JP6032206B2 - Planar light emitter - Google Patents

Description

  The present invention relates to a planar light emitter, and particularly to a planar light emitter produced by arranging a plurality of organic electroluminescent elements.

  An organic electroluminescent element is an element using electroluminescence of an organic material (hereinafter referred to as an organic EL element), and mainly includes an anode, a cathode, and an organic light emitting functional layer provided between the anode and the cathode. Composed. In the organic EL element having such a configuration, light generated in the organic light emitting functional layer (hereinafter referred to as light emission) is extracted from the surface of the anode or the cathode, so that uniform illumination can be obtained on the emission surface. In addition, since organic EL elements can obtain emitted light that does not contain ultraviolet rays, a light source that is gentle to the eyes can be obtained. Furthermore, since an organic EL element does not contain a harmful metal, it is an element with high environmental suitability. From the above, recently, organic EL elements are promising as planar light emitters in applications such as display devices and lighting devices (displays).

  In addition, with the recent increase in size of lighting devices and displays, it is desired to increase the area of the planar light emitter. Therefore, in the planar light emitting body using the above-described organic EL element (light emitting panel), a technique for increasing the area by arranging a plurality of organic EL elements in a predetermined form has been studied.

  However, since the organic EL element is sealed with a sealing material in order to prevent deterioration due to active gas or moisture, a sealing region is formed at the periphery of the organic EL element. Therefore, when a planar light emitter is configured by arranging a plurality of organic EL elements, a non-light-emitting region is formed at the seam portion between a plurality of organic EL elements adjacent to each other and in the vicinity thereof. The region becomes a cause of luminance unevenness of the planar light emitter. In order to eliminate such luminance unevenness, various techniques have been conventionally proposed (see, for example, Patent Documents 1 and 2).

  Patent Document 1 describes a light emitting element having a configuration in which a plurality of organic light emitting regions provided on a substrate are separated from each other by an inactive intermediate region. And in patent document 1, the technique which provides the light extraction element which has a big scattering power on the area | region corresponding to an inactive intermediate | middle area | region is proposed in the surface by the side of the light extraction of a board | substrate.

  In Patent Document 2, a plurality of light diffusing reflectors that are inclined obliquely outward from the bottom surface toward the emitting surface are provided on the light emitting side of each surface light source panel, and adjacent light diffusing reflectors are in contact with each other without any gap. A lighting device to be arranged has been proposed. According to Japanese Patent Laid-Open No. 2004-260688, this configuration prevents a dark portion from being formed at a joint portion between the surface light source panels, thereby obtaining in-plane uniformity of luminance.

JP 2010-92866 A JP 2009-87830 A

  As described above, conventionally, various techniques for reducing luminance unevenness caused by a non-light emitting region have been proposed for planar light emitters using electroluminescence of organic materials. However, for example, the technique proposed in Patent Document 1 is intended for a planar light emitter in which a plurality of organic light emitting regions are provided on a large substrate, and a plurality of organic EL elements are arranged (tiled). It does not consider the structure of the planar light emitter. Further, for example, in the configuration disclosed in Patent Document 2, it is actually difficult to arrange the light diffusing reflectors so that they are in contact with each other without any gap. Problems can arise.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to further suppress luminance unevenness caused by a non-light-emitting region in a planar light emitter obtained by tiling a plurality of organic EL elements. Thus, it is to improve the uniformity of the luminance within the light extraction surface of the planar light emitter.

In order to solve the above problems, the planar light emitter of the present invention is configured to include an organic electroluminescence element group and a light extraction member. The organic electroluminescence element group includes a transparent substrate, a first electrode formed on the transparent substrate, an organic compound layer formed on the first electrode and including a light emitting layer, an organic compound layer formed on the organic compound layer, and And a plurality of organic electroluminescence elements including a second electrode formed of silver or a silver alloy containing silver as a main component, and the transparent substrates of the plurality of organic electroluminescence elements are arranged facing the same side. . Moreover, the light extraction member is provided in the area | region including the seam part between several organic electroluminescent elements in the surface at the side of the transparent base material of an organic electroluminescent element group. Furthermore, the light extraction member extends over the entire region corresponding to the non-light-emitting region formed between the light-emitting regions of the plurality of organic electroluminescence elements adjacent to each other on the surface of the organic electroluminescence element group on the transparent substrate side. Is formed.

  As described above, in the planar light-emitting body of the present invention, a plurality of organic EL elements are arranged, and a region including a joint portion between a plurality of adjacent organic EL elements on the surface of the organic EL element on the transparent substrate side. And a cathode of each organic EL element is formed of silver or a silver alloy containing silver as a main component.

  According to the planar light emitter of the present invention having the above-described configuration, it becomes possible to increase the amount of emitted light extracted from the non-light emitting region formed at the joint portion between a plurality of adjacent organic EL elements. Even in a planar light-emitting body having an area, the in-plane uniformity of luminance can be improved.

1A to 1C are schematic configuration diagrams of a planar light emitter according to the first embodiment. FIG. 2 is a diagram illustrating a configuration example of the organic light emitting functional layer. 3A to 3C are schematic configuration diagrams of a planar light emitter according to the second embodiment. FIG. 4 is a schematic configuration diagram of a planar light emitter according to the third embodiment. FIG. 5 is a schematic cross-sectional view of a light emitting panel of various embodiments.

  Hereinafter, a configuration example of the planar light emitter according to the embodiment of the present invention will be specifically described with reference to the drawings, but the present invention is not limited to the following example.

<1. First Embodiment>
[Configuration of planar light emitter]
1A to 1C are schematic configuration diagrams of a planar light emitter according to a first embodiment of the present invention. FIG. 1A is a schematic plan view of a light extraction surface (light emitting surface) of the planar light emitter according to the first embodiment. 1B is a cross-sectional view taken along the line aa in FIG. 1A (cross-sectional view taken along the X direction in the figure), and FIG. 1C is a cross-sectional view taken along the line bb in FIG. 1A (taken along the Y direction in the figure). FIG. Furthermore, in the present embodiment, a planar light emitter 1 in which four organic EL elements 10 (hereinafter referred to as light emitting panels 10) are arranged (tiled) in a form of 2 rows × 2 columns will be described as an example. Note that the number and arrangement of the light-emitting panels 10 are appropriately set according to conditions such as usage.

  The planar light-emitting body 1 includes an organic EL element group including four light-emitting panels 10, a support substrate 11, an adhesive member 12 for fixing each light-emitting panel 10 on the support substrate 11, and four light-emitting panels. The light extraction member 13 provided in the joint part between 10 is provided. In addition, the planar light emitter 1 of the present embodiment is a bottom emission type planar light emitter, and light generated by each light emitting panel 10 (hereinafter referred to as light emission light h) is a transparent substrate described later of each light emitting panel 10. The light is extracted from a 21-side surface 21a (hereinafter referred to as a light extraction surface 21a).

  In the planar light emitter 1 of the present embodiment, the four light emitting panels 10 are supported so that the side surfaces of the transparent substrates 21 described later of the respective light emitting panels 10 are in contact with each other between the four light emitting panels 10 adjacent to each other. Arrange on the substrate 11. At this time, a later-described sealing material 25 side surface of each light emitting panel 10 is fixed on the large support substrate 11 via the adhesive member 12. At this time, the four light emitting panels 10 are attached to the support substrate 11 so that the light extraction surfaces (surfaces on the transparent substrate 21 side) of the four arranged light emitting panels 10 are flush with each other. Here, each structure of the support substrate 11, the adhesive member 12, and the light extraction member 13 is demonstrated more concretely. The detailed description of the light emitting panel 10 will be described later.

(1) Support substrate If the support substrate 11 is a plate-shaped member which can hold | maintain the state when the four light emission panels 10 are mounted via the adhesive member 12, it will be comprised by arbitrary plate-shaped members. be able to. In the present embodiment, since the emitted light h is not extracted from the support substrate 11 side, the support substrate 11 does not need to be formed of a light-transmitting material and can be formed of an arbitrary material.

  When the planar light emitter 1 is flexibly bent, the support substrate 11 is formed of a flexible substrate having flexibility. As such a flexible substrate, for example, a resin film or a glass substrate having a thickness of about 0.01 mm to 0.50 mm can be used.

(2) Adhesive member In the present embodiment, in various industrial fields, the adhesive member used on the support substrate 11 or the sealing material 25 among the adhesive members used in terms of pressure-sensitive adhesives, adhesives, etc., or pressure-sensitive adhesives, adhesives, etc. After applying and bonding the light-emitting panel 10 and the support substrate 11, a curable adhesive member 12 that forms a high molecular weight body or a crosslinked structure by various chemical reactions is used. That is, the adhesive member 12 is formed of a material that cures the bonded portion by irradiating light such as ultraviolet rays, applying heat, or applying pressure.

  Examples of the adhesive member 12 having the above-described physical properties include curable adhesives such as urethane, epoxy, fluorine-containing, aqueous polymer-isocyanate, and acrylic, moisture-cured urethane adhesive, and polyether. Examples include anaerobic adhesives such as methacrylate type, ester type methacrylate type, and oxidized polyether methacrylate, cyanoacrylate type instant adhesives, and acrylate and peroxide type two-pack type instant adhesives.

(3) Light Extraction Member The light extraction member 13 is configured by a sheet-like, film-like, plate-like, or film-like optical member (optical sheet) having a function of transmitting and emitting incident light. Hereinafter, the arrangement and configuration of the light extraction member 13 will be described in detail.

  The light extraction member 13 is provided on the light extraction surface 21 a of the transparent substrate 21 at a joint portion between the four light emitting panels 10 and a region in the vicinity thereof. Specifically, as shown in FIG. 1A, on the light extraction surface 21a, the light extraction member 13 is arranged between the light emission areas SA of the four light emission panels 10, that is, between the four light emission panels 10 adjacent to each other. The non-light emitting region SB including the joint portion is formed.

  At this time, in the present embodiment, the light extraction member 13 is formed in a region that does not overlap the light emitting region SA in a plan view when viewed from the light extraction surface 21a side. In the present embodiment, it is preferable to cover 50% or more of the non-light emitting area SB between the light emitting areas SA with the light extraction member 13. In particular, as shown in FIG. 1A, it is preferable to form the light extraction member 13 over the entire non-light emitting region SB between the light emitting regions SA. That is, it is preferable to cover 100% of the non-light emitting area SB between the light emitting areas SA with the light extraction member 13.

