Patents by Inventor Masashi Michijima

Masashi Michijima 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: 6628542
    Abstract: A magnetoresistive device has a first magnetic layer, a nonmagnetic layer, and a second magnetic layer, with the nonmagnetic layer being interposed between the first and second magnetic layers, the first and second magnetic layers having perpendicular magnetic anisotropy. Either the first magnetic layer or the second magnetic layer is made of a ferrimagnetic that has a compensation point around a room temperature.
    Type: Grant
    Filed: January 5, 2001
    Date of Patent: September 30, 2003
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hidekazu Hayashi, Masashi Michijima, Ryoji Minakata
  • Patent number: 6519179
    Abstract: A closed magnetic circuit layer is formed on a ferromagnetic layer serving as a memory layer of a magnetic tunnel junction device, in such a manner that a closed magnetic circuit layer is formed via a metal layer with a spacing at a central portion. With this structure, stable magnetization state can be ensured even for a miniaturized pattern.
    Type: Grant
    Filed: December 8, 2000
    Date of Patent: February 11, 2003
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Ryoji Minakata, Masashi Michijima, Hidekazu Hayashi
  • Patent number: 6504197
    Abstract: A magnetic memory element has a first ferromagnetic layer, a second ferromagnetic layer, and a non-magnetic layer disposed between these ferromagnetic layers. The non-magnetic layer has an electrical characteristic that is changeable depending on an external magnetic field applied to the non-magnetic layer.
    Type: Grant
    Filed: March 16, 2001
    Date of Patent: January 7, 2003
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Ryoji Minakata, Masashi Michijima, Hidekazu Hayashi
  • Patent number: 6442064
    Abstract: A magnetic tunnel junction element includes a first magnetic layer and a second magnetic layer acting as a memory layer, and a first insulating layer sandwiched between the first and second magnetic layers. Further, the magnetic tunnel junction element includes a third magnetic layer on a side of the second magnetic layer opposite from the first insulating layer. This third magnetic layer constitutes a closed magnetic circuit together with the second magnetic layer.
    Type: Grant
    Filed: February 17, 2001
    Date of Patent: August 27, 2002
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masashi Michijima, Hidekazu Hayashi, Ryoji Minakata
  • Patent number: 6396735
    Abstract: In a magnetic memory of the present invention which includes a magnetic memory element composed of at least a first ferromagnetic layer, a non-magnetic layer and a second ferromagnetic layer stacked, a third ferromagnetic layer is provided via at least one conductor layer, on one side of the second ferromagnetic layer the other side being closer to the non-magnetic layer. The magnetic memory elements can thereby be provided via a smaller interval in-between, thereby realizing a magnetic memory having higher density than a conventional magnetic memory. Further, the first conductor layer for supplying a current to provide magnetization information can be disposed in the vicinity of the second ferromagnetic layer as a storage layer, thereby providing a magnetic memory capable of generating magnetic poles sufficient to reverse magnetization even by a small current, and low power consumption.
    Type: Grant
    Filed: March 22, 2001
    Date of Patent: May 28, 2002
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masashi Michijima, Hidekazu Hayashi, Ryoji Minakata
  • Publication number: 20010040819
    Abstract: A magnetoresistive device has a first magnetic layer, a nonmagnetic layer, and a second magnetic layer, with the nonmagnetic layer being interposed between the first and second magnetic layers, the first and second magnetic layers having perpendicular magnetic anisotropy. Either the first magnetic layer or the second magnetic layer is made of a ferrimagnetic that has a compensation point around a room temperature.
    Type: Application
    Filed: January 5, 2001
    Publication date: November 15, 2001
    Inventors: Hidekazu Hayashi, Masashi Michijima, Ryoji Minakata
  • Publication number: 20010026471
    Abstract: In a magnetic memory of the present invention which includes a magnetic memory element composed of at least a first ferromagnetic layer, a non-magnetic layer and a second ferromagnetic layer stacked, a third ferromagnetic layer is provided via at least one conductor layer, on one side of the second ferromagnetic layer the other side being closer to the non-magnetic layer. The magnetic memory elements can thereby be provided via a smaller interval in-between, thereby realizing a magnetic memory having higher density than a conventional magnetic memory. Further, the first conductor layer for supplying a current to provide magnetization information can be disposed in the vicinity of the second ferromagnetic layer as a storage layer, thereby providing a magnetic memory capable of generating magnetic poles sufficient to reverse magnetization even by a small current, and low power consumption.
    Type: Application
    Filed: March 22, 2001
    Publication date: October 4, 2001
    Inventors: Masashi Michijima, Hidekazu Hayashi, Ryoji Minakata
  • Publication number: 20010022373
    Abstract: A magnetic memory element has a first ferromagnetic layer, a second ferromagnetic layer, and a non-magnetic layer disposed between these ferromagnetic layers. The non-magnetic layer has an electrical characteristic that is changeable depending on an external magnetic field applied to the non-magnetic layer.
    Type: Application
    Filed: March 16, 2001
    Publication date: September 20, 2001
    Inventors: Ryoji Minakata, Masashi Michijima, Hidekazu Hayashi
  • Publication number: 20010005011
    Abstract: A closed magnetic circuit layer is formed on a ferromagnetic layer serving as a memory layer of a magnetic tunnel junction device, in such a manner that a closed magnetic circuit layer is formed via a metal layer with a spacing at a central portion. With this structure, stable magnetization state can be ensured even for a miniaturized pattern.
    Type: Application
    Filed: December 8, 2000
    Publication date: June 28, 2001
    Inventors: Ryoji Minakata, Masashi Michijima, Hidekazu Hayashi
  • Patent number: 5020212
    Abstract: A method of manufacturing a magnetic head includes a first step of forming rectilinear V grooves on the top surface of a substrate, a second step of forming magnetic films on slant faces of the V grooves, a third step of leveling the top surface of the substrate after filing the V grooves with glass, a forth step of dividing the substrate into first and second substrates, a fifth step of forming grooves for coil winding on the top and bottom surfaces of each substrate, a sixth step of melting the glass of each V groove and bonding the first and second substrates, and a seventh step of slicing the bonded body, the first step including a step of forming the V grooves by means of a first grinding wheel and a step of finishing one of slant faces of the V grooves by means of a second grinding wheel, of which end is V-shaped, so that the slant has smaller surface roughness, the second grinding wheel being shaped such that one of the grinding wheel surfaces comes into contact with one of the slant faces of the V gro
    Type: Grant
    Filed: May 29, 1990
    Date of Patent: June 4, 1991
    Assignee: Sharp Corporation
    Inventors: Masashi Michijima, Masaru Kadono, Tatsushi Yamamoto