Granted Patent
Utility
US 5,009,486 · App. 07/327,542
Form depicting, optical interference authenticating device
Inventors:
Jerzy A. Dobrowolski, Fang-Chuan Ho, Allan J. Waldorf
Patented Case
View Patent ↗
Granted: Apr 23, 1991
Filed: Mar 23, 1989
Inventors
Jerzy A. Dobrowolski
Fang-Chuan Ho
Allan J. Waldorf
Assignee (at issue)
Canadian Patents and Development Limited/Societe Canadienne des Brevets et d'Exploitation Limitee
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.