Patents by Inventor Masahiko Nakayama
Masahiko Nakayama 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: 8009465Abstract: A magnetoresistive element includes a first ferromagnetic layer having a first magnetization, the first magnetization having a first pattern when the magnetoresistive element is half-selected during a first data write, a second pattern when the magnetoresistive element is selected during a second data write, and a third pattern of residual magnetization, the first pattern being different from the second and third pattern, a second ferromagnetic layer having a second magnetization, and a nonmagnetic layer arranged between the first ferromagnetic layer and the second ferromagnetic layer and having a tunnel conductance changing dependent on a relative angle between the first magnetization and the second magnetization.Type: GrantFiled: February 2, 2009Date of Patent: August 30, 2011Assignee: Kabushiki Kaisha ToshibaInventors: Masahiko Nakayama, Tadashi Kai, Tatsuya Kishi, Yoshiaki Fukuzumi, Toshihiko Nagase, Sumio Ikegawa, Hiroaki Yoda
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Patent number: 8000198Abstract: A dual-layer structure phase-change type optical recording medium includes a substrate (1), a reflective layer (2), a first protective layer (3), a first recording layer (4), a second protective layer (5), a resin intermediate layer (6), a third protective layer (7), a heat release layer (8) made of Cu or a Cu alloy, a fourth protective layer (9), a second recording layer (10), a fifth protective layer (11) and a cover substrate (12). A product of a reflectance of a high-reflection part and a modulation after recording is a value equal to or higher than a lower limit value for reproduction.Type: GrantFiled: May 19, 2006Date of Patent: August 16, 2011Assignee: Ricoh Company, Ltd.Inventors: Michiaki Shinotsuka, Masaru Shinkai, Hiroyoshi Sekiguchi, Eiko Hibino, Masaki Kato, Katsuyuki Yamada, Masahiko Nakayama
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Publication number: 20110073970Abstract: According to one embodiment, a magnetoresistive element includes a first magnetic layer with a variable magnetization and an easy-axis in a perpendicular direction to a film surface, a second magnetic layer with an invariable magnetization and an easy-axis in the perpendicular direction, and a first nonmagnetic layer between the first and second magnetic layers. The first magnetic layer comprises a ferromagnetic material including an alloy in which Co and Pd, or Co and Pt are alternately laminated on an atomically close-packed plane thereof. The first magnetic layer has C-axis directing the perpendicular direction. And a magnetization direction of the first magnetic layer is changed by a current flowing through the first magnetic layer, the first nonmagnetic layer and the second magnetic layer.Type: ApplicationFiled: September 10, 2010Publication date: March 31, 2011Inventors: Tadashi Kai, Katsuya Nishiyama, Toshihiko Nagase, Masatoshi Yoshikawa, Eiji Kitagawa, Tadaomi Daibou, Makoto Nagamine, Masahiko Nakayama, Naoharu Shimomura, Hiroaki Yoda, Kei Yakushiji, Shinji Yuasa, Hitoshi Kubota, Taro Nagahama, Akio Fukushima, Koji Ando
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Patent number: 7894246Abstract: A magnetoresistive element includes: a magnetization free layer having a first plane and a second plane located on the opposite side from the first plane, and having a variable magnetization direction; a magnetization pinned layer provided on the first plane side of the magnetization free layer, and having a pinned magnetization direction; a first tunnel barrier layer provided between the magnetization free layer and the magnetization pinned layer; a second tunnel barrier layer provided on the second plane of the magnetization free layer; and a non-magnetic layer provided on a plane on the opposite side of the second tunnel barrier layer from the magnetization free layer. The magnetization direction of the magnetization free layer is variable by applying current between the magnetization pinned layer and the non-magnetic layer, and a resistance ratio between the first tunnel barrier layer and the second tunnel barrier layer is in a range of 1:0.25 to 1:4.Type: GrantFiled: January 15, 2008Date of Patent: February 22, 2011Assignee: Kabushiki Kaisha ToshibaInventors: Tomomasa Ueda, Hisanori Aikawa, Masatoshi Yoshikawa, Naoharu Shimomura, Masahiko Nakayama, Sumio Ikegawa, Keiji Hosotani, Makoto Nagamine
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Patent number: 7875903Abstract: A magnetic memory device includes a magnetoresistive element and a first wiring layer. The magnetoresistive element includes a fixed layer, a recording layer, and a non-magnetic layer interposed therebetween. The first wiring layer extends in a first direction and generates a magnetic field for recording data in the magnetoresistive element. The recording layer includes a base portion extending in a second direction rotated from the first direction by an angle falling within a range of more than 0° to not more than 20°, and first and second projections projecting from the first and second sides of the base portion in a third direction perpendicular to the second direction. The third and fourth sides of the base portion are inclined with respect to the third direction in the same rotational direction as a rotational direction in which the second direction is rotated.Type: GrantFiled: February 26, 2008Date of Patent: January 25, 2011Assignee: Kabushiki Kaisha ToshibaInventors: Masahiko Nakayama, Tadashi Kai, Sumio Ikegawa, Yoshiaki Fukuzumi, Tatsuya Kishi
