Patents by Inventor Masahiko Hatatani
Masahiko Hatatani 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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Patent number: 9406322Abstract: 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: GrantFiled: September 11, 2015Date of Patent: August 2, 2016Assignee: HGST Netherlands B.V.Inventors: Jun Aoyama, Masahiko Hatatani, Hiroyuki Katada, Masato Shiimoto
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Patent number: 9263086Abstract: A hard disk drive (HDD) is described which includes a magnetic field-generating device in the vicinity of a load/unload ramp such that the write head moves into a magnetic field generated by the device while the head is being unloaded from disk, whereby the magnetic field pins in a predominant direction the direction of magnetization of a magnetic shield associated with the write head, and away from the direction toward the disk. Recording magnetic field leakage associated with the shield is thereby suppressed and corresponding far track interference is inhibited.Type: GrantFiled: March 27, 2014Date of Patent: February 16, 2016Assignee: HGST Netherlands B.V.Inventors: Satoshi Tabata, Norifumi Miyamoto, Akira Morinaga, Masahiro Ito, Masahiko Hatatani
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Publication number: 20160005428Abstract: 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: ApplicationFiled: September 11, 2015Publication date: January 7, 2016Inventors: Jun AOYAMA, Masahiko HATATANI, Hiroyuki KATADA, Masato SHIIMOTO
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Publication number: 20150279416Abstract: A hard disk drive (HDD) is described which includes a magnetic field-generating device in the vicinity of a load/unload ramp such that the write head moves into a magnetic field generated by the device while the head is being unloaded from disk, whereby the magnetic field pins in a predominant direction the direction of magnetization of a magnetic shield associated with the write head, and away from the direction toward the disk. Recording magnetic field leakage associated with the shield is thereby suppressed and corresponding far track interference is inhibited.Type: ApplicationFiled: March 27, 2014Publication date: October 1, 2015Applicant: HGST Netherlands B.V.Inventors: Satoshi Tabata, Norifumi Miyamoto, Akira Morinaga, Masahiro Ito, Masahiko Hatatani
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Patent number: 9142227Abstract: A microwave-assisted magnetic recording (MAMR) write head includes a yoke structure with a main pole, a flux return pole, and a trailing magnetic shield. The main pole includes a write pole with a tip at the disk-facing surface, a sub pole with an end recessed from the disk-facing surface and an electrically insulating layer between the write pole and the sub pole. The spin-torque oscillator (STO) is located at the disk-facing surface between the trailing shield and the write pole tip. The insulating layer assures that the STO current is not shorted between the return pole and the write pole. The insulating layer between the write pole and the sub pole increases the area of the junction between the return pole and write pole, which reduces the magnetic reluctance of the yoke structure.Type: GrantFiled: September 8, 2014Date of Patent: September 22, 2015Assignee: HGST Netherlands B.V.Inventors: Kimitoshi Etoh, Masahiko Hatatani, Kazuhiko Hosomi, Yohji Maruyama, Kenji Sugiura, Mikito Sugiyama
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Publication number: 20150092303Abstract: 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: ApplicationFiled: October 1, 2013Publication date: April 2, 2015Applicant: HGST NETHERLANDS B.V.Inventors: Jun AOYAMA, Masahiko HATATANI, Hiroyuki KATADA, Masato SHIIMOTO
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Patent number: 8976493Abstract: A magnetic sensor having improved pinned layer robustness for improved reliability and having improved side shielding for improved track resolution at very high data densities. The sensor has a pinned layer structure with laterally extending wing portions that become thicker with increasing distance from the air bearing surface and has a side shield structure has a thickness that decreases with increasing distance from the air bearing surface.Type: GrantFiled: December 11, 2013Date of Patent: March 10, 2015Assignee: HGST Netherlands B.V.Inventors: Hideki Mashima, Tutomu Yasuda, Masashige Sato, Masahiko Hatatani
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Patent number: 8149548Abstract: Embodiments of the present invention provide a magnetic head having a read head of stable reading operation and with less magnetic fluctuation noise. According to one embodiment, a free layer has a structure comprising two ferromagnetic layers (a first free layer and a second free layer) that are coupled anti-ferromagnetically by way of a non-magnetic intermediate layer, in which the magnetization amount of the first free layer is set to larger than the magnetization amount of the second free layer. Further, the magnetic domains in the first free layer and the second free layer are stabilized simultaneously by increasing the distance between the second free layer and the magnetic domain control film to be more than the distance between the first free layer and the magnetic domain control film, thereby adjusting the magnetization amount of the magnetic domain control film.Type: GrantFiled: April 17, 2009Date of Patent: April 3, 2012Assignee: Hitachi Global Storage Technologies Netherlands BVInventors: Masahiko Hatatani, Katsuro Watanabe, Nubuo Yoshida, Katsumi Hoshino
