JP2004213909A - Substrate for surface light emitting body, and el element using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate for a surface light emitting body, and an EL element using the same, for suppressing adverse effects on display by adjacent pixels and effectively taking emitted lights outward. <P>SOLUTION: In an organic EL element 11, a plurality of recessed portions 17 forming a plurality of reflecting surfaces 16 for reflecting lights which are emitted from an organic EL layer 14 and entered obliquely onto a light emitting surface 12a of a transparent substrate 12 in such a direction that entering angles onto the light emitting surface 12a become small are provided with at least a part of the surrounding of the EL layer 14 on the substrate 12. The recessed portions 17 are provided in a resin layer 18 formed on a surface 12b of the substrate 12. Among the lights emitted from the EL layer 14 of a certain pixel and emitted onto the substrate 12, the lights emitted obliquely onto the substrate 12 and incident on the reflecting surfaces 16 of the recessed portions 17 corresponding to the EL layer 14 are reflected by the reflecting surfaces 16 in such a direction that the incident angles on the light emitting surface 12a become small and emitted from the light emitting surface 12a. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a surface light emitter substrate and an EL device using the same.
[0002]
[Prior art]
2. Description of the Related Art Organic electroluminescence (EL) devices have attracted attention as being usable for flat light sources and surface light emitters (flat light emitting plates) such as flat panel displays (for example, organic EL displays). I have.
[0003]
2. Description of the Related Art As a conventional organic EL device, a device having a structure in which a transparent electrode, an organic EL layer, and a back electrode are sequentially stacked on a glass substrate is known (for example, see Patent Document 1). In such a conventional organic EL element, of the light emitted from the organic EL layer, the light emitted obliquely to the glass substrate and having a large incident angle on the light emission surface (display surface) of the glass substrate is the light emission It is totally reflected by the surface and does not exit to the outside. Therefore, light emitted from the organic EL layer cannot be effectively extracted from the light emission surface of the glass substrate (transparent substrate), and it has been difficult to realize a bright display.
[0004]
In order to solve such a problem, as an organic EL element in which a glass substrate (transparent substrate) is processed, there are, for example, those described in Patent Literature 2 and Patent Literature 3, respectively.
[0005]
In the organic EL device of Patent Document 2, a high refractive index portion corresponding to each pixel is formed in a columnar shape in a thickness direction of a transparent substrate to improve light extraction efficiency. Further, the organic EL device disclosed in Patent Document 3 is configured such that a transparent substrate is constituted by a convex lens portion and a concave lens portion formed thereon, and the refractive index of the concave lens portion is made smaller than the refractive index of the convex lens portion, so that light extraction efficiency is improved. (Extraction efficiency).
[0006]
[Patent Document 1]
JP-A-2002-170662
[Patent Document 2]
JP-A-7-037688
[Patent Document 3]
JP-A-2002-184567
[0007]
[Problems to be solved by the invention]
By the way, in the conventional technology described in Patent Document 2, among the light emitted from a certain pixel, there is a possibility that the light emitted obliquely to the transparent substrate and mixed with the adjacent pixel may adversely affect the display by the adjacent pixel. Certain light is absorbed by an absorber around the high refractive index portion. For this reason, there is a problem that light absorbed by the absorber cannot be extracted to the outside.
[0008]
Further, in the related art described in Patent Document 3, since the transparent substrate is provided with the convex lens portions corresponding to each pixel, the positional relationship between the focal length of each convex lens and the corresponding organic EL layer of each pixel. Becomes important. That is, it is considered that there is an optimum configuration for effectively extracting light emitted from each organic EL layer. However, even when this optimum configuration is adopted, among the light emitted from the organic EL layer of a certain pixel, the light emitted so as to deviate from the convex lens corresponding to the pixel remains the convex lens corresponding to the adjacent pixel. And the display may be adversely affected by the adjacent pixels.
[0009]
The present invention has been made in view of such a conventional problem, and its object is to suppress the adverse effect on the display by the adjacent pixels and to effectively extract the emitted light to the outside. It is an object of the present invention to provide a substrate for a surface light emitter and an EL device using the same.
