Patents by Inventor Takayoshi Ohtsu
Takayoshi Ohtsu 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: 8786986Abstract: A head-slider. The head-slider includes a slider, and a thin-film magnetic-recording head. The thin-film magnetic-recording head includes: a read element; a write element; a non-magnetic insulating protective layer disposed around both read and write elements; a resist disposed at a position further away from an air-bearing surface than the read element; and, a hard-material member including a material selected from the group consisting of silicon carbide and tungsten, which is disposed at a position further away from the air-bearing surface than the read element and the write element. Both an end of the resist and an end of the hard-material member overlap the write element when viewed in a stacking direction. A ratio of a distance from the air-bearing surface to a deepest end of the hard-material member to a distance from the air-bearing surface to a deepest end of the resist is at least 0.9.Type: GrantFiled: December 18, 2009Date of Patent: July 22, 2014Assignee: HGST Netherlands B.V.Inventors: Shigeo Fujita, Masahiko Soga, Hideaki Tanaka, Yuji Ueda, Tomohiro Okada, Takayoshi Ohtsu, Wataru Kimura, Yohji Maruyama
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Patent number: 8711520Abstract: In one embodiment, a method of manufacturing a magnetic disk includes rotating a magnetic disk, supporting a floating head on the rotating magnetic disk, the floating head having a slider body and an element unit formed on a trailing edge of the slider body, contacting a floating surface of the slider body with the magnetic disk, and protruding a portion of the floating head toward the magnetic disk due to application of power to a heater element within the element unit, wherein the element unit is positioned away from the magnetic disk. In another embodiment, a floating head includes a slider body comprising AlTiC, an element unit positioned on a trailing edge of the slider body, the element unit having an initial recess amount of at least about 4 nm, and a heater element positioned within an alumina protective film of the element unit.Type: GrantFiled: December 16, 2010Date of Patent: April 29, 2014Assignee: HGST Netherlands B.V.Inventors: Minoru Koike, Eiji Nakanishi, Yoshinori Takeuchi, Hiroshi Agari, Hiroyuki Matsumoto, Takayoshi Ohtsu
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Patent number: 8477455Abstract: A slider comprising a contact sensor element configured to respond to a change in resistance due to a change in temperature, and a shield structure. The shield structure comprises a lower thermal conductivity than the contact sensor element and a greater hardness than the contact sensor element.Type: GrantFiled: November 16, 2010Date of Patent: July 2, 2013Assignee: HGST Netherlands B.V.Inventors: Masaru Furukawa, Yuki Shimizu, Junguo Xu, Yohji Maruyama, Takayoshi Ohtsu, Toshiya Shiramatsu
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Patent number: 8431255Abstract: Embodiments of the present invention relate to a galvanomagnetic device for use as a magnetic sensor or magnetic memory device. In a particular embodiment, the galvanomagnetic device comprises a non-conductive substrate, a first magnetic layer having a magnetic anisotropy perpendicular to the surface thereof, and a ferromagnetic second magnetic layer formed on the first magnetic layer. On the second magnetic layer, current electrodes are disposed to pass a current between two points, and voltage electrodes are disposed to detect a Hall voltage between two points perpendicularly to the current flow direction.Type: GrantFiled: December 24, 2008Date of Patent: April 30, 2013Assignee: HGST Netherlands BVInventors: Das Sarbanoo, Hiroyuki Suzuki, Takayoshi Ohtsu
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Patent number: 8335057Abstract: According to one embodiment, a CPP magnetoresistive head includes a magnetoresistive film comprising a free layer above a non-magnetic intermediate layer and a fixed layer below the non-magnetic intermediate layer, wherein the magnetoresistive film is between a lower magnetic shield layer and an upper magnetic shield layer. The CPP magnetoresistive head also includes a domain control film on each side of the magnetoresistive film, wherein a sense current flows through the magnetoresistive film between the upper magnetic shield layer and the lower magnetic shield layer. The CPP magnetoresistive head also includes a high heat conductivity layer, and a heat dissipation layer having a high heat conductivity and a low linear expansion coefficient, the heat dissipation layer being disposed at the back in a device height direction of the magnetoresistive film and on each side of the domain control film.Type: GrantFiled: August 5, 2009Date of Patent: December 18, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Masahiro Osugi, Takayoshi Ohtsu, Shigeo Fujita, Katsuro Watanabe, Koji Kataoka
