Granted Patent
Utility
US 4,289,385 · App. 06/118,699
Photographic lens with rear stop diaphragm
Inventor:
Masakazu Yamagata
Patented Case
View Patent ↗
Granted: Sep 15, 1981
Filed: Feb 5, 1980
Inventor
Masakazu Yamagata
Assignee (at issue)
Asahi Kogaku Kogyo Kabushiki Kaisha
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.