JP2000030863A - Dispersion el element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive dispersion EL element used for various electronic apparatuses and capable of offering various luminescent colors. SOLUTION: Multiple light transmitting electrode layers 12A, 12B and a plurality of light emitter layers 13A, 13B made of a high-dielectric resin dispersed with phosphor powder are overlapped alternately on the whole face or the prescribed position of one face of a light transmitting insulating film 1, and a back electrode layer 14 is printed on the last light emitter layer to form a dispersion EL element. The inexpensive multi-color luminescence type dispertion EL element offering various luminescent colors can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a distributed EL device used as a backlight or the like in a display section or an operation section of various electronic devices.

[0002]

2. Description of the Related Art In recent years, with the diversification of various electronic devices, those equipped with a backlight for illumination behind a display panel or an LCD so as to be able to identify and operate a display unit even in darkness have increased. Dispersion type EL elements have been increasingly used for backlights.

[0003] Such a conventional dispersion type EL element will be described with reference to FIG. In the drawings, the dimensions in the thickness direction are enlarged for easy understanding of the configuration.

FIG. 6 is a cross-sectional view of a conventional dispersion type EL device. In FIG. 6, reference numeral 1 denotes a flexible light-transmitting insulating film such as polyethylene terephthalate or the like. A light-transmitting electrode layer 2 made of indium tin oxide (hereinafter, referred to as ITO) is formed by a beam method, and a high dielectric resin such as a fluoro rubber or a cyano resin is formed thereon as a base material for light emission. A phosphor layer 3 in which a phosphor powder such as zinc sulfide is dispersed, a dielectric layer 4 in which a dielectric powder such as barium titanate is dispersed in a high dielectric resin, and silver connected to the dielectric layer 4. A carbon resin-based back electrode layer 5 and an insulating layer 6 such as an epoxy resin or a polyester resin are sequentially formed by printing on each other.

The ends of the silver or carbon resin wiring patterns 7A and 7B are connected to the light-transmitting electrode layer 2 and the back electrode layer 5 to constitute a dispersion-type EL element.

[0006] The dispersion type EL element having the above-described configuration is mounted on an electronic device, and a circuit (not shown) of the electronic device is connected to a wiring pattern 7 A connected to the light transmitting electrode layer 2 and the back electrode layer 5. When an AC voltage is applied during 7B, the light-emitting layer 3 of the dispersion-type EL element is driven to emit light, and this light illuminates the display panel or LCD of the electronic device from behind, so that the display can be performed even when the surroundings are dark. The unit and the operation unit can be clearly identified.

The emission color of the dispersion-type EL element at this time is determined by the type of the phosphor powder dispersed in the high dielectric resin of the light emitting layer 3, but the fluorescent dye or the fluorescent pigment is contained in the high dielectric resin. Can be converted to a color other than the emission color of the phosphor powder by dispersing the phosphor or making the insulating film 1 colored.

[0008]

However, in the above-mentioned conventional dispersion type EL device, a fluorescent dye or a fluorescent pigment is dispersed in the high dielectric resin of the light emitting layer 3, or the insulating film 1 is made to be colored. Even if it is converted to a color other than the emission color, only a single emission color can be obtained, and in order to obtain a plurality of emission colors, it is necessary to mount a plurality of dispersion-type EL elements on an electronic device. As the number of parts increases, there is a problem that this mounting operation takes time and is expensive.

The present invention solves such a conventional problem. A single dispersive EL element can provide various luminescent colors, and can be easily mounted on an electronic device and is inexpensive. It is an object of the present invention to provide a dispersion type EL device.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a high-density insulating film in which a plurality of light-transmitting electrode layers and a phosphor powder are dispersed on one entire surface of a light-transmitting insulating film or at a predetermined position. A plurality of light-emitting layers made of a dielectric resin are alternately formed, and a back electrode layer is printed and formed on the last light-emitting layer to constitute a dispersion-type EL element.

As a result, it is possible to obtain an inexpensive dispersion-type EL device capable of obtaining various luminescent colors.

[0012]

DETAILED DESCRIPTION OF THE INVENTION The invention according to claim 1 of the present invention is directed to a light-transmitting insulating film and a plurality of light-transmitting insulating films formed alternately on the entire surface of one surface of the insulating film or on a predetermined position. EL device composed of a plurality of luminescent layers of different dielectric colors composed of a highly dielectric resin in which a conductive electrode layer and a phosphor powder are dispersed, and a back electrode layer printed on the last luminescent layer. By emitting a plurality of light-emitting layers individually or simultaneously, various luminescent colors can be obtained, and an inexpensive multicolor light-emitting distributed EL element can be obtained.

