Granted Patent
Utility
US 4,800,432 · App. 06/922,976
Video Difference key generator
Inventors:
Ronnie D. Barnett, Steven Parkes
Patented Case
View Patent ↗
Granted: Jan 24, 1989
Filed: Oct 24, 1986
Inventors
Ronnie D. Barnett
Steven Parkes
Assignee (at issue)
GRASS VALLEY 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.