JP2010123397A - Organic electroluminescent element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic electroluminescent element with little in-plane luminance unevenness and also excellent in quality as a plane light source. <P>SOLUTION: The organic electroluminescent element, used as a plane light source, is provided with an organic light-emitting part with an organic light-emitting layer pinched between electrode layers. It is provided with a heating mechanism for selectively heating the organic light-emitting part within a plane. The organic light-emitting part is preferred to be put under a film sealing or a sheet sealing treatment. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an organic electroluminescence element used as a surface light source in an illumination device or the like, and particularly relates to a technique for eliminating uneven brightness in a surface.

  In recent years, from the viewpoint of the global environment, the reduction of greenhouse gases such as carbon dioxide has become an urgent task, and for example, the spread of low-power-consumption light sources to replace fluorescent lamps is indispensable. Fluorescent lamps also contain mercury. From this point of view, development of alternative lighting is desired.

  An organic electroluminescence element (hereinafter referred to as an organic EL element) is a self-luminous light source, has low power consumption, and is relatively easy to increase in size and flexibility. Application is expected.

  As a configuration of the organic EL element, for example, a first electrode (for example, a transparent electrode), an organic compound multilayer film including an organic light emitting layer, and a second electrode are laminated in this order on a transparent substrate, and an element unit is formed. In general, light generated in the organic light emitting layer is extracted from the transparent substrate side by passing an electric current through the compound multilayer film.

  By the way, in the above-mentioned organic EL element, there are many problems in terms of practical characteristics such as cost and life, and the actual situation is that it has hardly been put into practical use particularly in the field of lighting devices. For example, an organic compound multilayer film or the like constituting an organic EL element is generally composed of an extremely unstable organic material, and thus has a drawback that it easily deteriorates under the influence of oxygen or moisture. Alternatively, although not only light but also heat is generated from the organic EL element, there is also a problem that the organic material is deteriorated by accumulating this heat inside the element.

  Under such circumstances, various sealing structures and heat dissipation structures have been proposed for organic EL elements (see Patent Documents 1 to 4, etc.). For example, Patent Document 1 discloses an organic electroluminescence light emitting device (illumination device) that has a high ability to block moisture from the outside and can suppress deterioration of element performance over a long period of time. A structure for heat dissipation is also disclosed. The organic electroluminescent light emitting device described in Patent Document 1 has a so-called film sealing structure, and an organic electroluminescent element including an organic light emitting layer is a photocurable resin sealing layer, a moisture-proof layer, or a thermosetting resin. It is covered with an adhesive layer or the like, and further has a structure in which a heat absorber or a heat radiator is installed thereon.

  In Patent Document 2, a laminate in which an organic light emitting layer is laminated between a pair of electrodes is provided on a substrate, and a sealing member in which a metal plate having a predetermined thermal conductivity is covered with an insulating layer is pasted on the laminate. An organic light emitting device in which a laminate is sealed is disclosed. In the organic light emitting device described in Patent Document 2, by using the sealing member, the barrier property of moisture and oxygen is high, and the light emission characteristics of the organic light emitting device can be improved for a long time by quickly removing heat generated during light emission. In addition to maintaining stable over a long period of time, uniform light emission with no light emission unevenness is realized, and the lifetime is shortened and the possibility of element destruction is reduced.

  The invention described in Patent Document 3 relates to an organic electroluminescence display device. In an organic electroluminescence panel provided with a light emitting element having an organic light emitting layer including an organic light emitting material in a plurality of pixels, in a plane direction. By providing a thermal diffusion layer whose thermal conductivity is higher than the thermal conductivity in the thickness direction, the temperature inside the panel is made uniform, and there is no uniform brightness unevenness such as burn-in over the entire display area. Display is possible.

The invention described in Patent Document 4 also relates to a display device. In a display panel including a light emitting element including a layer including a light emitting layer between a first electrode and a second electrode, a cooling unit and a heat dissipation unit are provided. By installing a cooling device that circulates the refrigerant between them, uneven brightness is prevented.
JP 2003-34142 A JP 2006-331695 A JP 2008-234890 A JP 2004-184035 A

  However, as in the inventions described in the above patent documents, even if luminance unevenness is to be eliminated by heat dissipation, a sufficient effect cannot be obtained, and there is a possibility that a problem such as a decrease in luminance may occur. In addition, the invention described in each of the above-mentioned patent documents provides heat dissipating means for the entire surface of the organic EL element, and even if the luminance of the entire organic EL element can be improved, the luminance unevenness is eliminated. It ’s difficult.

