JP2020080305A - Light emitting apparatus - Google Patents

Abstract

To provide a light emitting apparatus having a light reflection function, and capable of emitting light to a front surface by achieving suppression of increase in a thickness of the apparatus.SOLUTION: The light emitting apparatus comprises: a substrate 1; a plurality of organic EL elements arranged on one surface of the substrate 1; and a plurality of metal mirror surface parts MIR arranged on the one surface. Each of the plurality of organic EL elements has an organic layer formed between a transparent electrode and a reflection electrode, and each metal mirror surface part MIR is separated from the organic layer. At least a part of the transparent electrode overlaps each of the metal mirror surface parts MIR when viewing the transparent electrode from a direction vertical to the one surface.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light emitting device including an organic electroluminescence element and having a light emitting function.

  The organic electroluminescence element is constituted, for example, by sequentially laminating an anode, an organic layer including a light emitting layer and a cathode on a transparent glass substrate, and by injecting a current into the organic layer via the anode and the cathode, electroluminescence ( Hereinafter, it will be referred to as EL). The organic EL element is a self-luminous surface emitting device and is used in a display device and a lighting device.

  As a mirror device, there is an EL illumination built-in mirror in which an organic EL element is arranged around the mirror in a frame shape and an object such as a user's face can be projected on the mirror (see Patent Document 1).

  Further, a sun visor assembly for an automobile, which includes a rearview mirror with illumination, has also been proposed (see Patent Document 2).

JP, 2003-217868, A Japanese Patent No. 2625177

  In the mirror with a built-in EL illumination described in Patent Document 1, since the light source such as an organic EL element is arranged in the frame around the mirror, the area of the mirror is reduced, and the part of the face that the user wants to see is appropriate. It had the drawback of not giving light to.

  Further, the sun visor assembly described in Patent Document 2 also has a problem that it is difficult to uniformly emit light because the illumination parts by the lamps are directly provided in front of both sides of the mirror surface.

  The above-mentioned mirror device has a drawback in that the thickness of the entire mirror device is increased because the light-emitting portions are simply arranged in front of and behind the mirror.

  Therefore, in the present invention, it is mentioned as an example to provide a light emitting device which has a light reflecting function and which can suppress the increase of the device thickness and emit light to the front surface.

  The invention according to claim 1 is provided with a substrate, a plurality of organic EL elements arranged on one surface of the substrate, and a plurality of metal mirror surface portions arranged on the one surface, Each of the plurality of organic EL elements has an organic layer formed between a translucent electrode and a reflective electrode, the metal mirror surface portion is separated from the organic layer, and is in a direction perpendicular to the first surface. When viewed from above, at least a part of the translucent electrode overlaps with the metal mirror surface portion.

1 is a front view in which a part of a mirror device for an organic EL panel, which is Embodiment 1 of the present invention, is cut away. FIG. 2 is a sectional view taken along the line CC in FIG. FIG. 3 is an enlarged cross-sectional view of a part of the organic EL panel of Example 1. FIG. 4 is a rear view in which a part of the mirror device of the organic EL panel shown in FIG. 1 is cut away. FIG. 5 is a schematic sectional view of a part of the organic EL panel showing the operation of the first embodiment of the present invention. FIG. 6 is a schematic sectional view of a part of the organic EL panel of the modified example of the first embodiment. FIG. 7 is a schematic sectional view of a part of the organic EL panel of the modified example of the first embodiment. FIG. 8 is a partially cutaway front view of a mirror device of an organic EL panel that is Embodiment 2 of the present invention. FIG. 9 is a sectional view taken along the line CC in FIG. FIG. 10 is a sectional view taken along the line D-D in FIG. FIG. 11 is a schematic sectional view of a part of an organic EL panel of a modified example of the second embodiment. FIG. 12 is a front view in which a part of a mirror device of an organic EL panel which is another modification of the second embodiment is cut away. FIG. 13 is a schematic sectional view of a part of the organic EL panel of Example 3 of the present invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows the configuration of a mirror device which is an organic EL panel OELD of Example 1 of the present invention as a light emitting device. The organic EL panel OELD includes a plurality of organic EL elements OEL partitioned by a bank BK and a plurality of metal mirror surface portions MIR on a substrate 1 which is a light-transmissive flat plate such as glass or resin. The organic EL element OEL has strip-shaped light emitting portions each extending in the y direction of the xy main surface of the substrate 1, and the red light emission R, the green light emission G, and the blue light emission B are emitted from the front surface 1a of the transparent substrate 1. Is a group of organic EL elements R, G, and B that emit light of different emission colors. Each of the metal mirror surface portions MIR is a strip-shaped light reflecting portion that extends in the y direction of the xy main surface of the substrate 1, and reflects external light via the front surface 1 a of the transparent substrate 1. As shown in FIG. 1, the organic EL elements OEL and the metal mirror surface portions MIR are alternately arranged on the back surface of the transparent substrate. The bank BK is formed of a translucent dielectric material such as optical glass or optical resin. The organic EL elements R, G, B are juxtaposed in parallel. A set of organic EL elements OEL of RGB emission colors that emit red, green, and blue emission colors is arranged in the x direction for each set.

