Granted Patent
Utility
US 6,427,921 · App. 09/683,368
Hidden information on a document for authentication
Inventor:
Daniel F. Dlugos
Patented Case
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Granted: Aug 6, 2002
Filed: Dec 19, 2001
Inventor
Daniel F. Dlugos
Assignee (at issue)
Pitney Bowes Inc.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.