Patents by Inventor Masayuki Takagishi

Masayuki Takagishi 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: 20240194223
    Abstract: According to one embodiment, a magnetic recording device includes a magnetic head and a controller. The magnetic head includes first and second magnetic poles, a magnetic element provided between the first and second magnetic poles, and first and second terminals. The controller is configured to perform a recording operation. In the recording operation, the controller is configured to supply a recording current to the coil while applying an element voltage not less than a first voltage and not more than a second voltage between the first terminal and the second terminal. A differential resistance of the magnetic element when a positive applied voltage applied between the first terminal and the second terminal is changed while the recording current is supplied to the coil becomes a first peak when the applied voltage is the first voltage.
    Type: Application
    Filed: July 25, 2023
    Publication date: June 13, 2024
    Inventors: Yuji NAKAGAWA, Naoyuki NARITA, Masayuki TAKAGISHI, Tomoyuki MAEDA
  • Publication number: 20240185884
    Abstract: According to one embodiment, a magnetic recording medium includes a first magnetic region, a second magnetic region, and a third magnetic region. The second magnetic region is provided between the third magnetic region and the first magnetic region in a first direction from the third magnetic region to the first magnetic region. A first composition ratio of a first Pt atomic concentration in the first magnetic region to a first Co atomic concentration in the first magnetic region is higher than a second composition ratio of a second Pt atomic concentration in the second magnetic region to a second Co atomic concentration in the second magnetic region. A third composition ratio of a third Pt atom concentration in the third magnetic region to a third Co atom concentration in the third magnetic region is higher than the second composition ratio.
    Type: Application
    Filed: August 1, 2023
    Publication date: June 6, 2024
    Inventors: Ryo OSAMURA, Yuji NAKAGAWA, Tomoyuki MAEDA, Masayuki TAKAGISHI, Naoyuki NARITA, Kosuke KURIHARA
  • Publication number: 20240135962
    Abstract: According to one embodiment, a magnetic head includes first and second magnetic poles, a conductive part, an element part, and first to fourth terminals. The conductive part is electrically insulated from the first and second magnetic poles. The first and second terminals are electrically connected to the conductive part. The element part is provided between the first and second magnetic poles and electrically connected to the first and second magnetic poles. The element part is conductive. The third terminal is electrically connected to the first magnetic pole. The fourth terminal is electrically connected to the second magnetic pole. A first magnetic pole temperature in a first state is higher than a second magnetic pole temperature of the second magnetic pole in the first state. A first current is supplied between the first and second terminals in the first state.
    Type: Application
    Filed: July 24, 2023
    Publication date: April 25, 2024
    Inventors: Yuji NAKAGAWA, Naoyuki NARITA, Tomoyuki MAEDA, Masayuki TAKAGISHI, Tazumi NAGASAWA, Ryo OSAMURA, Kosuke KURIHARA
  • Patent number: 11935568
    Abstract: According to one embodiment, a magnetic recording device includes a magnetic head and a controller. The magnetic head includes first and second magnetic poles, a magnetic element provided between the first magnetic pole and the second magnetic pole, first and second terminals electrically connected to one end and another end of the magnetic element, respectively, and a coil. The controller is electrically connected to the magnetic element and the coil, and performs a recording operation. In the recording operation, the controller supplies a recording current to the coil while applying an element voltage between the first and second terminals. When the applied voltage is changed while the recording current is supplied, a differential resistance of the magnetic element becomes a first differential resistance peak when the applied voltage is a first voltage, and becomes a second differential resistance peak when the applied voltage is a second voltage.
    Type: Grant
    Filed: February 3, 2023
    Date of Patent: March 19, 2024
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Yuji Nakagawa, Naoyuki Narita, Masayuki Takagishi, Tomoyuki Maeda
  • Publication number: 20240046959
    Abstract: According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a stacked body. The first magnetic pole includes a first face and a second face crossing the first face. The second face includes a first face region continuous with the first face. The second magnetic pole includes a third face and a fourth face crossing the third face, and the fourth face includes a second face region that is continuous with the third face. The first face and the third face are along the third direction. The stacked body is provided between the first face region and the second face region. The stacked body includes a first magnetic layer, and a second magnetic layer provided between the first magnetic layer and the second face region. The second magnetic layer includes a second magnetic layer face facing the second face region.
