Granted Patent
Utility
US 4,933,729 · App. 07/275,622
Photointerrupter
Inventors:
Katsutoshi Soejima, Shunichi Yakata, Yoichi Sakumura
Patented Case
View Patent ↗
Granted: Jun 12, 1990
Filed: Nov 15, 1988
Inventors
Katsutoshi Soejima
Shunichi Yakata
Yoichi Sakumura
Assignee (at issue)
NEC 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.