Granted Patent
Utility
US 4,687,917 · App. 06/661,456
Focus detecting device for removing vignetting effects
Inventors:
Yosuke Kusaka, Ken Utagawa
Patented Case
View Patent ↗
Granted: Aug 18, 1987
Filed: Oct 16, 1984
Inventors
Yosuke Kusaka
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.