Granted Patent
Utility
US 4,267,439 · App. 06/102,663
Document reader lamp life extension system
Inventors:
Robert J. Thomas, Michael Piekarski
Patented Case
View Patent ↗
Granted: May 12, 1981
Filed: Dec 12, 1979
Inventors
Robert J. Thomas
Michael Piekarski
Assignee (at issue)
Key Tronic 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.