Patents by Inventor Hiroyasu Tanabe
Hiroyasu Tanabe 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).
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Publication number: 20150138937Abstract: A method of storing data includes providing a write signal for a write head of a hard disk drive, generating a transition pulse signal derived from the write signal using a transition pulse generator, and generating a logic signal to drive a thermal source associated with the write head of the hard disk drive. The logic signal includes the logical summation of a cyclical base pulse signal and the transition pulse signal.Type: ApplicationFiled: November 15, 2013Publication date: May 21, 2015Applicant: HGST Netherlands B.V.Inventors: Naoto Ito, Michiya Kazusawa, Hiroyasu Tanabe, Sarbanoo Das, Hideki Zaitsu
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Patent number: 9025420Abstract: A method of storing data includes providing a write signal for a write head of a hard disk drive, generating a transition pulse signal derived from the write signal using a transition pulse generator, and generating a logic signal to drive a thermal source associated with the write head of the hard disk drive. The logic signal includes the logical summation of a cyclical base pulse signal and the transition pulse signal.Type: GrantFiled: November 15, 2013Date of Patent: May 5, 2015Assignee: HGST Netherlands B.V.Inventors: Naoto Ito, Michiya Kazusawa, Hiroyasu Tanabe, Sarbanoo Das, Hideki Zaitsu
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Publication number: 20150109700Abstract: Techniques for writing data to a buffer region of a magnetic disk are described. In one example, a hard disk drive comprises a magnetic disk comprising a data buffer region including a first zone and a second zone. Data may be written to the magnetic disk using shingled magnetic recording (SMR) and the buffer region may be an exception region (E-region). A hard disk drive may be configured to calculate a position accuracy value associated with a data writing head. The hard disk drive may select one of the zones based on the position accuracy value. Further, a selected zone may have a determined zone format. The hard disk drive may be configured to write data to the selected zone using the determined zone format.Type: ApplicationFiled: October 18, 2013Publication date: April 23, 2015Applicant: HGST Netherlands B.V.Inventors: Hidekazu KASHIWASE, Hiroyasu TANABE, Hideki ZAITSU
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Patent number: 8976484Abstract: 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: GrantFiled: October 24, 2013Date of Patent: March 10, 2015Assignee: HGST Netherlands B.V.Inventors: Kyo Akagi, Takayuki Ichihara, Masafumi Mochizuki, Hiroyasu Tanabe
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Patent number: 8797672Abstract: SMR disk drives are described that adjust track pitch or magnetic write width to compensate for external temperature effects. In one embodiment track pitch is increased when the media temperature increases. The temperature of magnetic media during write operations can be determined from the drives' temperature sensor. In other embodiments track pitch is adjusted based on the magnetic write width (MWW) which is determined from read-back testing of previously written data tracks. In an alternative embodiment, the width of the MWW is adjusted instead of the track pitch. The various factors that affect the MWW that can be used to increase or decrease the MWW, including write current characteristics and when available thermal-assistance parameters.Type: GrantFiled: June 14, 2012Date of Patent: August 5, 2014Assignee: HGST Netherlands B.V.Inventors: Hiroyasu Tanabe, Hideki Zaitsu, Kyo Akagi, Naoto Ito
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Patent number: 8634163Abstract: 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: GrantFiled: July 27, 2011Date of Patent: January 21, 2014Assignee: HGST Netherlands B.V.Inventors: Hiroyasu Tanabe, Masafumi Mochizuki
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Publication number: 20130335856Abstract: SMR disk drives are described that adjust track pitch or magnetic write width to compensate for external temperature effects. In one embodiment track pitch is increased when the media temperature increases. The temperature of magnetic media during write operations can be determined from the drives' temperature sensor. In other embodiments track pitch is adjusted based on the magnetic write width (MWW) which is determined from read-back testing of previously written data tracks. In an alternative embodiment, the width of the MWW is adjusted instead of the track pitch. The various factors that affect the MWW that can be used to increase or decrease the MWW, including write current characteristics and when available thermal-assistance parameters.Type: ApplicationFiled: June 14, 2012Publication date: December 19, 2013Inventors: Hiroyasu Tanabe, Hideki Zaitsu, Kyo Akagi, Naoto Ito
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Patent number: 8553362Abstract: A magnetic write head for magnetic data recording that incorporates a novel magnetic oscillation generator stricture that sets up a magnetic oscillation in the magnetic media for improving writing and that also narrows the write width and reduces adjacent track interference by suppressing writing in regions outside of the desired data track. The magnetic oscillation generating structure includes a centrally disposed magnetic assist element that generates an oscillating magnetic field that oscillates in a direction that will assist the write pole in writing to the magnetic medium. The magnetic oscillation generating structure also includes first and second magnetic non-assist elements at either side of the assist element. The non-assist elements generate a magnetic field that oscillates in a second direction that is opposite to the first direction, which counteracts the magnetic write assist from the centrally disposed magnetic assist element and acts to suppress writing in these side regions.Type: GrantFiled: September 6, 2011Date of Patent: October 8, 2013Assignee: HGST Netherlands B.V.Inventors: Hiroyasu Tanabe, Hiroyasu Masuda