[0010]
[Means for Solving the Problems]
In order to solve the above problem, the invention according to claim 1 is a substrate for a surface light emitter having a transparent substrate on which a light emitting portion is formed, wherein the light emitting portion is formed on the transparent substrate. A reflecting surface that reflects light emitted from the light emitting portion and obliquely incident on the light emitting surface of the transparent substrate toward at least a part of the periphery of the portion where the incident angle becomes smaller at the light emitting surface The gist of the present invention is that a concave portion for forming is provided.
[0011]
According to this configuration, a plurality of (for each pixel) light-emitting portions such as organic EL layers can be formed on a transparent substrate, for example, on a transparent electrode formed on the surface of the transparent substrate to form a surface light-emitting body. it can. In this case, of the light emitted from a light emitting portion and emitted to the transparent substrate, the light emitted obliquely to the transparent substrate and incident on the reflection surface of the concave portion corresponding to the light emission portion is emitted by the reflection surface. The light is reflected toward the surface where the incident angle becomes smaller, and is emitted from the light emitting surface. Therefore, of the light emitted from a certain light emitting portion, light that is emitted obliquely to the transparent substrate and is mixed with the adjacent pixel, which may adversely affect the display by the adjacent pixel, can be extracted to the outside.
[0012]
Also, of the light emitted by the light emitting portion and emitted to the transparent substrate, light whose incident angle on the light emitting surface is larger than the critical angle of total reflection is incident on the light emitting surface by the reflecting surface of the concave portion. The light is reflected toward the smaller angle and is emitted from the light emitting surface.
[0013]
Therefore, it is possible to suppress the adverse effect on the display by the adjacent pixels, and effectively extract the emitted light to the outside. As a result of an increase in light extraction efficiency, less power is required for obtaining display and illumination light of the same brightness, and power consumption can be reduced. Here, the “light extraction efficiency” refers to the light amount (light amount) of light emitted from a light emitting portion of one pixel or all pixels, for example, an organic EL layer (light amount emitted from the light emitting surface of the transparent substrate). (Emitted light amount)).
[0014]
According to a second aspect of the present invention, in the surface light emitting substrate according to the first aspect, the concave portion is provided in a resin layer formed on a surface of the transparent substrate on which the light emitting portion is formed. That is the gist.
[0015]
According to this configuration, it is only necessary to provide a resin layer on the surface of the transparent substrate on which the light emitting portion is formed, and to form a concave portion in the resin layer. The surface light emitting substrate is used for forming a light emitting portion on a transparent substrate to produce a surface light emitting body such as an organic EL element or a line light source.
[0016]
According to a third aspect of the present invention, in the surface light emitting substrate according to the first aspect, the concave portion is provided on a surface of the transparent substrate on which the light emitting portion is formed. .
[0017]
According to this configuration, it is only necessary to form a concave portion on the surface of the transparent substrate on which the light-emitting portion is formed, and it is not necessary to add a special layer for providing the concave portion, and it is easy to manufacture the surface light emitting body. A substrate can be realized. The surface light emitting substrate is used for forming a light emitting portion on a transparent substrate to produce a surface light emitting body such as an organic EL element or a line light source.
[0018]
According to a fourth aspect of the present invention, in the surface light emitting device substrate according to any one of the first to third aspects, the concave portion is a V-shaped groove.
According to this configuration, by appropriately setting the shape of the V-groove, for example, the width and depth (groove height) of the V-groove, the shape of the reflection surface, for example, the inclination angle of the reflection surface is changed, and the light extraction efficiency is changed. Can be easily changed, and the extraction efficiency can be further improved.
[0019]
According to a fifth aspect of the present invention, in the surface light emitting device substrate according to any one of the first to third aspects, the concave portion is a groove in which two convex surfaces face each other at a predetermined angle. .
[0020]
According to this configuration, since the reflecting surface is concave, the shape of the concave surface is changed by appropriately changing the groove shape of the concave portion, for example, its width and depth, or the curvature of the convex surface, so that the light is reflected. The extraction efficiency can be easily changed, and the extraction efficiency can be further improved.
[0021]
According to a sixth aspect of the present invention, in the surface light emitting substrate according to the second aspect, a transparent electrode is formed on a surface of the resin layer where the concave portion is formed.
[0022]
According to this configuration, the surface (surface) of the resin layer where the concave portions are formed is a smooth surface, and the transparent electrode is formed on this surface, so that the transparent electrode can be easily formed.
[0023]
According to a seventh aspect of the invention, in the surface light emitting substrate according to the third aspect, a transparent electrode is formed on a surface of the transparent substrate on which the concave portion is formed.
