Patents by Inventor Masato Shiimoto

Masato Shiimoto 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: 11011190
    Abstract: A write head for a data storage device comprises a main pole, a trailing shield, and a write-field enhancement structure disposed in a write gap between the main pole and the trailing shield. The write-field enhancement structure comprises a non-magnetic spacer, a non-magnetic layer, and a magnetic DC-field-generation (DFG) layer. The DFG layer is sandwiched between the non-magnetic layer and the non-magnetic spacer. The write head also includes at least one magnetic notch adjacent to at least one of the main pole or the trailing shield. The non-magnetic spacer is adjacent to a magnetic notch. Some embodiments include multiple magnetic notches. Also disclosed are data storage devices comprising such write heads.
    Type: Grant
    Filed: April 24, 2020
    Date of Patent: May 18, 2021
    Assignee: Western Digital Technologies, Inc.
    Inventors: James Terrence Olson, Hiroyuki Hoshiya, Alexander Goncharov, Masato Shiimoto, Mikito Sugiyama
  • Publication number: 20200342899
    Abstract: A write head for a data storage device comprises a main pole, a trailing shield, and a write-field enhancement structure disposed in a write gap between the main pole and the trailing shield. The write-field enhancement structure comprises a non-magnetic spacer, a non-magnetic layer, and a magnetic DC-field-generation (DFG) layer. The DFG layer is sandwiched between the non-magnetic layer and the non-magnetic spacer. The write head also includes at least one magnetic notch adjacent to at least one of the main pole or the trailing shield. The non-magnetic spacer is adjacent to a magnetic notch. Some embodiments include multiple magnetic notches. Also disclosed are data storage devices comprising such write heads.
    Type: Application
    Filed: April 24, 2020
    Publication date: October 29, 2020
    Applicant: Western Digital Technologies, Inc.
    Inventors: James Terrence OLSON, Hiroyuki HOSHIYA, Alexander GONCHAROV, Masato SHIIMOTO, Mikito SUGIYAMA
  • Patent number: 10811039
    Abstract: Disclosed herein are perpendicular magnetic recording writers for providing spin-torque-assisted write field enhancement, and hard disk drives comprising such magnetic write heads. A spin-torque-assisting element is disposed in the write gap and extends to the air-bearing surface (ABS). The spin-torque-assisting element comprises a non-magnetic layer in contact with a main pole, a DC-field generation (DFG) layer with a first side in contact with the non-magnetic layer, and a spacer layer in contact with a second side of the DFG layer. A magnetization of the DFG layer is configured to be aligned substantially parallel to a write gap magnetic field generated by the main pole during a write process, and the magnetization of the DFG layer is configured to flip its direction in response to application of a bias current exceeding a specified magnitude.
    Type: Grant
    Filed: January 22, 2020
    Date of Patent: October 20, 2020
    Assignee: Western Digital Technologies, Inc.
    Inventors: James Terrence Olson, Hiroyuki Hoshiya, Alexander Goncharov, Masato Shiimoto, Mikito Sugiyama
  • Publication number: 20200234729
    Abstract: Disclosed herein are magnetic write heads for providing spin-torque-assisted write field enhancement, and hard disk drives comprising such magnetic write heads. Within the write gap, each magnetic write head comprises a main pole, a trailing shield, a spacer disposed between the main pole and the trailing shield, a non-magnetic layer disposed between the main pole and the trailing shield, and a magnetic DC-field-generation (DFG) layer adjacent to the spacer and disposed between the spacer and the non-magnetic layer. In some embodiments, the DFG layer is the only magnetic layer within the write gap that is not adjacent to the main pole or the trailing shield.
    Type: Application
    Filed: January 22, 2020
    Publication date: July 23, 2020
    Applicant: Western Digital Technologies, Inc.
    Inventors: James Terrence OLSON, Hiroyuki HOSHIYA, Alexander GONCHAROV, Masato SHIIMOTO, Mikito SUGIYAMA
  • Patent number: 10546603
    Abstract: Disclosed herein are magnetic write heads and hard disk drives comprising such magnetic write heads. A magnetic head comprises a magnetic pole, a first shield separated from the magnetic pole at an air-bearing surface (ABS) of the magnetic head, a magnetic layer disposed between the magnetic pole and the first shield, wherein the magnetic layer comprises at least of iron, cobalt, or nickel, a first non-magnetic layer disposed between the magnetic pole and the magnetic layer, and a second non-magnetic layer disposed between the magnetic layer and the first shield, wherein the magnetic layer is the only magnetic layer at the ABS that is between the main pole and the first shield that is not adjacent to the main pole or the first shield.
