Patents by Inventor Katsuhiko Koui

Katsuhiko Koui 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: 20190088302
    Abstract: According to one embodiment, a magnetic memory includes: magnetoresistive effect elements arranged on an conductive layer; and a first circuit which passes a write current through the conductive layer and applies a control voltage to the magnetoresistive effect elements, to write data including a first value and a second value into the magnetoresistive effect elements. The first circuit adjusts at least one of a write sequence of the first value and the second value, a current value of the write current, and a pulse width of the write current, on the basis of an arrangement of the first value and the second value in the data.
    Type: Application
    Filed: March 8, 2018
    Publication date: March 21, 2019
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Naoharu SHIMOMURA, Tomoaki INOKUCHI, Katsuhiko KOUI, Yuzo KAMIGUCHI, Hiroaki YODA, Hideyuki SUGIYAMA
  • Patent number: 10211394
    Abstract: A magnetic memory according to an embodiment includes: a first and second terminals; a conductive layer, which is nonmagnetic, the conductive layer including a first to third regions, the second region being disposed between the first region and the third region, the first region being electrically connected to the first terminal, and the third region being electrically connected to the second terminal; a magnetoresistive element disposed to correspond to the second region of the conductive layer, the magnetoresistive element including a first magnetic layer, a second magnetic layer disposed between the second region and the first magnetic layer and electrically connected to the second region, a nonmagnetic layer disposed between the first magnetic layer and the second magnetic layer, and a third terminal electrically connected to the first magnetic layer; and a third magnetic layer, the conductive layer being disposed between the third and second magnetic layers.
    Type: Grant
    Filed: March 5, 2018
    Date of Patent: February 19, 2019
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tomoaki Inokuchi, Katsuhiko Koui, Naoharu Shimomura, Yuuzo Kamiguchi, Satoshi Shirotori, Yuichi Ohsawa, Hiroaki Yoda
  • Patent number: 10192572
    Abstract: According to one embodiment, a magnetic recording head includes a magnetic pole, a stacked body, and a first non-magnetic layer. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic layer and the magnetic pole, and a non-magnetic intermediate layer provided between the first magnetic layer and the second magnetic layer. The first non-magnetic layer is provided between the second magnetic layer and the magnetic pole, and contacts the magnetic pole and the second magnetic layer. The first magnetic layer has a first thickness and a first saturation magnetic flux density. The second magnetic layer has a second thickness and a second saturation magnetic flux density. A second product of the second thickness and the second saturation magnetic flux density is larger than a first product of the first thickness and the first saturation magnetic flux density.
    Type: Grant
    Filed: December 14, 2017
    Date of Patent: January 29, 2019
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kenichiro Yamada, Shuichi Murakami, Naoyuki Narita, Katsuhiko Koui, Akihiko Takeo, Mariko Shimizu, Hitoshi Iwasaki
  • Patent number: 10186284
    Abstract: According to one embodiment, a magnetic head includes a magnetic pole, and a first shield, and a stacked body provided between the magnetic pole and the first shield. The stacked body includes a first layer, a second layer and a third layer. The first layer includes at least one first element selected from the group consisting of Fe, Co, and Ni. The second layer is provided between the magnetic pole and the first layer, and includes at least one second element selected from the group consisting of Cr, V, Mn, Ti, and Sc. The third layer is provided between the first layer and the first shield, and includes at least one third element selected from the group consisting of Cr, V, Mn, Ti, and Sc.
    Type: Grant
    Filed: September 13, 2017
    Date of Patent: January 22, 2019
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Naoyuki Narita, Hitoshi Iwasaki, Mariko Shimizu, Katsuhiko Koui, Kenichiro Yamada
  • Patent number: 10170694
    Abstract: A magnetic memory of an embodiment includes: a first conductive layer, which is nonmagnetic and includes at least a first element, the first conductive layer including a first to fifth regions; a first magnetoresistive element disposed corresponding to the third region and including a first magnetic layer, a second magnetic layer including at least a second element, a first nonmagnetic layer disposed between the first magnetic layer and the second magnetic layer, a second nonmagnetic layer disposed between the second magnetic layer and the first nonmagnetic layer and including at least a third element, and a third magnetic layer disposed between the second nonmagnetic layer and the first nonmagnetic layer; a second conductive layer disposed corresponding to the second region and including at least the first to third elements; and a third conductive layer disposed corresponding to the fourth region, and including at least the first to third elements.
