KR100717779B1 - Vacuum fluorescent display device - Google Patents

Abstract

The present invention relates to a fluorescent display tube that can improve design freedom, reduce manufacturing processes and costs, and prevent luminance characteristics and lifetime from being degraded due to residual gas in a container. The tube includes a pair of substrates which together with the side glass constitute a vacuum container; A filament mounted inside the vacuum container and emitting hot electrons when the power is applied; An anode electrode formed on any one of the substrates and comprising a fluorescent layer and a conductive layer forming a bottom surface of the fluorescent layer; A metal rib made of a single layer of metal material having high electrical conductivity and controlling hot electrons emitted from the filament; And insulating ribs partially provided around the anode electrode and individually supporting the metal ribs while being spaced apart from each other by a predetermined interval.

Ribbed, metal, insulated, grid, bulkhead,

Description

Fluorescent Display Tube {VACUUM FLUORESCENT DISPLAY DEVICE}

1 is a view showing the main part of a fluorescent display tube according to an embodiment of the prior art.

2 is a view showing a main part of a fluorescent display tube according to another embodiment of the prior art;

3 is an exploded perspective view of a fluorescent display tube according to the present invention;

4 is a plan view of the main part of FIG. 3;

5 is a partial cross-sectional view taken along line “A-A” of FIG. 4.

FIG. 6 is a sectional view of principal parts showing a modified embodiment of FIG. 3; FIG.

7 is a schematic diagram illustrating a method of making the metal rib of FIG. 6.

8 is an essential part cross-sectional view showing another modified embodiment of FIG.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent display tube having a rib grid, and more particularly, to improve design freedom, to reduce manufacturing processes and costs, and to reduce luminance characteristics and lifespan due to residual gas in a container. It relates to a fluorescent display tube that can be prevented from becoming.                         

The fluorescent display tube (VFD) is a self-luminous display element that selectively collides the hot electrons emitted from the filament with the fluorescent layer under the control of the control electrode and the anode electrode and emits light, and is excellent in visibility, wide viewing angle, and can be driven at low voltage. It has high reliability and is used for various purposes in various fields.

As an example of such a fluorescent display tube, a fluorescent display tube employing a metal mesh type mesh grid is disclosed as a control electrode for controlling hot electrons emitted from a filament (cathode electrode).

The control electrode is formed by etching a thin iron piece of SUS material to form a mesh and providing a support on the periphery of the mesh, the support is to support the mesh to a certain height for the control of electrons emitted from the filament do.

Accordingly, when the mesh grid is installed on the substrate, between the patterns of the support and the anode electrode, and adjacent to each other, in order to ensure that the hot electrons reach the end of the fluorescent layer satisfactorily, and to prevent leakage light emission of adjacent fluorescent layers, respectively. Since a constant distance between the mesh grids must be secured, the fluorescent display tube having the mesh grid is disadvantageous for the fine pattern design, and there is a problem that it cannot be applied to the complex polygonal pattern.

In addition, the mesh grid may sag in the center of the mesh due to thermal deformation during manufacturing and use, and in this case, the ability to accelerate and diffuse electrons may be degraded, resulting in a difference in luminance from a fluorescent layer inside an adjacent mesh grid. .

Therefore, in order to prevent the deflection of the center portion is necessary to increase the number of support is also a cause to inhibit the free pattern design of the anode electrode.                         

In order to solve this problem, Japanese Patent Laid-Open No. 6-251732 discloses a rib grid for fluorescent display tubes.

Referring to FIG. 1, the anode substrate 110 is provided with a wiring 112 electrically connecting the inside of the display tube and an insulating layer 114 to prevent unnecessary conduction between the wirings 112 and the wiring 112. ) Is provided on the conductive layer 116 through which the wiring 112 is energized, and on the conductive layer 116 is provided a fluorescent layer 118 that is excited and emitted by hot electrons emitted from a filament (not shown).

Here, the conductive layer 116 and the fluorescent layer 118 constitute an anode electrode.

An insulating rib 120 is provided around the conductive layer 116 at a height of about 100 to 150 µm, and an upper surface of the rib 120 is formed of a conductive material such as Ag, Al, Ni, or carbon. The conductive ribs 122 are provided in a thickness of 10 to 15 mu m.

