Patents by Inventor Koji Fukumoto

Koji Fukumoto 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: 5872691
    Abstract: A thin-film magnetic head, a magnetoresistance effect magnetic head and an MR inductive head are disclosed. The thin-film magnetic head has one of thin-film magnetic cores stacked on a substrate and formed of two magnetic films and a non-magnetic film held between them, with a current flowing through the thin-film magnetic core in the direction of hard axis thereof. The magnetoresistance effect magnetic head has one of a pair of shield cores having a magnetoresistive element between them formed of two magnetic films and a non-magnetic film held between them, the magnetoresistive element being electrically connected to the shield core, with a sense current flowing through the shield core. The current flowing through the one shield core via the magnetoresistive element is preferably an AC of decrement amplitude for demagnetizing the shield core along with a DC sense current.
    Type: Grant
    Filed: December 9, 1997
    Date of Patent: February 16, 1999
    Assignee: Sony Corporation
    Inventors: Munekatsu Fukuyama, Yasuo Sasaki, Yutaka Soda, Koji Fukumoto, Tetsuo Sekiya
  • Patent number: 5825594
    Abstract: A magneto-resistance effect-type magnetic head according to the present invention can generate a high reproduction output by increasing a quantity of magnetic flux passing across an effective magneto-sensitive zone of a magneto-resistance effect element, while maintaining its inherent functions as a means for preventing unnecessary magnetic flux from entering the MR element or as a recording pole. The magneto-resistance effect-type magnetic head for reproducing signals from a magnetic recording medium, includes a magneto-resistance effect element, upper and lower magnetic layers between which the magneto-resistance effect element is interposed, and a low-permeability magnetic layer provided on at least one of surfaces of the upper and lower magnetic layers which surfaces are opposed to the magneto-resistance effect element, the low-permeability magnetic layer having a magnetic permeability not more than half of a magnetic permeability of the upper or lower magnetic layer.
    Type: Grant
    Filed: November 6, 1996
    Date of Patent: October 20, 1998
    Assignee: Sony Corporation
    Inventors: Koji Fukumoto, Yutaka Soda, Norio Saito, Takuji Shibata
  • Patent number: 5822159
    Abstract: A thin-film magnetic head, a magnetoresistance effect magnetic head and an MR inductive head are disclosed. The thin-film magnetic head has one of thin-film magnetic cores stacked on a substrate and formed of two magnetic films and a non-magnetic film held between them, with a current flowing through the thin-film magnetic core in the direction of hard axis thereof. The magnetoresistance effect magnetic head has one of a pair of shield cores having a magnetoresistive element between them formed of two magnetic films and a non-magnetic film held between them, the magnetoresistive element being electrically connected to the shield core, with a sense current flowing through the shield core. The current flowing through the one shield core via the magnetoresistive element is preferably an AC of decrement amplitude for demagnetizing the shield core along with a DC sense current.
    Type: Grant
    Filed: April 4, 1997
    Date of Patent: October 13, 1998
    Assignee: Sony Corporation
    Inventors: Munekatsu Fukuyama, Yasuo Sasaki, Yutaka Soda, Koji Fukumoto, Tetsuo Sekiya