Granted Patent
Utility
US 4,952,226 · App. 07/316,192
Lightguide coating control
Inventors:
Ralph E. Frazee, Jr., David H. Smithgall, Sr.
Patented Case
View Patent ↗
Granted: Aug 28, 1990
Filed: Feb 27, 1989
Inventors
Ralph E. Frazee, Jr.
David H. Smithgall, Sr.
Assignee (at issue)
American Telephone and Telegraph, Co.
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.