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Publication number: 20130057983Abstract: A magnetic write head for magnetic data recording that incorporates a novel magnetic oscillation generator stricture that sets up a magnetic oscillation in the magnetic media for improving writing and that also narrows the write width and reduces adjacent track interference by suppressing writing in regions outside of the desired data track. The magnetic oscillation generating structure includes a centrally disposed magnetic assist element that generates an oscillating magnetic field that oscillates in a direction that will assist the write pole in writing to the magnetic medium. The magnetic oscillation generating structure also includes first and second magnetic non-assist elements at either side of the assist element. The non-assist elements generate a magnetic field that oscillates in a second direction that is opposite to the first direction, which counteracts the magnetic write assist from the centrally disposed magnetic assist element and acts to suppress writing in these side regions.Type: ApplicationFiled: September 6, 2011Publication date: March 7, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Hiroyasu Tanabe, Hiroyasu Masuda
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Publication number: 20130027803Abstract: 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: ApplicationFiled: July 27, 2011Publication date: January 31, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Hiroyasu Tanabe, Masafumi Mochizuki
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Patent number: 8248893Abstract: A head-slider configured to fly in proximity to a recording surface of a magnetic-recording disk. The head-slider includes a write element including a main pole configured to generate a magnetic-recording field from a pole tip of the main pole in a first localized portion of the magnetic-recording disk. The head-slider also includes a magnetic-recording assistance element configured to provide energy to a second localized portion of the magnetic-recording disk in order to increase reversibility of a magnetization in a first localized portion of the magnetic-recording disk. A width of the pole tip of the main pole on a leading-edge side is wider than a width of the pole tip of the main pole on a trailing-edge side.Type: GrantFiled: October 2, 2009Date of Patent: August 21, 2012Assignee: Hitachi Global Storage Tecnologies, Netherlands B.V.Inventors: Masafumi Mochizuki, Hiroyasu Tanabe, Hideki Zaitsu, Hideaki Maeda
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Patent number: 8169729Abstract: To synchronize a write/read frequency with media with high precision even when a write head is positioned in a different zone in a magnetic recording/reproducing device equipped with patterned media formed with writing hit patterns and having a zoned format function, a write head is positioned on a recording track in the vicinity of a boundary between zones, and the write head is positioned in a different zone from the zone in which the read head is positioned, the preamble pattern in the zone in which the read head is positioned is reproduced, a difference between frequencies of the preamble patterns of the zones is compensated to determine a write frequency used for writing data into a desired track, and then start timing for writing is determined based on a synchronization pattern obtained at the position of the read head. Other systems and methods are presented as well.Type: GrantFiled: December 10, 2009Date of Patent: May 1, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Hideki Zaitsu, Hiroyasu Tanabe
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Patent number: 8089720Abstract: A hard-disk drive. The hard-disk drive includes a magnetic-recording disk in which tracks adjacent to each other are magnetically separated, a spindle motor which drives the magnetic-recording disk, a magnetic-recording head equipped with write element and read element, an actuator for positioning the magnetic-recording head on a predetermined track on the magnetic-recording disk, and a control unit. The control unit is configured to store information about an over-write-only track that is provided for a plurality of tracks including n consecutive tracks in at least a partial radial area of the magnetic-recording disk and an offset amount. In a radial area of the magnetic disk where the over-write-only track is located, the control unit is configured to record with an offset by an offset amount from a center of a track toward the over-write-only track with respect to n?1 tracks of the plurality of n tracks, excluding the over-write-only track.Type: GrantFiled: August 6, 2009Date of Patent: January 3, 2012Assignee: Hitachi Global Storage Technologies, Netherlands B.V.Inventors: Yosuke Urakami, Jun Ohno, Hideaki Maeda, Hiroyasu Tanabe
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Patent number: 8018672Abstract: A magnetic recording device according to one embodiment includes a magnetic recording medium having a magnetic recording layer; a recording element positioned on a head slider; an assistance element for supplying assistance energy to an area on the recording layer to which a recording magnetic field generated by the recording element is applied, the assistance element being positioned on the head slider; and a controller for controlling a size of an assistance area from the assistance element in accordance with a position of the head slider in a radial direction of the magnetic recording medium. Additional systems and methods are also presented.Type: GrantFiled: November 19, 2009Date of Patent: September 13, 2011Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Hideaki Maeda, Hiroyasu Tanabe, Masafumi Mochizuki, Hideki Zaitsu
