Granted Patent
Utility
US 5,540,589 · App. 08/225,664
Audio interactive tutor
Inventor:
Richard C. Waters
Patented Case
View Patent ↗
Granted: Jul 30, 1996
Filed: Apr 11, 1994
Inventor
Richard C. Waters
Assignee (at issue)
MITSUBISHI ELECTRIC INFORMATION TECHNOLOGY CENTER
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.