Granted Patent
Utility
US 4,399,474 · App. 06/292,657
Automatic threshold tracking system
Inventor:
Charles H. Coleman, Jr.
Patented Case
View Patent ↗
Granted: Aug 16, 1983
Filed: Aug 10, 1981
Inventor
Charles H. Coleman, Jr.
Assignee (at issue)
Ampex 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.