Granted Patent
Utility
US 4,724,307 · App. 06/857,114
Marked card reader
Inventors:
Clifton Dutton, William R. Patterson
Patented Case
View Patent ↗
Granted: Feb 9, 1988
Filed: Apr 29, 1986
Inventors
Clifton Dutton
William R. Patterson
Assignee (at issue)
GTECH Corporation
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.