  In the present embodiment, an example in which the light extraction member 13 is not formed in the non-light emitting region SB formed in the outer peripheral end region of the planar light emitter 1 on the light extraction surface 21a of the transparent substrate 21 is shown. The invention is not limited to this. The light extraction member 13 may also be provided in the non-light emitting region SB formed in the outer peripheral end region of the planar light emitter 1. Also in this case, the light extraction member 13 is formed so as not to overlap the light emitting region SA in a plan view when viewed from the light extraction surface 21a side.

  The light extraction member 13 arranged in the above-described form is composed of a light diffusion sheet, a light collecting sheet, or the like. As the light diffusing sheet, conventionally used light diffusing sheets can be used. For example, a light diffusion sheet having irregularities formed on the sheet surface can be used.

  In addition, as the condensing sheet, a general condensing sheet called a prism sheet can be used. For example, a condensing sheet that is practically used for an LED (Light Emitting Diode) backlight of a liquid crystal display device is used. be able to. As the condensing sheet, for example, a sheet in which a plurality of stripes having a vertex angle of 90 degrees and a triangular cross-sectional shape are formed on a sheet base material at a pitch of 50 μm can be used. In addition, various shapes can be applied as the uneven shape on the surface of the condensing sheet, and for example, it can be appropriately set in consideration of the application, necessary condensing characteristics, and the like. For example, the uneven shape on the surface of the light collecting sheet may be a shape in which the vertical angle of the stripe is rounded (the cross-sectional shape is substantially triangular), or a shape in which the pitch of the stripe is changed randomly. Also good.

  The configuration of the light extraction member 13 may be a configuration in which a plurality of the above-described light diffusion sheets, condensing sheets, and the like are stacked. In this case, the emission angle (light extraction angle) of the emitted light h extracted from the light extraction member 13 can be adjusted. For example, when a plurality of light diffusion sheets are stacked or when a light diffusion sheet is stacked on the light extraction surface of the light collecting sheet, the emitted light h can be extracted over a wide angular range. On the other hand, for example, when a plurality of light collecting sheets are stacked or when a light collecting sheet is stacked on the light extraction surface of the light diffusion sheet, the emitted light h can be extracted from the light emitting surface in a narrow angle range. In addition, when using a condensing sheet for the light extraction member 13, a radiation angle can also be controlled by adjusting the shape and pitch of the stripe of the prism which comprises a condensing sheet. In the latter case where the amount of light extracted in a specific direction increases (when the emission angle is narrow), the luminance in that direction increases. Therefore, depending on the application to which the present invention is applied, the former (when the emission angle is wide) ) And the latter.

  The light extraction member 13 is attached to the transparent substrate 21 with an adhesive (not shown). In addition, it is preferable that this adhesive agent has high light transmittance. Further, this adhesive may have a refractive index comparable to that of the transparent substrate 21.

[Method for producing planar light emitter]
Next, a method for producing the planar light emitter 1 of the present embodiment will be briefly described. First, the anode 22, the organic light emitting functional layer 23, and the cathode 24 are formed on the transparent substrate 21. At this time, a cathode lead electrode 24 a is also formed on the transparent substrate 21. Next, a sealing material 25 is provided on the cathode 24 so that the lead electrode portions of the anode 22 and the cathode 24 are exposed and at least completely cover the organic light emitting functional layer 23. Thereby, the light emission panel 10 is obtained.

  Next, the four light emitting panels 10 are arranged on the support substrate 11. Specifically, the four light emitting panels 10 are tiled and bonded to the support substrate 11 in the form of 2 rows × 2 columns via the adhesive member 12. At this time, the surface of each light emitting panel 10 on the side of the sealing material 25 is attached to the support substrate 11 via the adhesive member 12. At this time, between the four light emitting panels 10 adjacent to each other, the side surfaces of the transparent substrates 21 facing each other are brought into contact with each other for tiling.

  Then, in the surface of the light extraction surface 21 a of the light emitting panel 10, the light extraction member 13 is bonded to the non-light emitting region SB between the light emitting regions SA of the four light emitting panels 10 so as not to overlap the light emitting region SA. Affix (not shown). Moreover, the extraction electrode of each electrode film is connected between each light emission panel 10 as needed. In the present embodiment, the planar light-emitting body 1 is manufactured in this way.

  The light extraction member 13 may be provided independently for each light emitting panel 10. In this case, after the light extraction member 13 is provided on the non-light emitting region SB arranged on the joint side of the light emission panel 10 on the light extraction surface 21a of the transparent substrate 21 of each light emission panel 10, the light extraction member 13 is provided. The provided light emitting panel 10 is tiled on the support substrate 11.

  In addition, you may connect so that the electrical connection method of each light emission panel 10 may drive independently, respectively (parallel). In this case, since the voltage applied to each light emitting panel 10 is constant, the characteristic variation between the light emitting panels 10 is reduced.

  Further, the light emitting panels 10 may be connected in series between the light emitting panels 10 adjacent to each other. Further, when tiling four or more light emitting panels 10 in a two-dimensional manner (2 rows × 2 columns or more), the light emitting panels 10 in one arrangement direction are connected in series, and the light emission in the other arrangement direction is performed. The panels 10 may be connected in parallel. Thus, when the part connected in series between the some light emission panels 10 is provided, size reduction of the planar light-emitting body 1 can be achieved. When the light emitting panels 10 adjacent to each other are connected in series, the lead electrodes exposed at the joints between the plurality of light emitting panels 10 adjacent to each other are connected with, for example, a conductive tape.

  Furthermore, although the planar light-emitting body 1 of this embodiment demonstrated the structural example which supports the several light emission panel 10 using the large sized support substrate 11, this invention is not limited to this. For example, you may join the side walls of the transparent substrate 21 which opposes between the mutually adjacent several light emission panels 10 with an adhesive agent. In this case, an adhesive can be used as a support member for the light-emitting panel, and the large support substrate 11 does not have to be provided separately.

[Entire configuration of light-emitting panel]
Next, the configuration of the light emitting panel 10 will be described in more detail.

  As shown in FIG. 1B, the light-emitting panel 10 includes a transparent substrate 21 (transparent substrate), an anode 22 (first electrode), an organic light-emitting functional layer 23 (organic compound layer), and a cathode 24 (second electrode). And a cathode lead electrode 24a and a sealing material 25.

  In the present embodiment, the anode 22, the organic light emitting functional layer 23, and the cathode 24 are laminated in this order on the surface (film lamination surface) opposite to the light extraction surface 21a of the transparent substrate 21. In other words, on the transparent substrate 21, the anode 22 and the cathode 24 are arranged in a state where insulation is maintained by the organic light emitting functional layer 23. The cathode lead electrode 24a is formed in a region different from the anode 22 on the film lamination surface of the transparent substrate 21, and a part of the cathode 24 is formed on the cathode lead electrode 24a. As a result, the cathode 24 is electrically connected to the cathode lead electrode 24a.

  In the light emitting panel 10, the sealing material 25 is formed so as to cover the surface of the transparent substrate 21 on the cathode 24 side. At this time, the sealing material 25 is formed so as to cover at least the organic light emitting functional layer 23. In this embodiment, as shown in FIG. 1B, the sealing material 25 is formed so that the lead electrode portions of the anode 22 and the cathode 24 are exposed. As shown in FIGS. 1B and 1C, in this embodiment, the lead-out electrode portion 22a and the cathode lead-out electrode 24a of the anode 22 are located in the vicinity of a pair of sides of each light emitting panel 10 orthogonal to the X direction in FIG. 1A. Each is provided.

  The light emitting panel 10 is an element (organic EL element) using electroluminescence of an organic material, and has a structure in which the organic light emitting functional layer 23 is sandwiched between the anode 22 and the cathode 24 as described above. As will be described later, the organic light emitting functional layer 23 is an organic material layer having at least a light emitting layer, and holes injected from the anode 22 and electrons injected from the cathode 24 are regenerated in the light emitting layer. The light emission h is generated by the combination.

  In this embodiment, the emitted light h generated in the organic light emitting functional layer 23 is taken out from the transparent substrate 21 side. Therefore, the anode 22 disposed on the transparent substrate 21 side is composed of a transparent electrode. On the other hand, the cathode 24 serving as the counter electrode of the anode 22 is formed of a reflective electrode (metal film). In the present embodiment, the cathode 24 is made of silver or a silver alloy containing silver as a main component, and is formed of a reflective electrode having a high reflectance.

  In the light emitting panel 10 of the present embodiment, the surface of the transparent substrate 21 on the cathode 24 side is sealed with the sealing material 25 in order to prevent the organic light emitting functional layer 23 from being deteriorated. Therefore, it is necessary to provide a space for sealing the light emitting panel 10 at the periphery of the film lamination surface of the transparent substrate 21, and the organic light emitting functional layer 23 is disposed at the center of the transparent substrate 21.

  In the light emitting panel 10 having the above configuration, only the portion where the organic light emitting functional layer 23 is sandwiched between the anode 22 and the cathode 24 on the transparent substrate 21 is the light emitting area SA. On the other hand, on the transparent substrate 21, the area around the light emitting area SA is a non-light emitting area SB.

  Hereinafter, the configuration of each part and each layer of the light emitting panel 10 will be described more specifically.

[Transparent substrate]
The transparent substrate 21 is a substrate that supports various electrode films and the organic light emitting functional layer 23. In the present embodiment, since the emitted light h generated in the organic light emitting functional layer 23 is taken out from the transparent substrate 21 side, the transparent substrate 21 is formed of a material having high light transmittance with respect to visible light. For example, as the transparent substrate 21, a plate-like member such as a glass substrate, a quartz substrate, or a transparent resin film can be used.

  Among these, as a forming material of the transparent resin film, for example, polyester such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) can be used. Moreover, as a formation material of a transparent resin film, materials, such as polyethylene, a polypropylene, a cellophane, can be used, for example. In addition, cellulose esters such as cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate propionate (CAP), cellulose acetate phthalate (TAC), and cellulose nitrate, or derivatives thereof can be added to the transparent resin film. It can be used as a forming material.

  Examples of the material for forming the transparent resin film include polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide, and polyether sulfone (PES). , Polyphenylene sulfide, polysulfones, polyether imide, polyether ketone imide, polyamide, fluororesin, nylon, polymethyl methacrylate, acrylic, polyarylate, and the like can be used. Furthermore, for example, cycloolefin-based resins called Arton (registered trademark: manufactured by JSR) or Apel (registered trademark: manufactured by Mitsui Chemicals) can be used as a material for forming a transparent resin film.

  When the transparent substrate 21 is composed of a transparent resin film, a barrier film made of an inorganic material or a barrier made of an organic material is formed on the surface of the transparent resin film in order to suppress, for example, the transmission of water vapor or oxygen into the light emitting panel 10. A film or a hybrid film in which these barrier films are stacked may be provided.