  The problem of uneven brightness described above becomes a serious problem particularly when an organic EL element having a large area to some extent is used as a lighting device, and hinders practical use. In an organic EL element used as a surface light source, in order to eliminate the luminance unevenness, it has been studied to divide the organic EL element into a plurality of regions in the plane. In this case, a non-light emitting area is formed, and the non-light emitting area is visually recognized in a linear manner, so that the quality of illumination is greatly impaired.

  The present invention has been proposed in view of the above-described conventional situation, and an object thereof is to provide a technique capable of effectively eliminating luminance unevenness of an organic EL element used as a surface light source. It is an object of the present invention to provide an organic electroluminescence device that can suppress unevenness in brightness and is excellent in appearance quality.

  As a result of various studies, the present inventors have found that when a part of the organic EL surface light source is heated, the current value of the heated portion increases and the luminance increases. Then, by utilizing this phenomenon and selectively heating a portion where the luminance of the organic EL element is low, the luminance of the heated portion is relatively increased, and as a result, the knowledge that luminance unevenness is eliminated is obtained. It came to.

  The present invention has been completed based on these findings. That is, the organic electroluminescence element of the present invention is an organic electroluminescence element used as a surface light source having an organic light emitting part in which an organic light emitting layer is sandwiched between electrode layers, and the organic light emitting part is disposed in the plane. It has a heating mechanism for selectively heating.

  In a surface light source (organic electroluminescence device) with uneven brightness, heating the low-luminance part of the organic light emitting part increases the brightness of the heated part, and there is a relative brightness difference from the originally high-luminance part. to shrink. As a result, luminance unevenness is eliminated. In addition, since it is not necessary to divide the organic light emitting portion that functions as a surface light source, a non-light emitting region is not formed in the light emitting surface and the quality of light emission is not impaired.

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide the organic electroluminescent element excellent in the light emission quality as a surface light source without a brightness nonuniformity. Furthermore, according to the present invention, the luminance at an arbitrary position can be increased or decreased within the light emitting surface of the organic electroluminescence element, and this can be solved in response to various luminance unevenness.

  Hereinafter, an embodiment of an organic electroluminescence element (organic EL element) to which the present invention is applied will be described in detail with reference to the drawings.

The present invention is suitable for application to, for example, a surface light source (for example, an organic EL element for illumination) having a large area that emits white light and has a light emission area exceeding, for example, 50 mm ² (preferably 10 mm × 10 mm = 100 mm ² ). is there. This is because, in a large-area organic EL element, the temperature varies depending on the location of the light emitting surface due to heat distribution, or the current value varies depending on the location of the light emitting surface due to electrode resistance, and the luminance varies accordingly. This is because uniform light emission is difficult. Therefore, in the following embodiments, description will be made assuming a large-area organic EL element for illumination.

(First embodiment)
FIG. 1 shows a schematic configuration of the organic EL element of the present embodiment. The organic EL element of the present embodiment is an organic EL element having a so-called can sealing structure, and a structure in which an organic light emitting unit 2 formed on a substrate 1 is sealed with a glass can 3 as shown in FIG. Have

  The substrate 1 functions as a support for supporting the organic light emitting unit, and also functions as a barrier layer for preventing moisture, oxygen, and the like from entering the organic light emitting unit 2. Although the constituent material of this board | substrate 1 is not specifically limited, Since the organic EL element of this embodiment is a bottom emission type organic EL element and light emission is taken out through the board | substrate 1, it is preferable that it is a light transmissive material. . Therefore, for example, glass or plastic can be used. Glass is a preferable material because it is excellent in barrier properties such as moisture and oxygen. When plastic is used, the barrier property may be insufficient. In that case, it is preferable to form a barrier layer on the surface.

  The organic light emitting unit 2 is configured by stacking, for example, a first electrode, a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, an electron injection layer, a second electrode, and the like. The organic light emitting layer emits light by applying a voltage between the second electrodes. Here, the 1st electrode distribute | arranged to the light emission surface side needs to be transparent like the board | substrate 1, for example, an ITO electrode etc. are used. On the other hand, the second electrode does not need to be transparent, and for example, an aluminum electrode or the like is used.

  The inside of the glass can 3 is filled with, for example, dry nitrogen gas or the like to prevent oxidation of the organic light emitting unit 2 due to oxygen. In the case of this embodiment, the desiccant 4 is affixed in the glass can 3, and the water | moisture content which penetrate | invaded in the glass can 3 is removed.

