Granted Patent
Utility
US 5,774,136 · App. 08/561,470
Ultrasonic method for monitoring inkjet cartridge levels
Inventors:
George Barbehenn, Martin K. Mason
Patented Case
View Patent ↗
Granted: Jun 30, 1998
Filed: Nov 21, 1995
Inventors
George Barbehenn
Martin K. Mason
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.