    Type: Grant
    Filed: March 5, 2018
    Date of Patent: January 1, 2019
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Satoshi Shirotori, Yuichi Ohsawa, Hideyuki Sugiyama, Mariko Shimizu, Altansargai Buyandalai, Naoharu Shimomura, Katsuhiko Koui, Tomoaki Inokuchi, Hiroaki Yoda
  • Publication number: 20180301179
    Abstract: According to one embodiment, a nonvolatile memory includes a conductive line including a first portion, a second portion and a third portion therebetween, a storage element including a first magnetic layer, a second magnetic layer and a nonmagnetic layer therebetween, and the first magnetic layer being connected to the third portion, and a circuit flowing a write current between the first and second portions, applying a first potential to the second magnetic layer, and blocking the write current flowing between the first and second portions after changing the second magnetic layer from the first potential to a second potential.
    Type: Application
    Filed: June 18, 2018
    Publication date: October 18, 2018
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tomoaki INOKUCHI, Naoharu SHIMOMURA, Katsuhiko KOUI, Yuuzo KAMIGUCHI, Satoshi SHIROTORI, Kazutaka IKEGAMI, Hiroaki YODA
  • Patent number: 10102894
    Abstract: A magnetic memory includes: a first and second terminals; a conductive layer including first to fourth regions, the first and fourth regions being electrically connected to the first and second terminals respectively; a first magnetoresistive element including: a first and second magnetic layers; a first nonmagnetic layer between the first and second magnetic layers; and a third terminal electrically connected to the first magnetic layer; a second magnetoresistive element including: a third and fourth magnetic layers; a second nonmagnetic layer between the third and fourth magnetic layers; and a fourth terminal electrically connected to the third magnetic layer; and a circuit configured to apply a write current between the first terminal and the second terminal and apply a first and second potentials to the third and fourth terminals respectively to write the first and second magnetoresistive elements, the first and second potentials being different from each other.
    Type: Grant
    Filed: September 7, 2017
    Date of Patent: October 16, 2018
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Naoharu Shimomura, Tomoaki Inokuchi, Hiroki Noguchi, Katsuhiko Koui, Yuuzo Kamiguchi, Kazutaka Ikegami, Hiroaki Yoda
  • Publication number: 20180277746
    Abstract: A magnetic memory includes: first to fourth wirings; first and second terminals; a first conductive layer including first to third regions, the second region being between the first region and the third region, the first region being electrically connected to the first terminal, and the third region being electrically connected to the second terminal; a first magnetoresistive element including a first and a second magnetic layer, and a first nonmagnetic layer disposed between the first and the magnetic layer; a first transistor including a third terminal electrically connected to the first magnetic layer, a fourth terminal electrically connected to the third wiring, and a first control terminal electrically connected to the first wiring; and a second transistor including a fifth terminal electrically connected to the first terminal, a sixth terminal electrically connected to the second wiring, and a second control terminal electrically connected to the first wiring.
    Type: Application
    Filed: September 14, 2017
    Publication date: September 27, 2018
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Keiko ABE, Kazutaka IKEGAMI, Shinobu FUJITA, Katsuhiko KOUI, Tomoaki INOKUCHI, Satoshi SHIROTORI, Yuichi OHSAWA, Hideyuki SUGIYAMA, Hiroaki YODA, Naoharu SHIMOMURA, Yuuzo KAMIGUCHI
  • Publication number: 20180261241
    Abstract: According to one embodiment, a magnetic head includes a magnetic pole, and a first shield, and a stacked body provided between the magnetic pole and the first shield. The stacked body includes a first layer, a second layer and a third layer. The first layer includes at least one first element selected from the group consisting of Fe, Co, and Ni. The second layer is provided between the magnetic pole and the first layer, and includes at least one second element selected from the group consisting of Cr, V, Mn, Ti, and Sc. The third layer is provided between the first layer and the first shield, and includes at least one third element selected from the group consisting of Cr, V, Mn, Ti, and Sc.
    Type: Application
    Filed: September 13, 2017
    Publication date: September 13, 2018
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Naoyuki NARITA, Hitoshi IWASAKI, Mariko SHIMIZU, Katsuhiko KOUI, Kenichiro YAMADA
  • Patent number: 10026465
    Abstract: According to one embodiment, a nonvolatile memory includes a conductive line including a first portion, a second portion and a third portion therebetween, a storage element including a first magnetic layer, a second magnetic layer and a nonmagnetic layer therebetween, and the first magnetic layer being connected to the third portion, and a circuit flowing a write current between the first and second portions, applying a first potential to the second magnetic layer, and blocking the write current flowing between the first and second portions after changing the second magnetic layer from the first potential to a second potential.