Here, the insulating ribs 120 protrude at least 20 μm from the top surface of the fluorescent layer 118 to prevent a short circuit between the conductive ribs 122 and the fluorescent layer 118.

However, in the fluorescent display tube having the rib grid having such a structure, since the insulating rib 120 is formed higher than the fluorescent layer 118, the negative charge charged on the surface of the insulator layer outer periphery of the insulating rib 120 is prevented. Electron density is uneven due to the generated electric field, which causes light emission stains on the fluorescent layer 118.

In order to solve this problem, Japanese Patent Laid-Open No. 8-138591 discloses a fluorescent display tube having an outer electrode.

Referring to FIG. 2, the anode substrate 130 is provided with a wiring 132, an insulating layer 134, a conductive layer 136, and a fluorescent layer 138, and conducts around the fluorescent layer 138. The layer 136 is provided with an insulating rib 140 higher than the fluorescent layer 138 by about 100 to 150 μm, and the upper surface of the rib 140 is formed of a conductive material such as Ag, Al, Ni, or carbon. The conductive ribs 142 are provided with a thickness of 10 to 50 mu m.

The auxiliary grids 140 ′ and 142 ′ having the same pattern as the rib grids 140 and 142 are provided around the conductive layer 136.

In this case, the conductive layer 136 serves as an outer circumferential electrode to prevent light emission from being generated in the fluorescent layer 138 by removing negative (-) charges charged on the surface of the insulator layer.

However, according to the prior art of the above configuration, there are the following problems.

That is, the rib grid of the conventional fluorescent display tube is formed by repeating the process of printing the insulating paste to a thickness of 10 to 30㎛ and drying it 3 to 15 times, and printing the thick film in the same pattern on the upper surface of the insulating rib in the same pattern. To form.

Therefore, the printing operation needs to be repeated several times to form the ribs, which requires a lot of time for the printing operation, and the gas generated from the conductive material remains in the vacuum container, and the flow of electrons is interrupted by this residual gas, or the residual The gas is adsorbed on the surface of the filament or the fluorescent layer to reduce the luminance characteristic and the lifetime of the fluorescent display tube.

In addition, since the conductive rib is formed by thick film printing, an insulating rib must be formed below the conductive rib.

Therefore, the rib grid having such a structure is not preferable in terms of improving design freedom, and since the paste for forming the rib grid is expensive, the manufacturing cost of the fluorescent display tube is increased.

Thus, in order to solve the above problems, the present invention can improve the degree of freedom of design, reduce the number of manufacturing processes and costs, and can prevent the luminance characteristics and life from being degraded due to residual gas in the container. An object of the present invention is to provide a fluorescent display tube.

The object of the present invention as described above,

A pair of substrates which together with the side glass constitute a vacuum container;

A filament mounted inside the vacuum container and emitting hot electrons when the power is applied;

An anode electrode formed on any one of the substrates and comprising a fluorescent layer and a conductive layer forming a bottom surface of the fluorescent layer;

A metal rib made of a single layer of metal material having high electrical conductivity and controlling hot electrons emitted from the filament;

An insulating rib partially provided around the anode electrode and supporting the metal ribs separately from each other by a predetermined distance;

It is achieved by a fluorescent display tube comprising a.                     

Fluorescent display tubes having such a configuration only need to form insulating ribs around the anode electrode at an appropriate location, thereby preventing a reduction in design freedom due to the formation of the insulating ribs, and reducing manufacturing costs by using less expensive insulating paste. Can be.

In addition, since the control electrode for controlling the hot electrons is made of metal ribs, the manufacturing process can be simplified compared to the prior art of forming a rib grid by printing a thick film of insulating and conductive pastes, thereby reducing labor and generating gas due to the conductive pastes. By minimizing this, the quality and lifespan characteristics of the fluorescent display tube can be improved.

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

3 is an exploded perspective view of the fluorescent display tube according to the present invention, FIG. 4 is a plan view of the main part of FIG. 3, and FIG. 5 is a partial cross-sectional view of "A-A" of FIG.

The fluorescent display tube has a side glass 2 and a front substrate 4 and a rear substrate 6 constituting a vacuum container.

