Granted Patent
Utility
US 4,617,554 · App. 06/527,131
Keyboard scanning
Inventors:
Charles A. Krause, Randy J. Vander Heyden
Patented Case
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Granted: Oct 14, 1986
Filed: Aug 26, 1983
Inventors
Charles A. Krause
Randy J. Vander Heyden
Assignee (at issue)
Zenith Electronics LLC
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.