JP2599192Y2 - Discharge tube - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge tube, and more particularly to a discharge tube in which a pair of electrode devices each composed of an arc discharge electrode and a glow discharge electrode are arranged in a discharge space so as to face each other.

[0002]

DESCRIPTION OF THE PRIOR ART In the Japanese Patent Application Nos. Hei 1-5753 and Hei 2-124177, the present applicant has disclosed a pair of electrode devices each comprising an arc discharge electrode and a glow discharge electrode in a discharge space. An opposed discharge tube is proposed.
These discharge tubes are used for backlights such as liquid crystal displays, fluorescent lamps for illumination, and the like. The pair of electrode devices disposed opposite to the discharge tube is, as described above,
It is composed of an arc discharge electrode and a glow discharge electrode, which are arranged adjacent to each other, and a super-high-intensity discharge can be stably obtained by the synergistic effect of the arc discharge and the glow discharge. At the same time, the glow discharge electrode captures electron emission materials that are scattered and released from the arc discharge electrode due to ion bombardment, and the captured electron emission material can be reused for electron emission. A discharge tube is obtained.

[0003] Recently, as an arc discharge electrode, powdered tungsten mixed with barium, lanthanum boride or cesium as an electron-emitting substance and pressed with a lead wire using a metal mold. A sintered version is provided.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to propose a discharge tube using the above-mentioned sintered arc discharge electrode and to provide a discharge tube having a longer life.

[0005]

Therefore, according to the present invention,
Of a pair of electrode devices disposed opposite to the discharge space in the discharge tube.
Each has its front end facing the partner electrode device and its rear end facing the discharge tube.
Placed at the end of the pipe and connected to each pipe end via a lead wire
Fixed, arc made of sintered body containing electron emitting material
Glow surrounding the discharge electrode and the arc discharge electrode coaxially
And discharge electrodes, which scatter and evaporate from the arc discharge electrodes.
The glow discharge electrode on the inner surface of the glow discharge electrode.
The glow discharge electrode of the discharge tube
The outer diameter of the arc discharge electrode is almost uniform in the axial direction.
Is a cylindrical rod like
Almost uniform narrow between the peripheral surface and the outer peripheral surface of the arc discharge electrode
An annular gap is defined, and an annular glow discharge electrode is formed.
The tip facing the counterpart electrode device is open,
The rear end facing the tube end is behind the rear end of the arc discharge electrode.
And crimped around the lead wire, and
The tip of the glow discharge electrode is the open tip of the glow discharge electrode.
Electrons that are located back from the inside in the axial direction and are scattered and evaporated
Emissive material hardly jumps out of the glow discharge electrode
An electronic discharge tube characterized in that
It is.

[0006]

According to the present invention, as compared with the conventional structure in which the surface of an arc discharge electrode is coated with an electron emitting material, the evaporative emission of the electron emitting material can be reduced, so that the service life of the arc electrode is further extended. The life of the tube can be further extended. In addition, since it can be integrally formed with the lead wire, it can be directly mounted on the discharge tube, thereby facilitating the manufacture of the discharge tube.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS The invention is explained in more detail in the form of an embodiment with reference to the accompanying drawings. FIG. 1 is a longitudinal sectional view of a discharge tube. A fluorescent substance 2 is applied to an inner surface of a glass tube main body 1 of the discharge tube.
Further, electrode devices 4 are provided at both ends of the main body 1 via lead wires 3 extending from the respective end walls. The electrode devices 4 form a pair and are arranged to face each other. Note that a mixed gas of argon and mercury is sealed in the discharge tube for discharge. In each of the electrode devices 4, as shown in FIG. 2, an arc discharge electrode 6 of a sintered metal body is coaxially arranged in a glow discharge electrode 5 composed of a cup-shaped sintered metal body. The arc discharge electrode 6 is passed through a through hole at the bottom of the cup-shaped glow discharge electrode 5 and is held by the lead electrode 3 fixed by caulking.

FIG. 3 is a perspective view showing the arc discharge electrode 6, which is obtained by mixing barium with tungsten powder, forming the column with the tip of the lead wire 3 using a mold, and sintering. Cesium, lanthanum boride and the like can be further used for the mixture. FIG. 4 shows a glow discharge electrode 5, which is obtained by molding a mixture of tungsten and nickel into a cup-like shape using a mold and then sintering the mixture. Further, a through hole is provided at the bottom of the cup-shaped glow discharge electrode 5, and as can be understood from FIG.
After the lead wire 3 is passed through this through hole, it is crimped to hold the arc discharge electrode 6 concentrically in the cup of the glow discharge electrode 6. Although a mixture of tungsten and nickel is used, aluminum may be used instead of nickel. Further, the glow discharge electrode 5 may be made of a pipe made of aluminum, nickel, iron, or the like instead of the sintered metal, but in this case, the discharge characteristics are slightly reduced.

