Granted Patent
Utility
US 4,641,928 · App. 06/593,924
Four-group telephoto zoom lens
Inventor:
Yoshinari Hamanishi
Patented Case
View Patent ↗
Granted: Feb 10, 1987
Filed: Mar 27, 1984
Inventor
Yoshinari Hamanishi
Assignee (at issue)
Nippon Kokagu 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.