Granted Patent
Utility
US 5,033,076 · App. 07/473,003
Enhanced privacy feature for telephone systems
Inventors:
William C. Jones, Wayne R. Kalbow, Eric T. Larsen, Elizabeth M. Mazur
Patented Case
View Patent ↗
Granted: Jul 16, 1991
Filed: Jan 31, 1990
Inventors
William C. Jones
Wayne R. Kalbow
Eric T. Larsen
Elizabeth M. Mazur
Assignee (at issue)
AT&T Bell Laboratories
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.