Granted Patent
Utility
US 4,489,340 · App. 06/228,935
PNPN Light sensitive semiconductor switch with phototransistor connected across inner base regions
Inventors:
Jun Ueda, Haruo Mori, Kazuo Hagimura, Hirokazu Tsukada, Kotaro Kato
Patented Case
View Patent ↗
Granted: Dec 18, 1984
Filed: Jan 28, 1981
Inventors
Jun Ueda
Haruo Mori
Kazuo Hagimura
Hirokazu Tsukada
Kotaro Kato
Assignees (at issue)
Nippon Telegraph and Telephone Public Corporation
OKI ELECTRIC INDUSTRY CO., 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.