Patents by Inventor Masafumi Mochizuki

Masafumi Mochizuki 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: 9305586
    Abstract: A magnetic head, according to one embodiment, includes a magnetized high-speed rotor placed in the vicinity of a main magnetic pole, wherein the main magnetic pole generates a magnetized rotating magnetic field, wherein information is recorded by generating a high-frequency magnetic field from the magnetized high-speed rotor and switching the magnetic head between a magnetic resonance state and a magnetization state, and wherein the magnetic head has a structure such that leaking is reduced for magnetic fields applied parallel to a magnetized rotating surface of the magnetized high-speed rotor from the main magnetic pole. Additional systems and methods are also presented.
    Type: Grant
    Filed: December 21, 2012
    Date of Patent: April 5, 2016
    Assignee: HGST Netherlands B.V.
    Inventors: Masafumi Mochizuki, Masukazu Igarashi
  • Patent number: 9099127
    Abstract: A magnetic read head and associated circuitry for reducing side track noise and decreasing read width, thereby providing increased data density. The magnetic read head includes first and second sensor elements that are aligned with one another in a data track direction, with the first sensor element being wider than the second sensor element. Electrical circuitry is connected with the read head in such a manner as to read a first signal from the first sensor element and a second signal from a second sensor element. Because the second sensor element is wider than the first sensor element, it will read more side signal noise from adjacent data tracks than will the second sensor element. The circuitry connected with the first and second sensor element detects and distinguishes the side signal noise and separates it out from the data signal, based sensor width difference and location difference.
    Type: Grant
    Filed: May 30, 2014
    Date of Patent: August 4, 2015
    Assignee: HGST Netherlands B.V.
    Inventors: Taku Shintani, Yohji Maruyama, Kouichi Nishioka, Masafumi Mochizuki
  • Patent number: 8976484
    Abstract: The embodiments of the present invention relate to a shingled magnetic recording system having a magnetic recording medium that has a magnetization easy axis in the recording layer of the medium that is oriented in from the bottom surface to the top surface of the recording layer. Additionally, a magnetization easy axis in the recording layer of the medium is inclined with respect to the recording track width direction.
    Type: Grant
    Filed: October 24, 2013
    Date of Patent: March 10, 2015
    Assignee: HGST Netherlands B.V.
    Inventors: Kyo Akagi, Takayuki Ichihara, Masafumi Mochizuki, Hiroyasu Tanabe
  • Patent number: 8861116
    Abstract: In one embodiment, a method includes spiral writing a DC pattern onto a magnetic disk medium using a writer of a magnetic head while moving the magnetic head in a direction about parallel to a radial direction of the magnetic disk medium while rotating the magnetic disk medium, reading the magnetic disk medium while moving the magnetic head in the direction about parallel to the radial direction of the magnetic disk medium while rotating the magnetic disk medium, and calculating a track pitch interval between data tracks of the magnetic disk medium based on the reading of the magnetic disk medium. In another embodiment, a magnetic disk medium includes a DC spiral pattern in a radial region further outward and/or a radial region further inward than a radial region where data is recorded.
    Type: Grant
    Filed: August 2, 2011
    Date of Patent: October 14, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Mao Nishiyama, Masafumi Mochizuki, Kyo Akagi, Shuji Nishida, Kazunari Usui
  • 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: 8817406
    Abstract: A magnetic-recording head with touch-down detector incorporating a carbon nano-tube (CNT). The magnetic-recording head includes a write element, a read element and a touch-down detector. The write element is configured to write data to a magnetic-recording disk. The read element is configured to read data from the magnetic-recording disk. The touch-down detector includes a thermal sensor, and a CNT portion. The thermal sensor is configured to convert heat to a voltage signal. The CNT portion is configured to touch down on the magnetic-recording disk. The CNT portion is also coupled to the thermal sensor, and is configured to transfer heat generated by contact between the CNT portion and the magnetic-recording disk to the thermal sensor. A hard-disk drive (HDD) including the magnetic-recording head with touch-down detector incorporating a CNT, and a method for detecting contact between the magnetic-recording head and a recording surface of a magnetic-recording disk are also provided.
