Granted Patent
Utility
US 4,303,800 · App. 06/041,984
Reproducing multichannel sound
Inventor:
Richard E. DeFreitas
Patented Case
View Patent ↗
Granted: Dec 1, 1981
Filed: May 24, 1979
Inventor
Richard E. DeFreitas
Assignee (at issue)
Analog and Digital 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.