Patents by Inventor Howard D. Nelson

Howard D. Nelson 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).

  • Black image from a thermographic imaging system
    Patent number: 4379835
    Abstract: A thermographic imaging system comprising a single layer and capable of providing a stable dark to black image upon localized heating is disclosed. The single layer comprises a polymeric binder, a combination of at least two leuco dyes, and a nitrate salt.
    Type: Grant
    Filed: December 22, 1980
    Date of Patent: April 12, 1983
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Robert D. Lowrey, Howard D. Nelson, George Van Dyke Tiers