Patents by Inventor Kenichi Aoshima

Kenichi Aoshima 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: 6759120
    Abstract: There is disclosed a magnetoresistive film in which increase of a coupling field accompanying thickness reduction of a middle layer is inhibited. The magnetoresistive film is a multilayered film including a pinned layer 3 having magnetization whose direction is fixed, a nonmagnetic middle layer 4 formed on the pinned layer, and a free layer 5 formed on the middle layer and provided with magnetization whose direction changes in accordance with an external magnetic field, the magnetoresistive film indicates a magnitude of resistance in accordance with an angle formed by the magnetization direction of the pinned layer and the magnetization direction of the free layer, and a copper oxide layer 7 of an oxide including a copper element is formed directly on the free layer, or on the free layer via an oxide layer 6 of a material fabricated by oxidizing a material constituting the free layer.
    Type: Grant
    Filed: November 30, 2000
    Date of Patent: July 6, 2004
    Assignee: Fujitsu Limited
    Inventors: Hong Jongill, Kenichi Aoshima, Kenji Noma, Junichi Kane, Hitoshi Kanai
  • Patent number: 6721147
    Abstract: A magnetoresistance effect magnetic head includes a magnetoresistance effect element having first and second ends. An electrically insulating biasing portion is at ends of the magnetoresistance effect element to apply a longitudinal bias magnetic field to the magnetoresistance effect element and to suppress leakage current at the ends of the magnetoresistance element. The biasing portion can include an intermediate longitudinal bias application layer disposed between a first insulating antiferromagnetic layer and a second layer that can be an antiferromagnetic layer. The bias portion can also be formed as one bias application layer.
    Type: Grant
    Filed: April 4, 2001
    Date of Patent: April 13, 2004
    Assignee: Fujitsu Limited
    Inventors: Kenichi Aoshima, Kenji Noma, Junichi Ito
  • Patent number: 6700758
    Abstract: A magnetoresistive head reproduces information recorded on a recording medium with high recording density, suppressing generation of Barkhausen noise. A magnetoresistive effect element in the head is a flat multi-layer film in which a free magnetic layer is set to a lowest layer. The head also includes a non-magnetic substrate, an insulating layer contacting a center portion of a lower surface of a substrate side of the free magnetic layer, and a pair of electrode layers. The electrode layers are formed with the insulating layer in between, contacting both edge portions of the free magnetic layer. The electrodes are formed with the same surface height as the surface height of the insulating layer. A pair of magnetic wall control layers suppress movement of a magnetic wall of the free magnetic layer.
    Type: Grant
    Filed: November 13, 2001
    Date of Patent: March 2, 2004
    Assignee: Fujitsu Limited
    Inventors: Junichi Hashimoto, Michiaki Kanamine, Takahiro Imamura, Kenichi Aoshima
  • Patent number: 6671138
    Abstract: An object of the present invention is to provide a magnetoresistive effect type of head that is high in the magnetoresistive rate while including the laminated ferrimagnetic film. The fixed magnetic layer of the magnetoresistive effect type of head has a first fixed magnetic layer, a second fixed magnetic layer laminated at a position farther from the free magnetic layer as compared with the first fixed magnetic layer, and an opposite-parallel-coupling intermediate layer interposed between the first fixed magnetic layer and the second fixed magnetic layer, in which magnetizations of the first and second fixed magnetic layers are coupled with one another in such a manner that the magnetizations are pointed in directions which are substantially parallel and mutually opposite. The second fixed magnetic layer is formed with a material that is different from a material of said first fixed magnetic layer, and has a resistivity higher than that of said first fixed magnetic layer.
    Type: Grant
    Filed: December 27, 2001
    Date of Patent: December 30, 2003
    Assignee: Fujitsu Limited
    Inventors: Kenji Noma, Hitoshi Kanai, Kenichi Aoshima
  • Patent number: 6556391
    Abstract: A magnetoresistance effect magnetic head includes a magnetoresistance effect element having a first end and a second end. A biasing portion is provided at the first end and the second end of the magnetoresistance effect element for applying a longitudinal bias magnetic field to the magnetoresistance effect element at the first end or the second end. The biasing portion includes an intermediate layer disposed between an antiferromagnetic first layer and a second layer.
