Gas discharge tube

• US 6,531,821 B1
• Filed: 06/22/2000
• Issued: 03/11/2003
• Est. Priority Date: 12/24/1997
• Status: Expired due to Fees

• Current Assignee: Hamamatsu Photonics KK
• Original Assignee: Hamamatsu Photonics KK
• Inventors: Adachi, Kouzou, Ito, Yoshinobu, Matui, Ryotaro, Ikedo, Tomoyuki
• Primary Examiner(s): O'Shea, Sandra
• Assistant Examiner(s): MACCHIAROLO, PETER J
• Application Number:
  US09/598,990
• Time in Patent Office: 992 Days
• Field of Search: 313/588, 313/613, 313/643, 313/614, 313/615
• US Class Current: 313/613
• CPC Class Codes: H01J 61/10 Shields, screens, or guides for influencing the discharge
• CPC Class Codes: H01J 61/30 Vessels; Containers
• CPC Class Codes: H01J 61/302 characterised by the material of the vessel
• CPC Class Codes: H01J 61/35 provided with coatings on the walls thereof; Selection of materials for the coatings using coloured coatings H01J61/40; using luminescent coatings H01J61/42
• CPC Class Codes: H01J 61/68 Lamps in which the main discharge is between parts of a current-carrying guide, e.g. halo lamp
• CPC Class Codes: H01J 63/02 Details, e.g. electrode, gas filling, shape of vessel

Abstract

While high heat is generated in the anode section in the gas discharge tube in accordance with the present invention during its use, the heat is transmitted to the stem by way of the anode support plate due to a configuration in which the anode support plate abuts against the stem, and is released outside from the stem, whereby the cooling efficiency of the anode section is improved. Since the anode section employs not a floating structure including stem pins interposed therein but a configuration in which it is seated on the stem by way of the anode support plate, the anode section is stabilized on the stem, whereby the resistance to vibration improves. Also, for assembling the anode section into a sealed envelope, it will be sufficient if the anode support plate is mounted on the stem, which contributes to improving the easiness in assembling the gas discharge tube.

Claims

1. A gas discharge tube having a sealed envelope at least a part of which transmits light, said sealed envelope being filled with a gas and being provided with anode and cathode sections disposed therein, electric discharge being generated between said anode and cathode sections, so that the light-transmitting part of said sealed envelope emits predetermined light outside;

said sealed envelope comprising;

a stem for securing said anode and cathode sections by way of respective stem pins independent from each other; and

an anode support plate mounted directly on an inner surface of said stem for mounting said anode section on a surface thereof.

2. A gas discharge tube according to claim 1, wherein said anode support plate is made of an electrically insulating material.

3. A gas discharge tube according to claim 1, wherein said anode support plate is provided with a cavity portion for containing said anode section.

4. A gas discharge tube according to claim 1, further comprising:

a spacer plate made of ceramics, in contact with an exposed surface of said anode support plate with said anode section interposed therebetween, having an opening for exposing said anode section; and

an electrically conductive focusing electrode plate, in contact with a surface of said spacer plate, having a focusing opening disposed coaxial with the opening of said spacer plate;

wherein said cathode section being secured within said sealed envelope so as to be spaced from said focusing electrode plate.

5. A gas discharge tube according to claim 4, wherein said sealed envelope has a light projection window opposite to said stem, and a cover plate disposed between said light projection window and said cathode section.

6. A gas discharge tube according to claim 4, wherein a body of said sealed envelope is formed from a metal.

7. A gas discharge tube according to claim 1, wherein said stem is provided with a first flange portion made of a metal, said sealed envelope is provided with a second flange portion made of a metal, and said first and second flange portions are secured to each other by welding.

8. A gas discharge tube having a sealed envelope at least a part of which transmits light, said sealed envelope being filled with a gas and being provided with anode and cathode sections disposed therein, electric discharge being generated between said anode and cathode sections, so that the light-transmitting part of said sealed envelope emits predetermined light outside;

said sealed envelope comprising;

a stem for securing said anode and cathode sections by way of respective stem pins independent from each other, said stem being provided with a first flange portion made of metal;

a side tube, made of a material at least a part of which transmits light and secured to said stem, surrounding said anode and cathode sections, said side tube being provided with a second flange portion made of metal, said first and second flange portions being secured to each other by welding; and

an anode support plate abutting against said stem so as to support said anode section on a surface thereof.