Granted Patent
Utility
US 4,355,098 · App. 06/233,657
Supersensitizing direct positive dye combinations
Inventor:
James Walter Wheeler
Patented Case
View Patent ↗
Granted: Oct 19, 1982
Filed: Feb 11, 1981
Inventor
James Walter Wheeler
Assignee (at issue)
E.I. DU PONT DE NEMOURS AND COMPANY
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.