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Patent number: 8284521Abstract: Embodiments of the present invention help to provide a flying height adjusting type magnetic head slider with reduced influence of a heater coil induction field. According to one embodiment, a magnetic head slider comprises a heater, a read element, and a write element, which are formed on a substrate. The heater is formed between a lower magnetic shield of the read element and the substrate by meandering a heater coil in direction Y going away from ABS. Magnetic fields by generated in direction Y orthogonal to a track width direction X of the lower magnetic field upon energization of the heater coil are offset each other, exerting no influence on the magnetized state in the track width direction X of the lower magnetic shield. A magnetic field hx induced in the track width direction X of the lower magnetic shield is coincident with the magnetizing direction of the lower magnetic shield, acting to maintain the magnetized state of the lower magnetic shield.Type: GrantFiled: November 30, 2007Date of Patent: October 9, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Takayoshi Ohtsu
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Patent number: 8270109Abstract: In one embodiment, a magnetic head slider includes a write head having a single magnetic pole, the single magnetic pole having a main magnetic pole piece that extends to a medium opposing surface facing a magnetic disk. The main magnetic pole piece generates a recording magnetic field from a medium opposing surface side end face thereof being divided into an injection region and a non-injection region. Impurities which deteriorate magnetic properties are present in a higher concentration in the injection region relative to a concentration of the impurities in the non-injection region due to injection of the impurities in the injection region. The non-injection region has a narrower width at a leading end of the medium opposing surface side end face than at a trailing end of the medium opposing surface side end face.Type: GrantFiled: December 8, 2009Date of Patent: September 18, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Takayoshi Ohtsu
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Patent number: 8221192Abstract: A magnetic-recording-disk test-head. The magnetic-recording-disk test-head includes a slider, a test pad and a slider-surface-shape control mechanism. The slider includes a leading edge and a trailing edge. The test pad is disposed at a trailing-edge side of the slider and is configured to remove and to detect asperities on a magnetic-recording disk. The slider-surface-shape control mechanism is configured to change a shape of an air-bearing surface of the slider and is disposed at a leading-edge side of the slider.Type: GrantFiled: August 7, 2009Date of Patent: July 17, 2012Assignee: Hitachi Global Storage Technologies, Netherlands B.V.Inventors: Hidekazu Kashiwase, Hiroyuki Suzuki, Masae Suzuki, legal representative, Mitsuhiro Shoda, Takayoshi Ohtsu, Kiyoshi Hashimoto
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Patent number: 8184406Abstract: Embodiments in accordance with the present invention provide a thin film magnetic head for preventing a short-circuit failure during formation of a track portion or a stripe-height portion and improving a yield. In one embodiment, a stripe-height direction is first formed, and then a track-width direction is formed. A third insulating film having a smoothly shaped wall surface is formed on a first insulating film during stripe-height formation. During formation of the third insulating film, an optimized lift-off pattern is used to smooth an edge shape.Type: GrantFiled: April 10, 2007Date of Patent: May 22, 2012Assignee: Hitachi Global Storage Technologies Netherlands BVInventors: Nubuo Yoshida, Katsuro Watanabe, Takayoshi Ohtsu
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Publication number: 20120120528Abstract: A slider comprising a contact sensor element configured to respond to a change in resistance due to a change in temperature, and a shield structure. The shield structure comprises a lower thermal conductivity than the contact sensor element and a greater hardness than the contact sensor element.Type: ApplicationFiled: November 16, 2010Publication date: May 17, 2012Inventors: Masaru Furukawa, Yuki Shimizu, Junguo Xu, Yohji Maruyama, Takayoshi Ohtsu, Toshiya Shiramatsu
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Patent number: 7983005Abstract: For a Tunneling Magnetoresistive (TMR) element, an electrode is used as a magnetic shield or vice versa. This can pose a problem in that noise from a heater source or electromagnetic induction has a direct influence on the TMR element, namely, on a read signal. According to one embodiment of the present invention, however, a thin film head portion has an insulating film, a heater, an electromagnetic shield, a read element, and a write element laminated in this order from the side of a slider. Insulating films isolate the constituent elements above from each other, and a protection film covers the group mentioned above. The heater is a thin film resistive element made of NiCr or the like, and is disposed above the insulating film. The electromagnetic shield is a magnetic film made of permalloy or the like, and covers the heater. The read element comprises a lower shield and electrode, a TMR element, and an upper shield and electrode.Type: GrantFiled: April 12, 2007Date of Patent: July 19, 2011Assignee: Hitachi Global Storage Technologies Netherlands BVInventors: Takayoshi Ohtsu, Nobumasa Nishiyama
