Granted Patent
Utility
US 4,284,839 · App. 05/970,673
Internal refractor focusing solar energy collector apparatus and method
Inventor:
Steven A. Johnson
Patented Case
View Patent ↗
Granted: Aug 18, 1981
Filed: Dec 18, 1978
Inventor
Steven A. Johnson
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.