[0024]
According to this configuration, the surface (surface) of the transparent substrate on which the concave portion is formed is a smooth surface, and since the transparent electrode is formed on this surface, the transparent electrode can be easily formed.
[0025]
The invention according to claim 8 is the substrate according to any one of claims 1 to 7, wherein the transparent substrate is made of glass or a resin having translucency. And
[0026]
According to this configuration, since the transparent substrate is made of glass or a translucent resin, it can be widely used for a surface light emitter such as an organic EL element or a line light source.
According to a ninth aspect of the present invention, a plurality of transparent electrodes, a plurality of EL layers, and a plurality of metal electrode layers are sequentially laminated on a transparent substrate, and light emitted from the EL layers is emitted from the transparent substrate. In an EL element configured to emit light from a surface and using a surface emitting substrate having the transparent substrate, at least a part of each of the plurality of EL layers on the transparent substrate includes the EL layer. A gist of the present invention is that a concave portion is provided that forms a reflection surface that reflects light that is emitted and is obliquely incident on the light emission surface of the transparent substrate in a direction in which the angle of incidence on the light emission surface becomes smaller.
[0027]
According to this configuration, of the light emitted from the organic EL layer of a certain pixel and emitted to the transparent substrate, the light emitted obliquely to the transparent substrate and incident on the reflection surface of the concave portion corresponding to the organic EL layer is The light is reflected by the reflecting surface in such a manner that the incident angle on the light emitting surface becomes smaller, and is emitted from the light emitting surface. For this reason, of the light emitted from the organic EL layer of a certain pixel, the light which is emitted obliquely to the transparent substrate and mixed with the adjacent pixel, which may adversely affect the display by the adjacent pixel, is also extracted to the outside. Can be.
[0028]
Further, of the light emitted from each organic EL layer and emitted to the transparent substrate, the light whose incident angle on the light emitting surface is larger than the critical angle of total reflection is reflected on the light emitting surface by the concave reflecting surface. Is reflected to the direction where the incident angle becomes smaller, and is emitted from the light emitting surface.
[0029]
Therefore, it is possible to suppress the adverse effect on the display by the adjacent pixels, and effectively extract the emitted light to the outside.
In addition, as a result of increasing the light extraction efficiency, less power is required to obtain display and illumination light of the same brightness, and power consumption can be reduced.
[0030]
According to a tenth aspect of the present invention, in the EL device according to the ninth aspect, the concave portion is provided in a resin layer formed between the transparent substrate and the transparent electrode.
[0031]
According to this configuration, it is only necessary to provide a resin layer on the surface of the transparent substrate on which the light emitting portion is formed, and to form a concave portion in the resin layer, thereby realizing an EL element such as an organic EL element which is easy to manufacture. .
[0032]
According to an eleventh aspect of the present invention, in the EL device according to the ninth aspect, the concave portion is provided on a surface of the transparent substrate on which the EL layer is formed.
[0033]
According to this configuration, it is only necessary to form a concave portion on the surface of the transparent substrate on which the EL layer is formed, and there is no need to add a special layer for providing the concave portion. EL element can be realized.
[0034]
According to a twelfth aspect of the present invention, in the EL device according to any one of the ninth to eleventh aspects, the concave portion is a V-shaped groove.
According to this configuration, by appropriately setting the shape of the V-groove, for example, the width and depth (groove height) of the V-groove, the shape of the reflection surface, for example, the inclination angle of the reflection surface is changed, and the light extraction efficiency is changed. Can be easily changed, and the extraction efficiency can be further improved.
[0035]
According to a thirteenth aspect of the present invention, in the EL device according to any one of the ninth to eleventh aspects, the concave portion is a groove in which two convex surfaces face each other at a predetermined angle.
[0036]
According to this configuration, since the reflecting surface is concave, the shape of the concave surface is changed by appropriately changing the groove shape of the concave portion, for example, its width and depth, or the curvature of the convex surface, so that the light is reflected. The extraction efficiency can be easily changed, and the extraction efficiency can be further improved.
[0037]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention embodied in an organic EL device will be described with reference to the drawings.
[0038]
[First Embodiment]
FIG. 1 shows a part of the organic EL element of the first embodiment in a cross section, FIG. 2 shows an enlarged part of the cross section, FIG. 3 is a plan view showing the organic EL element, and FIG. A part of FIG. 3 is enlarged.
