Granted Patent
Utility
US 4,377,632 · App. 06/334,168
Diffusion transfer film units with application of processing composition between dye developer layer and silver halide emulsion layer
Inventor:
William J. Pflingston
Patented Case
View Patent ↗
Granted: Mar 22, 1983
Filed: Dec 24, 1981
Inventor
William J. Pflingston
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.