Patents by Inventor Isao Nunokawa
Isao Nunokawa 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: 9135933Abstract: Embodiments described herein provide an MAMR head structure which provides a magnetic recording device equipped with a high density recording magnetic head. Characteristic variations caused by misalignment of a main pole and a STO may be reduced because the STO may be aligned with a position on the main pole where the field intensity is enhanced. The enhanced field intensity may be provided by an angle of inclination ?1 of an inclined surface on which the STO may be formed when compared to an angle of inclination ?2 around the main pole in the region of the ABS. Further embodiments provide a method for producing an MAMR head in which an exposed surface of the main pole has an angle of inclination ?2 which is less than the angle of inclination ?1 for the inclined surface of the main pole where the STO is mounted.Type: GrantFiled: November 8, 2013Date of Patent: September 15, 2015Assignee: HGST NETHERLANDS B.V.Inventors: Isao Nunokawa, Mikito Sugiyama, Yuta Udo
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Patent number: 9047885Abstract: Embodiments of the present invention provide a perpendicular magnetic recording head which can suppress reduction in recording field and efficiently reduce a fringe field. According to one embodiment, a side shield disposed at a side of each side face in a cross track direction of a main pole is arranged at a far leading side compared with the main pole.Type: GrantFiled: November 21, 2008Date of Patent: June 2, 2015Assignee: HGST Netherlands B.V.Inventors: Mikito Sugiyama, Isao Nunokawa, Hiroyuki Hoshiya
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Publication number: 20150131184Abstract: Embodiments described herein provide an MAMR head structure which provides a magnetic recording device equipped with a high density recording magnetic head. Characteristic variations caused by misalignment of a main pole and a STO may be reduced because the STO may be aligned with a position on the main pole where the field intensity is enhanced. The enhanced field intensity may be provided by an angle of inclination ?1 of an inclined surface on which the STO may be formed when compared to an angle of inclination ?2 around the main pole in the region of the ABS. Further embodiments provide a method for producing an MAMR head in which an exposed surface of the main pole has an angle of inclination ?2 which is less than the angle of inclination ?1 for the inclined surface of the main pole where the STO is mounted.Type: ApplicationFiled: November 8, 2013Publication date: May 14, 2015Applicant: HGST NETHERLANDS B.V.Inventors: Isao NUNOKAWA, Mikito SUGIYAMA, Yuta UDO
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Publication number: 20150109699Abstract: In accordance with one embodiment, a magnetic head includes a main pole configured to emit a recording magnetic field for affecting a magnetic medium, spin torque oscillator (STO) device in electrical communication with and positioned above the main pole in a track direction, the STO device being configured to generate a high-frequency magnetic field which is superimposed with the recording magnetic field in order to record data to the magnetic medium when current flows to the STO device, and a heat sink positioned near the STO device, the heat sink being configured to reduce a temperature of the STO device when current flows to the STO device. In another embodiment, a method includes forming a heat sink behind a STO device in an element height direction perpendicular to a media facing surface, and/or on both sides of the STO device in a cross-track direction at the media facing surface.Type: ApplicationFiled: October 22, 2013Publication date: April 23, 2015Applicant: HGST Netherlands B.V.Inventors: Carl Boone, Jianhua Li, Isao Nunokawa, Erhard Schreck, Mikito Sugiyama, Ikuya Tagawa, Yuta Udo
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Patent number: 8995088Abstract: In accordance with one embodiment, a magnetic head includes a main pole configured to emit a recording magnetic field for affecting a magnetic medium, a spin torque oscillator (STO) device in electrical communication with and positioned above the main pole in a track direction, the STO device being configured to generate a high-frequency magnetic field which is superimposed with the recording magnetic field in order to record data to the magnetic medium when current flows to the STO device, and a heat sink positioned near the STO device, the heat sink being configured to reduce a temperature of the STO device when current flows to the STO device. In another embodiment, a method includes forming a heat sink behind a STO device in an element height direction perpendicular to a media facing surface, and/or on both sides of the STO device in a cross-track direction at the media facing surface.Type: GrantFiled: October 22, 2013Date of Patent: March 31, 2015Assignee: HGST Netherlands B.V.Inventors: Carl Boone, Jianhua Li, Isao Nunokawa, Erhard Schreck, Mikito Sugiyama, Ikuya Tagawa, Yuta Udo