[0039]
The organic EL element 11 shown in FIG. 1 is formed by sequentially laminating a plurality of transparent electrodes 13, a plurality of organic EL layers 14 as a light emitting portion or an EL layer, and a plurality of metal electrode layers 15 on a transparent substrate 12. The organic EL element 11 is a bottom emission type organic EL element configured so that light emitted from the organic EL layer 14 is emitted from the light emitting surface 12a of the transparent substrate 12.
[0040]
Further, in the organic EL element 11, as shown in FIGS. 1 and 2, a plurality of recesses 17 are provided on at least a part of the periphery of the organic EL layer 14 on the transparent substrate 12. The plurality of recesses 17 form a plurality of reflecting surfaces that reflect light emitted from the organic EL layer 14 and obliquely incident on the light emitting surface 12a of the transparent substrate 12 in a direction in which the angle of incidence on the light emitting surface 12a becomes smaller. 16 are formed. These recesses 17 are provided in a resin layer 18 formed on the surface 12 b of the transparent substrate 12. The plurality of recesses 17 are formed in V-grooves on the surface 12 b of the resin layer 18 on the side opposite to the transparent substrate 12. A plurality of transparent electrodes 13 are formed on the surface of the resin layer 18.
[0041]
The transparent substrate 12 is a glass substrate. The transparent electrode 13 is an indium tin oxide (hereinafter, referred to as “ITO”) film. The resin layer 18 is, for example, an epoxy resin.
[0042]
The organic EL layer 14 is, for example, a two-layer type including a hole transporting layer formed on the surface of the transparent electrode 13 and a light emitting layer including an electron transporting layer formed thereon. . In the organic EL layer 14, when a DC voltage is applied between the transparent electrode 13 as an anode and the metal electrode layer 15 as a cathode, holes injected from the anode and electrons injected from the cathode are generated. Light is emitted from the light emitting layer.
[0043]
The plurality of transparent electrodes 13 are striped electrodes extending in the left-right direction (X direction) in FIGS. 3 and 4, and the transparent electrodes 13 are arranged in parallel with each other at a predetermined interval e (see FIG. 4). In. On the other hand, the plurality of metal electrode layers 15 are stripe-shaped electrodes each extending in a direction (Y direction) orthogonal to the plurality of transparent electrodes 13 respectively. 4) are placed in parallel with each other. A plurality of organic EL layers 14 are arranged in a matrix between the transparent electrodes 13 and the metal electrode layers 15 at the intersections of the plurality of transparent electrodes 13 and the plurality of metal electrode layers 15 as shown in FIG. Have been.
[0044]
The plurality of organic EL layers 14 in each column are composed of a red organic EL layer 14R, a green organic EL layer 14G, and a blue organic EL layer that respectively emit red, green, and blue light in the X direction. 14B. The three sets of the organic EL layer 14R for red, the organic EL layer 14G for green, and the organic EL layer 14B for blue constitute one set, and one set constitutes one pixel.
[0045]
Each of the plurality of organic EL layers 14 (a plurality of pixels) has a rectangular shape having a width of b and a length of d. They are arranged in a matrix at intervals e in the column direction.
[0046]
Then, at least a part of the periphery of each organic EL layer 14 on the transparent substrate 12, in this example, each gap (hatched portion in FIG. 4) between two adjacent organic EL layers 14 in the X direction, the concave portion 17 of the V-groove is formed. Are formed respectively.
[0047]
Next, a method for manufacturing the organic EL element 11 having the above configuration will be described with reference to FIG.
(Step 1) First, the transparent substrate 12 shown in FIG.
[0048]
(Step 2) Next, the surface of the transparent substrate 12 is washed, and a resin layer 18 is formed on the surface 12b opposite to the light emitting surface 12a as shown in FIG.
(Step 3) Next, as shown in FIG. 5B, the concave portion 17 of the V-groove is formed in a portion of the resin layer 18 corresponding to each of the gaps (shaded portions in FIG. 4) by using a dicing saw. Process. Out of the plurality of recesses 17, the two recesses 17A at both ends in the X direction are substantially vertical outside surfaces.
