Granted Patent
Utility
US 4,277,271 · App. 06/053,765
Method of manufacturing graded index optical fibers
Inventor:
David A. Krohn
Patented Case
View Patent ↗
Granted: Jul 7, 1981
Filed: Jul 2, 1979
Inventor
David A. Krohn
Assignee (at issue)
EOTEC
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.