JPH11121169A - Dispersed type electroluminescent element and attaching method the same to instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dispersed type electroluminescent element used for various electronics which has plural luminous parts and is low in cost and easy to use. SOLUTION: An EL element which has plural luminous parts and is low in cost and easy to use is obtained by sequentially printing and forming translucent electrode layers 12A, 12B formed by dispersing a conductive translucent in a translucent resin, illuminant layers 3A, 3B, and dielectric layers 4A, 4B in plural positions on the undersurface of a trans lucent insulating film 1, and by providing a flexible conductive pattern 13 connecting between the translucent electrode layers in the plural positions to compose an EL element 15 provided with plural illuminant part 14A, 14B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distributed electroluminescent element (hereinafter, referred to as an EL element) used as a backlight or the like for a display section or an operation section of various electronic devices, and a method of mounting the same on the device. Things.

[0002]

2. Description of the Related Art In recent years, with the diversification of various electronic devices, a backlight for illumination is provided behind a display panel, an LCD, or a switch key so that a display unit and an operation unit can be identified and operated even in darkness. The number of EL elements has increased, and EL elements have been increasingly used for backlights.

A conventional technique of such an EL element will be described with reference to FIG. FIG. 7 is a cross-sectional view of a conventional EL element. In FIG. 7, reference numeral 1 denotes a transparent insulating film having flexibility such as polyethylene terephthalate, and a light-transmitting electrode layer 2 formed by vapor deposition of indium tin oxide on the lower surface thereof. The light-emitting layers 3A and 3B formed on the lower surface and dispersing zinc sulfide as a base material for light emission in a high dielectric resin such as a fluoro rubber or a cyano resin at a plurality of positions on the lower surface.
Similarly, dielectric layers 4A and 4B in which barium titanate or the like is dispersed in a high dielectric resin are sequentially formed by printing.

Further, internal insulating layers 5A and 5B such as epoxy resin and polyester resin for insulating the light emitting layers 3A and 3B or the dielectric layers 4A and 4B, and silver connected to the dielectric layers 4A and 4B. An EL element 9 having a plurality of light emitting portions 8A and 8B is formed by sequentially printing and forming a back electrode layer 6 of carbon resin and a back insulating layer 7 covering them.

The EL element 9 having the above structure is mounted as a backlight for illumination behind a display panel, an LCD, or a switch key of various electronic devices, and the light transmitting electrode layer 2 and the back surface of the EL element 9 are mounted on the circuit of the electronic device. When a voltage is applied to the electrode layer 6, the EL element 9 is driven to emit light from the plurality of light emitting portions 8A and 8B, and this light illuminates the LCD and the switch key from behind, so that the LCD and the switch can be operated even when the surroundings are dark. The key display can be clearly confirmed.

In the case where the EL element 9 is made to emit light not at the entire surface but at a plurality of light emitting portions 8A and 8B at a plurality of places as described above, the light transmitting electrode layer 2 is formed on the entire surface of the insulating film 1. It is not necessary, and similarly to the light-emitting layers 3A and 3B and the dielectric layers 4A and 4B, even if each light-transmitting electrode layer 2 is formed at a plurality of places except for the connection portion, the structure as an EL element is possible. However, when the light transmitting electrode layer 2 is formed by forming a thin film of indium tin oxide by vacuum evaporation or sputtering as described above, the portions other than the respective light transmitting electrode layers and the connection locations are masked and vacuum evaporated. It is necessary to remove the indium tin oxide, which has been formed as a thin film on the entire lower surface of the insulating film 1 by performing sputtering or sputtering, on portions other than the respective light-transmitting electrode layers and connection portions by etching or the like. To Since the to high cost, which is usually used those remains to form a light transmitting electrode layer 2 on the entire surface of the insulating film 1.

[0007]

However, in the above-mentioned conventional EL device, the light-transmitting electrode layer 2 formed by vacuum evaporation or sputtering of indium tin oxide is formed on the entire lower surface of the insulating film 1, so that the back surface is not provided. Insulating layer 7
In addition, the internal insulating layers 5A and 5B for insulating the light transmissive electrode layer 2 and the back electrode layer 6 are required, so that the number of times of printing increases, and light is also emitted to unnecessary parts other than the light emitting parts 8A and 8B. There is a problem that expensive materials are wasted as much as the transparent electrode layer 2 is formed.

