Patents by Inventor Reiko Kondoh
Reiko Kondoh 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: 6483673Abstract: A GMR element part is formed of a laminated structure which comprises at least one pair of ferromagnetic layers and a nonmagnetic intermediate layer interposed between the pair of ferromagnetic layers. Signal magnetic field detecting ferromagnetic layers will be optionally disposed one each outside the pair of ferromagnetic layers. The GMR element part consists of a laminated structure which is provided with one pair of GMR ferromagnetic layers opposed to each other across a nonmagnetic intermediate layer or a laminated structure which is provided with one pair of GMR ferromagnetic layer opposed to each other across a nonmagnetic intermediate layer and at least one low-permeability ferromagnetic layer disposed there between through the medium of a nonmagnetic intermediate layer.Type: GrantFiled: May 28, 1998Date of Patent: November 19, 2002Assignee: Kabushiki Kaisha ToshibaInventors: Hitoshi Iwasaki, Yuichi Ohsawa, Reiko Kondoh, Yuzo Kamiguchi, Susumu Hashimoto, Tomomi Funayama, Hiromi Fuke, Junichi Akiyama, Kazuhiro Saito
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Patent number: 6395388Abstract: The present invention provides an exchange coupling film having a stacked-film-structure consisting of a ferromagnetic film made of at least one material of Fe, Co and Ni, and an antiferromagnetic film, wherein the exchange coupling film made of a ferromagnetic material to which an element is added, is provided at the interface between the ferromagnetic film and the antiferromagnetic film so as to improve the lattice matching, which results in the enhancement of the exchange coupling force, and a magnetoresistance effect element including such an exchange coupling film as described above, and an electrode for supplying a current to the ferromagnetic film which constitutes the exchange coupling film.Type: GrantFiled: November 17, 1999Date of Patent: May 28, 2002Assignee: Kabushiki Kaisha ToshibaInventors: Hitoshi Iwasaki, Yuichi Ohsawa, Reiko Kondoh, Susumu Hashimoto, Atsuhito Sawabe, Yuzo Kamiguchi, Masashi Sahashi, Hiromi Fuke
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Patent number: 6368706Abstract: The present invention provides an exchange coupling film having a stacked-film-structure consisting of a ferromagnetic film made of at least one material of Fe, Co and Ni, and an antiferromagnetic film, wherein the exchange coupling film made of a ferromagnetic material to which an element is added, is provided at the interface between the ferromagnetic film and the antiferromagnetic film so as to improve the lattice matching, which results in the enhancement of the exchange coupling force, and a magnetoresistance effect element including such an exchange coupling film as described above, and an electrode for supplying a current to the ferromagnetic film which constitutes the exchange coupling film.Type: GrantFiled: July 8, 1998Date of Patent: April 9, 2002Assignee: Kabushiki Kaisha ToshibaInventors: Hitoshi Iwasaki, Yuichi Ohsawa, Reiko Kondoh, Susumu Hashimoto, Atsuhito Sawabe, Yuzo Kamiguchi, Masashi Sahashi, Hiromi Fuke
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Patent number: 6327121Abstract: The invention provides a GMR head in which an adequate bias point may be set for the free magnetic layer 12 of the GMR head by suppressing the static magnetic field in the free magnetic layer which arises from a pinned magnetic layer 14 of the GMR head. The GMR head comprises a sensor section 10, a magnetic field correction section 20 disposed laterally adjacent to the sensor section 10. The sensor section 10 includes, in addition to the free magnetic layer 12 and the pinned magnetic layer 14, an intermediate layer 13 and an anti-ferromagnetic layer 15 in a specific arrangement. The magnetic field correction section 20 may have the same structure as the sensor section 10.Type: GrantFiled: November 13, 1998Date of Patent: December 4, 2001Assignee: Fujitsu LimitedInventors: Keiichi Nagasawa, Yutaka Shimizu, Hitoshi Kishi, Atsushi Tanaka, Reiko Kondoh
