Granted Patent
Utility
US 4,286,052 · App. 06/110,952
Method for making stained glass photomasks using stabilized glass
Inventor:
Fred M. Ernsberger
Patented Case
View Patent ↗
Granted: Aug 25, 1981
Filed: Jan 10, 1980
Inventor
Fred M. Ernsberger
Assignee (at issue)
PPG Industries, 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.