Further, since the light-transmitting electrode layer 2 on which indium tin oxide is deposited is weak in bending and easily broken, for example, an electronic device having a display portion and an operation portion disposed on the upper surface and the entire surface is used for the electronic device.
Since one EL element is folded and mounted, and multiple surfaces cannot be illuminated by one EL element, illuminating multiple surfaces of an electronic device requires the same number of EL elements as the illuminated surface. In addition, when the display unit or the operation unit of the electronic device is not a flat surface but a curved surface, the EL device is bent and cannot be disposed behind the display unit or the operation unit, and thus uneven illumination may easily occur. There was also a problem when attaching to.

An object of the present invention is to solve such a conventional problem, and an object of the present invention is to provide an inexpensive EL element which has a plurality of light emitting portions and is flexible since it has flexibility.

[0010]

According to the present invention, there is provided an EL device comprising a light-transmitting resin and light-transmitting conductive powder dispersed in a plurality of locations on the lower surface of a light-transmitting insulating film. By sequentially printing and forming the light-transmitting electrode layer and the light-emitting layer and the dielectric layer, and by providing a flexible conductive pattern that connects between the light-transmitting electrode layers at a plurality of locations,
This constitutes an EL element having a plurality of light emitting units.

As a result, an inexpensive and easy-to-use EL element having a plurality of light-emitting portions can be obtained.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention provides a light-transmitting insulating film and a light-transmitting resin printed on a plurality of locations on the lower surface of the insulating film. A light-transmitting electrode layer in which powder is dispersed, a plurality of light-emitting layers and dielectric layers sequentially printed on the light-transmitting electrode layer; a back electrode layer connecting each dielectric layer; It is a dispersion-type electroluminescent element provided with a plurality of light-emitting portions made of a flexible conductive pattern for connecting between light-transmitting electrode layers at locations, and the light-transmitting electrodes are provided at a plurality of locations by printing. Since the layers are formed and each light-transmitting electrode layer is connected by a conductive pattern, an internal insulating layer for insulating the light-transmitting electrode layer from the back electrode layer becomes unnecessary, and the light-transmitting electrode layer is formed. The layers and the conductive patterns connecting them are conductive Since it is formed by printing a resin having dispersed flexibility, used with never by bending or flexing results in a fracture inexpensive easy E
It has an effect that an L element can be obtained.

According to a second aspect of the present invention, in the first aspect of the present invention, the back electrode layer and the conductive pattern are simultaneously formed by printing, and the back electrode layer and the conductive pattern can be simultaneously formed by one printing. , The number of printing of the EL element can be reduced, and the cost can be further reduced.

According to a third aspect of the present invention, in the first or second aspect of the present invention, a color conversion layer is formed by printing on the upper surface of the insulating film of each light emitting section or the light emitting layers of the respective light emitting layers have different emission colors. The light emission color of each light emitting portion of the EL element can be varied by making the color conversion layer printed on each light emitting portion or the light emitting color of each light emitting layer different from each other. LCD
When it is used as a backlight of a switch or a switch key, it emits various colors, and has an effect that the display portions of various electronic devices can be diversified and multifunctional.

According to a fourth aspect of the present invention, the dispersion type electroluminescent element according to any one of the first to third aspects is bent, and the plurality of light emitting portions are formed on a plurality of planes or curved surfaces of the device. This is a method of mounting the arranged dispersed electroluminescent element on a device. Since each layer of the EL element is formed by printing a flexible resin, an EL having a plurality of light emitting portions is provided. The device can be mounted on the device by bending the device, and the display and operation unit can be illuminated by a single EL element with the display unit and operation unit arranged on multiple surfaces such as the top surface and the front surface. Even if it is a curved surface, the EL element can be flexed and arranged behind the display unit or the operation unit, so that it is possible to perform illumination that makes it possible to clearly check the display of the device without uneven illumination. With That.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. 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 sectional view of an EL device according to a first embodiment of the present invention, and FIG. 2 is a perspective view of the EL device. In FIG. 1, a transparent material such as polyethylene terephthalate has flexibility. Layer 3 in which zinc sulfide as a base material for light emission is dispersed in a plurality of places on the lower surface of a simple insulating film 1 in a high dielectric resin such as fluoro rubber or cyano resin.
A, 3B, and dielectric layers 4A, 4B and 4A, in which barium titanate or the like is dispersed in a similar high dielectric resin.
Back electrode layer 6 of silver or carbon resin connected to 4B
The back insulating layer 7 of epoxy resin, polyester resin, or the like covering these is sequentially formed by printing, as in the case of the prior art, but the light transmitting electrode layers 12A, 12A are formed.
B and 12C, 12D, and 12E are also printed on the lower surface of the insulating film 1 by printing a conductive paste in which indium tin oxide is dispersed in a light-transmitting resin such as polyester resin, epoxy resin, acrylic resin, phenoxy resin, and fluororubber. It is formed at a plurality of locations.