[0049]
In step 3, the groove shapes of the concave portions (V-grooves) 17 and 17A processed by the dicing saw conform to the blade tip shape of the dicing saw. The two inclined surfaces of the recesses 17 and 17A are mirror-finished. For example, the blades are sequentially ground and finished with a blade having a grain size of # 400 to # 3000. Alternatively, after grinding with a # 800 blade, polishing is performed by flowing abrasive grains.
[0050]
(Step 4) Next, as shown in FIG. 5C, a plurality of transparent electrodes 13 are formed on the resin layer 18 on which the concave portions 17 and 17A are formed by a vacuum evaporation method.
(Step 5) Next, as shown in FIG. 5D, a plurality of organic EL layers 14 arranged in a matrix are formed on the plurality of transparent electrodes 13. In this step, after evacuation is performed to a predetermined pressure or less in a vacuum evaporation apparatus, triphenyldiamine (TPD) as a hole transport layer and quinolinol aluminum complex (Alq3) as a light emitting layer are formed.
[0051]
(Step 6) Next, a plurality of metal electrode layers 15 are formed on the plurality of organic EL layers 14 formed in Step 5, as shown in FIG. In this step, a MgAg alloy film, for example, as a cathode is formed as a metal electrode layer 15 on each organic EL layer 14 in the vacuum evaporation apparatus. Thus, the organic EL element 11 shown in FIG. 1 is manufactured.
[0052]
According to the first embodiment configured as described above, the following operation and effect can be obtained.
(A) Among the light emitted from the organic EL layer 14 of a certain pixel and emitted to the transparent substrate 12, the light is emitted obliquely to the transparent substrate 12 and enters the reflection surface 16 of the concave portion 17 corresponding to the organic EL layer 14. The reflected light is reflected by the reflecting surface 16 in such a manner that the incident angle on the light emitting surface 12a becomes smaller, and is emitted from the light emitting surface 12a. For this reason, of the light emitted from the organic EL layer 14 of a certain pixel, the light which is emitted obliquely to the transparent substrate 12 and mixes with the adjacent pixel, which may adversely affect the display by the adjacent pixel, is also transmitted to the outside. Can be taken out.
[0053]
Also, of the light emitted from each organic EL layer 14 and emitted to the transparent substrate 12, the light whose incident angle on the light emitting surface 12 a is larger than the critical angle of total reflection is reflected on the reflecting surface 16 of the concave portion 17. As a result, the light is reflected in a direction in which the incident angle on the light emitting surface 12a becomes smaller, and is emitted from the light emitting surface 12a.
[0054]
Therefore, it is possible to suppress the adverse effect on the display by the adjacent pixels, and effectively extract the emitted light to the outside.
(B) In the prior art described in Patent Document 3, even when the above-described optimum configuration is adopted, light emitted from the organic EL layer of a certain pixel may still deviate from the convex lens corresponding to the pixel. Is mixed into the convex lens corresponding to the adjacent pixel, and may adversely affect the display by the adjacent pixel. For example, in the case of an organic EL element that performs color display, color mixing between pixels may occur. On the other hand, according to the first embodiment, the mixture of colors between pixels can be reduced, and a high-definition color display can be realized.
[0055]
(C) As a result of increasing the light extraction efficiency, less power is required to obtain a display with the same brightness, and lower power consumption can be achieved.
(D) By appropriately setting the shape of the V-groove of the concave portion 17, for example, the width and the depth (groove height) of the V-groove, the shape of the reflecting surface 16, for example, the inclination angle of the reflecting surface 16 with respect to the light emitting surface 12a is changed. In other words, the light extraction efficiency can be easily changed, and the light extraction efficiency can be further improved.
[0056]
(E) Among the constituent elements of the organic EL element 11, the transparent substrate 12 and the resin layer 18 formed on the transparent substrate 12 constitute the surface light emitting substrate 20. Alternatively, the surface emitting body substrate 20 is formed by forming a plurality of transparent electrodes 13 on the resin layer 18. Such a surface light emitter substrate 20 is formed by forming an organic EL layer 14 and a metal electrode layer 15 on a transparent electrode 13 in this order, so that an organic EL element 11 constituting an organic EL display and a surface light source such as a line light source are formed. A body can be made.
[0057]
(F) Utilizing each gap (hatched portion in FIG. 4) between two organic EL layers 14 adjacent in the X direction, a concave portion 17 of a V-groove is formed at a position corresponding to the gap in the resin layer 18. Accordingly, the concave portion 17 can be provided without increasing the dimension of the organic EL element 11 in the X direction.
