Granted Patent
Utility
US 4,372,647 · App. 06/192,704
Single mode optical fibers
Inventors:
Katsunari Okamoto, Takao Edahiro, Akio Kawana, Tetsuo Miya
Patented Case
View Patent ↗
Granted: Feb 8, 1983
Filed: Oct 1, 1980
Inventors
Katsunari Okamoto
Takao Edahiro
Akio Kawana
Tetsuo Miya
Assignee (at issue)
Nippon Telegraph and Telephone Public Corporation
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.