KR940010200B1 - Discharge tube having cup shape glow discharge electrode - Google Patents

Abstract

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Description

Discharge tube

1 is a side view showing a first embodiment of a discharge tube according to the present invention.

2 is a schematic partial cutaway perspective view of the electrode element shown in FIG.

3 is a perspective view of the sintered arc discharge electrode shown in FIG.

4 is a partial cross-sectional view of the glow discharge electrode shown in FIG.

5 is a perspective view of a modified glow discharge electrode.

FIG. 6 is a partially developed cross sectional view of the modified electrode element used in the discharge tube of FIG.

7 is a partially cutaway perspective view of one end of the second embodiment of the discharge vessel of the present invention.

8 is a partial cutaway perspective view of the electrode element used in the experiment.

9 and 10 are partially cutaway perspective views showing still another embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge tube, and in particular, each of the electrode elements consisting of an arc discharge electrode and a glow discharge electrode includes a pair of electrodes formed in opposite shapes in a discharge space. It relates to a discharge tube of.

The application of the present invention has been approved in Japanese Patent Application Nos. 1-5753 and 2-124177, and discharge tubes having a pair of electrode elements each composed of an acrylic electrode and a glow discharge electrode are disposed in a discharge space. Placed in the opposite relationship. Such a discharge tube is used for a tail lamp, an illumination fluorescent lamp or the like for a liquid crystal display device.

As described above, each pair of opposite electrode elements of the discharge tube is composed of an arc discharge electrode and a glow discharge electrode, and the two electrodes are disposed adjacent to each other. Because of the synergistic effect of arc discharge and glow discharge, ultra high brightness discharge can be obtained in a stable manner, and ultra high brightness discharge tubes can be obtained.

In addition, the electron radiating material evaporated and emitted from the arc discharge electrode by the scattering method may be focused by the glow discharge electrode and used again for electron radiating because of the focused transfer radiating material, and have a very long life span. Can be obtained.

Recently, after mixing electrons such as barium, lanthanum boride, cesium, and tungsten powder, the mixture is compression molded or compressed with a lead wire using a mold, and as a result, An arc discharge electrode formed by sintering the molding is provided.

It is an object of the present invention to provide a discharge tube having the above-mentioned sintered arc discharge electrode and a long useful life.

According to the present invention, a tube body having an interior defined by a discharge space, a pair of electrode elements disposed opposite to the inside of the discharge space, and the pair of electrode elements each include an arc discharge electrode and a glow discharge electrode, and the glow discharge electrode There is provided a discharge tube composed of an electron-spinning material evaporated and emitted from the arc discharge electrode connected by the scattering method and a sintered body in which the arc discharge electrode contains the electron-emitting material.

The surface of the arc discharge tube is covered with an electron emitting material so that the evaporation and emission of the electron emitting material from the arc discharge electrode can be reduced in the present invention as compared with the conventional discharge tube.

In addition, since the lead wire can be formed completely on the arc discharge electrode, the electrode element can be mounted directly on the discharge tube, which facilitates the manufacture of the discharge tube.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a vertical sectional view of a discharge tube. The discharge tube is composed of a glass tube body 1 whose inner surface is covered with a fluorescent substance 2. The two electrode elements 4 are disposed in the opposite end walls of the tubular body 1 by lead wires 3 respectively installed in the tubular body 1 and extending through the opposite end walls of the tubular body 1. The electrode elements 4 are arranged in pairs opposite to each other. A mixed gas of argon and mercury is sealed in the discharge tube for discharge.

As shown in FIG. 2, each of the electrode elements 4 is generally composed of a cup-shaped glow discharge electrode 5 made of a sintered metal body and an arc discharge electrode 6 made of a sintered metal body. It is received in the glow discharge electrode 5 of the shaft.

The arc discharge electrode 6 is supported by a lead wire 3 extending through a through hole extending at the closed end of the cup-shaped glow discharge electrode 5 and fixed thereto by compression or pressure.

3 is a perspective view of the arc discharge electrode 6. The tungsten powder is mixed with barium to form the arc discharge electrode 6 by using a mold, and the mixed powder is pressed or formed on a part of the cylindrical molded body. Thus, the columnar body is supplied to the arc discharge electrode 6 and sintered. Cesium, lanthanum boride and other suitable materials may be added to the mixture.

4 shows a glow discharge electrode 5. In order to form the glow discharge electrode 5, a mixture of tungsten and nickel is pressed or formed into a cup shape by the use of a glow shape, and the molded body is sintered and provided to the glow discharge electrode 5.