The rear substrate 6 is provided with a wiring 8 for electrically connecting the inside of the display tube, and an insulating layer 10 for forming an energizing hole and preventing unnecessary power supply between the wirings 8. ) Is provided with a conductive layer 12 electrically connected to the wiring 8, and above the conductive layer 12 is provided a fluorescent layer 16 which is excited by the hot electrons emitted from the filament 14 and emits light. .

And, a control electrode is provided around the anode electrode, the control electrode is a metal rib 18 for controlling the emission of the fluorescent layer 16 by accelerating or blocking the hot electrons emitted from the filament 14, and the metal It consists of an insulated rib 20 which supports the rib 18 to the height which can be controlled electronically.

Here, the metal ribs 18 will be described first, and the ribs 18 are made of a single layer of metal material having high electrical conductivity, for example, stainless steel, or have higher electrical conductivity than the stainless steel, depending on product characteristics. It may be made of a high material, for example metal material such as platinum, silver, copper.

As a method of applying power to the metal ribs 18 having such a configuration, a wiring terminal pin portion (not shown) that reaches the lead pad 22 is formed integrally with the ribs 18 through the wiring 8. A method of receiving an external power source, a method of forming a lead pin portion (not shown) extending outwardly of the substrate 6 integrally with the ribs 18 to be configured to receive an external power source through the wiring 8, or the like. In this case, the wiring terminal pin portion and the lead pin portion is preferably formed to be less than the thickness of the metal ribs (18).

As such, the metal ribs 18 function as grid electrodes that accelerate or block hot electrons emitted from the filament 14 when power is applied.

In addition, the metal ribs 18 are formed to have a height that can be easily controlled electronically, and are generally formed higher than the anode electrode using a metal material of about 0.05 to 0.25 mm, and preferably 50 to 300 from an upper surface of the fluorescent layer 16. The thickness is formed to be high, particularly about 180 to 200 m.

Here, the height of the metal ribs 18 may be variously adjusted according to product characteristics within the above range.

The metal rib 18 of such a structure can be manufactured as follows, for example.

First, a metal material having a width corresponding to the area of the anode electrode unit to be covered and a predetermined thickness capable of electronic control is prepared. Then, a part of the metal material is etched and removed by a known photolithography process to complete a metal rib of a specific pattern.

The control electrode is completed by attaching the completed metal rib 18 to the upper surface of the insulating rib 20 while being electrically connected to the wiring 8.

In addition, the insulating rib 20 is to prevent the rib 18 and the anode electrodes 12 and 16 from being energized by keeping the metal rib 18 at a predetermined height or more, and has a thickness of approximately 30 to 300 µm. It can be formed, preferably 10 to 20㎛ higher than the upper surface of the fluorescent layer 16.

Here, the height of the insulating rib 20 can be variously designed within the above range depending on the structure of the product, the power supply conditions, the dimensions of the display pattern, the height of the metal ribs.

By the way, the insulating ribs 20 of the present invention are not disposed in a form surrounding the anode electrodes 12 and 16, and the anode ribs 12 are subjected to a predetermined condition in which the metal ribs 18 do not sag due to load. And partly around (16).

That is, as shown in FIGS. 4 and 5, an insulating rib 20 is provided below the metal rib 18 at one point, but an insulating rib 20 is provided below the metal rib 18 at another point. It doesn't work.                     

For example, the insulating ribs 20 may be maintained at an interval of 5.0 to 25.0 mm with neighboring insulating ribs, and the rib width is preferably maintained at 100 μm or more.

In this way, when the insulating ribs 20 are partially formed at appropriate locations around the anode electrodes 12 and 16, the design freedom can be prevented from being lowered due to the formation of the insulating ribs 20, and the insulating ribs ( It is possible to use less expensive insulation paste forming 20), thereby reducing manufacturing costs.

Meanwhile, the metal ribs 18 may be formed in various patterns according to design specifications, in addition to the illustrated embodiment. The metal ribs 18 may also be formed in accordance with product characteristics. Deformation of the shape is possible.

6 shows a modified embodiment of the metal ribs, and the same reference numerals are used for the same components as the previous embodiment.