[0058]
(G) Since the concave portions 17 and 17A of the V-groove are formed in the resin layer 18 by a dicing saw in the above step 3, the concave portions 17 and 17A can be easily formed in the resin layer 18.
[0059]
Next, the organic EL element 11 of the first embodiment will be specifically described with reference to FIGS. The horizontal axis in FIG. 6 indicates the optical axis center facing position in one of a plurality of light emission areas corresponding to the plurality of organic EL layers 14 (a plurality of pixels) on the light emission surface 12a of the transparent substrate 12. Represents the distance L from. That is, the position (L = 0) of the light emitting region facing the optical axis center corresponds to the position where light emitted from the center of one organic EL layer 14 is perpendicularly incident on the light emitting surface 12a. The vertical axis in FIG. 6 represents the amount of light (light intensity) transmitted and emitted at each position deviated from the optical axis center facing position. Accordingly, the area enclosed by each curve and the horizontal axis shown in FIG. 6 represents the amount of light emitted from the organic EL layer 14 of each pixel and extracted (emitted) from the light emission surface 12a for each pixel. I have.
[0060]
In each of Examples and Comparative Examples, the amount of light emitted from the light emitting surface 12a of the transparent substrate 12 when a voltage is applied between the transparent electrode 13 and the metal electrode layer 15 to cause the organic EL layer 14 to emit light is shown. Calculated and shown. In each embodiment, the light amount is calculated by changing the width (interval a) of the concave portion 17 to 34 μm and changing the groove height (depth).
[0061]
<Example 1>
The groove height of the concave portion 17 is set to 10 μm (about 30% of the width of 34 μm), and the angle θ between two surfaces forming the concave portion 17 which is a V groove and the plane (the upper surface in FIG. 2) of the resin layer 18 is set. 2) was about 30 degrees, the removal efficiency was 45.1%. In other words, the “light extraction efficiency” referred to here is the light amount (light amount) emitted from the organic EL layer 14 of one pixel or all pixels (light amount (light amount) emitted from the light emission surface 12a). Is the ratio of
[0062]
Further, the angle θ is represented by the following equation.
θ = tan ^-1 D
Here, D is D = (groove height (depth) of concave portion 17) / (width of concave portion 17/2).
[0063]
<Example 2>
When the groove height of the concave portion 17 was 20 μm (about 35% of the width of 34 μm) and the angle θ was about 50 degrees, the extraction efficiency was 47.1%.
[0064]
<Example 3>
When the groove height of the recess 17 was 30 μm (about 88% of the width of 34 μm) and the angle θ was about 60 degrees, the extraction efficiency was 55.5%.
[0065]
<Example 4>
When the groove height of the concave portion 17 was 40 μm (about 118% of the width of 34 μm) and the angle θ was about 67 degrees, the extraction efficiency was 60.7%.
[0066]
<Example 5>
When the groove height of the concave portion 17 was 50 μm (about 147% of the width of 34 μm) and the angle θ was about 71 degrees, the extraction efficiency was 65.9%.
[0067]
<Example 6>
When the groove height of the recess 17 was 60 μm (about 176% of the width of 34 μm) and the angle θ was about 74 degrees, the removal efficiency was 62.9%.
[0068]
<Example 7>
When the groove height of the recess 17 was 70 μm (about 206% of the width of 34 μm) and the angle θ was about 76 degrees, the extraction efficiency was 63.0%.
[0069]
<Comparative example>
In the organic EL element 11 shown in FIG. 1, an organic EL element without the resin layer 18 provided with the concave portion 17 was used as a comparative example. The extraction efficiency in this comparative example was 36.1%.
[0070]
From the above simulation results, the amount of light emitted from the light emitting surface 12a of the organic EL element 11 of each of Examples 1 to 7 is larger than that of the comparative example, and the light emitted from the organic EL layer 14 is more effectively used outside. Can be taken out but can be understood.
[0071]
[Second embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 7 shows a partial cross section of the organic EL element of the second embodiment, and FIG. 8 shows a part of the cross section in an enlarged manner. In the second embodiment, a concave portion 27 corresponding to the concave portion 17 is formed in a resin layer 18A corresponding to the resin layer 18 of the first embodiment as a groove in which two convex surfaces are opposed at a predetermined angle. .