The light transmitting electrode layers 12A,
A flexible conductive pattern 13 of silver or carbon resin is connected between 12B, 12C, 12D, and 12E to form a plurality of light emitting portions 14A, 14B and 14C, 14D,
An EL element 15 having 14E is configured.

The printing method of the EL element 15 having the above configuration will be described with reference to FIGS. 3 (a) to 3 (d).
As shown in FIG. 3A, the light-transmitting electrode layers 12A, 12B, 12C, 12D, and 12E are printed on the insulating film 1, respectively, and then overlaid thereon, as shown in FIG.
A, 3B, 3C, 3D, 3E and dielectric layers 4A, 4B, 4
After sequentially printing C, 4D, and 4E, a conductive pattern 13 connecting the back electrode layer 6 and each light transmitting electrode layer is printed as shown in FIG. 3C, and finally, as shown in FIG. The back insulating layer 7 covering these is printed and the outer shape is cut to complete the EL element 15 having five light emitting portions.

The EL element 15 is mounted as a backlight for illumination behind a display panel, an LCD, or a switch key of various electronic devices.
When a voltage is applied to the conductive pattern 13 connecting the back electrode layer 6 of the L element 15 and each light transmitting electrode layer, the EL element 15
Are driven and the five light emitting units 14A, 14B, 14C, 14
D and 14E emit light, and this light illuminates the LCD and the switch key from behind.

As described above, according to the present embodiment, the light transmissive electrode layers 12A, 12B, 12
Since C, 12D, and 12E are formed by printing and the respective light-transmitting electrode layers are connected by the conductive pattern 13, an internal insulating layer for insulating each light-transmitting electrode layer from the back electrode layer 6 is unnecessary. Since each of the light-transmitting electrode layers and the conductive pattern 13 connecting the light-transmitting electrode layers are formed by printing a flexible resin in which conductive powder is dispersed,
It is possible to obtain an inexpensive and easy-to-use EL element which does not break due to bending or bending.

Further, since the back electrode layer 6 and the conductive pattern 13 are simultaneously formed by one printing, the EL element 1
5, the number of printings can be reduced and the printing cost can be reduced.

In the above description, the material of the back electrode layer 6 and the material of the conductive pattern 13 have been described as being the same. However, for example, the conductive pattern 13 which has a long wiring distance and tends to have a large wiring resistance has good conductivity. EL printing is performed by using silver paste and printing the back electrode layer 6 with a relatively short wiring distance using an inexpensive carbon paste.
Of course, it is possible to use different materials according to the shape and wiring of the element 15.

(Embodiment 2) FIG. 4 is a sectional view of an EL device according to a second embodiment of the present invention, and FIG. 5 is an exploded perspective view of a unit mounted on the same device. Light transmitting electrode layers 12A, 12B
The light emitting layers 3A and 3B, the dielectric layers 4A and 4B, the back electrode layer 6, the conductive pattern 13, and the back insulating layer 7 covering these are sequentially formed by printing, and the five light emitting portions 14 shown in FIG.
The EL element 16 including the elements A to 14E is configured in the same manner as in the first embodiment. However, the color in which a fluorescent pigment or a fluorescent dye is dispersed in a transparent resin is provided on the upper surface of the insulating film 1 of each light emitting unit. The conversion layers 17A and 17B are formed by printing.

Reference numeral 18 denotes an LCD, reference numeral 19 denotes a transparent milky white silicone rubber switch key, reference numeral 20 denotes an insulating resin holder, and reference numeral 21 denotes an electronic component (not shown) and a dome-shaped metal diaphragm 22 mounted on upper and lower surfaces. With the wiring board
The CD 18 is mounted on the holder 20 with the light emitting section 14A of the EL element 16 interposed therebetween, and the switch key 19 is mounted on the metal diaphragm 22 with the light emitting sections 14B, 14C, 14D, 14E of the EL element 16 interposed therebetween.

When these are mounted on the wiring board 21, the light emitting section 14A of the EL element 16 and the light emitting sections 14B, 1
On the 4C, 14D, and 14E sides, a step corresponding to the thickness of the holder 20 is generated.
The element 16 is mounted on the wiring board 21.

The light emitting layer of the EL element 16 is made of fluorescent powder that emits blue green light,
B shows color conversion layers 17A and 17B in which a red fluorescent pigment is dispersed.
However, color conversion layers 17C and 17D in which fluorescent pigments for yellow-orange conversion are dispersed are formed by printing on the light-emitting portions 14C and 14D.