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Publication number: 20100315864Abstract: A magnetoresistive element includes: a magnetization free layer having a first plane and a second plane located on the opposite side from the first plane, and having a variable magnetization direction; a magnetization pinned layer provided on the first plane side of the magnetization free layer, and having a pinned magnetization direction; a first tunnel barrier layer provided between the magnetization free layer and the magnetization pinned layer; a second tunnel barrier layer provided on the second plane of the magnetization free layer; and a non-magnetic layer provided on a plane on the opposite side of the second tunnel barrier layer from the magnetization free layer. The magnetization direction of the magnetization free layer is variable by applying current between the magnetization pinned layer and the non-magnetic layer, and a resistance ratio between the first tunnel barrier layer and the second tunnel barrier layer is in a range of 1:0.25 to 1:4.Type: ApplicationFiled: August 5, 2010Publication date: December 16, 2010Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Tomomasa UEDA, Hisanori Aikawa, Masatoshi Yoshikawa, Naoharu Shimomura, Masahiko Nakayama, Sumio Ikegawa, Keiji Hosotani, Makoto Nagamine
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Publication number: 20100238717Abstract: A magnetoresistive device includes: a magnetic recording layer including a first magnetic layer having perpendicular magnetic anisotropy, and a second magnetic layer having in-plane magnetic anisotropy and being exchange-coupled to the first magnetic layer, Curie temperature of the second magnetic layer being lower than Curie temperature of the first magnetic layer, and the magnetic recording layer having a magnetization direction perpendicular to a film plane; a magnetic reference layer having a magnetization direction which is perpendicular to a film plane and is invariable; and a nonmagnetic layer provided between the magnetic recording layer and the magnetic reference layer. The magnetization direction of the magnetic recording layer is changeable by spin-polarized electrons caused by flowing current between the magnetic recording layer and the magnetic reference layer in a direction perpendicular to the film plane.Type: ApplicationFiled: March 2, 2010Publication date: September 23, 2010Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Masahiko NAKAYAMA, Hiroaki Yoda, Tadashi Kai, Hisanori Aikawa, Katsuya Nishiyama, Jyunichi Ozeki
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Patent number: 7770916Abstract: A front face distance is obtained by measuring the position of a front face of an instrument panel held by an end effecter of a robot. An error on an optical axis, at the position of the front face is obtained based on the front face distance. Based on the error, the position of the instrument panel is adjusted so that a focal point of a laser meets the position at a predetermined depth defined with the front face as the standard. A back face of the instrument panel is irradiated with a laser to form a fine hole of a fragile section.Type: GrantFiled: March 6, 2006Date of Patent: August 10, 2010Assignee: Honda Motor Co., Ltd.Inventors: Tokuji Okumura, Kazushiro Wakabayashi, Mitsutaka Igaue, Hisashi Masuda, Yutaka Ebato, Masahiko Nakayama
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Publication number: 20100118600Abstract: A magnetoresistive element which records information by supplying spin-polarized electrons to a magnetic material, includes a first pinned layer which is made of a magnetic material and has a first magnetization directed in a direction perpendicular to a film surface, a free layer which is made of a magnetic material and has a second magnetization directed in the direction perpendicular to the film surface, the direction of the second magnetization reversing by the spin-polarized electrons, and a first nonmagnetic layer which is provided between the first pinned layer and the free layer. A saturation magnetization Ms of the free layer satisfies a relationship 0?Ms<?{square root over ( )}{Jw/(6?At)}. Jw is a write current density, t is a thickness of the free layer, A is a constant.Type: ApplicationFiled: January 12, 2010Publication date: May 13, 2010Inventors: Toshihiko NAGASE, Masatoshi Yoshikawa, Eiji Kitagawa, Masahiko Nakayama, Tadashi Kai, Tatsuya Kishi, Hiroaki Yoda
