JPH088559Y2 - EL device - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescence device, and more particularly, to an electroluminescence device which is improved in luminance deterioration of a peripheral portion due to lighting and noise is reduced by a driving frequency.

[0002]

2. Description of the Related Art Generally, a dispersion type electroluminescent device includes a light emitting layer in which fluorescent particles such as ZnS: Cu are dispersed in a high dielectric constant organic binder between a transparent electrode and a back electrode. A reflective insulating layer having a specific ratio, is surrounded by a pair of water trapping layers, and a pair of outer cover films are further laminated, and the peripheral edge portion of the outer cover film is sealed by thermocompression bonding.

In such a dispersion type electroluminescent device, in order to prevent luminance deterioration due to humidity, an outer film made of trifluorochloroethylene resin (PCTFE) having an extremely low moisture permeability is used. Since the heat-sealing property of the chlorinated ethylene resin itself is weak, an adhesive layer of a polyolefin-based thermoplastic resin is usually formed on this outer film, and this adhesive layer is formed on the peripheral portion of the outer film. A heat-seal seal is formed therethrough.

[0004]

However, in such an electroluminescent device, when light is emitted for a long time due to moisture permeation from the peripheral side surface of the outer film through the seal portion of the adhesive layer having a poor moisture-proof effect, the light emitting surface is not illuminated. There was a problem that the peripheral part of was blackened.

Further, since the AC power frequency for driving the electroluminescent device is in the audible range, there is a problem that noise such as a beat is generated by the driving AC power supply.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an electroluminescent device which suppresses the blackening of the periphery of the light emitting surface to prolong the life and at the same time reduces the noise due to the driving AC power supply.

[0007]

Means for Solving the Problems In the previous application (Japanese Patent Application No. Hei 2-1075544), the inventors of the present invention have proposed that a water catching layer on the back electrode side is provided on the water catching layer on the back electrode side in order to prevent the deterioration of the brightness of the peripheral portion of the light emitting surface. Although it has been proposed to laminate a porous sheet, the present invention has been completed by focusing on integrating the electrode layer by phase cancellation into this porous sheet.

That is, the above-mentioned object is to provide a light emitting layer, a transparent electrode and a back electrode sandwiching the light emitting layer, a pair of water catching layers surrounding the transparent electrode and the back electrode, and a stack on the water catching layer. In the electroluminescent device having an outer skin film whose peripheral portion is sealed, a porous sheet and an electrode layer are formed between the water catching layer on the back electrode side and the outer skin film. This is solved by an electroluminescence device characterized in that an electrode layer is electrically connected to the transparent electrode.

Preferably, the porous sheet is made of either paper or cellophane, and the electrode layer is made of a metal vapor deposition film laminated on the surface of the porous sheet.

Preferably, the porous sheet and the electrode layer are laminated via a thermoplastic resin, and the electrode layer may be an aluminum foil layer.

[0011]

[Function] By forming a porous sheet between the water catching layer on the back electrode side and the outer cover film, the water that has penetrated through the adhesive layer in the peripheral portion of the outer cover film has pores inside the porous sheet. Since it spreads over the entire surface of the water catching layer on the back electrode side as a ventilation hole, the periphery of the light emitting surface is not deteriorated in brightness and blackened. This is more effective because the function of the ventilation hole becomes more prominent by the electrode layer laminated on the porous sheet.

Further, since the electrode layer laminated on the porous sheet is connected to the transparent electrode to cancel the phase between the back electrode and the electrode layer, beat noise due to the audible frequency of the driving AC power source is reduced. To do. This is more significantly and effectively reduced because the porous sheet makes the distance between the transparent electrode and the back electrode closer.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a sectional view showing a part of an electroluminescent device according to an embodiment of the present invention. In this electroluminescent device, a light emitting layer 6 and a reflective insulating layer 8 are provided between a transparent electrode 2 and a back electrode 4, and these are surrounded by a pair of water catching layers 10 and 12.
The porous sheet 14 and the electrode layer 16 are laminated on the water capturing layer 12 on the back electrode 4 side, and the skin films 18 and 20 are laminated on the water capturing layer 10 and the electrode layer 16, respectively.

The porous sheet 14 and the electrode layer 16 are integrally formed in advance by vapor-depositing aluminum having a thickness of 0.1 μm on cellophane paper having a thickness of 30 μm. It is formed by pressure bonding to the water layer.

And, importantly, the aluminum deposition surface of the electrode layer 16 is connected to the transparent electrode 2 through a suitable connecting means.
Electrically connected to. The electrical connection between the electrode layer 16 and the transparent electrode 2 is made by folding back the electrode lead attached to the electrode layer 16 to the electrode lead attached to the transparent electrode 2 and connecting inside the sealing films 18 and 20. Alternatively, they may be connected outside the outer skin films 18, 20.

The porous sheet 14 need not be cellophane paper, but may be paper that is sufficiently dried of water. In this case, the electrode layer 16 having aluminum vapor deposited on one surface of the paper is used.
It may be formed of.

The outer cover film 18 comprises a base material layer 18A made of trifluorochloroethylene resin (PCTFE resin) and a modified resin adhesive layer 18B, while the outer cover film on the back electrode 4 side is made of: Polyester resin layer 20A
And a thermoplastic resin layer 20B, an aluminum foil layer 20C, and a modified resin adhesive layer 20D, which are sequentially laminated on the polyester resin layer 20A. As shown on the right side of FIG. 1, the adhesive layer 18B of the outer cover film 18 and the adhesive layer 20D of the outer cover film 20 are thermocompression bonded at their peripheral portions.

