Granted Patent
Utility
US 6,069,957 · App. 08/810,441
Method and apparatus for providing hierarchical key system in restricted-access television system
Inventor:
William Richards
Patented Case
View Patent ↗
Granted: May 30, 2000
Filed: Mar 7, 1997
Inventor
William Richards
Assignee (at issue)
LUCENT TECHNOLOGIES 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.