Granted Patent
Utility
US 4,574,178 · App. 06/650,403
Electron gun
Inventor:
Helmut Spruck
Patented Case
View Patent ↗
Granted: Mar 4, 1986
Filed: Sep 13, 1984
Inventor
Helmut Spruck
Assignee (at issue)
Leybold-Heraeus GmbH
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.