Granted Patent
Utility
US 6,157,489 · App. 09/198,733
Color shifting thin film pigments
Inventors:
Richard A. Bradley, Jr., Matthew R. Witzman
Patented Case
View Patent ↗
Granted: Dec 5, 2000
Filed: Nov 24, 1998
Inventors
Richard A. Bradley, Jr.
Matthew R. Witzman
Assignee (at issue)
Flex Products, 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.