    Type: Grant
    Filed: June 14, 2000
    Date of Patent: April 29, 2003
    Assignee: Fujitsu Limited
    Inventors: Kenichi Aoshima, Kenji Noma
  • Patent number: 6526425
    Abstract: A digitized document circulating system includes a unit provided in a transmission source of a digitized document and for sending the digitized document, a unit for delivering the digitized document to a transmission destination to thereby circulate the digitized document, a unit provided in the transmission destination and for receiving the digitized document, a unit operated by the delivery unit and for obtaining a circulation history containing delivery time, an identifier of the digitized document, the transmission source and the transmission destination, a unit for reading the circulation history and transferring the circulation history to a requester in response to a request for the circulation history issued from the requester, and a unit for displaying the circulation history received.
    Type: Grant
    Filed: March 20, 2001
    Date of Patent: February 25, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Yuichi Mori, Kazuyasu Tsuiki, Hiroshi Majima, Kenichi Aoshima, Shunsuke Akifuji, Tetsuji Toge, Kazuhiro Suga
  • Patent number: 6516328
    Abstract: A digitized document circulating system includes a unit provided in a transmission source of a digitized document and for sending the digitized document, a unit for delivering the digitized document to a transmission destination to thereby circulate the digitized document, a unit provided in the transmission destination and for receiving the digitized document, a unit operated by the delivery unit and for obtaining a circulation history containing delivery time, an identifier of the digitized document, the transmission source and the transmission destination, a unit for reading the circulation history and transferring the circulation history to a requester in response to a request for the circulation history issued from the requester, and a unit for displaying the circulation history received.
    Type: Grant
    Filed: March 27, 1998
    Date of Patent: February 4, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Yuichi Mori, Kazuyasu Tsuiki, Hiroshi Majima, Kenichi Aoshima, Shunsuke Akifuji, Tetsuji Toge, Kazuhiro Suga
  • Patent number: 6501627
    Abstract: A spin-valve magnetoresistive head having end parts of a free magnetic layer insensitive to an external magnetic field so as to improve sensitivity is provided. The spin-valve magnetoresistive head includes, at least on the terminal part sides, a lamination formed of a first antiferromagnetic layer, a soft magnetic layer, an antiparallel coupling intermediate layer, and a first free magnetic layer.
    Type: Grant
    Filed: November 26, 2001
    Date of Patent: December 31, 2002
    Assignee: Fujitsu Limited
    Inventors: Kenji Noma, Hitoshi Kanai, Junichi Kane, Kenichi Aoshima
  • Patent number: 6493196
    Abstract: A spin-valve magnetoresistive sensor includes a free layer of a ferromagnetic material, a pinned layer provided on the free layer and a pinning layer of an anti-ferromagnetic material provided on the pinned layer, the anti-ferromagnetic material being an ordered alloy containing manganese. The pinned layer includes a first pinned layer of a ferromagnetic material, a second pinned layer of a ferromagnetic material provided on the first pinned layer and an intermediate layer interposed between the first and second pinned layers such that the first and second pinned layers establish a super-exchange interaction in an anti-parallel manner. The second pinned layer has a magnetic moment smaller than a magnetic moment of the first pinned layer.
    Type: Grant
    Filed: December 29, 1999
    Date of Patent: December 10, 2002
    Assignee: Fujitsu Ltd.
    Inventors: Kenji Noma, Hitoshi Kanai, Junichi Kane, Kenichi Aoshima
  • Patent number: 6477020
    Abstract: A magneto-resistive head includes a stabilizing bias layer which applies a magnetization stabilizing bias field on a magneto-resistive layer of a magneto-resistive element, and a ferromagnetic underlayer which forms an underlayer with respect to the stabilizing bias layer. The ferromagnetic underlayer is made of Fe and has a film thickness in a range of 1.3 to 2.5 nm.