The barrier film is preferably a barrier film having a water vapor permeability (measuring environment: 40 ° C., relative humidity 90% RH) of 0.01 g / (m ² · 24 h) or less. The barrier film has an oxygen permeability (measuring environment: 20 ° C., relative humidity 100% RH) of 10 ⁻³ cm ³ / (m ² · 24 h · atm) or less and a water vapor permeability of 10 ^−3. It is preferable that it is a high-barrier film which becomes g / (m < ² > * 24h) or less. Furthermore, it is particularly preferable that the water vapor permeability of the barrier film is 10 ⁻⁵ g / (m ² · 24 h) or less and the oxygen permeability is 10 ⁻⁵ cm ³ / (m ² · 24 h · atm) or less. preferable. In addition, “water vapor permeability” as used in the present specification is a value measured by a technique based on JIS-K-7129-1992, and “oxygen permeability” conforms to JIS-K-7126-1992. It is a value measured by the method.

  As the barrier film having the above-described characteristics, for example, an inorganic material film such as a silicon oxide film, a silicon dioxide film, or a silicon nitride film can be used. Furthermore, in order to improve the fragility of the barrier film, a hybrid barrier film in which the inorganic material film and the organic material film are stacked may be used as the barrier film. In this case, the order of laminating the inorganic material film and the organic material film is arbitrary, but it is preferable that the both are alternately laminated a plurality of times.

  As a method for forming the barrier film, any method can be used as long as the barrier film can be formed on the transparent substrate 21 (transparent resin film). For example, vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma polymerization method (see JP 2004-68143 A), Techniques such as plasma CVD (Chemical Vapor Deposition), laser CVD, thermal CVD, and coating can be used. In the present embodiment, it is particularly preferable to use an atmospheric pressure plasma polymerization method.

[anode]
The anode 22 is an electrode film that supplies holes to the organic light emitting functional layer 23, and can be formed of a conductive material having a large work function (for example, 4 eV or more) that can exhibit a hole injection function. As such a conductive material, a metal, an alloy, an organic or inorganic conductive compound, and a mixture thereof are used. However, in this embodiment, since the emitted light h is extracted from the anode 22 side, the anode 22 is formed using a light-transmitting conductive material.

Specifically, light of metals such as gold (Au), copper iodide (CuI), indium tin oxide (SnO ₂ -In ₂ O ₃ : ITO), tin oxide (SnO ₂ ), zinc oxide (ZnO), etc. The anode 22 can be formed using a conductive material having transparency. Alternatively, the anode 22 can be formed of an amorphous transparent electrode material such as indium zinc oxide (In ₂ O ₃ —ZnO: for example, IDIXO (registered trademark: manufactured by Idemitsu Kosan Co., Ltd.)).

  The sheet resistance of the anode 22 is several hundred Ω / sq. The following is preferable. Furthermore, the film thickness of the anode 22 is appropriately set according to the forming material, and is usually set in the range of about 10 to 1000 nm, preferably about 10 to 200 nm.

  The anode 22 having the above-described configuration can be formed on the transparent substrate 21 by a technique such as vapor deposition or sputtering. At this time, the anode 22 may be formed in a desired pattern shape using a photolithography technique or the like. In the case where the accuracy of the pattern shape is not required in the anode 22 (when the accuracy is about 100 μm or more), a desired pattern shape is formed when the anode 22 is formed by a technique such as vapor deposition or sputtering. Alternatively, the anode 22 having a desired pattern may be formed on the transparent substrate 21 through the mask.

  Further, when the anode 22 is formed using a conductive material such as an organic conductive compound, a wet film formation method such as a printing method or a coating method can be used.

[Cathode and cathode lead electrode]
The cathode 24 is an electrode film that supplies electrons to the organic light emitting functional layer 23, and is formed of silver (Ag) or a silver alloy containing silver as a main component in this embodiment. More preferably, the cathode 24 is formed of silver or a silver alloy having a silver content of 90 atomic percent or more. More preferably, the cathode 24 is made of silver or a silver alloy having a silver content of 95 atomic percent or more.

  Examples of the metal contained in the silver alloy include magnesium (Mg), palladium (Pd), copper (Cu), gold (Au), platinum (Pt), neodymium (Nd), nickel (Ni), tin ( Sn) or the like can be used. Note that the silver alloy may contain only one type of these metals, or may contain multiple types of metals.

  It is important that the cathode 24 reflects the emitted light h generated in the organic light emitting functional layer 23 toward the light extraction surface 21a without loss. Therefore, from the viewpoint of reflection efficiency, the thickness of the cathode 24 is preferably 60 nm or more, and more preferably 100 nm or more.

  The cathode 24 having the above configuration can be formed by a technique such as vapor deposition or sputtering. When the cathode 24 is made of a silver alloy, the cathode 24 is formed by, for example, a method in which silver and a metal to be contained are filled in different boats and subjected to multi-source deposition, or sputtering using a silver alloy target. Techniques etc. can be adopted. Further, when the cathode 24 is formed in a predetermined pattern, a method similar to the above-described pattern forming method of the anode 22 can be employed.

  Further, since the cathode lead electrode 24 a is formed on the film lamination surface of the transparent substrate 21 like the anode 22, it can be formed of the same material as the anode 22. In particular, it is preferable that the material for forming the cathode lead electrode 24a is the same as that of the anode 22, and in this case, the cathode lead electrode 24a can be formed simultaneously with the anode 22; It becomes simpler.

[Organic light emitting functional layer]
FIG. 2 shows a configuration example of the organic light emitting functional layer 23 in the light emitting panel 10. FIG. 2 is a schematic cross-sectional view in the vicinity of the organic light emitting functional layer 23, and the anode 22 and the cathode 24 are also shown for convenience of explanation.

  In the example shown in FIG. 2, the organic light emitting functional layer 23 includes a light emitting layer 23a, a hole transport layer 23b provided on the anode 22 side of the light emitting layer 23a, and an electron transport provided on the cathode 24 side of the light emitting layer 23a. A layer 23c.

  In the organic light emitting functional layer 23 having such a configuration, holes are injected from the anode 22 into the light emitting layer 23a through the hole transport layer 23b, and electrons are injected from the cathode 24 into the light emitting layer 23a through the electron transport layer 23c. Is done. Then, the injected holes and the injected electrons are recombined in the light emitting layer 23a, so that light emission occurs. The emitted light h generated in the light emitting layer 23a is extracted from the anode 22 to the outside. Below, each layer which comprises the organic light emission functional layer 23 is demonstrated in detail.

(1) Light-Emitting Layer The light-emitting layer 23a is a layer that generates emitted light h by recombination of holes supplied from the anode 22 and electrons supplied from the cathode 24. Such a light emitting layer 23a contains a host material and a guest material having a light emitting property (also referred to as a light emitting dopant compound). In the light emitting layer 23a, the light emission efficiency can be increased by causing the guest material to emit light.

  Moreover, the light emitting layer 23a may be composed of a single layer, or may be a structure in which a plurality of light emitting layers having different emission colors (wavelength regions) are stacked. In the latter case, an intermediate layer may be provided between the emission colors. Note that the intermediate layer may function as a hole blocking layer or an electron blocking layer.

  As the host material, a known host material can be used. In this case, the known host material may be used alone, or a plurality of types of host materials may be used in combination. When a plurality of host materials are used, the movement of charges in the light emitting layer 23a can be adjusted, and the light emission efficiency of the light emitting panel 10 can be increased. In addition, by using a plurality of types of light emitting materials (guest materials) described later, it is possible to mix a plurality of light emissions having different wavelengths, thereby obtaining an arbitrary light emission color.

  As such a host material, a conventionally known low molecular compound may be used, or a high molecular compound having a repeating unit may be used. For example, a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (evaporation polymerizable light emitting host) may be used as the host material.

  Further, as a known host material, it is a substance responsible for transporting holes and electrons (carriers), has a hole transport function and an electron transport function, has a function of preventing the emission of longer wavelengths, and It is preferable to use a compound having a high glass transition point (Tg). In addition, the “glass transition temperature (Tg)” in the present specification is a value obtained by a method based on JIS-K7121, using a DSC (Differential Scanning Calorimetry) method.

  Therefore, as the host material, it is preferable to use a material having a hole transport function and an electron transport function, that is, a carrier transport function as described above. However, generally, since the carrier transport function (carrier mobility) of an organic material depends on the electric field strength, the material having high electric field strength dependency tends to break the balance between injection and transport of holes and electrons. Therefore, as the host material, it is preferable to use a material whose carrier mobility is less dependent on the electric field strength, or a combination of a plurality of materials having the same electric field strength dependency. In this case, the variation of the luminescent color in the light emission panel 10 can be suppressed to the minimum.

  As the host material, for example, a material having a basic skeleton such as a carbazole derivative, a triarylamine derivative, an aromatic borane derivative, a nitrogen-containing heterocyclic compound, a thiophene derivative, a furan derivative, an oligoarylene compound, or a carboline derivative Diazacarbazole derivatives (herein, diazacarbazole derivatives are those in which at least one carbon atom of the hydrocarbon ring constituting the carboline ring of the carboline derivative is substituted with a nitrogen atom) and the like can be used .

  Note that, in a configuration in which a plurality of light emitting layers having different emission colors are provided via an intermediate layer, the intermediate layer also has properties similar to those of the host material. Therefore, by using the material having the above-described physical properties as a material constituting the intermediate layer, variation in emission color in the light-emitting panel can be minimized.

  On the other hand, as the guest material, a phosphorescent material (phosphorescent dopant) and a fluorescent material (fluorescent dopant) can be used, and it is particularly preferable to use a phosphorescent material. A plurality of guest materials may be mixed, or a phosphorescent material and a fluorescent material may be mixed in the same light emitting layer 23a.

  The phosphorescent material is also referred to as a phosphorescent compound or a phosphorescent compound, and can be appropriately selected from known materials generally used for the light emitting layer of the organic EL element. Among them, it is preferable to use a complex compound containing a group 8-10 metal in the periodic table of elements as the phosphorescent material, and further, an iridium compound, an osmium compound, a platinum compound (platinum complex compound) or a rare earth element. It is preferable to use a complex. In particular, it is preferable to use an iridium compound (iridium complex) as the phosphorescent material.

  Examples of fluorescent light-emitting materials include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, pyrylium dyes, and perylene dyes. Examples of the material include dyes, stilbene dyes, polythiophene dyes, and rare earth complex phosphors.

