JPH11233265A - Electroluminescent device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electroluminescent device that can provide luminescent colors having bright and vivid hues, and at the same time, can provide luminescent colors having plenty of color variation, and can also provide a colorful color EL display. SOLUTION: An EL(electroluminescent) device 1 is composed by flatly arranging one or more kinds of fluorescent color layers 3 having color tones different from one another on the surface of a transparent base substance 4 of an EL 2 composed by laminating an insulating layer 9, a back electrode layer 8, a dielectric layer 7, an illuminant layer 6, a transparent electrode layer 5 and the transparent base substance 4 in that order from the lowermost layer. The fluorescent color layers 3 is made by diffusively mixing color pigments in an organic binder. In addition, at least one kind of fine pieces of pearls or mica, or noble metal powder of gold, silver or the like are diffusively mixed, or a layer formed by diffusively mixing them is formed. An ultraviolet ray absorbing agent is mixed or a layer formed from it is formed. A light diffusing surface is formed on the upper surface of the transparent base substance 4. Luminescent colors keeping bright and brilliant hues for a long time can thereby be provided. A colorful color EL display can also be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroluminescence device.

[0002]

2. Description of the Related Art In recent years, electroluminescence (hereinafter abbreviated as EL) has been used for backlight illumination of a liquid crystal device, a timepiece dial, and the like. It has come to be used a lot. In order to give the emission color a color variation, for example, Japanese Patent Laid-Open No. 8-179
No. 701 discloses the technique. The outline will be described below with reference to the drawings.

FIG. 4 is an enlarged sectional view of an EL device. E
The L device 10 is made of polyethylene terephthalate (PET)
On a transparent electrode 12 formed by evaporating indium trioxide (ITO) on a transparent substrate 11 made of a synthetic resin such as
4. The insulating layer 15 and the back electrode 16 are sequentially formed by printing means such as screen printing. The back electrode 16 is made of carbon paste.
The light-emitting layer 4 is obtained by printing and drying the stirred ink.
Is obtained by printing and drying an ink obtained by mixing and stirring a luminous body obtained by doping copper into zinc sulfide as a fluorescent substance and a fluororesin binder. The fluorescent layer 13 is used as a display layer. The fluorescent layer 13 is obtained by printing and drying an ink obtained by mixing and stirring a fluorescent pigment and a fluororesin binder. The mixing amount of the fluorescent pigment is determined by the weight ratio of the binder and the binder. It is configured to be 3:10 or more.

[0006] The above-described structure is composed of the transparent electrode 12 and the light emitting layer 14.
Between them, a fluorescent layer 13 (display layer) of fluorescent light containing a fluorescent pigment or a fluorescent dye is provided, and a display pattern of the fluorescent color display layer appears in the EL emission color.

[0005]

However, the above-mentioned prior art has the following problems.
That is, the light emitted by the EL is transmitted through the display layer, further transmitted through the transparent electrode and the transparent substrate, and emitted to the viewer side. The light that has passed through the display layer and has been converted to a fluorescent color wavelength passes through the transparent electrode, and further passes through the transparent substrate and is emitted to the viewer side, but light that is absorbed by the transparent electrode also occurs. Further, when the light passes through the transparent substrate, the light is refracted by the refractive index of the transparent substrate, and is emitted to the viewer side in the refracted state. For this reason, the light entering the eye on the viewing side is a state in which the amount of light emitted from the fluorescent color display layer is reduced, and the light that is refracted instead of entering straight from the display layer. As a result, there is a problem that the fluorescent color is visually recognized in a state where the brightness and the vividness of the color are lacking.

The present invention has been made in view of the above problems, and an object of the present invention is to obtain a bright and colorful color light emission color and a light emission color with a wide variety of color variations. Another object of the present invention is to provide an electroluminescence device for obtaining a colorful EL display.

