Granted Patent
Utility
US 4,660,978 · App. 06/683,783
Direct slope measurement shearing interferometer
Inventor:
Ning Wu
Patented Case
View Patent ↗
Granted: Apr 28, 1987
Filed: Dec 19, 1984
Inventor
Ning Wu
Assignee (at issue)
Hughes Aircraft Company
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.