JPH118070A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device which can make a clear indication by restraining the light from leaking to an adjacent picture element. SOLUTION: A black mask 13 is formed at the back surface of a glass substrate 12 so that a line width may decrease, and a light diffusing layer 16 is formed in a gap partitioned by the black mask 13. A front electrode 18, an organic EL layer 19, and a back surface electrode 20 are formed sequentially 17 at the back surfaces of the black mask 13 and the light diffusing layer 16 through a protective film. The luminous part (the area where electrodes overlap) of the organic EL layer 19 is set so as to be smaller than the light diffusing layer 16. The light from a luminous part can be restrained from entering a picture element area adjacent to it by the black mask 13, thus it is possible to make a clear indication without generating light leakage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a display device, and more particularly, to a display device that emits electroluminescence (hereinafter, referred to as EL).

[0002]

2. Description of the Related Art In recent years, an organic EL display device using an organic EL material has attracted attention as a display device using EL light emission. This organic EL display device is, for example, shown in FIG.
As shown in FIG. 1, a plurality of transparent front electrodes 2 are formed on the back surface of the glass substrate 1 so as to be parallel, and an organic EL layer 3 is formed so as to cover the glass substrate 1 and the front electrode 2.
A plurality of back electrodes 4 are formed on the back surface of the organic EL layer 3 so as to be parallel to a direction orthogonal to the front electrode 2. Examples of the organic EL layer 3 include a two-layer structure and a three-layer structure including a light-emitting layer and a carrier transport layer. In this display device, by applying a DC voltage between the front electrode 2 and the back electrode 4, carriers are injected into the organic EL layer 3 and light is emitted by the action of recombination of holes and electrons. I'm getting up.

Further, as an organic EL display device capable of performing color display, for example, a configuration as shown in FIG. 17 has been proposed. In this display device, as shown in FIG. 1, color filters 5R, 5G, and 5B are disposed on the back surface of a glass substrate 1, and these color filters 5R (red), 5G (green),
A transparent protective film 6 is formed so as to cover B (blue), and a front electrode 2, an organic EL layer 3 for generating white light, and a rear electrode 4 are sequentially formed on the back surface of the protective film 6. Each of the color filters 5R, 5G, and 5B is disposed so as to correspond to a portion (light emitting portion) where the front electrode 2 and the back electrode 4 intersect.

Further, as a display device for performing color display without using a color filter, for example, a display device having a configuration as shown in FIG. 18 has been proposed. In this display device, as shown in FIG. 1, light wavelength conversion layers 7R and 7G that absorb incident light and emit light in a wavelength range different from the incident light are arranged on the back surface of the glass substrate 1. The light wavelength conversion layer 7R has a function of absorbing blue light and emitting red light, and the light wavelength conversion layer 7G has a function of absorbing blue light and emitting green light. For this reason, the light wavelength conversion layer 7R is disposed in a dot portion that performs red display, and the light wavelength conversion layer 7G is disposed in a dot portion that performs green display. Then, a protective film 6 is formed so as to cover the glass substrate 1 and the light wavelength conversion layers 7R and 7G. On the back surface of the protective film 6, a front electrode 2, an organic EL
The layer 3 and the back electrode 4 are sequentially formed. Note that the organic EL layer 3 of this display device is set to generate blue light. Therefore, blue light is emitted from the dot portion where the light wavelength conversion layer is not disposed, and the light wavelength conversion layer 7R
Is absorbed and the red light is emitted from the light wavelength conversion layer 7R, and the blue light that is incident on the light wavelength conversion layer 7G is absorbed and green light is emitted from the light wavelength conversion layer 7G. Thus, in the display device shown in FIG.
Color display can be performed.

In each of the above-mentioned conventional display devices, when the front electrode 2 and the back electrode 4 are formed, FIG.
As shown in FIG. 1A, a metal mask 8 in which an opening 8A is previously formed in a wiring shape is formed on a glass substrate 1, a protective film 6, an organic EL device, or the like.
A method of forming a wiring metal in the opening 8A by vacuum deposition, sputtering, or the like in a state of being in close contact with the back surface of the layer 3 is performed.