    Type: Grant
    Filed: March 8, 2017
    Date of Patent: July 17, 2018
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tomoaki Inokuchi, Naoharu Shimomura, Katsuhiko Koui, Yuuzo Kamiguchi, Satoshi Shirotori, Kazutaka Ikegami, Hiroaki Yoda
  • Publication number: 20180158499
    Abstract: A magnetic memory includes: a first and second terminals; a conductive layer including first to fourth regions, the first and fourth regions being electrically connected to the first and second terminals respectively; a first magnetoresistive element including: a first and second magnetic layers; a first nonmagnetic layer between the first and second magnetic layers; and a third terminal electrically connected to the first magnetic layer; a second magnetoresistive element including: a third and fourth magnetic layers; a second nonmagnetic layer between the third and fourth magnetic layers; and a fourth terminal electrically connected to the third magnetic layer; and a circuit configured to apply a write current between the first terminal and the second terminal and apply a first and second potentials to the third and fourth terminals respectively to write the first and second magnetoresistive elements, the first and second potentials being different from each other.
    Type: Application
    Filed: September 7, 2017
    Publication date: June 7, 2018
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Naoharu SHIMOMURA, Tomoaki INOKUCHI, Hiroki NOGUCHI, Katsuhiko KOUI, Yuuzo KAMIGUCHI, Kazutaka IKEGAMI, Hiroaki YODA
  • Publication number: 20180114539
    Abstract: According to one embodiment, a magnetic recording head includes a magnetic pole, a stacked body, and a first non-magnetic layer. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic layer and the magnetic pole, and a non-magnetic intermediate layer provided between the first magnetic layer and the second magnetic layer. The first non-magnetic layer is provided between the second magnetic layer and the magnetic pole, and contacts the magnetic pole and the second magnetic layer. The first magnetic layer has a first thickness and a first saturation magnetic flux density. The second magnetic layer has a second thickness and a second saturation magnetic flux density. A second product of the second thickness and the second saturation magnetic flux density is larger than a first product of the first thickness and the first saturation magnetic flux density.
    Type: Application
    Filed: December 14, 2017
    Publication date: April 26, 2018
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Kenichiro Yamada, Shuichi Murakami, Naoyuki Narita, Katsuhiko Koui, Akihiko Takeo, Mariko Shimizu, Hitoshi Iwasaki
  • Publication number: 20180075868
    Abstract: A magnetic recording head includes a main magnetic pole extending to an air bearing surface of the magnetic recording head and having an end portion that is exposed at the air bearing surface, a magnetic shield having an end portion that is exposed at the air bearing surface and faces the end portion of the main magnetic pole with a gap therebetween, a stacked-layer element disposed in the gap, and including a first conductive layer in contact the main magnetic pole, a second conductive layer in contact with the magnetic shield, and an magnetic permeability adjusting layer disposed between the first conductive layer and the second conductive layer, and first and second terminals between which a current flows through the main magnetic pole, the stacked-layer element, and the magnetic shield when the current is supplied to one of the terminals.
    Type: Application
    Filed: February 28, 2017
    Publication date: March 15, 2018
    Inventors: Katsuhiko KOUI, Kenichiro YAMADA, Tomoko TAGUCHI
  • Publication number: 20180040359
    Abstract: According to one embodiment, a nonvolatile memory includes a conductive line including a first portion, a second portion and a third portion therebetween, a storage element including a first magnetic layer, a second magnetic layer and a nonmagnetic layer therebetween, and the first magnetic layer being connected to the third portion, and a circuit flowing a write current between the first and second portions, applying a first potential to the second magnetic layer, and blocking the write current flowing between the first and second portions after changing the second magnetic layer from the first potential to a second potential.
    Type: Application
    Filed: March 8, 2017
    Publication date: February 8, 2018
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tomoaki INOKUCHI, Naoharu SHIMOMURA, Katsuhiko KOUI, Yuuzo KAMIGUCHI, Satoshi SHIROTORI, Kazutaka IKEGAMI, Hiroaki YODA
  • Patent number: 9886971
    Abstract: According to one embodiment, a magnetic recording head includes a magnetic pole, a stacked body, and a first non-magnetic layer. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic layer and the magnetic pole, and a non-magnetic intermediate layer provided between the first magnetic layer and the second magnetic layer. The first non-magnetic layer is provided between the second magnetic layer and the magnetic pole, and contacts the magnetic pole and the second magnetic layer. The first magnetic layer has a first thickness and a first saturation magnetic flux density. The second magnetic layer has a second thickness and a second saturation magnetic flux density. A second product of the second thickness and the second saturation magnetic flux density is larger than a first product of the first thickness and the first saturation magnetic flux density.
