Granted Patent
Utility
US 4,276,471 · App. 06/076,550
Focus detecting device
Inventor:
Ken Utagawa
Patented Case
View Patent ↗
Granted: Jun 30, 1981
Filed: Sep 18, 1979
Inventor
Ken Utagawa
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.