Granted Patent
Utility
US 4,186,993 · App. 05/835,786
Epidark illumination system
Inventors:
Yoshiyuki Shimizu, Takeshi Sudo
Patented Case
View Patent ↗
Granted: Feb 5, 1980
Filed: Sep 22, 1977
Inventors
Yoshiyuki Shimizu
Takeshi Sudo
Assignee (at issue)
Nippon Kogaku K.K.
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.