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: 20170186450
    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: September 1, 2016
    Publication date: June 29, 2017
    Inventors: Kenichiro YAMADA, Shuichi MURAKAMI, Naoyuki NARITA, Katsuhiko KOUI, Akihiko TAKEO, Mariko SHIMIZU, Hitoshi IWASAKI
  • Patent number: 9691415
    Abstract: According to one embodiment, a disk device includes a disk includes a recording layer, a recording head includes a main pole configured to apply a recording magnetic field onto the recording layer, and a microwave oscillator adjacent to the main pole, configured to apply a microwave magnetic field to the recording layer, a current supply circuit configured to supply a current to the microwave oscillator, and a switching circuit configured to switch a direction of current flow to the microwave oscillator.
    Type: Grant
    Filed: February 11, 2016
    Date of Patent: June 27, 2017
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Katsuhiko Koui
  • Patent number: 9679587
    Abstract: According to one embodiment, a magnetic recording head includes an air-bearing surface, a main magnetic pole, a write shield opposed to the main magnetic pole with a write gap therebetween, a high-frequency oscillator which includes a spin injection layer and a oscillation layer and is provided between the main magnetic pole and the write shield, the oscillation layer and the spin injection layer including a stack surface extending in a direction intersecting with the air-bearing surface, and a magnetic material layer which is provided in at least one of the main magnetic pole and the write shield, faces the high-frequency oscillator, and has negative magnetic anisotropy with respect to a direction intersecting with the stack surfaces of the high-frequency oscillator.
    Type: Grant
    Filed: November 18, 2015
    Date of Patent: June 13, 2017
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tomoko Taguchi, Katsuhiko Koui
  • Publication number: 20170140779
    Abstract: According to one embodiment, a disk device includes a disk includes a recording layer, a recording head includes a main pole configured to apply a recording magnetic field onto the recording layer, and a microwave oscillator adjacent to the main pole, configured to apply a microwave magnetic field to the recording layer, a current supply circuit configured to supply a current to the microwave oscillator, and a switching circuit configured to switch a direction of current flow to the microwave oscillator.
    Type: Application
    Filed: February 11, 2016
    Publication date: May 18, 2017
    Inventor: Katsuhiko Koui
  • Publication number: 20170092304
    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: Application
    Filed: December 21, 2015
    Publication date: March 30, 2017
    Inventors: Gaku Koizumi, Tomoko Taguchi, Katsuhiko Koui
  • Publication number: 20170061995
    Abstract: According to one embodiment, a magnetic recording head includes an air-bearing surface, a main magnetic pole, a write shield opposed to the main magnetic pole with a write gap therebetween, a high-frequency oscillator which includes a spin injection layer and a oscillation layer and is provided between the main magnetic pole and the write shield, the oscillation layer and the spin injection layer including a stack surface extending in a direction intersecting with the air-bearing surface, and a magnetic material layer which is provided in at least one of the main magnetic pole and the write shield, faces the high-frequency oscillator, and has negative magnetic anisotropy with respect to a direction intersecting with the stack surfaces of the high-frequency oscillator.
    Type: Application
    Filed: November 18, 2015
    Publication date: March 2, 2017
    Inventors: Tomoko Taguchi, Katsuhiko Koui
  • Patent number: 9390731
    Abstract: The magnetic recording head according to an embodiment includes an air bearing surface configured to face a magnetic recording medium, a main magnetic pole including a main magnetic pole distal end, a first spin injection layer disposed on a leading side of the main magnetic pole, a field generation layer disposed on a trailing side of the main magnetic pole, and an intermediate layer configured to connect electrically the field generation layer to the first spin injection layer. The main magnetic pole is configured to apply a recording magnetic field to the magnetic recording medium.
    Type: Grant
    Filed: July 11, 2014
    Date of Patent: July 12, 2016
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Katsuhiko Koui
  • Patent number: 9355659
    Abstract: A magnetic recording head includes a main magnetic pole in which a recording magnetic field is generated, a write shield magnetic pole disposed alongside the main magnetic pole with a gap therebetween, a spin torque oscillator disposed within the gap and configured to generate a microwave, an anti-ferromagnetic layer disposed within the gap between the write shield magnetic pole and the spin torque oscillator, and a non-magnetic metal layer disposed within the gap between the spin torque oscillator and the anti-ferromagnetic layer.
