Granted Patent
Utility
US 4,697,892 · App. 06/642,825
Projection lens
Inventor:
Ellis I. Betensky
Patented Case
View Patent ↗
Granted: Oct 6, 1987
Filed: Aug 21, 1984
Inventor
Ellis I. Betensky
Assignee (at issue)
U.S. Precision Lens Incorporated
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.