Granted Patent
Utility
US 4,797,593 · App. 06/886,777
Cathode for electron tube
Inventors:
Masato Saito, Keiji Fukuyama, Masako Ishida, Keiji Watanabe, Toyokazu Kamata, Kinjiro Sano
Patented Case
View Patent ↗
Granted: Jan 10, 1989
Filed: Jul 17, 1986
Inventors
Masato Saito
Keiji Fukuyama
Masako Ishida
Keiji Watanabe
Toyokazu Kamata
Kinjiro Sano
Assignee (at issue)
MITSUBISHI ELECTRIC 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.