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Shield structure for reducing the magnetic induction rate of the trailing shield and systems thereof
Patent number: 8830623Abstract: In one embodiment, a magnetic head includes a main magnetic pole, a trailing shield positioned on a trailing side of the main magnetic pole, a trailing gap positioned between the trailing shield and the main magnetic pole, side shields positioned on either side of the main magnetic pole in a cross-track direction, side gaps positioned between the side shields and the main magnetic pole on either side of the main magnetic pole in the cross-track direction, and trailing shield gaps positioned on either side of the main magnetic pole in the cross-track direction between the trailing shield and the side shields, wherein the trailing shield gaps extend beyond the side gaps in a direction parallel to the cross-track direction. In addition, a method for producing a magnetic head as described above is also disclosed, according to one embodiment.Type: GrantFiled: December 19, 2011Date of Patent: September 9, 2014Assignee: HGST Netherlands B.V.Inventors: Tomoaki Hamasaki, Hiroyuki Katada, Isao Nunokawa, Kimitoshi Etoh -
Patent number: 8824103Abstract: The strength of a magnetic field applied from a main pole to an oscillator and the strength of a magnetic field applied from the main pole to a recording medium are improved in a magnetic recording head for microwave assisted recording. In the magnetic recording head according to the present invention, an interval between the main pole and a trailing shield at a place in a position above an air bearing surface is larger than an interval between the main pole and the trailing shield on the air bearing surface.Type: GrantFiled: February 24, 2012Date of Patent: September 2, 2014Assignee: Hitachi, Ltd.Inventors: Masato Shiimoto, Kenji Sugiura, Mikito Sugiyama, Isao Nunokawa, Yo Sato, Katsuro Watanabe, Kazuhiko Hosomi, Nobuo Yoshida
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SHIELD STRUCTURE FOR REDUCING THE MAGNETIC INDUCTION RATE OF THE TRAILING SHIELD AND SYSTEMS THEREOF
Publication number: 20130155544Abstract: In one embodiment, a magnetic head includes a main magnetic pole, a trailing shield positioned on a trailing side of the main magnetic pole, a trailing gap positioned between the trailing shield and the main magnetic pole, side shields positioned on either side of the main magnetic pole in a cross-track direction, side gaps positioned between the side shields and the main magnetic pole on either side of the main magnetic pole in the cross-track direction, and trailing shield gaps positioned on either side of the main magnetic pole in the cross-track direction between the trailing shield and the side shields, wherein the trailing shield gaps extend beyond the side gaps in a direction parallel to the cross-track direction. In addition, a method for producing a magnetic head as described above is also disclosed, according to one embodiment.Type: ApplicationFiled: December 19, 2011Publication date: June 20, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Tomoaki Hamasaki, Hiroyuki Katada, Isao Nunokawa, Kimitoshi Etoh -
Publication number: 20130057980Abstract: The strength of a magnetic field applied from a main pole to an oscillator and the strength of a magnetic field applied from the main pole to a recording medium are improved in a magnetic recording head for microwave assisted recording. In the magnetic recording head according to the present invention, an interval between the main pole and a trailing shield at a place in a position above an air bearing surface is larger than an interval between the main pole and the trailing shield on the air bearing surface.Type: ApplicationFiled: February 24, 2012Publication date: March 7, 2013Inventors: Masato SHIIMOTO, Kenji SUGIURA, Mikito SUGIYAMA, Isao NUNOKAWA, Yo SATO, Katsuro WATANABE, Kazuhiko HOSOMI, Nobuo YOSHIDA