    Type: Grant
    Filed: June 13, 2019
    Date of Patent: January 28, 2020
    Assignee: Western Digital Technologies, Inc.
    Inventors: James Terrence Olson, Hiroyuki Hoshiya, Alexander Goncharov, Masato Shiimoto, Mikito Sugiyama
  • Publication number: 20190295572
    Abstract: Disclosed herein are magnetic write heads and hard disk drives comprising such magnetic write heads. A magnetic head comprises a magnetic pole, a first shield separated from the magnetic pole at an air-bearing surface (ABS) of the magnetic head, a magnetic layer disposed between the magnetic pole and the first shield, wherein the magnetic layer comprises at least of iron, cobalt, or nickel, a first non-magnetic layer disposed between the magnetic pole and the magnetic layer, and a second non-magnetic layer disposed between the magnetic layer and the first shield, wherein the magnetic layer is the only magnetic layer at the ABS that is between the main pole and the first shield that is not adjacent to the main pole or the first shield.
    Type: Application
    Filed: June 13, 2019
    Publication date: September 26, 2019
    Applicant: Western Digital Technologies, Inc.
    Inventors: James Terrence OLSON, Hiroyuki HOSHIYA, Alexander GONCHAROV, Masato SHIIMOTO, Mikito SUGIYAMA
  • Patent number: 10366714
    Abstract: Disclosed herein are magnetic write heads for providing spin-torque-assisted write field enhancement, and hard disk drives comprising such magnetic write heads. Within the write gap, each magnetic write head comprises a main pole, a trailing shield, a spacer disposed between the main pole and the trailing shield, a non-magnetic layer disposed between the main pole and the trailing shield, and a magnetic DC-field-generation (DFG) layer adjacent to the spacer and disposed between the spacer and the non-magnetic layer. In some embodiments, the DFG layer is the only magnetic layer within the write gap that is not adjacent to the main pole or the trailing shield.
    Type: Grant
    Filed: July 26, 2017
    Date of Patent: July 30, 2019
    Assignee: Western Digital Technologies, Inc.
    Inventors: James Terrence Olson, Hiroyuki Hoshiya, Alexander Goncharov, Masato Shiimoto, Mikito Sugiyama
  • Patent number: 10283159
    Abstract: A magnetic recording system for preventing data loss resulting magnetic oscillator current. The magnetic recording system includes a magnetic write head with a magnetic write pole, a magnetic oscillator near the magnetic write pole, and a write coil for magnetizing the write pole. Circuitry is connected with the magnetic write coil to supply a current to the write coil and connected with the magnetic oscillator to supply a current to the magnetic oscillator. The circuitry is configured to ensure that the current to the magnetic oscillator does not inadvertently magnetize the write pole after the magnetic write pole has demagnetized.
    Type: Grant
    Filed: June 8, 2018
    Date of Patent: May 7, 2019
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Satoshi Tabata, Atsushi Yamada, Michiya Kazusawa, Masato Shiimoto
  • Publication number: 20180294010
    Abstract: A magnetic recording system for preventing data loss resulting magnetic oscillator current. The magnetic recording system includes a magnetic write head with a magnetic write pole, a magnetic oscillator near the magnetic write pole, and a write coil for magnetizing the write pole. Circuitry is connected with the magnetic write coil to supply a current to the write coil and connected with the magnetic oscillator to supply a current to the magnetic oscillator. The circuitry is configured to ensure that the current to the magnetic oscillator does not inadvertently magnetize the write pole after the magnetic write pole has demagnetized.
    Type: Application
    Filed: June 8, 2018
    Publication date: October 11, 2018
    Inventors: SATOSHI TABATA, Atsushi Yamada, MICHIYA KAZUSAWA, Masato Shiimoto
  • Patent number: 10020020
    Abstract: A magnetic recording system for preventing data loss resulting magnetic oscillator current. The magnetic recording system includes a magnetic write head with a magnetic write pole, a magnetic oscillator near the magnetic write pole, and a write coil for magnetizing the write pole. Circuitry is connected with the magnetic write coil to supply a current to the write coil and connected with the magnetic oscillator to supply a current to the magnetic oscillator. The circuitry is configured to ensure that the current to the magnetic oscillator does not inadvertently magnetize the write pole after the magnetic write pole has demagnetized.