    Type: Grant
    Filed: December 30, 2011
    Date of Patent: August 26, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Sarbanoo Das, Masafumi Mochizuki
  • Patent number: 8792210
    Abstract: In one embodiment, a system includes a writer for shingled recording which includes a write pole having a trailing edge and first and second side edges extending from the trailing edge. The writer further includes a shield extending along and about parallel to at least an entire length of the trailing edge, the shield also extending along at least a portion of the first side edge. Other systems are also presented which include advanced shingled writing head designs.
    Type: Grant
    Filed: September 12, 2012
    Date of Patent: July 29, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Anton R. de la Fuente, Masafumi Mochizuki, James T. Olson, Roger W. Wood
  • Patent number: 8786984
    Abstract: In one embodiment, a magnetic head includes a main pole configured to produce a magnetic writing field applied to a magnetic medium at an overall angle with respect to a magnetic anisotropy axis which is oriented in a direction perpendicular to a plane of a surface of the magnetic medium, and at least one current carrying element positioned near a media facing surface of the main pole configured to produce an assisting magnetic field applied in a cross-track direction parallel to the plane of the surface of the magnetic medium. In another embodiment, a method includes applying a writing magnetic field to write data to a magnetic medium and applying an assisting magnetic field to the magnetic medium for assisting the writing magnetic field, the assisting magnetic field being applied in a cross-track direction of the magnetic medium and parallel to a plane of a surface of the magnetic medium.
    Type: Grant
    Filed: November 15, 2011
    Date of Patent: July 22, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Sarbanoo Das, Masafumi Mochizuki
  • Patent number: 8760801
    Abstract: In one embodiment a magnetic head includes a sensor thin film adapted for producing a planar Hall voltage, the sensor thin film having a thickness along a down-track direction that is greater than a thickness along a cross-track direction. The down-track direction is in a direction of travel of a magnetic medium relative to the sensor thin film, and the cross-track direction is perpendicular to the down-track direction. In another embodiment, at least one magnetic head as described above is included in a magnetic data storage system, which includes a magnetic medium, a drive mechanism for passing the magnetic 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. Other heads and systems are described according to various other embodiments.
    Type: Grant
    Filed: December 22, 2010
    Date of Patent: June 24, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Sarbanoo Das, Masafumi Mochizuki
  • Patent number: 8717708
    Abstract: Embodiments of the present invention provide a magnetic head for perpendicular magnetic recording, and a magnetic disk apparatus capable of preventing data erasure caused by alignment marks. In an embodiment, the magnetic head includes a head element including at least a main pole having a pole face on a flying surface and an auxiliary pole; alignment marks made of a magnetic material and used to detect the amount of lapping work when lapping the pole face of the main pole; and members made of a magnetic material, continuously extending in either direction with respect to the position of the main pole from within the alignment marks outward at least beyond the alignment marks.
    Type: Grant
    Filed: December 3, 2008
    Date of Patent: May 6, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Mao Nishiyama, Shuji Nishida, Hideaki Maeda, Masafumi Mochizuki
  • Patent number: 8634163
    Abstract: In one embodiment, a magnetic head includes a main magnetic pole, a first MAMR element positioned above and wider than the main magnetic pole that is positioned to extend beyond sides of the main magnetic pole in a track width direction, a spin-rectifying-current-pinned-magnetic layer, a magnetic interlayer, a FGL, a magnetic-zone-control layer, and a second MAMR element that is wider than the main magnetic pole and is positioned to extend beyond sides of the main magnetic pole in the track width direction positioned above the first MAMR element, and a trailing shield positioned above the second MAMR element, wherein the main magnetic pole is adapted for producing a high-frequency magnetic field comprising oscillating microwaves, wherein during a writing operation, current is applied to the first and second MAMR elements to produce magnetic fields which oppose bit-switching in the magnetic medium to avoid adjacent track bit reversal.