[0006]

When the above-described metal mask 8 is used, the minimum line width and the minimum space width of the wiring that can be formed depend on the thickness of the metal mask 8.
As shown in FIG. 19B, the line of the metal mask 8 becomes, for example, a space of the back electrode 4.
The line width of (1) (aspect ratio 1) becomes the minimum with the mask thickness in order to maintain the mask strength. At present, the minimum thickness of the mask is practically 0.1 mm. If the mask is made thinner, the line width can be made narrower, but there is a problem in the strength of the mask. Therefore, in the current method, the minimum space of the back electrode 4 formed on the back surface of the organic EL layer is about 0.1 mm. For this reason, it has been difficult to reduce the distance between pixels to 0.1 mm or less. Further, even if the distance between the pixels of the organic EL layer 3 can be reduced, light generated at a predetermined pixel leaks to an adjacent pixel region, so that a problem of light bleeding may occur. When the line width of the back electrode 4 is reduced,
There has been a problem that the light emitting area itself becomes small and a display that is easy to see cannot be performed.

Further, the back electrode is formed by a character pattern,
In the case of forming a complicated intricate shape, a donut shape, or the like, such a shape cannot be processed as an opening in a metal mask, so that it is difficult to realize the shape. Similarly,
It was also difficult to realize a seven-segment pattern used for numerical notation and the like. Furthermore, even if the figure can be realized as the shape of the back electrode, there is a problem that an electric field is generated in the organic EL layer between the lead wiring and the facing electrode, causing light emission, and alignment between the front electrode and the back electrode. However, there is a problem that high precision is required.

Further, in the case of a display device that performs multicolor display,
As shown in FIG. 17, the combination of white light emission and a color filter has a problem in that the energy efficiency for causing white light emission is low, and thus the light emission efficiency is reduced. Further, as shown in FIG.
In the display device using R and 7G, the luminous efficiency of the organic EL layer 3 is blue because the luminescent color is blue.
When the film thicknesses of R and 7G are small, it is difficult to efficiently absorb and convert light, so that there is a problem in that blue light emission is transmitted. Also, if the light wavelength conversion layer is made thicker, the fluorescent dye per unit area increases, so that the light wavelength conversion efficiency is improved and the color purity of the light emitted from the light wavelength conversion layer is increased, but the energy efficiency is reduced. There is a problem that the luminance after light wavelength conversion is reduced.

The problem to be solved by the present invention is to determine what means should be taken to obtain a display device capable of suppressing a light leak to an adjacent pixel and enabling a clear display. is there. Further, the problem to be solved by the present invention is that what kind of means should be taken to obtain a display device capable of minimizing the influence of a back electrode pattern having a complicated shape or a lead line from a segment electrode. It is in the point.

[0010]

According to the first aspect of the present invention,
A transparent front electrode is formed on the front surface of the EL layer;
A back electrode is formed on the back surface of the L layer, and a light diffusion layer is arranged in front of the front electrode so that the front electrode and the back electrode correspond to a light emitting portion where the back electrode overlaps via the EL layer. It is characterized by having. According to the first aspect of the present invention, since the light diffusion layer is disposed in front of the front electrode so as to correspond to the light emitting portion where the front electrode and the back electrode overlap, it is possible to diffuse light incident from the light emitting portion. And display that is easy to see.

According to a second aspect of the present invention, the light diffusion layer comprises:
It is characterized in that it is formed wider than the corresponding light emitting portion. According to the second aspect of the present invention, since the light diffusion layer is set wider than the light emitting portion, the width of the front electrode and the back electrode is small, and even if the overlapping portion (light emitting portion) of these electrodes is small, the display pixel is large. You can earn area. Therefore, a wiring having a small line width may be formed using a conventional metal mask.

