Patents by Inventor Masayoshi Shimokoshi

Masayoshi Shimokoshi 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: 20230005503
    Abstract: Various apparatuses, systems, methods, and media are disclosed to provide a heat-assisted magnetic recording (HAMR) medium that has a magnesium (Mg) trapping layer that is configured to mitigate Mg migration in the HAMR medium so as to prevent near field transducer (NFT) damage caused by dissociated Mg reacting with a compound used in the NFT. In one example, the HAMR medium can include a substrate, a seed layer on the substrate and including MgO, a magnetic recording layer on the seed layer, and a Mg trapping layer on the substrate and configured to mitigate Mg migration from the seed layer to a surface of the HAMR medium above the magnetic recording layer.
    Type: Application
    Filed: July 1, 2021
    Publication date: January 5, 2023
    Inventors: Takashi Iwanami, Kouji Matsuda, Junguo Xu, Kenji Tasaka, Hoan Cong Ho, Tomoko Seki, Paul Christopher Dorsey, Masayoshi Shimokoshi
  • Patent number: 8169730
    Abstract: A hard disk drive (HDD) comprising a magnetic disk that includes a data storage surface and an external magnetic field parallel to the data storage surface for suppressing track interference.
    Type: Grant
    Filed: December 17, 2009
    Date of Patent: May 1, 2012
    Assignee: Hitachi Global Storage Technologies, Netherlands, B.V.
    Inventors: Nelson Cheng, Lakshmi Ramamoorthy, Kris Schouterden, Masayoshi Shimokoshi
  • Patent number: 8068306
    Abstract: Approaches for improving the write quality of a hard-disk drive (HDD) head experiencing temporary fly-height problem. When the hard-disk drive is idle and heads are parked on the ramp, fluid, such as a lubricant or the condensation of vapor, may collect between the surface of a platter and the head or a slider, thereby causing the head to temporarily fly higher than normal. An HDD may include electronic component(s) configured to (a) determine whether it is likely that fluid is interposed between the surface of a magnetic-recording disk and the slider or the head, and (b) temporarily adjust one or more of (i) a thermal fly height control setting of the head and (ii) a write parameter of the head to compensate for the head flying higher than normal as a result of the fluid being interposed between the surface of the disk and the slider or the head.
    Type: Grant
    Filed: December 14, 2009
    Date of Patent: November 29, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Lakshmi Ramamoorthy, David Jen, Douglas Zuercher, Masayoshi Shimokoshi, Kris Schouterden
  • Publication number: 20110149427
    Abstract: A hard disk drive (HDD) comprising a magnetic disk that includes a data storage surface and an external magnetic field parallel to the data storage surface for suppressing track interference.
    Type: Application
    Filed: December 17, 2009
    Publication date: June 23, 2011
    Inventors: Nelson Cheng, Lakshmi Ramamoorthy, Kris Schouterden, Masayoshi Shimokoshi
  • Publication number: 20110141607
    Abstract: Approaches for improving the write quality of a hard-disk drive (HDD) head experiencing temporary fly-height problem. When the hard-disk drive is idle and heads are parked on the ramp, fluid, such as a lubricant or the condensation of vapor, may collect between the surface of a platter and the head or a slider, thereby causing the head to temporarily fly higher than normal. An HDD may include electronic component(s) configured to (a) determine whether it is likely that fluid is interposed between the surface of a magnetic-recording disk and the slider or the head, and (b) temporarily adjust one or more of (i) a thermal fly height control setting of the head and (ii) a write parameter of the head to compensate for the head flying higher than normal as a result of the fluid being interposed between the surface of the disk and the slider or the head.
    Type: Application
    Filed: December 14, 2009
    Publication date: June 16, 2011
    Inventors: Lakshmi Ramamoorthy, David Jen, Douglas Zuercher, Masayoshi Shimokoshi, Kris Schouterden
  • Patent number: 7369351
    Abstract: Embodiments of the invention reduce the error rate of a read error that is caused by a spacing interval between a write head and a read head, which are formed on a slider. In one embodiment, a write head writes user data, which is placed at a position, on a magnetic disk when a read head is placed at a target position in accordance with a head spacing interval and yaw angle. DHO adjustment data is written at a second position, which is obtained by subjecting the read head to DHO correction in order to read the user data written at the target position. When the user data is to be read, a processor reads the DHO adjustment data, changes the read head position to the first position, and controls the operation of a magnetic disk drive to read the user data.
    Type: Grant
    Filed: November 22, 2005
    Date of Patent: May 6, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Kazuyuki Date, Masayoshi Shimokoshi
  • Patent number: 7110203
    Abstract: A magnetic disk drive improved in reliability of data retrieve. This invention prevents the drive from decoding already-written old data. The failure decoding is caused by a deviation in a write operation, by a malfunction of a writing head and so on. When data in a sector is renewed, the sector's location and renewal frequency information are saved not only in the sector of the disk media but also in a temporary memory. When the magnetic disk drive is in an idle mode, those renewal information written in the sector and stored in the temporary memory, are checked. If both renewal information match, the data is regarded “not old” and the information about the sector in the temporary memory is deleted. In the deleting operation, check mark information indicating that the written data has been checked is written in the sector of the magnetic disk medium.
