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).

  • Patent number: 9076463
    Abstract: According to one embodiment, a magnetic head includes a main pole configured to apply a recording magnetic field to a recording layer included in a recording medium, a trailing shield opposing the main pole in a down-track direction, with a write gap interposed therebetween, a pair of side shields opposing the main pole on opposite sides of the main pole in a cross-track direction, with respective gaps interposed therebetween, a recording coil configured to cause the main pole to generate a magnetic field, a first high-frequency oscillator interposed between the main pole and one of the side shields, and a second high-frequency oscillator interposed between the main pole and the other side shield.
    Type: Grant
    Filed: October 25, 2013
    Date of Patent: July 7, 2015
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kenichiro Yamada, Katsuhiko Koui, Akihiko Takeo
  • Publication number: 20150162031
    Abstract: According to one embodiment, a magnetic head includes a spin torque oscillator formed between a main magnetic pole and auxiliary magnetic pole. The spin torque oscillator includes a transmission-type spin transfer layer, first interlayer, oscillation layer, second interlayer, and reflection-type spin transfer layer. The transmission-type spin transfer layer includes a first perpendicular magnetization film and first interface magnetic layer. The first interface magnetic layer contains at least one element selected from Fe, Co, and Ni, and at least one element selected from Cr, V, Mn, Ti, and Sc. The reflection-type spin transfer layer includes a second perpendicular magnetization film.
    Type: Application
    Filed: December 12, 2014
    Publication date: June 11, 2015
    Inventors: Mariko Shimizu, Katsuhiko Koui, Shuichi Murakami, Hiromi Yuasa
  • Publication number: 20150162032
    Abstract: According to one embodiment, a magnetic head includes a spin torque oscillator formed between a main magnetic pole and auxiliary magnetic pole. The spin torque oscillator includes a transmission-type spin transfer layer, first interlayer, oscillation layer, second interlayer, and reflection-type spin transfer layer. The transmission-type spin transfer layer includes a first perpendicular magnetization film and first interface magnetic layer. The first interface magnetic layer contains at least one element selected from Fe, Co, and Ni, and at least one element selected from Cr, V, Mn, Ti, and Sc. The reflection-type spin transfer layer includes a second perpendicular magnetization film.
    Type: Application
    Filed: December 12, 2014
    Publication date: June 11, 2015
    Inventors: Mariko Shimizu, Katsuhiko Koui, Shuichi Murakami, Hiromi Yuasa
  • Publication number: 20150146324
    Abstract: According to one embodiment, a magnetic recording head includes a main pole configured to apply a recording magnetic field to a recording layer of a recording medium, a trailing shield opposed to the main pole with a write gap therebetween, and a high-frequency oscillator between the main pole and the trailing shield in a range of a width of the main pole in a track width direction, and configured to generate a high-frequency magnetic field. The high-frequency oscillator includes a spin injection layer, an intermediate layer, and an oscillation layer, and at least the oscillation layer comprises divided oscillation regions.
    Type: Application
    Filed: January 30, 2015
    Publication date: May 28, 2015
    Inventors: Kenichiro YAMADA, Katsuhiko KOUI
  • Publication number: 20150146323
    Abstract: According to one embodiment, a magnetic recording head includes a main pole configured to apply a recording magnetic field to a recording layer of a recording medium, a trailing shield opposed to the main pole with a write gap therebetween, and a high-frequency oscillator between the main pole and the trailing shield in a range of a width of the main pole in a track width direction, and configured to generate a high-frequency magnetic field. The high-frequency oscillator includes a spin injection layer, an intermediate layer, and an oscillation layer, and at least the oscillation layer comprises divided oscillation regions.
    Type: Application
    Filed: January 30, 2015
    Publication date: May 28, 2015
    Inventors: Kenichiro YAMADA, Katsuhiko KOUI
  • Publication number: 20150138672
    Abstract: According to one embodiment, a magnetic recording head includes a main pole configured to apply a recording magnetic field to a recording layer of a recording medium, a trailing shield opposed to the main pole with a write gap therebetween, and a high-frequency oscillator between the main pole and the trailing shield in a range of a width of the main pole in a track width direction, and configured to generate a high-frequency magnetic field. The high-frequency oscillator includes a spin injection layer, an intermediate layer, and an oscillation layer, and at least the oscillation layer comprises divided oscillation regions.
