Granted Patent
Utility
US 4,254,502 · App. 06/071,244
Digital encoding circuitry
Inventors:
Richard E. DeFreitas, John J. Blake
Patented Case
View Patent ↗
Granted: Mar 3, 1981
Filed: Aug 30, 1979
Inventors
Richard E. DeFreitas
John J. Blake
Assignee (at issue)
DeltaLab Research, 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.