    Type: Grant
    Filed: September 1, 2016
    Date of Patent: February 6, 2018
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kenichiro Yamada, Shuichi Murakami, Naoyuki Narita, Katsuhiko Koui, Akihiko Takeo, Mariko Shimizu, Hitoshi Iwasaki
  • Patent number: 9799354
    Abstract: According to one embodiment, a magnetic recording head includes a magnetic pole, a stacked body, and a first nonmagnetic layer. The stacked body includes first magnetic layer, a second magnetic layer provided between the first magnetic layer and the magnetic pole, and an intermediate layer provided between the first magnetic layer and the second magnetic layer and being nonmagnetic. The first nonmagnetic layer is provided between the second magnetic layer and the magnetic pole. A product of a thickness and a saturation magnetic flux density of the second magnetic layer is larger than a product of a thickness and a saturation magnetic flux density of the first magnetic layer. The length of the first magnetic layer is shorter than a length of the second magnetic layer. A current flows from the second magnetic layer toward the first magnetic layer.
    Type: Grant
    Filed: September 12, 2016
    Date of Patent: October 24, 2017
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shuichi Murakami, Kenichiro Yamada, Katsuhiko Koui, Mariko Shimizu, Akihiko Takeo, Naoyuki Narita, Hitoshi Iwasaki
  • Patent number: 9792933
    Abstract: According to one embodiment, a magnetic head includes an air bearing surface, a first surface on which contact pads connected to elements are provided, a pair of second surfaces provided respectively with a connection terminal connected to the contact pad, a main pole with a distal end portion extending to the air bearing surface, a write shield opposing the distal end portion of the main pole with a write gap therebetween, and a high-frequency oscillator provided between the main pole and the write shield within the write gap and electrically connected to the main pole and the write shield. The high-frequency oscillator includes a spin injection layer and an oscillation layer, and at least the oscillation layer is recessed in a direction away from the air bearing surface.
    Type: Grant
    Filed: December 21, 2015
    Date of Patent: October 17, 2017
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Gaku Koizumi, Tomoko Taguchi, Katsuhiko Koui
  • Patent number: 9792930
    Abstract: A microwave-assisted magnetic recording head includes a main magnetic pole, an auxiliary magnetic pole facing the main magnetic pole with a gap therebetween, and a stacked-layer element disposed in the gap. The stacked-layer element includes, in the order from the main magnetic pole to the auxiliary magnetic pole, a thermal spin injection layer that is formed on the main magnetic pole, exchange-coupled with the main magnetic pole, and formed of a magnetic material of which spin-dependent Seebeck coefficient is negative, a first non-magnetic layer formed on the thermal spin injection layer, an oscillation layer formed on the first non-magnetic layer, a second non-magnetic layer formed on the oscillation layer, and a spin injection layer formed on the second non-magnetic layer.
    Type: Grant
    Filed: February 28, 2017
    Date of Patent: October 17, 2017
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Mariko Shimizu, Katsuhiko Koui, Shuichi Murakami
  • Publication number: 20170236537
    Abstract: According to one embodiment, a magnetic recording head includes a magnetic pole, a stacked body, and a first nonmagnetic layer. The stacked body includes first magnetic layer, a second magnetic layer provided between the first magnetic layer and the magnetic pole, and an intermediate layer provided between the first magnetic layer and the second magnetic layer and being nonmagnetic. The first nonmagnetic layer is provided between the second magnetic layer and the magnetic pole. A product of a thickness and a saturation magnetic flux density of the second magnetic layer is larger than a product of a thickness and a saturation magnetic flux density of the first magnetic layer. The length of the first magnetic layer is shorter than a length of the second magnetic layer. A current flows from the second magnetic layer toward the first magnetic layer.
    Type: Application
    Filed: September 12, 2016
    Publication date: August 17, 2017
    Inventors: Shuichi MURAKAMI, Kenichiro YAMADA, Katsuhiko KOUI, Mariko SHIMIZU, Akihiko TAKEO, Naoyuki NARITA, Hitoshi IWASAKI
  • Patent number: 9721594
    Abstract: According to one embodiment, there is provided a spin torque oscillator including an oscillation layer formed of a magnetic material, a spin injection layer formed of a magnetic material and configured to inject a spin into the oscillation layer, and a current confinement layer including an insulating portion formed of an oxide or a nitride and a conductive portion formed of a nonmagnetic metal and penetrating the insulating portion in a direction of stacking. The conductive portion of the current confinement layer is positioned near a central portion of a plane of a device region including the oscillation layer and the spin injection layer.
    Type: Grant
    Filed: November 21, 2014
    Date of Patent: August 1, 2017
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Akihiko Takeo, Satoshi Shirotori, Kenichiro Yamada, Katsuhiko Koui