Granted Patent
Utility
US 4,837,133 · App. 06/943,942
Photographic four-color material for the silver dye bleach process
Inventor:
Jakob Kuhn
Patented Case
View Patent ↗
Granted: Jun 6, 1989
Filed: Dec 9, 1986
Inventor
Jakob Kuhn
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.