KR930008250B1 - Scattering el element - Google Patents

Abstract

The dispersion-type electroluminescent displayer device comprises a back electrode, an insulating layer, a luminous layer and a front electrode and then the luminous layer and the front electrode consist of the first luminescent layer containing a binder, a solvent and ZnS, Cu luminescent material, the second luminescent conductive layer containing a binder, a solvent, ZnS, Cu luminiscent material, Indium oxide and tin oxide. The insulating layer has the composition of titanic acid barium, a solvent and a binder and the binder is the mixture of cyanoethyl-pulluran and cyanoethyl-polyvinyl clcohol. The device has a low production cost for not using the expesive transparent electrode film.

Description

Distributed Electroluminescent Display

1 is a schematic view showing a conventional distributed electroluminescent display device,

2 is a schematic view showing an embodiment of a distributed electroluminescent display device according to the present invention.

* Explanation of symbols for main parts of the drawings

1: moisture proof film 2: absorbent film

3: front electrode (transparent electrode film) 3a: fluorescent conductor layer

4: light emitting layer 4a: phosphor layer

5: insulation layer 6: back electrode

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distributed electroluminescent display device, and more particularly, to a distributed electroluminescent display device that emits bright colors with high brightness and has a long lifetime.

In general, electroluminescent displays are highly visible for self-luminous and also have excellent impact resistance because they are completely solid devices. Such electroluminescent display devices include intrinsic electroluminescent light emitting by a light emitting material such as ZnS and charge injection type light emitting light such as a light emitting diode. Intrinsic electroluminescent display devices are divided into thin film type and dispersion type, and the dispersion type is divided into inorganic type and organic type. In addition, the driving method is classified into a direct current (DC) driving type and an alternating current (AC) driving type.

Currently, electroluminescent display devices using ZnS: Mn, which are inorganic phosphors, have been widely used. However, such an inorganic electroluminescent display device requires a voltage of nearly 200V to emit light, and thus the driving method is complicated.

On the other hand, the organic light emitting display device emits light having a luminance of 5 to 90 cd / m 2 by applying a low voltage of about 10V. However, since this device manufactures a laminated film of an electron accepting and electron donating light emitting material, its composition is complicated and difficult to manufacture, which causes problems in practical use.

There is a need for an electroluminescent display device having a simple structure and easy manufacturing to solve such a problem.

As shown in FIG. 1, the insulating layer 5 is formed on the back electrode 6 made of aluminum foil, and then a phosphor is coated on the light emitting layer 4 thereon, and the front electrode 3 is formed using a transparent conductive film thereon. ) To emit light. After that, the absorbent film 2 is attached to both ends to remove internal moisture or moisture of the light emitting display device, and the moisture-proof film 1 is attached onto the moisture absorbing film 2 for the purpose of blocking external moisture or air. A distributed electroluminescent device is manufactured.

As described above, in the fabrication of the distributed type electroluminescent device, the defect rate of the process due to the sliding and distortion of the film increases in the process of attaching the transparent conductive film used as the front electrode 3 with the moisture absorption and moisture proof film, and the transparent used. Since the conductive film is expensive, there is a problem that increases the manufacturing cost.

DISCLOSURE OF THE INVENTION In view of the above problems, an object of the present invention is to provide a dispersive electroluminescent display device which emits bright colors with high brightness, has an excellent horizontal plane, and reduces a defect rate in a laminating process for attaching a film.

In order to achieve the above object, the distributed type electroluminescent display device of the present invention is an electroluminescent display device having a back electrode, an insulating layer, a light emitting layer and a front electrode, wherein the light emitting layer and the front electrode are formed of a first phosphor layer and a second fluorescent light. It is characteristic in that it consists of a conductor layer.

The present invention will be described in detail as follows.

The distributed electroluminescent display device of the present invention may use either a direct current (DC) driven type or an alternating current (AC) driven type, but the following description will be made with respect to the direct current (DC) driven type with reference to FIG. .

In FIG. 2, the back electrode 6 is used as a substrate, and this back electrode 6 is formed using what was degreased with a soft aluminum thin plate. The insulating layer 5, the first phosphor layer 4a, the second fluorescent conductor layer 3a, the moisture absorption film 2 and the moisture proof film 1 are sequentially formed thereon.

On the other hand, the insulating layer 5 is applied to the back electrode 6 using a roll coater method or a screen printing method, the mixture obtained by mixing a binder and a solvent to maintain the barium titanate and proper viscosity as an insulator. It is formed by drying.

The phosphor layer 4a is formed into a paste-like mixture by mixing a binder and a solvent with a ZnS: Cu phosphor and is formed to a thickness of about 25 μm by using a roll coater method or a screen printing method on the insulating layer 5.

The binder used to form the insulating layer 5 and the phosphor layer 4a is a mixture of cyanoethyl pulluran and cyanoethyl-polyvinyl alcohol, and the phosphor The ratio of the fluorescent substance, binder, and solvent which form the layer 4a is a ratio mixed suitably in consideration of viscosity and brightness.

In the second fluorescent conductor layer 3a, a mixture obtained by mixing a binder and a solvent with a ZnS: Cu phosphor and mixing indium oxide and tin oxide powder as a conductive component thereon is roll coated or screen printed onto the phosphor layer 4a. It is formed to a thickness of about 25μm using the method. At this time, the mixture used to form the second fluorescent conductor layer is maintained for 24 to 48 hours by using a three-roll mill so that the phosphors are not destroyed when mixed, so that particles of conductive components are present between the phosphors. Let's do it.

Therefore, the first phosphor layer 4a serves as a main electroluminescent layer, and the second fluorescent conductor layer 3a serves as an auxiliary electroluminescent layer and a front electrode. At this time, Ag is printed on the busbar electrode to help uniformly emit light on the entire surface to form a distributed electroluminescent display device. Next, in order to remove moisture and moisture inside, a moisture absorbing film is applied under the back electrode and on the second fluorescent conductor layer. As a mounting method, a conventional laminating method is used. Next, the moisture-proof film is laminated on the moisture-absorbing film to block external moisture or moisture components. In this way, a distributed electroluminescent display device of the present invention was obtained.

As described above, according to the present invention, the first phosphor layer and the second fluorescent conductor layer are formed without using the conventional expensive transparent electrode film, and do not use the expensive transparent electrode film. It was reduced, and the defects in the adhesion of the transparent electrode film was reduced, and the light emitting layer was double treated to extend the life of the phosphor and greatly improve the luminance of light.

Claims (6)

A distributed electroluminescent display device having a back electrode, an insulating layer, a light emitting layer, and a front electrode, wherein the light emitting layer and the front electrode comprise a first phosphor layer and a second fluorescent conductor layer. device. 2. The dispersive electroluminescent display device according to claim 1, wherein the first phosphor layer is made of a mixture obtained by adding a binder and a solvent to a ZnS: Cu phosphor. 2. The dispersive electroluminescent display device according to claim 1, wherein the second fluorescent conductor layer is made of a mixture obtained by adding a binder, a solvent, an indium oxide, and a tin oxide powder to a ZnS: Cu phosphor. 2. The dispersive electroluminescent display device according to claim 1, wherein the insulating layer is made of a mixture obtained by adding a binder and a solvent to barium titanate. The dispersive electroluminescent display device according to any one of claims 1 to 4, wherein the binder is a mixture of cyanoethyl-pullutan and cyanoethyl-polyvinyl alcohol. The dispersion type according to any one of claims 1 to 4, wherein the first phosphor layer, the second fluorescent conductor layer, and the insulating layer are formed by either a roll coater method or a screen printing method. EL display device.