JPH11297479A - Organic electroluminescence device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form high quality appearance of high grade feeling by preventing a display surface from being seen as a mirror surface, when an organic electroluminescent light-emitting body is not emitting light. SOLUTION: This device includes an organic electroluminescence light- emitting body 10, provided with a transparent electrode 14 on the surface side of an organic light-emitting layer 17 which emits light as a voltage is applied, and provided with a metal electrode 19 on the back side of the organic light- emitting layer 17, where the transparent electrode 14 is formed on the back surface side of a transparent substrate 12. In addition, a diffusion plate 11 having light diffusing property is provided on the surface side of the transparent substrate 12, and a color filter 26 to transmit the light of the same color as the emitted light of the organic electroluminescence light-emitting body 10, or emit fluorescence is provided on the surface side of the diffusion plate 11 or between the diffusion plate 11 and the transparent substrate 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Electroluminescent devices include inorganic electroluminescent devices and organic electroluminescent devices. In general, inorganic electroluminescence devices require a few tens of
It is necessary to apply the above high AC voltage. In contrast,
The organic electroluminescence device has an advantage that it emits light with high luminance at a DC voltage of about 10 V or less.

In general, an organic electroluminescence device forms a luminous body (organic electroluminescent luminous body) by sequentially laminating a transparent electrode, an organic luminescent layer and a metal electrode on a transparent substrate. Here, the organic light emitting layer is a laminate of various organic thin films, for example, a laminate of a hole injection layer made of a triphenylamine derivative or the like and a light emitting layer made of a fluorescent organic solid such as anthracene, Alternatively, a configuration having various combinations such as a laminate of such a light-emitting layer and an electron injection layer made of a perylene derivative or a laminate of a hole injection layer, a light-emitting layer, and an electron injection layer is known. Have been.

In an organic electroluminescence device, holes and electrons are injected into an organic light emitting layer by applying a voltage to a transparent electrode and a metal electrode, and energy generated by recombination of these holes and electrons is generated. It emits light on the principle that the fluorescent substance is excited and emits light when the excited fluorescent substance returns to the ground state. The mechanism of recombination on the way is the same as that of a general diode, and as can be expected from this, the current and the emission intensity show strong nonlinearity with rectification with respect to the applied voltage.

In an organic electroluminescence device, at least one electrode must be transparent in order to extract light emitted from the organic light emitting layer, and is usually formed of a transparent conductor such as indium tin oxide (ITO). A transparent electrode is used as the anode. On the other hand, in order to facilitate electron injection and increase luminous efficiency, it is important to use a material having a small work function for the cathode, and usually a metal electrode such as Mg-Ag or Al-Li is used.

[0006]

SUMMARY OF THE INVENTION In the organic electroluminescence device having such a structure, the organic light emitting layer comprises:
It is formed of an extremely thin film having a thickness of about 10 nm.
Therefore, the organic light emitting layer transmits light almost completely, similarly to the transparent electrode. As a result, when light is emitted from the surface of the transparent substrate during non-emission, the light transmitted through the transparent electrode and the organic light-emitting layer and reflected by the metal electrode returns to the surface of the transparent substrate again. The display surface of the organic electroluminescence device looks like a mirror surface.

When the organic electroluminescence device is used as a light emitting element or a display element, it is extremely unnatural that the display surface looks like a mirror surface when light is not emitted, and the use is extremely limited. This problem is more serious especially in a bright environment. The present invention has been made to solve the above-described problems of the conventional organic electroluminescence device, and prevents the display surface from being seen as a mirror surface by light reflected from the metal electrode when light is not emitted. Main purpose.

[0008]

In order to achieve this object, a first aspect of the present invention is to provide a transparent electrode on a front surface side of an organic light emitting layer which emits light by applying a voltage, and a metal electrode on a rear surface side of the organic light emitting layer. Provided organic electroluminescent light emitter (hereinafter sometimes abbreviated as organic EL light emitter)
The transparent electrode of the organic electroluminescent luminous body is formed on the back side of the transparent substrate, and a diffusion plate having a light diffusing property is provided on the front side of the transparent substrate.

In this specification and claims, the “front surface” of each member refers to a surface close to the display surface seen from the outside, and the “back surface” of each member refers to the front surface of each member. The opposite surface (the surface closer to the metal electrode) is referred to.

As the diffusion plate, a ceramic thin plate or the like can be used. As described above, according to the present invention in which the diffusion plate is formed on the surface of the transparent substrate, when the organic EL luminous body does not emit light (when light is not emitted), part of the light emitted from the outside is exposed to the surface of the diffusion plate. Alternatively, the light is diffusely reflected inside, and the remaining light passes through the diffusion plate. Then, the light transmitted through the diffusion plate is reflected by the metal electrode, is incident on the diffusion plate again, and is diffused. As a result, there is an effect that the mirror surface of the metal electrode is not visually recognized from the outside.

Further, the first invention provides a color filter or a fluorescent light which transmits light of the same color as the emission color of the organic electroluminescent luminous body, on the surface side of the diffusion plate or between the diffusion plate and the transparent substrate. A color filter that emits light is provided. By providing such a color filter,
When the organic EL luminous element does not emit light, the mirror surface of the metal electrode is shielded by the diffusion plate, and the entire display surface looks the same color as the luminous color of the organic electroluminescent luminous element or the luminous color of the color filter.

This is because the diffusion plate is milky white, has no wavelength selectivity, and when the organic EL luminous body does not emit light,
This is because this diffusion plate functions as a kind of reflection plate.
When the organic EL luminous body emits light, since the spectral curve related to the luminescence of the organic EL luminous body and the spectral curve related to the transmittance of the color filter substantially match, the color of the recognizable light is substantially the same. Emission color remains as it is. In this way, the light emitted by the organic EL luminous body can be used efficiently without being absorbed by the color filter, and a light emitting surface with high luminance can be obtained.

In the first invention, the transparent electrode is divided into a plurality of parts, and a shielding layer for shielding light is provided between the transparent substrate and the diffusion plate except at least a part facing the transparent electrode. You may. The transparent electrodes divided into a plurality of parts can be arranged in arbitrary patterns indicating, for example, characters, numbers, figures, and the like, and can be illuminated and displayed by arbitrarily energizing each of them independently.

Light emitted from the organic EL luminous body spreads radially while passing through the transparent substrate. However, since a shielding layer is formed on the surface side of the transparent substrate, only light passing through the gap between the shielding layers exits to the surface side through the diffusion plate. That is, by narrowing down the light emitted from the organic EL luminous body by the shielding layer, the contour of the luminescent display pattern can be made clear.

In the first invention having such a configuration,
A color filter that transmits light of a predetermined wavelength or emits fluorescence of a predetermined wavelength is provided on the front surface or the back surface of the diffusion plate, so that various color configurations of the display surface can be realized. Also,
Color filters that transmit light of a predetermined wavelength or emit fluorescent light of a predetermined wavelength may be provided in gaps between the shielding layer facing the transparent electrode.

Further, if the shielding layer is formed of a reflecting layer that reflects light and an absorbing layer that absorbs light, and the reflecting layer is disposed on the front side and the absorbing layer is disposed on the back side, the organic EL light emitting element can emit light during light emission. The light-emitting display pattern can be made clearer, and the entire surface can be made to have uniform brightness when no light is emitted.

That is, when the layer on the light receiving side from the organic EL luminous body has the property of reflecting light during light emission, the light spread on the transparent substrate is reflected on the shielding layer and is incident on the metal electrode. In addition, the light is further reflected by the metal electrode and a part of the light leaks from the gap in the shielding layer. As a result, the luminescent display pattern of the organic EL luminous body becomes unclear and the display quality is reduced. The absorbing layer prevents such disadvantages.

On the other hand, at the time of non-emission, the diffuser diffuses the light that enters from the surface, passes through the gap in the shielding layer, is reflected by the metal electrode, and again passes through the gap in the shielding layer, and is emitted to the surface side. . The light diffusion action at this time makes the mirror surface of the metal electrode invisible from the outside.

However, when the reflected light from the metal electrode enters the diffusion plate only from the gap between the shielding layers, the light is not diffused to the entire diffusion plate, and thus, when viewed from the outside, An uneven brightness difference occurs on the surface. As a result, especially when the outside is bright, the display pattern of the organic EL luminous body can be identified even when the light is not emitted. Then, by reflecting the same amount of light as the reflected light from the metal electrode passing through the gap of the shielding layer on the reflecting layer, the entire surface of the diffusion plate can be made uniform in brightness.

The diffusion plate can be formed of a light-transmitting transparent plate and a thin-film diffusion layer formed on the back side of the transparent plate. If the diffusion layer having the light diffusing property is formed in a thin film shape, the degree of blurring of the contour of the display pattern can be suppressed by the light diffusing action when the light from the organic EL luminous body passes through the diffusion plate. In addition, the contour of the display pattern can be made clearer.

Here, a color filter which transmits or emits light of a predetermined wavelength may be provided on the front or back surface of the transparent plate. Next, the second invention has a configuration in which the transparent electrode of the organic EL luminous body is formed on the back side of a diffusion plate having a light diffusing property. That is, it has a structure in which the transparent substrate in the first invention described above is omitted.

