Granted Patent
Utility
US 4,641,189 · App. 06/540,740
Digital vertical sync filter
Inventor:
Julian E. Warrick
Patented Case
View Patent ↗
Granted: Feb 3, 1987
Filed: Oct 11, 1983
Inventor
Julian E. Warrick
Assignee (at issue)
Zenith Electronics 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.