Patents by Inventor Hitoshi Numasaka

Hitoshi Numasaka 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).

  • Multilayered magnetic films and thin-film magnetic heads using the same as a pole
    Patent number: 4814921
    Abstract: Multilayered magnetic films of the invention comprising at least two unit magnetic films each of which has a thickness of from 0.05 to 0.9 .mu.m and includes a plurality of ferromagnetic layers each having a thickness of from 0.01 to 0.2 .mu.m and a 1 nm to 10 nm thick first intermediate layer consisting of a ferromagnetic, nonmagnetic or antiferromagnetic material and provided between adjacent ferromagnetic layers, and a second intermediate layer having a thickness of from 10 to 40 nm, consisting of a nonmagnetic or antiferromagnetic material and provided between the at least two unit magnetic films. The multilayered magnetic film is suitable as a pole of a thin-film magnetic head. An underlayer may be further provided between the magnetic film and a substrate whereby a multilayered magnetic film having good characteristics can be obtained.
    Type: Grant
    Filed: February 1, 1988
    Date of Patent: March 21, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Yoshihiro Hamakawa, Kazuo Shiiki, Yoshihiro Shiroishi, Isamu Yuitoo, Hitoshi Numasaka, Noriyuki Kumasaka, Shigekazu Otomo, Eijin Moriwaki