Patents by Inventor Katsumi Hoshino

Katsumi Hoshino 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: 20150228297
    Abstract: A magnetic read sensor having an extended pinned layer and having a free layer structure with a back edge formed at an angle for optimizing sensor performance and pinned layer pinning. The magnetic free layer has a back edge that is formed at an angle of between 6 and 10 degrees relative to a plane parallel with the air bearing surface plane. The magnetic sensor can be formed by forming the free layer stripe height with an ion milling that is performed at an angle of 6 to 10 degrees relative to normal.
    Type: Application
    Filed: February 11, 2014
    Publication date: August 13, 2015
    Applicant: HGST NETHERLANDS B.V.
    Inventors: Takashi Wagatsuma, Yukimasa Okada, Katsumi Hoshino, Kouji Kataoka
  • Patent number: 9099123
    Abstract: A magnetic read sensor having an extended pinned layer and having a free layer structure with a back edge formed at an angle for optimizing sensor performance and pinned layer pinning. The magnetic free layer has a back edge that is formed at an angle of between 6 and 10 degrees relative to a plane parallel with the air bearing surface plane. The magnetic sensor can be formed by forming the free layer stripe height with an ion milling that is performed at an angle of 6 to 10 degrees relative to normal.
    Type: Grant
    Filed: February 11, 2014
    Date of Patent: August 4, 2015
    Assignee: HGST Netherlands B.V.
    Inventors: Takashi Wagatsuma, Yukimasa Okada, Katsumi Hoshino, Kouji Kataoka
  • Patent number: 9019649
    Abstract: In one embodiment, a magnetic disk device includes a magnetic disk medium, at least one magnetic head having at least one of: a magnetic read element configured to read data from the magnetic disk medium and a magnetic write element configured to write data to the magnetic disk medium, and a heating element configured to generate heat upon application of a voltage/current thereto, wherein the heating element is positioned on, near, or within the magnetic head, a drive mechanism for passing the magnetic disk medium over the at least one magnetic head, and a controller electrically coupled to the at least one magnetic head for controlling operation of the at least one magnetic head, wherein the controller is configured to retract the at least one magnetic head from a flying state above the magnetic disk medium and apply the voltage/current to the heating element while the magnetic head is retracted.
    Type: Grant
    Filed: April 23, 2014
    Date of Patent: April 28, 2015
    Assignee: HGST Netherlands B.V.
    Inventors: Yukimasa Okada, Katsumi Hoshino, Kouji Kataoka, Takashi Wagatsuma
  • Patent number: 8976492
    Abstract: In one embodiment, a magnetic head includes a lower shield, a read element positioned above the lower shield at a media-facing surface of the magnetic head, the read element having a free layer, an upper shield positioned above the read element, a first domain control layer having a direction of magnetization in a predetermined direction, the first domain control layer being configured to control a direction of magnetization of the free layer toward the predetermined direction, and a second domain control layer configured to have a magnetization in a same direction as the direction of magnetization of the first domain control layer, the second domain control layer being positioned above the first domain control layer, wherein the first domain control layer is a hard magnetic layer, and wherein the second domain control layer is a soft magnetic layer.
    Type: Grant
    Filed: October 29, 2013
    Date of Patent: March 10, 2015
    Assignee: HGST Netherlands B.V.
    Inventors: Kouji Kataoka, Takashi Wagatsuma, Katsumi Hoshino, Takahiro Ibusuki, Yukimasa Okada, Norihiro Ookawa
  • Patent number: 8873203
    Abstract: A magnetic head according to one embodiment includes a read sensor adapted for sensing an external magnetic field; an upper magnetic shield positioned above the read sensor along an air bearing surface (ABS) of the read sensor; a lower magnetic shield positioned below the read sensor along the ABS of the read sensor; a rear insulating layer positioned on a rear side of the read sensor, the rear side being on an opposite side of the read sensor as the ABS of the read sensor; and a soft magnetic layer positioned near the rear side of the read sensor opposite the ABS of the read sensor, wherein the rear insulating layer is positioned between the soft magnetic layer and the read sensor, and wherein the rear insulating layer is positioned between the soft magnetic layer and the lower magnetic shield.
    Type: Grant
    Filed: December 21, 2012
    Date of Patent: October 28, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Katsumi Hoshino, Kouji Kataoka, Takashi Wagatsuma, Yukimasa Okada
  • Patent number: 8830635
    Abstract: Embodiments in accordance with the present invention provide a magnetic head of the CPP structure for perpendicular magnetic recording, that is excellent in read performance, and stable in write/read performances by enhancing the external field durability, and further, suppresses deterioration in read sensor property, due to thermal factors. At least either shield layer of a lower magnetic shield layer, and an upper magnetic shield layer, closer to a perpendicular magnetic write head, is made up so as to have a multi-layered structure comprising low thermal expansion nonmagnetic layers, and magnetic layers. Material having a coefficient of thermal expansion smaller than that of a magnetoresistive film is selected as a material for the low thermal expansion nonmagnetic layers of the shield layer.