  In this way, the organic EL element OEL and the metal mirror surface portion MIR are repeatedly arranged in parallel in a fixed order in a stripe shape so as to be evenly spaced. Therefore, in the present embodiment, the width of the metal mirror surface portion MIR and the organic EL element OEL cannot be visually identified, for example, 0.1 mm or less, and the distance between the metal mirror surface portion MIR and the organic EL element OEL is, for example, 0.1 mm or less. In this case, since the surface emitting organic EL element emits light when the element is driven, it can be used as a mirror for emitting light, as if it is a mirror for emitting light over the entire surface. Further, it can function as a single mirror when the element is not driven. Furthermore, by adjusting the brightness of the organic EL element or for each group of colors, from the front surface of the substrate 1 which is the light extraction surface, red, green, and blue lights are mixed at an arbitrary ratio to form a single light. Light perceived as the emission color is emitted. Although not shown, all the organic EL elements OEL are connected to the element driving section.

  As shown in FIG. 2, in each of the organic EL elements OEL, a translucent electrode 2, an organic layer 3 including a light emitting layer 3 and a reflective electrode 4 are laminated on a back surface 1b of a substrate 1 between adjacent banks BK. Composed. The transparent electrode 2 is formed on the substrate 1 so as to extend along the xy direction. The transparent electrode 2 functions as a common anode, for example, for a plurality of organic EL elements OEL. Each of the metal mirror surface portions MIR is formed along the y direction on the transparent electrode 2 between the adjacent banks BK. The metal mirror surface portion MIR and the reflective electrode 4 are formed of the same material. The metal mirror surface portion MIR is electrically connected to the translucent electrode 2. The metal mirror surface portion MIR is connected to a power source (not shown), and the metal mirror surface portion MIR functions as a bus line that supplies a power supply voltage to the connected transparent electrode 2. The mirror device of the present embodiment is a so-called bottom emission type organic device in which light generated in the organic layer 3 is extracted from the front surface 1 a of the substrate 1 by applying a voltage between the transparent electrode 2 and the reflective electrode 4. Functions as an EL panel.

  As shown in FIG. 3, typically, in each organic layer 3 of the organic EL element OEL, when the translucent electrode 2 is an anode and the reflective electrode 4 is a cathode, positive electrodes are sequentially provided from the anode to the cathode. The hole injection layer 3a, the hole transport layer 3b, the light emitting layer 3c, the electron transport layer 3d, and the electron injection layer 3e are stacked. In addition, in the laminated structure of the organic layer 3, the constituent elements other than the substrate can be laminated in the reverse order. The organic layer 3 is not limited to these laminated structures and may include at least a light emitting layer, for example, by adding a hole blocking layer (not shown) between the light emitting layer 3c and the electron transporting layer 3d, or may be used in combination. A laminated structure including a charge transport layer may be used. The organic layer 3 may be formed by omitting the hole transport layer 3b or the hole injection layer 3a or by omitting the hole injection layer 3a and the electron transport layer 3d from the above laminated structure. May be.