  Two or more kinds of guest materials having light emission properties as described above may be contained in one light emitting layer 23a, and the concentration ratio of guest materials in the light emitting layer 23a changes in the thickness direction of the light emitting layer 23a. You may do it.

  As described above, the light emitting layer 23a and the intermediate layer formed using the host material and the guest material include, for example, a vapor deposition method, a spin coating method, a casting method, an LB (Langmuir Blodgett) method, an ink jet method, a printing method, and the like. It can form by the well-known thin film formation method.

(2) Hole transport layer, electron transport layer The hole transport layer 23b and the electron transport layer 23c provided between the anode 22 and the light emitting layer 23a, and between the cathode 24 and the light emitting layer 23a, respectively, are the light emitting layer 23a. In consideration of the combination, it can be formed of a conventionally known material.

(3) Other configuration layers In the present embodiment, the layer configuration of the organic light emitting functional layer 23 is not limited to the configuration example illustrated in FIG. 2, and any layer configuration generally known from the past is applied. Can do. The organic light emitting functional layer 23 can be arbitrarily configured as long as it has at least the light emitting layer 23a.

  For example, a hole injection layer may be provided between the anode 22 and the hole transport layer 23b, and an electron injection layer may be provided between the cathode 24 and the electron transport layer 23c. Furthermore, you may provide a hole-blocking layer, an electron blocking layer, etc. suitably as needed. Various injection layers are provided for lowering the driving voltage and improving the luminance of light emission. Examples of the material for forming them include “Organic EL elements and their forefront of industrialization” (published by NTS Corporation on November 30, 1998). The materials described in detail in Chapter 2, “Electrode Materials” (pages 123 to 166) of the 2nd volume of “)” can be used as appropriate.

  Also, the structure of each electrode film (anode 22 and cathode 24) may be a multilayer structure as required. 1A to 1C show an example in which the anode 22, the organic light emitting functional layer 23, and the cathode 24 are formed in this order on the transparent substrate 21, but the stacking order of these layers may be reversed. .

(4) Example of Manufacturing Method of Light-Emitting Panel Here, an example of a manufacturing method of the element body (transparent substrate 21, organic light-emitting functional layer 23, and various electrode films) of the light-emitting panel 10 of the present embodiment shown in FIGS. 1A to 1C. Will be explained.

  First, the anode 22 is formed by laminating a thin film made of an anode material on the film lamination surface of the transparent substrate 21 by a technique such as vapor deposition or sputtering. At this time, the film thickness of the anode 22 is set to 1 μm or less, preferably about 10 nm to 200 nm. At this time, in this embodiment, the cathode lead electrode 24 a is formed in a region different from the anode 22 on the film lamination surface of the transparent substrate 21. The film configuration of the cathode lead electrode 24 a is preferably the same as that of the anode 22, and the cathode lead electrode 24 a is preferably formed simultaneously with the anode 22.

  Next, the organic light emitting functional layer 23 is formed on the anode 22. Specifically, the organic light-emitting functional layer 23 is formed on the anode 22 by forming the organic compound thin films of the hole transport layer 23b, the light-emitting layer 23a, and the electron transport layer 23c in this order.

  In addition, as a film-forming method of each organic compound thin film, a vapor deposition method, a spin coat method, a casting method, an LB method, an inkjet method, a printing method, etc. can be used as mentioned above. Among these methods, it is particularly preferable to use a vapor deposition method, a spin coating method, an ink jet method, or a printing method. When each organic compound thin film is formed by these methods, for example, there are obtained advantages such that a homogeneous film is easily obtained and pinholes are hardly generated. In the step of forming the organic light emitting functional layer 23, all the organic compound thin films may be formed by the same film forming method, or the film forming method may be changed for each organic compound thin film.

Moreover, when employ | adopting a vapor deposition method as a film-forming method of an organic compound thin film, the vapor deposition conditions are suitably set according to conditions, such as the kind of organic compound to be used. Specifically, the boat heating temperature is about 50 ° C. to 450 ° C., the degree of vacuum is about 10 ⁻⁶ Pa to 10 ⁻² Pa, the deposition rate is about 0.01 nm / second to 50 nm / second, and the substrate temperature is about −50. It is preferable to set vapor deposition conditions by appropriately selecting from a range of from about 0.1 to 5 ° C. and a film thickness of about 0.1 nm to 5 μm (preferably 5 nm to 200 nm).

  After forming the organic light emitting functional layer 23 as described above, a thin film made of silver or a silver alloy containing silver as a main component is laminated on the organic light emitting functional layer 23 by a method such as vapor deposition or sputtering. Then, the cathode 24 is formed. At this time, the thickness of the cathode 24 is set to 1 μm or less, preferably about 60 nm to 300 nm. At this time, the cathode 24 is formed in a pattern shape so as to be electrically connected to the cathode lead electrode 24 a while maintaining an insulating state with respect to the anode 22 through the organic light emitting functional layer 23.

  In the present embodiment, the organic light emitting functional layer 23 and various electrode films are formed on the transparent substrate 21 as described above. In the above-described manufacturing method, it is preferable to form the anode 22, the organic light emitting functional layer 23, and the cathode 24 consistently by a single evacuation in the same film forming apparatus, but the present invention is not limited to this. . The organic light emitting functional layer 23 and various electrode films may be formed by taking out the substrate member from the film forming apparatus for each film forming process and applying different film forming methods. In that case, it is necessary to consider that the work is performed in a dry inert gas atmosphere.

[Encapsulant]
The sealing material 25 is a member that covers the element main body (the transparent substrate 21, the organic light emitting functional layer 23, and various electrode films) of the light emitting panel 10. In the present embodiment, the element body is sealed with the sealing material 25 in a state where the lead electrode portions of the anode 22 and the cathode 24 are exposed.

  The sealing material 25 can be comprised with a plate-shaped (film-shaped) sealing member. In this case, as the sealing material 25, a substantially plate-like base material in which a concave portion is formed on one surface, that is, a concave plate-like sealing member may be used, or a plate-like base material having a flat surface, that is, A flat sealing member may be used. The plate-like (concave plate or flat plate) sealing material 25 is disposed at a position facing the transparent substrate 21 with the element main body interposed therebetween.

  As the sealing material 25, for example, a transparent substrate such as a glass plate, a polymer plate, or a metal plate can be used. As the glass plate, for example, a substrate formed of a material such as alkali-free glass, soda lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, or quartz is used. be able to. Moreover, as a polymer board, the board | substrate formed with materials, such as a polycarbonate, an acryl, a polyethylene terephthalate, a polyether sulfide, a polysulfone, can be used, for example. Furthermore, the metal plate is formed of, for example, one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium, and tantalum. A substrate can be used.

From the viewpoint of reducing the thickness of the light emitting panel 10, it is preferable to use a polymer plate, a metal plate, or the like as the sealing material 25. The polymer plate is a substrate having an oxygen permeability of 10 ⁻³ cm ³ / (m ² · 24 h · atm) or less and a water vapor permeability of 10 ⁻³ g / (m ² · 24 h) or less. Is preferably used. Furthermore, the water vapor permeability of the polymer plate is 10 ⁻⁵ g / (m ² · 24 h) or less, or the oxygen permeability of the polymer plate is 10 ⁻⁵ cm ³ / (m ² · 24 h · atm) or less. Preferably there is.

  Further, when the sealing material 25 is formed of a concave plate-shaped sealing member (when can sealing), the concave portion is formed by a process such as sand blasting or chemical etching. In addition, when comprising the sealing material 25 with a concave-plate-shaped sealing member, between the sealing material 25 and the element main-body part (The transparent substrate 21, the organic light emission functional layer 23, and various electrode films) of the light emission panel 10. The void is preferably filled with an inert gas such as nitrogen or argon, or an inert liquid such as fluorinated hydrocarbon or silicon oil. Moreover, the space | gap between the sealing material 25 and the element main-body part of the light emission panel 10 may be made into a vacuum state, and a hygroscopic compound may be enclosed with a space | gap.

  Examples of the hygroscopic compound include metal oxides (for example, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide, etc.), sulfates (for example, sodium sulfate, calcium sulfate, magnesium sulfate, Cobalt sulfate, etc.), metal halides (eg, calcium chloride, magnesium chloride, cesium fluoride, tantalum fluoride, cerium bromide, magnesium bromide, barium iodide, magnesium iodide, etc.), perchloric acids (eg, perchloric acid) Barium chlorate, magnesium perchlorate, etc.) can be used. Among these compounds, when a sulfate, a metal halide, or perchloric acid is used as the hygroscopic compound, it is preferable to use an anhydrous salt.

  Moreover, when using a flat sealing member as the sealing material 25, as an adhesive used for adhesion | attachment with the sealing material 25 and the transparent substrate 21, the reactive vinyl group of an acrylic acid type oligomer or a methacrylic acid type oligomer is used. Examples thereof include a photo-curing type or thermosetting type adhesive, and a moisture-curing type adhesive such as 2-cyanoacrylate. Moreover, you may use the thermosetting type or chemical curing type (two-component mixing) adhesives, such as an epoxy type, as an adhesive agent. Furthermore, hot-melt type polyamide, polyester, and polyolefin may be used as an adhesive. In addition, a cationic curing type ultraviolet curing epoxy resin adhesive may be used as the adhesive.

  Among the various adhesives, it is preferable to use an adhesive that can be adhesively cured in a temperature range from room temperature to 80 ° C. in order to prevent deterioration of the light-emitting panel 10 due to heat treatment. A desiccant may be dispersed in the various adhesives. In addition, application | coating of the adhesive agent to a sealing part may be performed using a dispenser, and may be performed by screen printing.

  Further, a sealing film may be used as the sealing material 25. When the film sealing method is used, the sealing film is formed on the transparent substrate 21 so that the organic light emitting functional layer 23 is completely covered with the sealing film and the lead electrode portions of the anode 22 and the cathode 24 are exposed. Provide on top.

  Such a sealing film can be composed of a film made of an inorganic material or an organic material. Note that the sealing film is formed of a material having a function of suppressing intrusion of a substance such as moisture or oxygen, which causes deterioration of the organic light emitting functional layer 23. Examples of the material having such properties include inorganic materials such as silicon oxide, silicon dioxide, and silicon nitride. Furthermore, in order to improve the brittleness of the sealing film, the structure of the sealing film may be a multilayer structure in which a film made of these inorganic materials and a film made of an organic material are laminated.

