Granted Patent
Utility
US 5,889,870 · App. 08/684,311
Acoustic heterodyne device and method
Inventor:
Elwood G. Norris
Patented Case
View Patent ↗
Granted: Mar 30, 1999
Filed: Jul 17, 1996
Inventor
Elwood G. Norris
Assignee (at issue)
American Technology 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.