    Type: Application
    Filed: February 6, 2023
    Publication date: February 8, 2024
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Yuji NAKAGAWA, Masayuki TAKAGISHI, Naoyuki NARITA, Tomoyuki MAEDA, Tazumi NAGASAWA, Ryo OSAMURA, Kosuke KURIHARA
  • Patent number: 11881234
    Abstract: According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a stacked body provided between the first and second magnetic poles. The stacked body includes first to fourth magnetic layers, and first to fifth non-magnetic layers. The second non-magnetic layer is in contact with the second and first magnetic layers. The third non-magnetic layer is in contact with the third and second magnetic layers. The fourth non-magnetic layer is in contact with the fourth and third magnetic layers. A fourth thickness of the fourth magnetic layer along a first direction from the first magnetic pole to the second magnetic pole is not less than 0.5 times and not more than 1.6 times a first thickness of the first magnetic layer along the first direction. A second thickness of the second magnetic layer along the first direction is less than the first thickness.
    Type: Grant
    Filed: July 18, 2022
    Date of Patent: January 23, 2024
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Yuji Nakagawa, Naoyuki Narita, Masayuki Takagishi, Tomoyuki Maeda, Tazumi Nagasawa
  • Patent number: 11869540
    Abstract: According to one embodiment, a magnetic head includes first and second magnetic poles, a stacked body, and first to third terminals. The stacked body is provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer between the first magnetic layer and the second magnetic pole, a third magnetic layer between the second magnetic layer and the second magnetic pole, a fourth magnetic layer between the third magnetic layer and the second magnetic pole, a first nonmagnetic layer between the first magnetic pole and the first magnetic layer, a second nonmagnetic layer between the first and second magnetic layers, a third nonmagnetic layer between the second and third magnetic layers, a fourth nonmagnetic layer between the third and fourth magnetic layers and a fifth nonmagnetic layer between the fourth magnetic layer and the second magnetic pole.
    Type: Grant
    Filed: August 10, 2022
    Date of Patent: January 9, 2024
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Tazumi Nagasawa, Yuji Nakagawa, Naoyuki Narita, Masayuki Takagishi, Tomoyuki Maeda, Ryo Osamura
  • Publication number: 20230386510
    Abstract: According to one embodiment, a magnetic recording device includes a magnetic head and a controller. The magnetic head includes first and second magnetic poles, a magnetic element provided between the first magnetic pole and the second magnetic pole, first and second terminals electrically connected to one end and another end of the magnetic element, respectively, and a coil. The controller is electrically connected to the magnetic element and the coil, and performs a recording operation. In the recording operation, the controller supplies a recording current to the coil while applying an element voltage between the first and second terminals. When the applied voltage is changed while the recording current is supplied, a differential resistance of the magnetic element becomes a first differential resistance peak when the applied voltage is a first voltage, and becomes a second differential resistance peak when the applied voltage is a second voltage.
    Type: Application
    Filed: February 3, 2023
    Publication date: November 30, 2023
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Yuji NAKAGAWA, Naoyuki NARITA, Masayuki TAKAGISHI, Tomoyuki MAEDA
  • Patent number: 11810601
    Abstract: According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic layer and the second magnetic pole, a third magnetic layer provided between the second magnetic layer and the second magnetic pole, a first non-magnetic layer provided between the first and second magnetic layers, a second non-magnetic layer provided between the second and third magnetic layers, a third non-magnetic layer provided between the first magnetic pole and the first magnetic layer, and a fourth non-magnetic layer provided between the third magnetic layer and the second magnetic pole. A first magnetic pole length is shorter than a second magnetic pole length. A first magnetic layer length is longer than a second magnetic layer length.
    Type: Grant
    Filed: January 14, 2022
    Date of Patent: November 7, 2023
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Yuji Nakagawa, Masayuki Takagishi, Naoyuki Narita, Tazumi Nagasawa, Tomoyuki Maeda
  • Publication number: 20230335154
    Abstract: According to one embodiment, a magnetic head includes first and second magnetic poles, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic layer and the second magnetic pole, a first nonmagnetic layer provided between the first and second magnetic layers, a second nonmagnetic layer provided between the second magnetic layer and the second magnetic pole, and a third nonmagnetic layer provided between the first magnetic pole and the first magnetic layer. The first magnetic layer includes a first element including at least one of Fe, Co, or Ni. The second magnetic layer includes (Fe100-xCox)100-yEy. A second element E includes at least one selected from the group consisting of Cr, V, Mn, Yi, and Sc. The first magnetic layer does not include the second element.
