JP2014157759A - Organic electroluminescence panel and organic el panel complex - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic EL panel in which a nonluminescent region resulting from a sealing structure on a substrate is inconspicuous.SOLUTION: An organic EL panel includes: a transparent board 2000; a luminescence function layer which is installed on the transparent board 2000 and includes an organic layer; a sealing structure 2006 which connects with the transparent board 2000 in a peripheral region surrounding a luminous region of the transparent board 2000 in which the luminescence function layer is installed, and covers the luminescence function layer; and a reflection film 500 installed in the peripheral region.

Description

  The present invention relates to an organic electroluminescence (EL) panel and an organic EL panel composite in which a plurality of them are connected.

  In recent years, surface illumination devices using organic EL panels have been developed. FIG. 14 is a diagram showing a general structure assumed as an organic EL panel. 14A is a top view, and FIG. 14B is a cross-sectional view taken along line AA in FIG.

  An organic layer formed by forming a patterned transparent electrode 2001 on a transparent substrate 2000 such as glass and laminating an electron injection layer, an electron transport layer, a light emitting layer, a hole transport layer, and a hole injection layer on a part of the transparent electrode 2001. 2002 is formed. In order to apply a voltage to the organic layer, a reflective electrode 2003 is formed on the organic layer. The reflective electrode 2003 is made of Al, Ag, or an alloy thereof having high reflectivity. Light is radiated to the outside from the extraction surface 2009 through the transparent substrate 2000. In this specification, a laminated structure including the transparent electrode 2001, the organic layer 2002, and the reflective electrode 2003 may be referred to as a light emitting functional layer.

  On the other hand, an organic material used for the organic layer 2002 is deteriorated in an environment of oxygen and moisture, and thus needs to be protected by covering with a sealing structure 2006. The sealing structure 2006 includes, for example, a sealing substrate 2004 that faces the reflective electrode 2003, and a sealing material 2005 that connects the sealing substrate 2004 and the transparent substrate 2000 in the peripheral region of the transparent substrate 2000.

  In order to apply a voltage to the organic EL, a power feeding unit 100 electrically connected to the transparent electrode 2001 and the reflective electrode 2003 through the sealing material 2005 and the transparent substrate 2000 is provided in the peripheral region of the transparent substrate 2000.

  In response to the demand for emitting a large area as a surface light source, when a plurality of organic EL panels are simply connected to obtain a single large area organic EL panel composite, Since there is a peripheral region where the power supply unit 100 and the sealing material 2005 that do not emit light exist, the joint between adjacent EL panels is conspicuous and the appearance of the organic EL panel composite is impaired.

  In order to solve this problem, for example, in Patent Document 1 and Patent Document 2, when a plurality of organic EL panels are connected, the position where the power feeding unit 100 of one organic EL panel sinks into the back surface of the other organic EL panel And a technique of omitting the power feeding part 100 of the upper organic EL panel in the connection part is disclosed. According to this technique, since the non-light-emitting region derived from the power feeding unit 100 in the connection unit is reduced, it is possible to make the joint inconspicuous.

JP 2001-126871 A JP-A-2005-123153

  However, if the power feeding unit 100 is simply placed at a position where it sinks into the back side of another organic EL panel according to the conventional technique, it is derived from a non-light emitting region provided in the outer peripheral portion of the organic EL panel in order to install the sealing material 2005. There is a problem that the joints still stand out.

  The present invention solves the above-described conventional problems. In an organic EL panel in which a non-light-emitting region for placing a sealing material is not conspicuous, and an organic EL panel composite in which a plurality of organic EL panels are arranged, An object of the present invention is to provide an organic EL panel composite in which joints between organic EL panels are hardly noticeable.

  In order to solve the conventional problems, an aspect of the organic EL panel according to the present invention includes a transparent substrate, a light emitting functional layer that is disposed on the transparent substrate and includes an organic layer, and the light emission of the transparent substrate. A sealing structure that covers the light emitting functional layer by connecting to the transparent substrate in a peripheral region surrounding the light emitting region provided with the functional layer, and a reflective film provided in the peripheral region.

