Granted Patent
Utility
US 5,195,143 · App. 07/708,919
Acoustical ribbon transducer loudspeaker system
Inventors:
Leo Spiegel, Mark B. Nazar
Patented Case
View Patent ↗
Granted: Mar 16, 1993
Filed: May 31, 1991
Inventors
Leo Spiegel
Mark B. Nazar
Assignee (at issue)
Apogee Acoustics, 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.