Granted Patent
Utility
US 5,271,816 · App. 07/815,582
Oxygen sensor
Inventors:
Hiroshi Tanaka, Masashi Tanaka, Shigekazu Yamauchi, Masaru Fukunaga
Patented Case
View Patent ↗
Granted: Dec 21, 1993
Filed: Dec 30, 1991
Inventors
Hiroshi Tanaka
Masashi Tanaka
Shigekazu Yamauchi
Masaru Fukunaga
Assignee (at issue)
MITSUBISHI JIDOSHA KOGYO 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.