    Type: Grant
    Filed: November 10, 1999
    Date of Patent: November 5, 2002
    Assignee: Fujitsu Limited
    Inventors: Kenichi Aoshima, Hitoshi Kanai
  • Publication number: 20020101693
    Abstract: An object of the present invention is to provide a magnetoresistive effect type of head for preferably reproducing information recorded on a recording medium with high recording density suppressing generation of Barkhausen noise. The magnetoresistive effect type of head has a magnetoresistive effect element offering a resistive change according to intensity of an external magnetic field, for detecting a magnitude of a resistance of the magnetoresistive effect element to detect intensity of a magnetic field. The magnetoresistive effect element consists of a flat multi-layer film in which a free magnetic layer changing in a direction of a magnetization in accordance with the external magnetic field is set up to a lowest layer.
    Type: Application
    Filed: November 13, 2001
    Publication date: August 1, 2002
    Applicant: FUJITSU LIMITED
    Inventors: Junichi Hashimoto, Michiaki Kanamine, Takahiro Imamura, Kenichi Aoshima
  • Publication number: 20020044397
    Abstract: A spin valve magnetoresistive head using a hard ferromagnetic layer, and a magnetic recording medium drive device using this head are provided.
    Type: Application
    Filed: December 6, 2001
    Publication date: April 18, 2002
    Applicant: FUJITSU LIMITED
    Inventors: Kenji Noma, Hitoshi Kanai, Junichi Kane, Kenichi Aoshima
  • Publication number: 20020034057
    Abstract: A spin-valve magnetoresistive head having end parts of a free magnetic layer insensitive to an external magnetic field so as to improve sensitivity is provided.
    Type: Application
    Filed: November 26, 2001
    Publication date: March 21, 2002
    Applicant: FUJITSU LIMITED
    Inventors: Kenji Noma, Hitoshi Kanai, Junichi Kane, Kenichi Aoshima
  • Publication number: 20010014001
    Abstract: A magnetoresistance effect magnetic head includes a magnetoresistance effect element having first and second ends. An electrically insulating biasing portion is at ends of the magnetoresistance effect element to apply a longitudinal bias magnetic field to the magnetoresistance effect element and to suppress leakage current at the ends of the magnetoresistance element. The biasing portion can include an intermediate longitudinal bias application layer disposed between a first insulating antiferromagnetic layer and a second layer that can be an antiferromagnetic layer. The bias portion can also be formed as one bias application layer.
    Type: Application
    Filed: April 4, 2001
    Publication date: August 16, 2001
    Applicant: FUJITSU LIMITED
    Inventors: Kenichi Aoshima, Kenji Noma, Junichi Ito
  • Publication number: 20010014412
    Abstract: There is disclosed a magnetoresistive film in which increase of a coupling field accompanying thickness reduction of a middle layer is inhibited. The magnetoresistive film is a multilayered film including a pinned layer 3 having magnetization whose direction is fixed, a nonmagnetic middle layer 4 formed on the pinned layer, and a free layer 5 formed on the middle layer and provided with magnetization whose direction changes in accordance with an external magnetic field, the magnetoresistive film indicates a magnitude of resistance in accordance with an angle formed by the magnetization direction of the pinned layer and the magnetization direction of the free layer, and a copper oxide layer 7 of an oxide including a copper element is formed directly on the free layer, or on the free layer via an oxide layer 6 of a material fabricated by oxidizing a material constituting the free layer.
    Type: Application
    Filed: November 30, 2000
    Publication date: August 16, 2001
    Applicant: FUJITSU LIMITED
    Inventors: Hong Jongill, Kenichi Aoshima, Kenji Noma, Junichi Kane, Hitoshi Kanai
  • Publication number: 20010013044
    Abstract: A digitized document circulating system including a unit provided in a transmission source of a digitized document and for sending the digitized document, a unit for delivering the digitized document to a transmission destination to thereby circulate the digitized document, a unit provided in the transmission destination and for receiving the digitized document, a unit operated by the delivery unit and for obtaining a circulation history containing delivery time, an identifier of the digitized document, the transmission source and the transmission destination, a unit for reading the circulation history and transferring the circulation history to a requester in response to a request for the circulation history issued from the requester, and a unit for displaying the circulation history received.