As the diffusion plate, a ceramic plate or the like having a sufficient thickness as a substrate can be used. According to the second aspect, since the transparent substrate is omitted, the structure can be made thinner accordingly. According to the second aspect, when the organic EL light-emitting body does not emit light, the light reflected from the metal electrode is diffused by the diffusion plate, so that the mirror surface of the metal electrode can be made invisible from the outside of the device.

In the second invention, as in the first invention, a color filter that transmits light of a predetermined wavelength or emits fluorescence of a predetermined wavelength can be provided on the front or back surface of the diffusion plate. Also, instead of color filters,
Similarly, by coloring the diffuser plate with an arbitrary color, various color configurations of the display surface can be realized.

Next, a third invention is to form a transparent electrode of an organic EL luminous body on the back side of a transparent substrate and to form a light-diffusing thin-film diffusion layer between the transparent substrate and the transparent electrode. Is formed. Also according to the third aspect, there is an effect that the mirror surface of the metal electrode is not visually recognized from the outside by the light diffusion action of the diffusion layer. Here, the transparent electrode may be divided into a plurality of parts.

Further, a color filter which transmits light of a predetermined wavelength or emits fluorescence of a predetermined wavelength may be provided on the surface of the transparent substrate or between the transparent substrate and the diffusion layer. On the other hand, instead of the color filter, the diffusion layer may be colored in an arbitrary color. By installing these color filters and coloring the diffusion layer, it is possible to realize various color configurations of the display surface.

Further, a transparent coat layer for smoothing the surface on which the transparent electrode is formed may be provided on the back side of the diffusion layer. That is, the organic light-emitting layer that constitutes the organic EL light-emitting body is generally very thin, and if the surface on which the transparent electrode is formed is rough, defects such as a short circuit between the transparent electrode and the metal electrode may occur. From the viewpoint of preventing such defects, it is preferable to smooth the back surface side of the diffusion layer with the transparent coat layer.

The transparent coat layer may be formed of an organic transparent coat layer made of an organic material having acid resistance and an inorganic transparent coat layer made of an inorganic material formed on the back of the organic transparent coat layer. . With such a two-layer structure, the organic transparent coat layer smoothes the back surface side of the diffusion layer, and the inorganic transparent coat layer improves the etching performance of the transparent electrode.

In addition, a color filter that transmits light of a predetermined wavelength or emits fluorescence of a predetermined wavelength is provided between the diffusion layer and the transparent coat layer and at least at a position facing the transparent electrode. Can be realized. Here, due to the formation of the color filter, irregularities are formed on the back surface side of the diffusion layer. The transparent coat layer eliminates the unevenness and smoothes the surface on which the organic EL luminous body is formed.

Further, as these color filters,
If a plurality of types of color filters that transmit light of different wavelengths or emit fluorescent light of different wavelengths are used, it is possible to realize more various display surface color configurations by displaying a plurality of colors. On the other hand, instead of the transparent coat layer, a transparent sheet made of thin glass may be provided between the diffusion layer and the transparent electrode.

A color filter that transmits light of a predetermined wavelength or emits fluorescence of a predetermined wavelength is provided between the diffusion layer and the transparent sheet and at least at a position facing the transparent electrode. Is filled with an adhesive and the transparent sheet is adhered with the adhesive, so that a variety of display surfaces can be formed in the same manner as when a color filter is added to the organic electroluminescence device having the transparent coat layer. A color configuration can be realized.

If a plurality of types of color filters that transmit light of different wavelengths or emit fluorescence of different wavelengths are used as these color filters, a more diverse color configuration of the display surface can be realized by displaying a plurality of colors. It can also be achieved.

Next, a fourth invention relates to an organic EL luminous body,
An organic electroluminescence device including a transparent substrate provided on the front surface side of a transparent electrode, and a light-diffusing thin film diffusion layer formed on the back surface of the transparent substrate, wherein the transparent substrate and the diffusion layer The interface is configured as a rough surface that irregularly reflects light.

Also according to the fourth aspect, there is an effect that the mirror surface of the metal electrode is not visually recognized from the outside by the light diffusion action of the diffusion layer. Further, according to the fourth aspect, the specular reflection of light that might occur at the interface between the transparent substrate and the diffusion layer is prevented by making the interface rough, thereby further improving the display surface. You can make it look soft.

According to the fifth aspect of the present invention, the organic electroluminescent device includes a transparent electrode on the front side of the organic light emitting layer that emits light by applying a voltage and a metal electrode on the back side of the organic light emitting layer.
L light-emitting body, a transparent substrate provided on the front side of the transparent electrode, a thin diffusion layer also formed on the front side of the transparent electrode and on the back side of the transparent substrate, and a back surface of the transparent substrate and a surface of the diffusion layer. An organic electroluminescent device including a color filter that is provided in contact with at least one surface thereof and transmits light of a predetermined wavelength or emits fluorescence of a predetermined wavelength, and includes at least one of a transparent substrate and a diffusion layer. ,
The interface with the color filter is formed as a rough surface that irregularly reflects light.

According to the fifth aspect, similarly to the fourth aspect, there is an effect that the mirror surface of the metal electrode is not visually recognized from the outside by the light diffusion effect of the diffusion layer. Specular reflection of light that may occur at either the interface between the transparent substrate and the color filter or the interface between the diffusion layer and the color filter is prevented by roughening the interface, and the display surface is prevented. You can make it look softer.

Next, a sixth aspect of the present invention is directed to an organic electroluminescent luminous element comprising a transparent electrode on the front side of an organic luminescent layer which emits light by applying a voltage, and a metal electrode on the back side of the organic luminescent layer. And a polarizing plate is provided on the surface side of the transparent electrode, and a phase plate is provided between the transparent electrode and the polarizing plate.

Since the phase plate and the polarizing plate have a function of polarizing light incident from the outside and reflected on the metal electrode, there is an effect that the mirror surface of the metal electrode is not visually recognized by the polarization action. In particular, if the phase plate is formed of a quarter-wave plate and the angle between the polarization directions of the polarizing plate and the phase plate is adjusted to π / 4, the mirror surface of the metal electrode can be completely shielded.

That is, as for the external light incident on the organic electroluminescence device, only the linearly polarized light component is transmitted by the polarizing plate. This linearly polarized light is generally converted into elliptically polarized light by a phase plate. In particular, when the phase plate is a quarter-wave plate and the angle between the polarization directions of the polarizing plate and the phase plate is π / 4, the light becomes circularly polarized light.

This circularly polarized light transmits through the transparent substrate, the transparent electrode, and the organic thin film, is reflected by the metal electrode, passes through the organic thin film, the transparent electrode, and the transparent substrate again, and becomes linearly polarized light again on the phase plate. The linearly polarized light is orthogonal to the polarization direction of the polarizing plate, and therefore cannot pass through the polarizing plate. As a result, the mirror surface of the metal electrode can be completely shielded.

[0040]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to explain the contents of the present invention in more detail, embodiments of the present invention will be described with reference to the accompanying drawings.

[First Embodiment] FIG. 1 is a sectional view showing a first embodiment of an organic electroluminescence device according to the present invention. In this organic electroluminescent device, an organic electroluminescent luminous body (organic EL luminous body) 10 is formed by a transparent electrode 14, an organic luminescent layer 17, and a metal electrode 19.

This organic EL light-emitting body 10 has a transparent substrate 12
Is provided on the back surface. On the surface of the transparent substrate 12, a diffusion plate 11 having a light diffusion action is provided. That is, a transparent electrode 14, an organic light emitting layer 17,
And a metal electrode 19 are sequentially laminated, and a diffusion plate 11 having a thickness of 0.2 mm is adhered to the surface of the transparent substrate 12.

For the transparent electrode 14, for example, indium tin oxide (ITO) is used. This transparent electrode 14
A thickness of about 100 is formed on the surface of the transparent substrate 12 by a sputtering method.
After forming a thin film with a thickness of nm, an etching process is performed to form a predetermined pattern shape.

The organic light emitting layer 17 includes a hole injection layer having a thickness of 60 nm made of, for example, a triphenylamine derivative and a light emitting layer having a thickness of 60 nm made of, for example, an aluminum chelate complex, so that the total thickness becomes 120 nm. Is formed on the back surface of the transparent electrode 14 by a vacuum evaporation method. When the organic light emitting layer 17 is formed of the above-described material, the organic light emitting layer 17 emits green light when a voltage is applied.

The metal electrode 19 is made of, for example, Mg-Ag (Ag
Of the organic light emitting layer 17 is about 1%.
It is formed by multiple vapor deposition to a thickness of 50 nm. In this embodiment, a thin alumina ceramic plate having a thickness of 0.2 mm is used as the diffusion plate 11. Ceramic thin plate
By adjusting the crystal structure, desired light transmittance and diffusivity can be easily obtained. In this embodiment, a ceramic thin plate having a milky white characteristic with a light transmittance of 60% was manufactured and used as the diffusion plate 11.

In this embodiment, since the diffusion plate 11 is formed on the surface of the transparent substrate 12 as described above, when the organic EL luminous body 10 does not emit light (when it does not emit light), light emitted from outside is emitted. Are diffusely reflected on the surface of or inside the diffusion plate 11, and the remaining light passes through the diffusion plate 11. Then, the light transmitted through the diffusion plate 11 is reflected by the metal electrode 19, enters the diffusion plate 11 again, and is diffused.