    Type: Grant
    Filed: May 29, 2007
    Date of Patent: September 9, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Katsuro Watanabe, Katsumi Hoshino, Masafumi Mochizuki
  • Patent number: 8810953
    Abstract: In one embodiment, a magnetic disk device includes a magnetic disk medium, at least one magnetic head having at least one of: a magnetic read element adapted for reading data from the magnetic disk medium and a magnetic write element adapted for writing data to the magnetic disk medium, and a heating element adapted for generating heat upon application of a voltage/current thereto, wherein the heating element is positioned on, near, or within the magnetic head, a drive mechanism for passing the magnetic disk medium over the at least one magnetic head, and a controller electrically coupled to the at least one magnetic head for controlling operation of the at least one magnetic head, wherein the controller is configured to retract the at least one magnetic head from a flying state above the magnetic disk medium and apply the voltage/current to the heating element while the magnetic head is retracted.
    Type: Grant
    Filed: December 2, 2011
    Date of Patent: August 19, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Yukimasa Okada, Katsumi Hoshino, Koji Kataoka, Takashi Wagatsuma
  • Publication number: 20140226237
    Abstract: In one embodiment, a magnetic disk device includes a magnetic disk medium, at least one magnetic head having at least one of: a magnetic read element configured to read data from the magnetic disk medium and a magnetic write element configured to write data to the magnetic disk medium, and a heating element configured to generate heat upon application of a voltage/current thereto, wherein the heating element is positioned on, near, or within the magnetic head, a drive mechanism for passing the magnetic disk medium over the at least one magnetic head, and a controller electrically coupled to the at least one magnetic head for controlling operation of the at least one magnetic head, wherein the controller is configured to retract the at least one magnetic head from a flying state above the magnetic disk medium and apply the voltage/current to the heating element while the magnetic head is retracted.
    Type: Application
    Filed: April 23, 2014
    Publication date: August 14, 2014
    Applicant: HGST Netherlands B.V.
    Inventors: Yukimasa Okada, Katsumi Hoshino, Kouji Kataoka, Takashi Wagatsuma
  • Patent number: 8778515
    Abstract: Embodiments of the present invention provide a practical magneto-resistive effect element for CPP-GMR, which exhibits appropriate resistance-area-product and high magnetoresistance change ratio, and meets the demand for a narrow read gap. Certain embodiments of a magneto-resistive effect element in accordance with the present invention include a pinned ferromagnetic layer containing a first ferromagnetic film having a magnetization direction fixed in one direction, a free ferromagnetic layer containing a second ferromagnetic film having a magnetization direction varying in response to an external magnetic field, an intermediate layer provided between the pinned ferromagnetic layer and the free ferromagnetic layer, and a current confinement layer for confining a current. At least one of the pinned ferromagnetic layer or the free ferromagnetic layer includes a highly spin polarized layer.
    Type: Grant
    Filed: November 21, 2008
    Date of Patent: July 15, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Yo Sato, Katsumi Hoshino, Hiroyuki Hoshiya
  • Publication number: 20140177093
    Abstract: A magnetic head according to one embodiment includes a read sensor adapted for sensing an external magnetic field; an upper magnetic shield positioned above the read sensor along an air bearing surface (ABS) of the read sensor; a lower magnetic shield positioned below the read sensor along the ABS of the read sensor; a rear insulating layer positioned on a rear side of the read sensor, the rear side being on an opposite side of the read sensor as the ABS of the read sensor; and a soft magnetic layer positioned near the rear side of the read sensor opposite the ABS of the read sensor, wherein the rear insulating layer is positioned between the soft magnetic layer and the read sensor, and wherein the rear insulating layer is positioned between the soft magnetic layer and the lower magnetic shield.
    Type: Application
    Filed: December 21, 2012
    Publication date: June 26, 2014
    Applicant: HGST NETHERLANDS B.V.
    Inventors: Katsumi Hoshino, Kouji Kataoka, Takashi Wagatsuma, Yukimasa Okada
  • Patent number: 8760821
    Abstract: According to one embodiment, a method for forming a magnetic head having a current perpendicular to plan (CPP) sensor, includes forming a magnetoresistance effect film, performing a subtractive process for defining a back edge and a height length of the magnetoresistance effect film, depositing an insulating film adjacent the back edge of the magnetoresistance effect film, and ion milling at least an upper surface of a first portion of the insulating film located closest to the magnetoresistance effect film, where the upper surface of the first portion of the insulating film lies substantially along a plane. After the ion milling, the insulating film has no overlap of the insulating film above and/or onto the magnetoresistance effect film and no bulging in a region immediately adjacent a boundary between the insulating film and the magnetoresistance effect film.
