Granted Patent
Utility
US 5,009,992 · App. 07/453,833
Photographic silver halide emulsion
Inventors:
Wolfgang Friedrich, Alfred Worsching
Patented Case
View Patent ↗
Granted: Apr 23, 1991
Filed: Dec 20, 1989
Inventors
Wolfgang Friedrich
Alfred Worsching
Assignee (at issue)
E.I. DU PONT DE NEMOURS AND COMPANY
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.