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Publication number: 20100080050Abstract: A magnetic memory includes a magnetoresistive effect device comprising: a first ferromagnetic layer that has magnetic anisotropy in a direction perpendicular to a film plane thereof; a first nonmagnetic layer that is provided on the first ferromagnetic layer; a first reference layer that is provided on the first nonmagnetic layer, has magnetic anisotropy in a direction perpendicular to a film plane thereof, has magnetization antiparallel to a magnetization direction of the first ferromagnetic layer, and has a film thickness that is 1/5.2 to 1/1.Type: ApplicationFiled: September 10, 2009Publication date: April 1, 2010Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Jyunichi OZEKI, Naoharu SHIMOMURA, Sumio IKEGAWA, Tadashi KAI, Masahiko NAKAYAMA, Hisanori AIKAWA, Tatsuya KISHI, Hiroaki YODA, Eiji KITAGAWA, Masatoshi YOSHIKAWA
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Publication number: 20100073998Abstract: A data writing method for a magnetoresistive effect element of an aspect of the present invention including generating a write current in which a falling period from the start of a falling edge to the end of the falling edge is longer than a rising period from the start of a rising edge to the end of the rising edge, and flowing the write current through the magnetoresistive effect element which comprises a first magnetic layer having an invariable magnetizing direction, a second magnetic layer having a variable magnetizing direction, and a tunnel barrier layer provided between the first magnetic layer and the second magnetic layer, to change the magnetizing direction of the second magnetic layer.Type: ApplicationFiled: September 17, 2009Publication date: March 25, 2010Inventors: Masahiko NAKAYAMA, Hisanori Aikawa, Tsuneo Inaba, Kenji Tsuchida, Sumio Ikegawa, Hiroaki Yoda, Naoharu Shimomura
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Patent number: 7663197Abstract: A magnetoresistive element which records information by supplying spin-polarized electrons to a magnetic material, includes a first pinned layer which is made of a magnetic material and has a first magnetization directed in a direction perpendicular to a film surface, a free layer which is made of a magnetic material and has a second magnetization directed in the direction perpendicular to the film surface, the direction of the second magnetization reversing by the spin-polarized electrons, and a first nonmagnetic layer which is provided between the first pinned layer and the free layer. A saturation magnetization Ms of the free layer satisfies a relationship 0?Ms<?{square root over ( )}{Jw/(6?At)}. Jw is a write current density, t is a thickness of the free layer, A is a constant.Type: GrantFiled: September 22, 2006Date of Patent: February 16, 2010Assignee: Kabushiki Kaisha ToshibaInventors: Toshihiko Nagase, Masatoshi Yoshikawa, Eiji Kitagawa, Masahiko Nakayama, Tadashi Kai, Tatsuya Kishi, Hiroaki Yoda
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Publication number: 20100020592Abstract: A first magnetic layer has a magnetization fixed along one direction. A first nonmagnetic layer on the first magnetic layer functions as a first tunnel barrier. A second magnetic layer on the first nonmagnetic layer has a magnetization whose direction can be reversed by spin transfer current injection. A second nonmagnetic layer on the second magnetic layer functions as a second tunnel barrier. A third magnetic layer on the second nonmagnetic layer has a magnetization whose direction can be reversed by spin transfer through current injection at a current density different from the second magnetic layer. First magnetic, first nonmagnetic layer, and second magnetic layers exhibit a first magnetoresistive effect. Second magnetic, second nonmagnetic, and third magnetic layers exhibit a second magnetoresistive effect. A magnetoresistive effect element records and reads out data of at least three levels based on a synthetic resistance from the first and second magnetoresistive effects.Type: ApplicationFiled: July 27, 2009Publication date: January 28, 2010Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Keiji HOSOTANI, Masahiko NAKAYAMA
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Patent number: 7640033Abstract: A transmission power control information section issues an indication to a variable gain control amplifier at a predetermined control cycle. The variable gain control amplifier controls a transmission power according to the given indication amount. An adjustment amount generator adjusts the indication amount to be given to the variable gain control amplifier while maintaining a change in the transmission power between an indication from a transmission power control information section and subsequent indication within a predetermined range.Type: GrantFiled: October 13, 2005Date of Patent: December 29, 2009Assignee: NEC CorporationInventor: Masahiko Nakayama
