JP2001052856A - Electroluminescent element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use an electroluminescence element for a display of a curved- surface shape by making it foldable. SOLUTION: This electroluminescence element has a foldable sheet-like base material 11, a moisture-resistant insulating layer 12 provided on the base material 11, first and second electrodes 13, 14 alternately disposed at regular intervals in one plane on the insulating layer 12, a dielectric layer 15 provided on the insulating layer 12 so as to cover the first and second electrodes 13, 14, a luminous layer 16 provided on the dielectric layer 15, and a transparent insulating layer 17 provided on the luminous layer 16. The base material 11 is made of cloth or paper, and preferably, the insulating layer 12 is a smoothly coated fluororesin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electroluminescence (hereinafter referred to as EL in the specification).

[0002]

2. Description of the Related Art One of recent electronic display devices is an EL, and its basic structure is as shown in FIG.
A back electrode 2 is provided on an insulating layer 1 serving as a base, and a dielectric layer 3, a light emitting layer 4, a transparent electrode 5, and a transparent insulating layer 6 are sequentially provided in layers on the back electrode 2.

Generally, the insulating layer 1 has a moisture-resistant P
An ET film is used, and the back electrode 2 is formed by screen-printing a conductive paste such as a silver paste or a graphite paste on the insulating layer 1. Also,
The dielectric layer 3 is formed by screen-printing barium titanate dispersed in a high dielectric resin binder on the back electrode 2. The light emitting layer 4 provided on the dielectric layer 3 has a light emitting matrix of zinc sulfide, and a light emitting powder obtained by doping a small amount of an activator (metal or halogen element) with a light emitting material such as a cyanoresin compound. And the like, and is formed by screen-printing this dispersing material. Further, the transparent electrode 5 is obtained by doping indium oxide with tin oxide and obtaining the obtained ITO (indium oxide).
um Tin Oxide) powder is formed by vapor deposition, and the transparent insulating layer 6 covering the powder is formed of a transparent PET film, glass, or the like. Although not shown in the figure, a conductive pattern is extended on the back electrode 2 and the transparent electrode 5, and a terminal for voltage application is provided at an end thereof. By applying an AC voltage, a display using the light emitting layer 4 becomes possible.

[0004]

However, in the above-mentioned conventional EL, the transparent electrode 5 is formed of an ITO vapor-deposited film. Could only be used for the display.

[0005] Therefore, an object of the present invention is to increase the selection range of materials that can be used as electrodes, thereby avoiding electrode formation by an ITO vapor-deposited film, and making it possible to bend EL to use it for curved displays. To make it possible.

[0006]

In order to solve the above-mentioned problems, an EL according to a first aspect of the present invention has a bendable sheet-like base material and a moisture-proof material provided on the base material. An insulating layer, first and second electrodes alternately arranged on the same surface with a predetermined gap therebetween on the insulating layer, and an insulating layer covering the first and second electrodes. , A light emitting layer provided on the dielectric layer, and a transparent insulating layer provided on the light emitting layer.

[0007] An EL according to a second aspect of the present invention is characterized in that the substrate is formed of cloth or paper.

Further, the EL according to claim 3 of the present invention is characterized in that the insulating layer is formed of a fluororesin which is smoothly applied on a sheet-like substrate.

An EL according to a fourth aspect of the present invention is characterized in that the EL has an insulating layer adhered to release paper via a foldable adhesive layer, and has a predetermined gap above the insulating layer. First and second electrodes alternately arranged above, a dielectric layer provided on the insulating layer so as to cover the first and second electrodes, and A light-emitting layer provided,
And a transparent insulating layer provided on the light-emitting layer.

In the EL according to a fifth aspect of the present invention, the first and second electrodes each have a width of 5 to 15 mm.
0 μm, the thickness is 0.1 to 50 μm, and the gap between them is 30 to 300 μm.

The EL according to claim 6 of the present invention is characterized in that the first and second electrodes are formed in a spiral shape.

An EL according to a seventh aspect of the present invention is characterized in that the first and second electrodes are formed in a ladder shape.

An EL according to an eighth aspect of the present invention is characterized in that the first and second electrodes are formed of a metal foil.