[0007]

In order to achieve the above object, an electroluminescent device according to the present invention comprises:
In an electroluminescent device laminated with an insulating layer, a back electrode layer, a dielectric layer, a luminescent layer, a transparent electrode layer, and a transparent substrate in order from the lower layer constituting the electroluminescence, a fluorescent color layer was formed on the surface of the transparent substrate. It is characterized by the following.

Further, the fluorescent color layer is formed by arranging at least one kind of fluorescent color layer having a different color tone in a plane.

The fluorescent color layer is characterized in that a color fluorescent pigment is dispersed and compounded in an organic binder.

The fluorescent color layer is characterized in that a color fluorescent pigment is dispersed and blended in an organic binder 1 at a weight ratio of 0.2 to 0.5.

The fluorescent color layer is characterized in that a color fluorescent pigment and at least one kind of fine particles of pearl or mica or a noble metal powder such as gold or silver are dispersed and mixed in an organic binder. .

The fluorescent color layer comprises a layer formed by dispersing and blending a color fluorescent pigment in an organic binder, and an organic binder and at least one kind of fine particles of pearl or mica or a noble metal powder such as gold or silver. And a layer formed by dispersion blending.

The fluorescent color layer is characterized in that an ultraviolet absorber is dispersed and blended.

The fluorescent color layer is characterized in that an ultraviolet absorbing paint layer is formed on the surface thereof.

Further, the transparent substrate has a light diffusion surface formed on an upper surface thereof.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An EL device according to the present invention will be described below with reference to the drawings. FIG. 1 is an enlarged sectional view of the EL device according to the first embodiment of the present invention.

In FIG. 1, an EL device 1 has a fluorescent color layer 3 laminated on a viewing side of an EL 2. The EL 2 is composed of a transparent substrate 4 made of a transparent resin film or a transparent glass or the like from a viewing side, and a transparent substrate 4. A transparent electrode 5, a light emitting layer 6, a dielectric layer 7, a back electrode 8, and an insulating layer 9 formed by depositing ITO on the surface of the transparent substrate 4 on the outermost surface of the EL2. The EL device 1 is composed of a fluorescent color layer 3 formed by printing or applying a color fluorescent pigment as a paint. The dielectric layer 7 also has a role of protecting the luminous body from electrical breakdown and a role of reflecting the light emitted from the luminous body layer 6 to the viewing side.

As described above, by providing the fluorescent color layer 3 on the surface of the transparent substrate 4, the fluorescent color layer 3 is provided.
Is directly visible, so that the vividness of the fluorescent color clearly appears on the viewer side. At the same time, the fluorescent agent emits light in response to the light emitted by the EL, so that brightness also appears.

The reason that the fluorescent color appears is that the EL emission color is green, and the emission spectrum is about 500 nm.
It has a peak at the wavelength. This is because when a color having a peak higher than this wavelength is transmitted, wavelength conversion is performed, and a color tone of a high wavelength appears strongly. For example, when an orange color layer having a peak wavelength of 600 nm is formed on the surface of the EL light emitting layer, an orange color appears.

FIG. 2 is an enlarged sectional view of an EL device according to a second embodiment of the present invention, and FIG. 3 is a perspective view of FIG. FIG. 2 shows the EL device 1 shown in FIG. 1, in which fluorescent color layers having different tones are formed in a plurality of regions, for example, fluorescent color layers 3a and 3b are arranged in two regions on the surface of the transparent substrate 4 of the EL 2. . Other configurations are the same as those in FIG.

As described above, for example, the upper fluorescent color layer 3a is composed of an orange color fluorescent pigment, and the lower fluorescent color layer 3b is composed of a red color fluorescent pigment. By arranging the fluorescent color layers having different color tones in this manner, various color colors appear and the emission color becomes rich,
The color variation of L color display is expanded.