Therefore, when the surface of the diffusion plate 11 is viewed from the outside, it looks milky white. That is, there is an effect that the mirror surface of the metal electrode 19 is not seen from the outside. When the organic EL luminous body 10 is emitting light (when light is emitted), the light is diffused by the diffusion plate 11, and when viewed from the outside, the entire diffusion plate 11 is green, which is the luminescent color of the organic EL luminous body 10. Was observed as a uniform light emitting surface.

FIG. 2 is a sectional view showing a modification (modification 1-1) of the first embodiment shown in FIG. The organic electroluminescence device of FIG. 2 has a configuration in which a color filter 26 is provided on the surface of the diffusion plate 11 in addition to the configuration shown in FIG. The color filter 26 can be formed of, for example, gelatin dyed with a green azo acid dye, and is formed with a thickness of 1 μm on the surface of the diffusion plate 11 here.

It is preferable that the color filter 26 has a transparent structure without light diffusion. There are no strict restrictions on the thickness of the color filter 26,
Usually, it may be formed to a thickness of about several μm. Color filter 2
In the structure of Modification 1-1 in which No. 6 is formed, the mirror surface of the metal electrode 19 is shielded by the diffusion plate 11 and the display surface (the surface of the diffusion plate 11) when the organic EL light-emitting body 10 does not emit light.
The whole looks like the color of the color filter 26 (for example, green).

This is because the diffusion plate 11 is milky white, has no wavelength selectivity, and functions as a kind of reflection plate when the organic EL light-emitting body 10 is not emitting light. When the organic EL light emitting device 10 emits light, the color of the light of the spectral curve obtained by superimposing the spectral curve related to the light emission of the organic EL light emitting device 10 and the spectral curve related to the transmittance of the color filter 26 (in the above structure, Green) can be visually recognized from the outside.

Here, if the spectral curve relating to the light emission of the organic EL luminous body 10 and the spectral curve relating to the transmittance of the color filter 26 are substantially matched (the same color), the color of the recognizable light will be substantially the same. The light emission color of the body 10 remains unchanged. In this way, the emitted light is hardly absorbed by the color filter 26. As a result, a light emitting surface with high luminance can be obtained by efficiently using the light emission of the organic EL light emitting body 10.

As the color filter 26, in addition to a dye obtained by dyeing gelatin with a dye, for example, a filter obtained by dispersing an organic pigment in a resin such as polyimide or acrylic can be used. Further, if the inorganic pigment is dispersed in glass and baked at a high temperature on the diffusion plate 11, a color filter 26 having excellent durability can be obtained.

FIG. 3 is a sectional view showing another modification (modification 1-2) of the first embodiment shown in FIG.
The organic electroluminescence device of FIG. 3 has a configuration in which a color filter 26 is provided at an intermediate position between the diffusion plate 11 and the transparent electrode 14 in addition to the configuration shown in FIG. Here, the color filter 26 may be formed on the front surface of the transparent substrate 12 or may be formed on the back surface of the diffusion plate 11.

In this modified example 1-2, the color filter 2
6 is formed by doping a fluorescent dye into a polymer film of acrylic or the like. Here, at the time of light emission of the organic electroluminescence device, the color visually recognized on the surface (display surface) side is organic E
The emission color of the L light emitter 10 and the optical characteristics of the color filter 26 are determined.

That is, if a colorant having a property of absorbing the light emitted from the organic EL luminous body 10 and emitting light of a desired color is appropriately selected as a fluorescent dye to be doped into the color filter 26, the color visually recognized from the outside can be obtained. Since the light emission color of the fluorescent dye is used, it is possible to express a desired light emission color with one kind of organic EL light emitting body 10.

For example, an organic EL emitting blue light of a short wavelength
The luminous body 10 is formed. If the color filter 26 is formed of a film doped with a fluorescent dye that absorbs blue light, which is the emission color of the organic EL light emitting body 10 and emits an arbitrary color of green or red, the emission color of the fluorescent dye can be changed to an external color. Can be seen from

In the configuration of the modification 1-2, the diffusion plate 11 is provided on the surface (display surface) of the organic electroluminescence device.
Is exposed. Therefore, when no light is emitted, the display surface looks almost white due to the action of the diffusion plate 11. In addition,
Color filter 26 formed in Modification Example 1-1
-2, or conversely, the color filter 26 formed in Modification 1-2 can be applied to Modification 1-1.

[Second Embodiment] FIG. 4 is a sectional view showing a second embodiment of the organic electroluminescence device according to the present invention. This organic electroluminescence device has a configuration in which an organic electroluminescence luminous body (organic EL luminous body) 10 including a transparent electrode 14, an organic luminescent layer 17, and a metal electrode 19 is formed on the back surface of a diffusion plate 11. ing. That is, the structure is such that the transparent substrate 12 (see FIG. 1) in the first embodiment described above is omitted.

The diffusion plate 11 has a light transmittance of about 60, for example.
%, An alumina ceramic thin plate having a thickness of 0.2 mm can be used. Here, the back surface of the diffusion plate 11 needs to be optically polished or the like so as to have a smooth surface on which the organic EL light emitting body 10 can be formed without any trouble. In addition, the organic EL luminous body 1
Since the configuration of 0 is the same as that of the first embodiment described above, detailed description is omitted here.

According to the second embodiment, since the transparent substrate 12 is omitted, the structure can be made thinner accordingly. This embodiment of the thin structure is effective when incorporated in a narrow space with a limited thickness dimension, such as when it is incorporated in a wristwatch for illumination of a dial. Also according to the second embodiment, when the organic EL light emitting body 10 does not emit light, the light reflected from the metal electrode 19 is diffused by the diffusion plate 11, so that the mirror surface of the metal electrode 19 can be made invisible from outside the device. it can.

FIG. 5 is a sectional view showing a modification (modification 2-1) of the second embodiment shown in FIG. The organic electroluminescence device of FIG. 5 has a configuration in which a color filter 26 is provided on the surface of the diffusion plate 11 in addition to the configuration shown in FIG.

FIG. 6 is a sectional view showing another modification (modification 2-2) of the second embodiment shown in FIG. The organic electroluminescence device of FIG.
In addition to the configuration shown in FIG. 1, a color filter 26 is provided at an intermediate position between the diffusion plate 11 and the transparent electrode 14.

The color filter 2 in each of these modified examples
The configuration and operation of the sixth embodiment are the same as those of the modified example 1-1 or the modified example 1-2 according to the first embodiment described above. The color at the time of light emission can be set arbitrarily. When the color filter 26 is provided on the back surface side of the diffusion plate 11 as in Modifications 1-2 and 2-2, a dichroic mirror can be used as the color filter 26.

[Third Embodiment] FIG. 7 is a sectional view showing a third embodiment of the organic electroluminescence device according to the present invention. In the organic electroluminescence device of this embodiment, the transparent electrode 14 shown in the first embodiment (see FIG. 1) is replaced with a plurality of segments 14a, 14b, 1
4c,... And arranged in a specific pattern as shown in FIG. 8, for example. The organic light emitting layer 1
The configurations of the metal electrode 7 and the metal electrode 19 are the same as those of the first embodiment, and the transparent substrate 12 and the diffusion plate 11 are provided similarly to the first embodiment.

Each of the transparent electrodes 14a, 14b, 14c,... Divided into a plurality of segments is connected to a power supply so as to be able to independently supply current. Then, each transparent electrode 14
a, 14b, 14c,... are selectively energized, so that the portion of the organic light-emitting layer 17 sandwiched between the energized transparent electrode 14a and the like and the metal electrode 19 emits light. Light-emitting display is performed by appropriately changing the content of the display pattern. When the display pattern is configured to be used for light-emitting display in this manner, when viewed from the front side of the device,
It is preferable that the contour of the emitted display pattern is clear.

However, in the structure of this embodiment based on the first embodiment, since the transparent substrate 12 is interposed as a component, light from the organic EL luminous body 10 passes through the transparent substrate 12. Spread radially
There is a problem that the outline of the emitted display pattern is blurred. Therefore, in this embodiment, the transparent substrate 12
A shielding layer 41 for shielding light from the organic EL luminous body side is interposed between the light emitting device and the diffusion plate 11.

This shielding layer 41 is formed in a thin film shape from various materials having a characteristic of absorbing light from the organic EL luminous body side. It is preferable that the thickness of the shielding layer 41 be sufficiently thinner than the transparent substrate 12 used in the first embodiment. Here, the shielding layer 41 is formed excluding a portion facing the arrangement pattern of the transparent substrate 12. That is, as shown in FIG. 8, when the surfaces of the transparent substrate 12 and the shielding layer 41 are viewed from the vertical direction, the shielding layer 41 is located at a position facing the transparent electrode 14 and has substantially the same size and shape as the arrangement pattern of the transparent electrode 14. Gap 41a.

Light r emitted from the organic EL luminous body 10
Spread radially while passing through the transparent substrate 12. However, since the shielding layer 41 is formed on the front surface side of the transparent substrate 12, only light passing through the gap 41 a of the shielding layer 41 passes through the diffusion plate 11 and exits to the front surface side.

