Granted Patent
Utility
US 4,190,843 · App. 05/846,667
Recording methods for a multilayer optical record
Inventor:
Fred W. Spong
Patented Case
View Patent ↗
Granted: Feb 26, 1980
Filed: Oct 28, 1977
Inventor
Fred W. Spong
Assignee (at issue)
RCA 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.