  According to such a configuration, by providing the reflective film in the peripheral region, the light propagating in the transparent substrate is reflected by the reflective film, so that the light propagating in the transparent substrate longer increases. By this reflected light, the non-light-emitting area | region originating in the area | region which installs the sealing material of an organic EL panel can be made not conspicuous.

Structure diagram of organic EL panel in Embodiment 1 of the present invention The figure explaining the manufacturing method of the organic electroluminescent panel in Embodiment 1 of this invention The figure explaining the propagation of the light in Embodiment 1 of this invention The figure explaining the integration | stacking of the extraction light quantity in Embodiment 1 of this invention Structure diagram of organic EL panel in Embodiment 2 of the present invention The figure explaining the manufacturing method of the organic electroluminescent panel in Embodiment 2 of this invention Structure diagram of organic EL panel in Embodiment 3 of the present invention The figure explaining the manufacturing method of the organic electroluminescent panel in Embodiment 3 of this invention Structure diagram of organic EL panel in Embodiment 4 of the present invention The figure explaining the manufacturing method of the organic electroluminescent panel in Embodiment 4 of this invention A diagram showing the distribution of light distribution in curved coordinates A diagram showing the distribution of light distribution in curved coordinates A diagram showing the distribution of light distribution in curved coordinates A diagram showing the distribution of light distribution in curved coordinates A diagram showing the distribution of light distribution in curved coordinates The figure explaining the extraction light quantity at the time of utilizing the light of wide angle orientation in Embodiment 1 of this invention The figure explaining the structure which seals an organic electroluminescent panel with transparent resin General assumed structure of conventional organic EL panel The figure explaining the extraction light quantity in the edge part vicinity of the light emission area | region of the conventional organic electroluminescent panel

  Prior to the description of the embodiments of the present invention, the results of investigations by the present inventor on an organic EL panel having a conventional configuration will be described.

  FIG. 15 shows an enlarged view of the vicinity of the boundary between the light emitting region and the peripheral region of the organic EL panel, and the amount of light extracted from the extraction surface 2009 of the transparent substrate 2000. Here, the light emitting region refers to a region where the light emitting functional layer of the transparent substrate 2000 is installed, and the peripheral region refers to a non-light emitting region surrounding the light emitting region of the transparent substrate 2000.

  A part of the light emitted from the light emitting layer travels along the path indicated by the arrow 502 while being reflected many times by total reflection in the transparent substrate 2000. At that time, light having an angle greater than the total reflection angle with respect to the transparent substrate 2000 is gradually extracted from the transparent substrate 2000 to the outside. Accordingly, a fade area 2008 in which the light amount gradually decreases occurs in the peripheral area. The width of the fade region 2008 varies depending on the distance from the light emitting layer to the extraction surface 2009.

  The amount of light at the joint where the organic EL panels are stacked is as follows.

  If the sealing material 2005 is non-translucent, the light from the organic EL panel arranged on the back surface is blocked, and the joints are conspicuous. By narrowing the width of the peripheral region where the sealing material 2005 is provided to the limit, it is possible to prevent the joints from being recognized by humans. In that case, however, the sealing performance is insufficient, and as a result, the lifetime of the organic EL is reduced. Because it becomes shorter, it is not realistic.

  By using a translucent material for the sealing material 2005, the result of integrating the light amounts in the respective fade regions 2008 of the stacked organic EL panels becomes the light amount at the joint of the organic EL panels. Therefore, it is possible to mitigate a decrease in the amount of light at the joint of the organic EL panel.

  However, as described above, there is a limit to narrowing the peripheral region where the sealing material 2005 is provided. Therefore, further measures are required to make the joint of the organic EL panel inconspicuous while securing the width of the peripheral region.

