Granted Patent
Utility
US 6,714,640 · App. 09/272,354
Communication system, exchange and extension call processing method
Inventors:
Hiroki Yabe, Hideo Kobayashi
Patented Case
View Patent ↗
Granted: Mar 30, 2004
Filed: Mar 19, 1999
Inventors
Hiroki Yabe
Hideo Kobayashi
Assignee (at issue)
Hitachi Telecom Technologies, Ltd
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.