[0072]
As a result, the reflecting surface 26 that reflects light emitted from the organic EL layer 14 and obliquely incident on the light emitting surface 12a of the transparent substrate 12 toward the direction where the incident angle on the light emitting surface 12a becomes smaller becomes concave. The reflection surface 26 allows light emitted from each organic EL layer 14 and obliquely incident on the transparent substrate 12 to be more efficiently reflected toward a smaller incident angle on the light emitting surface 12a. I have. Other configurations are the same as those of the first embodiment.
[0073]
The resin layer 18A having the concave portions 27 is produced by a 2P molding method (photopolymer molding method).
In the 2P molding method, first, an intaglio is formed on the surface 12b of the transparent substrate 12, and then the resin layer 18 having a plurality of concave portions 27 is formed by using the intaglio by molding an epoxy resin.
[0074]
<Intaglio production process (corrosion processing)>
An intaglio is formed on the surface 12b of the transparent substrate 12 by the following procedure.
(A) A corrosion-resistant metal (such as chromium) film is formed on the surface 12b of the transparent substrate 12.
[0075]
(B) Exposing a glass surface exposed portion at a position corresponding to the plurality of recesses 17 on the surface 12b of the transparent substrate 12 by pattern processing by photolithography.
(C) The exposed portion of the glass surface is corroded with an acid (such as hydrofluoric acid).
[0076]
(D) The corrosion-resistant film (metal film such as chromium) is peeled off, and the surface 12b of the transparent substrate 12 is again corroded to finish the exposed portion on the glass surface into the final shape.
According to the second embodiment configured as described above, the following operation and effect can be obtained in addition to the operation and effect (a) to (c) and (e) to (g).
[0077]
(H) Since the reflecting surface 26 is concave, the shape of the concave surface of the reflecting surface 26 is changed by appropriately changing the shape of the concave portion 27, for example, its width and depth, or the curvature of the convex surface. The extraction efficiency can be easily changed, and the extraction efficiency can be further improved. As a result, the efficiency of taking out the light emitted from each organic EL layer 14 can be further increased, whereby a brighter display can be realized.
[0078]
[Modification]
The present invention can be embodied with the following modifications.
In the first embodiment, the concave portions 17 and 17A are provided in the resin layer 18 formed on the surface 12b of the transparent substrate 12, but the resin layer 18 is not formed on the surface 12b, but the concave portion 17 is formed on the surface 12b. , 17A may be provided. Similarly, in the second embodiment, the concave portion 27 may be provided on the surface 12b of the transparent substrate 12. In such a case, the surface 12b of the transparent substrate 12 can be directly processed using the above-mentioned dicing saw, and the concave portions 17, 17A or the concave portions 27 can be formed on the surface 12b.
[0079]
In the first embodiment, the recesses 17 and 17A provided in the resin layer 18 may be formed by laser processing. Similarly, in the second embodiment, the concave portion 27 provided in the resin layer 18A can be formed by laser processing.
[0080]
In the first embodiment, an example in which the present invention is applied to the organic EL element 11 capable of color display has been described. However, the present invention is also applicable to a black-and-white organic EL element.
[0081]
In the first embodiment, not only each gap between the two organic EL layers 14 adjacent in the X direction (hatched portion in FIG. 4) but also each gap between the two organic EL layers 14 adjacent in the Y direction. The present invention is also applicable to a configuration in which the concave portion 17 of the V groove is provided.
[0082]
-The shape of the concave portion provided in the organic EL element 11 or the surface light emitting substrate 20 according to the present invention is not limited to the concave portion 17 or 27. For example, the shape of the concave portion 17 may be changed so that the reflection surface 16 shown in FIG. 1 has a plurality of planes, that is, a plurality of reflection surfaces having different angles, instead of one plane.
[0083]
In the above embodiments, the epoxy resin is used for the resin layers 18 and 18A. However, the resin layer 18 may be made of a photo-curing or thermosetting resin such as an acrylic resin in addition to the epoxy resin. .
[0084]
In each of the above embodiments, an example in which the present invention is applied to an organic EL device has been described. However, the present invention is not limited to an organic EL device, but is also applicable to an inorganic EL device.
In each of the above embodiments, the organic EL layer 14 is a two-layer type, but the organic EL layer 14 is a three-layer type including a hole transport layer, a light emitting layer, and an electron transport layer. There may be.