  As a method for forming the sealing film described above, any method can be used. For example, a vacuum deposition method, a sputtering method, a reactive sputtering method, a molecular beam epitaxy method, a cluster ion beam method, an ion plating method, Techniques such as plasma polymerization, atmospheric pressure plasma polymerization, plasma CVD, laser CVD, thermal CVD, and coating can be used.

[Protective film, protective plate]
Although not shown in FIGS. 1B and 2, a protective film or a protective plate may be provided on the sealing material 25. When the protective film or the protective plate is provided, the light emitting panel 10 can be mechanically protected, and the mechanical strength of the light emitting panel 10 and the planar light emitter 1 can be improved. In particular, when the sealing material 25 is a sealing film, mechanical protection for the light-emitting panel 10 is not sufficient, and thus it is preferable to provide such a protective film or a protective plate.

  As the protective film or protective plate having the above configuration, for example, a glass plate, a polymer plate, a polymer film, a metal plate, a metal film, or a film such as a polymer material film or a metal material film can be applied. Among these members, it is preferable to use a polymer film as a protective film or a protective plate, particularly from the viewpoint of weight reduction and thinning.

[Effects]
As described above, in the planar light-emitting body 1 of the present embodiment, the light extraction surfaces 21a of the plurality of light-emitting panels 10 arranged in a two-dimensional manner include non-joints between the plurality of light-emitting panels 10 adjacent to each other. The light extraction member 13 is provided over the entire surface of the light emitting region SB.

  In this case, of the emitted light h generated in each light emitting panel 10, a part of the emitted light h propagating in the transparent substrate 21 without being emitted to the outside due to total reflection on the light extraction surface 21a of the transparent substrate 21, As shown in FIG. 1B, the light reaches the non-light emitting region SB where the light extraction member 13 is formed while repeating internal reflection in the transparent substrate 21. A part of the emitted light h is extracted from the light extraction member 13. Therefore, in the present embodiment, a part of the emitted light h is extracted to the outside through the light extraction member 13 also from the non-emission region SB between the adjacent emission regions SA. The amount of light h increases.

  Moreover, in the planar light-emitting body 1 of this embodiment, the cathode 24 of each light emission panel 10 is formed with silver or the silver alloy which has silver as a main component. That is, the cathode 24 is composed of a highly reflective electrode film.

  That is, in this embodiment, the light extraction member 13 is provided in a non-light emitting region SB (non-light emitting region SB between light emitting regions SA adjacent to each other) including a joint portion between a plurality of light emitting panels 10 adjacent to each other, and each The cathode 24 of the light emitting panel 10 is formed of silver or a silver alloy containing silver as a main component. By adopting such a configuration, it is possible to improve the uniformity of luminance within the light extraction surface 21a. This effect will be described in detail in an evaluation test described later.

  Further, the planar light emitter 1 of the present embodiment has a configuration in which a plurality of light emitting panels 10 are tiled. Therefore, a quality inspection can be performed for each light emitting panel 10 and rejected light emitting panels 10 can be excluded as defective products. That is, in the configuration of the planar light emitter 1 of the present embodiment, the planar light emitter 1 can be produced using only the non-defective light emitting panel 10. Therefore, it is possible to improve the yield when manufacturing the planar light-emitting body 1 having a large area.

<2. Second Embodiment>
[Configuration of planar light emitter]
3A to 3C are schematic configuration diagrams of a planar light emitter according to the second embodiment of the present invention. FIG. 3A is a schematic plan view seen from the light extraction surface (light emitting surface) side of the planar light emitter according to the second embodiment. 3B is a cross-sectional view taken along line cc in FIG. 3A (cross-sectional view taken along the X direction in the figure), and FIG. 3C is a cross-sectional view taken along line dd in FIG. 3A (taken along the Y direction in the figure). FIG.

  In the present embodiment, as in the first embodiment, a planar light emitter in which four light emitting panels 30 are arranged (tiled) in a form of 2 rows × 2 columns for the sake of simplicity. 2 will be described as an example. Furthermore, in the planar light-emitting body 2 of this embodiment shown to FIG. 3A-3C, the same code | symbol is attached | subjected and shown to the structure similar to the planar light-emitting body 1 of 1st Embodiment shown to FIG. .

  The planar light-emitting body 2 includes an organic EL element group including four light-emitting panels 30, a support substrate 11, an adhesive member 12 for fixing each light-emitting panel 30 on the support substrate 11, and four light-emitting panels. The light extraction member 13 provided in the joint part between 30 is provided. In the planar light emitter 2 of this embodiment, the emitted light h generated by the light emitting panel 30 is extracted from the light extraction surface 21 a of the transparent substrate 21 of the light emitting panel 30.

  As is clear from a comparison between FIGS. 3A to 3C and FIGS. 1A to 1C, in the planar light emitter 2 of the present embodiment, the configuration other than the light emitting panel 30 is the same as that of the planar light emitter 1 of the first embodiment. This is the same as the corresponding configuration. Therefore, only the configuration of the light emitting panel 30 will be described here.

[Configuration of light-emitting panel]
The light emitting panel 30 includes a transparent substrate 21 (transparent substrate), an anode 22 (first electrode), an organic light emitting functional layer 23 (organic compound layer), a cathode 24 (second electrode), and a cathode lead electrode 24a. The sealing material 25 and the four metal films 31 are provided.

  As is clear from a comparison between FIGS. 3A to 3C and FIGS. 1A to 1C, the light emitting panel 30 of the present embodiment has a configuration in which four metal films 31 are further added to the light emitting panel 10 of the first embodiment. It is. Therefore, only the configuration of the metal film 31 will be described here. Also in this embodiment, the cathode 24 of the light emitting panel 30 is formed of silver or a silver alloy containing silver as a main component.

  The four metal films 31 are formed on the surface (film laminated surface) opposite to the light extraction surface 21a of the transparent substrate 21, and are provided in the vicinity of the four outer peripheral portions of the light emitting panel 30 having a square surface shape. It is done. At this time, the four metal films 31 are formed in the non-light emitting region SB of the light emitting panel 30.

  In the present embodiment, as shown in FIG. 3B, when the extraction electrodes (22a, 24a) of the respective electrode films are formed in the non-light emitting region SB that forms the metal film 31, on the extraction electrode A metal film 31 is formed. On the other hand, as shown in FIG. 3C, when the extraction electrode of each electrode film is not formed in the non-light-emitting region SB forming the metal film 31, the metal film 31 is formed on the film lamination surface of the transparent substrate 21. To do.

  The metal film 31 is made of silver or a silver alloy containing silver as a main component. More preferably, the metal film 31 is formed of silver or a silver alloy having a silver content of 90 atomic percent or more. More preferably, the metal film 31 is formed of silver or a silver alloy having a silver content of 95 atomic percent or more.

  Examples of the metal contained in the silver alloy include magnesium (Mg), palladium (Pd), copper (Cu), gold (Au), platinum (Pt), neodymium (Nd), nickel (Ni), tin ( Sn) or the like can be used. Note that the silver alloy may contain only one type of these metals, or may contain multiple types of metals.

  The metal film 31 is preferably formed of the same material as the cathode 24. In this case, the metal film 31 and the cathode 24 can be formed simultaneously in the same process, and the process can be simplified.

  The pattern shape of the metal film 31 may be any pattern shape as long as the anode 22 and the cathode 24 are not short-circuited. In consideration of the action (effect) of the metal film 31 to be described later, it is preferable that the ratio of the metal film 31 to the non-light-emitting region SB is large. It is preferable to provide the film 31.

  As a method for forming the metal film 31 having the above-described configuration, for example, a method such as vapor deposition or sputtering can be used in the same manner as the method for forming the cathode 24. Further, when the metal film 31 is formed in a predetermined pattern shape, a technique similar to the pattern forming technique of the cathode 24 described above can be employed.

[Function of metal film]
In the planar light-emitting body 2 of the present embodiment having the above-described configuration, part of the emitted light h generated from each light-emitting panel 30 is emitted from the transparent substrate 21 as in the first embodiment. It propagates through the transparent substrate 21 without being emitted to the outside due to total reflection on the extraction surface 21a. Then, as shown in FIG. 3B, a part of the emitted light h totally reflected by the light extraction surface 21a is repeatedly reflected on the non-light emitting region SB where the light extraction member 13 is formed while repeating internal reflection in the transparent substrate 21. To reach.

  At this time, part of the emitted light h that has reached the non-light emitting region SB is extracted from the light extraction member 13, and the remaining emitted light h is transmitted (leaks) to the sealing material 25 side. However, in the present embodiment, a metal film 31 having a high reflectance formed of silver or a silver alloy mainly containing silver is disposed on the transparent substrate 21 in the non-light emitting region SB. As shown in FIG. 3B, the emitted light h leaked from the transparent substrate 21 toward the sealing material 25 is reflected by the metal film 31. Then, the light reflected by the metal film 31 returns to the light extraction member 13 side and is extracted from the light extraction member 13. Therefore, in the present embodiment, the amount of emitted light h extracted outside through the light extraction member 13 can be further increased.

[Effects]
In the planar light-emitting body 2 of the present embodiment, as described above, the non-light-emitting panel 10 is not disposed on the surface opposite to the light extraction surface 21a (the sealing material 25 side) of the transparent substrate 21 of each light-emitting panel 10. A metal film 31 is provided in the light emitting region SB. Thereby, in the non-light emitting area SB, the reflectance of the emitted light h at the interface opposite to the light extraction surface 21a of the transparent substrate 21 is increased and extracted from the non-light emitting area SB through the light extraction member 13 to the outside. The amount of the emitted light h can be further increased.

  Further, in the planar light emitter 2 of the present embodiment, as in the first embodiment, a non-light emitting region including a joint portion between a plurality of light emitting panels 30 adjacent to each other on the light extraction surface 21a of the transparent substrate 21. The light extraction member 13 is provided on the SB, and the cathode 24 of each light-emitting panel 30 is formed of silver or a silver alloy containing silver as a main component. Therefore, in the present embodiment, the uniformity of luminance can be improved in the surface of the light extraction surface 21a, as in the first embodiment.

  Furthermore, the planar light-emitting body 2 of the present embodiment has a configuration in which a plurality of light-emitting panels 30 are tiled, as in the first embodiment. Therefore, also in this embodiment, as in the first embodiment, it is possible to improve the yield when manufacturing the large-area planar light emitter 2.

<3. Third Embodiment>
[Configuration of planar light emitter]
FIG. 4 is a schematic cross-sectional configuration diagram of a planar light emitter according to the third embodiment. In addition, in the planar light-emitting body 3 of this embodiment shown in FIG. 4, the same code | symbol is attached | subjected and shown to the structure similar to the planar light-emitting body 1 of 1st Embodiment shown to FIG. 1B. Although not shown, in the present embodiment as well, in the same manner as in the first embodiment, the four light emitting panels 10 are arranged (tiled) in a form of 2 rows × 2 columns to form the planar light emitter 3. Is configured.

