Granted Patent
Utility
US 4,393,404 · App. 06/238,510
Special services teletext communications system
Inventors:
Charles Cox, William L. Thomas
Patented Case
View Patent ↗
Granted: Jul 12, 1983
Filed: Feb 26, 1981
Inventors
Charles Cox
William L. Thomas
Assignee (at issue)
Zenith Radio 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.