Here, in FIG. 1, the EL device provided with the fluorescent color layer described in the basic structure of the present invention will be described in detail. As described above, the EL device 1 forms a color fluorescent pigment on the surface of the EL 2, that is, the surface of the transparent substrate 4 made of a transparent resin film or transparent glass provided on the uppermost layer of the EL 2, and prints. And a fluorescent color layer 3 is provided. In the present embodiment, the fluorescent color layer 3 is formed by dispersing and blending a color fluorescent pigment with the organic binder 1 at a weight ratio of 0.2 to 0.5 to form a paint.
It is formed to a thickness of about 20 μm by means such as screen printing. The mixing ratio of the fluorescent pigment to the binder 1 is optimally 0.2 to 0.5 (weight ratio). If the amount is less than this, the viscosity of the paint becomes low and the paint may flow during printing, resulting in poor workability, and at the same time, the color tint may be reduced. On the other hand, if the amount is more than this, the viscosity becomes high, causing blurring or peeling during printing, which affects quality. At the same time, the light transmittance also decreases, so that the luminance of the light emission also decreases and the color tone becomes darker.

Also, by blending a color fluorescent pigment with an organic binder and further a pearl fine piece or a mica fine piece, a color with some glittering appearance appears. Further, by dispersing and blending a color fluorescent pigment and at least one kind of noble metal powder such as gold or silver into an organic binder, a color in which a gold shine or a silver shine partially appears in a color color. Colors can appear.

Also, a thin coating formed by dispersing and blending a color fluorescent pigment in an organic binder and at least one kind of an organic binder and pearl fine particles or mica fine particles or a noble metal powder of gold or silver. By providing a layer on the surface of the fluorescent color layer 3, the same color as described above can be obtained.

In this embodiment, a polyester resin is used as the organic binder. Fluorescent pigments are susceptible to the effects of ultraviolet light, and discoloration occurs over a long period of time.
By adding an ultraviolet absorber to the binder, the effect of ultraviolet light of the fluorescent pigment can be prevented.

Further, by printing an ultraviolet absorbing paint on the surface of the fluorescent color layer 3 and providing an ultraviolet absorbing layer, the influence of ultraviolet light of the fluorescent pigment can be prevented. Examples of the ultraviolet absorber include benzophenone-based, benzotriazole-based, and oxalic acid anilide-based absorbers.

It is preferable that the thickness of the fluorescent color layer 3 is appropriately set within a thickness of at least 8 μm. 8μ
When the thickness is less than m, the color tone becomes lighter, the color becomes less vivid, and the fluorescent discoloration life is shortened. On the other hand, if it is too thick, it will affect the transmittance of the light emitted from EL2 and affect the luminance. The thickness is preferably determined appropriately in the above-mentioned range in consideration of the degree of vividness and luminance.
The formation of the fluorescent color layer 3 is favorable because the screen printing method can secure a uniform thickness. Further, with the above-mentioned thickness, printing can be performed at a low cost because only one or two printings are required. However, the present invention is not particularly limited, and it goes without saying that another printing method or coating method may be used.

Further, by making the surface of the transparent substrate 4 of the EL 2 a light diffusing surface, the light emitted from the EL 2 is diffused by the diffusing surface and uniformly enters the fluorescent color layer 3. In many cases, the luminous layer 6 of the EL 2 is formed by screen printing in view of the manufacturing cost and the like. Tend to be lower than elsewhere. Since the film has a diffusion surface, the light is sufficiently diffused, and the light radiated from the film is radiated in a uniform light amount and is incident on the fluorescent color layer 3 so as to pass through the fluorescent color layer 3. Light is transmitted with a uniform amount of light. This appears as an effect of obtaining a uniform color. This diffusion surface is formed by providing minute irregularities on the film by honing.

The EL device 1 formed as described above is
The light emitted in 2 immediately passes through the transparent substrate 4 and enters the fluorescent color layer 3. At this time, when the light passes through the transparent substrate 4, the light is dispersed, and the light enters the fluorescent color layer 3 in a uniform state. The incident light passes through the fluorescent color layer 3 and radiates to the surface of the fluorescent color layer 3. When the fluorescent pigment itself receives the light of EL2 when transmitted through the fluorescent color layer 3, the fluorescent pigment itself also emits light, the wavelength is converted, and the color EL of the fluorescent color layer 3 is emitted. And bright and vivid colors appear.

