Patents by Inventor Masayuki Takagishi

Masayuki Takagishi 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).

  • Patent number: 8363362
    Abstract: According to one embodiment, a magnetoresistive element includes a first ferromagnetic layer a magnetization direction of which is pinned, a second ferromagnetic layer a magnetization direction of which is changed depending on an external magnetic field, an intermediate layer arranged between the first ferromagnetic layer and the second ferromagnetic layer and including an insulating layer and a magnetic conductive column, an alloy layer formed between the magnetic conductive column in the intermediate layer and the second ferromagnetic layer and including at least one of FeCoAl and FeCoAlCu, and a pair of electrodes configured to supply a current perpendicularly to a film plane of a stacked film including the first ferromagnetic layer, the intermediate layer, the alloy layer and the second ferromagnetic layer.
    Type: Grant
    Filed: January 30, 2012
    Date of Patent: January 29, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiromi Fuke, Susumu Hashimoto, Masayuki Takagishi, Hitoshi Iwasaki
  • Patent number: 8331062
    Abstract: A magneto-resistance effect element includes: a first magnetization layer of which a magnetization is substantially fixed in one direction; a second magnetization layer of which a magnetization is rotated in accordance with an external magnetic field; an intermediate layer which contains insulating portions and magnetic metallic portions and which is provided between the first magnetic layer and the second magnetic layer; and a pair of electrodes to flow current in a direction perpendicular to a film surface of a multilayered film made of the first magnetic layer, the intermediate layer and the second magnetic layer; wherein the magnetic metallic portions of the intermediate layer contain non-ferromagnetic metal.
    Type: Grant
    Filed: November 8, 2011
    Date of Patent: December 11, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiromi Fuke, Susumu Hashimoto, Masayuki Takagishi, Hitoshi Iwasaki
  • Patent number: 8320079
    Abstract: It is made possible to reduce the write magnetic field generated from the main magnetic pole toward the spin torque oscillator, so as to reduce the variation in the oscillation characteristics of the spin torque oscillator, and reduce the current required for oscillation. The magnetic head assembly includes: a recording magnetic pole; a spin torque oscillator that has first and second magnetic layers, and an intermediate layer interposed between the first and second magnetic layers, the spin torque oscillator generating a high-frequency magnetic field by applying a current between the first and second magnetic layers; and a third magnetic layer that is placed adjacent to at least part of a side face of the second magnetic layer.
    Type: Grant
    Filed: June 17, 2009
    Date of Patent: November 27, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hitoshi Iwasaki, Kenichiro Yamada, Masayuki Takagishi, Tomomi Funayama, Masahiro Takashita, Mariko Shimizu, Soichi Oikawa, Katsuhiko Koui
  • Publication number: 20120275060
    Abstract: An example magnetic head includes a recording magnetic pole to generate a recording magnetic field; a spin torque oscillator formed in the vicinity of the recording magnetic pole; and a hard bias film for applying a magnetic field to the spin torque oscillator.
    Type: Application
    Filed: July 10, 2012
    Publication date: November 1, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Mariko Shimizu, Hitoshi Iwasaki, Kenichiro Yamada, Junichi Akiyama, Masayuki Takagishi, Tomomi Funayama, Masahiro Takashita
  • Publication number: 20120275061
    Abstract: According to one embodiment, a magnetic recording device includes a magnetic recording head and a magnetic recording medium. The magnetic recording head includes a main magnetic pole, a shield and a stacked structure. The main magnetic pole has a medium facing surface and a main magnetic pole side surface. The shield has a shield side surface. The stacked structure is provided between the main magnetic pole and shield, and includes first and second magnetic layers, and an intermediate layer. The magnetic recording medium includes a backing layer and a magnetic recording layer. A distance between an end portion of the medium facing surface on a side of the stacked structure and the backing layer is twice or more of a distance between the main magnetic pole side surface and the shield side surface.
