Patents by Inventor David R Dinn

David R Dinn 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).

  • Method of authenticating watermarked paper
    Patent number: 5854673
    Abstract: A method of authenticating watermarked paper comprises the steps of transtly heating a first surface (50) of a watermarked sheet of paper (40) using a hot air source (22); forming a thermal image of the watermark (42) using a thermal imager (30); and analyzing the thermal image to determine whether or not the watermarked paper is authentic. The evolution of the thermal image with time is characteristic of the watermark and is dependent on the local thermal mass of the paper in the region of the watermark.
    Type: Grant
    Filed: June 3, 1997
    Date of Patent: December 29, 1998
    Assignees: Secretary of State for Defence in her Britannic Majesty's Government of the United Kingdom of Great Britain & Northern Ireland of Defence, Evaluation Research Agency
    Inventors: Marc I J Beale, David R Dinn