Patents by Inventor Wu S. Li

Wu S. Li 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).

  • Tamper resistant security film
    Patent number: 4630891
    Abstract: Security film comprising a monolayer of transparent microspheres supported in a thin layer of binder material, a pressure-sensitive adhesive layer coated on the layer of binder material, and disposed between the pressure-sensitive adhesive and binder layers, at least one patterned layer that has differential adhesion to the pressure-sensitive adhesive layer and the binder layer such that upon attempted elevated-temperature removal of the film from a substrate the film splits, with part of the film remaining on the substrate and part being removed.
    Type: Grant
    Filed: September 14, 1984
    Date of Patent: December 23, 1986
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Wu S. Li