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Patent number: 6172858Abstract: The present invention provides a thin film head having a magnetoresistance effect element which includes at least two magnetic films, a nonmagnetic film sandwiched between the magnetic films, and leads connected to the magnetoresistance effect element wherein the width of one of the magnetic films, which essentially responds to a signal magnetic field, is not more than a distance between leads. The present invention provides a thin film head having a magnetoresistance effect element which includes at least two magnetic films and a nonmagnetic film sandwiched between the magnetic films, which makes use of a change in magnetic resistance caused by spin-dependent scattering, wherein at least a portion of one magnetic films, which essentially respond to a signal magnetic field extends in a direction same as that of the signal magnetic field.Type: GrantFiled: January 7, 2000Date of Patent: January 9, 2001Assignee: Kabushiki Kaisha ToshibaInventors: Hiroaki Yoda, Yuichi Ohsawa, Kohichi Tateyama, Reiko Kondoh, Toshihiko Ohta, Junichi Akiyama, Hitoshi Iwasaki
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Patent number: 6159593Abstract: The present invention provides an exchange coupling film having a stacked-film-structure consisting of a ferromagnetic film made of at least one material of Fe, Co and Ni, and an antiferromagnetic film, wherein the exchange coupling film made of a ferromagnetic material to which an element is added, is provided at the interface between the ferromagnetic film and the antiferromagnetic film so as to improve the lattice matching, which results in the enhancement of the exchange coupling force, and a magnetoresistance effect element including such an exchange coupling film as described above, and an electrode for supplying a current to the ferromagnetic film which constitutes the exchange coupling film.Type: GrantFiled: April 16, 1998Date of Patent: December 12, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Hitoshi Iwasaki, Yuichi Ohsawa, Reiko Kondoh, Susumu Hashimoto, Atsuhito Sawabe, Yuzo Kamiguchi, Masashi Sahashi, Hiromi Fuke
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Patent number: 6157525Abstract: A magnetoresistive head includes a magnetoresistive effect element including a magnetoresistive film, which has a first ferromagnetic layer and a second ferromagnetic layer separated by a nonmagnetic layer. A magnetization direction of the first ferromagnetic layer is perpendicular to a magnetization direction of the second ferromagnetic layer when a signal magnetic field is zero. A pair of bias layers provide magnetic bias, and a top surface of each of the pair of bias layers faces a lower surface of each edge region of the magnetoresistive film. A pair of lead electrodes produce a current flow through the magnetoresistive film, and each of the pair of lead electrodes is disposed on or above the magnetoresistive film.Type: GrantFiled: June 29, 1999Date of Patent: December 5, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Hitoshi Iwasaki, Reiko Kondoh, Hiroaki Yoda, Yuichi Ohsawa, Yuzo Kamiguchi, Susumu Hashimoto
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Patent number: 6046891Abstract: The present invention provides a thin film head having a magnetoresistance effect element which includes at least two magnetic films, a nonmagnetic film sandwiched between the magnetic films, and leads connected to the magnetoresistance effect element wherein the width of one of the magnetic films, which essentially responds to a signal magnetic field, is not more than a distance between leads. The present invention provides a thin film head having a magnetoresistance effect element which includes at least two magnetic films and a nonmagnetic film sandwiched between the magnetic films, which makes use of a change in magnetic resistance caused by spin-dependent scattering, wherein at least a portion of one magnetic films, which essentially respond to a signal magnetic field, extends in a direction same as that of the signal magnetic field.Type: GrantFiled: February 11, 1998Date of Patent: April 4, 2000Assignee: Kabushiki Kaisha ToshibaInventors: Hiroaki Yoda, Yuichi Ohsawa, Kohichi Tateyama, Reiko Kondoh, Toshihiko Ohta, Junichi Akiyama, Hitoshi Iwasaki
