Granted Patent
Utility
US 4,557,434 · App. 06/418,907
Tape remaining circuit
Inventor:
Marshall Williams
Patented Case
View Patent ↗
Granted: Dec 10, 1985
Filed: Sep 16, 1982
Inventor
Marshall Williams
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.