Granted Patent
Utility
US 4,229,577 · App. 05/900,675
Yellow photographic color couplers containing 3-imino-1,3,4-thiadiazolyl-4 groups
Inventors:
Graham Evans, Mario Fryberg, Thomas Stauner, Paul Tschopp, David G. Leppard
Patented Case
View Patent ↗
Granted: Oct 21, 1980
Filed: Apr 27, 1978
Inventors
Graham Evans
Mario Fryberg
Thomas Stauner
Paul Tschopp
David G. Leppard
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.