    Type: Application
    Filed: June 16, 2023
    Publication date: October 19, 2023
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Yuji NAKAGAWA, Naoyuki NARITA, Tomoyuki MAEDA, Masayuki TAKAGISHI, Tazumi NAGASAWA
  • Publication number: 20230326482
    Abstract: According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, a magnetic element, and a magnetic member. The magnetic element is provided between the first and second magnetic poles, and includes a first magnetic layer. The magnetic member includes a first magnetic part. A second direction from the first magnetic part to the magnetic element crosses a first direction from the first to second magnetic pole. The first magnetic part includes a magnetic material including at least one of first to third materials. The first material includes at least one selected from the group consisting of Mn3Sn, Mn3Ge and Mn3Ga. The second material includes at least one selected from the group consisting of a cubic or tetragonal compound including Mn and Ni, a cubic alloy including ?-phase Mn, and a cubic alloy including Fe. The third material includes an antiferromagnet.
    Type: Application
    Filed: June 6, 2023
    Publication date: October 12, 2023
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Yuji NAKAGAWA, Naoyuki NARITA, Masayuki TAKAGISHI, Tomoyuki MAEDA, Tazumi NAGASAWA, Kenichiro YAMADA, Akira KIKITSU
  • Publication number: 20230267961
    Abstract: According to one embodiment, a magnetic head includes first and second magnetic poles, a stacked body, and first to third terminals. The stacked body is provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer between the first magnetic layer and the second magnetic pole, a third magnetic layer between the second magnetic layer and the second magnetic pole, a fourth magnetic layer between the third magnetic layer and the second magnetic pole, a first nonmagnetic layer between the first magnetic pole and the first magnetic layer, a second nonmagnetic layer between the first and second magnetic layers, a third nonmagnetic layer between the second and third magnetic layers, a fourth nonmagnetic layer between the third and fourth magnetic layers and a fifth nonmagnetic layer between the fourth magnetic layer and the second magnetic pole.
    Type: Application
    Filed: August 10, 2022
    Publication date: August 24, 2023
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Tazumi NAGASAWA, Yuji NAKAGAWA, Naoyuki NARITA, Masayuki TAKAGISHI, Tomoyuki MAEDA, Ryo OSAMURA
  • Patent number: 11721359
    Abstract: According to one embodiment, a magnetic head includes first and second magnetic poles, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic layer and the second magnetic pole, a first nonmagnetic layer provided between the first and second magnetic layers, a second nonmagnetic layer provided between the second magnetic layer and the second magnetic pole, and a third nonmagnetic layer provided between the first magnetic pole and the first magnetic layer. The first magnetic layer includes a first element including at least one of Fe, Co, or Ni. The second magnetic layer includes (Fe100-xCox)100-yEy. A second element E includes at least one selected from the group consisting of Cr, V, Mn, Yi, and Sc. The first magnetic layer does not include the second element.
    Type: Grant
    Filed: January 28, 2022
    Date of Patent: August 8, 2023
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Yuji Nakagawa, Naoyuki Narita, Masayuki Takagishi, Tomoyuki Maeda, Tazumi Nagasawa
  • Patent number: 11710501
    Abstract: A magnetic head includes a first magnetic pole, a second magnetic pole, a magnetic element, and a magnetic member. The magnetic element is provided between the first and second magnetic poles, and includes a first magnetic layer. The magnetic member includes a first magnetic part. A second direction from the first magnetic part to the magnetic element crosses a first direction from the first to second magnetic pole. The first magnetic part includes a magnetic material including at least one of first to third materials. The first material includes at least one selected from the group consisting of Mn3Sn, Mn3Ge and Mn3Ga. The second material includes at least one selected from the group consisting of a cubic or tetragonal compound including Mn and Ni, a cubic alloy including ?-phase Mn, and a cubic alloy including Fe. The third material includes an antiferromagnet.
    Type: Grant
    Filed: January 28, 2022
    Date of Patent: July 25, 2023
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Yuji Nakagawa, Naoyuki Narita, Masayuki Takagishi, Tomoyuki Maeda, Tazumi Nagasawa, Kenichiro Yamada, Akira Kikitsu
  • Patent number: 11705152
    Abstract: A magnetic head includes a first magnetic pole, a second magnetic pole, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic member, a second magnetic member provided between the first magnetic member and the second magnetic pole, a first layer provided between the first and second magnetic members, and a second layer provided between the second magnetic member and the second magnetic pole. The first magnetic member includes first magnetic regions and a first nonmagnetic region. The first nonmagnetic region is between the one of the first magnetic regions and the other one of the first magnetic regions.
