Granted Patent
Utility
US 4,621,156 · App. 06/309,914
Optical filter agents and photographic products and processes containing same
Inventors:
Derek H. R. Barton, Irena Y. Bronstein-Bonte, Lloyd D. Taylor
Patented Case
View Patent ↗
Granted: Nov 4, 1986
Filed: Oct 8, 1981
Inventors
Derek H. R. Barton
Irena Y. Bronstein-Bonte
Lloyd D. Taylor
Assignee (at issue)
Polaroid 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.