That is, by narrowing down the light r emitted from the organic EL luminous body 10 by the shielding layer 41,
The outline of the light emitting display pattern can be made clear. Although the light spreads again while passing through the diffusion plate 11, the light r is once narrowed down at the intermediate portion, so that a light emitting display pattern which is practically sufficiently acceptable can be obtained.

FIG. 9 is a sectional view showing a modification (modification 3-1) of the third embodiment shown in FIG. The organic electroluminescence device of FIG. 9 has a configuration in which a color filter 26 is provided on the surface of the diffusion plate 11 in addition to the configuration shown in FIG.

FIG. 10 is a sectional view showing another modification (modification 3-2) of the third embodiment shown in FIG. The organic electroluminescence device of FIG.
In addition to the configuration shown in FIG. 7, a color filter 26 is provided at an intermediate position between the diffusion plate 11 and the shielding layer 41.

The color filter 2 in each of these modified examples
The configuration and operation of the sixth embodiment are the same as those of the modified example 1-1 or the modified example 1-2 according to the first embodiment described above. The color at the time of light emission can be set arbitrarily. In addition, the modification example 3 shown in FIG.
2, the color filter 26 is placed on the back surface of the transparent substrate 12 (ie, at an intermediate position between the transparent substrate 12 and the shielding layer 41).
Even if it forms, the same effect as the modification can be obtained.

[Fourth Embodiment] FIG. 11 is a sectional view showing a fourth embodiment of the organic electroluminescence device according to the present invention. This embodiment is characterized in that the shielding layer 41 in the previously described third embodiment (see FIG. 7) is improved. Other configurations, that is, the organic EL light-emitting body 10, the transparent substrate 12, and the diffusion plate 11 are the same as those in the third embodiment, and thus detailed description thereof will be omitted.

In the fourth embodiment, the shielding layer 41 is
Light absorbing layer 51 for absorbing light, and reflecting layer 5 for reflecting light
It consists of two layers. Here, the shielding layer 41
Is the side that receives the light from the organic EL emitter 10 (organic EL
The layer on the side closer to the light emitting body 10) is an absorption layer 51 made of a material having a characteristic of absorbing almost all of the received light without reflecting light.

If the layer on the light receiving side from the organic EL luminous body 10 has the property of reflecting light, the light spread on the transparent substrate 12 is reflected on the shielding layer 41 and the metal electrode 1
9 and is further reflected by the metal electrode 19 and a part thereof leaks out from the gap 41 a of the shielding layer 41. As a result, the luminescent display pattern of the organic EL luminous body 10 becomes unclear, and the display quality deteriorates. The absorption layer 51 has a function of preventing such inconvenience.

The shielding layer 41 has a layer on the side that receives external light (closer to the diffusion plate 11) as a reflective layer 52 made of a material having a characteristic of efficiently reflecting light. When the organic EL light-emitting body 10 does not emit light, the diffusion plate 11 enters from the surface, passes through the gap 41 a of the shielding layer 41, and
The light reflected at 9 and passed again through the gap 41a of the shielding layer 41 is diffused and emitted to the surface side. The light diffusion action at this time makes the mirror surface of the metal electrode 19 invisible from the outside.

However, when the reflected light from the metal electrode 19 enters the diffusion plate 11 only from the gap 41 a of the shielding layer 41, the light is not diffused to the entire diffusion plate 11, and therefore, is not viewed from the outside. When this occurs, an uneven brightness difference occurs on the surface of the diffusion plate 11. As a result, especially when the outside is bright,
The display pattern of the organic EL luminous body 10 is in a state where it can be identified even when no light is emitted. Therefore, the same amount of light as the reflected light from the metal electrode 19 transmitted through the gap 41a is reflected by the reflection layer 52, so that the entire surface of the diffusion plate 11 is made uniform.

The shielding layer 41 of this embodiment can be formed, for example, by the following method. First, the light transmittance 70%
0.2mm thick alumina ceramic sheet (diffusion plate 1)
In 1), aluminum (Al) is deposited in a thickness of 0.5 μm. Thereafter, the Al film (reflection layer 52) is etched to form a gap 41a at a position facing the arrangement pattern of the transparent electrodes 14. Next, the absorption layer 51 is printed on the Al film using a black pigment ink obtained by dispersing a black pigment in a resin binder.

As a result of the configuration of this embodiment, the organic EL
When the display pattern of the luminous body 10 was not emitting light, it could hardly be identified. FIG. 12 is a cross-sectional view illustrating a modification (modification 4-1) of the fourth embodiment illustrated in FIG.
The organic electroluminescence device of FIG. 12 has a configuration in which color filters 26a, 26b, and 26c are provided in gaps 41a of the shielding layer 41, respectively, in addition to the configuration shown in FIG.

The materials, characteristics, and the like of the color filters 26a, 26b, and 26c are the same as those of the modified examples 1-1 and 1 described above.
Same as -2. In addition, each color filter 26a, 26b, 26c may be configured with a different color as needed. Thus, the color filters 26a, 26b, 26c
The display pattern can be displayed in a desired color by emitting light.

Further, by providing the color filter described in the above-described modification example 1-1 or modification example 1-2 on the front surface or the back surface of the diffusion plate 11, colored light-emitting display can be easily realized. .

[Fifth Embodiment] FIG. 13 is a sectional view showing an organic electroluminescence device according to a fifth embodiment of the present invention. The organic electroluminescence device of FIG. 13 is the same as the diffusion plate 11 of the fourth embodiment described above.
Is improved to make the contour of the display pattern clearer when the organic EL light emitting body 10 emits light.

That is, when light from the organic EL luminous body 10 passes through the diffusion plate 11, it is inevitable that the contour of the display pattern is blurred due to the light diffusion effect of the diffusion plate 11. However, the degree to which the outline is blurred corresponds to the thickness of the diffusion plate 11, and therefore, by making the thickness of the diffusion plate 11 as small as possible, the outline of the display pattern can be made clearer.

However, simply reducing the thickness of the diffusion plate 11 results in insufficient strength. Therefore, in this embodiment, the diffusion plate 11 is constituted by the transparent plate 62 and the diffusion layer 61 formed on the back surface thereof in a thin film shape. The diffusion layer 61 is formed of a material having a high ability to diffuse light, for example, a white pigment ink obtained by dispersing a white pigment in a resin binder. When the diffusion layer 61 is formed of a white pigment, it has a white or milky appearance. The transparent plate 62 is a reinforcing means for the diffusion layer 61.

More specifically, a transparent plate 62 was formed from glass having a thickness of 0.2 mm, and a diffusion layer 61 made of white pigment ink was formed on the rear surface of the transparent plate 62 to a thickness of about 50 μm. Further, the absorption layer 51 and the reflection layer 52 constituting the shielding layer 41 can also be formed by printing black pigment ink and silver pigment ink, respectively. Further, as another configuration of the diffusion plate 11, the surface of the transparent plate 62 can be roughened, and the rough surface can be used as the diffusion layer 61.

By providing the color filter described in the above-described modification 1-1 or modification 1-2 on the front surface or the back surface of the transparent plate 62, it is possible to easily realize colored light-emitting display. it can. FIG. 14 shows a configuration in which the color filter 26 is formed on the back surface of the transparent plate 62.

[Sixth Embodiment] FIG. 15 is a sectional view showing an organic electroluminescence device according to a sixth embodiment of the present invention. The organic electroluminescence device includes, for example, a diffusion layer 21, a transparent electrode 14a,
14b, 14c, an organic light emitting layer 17, and a metal electrode 19 are laminated.

As the transparent substrate 12, a plastic substrate, film or the like can be used. However, since the organic EL light emitting body 10 formed on the back side of the transparent substrate 12 has a very thin organic light emitting layer 17 of about 100 nm, if the surface on which it is formed is rough, the transparent electrode 14 and the metal electrode 19 are short-circuited. May cause defects such as From the viewpoint of preventing such defects, it is better to form the transparent substrate 12 from a glass plate having excellent surface smoothness.

The diffusion layer 21 is made of a white pigment ink in which fine particles of titanium oxide are dispersed in an epoxy resin.
Is printed on the back surface of the substrate and cured by heating.
The diffusion layer 21 thus obtained is a thin film having a thickness of about 10 μm, has a translucent milky white appearance, and has good light diffusivity.

The transparent electrodes 14a, 14b, 14c
Using O (indium tin oxide), the back surface of the diffusion layer 21 is
After a film was formed to a thickness of about 100 nm by a sputtering method, a predetermined pattern was formed by etching. Organic light emitting layer 17
Is a method in which a hole injection layer (here, a triphenylamine derivative) having a thickness of about 60 nm and a light emitting layer (here, an aluminum chelate complex) having a thickness of about 60 nm are successively deposited.
It was formed to a thickness of about nm.

Further, on the back surface of the organic light emitting layer 17, a thickness of about 1
A 50 nm Mg-Ag (Ag content: 5%) metal electrode 19 was vapor-deposited to form an organic EL luminous body. Now,
The present inventors experimentally confirmed the following. That is,
In order for the outline of the display pattern formed by the transparent electrodes 14a, 14b, 14c,... To be clearly visible from the outside, the outline of the display pattern is compared with the width L of the narrowest display pattern (see FIG. 8). The distance from the surface of the organic light emitting layer 17 to the surface of the diffusion layer 21 may be sufficiently reduced.