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Publication number: 20110149429Abstract: In one embodiment, a method of manufacturing a magnetic disk includes rotating a magnetic disk, supporting a floating head on the rotating magnetic disk, the floating head having a slider body and an element unit formed on a trailing edge of the slider body, contacting a floating surface of the slider body with the magnetic disk, and protruding a portion of the floating head toward the magnetic disk due to application of power to a heater element within the element unit, wherein the element unit is positioned away from the magnetic disk. In another embodiment, a floating head includes a slider body comprising AlTiC, an element unit positioned on a trailing edge of the slider body, the element unit having an initial recess amount of at least about 4 nm, and a heater element positioned within an alumina protective film of the element unit.Type: ApplicationFiled: December 16, 2010Publication date: June 23, 2011Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Minoru Koike, Eiji Nakanishi, Yoshinori Takeuchi, Hiroshi Agari, Hiroyuki Matsumoto, Takayoshi Ohtsu
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Publication number: 20110116192Abstract: A head-slider. The head-slider includes a slider, and a thin-film magnetic-recording head. The thin-film magnetic-recording head includes: a read element; a write element; a non-magnetic insulating protective layer disposed around both read and write elements; a resist disposed at a position further away from an air-bearing surface than the read element; and, a hard-material member including a material selected from the group consisting of silicon carbide and tungsten, which is disposed at a position further away from the air-bearing surface than the read element and the write element. Both an end of the resist and an end of the hard-material member overlap the write element when viewed in a stacking direction. A ratio of a distance from the air-bearing surface to a deepest end of the hard-material member to a distance from the air-bearing surface to a deepest end of the resist is at least 0.9.Type: ApplicationFiled: December 18, 2009Publication date: May 19, 2011Inventors: Shigeo FUJITA, Masahiko Soga, Hideaki Tanaka, Yuji Ueda, Tomohiro Okada, Takayoshi Ohtsu, Wataru Kimura, Yohji Maruyama
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Publication number: 20110069410Abstract: A magnetic-recording-disk test-head. The magnetic-recording-disk test-head includes a slider, a test pad and a slider-surface-shape control mechanism. The slider includes a leading edge and a trailing edge. The test pad is disposed at a trailing-edge side of the slider and is configured to remove and to detect asperities on a magnetic-recording disk. The slider-surface-shape control mechanism is configured to change a shape of an air-bearing surface of the slider and is disposed at a leading-edge side of the slider.Type: ApplicationFiled: August 7, 2009Publication date: March 24, 2011Inventors: Hidekazu KASHIWASE, Hiroyuki SUZUKI, Mitsuhiro SHODA, Takayoshi OHTSU, Kiyoshi HASHIMOTO
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Patent number: 7911738Abstract: According to embodiments of the present invention, a magnetic head slider provided with a heater disposed near a read element to adjust flying height, is required to increase a thermal protrusion by heat generated by the heater without increasing a thermal protrusion attributable to heat generated by a recording current or environmental temperature. A magnetic head slider includes a thin-film head unit including a read element, a heater having a thin heating line extended above and below the read element, a write element, and an insulating layer of alumina (Al2O3) or the like insulating those components. The thin heating line of the heater is formed from a thin resistive film of NiCr or the like. The thin heating line of the heater is extended above and below the read element so as to meander in a zigzag shape in a direction perpendicular to the device forming surface. The thin heating line has a thickness between about 0.1 and 0.Type: GrantFiled: April 19, 2007Date of Patent: March 22, 2011Assignee: Hitachi Global Storage Technologies Netherlands, B.V.Inventors: Masayuki Kurita, Toshiya Shiramatsu, Masanori Tanabe, Takayoshi Ohtsu
