Granted Patent
Utility
US 5,053,928 · App. 07/568,256
Light guide
Inventor:
Ian K. Pasco
Patented Case
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Granted: Oct 1, 1991
Filed: Aug 15, 1990
Inventor
Ian K. Pasco
Assignee (at issue)
Technophone Limited
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.