Granted Patent
Utility
US 5,691,847 · App. 08/285,540
Athermalized and achromatized optical systems employing diffractive optical element
Inventor:
Chungte W. Chen
Patented Case
View Patent ↗
Granted: Nov 25, 1997
Filed: Aug 8, 1994
Inventor
Chungte W. Chen
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.