2006
    Publication date: February 1, 2007
    Inventors: Kiyoyuki Masuzawa, Toshinori Miya, Yasumi Takatsuka, Hitoshi Taguchi, Shunsuke Kurasawa
  • Publication number: 20060219323
    Abstract: The objects of the present invention are to provide a magnetic field molding device, and method for producing a ferrite magnet, or the like, capable of improving yield in a production line and stabilizing product quality, and method for producing a ferrite magnet. In molding in a magnetic field, the mortar-shaped die 19 provided with a plurality of the cavities 13 is heated by the heater member 20 at a given temperature level, under the control of the controller 23. The temperature level is preferably controlled by the controller 23 at 40° C. or higher as mortar-shaped die 19 temperature T1, sensed by the sensor 22. A molding slurry can be kept at a high temperature level in the cavities 13 by heating the mortar-shaped die 19, and can have high dehydration properties and improve product yield.
    Type: Application
    Filed: March 30, 2005
    Publication date: October 5, 2006
    Inventors: Kiyoyuki Masuzawa, Hideo Kurita, Masayuki Ohtsuka, Yasuhiro Nagatsuka, Hitoshi Taguchi
  • Patent number: 7084603
    Abstract: A motor control device that can reduce electrical noise is provided. A motor control device includes an inverter, a current controller, a high frequency wave superpositioner, and a high frequency wave setter. An inverter applies a current to the motor. A current controller outputs a voltage to the inverter according to a current applied to the motor from the inverter. A high frequency wave superpositioner applies a high frequency wave to the voltage from the current controller as a superpositioned wave to infer a position of a rotor in the motor. A high frequency wave setter varies at least one characteristic of the superpositioned wave applied by the high frequency wave superpositioner.
    Type: Grant
    Filed: May 13, 2004
    Date of Patent: August 1, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hitoshi Taguchi, Takeshi Kitahata, Yosuke Nakazawa