Patents by Inventor Toshio Sakiyama

Toshio Sakiyama 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).

  • Method of manufacturing a magnetic disk substrate of titanium
    Patent number: 5221459
    Abstract: A method of manufacturing a magnetic disk substrate made of titanium, in which chemical etching is performed on a titanium disk for magnetic disk substrate, thereby removing a surface portion thereof having a thickness of at least 2 nm, and the new surface of the titanium disk, formed by the chemical etching, is anodized, thereby forming anodized film on the titanium disk.
    Type: Grant
    Filed: April 24, 1992
    Date of Patent: June 22, 1993
    Assignee: NKK Corporation
    Inventors: Yoko Okano, Hiroyoshi Suenaga, Toshio Sakiyama, Kenji Morita, Masanori Ohmura, Iwao Ida, Hitoshi Nagashima
  • Method for mirror polishing of ti-made magnetic disk substrate
    Patent number: 5136819
    Abstract: According to a mirror surface polishing process of the present invention, it is possible to produce Ti-made magnetic disc substrate which have the excellent flatness degree and surface roughness in that the average roughness is not more than 0.05 .mu.m and the flatness degree of the outer periphery is not more than 0.15 .mu.m.
    Type: Grant
    Filed: February 1, 1991
    Date of Patent: August 11, 1992
    Inventors: Masakuni Takagi, Hiroyoshi Takeuchi, Hideaki Fukai, Toshio Sakiyama, Hiroyoshi Suenaga, Kuninori Minakawa
  • Method of manufacturing titanium magnetic disk substrate
    Patent number: 5131995
    Abstract: After the surface roughness of a titanium substrate is set to be R.sub.max .ltoreq.0.08 .mu.m, a hardened layer having a hardness of H.sub.v .gtoreq.250 is formed thereon to have a thickness of 50 to 250 .mu.m by sputtering, thereby manufacturing a titanium magnetic disk substrate.
    Type: Grant
    Filed: February 28, 1991
    Date of Patent: July 21, 1992
    Assignee: NKK Corporation
    Inventors: Hiroyoshi Suenaga, Hideaki Fukai, Toshio Sakiyama, Kuninori Minakawa