Granted Patent
Utility
US 4,871,219 · App. 07/218,420
Wide spectral band infrared refractive lens
Inventor:
Erwin E. Cooper
Patented Case
View Patent ↗
Granted: Oct 3, 1989
Filed: Jul 12, 1988
Inventor
Erwin E. Cooper
Assignee (at issue)
Texas Instruments 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.