  The above is the basic structure of the organic EL element, but in the organic EL element of the present embodiment, the heating plate 5 for heating a part of the surface of the organic light emitting unit 2 is installed as a heating mechanism. The organic light emitting unit 2 is selectively heated by the heating plate 5 to change the in-plane luminance distribution and eliminate the luminance unevenness in the organic EL element.

  The heating mechanism will be described. The heating plate 5 is formed of a material excellent in heat conduction, such as a stainless plate, and heat is transmitted by bringing the end portion into contact with a heat source. The organic EL element in contact with is heated. Further, the heating plate 5 is attached so as to be in contact with the glass can 3 on the back side (opposite side of the light emitting surface) of the organic EL element. Therefore, the organic light emitting unit 2 is indirectly heated by heat conduction. Will be.

  In the case of the organic EL element of the present embodiment, since the extraction electrode of the organic light emitting unit 2 is installed on the right side in the figure, the heating plate 5 is on the opposite side. It is attached. In the organic light emitting unit 2, the current flowing through the organic light emitting layer differs depending on the position away from the extraction electrode due to the electrical resistance of the first electrode and the second electrode, and at the position away from the extraction electrode. It is difficult for current to flow (that is, luminance is low). As described above, when the heating plate 5 is attached at a position away from the extraction electrode and the organic light emitting unit 2 at a position away from the extraction electrode is heated, the current flow in the surface changes, and the organic light emitting unit 2 in the heating portion changes. The current flowing in the current increases and the luminance increases.

  In other words, the luminance unevenness can be eliminated in the organic light emitting portion 2 of the organic EL element driven by constant current by heating the portion where the luminance is uneven (particularly where the luminance is low). become. In an organic EL element driven at a constant current, a current distribution is generated due to the electrical resistance of the first electrode and the second electrode, thereby causing luminance unevenness. In such a surface light source with uneven brightness, when a part with low brightness is heated, the current value of the heated part increases and the brightness increases, and the brightness (current value) of the part with originally high brightness is relatively As a result, the luminance unevenness is eliminated.

(Second Embodiment)
The present inventor has found out that heat generation promotes in-plane luminance unevenness by verifying heat generation characteristics of organic EL elements having different sealing forms. Further, it was confirmed that by making the sealing into a sheet (film sealing), the in-plane temperature distribution can be made uniform and the occurrence of uneven brightness can be suppressed. From these findings, it is considered that it is advantageous to employ a sheet sealing structure for eliminating luminance unevenness. Therefore, in the organic EL element of this embodiment, in addition to adopting the sheet sealing structure, a heating mechanism is provided to further eliminate the luminance unevenness.

  FIG. 2 is a cross-sectional view illustrating a schematic configuration of the organic EL element of the present embodiment that employs a sheet sealing structure. The organic EL element 11 of the present embodiment has an organic light emitting unit 16 formed by laminating an anode 13, an organic layer 14 formed of a multilayer film of one or more organic materials, and a cathode 15 in this order on a substrate 12. The organic light emitting section 16 is sealed with various sheets (films) to prevent the intrusion of air (oxygen) and moisture. Specifically, the surface of the organic light emitting unit 16 is covered with a planarizing layer 17, and a shield layer 18, an adhesive layer 19, and a glass plate 20 are laminated on the planarizing layer 17.

  The organic EL element 11 of the present embodiment also takes out light emitted from the organic light emitting layer in the organic light emitting unit 16 from the substrate 12 side. Therefore, as the substrate 12, for example, a light transmissive material such as glass or plastic. It is preferable to use a substrate having

  The organic light emitting unit 16 formed on the substrate 12 is configured, for example, by laminating an anode 13, an organic layer 14, and a cathode 15 in this order. Here, the anode 13 is formed by forming a light-transmitting conductive material such as ITO (indium tin oxide) or indium zinc oxide by sputtering or the like. The organic layer 14 stacked on the anode 13 is formed by sequentially stacking a hole injection layer, a light emitting layer, an electron injection layer, and the like from the anode 13 side, for example. The organic layer 14 has a configuration in which a hole transport layer exists between the light emitting layer and the hole injection layer, a configuration in which an electron transport layer exists between the light emitting layer and the electron injection layer, and a single layer. But you can. Furthermore, the organic layer 14 is not limited to the above-described structure, and can have various structures. The cathode 15 stacked on the organic layer 14 is configured by depositing a metal such as aluminum or an alloy by sputtering or vapor deposition, for example.