According to a third aspect of the present invention, the light diffusion layer comprises:
It is characterized by being surrounded by a black mask formed using a photolithography method and an etching method. According to the third aspect of the invention, the light scattered in the light diffusion layer can be prevented from entering the adjacent pixel region by the black mask. For this reason, a clear display without light leakage or color bleeding can be performed. Further, since the black mask is formed by using the photolithography method and the etching method, the line width of the black mask can be extremely reduced, so that adjacent pixels can be brought close to each other, and a dense display can be performed.

According to a fourth aspect of the present invention, the light diffusion layer comprises:
Light scattering fine particles are dispersed in a transparent resin binder.

According to a fifth aspect of the present invention, the light diffusion layer is
Light scattering particles are dispersed in a light wavelength conversion layer that absorbs incident light and emits light in a wavelength range different from that of the incident light.

The invention according to claim 6 is characterized in that the electroluminescent layer is an organic electroluminescent layer.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of a display device according to the present invention will be described below based on embodiments shown in the drawings. (Embodiment 1) FIGS. 1 to 3 show Embodiment 1 of a display device according to the present invention. 1 is a cross-sectional view of a main part of the display device, FIG. 2 is an explanatory plan view, and FIG.
In the figure, reference numeral 11 denotes a display device, and a black mask 13 is formed on a back surface of a glass substrate 12 in a lattice shape of pixels using photolithography technology and etching technology. In the present embodiment, for example, the line width of the black mask 13 is set to 0.03 mm, and the space width is set to 0.47 mm. As shown in FIGS. 1 and 3, the space defined by the black mask 13 is filled with a transparent resin binder 14 in which light diffusion particles 15 having light scattering properties are dispersed. A layer 16 has been formed.
Note that the light diffusion layer 16 can also be formed using photolithography technology. Then, the glass substrate 12
Protective film 17 made of a transparent synthetic resin so as to cover the black mask 13 and the light diffusion layer 16 formed in
Are formed. On the back surface of the protective film 17, a plurality of front electrodes 18 corresponding to the respective rows of the light diffusion layers 16 are formed so as to pass through substantially the center in the width direction of the light diffusion layers 16 which form a row in a plan view. ing. On the back side of the protective film 17 and the front electrode 18, an organic EL layer 19 is formed over the entire display area. Further, a plurality of back electrodes 20 are formed on the back surface of the organic EL layer 19 in a direction orthogonal to the front electrode 18. In the present embodiment, for example, the line width of the back electrode 20 and the front electrode 18 is set to 0.3 mm, and the space width is set to 0.2 mm. The portion where the back electrode 20 and the front electrode 18 intersect is located substantially at the center of each light diffusion layer 16. The front electrode 18 and the back electrode 20 can be formed using, for example, a metal mask 8 as shown in FIG.

Next, the operation of the display device 11 of the present embodiment will be described. When the front electrode 18 and the back electrode 20 are driven line-sequentially, a predetermined front electrode 18 and
Between the front electrode 18 and the back electrode 20.
Carriers are injected into the organic EL layer 19 at the crossing point with EL to generate EL light. The light-emitting region is a region where the electrodes intersect, and in this embodiment, is a square region having a side of 0.3 mm. Light diffusion layer 1 corresponding to this light emitting region
Reference numeral 6 denotes a square area having a side of 0.47 mm. Light emitted from the light emitting region enters the light diffusion layer 16 and is scattered by the light diffusion particles 15. Therefore, it appears that the entire light diffusion layer 16 which is a region larger than the actual light emitting region emits light. The distance between adjacent light diffusion layers 16 is
The line width of the black mask 13 is 0.03 mm, and the distance between the actual light emitting regions (the electrode space width of 0.2 m)
m), which is much smaller than that of m), and a dense display can be performed. Further, the light generated in this light emitting region has a structure in which the black mask 13 is provided, so that it is difficult for the light to enter the adjacent light diffusion layer 16. Can be suppressed. As described above, in the present embodiment, when the front electrode 18 and the rear electrode 20 are formed using a metal mask, the space width of these electrodes is about 0.1 mm at present, but the black mask is Since the line 13 can be easily processed with a line / space of less than 0.1 mm by using photolithography technology, there is an advantage that a display area can be formed in a smaller space than before.

