Granted Patent
Utility
US 4,488,807 · App. 06/401,199
Light valve/fader and control circuit
Inventor:
Charles J. Watson
Patented Case
View Patent ↗
Granted: Dec 18, 1984
Filed: Jul 23, 1982
Inventor
Charles J. Watson
Assignee (at issue)
Bell and Howell, LLC
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.