As shown on the left side of FIG. 1, the electrode layer 16
The electrode wire of the transparent electrode 2 and the electrode wire of the back electrode 6 which are connected to each other are electrically connected to the driving AC power source 22 through a suitable inverter circuit.

In the electroluminescent device having the above structure,
For example, even when driven at 100 V and 500 Hz, the electrode layer 16 having the same phase as the transparent electrode 2 has a phase opposite to that of the back electrode 4, and in particular, the water trapping layer 12 is provided between the back electrode 4 and the electrode layer 16.
Also, since the porous sheet 14 is used as an insulator, beat noise of the thin film element can be reduced. In other words, under the same conditions except that the electrode layer 16 and the porous sheet 14 are not formed,
The noise level could be reduced to about 1/4 as compared with the conventional electroluminescent device having a size of × 200 mm. That is, the conventional electroluminescence device had a value of about 30 dB, but the present embodiment has a value of about 20 dB.

Further, the water that has penetrated from the peripheral side surfaces of the adhesive layers 18B and 20D of the outer skin films 18 and 20 uses the pores of the porous sheet 14 of the electrode layer 16 as ventilation holes, and the water capturing layer 12 is formed.
Since it is diffused over the entire surface of the water trapping layer 12, the reduction of the light emission luminance is suppressed until the water catching layer 12 reaches the limit of the water catching capacity, and the periphery of the light emitting surface near the peripheral side surfaces of the adhesive layers 18B and 20D is reduced as in the conventional case. There is little blackening of the part. Further, it is important to note that since the porous sheet 14 allows the water-trapping capacity of the water-trapping layer 12 to cover the entire surface, the water-trapping layer is conventionally 200 × 200 m
The thickness of about 100 μm before and after m can be reduced to about 60 μm, which means that the distance between the back electrode 4 and the electrode layer 16 can be shortened even for the above-mentioned beat noise. , Is advantageous.

Conventionally, as a result of a forced deterioration test at a humidity of 95% and a temperature of 40 ° C., blackening of the periphery occurred around 600 hours, whereas in this embodiment, blackening occurs even after 1100 hours. There was no unevenness in brightness including the change in color.

Example 2 Next, an example using an aluminum foil as an electrode layer will be described with reference to FIG.

In this embodiment, as shown in FIG. 2, an unstretched nylon 60 μm water trapping layer 12 ′, a 30 μm cellophane paper porous sheet 14 ′, and a 10 μm aluminum foil electrode layer 16 ′ were used. Are integrally formed in advance through the adhesive layers 24 and 26 containing modified polyethylene as a main component.

Using such a laminated body, it is assembled at the time of pressure bonding of the water catching layer of an ordinary electroluminescent element, and is numbered 2 in FIG.
Connecting the electrode layer 16 'to the transparent electrode, as shown at 8,
Then, it was sealed with a pair of outer films having a trifluoroethylene chloride resin as a base material layer.

In the electroluminescent device having such a structure, in the forced deterioration test, as in Example 1, 1100 was obtained.
The blackening of the periphery did not occur even after a lapse of time, and the noise level was about 18 dB, which was slightly higher than that of Example 1.

(Example 3) In the electrode layer 16 'of Example 2, since it is difficult to handle the aluminum foil during working, as shown in FIG.
2 ″ and a porous sheet 14 ″, and 12 μm on the electrode layer 16 ″ made of aluminum foil with an adhesive layer 30 containing modified polyethylene as a main component on the electrode layer 16 ″ made of aluminum foil.
The electroluminescent element was formed by using the laminated body in which the polyester film layer 32 having a thickness of m was laminated at the time of incorporating the ordinary water-trapping layer.

After the assembly, the adhesive layer 3 is formed on a part of the laminate.
0 and the polyester film layer 32 are peeled off, and the electrode layer 1
6 ″ and the transparent electrode were electrically connected.

The electroluminescent device having the above-described structure also had substantially the same effect as that of the second embodiment.

[0030]

As described above, according to the present invention,
It has been possible to provide an electroluminescent device that suppresses blackening on the periphery of the light emitting surface to prolong the life and at the same time reduce noise due to a driving AC power supply.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of an electroluminescent device according to an exemplary embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of a stack used in an electroluminescent device according to another embodiment of the present invention.

FIG. 3 is a partial cross-sectional view similar to FIG. 2 according to another embodiment of the present invention.

[Explanation of symbols]

 2 transparent electrode 4 back electrode 10, 12, 12 ', 12 "water trapping layer 14, 14', 14" porous sheet 16, 16 ', 16 "electrode layer

Claims (3)

[Scope of utility model registration request] 1. A light emitting layer, a transparent electrode and a back electrode sandwiching the light emitting layer, a pair of water catching layers surrounding the transparent electrode and the back electrode, and a layer formed on the water catching layer and its peripheral edge. In an electroluminescent device having an outer skin film having a sealed portion, a porous sheet and an electrode layer are formed between the water catching layer on the back electrode side and the outer skin film, and the electrode layer is transparent. An electroluminescent device characterized by being electrically connected to an electrode. 2. The porous sheet is made of either paper or cellophane, and the electrode layer is made of a metal deposition film laminated on the surface of the porous sheet. The electroluminescent device according to item 1. 3. The porous sheet and the electrode layer are laminated via a thermoplastic resin, and the electrode layer is formed of an aluminum foil layer. Electroluminescent device.