Granted Patent
Utility
US 4,309,718 · App. 06/189,498
Service switch arrangement for low level matrixing type television receiver
Inventor:
Fred D. Johnson
Patented Case
View Patent ↗
Granted: Jan 5, 1982
Filed: Sep 22, 1980
Inventor
Fred D. Johnson
Assignee (at issue)
Zenith Radio Corporation
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.