Granted Patent
Utility
US 6,793,721 · App. 10/293,603
Invisible ink composition and method to ensure document confidentiality
Inventors:
Yu-Chang Shen, In-Shan Sir, Chia-Hsin Chien, Yu-Ting Lin
Patented Case
View Patent ↗
Granted: Sep 21, 2004
Filed: Nov 14, 2002
Inventors
Yu-Chang Shen
In-Shan Sir
Chia-Hsin Chien
Yu-Ting Lin
Assignee (at issue)
BenQ Corporation
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.