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Publication number: 20090262465Abstract: Embodiments of the present invention provide a magnetic head having a read head of stable reading operation and with less magnetic fluctuation noise. According to one embodiment, a free layer has a structure comprising two ferromagnetic layers (a first free layer and a second free layer) that are coupled anti-ferromagnetically by way of a non-magnetic intermediate layer, in which the magnetization amount of the first free layer is set to larger than the magnetization amount of the second free layer. Further, the magnetic domains in the first free layer and the second free layer are stabilized simultaneously by increasing the distance between the second free layer and the magnetic domain control film to be more than the distance between the first free layer and the magnetic domain control film, thereby adjusting the magnetization amount of the magnetic domain control film.Type: ApplicationFiled: April 17, 2009Publication date: October 22, 2009Inventors: Masahiko Hatatani, Katsuro Watanabe, Nubuo Yoshida, Katsumi Hoshino
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Patent number: 7599151Abstract: Embodiments of the invention provide a magnetic recording and read head which reduces the spread read width in a narrow track having a width of 100 nm or less and shows stable read operation. In one embodiment, a side magnetic shield has a multi-layered structure including non-magnetic separate layers and soft magnetic layers, and the soft magnetic layers are magnetized in opposite directions to reduce a magnetic field induced by the side magnetic shield.Type: GrantFiled: October 29, 2004Date of Patent: October 6, 2009Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Masahiko Hatatani, Chiseki Haginoya, Kenichi Meguro, Kazuhiro Nakamoto
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Patent number: 7535683Abstract: A magnetoresistive head and a fabricating method thereof accomplishing high sensitivity and low noise are provided even if track width narrowing makes progress. In one embodiment, a pinned layer includes a laminate which includes at least two magnetic layers and where adjacent magnetic layers are coupled antiferromagnetically to each other, and a mechanism to apply a longitudinal biasing field to a free layer is made to function by laminating a nonmagnetic separate layer/longitudinal biasing layer/antiferromagnetic layer connecting the free layer and opposite a nonmagnetic conductive layer (or nonmagnetic tunneling barrier layer). Controlling a magnetization direction of the longitudinal biasing layer which bears application of a longitudinal biasing field to the pinned layer and free layer is achieved by annealing carried out while applying a magnetic field in a track width direction and applying a magnetic field at room temperature.Type: GrantFiled: October 29, 2004Date of Patent: May 19, 2009Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Kenichi Meguro, Kouichi Nishioka, Masahiko Hatatani, Chiseki Haginoya
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Patent number: 7505232Abstract: In a side shield structure employed to narrow the effective track, a noise caused by the side shield structure can be reduced. In one embodiment, the side shield is inclined with respect to the film plane to suppress the generation of a magnetic pole in the end portion of the side shield. To this end, the side face of a device is inclined at a desired angle. Further, a reproduction device is formed at two or more angles ?1 and ?2 to improve the track width accuracy.Type: GrantFiled: June 24, 2005Date of Patent: March 17, 2009Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Chiseki Haginoya, Masahiko Hatatani, Chiaki Ishakawa, Kenichi Meguro, Kazuhiro Nakamoto, Katsuro Watanabe
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Patent number: 7440240Abstract: Embodiments of the invention provide a spin-valve type magnetic head that satisfies the requirements of both high read output and stability with narrow tracks. In one embodiment, a domain control film is formed on a magnetoresistive layered film in the same track width. A double closed flux path structure that uses three magnetic layers is employed with magnetic coupled structure in both ends of the track. The three magnetic layers are a soft magnetic free layer, a domain-stabilization ferromagnetic layer, and a soft magnetic anti-parallel layer.Type: GrantFiled: April 8, 2005Date of Patent: October 21, 2008Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Hiroyuki Hoshiya, Katsumi Hoshino, Masahiko Hatatani, Kenichi Meguro
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Patent number: 7274542Abstract: A magnetic sensor includes a spacer having at least a nonmagnetic metal layer inserted between the upper shield layer and the longitudinal bias layers or between the upper shield layer and the longitudinal bias layers plus the magnetoresistive film, the shortest distance between the longitudinal bias layers and the free layer of the magnetoresistive film is set smaller than the shortest distance between the longitudinal bias layers and the upper shield layer, and this arrangement ensures that the amount of magnetic flux entering the magnetoresistive film from the longitudinal bias layers is larger than that absorbed by the upper shield layer, thus realizing a magnetic sensor whose Barkhausen noise is suppressed.Type: GrantFiled: February 5, 2003Date of Patent: September 25, 2007Assignee: Hitachi Global Storage Technologies Japan, Ltd.Inventors: Taku Shintani, Katsuro Watanabe, Masahiko Hatatani, Kikuo Kusukawa
