Granted Patent
Utility
US 4,621,909 · App. 06/485,481
Photographic lens of a great aperture ratio
Inventor:
Yoshinari Hamanishi
Patented Case
View Patent ↗
Granted: Nov 11, 1986
Filed: Apr 15, 1983
Inventor
Yoshinari Hamanishi
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.