[Transparent electrode]
The transparent electrode 2 of the anode is formed of ITO (Indium-tin-oxide), ZnO, ZnO-Al2O3 (so-called AZO), In2O3-ZnO (so-called IZO), SnO2-Sb2O3 (so-called A).
TO), RuO2, etc. Further, it is preferable to select a material having a transmittance of at least 10% or more at the emission wavelength obtained from the light emitting layer for the transparent electrode 2. The translucent electrode 2 usually has a single layer structure, but it may have a laminated structure with a metal thin film. As the material of the metal thin film, for example, a suitable metal such as tin, magnesium, indium, calcium, aluminum, silver, or an alloy thereof is used. Specific examples include magnesium-silver alloys, magnesium-indium alloys, aluminum-lithium alloys and the like. A silver thin film having a thickness of 20 nm of the metal thin film has a transmittance of 50%. An Al film having a film thickness of 10 nm as a metal thin film has a transmittance of 50%. The MgAg alloy film having a film thickness of 20 nm as the metal thin film has a transmittance of 50%. When forming the metal thin film, the conductivity can be ensured if the lower limit of the film thickness is 5 nm, although it depends on the material, the film forming method, and the conditions.

[Hole injection layer]
The hole injection layer 3a is preferably a layer containing an electron-accepting compound (so-called hole-transporting compound).

  The hole transporting compound is preferably a compound having an ionization potential of 4.5 eV to 6.0 eV from the viewpoint of a charge injection barrier from the anode to the hole injection layer. Examples of the hole-transporting compound include aromatic amine derivatives, phthalocyanine derivatives represented by phthalocyanine copper (so-called CuPc), porphyrin derivatives, oligothiophene derivatives, polythiophene derivatives, benzylphenyl derivatives, and tertiary amines with a fluorene group. Examples thereof include linked compounds, hydrazone derivatives, silazane derivatives, silanamine derivatives, phosphamine derivatives, quinacridone derivatives, polyaniline derivatives, polypyrrole derivatives, polyphenylene vinylene derivatives, polythienylene vinylene derivatives, polyquinoline derivatives, polyquinoxaline derivatives, and carbon. Here, for example, when the derivative is an aromatic amine derivative, the derivative includes an aromatic amine itself and a compound having an aromatic amine as a main skeleton. It may be.

  Further, as the hole transporting compound, a conductive polymer (so-called PEDOT/PSS) obtained by polymerizing 3,4-ethylenedioxythiophene which is a derivative of polythiophene in high molecular weight polystyrene sulfonic acid is also preferable. Further, the end of the PEDOT/PSS polymer may be capped with methacrylate or the like.

[Hole transport layer]
The material of the hole transport layer 3b may be any material conventionally used as a constituent material of the hole transport layer, and is exemplified as the hole transport compound used in the hole injection layer described above. There are things. In addition, arylamine derivatives, fluorene derivatives, spiro derivatives, carbazole derivatives, pyridine derivatives, pyrazine derivatives, pyrimidine derivatives, triazine derivatives, quinoline derivatives, phenanthroline derivatives, phthalocyanine derivatives, porphyrin derivatives, silole derivatives, oligothiophene derivatives, condensed polycyclic aromatics. Examples include group derivatives and metal complexes. In addition, for example, polyvinylcarbazole derivative, polyarylamine derivative, polyvinyltriphenylamine derivative, polyfluorene derivative, polyarylene derivative, polyaryleneethersulfone derivative containing tetraphenylbenzidine, polyarylenevinylene derivative, polysiloxane derivative, polythiophene Examples thereof include derivatives and poly(p-phenylene vinylene) derivatives. These may be alternating copolymers, random polymers, block polymers or graft copolymers. Further, a polymer having a branched main chain and three or more terminal portions, or a so-called dendrimer may be used.

[Light emitting layer]
The light emitting layer 3c may be an independent light emitting layer for red, green and blue light emission, or a mixed light emitting layer thereof, or a compound having a hole transporting property (hole transporting compound), or A compound having an electron-transporting property (electron-transporting compound) can also be contained. An organic EL material may be used as a dopant material, and a hole transporting compound, an electron transporting compound or the like may be appropriately used as a host material. The organic EL material is not particularly limited, and a substance that emits light at a desired emission wavelength and has good emission efficiency may be used.