  The present invention has been made to solve such problems, and an organic EL panel according to one aspect of the present invention includes a transparent substrate and a light emitting functional layer that is disposed on the transparent substrate and includes an organic layer. A sealing structure that covers the light emitting functional layer by connecting to the transparent substrate in a peripheral region surrounding the light emitting region where the light emitting functional layer of the transparent substrate is installed, and a reflective film installed in the peripheral region, Is provided.

  The light emitting functional layer is formed by laminating a transparent electrode, the organic layer including the light emitting layer, and a reflective electrode in this order on the transparent substrate, and the reflective film includes the transparent substrate and the sealing structure. May be provided between the two.

  According to such a configuration, by providing the reflection film in the peripheral region, the light propagating in the transparent substrate is reflected by the reflection film, so that the light propagating in the substrate longer increases. By this reflected light, the non-light emitting region derived from the region where the sealing material for the organic EL panel is installed can be made inconspicuous.

  In addition, the sealing structure includes a sealing substrate made of glass, a transparent material, and a sealing material connected to the sealing substrate and the transparent substrate in the peripheral region of the transparent substrate. It may consist of

  According to such a configuration, when organic EL panels are arranged in an overlapping manner, light from another organic panel can be extracted through the sealing substrate and the sealing material.

  Further, the sealing structure may be integrally formed of a translucent resin.

  According to such a configuration, when organic EL panels are arranged in an overlapping manner, light from another organic panel can be extracted through the sealing substrate and the sealing material.

  Further, a first adhesion layer may be further provided between the transparent substrate and the reflection film, and a second adhesion layer may be further provided between the reflection film and the sealing material. .

  According to such a configuration, the sealing performance of the organic EL panel can be improved.

  Further, when light having a central emission wavelength of λ is generated in the light emitting layer, the distance between the reflective electrode and the central light emission position in the light emitting layer is (4m + 3) λ / 16 or more and (4m + 5) λ / 16 or less. However, m may be an integer of 0 or more.

  According to such a configuration, the light emitted in the front direction of the organic EL panel is weakened by interference, and the light emitted to the wide angle side is strengthened by interference. As a result, the total amount of light guided through the transparent substrate is increased, and the attenuation of the amount of light around the light emitting region is moderated. Therefore, the alignment accuracy required when organic EL panels are stacked is relaxed. Moreover, since the width of the region where the amount of light attenuates in the periphery of the light emitting region is widened, the width of the sealing material can be widened, and the sealing performance of the organic EL can be further improved.

  Moreover, the organic EL panel composite according to one aspect of the present invention includes a plurality of the above-described organic EL panels, and the peripheral regions of adjacent organic EL panels are arranged so as to overlap each other.

  According to such a configuration, a large-area organic EL panel composite in which ends of a plurality of organic EL panels are overlapped is obtained.

  An embodiment of the present invention devised by the present inventor based on the above examination will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a structural diagram of an organic EL panel according to Embodiment 1 of the present invention. 1A is a top view, and FIG. 1B is a cross-sectional view taken along line AA in FIG. In FIG. 1, the same components as those in FIG.

  The reflective film 500 is provided between the sealing material 2005 extending from the end of the sealing substrate 2004 toward the transparent substrate 2000 and the transparent substrate 2000. The reflection film 500 only needs to be installed on at least one side of the organic EL panel, and is not necessarily installed all around.

  In FIG. 1, the power feeding unit 100 is installed on one side.

  The reflective film 500 is made of Al, Ag, an alloy thereof, or the like with high reflectivity.

  The sealing substrate 2004 and the sealing material 2005 are characterized by being made of a material that can transmit light. For example, the sealing substrate 2004 is made of glass, and the sealing material 2005 is made of a translucent resin.

  The width of the fade region 2008 in which the amount of light around the light emitting region of the first organic EL panel decreases is determined by the distance from the light emitting layer generated in the organic layer 2002 to the extraction surface 2009.

  FIG. 2 is a process diagram illustrating an example of a method for manufacturing an organic EL panel. First, a transparent substrate 2000 is prepared (FIG. 2A), and a transparent electrode 2001 made of ITO (Indium Tin Oxide) or the like is formed on the transparent substrate 2000. A part of the transparent electrode 2001 is removed at the separation part 400 to form the power feeding part 100 (FIG. 2B). A reflective film 500 is formed around the transparent electrode 2001 (FIG. 2C).

