Patents by Inventor Ho Wai-Kwan

Ho Wai-Kwan 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).

  • Calculator
    Patent number: 4892999
    Abstract: A see-through calculator or memory device comprises a transparent base, a see-through printed circuit board and a transparent switch panel. Liquid is housed in a cavity in the base, formed by welding to the base a panel above a recess in the base.
    Type: Grant
    Filed: July 15, 1988
    Date of Patent: January 9, 1990
    Assignee: Leona Electronics Co., Ltd.
    Inventor: Ho Wai-Kwan