Patents by Inventor Russell E. Hopson

Russell E. Hopson 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).

  • Eradicable inks
    Patent number: 6221432
    Abstract: A method of changing the color of an ink mark includes applying an ink including a solvent and a triarylmethane dye dissolved in the solvent that changes color if contacted with a chemical agent to a substrate. The dye is soluble in phenyl cellosolve. A chemical agent is then applied to cause the dye to change color.
    Type: Grant
    Filed: April 28, 1999
    Date of Patent: April 24, 2001
    Inventors: Yichun Wang, Russell E. Hopson
  • Solvent-based pen inks
    Patent number: 6149721
    Abstract: Solvent-based pen inks are provided. The inks include an acid dye and a solvent system that includes an oxa acid solvent, the oxa acid solvent functioning as the primary solvent for the acid dye. Preferred inks are eradicable, and include an acid dye that decolorizes if contacted with a decolorizing compound.
    Type: Grant
    Filed: February 3, 1999
    Date of Patent: November 21, 2000
    Assignee: The Gillette Company
    Inventors: Yichun Wang, Russell E. Hopson
  • Eradicable inks
    Patent number: 5916357
    Abstract: An eradicable ink contains an essentially non-aqueous solvent and a colorant, dissolved in the solvent, that changes color if contacted with a sulfite or an amine. Moreover, a water soluble colorant containing a counterion hydrophilic can be converted into a water insoluble colorant by substituting a hydrophobic counterion for the hydrophilic counterion.
    Type: Grant
    Filed: March 25, 1997
    Date of Patent: June 29, 1999
    Assignee: The Gillette Company
    Inventors: Yichun Wang, Russell E. Hopson