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).
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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: 8363355Abstract: A magnetic head, according to one embodiment, includes a microwave generator provided with a main magnetic pole, an auxiliary magnetic pole, a coil wound around a magnetic circuit, the magnetic circuit including the main magnetic pole and the auxiliary magnetic pole, and a magnetic film, the film being provided near an ABS side of the main magnetic pole. A first distance in an element thickness direction between film surfaces of the magnetic film and the main magnetic pole at a top end in an element height direction of the microwave generator is greater than a second distance between film surfaces of the magnetic film comprising the microwave generator and the main magnetic pole at the ABS. In other approaches, the main magnetic pole may have a shape which gradually widens from a flare point away from the ABS in an element height direction. Additional systems and methods are also presented.Type: GrantFiled: February 2, 2010Date of Patent: January 29, 2013Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Masafumi Mochizuki, Masukazu Igarashi
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Publication number: 20130016443Abstract: 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: ApplicationFiled: September 12, 2012Publication date: January 17, 2013Applicant: HGST NETHERLANDS B.V.Inventors: Anton R. de la Fuente, Masafumi Mochizuki, James T. Olson, Roger W. Wood
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Patent number: 8339749Abstract: Embodiments of the invention reduce generation of a magnetic field with a polarity reverse to that of the recording magnetic field, without deteriorating a gradient in the magnetic field. An embodiment of a magnetic disk device according to the present invention suppresses deviation and erase of already recorded data. In an embodiment, the perpendicular magnetic recording head includes the main magnetic pole, an auxiliary magnetic pole, a trailing shield disposed on the trailing side of the main magnetic pole with a non-magnetic film placed in-between, and side shields disposed on both the sides of the main magnetic pole in the direction of the track width with a non-magnetic film placed in-between. The trailing shield has on the trailing side a portion where film thickness is thinner on the trailing side than the thickness of its element in the height direction in its position facing the main magnetic pole.Type: GrantFiled: November 19, 2008Date of Patent: December 25, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Masafumi Mochizuki, Hideaki Maeda, Shuji Nishida, Takaaki Izumida
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Publication number: 20120307394Abstract: 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: ApplicationFiled: June 6, 2011Publication date: December 6, 2012Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Masafumi Mochizuki, Ichiro Yokokawa, Satoshi Ohki
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Patent number: 8310786Abstract: 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 only a portion of the trailing edge or only a portion of the first side edge, and the shield does not extend along the second side edge. In addition, an angle formed between the first side edge and the trailing edge along an air bearing surface side of the writer is different than an angle formed between the second side edge and the trailing edge along the air bearing surface side of the writer. Other systems are also presented which include advanced shingled writing head designs.Type: GrantFiled: September 9, 2009Date of Patent: November 13, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Anton R. de la Fuente, Masafumi Mochizuki, James T. Olson, Roger W. Wood
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Patent number: 8270111Abstract: Embodiments of the invention provide a perpendicular magnetic recording head that causes the difference between a physical track width and an effective track width to be small. Sides of a main pole are made concave with the concave vertex on each side located close to a trailing edge of the main pole.Type: GrantFiled: March 24, 2006Date of Patent: September 18, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Tomohiro Okada, Masafumi Mochizuki, Hisashi Kimura, Wataru Kimura
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Patent number: 8254061Abstract: A head-slider. The head-slider includes a slider and a magnetic-recording head formed on the slider. The magnetic-recording head includes a main pole, a return pole to which a recording magnetic field from the main pole returns, a sensor element, a shield provided between the sensor element and the main pole, and a heater element for adjusting a shape of a flying surface of the magnetic-recording head. The magnetic-recording head further includes a first recess provided at a tip end face of at least one element selected from the group consisting of the return pole and the shield, and a second recess provided on an exposed flying surface and corresponding to the first recess.Type: GrantFiled: November 10, 2009Date of Patent: August 28, 2012Assignee: Hitachi Global Storage Technologies, Netherlands B.V.Inventors: Kenji Kuroki, Masafumi Mochizuki, Toshiya Shiramatsu
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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: 8225486Abstract: In a manufacturing process of a head slider, a plurality of head elements are formed on a wafer, each head element comprising: a return pole, a coil, and a main pole. The wafer is cut into respective head elements so that individual head sliders are formed. A ratio of an amplitude of an electrical signal applied to the coil of the write head on the head slider to an amplitude of output from an independent magnetic field sensor not embedded in the head slider is calculated, where the independent magnetic field sensor is disposed near the main pole so as to be opposed to the main pole across the air bearing surface, and where the ratio is calculated while a displacement between the main pole and the magnetic field sensor is swept. A flare point height of the main pole is determined from the calculated amplitude ratio.Type: GrantFiled: June 18, 2009Date of Patent: July 24, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Toshio Takahashi, Akihiro Namba, Masafumi Mochizuki
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Patent number: 8223458Abstract: A magnetic head, according to one embodiment, includes a main magnetic pole having a protruding portion such that a distance from a first side of a trailing edge of the main magnetic pole to a leading edge of the main magnetic pole is different from a distance from a second side of the trailing edge of the main magnetic pole to the leading edge of the main magnetic pole, an auxiliary magnetic pole, and a coil wound around a magnetic circuit, the magnetic circuit including the main magnetic pole and the auxiliary magnetic pole. In another embodiment, a disk drive system includes a magnetic storage medium, at least one magnetic head as described previously for writing to the magnetic medium, a slider for supporting the magnetic head, and a control unit coupled to the magnetic head for controlling operation of the magnetic head. Additional systems and heads are also presented.Type: GrantFiled: April 8, 2010Date of Patent: July 17, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Masafumi Mochizuki, Yohji Maruyama, Etoh Kimitoshi
