Title:
COLD-CATHODE ELECTRON SOURCE, MICROWAVE TUBE USING THIS, AND ITS MANUFACTURING METHOD
Document Type and Number:
WIPO Patent Application WO/2004/088703
Kind Code:
A1
Abstract:
A cold-cathode electron source of both high frequency and high output, a microwave tube using the same, and its manufacturing method are disclosed. An emitter (24) of the cold-cathode electron source has a sharp point so that the aspect ratio R may be 4 or more. As a result, the capacitance between the emitter (24) and a gate electrode (16) is small correspondingly to the distance from the gate electrode (16). Therefore, the cold-cathode electrons can behave in response to a high frequency. The material of the cathode of this cold-cathode electron source is diamond having a high melting point and a high thermal conductivity, not a conventional material such as tungsten or silicon. Even if the density of the current flowing through the emitter (24) is high, the emitter (24) hardly melts, and consequently the cold-cathode electron source can be adapted to high output.
Inventors:
Tatsumi, Natsuo c/o Itami Works of Sumitomo Electric Industries Ltd. (1-1, Koyakita 1-chome, Itami-sh, Hyogo 16, 66400, JP)
Imai, Takahiro c/o Itami Works of Sumitomo Electric Industries Ltd. (1-1, Koyakita 1-chome, Itami-sh, Hyogo 16, 66400, JP)
Imai, Takahiro c/o Itami Works of Sumitomo Electric Industries Ltd. (1-1, Koyakita 1-chome, Itami-sh, Hyogo 16, 66400, JP)
Application Number:
PCT/JP2004/004245
Publication Date:
October 14, 2004
Filing Date:
March 26, 2004
Export Citation:
Assignee:
SUMITOMO ELECTRIC INDUSTRIES LTD. (5-33, Kitahama 4-chome Chuo-ku Osaka-shi Osaka, 41, 54100, JP)
Tatsumi, Natsuo c/o Itami Works of Sumitomo Electric Industries Ltd. (1-1, Koyakita 1-chome, Itami-sh, Hyogo 16, 66400, JP)
Imai, Takahiro c/o Itami Works of Sumitomo Electric Industries Ltd. (1-1, Koyakita 1-chome, Itami-sh, Hyogo 16, 66400, JP)
Tatsumi, Natsuo c/o Itami Works of Sumitomo Electric Industries Ltd. (1-1, Koyakita 1-chome, Itami-sh, Hyogo 16, 66400, JP)
Imai, Takahiro c/o Itami Works of Sumitomo Electric Industries Ltd. (1-1, Koyakita 1-chome, Itami-sh, Hyogo 16, 66400, JP)
International Classes:
H01J1/304; H01J3/02; H01J9/02; H01J23/04; H01J23/06; (IPC1-7): H01J1/304; H01J23/06; H01J9/02
Attorney, Agent or Firm:
Hasegawa, Yoshiki (SOEI PATENT AND LAW FIRM, Ginza First Bldg. 10-6, Ginza 1-chome, Chuo-k, Tokyo 61, 10400, JP)
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