(19)
(11) EP 0 378 338 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
12.06.1991 Bulletin 1991/24

(43) Date of publication A2:
18.07.1990 Bulletin 1990/29

(21) Application number: 90300190.7

(22) Date of filing: 08.01.1990
(51) International Patent Classification (IPC)5: H01J 61/92, H01J 61/067
(84) Designated Contracting States:
DE FR GB NL

(30) Priority: 12.01.1989 JP 5753/89

(71) Applicant: TOKYO DENSOKU KABUSHIKI KAISHA
Kamakura-shi Kanagawa-ken (JP)

(72) Inventor:
  • Nieda, Yoriyuki
    Kamakura-shi, Kanagawa-ken (JP)

(74) Representative: Nettleton, John Victor et al
Abel & Imray Northumberland House 303-306 High Holborn
London, WC1V 7LH
London, WC1V 7LH (GB)


(56) References cited: : 
   
       


    (54) Discharge tube


    (57) A discharge tube having a pair of opposite electrode assemblies disposed in a discharge space (6) defined by a peripheral wall and charged with gas, and an a.c. source (11) connected at one end to one of the pair of electrode assemblies and at the other end to the other of the electrode assemblies, each of said opposite electrode assemblies comprising a sintered metallic electrode (2) for emitting electrons and a filament electrode (3) disposed closely adjacent to the sintered metallic electrode (2), for emitting thermoelectrons, and the sintered metallic electrode and the filament electrode being electrically connected in parallel by means of the associated lead wires (8).






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