    Type: Grant
    Filed: October 19, 2017
    Date of Patent: July 10, 2018
    Assignee: Western Digital Technologies, Inc.
    Inventors: Satoshi Tabata, Atsushi Yamada, Michiya Kazusawa, Masato Shiimoto
  • Publication number: 20180061450
    Abstract: A magnetic recording system for preventing data loss resulting magnetic oscillator current. The magnetic recording system includes a magnetic write head with a magnetic write pole, a magnetic oscillator near the magnetic write pole, and a write coil for magnetizing the write pole. Circuitry is connected with the magnetic write coil to supply a current to the write coil and connected with the magnetic oscillator to supply a current to the magnetic oscillator. The circuitry is configured to ensure that the current to the magnetic oscillator does not inadvertently magnetize the write pole after the magnetic write pole has demagnetized.
    Type: Application
    Filed: October 19, 2017
    Publication date: March 1, 2018
    Inventors: SATOSHI TABATA, Atsushi Yamada, MICHIYA KAZUSAWA, Masato Shiimoto
  • Patent number: 9799369
    Abstract: A magnetic recording system for preventing data loss resulting magnetic oscillator current. The magnetic recording system includes a magnetic write head with a magnetic write pole, a magnetic oscillator near the magnetic write pole, and a write coil for magnetizing the write pole. Circuitry is connected with the magnetic write coil to supply a current to the write coil and connected with the magnetic oscillator to supply a current to the magnetic oscillator. The circuitry is configured to ensure that the current to the magnetic oscillator does not inadvertently magnetize the write pole after the magnetic write pole has demagnetized.
    Type: Grant
    Filed: November 24, 2015
    Date of Patent: October 24, 2017
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Satoshi Tabata, Atsushi Yamada, Michiya Kazusawa, Masato Shiimoto
  • Publication number: 20170148471
    Abstract: A magnetic recording system for preventing data loss resulting magnetic oscillator current. The magnetic recording system includes a magnetic write head with a magnetic write pole, a magnetic oscillator near the magnetic write pole, and a write coil for magnetizing the write pole. Circuitry is connected with the magnetic write coil to supply a current to the write coil and connected with the magnetic oscillator to supply a current to the magnetic oscillator. The circuitry is configured to ensure that the current to the magnetic oscillator does not inadvertently magnetize the write pole after the magnetic write pole has demagnetized.
    Type: Application
    Filed: November 24, 2015
    Publication date: May 25, 2017
    Inventors: Satoshi Tabata, Atsushi Yamada, Michiya Kazusawa, Masato Shiimoto
  • Patent number: 9406322
    Abstract: Embodiments of the present invention generally include magnetoresistive heads, such as read heads, having a sensor structure and side shields disposed adjacent to the sensor structure. The distance between the side shields and the sensor structure increase in a direction from an ABS in the off-track direction. The magnetoresistive heads may include tapered surfaces on the side shields or sensor structure, or may include stepped surfaces on the side shields or sensor structure.
    Type: Grant
    Filed: September 11, 2015
    Date of Patent: August 2, 2016
    Assignee: HGST Netherlands B.V.
    Inventors: Jun Aoyama, Masahiko Hatatani, Hiroyuki Katada, Masato Shiimoto
  • Patent number: 9406316
    Abstract: The present disclosure generally relates to the structure of a perpendicular magnetic write head for use in a magnetic disk drive. A shingled-microwave-assisted magnetic recording head for use in a high-areal-density hard disk drive comprises a trailing shield, a flare-shaped main pole, one or more side shields, a spin torque oscillator, and two asymmetric side gaps, where one side gap has a smaller width than the other side gap. The spin torque oscillator shares a first continuous edge with the main pole on a side adjacent the side gap having the smaller width and shares a second continuous edge adjacent a media facing surface. The angle of the spin torque oscillator and the main pole formed by the media facing surface and the narrow side gap is greater than about 90°.
    Type: Grant
    Filed: May 15, 2014
    Date of Patent: August 2, 2016
    Assignee: HGST NETHERLANDS B.V.