    Type: Application
    Filed: April 30, 2012
    Publication date: November 1, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Masayuki TAKAGISHI, Hitoshi Iwasaki, Kenichiro Yamada, Katsuhiko Koui, Tomomi Funayama, Masahiro Takashita, Mariko Kitazaki, Soichi Oikawa
  • Publication number: 20120268844
    Abstract: An example magnetic writing head includes a main magnetic pole, a coil to generate an ampere magnetic field to magnetize the main magnetic pole to cause the magnetized main magnetic pole to generate a magnetic field, and a laminated body. The laminated body includes a first magnetic layer having a coercivity lower than the magnetic field applied by the main magnetic pole and a second magnetic layer having a coercivity lower than the magnetic field applied by the main magnetic pole.
    Type: Application
    Filed: July 3, 2012
    Publication date: October 25, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kenichiro Yamada, Hitoshi Iwasaki, Junichi Akiyama, Masayuki Takagishi, Tomomi Funayama, Masahiro Takashita, Mariko Shimizu, Shuichi Murakami, Tadashi Kai
  • Patent number: 8295009
    Abstract: An example magnetic recording head includes: a main magnetic pole; a laminated body; and a pair of electrodes. The laminated body includes a first magnetic layer having a coercivity lower than magnetic field applied by the main magnetic pole, a second magnetic layer having a coercivity lower than the magnetic field applied by the main magnetic pole, and an intermediate layer provided between the first magnetic layer and the second magnetic layer. The pair of electrodes is operable to pass a current through the laminated body.
    Type: Grant
    Filed: August 19, 2011
    Date of Patent: October 23, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kenichiro Yamada, Hitoshi Iwasaki, Junichi Akiyama, Masayuki Takagishi, Tomomi Funayama, Masahiro Takashita, Mariko Shimizu, Shuichi Murakami, Tadashi Kai
  • Publication number: 20120262821
    Abstract: According to one embodiment, a magnetic recording head includes a main pole configured to apply a recording magnetic field perpendicular to a recording medium, a trailing-shield pole opposed to the main pole with a recording gap therebetween, a high-frequency oscillator between the main pole and the trailing-shield pole in the recording gap, configured to produce a high-frequency magnetic field, a magnetic seed layer between the main pole and the high-frequency oscillator and in contact with the main pole, and a highly oriented magnetic layer of a soft magnetic material superposed on the magnetic seed layer between the main pole and the high-frequency oscillator and in contact with the high-frequency oscillator.
    Type: Application
    Filed: November 14, 2011
    Publication date: October 18, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tomoko Taguchi, Masayuki Takagishi, Katsuhiko Koui, Kenichiro Yamada, Hitoshi Iwasaki
  • Publication number: 20120262820
    Abstract: According to one embodiment, a magnetic head includes a main pole configured to apply a recording magnetic field to a recording layer of a recording medium, a return pole opposed to the main pole with a write gap therebetween, and a high-frequency oscillator between respective facing surfaces of the main pole and the return pole and configured to produce a high-frequency magnetic field. At least one of the main and return poles faces the high-frequency oscillator and includes a laminated structure portion includes a magnetic layer and a nonmagnetic layer laminated to one another.
    Type: Application
    Filed: November 14, 2011
    Publication date: October 18, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Takuya MATSUMOTO, Kenichiro YAMADA, Masayuki TAKAGISHI, Katsuhiko KOUI, Hitoshi IWASAKI
  • Publication number: 20120243127
    Abstract: According to one embodiment, a magnetic head includes a reproducing section. The reproducing section detects a medium magnetic field recorded in a magnetic recording medium. The reproducing section includes a stacked film and a magnetic field application unit. The stacked film includes a first magnetization layer and a second magnetization layer. The first magnetization layer has a perpendicular magnetic anisotropy. A magnetization of the first magnetization layer being is fixed. The second magnetization layer is stacked with the first magnetization layer and oscillates. The magnetic field application unit is stacked with the stacked film and applies a bias magnetic field having a component along the first axis to the stacked film. A resistance of the stacked film changes in accordance with the medium magnetic field when a current not less than a value at which the second magnetization layer oscillates is passed.