Further, the fluorescent color layer 3 in the present embodiment
Is formed by blending, for example, an orange fluorescent pigment having a wavelength of 600 nm with an organic binder. As the color fluorescent pigments, many other color fluorescent pigments such as red, pink, and yellow can be used. By mixing these, more color variations can be freely provided.

[0031]

As described above, by providing the fluorescent color layer on the surface of the transparent substrate of the EL as described in the basic constitution of the present invention, the fluorescent color layer can be directly viewed, so that the color of the fluorescent color is obtained. Vividness appears clearly. at the same time,
Since the fluorescent agent emits light in response to the light emitted by the EL, it appears bright.

By arranging a plurality of color layers having different tones in a plurality of regions, various color colors appear, the emission color becomes rich, and the color variation of EL color display is widened.

Further, by appropriately dispersing and mixing the color fluorescent pigment in the organic binder, the printing workability, the printing quality, the transparency of the EL emission light, and the vividness of the color are brought into a preferable state.

Further, by mixing pearl or mica fine pieces, the part reflects light, and a glittering part appears on the color light emitting surface, so that the color variation can be increased.

Further, by mixing the noble metal, a shining portion of gold or silver appears in the color light emitting surface, and the color variation can be increased.

Further, by mixing an ultraviolet absorbing agent or providing an ultraviolet absorbing paint layer, the deterioration of the fluorescent agent can be prevented, and the vividness can be always ensured.

Further, by forming a light diffusing surface on the surface of the transparent substrate, the EL light is diffused and transmitted through the fluorescent color layer, so that the unevenness in luminance and color is reduced by the diffusion. .

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional view illustrating a basic configuration of an EL device according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view of an EL device according to a second embodiment of the present invention.

FIG. 3 is a perspective view of the EL device of FIG. 2;

FIG. 4 is an enlarged sectional view of a conventional EL device.

[Explanation of symbols]

 Reference Signs List 1 EL device 2 EL 3 Fluorescent color layer 4 Transparent substrate 5 Transparent electrode (ITO electrode) 6 Light emitting layer 7 Dielectric layer 8 Back electrode 9 Insulating layer

Claims (9)

[Claims] 1. An insulating layer, a back electrode layer, a dielectric layer, a light emitting layer,
An electroluminescent device laminated with a transparent electrode layer and a transparent substrate, wherein a fluorescent color layer is formed on a surface of the transparent substrate. 2. The electroluminescent device according to claim 1, wherein said fluorescent color layer is formed by arranging at least one kind of fluorescent color layer having a different color tone in a plane. 3. The electroluminescent device according to claim 1, wherein the fluorescent color layer is formed by dispersing and mixing a color fluorescent pigment in an organic binder. 4. The fluorescent color layer comprises an organic binder 1
4. The electroluminescent device according to claim 3, wherein a color fluorescent pigment is dispersed and compounded at a weight ratio of 0.2 to 0.5. 5. The fluorescent color layer according to claim 1, wherein a color fluorescent pigment and at least one kind of fine particles of pearl or mica or a noble metal powder such as gold or silver are mixed in an organic binder. 5. The electroluminescent device according to any one of items 1 to 4, 6. The fluorescent color layer comprises a layer formed by dispersing and blending a color fluorescent pigment in an organic binder, and at least one kind of an organic binder and fine particles of pearl or mica or a noble metal powder such as gold or silver. The electroluminescent device according to any one of claims 1 to 4, comprising a layer formed by dispersing and blending. 7. The electroluminescent device according to claim 1, wherein the fluorescent color layer contains an ultraviolet absorber dispersed therein. 8. The fluorescent color layer according to claim 1, wherein an ultraviolet absorbing paint layer is formed on a surface of the fluorescent color layer.
5. The electroluminescent device according to any one of items 1 to 4, 9. The electroluminescent device according to claim 1, wherein the transparent substrate has a light diffusion surface formed on an upper surface thereof.