Patents by Inventor Atsuhiko Nagai

Atsuhiko Nagai 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: 6717779
    Abstract: A magnetoresistive head includes a first magnetic shield, an antiferromagnetic layer provided on the first magnetic shield, a pinned ferromagnetic layer provided on the antiferromagnetic layer, a nonmagnetic intermediate layer provided on the pinned ferromagnetic layer, and a free ferromagnetic layer provided on the nonmagnetic intermediate layer. The magnetoresistive head further includes a pair of hard magnetic film bias layers provided on the opposite sides of the free ferromagnetic layer, a pair of terminal layers provided on the hard magnetic film bias layers, a metal oxide film formed on the free ferromagnetic layer at an exposed portion between the pair of terminal layers, and a second magnetic shield provided on the pair of terminal layers and the metal oxide film.
    Type: Grant
    Filed: September 26, 2001
    Date of Patent: April 6, 2004
    Assignee: Fujitsu Limited
    Inventor: Atsuhiko Nagai
  • Publication number: 20020181173
    Abstract: A magnetoresistive head includes a first magnetic shield, an antiferromagnetic layer provided on the first magnetic shield, a pinned ferromagnetic layer provided on the antiferromagnetic layer, a nonmagnetic intermediate layer provided on the pinned ferromagnetic layer, and a free ferromagnetic layer provided on the nonmagnetic intermediate layer. The magnetoresistive head further includes a pair of hard magnetic film bias layers provided on the opposite sides of the free ferromagnetic layer, a pair of terminal layers provided on the hard magnetic film bias layers, a metal oxide film formed on the free ferromagnetic layer at an exposed portion between the pair of terminal layers, and a second magnetic shield provided on the pair of terminal layers and the metal oxide film.
    Type: Application
    Filed: September 26, 2001
    Publication date: December 5, 2002
    Applicant: FUJITSU LIMITED
    Inventor: Atsuhiko Nagai
  • Patent number: 6199267
    Abstract: A method for the production of a magnetic head, where first a lower magnetic pole is formed on a wafer. Next, a nonmagnetic write gap layer is formed on the lower magnetic pole. A coil is then formed to be sandwiched between nonmagnetic insulating layers on the nonmagnetic write gap layer. Finally, an upper magnetic pole, provided with a pole tip, is formed to contact the write gap layer on the nonmagnetic write gap layer. After formation, a focused ion beam is irradiated in the direction from a thickness of the pole tip to the lateral parts of the pole tip, the nonmagnetic write gap layer lying directly thereunder. The lower magnetic pole thereby trims the lateral parts of the pole tip while consequently decreasing the width of the pole tip. At the same time, depressed parts are formed in the lower magnetic pole in the areas extending outward from directly below the lateral parts of the pole tip.
    Type: Grant
    Filed: March 31, 1999
    Date of Patent: March 13, 2001
    Assignee: Fujitsu, Limited
    Inventors: Takao Koshikawa, Atsuhiko Nagai
  • Patent number: 5966277
    Abstract: A magnetic head comprising a lower magnetic pole formed on a wafer, a nonmagnetic write gap layer formed on the lower magnetic pole, an upper magnetic pole formed on the nonmagnetic write gap layer and provided with a pole tip possessing a thin leading end, two depressed parts formed in the lateral directions from directly below the lateral sides of the pole tip and opposed to each other across areas equal in width with the pole tip, a protective layer of a nonmagnetic insulating material adapted to fill the depressed parts and, at the same time, cover the upper magnetic pole and the lower magnetic pole, and a coil nipped between the opposed parts of a nonmagnetic insulating layer interposed between the upper magnetic pole and the lower magnetic pole.
    Type: Grant
    Filed: December 29, 1997
    Date of Patent: October 12, 1999
    Assignee: Fujitsu Limited
    Inventors: Takao Koshikawa, Atsuhiko Nagai