    Type: Application
    Filed: March 20, 2001
    Publication date: August 9, 2001
    Inventors: Yuichi Mori, Kazuyasu Tsuiki, Hiroshi Majima, Kenichi Aoshima, Shunsuke Akifuji, Tetsuji Toge, Kazuhiro Suga
  • Patent number: 6249407
    Abstract: In a current perpendicular type magnetoresistive device, a current efficiently flows in a direction perpendicular to a plane of an MR element and the sensitivity of the MR element is increased. Upper and lower shielding layers form a gap therebetween so that the MR element is situated within the gap. Upper and lower gap layers are provided within the gap so that the MR element is interposed between the upper and lower gap layers. The upper gap layer is provided between the upper shielding layer and the MR element. The lower gap layer is provided between the lower shielding layer and the MR element. The lower gap layer is formed from tantalum. An under layer formed from a material having a body-centered cubic structure is interposed between the lower shielding layer and the lower gap layer.
    Type: Grant
    Filed: October 1, 1999
    Date of Patent: June 19, 2001
    Assignee: Fujitsu Limited
    Inventors: Kenichi Aoshima, Kenji Noma
  • Patent number: 6123780
    Abstract: A method for manufacturing a spin valve GMR head is describe in which a fixed magnetic layer of the head may maintain magnetization in a desired orientation. In one aspect of the invention, the method comprises steps of: forming a magnetic film including at least a free magnetic layer, a non-magnetic metallic layer, a fixed magnetic layer, and a magnetic domain control layer; subjecting the magnetic film to a first heat treatment under a magnetic field to enhance magnetic anisotropy of the free magnetic layer; and subjecting the magnetic film to a second heat treatment under a magnetic field and at a higher temperature than the maximum temperature applied in the processes that precede the second heat treatment, to fix the magnetization in the fixed magnetic layer.
    Type: Grant
    Filed: January 14, 1998
    Date of Patent: September 26, 2000
    Assignee: Fujitsu Limited
    Inventors: Hitoshi Kanai, Kenichi Aoshima, Kenichiro Yamada, Mitsumasa Okada, Eiji Shimizu, Junichi Kane
  • Patent number: 6046892
    Abstract: A magnetoresistive head includes an underlayer composed of one of Ni and NiFe alloy and at least one additive selected from the group consisting of Cr, Nb, Rh, and Pd. An anti-ferromagnetic layer is formed on the underlayer, and a first ferromagnetic layer is formed on the anti-ferromagnetic layer. The magnetic head also includes a nonmagnetic layer formed on the first ferromagnetic layer, and a second ferromagnetic layer formed on the nonmagnetic layer.
    Type: Grant
    Filed: March 17, 1998
    Date of Patent: April 4, 2000
    Assignee: Fujitsu Limited
    Inventors: Kenichi Aoshima, Hitoshi Kanai
  • Patent number: 6038093
    Abstract: There is provided a magnetic recording/reproducing apparatus which has an improved reliability for a reproduced signal by eliminating a deformation in a reproduced signal waveform due to a residual magnetization generated in a magnetic head. The magnetic recording/reproducing apparatus has a magnetic recording medium including a magnetic film to which information is magnetically recorded and a thin-film magnetic head including a magnetic pole and a coil provided around the magnetic pole. A current supplying circuit supplies a current to the coil so that a magnetic state of the magnetic pole is stabilized. The current is supplied to the coil after a recording operation has been completed by the thin-film magnetic head. The current may demagnetize the magnetic pole of the magnetic head, or stabilize the magnetic state of the magnetic pole.
    Type: Grant
    Filed: June 24, 1997
    Date of Patent: March 14, 2000
    Assignee: Fujitsu Limited
    Inventors: Noboru Takada, Chie Takeda, Hiroaki Wakamatsu, Masayoshi Shinohara, Kenji Sato, Kenichi Aoshima