Granted Patent
Utility
US 4,925,594 · App. 07/341,887
Hydrolysis resistance of rare earth oxysulfide phosphors produced by the addition of zinc in synthesis
Inventor:
Ramon L. Yale
Patented Case
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Granted: May 15, 1990
Filed: Apr 24, 1989
Inventor
Ramon L. Yale
Assignee (at issue)
GTE Products 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.