Patents by Inventor Hideyuki Akimoto

Hideyuki Akimoto 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: 6541104
    Abstract: A magnetic recording medium has a construction in which on a non-magnetic support member are successively stacked a seed layer made of a non-magnetic material that is mainly composed of Cr, a keeper layer made of an NiFe-type soft magnetic material, an intermediate layer made of a non-magnetic material that is mainly composed of Cr and a recording layer made of a magnetic material that is mainly composed of Co.
    Type: Grant
    Filed: March 8, 2001
    Date of Patent: April 1, 2003
    Assignee: Fujitsu Limited
    Inventors: Hideyuki Akimoto, Chiaki Okuyama, Iwao Okamoto
  • Publication number: 20030059648
    Abstract: A magnetic recording medium for high areal recording density that has excellent thermal fluctuation resistance and recording/reproduction characteristics, and a method of producing the same. The magnetic recording medium includes a glass substrate, an NiP layer having an oxide film on its surface provided on the glass substrate, a ground layer provided on the NiP layer, and a nonmagnetic intermediate layer provided on the ground layer. The magnetic recording medium further includes an exchange layer structure composed of a ferromagnetic layer and a nonmagnetic coupling layer provided on the nonmagnetic intermediate layer, and a magnetic recording layer provided on the exchange layer structure. The oxide film on the NiP layer is formed by introducing a small quantity of oxygen into a vacuum chamber of a sputter device. The formation and oxidation of the NiP layer are conducted at a temperature of not less than 140° C.
    Type: Application
    Filed: June 11, 2002
    Publication date: March 27, 2003
    Applicant: FUJITSU LIMITED
    Inventors: Hideyuki Akimoto, Kenji Sato, Yuki Yoshida, Masaya Suzuki, Akira Kikuchi, Tohru Horie, Naoya Saito, Akiko Honda
  • Patent number: 6534204
    Abstract: There is provided a magnetic storage medium capable of recording information at high recording density and also regenerating the information with a high quality of signal (high S/Nm), and in addition contributing to the elongation of a life span of the recorded information. The magnetic storage medium comprises a non-magnetic substrate, a plurality of magnetic recording layers of ferromagnetism formed on the non-magnetic substrate, and a dividing layer of antiferromagnetism for dividing said plurality of magnetic recording layers from one another through intervening between the magnetic recording layer-to-layer.
    Type: Grant
    Filed: September 24, 1999
    Date of Patent: March 18, 2003
    Assignee: Fujitsu Limited
    Inventors: Hideyuki Akimoto, Yuki Yoshida, Kenji Sato, Iwao Okamoto
  • Publication number: 20030039862
    Abstract: A glass substrate for a magnetic recording medium has a textured surface having numerous grooves extending in the circumferential direction of the glass substrate. The average roughness of the textured surface is 0.4 nm or less. The number of the grooves is 15 or more per micrometer. The average depth of the grooves is 2 nm or less. The grooves are formed by mechanical texturing using a texturing liquid applied between a texturing tape and the surface of a blank glass substrate rotating. The texturing liquid is an aqueous dispersion of fine diamond abrasive grains.
    Type: Application
    Filed: March 13, 2002
    Publication date: February 27, 2003
    Applicant: FUJITSU LIMITED
    Inventors: Susumu Yoshida, Hideyuki Akimoto, Masaya Suzuki
  • Publication number: 20020001736
    Abstract: A magnetic recording medium for high density recording has a high signal to noise ratio and improved read out characteristics. The medium is made on a non-magnetic substrate having a magnetic layer containing Co, with about 26 to 35 at % Cr and about 0.5 to 4 at % Ta added. The magnetic layer can also have about 15 to 30 at % Pt, and Nb. An underlayer can be provided between the substrate and the magnetic layer, the underlayer containing Cr as its main constituent and containing one or more of Mo, W, Ti, Ir, Ru and Re.
    Type: Application
    Filed: February 4, 2000
    Publication date: January 3, 2002
    Inventors: Hideyuki Akimoto, Kenji Sato, Yuki Yoshida, Iwao Okamoto
  • Publication number: 20010009727
    Abstract: A magnetic recording medium has a construction in which on a non-magnetic support member are successively stacked a seed layer made of a non-magnetic material that is mainly composed of Cr, a keeper layer made of an NiFe-type soft magnetic material, an intermediate layer made of a non-magnetic material that is mainly composed of Cr and a recording layer made of a magnetic material that is mainly composed of Co.
    Type: Application
    Filed: March 8, 2001
    Publication date: July 26, 2001
    Applicant: FUJITSU LIMITED
    Inventors: Hideyuki Akimoto, Chiaki Okuyama, Iwao Okamoto
  • Patent number: 6213382
    Abstract: A gold alloy wire in which 0.2 to 5.0% by weight of palladium (Pd) and 1 to 100 ppm by weight of bismuth (Bi) are added to gold having a purity of at least 99.99% by weight. Preferably, at least one element selected from the group consisting of yttrium (Y), lanthanum (La), calcium (Ca) and beryllium (Bi) in an amount of 3 to 250 ppm by weight is further added to said gold. The gold alloy wire is especially adapted to forming a gold bump.
    Type: Grant
    Filed: January 5, 1999
    Date of Patent: April 10, 2001
    Assignee: Tanaka Denshi Kogyo K.K.
    Inventor: Hideyuki Akimoto
  • Patent number: 6159420
    Abstract: A gold alloy wire in which 0.2 to 5.0% by weight of palladium (Pd) and 1 to 100 ppm by weight of bismuth (Bi) are added to gold having a purity of at least 99.99% by weight. Preferably, at least one element selected from the group consisting of yttrium (Y), lanthanum (La), calcium (Ca) and beryllium (Be) in an amount of 3 to 250 ppm by weight is further added to said gold. The gold alloy wire is especially adapted to forming a gold bump.
    Type: Grant
    Filed: May 23, 1997
    Date of Patent: December 12, 2000
    Assignee: Tanaka Denshi Kogyo K.K.
    Inventor: Hideyuki Akimoto
  • Patent number: 5900323
    Abstract: A non-magnetic substrate, a Cu layer having a film thickness ranging from 0.5 to 10 nm, a Cr layer having a film thickness of 100 nm or less, a magnetic layer made of CoCrPt alloy in which a percentage content of Cr ranges from 12 atoms % to 20 atoms % and a percentage content of Pt ranges from 4 atoms % to 18 atoms %, a protective layer and a lubricating layer are arranged in that order to form a magnetic recording medium. Because the Cu layer is sufficiently thinned, a medium noise is sufficiently reduced, and a medium S/N ratio is sufficiently heightened. Because the film thickness of the Cr layer is 100 nm or less, the medium noise is reduced. Because the composition of CoCrPt alloy is limited in the magnetic layer, the medium S/N ratio is heightened. In addition, it is preferred that another Cu layer having a film thickness ranging from 0.5 to 10 nm be inserted into the magnetic layer to divide the magnetic layer into two layers.
    Type: Grant
    Filed: October 2, 1995
    Date of Patent: May 4, 1999
    Assignee: Fujitsu Limited
    Inventors: Iwao Okamoto, Hideyuki Akimoto, Masayoshi Shinohara