Patents by Inventor Shigeo Shirai

Shigeo Shirai 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).

  • Felt-tipped pen
    Patent number: D331940
    Type: Grant
    Filed: June 14, 1990
    Date of Patent: December 22, 1992
    Assignee: Shachihata Industrial Co., Inc.
    Inventors: Shigeo Shirai, Tatsuro Funahashi