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Patent number: 8351154Abstract: A perpendicular recording magnetic head is provided, according to one embodiment, in which even if a thickness of a main pole is reduced corresponding to a reduction in a recording track width, recording performance is not degraded. A magnetic-field auxiliary pole and a nonmagnetic layer are stacked on a main pole, and a nonmagnetic portion is provided on each side face on a flying surface side of the magnetic-field auxiliary pole and the nonmagnetic layer, in one approach. In all regions except for a region near a flying surface, an interval between the main pole and a shield is increased by the nonmagnetic portion and the nonmagnetic layer, so that magnetic field loss is prevented, and consequently magnetic field strength and a magnetic field gradient are increased. Other systems and methods are also disclosed for retaining magnetic recording performance while reducing a thickness of a main pole.Type: GrantFiled: December 11, 2009Date of Patent: January 8, 2013Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Kimitoshi Etoh, Mikito Sugiyama, Isao Nunokawa, Tomohiro Okada
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Magnetic recording head, method of manufacturing the same, and magnetic recording/reproducing device
Patent number: 8351153Abstract: According to one embodiment, a magnetic recording head includes a main pole having a throat height portion and a flare portion that is connected to the throat height portion, the flare portion gradually being expanded in width to an upper part in an element height direction. The head also includes a sub pole, magnetic shields disposed via a nonmagnetic layer on a trailing side of the main pole and on both sides in a track width direction of the main pole, and a coil for generating a recording magnetic field from the main pole. The nonmagnetic layer has an upper portion of which the thickness is increased stepwise or in a tapered manner in the element height direction with respect to an ABS side, and each portion of the magnetic shields adjacent to the main pole has a shape corresponding to a surface shape of the nonmagnetic layer.Type: GrantFiled: September 14, 2009Date of Patent: January 8, 2013Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Isao Nunokawa, Mikito Sugiyama, Kikuo Kusukawa, Hiroyuki Hoshiya -
Patent number: 8351162Abstract: Embodiments of the invention reduce the throat height of a single pole type head with high accuracy. In one embodiment, a head with an electro lapping guide for controlling a write head's throat height during air bearing surface processing is made. Air bearing surface processing is performed using the electro lapping guide. For a read head, processing is performed using the read head itself or an electro lapping guide for the read head so that both the throat height of write head and the element height of read head are controlled.Type: GrantFiled: July 29, 2005Date of Patent: January 8, 2013Assignee: HGST Netherlands BVInventors: Kimitoshi Etoh, Hisashi Kimura, Isao Nunokawa, Tomohiro Okada
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Patent number: 8335051Abstract: A recording head having a narrowed track has a high recording magnetic field strength and a high recording magnetic field gradient has certain problems which may be difficult to overcome. In one embodiment, a magnetic film, which overhangs from a track width, is provided on a trailing side of a. region retracted from an ABS of a main pole facing a recording medium. Thereby, a magnetic field strength on the trailing side is increased so that a difference in distribution of magnetic field strength defined by a geometrical bevel angle given to the main pole is increased. Consequently, writing performance of the main pole is improved while forming a large magnetic clearance angle with respect to an adjacent track and suppresses writing into an adjacent track when skew occurs. Other systems and methods are also disclosed regarding a head with a high recording magnetic field using an overhanging magnetic film.Type: GrantFiled: December 11, 2009Date of Patent: December 18, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Isao Nunokawa, Mikito Sugiyama, Kikuo Kusukawa, Kimitoshi Etoh
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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: 8107193Abstract: According to one embodiment, a perpendicular magnetic recording head includes a main magnetic pole including a write magnetic pole layer for recording, the write magnetic pole layer comprising magnetic layers being antiferromagnetically coupled via a thin non-magnetic conductor layer between the magnetic layers, wherein the write magnetic pole layer for recording has a flare section which gradually widens in a height-wise direction of a throat height section. The main magnetic pole also includes a non-magnetic cap layer laminated above an uppermost layer of the write magnetic pole layer, the non-magnetic cap layer being textured to provide anisotropy, and a subsidiary magnetic pole layer for supplementing the recording laminated above the non-magnetic cap layer. The head also includes an auxiliary magnetic pole, a magnetic shield positioned via a non-magnetic layer on a trailing edge and both sides of the main magnetic pole in a track width direction, and a coil for generating a recording magnetic field.Type: GrantFiled: April 8, 2010Date of Patent: January 31, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Isao Nunokawa, Mikito Sugiyama, Kikuo Kusukawa, Keizo Kato