Embodiment 2 FIG. 4 is a sectional view showing Embodiment 2 of the display device according to the present invention. The configuration of the display device of the present embodiment includes a glass substrate 12 as shown in FIG.
A black mask 13 is formed on the front surface, and a light diffusion layer 16 is formed in a space defined by the black mask 13. Further, an organic EL layer 19 is provided on the rear surface of the glass substrate 12 so as to be sandwiched between the front electrode 18 and the back electrode 20 constituting the XY matrix. The protective film 17 covers the black mask 13 and the light diffusion layer 16.
Are formed. In this embodiment, the light diffusion layer 16 and the black mask 13 are formed on the front surface of the glass substrate 12, and the front electrode 18, the organic EL layer 19, and the back electrode 20 are formed on the back surface of the glass substrate 12. Becomes easier. Other operations and effects in the present embodiment are the same as those in the first embodiment.

(Embodiment 3) FIG. 5 is a sectional view showing Embodiment 3 of the display device according to the present invention. In the present embodiment, as shown in the figure, a black mask 13 and a light diffusion layer 16 are formed on the rear surface of the glass substrate 12A, and a protective film 17 is formed so as to cover the black mask 16 and the light diffusion layer 16. ing. Also, another glass substrate 12B
The front electrode 18, the organic EL layer 19, and the back electrode 2
0 is formed. The display device 11 of the present embodiment includes:
In this configuration, a glass substrate 12B on which an organic EL layer 19 is formed is disposed behind a glass substrate 12A on which a light diffusion layer 16 is formed. As described above, since the black mask 13 and the light diffusion layer 16 and the organic EL layer and the electrodes sandwiching the organic EL layer can be separately manufactured, the yield can be improved. The operation and effect of this embodiment are the same as those of the first embodiment.

(Embodiment 4) FIG. 6 is a sectional view showing Embodiment 4 of the display device according to the present invention. In this embodiment, as shown in the figure, a black mask 13, a light diffusion layer 16 and a protective film 17 are formed on the front surface of a glass substrate 12A, and a position corresponding to each light diffusion layer 16 is formed on the rear surface of the glass substrate 12A. Alternatively, a hologram 21 is formed on the entire back surface. Behind the glass substrate 12A, a glass substrate 12B having the same configuration as that of the third embodiment is disposed. In the present embodiment, the glass substrate 12A
The hologram 21 is formed on the back surface of the organic EL layer 19 so that the display light emitted from the organic EL layer 19 can be efficiently and selectively incident on the light diffusion layer 16. For this reason, the black mask 13 prevents light from leaking to the adjacent pixels, and the hologram 21 regulates the incident direction so that the light from the light emitting portion does not enter the adjacent light diffusion layer 16, so that the hologram 21 is more efficiently used. A clear display can be made possible.

(Embodiment 5) FIG. 7 is a sectional view showing Embodiment 5 of the display device according to the present invention. In this embodiment, as shown in the figure, a black mask 13, a light diffusion layer 16 and a protective film 17 are formed on the front surface of a glass substrate 12A, and a position corresponding to each light diffusion layer 16 is formed on the rear surface of the glass substrate 12A. Alternatively, a micro lens 22 is formed on the entire back surface. Behind the glass substrate 12A, a glass substrate 12B having the same configuration as that of the third embodiment is disposed. In the present embodiment, the glass substrate 1
By forming the micro lens 22 on the back surface of the 2A, the display light emitted from the organic EL layer 19 side can be efficiently and selectively made incident on the light diffusion layer 16 by the micro lens 22. For this reason, the black mask 13 prevents light leakage to the adjacent pixels, and the microlenses 22 allow the light from the light-emitting portion formed by the intersection of the electrodes 18 and 20 in the organic EL layer 19 to be adjacent to the light diffusion layer 16. Since the incident direction is regulated so as not to be incident on the screen, clearer display can be realized.

