Granted Patent
Utility
US 4,753,527 · App. 06/945,944
Visual acuity testing apparatus
Inventor:
Taketoshi Ishihara
Patented Case
View Patent ↗
Granted: Jun 28, 1988
Filed: Dec 24, 1986
Inventor
Taketoshi Ishihara
Assignee (at issue)
Kigaku Kikai Kabushiki Kaisha
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.