Granted Patent
Utility
US 4,975,663 · App. 07/206,913
Frequency equalizer
Inventor:
Dan Barbour
Patented Case
View Patent ↗
Granted: Dec 4, 1990
Filed: Jun 10, 1988
Inventor
Dan Barbour
Assignee (at issue)
Rockwell International Corporation
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.