In this embodiment, the transparent electrodes 14a,
The width of the display pattern formed by 14b, 14c,... Was about 250 μm. The distance from the surface of the organic light emitting layer 17 to the surface of the diffusion layer is determined by the sum of the thickness of the transparent electrode (about 100 nm) and the thickness of the diffusion layer (about 10 μm). Is also small enough.

As a result, when the organic EL luminous body 10 emits light,
The outline of the display pattern could be clearly confirmed from the outside. For this reason, the organic electroluminescence device according to the present embodiment could be seen white when not emitting light and was completely unaware of the metal electrode 19, and could recognize a light emitting pattern with a clear outline green when emitting light. In the structure of this embodiment, the thickness of the diffusion layer was increased to a maximum of 50 μm, but the clarity of the contour of the display pattern during light emission hardly decreased.

[Seventh Embodiment] FIG. 16 is a sectional view showing an organic electroluminescence device according to a seventh embodiment of the present invention. This organic electroluminescence device has a configuration in which a transparent coat layer 22 is further added to the same components as in the sixth embodiment. In this embodiment, the transparent substrate 12, the diffusion layer 21, the transparent electrode 1
The materials and film thicknesses of 4a, 14b, 14c,..., The organic light emitting layer 17, and the metal electrode 19 were the same as in the sixth embodiment described above.

The transparent coating layer 22 was formed to a thickness of about 3 μm by applying a polyimide resin solution to the back surface of the diffusion layer 21 and curing it by heating. The first purpose of the transparent coat layer 22 is to smooth the back surface side of the diffusion layer 21 by the thixotropic property of the polyimide resin solution. That is, as described above, the organic E
In the L light-emitting body 10, since the organic light-emitting layer 17 is very thin, about 100 nm, if the surface on which the organic light-emitting layer 17 is formed (the back side of the diffusion layer 21) is rough, defects such as a short circuit between the transparent electrode 14 and the metal electrode 19 are caused. May occur.

From the viewpoint of preventing such defects, the back surface of the diffusion layer 21 is smoothed by the transparent coat layer 22. The transparent coat layer 22 includes the transparent electrodes 14a, 1
The second object of the present invention is to protect the diffusion layer 21 from the etching treatment with an acid performed in the step of forming 4b, 14c,.

The transparent coat layer 22 can be formed by using a solution of a polymer material such as an acrylic or epoxy material other than the above-mentioned polyimide resin. When the diffusion layer 21 is flat, silicon oxide,
An oxide or nitride material such as tantalum oxide or silicon nitride may be used to form an inorganic thin film on the back surface of the diffusion layer 21 by a vapor deposition method, a sputtering method, or the like, and this may be used as the transparent coat layer 22. In this case, the film thickness is appropriately about 1 μm.

Further, when it is not necessary to protect the diffusion layer 21 from the etching treatment, as described in an eighth embodiment to be described later, an extremely thin inorganic thin film having a thickness of several nm to several tens nm is used. The transparent coat layer 22 may be used.

Also in the case of the organic electroluminescence device of this embodiment, the transparent electrodes 14a, 14b, 14c,.
(About 100 nm), the thickness of the transparent coat layer 22 (about 3 μm), and the thickness of the diffusion layer 21 (10 μm), the distance from the surface of the organic light emitting layer 17 to the surface of the diffusion layer 21 is transparent. .. Are sufficiently smaller than the width (250 μm) of the display pattern formed by the electrodes 14a, 14b, 14c,. As a result, when the organic EL light-emitting body 10 emitted light, the outline of the display pattern could be clearly confirmed from the outside.

[Eighth Embodiment] FIG. 17 is a sectional view showing an organic electroluminescence device according to an eighth embodiment of the present invention. This organic electroluminescence device is characterized in that the transparent coat layer 22 in the seventh embodiment described above is formed of two layers, an organic transparent coat layer 23 and an inorganic transparent coat layer 24.

In this embodiment, the transparent substrate 12
The materials and thicknesses of the diffusion layer 21, the transparent electrodes 14a, 14b, 14c,..., The organic light emitting layer 17, and the metal electrode 19 were the same as those in the seventh embodiment described above. The organic transparent coat layer 23 is formed to a thickness of about 2 μm by applying an acrylic resin solution to the back surface of the diffusion layer 21 with a spinner and curing the solution.

The organic transparent coat layer 23 is, like the transparent coat layer 22 in the seventh embodiment, smoothed on the surface of the diffusion layer 21 and provided with transparent electrodes 14a, 14b, 14c,
Are provided for the two purposes of protecting the diffusion layer 21 from the etching process in the forming process.

The inorganic transparent coat layer 24 is a very thin film of silicon oxide formed to a thickness of about 10 nm.
This inorganic transparent coat layer 24 is formed of transparent electrodes 14a, 14a.
When etching and patterning b, 14c,.
It is provided for the purpose of improving the etching property.

By forming the inorganic transparent coat layer 24, it is possible to pattern the transparent electrodes 14a, 14b, 14c,... The inorganic transparent coat layer 24 is preferably an inorganic thin film of an oxide or a nitride such as silicon oxide, tantalum oxide, or silicon nitride formed by an evaporation method, a sputtering method, or the like. According to experiments by the present inventors, when the film thickness was set to several nm to several tens nm, the etching property was significantly improved.

According to the structure of this embodiment, the transparent electrode 1
Since the etching properties of the transparent electrodes 4a, 14b, 14c,... Are improved, the width L (see FIG. 8) of the display pattern formed by the transparent electrodes 14a, 14b, 14c,. According to the experiments performed by the inventors, the width L of the display pattern could be reduced to 80 μm.

Also in this case, the distance from the back surface of the organic light emitting layer 17 to the surface of the diffusion layer 21, that is, the transparent electrode 14
a, 14b, 14c,..., the sum of the thicknesses of the organic transparent coat layer 23, the inorganic transparent coat layer 24, and the diffusion layer (approximately 12.
1 μm) is sufficiently smaller than the width L (80 μm) of the display pattern. For this reason, when the organic EL light-emitting body 10 emitted light, the outline of the display pattern could be clearly confirmed from the outside.

[Ninth Embodiment] FIG. 18 is a sectional view showing a ninth embodiment of the organic electroluminescence device according to the present invention. This organic electroluminescence device has a structure in which the transparent coat layer 22 in the previously described seventh embodiment is replaced by a transparent sheet 25.

The transparent sheet 25 has a thickness of 20 to 100 μm.
It is formed of a polymer sheet such as thin glass or polyester having the same thickness. In particular, since the thin glass is excellent in smoothness, if the transparent sheet 25 is formed by this, the quality of the organic EL luminous body 10 formed on the back surface is stabilized, and the yield is improved.

More specifically, the inventors of the present invention have prepared a transparent sheet 25 made of non-alkali glass having a thickness of 50 μm.
This thin glass was overlaid at the stage where the epoxy resin of the diffusion layer 21 was not cured, and was heated and joined. When the transparent electrodes 14a, 14b, 14c,... Are formed on thin glass having excellent smoothness, the etching properties of the transparent electrodes 14a, 14b, 14c,. And the display pattern width L is 80 μm
Could be miniaturized.

Also in this case, the distance from the back surface of the organic light emitting layer 17 to the surface of the diffusion layer 21, that is, the transparent electrode 14
, 14b, 14c,..., the transparent sheet 25, and the thickness of the diffusion layer 21 (about 60 μm) are smaller than the width L (80 μm) of the display pattern. For this reason, when the organic EL light-emitting body 10 emitted light, the outline of the display pattern could be clearly confirmed from the outside.

However, compared to the eighth embodiment, the transparent sheet 25 is slightly thicker and the difference between the distance from the back surface of the organic light emitting layer 17 to the surface of the diffusion layer 21 and the width L of the display pattern is smaller. The clarity of this outline was lower than that of the embodiment. In addition, there was no problem even if the transparent sheet 25 was joined using an adhesive after the diffusion layer 21 was cured.

[Tenth Embodiment] FIG. 19 is a sectional view showing an organic electroluminescence device according to a tenth embodiment of the present invention. This organic electroluminescent device is the same as the organic electroluminescent device of the sixth embodiment described above (see FIG. 15) except that a color made of gelatin having a thickness of about 1 μm and dyed with a green azo acid dye is used. The structure has a filter 26 added.

The color filter 26 is formed on the transparent substrate 12.
Formed on the surface of With this configuration, when the organic EL light emitting body 10 does not emit light, the reflected light from the metal electrode 19 is diffused by the diffusion layer 21 so that the mirror surface of the metal electrode 19 is hidden, and as a result, the entire display surface is covered with the color filter. It looks like 26 colors (eg green). When the organic EL light emitting body 10 emits light, the color filter 26
A bright and clear green display pattern is visible.

The color filter 26 can be formed in the same manner as the color filters 26 of Modifications 1-1 and 1-2 related to the first embodiment described above, and has the same function. Here, detailed description is omitted. In addition, the same color filters are provided on the surface of the transparent substrate 12 in the previously described seventh embodiment (see FIG. 16), eighth embodiment (see FIG. 17), and ninth embodiment (see FIG. 18). Even if 26 is formed, the same effect as described above can be obtained.