According to a second aspect of the present invention, there is provided a light-transmitting insulating film, and a plurality of light-transmitting electrode layers and a phosphor powder formed alternately on the entire surface of one surface of the insulating film or on a predetermined position. A plurality of light-emitting layers made of a high dielectric resin in which a light-emitting layer is dispersed, a color conversion layer printed between the light-transmitting electrode layers and light-emitting layers of the second and subsequent layers, and a light-emitting layer on the uppermost layer. This is a dispersion-type EL element composed of a printed back electrode layer. By changing the emission color of each light-emitting layer by using a color conversion layer, various light-emissions can be made while maintaining the same light-emitting color of each light-emitting layer. Inexpensive multi-color emission type dispersion type EL that can obtain color
It has an effect that an element can be obtained.

According to a third aspect of the present invention, in the second aspect of the present invention, a light-transmitting conductive layer is formed on the color conversion layer by printing, and the light-emitting layer is provided with the color conversion layer interposed therebetween. The light-transmitting conductive layer and the light-transmitting electrode layer or the back electrode layer apply a voltage to each light-emitting layer, as compared with the case where the light-transmitting electrode layer or the light-transmitting electrode layer and the back electrode layer sandwich the light-emitting electrode layer or the light-transmitting electrode layer or the back electrode layer. Light emission by direct application has the effect of increasing light emission luminance.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the light emitting device further comprises:
It is formed by printing a dielectric layer in which a high dielectric resin is dispersed on a high dielectric resin, and printing it.The insulation between each electrode layer is assured and a certain thickness to ensure the insulation. Among them, by forming a higher dielectric layer on the luminescent layer, the applied voltage is higher in the luminescent layer than in the dielectric layer. It has the effect of increasing light emission luminance.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the uppermost dielectric layer is white, and light of the light emitting layer is reflected by the white dielectric layer. Since all the light is emitted to the insulating film side, there is an effect that the emission luminance can be further increased.

According to a sixth aspect of the present invention, in the first aspect of the invention, the light-transmitting electrode layer is formed by printing with a light-transmitting resin in which a light-transmitting conductive powder is dispersed. By forming the light-transmitting electrode layer by printing using a light-transmitting resin having flexibility, like other forming layers in which each element material powder is dispersed in a flexible resin, It is excellent in flexibility that can be bent or attached to a curved surface, and has an effect that an inexpensive distributed EL element can be obtained.

According to a seventh aspect of the present invention, in the first aspect of the present invention, the light-transmitting electrode layer is colored in a fluorescent color, and the luminescent color of the light-emitting layer is different from that of the first aspect. Has an effect that further various emission colors can be obtained.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In addition, in order to make the configuration easy to understand, each drawing shows an enlarged dimension in the thickness direction.

The same components as those described in the section of the related art are denoted by the same reference numerals, and detailed description will be omitted.

(Embodiment 1) FIG. 1 is a cross-sectional view of a dispersion-type EL device according to a first embodiment of the present invention, and FIG. 2 is a perspective view of the same, in which 1 is a polyethylene terephthalate or the like. A flexible, light-transmitting insulating film that, on the entire surface of one side or at a predetermined position, has the flexibility of a phenoxy resin, epoxy resin, fluororubber, or the like in which a light-transmitting conductive powder such as acicular ITO is dispersed. A plurality of light-transmitting electrode layers 12A and 12B made of a light-transmitting resin and a light-emitting material made of a highly dielectric resin such as fluororubber or cyano-based resin in which a phosphor powder such as zinc sulfide as a base material for light emission is dispersed. A plurality of illuminant layers 13A and 13B of different colors are formed by printing alternately.

A silver or carbon resin-based back electrode layer 14 connected to the light emitting layer 13B and an insulating layer 15 such as an epoxy resin or a polyester resin are successively formed thereon by printing. And the end portions of the carbon resin based wiring patterns 16A, 16B, 16C are connected to the light-transmitting electrode layers 12A, 12B and the back electrode layer 14, respectively.
A dispersion type EL element is configured.

The dispersion type EL device having the above-described configuration is mounted on an electronic device, and a wiring pattern connected to the light-transmitting electrode layers 12A and 12B and the back electrode layer 14 is obtained from a circuit (not shown) of the electronic device. When an AC voltage is applied between the light-emitting layers 16A, 16B, and 16C, the light-emitting layers 13A, 13
B drives and emits light, and this light illuminates the display panel, LCD, etc. of the electronic device from behind, as in the case of the conventional technology. However, the emission color of the light emitting layers 13A and 13B is high dielectric constant. The emission color of the phosphor powder dispersed in the conductive resin is different, or the emission color is different by adding a fluorescent dye or a fluorescent pigment to the highly dielectric resin and coloring the resin.