In order to obtain a getter function (absorb miscellaneous gas), zirconium is mixed in the above-mentioned mixture of tungsten and nickel, or zirconium is coated on a completed sintered body. good. Alternatively, the getter member 11 may be provided near the outer periphery of the glow discharge electrode 5 as shown in FIG. In the case of FIG. 5, the rear end of the getter member 11 is bent and welded to the lead wire 3 that has passed through the through hole. It is preferable to use a zirconium / mercury getter as such a getter member. When such a getter is used, since mercury is contained, it is not necessary to enclose the mercury in the discharge tube.

FIG. 6 shows a modification of this embodiment. In this embodiment, a filament coil electrode 6a is further connected to the tip of the arc discharge electrode 6 of the electrode device 4,
With this configuration, only the sintered body arc discharge electrode 6 requires 1 to 2 minutes to shift to normal discharge from the start of lighting, but can shift to normal discharge in about 10 to 20 seconds. That is, first, the filament coil electrode 6a starts an arc discharge, and the heat generated by the filament coil electrode 6a heats the sintered body arc discharge electrode 6, and immediately shifts to a normal discharge. Further, since the discharge of the filament coil electrode 6a is also applied, the luminance also increases. The filament coil electrode is formed by applying an active oxide to the coil surface and then quenching the active oxide. The discharge tube described above is an example of a cold cathode fluorescent discharge tube. Next, an example of a hot cathode fluorescent discharge tube will be described.

[0011]

Embodiment 1 Referring to FIG. 7 , the results of an experiment conducted on the discharge tube of the present invention will be described. The use of the discharge tube is as follows.

The superluminance and the long life as described above are obtained because the blackening phenomenon due to electron and ion bombardment occurs in the cup-shaped electrode, and these are reused for discharge. This is because the blackening is prevented, the life is prolonged, and glow discharge and arc discharge occur simultaneously, so that an ultra-high brightness can be obtained by the synergistic effect of the two .

[0014]

[0015]

With the above structure, a stable discharge tube with high mass productivity, low cost and good discharge characteristics can be manufactured. It is more effective if an electron emitting material such as barium is applied to the surface or the surface of the arc discharge electrode 6a and the inner wall surface of the glow discharge electrode 5. That is, in this case, the brightness of the discharge tube is improved. This embodiment is suitable for a hot cathode fluorescent discharge tube such as a fluorescent lamp.

[0017]

As described above, in a discharge tube in which a pair of electrode devices each having an arc discharge electrode and a glow discharge electrode are arranged opposite to each other, a sintered arc discharge electrode containing an active oxidizing substance is used. Since a discharge tube having a long life is obtained, the discharge tube is extremely resistant to vibration and impact, and the arc discharge electrode can be formed and sintered integrally with the lead wire, thereby facilitating the assembly and production of the discharge tube.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a discharge tube according to an embodiment of the present invention.

FIG. 2 is a schematic perspective view of the electrode device shown in FIG.

FIG. 3 is a perspective view of a sintered body arc discharge electrode shown in FIG. 2;

FIG. 4 is a partially broken perspective view of the sintered body glow discharge electrode shown in FIG. 2;

FIG. 5 is a perspective view of a modification of the glow discharge electrode.

FIG. 6 is a partially broken perspective view showing an electrode device according to another embodiment of the embodiment shown in FIG. 1;

FIG. 7 is a partially broken perspective view of the electrode device used in the experiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Discharge tube main body 2 Fluorescent substance 3 Lead wire 4 Electrode device 5 Glow discharge electrode 6 Arc discharge electrode 11 Getter member

Claims (1)

(57) [Scope of request for utility model registration] 1. A pair of electrode devices disposed opposite to a discharge space in a discharge tube, each having a front end directed toward a counter electrode device, a rear end directed toward a tube end of the discharge tube, and a lead wire connected thereto. An arc discharge electrode made of a sintered body containing an electron emitting substance and fixed to each tube end via a glow discharge electrode coaxially surrounding the arc discharge electrode. The glow discharge electrode is made of a metal pipe, and the arc discharge electrode has an outer diameter of approximately one in the axial direction. a such cylindrical rod-shaped body, thus the glow discharge narrow annular gap almost uniform between the inner peripheral surface and the outer peripheral surface of the arc discharge electrodes of the electrode is defined, further glow of said annular body previously facing the counterpart electrode equipment of discharge electrodes End is opened, Thus the rear end facing the tube end is sealed by crimping around said lead wire at the rear of the rear end portion of the arc discharge electrodes, also the tip of the arc discharge electrodes, wherein the electron emitting material described above scattered evaporated position retracted to the open released the tip or al axially inner direction of the glow discharge electrode is prevented protrude most from the glow discharge electrode Electronic discharge tube.