An EL according to a ninth aspect of the present invention is characterized in that the first and second electrodes are formed by printing a conductive paste.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an EL according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a cross-sectional structure of an EL according to the present invention.
FIG. 3 shows an embodiment of the electrode pattern. The EL 10 according to this embodiment is provided with an insulating layer 12 having moisture resistance on a foldable sheet-like base material 11,
A predetermined gap is formed on the insulating layer 12 so that the first and second
Are alternately arranged, and the first and second electrodes 13 and 14 are alternately arranged.
A dielectric layer 15 is printed and formed on the insulating layer 12 so as to cover the electrodes 13 and 14, and a light emitting layer 16 and a transparent insulating layer 17 are provided thereon in layers.

The sheet-like base material 11 is formed of a foldable material such as cloth or paper, and the main body of the EL 10 is directly provided thereon. Even if EL10 is provided directly on a part of clothing such as work clothes or sportswear, the body can be freely moved, so this clothing can be used for night road construction or jogging, etc. Demonstrate excellent visibility. The type, weaving, and roughness of the cloth are not particularly limited, and a non-woven cloth may be used. It should be noted that the type of paper, the type, the material, and the like of Western paper and Japanese paper are not limited at all.

Due to its nature, the sea-g-shaped substrate 11 has fine irregularities on its surface, and particularly has fine holes in the case of cloth. For this purpose, the surface of the sheet-shaped base material 11 is coated with a fluororesin to smooth out the irregularities and fine holes and to smooth the surface. This insulating layer 12 made of fluororesin replaces the insulating layer in the conventional example. The first and second electrodes 13 and 14 are formed on the fluororesin layer having water resistance and moisture resistance. Note that the insulating layer 12 made of the fluororesin can also be bent.

The first and second electrodes 13 and 14 formed on the insulating layer 12 correspond to the back electrode and the transparent electrode of the above-described conventional example. Since it is provided on the back surface side, it is not always necessary to be transparent, and it is possible to provide a wide range of material selection and electrode forming method. For example, an electrode pattern can be formed by using various conductive metal materials as a foil, or an electrode pattern can be formed by printing using a conductive paste. First
And the second electrodes 13 and 14 have a constant gap 1 between them.
8 are alternately arranged on the same surface of the insulating layer 12, for example, other than the spiral electrode pattern 19 shown in FIG. 2 and the ladder electrode pattern 20 shown in FIG. , Can take various pattern shapes.

The thickness t of the first and second electrodes 13 and 14 is preferably in the range of 0.1 to 50 μm. In the case of metal deposition, it can be made thinner than 0.1 μm, but if it is made thinner than that, the electric resistance value is undesirably increased. When a conductive paste is formed by printing, the limit is about 3 μm from the relation with the electric resistance value. On the other hand, when the thickness of the electrode is 50 μm or more, the thickness of the entire EL becomes large, and the significance of providing the first and second electrodes 13 and 14 on the same surface is impaired. When printed with metal foil or conductive paste, the thickness is 50 μm.
If it is below, no problem occurs even if it is bent.

Also, the first and second electrodes 13 and 14
Is desirably set in the range of 5 to 150 μm. This is not preferable because the electrical resistance increases when the width dimension w is 5 μm or less.
This is because when the thickness is 50 μm or more, the intensity of the electric field is increased or decreased to cause uneven light emission.

Further, a gap 18 having a fixed width is secured between the first and second electrodes 13 and 14, and the gap dimension s is preferably in the range of 30 to 300 μm. this is,
If it is smaller than 30 μm, the left and right electrodes 13,
14 while the gap 18 is 300
If it becomes wider than μm, it will not emit light unless high voltage is applied,
This is because current consumption may be extremely large and battery life may be shortened.

The metal material that can be used for the first and second electrodes 13 and 14 is not particularly limited as long as it is a metal material having good conductivity, as described above. These foils and vapor-deposited films are useful because they are conductive, have high light reflectance, and are excellent in workability and cost.

Next, first and second aluminum foils are used.
The method of forming the electrodes 13 and 14 will be described with reference to FIG.
First, an aluminum foil is stuck on the entire surface of the insulating layer (fluororesin layer) 12 coated on the sheet-like base material 11 (S1), and then the aluminum foil is formed on the aluminum foil by using an electrode pattern mask. A resist film is formed by printing (S
2). Next, this is etched by a known method (S
3) Further, the aluminum foil in the portion where the resist film is not printed is peeled off and removed (S4). Finally, the whole is thoroughly washed to remove the resist film (S5), and FIG.
The electrode pattern shown in FIG.

On the other hand, when the first and second electrodes 13 and 14 are formed by printing, silver powder or graphite powder having excellent conductivity is pasted, and both electrodes 13 and 14 are screen-printed. Can be formed at once. Since the aluminum foil and the conductive paste can withstand bending, the EL10 can be bent and a display with a curved surface can be performed.

