Granted Patent
Utility
US 4,403,231 · App. 06/343,983
Data recording medium
Inventors:
Hideo Ando, Toshiharu Nakagawa
Patented Case
View Patent ↗
Granted: Sep 6, 1983
Filed: Jan 29, 1982
Inventors
Hideo Ando
Toshiharu Nakagawa
Assignee (at issue)
Tokyo Shibaura Denki Kabushiki Kaisha
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.