Granted Patent
Utility
US 4,928,307 · App. 07/318,073
Time dependent, variable amplitude threshold output circuit for frequency variant and frequency invariant signal discrimination
Inventor:
Dwight D. Lynn
Patented Case
View Patent ↗
Granted: May 22, 1990
Filed: Mar 2, 1989
Inventor
Dwight D. Lynn
Assignee (at issue)
ACS Communications, Inc.
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.