    Type: Grant
    Filed: August 30, 2002
    Date of Patent: September 19, 2006
    Assignee: Hitachi Global Storage Technologies Japan Ltd.
    Inventor: Masayoshi Shimokoshi
  • Publication number: 20060139791
    Abstract: Embodiments of the invention reduce the error rate of a read error that is caused by a spacing interval between a write head and a read head, which are formed on a slider. In one embodiment, a write head writes user data, which is placed at a position, on a magnetic disk when a read head is placed at a target position in accordance with a head spacing interval and yaw angle. DHO adjustment data is written at a second position, which is obtained by subjecting the read head to DHO correction in order to read the user data written at the target position. When the user data is to be read, a processor reads the DHO adjustment data, changes the read head position to the first position, and controls the operation of a magnetic disk drive to read the user data.
    Type: Application
    Filed: November 22, 2005
    Publication date: June 29, 2006
    Applicant: Hitachi Global Storage Technogoies Netherlands B.V.
    Inventors: Kazuyuki Date, Masayoshi Shimokoshi
  • Patent number: 7023641
    Abstract: In a magnetic disk drive, a writing element and its surrounding area thermally expand due to the heat generated by a write head coil. The transient phenomenon of such thermal expansion may invoke the transient phenomenon of inadequate writing capacity, thereby causing a writing error at an early stage of a write operation. Control is provided which increases/decreases either or both the write current to be applied to a write head and the amount of its overshoot on an individual sector basis during a writing sequence.
    Type: Grant
    Filed: September 26, 2003
    Date of Patent: April 4, 2006
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Takeshi Doi, Masayoshi Shimokoshi, Hitoshi Yoshida
  • Publication number: 20040184177
    Abstract: In a magnetic disk drive, a writing element and its surrounding area thermally expand due to the heat generated by a write head coil. The transient phenomenon of such thermal expansion may invoke the transient phenomenon of inadequate writing capacity, thereby causing a writing error at an early stage of a write operation. Control is provided which increases/decreases either or both the write current to be applied to a write head and the amount of its overshoot on an individual sector basis during a writing sequence.
    Type: Application
    Filed: September 26, 2003
    Publication date: September 23, 2004
    Applicant: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Takeshi Doi, Masayoshi Shimokoshi, Hitoshi Yoshida
  • Patent number: 6747833
    Abstract: The position information of the magnetic head is generated also from the data area to improve the positioning accuracy. The magnetic disk drive has a function of oscillating the magnetic head in the radial direction in the data area at a specific frequency and a function of detecting a read signal during the execution of the oscillation function and detects position information of the magnetic head from the detected read signal. The magnetic head position control can be performed in the data area. The magnetic head position signal not dependent on the frequency of a sampling signal generated from the servo information area can be generated. This in turn improves the data recording density and allows a highly precise position control of the magnetic head, thus improving the reliability of the magnetic disk drive.
    Type: Grant
    Filed: June 25, 2001
    Date of Patent: June 8, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Masayoshi Shimokoshi, Takeshi Doi
  • Publication number: 20030193729
    Abstract: A magnetic disk drive improved in reliability of data retrieve. This invention prevents the drive from decoding already-written old data. The failure decoding is caused by a deviation in a write operation, by a malfunction of a writing head and so on. When data in a sector is renewed, the sector's location and renewal frequency information are saved not only in the sector of the disk media but also in a temporary memory. When the magnetic disk drive is in an idle mode, those renewal information written in the sector and stored in the temporary memory, are checked. If both renewal information match, the data is regarded “not old” and the information about the sector in the temporary memory is deleted. In the deleting operation, check mark information indicating that the written data has been checked is written in the sector of the magnetic disk medium.
    Type: Application
    Filed: August 30, 2002
    Publication date: October 16, 2003
    Inventor: Masayoshi Shimokoshi
  • Publication number: 20020089778
    Abstract: The position information of the magnetic head is generated also from the data area to improve the positioning accuracy. The magnetic disk drive has a function of oscillating the magnetic head in the radial direction in the data area at a specific frequency and a function of detecting a read signal during the execution of the oscillation function and detects position information of the magnetic head from the detected read signal. The magnetic head position control can be performed in the data area. The magnetic head position signal not dependent on the frequency of a sampling signal generated from the servo information area can be generated. This in turn improves the data recording density and allows a highly precise position control of the magnetic head, thus improving the reliability of the magnetic disk drive.
    Type: Application
    Filed: June 25, 2001
    Publication date: July 11, 2002
    Inventors: Masayoshi Shimokoshi, Takeshi Doi