Granted Patent
Utility
US 5,237,448 · App. 07/890,391
Visibility enhancing material
Inventors:
Andrew B. Spencer, Clifford S. Ferguson
Patented Case
View Patent ↗
Granted: Aug 17, 1993
Filed: May 26, 1992
Inventors
Andrew B. Spencer
Clifford S. Ferguson
Assignee (at issue)
American Ingenuity, LLC
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.