The through hole is formed in the axial direction through the closed end of the cup-shaped glow discharge electrode 5. As can be seen from FIG. 2, after the lead wire 3 has passed through the through hole, the arc discharge electrode 6 has the same axis because the closed end of the glow discharge tube 5 is compressed radially inside. It is supported by the cup-shaped glow discharge electrode 5.

Although a mixture of tungsten and nickel is used here, the nickel can be replaced by aluminum. Also, without using the sintered metal, the glow discharge electrode 5 can be formed from a pipe of aluminum, nickel, iron or any other suitable material. In this case, the discharge characteristics are slightly lowered (for absorption gas). In order to obtain a getter effect, zirconium may be added to the mixture of tungsten and nickel or coated with zirconium on the sintered body.

As shown in FIG. 5, the getter member 11 is attached adjacent to the outer circumferential surface of the glow discharge electrode 5. As shown in FIG. In this case, the rear end of the getter member 11 is bent and bonded to the lead wire 3 extending through the through hole. Preferably, a zirconium-mercury getter is used for the getter member 11.

If the getter is used, mercury is already contained in the getter, and there is no need to seal the mercury in the discharge tube.

6 is a view showing a modified form of the embodiment. In the above embodiment, the filament coil electrode 6a is connected to the distal end of the arc discharge electrode 6 of the electrode element 4.

The sintered arc discharge electrode 6 having no filament coil electrode 6a takes 1-2 minutes to reach normal discharge when the discharge tube is turned on, but according to the structure of FIG. It takes about 10-20 seconds to turn on.

In particular, since arc discharge is first started at the filament coil electrode 6a, and the sintered arc discharge electrode 6 is heated by the heat generated by the arc discharge, a normal discharge condition can be secured soon. In addition, since the discharge of the filament coil electrode 6a is added, the brightness is improved.

The filament coil electrode 6a is formed by coating an active oxide film on the surface of the coil and hardening the coil.

The above examples are examples of cold-cathode fluorescent discharge tubes. An example of a hat-cathode fluorescent discharge tube will be described in detail below.

Another embodiment of the present invention will be described with reference to the seventh road sign. 7 shows one end of the discharge tube. A semi-cylindrical glow discharge electrode 25 composed of a sintered body is disposed in the discharge tube body, and its open side (ie, the concave surface) extends perpendicularly to the axis of the tube body toward the other end of the discharge electrode. .

The glow discharge electrode 25 is supported by a lead wire 23 extending through the end of the discharge tube and an anchor 27 extending from the end of the discharge tube. An arc discharge electrode 26 including a sintered body containing an electron emitting material is disposed in the semi-cylindrical glow discharge electrode 25 and extends along its axis.

The discharge electrode 26 is supported at one end thereof by the lead wire 23 and at the other end thereof by another lead wire 28 extending beyond the end of the discharge tube.

[Example 1]

Experimental progress of the discharge tube according to the present invention will be described in detail with the eighth road sign.

The details of the discharge section are as follows.

Oscillation Frequency: 50KHz

Oscillation voltage: 700V (effective value)

Sealing gas: 50 tor argon

Mercury 5mg

Outside diameter of glass tube: 6.5mm (thickness: 0.5mm)

Glass tube length: 250mm

Fluorescent material: triple wavelendqth fluorescent material (white)

Air temperature: 20deg.C

Opposite electrodes (see FIG. 8)

External diameter of glow discharge electrode (D1): 4.5mm

Internal diameter of glow discharge electrode (d1): 3.5mm

Glow Discharge Electrode Length (L1): 4.5mm (Effective Length: 3.5mm)

External diameter of arc discharge electrode (D2): 2.5mm

Arc discharge electrode length (L2): 2.0mm

Distance between end of arc discharge electrode and end of pipe (DIS): 7.0mm

External diameter of lead wire (Ds): 1.5mm

The results of the experiment are as follows.

Discharge current: 16mA (effective value)

Brightness of discharge tube: 30,000nt

Lifespan: 20,000hr

The reason for achieving the ultra high brightness and the long life will be explained in detail. Blackening is caused by electrospinning materials evaporated by electrons and ion collisions occur in cup-shaped electrodes, and the coloring also exhibits an electronspinning function. Therefore, the life of a discharge tube can be extended by preventing a glass tube from becoming black.

In addition, glow discharge and arc discharge occur at the same time, and ultra high brightness can be obtained by synergistic effects of the two discharges.

