Patents by Inventor Keiji Shono

Keiji Shono 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: 8188466
    Abstract: A resistance variable element is provided, which is capable of performing bipolar operation by a specified mechanism and usable as a memory. The resistance variable element has a laminated structure including an electrode, another electrode, an oxide layer between the electrodes, and an oxide layer in contact with the oxide layer between the oxide layer and the electrode. The oxide layer is switchable from the low-resistance state to the high-resistance state by donating oxygen ions to the oxide layer, and from the high-resistance state to the low-resistance state by accepting oxygen ions from the oxide layer. The oxide layer is switchable from the low-resistance state to the high-resistance state by accepting oxygen ions from the oxide layer, and from the high-resistance state to the low-resistance state by donating oxygen ions to the oxide layer.
    Type: Grant
    Filed: April 14, 2009
    Date of Patent: May 29, 2012
    Assignees: Fujitsu Limited, National University Corporation Nagoya Institute of Technology
    Inventors: Hiroyasu Kawano, Keiji Shono, Manabu Gomi, Takeshi Yokota
  • Publication number: 20100200832
    Abstract: A resistance variable device is provided, which is capable of making a bipolar operation based on a predetermined operation principle. The resistance variable device is usable as a storage device. The resistance variable device has a laminated structure which include, for example, a first electrode, a second electrode, and a hole conductive layer between the first and second electrodes. The hole conductive layer gives anions to the second electrode, thereby changing its state from a reference electric field state to a positive electric field state. The hole conductive layer also receives anions from the second electrode, thereby changing its state from the positive electric field state to the reference electric field state.
    Type: Application
    Filed: February 18, 2010
    Publication date: August 12, 2010
    Applicant: FUJITSU LIMITED
    Inventors: Hiroyasu Kawano, Keiji Shono
  • Patent number: 7764160
    Abstract: The invention provides a variable-resistance element having a multilayer structure. The variable-resistance element includes, for example, a first electrode, a second electrode, and an oxygen ion migration layer disposed between the first electrode and the second electrode. In the oxygen ion migration layer, oxygen vacancy can be produced owing to oxygen ion migration, thereby forming a low resistance path. The variable-resistance element also includes an oxygen ion generation promoting layer disposed between the oxygen ion migration layer and the first electrode and held in contact with the oxygen ion migration layer.
    Type: Grant
    Filed: January 12, 2009
    Date of Patent: July 27, 2010
    Assignee: Fujitsu Limited
    Inventors: Hiroyasu Kawano, Keiji Shono
  • Publication number: 20090218565
    Abstract: A resistance variable element is provided, which is capable of performing bipolar operation by a specified mechanism and usable as a memory. The resistance variable element has a laminated structure including an electrode, an electrode, an oxide layer between the electrodes, and an oxide layer in contact with the oxide layer between the oxide layer and the electrode. The oxide layer is switchable from the low-resistance state to the high-resistance state by donating oxygen ions to the oxide layer, and from the high-resistance state to the low-resistance state by accepting oxygen ions from the oxide layer. The oxide layer is switchable from the low-resistance state to the high-resistance state by accepting oxygen ions from the oxide layer, and from the high-resistance state to the low-resistance state by donating oxygen ions to the oxide layer.
    Type: Application
    Filed: April 14, 2009
    Publication date: September 3, 2009
    Applicants: FUJITSU LIMITED, NATIONAL UNIVERSITY CORPORATION NAGOYA INSTITUTE OF TECHNOLOGY
    Inventors: Hiroyasu Kawano, Keiji Shono, Manabu Gomi, Takeshi Yokota
  • Publication number: 20090121823
    Abstract: The invention provides a variable-resistance element having a multilayer structure. The variable-resistance element includes, for example, a first electrode, a second electrode, and an oxygen ion migration layer disposed between the first electrode and the second electrode. In the oxygen ion migration layer, oxygen vacancy can be produced owing to oxygen ion migration, thereby forming a low resistance path. The variable-resistance element also includes an oxygen ion generation promoting layer disposed between the oxygen ion migration layer and the first electrode and held in contact with the oxygen ion migration layer.