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Publication number: 20100157483Abstract: In one embodiment, a magnetic head slider includes a write head having a single magnetic pole, the single magnetic pole having a main magnetic pole piece that extends to a medium opposing surface facing a magnetic disk. The main magnetic pole piece generates a recording magnetic field from a medium opposing surface side end face thereof being divided into an injection region and a non-injection region. Impurities which deteriorate magnetic properties are present in a higher concentration in the injection region relative to a concentration of the impurities in the non-injection region due to injection of the impurities in the injection region. The non-injection region has a narrower width at a leading end of the medium opposing surface side end face than at a trailing end of the medium opposing surface side end face.Type: ApplicationFiled: December 8, 2009Publication date: June 24, 2010Inventor: Takayoshi Ohtsu
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Patent number: 7738214Abstract: When exogenous noise is applied to the ground wire of a thin film magnetic head, crosstalk noise occurs in a lead line and a ground lines located near the ground wire. Embodiments in accordance with the present invention avoid this by providing a common terminal near the central portion of a thin film head portion. Write element terminals are connected to lines extending from a coil. Read element terminals are connected to lead wires extending from electrodes of a GMR element. A heater terminal is connected to a line extending from a heater. The common terminal is connected to a ground line of upper and lower shields via a resistor, to ground lines of electrodes via other resistors and to a ground line of upper and lower magnetic pole pieces of a write element via another resistor. A ground line of a slider, a ground line of the heater, and a ground line of the common terminal are all connected to a ground terminal.Type: GrantFiled: April 12, 2007Date of Patent: June 15, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Takayoshi Ohtsu
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Patent number: 7723982Abstract: A magnetic head suffers mechanical stresses by striking against a magnetic disc surface and dust, so that there are problems such as the reduction of reproduction output due to the mechanical stresses and the reversal of output polarity due to the mechanical stresses. Embodiments in accordance with the present invention relate to a method of testing reliability of reproduction elements of a magnetic head against outside stress. In a first step, a Giant Magnetoresistive (GMR) element on a row bar of the object of inspection, or a GMR element on a slider is measured for the output against external magnetic field. In the next step, prescribed shearing stress is applied with indenter to the edge where the GMR element-formed surface of the row bar or slider and the air-bearing surface are crossed. Then, output of the GMR element is measured again. Lastly, the outputs of the GMR element before and after application of stress are compared.Type: GrantFiled: January 19, 2007Date of Patent: May 25, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Shinji Sasaki, Makoto Torigoe, Takayoshi Ohtsu, Kouji Kataoka
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Patent number: 7719796Abstract: In a dynamic electric test, a head slider is to be fixed positively to a suspension and to be removable easily from the suspension in accordance with the result of the test. In one embodiment of the present invention a head gimbal assembly includes a head slider, a gimbal and a load beam. The head slider is disposed on a gimbal tongue and is held with an urging force of a resilient clamp at a position between the resilient clamp formed on the leading side of the head slider and connecting terminals formed on the opposite side thereof.Type: GrantFiled: June 30, 2006Date of Patent: May 18, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Haruhide Takahashi, Kousaku Wakatsuki, Shinobu Hagiya, Takayoshi Ohtsu, Kouji Kataoka, Yohtaroh Ichimura
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Patent number: 7684153Abstract: Crosstalk from a write signal on wiring on a suspension needs to be reduced since an ESD withstand voltage is decreased due to high sensitivity of a GMR head. In one embodiment, a terminal arrangement on an element-forming surface of a magnetic head slider consists of a ground terminal G, a read terminal R+, a read terminal R?, a write terminal W+ and a write terminal W? in order from the outside. With this terminal arrangement, the wiring order on a suspension consists of a read wire R?, a read wire R+, a ground line G, a write wire W? and a write wire W+ in an arrangement unlike the terminal arrangement. In other words, the ground line G is interposed between the write wires W and the read wires R.Type: GrantFiled: May 23, 2006Date of Patent: March 23, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Takayoshi Ohtsu, Nobumasa Nishiyama