Granted Patent
Utility
US 4,531,021 · App. 06/640,212
Two level encripting of RF signals
Inventors:
Leo I. Bluestein, Paul E. Crandell, David A. Drake, Leo Jedynak, Larry Wayne Simpson
Patented Case
View Patent ↗
Granted: Jul 23, 1985
Filed: Aug 13, 1984
Inventors
Leo I. Bluestein
Paul E. Crandell
David A. Drake
Leo Jedynak
Larry Wayne Simpson
Assignee (at issue)
Oak Industries 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.