Granted Patent
Utility
US 4,030,128 · App. 05/526,019
Video record scrambling and unscrambling
Inventor:
Ludwig A. Perret
Patented Case
View Patent ↗
Granted: Jun 14, 1977
Filed: Nov 21, 1974
Inventor
Ludwig A. Perret
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.