FIG. 20 is a sectional view showing a modification (modification 10-1) of the tenth embodiment shown in FIG. The organic electroluminescence device shown in FIG. 20 uses the color filter 26 shown in FIG.
(Specifically, the back surface of the transparent substrate 12).

With such a configuration, the first
The same operation and effect as those of the embodiment of FIG. In addition, other components (the color filter 26, the diffusion layer 21, the organic EL element 1)
According to the configuration of this modified example of forming 0), there is an advantage that the manufacturing process is simplified and handling of the completed organic electroluminescent device is convenient.

The seventh embodiment described above (FIG. 1)
6), an intermediate position between the transparent substrate 12 and the diffusion layer 21 (specifically, the back surface of the transparent substrate 12) in the eighth embodiment (see FIG. 17) and the ninth embodiment (see FIG. 18). Even if the color filter 26 is formed, the same effect as described above can be obtained. Although the sixth to tenth embodiments described above and the modified examples in which some of the embodiments are applied have been described with the configuration in which the transparent electrode is divided into a plurality of parts, the transparent electrode may be divided as necessary. One transparent electrode may be used.

[Eleventh Embodiment] FIG. 21 is a sectional view showing an eleventh embodiment of the organic electroluminescence device according to the present invention. In this organic electroluminescent device, a diffusion layer 21, a plurality of color filters 26a, 26b, 26c,..., A transparent coat layer 22, and an organic EL luminous body 10 are sequentially laminated on the back surface of a transparent substrate 12. .

Here, each color filter 26a, 26
b, 26c,... are generally transparent electrodes 14a, 14b,
14c,... Are disposed at positions facing each other. These color filters 26a, 26b, 26c,...
Although the same color can be used, it may be divided into a plurality of types of colors.

In this embodiment, the transparent electrodes 14a, 14a
are arranged in a matrix, for example, and color filters 26a, 26b, 26 are located at positions substantially corresponding to the transparent electrodes 14a, 14b, 14c,.
c,... are arranged. Here, the color filters 26a, 2
6b, 26c,... Are selectively arranged in a plurality of colors under a certain rule. For example, red color filters and yellow color filters are alternately arranged.

The thickness of the color filter 26 is preferably as thin as possible within a colorable range.
The thickness is preferably about 1 to 1 μm. By the formation of the color filters 26a, 26b, 26c,..., Irregularities are formed on the back surface side of the diffusion layer 21. Transparent coat layer 22
Removes the unevenness and smoothes the surface on which the organic EL light emitting body 10 is formed.

According to the structure of this embodiment, even if the organic light emitting layer 17 emits only one kind of color, a plurality of colors are used in accordance with the colors of the color filters 26a, 26b, 26c,. Display can be realized. That is,
The color of the display pattern to be recognized depends on the spectral curve of the light emitted from the organic EL luminous body 10 and the color filters 26a, 26b, 2
The light color of the spectral curve obtained by superimposing the spectral curves of the transmittances 6c,... Such a combination of spectral curves can be arbitrarily designed according to the purpose, thereby realizing various color displays.

Here, the emission color of the organic EL luminous body 10 is
As the color approaches white, the recognized color of the light-emitting display is substantially the color of the corresponding color filters 26a, 26b, 26c,. In order to make the organic EL light-emitting body 10 emit light of a color close to white, the organic light-emitting layer 17 is formed, for example, by mixing the three primary colors DCM1 (red), coumarin 6 (green), and tetraphenylbutadiene (blue) in PVK (polyvinylcarbazole). And a film doped with the three colors of fluorescent dyes.

Further, for example, the emission color of the organic EL luminous body 10 is set to short wavelength blue, and the color filters 26a, 26
As b, 26c,..., a film doped with a fluorescent dye that converts the wavelength to green or red may be used. In the organic electroluminescence device of this embodiment, the diffusion layer 21 is viewed from the outside, and when the organic EL light-emitting body 10 does not emit light, the entire display surface looks almost white, which is the color of the diffusion layer 21.

However, since the colors of the color filters 26a, 26b, 26c,... On the back side of the diffusion layer 21 can be recognized to some extent, the color filters 26a, 26b, 26c,. .. May be finely divided so that the colors of the color filters 26a, 26b, 26c,.

The color filters 26a, 26b, 2
6c,... Are arranged only in a portion facing the organic EL light-emitting body 10, when the organic EL light-emitting body 10 does not emit light,
There is a possibility that non-uniform colors may occur between the opposing portion of the L light emitter 10 and the peripheral portion deviating therefrom due to the presence or absence of the color filters 26a, 26b, 26c,. Therefore, in order to make the entire display surface a uniform color when the organic EL light-emitting body 10 does not emit light, the peripheral portion (organic EL light-emitting body 1
It is preferable that dummy color filters 26x and 26y are also formed on the portions not facing 0.

Further, since the metal electrode 19 does not exist in the peripheral portion other than the portion where the organic EL light-emitting body 10 is formed, it does not reflect the incident light from the outside. Therefore, the metal electrode 19
The internal reflection state of light is different between the portion where is present and the peripheral portion. As a result, the color and brightness of the display surface become uneven.

Therefore, by providing a reflector 20 that reflects the same metal color as the metal electrode 19 with the same reflection characteristics even in a portion where the formation of the organic EL luminous body 10 is not necessary, When no light is emitted, the entire display surface can be made uniform in color and uniform in brightness.

The reflector 20 may be formed of the same member as the metal electrode 19, or may be formed of a member different from the metal electrode 19. The reflector 20 includes a transparent substrate 12, a diffusion layer 21, color filters 26a, 26b, 26c,.
It may be disposed on the entire back surface of the unit composed of the transparent coat layer 22 and the organic EL luminous body 10. The reflector 20 is
In each embodiment of the present invention, it can be a component of an organic electroluminescent device.

Now, specifically, the present inventors have set forth the first
An organic electroluminescence device having the configuration of the first embodiment was manufactured as follows. First, a diffusion layer 21 having a size of 40 mm × 40 mm was formed at the center of the transparent substrate 12. Subsequently, blue-green color filters 26a, 26c, 26e, 26x (200 μm in width, 40 mm in length, 0.5 μm in thickness) formed by dispersing a phthalocyanine-based blue-green pigment in a photosensitive polyimide resin are arranged at a pitch of 400 μm. And 100 were formed linearly.

Further, these blue-green color filters 2
6a, 26c, 26e, 26x, a yellow color filter 26 in which a yellow pigment is dispersed so as to be filled in.
One hundred y, 26b, 26d, and 26f (shape specifications are the same as blue-green) were formed on the entire surface of the diffusion layer 21. The patterning of the color filter was performed by ultraviolet exposure using a photomask utilizing the photosensitivity of the polyimide resin.

Next, the color filters 26a, 26b,
A polyimide resin solution was applied to the entire region where 26c,... Were formed and cured by heating to form a transparent coat layer 22 having a thickness of 3 μm. Further, at the center of this region, a width of 180 μm and a length of 4
mm transparent electrodes 14a, 14b, 14c,...
With a color filter 26 at a pitch of 200 μm.
a, 26b, 26c,...

Finally, the organic light emitting layer 17 and the metal electrode 19 were provided. At this time, the reflector 2 was formed by the dummy metal electrode.
0 was also formed. In particular, the transparent electrodes 14a, 14b, 14
The metal electrode 1 in a region opposed to the outgoing line of c,.
Reference numeral 9 denotes a dummy metal electrode, to which unnecessary voltage is not applied to limit unnecessary light emission. In the organic electroluminescence device thus manufactured, when the organic EL light-emitting body 10 did not emit light, the entire display surface having a size of 40 mm × 40 mm looked pale green, and no unevenness was observed.

Next, the blue-green color filters 26a and 26a
10c transparent electrodes 14a, 14 corresponding to 6c, 26e
When a voltage was applied only to c and 14e to selectively emit light, an approximately 4 mm × 4 mm square area at the center of the display surface became bluish green. In addition, yellow color filter 2
10 transparent electrodes 14 corresponding to 6b, 26d, 26f
When a voltage was applied only to b, 14d, and 14f to selectively emit light, a square area of approximately 4 mm × 4 mm at the center of the display surface became bright yellow-green.

Further, all the 20 transparent electrodes 14a,
When light is emitted from 14b, 14c,...
A square area of mm × 4 mm became green. The effect obtained in the eleventh embodiment is that the transparent coat layer 2
The same can be achieved by using a laminated film of the organic transparent coat layer 23 and the inorganic transparent coat layer 24 as in the eighth embodiment (see the seventeenth embodiment) instead of 2.

[Twelfth Embodiment] FIG. 22 is a sectional view showing an organic electroluminescent device according to a twelfth embodiment of the present invention. This organic electroluminescence device aims at the same objects and effects as those of the eleventh embodiment described above, and realizes this with a configuration corresponding to the ninth embodiment.

