Granted Patent
Utility
US 4,253,752 · App. 06/079,087
Focus condition detecting device
Inventor:
Yutaka Ichihara
Patented Case
View Patent ↗
Granted: Mar 3, 1981
Filed: Sep 26, 1979
Inventor
Yutaka Ichihara
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.