    Type: Application
    Filed: January 12, 2009
    Publication date: May 14, 2009
    Applicant: FUJITSU LIMITED
    Inventors: Hiroyasu Kawano, Keiji Shono
  • Patent number: 7090933
    Abstract: The invention is a magneto-optical recording medium characterized by containing at least a soft magnetic layer, a protective layer, a resin layer having a servo pattern formed thereon, a reflecting film, a lower dielectric material film, a recording film, an upper dielectric material film, and a cover layer, formed on a substrate in this order.
    Type: Grant
    Filed: June 8, 2004
    Date of Patent: August 15, 2006
    Assignee: Fujitsu Limited
    Inventors: Yuzuru Yamakage, Takuya Kamimura, Ken Tamanoi, Mineo Moribe, Keiji Shono
  • Publication number: 20060127702
    Abstract: In a magneto-optical recording medium having a recording reproduction layer between a substrate and a protective film layer, a recording head disposed at the protective film layer side produces a magnetic field and a light is projected from the recording head side so that information is recorded on the recording reproduction layer. A ratio (Bs2×t2 /Bs1×t1) of a product Bs2×t2 to a product Bs1×t1 is not less than 0.2, where t1 denotes a film thickness of a soft magnetic layer constituting a recording head for supplying the magnetic field to the magneto-optical recording medium, the recording head having a magnetic field generating coil, Bs1 denotes a saturation magnetic flux density of the soft magnetic layer, t2 denotes a film thickness of a soft magnetic layer constituting the magneto-optical recording medium, and Bs2 denotes a saturation magnetic flux density of the soft magnetic layer.
    Type: Application
    Filed: January 26, 2006
    Publication date: June 15, 2006
    Applicant: FUJITSU LIMITED
    Inventors: Takahiro Umada, Koji Matsumoto, Keiji Shono
  • Publication number: 20050226136
    Abstract: A magneto-optical recording medium (D1) includes a soft magnetic layer (2) and a magneto-optical recording layer (3) laminated sequentially onto a substrate (1) and is provided with a plurality of grooves (G) and lands (L). The product of the saturation magnetic flux density and thickness of the soft magnetic layer (2) is made different for the respective grooves (G) and lands (L). Thus, with respect to each groove (G) and each land (L), the magnetic focusing effect can be enhanced for one of these with a greater product of saturation magnetic flux density and thickness of the soft magnetic layer (2), while the effect can be weakened for the other one with a smaller product of saturation magnetic flux density and thickness of the soft magnetic layer. This enables the incidence of cross-writing to be suppressed.
    Type: Application
    Filed: May 10, 2005
    Publication date: October 13, 2005
    Inventors: Mineo Moribe, Takahiro Umada, Keiji Shono
  • Publication number: 20040224119
    Abstract: The invention is a magneto-optical recording medium characterized by containing at least a soft magnetic layer, a protective layer, a resin layer having a servo pattern formed thereon, a reflecting film, a lower dielectric material film, a recording film, an upper dielectric material film, and a cover layer, formed on a substrate in this order.
    Type: Application
    Filed: June 8, 2004
    Publication date: November 11, 2004
    Applicant: FUJITSU LIMITED
    Inventors: Yazuru Yamakage, Takuya Kamimura, Ken Tamanoi, Mineo Moribe, Keiji Shono
  • Publication number: 20040048108
    Abstract: In a magneto-optical recording medium having a recording reproduction layer between a substrate and a protective film layer, a recording head disposed at the protective film layer side produces a magnetic field and a light is projected from the recording head side so that information is recorded on the recording reproduction layer. A ratio (Bs2×t2/Bs1×t1) of a product Bs2×t2 to a product Bs1×t1 is not less than 0.2, where t1 denotes a film thickness of a soft magnetic layer constituting a recording head for supplying the magnetic field to the magneto-optical recording medium, the recording head having a magnetic field generating coil, Bs1 denotes a saturation magnetic flux density of the soft magnetic layer, t2 denotes a film thickness of a soft magnetic layer constituting the magneto-optical recording medium, and Bs2 denotes a saturation magnetic flux density of the soft magnetic layer.
