Granted Patent
Utility
US 4,019,201 · App. 05/609,573
Method and apparatus for scrambling and unscrambling communication signals
Inventors:
Albert F. Hartung, Frank W. Lehan, Charles T. Barooshian, Edward J. Zacharski
Patented Case
View Patent ↗
Granted: Apr 19, 1977
Filed: Sep 2, 1975
Inventors
Albert F. Hartung
Frank W. Lehan
Charles T. Barooshian
Edward J. Zacharski
Assignee (at issue)
SYSTEM DEVELOPMENT INC.
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.