    Inventors: Yosuke Urakami, Masato Shiimoto, Kazue Kudo, Hiromi Shiina
  • Patent number: 9406315
    Abstract: The embodiments disclosed generally relate to an STO structure for a magnetic head. The STO structure has an FGL having a greater thickness than the SPL. The SPL may have multiple layers. In one embodiment, a MAMR head comprises a main pole; a trailing shield; and an STO coupled between the main pole and the trailing shield. The STO includes: a first magnetic layer having a first thickness; a non-magnetic spacer layer coupled to the first magnetic layer; and a second magnetic layer having a second thickness and coupled to the non-magnetic spacer layer, wherein the first thickness is greater than the second thickness, wherein a current is charged from the first magnetic layer to the second magnetic layer, and wherein a vertical magnetic anisotropy field of the second magnetic film is less than 0 kOe.
    Type: Grant
    Filed: February 12, 2014
    Date of Patent: August 2, 2016
    Assignee: HGST Netherlands B.V.
    Inventors: Masato Shiimoto, Masukaza Igarashi, Keiichi Nagasaka, Yo Sato
  • Patent number: 9396744
    Abstract: A magnetic read head configured for two dimensional magnetic recording and having asymmetrical secondary read elements. The magnetic read head includes a primary read element configured to read a data track (i.e. n data track) and first and second secondary read elements located over adjacent data tracks (i.e. n+1, n?1 data track) at either side of the data track to be read. The secondary read element have asymmetrical off track amplitude profiles, preferably such that they each have a steep amplitude profile at the outer side and a broader cross-track amplitude profile at their inner sides. This allows the secondary read elements to detect signals of the adjacent data track (so that those signals can be subtracted out of the signal from the primary reader) without the secondary read elements also picking up further adjacent data tracks (i.e. n+2, n?2).
    Type: Grant
    Filed: August 10, 2015
    Date of Patent: July 19, 2016
    Assignee: HGST Netherlands B.V.
    Inventors: Masato Yamashita, Hiroyuki Katada, Jun Aoyama, Masato Shiimoto
  • Patent number: 9378759
    Abstract: Embodiments disclosed herein generally relate to a magnetic disk device employing a MAMR head. The MAMR head includes an STO. The STO comprises an underlayer, an SPL, an interlayer, an FGL, and a capping layer. The SPL is comprised of a high perpendicular magnetic anisotropy material. The SPL has a large effective perpendicular magnetic anisotropy field, and the SPL has a lower magnetic moment than the FGL. An applied current is adapted to flow in a direction from the FGL to the SPL resulting in the magnetization direction of the SPL being almost perpendicular to the FGL and anti-parallel to a head-gap magnetic field due to a relation between a first spin torque directed from the SPL to the FGL and a second spin torque directed from the FGL to the SPL.
    Type: Grant
    Filed: November 20, 2014
    Date of Patent: June 28, 2016
    Assignee: HGST NETHERLANDS B.V.
    Inventors: Keiichi Nagasaka, Yo Sato, Masashige Sato, Susumu Okamura, Masato Shiimoto, Masukazu Igarashi
  • Patent number: 9355668
    Abstract: A hard-disk drive having a structurally efficient magnetic head slider utilizes a MAMR-based spin torque oscillator (STO) for head-disk contact detection and for flying height sensing. Contact detection and spacing estimation techniques consider the nominal temperature difference, and thus different criteria, between read and write operations.
    Type: Grant
    Filed: May 21, 2013
    Date of Patent: May 31, 2016
    Assignee: HGST Netherlands B.V.
    Inventors: Yasutaka Nishida, Masato Shiimoto, Hiroyuki Katada, Ikuya Tagawa, Junguo Xu
  • Patent number: 9355657
    Abstract: A method, apparatus, and system are provided for implementing spin-torque oscillator (STO) erasure prevention for microwave assisted magnetic recording (MAMR) hard disk drives (HDDs). A first voltage is applied to an STO element in the MAMR head at the time of write operation. A second voltage is applied to the STO element at the time of read operation, or not write operation, to prevent STO erasure otherwise resulting from remnant magnetization of STO at the time of read operation.
    Type: Grant
    Filed: June 5, 2015
    Date of Patent: May 31, 2016
    Assignee: HGST Netherlands B.V.
    Inventors: Jun Aoyama, Masato Shiimoto