Granted Patent
Utility
US 4,994,354 · App. 07/427,509
Optical recording media
Inventors:
Hisaharu Toibana, Mitsuyuki Kuroiwa, Takeshi Minoda, Akira Todo
Patented Case
View Patent ↗
Granted: Feb 19, 1991
Filed: Oct 27, 1989
Inventors
Hisaharu Toibana
Mitsuyuki Kuroiwa
Takeshi Minoda
Akira Todo
Assignee (at issue)
Mitsui Petrochemical Industries, Ltd.
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.