Granted Patent
Utility
US 4,268,312 · App. 06/082,883
Optical glass
Inventors:
Kazufumi Ishibashi, Takeo Ichimura
Patented Case
View Patent ↗
Granted: May 19, 1981
Filed: Oct 9, 1979
Inventors
Kazufumi Ishibashi
Takeo Ichimura
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.