Granted Patent
Utility
US 4,338,111 · App. 06/218,226
Process for producing a glass preform for optical fiber
Inventors:
Takao Edahiro, Michihisa Kyoto, Gotaro Tanaka, Toru Kuwahara
Patented Case
View Patent ↗
Granted: Jul 6, 1982
Filed: Dec 19, 1980
Inventors
Takao Edahiro
Michihisa Kyoto
Gotaro Tanaka
Toru Kuwahara
Assignees (at issue)
Nippon Telegraph and Telephone Public Corporation
SUMITOMO ELECTRIC INDUSTRIES, LTD.
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.