Granted Patent
Utility
US 4,881,271 · App. 07/153,906
Portable wireless communication systems
Inventors:
Yukiji Yamauchi, Nobuo Tsukamoto, Masahiro Koya
Patented Case
View Patent ↗
Granted: Nov 14, 1989
Filed: Feb 9, 1988
Inventors
Yukiji Yamauchi
Nobuo Tsukamoto
Masahiro Koya
Assignee (at issue)
HITACHI, 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.