Granted Patent
Utility
US 5,280,218 · App. 07/764,604
Electrodes with primary and secondary emitters for use in cross-field tubes
Inventor:
Burton H. Smith
Patented Case
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Granted: Jan 18, 1994
Filed: Sep 24, 1991
Inventor
Burton H. Smith
Assignee (at issue)
Raytheon Company
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.