Patents by Inventor Katuo Uda

Katuo Uda 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).

  • Magnetic disk with surface protective layer having convex portions and magnetic disk apparatus including such a magnetic disk
    Patent number: 5285343
    Abstract: There is provided a magnetic disk apparatus including at least one magnetic disk having a magnetic layer and a surface protective layer on a substrate; a magnetic head which faces the magnetic disk in a rotating state with a micro gap and is supported by a slider; rotating means for rotating the magnetic disk; and magnetic head positioning means for moving and positioning the magnetic head to a predetermined position on the magnetic disk, wherein a plurality of protrusions each having a flat surface are formed in at least a region on the surface of the magnetic disk where a contact start/stop operation can be executed, an area ratio of the protrusions per 1 mm.sup.2 lies within a range from 0.1 to 80%, a height of the protrusion of the maximum height among the protrusions lies within a range from 5 to 40 nm, and the magnetic layer is formed on the whole surface on the base plate.
    Type: Grant
    Filed: October 11, 1990
    Date of Patent: February 8, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Hideaki Tanaka, Kenichi Gomi, Shoichi Sawahata, Maki Kondo, Masaki Ohura, Norikazu Tsumita, Katuo Uda, Yoshiki Kato, Yoshihiko Miyake, Toyoji Okuwaki, Noriaki Okamoto, Nobuo Nakagawa