    Type: Grant
    Filed: February 25, 2013
    Date of Patent: June 24, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Masashi Hattori, Kouichi Nishioka, Katsumi Hoshino, Hideki Mashima
  • Patent number: 8570689
    Abstract: According to one embodiment, a differential magnetoresistive effect element comprises a first magnetoresistive effect element having a first pinning layer, a first intermediate layer, and a first free layer. The differential magnetoresistive effect element also comprises a second magnetoresistive effect element stacked via a spacer layer above the first magnetoresistive effect element, the second magnetoresistive effect element having a second pinning layer, a second intermediate layer, and a second free layer. The first magnetoresistive effect element and the second magnetoresistive effect element show in-opposite-phase resistance change in response to a magnetic field in the same direction, and tp2>tp1 is satisfied when a thickness of the first pinning layer is tp1, and a thickness of the second pinning layer is tp2. In another embodiment, the first and second magnetoresistive effect elements may be CPP-GMR elements.
    Type: Grant
    Filed: December 1, 2009
    Date of Patent: October 29, 2013
    Assignee: HGST Netherlands B.V.
    Inventors: Yo Sato, Katsumi Hoshino, Masato Shiimoto, Takeshi Nakagawa, Hiroyuki Hoshiya
  • Patent number: 8514527
    Abstract: According to one embodiment, a magnetoresistive effect head includes a magnetically pinned layer having a direction of magnetization that is pinned, a free magnetic layer positioned above the magnetically pinned layer, the free magnetic layer having a direction of magnetization that is free to vary, and a barrier layer comprising an insulator positioned between the magnetically pinned layer and the free magnetic layer, wherein at least one of the magnetically pinned layer and the free magnetic layer has a layered structure, the layered structure including a crystal layer comprising one of: a CoFe magnetic layer or a CoFeB magnetic layer and an amorphous magnetic layer comprising CoFeB and an element selected from: Ta, Hf, Zr, and Nb, wherein the crystal layer is positioned closer to a tunnel barrier layer than the amorphous magnetic layer. In another embodiment, a magnetic data storage system includes the magnetoresistive effect head described above.
    Type: Grant
    Filed: November 29, 2010
    Date of Patent: August 20, 2013
    Assignee: HGST Netherlands B.V.
    Inventors: Kojiro Komagaki, Katsumi Hoshino, Masashige Sato, Hiroyuki Hoshiya
  • Publication number: 20130141814
    Abstract: In one embodiment, a magnetic disk device includes a magnetic disk medium, at least one magnetic head having at least one of: a magnetic read element adapted for reading data from the magnetic disk medium and a magnetic write element adapted for writing data to the magnetic disk medium, and a heating element adapted for generating heat upon application of a voltage/current thereto, wherein the heating element is positioned on, near, or within the magnetic head, a drive mechanism for passing the magnetic disk medium over the at least one magnetic head, and a controller electrically coupled to the at least one magnetic head for controlling operation of the at least one magnetic head, wherein the controller is configured to retract the at least one magnetic head from a flying state above the magnetic disk medium and apply the voltage/current to the heating element while the magnetic head is retracted.
    Type: Application
    Filed: December 2, 2011
    Publication date: June 6, 2013
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Yukimasa Okada, Katsumi Hoshino, Koji Kataoka, Takashi Wagatsuma
  • Patent number: 8189304
    Abstract: A magnetoresistive magnetic head according to one embodiment uses a current-perpendicular-to-plane magnetoresistive element having a laminate of a free layer, an intermediate layer, and a pinned layer, the pinned layer being substantially fixed to a magnetic field to be detected, wherein either the pinned layer or the free layer includes a Heusler alloy layer represented by a composition of X—Y—Z, wherein X is between about 45 at. % and about 55 at. % and is Co or Fe, Y accounts for between about 20 at. % and about 30 at. % and is one or more elements selected from V, Cr, Mn, and Fe, and Z is between about 20 at. % and about 35 at.
