Granted Patent
Utility
US 4,575,482 · App. 06/552,220
Photographic silver dye bleach materials containing formyl-substituted azo compounds as image dyes
Inventor:
John Lenoir
Patented Case
View Patent ↗
Granted: Mar 11, 1986
Filed: Nov 14, 1983
Inventor
John Lenoir
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.