Granted Patent
Utility
US 4,987,569 · App. 07/333,992
Fast training echo canceller
Inventors:
Fuyun Ling, Guozhu Long
Patented Case
View Patent ↗
Granted: Jan 22, 1991
Filed: Apr 5, 1989
Inventors
Fuyun Ling
Guozhu Long
Assignee (at issue)
Codex Corporation
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.