Granted Patent
Utility
US 4,954,132 · App. 07/323,355
Tinted contact lens and method of tinting with reactive dye and quaternary ammonium salt
Inventors:
William M. Hung, Kai C. Su
Patented Case
View Patent ↗
Granted: Sep 4, 1990
Filed: Mar 14, 1989
Inventors
William M. Hung
Kai C. Su
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.