Granted Patent
Utility
US 4,412,153 · App. 06/293,026
Dual filament ion source
Inventors:
Charles R. Kalbfus, Norman L. Turner
Patented Case
View Patent ↗
Granted: Oct 25, 1983
Filed: Aug 14, 1981
Inventors
Charles R. Kalbfus
Norman L. Turner
Assignee (at issue)
Varian, 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.