The EL element 16 having the above-described structure is mounted on a display section or an operation section of an electronic device together with the LCD 18, the switch key 19, the wiring board 21 and the like, and the EL element 16
When a voltage is applied to the conductive pattern 13 connecting the back electrode layer 6 and each light transmissive electrode layer, the EL element 16 is driven to emit light from the five light emitting portions. At this time, the light emission without the color conversion layer is provided. The portion 14E emits blue-green light emitted from the light-emitting layer, and the light-emitting portions 14A and 14B disperse a red fluorescent pigment to provide white night-vision color by the color conversion layers 17A and 17B and the light-emitting portions 14C and 14D. Are the color conversion layers 17C and 17D
The LCD 18 and the switch key 19A are white and the switch keys 19B and 1
9C is illuminated in yellow-orange, and the switch key 19D is illuminated in blue-green.

As described above, according to the present embodiment, a color conversion layer is formed by printing on the upper surface of the insulating film 1 of each light-emitting portion, so that the light-emitting color of each light-emitting portion of the EL element 16 can be changed by the light-emitting layer. Since various colors different from the colors can be used, various colors are emitted when used as a backlight of the LCD 18 and the switch key 19, etc. Can be achieved.

In the above description, the configuration in which each light emitting portion of the EL element 16 emits various colors by printing the color conversion layer has been described.
The fluorescent powder dispersed in the resin B has a different emission color,
It goes without saying that the same effect can be obtained even if the emission color of the light emitting layer itself is changed.

In the above description, the configuration in which the connecting portion 16A is bent and the EL element 16 is mounted on the wiring board 21 has been described. However, each layer of the EL elements 15 and 16 is made of a flexible material in which conductive powder or fluorescent powder is dispersed. Since the connection portion 16A is bent at a right angle to the electronic device 23 in which the display portion 23A and the operation portion 23B are arranged on the upper surface and the front surface as shown in FIG. Element 16
By mounting the, it is possible to illuminate a plurality of surfaces of the electronic device 23 with one EL element.

Further, even when the display unit or the operation unit of the device has a curved surface instead of a flat surface, the EL element can be bent and disposed behind the display unit or the operation unit, so that the display of the device can be performed without uneven illumination. Illumination that can be clearly identified is also possible.

[0033]

As described above, according to the present invention, since a plurality of light-emitting portions are provided and have flexibility, it is easy to use, and is inexpensive.
An advantageous effect that an element can be obtained is obtained.

[Brief description of the drawings]

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

FIG. 2 is a perspective view of the same.

FIGS. 3A to 3D are plan views of the printing method.

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

FIG. 5 is an exploded perspective view of a unit mounted on the device.

FIG. 6 is a perspective view attached to the device.

FIG. 7 is a cross-sectional view of a conventional EL element.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Insulating film 3A, 3B Light emitting layer 4A, 4B Dielectric layer 6 Back electrode layer 7 Back insulating layer 12A, 12B, 12C, 12D, 12E Light transmitting electrode layer 13 Conductive pattern 14A, 14B, 14C, 14D, 14E Light emission Units 15, 16 EL element 16A Connecting unit 17A, 17B Color conversion layer 18 LCD 19 Switch key 20 Holder 21 Wiring board 22 Metal diaphragm 23 Electronic device 23A Display unit 23B Operation unit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshiharu Abe 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] A light-transmitting insulating film; a light-transmitting electrode layer in which light-transmitting conductive powder is dispersed in a light-transmitting resin printed on a plurality of locations on the lower surface of the insulating film; A plurality of light-emitting layers and dielectric layers sequentially formed on the transparent electrode layer, a back electrode layer connecting the dielectric layers, and a flexible connection between the plurality of light-transmitting electrode layers. Dispersion type electroluminescent element provided with a plurality of light emitting portions made of conductive patterns having a characteristic. 2. The dispersion-type electroluminescent device according to claim 1, wherein the back electrode layer and the conductive pattern are simultaneously formed by printing. 3. The light emitting section according to claim 1, wherein a color conversion layer is printed on the upper surface of the insulating film of each light emitting section, or the light emitting layer has a different light emitting color, and the light emitting section has a plurality of light emitting colors. Dispersion type electroluminescent element. 4. A dispersion-type electroluminescence device, wherein the dispersion-type electroluminescence device according to claim 1 is bent, and a plurality of light-emitting portions are arranged on a plurality of planes or curved surfaces of the device. How to attach the element to the device.