The color filter 26 is provided on the back surface of the diffusion layer 21.
a, 26b, 26c...
This is the same as the embodiment. Subsequently, as described in the ninth embodiment, the transparent sheet 25 is joined by the adhesive layer 27. As the adhesive layer 27, a thermosetting or ultraviolet curable epoxy-based or acrylic-based adhesive is used, and the thickness of the adhesive layer 27 is set so as to sufficiently absorb the steps of the color filter 26.

Further, the transparent electrodes 14a, 14b, 14
c, an organic light emitting layer 17 and a metal electrode 19 were formed to produce an organic electroluminescence device. The organic electroluminescence device manufactured in this manner had the same characteristics as those of the eleventh embodiment.

In this embodiment and the eleventh embodiment, it is preferable that the transparent electrodes 14a, 14b, 14c,... That is, in these embodiments, the color filter 26 is used to visually uniform the color and brightness of the display surface.
It is preferable that a, 26b, and 26c are subdivided and arranged. In order to realize such an arrangement, a matrix type arrangement is suitable.

[Thirteenth Embodiment] In the organic electroluminescence of various embodiments using the diffusion plate 11 and the diffusion layer 21, the diffusion plate 11 and the diffusion layer 21 are colored in an appropriate color by the metal electrode 19. In addition to diffusing the reflected light, the organic EL emission diffuses the reflected light from the metal electrode 19 and looks colored when the organic EL luminous body 10 is not emitting light. Further, when the organic EL light emitting body 10 emits light,
The emission color of the organic EL luminous body 10 and the diffusion plate 11 or the diffusion layer 21
It looks like a color determined by the optical properties of

That is, by coloring the diffusion plate 11 and the diffusion layer 21, the function of the color filter 26 can be given to the diffusion plate 11 and the diffusion layer 21. As a result, the structure is simplified, and the simplification of the manufacturing and the reduction of the manufacturing cost can be realized.

For coloring the diffusion plate 11 and the diffusion layer 21, for example, a colored dye or pigment is added to a white pigment ink which plays a role of diffusing light, or only the colored pigment is dispersed in a resin such as epoxy. A colored pigment ink prepared in this manner may be used. When a ceramic plate is used as the diffusion plate 11, an inorganic pigment may be added at a ceramic powder stage before firing, and then molding and firing may be performed.

[Fourteenth Embodiment] FIG. 23 is a sectional view showing a fourteenth embodiment of the present invention. This embodiment is characterized in that the interface 90 between the transparent substrate 12 and the diffusion layer 21 has a fine rough surface. This embodiment can be applied to various embodiments in which the diffusion layer 21 is in contact with the back surface of the transparent substrate 12 to form an interface, among the various embodiments described above.

Note that, also in the fifth embodiment, the transparent plate 62 has the same function as the transparent substrate 12, so that the same can be applied (see FIGS. 13 and 14). Interface 90
Is suitably a rough surface having irregularities with a height of about 1 μm, but if necessary, the height of the irregularities is 0.1 to 10 μm.
It can be arbitrarily adjusted in the range of m.

To make the interface 90 rough, for example, the transparent substrate 12 may be etched or blasted. With such a configuration, specular reflection of light at the interface 90 between the back surface of the transparent substrate 12 and the diffusion layer 21 is suppressed, and a display surface having a soft feeling without gloss can be formed.

As a modification of the fourteenth embodiment, the interface between the back surface of the transparent substrate 12 and the color filter 26 and the interface between the surface of the diffusion layer 21 and the color filter 26 can be roughened. As a result, specular reflection of light at those interfaces can be suppressed, and a display surface with a soft feeling without gloss can be formed.

This modified example is applied to the organic electroluminescence devices of various embodiments having an interface between the back surface of the transparent substrate 12 and the color filter 26 and an interface between the surface of the diffusion layer 21 and the color filter 26. Of course.

In this case, the interface between the transparent substrate 12 and the color filter 26 can be realized by roughening the surface of the transparent substrate 12. The color filter 26 and the diffusion layer 2
1, the surface of the color filter 26
The roughened surface can be formed by performing gas phase etching by plasma processing or pressing the color filter 26 in a semi-cured state in the process of forming by using a mold.

[Fifteenth Embodiment] FIG. 24 is a sectional view showing an organic electroluminescence device according to a fifteenth embodiment of the present invention. The organic electroluminescence device includes a transparent electrode 14,
Organic EL comprising organic light emitting layer 17 and metal electrode 19
A luminous body 10 is formed. This basic configuration is the same as, for example, the first embodiment described above.

The fifteenth embodiment is characterized in that a phase plate 31 and a polarizing plate 32 are added to the basic configuration. The phase plate 31 is provided on the surface side of the transparent substrate, and further has a configuration in which a polarizing plate 32 is provided on the surface of the phase plate. The phase plate 31 and the polarizing plate 32 have a function of blocking light incident from the outside and reflected by the metal electrode 19.

As the phase plate 31, a λ / 4 plate is preferable because it has the best light shielding property. As the phase plate 31, for example, a sheet formed by stretching polycarbonate having a thickness of 0.1 mm can be used. Further, as the polarizing plate 32, for example, a sheet obtained by stretching polyvinyl acetate having a thickness of 0.2 mm and doping with iodine can be used. The angle between the stretching axes of these sheets is π / 4.
It is advisable to adjust the thickness and join.

According to the organic electroluminescence device configured as described above, external light incident on the polarizing plate 32 is
Only the linearly polarized light component is transmitted, and the linearly polarized light component is converted into circularly polarized light by the phase plate 31. This circularly polarized light sequentially transmits through the transparent substrate 12, the transparent electrode 14, and the organic light emitting layer 17, is reflected by the metal electrode 19, and again transmits through the organic light emitting layer 17, the transparent electrode 14, and the transparent substrate 12 sequentially, and has a phase shift. Board 31
Is converted to linearly polarized light.

However, since this linearly polarized light is orthogonal to the polarization direction of the polarizing plate 32, it cannot pass through the polarizing plate 32. For this reason, when the organic EL luminous body 10 does not emit light, the display surface looks dark and almost black, and the metal electrode 19 is completely invisible. When the organic EL light-emitting body 10 emits light,
Since the light emitted from the light emitting body 10 is not polarized, about half of the light passes through the phase plate 31 and the polarizing plate 32 to form a bright green transparent light emitting surface. As a result, the contrast between non-light emission and light emission is extremely clear, and high-quality light emission display is possible.

[0154]

As described above, the organic electroluminescence device according to the present invention can form a high-quality, high-quality appearance without the display surface appearing as a mirror surface when the organic EL luminous body does not emit light. Therefore, the present invention can be applied to a light-emitting display unit of a variety of electric products, a dial of a timepiece, and the like, so that the added value of those products can be increased. Further, the contour of an arbitrary light emitting display pattern can be clearly displayed, and the entire surface can be made uniform in brightness. Further, it is possible to realize various color configurations of the display surface. Alternatively, the display surface can be made soft.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of an organic electroluminescence device according to the present invention.

FIG. 2 is a cross-sectional view showing a modification (modification 1-1) of the first embodiment shown in FIG.

FIG. 3 is a sectional view showing another modification (modification 1-2) of the first embodiment shown in FIG. 1;

FIG. 4 is a sectional view showing a second embodiment of the organic electroluminescence device according to the present invention.

FIG. 5 is a sectional view showing a modification (modification 2-1) of the second embodiment shown in FIG. 4;

FIG. 6 is a cross-sectional view illustrating another modification (modification 2-2) of the second embodiment illustrated in FIG. 4;

FIG. 7 is a sectional view showing a third embodiment of the organic electroluminescence device according to the present invention.

8 is a plan view showing an example of an arrangement pattern of the transparent electrodes shown in FIG.

FIG. 9 is a sectional view showing a modification (modification 3-1) of the third embodiment shown in FIG. 7;

FIG. 10 is a sectional view showing another modification (modification 3-2) of the third embodiment shown in FIG. 7;

FIG. 11 is a sectional view showing a fourth embodiment of the organic electroluminescence device according to the present invention.

FIG. 12 is a sectional view showing a modification (modification 4-1) of the fourth embodiment shown in FIG. 11;

FIG. 13 is a sectional view showing a fifth embodiment of the organic electroluminescence device according to the present invention.

FIG. 14 is a cross-sectional view showing a configuration in which a color filter is added to the fifth embodiment shown in FIG.

FIG. 15 is a sectional view showing a sixth embodiment of the organic electroluminescence device according to the present invention.

FIG. 16 is a sectional view showing a seventh embodiment of the organic electroluminescence device according to the present invention.

FIG. 17 is a sectional view showing an eighth embodiment of the organic electroluminescence device according to the present invention.

FIG. 18 is a sectional view showing a ninth embodiment of the organic electroluminescence device according to the present invention.

FIG. 19 is a cross-sectional view illustrating a tenth embodiment of the organic electroluminescence device according to the present invention.

FIG. 20 is a sectional view showing a modification (modification 10-1) of the tenth embodiment shown in FIG. 19;

FIG. 21 is a sectional view showing an eleventh embodiment of the organic electroluminescence device according to the present invention.

FIG. 22 is a sectional view showing a twelfth embodiment of the organic electroluminescence device according to the present invention.

FIG. 23 is a sectional view showing a fourteenth embodiment of the organic electroluminescence device according to the present invention.