(Embodiment 6) FIG. 8 is a sectional view showing Embodiment 6 of the display device according to the present invention. In this embodiment, as shown in the figure, a black mask 13, a light diffusion layer 16 and a protective film 17 are formed on the front surface of a glass substrate 12A, and a position corresponding to each light diffusion layer 16 is formed on the rear surface of the glass substrate 12A. Alternatively, a fine lattice 23 is formed on the entire back surface. Behind the glass substrate 12A, a glass substrate 12B having the same configuration as that of the third embodiment is disposed. In the present embodiment, the fine grating 23 is formed on the back surface of the glass substrate 12A, so that the display light emitted from the organic EL layer 19 side can be efficiently and selectively incident on the light diffusion layer 16. Can be. For this reason, the black mask 13 prevents light leakage to an adjacent pixel, and the fine grating 23 regulates the incident direction so that light from the light emitting portion does not enter the adjacent light diffusion layer 16, so that the light is sharper. Display can be made possible.

(Embodiment 7) FIG. 9 is a sectional view showing Embodiment 7 of the display device according to the present invention. In the display device 11 of the present embodiment, the light diffusion layer 16R according to the above-described first embodiment includes a light wavelength conversion layer 16R including light diffusion particles.
16G and the transparent layer 16B. The light wavelength conversion layer 16R has a function of absorbing blue light and emitting light in a wavelength range corresponding to red light. The light wavelength conversion layer 16G has a function of absorbing blue light and emitting and diffusing light in a wavelength range corresponding to green light. Further, the transparent layer 16B is formed of, for example, a transparent synthetic resin material with light, and has a light transmission function and a diffusion function. Light wavelength conversion layer 16
R and 16G are configured by dispersing light diffusion particles having light scattering properties in a light wavelength conversion material. The light wavelength conversion material is a material in which a fluorescent dye is dispersed at a molecular level in a resin binder, and has a property of absorbing light on the short wavelength side and fluorescing light on the long wavelength side to emit light. Also in this embodiment, a protective film 17 made of, for example, a transparent synthetic resin is formed so as to cover the black mask 13 and the light diffusion layer 13. On the back surface of the protective film 17, a front electrode 18, an organic EL layer 19, and a back electrode 20 are formed. Particularly, in the present embodiment, the organic EL layer 19
Is set to generate blue light. The configuration of the organic EL layer that emits blue light includes, for example, an electron transport layer made of Alq3 and a light-emitting layer made of a group of blue light-emitting materials (such as DTVBi) called distyrarylarylene derivatives.
and a hole transport layer made of α-NPD. The other configurations in the present embodiment are the same as those in the first embodiment.

In this embodiment, the light wavelength conversion layers 16R, 1R
Since the light conversion efficiency of the wavelength conversion material constituting 6G is high,
Color display with high luminous efficiency can be performed. In addition,
In the light wavelength conversion layers 16R, 16G and the transparent layer 16B,
Since the light diffusion particles are included, the path length of the incident light can be increased, the probability of absorption into the fluorescent dye can be increased, and the fluorescence intensity can be increased. Therefore, it is possible to reduce the thickness of the light wavelength conversion layers 16R and 16G. Note that, also in the present embodiment, it is possible to secure a light emitting area even in a narrow space as in the first embodiment.
In the present embodiment, the wavelength conversion is performed so that blue light is converted into red and green light. However, if the wavelength is longer than blue, wavelengths of other colors such as yellow and orange are used. The wavelength may be converted to a range. The organic EL layer 19
May emit light of a color other than blue. For example, a fluorescent dye and light that emit green light but use an organic EL layer to convert the wavelength from green to yellow, orange, and red to a longer wavelength side than green. Of course, a light wavelength conversion layer in which diffused particles are dispersed may be provided. Further, in the present embodiment, the light wavelength conversion layer has a configuration in which the fluorescent dye and the light diffusion particles are mixed in the resin binder, but may have a configuration in which a fluorescent pigment having light scattering properties is mixed. In this case, as the fluorescent pigment, fine particles obtained by dissolving and solidifying inorganic fine particles or a fluorescent dye in a binder can be used. Then, a fluorescent pigment having a peak of the fluorescent wavelength from the fluorescent pigment which is substantially the same as the fluorescent material dispersed in the light wavelength conversion layer is used. Also, since fluorescent pigments have the property of easily absorbing incident light,
It is also possible to improve the absorptance of light in the wavelength range that excites the light wavelength conversion layer of the incident light, thereby improving the fluorescence characteristics of the light wavelength conversion layer, and further increasing the light wavelength conversion efficiency by adding fluorescence from the fluorescent pigment. Can be improved.

