Granted Patent
Utility
US 6,005,941 · App. 08/857,481
Method and apparatus for providing optional service functions in a private branch exchange
Inventor:
Hodaka Kurosawa
Patented Case
View Patent ↗
Granted: Dec 21, 1999
Filed: May 16, 1997
Inventor
Hodaka Kurosawa
Assignee (at issue)
Oki Electric Co., 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.