Granted Patent
Utility
US 4,864,187 · App. 06/864,566
Cathode for electron tube and manufacturing method thereof
Inventors:
Kinjiro Sano, Toyokazu Kamata, Keiji Fukuyama, Masato Saito, Keiji Watanabe
Patented Case
View Patent ↗
Granted: Sep 5, 1989
Filed: May 16, 1986
Inventors
Kinjiro Sano
Toyokazu Kamata
Keiji Fukuyama
Masato Saito
Keiji Watanabe
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.