  An organic layer 2002 is formed on the transparent electrode 2001 so as to overlap the separation part 400 from which the transparent electrode 2001 has been removed (FIG. 2D). A reflective electrode 2003 is formed on the organic layer 2002 (FIG. 2E). With such a structure, a short circuit between the metal electrode 2003 and the transparent electrode 2001 can be prevented. Thereafter, a sealing material 2005 made of a UV curable material or the like is formed (FIG. 2E), and the sealing substrate 2004 is bonded and fixed. The reflective film 500 is made of Al, Ag, or an alloy thereof. The metal electrode 2003 and the power supply unit 100 are connected by the connection unit 300 (FIG. 2 (f)).

  FIG. 3 illustrates the light propagation at the light emitting region boundary and the effect of the reflective film 500. In the case where there is no reflective film 500, as shown in FIG. 15, the light reflected and returned from the extraction surface 2009 out of the light emitted toward the substrate passes along the path indicated by the arrow 501 to the sealing glass side. Cannot be taken out. However, by providing the reflective film 500, the light reflected and returned from the extraction surface 2009 can be reflected along the path indicated by the arrow 503 toward the transparent substrate 2000 and extracted outside.

  FIG. 4 shows the light extraction amount at the boundary of the light emitting region when the Ag reflection film is provided. The broken line indicates the light amount distribution for each place before the reflection film is provided, and the solid line indicates the light amount distribution when the reflection film is provided. When the reflective film is provided, the light is used more effectively, the total amount of light that can be extracted is increased, and attenuation is moderated. Therefore, the width of the attenuation region, that is, the width of the fade region is widened, so that the width of the sealing material can be widened and the sealing performance of the organic EL can be improved.

  Note that FIG. 2 shows an example of a manufacturing method in which the outer shape of the substrate is processed first, but it is not necessary to be limited thereto. For example, a plurality of organic EL panels are simultaneously manufactured on a large-area substrate, and finally, The substrate may be cut.

  It is also known that total reflection occurs due to a difference in refractive index between the transparent electrode 2001 and the transparent substrate 2000 of the organic EL panel. The effect of the present invention can be obtained even in an organic EL panel in which a light extraction structure such as a diffraction grating or a nanostructure is provided between the transparent substrate 2000 and the transparent electrode 2001.

(Embodiment 2)
FIG. 5 is a structural diagram of the organic EL panel according to the second embodiment of the present invention. 5A is a top view, and FIG. 5B is a cross-sectional view taken along line AA in FIG. In FIG. 5, the same components as those in FIG. The difference between the present embodiment and the first embodiment is that a first adhesion layer 600 is provided at the interface between the transparent substrate 2000 and the reflective film 500.

  FIG. 6 is a process diagram showing an example of a method for producing the organic EL panel of the present embodiment. The difference from Embodiment 1 is that the first adhesion layer 600 is formed after the patterned transparent electrode 2001 is formed (FIG. 6C). The other steps can be manufactured in the same manner as in Embodiment Mode 1.

The first adhesion layer 600 uses a glass paste or an oxide buffer layer (Al ₂ O ₃ ) in order to adhere the transparent substrate and the reflective film.

(Embodiment 3)
FIG. 7 is a structural diagram of an organic EL panel according to Embodiment 3 of the present invention. 7A is a top view, and FIG. 7B is a cross-sectional view taken along line AA in FIG. In FIG. 7, the same components as those in FIG. The difference between this embodiment and Embodiments 1 and 2 is that a second adhesion layer 700 is provided at the interface between the reflective film 500 and the sealing material 2005.

  FIG. 8 is a process diagram showing an example of a method for producing the organic EL panel of the present embodiment. The difference from the first and second embodiments is that the second adhesion layer 700 is formed after the reflective film 500 is formed (FIG. 8D). The other steps can be manufactured in the same manner as in Embodiment Mode 1.