  Any known material can be applied as the organic EL material. For example, although it may be a fluorescent material or a phosphorescent material, it is preferable to use a phosphorescent material from the viewpoint of internal quantum efficiency. The light emitting layer may have a single layer structure or a multilayer structure made of a plurality of materials, if desired. For example, a fluorescent material may be used for the blue light emitting layer and a phosphorescent material may be used for the green and red light emitting layers, and various combinations may be used. Further, a diffusion prevention layer may be provided between the light emitting layers.

  Examples of the fluorescent material that gives blue light emission (blue fluorescent dye) include naphthalene, perylene, pyrene, chrysene, anthracene, coumarin, p-bis(2-phenylethenyl)benzene, and derivatives thereof.

Examples of the fluorescent material (green fluorescent dye) that emits green light include quinacridone derivatives,
Examples include coumarin derivatives and aluminum complexes such as Alq3 (tris (8-hydroxy-quinoline) aluminum).

  Examples of the fluorescent material that gives yellow emission (yellow fluorescent dye) include rubrene and perimidone derivatives.

Examples of the fluorescent material (red fluorescent dye) that emits red light include DCM (4-(dicyanome
thylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran)-based compounds, benzopyran derivatives, rhodamine derivatives, benzothioxanthene derivatives, azabenzothioxanthene and the like.

  The phosphorescent material is selected from, for example, long period type periodic table (hereinafter, unless otherwise specified, "periodic table" means long period type periodic table) from groups 7 to 11. An organometallic complex containing a metal can be used. Preferable examples of the metal selected from Groups 7 to 11 of the periodic table include ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum and gold. As the ligand of the complex, a ligand in which a (hetero)aryl group such as a (hetero)arylpyridine ligand or a (hetero)arylpyrazole ligand is linked to pyridine, pyrazole, phenanthroline or the like is preferable, and phenyl is particularly preferable. Pyridine ligands and phenylpyrazole ligands are preferred. Here, (hetero)aryl represents an aryl group or a heteroaryl group.

  Specific examples of the phosphorescent material include tris(2-phenylpyridine)iridium (so-called Ir(ppy)3), tris(2-phenylpyridine)ruthenium, tris(2-phenylpyridine)palladium, and bis(2-phenyl). Pyridine) platinum, tris(2-phenylpyridine) osmium, tris(2-phenylpyridine) rhenium, octaethyl platinum porphyrin, octaphenyl platinum porphyrin, octaethyl palladium porphyrin, octaphenyl palladium porphyrin and the like.

  The light emitting layer may contain a hole transporting compound as its constituent material. Here, of the hole transporting compounds, examples of the low molecular weight hole transporting compound include various compounds exemplified as the hole transporting compound in the hole injection layer 3a described above, and, for example, diphenylnaphthyl. Aromatic diamines represented by diamines (so-called α-NPD) in which two or more tertiary amines are substituted and two or more condensed aromatic rings are substituted with nitrogen atoms, and 4,4′,4″- Aromatic amine compounds having a starburst structure such as tris(1-naphthylphenylamino)triphenylamine, aromatic amine compounds composed of triphenylamine tetramers, and 2,2′,7,7′-tetrakis Examples thereof include spiro compounds such as -(diphenylamino)-9,9'-spirobifluorene.

  The light emitting layer may contain an electron transporting compound as its constituent material. Here, of the electron transporting compounds, examples of the low molecular weight electron transporting compounds include 2,5-bis(1-naphthyl)-1,3,4-oxadiazole (so-called BND) and 2 ,5-bis(6'-(2',2"-bipyridyl))-1,1-dimethyl-3,4-diphenylsilole (so-called PyPySPyPy), bathophenanthroline (so-called BPhen), 2,9 -Dimethyl-4,7-diphenyl-1,10-phenanthroline (so-called BCP, bathocuproin), 2-(4-biphenylyl)-5-(p-tert-butylphenyl)-1,3,4-oxadiazole (So-called tBu-PBD), 4,4'-bis(9H-carbazol-9-yl)biphenyl (so-called CBP) and the like can be mentioned.