The dielectric layer 15 provided so as to cover the first and second electrodes 13 and 14 is screen-printed with barium titanate dispersed in a high dielectric resin binder, as in the above-described conventional example. The luminescent layer 16 is also made of zinc sulfide as a luminescent matrix, and a luminescent powder obtained by doping a small amount of an activator (metal or halogen element) with the luminescent material is converted into a high dielectric material such as a cyanoresin compound. It is formed by dispersing in a resin binder and screen-printing this dispersing material. Further, it is preferable that the transparent insulating layer 17 covering the PET layer has moisture resistance.
It is formed by screen printing of a film, glass, or fluorine resin. Although not shown in the drawing, conductive patterns extend from the first and second electrodes 13 and 14 to the outside. A terminal for voltage application is provided at an end of the conductive pattern, and the first and second electrodes 1 are provided.
By applying a predetermined AC voltage to the light-emitting layers 3 and 14,
6 emits light and is transmitted upward through the transparent insulating layer 17.

FIG. 5 shows a second embodiment of the EL according to the present invention. The EL 10a according to this embodiment has a P
An insulating layer 12a formed of an ET film or the like is provided with an adhesive layer 21 and a release paper 22 on the back side thereof.
2a, first and second electrodes 13, 14,
Since the dielectric layer 15, the light emitting layer 16 and the transparent insulating layer 17 have the same configuration as in the first embodiment, detailed description will be omitted.

According to this embodiment, since the release paper 22 on the back surface can be freely adhered just by peeling the release paper 22, the EL 10a itself, including the adhesive layer 21, is flexible and can be bent. Then, for example, a display having a curved shape can be formed by sticking to a utility pole or the like.

[0028]

As described above, the EL according to the present invention is provided.
According to the method, the EL can be provided directly on a foldable sheet-like base material such as cloth or paper, so that it can be widely used for clothing and other curved displays.

Further, according to the present invention, since the release paper is provided on the back side of the EL with an adhesive therebetween, when used, the release paper is simply peeled off and affixed to the surface of the object, so that various curved surface shapes can be obtained. Can be used for display.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of an EL according to the present invention.

FIG. 2 is an explanatory diagram showing an example of an electrode pattern according to the present invention.

FIG. 3 is an explanatory view showing another example of the electrode pattern according to the present invention.

FIG. 4 is a process drawing of an electrode pattern using an aluminum foil.

FIG. 5 is a sectional view showing a second embodiment of the EL according to the present invention.

FIG. 6 is a cross-sectional view showing the internal structure of a conventional EL.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 EL (electroluminescence) 11 sheet-like base material 12 insulating layer 13 first electrode 14 second electrode 15 dielectric layer 16 luminous layer 17 transparent insulating layer 18 gap 19, 20 electrode pattern 21 adhesive layer 22 release paper t electrode thickness w electrode width s gap between electrodes

Claims (9)

[Claims] 1. A bendable sheet-like base material, a moisture-resistant insulating layer provided on the base material, and alternately arranged on the same surface with a predetermined gap on the insulating layer. First and second electrodes, a dielectric layer provided on the insulating layer so as to cover the first and second electrodes, and a luminous body provided on the dielectric layer An electroluminescent device comprising a layer and a transparent insulating layer provided on the light emitting layer. 2. The electroluminescence according to claim 1, wherein said base material is formed of a fabric or paper. 3. The electroluminescence according to claim 1, wherein the insulating layer is formed of a fluororesin that is smoothly applied on a sheet-like substrate. 4. An insulating layer attached to a release paper via a foldable adhesive layer, and first and second insulating layers alternately arranged on the same surface with a predetermined gap on the insulating layer. Electrode, a dielectric layer provided on the insulating layer so as to cover the first and second electrodes, a light emitting layer provided on the dielectric layer, And a transparent insulating layer provided on the layer. 5. The first and second electrodes have a width of 5 to 150 μm and a thickness of 0.1 to 50 μm.
5. The electroluminescence according to claim 1, wherein a gap between the two is 30 to 300 μm. 6. The electroluminescence according to claim 1, wherein the first and second electrodes are formed in a spiral shape. 7. The electroluminescence according to claim 1, wherein the first and second electrodes are formed in a ladder shape. 8. The method according to claim 1, wherein said first and second electrodes are formed of a metal foil.
The electroluminescence according to any one of the above. 9. The electroluminescence according to claim 1, wherein the first and second electrodes are formed by printing a conductive paste.