Granted Patent
Utility
US 5,040,217 · App. 07/423,088
Perceptual coding of audio signals
Inventors:
Karlheinz Brandenburg, James David Johnston
Patented Case
View Patent ↗
Granted: Aug 13, 1991
Filed: Oct 18, 1989
Inventors
Karlheinz Brandenburg
James David Johnston
Assignee (at issue)
AT&T Bell Laboratories
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.