[0085]
In each of the above embodiments, the surface light emitter substrate 20 used for the organic EL element 11 has been described. However, the present invention is directed to a surface light emitter such as a display device or a line light source using a light emitting unit other than the organic EL layer 14, or The present invention is also applicable to the surface light emitting body substrate 20 used for the liquid crystal display device.
[0086]
【The invention's effect】
As described above, according to the first and ninth aspects of the present invention, it is possible to suppress the adverse effect on the display by the adjacent pixels, and to effectively extract the emitted light to the outside.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view illustrating a configuration of an organic EL element according to a first embodiment.
FIG. 2 is an enlarged sectional view showing a part of FIG. 1;
FIG. 3 is a plan view showing a plurality of pixels of the organic EL element.
FIG. 4 is an enlarged view of a portion A in FIG. 3;
FIGS. 5A to 5E are explanatory views showing a method for manufacturing the organic EL device according to the first embodiment.
FIG. 6 is a graph showing simulation results of each example and a comparative example.
FIG. 7 is a partial cross-sectional view illustrating a configuration of an organic EL element according to a second embodiment.
8 is an enlarged sectional view showing a part of FIG. 7;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Organic EL element, 12 ... Transparent substrate, 12a ... Light emission surface, 12b ... Surface, 13 ... Transparent electrode, 14 ... Organic EL layer, 15 ... Metal electrode layer, 16, 26 ... Reflection surface, 17, 17A, 27 ... recess, 18, 18A ... resin layer, 20 ... substrate for surface light emitter.

Claims (13)

A surface emitting body substrate having a transparent substrate, on which a light emitting portion is formed,
Light that is emitted by the light emitting unit and is obliquely incident on the light emitting surface of the transparent substrate is incident on at least a part of the periphery of the place where the light emitting unit is formed on the transparent substrate. A substrate for a surface light emitter, comprising a concave portion forming a reflection surface that reflects light in a direction in which an angle becomes smaller. The substrate for a surface light emitter according to claim 1,
The substrate for a surface light emitter, wherein the recess is provided in a resin layer formed on a surface of the transparent substrate on which the light emitting portion is formed. The substrate for a surface light emitter according to claim 1,
The substrate for a surface light emitter, wherein the recess is provided on a surface of the transparent substrate on which the light emitting unit is formed. The substrate for a surface light emitter according to any one of claims 1 to 3,
The substrate for a surface light emitter, wherein the recess is a V-shaped groove. The substrate for a surface light emitter according to any one of claims 1 to 3,
The concave portion is a groove in which two convex surfaces face each other at a predetermined angle. The substrate for a surface light emitter according to claim 2,
A surface light emitter substrate, wherein a transparent electrode is formed on a surface of the resin layer on which the concave portion is formed. The substrate for a surface light emitter according to claim 3,
A substrate for a surface light emitter, wherein a transparent electrode is formed on a surface of the transparent substrate on which the concave portion is formed. The surface light emitting substrate according to any one of claims 1 to 7,
The substrate for a surface light emitter, wherein the transparent substrate is made of glass or a translucent resin. A plurality of transparent electrodes, a plurality of EL layers, and a plurality of metal electrode layers are sequentially stacked on a transparent substrate, and light emitted from the EL layers is emitted from a light emission surface of the transparent substrate, In an EL device using the surface light emitting substrate having the transparent substrate,
At least a part of the periphery of each of the plurality of EL layers on the transparent substrate, the light emitted from the EL layer and obliquely incident on the light exit surface of the transparent substrate is incident at an angle of incidence on the light exit surface. An EL element using a substrate for a surface light emitter, comprising: a concave portion forming a reflection surface that reflects light in a direction in which the light emission becomes smaller. The EL device according to claim 9,
The EL element using a substrate for a surface light emitter, wherein the recess is provided in a resin layer formed between the transparent substrate and the transparent electrode. The EL device according to claim 9,
The EL element using a substrate for a surface light emitter, wherein the concave portion is provided on a surface of the transparent substrate on a side where the EL layer is formed. The EL device according to any one of claims 9 to 11,
An EL device using a surface light-emitting body substrate, wherein the recess is a V-shaped groove. The EL device according to any one of claims 9 to 11,
The concave element is a groove in which two convex surfaces face each other at a predetermined angle.

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