Granted Patent
Utility
US 4,622,441 · App. 06/623,267
Two-wire/four wire communication interface with noise rejection
Inventor:
Philip T. Martin
Patented Case
View Patent ↗
Granted: Nov 11, 1986
Filed: Jun 21, 1984
Inventor
Philip T. Martin
Assignee (at issue)
ITT Corporation
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.