    Type: Application
    Filed: September 22, 2011
    Publication date: September 27, 2012
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hitoshi IWASAKI, Masayuki Takagishi, Kenichiro Yamada, Susumu Hashimoto, Yusuke Tomoda
  • Patent number: 8274765
    Abstract: A method of manufacturing a magnetoresistive element includes forming a metal layer on a first ferromagnetic layer, oxidizing the metal layer to form an oxide layer in which unoxidized metal is remained and a magnetic conduction column penetrating the oxide layer in a thickness direction and including at least a part of constituent elements of the first ferromagnetic layer, annealing a resultant structure at a higher temperature than a temperature at which the oxide layer is formed to convert at least a part of a periphery of the magnetic conduction column into a magnetic oxide including a part of constituent elements of the oxide layer and at least a part of constituent elements of the magnetic conduction column, and forming a second ferromagnetic layer.
    Type: Grant
    Filed: September 18, 2009
    Date of Patent: September 25, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiromi Fuke, Susumu Hashimoto, Masayuki Takagishi, Hitoshi Iwasaki
  • Patent number: 8270112
    Abstract: It is made possible to provide a magnetic head that generates a sufficient high-frequency magnetic field for assisting recording operations, and a magnetic recording device that includes the magnetic head. A magnetic head includes: a recording magnetic pole; a return yoke magnetically coupled to the recording magnetic pole; and at least two spin torque oscillators provided near the recording magnetic pole.
    Type: Grant
    Filed: September 16, 2008
    Date of Patent: September 18, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tomomi Funayama, Kenichiro Yamada, Masayuki Takagishi, Masahiro Takashita, Mariko Shimizu, Junichi Akiyama, Hitoshi Iwasaki
  • Patent number: 8264799
    Abstract: A magnetic device includes a first magnetic layer having at least one magnetic material layer, a second magnetic layer having at least one magnetic material layer, a first nonmagnetic layer provided between the first magnetic layer and the second magnetic layer, a third magnetic layer including a ferromagnetic material with a fixed magnetization direction, and a pair of electrodes. The pair of electrodes are operable to pass a current through a laminated body including the first and second magnetic layers, the nonmagnetic layer, and the third magnetic layer.
    Type: Grant
    Filed: April 25, 2008
    Date of Patent: September 11, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Junichi Akiyama, Kenichiro Yamada, Masayuki Takagishi, Hitoshi Iwasaki
  • Patent number: 8238058
    Abstract: According to one embodiment, a magnetic recording head includes a main magnetic pole, a shield, and a stacked structure body. The shield is provided to oppose the main magnetic pole. The stacked structure body is provided between the main magnetic pole and the shield. The stacked structure body includes a first magnetic layer, a second magnetic layer, and an intermediate layer. The first magnetic layer has coercivity lower than a magnetic field applied from the main magnetic pole. A size of a film surface of the second magnetic layer is larger than a size of a film surface of the first magnetic layer. The intermediate layer is provided between the first magnetic layer and the second magnetic layer and is made of a nonmagnetic material. A current is configured to pass between the first magnetic layer and the second magnetic layer.
    Type: Grant
    Filed: February 7, 2011
    Date of Patent: August 7, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Mariko Shimizu, Hitoshi Iwasaki, Kenichiro Yamada, Katsuhiko Koui, Masayuki Takagishi, Tomomi Funayama, Masahiro Takashita, Soichi Oikawa
  • Patent number: 8238060
    Abstract: A magnetic recording head includes: a main magnetic pole; a laminated body; and a pair of electrodes. The laminated body includes a first magnetic layer having a coercivity lower than magnetic field applied by the main magnetic pole, a second magnetic layer having a coercivity lower than the magnetic field applied by the main magnetic pole, and an intermediate layer provided between the first magnetic layer and the second magnetic layer. The pair of electrodes are operable to pass a current through the laminated body.