(Eighth Embodiment) FIG. 10 is a sectional view showing an eighth embodiment of the display device according to the present invention. The configuration of the present embodiment is the same as the configuration of Embodiment 7 described above, except that the glass substrate 12 and the light wavelength conversion layers 16R,
6G and the transparent layer 16 between the red filter layer 24R, the green filter layer 24G, and the blue filter layer 24, respectively.
B is interposed. The red filter layer 24R is
When light including a red wavelength range is incident, the light has a characteristic of emitting substantially red wavelength range light and absorbing visible light of other wavelength ranges. The green filter layer 24G has a green wavelength range. When the light including the color wavelength range is emitted, the light has a characteristic of emitting light in a substantially green wavelength range and absorbing visible light in other wavelength ranges. When it is incident, it emits light in a substantially red wavelength range and absorbs visible light in other wavelength ranges. In this embodiment,
The color purity of the R, G, and B light emitted from the light wavelength conversion layers 16R, 16G and the transparent layer 16B can be increased by each color filter layer.

Ninth Embodiment FIG. 11 is a sectional view showing a ninth embodiment of the display device according to the present invention. In the present embodiment, a red filter layer 24R, a green filter layer 24G, and a blue filter layer 24B are formed in gaps defined by the black mask 13 as shown in FIG. It is set to generate light. Then, each color filter layer 24R, 24G, 2
In 4B, light diffusion particles are dispersed, and each of the color filter layers 24R, 24G, 24B has a function as a light diffusion layer. The other configurations in the present embodiment are the same as those in the first embodiment.

In the present embodiment, white light generated in each dot portion of the organic EL layer 19 can be converted into R, G, and B light by passing through each color filter layer. The operation and effect of this embodiment are the same as those of the first embodiment.

(Embodiment 10) FIG. 12 is an explanatory plan view showing a main part of a display apparatus according to Embodiment 10 of the present invention. In the present embodiment, as shown in the drawing, display openings 13A and 13B through which light is transmitted are formed in a black mask 13. In the display openings 13A and 13B, a light diffusion layer 16 in which light diffusion particles are dispersed in a resin binder is formed. In the present embodiment, the display openings 13A and 13B are concentric circles and donut-shaped, and the display openings 13A and 13B are fitted in a region where the front electrode 18 and the back electrode 20 intersect. Is formed. By processing the shapes of the black mask 13 and the light diffusion layer 16 as described above, light emission display of various shapes can be made possible, so that a character pattern display that could not be formed conventionally can be realized. .

(Embodiment 11) FIG. 13 is a plan view showing a black mask and a light diffusion layer of an embodiment 11 of the display device according to the present invention. In the present embodiment, the shape of the opening of the black mask 13 is formed into a seven-segment shape, and the light diffusion layer 16 is formed in these openings. The shapes of the front electrode (segment) 18 and the back electrode (common) with respect to the opening of the black mask 13 are, as shown in FIG.
May be formed smaller than the opening. This makes it possible to form a 7-segment pattern which has been difficult to form using a metal mask. That is, since the portion where the front electrode 18 and the back electrode 20 overlap may be smaller than the opening, the degree of freedom in the area where the lead line from each segment is formed is increased, and the pattern rule can be relaxed.

(Twelfth Embodiment) FIG. 15 is an exploded perspective view showing a twelfth embodiment of the display device according to the present invention. In this embodiment, as shown in the figure, a pixel electrode 25 as a back electrode is formed for each pixel on a glass substrate 12, and a thin film transistor (TFT) 26 as a switching element is connected to each pixel electrode 25. , Enabling active driving. The front electrode 18 is a common electrode formed over the entire display area, and the black mask 13 and the light diffusion layer 16 are formed on the front electrode 18. Note that other configurations in the present embodiment are as follows.
This is the same as Embodiment 1 described above. In the present embodiment, since the line width of the black mask 13 can be set small by the photolithography technology, the pixel electrode 2
The aperture ratio can be increased irrespective of the size of 5.

