Granted Patent
Utility
US 4,297,571 · App. 06/109,282
Focus detecting device
Inventors:
Ken Utagawa, Kunihisa Hoshino, Hiroshi Shirasu, Akira Ogasawara
Patented Case
View Patent ↗
Granted: Oct 27, 1981
Filed: Jan 3, 1980
Inventors
Ken Utagawa
Kunihisa Hoshino
Hiroshi Shirasu
Akira Ogasawara
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.