  The planar light-emitting body 3 includes an organic EL element group including four light-emitting panels 10, a support substrate 11, an adhesive member 12 for fixing each light-emitting panel 10 on the support substrate 11, and four light-emitting panels. The light extraction member 13 and the transparent substrate member 40 provided in the joint part between 10 are provided. In the planar light emitter 3 of the present embodiment, the emitted light h generated in each light emitting panel 10 is extracted from the light extraction surface 21 a of the transparent substrate 21 of the light emitting panel 10. Also in this embodiment, the cathode 24 of each light emitting panel 10 is formed of silver or a silver alloy containing silver as a main component.

  As is clear from a comparison between FIG. 4 and FIG. 1B, in the planar light emitter 3 of the present embodiment, between the transparent substrate 21 and the light extraction member 13 in the planar light emitter 1 of the first embodiment. In addition, a transparent substrate member 40 is further provided. Therefore, only the transparent substrate member 40 will be described here.

[Transparent substrate material]
The transparent substrate member 40 is a member provided to partially increase the thickness of the transparent substrate 21. The transparent substrate member 40 is formed on the light extraction surface 21a of the transparent substrate 21 in the non-light emitting region SB including the joint portion between the four light emitting panels 10 adjacent to each other and not overlapping the light emitting region SA. Is done. The light extraction member 13 is provided on the transparent substrate member 40.

  In the present embodiment, the transparent substrate member 40 may be provided so as to cover 50% or more of the non-light emitting area SB between the adjacent light emitting areas SA, or the entire non-light emitting area SB (100% area). ) May be provided so as to cover (example of FIG. 4). Further, the transparent substrate member 40 may be provided in the non-light emitting region SB located at the outer peripheral edge of the planar light emitter 3. Further, in the present embodiment, the transparent substrate member 40 may be provided for each light-emitting panel 10 similarly to the light extraction member 13.

  The transparent substrate member 40 is preferably formed of a material having a light transmittance equal to or higher than the light transmittance of the transparent substrate 21. The refractive index n2 of the transparent substrate member 40 preferably satisfies the relationship n2 ≧ n1-0.1 with respect to the refractive index n1 of the transparent substrate 21.

  Since the transparent substrate member 40 is for partially increasing the thickness of the transparent substrate 21 in the non-light emitting region SB, it is preferable to increase the film thickness t. However, as the thickness of the transparent substrate member 40 increases, the thickness of the planar light emitter 3 also increases. Therefore, the film thickness t of the transparent substrate member 40 is appropriately set within a range that does not hinder the thinning that is a feature of the planar light emitter using the organic EL element.

  In addition, as a forming material of the transparent substrate member 40, any material can be used as long as it satisfies the light transmittance and the refractive index n2. For example, known materials such as glass, PET (polyethylene terephthalate), or PEN (polyethylene naphthalate) can be used. The material for forming the transparent substrate member 40 is appropriately selected from these known materials depending on the combination with the transparent substrate 21.

  The transparent substrate member 40 is attached to the transparent substrate 21 with an adhesive (not shown). The adhesive used here preferably has a higher light transmittance with respect to visible light, for example, preferably has a light transmittance of 90% or more. The refractive index of the adhesive is preferably about the same as the refractive index of the transparent substrate 21, and the refractive index difference between the two is preferably within 0.1.

[Effects]
In the planar light emitter 3 of the present embodiment, as described above, the transparent substrate member 40 is provided in the non-light emitting region SB including the joint portion between the plurality of adjacent light emitting panels 10 on the light extraction surface 21a of the transparent substrate 21. The thickness of the transparent substrate 21 in the non-light emitting area SB is substantially increased. In this case, in the non-light emitting region SB, the number of reflections of the emitted light h at the interface of the transparent substrate 21 is reduced, so that the inactivation of the emitted light h due to repeated internal reflection in the transparent substrate 21 can be suppressed. Therefore, in the present embodiment, it is possible to further increase the amount of the emitted light h extracted outside from the non-emitting region SB via the light extraction member 13.

  Further, in the planar light emitter 3 of the present embodiment, similarly to the first embodiment, the light extraction member 13 is provided in the non-light emitting region SB including the joint portion between the plurality of light emitting panels 10 adjacent to each other, and The cathode 24 of each light emitting panel 10 is formed of silver or a silver alloy containing silver as a main component. Therefore, in the present embodiment, the uniformity of luminance can be improved in the surface of the light extraction surface 21a, as in the first embodiment.

  Furthermore, the planar light-emitting body 3 of the present embodiment has a configuration in which a plurality of light-emitting panels 10 are tiled, as in the first embodiment. Therefore, also in the present embodiment, as in the first embodiment, it is possible to improve the yield when manufacturing the large-area planar light-emitting body 3.

  In addition, in this embodiment, although the structural example which applies the transparent substrate member 40 to the planar light-emitting body (FIG. 1A-1C) of the said 1st Embodiment was demonstrated, this invention is not limited to this, The said You may apply the transparent substrate member 40 to the planar light-emitting body (FIG. 3A-3C) of 2nd Embodiment.

<4. Various modifications and application examples>
Below, the various modifications and application examples of the planar light-emitting body of the said various embodiment are demonstrated.

[Modification 1]
Although the planar light-emitting body of the said various embodiment demonstrated the structural example which supports four light emission panels using a large sized support substrate, this invention is not limited to this. For example, you may join the side walls of the transparent substrate which opposes between the several light emission panels adjacent to each other with the adhesive agent (modification 1). In this case, the adhesive can also act as a support member for supporting the four light emitting panels, and a large support substrate does not have to be provided separately as in the above-described various embodiments.

  In this example, the adhesive only needs to be filled at least between a plurality of adjacent transparent substrates. Further, the adhesive may be filled not only between the transparent substrates of the plurality of adjacent light emitting panels but also to the region between the sealing materials.

  In addition, as an adhesive agent which can be used in this example, the same material as the adhesive member of the said various embodiment can be used.

  In this example, the adhesive preferably has optical transparency, and its refractive index n3 is preferably about the same as the refractive index n1 of the transparent substrate. Specifically, regarding the light transmittance of the adhesive, it is preferable that the adhesive has a high light transmittance with respect to visible light. For example, the adhesive has a light transmittance of 90% or more with respect to visible light. It is preferable to have. Regarding the refractive index n3 of the adhesive, for example, the difference | n3-n1 | between the refractive index n3 of the adhesive and the refractive index n1 of the transparent substrate may be at least 0.2 or less. n1 | is preferably 0.1 or less.

  As described above, the refractive index n3 of the adhesive is set relative to the refractive index n1 of the transparent substrate, and is not limited to the absolute value of the refractive index n3. For example, when the refractive index n1 of the transparent substrate is 1.5, the refractive index n3 of the adhesive is set to about 1.3 to 1.7, more preferably 1.4 to 1.6. The The adhesive material having such physical properties is selected from the above-described adhesive member forming materials in consideration of the refractive index n1 of the transparent substrate.

  As an adhesive forming method, any method can be used as long as it can supply an uncured adhesive between transparent substrates of a plurality of adjacent light emitting panels. For example, a technique such as a gravure coater, a micro gravure coater, a comma coater, a bar coater, spray coating, or an ink jet method can be used as an adhesive forming method.

  Moreover, the method suitable for every adhesive agent is applied for the hardening method of an uncured adhesive agent. For example, when using a photo-curing adhesive, the adhesive is cured by irradiating light with the light emitting area SA covered with a mask in order to prevent deterioration of the organic light emitting functional layer due to light irradiation. When a thermosetting adhesive is used, the adhesive is cured by low-temperature heating that can prevent deterioration of the organic light emitting functional layer due to heating.

  Furthermore, you may add another material to the curable adhesive mentioned above in the range which does not impair adhesiveness. In this case, as a material added to the adhesive, an inorganic material such as glass or silica may be dispersed and used. Moreover, you may add resin, an adhesive, or another adhesive agent.

  As the resin to be added to the adhesive, a transparent resin such as PET (polyethylene terephthalate), TAC (triacetyl cellulose), PC (polycarbonate), PMMA (polymethyl methacrylate) or the like is used. Adhesives include urethane-based, epoxy-based, aqueous polymer-isocyanate-based, acrylic-based adhesives, anaerobic adhesives such as polyether methacrylate-type, ester-based methacrylate-type, and oxidized-type polyether methacrylate, or urethane. Curable adhesives such as epoxy-based, epoxy-based, aqueous polymer-isocyanate-based, and acrylic-based adhesives are used. Furthermore, various UV curable resins, thermosetting resins, and the like can be used as the additive resin. Further, a light scattering or light reflective material may be added (dispersed) to the adhesive.

[Modification 2]
In the planar light emitters of the second and third embodiments, the configuration example in which the light extraction amount from the non-light emitting region SB including the joint portion between the plurality of light emitting panels adjacent to each other is increased is shown. Is not limited to this. In order to further increase the amount of light extracted from the non-light emitting region SB, for example, a low refractive index member may be provided in the non-light emitting region SB (see, for example, Japanese Patent Application Laid-Open No. 2001-202827). In this case, a low refractive index member having a refractive index lower than the refractive index (n1) of the transparent substrate is provided between the light extraction member and the transparent substrate.

  The low refractive index member can be formed of a sheet-like, film-like, plate-like, or flat film-like member. The film thickness of the low refractive index member is preferably larger than the wavelength of light in the medium of the low refractive index member, and is preferably set to a value that is 10% or more larger than the wavelength of the light, for example. This is because when the film thickness of the low refractive index member is about the wavelength of light in the medium, the evanescent wave (electromagnetic wave) that has penetrated into the low refractive index member oozes out from the low refractive index member and enters the transparent substrate. This is because the effect of entering the low refractive index member is reduced.

  In addition, examples of the material for forming the low refractive index member include airgel, porous silica, magnesium fluoride, and a fluorine-based polymer. Since the refractive index of the transparent substrate is generally about 1.5 to 1.7, the refractive index of the low refractive index member is preferably about 1.5 or less. Note that the lower the refractive index of the low refractive index member, the higher the light extraction efficiency to the outside. Therefore, the refractive index of the low refractive index member is preferably 1.35 or less.

  By using the low refractive index member having the above configuration, it is possible to further increase the extraction amount of the emitted light h from the non-light emitting region SB.

