Granted Patent
Utility
US 4,839,720 · App. 07/078,341
Compatible widescreen television system with auxiliary subcarrier modulated by side panel high frequency information
Inventor:
Michael A. Isnardi
Patented Case
View Patent ↗
Granted: Jun 13, 1989
Filed: Jul 27, 1987
Inventor
Michael A. Isnardi
Assignee (at issue)
General Electric Company
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.