  The planarization layer 17 covering the organic light emitting unit 16 is provided with a step on the surface of the organic light emitting unit 16, unevenness, pins from the viewpoint of improving the film quality of the shield layer 18 formed thereon and improving the barrier property of the shield layer 18. Smoothness for uniformly covering holes and the like is required. At the same time, the planarizing layer 17 has a gas barrier property for protecting the organic light emitting unit 16 from oxygen, moisture, and the like, and a high thermal conductivity for quickly transferring the heat generated from the organic light emitting unit 16 to the glass plate 20 and the like. It is preferable to have a function of reducing damage to the element that occurs when the shield layer is formed. From these viewpoints, an organic insulating material such as a xylylene polymer compound, a polyimide polymer compound, an acrylic polymer compound, an epoxy polymer compound, or a polyurea polymer compound is applied to a CVD method such as plasma CVD or resistance. It is preferable to form the planarization layer 17 by forming a film by a vapor phase method (dry process) such as PVD method such as heat evaporation. Alternatively, the planarizing layer 17 can be formed by forming a film of a triphenylamine compound, a triarylamine compound, a tris (arylamine) benzene compound, or the like by a vacuum deposition method or the like. For example, there is a method of forming the planarization layer by a wet process such as coating, but the solvent used to dissolve the material forming the planarization layer 17 and the moisture contained in the solvent adversely affect the organic light emitting unit 16. There is a risk.

  A shield layer 18 is laminated on the planarization layer 17, and the shield layer 18 is required to have a function of blocking the adverse effect of the organic light emitting unit 16 such as the organic layer 14 when the adhesive layer 19 is cured. . For example, when the adhesive layer 19 is a photo-curable adhesive layer, the shield layer 18 may be formed so as to absorb or reflect and block light such as UV light and visible light used during curing. preferable. Materials that block light include metals such as aluminum, gold, silver, metal oxides such as zinc oxide, titanium oxide, cesium oxide, metal sulfates such as barium sulfate, barium titanate, zirconate titanate At least one of barium, strontium titanate, and the like can be used. Among these, it is preferable to use metals such as aluminum, gold, and silver because of excellent barrier properties. When the photocurable adhesive layer is cured, light such as UV light is blocked by the shield layer 18, so that the organic light emitting unit 16 is protected during photocuring of the adhesive layer 19, and the glass plate 20 is organically fixed. Deterioration of the layer 14 and the like can be suppressed.

  Further, when the adhesive layer 19 is a thermosetting adhesive layer, it is preferable to form the shield layer 18 so as to block outgas generated from the thermosetting resin during curing. Examples of materials having gas barrier properties that block the gas generated from the thermosetting resin include materials that block the light used at the time of curing the photocurable adhesive layer, magnesium fluoride, calcium fluoride, lithium fluoride, etc. At least one selected from the group consisting of metal fluorides, metal nitrides such as aluminum nitride, silicon oxides such as silicon dioxide, silicon nitrides such as silicon nitride, and the like can be used. Above all, it has excellent barrier properties and is highly effective in preventing outgassing during curing, so it can be used for metals such as aluminum, gold and silver, oxides such as silicon dioxide and aluminum oxide, and nitriding such as silicon nitride and aluminum nitride. It is preferable to use things. In this way, by blocking outgas generated when the thermosetting adhesive layer is cured by the shield layer 18, the organic light emitting unit 16 is protected from the gas generated when the adhesive layer 19 is cured, and the glass plate 20 is fixed. It is possible to suppress the deterioration of the organic layer 14 and the like.

  As the film configuration of the planarization layer 17 and the shield layer 18 described above, one layer of the shield layer 18 may be basically stacked on the one layer of the planarization layer 17, but is not limited thereto, and the planarization layer is not limited thereto. One or both of 17 and shield layer 18 may be two or more layers. Specifically, a film configuration in which three layers of the shield layer 18, the planarization layer 17, and the shield layer 18 are laminated in this order, or three layers of the planarization layer 17, the shield layer 18, and the planarization layer 17 are laminated in this order. be able to. Furthermore, a plurality of sets of the planarizing layer 17 and the shield layer 18 can be laminated repeatedly.

