JPH04312757A - Discharge tube - Google Patents

Abstract

PURPOSE: To provide a linear discharge tube wherein a discharge maintaining potential is low and whole luminous brightness caused by a discharge gas is uniformly improved. CONSTITUTION: In a discharge tube which is equipped with a linear transparent container 10 into whose internal space a discharge gas is infected and with two pieces of electrodes 11, 12 for inducing spacial discharge in the internal space, the two electrodes 11, 12 being disposed in parallel in the longitudinal direction of the container 10, one electrode 11 of them is positioned in the internal space and the other electrode 12 is provided so as to make contact with an outside surface of the container 10. Further, a fluorescent layer 13 is formed on a part excluding an inner surface of the container 10 where the two electrodes 11, 12 stand opposite to each other. With this, a discharge tube having an extremely suitable configuration can be acquired by functional elements being provided in one container in a composite manner, and easy gap adjustment between an initial discharge voltage and a maintaining voltage is made possible.

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 linear discharge tube with a low discharge sustaining voltage and improved uniformity in overall luminance due to discharge gas.

0002

2. Description of the Related Art A discharge tube is a closed space filled with discharge gas and is equipped with at least two electrodes to which a high voltage is applied. A typical example is shown in FIG. . These are neon, argon, and xenon.
A tubular container 1 filled with an inert gas such as It has an extremely long discharge path.

However, since the electrodes 2 and 3 are provided at both longitudinal ends of the container 1, the larger the conventional discharge tube becomes, the higher the discharge starting voltage and sustaining voltage become. It has the disadvantage of becoming.

0004

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a discharge tube which has low discharge starting and sustaining voltages and particularly excellent luminous efficiency.

[0005]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the discharge tube of the present invention includes a tubular transparent container into which a discharge gas is injected into its internal space, and two containers that generate a space discharge in the internal space. The electrodes are arranged in parallel in the length direction of the container, with one electrode being located in the inner space and the other electrode being in contact with the outer surface of the container. It is characterized by being

In the present invention as described above, the other side electrode has a substantially U-shaped cross section, and furthermore, the other side electrode may be formed from a conductive material coated on the outer surface of the container. suitable.

[0007] Furthermore, a coating material made of at least one of a metal and a dielectric having a high secondary electron emission ratio is applied to at least one of the inner electrode and the inner surface of the container. It is even more preferable. As such a coating material, rare earth oxides, Al2O3, SiO2, Mgo, etc. can be used. In particular, MgO is also expected to play a role as a protective film, and is therefore more suitable as a coating material.

[0008] In the above-mentioned type of the present invention, the linear tubular transparent container may be bent into a planar shape so that an enlarged light emitting plane with a certain area can be formed.

[0009] Furthermore, it is also preferred that the coating material applied to the inner surface of the container is of substantially the same width as the outer electrode and is positioned opposite thereto.

[0010] Another type of the present invention that meets the various conditions described above includes a container into which a discharge gas is injected into its inner space and whose inner wall is coated with a fluorescent material, and a container in which a discharge is caused in the inner space. Application to discharge tubes with two electrodes is also possible.

[0011]

[Operation] According to the present invention, functional elements are provided in one container in a composite manner, and a planar light source having a constant planar area can be obtained.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings.

FIG. 2 shows in cross section the basic structure of the discharge tube according to the present invention, and FIG. 3 is a sectional view taken along the line III--III in FIG.

The discharge tube according to the first embodiment of the present invention includes a tubular transparent container 1 made of a dielectric material, such as glass.
An inner electrode 11 is provided in the longitudinal direction at the center of the inner side of the container 10, and an outer electrode 12 of a predetermined width is provided on the outer surface of the container 10.
It has a structure attached side by side with 1. At this time, the outer electrode 1
2 may be formed in a simple linear shape, but as shown in FIG. 3, it is formed in a strip shape with a substantially U-shaped cross section for more effective discharge.

A discharge tube having such a structure has parallel electrodes 11 provided on the inside and outside of the container 10 in the longitudinal direction.
12, a discharge occurs in the longitudinal direction of the container 10. The voltage applied to both electrodes 11 and 12 is of alternating current type, and the wall of the container 10 to which the outer electrode 12 is attached functions as a capacitor. Ultimately, such structural features provide a design advantage in which the spacing between the two electrodes can be determined as desired, regardless of the length of the container. Furthermore, since the distance between the electrodes can be adjusted regardless of the length of the discharge tube container, the initial discharge voltage and the sustaining voltage can be easily adjusted. Therefore, the discharge tube of the present invention has two parallel
Since the discharge tube has two electrodes, it has the advantage that it can be operated with an extremely low driving voltage compared to conventional discharge tubes. In particular, the outer electrode 12 surrounds the inner electrode 11
Since it has a shaped cross section, it can be expected to function as a halo cathode with high discharge efficiency.

Based on the basic structure of the present invention as described above, it is possible to realize other types of discharge tubes whose functions and performance are further improved and expanded.

A second and third embodiment of the invention is shown in FIGS. 4A and 4B.

The discharge tube shown in FIG. 4A has a fluorescent layer 13 formed on the inner surface of the container 10 facing the outer electrode 12, and the fluorescent layer 13 of a predetermined hue is excited by ultraviolet rays generated during discharge. By doing so, visible light can be generated.