    Type: Grant
    Filed: July 27, 2011
    Date of Patent: January 21, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Hiroyasu Tanabe, Masafumi Mochizuki
  • Patent number: 8630064
    Abstract: A magnetic write head having a gap structure that improves write head performance. The write head includes a magnetic write pole and a magnetic shield that is separated from the trailing edge of the write pole by a non-magnetic trailing gap layer and is separated from the sides of the write pole by non-magnetic side gap layers. The trailing gap extends laterally beyond the side gap layers, and a convex bump is formed at an edge of the magnetic shield at a location near the trailing end of each of the side gap layers.
    Type: Grant
    Filed: November 11, 2011
    Date of Patent: January 14, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Maki Maeda, Kimitoshi Eto, Hiromi Shiina, Kazue Kudo, Masafumi Mochizuki
  • Publication number: 20130170070
    Abstract: A magnetic-recording head with touch-down detector incorporating a carbon nano-tube (CNT). The magnetic-recording head includes a write element, a read element and a touch-down detector. The write element is configured to write data to a magnetic-recording disk. The read element is configured to read data from the magnetic-recording disk. The touch-down detector includes a thermal sensor, and a CNT portion. The thermal sensor is configured to convert heat to a voltage signal. The CNT portion is configured to touch down on the magnetic-recording disk. The CNT portion is also coupled to the thermal sensor, and is configured to transfer heat generated by contact between the CNT portion and the magnetic-recording disk to the thermal sensor. A hard-disk drive (HDD) including the magnetic-recording head with touch-down detector incorporating a CNT, and a method for detecting contact between the magnetic-recording head and a recording surface of a magnetic-recording disk are also provided.
    Type: Application
    Filed: December 30, 2011
    Publication date: July 4, 2013
    Inventors: Sarbanoo Das, Masafumi Mochizuki
  • Patent number: 8472139
    Abstract: In one embodiment, a magnetic head includes a main pole, a trailing shield positioned near a trailing side of the main pole, a side shield positioned near both sides of the main pole in a cross-track direction, a leading shield positioned near a leading side of the main pole, and a gap positioned between the main pole and the shields, characterized in that Sg1<Sg2, wherein Sg1 is a distance in the cross-track direction between a bending point of a leading edge of the trailing shield and a trailing corner of the main pole nearest to the bending point, and Sg2 is a distance in the cross-track direction between a first point on an edge of the side shield parallel in the cross-track direction to the trailing corner of the main pole and the trailing corner of the main pole nearest to the first point.
    Type: Grant
    Filed: September 6, 2011
    Date of Patent: June 25, 2013
    Assignee: HGST Netherlands B.V.
    Inventors: Yosuke Urakami, Kazue Kudo, Hiromi Shiina, Masafumi Mochizuki, Shouji Tokutake
  • Publication number: 20130120876
    Abstract: A magnetic write head having a gap structure that improves write head performance. The write head includes a magnetic write pole and a magnetic shield that is separated from the trailing edge of the write pole by a non-magnetic trailing gap layer and is separated from the sides of the write pole by non-magnetic side gap layers. The trailing gap extends laterally beyond the side gap layers, and a convex bump is formed an edge of the magnetic shield at a location near the trailing end of the side gap layers.
    Type: Application
    Filed: November 11, 2011
    Publication date: May 16, 2013
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Maki Maeda, Kimitoshi Eto, Hiromi Shiina, Kazue Kudo, Masafumi Mochizuki
  • Publication number: 20130120869
    Abstract: In one embodiment, a magnetic head includes a main pole configured to produce a magnetic writing field applied to a magnetic medium at an overall angle with respect to a magnetic anisotropy axis which is oriented in a direction perpendicular to a plane of a surface of the magnetic medium, and at least one current carrying element positioned near a media facing surface of the main pole configured to produce an assisting magnetic field applied in a cross-track direction parallel to the plane of the surface of the magnetic medium. In another embodiment, a method includes applying a writing magnetic field to write data to a magnetic medium and applying an assisting magnetic field to the magnetic medium for assisting the writing magnetic field, the assisting magnetic field being applied in a cross-track direction of the magnetic medium and parallel to a plane of a surface of the magnetic medium.
