Patents by Inventor Atsushi Tokuma

Atsushi Tokuma 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 for producing a glass substrate for a magnetic disk
    Patent number: 5871654
    Abstract: To reduce occurrence of flaws in a polishing process by preventing an abrasive grain or metallic particles deposited on the surface of a glass substrate for a magnetic disk in a lapping process from entering into the subsequent polishing process. A lapping process for the main surface is a glass substrate for a magnetic disk is conducted; an etching process for the main surface of the glass substrate is conducted to the extent of a depth of 0.1 .mu.m to 3 .mu.m, followed by conducting a polishing process for the main surface of the glass substrate where the etching process has been conducted.
    Type: Grant
    Filed: December 2, 1996
    Date of Patent: February 16, 1999
    Assignee: AG Technology Co., Ltd.
    Inventors: Kazuo Mannami, Ichiro Hayashi, Atsushi Tokuma