Granted Patent
Utility
US 4,907,069 · App. 07/201,137
Two-channel compatible HDTV system
Inventor:
Wayne E. Bretl
Patented Case
View Patent ↗
Granted: Mar 6, 1990
Filed: Jun 1, 1988
Inventor
Wayne E. Bretl
Assignee (at issue)
Zenith Electronics 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.