Although the first to twelfth embodiments have been described above, the present invention is not limited to these embodiments, and various changes accompanying the gist of the configuration are possible. For example, in each of the above-described embodiments, the organic EL layer 19 can be appropriately set to various structures such as a two-layer structure and a three-layer structure, and include an electron transport layer, a light emitting layer, and a hole transport layer. Selection of a material such as is possible as appropriate.

[0032]

As is apparent from the above description, according to the present invention, it is possible to realize a display device capable of suppressing light leakage to adjacent pixels and providing a clear display. Also,
It is possible to obtain a display device that minimizes the influence of an electrode pattern having a complicated shape or a lead line from a segment electrode.

[Brief description of the drawings]

FIG. 1 is a sectional view showing Embodiment 1 of a display device according to the present invention.

FIG. 2 is an explanatory plan view of a main part of the first embodiment;

FIG. 3 is an enlarged sectional view of a main part of the first embodiment.

FIG. 4 is a sectional view showing Embodiment 2 of the display device according to the present invention.

FIG. 5 is a sectional view showing Embodiment 3 of the display device according to the present invention.

FIG. 6 is a sectional view showing Embodiment 4 of the display device according to the present invention.

FIG. 7 is a sectional view showing Embodiment 5 of the display device according to the present invention.

FIG. 8 is a sectional view showing Embodiment 6 of the display device according to the present invention.

FIG. 9 is a sectional view showing Embodiment 7 of the display device according to the present invention.

FIG. 10 is a sectional view showing Embodiment 8 of the display device according to the present invention.

FIG. 11 is a sectional view showing Embodiment 9 of the display device according to the present invention.

FIG. 12 is an explanatory plan view showing Embodiment 10 of the display device according to the present invention.

FIG. 13 is an explanatory plan view of a black mask and a light diffusion layer showing Embodiment 11 of the display device according to the present invention.

FIG. 14 is an explanatory plan view showing an electrode configuration of the eleventh embodiment.

FIG. 15 is an exploded perspective view showing Embodiment 12 of the display device according to the present invention.

FIG. 16 is a cross-sectional view illustrating a conventional display device.

FIG. 17 is a cross-sectional view showing a conventional color display device.

FIG. 18 is a sectional view showing another conventional color display device.

FIG. 19A is a plan view showing a metal mask, and FIG.
3A is a sectional view taken along line AA of FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 display device 12 glass substrate 13 black mask 13A, 13B display opening 14 resin binder 15 light diffusion particles 16 light diffusion layer 16R, 16G, 16B light wavelength conversion layer 18 front electrode 19 organic EL layer 20 back electrode 21 hologram 22 micro Lens 23 Micro lattice 24R Red filter layer 24G Green filter layer 24B Blue filter layer 25 Pixel electrode 26 Thin film transistor

Claims (6)

[Claims] 1. A transparent front electrode is formed on a front surface of an electroluminescence layer, and a back electrode is formed on a back surface of the electroluminescence layer. A display device, wherein a light diffusion layer is disposed in front of the front electrode so as to correspond to the light emitting portions that overlap each other. 2. The display device according to claim 1, wherein the light diffusion layer is formed wider than a corresponding light emitting portion. 3. The display device according to claim 1, wherein the light diffusion layer is surrounded by a black mask formed using a photolithography method and an etching method. 4. The display device according to claim 1, wherein the light diffusion layer is formed by dispersing light scattering fine particles in a resin binder having transparency. 5. The light diffusion layer according to claim 1, wherein light scattering fine particles are dispersed in a light wavelength conversion layer that absorbs incident light and emits light in a wavelength range different from that of the incident light. The display device according to claim 1. 6. The display device according to claim 1, wherein the electroluminescent layer is an organic electroluminescent layer.