Granted Patent
Utility
US 4,489,152 · App. 06/584,597
Photographic product for silver transfer images with polyvinylpyrrolidone in carbon black layer
Inventors:
David F. Oberhauser, Peter H. Roth
Patented Case
View Patent ↗
Granted: Dec 18, 1984
Filed: Feb 29, 1984
Inventors
David F. Oberhauser
Peter H. Roth
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.