Granted Patent
Utility
US 5,007,000 · App. 07/373,281
Classification of audio signals on a telephone line
Inventor:
Charles A. Baldi
Patented Case
View Patent ↗
Granted: Apr 9, 1991
Filed: Jun 28, 1989
Inventor
Charles A. Baldi
Assignee (at issue)
International Telesystems, 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.