    Type: Grant
    Filed: June 18, 2015
    Date of Patent: May 31, 2016
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Katsuhiko Koui, Mariko Shimizu, Shuichi Murakami, Kenichiro Yamada
  • Patent number: 9311936
    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: January 30, 2015
    Date of Patent: April 12, 2016
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kenichiro Yamada, Katsuhiko Koui
  • Patent number: 9305577
    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: January 30, 2015
    Date of Patent: April 5, 2016
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kenichiro Yamada, Katsuhiko Koui
  • Patent number: 9230567
    Abstract: According to one embodiment, a microwave-assisted magnetic recording head includes a SIL formed either in an area outside a FGL in a track width direction or in an area outside a FGL in a depth direction perpendicular to an air bearing surface of the FGL. An area between the SIL and the FGL can be enlarged, and an intermediate layer can be formed therebetween such that an area in which the intermediate layer contacts the FGL can be enlarged as well.
    Type: Grant
    Filed: July 29, 2015
    Date of Patent: January 5, 2016
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Norihito Fujita, Katsuhiko Koui, Satoshi Shirotori, Mariko Shimizu, Shuichi Murakami
  • Publication number: 20150380022
    Abstract: A magnetic recording head includes a main magnetic pole in which a recording magnetic field is generated, a write shield magnetic pole disposed alongside the main magnetic pole with a gap therebetween, a spin torque oscillator disposed within the gap and configured to generate a microwave, an anti-ferromagnetic layer disposed within the gap between the write shield magnetic pole and the spin torque oscillator, and a non-magnetic metal layer disposed within the gap between the spin torque oscillator and the anti-ferromagnetic layer.
    Type: Application
    Filed: June 18, 2015
    Publication date: December 31, 2015
    Inventors: Katsuhiko KOUI, Mariko SHIMIZU, Shuichi MURAKAMI, Kenichiro YAMADA
  • Patent number: 9218828
    Abstract: According to one embodiment, a magnetic head includes a spin-torque oscillator which further includes a non-magnetic separation seed layer formed directly on a main magnetic pole and containing an element selected from W, Re, Os and Ir, an SIL, an IL and FGL formed one on another in this order.
    Type: Grant
    Filed: February 12, 2015
    Date of Patent: December 22, 2015
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Katsuhiko Koui, Shuichi Murakami
  • Patent number: 9208802
    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: January 30, 2015
    Date of Patent: December 8, 2015
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kenichiro Yamada, Katsuhiko Koui
  • Patent number: 9196271
    Abstract: According to one embodiment, a spin-torque oscillation element includes a lamination structure containing a spin injection layer, a non-magnetic interlayer formed on the spin injection layer and an oscillation layer formed on the non-magnetic interlayer, and a non-magnetic conductive layer provided on a sidewall of the lamination structure, and the thickness of the lamination structure in a longitudinal direction is 60 nm or less.
    Type: Grant
    Filed: February 4, 2015
    Date of Patent: November 24, 2015
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Satoshi Shirotori, Katsuhiko Koui, Mariko Shimizu, Shuichi Murakami, Norihito Fujita
  • Publication number: 20150310881
    Abstract: The magnetic recording head according to an embodiment includes an air bearing surface configured to face a magnetic recording medium, a main magnetic pole including a main magnetic pole distal end, a first spin injection layer disposed on a leading side of the main magnetic pole, a field generation layer disposed on a trailing side of the main magnetic pole, and an intermediate layer configured to connect electrically the field generation layer to the first spin injection layer. The main magnetic pole is configured to apply a recording magnetic field to the magnetic recording medium.
    Type: Application
    Filed: July 11, 2014
    Publication date: October 29, 2015
    Applicant: Kabushiki Kaisha Toshiba
    Inventor: Katsuhiko Koui
  • Patent number: 9171558
    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: Grant
    Filed: January 10, 2014
    Date of Patent: October 27, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Akihiko Takeo, Kazuto Kashiwagi, Kenichiro Yamada, Katsuhiko Koui, Tomomi Funayama
  • Patent number: 9111552
    Abstract: A magnetic recording head includes a main magnetic pole that applies a recording magnetic field to a recording layer of a recording medium, a write shield that faces the main magnetic pole with a write gap therebetween, a recording coil that generates a magnetic field in the main magnetic pole, a high-frequency oscillator that includes a field generation layer and a spin injection layer, and is disposed within the write gap between the main magnetic pole and the write shield, a wiring electrically connected to the high-frequency oscillator, a modulation electrode that applies a modulation voltage to the field generation layer, and a modulation insulating layer that is interposed between the field generation layer and the modulation electrode.
    Type: Grant
    Filed: September 2, 2014
    Date of Patent: August 18, 2015
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Akihiko Takeo, Kenichiro Yamada, Noayuki Narita, Katsuhiko Koui
  • Patent number: 9087532
    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 12, 2014
    Date of Patent: July 21, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Mariko Shimizu, Katsuhiko Koui, Shuichi Murakami, Hiromi Yuasa
  • Patent number: 9087533
    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 12, 2014
    Date of Patent: July 21, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Mariko Shimizu, Katsuhiko Koui, Shuichi Murakami, Hiromi Yuasa