    Type: Application
    Filed: January 30, 2015
    Publication date: May 21, 2015
    Inventors: Kenichiro YAMADA, Katsuhiko KOUI
  • Publication number: 20150074986
    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: Application
    Filed: November 21, 2014
    Publication date: March 19, 2015
    Inventors: Akihiko TAKEO, Satoshi SHIROTORI, Kenichiro YAMADA, Katsuhiko KOUI
  • Patent number: 8976490
    Abstract: According to one embodiment, a magnetic recording head includes a main pole configured to apply a recording magnetic field to a recording layer of a recording medium, a trailing shield opposed to the main pole with a write gap therebetween, and a high-frequency oscillator between the main pole and the trailing shield in a range of a width of the main pole in a track width direction, and configured to generate a high-frequency magnetic field. The high-frequency oscillator includes a spin injection layer, an intermediate layer, and an oscillation layer, and at least the oscillation layer comprises divided oscillation regions.
    Type: Grant
    Filed: August 2, 2012
    Date of Patent: March 10, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kenichiro Yamada, Katsuhiko Koui
  • Patent number: 8970986
    Abstract: A magnetic head includes a main magnetic pole, a trailing shield that forms a magnetic circuit with the main magnetic pole, a spin torque oscillator that is provided between the main magnetic pole and the trailing shield, a first cooling layer that partially has a Heusler structure, and a second cooling layer that is provided on the first cooling layer and mainly comprised of silver. The first cooling layer and the second cooling layer are provided either between the main magnetic pole and spin torque oscillator or between the trailing shield and the spin torque oscillator, with either of the two cooling layers being disposed closer to the spin torque oscillator. A third cooling layer may be formed to be in contact with the first cooling layer.
    Type: Grant
    Filed: June 11, 2013
    Date of Patent: March 3, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masahiro Takashita, Shuichi Murakami, Naoki Hase, Katsuhiko Koui
  • Publication number: 20150043106
    Abstract: According to one embodiment, a magnetic head includes a main pole configured to apply a recording magnetic field to a recording layer included in a recording medium, a trailing shield opposing the main pole in a down-track direction, with a write gap interposed therebetween, a pair of side shields opposing the main pole on opposite sides of the main pole in a cross-track direction, with respective gaps interposed therebetween, a recording coil configured to cause the main pole to generate a magnetic field, a first high-frequency oscillator interposed between the main pole and one of the side shields, and a second high-frequency oscillator interposed between the main pole and the other side shield.
    Type: Application
    Filed: October 25, 2013
    Publication date: February 12, 2015
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kenichiro YAMADA, Katsuhiko KOUI, Akihiko TAKEO
  • Patent number: 8953283
    Abstract: According to one embodiment, a magnetic head includes a spin torque oscillator formed between a main magnetic pole and auxiliary magnetic pole. The spin torque oscillator includes a transmission-type spin transfer layer, first interlayer, oscillation layer, second interlayer, and reflection-type spin transfer layer. The transmission-type spin transfer layer includes a first perpendicular magnetization film and first interface magnetic layer. The first interface magnetic layer contains at least one element selected from Fe, Co, and Ni, and at least one element selected from Cr, V, Mn, Ti, and Sc. The reflection-type spin transfer layer includes a second perpendicular magnetization film.
    Type: Grant
    Filed: December 9, 2013
    Date of Patent: February 10, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Mariko Shimizu, Katsuhiko Koui, Shuichi Murakami, Hiromi Yuasa
  • Patent number: 8929031
    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 8, 2011
    Date of Patent: January 6, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Akihiko Takeo, Satoshi Shirotori, Kenichiro Yamada, Katsuhiko Koui
  • Patent number: 8922949
    Abstract: According to one embodiment, the magnetic recording head comprises a cooling/heating material between a laminated oscillator and a main magnetic pole, the cooling/heating material including the following layers laminated from the laminated oscillator side in the following order, a first thermoelectric material layer having the same junction area as that of the laminated oscillator, a first metal material layer having the same junction area as that of the laminated oscillator, a second metal material layer having the same junction area as that of the main magnetic pole, and a second thermoelectric material layer having the same junction area as that of the main magnetic pole.
    Type: Grant
    Filed: December 6, 2013
    Date of Patent: December 30, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Katsuhiko Koui, Hiromi Yuasa, Mariko Shimizu, Shuichi Murakami
  • Publication number: 20140376130
    Abstract: A magnetic head includes a plurality of reproducing elements so that the magnetic head can acquire reproduction signals from a plurality of tracks at the same time. The magnetic head includes a first reproducing element, a first magnetic film formed on a first side wall of the first reproducing element with a first side wall insulating film interposed therebetween, a second magnetic film formed on a second side wall of the first reproducing element with a second side wall insulating film interposed therebetween, a second reproducing element electrically isolated from the first reproducing element and formed on the first magnetic film, a third magnetic film formed on the first magnetic film, and a fourth magnetic film formed on the first reproducing element and electrically isolated from the second reproducing element.