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Patent number: 5991125Abstract: A magnetoresistive head includes a magnetoresistive effect element including a magnetoresistive film, which has a first ferromagnetic layer and a second ferromagnetic layer separated by a nonmagnetic layer. A magnetization direction of the first ferromagnetic layer is perpendicular to a magnetization direction of the second ferromagnetic layer when a signal magnetic field is zero. A pair of bias layers provide magnetic bias, and a top surface of each of the pair of bias layers faces a lower surface of each edge region of the magnetoresistive film. A pair of lead electrodes produce a current flow through the magnetoresistive film, and each of the pair of lead electrodes is disposed on or above the magnetoresistive film.Type: GrantFiled: May 6, 1997Date of Patent: November 23, 1999Assignee: Kabushiki Kaisha ToshibaInventors: Hitoshi Iwasaki, Reiko Kondoh, Hiroaki Yoda, Yuichi Ohsawa, Yuzo Kamiguchi, Susumu Hashimoto
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Patent number: 5905611Abstract: The present invention provides a thin film head having a magnetoresistance effect element which includes at least two magnetic films, a nonmagnetic film sandwiched between the magnetic films, and leads connected to the magnetoresistance effect element wherein the width of one of the magnetic films, which essentially responds to a signal magnetic field, is not more than a distance between leads. The present invention provides a thin film head having a magnetoresistance effect element which includes at least two magnetic films and a nonmagnetic film sandwiched between the magnetic films, which makes use of a change in magnetic resistance caused by spin-dependent scattering, wherein at least a portion of one magnetic films, which essentially respond to a signal magnetic field extends in a direction same as that of the signal magnetic field.Type: GrantFiled: May 22, 1997Date of Patent: May 18, 1999Assignee: Kabushiki Kaisha ToshibaInventors: Hiroaki Yoda, Yuichi Ohsawa, Kohichi Tateyama, Reiko Kondoh, Toshihiko Ohta, Junichi Akiyama, Hitoshi Iwasaki
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Patent number: 5896251Abstract: A magnetoresistance effect head comprises a magnetoresistance effect element portion including a magnetoresistance effect film having a magnetic field response portion, a magnetic field providing film for providing the magnetoresistance effect film with a bias magnetic field, and a conductor film for supplying a current to the magnetoresistance effect film, wherein the magnetoresistance effect element portion has a laminate structure portion being composed of at least the conductor film, the magnetic field providing film, and the magnetoresistance effect film layered in this order at other than the magnetic field response portion. The magnetoresistance effect head is obtained by patterning a laminate film composed of a conductor film and a magnetic field providing film corresponding to a lead shape, forming an MR film, and patterning the MR film corresponding to a lead shape and the shape of a magnetic field response portion.Type: GrantFiled: December 22, 1995Date of Patent: April 20, 1999Assignee: Kabushiki Kaisha ToshibaInventors: Yuichi Ohsawa, Hiroaki Yoda, Reiko Kondoh
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Patent number: 5828525Abstract: A GMR element part is formed of a laminated structure which comprises at least one pair of ferromagnetic layers and a nonmagnetic intermediate layer interposed between the pair of ferromagnetic layers. Signal magnetic field detecting ferromagnetic layers will be optionally disposed one each outside the pair of ferromagnetic layers. The GMR element part consists of a laminated structure which is provided with one pair of GMR ferromagnetic layers opposed to each other across a nonmagnetic intermediate layer or a laminated structure which is provided with one pair of GMR ferromagnetic layer opposed to each other across a nonmagnetic intermediate layer and at least one low-permeability ferromagnetic layer disposed there between through the medium of a nonmagnetic intermediate layer.Type: GrantFiled: March 10, 1995Date of Patent: October 27, 1998Assignee: Kabushiki Kaisha ToshibaInventors: Hitoshi Iwasaki, Yuichi Ohsawa, Reiko Kondoh, Yuzo Kamiguchi, Susumu Hashimoto, Tomomi Funayama, Hiromi Fuke, Junichi Akiyama, Kazuhiro Saito