In the discharge tube shown in FIG. 4B,
At least one of the inner electrode 11 and the inner surface of the container 10 is coated with a metal or dielectric material 14 having a high secondary electron emission ratio, such as a rare earth oxide, Al2O3, or S.
Although iO, MgO, etc. may be applied singly or in combination, MgO is suitable as a coating material since it can also be expected to play a role as a protective film for electrodes.

On the other hand, although not shown in the drawings, by providing a single container 10 with the functional elements shown in FIGS. 4A and 4B in a composite manner, an extremely suitable discharge tube can be obtained. Although the discharge tube according to the present invention having the above-mentioned functional elements can be transformed into the shapes shown in FIGS. 5A and 5B in terms of external shape, containers 10', 1 so as to provide a light source of
0" are bent into a zigzag shape or a coil (spiral shape).

[0021] This type of discharge tube can be used in many fields including as a backlight source for a liquid crystal display device.

[0022]

[Effects of the Invention] As a result, a discharge tube with an extremely suitable form can be obtained by providing functional elements in a composite manner in one container, and it is possible to easily adjust the interval between the discharge initial voltage and the maintenance voltage. .

The embodiments of the present invention described above may be modified into a wide variety of forms through simple modifications and additions of functional elements and other design requirements. However, any one type of discharge tube is naturally within the scope of the present invention as long as it includes the basic technical idea of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a discharge tube in a conventional general display element.

FIG. 2 is a partially enlarged sectional view of the discharge tube according to the present invention.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4A is a sectional view of another embodiment of the invention corresponding to FIG. 3; B is a sectional view of still another embodiment of the present invention corresponding to FIG. 3;

FIGS. 5A and 5B are plan views of still another embodiment of the present invention.

[Explanation of symbols]

10 Container 11 Inner electrode 12 Outer electrode 13. Fluorescent layer 14 Dielectric material

Claims (21)

[Claims] Claim 1: A linear transparent container into which a discharge gas is injected; and 2 which causes a space discharge in the internal space.
In a discharge tube having two electrodes, the two electrodes are arranged in parallel in the length direction of the container, one electrode being located in the inner space and the other electrode being in contact with the outer surface of the container. A discharge tube characterized in that it is provided as follows. 2. The other side electrode has a cross section that is substantially U.
2. The discharge tube according to claim 1, characterized in that it is shaped. 3. The discharge tube according to claim 2, wherein the other electrode is made of a conductive material coated on the outer surface of the container. 4. The discharge tube according to claim 1, wherein the linear transparent container is bent into a planar shape so that a constant area can form a light emitting plane. 5. A coating material made of at least one of a metal and a dielectric having a high secondary electron emission ratio is applied to at least one of the inner electrode and the inner surface of the container. Claim 1
3. The discharge tube according to any one of 3 to 3. 6. The discharge tube according to claim 5, wherein the coating material contains at least one of rare earth oxides, Al2 O3, SiO2, and MgO, either singly or in combination. 7. The discharge tube according to claim 5, wherein the linear transparent container is bent into a planar shape so as to form a light emitting plane over a constant area. 8. The discharge tube according to claim 5, wherein the coating material contains at least one of rare earth oxides, Al2O3, SiO2, and MgO, either singly or in combination. 9. A discharge vessel as claimed in claim 5, characterized in that the coating material applied to the inner surface of the vessel is positioned facing the outer electrode and having a width substantially equal to the outer electrode. 10. The discharge tube according to claim 9, wherein the coating material contains at least one of rare earth oxides, Al2 O3, SiO2, and Mgo, singly or in combination. 11. The discharge tube according to claim 10, wherein the linear transparent container is bent into a planar shape so as to form a light emitting plane over a constant area. 12. A discharge tube comprising: a container into which a discharge gas is injected and a fluorescent substance coated on the inner wall; and two electrodes which cause a discharge in the inner space.
The two electrodes are arranged in parallel in the length direction of the container, one electrode is located in the inner space, the other electrode is provided on the outside of the container, and the fluorescent layer is arranged such that the two electrodes face each other. A discharge tube characterized in that it is formed in a portion of the container excluding the inner surface. 13. The other side electrode has a cross section that is substantially U.
13. The discharge tube according to claim 12, characterized in that it is shaped. 14. The discharge tube according to claim 13, wherein the other electrode is made of a conductive material coated on the outer surface of the container. 15. The discharge tube according to claim 12, wherein the linear transparent container is bent into a flat shape so as to form a light emitting plane over a constant area. . 16. A coating material made of at least one of a metal and a dielectric having a high secondary electron emission ratio is applied to at least one of the inner electrode and the inner surface of the container. The discharge tube according to any one of claims 12 to 14, characterized in that: 17. The discharge tube according to claim 16, wherein the coating material contains at least one of rare earth oxides, Al2O3, SiO2, and Mgo, singly or in combination. 18. The discharge tube according to claim 16, wherein the linear transparent container is bent into a planar shape so as to form a light emitting plane over a constant area. 19. The discharge vessel of claim 16, wherein the coating material applied to the inner surface of the vessel is positioned opposite the outer electrode and of substantially equal width. 20. The coating material according to claim 18 or 19, characterized in that the coating material contains at least one of rare earth oxides, Al2O3, SiO2, and MgO, singly or in combination. 1. The discharge tube according to 1. 21. The discharge tube according to claim 20, wherein the linear transparent container is bent into a planar shape so as to form a light emitting plane over a constant area.