Granted Patent
Utility
US 4,040,825 · App. 05/665,981
Spectral sensitization of photographic material with natural colloids containing sensitizing dye groups
Inventors:
Rolf Steiger, Jean-Francois Reber, Aaron David Ezekiel, Geoffrey E. Ficken
Patented Case
View Patent ↗
Granted: Aug 9, 1977
Filed: Mar 11, 1976
Inventors
Rolf Steiger
Jean-Francois Reber
Aaron David Ezekiel
Geoffrey E. Ficken
Assignee (at issue)
Ciba-Geigy
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.