Granted Patent
Utility
US 4,973,993 · App. 07/378,354
Ink-quantity and low ink sensing for ink-jet printers
Inventor:
Ross R. Allen
Patented Case
View Patent ↗
Granted: Nov 27, 1990
Filed: Jul 11, 1989
Inventor
Ross R. Allen
Assignee (at issue)
Hewlett-Packard Company, L.P.
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.