[Electron transport layer]
The electron transport layer 3d is provided for the purpose of further improving the light emission efficiency of the organic EL device, and efficiently transports the electrons injected from the cathode between the electrodes to which an electric field is applied toward the light emitting layer. And an electron transporting compound capable of

  The electron-transporting compound used in the electron-transporting layer generally has high electron injection efficiency from the cathode and the electron-injection layer 3e, and has high electron mobility and can efficiently transport the injected electrons. Compounds are used. Examples of compounds satisfying such conditions include metal complexes of Alq3 and 10-hydroxybenzo[h]quinoline, oxadiazole derivatives, distyrylbiphenyl derivatives, silole derivatives, 3-hydroxyflavone metal complexes, and 5-hydroxyflavone. Metal complex, benzoxazole metal complex, benzothiazole metal complex, trisbenzimidazolylbenzene, quinoxaline compound, phenanthroline derivative, 2-t-butyl-9,10-N,N'-dicyanoanthraquinonediimine, n-type hydrogenated amorphous Examples thereof include high-quality silicon carbide, n-type zinc sulfide, and n-type zinc selenide.

[Electron injection layer]
The electron injection layer 3e plays a role of efficiently injecting electrons injected from the cathode into the electron transport layer or the light emitting layer. For example, in the electron injection layer 3e, a nitrogen-containing heterocyclic compound such as bathophenanthroline or an organic electron transport compound represented by a metal complex such as an aluminum complex of 8-hydroxyquinoline can be used. Further, the electron injection efficiency can be increased by doping the electron injection layer 3e of the organic electron transport compound with the electron donating material. Examples of the electron donating material include alkali metals such as sodium and cesium, alkaline earth metals such as barium and calcium, their compounds (CsF, Cs2CO3, Li2O, LiF), sodium, potassium, cesium and lithium. , An alkali metal such as rubidium, or the like is used.

  As a method for forming each of the organic layers 3 described above, a dry coating method such as a sputtering method or a vacuum deposition method, or a wet coating such as a screen printing, a spray method, an inkjet method, a spin coating method, a gravure printing, or a roll coater method. The law is known. For example, the hole injection layer, the hole transport layer, and the light emitting layer are uniformly formed by a wet coating method, and the electron transport layer and the electron injection layer are sequentially formed by a dry coating method. You may film. Further, all functional layers may be sequentially formed to have uniform film thickness by a wet coating method.

[Reflective electrode]
It is preferable that the material of the reflective electrode 4 of the cathode includes a metal having a low work function in order to efficiently inject electrons, and for example, a suitable metal such as tin, magnesium, indium, calcium, aluminum, silver, or the like Alloy is used. Specific examples thereof include low work function alloy electrodes such as magnesium-silver alloy, magnesium-indium alloy, and aluminum-lithium alloy. The reflective electrode 4 can be formed as a single layer film or a multilayer film on the organic layer 3 by a sputtering method, a vacuum deposition method, or the like. Note that the film thickness is not limited as long as it is a thickness that maintains the reflective action of the reflective electrode 4.

  FIG. 4 shows an organic EL panel OELD facing from the back surface 1b side of the substrate 1. The metal mirror surface portion MIR and the reflective electrode 4 are formed between adjacent banks BK along the y direction. The metal mirror surface portion MIR and the reflective electrode 4 are formed by using a bank BK having a so-called reverse taper structure in which the side surfaces of the bank BK shown in FIG. 2 are narrowed toward the transparent electrode 2 side. First, the reverse taper structure bank BK made of a transparent dielectric material is provided on the transparent electrode 2 along the y direction by photolithography or the like. Then, a predetermined organic layer 3 is formed on the translucent electrodes 2 between every other banks BK by an inkjet method or the like. Then, a reflective electrode material is deposited on the organic layer 3 between the banks BK and the transparent electrode 2 and the top surface of the bank BK by a vapor deposition method or the like. As a result, as shown in FIG. 2, the metal film of the reflective electrode material is divided into the metal mirror surface portion MIR and the reflective electrode 4 across the bank BK. A metal film 4M made of the same material as the metal mirror surface portion MIR and the reflective electrode 4 is also formed on the top surface of the bank BK, and the metal film 4M contributes to the mirror function of the mirror device if the bank BK is a transparent dielectric material. .. As described above, in the case of the first embodiment, the metal mirror surface portion MIR and the mirror surface of the metal film 4M can be brought close to each other to the extent that they overlap the organic EL element OEL. Furthermore, according to such a method, the reflective electrode 4 of the organic EL element OEL and the bus line also serving as a mirror can be formed at the same time, which is a great advantage.