The second adhesion layer 700 uses a silane coupling agent and an oxide / nitride buffer layer (SiO ₂ , SiN, SiO _2x N _1-2x , ITO) in order to adhere the reflective film and the sealant.

(Embodiment 4)
FIG. 9 is a structural diagram of an organic EL panel according to Embodiment 3 of the present invention. 9A is a top view, and FIG. 9B is a cross-sectional view taken along line AA in FIG. 9, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. The difference between the present embodiment and the first to third embodiments is that a first adhesion layer 600 is provided at the interface between the transparent substrate 2000 and the reflective film 500, and the second is formed at the interface between the reflective film 500 and the sealing material 2005. The adhesion layer 700 is provided.

The first adhesion layer 600 uses a glass paste or an oxide buffer layer (Al ₂ O ₃ ) in order to adhere the transparent substrate and the reflective film.

The second adhesion layer 700 uses a silane coupling agent and an oxide / nitride buffer layer (SiO ₂ , SiN, SiO _2x N _1-2x , ITO) in order to adhere the reflective film and the sealant.

  FIG. 10 is a process diagram showing an example of a method for producing the organic EL panel of the present embodiment. The difference from the first to third embodiments is that the first adhesion layer 600 is provided at the interface between the transparent substrate and the reflection film 500 (FIG. 10B), and after the reflection film 500 is formed, the second adhesion layer is formed. 700 is formed (FIG. 10D). The other steps can be manufactured in the same manner as in Embodiment Mode 1.

(Embodiment 5)
In the present invention, light guided through the transparent substrate 2000 is utilized in order to make the boundary of the connection portion of the organic EL panel inconspicuous. The ratio of the light that is guided in the transparent substrate 2000 by changing the light distribution pattern of the light emitted from the light emitting layer by changing the distance d between the center light emitting position of the light emitting layer and the reflective electrode 2003 generated in the organic layer 2002. Can be increased.

  A part of the light generated in the light emitting layer goes directly to the air layer, and another part of the light generated in the light emitting layer is reflected by the reflective electrode 2003 and then goes to the air layer. Since these lights interfere with each other, the pattern of light emitted from the central light emission position varies depending on the distance d between the central light emission position and the reflective electrode 2003.

  The light intensity I (θ) in the θ direction is expressed by Equation 1, where θ is the light emission direction, d is the distance between the center emission position and the reflective electrode, and λ is the center emission wavelength of the light.

  11A to 11E show the distribution of light distribution at the central light emission position S in polar coordinates when d / λ = 1/8, 3/16, 2/8, 5/16, 3/8, respectively. FIG. For example, as shown in FIGS. 11A and 11E, when d / λ = (2m + 1) / 8 (m is an integer equal to or larger than 0), the light in the front direction is strengthened by interference. For example, as shown in FIG. 11C, when d / λ = (2m) / 8 (m is an integer equal to or greater than 1), the light in the front direction is weakened by interference, and the light on the wide angle side is strengthened by interference. Regardless of the presence or absence of the light extraction structure, the light distribution of the light generated at the central light emission position S is the light distribution shown in FIGS. 11A to 11E.

  In view of this, an organic EL panel in which the distance between the light emitting layer that increases the amount of light guided through the transparent substrate 2000 and the reflective electrode is larger than 3 / 16λ was studied.

  FIG. 12 shows a light amount distribution (dashed line) at the boundary of the light emitting region when the Ag distribution film is not provided with the light distribution A, and a light amount distribution (one point at the boundary of the light emitting region when the Ag reflective film is provided with the light distribution A. The light amount distribution (solid line) at the boundary of the light emitting region when the Ag reflection film is provided with the light distribution B and the light distribution B is shown. In the light distribution B, the total amount of light guided through the substrate is increased, and the attenuation of the amount of light around the light emitting region is moderated. Therefore, the accuracy required for alignment required when organic EL panels are stacked is relaxed. In addition, since the width of the area where the amount of light attenuates around the light emitting area, that is, the fade area described above is widened, the width of the sealing material can be widened, and the sealing performance of the organic EL can be further improved. it can.