9 and 10 show yet another embodiment of the present invention. In each of the above-mentioned embodiments, the arc discharge electrode 6 is disposed in the cup-shaped glow discharge electrode 5. In the discharge stage (the last stage) the vacuum is discharged ( ^10-6 to ^10-8 ) in the discharge tube to eliminate flicker of light emitted during the manufacture of the discharge tube (i.e. the discharge is safe). It is heated by particle collision at 900-1000 ℃ to remove harmful gas.

At this time, the arc discharge electrode 6 may be blocked by the cup-shaped glow discharge electrode 5 sufficiently heated. As a result, in such a case, dust and noxious gas cannot be satisfactorily removed from the electrode 6.

The electrode element shown in FIG. 9 is similar to the electrode element structure of FIG. 2 except that the arc discharge electrode 6a is provided at a distance of about 2 mm from the rear end of the glow discharge electrode 5.

The heat is propagated from the protruding rear end of the arc discharge electrode 6a in the direction of the distal end of the one installed in the cup-shaped glow discharge electrode 5 during the heating, so that the entire arc discharge electrode 6a is sufficiently filled. It can be heated quickly and the problem is overcome in manufacturing.

However, in this case, the amount of electron radiation from the arc discharge electrode 6a should be larger than the amount of electron radiation from the glow discharge electrode 5. In this case, it is preferable that copper coating wire (Dymet) is used as the lead wire 23.

10 shows a modification of the structure of FIG. In this embodiment, the cup-shaped glow discharge electrode 5 is formed by winding a tungsten wire having a diameter of 0.3 to 0.5 mm (like a coil) in a funnel shape.

By this arrangement, the thickness of the cup glow discharge electrode 5 can be reduced.

[Example 2]

The coupling experiment of the discharge tube shown in FIG. 1 and the electrode element of FIG. 9 is performed.

Details of the discharge tube is as follows.

Oscillation Frequency: 50Hz

Oscillation voltage: 2.500V (maximum value)

Sealing gas: Argon 70 torr

Mercury 5mg

Outside diameter of glass tube: 5.8mm (thickness: 0.5mm)

Glass tube length: 260mm

Fluorescent material: Triple wavelength fluorescent material (white)

600 K (Kelvin)

Air temperature: 20deg.C

Opposite electrodes (see FIG. 8)

External diameter of arc discharge electrode: 1.5mm

Length of arc discharge electrode disposed on glow discharge electrode: 2.0mm

Length of protruding portion of arc discharge electrode: 2.0mm

The results of the experiment are as follows.

Discharge current: 14mA (effective value)

Brightness of discharge tube: 28,000nt

Life (half brightness): 20,000hr

In addition, similar results are obtained when other experiments are carried out by use of the discharge tube of the above description including the electrode element of FIG. 10. In this case, the diameter of the coil-shaped tungsten wire is 0.2 mm.

According to the above structure, it is possible to manufacture a discharge tube with high mass productivity, low cost, and stable operation with good discharge characteristics.

A further improved effect can be obtained by applying an electron emitting material such as barium to the surface of the arc discharge electrode 6a or the surface of the glow discharge electrode 5 and the inner surface thereof.

By doing so, the brightness of the discharge tube is further improved. This embodiment is suitable for a zero cathode fluorescence discharge tube.

According to the above description, in the discharge tube including the arc discharge electrode and the glow discharge electrode and composed of a pair of opposite electrode elements, the effective life of the discharge tube is further extended by the arc discharge electrode composed of the sintered body including the active oxide film. The discharge tube has a high resistance to vibration and collision. In addition, the arc discharge electrode may be molded and sintered together with the lead wire to facilitate assembly and manufacture of the discharge tube.

Claims (5)

In a discharge tube composed of a tube body having a discharge space therein and a pair of electrode elements disposed to face each other in the discharge space, each of the pair of electrode elements has a cylindrical discharge body and a glow discharge electrode and an electron emitting material. The glow discharge electrode is composed of an arc discharge electrode made of aluminum, nickel or steel, wherein the glow discharge electrode has a uniform microcyclic gap between the arc discharge electrode while coaxially wrapping the cylindrical cylindrical sintered body in the form of a cup. Discharge tube made. The discharge tube according to claim 1, wherein the sintered body is connected to an end portion of the lead wire extending through the adjacent closed end of the glow discharge electrode and supported on one end of the tube body. The discharge tube according to claim 1, wherein a filament-shaped electrode is connected to one end of the arc discharge electrode. The discharge tube according to claim 1, wherein the sintered body protrudes toward the defecation side of the glow discharge electrode through an adjacent closed end of the glow discharge electrode. The discharge tube according to claim 1, wherein a getter member is arranged adjacent to an outer circumferential portion of the glow discharge electrode.