    Type: Grant
    Filed: May 14, 2010
    Date of Patent: August 7, 2012
    Inventors: Kenichiro Yamada, Hitoshi Iwasaki, Junichi Akiyama, Masayuki Takagishi, Tomomi Funayama, Masahiro Takashita, Mariko Shimizu, Shuichi Murakami, Tadashi Kai
  • Patent number: 8233230
    Abstract: According to one embodiment, a disk drive has a magnetic disk and a magnetic head having a spin-torque oscillator. The disk drive further has a head amplifier IC configured to supply a write signal and a drive signal to the magnetic head. The write signal corresponds to write data. The drive signal is supplied to generate a high-frequency magnetic field. The head amplifier IC continuously supplies a drive signal of normal level to the spin-torque oscillator, and supplies a drive signal of high level higher than the normal level, only for a prescribed time after the polarity inversion of the write signal.
    Type: Grant
    Filed: January 25, 2010
    Date of Patent: July 31, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Yano, Kazuhito Shimomura, Akihiko Takeo, Masayuki Takagishi, Kenichiro Yamada
  • Publication number: 20120182647
    Abstract: According to one embodiment, a magnetoresistive element includes a first ferromagnetic layer a magnetization direction of which is pinned, a second ferromagnetic layer a magnetization direction of which is changed depending on an external magnetic field, an intermediate layer arranged between the first ferromagnetic layer and the second ferromagnetic layer and including an insulating layer and a magnetic conductive column, an alloy layer formed between the magnetic conductive column in the intermediate layer and the second ferromagnetic layer and including at least one of FeCoAl and FeCoAlCu, and a pair of electrodes configured to supply a current perpendicularly to a film plane of a stacked film including the first ferromagnetic layer, the intermediate layer, the alloy layer and the second ferromagnetic layer.
    Type: Application
    Filed: January 30, 2012
    Publication date: July 19, 2012
    Inventors: Hiromi Fuke, Susumu Hashimoto, Masayuki Takagishi, Hitoshi Iwasaki
  • Publication number: 20120170151
    Abstract: According to one embodiment, a recording track has a surface modification layer in the surface region. This surface modification layer has an anisotropic magnetic field Hk reduced from that of a region between adjacent recording tracks.
    Type: Application
    Filed: March 14, 2012
    Publication date: July 5, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Soichi OIKAWA, Hitoshi IWASAKI, Masayuki TAKAGISHI, Kenichiro YAMADA, Tomomi FUNAYAMA, Masahiro TAKASHITA, Katsuhiko KOUI, Mariko SHIMIZU
  • Publication number: 20120154952
    Abstract: A magnetic recorder includes: a magnetic recording medium; a reproducing head; a magnetic recording head including: a main magnetic pole; a first magnetic layer containing a TM alloy; a second magnetic layer containing a TM alloy or an RE-TM alloy; a third magnetic layer containing an RE-TM alloy; a first intermediate layer provided between the first magnetic layer and the second magnetic layer; and a second intermediate layer provided between the second magnetic layer and the third magnetic layer; and a signal processing portion which performs signal writing into the magnetic recording medium by using the magnetic recording head and reading from the magnetic recording medium by using the reproducing head.
    Type: Application
    Filed: February 24, 2012
    Publication date: June 21, 2012
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Kenichiro YAMADA, Hitoshi IWASAKI, Masayuki TAKAGISHI, Tomomi FUNAYAMA, Masahiro TAKASHITA, Katsuhiko KOUI, Mariko KITAZAKI, Soichi OIKAWA
  • Publication number: 20120134046
    Abstract: According to one embodiment, a magnetic head includes a main pole configured to apply a recording magnetic field, a return pole opposed to a trailing side of the main pole across a write gap and configured to return magnetic flux from the main pole, a coil configured to excite magnetic flux in the main pole, a spin-torque oscillator located between respective facing surfaces of the return pole and an end portion of the main pole on the recording-medium side and configured to produce a high-frequency magnetic field, a current source configured to apply current to the spin-torque oscillator through the return and main poles, and a nonmagnetic layer provided in at least one of the poles and extending from a facing surface of the at least one of the poles, which faces the spin-torque oscillator, in a direction across the facing surface.
    Type: Application
    Filed: August 25, 2011
    Publication date: May 31, 2012
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Takuya MATSUMOTO, Tomoko Taguchi, Masayuki Takagishi