Granted Patent
Utility
US 5,997,993 · App. 08/975,279
Protective overcoat useful for enhancing an article resistance to ambient humidity
Inventors:
Daoshen Bi, John M. Hardin
Patented Case
View Patent ↗
Granted: Dec 7, 1999
Filed: Nov 20, 1997
Inventors
Daoshen Bi
John M. Hardin
Assignee (at issue)
Polaroid 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.