    Type: Application
    Filed: August 27, 2003
    Publication date: March 11, 2004
    Applicant: Fujitsu Limited
    Inventors: Takahiro Umada, Koji Matsumoto, Keiji Shono
  • Publication number: 20020118832
    Abstract: The present invention is a system capable of protecting copyright and personal information appropriately and allowing users to readily obtain desired contents in a short time at low prices. A recording device stores contents in advance. The recording device encrypts the contents, based on an identifier given uniquely to a medium. The recording device records the encrypted contents on the medium. Moreover, the recording device records limiting conditions for reproducing, displaying or executing the contents on the medium. An execution device decrypts the contents recorded on the medium, based on the identifier. The execution device reproduces, displays or executes the contents under the limiting conditions recorded on the medium.
    Type: Application
    Filed: July 3, 2001
    Publication date: August 29, 2002
    Inventors: Michio Matsuura, Keiji Shono, Kazuyuki Ozaki, Mineo Moribe, Motonobu Mihara, Koji Matsumoto, Seigo Kotani
  • Patent number: 6356516
    Abstract: A magneto-optical recording medium capable of perfectly masking a mark adjacent to a mark to be reproduced thereby improvng reproduction output. The magneto-optical recording medium includes a transparent substrate, a magnetic reproducing layer laminated on the transparent substrate, a nonmagnetic intermediate layer laminated on the magnetic reproducing layer, and a magnetic recording layer laminated on the nonmagnetic intermediate layer. The reproducing layer has an easy direction of magnetization in a plane at room temperature, and has an easy direction of magnetization perpendicular to a film surface at a given temperature or higher. The nonmagnetic intermediate layer is thin enough to allow magnetostatic bond between the recording layer and the reproducing layer at the given temperature or higher.
    Type: Grant
    Filed: December 7, 2000
    Date of Patent: March 12, 2002
    Assignee: Fujitsu Limited
    Inventors: Ken Tamanoi, Keiji Shono, Sumio Kuroda, Motonobu Mihara, Koji Matsumoto
  • Patent number: 6248439
    Abstract: A magneto-optical recording medium capable of perfectly masking a mark adjacent to a mark to be reproduced thereby improving a reproduction output. The magneto-optical recording medium includes a transparent substrate, a magnetic reproducing layer laminated on the transparent substrate, a nonmagnetic intermediate layer laminated on the magnetic reproducing layer, and a magnetic recording layer laminated on the nonmagnetic intermediate layer. The reproducing layer has an easy direction of magnetization in a plane at room temperature, and has an easy direction of magnetization perpendicular to a film surface at a given temperature or higher. The nonmagnetic intermediate layer is thin enough to allow magnetostatic bond between the recording layer and the reproducing layer at the given temperature or higher.
    Type: Grant
    Filed: January 4, 1995
    Date of Patent: June 19, 2001
    Assignee: Fujitsu Ltd.
    Inventors: Ken Tamanoi, Keiji Shono, Sumio Kuroda, Motonobu Mihara, Koji Matsumoto
  • Publication number: 20010000483
    Abstract: A magneto-optical recording medium capable of perfectly masking a mark adjacent to a mark to be reproduced to thereby improve a reproduction output. The magneto-optical recording medium includes a transparent substrate, a magnetic reproducing layer laminated on the transparent substrate, a nonmagnetic intermediate layer laminated on the magnetic reproducing layer, and a magnetic recording layer laminated on the nonmagnetic intermediate layer. The reproducing layer has an easy direction of magnetization in a plane at room temperature, and has an easy direction of magnetization perpendicular to a film surface at a given temperature or higher. The nonmagnetic intermediate layer is thin enough to allow magnetostatic bond between the recording layer and the reproducing layer at the given temperature or higher.
    Type: Application
    Filed: December 7, 2000
    Publication date: April 26, 2001
    Applicant: Fujitsu Limited
    Inventors: Ken Tamanoi, Keiji Shono, Sumio Kuroda, Motonobu Mihara, Koji Matsumoto
  • Patent number: 6128254
    Abstract: A magneto-optical recording medium composed of a plurality of magnetic layers including a rare earth metal and a transition metal as main components. The magneto-optical recording medium includes a magnetic reproducing layer having an easy axis of magnetization perpendicular to a film plane, and a magnetic control layer formed over the magnetic reproducing layer and having an easy axis of magnetization in a plane at a room temperature. A magnetic moment of the rare earth metal of the magnetic control layer being predominant over a magnetic moment of the transition metal of the magnetic control layer. The magnetic control layer includes at least Gd as the rare earth metal and Fe as the transition metal. The magneto-optical recording medium further includes a magnetic recording layer formed over the magnetic control layer and having an easy axis of magnetization perpendicular to the film plane.