FIG. 24 is a sectional view showing a fifteenth embodiment of the organic electroluminescent device according to the present invention.

[Explanation of symbols]

10: Organic electroluminescence luminous body (organic EL luminous body) 11: Diffusion plate 12: Transparent plate 14: Transparent electrode 17: Organic luminous body 19: Metal electrode 21: Diffusion layer 22: Transparent coat layer 23: Organic transparent coat layer 24: Inorganic transparent coat layer 25: Transparent sheet 26: Color filter 27: Adhesive layer 31: Phase plate 32: Polarizer 41: Shielding layer 51: Absorbing layer 52: Reflecting layer 61: Diffusion layer 62: Transparent plate

Claims (16)

[Claims] 1. An organic electroluminescent device comprising: an organic electroluminescent luminous body including a transparent electrode on a front surface side of an organic luminescent layer that emits light by application of a voltage and a metal electrode on a back surface side of the organic luminescent layer. In the device, a transparent electrode of the organic electroluminescence luminous body is formed on a back surface side of a transparent substrate, and a diffusion plate having a light diffusing property is provided on a front surface side of the transparent substrate, and a front surface side of the diffusion plate or the diffusion plate is provided. An organic electroluminescence device, comprising: a color filter that transmits light of the same color as the emission color of the organic electroluminescence light emitter between a plate and a transparent substrate. 2. An organic electroluminescence including an organic electroluminescence luminous body having a transparent electrode on a front surface side of an organic light emitting layer that emits light by application of a voltage and a metal electrode on a rear surface side of the organic light emitting layer. In the device, a transparent electrode of the organic electroluminescent light-emitting body is formed on a back surface side of a transparent substrate, and a diffusion plate having a light diffusing property is provided on a front surface side of the transparent substrate; An organic electroluminescence device comprising a color filter that emits fluorescence between a plate and a transparent substrate. 3. An organic electroluminescence including an organic electroluminescence luminous body having a transparent electrode on a front surface side of an organic luminescence layer emitting light by application of a voltage and a metal electrode on a back surface side of the organic luminescence layer. In the device, a transparent electrode of the organic electroluminescent luminous body is formed on a back surface side of a diffusion plate having a light diffusing property, and a light emission color of the organic electroluminescent luminous body is formed on a front side or a back side of the diffusion plate. An organic electroluminescence device comprising a color filter that transmits light of the same color. 4. An organic electroluminescence including an organic electroluminescence luminous body having a transparent electrode on a front surface side of an organic luminescence layer emitting light by application of a voltage and a metal electrode on a back surface side of the organic luminescence layer. In the apparatus, a transparent electrode of the organic electroluminescence luminous body is formed on a back side of a diffusion plate having a light diffusing property, and a color filter for emitting fluorescence is provided on the front side or the back side of the diffusion plate. Characteristic organic electroluminescence device. 5. An organic electroluminescence including an organic electroluminescence luminous body having a transparent electrode on a front surface side of an organic luminescence layer emitting light by application of a voltage and a metal electrode on a back surface side of the organic luminescence layer. In the apparatus, the transparent electrode of the organic electroluminescent light emitting device is formed by dividing the transparent electrode into a plurality of parts on the rear surface side of the transparent substrate, and a diffusion plate having light diffusing property is provided on the front surface side of the transparent substrate, A light-shielding layer is provided between the light-diffusing plate and at least a portion opposed to each of the transparent electrodes, and a light-shielding layer is provided between the light-shielding layers opposed to the transparent electrodes. An organic electroluminescence device comprising a color filter that transmits light of the same color as the emission color. 6. An organic electroluminescent device comprising an organic electroluminescent luminous body having a transparent electrode on the front side of an organic luminescent layer emitting light by application of a voltage and a metal electrode on the back side of the organic luminescent layer. In the apparatus, the transparent electrode of the organic electroluminescent light emitting device is formed by dividing the transparent electrode into a plurality of parts on the rear surface side of the transparent substrate, and a diffusion plate having light diffusing property is provided on the front surface side of the transparent substrate, A light-shielding layer is provided between the diffusion plate and at least a portion opposed to each of the transparent electrodes, and a color filter that emits fluorescence is provided in a gap between the transparent electrodes and the shielding layer. An organic electroluminescent device, comprising: 7. An organic electroluminescence including an organic electroluminescence luminous body having a transparent electrode on a front surface side of an organic luminescence layer emitting light by application of a voltage and a metal electrode on a back surface side of the organic luminescence layer. In the device, while forming a transparent electrode of the organic electroluminescent luminescent material on the back side of the transparent substrate, providing a diffusion plate having a light diffusing property on the front side of the transparent substrate, dividing the transparent electrode into a plurality provided with, between the transparent substrate and the diffusing plate is provided with a shielding layer for shielding light except the portion facing at least the transparent electrode, the diffusion plate, a transparent plate having a light-transparent An organic electroluminescence device comprising: a thin film-like diffusion layer formed on the side of the plate on the shielding layer side. 8. The organic electroluminescence device according to claim 7, wherein a color filter that transmits light of the same color as the emission color of the organic electroluminescence luminous body is provided on the front side or the back side of the transparent plate. An organic electroluminescence device characterized by the above-mentioned. 9. The organic electroluminescence device according to claim 7, wherein a color filter that emits fluorescent light is provided on a front side or a back side of the transparent plate. 10. An organic electroluminescence including an organic electroluminescence luminous body having a transparent electrode on a front surface side of an organic luminescence layer emitting light by application of a voltage and a metal electrode on a back surface side of the organic luminescence layer. In the apparatus, the transparent electrode of the organic electroluminescent light-emitting device is formed by dividing the transparent electrode into a plurality of parts on the back surface side of a transparent substrate, and a thin-film-like diffusion layer having light diffusibility is provided between the transparent substrate and the transparent electrode. Wherein a color filter that transmits light of the same color as the emission color of the organic electroluminescent luminous body is provided between the surface side of the transparent substrate or the transparent substrate and the diffusion layer. Electroluminescence device. 11. An organic electroluminescence including an organic electroluminescence luminous body having a transparent electrode on a front surface side of an organic luminescence layer emitting light by application of a voltage and a metal electrode on a back surface side of the organic luminescence layer. In the apparatus, the transparent electrode of the organic electroluminescent light-emitting device is formed by dividing the transparent electrode into a plurality of parts on the back surface side of a transparent substrate, and a thin-film-like diffusion layer having light diffusibility is provided between the transparent substrate and the transparent electrode. An organic electroluminescence device, comprising: forming a color filter that emits fluorescent light on the front side of the transparent substrate or between the transparent substrate and the diffusion layer. 12. An organic electroluminescence including an organic electroluminescence luminous body having a transparent electrode on a front surface side of an organic light emitting layer that emits light by application of a voltage and a metal electrode on a back surface side of the organic light emitting layer. In the apparatus, the transparent electrode of the organic electroluminescent light-emitting device is formed by dividing the transparent electrode into a plurality of parts on the back surface side of a transparent substrate, and a thin-film-like diffusion layer having light diffusibility is provided between the transparent substrate and the transparent electrode. An organic electroluminescence device comprising: a transparent sheet made of thin glass provided between the diffusion layer and each of the transparent electrodes. 13. An organic electroluminescence including an organic electroluminescence luminous body having a transparent electrode on a front surface side of an organic luminescence layer emitting light by application of a voltage and a metal electrode on a back surface side of the organic luminescence layer. In the apparatus, the transparent electrode of the organic electroluminescent light-emitting device is formed by dividing the transparent electrode into a plurality of parts on the back surface side of a transparent substrate, and a thin-film-like diffusion layer having light diffusibility is provided between the transparent substrate and the transparent electrode. Forming a transparent sheet made of thin glass between the diffusion layer and each of the transparent electrodes, between the diffusion layer and the transparent sheet, and at least at a position facing each of the transparent electrodes, A color filter that transmits light of a predetermined wavelength is provided, and an adhesive is filled around each color filter, and the transparent sheet is connected with the adhesive. An organic electroluminescent device characterized by being worn. 14. An organic electroluminescence including an organic electroluminescence luminous body having a transparent electrode on a front surface side of an organic luminescence layer that emits light by application of a voltage and a metal electrode on a back surface side of the organic luminescence layer. In the apparatus, the transparent electrode of the organic electroluminescent light-emitting device is formed by dividing the transparent electrode into a plurality of parts on the back surface side of a transparent substrate, and a thin-film-like diffusion layer having light diffusibility is provided between the transparent substrate and the transparent electrode. Forming a transparent sheet made of thin glass between the diffusion layer and each of the transparent electrodes, between the diffusion layer and the transparent sheet, and at least at a position facing each of the transparent electrodes, A color filter that emits fluorescence is provided, and an adhesive is filled around each color filter, and the transparent sheet is adhered with the adhesive. An organic electroluminescence device characterized by the following. 15. The organic electroluminescence device according to claim 13, wherein a plurality of types of color filters that transmit light of different wavelengths are arranged at different positions as the color filters. Electroluminescence device. 16. The organic electroluminescence device according to claim 14, wherein a plurality of types of color filters that emit fluorescence of different wavelengths are arranged at different positions as the color filters. Electroluminescence device.