    Type: Application
    Filed: January 10, 2014
    Publication date: December 25, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Akihiko TAKEO, Kazuto KASHIWAGI, Kenichiro YAMADA, Katsuhiko KOUI, Tomomi FUNAYAMA
  • Patent number: 8908329
    Abstract: According to one embodiment, a magnetic head manufacturing method includes forming a protective layer on the surfaces of a main magnetic pole layer, a processed spin torque oscillator, and a mask formed on the spin torque oscillator, and further performing ion beam etching on the main magnetic pole layer and the protective layer on the surface of the main magnetic pole layer through the mask such that the protective layer is left behind on the side surfaces of the spin torque oscillator and removed from the surface of the main magnetic pole layer, thereby processing the main magnetic pole layer such that its side surfaces have a shape tapered toward the substrate.
    Type: Grant
    Filed: October 22, 2012
    Date of Patent: December 9, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Satoshi Shirotori, Katsuhiko Koui, Shinobu Sugimura, Norihito Fujita, Akihiko Takeo
  • Patent number: 8879206
    Abstract: According to one embodiment, a magnetic recording head includes a main magnetic pole, an auxiliary magnetic pole, and a spin torque oscillator formed between them. The spin torque oscillator includes a main oscillation layer and spin sink layer as an oscillation layer. The spin sink layer contains one of iron and cobalt, and at least one element selected from the group consisting of platinum, palladium, ruthenium, tantalum, chromium, terbium, gadolinium, europium, dysprosium, and samarium.
    Type: Grant
    Filed: December 17, 2012
    Date of Patent: November 4, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Mariko Shimizu, Katsuhiko Koui, Shuichi Murakami, Masahiro Takashita
  • Patent number: 8824104
    Abstract: According to one embodiment, a magnetic head according to the embodiment includes a main magnetic pole, a spin torque oscillator, and an auxiliary magnetic pole. The spin torque oscillator includes a spin injection layer, a nonmagnetic intermediate layer, and an oscillation layer. The spin injection layer has an artificial lattice film obtained by stacking a first metal layer of a Heusler alloy and a second metal layer including at least one of platinum, palladium, and nickel two times or more repeatedly, and the first metal layer has a thickness of 0.3 to 3.5 nm.
    Type: Grant
    Filed: October 7, 2013
    Date of Patent: September 2, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Katsuhiko Koui, Shuichi Murakami
  • Patent number: 8817419
    Abstract: According to one embodiment, a magnetic recording head includes a main magnetic pole generating a recording magnetic field in a magnetic recording medium, a return yoke paired with the main magnetic pole, and a spin torque oscillator interposed between the main magnetic pole and the return yoke and including a spin injection layer, an oscillation layer, a nonmagnetic metal layer, and spin assist layer stacked in this order, wherein the nonmagnetic metal layer includes at least one metal selected from the group consisting of Cu, Au, Ag, Al, Pd, Pt, Os, and Ir, and the spin assist layer is a soft magnetic layer whose saturation magnetic flux density (Bs), diamagnetic field coefficient (N) and gap magnetic field (Hg) show a relationship expressed by Bs×N>Hg.
    Type: Grant
    Filed: June 28, 2011
    Date of Patent: August 26, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Soichi Oikawa, Katsuhiko Koui
  • Patent number: 8780500
    Abstract: According to one embodiment, a magnetic recording head manufacturing method includes forming a spin torque oscillator layer on a main magnetic pole layer, forming a mask on the spin torque oscillator layer, processing the spin torque oscillator layer by performing ion beam etching through the mask, and partially modifying the main magnetic pole layer through the mask. The partially modifying the main magnetic pole layer makes it possible to decrease the saturation flux density of the main magnetic pole layer in the modified portion, and form an unmodified main magnetic pole portion covered with the mask, and a modified portion around the main magnetic pole.
    Type: Grant
    Filed: January 29, 2013
    Date of Patent: July 15, 2014
    Assignees: Kabushiki Kaisha Toshiba, TDK Corporation
    Inventors: Satoshi Shirotori, Katsuhiko Koui, Shinobou Sugimura, Norihito Fujita, Akihiki Takeo, Min Li, Ruhang Ding
  • Publication number: 20140177101
    Abstract: According to one embodiment, an oscillation layer of a spin torque oscillator for use in a magnetic head includes a stack of first and second metal films. The first metal film is formed by repetitively stacking a combination of first and second magnetic layers twice or more. The thickness of the first metal film is 0.4 to 5.0 nm. The first magnetic layer has a bcc structure and contains Fe. The second magnetic layer contains Co. The second metal film is made of Cu.
    Type: Application
    Filed: May 28, 2013
    Publication date: June 26, 2014
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Katsuhiko KOUI, Shuichi Murakami, Mariko Shimizu, Kenichiro Yamada