    Type: Grant
    Filed: April 19, 1999
    Date of Patent: October 3, 2000
    Assignee: Fujitsu Limited
    Inventors: Koji Matsumoto, Keiji Shono
  • Patent number: 6096444
    Abstract: A magneto-optical recording medium of a three-layered structure (consisting of a readout layer, an intermediate layer, and a recording layer), capable of double-mask magnetically-induced super-resolution readout, has magnetic properties such that the exchange coupled force between the readout layer (a GdFeCo film) and the intermediate layer (a GdFe film) decrease with increasing temperature, while the exchange coupled force between the intermediate layer and the recording layer (a TbFeCo film) increase with increasing temperature. The magnetic property of the readout layer is transition-metal magnetization dominant, and that of the intermediate layer is rare-earth magnetization dominant.
    Type: Grant
    Filed: February 2, 1998
    Date of Patent: August 1, 2000
    Assignee: Fujitsu Limited
    Inventors: Ken Tamanoi, Koji Matsumoto, Keiji Shono
  • Patent number: 6031794
    Abstract: A magneto-optical recording medium, and a method of its production, a method of reading and an apparatus of reading the same capable of decreasing the magnetic field to be applied during MSR readout, or reading without applying magnetic field, by including first, second and third magnetic layers having specified magnetic characteristics.
    Type: Grant
    Filed: December 15, 1998
    Date of Patent: February 29, 2000
    Assignee: Fujitsu Limited
    Inventors: Ken Tamanoi, Toshio Sugimoto, Tsutomu Tanaka, Motonobu Mihara, Keiji Shono
  • Patent number: 6020079
    Abstract: A magneto-optical recording medium capable of performing magnetically induced super resolution reproduction by perfectly masking a mark adjacent to a mark to be reproduced. The magneto-optical recording medium includes a transparent substrate, a magnetic reproducing layer laminated on the transparent substrate, a magnetic control layer laminated on the reproducing layer, and a magnetic recording layer laminated on the control layer. The reproducing layer has an easy axis of magnetization in a plane at room temperature. Each of the control layer and the recording layer has an easy axis of magnetization perpendicular to the substrate.
    Type: Grant
    Filed: February 25, 1998
    Date of Patent: February 1, 2000
    Assignee: Fujitsu Limited
    Inventors: Koji Matsumoto, Keiji Shono
  • Patent number: 5896350
    Abstract: A magneto-optical recording medium, and a method of its production, a method of reading and an apparatus of reading the same capable of decreasing the magnetic field to be applied during MSR readout, or reading without applying magnetic field, by including first, second and third magnetic layers having specified magnetic characteristics.
    Type: Grant
    Filed: February 24, 1997
    Date of Patent: April 20, 1999
    Assignee: Fujitsu Limited
    Inventors: Ken Tamanoi, Toshio Sugimoto, Tsutomu Tanaka, Motonobu Mihara, Keiji Shono
  • Patent number: 5747136
    Abstract: A magneto-optic disk has a readout layer formed of a bismuth-substituted garnet having a chemical composition represented by Bi.sub.x R.sub.3-x M.sub.y Fe.sub.5-y O.sub.12 and a recording layer formed of a nonbismuth-substituted garnet having a chemical composition represented by R.sub.3 M, Fe.sub.5-z O.sub.12 (where 0.ltoreq.x.ltoreq.3, 0.ltoreq.y<2, 0.ltoreq.z<2, R represents yttrium or a rare earth element, and M represents element which can be substituted for iron (Fe). The readout layer has a smaller coercive force and a higher Curie temperature in comparison with the recording layer, and exhibits a characteristic of a large angle of Faraday rotation 200 times that of the recording layer with respect to a short-wavelength laser beam of about 500 nm.
    Type: Grant
    Filed: September 20, 1994
    Date of Patent: May 5, 1998
    Assignee: Fujitsu, Ltd.
    Inventors: Keiji Shono, Yasunobu Hashimoto, Sumio Kuroda, Ken Tamanoi