    Type: Grant
    Filed: August 5, 2022
    Date of Patent: July 18, 2023
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Hitoshi Iwasaki, Naoyuki Narita, Hirofumi Suto, Masayuki Takagishi, Tazumi Nagasawa
  • Publication number: 20230178102
    Abstract: According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a stacked body provided between the first and second magnetic poles. The stacked body includes first to fourth magnetic layers, and first to fifth non-magnetic layers. The second non-magnetic layer is in contact with the second and first magnetic layers. The third non-magnetic layer is in contact with the third and second magnetic layers. The fourth non-magnetic layer is in contact with the fourth and third magnetic layers. A fourth thickness of the fourth magnetic layer along a first direction from the first magnetic pole to the second magnetic pole is not less than 0.5 times and not more than 1.6 times a first thickness of the first magnetic layer along the first direction. A second thickness of the second magnetic layer along the first direction is less than the first thickness.
    Type: Application
    Filed: July 18, 2022
    Publication date: June 8, 2023
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Yuji NAKAGAWA, Naoyuki NARITA, Masayuki TAKAGISHI, Tomoyuki MAEDA, Tazumi NAGASAWA
  • Patent number: 11631423
    Abstract: According to one embodiment, a magnetic recording device includes a magnetic head and a controller. The magnetic head includes a first magnetic pole, a magnetic element including a first magnetic layer, and a coil. The controller is electrically connected to the magnetic element and the coil. The controller is configured to supply a recording current to the coil and supply an element current to the magnetic element. The recording current includes a first period of a first polarity, a second period of a second polarity, a third period that shifts from the first to second period, and a fourth period that shifts from the second to first period. The element current includes DC and AC components. The AC component in the first period is the same as the AC component in the second period, the AC component in the third period, and the AC component in the fourth period.
    Type: Grant
    Filed: January 28, 2022
    Date of Patent: April 18, 2023
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Yuji Nakagawa, Naoyuki Narita, Masayuki Takagishi, Tazumi Nagasawa, Tomoyuki Maeda
  • Patent number: 11626130
    Abstract: According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic pole and the first magnetic layer, a third magnetic layer provided between the first magnetic pole and the second magnetic layer, a first nonmagnetic layer provided between the first magnetic layer and the second magnetic pole, a second nonmagnetic layer provided between the second and first magnetic layers, and a third nonmagnetic layer provided between the third and second magnetic layers. The third magnetic layer includes first and second elements. The first and second magnetic layers do not include the second element. Or concentrations of the second element in the first and second magnetic layers are less than in the third magnetic layer.
    Type: Grant
    Filed: July 7, 2022
    Date of Patent: April 11, 2023
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Naoyuki Narita, Masayuki Takagishi, Hitoshi Iwasaki, Tomoyuki Maeda
  • Patent number: 11615808
    Abstract: According to one embodiment, a magnetic head includes first and second magnetic poles, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer provided between the second magnetic pole and the first magnetic layer, a third magnetic layer provided between the second magnetic pole and the second magnetic layer, a first non-magnetic layer provided between the first magnetic layer and the first magnetic pole, a second non-magnetic layer provided between the second and first magnetic layers, a third non-magnetic layer provided between the third and second magnetic layers, and a fourth non-magnetic layer provided between the second magnetic pole and the third magnetic layer. A thickness of the first magnetic layer is thicker than a thickness of the second magnetic layer. A thickness of the third magnetic layer is thicker than the second layer thickness.
    Type: Grant
    Filed: August 9, 2021
    Date of Patent: March 28, 2023
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Yuji Nakagawa, Naoyuki Narita, Masayuki Takagishi, Tomoyuki Maeda, Tazumi Nagasawa, Hirofumi Suto
  • Publication number: 20230062839
    Abstract: According to one embodiment, a magnetic head includes a magnetic pole, a shield, and a non-magnetic layer. The non-magnetic layer is provided between the magnetic pole and the shield. The non-magnetic layer is in contact with the magnetic pole and the shield. The non-magnetic layer includes a first element including at least one selected from the group consisting of Cu, Au, Cr, V, Al and Ag.
    Type: Application
    Filed: January 27, 2022
    Publication date: March 2, 2023
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Yuji NAKAGAWA, Masayuki TAKAGISHI, Naoyuki NARITA, Tazumi NAGASAWA, Tomoyuki MAEDA