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Patent number: 5780176Abstract: The present invention provides an exchange coupling film having a stacked-film-structure consisting of a ferromagnetic film made of at least one material of Fe, Co and Ni, and an antiferromagnetic film, wherein the exchange coupling film made of a ferromagnetic material to which an element is added, is provided at the interface between the ferromagnetic film and the antiferromagnetic film so as to improve the lattice matching, which results in the enhancement of the exchange coupling force, and a magnetoresistance effect element including such an exchange coupling film as described above, and an electrode for supplying a current to the ferromagnetic film which constitutes the exchange coupling film.Type: GrantFiled: June 28, 1996Date of Patent: July 14, 1998Assignee: Kabushiki Kaisha ToshibaInventors: Hitoshi Iwasaki, Yuichi Ohsawa, Reiko Kondoh, Susumu Hashimoto, Atsuhito Sawabe, Yuzo Kamiguchi, Masashi Sahashi, Hiromi Fuke
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Patent number: 5738946Abstract: It is an object of the present invention to provide a magnetoresistance effect element which has a film with a spin valve structure or an artificial lattice film having good soft magnetic characteristics, and which can be applied to a high-sensitivity magnetic head. The present invention provides a magneto-resistance effect element including a stacked film formed on a substrate by sequentially stacking a ferromagnetic film containing as its main constituents at least one elements selected from the group consisting of Co, Fe, and Ni, a nonmagnetic film, and the ferromagnetic film, wherein the two ferromagnetic films are not coupled with each other, and the closest packed plane of each ferromagnetic film is oriented in a direction perpendicular to the film surface.Type: GrantFiled: May 23, 1996Date of Patent: April 14, 1998Assignee: Kabushiki Kaisha ToshibaInventors: Hitoshi Iwasaki, Yuichi Ohsawa, Reiko Kondoh, Susumu Hashimoto, Atsuhito Sawabe, Yuzo Kamiguchi, Masashi Sahashi
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Patent number: 5725963Abstract: It is an object of the present invention to provide a magnetoresistance effect element which has a film with a spin valve structure or an artificial lattice film having good soft magnetic characteristics, and which can be applied to a high-sensitivity magnetic head. The present invention provides a magnetoresistance effect element including a stacked film formed on a substrate by sequentially stacking a ferromagnetic film containing as its main constituents at least one elements selected from the group consisting of Co, Fe, and Ni, a nonmagnetic film, and the ferromagnetic film, wherein the two ferromagnetic films are not coupled with each other, and the closest packed plane of each ferromagnetic film is oriented in a direction perpendicular to the film surface.Type: GrantFiled: May 23, 1996Date of Patent: March 10, 1998Assignee: Kabushiki Kaisha ToshibaInventors: Hitoshi Iwasaki, Yuichi Ohsawa, Reiko Kondoh, Susumu Hashimoto, Atsuhito Sawabe, Yuzo Kamiguchi, Masashi Sahashi
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Patent number: 5702832Abstract: It is an object of the present invention to provide a magnetoresistance effect element which has a film with a spin valve structure or an artificial lattice film having good soft magnetic characteristics, and which can be applied to a high-sensitivity magnetic head. The present invention provides a magnetoresistance effect element including a stacked film formed on a substrate by sequentially stacking a ferromagnetic film containing as its main constituents at least one elements selected from the group consisting of Co, Fe, and Ni, a nonmagnetic film, and the ferromagnetic film, wherein the two ferromagnetic films are not coupled with each other, and the closest packed plane of each ferromagnetic film is oriented in a direction perpendicular to the film surface.Type: GrantFiled: May 23, 1996Date of Patent: December 30, 1997Assignee: Kabushiki Kaisha ToshibaInventors: Hitoshi Iwasaki, Yuichi Ohsawa, Reiko Kondoh, Susumu Hashimoto, Atsuhito Sawabe, Yuzo Kamiguchi, Masashi Sahashi