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Publication number: 20060018055Abstract: In a side shield structure employed to narrow the effective track, a noise caused by the side shield structure can be reduced. In one embodiment, the side shield is inclined with respect to the film plane to suppress the generation of a magnetic pole in the end portion of the side shield. To this end, the side face of a device is inclined at a desired angle. Further, a reproduction device is formed at two or more angles ?1 and ?2 to improve the track width accuracy.Type: ApplicationFiled: June 24, 2005Publication date: January 26, 2006Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Chiseki Haginoya, Masahiko Hatatani, Chiaki Ishikawa, Kenichi Meguro, Kazuhiro Nakamoto, Katsuro Watanabe
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Publication number: 20050225907Abstract: Embodiments of the invention provide a spin-valve type magnetic head that satisfies the requirements of both high read output and stability with narrow tracks. In one embodiment, a domain control film is formed on a magnetoresistive layered film in the same track width. A double closed flux path structure that uses three magnetic layers is employed with magnetic coupled structure in both ends of the track. The three magnetic layers are a soft magnetic free layer, a domain-stabilization ferromagnetic layer, and a soft magnetic anti-parallel layer.Type: ApplicationFiled: April 8, 2005Publication date: October 13, 2005Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Hiroyuki Hoshiya, Katsumi Hoshino, Masahiko Hatatani, Kenichi Meguro
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Patent number: 6937449Abstract: To provide a spin-valve type magnetic head having high read output even if track width is narrow and high stability, a magnetic head according to the invention is provided with a spin-valve type magnetoresistive element in which a single magnetic domain turning ferromagnetic layer is formed on a soft magnetic free layer via a non-magnetic separating layer, the soft magnetic free layer and the single magnetic domain turning ferromagnetic layer are magnetostatically coupled at the end of track width, a closed magnetic circuit is formed and the soft magnetic layer has magnetization substantially induced in a direction substantially perpendicular to an external magnetic field.Type: GrantFiled: February 20, 2002Date of Patent: August 30, 2005Assignee: Hitachi, Ltd.Inventors: Hiroyuki Hoshiya, Masahiko Hatatani, Hisashi Kimura, Hiroshi Ide
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Publication number: 20050162786Abstract: A magnetoresistive head and a fabricating method thereof accomplishing high sensitivity and low noise are provided even if track width narrowing makes progress. In one embodiment, a pinned layer includes a laminate which includes at least two magnetic layers and where adjacent magnetic layers are coupled antiferromagnetically to each other, and a mechanism to apply a longitudinal biasing field to a free layer is made to function by laminating a nonmagnetic separate layer/longitudinal biasing layer/antiferromagnetic layer connecting the free layer and opposite a nonmagnetic conductive layer (or nonmagnetic tunneling barrier layer). Controlling a magnetization direction of the longitudinal biasing layer which bears application of a longitudinal biasing field to the pinned layer and free layer is achieved by annealing carried out while applying a magnetic field in a track width direction and applying a magnetic field at room temperature.Type: ApplicationFiled: October 29, 2004Publication date: July 28, 2005Applicant: Hitachi Global Storage Technologies Netherlands, B.V.Inventors: Kenichi Meguro, Kouichi Nishioka, Masahiko Hatatani, Chiseki Haginoya
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Publication number: 20050157431Abstract: Embodiments of the invention provide a magnetic recording and read head which reduces the spread read width in a narrow track having a width of 100 nm or less and shows stable read operation. In one embodiment, a side magnetic shield has a multi-layered structure including non-magnetic separate layers and soft magnetic layers, and the soft magnetic layers are magnetized in opposite directions to reduce a magnetic field induced by the side magnetic shield.Type: ApplicationFiled: October 29, 2004Publication date: July 21, 2005Applicant: Hitachi Global Storage Technologies Netherlands, B.V.Inventors: Masahiko Hatatani, Chiseki Haginoya, Kenichi Meguro, Kazuhiro Nakamoto
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Publication number: 20040080873Abstract: A magnetic sensor includes a spacer having at least a nonmagnetic metal layer inserted between the upper shield layer and the longitudinal bias layers or between the upper shield layer and the longitudinal bias layers plus the magnetoresistive film, the shortest distance between the longitudinal bias layers and the free layer of the magnetoresistive film is set smaller than the shortest distance between the longitudinal bias layers and the upper shield layer, and this arrangement ensures that the amount of magnetic flux entering the magnetoresistive film from the longitudinal bias layers is larger than that absorbed by the upper shield layer, thus realizing a magnetic sensor whose Barkhausen noise is suppressed.Type: ApplicationFiled: February 5, 2003Publication date: April 29, 2004Inventors: Taku Shintani, Katsuro Watanabe, Masahiko Hatatani, Kikuo Kusukawa