  Next, an adhesive layer 19 is formed on the adhesive layer 19. The adhesive layer 19 includes a resin material such as a photocurable resin or a thermosetting resin, specifically, an acrylic polymer compound, an epoxy high polymer, and the like. Molecular compounds and the like can be used. Among these, it is preferable to use a thermosetting adhesive, and particularly by using a sheet-like thermosetting adhesive (so-called hot melt adhesive), for example, in an organic EL element having a large light emitting area. The adhesive layer 19 having a uniform thickness can be formed, and when the adhesive layer 19 is formed, the problem of air clogging that occurs when a liquid adhesive is applied can be eliminated. It is possible to suppress an increase in coating time.

  The sheet-like thermosetting adhesive exhibits fluidity by heating and exhibits adhesiveness. Here, in the organic EL element 11, the element structure has a multistage structure of thin films, and high fluidity is required to obtain good coverage. Therefore, the sheet-like thermosetting adhesive needs to have a low flow start temperature and low viscosity. On the other hand, the organic EL element has a heat-resistant temperature of about 110 ° C., and heat treatment at a temperature exceeding this causes deterioration of the characteristics of the organic EL element. In consideration of these matters, the sheet-like thermosetting adhesive needs to have sufficient fluidity and curability for coating under an environment of 110 ° C. or lower. The curing temperature is preferably 110 ° C. or lower.

  In the adhesive layer 19, fillers such as a filler having high thermal conductivity, a filler having gas adsorption, and a filler having hygroscopicity may be dispersed. By containing the filler in the adhesive layer 19, the heat dissipation of the organic EL element, the barrier property against oxygen, moisture, and the like can be further enhanced according to the type of the filler.

  The glass plate 20 is fixed to the surface of the film formed in close contact with the organic light emitting unit 16 and has a function as a sealing material that suppresses the entry of oxygen, moisture, or the like into the element, and the sealing film It also serves to reinforce the gas barrier properties. In order to further increase the gas barrier property in the thickness direction, the area of the glass plate 20 is preferably larger than the area of the organic light emitting unit 16. Here, the glass plate 20 is provided, but it is also possible to use a metal plate or an alloy plate having high thermal conductivity such as aluminum, copper, stainless steel, aluminum nitride, copper tungsten, or the like.

  The above is the basic configuration of the organic EL element 11 having a sheet sealing structure, but the organic EL element 11 of the present embodiment has a heat dissipation structure added to the above-described sheet sealing structure. Specifically, a heat diffusion plate 21 and a heat radiating plate 22 are further laminated on the glass plate 20. The heat diffusing plate is made of, for example, aluminum. By installing the heat diffusing plate 21 and the heat radiating plate 22 on the glass plate 20, the thermal burden on the organic EL element is reduced, and the in-plane temperature distribution ( (Luminance distribution) can be made uniform to some extent.

  Also in the organic EL element 11 having the sheet sealing structure as described above, the resistance film 23 for heating a part of the surface of the organic light emitting unit 16 is installed on the glass plate 20 as a heating mechanism, The organic light emitting unit 16 is selectively heated by the resistance film 23 to change the in-plane luminance distribution, thereby eliminating luminance unevenness in the organic EL element 11.

  The resistance film 23 is formed, for example, by depositing a conductive material having a predetermined resistance value. The resistance film 23 generates heat when a current is passed, and functions as a so-called heater. The resistance film 23 is formed in a region opposite to the extraction position of the extraction electrode of the organic EL element 11 (for example, the extraction electrode 13A of the anode 13), and this resistance film 23 is the same as in the first embodiment. By heating the part of the organic light emitting unit 16 away from the extraction electrode 13A, the luminance unevenness is eliminated.

  As mentioned above, although embodiment of the organic EL element to which this invention was applied was described, the structure of the organic EL element of this invention is not necessarily restricted to the thing of these embodiment, In the range which does not deviate from the summary of this invention, it is various. Needless to say, it is possible to make changes.

  For example, the heating mechanism is not limited to the heating plate and the resistance film described above, and any heating mechanism may be used as long as it can selectively heat the organic light emitting unit. Moreover, the installation position is also arbitrary, and may be appropriately designed according to the temperature distribution of the organic EL element (organic light emitting unit). Furthermore, the organic EL element can be applied to any known organic EL element.

  In this example, in order to confirm the effect of the present invention, an organic EL element was actually fabricated and the situation of luminance unevenness was examined.

Example 1
The organic EL device produced in this example has a can sealing structure as shown in FIG. FIG. 3 shows a planar arrangement and dimensions of the produced organic EL element. The size of the produced organic EL element is 50 mm × 50 mm. The shaded area in the figure is the light emitting area, and the size of the light emitting area is 29 mm × 34 mm. A seal area 32 is formed around the light emitting area (organic layer 31), and the extraction electrodes of the first electrode 33 and the second electrode 34 are arranged on the lower side in the figure.