For example, when the luminescent color of the luminescent layer 13A is blue and the luminescent color of the luminescent layer 13B is orange, the wiring pattern between the wiring patterns 16A and 16B connected to the light-transmitting electrode layers 12A and 12B. When an AC voltage is applied to the light emitting layer 13A, the light emitting layer 13A emits blue light, and the light transmitting electrode layer 12B
And the wiring patterns 16B and 1 connected to the back electrode layer 14.
When an AC voltage is applied during 6C, the light emitting layer 13B emits orange light, and the wiring patterns 16A, 16B, 16C
When an AC voltage is applied to all, the light emitting layers 13A and 13B
Are emitted, and this light is synthesized to emit yellow light.

As described above, according to the present embodiment, various light-transmitting electrode layers 12A and 12B and a plurality of light-emitting body layers 13A and 13B having different emission colors are alternately overlapped and formed by printing. An emission color can be obtained, and an inexpensive multicolor emission type dispersion EL element can be obtained.

Similarly to other forming layers in which each element material powder is dispersed in a flexible resin, the light transmitting electrode layers 12A and 12B are formed by printing using a flexible light transmitting resin. Therefore, a dispersion-type EL element having excellent flexibility, which can be bent or attached to a curved surface, can be obtained.

Furthermore, by adding a fluorescent dye or a fluorescent pigment to the light-transmitting electrode layers 12A and 12B and coloring them in a fluorescent color, a variety of luminescent colors can be obtained in combination with the luminescent colors of the luminescent layers 13A and 13B. Can be obtained.

Further, as shown in FIG.
Dielectric layers 17A, 17 in which a dielectric powder such as barium titanate is dispersed in a high dielectric resin such as fluororubber or cyano-based resin similar to the light-emitting layers 13A, 13B on the light-emitting layers 13A, 13B.
B is formed by printing, so that the insulation between the electrode layers is ensured, and the voltage applied to the dielectric layers 17A, 1A within a certain thickness for securing the insulation.
Since the luminous body layers 13A and 13B are larger than the luminous body layer 7B, the luminous brightness of the luminous body layer can be increased.

In this case, if the addition amount of barium titanate in the first dielectric layer 17A is too large, the light in the second light emitting layer 13B is blocked, so that the second dielectric layer 17B
The amount of barium titanate added is 6 with respect to the high dielectric resin.
It is preferable that the amount is 0 to 95% by weight, and the addition amount of barium titanate in the first dielectric layer 17A is about 2 to 60% by weight.

Further, the dielectric powder dispersed in the high dielectric resin of the dielectric layers 17A and 17B is added to ferroelectric barium titanate or titanium oxide, preferably fine particles of 0.1 μm or less, or hydrolyzed. By using a hydrolyzable organic metal such as barium ethoxide or titanium ethoxide that produces a ferroelectric metal oxide, light blocking from the light emitting layer can be minimized.

By making the second dielectric layer 17B white, light emitted from the light emitting layers 13A and 13B is reflected by the white dielectric layer and all light is emitted to the insulating film side. The light emission luminance can be further increased.

(Embodiment 2) FIG. 4 is a sectional view of a dispersion-type EL element according to a second embodiment of the present invention. In FIG. The light-transmitting electrode layers 12A and 12B and the plurality of light-emitting layers 13A and 13B are alternately printed and formed, and the back electrode layer 14 and the insulating layer 15 are sequentially printed and formed thereon. , Wiring patterns 16A, 16
B and 16C (not shown) have the light transmissive electrode layers 1 respectively.
The connection between the second electrode 12B and the back electrode layer 14 is the same as that of the first embodiment, but a polyester resin is provided between the second light transmitting electrode layer 12B and the light emitting layer 13B. A color conversion layer 18 in which a fluorescent dye or a fluorescent pigment is dispersed in a resin, an epoxy resin, an acrylic resin, a phenoxy resin, a fluorine rubber, or the like is formed by printing.

In the above configuration, for example, the color of the light-emitting layers 13A and 13B is blue,
In the case where 8 is orange, when an AC voltage is applied between the wiring patterns 16A and 16B connected to the light transmitting electrode layers 12A and 12B, the light emitting layer 13A emits blue light and the light transmitting electrode layer When an AC voltage is applied between the wiring patterns 12B and the wiring patterns 16B and 16C connected to the back electrode layer 14, the light emitting layer 13B also emits blue light, but this light is converted by the color conversion layer 18 to emit orange light. When an AC voltage is applied to all of the wiring patterns 16A, 16B, and 16C, the blue of the light emitting layer 13A and the orange from the color conversion layer 18 are combined to emit yellow light.