In the metal ribs 24 according to the present exemplary embodiment, as the area of the anode electrodes 12 and 16 increases, the influence on the center portion of the anode decreases, thereby preventing the luminance and cut-off characteristics of the fluorescent layer 16 from being lowered. In order to do this, the upper end of the rib 24 is provided with an extension 24 'extending vertically toward the inside of the anode electrode.

As a result, the planar area of the rib 24 is enlarged as compared with the previous embodiment, so that even when the anode electrode is patterned with a large area, the electronic control function is satisfactorily due to the smooth functioning of the metal rib 24. You lose.

At this time, the extended portion 24 ′ of the metal ribs 24 is formed so as not to overlap the fluorescent layer 16 substantially so as not to cover the display pattern by the fluorescent layer 16.                     

The metal ribs 24 having the extensions 24 'above pattern the photoresist film 28 on the surface of the metal material 26 to have the extensions 24', as shown in FIG. In addition, an etching solution is simultaneously added to both surfaces of the metal material 26 and can be easily produced by double etching.

On the other hand, when the width of the insulating ribs is very narrow for product design reasons, as shown in FIG. 8, the insulating ribs 20 'of the portion supporting the metal ribs 18 or 24 are integrated into one piece, and printed are formed. It is also possible to form the metal ribs 18 or 24 on the surface of the insulating rib 20 'in a state spaced apart by a predetermined interval.

As described above, the fluorescent display tube of the present invention can increase the degree of freedom of design and reduce manufacturing cost by providing insulating ribs supporting the metal ribs only at appropriate places around the anode electrode, and printing the conductive paste by using metal ribs. Therefore, various problems occurring when the conductive ribs are formed can be eliminated.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to

The fluorescent display tube according to the present invention configured as described above has the following effects.

Since insulating ribs for supporting the metal ribs to an electronically controllable height are not provided at the lower side of the metal ribs as a whole, but only at a proper place, the design freedom can be prevented from being lowered by forming the insulated ribs, and The manufacturing cost can be reduced by reducing the amount of phosphorus insulation paste used.

In addition, metal ribs made of a metal material can shorten the labor time compared to conventional conductive ribs formed by repeatedly printing a conductive paste several times, and do not require printing and firing operations. And it is possible to prevent the shortage of life due to short-lived and repeated printing can be improved the yield of the fluorescent display tube.

In addition, since the electrical conductivity of the metal rib is much higher than that of the conventional conductive rib formed by repeatedly printing the conductive paste, it is possible to more efficiently control the hot electrons emitted from the filament, and the metal rib having the extension part has a wide anode electrode. Even when the area is patterned, the luminance and cut-off characteristics of the fluorescent layer can be prevented from being lowered.

Claims (8)

A pair of substrates which together with the side glass constitute a vacuum container; A filament mounted inside the vacuum container and emitting hot electrons when the power is applied; An anode electrode formed on any one of the substrates and comprising a fluorescent layer and a conductive layer forming a bottom surface of the fluorescent layer; A metal rib which controls the hot electrons emitted from the filament and is made of a single layer metal material having high electrical conductivity; A plurality of insulating ribs that individually support the metal ribs in a state spaced apart from each other by a predetermined distance along the circumference of the anode electrode so as to partially surround the anode electrode; Fluorescent display tube comprising a. The fluorescent display tube according to claim 1, wherein the insulating ribs are maintained at a distance of 5.0 to 25.0 mm from neighboring insulating ribs. The fluorescent display tube according to claim 1 or 2, wherein the metal ribs are formed by etching the metal material in a predetermined pattern. The fluorescent display tube according to claim 1 or 2, wherein the metal ribs are made of any one metal material selected from stainless steel, platinum, silver, and copper. The fluorescent display tube according to claim 1 or 2, wherein the metal rib is formed to be about 50 to 300 mu m high from an upper surface of the fluorescent layer. 3. The fluorescent display tube according to claim 1 or 2, wherein the metal ribs are arranged to surround respective segments of the anode electrode. The fluorescent display tube according to claim 6, wherein one insulating rib is provided between two adjacent segments, and the surface of the insulating rib is provided with two metal ribs for controlling the segments on both sides, spaced apart by a predetermined interval. . 3. The fluorescent display tube according to claim 1 or 2, wherein the metal ribs are provided with an extension portion formed by extending an upper end of the ribs vertically toward the inside of the anode electrode.

Images