  While the organic EL panel according to one or more aspects of the present invention has been described based on the embodiment, the present invention is not limited to this embodiment. Unless it deviates from the gist of the present invention, one or more of the present invention may be applied to various modifications that can be conceived by those skilled in the art, or forms constructed by combining components in different embodiments. It may be included within the scope of the embodiments.

  In the embodiment of the present invention, the description has been made using the structure in which the organic layer is protected from moisture and oxygen by the transparent sealing material and the sealing substrate. However, the sealing method needs to be limited to this structure. However, the same effect can be obtained as long as the structure transmits light.

  For example, as illustrated in FIG. 13, the sealing structure 2006 may be a transparent resin 1101 that functions as the sealing substrate 2004 and the sealing material 2005, and the organic EL is integrally formed with such a sealing structure 2006. The panel may be sealed. With such a configuration, the manufacturing process can be simplified.

  Further, a diffusion sheet 2007 may be provided on the surface of the transparent substrate 2000.

  In general, the refractive index of the organic layer 2002 and the transparent electrode 2001 is 1.8 or more, and total reflection occurs at the interface with the transparent substrate 2000. In order to suppress this total reflection, a take-out structure may be provided inside the organic EL panel. By applying the embodiment of the present invention to such an organic EL panel, it is possible to obtain an effect of making the joint of the organic EL panel inconspicuous. As the extraction structure, a concavo-convex structure capable of performing angle conversion of light, such as a diffraction grating, a microlens, or a pyramid structure, can be used.

  A plurality of the organic EL panels according to the present invention can be used as surface illumination that emits light in a free shape. The organic EL panel according to the present invention can be applied to, for example, flat panel displays, liquid crystal display backlights, illumination light sources, and the like. In addition, the organic EL panel according to the present invention is not limited to a monochromatic light source, and can also be applied to a white light emitting device.

DESCRIPTION OF SYMBOLS 100 Power supply part 300 Connection part 400 Separation part 500 Reflective film 600 1st adhesion layer 700 2nd adhesion layer 1101 Resin 2000 Transparent substrate 2001 Transparent electrode 2002 Organic layer 2003 Reflective electrode 2004 Sealing substrate 2005 Sealing material 2006 Sealing structure 2007 Diffusion sheet 2008 Fade area 2009 Extraction surface

Claims (8)

A transparent substrate;
A light emitting functional layer installed on the transparent substrate and including an organic layer;
A sealing structure that covers the light emitting functional layer by connecting to the transparent substrate in a peripheral region surrounding the light emitting region where the light emitting functional layer of the transparent substrate is installed;
A reflective film installed in the peripheral region,
Organic EL panel. The light emitting functional layer is formed by laminating a transparent electrode, the organic layer including a light emitting layer, and a reflective electrode in this order on the transparent substrate.
The organic EL panel according to claim 1, wherein the reflective film is provided between the transparent substrate and the sealing structure. The sealing structure includes a sealing substrate made of glass and a sealing material that is made of a light-transmitting resin and is connected to the sealing substrate and the transparent substrate in the peripheral region of the transparent substrate. The organic EL panel according to claim 1 or 2. The organic EL panel according to claim 1, wherein the sealing structure is integrally formed of a translucent resin. The organic EL panel according to claim 1, further comprising a first adhesion layer between the transparent substrate and the reflective film. The organic EL panel according to claim 1, further comprising a second adhesion layer between the reflective film and the sealing structure. When light having a central emission wavelength of λ is generated in the light emitting layer, the distance between the reflective electrode and the central light emission position in the light emitting layer is (4m + 3) λ / 16 or more (4m + 5) λ / 16 or less, m is an integer greater than or equal to 0,
The organic EL panel according to any one of claims 1 to 6. An organic EL panel composite comprising the plurality of organic EL panels according to claim 1, wherein peripheral regions of adjacent organic EL panels are overlapped with each other.

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