As described above, according to the present embodiment, the color of light emitted from each light emitting layer is changed by the color conversion layer 18 formed between the light transmitting electrode layer 12B and the light emitting layer 13B of the second and subsequent layers by printing. Thereby, various luminescent colors can be obtained while the luminescent colors of the luminescent layers 13A and 13B are the same, and an inexpensive multi-color luminescent distributed EL element can be obtained.

It should be noted that the light emitting layer 13B is formed of the light transmitting electrode layer 1
2B and the color conversion layer 18 not directly between the back electrode layer 14
, The light emission luminance of the light emitting layer 13B is reduced by about 5 to 30%, but as shown in FIG. 5, the light emitting layer 13B is connected to the light transmissive electrode layer 12B on the color conversion layer 18. The light-transmissive conductive layer 19 is superposed and printed, and an AC voltage is directly applied to the light-emitting layer 13B by the light-transmissive conductive layer 19 and the back electrode layer 14, thereby preventing a decrease in emission luminance. it can.

In the above description, the structure in which the two light-transmitting electrode layers and the luminous body layers are alternately overlapped and printed is described. Of course, more luminescent colors can be obtained.

The first light-transmitting electrode layer 12A can be formed by a sputtering method or an electron beam method. It is practically difficult to form the film by a sputtering method or an electron beam method, and the sheet resistance value when formed by printing is preferably 1 kΩ or less. There is no.

Further, in the above description, the insulating film 1
A configuration in which a plurality of light transmissive electrode layers 12A and 12B, luminous body layers 13A and 13B, a color conversion layer 18, and the like are formed on one entire surface has been described. Alternatively, it is a matter of course that further various kinds of multi-color emission type dispersion EL elements can be realized by making the upper and lower emission colors different, or by combining and combining light in various ways.

[0039]

As described above, according to the present invention, there is obtained an advantageous effect that an inexpensive dispersed EL device capable of obtaining various luminescent colors can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a dispersion-type EL element according to a first embodiment of the present invention.

FIG. 2 is an external perspective view of the same.

FIG. 3 is a sectional view of the same.

FIG. 4 is a sectional view of a dispersion-type EL element according to a second embodiment of the present invention.

FIG. 5 is a sectional view of the same.

FIG. 6 is a cross-sectional view of a conventional dispersion type EL element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating film 12A, 12B Light transmitting electrode layer 13A, 13B Light emitting layer 14 Back electrode layer 15 Insulating layer 16A, 16B, 16C Wiring pattern 17A, 17B Dielectric layer 18 Color conversion layer 19 Light transmitting conductive layer

Continuing on the front page (72) Inventor Naohiro Nishioka 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. Reference) 3K007 AB02 AB04 AB18 BB00 BB01 CA06 CB01 DA04 DA05 DB02 EB00 EB04 EC01 FA01

Claims (7)

[Claims] 1. A highly dielectric resin in which a plurality of light-transmitting electrode layers and a phosphor powder are dispersedly formed on a light-transmitting insulating film and alternately over the entire surface of one surface of the insulating film or on a predetermined position. A dispersion-type EL device comprising a plurality of light-emitting layers having different emission colors and a back electrode layer formed by printing on the last light-emitting layer. 2. A highly dielectric resin in which a plurality of light-transmitting electrode layers and a phosphor powder are dispersedly formed on a light-transmitting insulating film and alternately over the entire surface of one surface of the insulating film or on a predetermined position. A plurality of light-emitting layers, a color conversion layer printed between the second and subsequent light-transmitting electrode layers and the light-emitting layer, and a back electrode layer printed on the uppermost light-emitting layer A dispersion-type EL device comprising: 3. The dispersion-type EL element according to claim 2, wherein a light-transmitting conductive layer is formed on the color conversion layer by printing. 4. The dispersion according to claim 1, wherein a dielectric layer in which a high dielectric resin is dispersed in a high dielectric resin is formed on the luminous layer by printing. Type EL element. 5. The color filter according to claim 4, wherein the uppermost dielectric layer is white.
The dispersion-type EL device according to the above. 6. The light-transmitting electrode layer formed by printing with a light-transmitting resin in which a light-transmitting conductive powder is dispersed.
6. The dispersion-type EL device according to any one of 5. 7. The dispersion-type EL device according to claim 1, wherein the light-transmitting electrode layer is colored in a fluorescent color.