Granted Patent
Utility
US 6,608,215 · App. 09/957,403
Oxygen-containing heterocyclic fused naphthopyrans
Inventor:
Xuzhi Qin
Patented Case
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Granted: Aug 19, 2003
Filed: Sep 20, 2001
Inventor
Xuzhi Qin
Assignee (at issue)
Vision-Ease Lens
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.