Granted Patent
Utility
US 6,044,138 · App. 09/197,399
Billing system
Inventors:
R. William Graham, Tony Xu, David M. Tumey
Patented Case
View Patent ↗
Granted: Mar 28, 2000
Filed: Nov 20, 1998
Inventors
R. William Graham
Tony Xu
David M. Tumey
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.