    Type: Application
    Filed: November 15, 2011
    Publication date: May 16, 2013
    Inventors: Sarbanoo Das, Masafumi Mochizuki
  • Patent number: 8411384
    Abstract: In one embodiment, a data storage system includes a magnetic head having a main magnetic pole and a wrap around shield positioned around the main magnetic pole at an ABS thereof, a magnetic medium, a drive mechanism for passing the magnetic medium over the magnetic head, and a controlling mechanism electrically coupled to the magnetic head for controlling operation of the magnetic head that initiates rewriting of information of a recording track of the magnetic medium if a recording magnetic field applied to the recording track exceeds a threshold. In another embodiment, a method includes writing data to a first track of a magnetic medium using a magnetic head, determining characteristics consistent with data degradation from tracks adjacent to the first track and far tracks away from the first track using a controlling mechanism, and rewriting data in tracks determined to be degraded due to ATI and/or FTI.
    Type: Grant
    Filed: June 6, 2011
    Date of Patent: April 2, 2013
    Assignee: HGST Netherlands B.V.
    Inventors: Masafumi Mochizuki, Ichiro Yokokawa, Satoshi Ohki
  • Publication number: 20130057981
    Abstract: In one embodiment, a magnetic head includes a main pole, a trailing shield positioned near a trailing side of the main pole, a side shield positioned near both sides of the main pole in a cross-track direction, a leading shield positioned near a leading side of the main pole, and a gap positioned between the main pole and the shields, characterized in that Sg1<Sg2, wherein Sg1 is a distance in the cross-track direction between a bending point of a leading edge of the trailing shield and a trailing corner of the main pole nearest to the bending point, and Sg2 is a distance in the cross-track direction between a first point on an edge of the side shield parallel in the cross-track direction to the trailing corner of the main pole and the trailing corner of the main pole nearest to the first point.
    Type: Application
    Filed: September 6, 2011
    Publication date: March 7, 2013
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Yosuke Urakami, Kazue Kudo, Hiromi Shiina, Masafumi Mochizuki, Shouji Tokutake
  • Patent number: 8373940
    Abstract: According to one embodiment, a magnetic head for recording magnetic data by changing the magnetization direction of a magnetic recording layer of a magnetic medium comprises a magnetic pole for generating a magnetic field to change the magnetization direction of the magnetic recording layer, and a facing electrode pair for generating an electromagnetic field and applying energy to the magnetic recording layer to assist the change of the magnetization direction of the magnetic recording layer caused by the magnetic field from the magnetic pole. Other embodiments are also presented.
    Type: Grant
    Filed: August 26, 2009
    Date of Patent: February 12, 2013
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Yohji Maruyama, Nobumasa Nishiyama, Masafumi Mochizuki
  • Publication number: 20130033778
    Abstract: In one embodiment, a method includes spiral writing a DC pattern onto a magnetic disk medium using a writer of a magnetic head while moving the magnetic head in a direction about parallel to a radial direction of the magnetic disk medium while rotating the magnetic disk medium, reading the magnetic disk medium while moving the magnetic head in the direction about parallel to the radial direction of the magnetic disk medium while rotating the magnetic disk medium, and calculating a track pitch interval between data tracks of the magnetic disk medium based on the reading of the magnetic disk medium. In another embodiment, a magnetic disk medium includes a DC spiral pattern in a radial region further outward and/or a radial region further inward than a radial region where data is recorded.
    Type: Application
    Filed: August 2, 2011
    Publication date: February 7, 2013
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Mao Nishiyama, Masafumi Mochizuki, Kyo Akagi, Shuji Nishida, Kazunari Usui