A heating plate was installed on the side opposite to the take-out electrode formation position of the sealing can and heated in order from the initial state (27 ° C.) to examine the state of the luminance distribution. Heating was performed in the following order under a constant current (60 mA).
27 ° C → 35 ° C → 45 ° C → 32 ° C (natural cooling) → 55 ° C → 30 ° C (natural cooling)

  As a result, when the temperature of a part of the organic EL element was increased, the luminance at that position increased. It was confirmed that this phenomenon was reproducible because the initial luminance distribution was restored when the temperature was lowered.

Example 2
The organic EL device produced in this example has a film sealing structure (sheet sealing structure) as shown in FIG. However, in the organic EL device produced in this example, no heat diffusion plate or heat radiating plate on the glass plate is installed. The produced organic EL element has a substrate size of 100 mm × 100 mm and a light emitting area of 74 mm × 81 mm. Moreover, the thickness of both the substrate (glass substrate) and the glass plate is 0.7 mm.

  The produced organic EL element has +++ electrodes along one side of the substrate, and +++ electrodes on the opposite side. Therefore, luminance unevenness occurs between these two sides, as shown in FIG. Thus, the center part farthest from the electrode (the accumulation of the sheet resistance of ITO constituting the electrode is the largest) is dark.

  Therefore, when an external heater was disposed in the central portion where the luminance was low and the heating was performed at about + 15 ° C., the luminance unevenness was improved after the heating as shown in FIG. Specifically, as shown in Table 1, the average luminance is hardly changed because of constant current driving, but the uniformity is improved by 10% or more, and the in-plane luminance variation is reduced. . This is because the brightness is increased by heating the portion with low luminance (the portion where no current flows), and the total amount of current injected into the organic EL element is fixed. Therefore, the in-plane luminance distribution is made uniform.

It is a schematic sectional drawing which shows 1st Embodiment of the organic EL element to which this invention is applied. It is a schematic sectional drawing which shows 2nd Embodiment of the organic EL element to which this invention is applied. It is a schematic plan view of the organic EL element used for the Example. (A) is a figure which shows the luminance distribution of the organic EL element before a heating, (b) is a figure which shows the luminance distribution of the organic EL element after a heating.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 board | substrate, 2 organic light emission part, 3 glass can, 4 desiccant, 5 heating plate, 12 board | substrate, 13 anode, 14 organic layer, 15 cathode, 16 organic light emission part, 17 planarization layer, 18 shield layer, 19 adhesion layer , 20 glass plate, 21 heat diffusion plate, 22 heat radiating plate, 23 resistance film, 31 organic layer, 32 seal area, 33 first electrode, 34 second electrode

Claims (11)

An organic electroluminescence element used as a surface light source, having an organic light emitting portion in which an organic light emitting layer is sandwiched between electrode layers,
An organic electroluminescence device comprising a heating mechanism that selectively heats the organic light emitting unit in a plane.   The organic electroluminescence device according to claim 1, wherein the heating mechanism is installed at a position away from the extraction electrode of the electrode layer.   The organic electroluminescence element according to claim 1, wherein the organic light emitting portion is sealed with a film.   4. The organic electroluminescence device according to claim 3, wherein the organic light-emitting portion is covered with a planarizing layer, and a heat radiating plate and / or a heat diffusing plate is fixed on the planarizing layer.   The organic electroluminescence device according to claim 4, wherein the heat radiating plate is fixed on the planarizing layer by an adhesive layer, and a shield layer is formed between the planarizing layer and the adhesive layer.   4. The organic electroluminescence device according to claim 3, wherein the organic light-emitting portion is covered with a planarization layer, and a glass substrate, a heat diffusion plate, and a heat dissipation plate are laminated on the planarization layer.   The organic electroluminescence device according to claim 6, wherein the glass substrate is fixed on the planarization layer by an adhesive layer, and a shield layer is formed between the planarization layer and the adhesive layer.   The organic electroluminescence element according to claim 1, wherein the heating mechanism is formed by forming a resistor film functioning as a heater.   The organic electroluminescence device according to any one of claims 1 to 7, wherein the heating mechanism is installed in a form of contacting a heat transfer body connected to an external heat source.   The organic electroluminescence device according to claim 1, wherein the heating mechanism is installed on a surface opposite to the light emitting surface.   The organic electroluminescence element according to claim 1, wherein the organic electroluminescence element is driven by a constant current.

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