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Patent number: 7599156Abstract: A magnetoresistive element according to an example of the present invention has a stacked structure comprised first and second ferromagnetic layers and a nonmagnetic layer disposed between these ferromagnetic layers, and a planar shape of at least one of the first and second ferromagnetic layers has a shape formed by combining two or more parts each having a shape of a character C.Type: GrantFiled: October 6, 2005Date of Patent: October 6, 2009Assignee: Kabushiki Kaisha ToshibaInventors: Tatsuya Kishi, Masahiko Nakayama, Yoshiaki Fukuzumi, Tadashi Kai
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Publication number: 20090244792Abstract: A magnetoresistance effect element includes: a first ferromagnetic layer having invariable magnetization perpendicular to a film plane; a second ferromagnetic layer having variable magnetization perpendicular to the film plane; a first nonmagnetic layer interposed between the first ferromagnetic layer and the second ferromagnetic layer; a third ferromagnetic layer provided on an opposite side of the second ferromagnetic layer from the first nonmagnetic layer, and having variable magnetization parallel to the film plane; and a second nonmagnetic layer interposed between the second and third ferromagnetic layers.Type: ApplicationFiled: March 3, 2009Publication date: October 1, 2009Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Masahiko NAKAYAMA, Tadashi KAI, Sumio IKEGAWA, Hiroaki YODA, Tatsuya KISHI
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Publication number: 20090224342Abstract: A magnetoresistive effect element includes a reference layer, a recording layer, and a nonmagnetic layer. The reference layer is made of a magnetic material, has an invariable magnetization which is perpendicular to a film surface. The recording layer is made of a magnetic material, has a variable magnetization which is perpendicular to the film surface. The nonmagnetic layer is arranged between the reference layer and the recording layer. A critical diameter which is determined by magnetic anisotropy, saturation magnetization, and switched connection of the recording layer and has a single-domain state as a unique stable state or a critical diameter which has a single-domain state as a unique stable state and is inverted while keeping the single-domain state in an inverting process is larger than an element diameter of the magnetoresistive effect element.Type: ApplicationFiled: October 9, 2008Publication date: September 10, 2009Inventors: Masahiko NAKAYAMA, Kay Yakushiji, Sumio Ikegawa, Shinji Yuasa, Tadashi Kai, Toshihiko Nagase, Minoru Amano, Hisanori Aikawa, Tatsuya Kishi, Hiroaki Yoda
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Patent number: 7577183Abstract: There is a problem that a delay is caused in signal processing by exercising control so as to cause amplitude peaks in a transmission signal to fall in a prescribed range. A transmission apparatus for conducting wireless communication makes a decision whether a specific pattern which causes a peak exceeding a predetermined amplitude range to be generated in frequency characteristics of a transmission signal is included in a transmission code sequence for forming the transmission signal. And the transmission apparatus selects filter coefficients which prescribe a band limiting factor for the frequency characteristics of the transmission signal, on the basis of a result of the decision, and conducts filtering on the transmission code sequence by using the selected filter coefficients.Type: GrantFiled: July 27, 2005Date of Patent: August 18, 2009Assignee: NEC CorporationInventor: Masahiko Nakayama
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Publication number: 20090166322Abstract: A magneto-resistive element according to an aspect of the present invention includes a free layer whose magnetized state changes and a pinned layer whose magnetized state is fixed. The free layer comprises first and second ferromagnetic layers and a non-magnetic layer which is arranged between the first and second ferromagnetic layers. An intensity of exchange coupling between the first and second ferromagnetic layers is set so that an astroid curve in a hard axis direction opens.Type: ApplicationFiled: January 29, 2009Publication date: July 2, 2009Inventors: Sumio IKEGAWA, Masahiko Nakayama, Tadashi Kai, Eiji Kitagawa, Hiroaki Yoda
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Publication number: 20090140358Abstract: A magnetoresistive element includes a first ferromagnetic layer having a first magnetization, the first magnetization having a first pattern when the magnetoresistive element is half-selected during a first data write, a second pattern when the magnetoresistive element is selected during a second data write, and a third pattern of residual magnetization, the first pattern being different from the second and third pattern, a second ferromagnetic layer having a second magnetization, and a nonmagnetic layer arranged between the first ferromagnetic layer and the second ferromagnetic layer and having a tunnel conductance changing dependent on a relative angle between the first magnetization and the second magnetization.Type: ApplicationFiled: February 2, 2009Publication date: June 4, 2009Inventors: Masahiko Nakayama, Tadashi Kai, Tatsuya Kishi, Yoshiaki Fukuzumi, Toshihiko Nagase, Sumio Ikegawa, Hiroaki Yoda