Granted Patent
Utility
US 5,160,171 · App. 07/652,260
Security coding
Inventors:
Peter Gregory, Arthur Quayle
Patented Case
View Patent ↗
Granted: Nov 3, 1992
Filed: Feb 6, 1991
Inventors
Peter Gregory
Arthur Quayle
Assignee (at issue)
IMPERIAL CHEMICAL INDUSTRIES LIMITED
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.