  Next, the operation of the organic EL panel of the mirror device will be described with reference to FIG. When a driving voltage is applied to the light emitting layer 3c in the organic layer through the transparent electrode 2 and the reflective electrode 4, the light generated in the light emitting layer 3c passes through the transparent electrode 2 and is further reflected. After being reflected by the electrode 4, it passes through the translucent electrode 2 and about several tens of percent is taken out from the front surface of the translucent substrate 1. That is, of the light emitted from the light emitting layer 3c, the light L1 having a critical angle of each interface or less, which passes through the translucent electrode 2 to the glass substrate 1, and the light L2 traveling to another reflective electrode 4 is reflected there. The light travels through the layer 3 c and the transparent electrode 2 to the glass substrate 1, and those lights are emitted to the front space of the substrate 1. The light L3 that exceeds the remaining critical angle is totally reflected and travels to the bank BK. The light emitted from the end face of the light emitting layer 3c and the light traveling in the lateral direction also enter the bank BK. The light entering these banks BK is reflected by the metal film 4M and the like, and emitted from the bank BK to the front side space through the substrate 1. On the other hand, external light L4, L5 entering from the space on the front surface side of the substrate 1 is reflected by the metal mirror surface portion MIR between the organic EL elements OEL and the metal film 4M of the bank BK, and further reflected by the reflective electrode 4. It is emitted to the outside.

  Hereinafter, a modified example of the first embodiment will be mainly described with reference to FIGS. 6 and 7 as to portions different from the first embodiment. The elements denoted by the same reference numerals as those in the first embodiment are the same, and therefore their explanations are omitted.

  FIG. 6 shows a modification of the mirror device which is the same as the embodiment shown in FIG. 2 except that the transparent dielectric film TR is arranged between the metal mirror surface portion MIR and the transparent electrode 2. The metal mirror surface portion MIR is electrically connected to the transparent electrode 2 in the gap between the transparent dielectric film TR and the adjacent bank BK and functions as a bus line. By inserting the transparent dielectric film TR and adjusting the film thickness thereof, a mirror surface having the same distance from the back surface 1b of the substrate 1 to the reflective electrode 4 and the metal mirror surface portion MIR can be achieved.

  FIG. 7 shows a modification of the mirror device which is the same as the embodiment shown in FIG. 2 except that the metal mirror surface portion MIR and the substrate 1 are brought into contact with each other. In this case, in the embodiment shown in FIG. 2, the translucent electrode 2 is formed by expanding the film along the xy direction on the substrate 1 and functions as a common anode of a plurality of organic EL elements OEL. In this modified example, the strip-shaped light-transmitting electrodes 2A extend in parallel in the y direction between the banks BK on the substrate 1 for each organic EL element OEL and are juxtaposed and connected to the metal mirror surface portion MIR.

  According to the mirror device having the above configuration, it can be used as a mirror with illumination such as a hand mirror or a vanity mirror, and can also be used as an advertising board or a mirror/illumination that is attached to a pillar, a ceiling, or the like to make the space in a store look wide. ..

  Hereinafter, with respect to the second embodiment, portions different from the first embodiment will be mainly described with reference to FIG. The elements denoted by the same reference numerals as those in the first embodiment are the same, and therefore their explanations are omitted.

  As shown in FIG. 8, the second embodiment is different from the first embodiment except that each of the organic EL element OEL and the metal mirror surface portion MIR is arranged in a checkered pattern, that is, in a matrix shape, not in a stripe shape but in a rectangular shape. It has the same configuration as. That is, in one x direction of the substrate 1, the red organic EL element R, the metal mirror surface portion MIR, the blue organic EL element B, the metal mirror surface portion MIR, the green organic EL element G, the metal mirror surface portion MIR, and the red organic EL element again. In the bank extending direction (y direction), which is arranged in order with R and intersects in one direction, the light emitting units are arranged so that the light emitting portions for each row have the same light emitting color when all the lights are emitted. Also in this case, the light emitting portions of the organic EL element OEL and the metal mirror surface portions MIR are alternately arranged at a constant interval. The organic EL elements OEL and the metal mirror surface portion MIR which are juxtaposed in a matrix or stripe are arranged so that the light emitting portions emit light with a uniform distribution during light emission.