[Modification 3]
Further, in order to further increase the light extraction amount from the non-light emitting region SB including the joint portions between the plurality of light emitting panels adjacent to each other, for example, a diffraction grating may be provided in the non-light emitting region SB (see, for example, 11-283751).

  In this case, the diffraction grating can be provided between the light extraction member and the transparent substrate. Further, when the above-described various optical members (such as a transparent substrate member and a low refractive index member) are provided between the light extraction member and the transparent substrate, between the light extraction member and the optical member, between the transparent substrate and the optical member, Alternatively, a diffraction grating can be provided between the optical members. In this example, it is particularly preferable to provide the diffraction grating on the light extraction surface (interface) of the transparent substrate.

  The diffraction grating used in this example is a diffraction grating having a configuration in which an array of concave and convex patterns such as a square lattice shape, a triangular lattice shape, and a honeycomb lattice shape is two-dimensionally repeated, and has a two-dimensional periodic refractive index. A diffraction grating is desirable. This is because the emitted light h generated in the light-emitting panel is randomly emitted in all directions, so that a general one-dimensional diffraction grating having a periodic refractive index distribution only in a predetermined direction propagates in the predetermined direction. Since only light is diffracted, the light extraction efficiency is not so improved. However, by making the refractive index distribution of the diffraction grating a two-dimensional periodic distribution, light propagating in all directions can be diffracted by the diffraction grating, and the light extraction efficiency can be improved.

  The period of the diffraction grating is preferably set to a length of about 1/2 to 3 times the wavelength of light in the medium.

  By using the diffraction grating having the above-described configuration, the traveling direction of light that is not emitted to the outside due to total reflection at the interface of the transparent substrate among the emitted light h generated in the light-emitting panel is refracted by Bragg diffraction in the diffraction grating. Changes in different specific directions. In this case, light that is not emitted to the outside due to total reflection at the interface of the transparent substrate can be made incident on the light extraction member and extracted to the outside. Therefore, also in the configuration of this example, it is possible to further increase the extraction amount of the emitted light h from the non-light emitting region SB.

[Application example]
The planar light emitters of the various embodiments and various modifications described above can be used as a display device, a display, and various light emission sources.

  Examples of light-emitting light sources include, for example, home lighting, interior lighting, clock and liquid crystal backlights, billboard advertisements, traffic lights, light sources of optical storage media, light sources of electrophotographic copying machines, light sources of optical communication processors, light Examples include a light source of a sensor.

  In addition, the use of the planar light emitters of the above-described various embodiments and various modifications is not limited to the above-described use, and in particular, as a backlight of a liquid crystal display device that combines a light-emitting light source and a color filter, and an illumination light source. Suitable for use. In addition, when the planar light emitters of the various embodiments and modifications described above are used as a backlight of a liquid crystal display device in which a light emission source and a color filter are combined, in order to further increase the luminance, in combination with a light collecting sheet It is preferable to use it.

<5. Various Examples and Evaluation Results>
Next, configurations of samples of various examples of the planar light-emitting body of the present invention actually manufactured, evaluation tests performed on the samples of the planar light-emitting bodies manufactured in each example, and results thereof will be described. .

[Configuration and manufacturing method of light-emitting panel]
First, the structure and manufacturing method of the light emitting panel used in the planar light emitters of various examples described below will be described. In FIG. 5, the schematic structure cross section of the light emission panel 100 used with the planar light-emitting body of various Examples is shown.

  The light emitting panel 100 includes a transparent substrate 101, an anode 102, an organic light emitting functional layer 103, a cathode 104, and a sealing material 105. The anode 102, the organic light emitting functional layer 103, the cathode 104, and the sealing material 105 are formed in this order on the surface of the transparent substrate 101 opposite to the light extraction surface 101a. As shown in FIG. 5, the sealing material 105 is provided so as to cover the anode 102, the organic light emitting functional layer 103, and the cathode 104. However, at this time, the sealing material 105 is provided so that the lead electrode portions of the anode 102 and the cathode 104 are exposed.

  The organic light emitting functional layer 103 includes a hole injection layer 131, a hole transport layer 132, a blue light emitting layer 133, an intermediate layer 134, a green light emitting layer 135, an intermediate layer 136, and a red light emitting layer 137. , A hole blocking layer 138, an electron transport layer 139, and an electron injection layer 140. In this example, the positive hole injection layer 131, the positive hole transport layer 132, the blue light emitting layer 133, the intermediate layer 134, the green light emitting layer 135, the intermediate layer 136, the red light emitting layer 137, and the hole blocking layer are formed on the anode 102. 138, the electron transport layer 139, and the electron injection layer 140 are laminated in this order. That is, in this example, the light emitting layer is composed of red, green and blue light emitting layers and an intermediate layer provided between adjacent light emitting layers.

  Next, the structure (formation material, film thickness, etc.) of each layer will be described while describing a method for manufacturing the light-emitting panel 100 illustrated in FIG.

  First, a transparent glass substrate having a refractive index n1 = 1.51, a thickness of 0.7 mm, and an area of 50 mm × 50 mm was prepared as the transparent substrate 101. Next, an ITO (transparent conductive material) film having a thickness of 150 nm was formed in a predetermined pattern on one surface of the transparent substrate 101 to form the anode 102. At this time, in this example, as shown in FIG. 5, the cathode lead electrode 104a is formed of an ITO film in a region different from the anode 102 on one surface of the transparent substrate 101. Next, the transparent substrate 101 on which the anode 102 was formed was ultrasonically cleaned with isopropyl alcohol. Thereafter, the cleaned transparent substrate 101 was dried with dry nitrogen gas, and further, UV ozone cleaning was performed on the dried transparent substrate 101 for 5 minutes.

  Next, the transparent substrate 101 on which the anode 102 was formed was mounted on a substrate holder of a vacuum vapor deposition apparatus, and a vapor deposition mask was disposed on the transparent substrate 101 on the surface where the anode 102 was formed. In addition, the respective crucibles for vapor deposition in the vacuum vapor deposition apparatus were filled with the materials constituting the organic light emitting functional layer 103 and the cathode 104 in the optimum amounts for forming the respective layers. In addition, what was produced with the resistance heating material of molybdenum or tungsten was used for the crucible for vapor deposition.

Next, after reducing the pressure in the vapor deposition chamber of the vacuum vapor deposition apparatus to a vacuum degree of 4 × 10 ⁻⁴ Pa, the vapor deposition crucible containing each material is sequentially energized and heated, and the organic material is formed on the anode 102 as follows. The light emitting functional layer 103 and the cathode 104 were formed.

  First, as a material for forming the hole injection layer 131, CuPc (copper phthalocyanine) represented by the following structural formula (1) is used, and this hole injection material is deposited on the anode 102 at a deposition rate of 0.1 nm / second. Evaporation was performed to form a hole injection layer 131 having a thickness of 15 nm.

  Next, a triarylamine derivative represented by the following structural formula (2) (α-NPD) is used as a material for forming the hole transport layer 132, and this hole transport material is deposited on the hole injection layer 131. Vapor deposition was performed at a rate of 0.1 nm / second to form a hole transport layer 132 having a thickness of 25 nm.

  Next, a distyryl biphenyl derivative represented by the following structural formula (3) (DPVBi) is used as the host material, and an iridium represented by the following structural formula (4) (Fir (pic)) is used as the blue guest material. Using a complex, these materials are co-deposited on the hole transport layer 132 at a total deposition rate (sum of deposition rates of each material) of 0.1 nm / second to form a blue light-emitting layer 133 having a thickness of 15 nm. did. In addition, the ratio of the blue guest material in the blue light emitting layer 133 was 3 mass%.

  Next, a carbazole derivative represented by the following structural formula (5) (CBP) is used as a material for forming the intermediate layer 134, and this intermediate layer material is deposited on the blue light-emitting layer 133 at a deposition rate of 0.1 nm / second. Then, an intermediate layer 134 having a thickness of 5 nm was formed.

Next, the carbazole derivative represented by the structural formula (5) (CBP) is used as the host material, and the iridium complex represented by the following structural formula (6) (Ir (ppy) ₃ ) is used as the green guest material. These materials were co-evaporated on the intermediate layer 134 at a total deposition rate of 0.1 nm / second to form a 10-nm-thick green light-emitting layer 135. In addition, the ratio of the green guest material in the green light emitting layer 135 was 5 mass%.

  Next, a carbazole derivative represented by the above structural formula (5) (CBP) is used as a material for forming the intermediate layer 136, and this intermediate layer material is deposited on the green light emitting layer 135 at a deposition rate of 0.1 nm / second. Then, an intermediate layer 136 having a thickness of 5 nm was formed.

Next, the carbazole derivative represented by the structural formula (5) (CBP) is used as the host material, and the iridium complex represented by the following structural formula (7) (Ir (piq) ₃ ) is used as the red guest material. These materials were co-evaporated on the intermediate layer 136 at a total deposition rate of 0.1 nm / second to form a red light emitting layer 137 having a thickness of 10 nm. In addition, the ratio of the red guest material in the red light emitting layer 137 was 8 mass%.

  Next, an aluminum quinolinol complex represented by the following structural formula (8) (BAlq) is used as a material for forming the hole blocking layer 138, and this hole blocking material is deposited on the red light emitting layer 137 at a deposition rate of 0.1 nm. The hole blocking layer 138 having a thickness of 15 nm was formed by vapor deposition at a rate of / sec.

Next, an aluminum quinolinol complex represented by the following structural formula (9) (Alq ₃ ) is used as a material for forming the electron transport layer 139, and this electron transport material is deposited on the hole blocking layer 138 at a deposition rate of 0.1 nm. The electron transport layer 139 having a thickness of 30 nm was formed by vapor deposition at a rate of / sec.

  Next, lithium fluoride (LiF) is used as a material for forming the electron injection layer 140. This electron injection material is deposited on the electron transport layer 139 at a deposition rate of 0.1 nm / second, and an electron injection having a thickness of 1 nm is performed. Layer 140 was formed.

  Finally, silver (Ag) or a silver alloy was used as a material for forming the cathode 104, and this cathode material was deposited on the electron injection layer 140 to form a cathode 104 with a thickness of 110 nm. At this time, as shown in FIG. 5, a part of the cathode 104 was formed on a partial region of the cathode lead electrode 104a, and the cathode 104 and the cathode lead electrode 104a were electrically connected. At this time, the cathode 104 was formed so that the anode 102 and the cathode 104 were insulated through the organic light emitting functional layer 103. In this example, the organic light emitting functional layer 103 and the cathode 104 were formed as described above.

