Patents by Inventor Tatsuo Kumura

Tatsuo Kumura 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: 4953050
    Abstract: A magnetic head is disclosed which is formed by magnetic core halves constituted of an oxide magnetic material and soft magnetic thin films, wherein the boundary surfaces between the thin films and the oxide magnetic material runs substantially parallel to the gap surface in the vicinity of the magnetic gap. The soft magnetic thin films are soft magnetic thin films of the Fe-Ga-Si system consisting essentially of Fe, Ga and Si.
    Type: Grant
    Filed: January 10, 1990
    Date of Patent: August 28, 1990
    Assignee: Sony Corporation
    Inventors: Tatsuo Kumura, Heikichi Sato, Yoshiyuki Kunito, Yoshito Ikeda, Etsuo Izu, Masatoshi Hayakawa
  • Patent number: 4819113
    Abstract: A magnetic transducer head in which the magnetic core elements of ferromagnetic oxides are sliced obliquely across the junction surface of the core elements, ferromagnetic metal thin films are formed on the resulting inclined surfaces by employing a physical vapor deposition, and the core elements are placed with the respective ferromagnetic metal thin films abutting to each other for defining a magnetic gap therebetween, wherein the improvement consists in that said inclined surfaces with the ferromagnetic metal thin films formed thereon are inclined at a preset angle with the magnetic gap forming surface, in that non-magnetic films having high-hardness are interposed between the ferromagnetic oxide and the ferromagnetic metal thin films, and in that said ferromagnetic metal thin films and the oxide glass fillers are provided on the tape abutment surface by the intermediary of the non-magnetic film having high-hardness.
    Type: Grant
    Filed: March 19, 1985
    Date of Patent: April 4, 1989
    Assignee: Sony Corporation
    Inventors: Makoto Kubota, Tatsuo Kumura, Junichi Saito, Tomio Kobayashi, Heikichi Sato
  • Patent number: 4755899
    Abstract: A magnetic transducer head comprising a first magnetic core element and a second magnetic core element, each of the first and second core elements comprising a magnetic ferrite block and a magnetic metal thin film integrated with the magnetic ferrite block. These core elements having a first planar surface and a second planar surface. The magnetic metal thin film being provided on the second planar surface and having an edge thereof facing to the first planar surface, and the second planar surface being slantly provided with respect to said first planar surface. These core elements being bonded together to form an operating magnetic gap between the edge of the magnetic metal thin film on the first core element and the edge of the magnetic metal thin film on the second core element. The magnetic metal thin film on the first core element or the magnetic thin film on the second core element is formed in one common plane.
    Type: Grant
    Filed: December 26, 1984
    Date of Patent: July 5, 1988
    Assignee: Sony Corporation
    Inventors: Tomio Kobayashi, Heikichi Sato, Makoto Kubota, Shoichi Kano, Tatsuo Kumura, Kazushi Yamauchi, Yoshimi Takahashi, Junichi Saito
  • Patent number: 4683012
    Abstract: A magnetic thin film consisting essentially of Fe, Al and Si and further containing nitrogen has high magnetic permeability and high hardness without lowering the magnetic properties such as saturation magnetic flux density or coercive force.The magnetic thin film has an increased specific resistivity and a lowered eddy current loss in the high frequency region and is suitable for a core material of magnetic transducer heads used in a high frequency region.The magnetic thin film is prepared by, for example, physical vapor deposition or ion implantation.
    Type: Grant
    Filed: April 5, 1985
    Date of Patent: July 28, 1987
    Assignee: Sony Corporation
    Inventors: Kazushi Yamauchi, Muneyuki Ogata, Tomio Kobayashi, Makoto Kubota, Tatsuo Kumura
  • Patent number: 4671828
    Abstract: A magnetic thin film consisting essentially of Fe, Al and Si and further containing oxygen has high magnetic permeability and high hardness without lowering the magnetic properties such as saturation magnetic flux density or coercive force.The magnetic thin film has an increased specific resistivity and a lowered eddy current loss in the high frequency region and is suitable for a core material of magnetic transducer heads used in a high frequency region.The magnetic thin film is prepared by, for example, physical vapor deposition or ion implantation.
    Type: Grant
    Filed: April 5, 1985
    Date of Patent: June 9, 1987
    Assignee: Sony Corporation
    Inventors: Kazushi Yamauchi, Muneyuki Ogata, Tomio Kobayashi, Makoto Kubota, Tatsuo Kumura