Granted Patent
Utility
US 5,483,528 · App. 08/321,428
TDM digital matrix intercom system
Inventor:
Steven G. Christensen
Patented Case
View Patent ↗
Granted: Jan 9, 1996
Filed: Oct 11, 1994
Inventor
Steven G. Christensen
Assignee (at issue)
Telex Communications, 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.