    Type: Grant
    Filed: December 11, 2009
    Date of Patent: May 29, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Susumu Okamura, Yo Sato, Katsumi Hoshino, Hiroyuki Hoshiya, Kenichi Meguro, Keizo Kato
  • Patent number: 8174799
    Abstract: Embodiments of the present invention help to provide a single element type differential magnetoresistive magnetic head capable of achieving high resolution and high manufacturing stability. According to one embodiment, a magnetoresistive layered film is formed by stacking an underlayer film, an antiferromagnetic film, a ferromagnetic pinned layer, a non-magnetic intermediate layer, a soft magnetic free layer, a long distance antiparallel coupling layered film, and a differential soft magnetic free layer. The long distance antiparallel coupling layered film exchange-couples the soft magnetic free layer and the differential soft magnetic free layer in an antiparallel state with a distance of about 3 nanometers through 20 nanometers. By manufacturing the single element type differential magnetoresistive magnetic head using the magnetoresistive layered film, it becomes possible to achieve the high resolution and the high manufacturing stability without spoiling the GMR effect.
    Type: Grant
    Filed: July 17, 2008
    Date of Patent: May 8, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hiroyuki Hoshiya, Kenichi Meguro, Katsumi Hoshino, You Sato, Hiroyuki Katada, Kazuhiro Nakamoto
  • Patent number: 8149548
    Abstract: Embodiments of the present invention provide a magnetic head having a read head of stable reading operation and with less magnetic fluctuation noise. According to one embodiment, a free layer has a structure comprising two ferromagnetic layers (a first free layer and a second free layer) that are coupled anti-ferromagnetically by way of a non-magnetic intermediate layer, in which the magnetization amount of the first free layer is set to larger than the magnetization amount of the second free layer. Further, the magnetic domains in the first free layer and the second free layer are stabilized simultaneously by increasing the distance between the second free layer and the magnetic domain control film to be more than the distance between the first free layer and the magnetic domain control film, thereby adjusting the magnetization amount of the magnetic domain control film.
    Type: Grant
    Filed: April 17, 2009
    Date of Patent: April 3, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands BV
    Inventors: Masahiko Hatatani, Katsuro Watanabe, Nubuo Yoshida, Katsumi Hoshino
  • Patent number: 8081402
    Abstract: Embodiments of the present invention provide a magnetic head incorporating a CPP-GMR device having a high output at a suitable resistance. According to one embodiment, in a Current Perpendicular to Plane-Giant Magneto Resistive (CPP-GMR) head comprising a pinned layer, a free layer, and a current screen layer for confining current therein, a planarization treatment is applied to the surface of the current screen layer, thereby allowing the current screen layer to have a fluctuation in film thickness thereof. As a result of the fluctuation being provided in the film thickness of the current screen layer, parts of the current screen layer, smaller in the film thickness, will be selectively turned into metal areas low in resistance, and as the metal areas low in resistance serve as current paths, effects of confining current can be adjusted by controlling the fluctuation in the film thickness.
    Type: Grant
    Filed: November 29, 2007
    Date of Patent: December 20, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Yo Sato, Katsumi Hoshino, Hiroyuki Hoshiya
  • Patent number: 8064159
    Abstract: One general embodiment of the present invention is a magnetic read head including a magnetoresistive sensor where sense current flows in a stacking direction of the magnetoresistive sensor, i.e., perpendicular to the plane of the layers of the head. The magnetoresistive sensor comprises a free layer having a magnetization direction that is affected by external magnetic fields and includes a Heusler alloy layer and a Co-based amorphous metal layer, a fixed layer which is stacked with the free layer and has a fixed magnetization direction, and a non-magnetic intermediate layer between the free layer and the fixed layer.
    Type: Grant
    Filed: December 18, 2009
    Date of Patent: November 22, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Koji Sakamoto, Koichi Nishioka, Katsuya Mitsuoka, Katsumi Hoshino, Yo Sato
  • Publication number: 20110134563
    Abstract: According to one embodiment, a magnetoresistive effect head includes a magnetically pinned layer having a direction of magnetization that is pinned, a free magnetic layer positioned above the magnetically pinned layer, the free magnetic layer having a direction of magnetization that is free to vary, and a barrier layer comprising an insulator positioned between the magnetically pinned layer and the free magnetic layer, wherein at least one of the magnetically pinned layer and the free magnetic layer has a layered structure, the layered structure including a crystal layer comprising one of: a CoFe magnetic layer or a CoFeB magnetic layer and an amorphous magnetic layer comprising CoFeB and an element selected from: Ta, Hf, Zr, and Nb, wherein the crystal layer is positioned closer to a tunnel barrier layer than the amorphous magnetic layer. In another embodiment, a magnetic data storage system includes the magnetoresistive effect head described above.
    Type: Application
    Filed: November 29, 2010
    Publication date: June 9, 2011
    Inventors: Kojiro Komagaki, Katsumi Hoshino, Masashige Sato, Hiroyuki Hoshiya