  Next, the surface of the transparent substrate 101 on the cathode 104 side was covered with an epoxy resin having a thickness of 300 μm, and the epoxy resin was further covered with an aluminum foil having a thickness of 12 μm. And the epoxy resin was hardened and the sealing material 105 of the 2 layer structure which consists of an epoxy resin layer and aluminum foil was formed. At this time, the sealing material 105 was formed so that the lead electrode portions of the anode 102 and the cathode 104 were exposed at the periphery of the transparent substrate 101.

  The above-described steps from the formation of the anode 102 to the formation of the sealing material 105 are performed in a glove box (high-purity nitrogen having a purity of 99.999% or more) in a nitrogen atmosphere without bringing the organic electroluminescent element into contact with the atmosphere. In a gas atmosphere). Further, in the step of forming each layer of the organic light emitting functional layer 103 and each electrode film, a light emitting region SA was formed in the approximate center of the transparent substrate 101 using a vapor deposition mask for forming each layer. Specifically, in the surface of the transparent substrate 101 having a size of 50 mm × 50 mm, a light emitting area SA is provided in an area having a size of 45 mm × 45 mm in the center, and non-light emitting with a width of 2.5 mm around the light emitting area SA. Region SB was provided.

  In various examples described below, the light emitting panel 100 was manufactured as described above. In the light emitting panel 100 configured as described above, the emitted light h of each color generated in each of the blue light emitting layer 133, the green light emitting layer 135, and the red light emitting layer 137 is on the anode 102 side formed of the ITO film, that is, on the transparent substrate 101. The light is extracted from the light extraction surface 101a.

[Method for producing planar light emitter]
In the following various embodiments, four light emitting panels 100 manufactured as described above are prepared, and the four light emitting panels 100 are arranged in a form of 2 rows × 2 columns on a support substrate via an adhesive member. And attached. At this time, the four light emitting panels 100 were arranged between the four light emitting panels 100 adjacent to each other so that the side surfaces of the opposing transparent substrates 101 were in contact with each other.

  Next, on the light extraction surface 101a of the light emitting panel 100, the light extraction member is attached to the non-light emitting region SB formed in the region including the joint portion between the four adjacent light emitting panels 100 with an adhesive. It was. At this time, the light extraction member was attached over the entire non-light emitting area SB (100%) having a width of 5 mm (2.5 mm × 2) formed at the joint portion between the four light emitting panels 100 adjacent to each other. For the light extraction member, a light diffusing sheet (Light Up 100NSH: trade name, manufactured by Kimoto Co.) was used. In various examples described below, a planar light emitter was manufactured in this manner.

[Example 1]
In Example 1, a planar light emitter having the configuration described in the first embodiment (FIGS. 1A to 1C) was produced.

(1) Example 1-1
In the planar light emitter of Example 1-1, the cathode 104 was formed of silver in the light-emitting panel 100 shown in FIG.

(2) Example 1-2
In the planar light emitter of Example 1-2, the cathode 104 was formed of a silver alloy in the light-emitting panel 100 shown in FIG. Specifically, the cathode 104 was formed of a silver alloy containing 97.4 atomic% of silver, 0.91 atomic% of palladium, and 1.69 atomic% of copper.

(3) Example 1-3
In the planar light emitter of Example 1-3, the cathode 104 was formed of a silver alloy in the light-emitting panel 100 shown in FIG. In this example, the cathode 104 was formed of a silver alloy containing 90 atomic% silver and 10 atomic% magnesium.

(4) Example 1-4
In the planar light emitter of Example 1-4, the cathode 104 was formed of a silver alloy in the light emitting panel 100 shown in FIG. In this example, the cathode 104 was formed of a silver alloy containing 80 atomic% silver and 20 atomic% magnesium.

(5) Comparative Example 1
In the planar light emitter of Comparative Example 1, the cathode 104 was formed of aluminum (Al) in the light emitting panel 100 shown in FIG. Further, the planar light-emitting body of Comparative Example 1 has a configuration in which no light extraction member (light diffusion sheet) is provided. Other configurations in this example were the same as the planar light emitters of the various examples described above.

(6) Comparative Example 2
In the planar light emitter of Comparative Example 2, the cathode 104 was formed of aluminum (Al) in the light emitting panel 100 shown in FIG. Other configurations in this example were the same as the planar light emitters of the various examples described above.

(7) Comparative Example 3
In the planar light-emitting body of Comparative Example 3, the cathode 104 was formed of silver in the light-emitting panel 100 shown in FIG. 5, but the light extraction member (light diffusion sheet) was not provided. Other configurations in this example were the same as the planar light emitters of the various examples described above.

(8) Comparative Example 4
In the planar light emitter of Comparative Example 4, the cathode 104 is formed of silver in the light emitting panel 100 shown in FIG. 5, but the light extraction member (light diffusion sheet) is the entire surface of the light extraction surface 101 a (4 It was provided over the entire area including the light emitting area SA and the non-light emitting area SB of the light emitting panel. Other configurations in this example were the same as the planar light emitters of the various examples described above.

[Evaluation Test 1]
In the evaluation test 1, the light emission characteristics of the planar light emitters of Examples 1-1 to 1-4 and Comparative Examples 1 to 4 manufactured as described above were evaluated. Specifically, the anode and cathode lead electrode portions (external lead electrodes) of the planar light emitters of Examples 1-1 to 1-4 and Comparative Examples 1-4 are connected to a power source to emit light entirely, The visibility of the joint between the light emitting panels was evaluated.

Regarding the evaluation of the visibility of the seam, the light emitting state was visually observed at a position 5 m away from the planar light emitter with the entire surface light emitter emitting light, and the observation result was based on the following criteria. The visibility was evaluated in the light of comparison. Table 1 below shows the results of Evaluation Test 1.
A: A seam is not visually recognized at all.
B: A seam is hardly visually recognized.
C: The seam is somewhat visible, but at a level that does not matter.
D: A joint is visually recognized.
E: The seam is dark and clearly visible.

  As is clear from the results in Table 1, in the planar light emitters of Comparative Examples 1 to 4, the evaluation was “E” or “D”, but in the planar light emitters of Examples 1-1 to 1-4, , "B" rating or "C" rating was obtained. From this, like the planar light emitters of Examples 1-1 to 1-4, the cathode 104 of the light-emitting panel 100 is formed of silver or a silver alloy, and a plurality of adjacent ones on the light extraction surface 101a. It has been found that by providing the light extraction member in the non-light emitting region SB formed in the joint portion between the light emitting panels 100, the dark portion of the joint portion becomes inconspicuous and the luminance in-plane uniformity is improved.

[Example 2]
In Example 2, a planar light emitter having the configuration described in the second embodiment (FIGS. 3A to 3C) was produced. That is, in Example 2, a metal film made of silver or a silver alloy was further provided in a region opposite to the light extraction surface 101a of the transparent substrate 101 in the non-light emitting region SB of the light emitting panel 100 shown in FIG.

  Specifically, in the manufacturing process of the light-emitting panel 100 described above, the deposition mask pattern when forming the cathode 104 is changed, and at the same time as the cathode 104 is formed, the metal film (thickness 110 nm) is formed in the non-light-emitting region SB. Formed. At this time, the metal film was formed so that the area occupied by the metal film in the non-light emitting region SB was 70%.

  In Example 2, a planar light emitter was fabricated in the same manner as in Example 1 except that a metal film made of silver or a silver alloy was added. In this example as well, as in Example 1, the light extraction surface 101a of the light emitting panel 100 covers the entire non-light emitting region SB formed at the joint between the four light emitting panels 100 adjacent to each other. The light extraction member was attached via an adhesive.

(1) Example 2-1
In the planar light emitter of Example 2-1, the cathode 104 was formed of silver in the light emitting panel 100 shown in FIG.

(2) Example 2-2
In the planar light emitter of Example 2-2, the cathode 104 was formed of a silver alloy in the light emitting panel 100 shown in FIG. Specifically, the cathode 104 was formed of a silver alloy containing 97.4 atomic% of silver, 0.91 atomic% of palladium, and 1.69 atomic% of copper.

[Evaluation Test 2]
In the evaluation test 2, the luminous characteristics (seamability of the seam) were evaluated in the same manner as the evaluation test 1 for the planar light emitters of Examples 2-1 and 2-2 produced as described above. went. The evaluation results are shown in Table 2 below. The criteria for the seam evaluation in Table 2 are the same as those in the evaluation test 1 described above.

  As is apparent from the results in Table 2, “A” evaluation was obtained for the planar light emitters of Examples 2-1 and 2-2. Therefore, in the non-light emitting region SB, by providing a metal film made of silver or a silver alloy in a region opposite to the light extraction surface 101a of the transparent substrate 101, the dark portion of the joint portion cannot be recognized, and the luminance is reduced. It was found that the in-plane uniformity was further improved.

  DESCRIPTION OF SYMBOLS 1,2 ... Planar light-emitting body 10,30 ... Light emission panel, 11 ... Support board | substrate, 12 ... Adhesive member, 13 ... Light extraction member, 21 ... Transparent substrate, 21a ... Light extraction surface, 22 ... Anode, 23 ... Organic Light emitting functional layer, 24 ... cathode, 24a ... cathode extraction electrode, 25 ... sealing material, 31 ... metal film, SA ... light emitting region, SB ... non-light emitting region

Claims (4)

A transparent substrate, a first electrode formed on the transparent substrate, an organic compound layer formed on the first electrode and including a light emitting layer, and silver or silver formed on the organic compound layer An organic electroluminescence element group having a plurality of organic electroluminescence elements including a second electrode formed of a silver alloy as a main component, wherein the transparent substrates of the plurality of organic electroluminescence elements are arranged facing the same side When,
In the surface of the organic electroluminescence element group on the transparent substrate side, a light extraction member provided in a region including a joint portion between the plurality of organic electroluminescence elements adjacent to each other , and
The light extraction member is disposed over the entire region corresponding to the non-light emitting region formed between the light emitting regions of the plurality of organic electroluminescent elements adjacent to each other on the surface of the organic electroluminescent element group on the transparent substrate side. A planar illuminant formed across . The planar light-emitting body according to claim 1, wherein the silver content of the second electrode is 90 atomic% or more. Furthermore, on the surface opposite to the transparent substrate side of the organic electroluminescence element group, at least a region of the transparent substrate and a region of the first electrode corresponding to a non-light emitting region of the organic electroluminescence element The planar light-emitting body according to claim 1 or 2, comprising a metal film provided on one region and formed of silver or a silver alloy containing silver as a main component . The planar light-emitting body according to claim 3 , wherein the metal film is formed of the same material as the second electrode .

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