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Publication number: 20120162810Abstract: 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: ApplicationFiled: December 22, 2010Publication date: June 28, 2012Applicant: Hitachi Global Storage Technologies Netherlands B.VInventors: Sarbanoo Das, Masafumi Mochizuki
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Patent number: 8203803Abstract: Embodiments of the invention are directed to narrowing a read/write gap of a perpendicular magnetic head by applying a wrap around shield, data erasing from return pole edges by returning recording field, and reducing TPR of a magnetic material. In one embodiment, the wrap around shields are formed by partitioning and making Gd, which is the height of the shield at the main pole side in the sensor height direction, smaller than the height of the shield connected to the return pole in the sensor height direction.Type: GrantFiled: October 18, 2005Date of Patent: June 19, 2012Assignee: HGST Netherlands B.V.Inventors: Kimitoshi Etoh, Masafumi Mochizuki, Isao Nunokawa, Tomohiro Okada
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Patent number: 8107180Abstract: A hard-disk drive. The hard-disk drive includes a magnetic-recording disk including tracks on which a plurality of patterned bit-cells that are isolated magnetically are aligned at predetermined alignment pitches. The hard-disk drive includes a magnetic-recording head which is configured to follow tracks, and to write and to read data. The hard-disk drive includes a signal-processing unit which is configured to generate a recording signal based on a write-clock signal with cycles corresponding to alignment pitches of patterned bit-cells, and to output a recording signal. The hard-disk drive includes a phase-detecting unit which is configured to detect a phase of the write-clock signal when the magnetic-recording head reaches an end point of a predetermined range. The hard disk drive includes a determination-processing unit which is configured to determine success of data writing based on a difference between an expected value and a detected value of the phase of the write-clock signal.Type: GrantFiled: July 17, 2009Date of Patent: January 31, 2012Assignee: Hitachi Global Storage Technologies, Netherlands, B.V.Inventors: Shuji Nishida, Yasutaka Nishida, Masafumi Mochizuki, Hideaki Maeda
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Patent number: 8085499Abstract: Thin film perpendicular magnetic head with a narrow main pole capable of a high recording density in excess of 100 gigabits per square inch and generating a high magnetic recording field, while also being modified to suppress remanent magnetic fields occurring immediately after writing operation. A return path is provided for supplying a magnetic flux to the main pole, and an conductive coil for excitation of the main pole and return path. The main pole has a pole width of 200 nanometers or less, and a magnetic multilayer made up of a high saturation flux density layer and low saturation flux density layer. The low saturation flux density layer and the high saturation flux density suppress remanent magnetization and prevent erasing after writing by utilizing a closed magnetic domain structure in the pole.Type: GrantFiled: September 23, 2010Date of Patent: December 27, 2011Assignee: Hitachi Global Storage Technologies Japan, Ltd.Inventors: Yoshiaki Kawato, Kazuhiro Nakamoto, Hiroyuki Hoshiya, Yasuyuki Okada, Masafumi Mochizuki
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Publication number: 20110249359Abstract: A magnetic head, according to one embodiment, includes a main magnetic pole having a protruding portion such that a distance from a first side of a trailing edge of the main magnetic pole to a leading edge of the main magnetic pole is different from a distance from a second side of the trailing edge of the main magnetic pole to the leading edge of the main magnetic pole, an auxiliary magnetic pole, and a coil wound around a magnetic circuit, the magnetic circuit including the main magnetic pole and the auxiliary magnetic pole. In another embodiment, a disk drive system includes a magnetic storage medium, at least one magnetic head as described previously for writing to the magnetic medium, a slider for supporting the magnetic head, and a control unit coupled to the magnetic head for controlling operation of the magnetic head. Additional systems and heads are also presented.Type: ApplicationFiled: April 8, 2010Publication date: October 13, 2011Inventors: Masafumi Mochizuki, Yohji Maruyama, Etoh Kimitoshi
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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: 8000058Abstract: Embodiments of the invention provide a perpendicular recording magnetic head capable of reducing leakage magnetic fields from the soft magnetic films on the air bearing surface side and reducing the protrusion of the soft magnetic films in the direction of the air bearing surface side due to thermal deformation of the soft magnetic films. In one embodiment, the write functional section includes a coil conductor, second soft magnetic film pattern and first soft magnetic film pattern that cover the coil conductor from top and bottom and are magnetically coupled to each other, and a main magnetic pole piece determining a track width. The read functional section includes a reading element sandwiched between two magnetic shield films. A pedestal magnetic pole pattern is formed at the frontal end position of the first soft magnetic film pattern.Type: GrantFiled: October 24, 2005Date of Patent: August 16, 2011Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Tadayuki Iwakura, Youji Maruyama, Masafumi Mochizuki, Ichiro Ohdake
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Patent number: 7990653Abstract: Embodiments in accordance with the present invention provide a perpendicular recording magnetic head whose dimensional dependency on the nonuniformity of magnetic field strength and distribution during manufacture is minimized, with narrowed tracks and without attenuation or erasure of adjacent track data while maintaining high magnetic field strength. According to one embodiment, a magnetic material (trailing/side shield) for creating a steep gradient of magnetic field strength is provided at a trailing side of a pole tip of a main magnetic pole piece and in a direction of the track width. The magnetic head is formed so that a gap (side gap length “gl”) between a side shield and a throat height portion of the pole tip progressively decreases with an increasing distance from an air-bearing surface, in a direction of an element height.Type: GrantFiled: April 27, 2007Date of Patent: August 2, 2011Assignee: Hitachi Global Storage Technologies Netherland BVInventors: Masafumi Mochizuki, Shuji Nishida, Kimitoshi Etoh, Isao Nunokawa
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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