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Patent number: 5698335Abstract: It is an object of the present invention to provide a magnetoresistance effect element which has a film with a spin valve structure or an artificial lattice film having good soft magnetic characteristics, and which can be applied to a high-sensitivity magnetic head. The present invention provides a magnetoresistance effect element including a stacked film formed on a substrate by sequentially stacking a ferromagnetic film containing as its main constituents at least one elements selected from the group consisting of Co, Fe, and Ni, a nonmagnetic film, and the ferromagnetic film, wherein the two ferromagnetic films are not coupled with each other, and the closest packed plane of each ferromagnetic film is oriented in a direction perpendicular to the film surface.Type: GrantFiled: May 23, 1996Date of Patent: December 16, 1997Assignee: Kabushiki Kaisha ToshibaInventors: Hitoshi Iwasaki, Yuichi Ohsawa, Reiko Kondoh, Susumu Hashimoto, Atsuhito Sawabe, Yuzo Kamiguchi, Masashi Sahashi
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Patent number: 5688605Abstract: It is an object of the present invention to provide a magnetoresistance effect element which has a film with a spin valve structure or an artificial lattice film having good soft magnetic characteristics, and which can be applied to a high-sensitivity magnetic head. The present invention provides a magnetoresistance effect element including a stacked film formed on a substrate by sequentially stacking a ferromagnetic film containing as its main constituents at least one elements selected from the group consisting of Co, Fe, and Ni, a nonmagnetic film, and the ferromagnetic film, wherein the two ferromagnetic films are not coupled with each other, and the closest packed plane of each ferromagnetic film is oriented in a direction perpendicular to the film surface.Type: GrantFiled: May 23, 1996Date of Patent: November 18, 1997Assignee: Kabushiki Kaisha ToshibaInventors: Hitoshi Iwasaki, Yuichi Ohsawa, Reiko Kondoh, Susumu Hashimoto, Atsuhito Sawabe, Yuzo Kamiguchi, Masashi Sahashi
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Patent number: 5587026Abstract: Disclosed is a ferromagnetic film consisting of an alloy represented by a formula Co.sub.x Fe.sub.y T.sub.z, where T is an element selected from the group consisting of Ta, Ti, Zr, Hf, Mo, and W, and x, y, and z represent atomic % and satisfy 73<x<94, 5<y<15, 1<z<12, and x+y+z=100. This ferromagnetic film has high saturation magnetic flux density, and soft magnetism not to be degraded by high-temperature annealing, and which is suitably applied to a magnetic head.Type: GrantFiled: July 5, 1995Date of Patent: December 24, 1996Assignee: Kabushiki Kaisha ToshibaInventors: Hitoshi Iwasaki, Yuichi Ohsawa, Reiko Kondoh
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Patent number: 5549978Abstract: It is an object of the present invention to provide a magnetoresistance effect element which has a film with a spin valve structure or an artificial lattice film having good soft magnetic characteristics, and which can be applied to a high-sensitivity magnetic head. The present invention provides a magnetoresistance effect element including a stacked film formed on a substrate by sequentially stacking a ferromagnetic film containing as its main constituents at least one elements selected from the group consisting of Co, Fe, and Ni, a nonmagnetic film, and the ferromagnetic film, wherein the two ferromagnetic films are not coupled with each other, and the closest packed plane of each ferromagnetic film is oriented in a direction perpendicular to the film surface.Type: GrantFiled: November 1, 1993Date of Patent: August 27, 1996Assignee: Kabushiki Kaisha ToshibaInventors: Hitoshi Iwasaki, Yuichi Ohsawa, Reiko Kondoh, Susumu Hashimoto, Atsuhito Sawabe, Yuzo Kamiguchi, Masashi Sahashi