Granted Patent
Utility
US 6,827,420 · App. 10/323,050
Device verification using printed patterns and optical sensing
Inventors:
Michael Clark Campbell, Gregory Scott Woods
Patented Case
View Patent ↗
Granted: Dec 7, 2004
Filed: Dec 18, 2002
Inventors
Michael Clark Campbell
Gregory Scott Woods
Assignee (at issue)
Lexmark International, 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.