Granted Patent
Utility
US 6,141,406 · App. 08/866,587
Method and apparatus for detecting a secondary destination of a telephone call based on changes in the telephone signal path
Inventor:
John C. Johnson
Patented Case
View Patent ↗
Granted: Oct 31, 2000
Filed: May 30, 1997
Inventor
John C. Johnson
Assignee (at issue)
T-Netix, 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.