Granted Patent
Utility
US 4,791,257 · App. 06/484,804
Key element for a contactless keyboard
Inventors:
Werner Frey, Johannes Rometsch, Karl Iseli, Peter Wild
Patented Case
View Patent ↗
Granted: Dec 13, 1988
Filed: Apr 14, 1983
Inventors
Werner Frey
Johannes Rometsch
Karl Iseli
Peter Wild
Assignee (at issue)
Alcatel N.V.
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.