Granted Patent
Utility
US 4,017,725 · App. 05/538,308
Solar powered portable calculator
Inventor:
Stephen A. Roen
Patented Case
View Patent ↗
Granted: Apr 12, 1977
Filed: Jan 3, 1975
Inventor
Stephen A. Roen
Assignee (at issue)
Litton Business Systems, Inc.
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.