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Publication number: 20110249360Abstract: According to one embodiment, a perpendicular magnetic recording head includes a main magnetic pole including a write magnetic pole layer for recording, the write magnetic pole layer comprising magnetic layers being antiferromagnetically coupled via a thin non-magnetic conductor layer between the magnetic layers, wherein the write magnetic pole layer for recording has a flare section which gradually widens in a height-wise direction of a throat height section. The main magnetic pole also includes a non-magnetic cap layer laminated above an uppermost layer of the write magnetic pole layer, the non-magnetic cap layer being textured to provide anisotropy, and a subsidiary magnetic pole layer for supplementing the recording laminated above the non-magnetic cap layer. The head also includes an auxiliary magnetic pole, a magnetic shield positioned via a non-magnetic layer on a trailing edge and both sides of the main magnetic pole in a track width direction, and a coil for generating a recording magnetic field.Type: ApplicationFiled: April 8, 2010Publication date: October 13, 2011Inventors: Isao Nunokawa, Mikito Sugiyama, Kikuo Kusukawa, Keizo Kato
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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: 7895732Abstract: An embodiment of the present invention relates to a method of manufacturing a perpendicular magnetic recording having a main pole, return pole and trailing side shield disposed on the trailing side and the cross track direction side of said main pole. A process is described where the main pole has an etching layer in the upper part. The top and sides of the main pole having the etching signal layer in the upper part are covered with a nonmagnetic gap layer while leaving open a region forming the side shield. The nonmagnetic gap layer is then etched until a signal from the etching signal layer is detected by an etching signal detector. The trailing side shield on the top and sides of the nonmagnetic gap layer are then formed after the etching is halted.Type: GrantFiled: March 15, 2007Date of Patent: March 1, 2011Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Tomohiro Okada, Isao Nunokawa, Kimitoshi Etoh, Kikuo Kusukawa
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Patent number: 7882617Abstract: The main magnetic pole piece of a magnetic head for perpendicular magnetic recording preferably has an inverted trapezoidal shape in order to maintain a sufficient recording magnetic field. Embodiments of the present invention enhance the covering power of the protective film around the main magnetic pole piece of the magnetic head and thereby ensure reliability even when the main magnetic pole piece has such a shape. In one embodiment, the protective film for protecting the main magnetic pole piece is formed by a sputtering apparatus while applying a bias, or it is formed by a carousel type sputtering apparatus or the chemical vapor deposition (CVD) technique.Type: GrantFiled: October 25, 2005Date of Patent: February 8, 2011Inventors: Atsushi Kato, Isao Nunokawa, Tomohiro Okada, Ichiro Oodake
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Publication number: 20100157484Abstract: A perpendicular recording magnetic head is provided, according to one embodiment, in which even if a thickness of a main pole is reduced corresponding to a reduction in a recording track width, recording performance is not degraded. A magnetic-field auxiliary pole and a nonmagnetic layer are stacked on a main pole, and a nonmagnetic portion is provided on each side face on a flying surface side of the magnetic-field auxiliary pole and the nonmagnetic layer, in one approach. In all regions except for a region near a flying surface, an interval between the main pole and a shield is increased by the nonmagnetic portion and the nonmagnetic layer, so that magnetic field loss is prevented, and consequently magnetic field strength and a magnetic field gradient are increased. Other systems and methods are also disclosed for retaining magnetic recording performance while reducing a thickness of a main pole.Type: ApplicationFiled: December 11, 2009Publication date: June 24, 2010Inventors: Kimitoshi Etoh, Mikito Sugiyama, Isao Nunokawa, Tomohiro Okada