Granted Patent
Utility
US 4,311,786 · App. 06/167,551
Novel sensitizers and their use in direct-positive photographic materials
Inventors:
Rolf Steiger, Jean-Francois Reber
Patented Case
View Patent ↗
Granted: Jan 19, 1982
Filed: Jul 11, 1980
Inventors
Rolf Steiger
Jean-Francois Reber
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.