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Patent number: 7969678Abstract: In one embodiment, a magnetic disk drive includes a magnetic disk, a head slider for flying above the spinning magnetic disk, a pattern analyzer for analyzing a data pattern of data to be recorded on the magnetic disk to determine a recording current reversal timing and a recording assistance area in accordance with the analysis so that the rear end of the determined recording assistance area is shifted forward if the determined recording current reversal timing is earlier than a criterion, or the rear end of the determined recording assistance area is shifted backward if the determined recording current reversal timing is later than the criterion, a recording assistance element on the slider for forming the determined recording assistance area on the magnetic disk, and a recording element for recording the data on the magnetic disk using the recording current in accordance with the determined recording current reversal timing.Type: GrantFiled: November 9, 2009Date of Patent: June 28, 2011Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Hiroyasu Tanabe, Hideaki Maeda, Hideki Zaitsu, Masafumi Mochizuki
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Publication number: 20110096638Abstract: A head-slider configured to fly in proximity to a recording surface of a magnetic-recording disk. The head-slider includes a write element including a main pole configured to generate a magnetic-recording field from a pole tip of the main pole in a first localized portion of the magnetic-recording disk. The head-slider also includes a magnetic-recording assistance element configured to provide energy to a second localized portion of the magnetic-recording disk in order to increase reversibility of a magnetization in a first localized portion of the magnetic-recording disk. A width of the pole tip of the main pole on a leading-edge side is wider than a width of the pole tip of the main pole on a trailing-edge side.Type: ApplicationFiled: October 2, 2009Publication date: April 28, 2011Inventors: Masafumi Mochizuki, Hiroyasu Tanabe, Hideki Zaitsu, Hideaki Maeda
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Publication number: 20110069414Abstract: A hard-disk drive. The hard-disk drive includes a magnetic-recording disk in which tracks adjacent to each other are magnetically separated, a spindle motor which drives the magnetic-recording disk, a magnetic-recording head equipped with write element and read element, an actuator for positioning the magnetic-recording head on a predetermined track on the magnetic-recording disk, and a control unit. The control unit is configured to store information about an over-write-only track that is provided for a plurality of tracks including n consecutive tracks in at least a partial radial area of the magnetic-recording disk and an offset amount. In a radial area of the magnetic disk where the over-write-only track is located, the control unit is configured to record with an offset by an offset amount from a center of a track toward the over-write-only track with respect to n?1 tracks of the plurality of n tracks, excluding the over-write-only track.Type: ApplicationFiled: August 6, 2009Publication date: March 24, 2011Inventors: Yosuke URAKAMI, Jun OHNO, Hideaki MAEDA, Hiroyasu TANABE
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Patent number: 7808740Abstract: Embodiments of the present invention provide a magnetic disk drive capable of suppressing variations in flying height of a magnetic head caused by decrease in the amount of a low density gas inside a housing and a control method therefore. According to one embodiment, the magnetic disk drive includes a magnetic head, a magnetic disk, and a housing containing the magnetic head and the magnetic disk, wherein the housing is filled with a low density gas having a lower density than air. An amount of the low density gas in the housing is estimated and, based on the amount of the low density gas, a flying height of the magnetic head from a surface of the magnetic disk is controlled.Type: GrantFiled: November 4, 2008Date of Patent: October 5, 2010Assignee: Hitachi Global Storage Technologies Netherlands, B.V.Inventor: Hiroyasu Tanabe
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Publication number: 20100142077Abstract: To synchronize a write/read frequency with media with high precision even when a write head is positioned in a different zone in a magnetic recording/reproducing device equipped with patterned media formed with writing hit patterns and having a zoned format function, a write head is positioned on a recording track in the vicinity of a boundary between zones, and the write head is positioned in a different zone from the zone in which the read head is positioned, the preamble pattern in the zone in which the read head is positioned is reproduced, a difference between frequencies of the preamble patterns of the zones is compensated to determine a write frequency used for writing data into a desired track, and then start timing for writing is determined based on a synchronization pattern obtained at the position of the read head. Other systems and methods are presented as well.Type: ApplicationFiled: December 10, 2009Publication date: June 10, 2010Inventors: Hideki Zaitsu, Hiroyasu Tanabe
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Publication number: 20100128376Abstract: In one embodiment, a magnetic disk drive includes a magnetic disk, a head slider for flying above the spinning magnetic disk, a pattern analyzer for analyzing a data pattern of data to be recorded on the magnetic disk to determine a recording current reversal timing and a recording assistance area in accordance with the analysis so that the rear end of the determined recording assistance area is shifted forward if the determined recording current reversal timing is earlier than a criterion, or the rear end of the determined recording assistance area is shifted backward if the determined recording current reversal timing is later than the criterion, a recording assistance element on the slider for forming the determined recording assistance area on the magnetic disk, and a recording element for recording the data on the magnetic disk using the recording current in accordance with the determined recording current reversal timing.Type: ApplicationFiled: November 9, 2009Publication date: May 27, 2010Inventors: Hiroyasu Tanabe, Hideaki Maeda, Hideki Zaitsu, Masafumi Mochizuki