Granted Patent
Utility
US 4,661,702 · App. 06/664,196
Primary ion beam raster gating technique for secondary ion mass spectrometer system
Inventor:
David G. Welkie
Patented Case
View Patent ↗
Granted: Apr 28, 1987
Filed: Oct 24, 1984
Inventor
David G. Welkie
Assignee (at issue)
PerkinElmer, 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.