  As shown in FIG. 9, in the case of Example 2, a bank BKA having a so-called forward taper structure in which the side surface of the bank is widened toward the transparent electrode 2 side is adopted instead of the bank having the reverse taper structure, and the reflective electrode is used. The metal film of the material is not divided into the metal mirror surface portion MIR and the reflective electrode 4. Therefore, the metal mirror surface portion MIR and the reflective electrode 4 are made of the same metal and serve as a common electrode having the same potential. Further, the strip-shaped light-transmissive electrodes 2A extend in parallel in the y direction between the banks BK on the substrate 1 for each organic EL element OEL and are arranged in parallel. A metal bus line MBL electrically connected to supply a power supply voltage to the transparent electrodes 2A is provided on each end side of the transparent electrodes 2A embedded in the bank BK along the y direction. It is formed by stretching. Although not shown, the bus line MBL of the organic EL element OEL is connected to the element driving section. In addition, immediately below the metal mirror surface portion MIR, a transparent dielectric film TR is arranged between the metal mirror surface portion MIR and the organic layer 3 and electrically insulated, so that the organic EL element is not formed and a non-light emitting portion is formed. ..

  Further, as shown in FIG. 10, between the adjacent banks BK, the light emitting portions of the organic EL elements OEL and the metal mirror surface portions MIR are alternately arranged in the y direction. As in FIG. 9, immediately below the metal mirror surface portion MIR is a non-light emitting portion which is not an organic EL element because the transparent dielectric film TR is arranged and insulated between the metal mirror surface portion MIR and the organic layer 3.

  Further, a modified example of the second embodiment will be mainly described with reference to FIG. 11 regarding parts different from the second embodiment. Since the elements denoted by the same reference numerals as those in the second embodiment are the same, the description thereof will be omitted.

  FIG. 11 is the same as the embodiment shown in FIG. 10 except that the transparent dielectric film is not provided immediately below the metal mirror surface portion MIR, and a through opening is provided in the transparent electrode 2 at the site where the metal mirror surface portion MIR is to be formed. A modified example of the mirror device of FIG. The metal mirror surface portion MIR of the reflective electrode material is in contact with the organic layer 3, but since there is no light-transmitting electrode 2, the portion directly below the metal mirror surface portion MIR is a non-light emitting portion.

  FIG. 12 shows a modification of the mirror device which is the same as the embodiment shown in FIG. 8 except that the light emitting portion of the organic EL element OEL and the metal mirror surface portion MIR are arranged in groups. In the embodiment of FIG. 8, the organic EL elements OEL and the metal mirror surface portions MIR are always arranged alternately. However, in this modified example, as shown in FIG. 12, the organic EL elements OEL are arranged in a certain row (x direction). 3 (R, G, B) and then three metal mirror surface portions MIR are arranged, and further, a plurality of organic EL elements OEL and metal mirror surface portions MIR are alternately arranged in a row (y direction). The organic EL element is divided into a plurality of organic EL element groups having a smaller number, and similarly, the plurality of metal mirror surface portions is divided into a plurality of metal mirror surface portion groups having a smaller number, and the metal mirror surface portion MIR One group and one group of the organic EL elements OEL are alternately arranged in a group configuration in which they are alternately arranged. Therefore, in the mirror device, one group of the plurality of metal mirror surface portions MIR and one group of the plurality of organic EL elements OEL may be alternately arranged.

  Next, although not shown, in any of the above-described mirror devices, a sealing member that covers the light emitting portions of the plurality of organic EL elements formed on the back surface 1b of the substrate 1 and seals them is provided. .. A glass-shaped transparent sealing cap made of glass may be used as the sealing member. The transparent sealing cap is fixed to the periphery of the light emitting portion with an adhesive so as to cover the light emitting portion and hermetically protects the light emitting portion. The inside of the transparent sealing cap may be sealed by filling it with an inert gas or an inert liquid. Further, as the sealing member, a transparent resin such as polyparaxylylene or a gas barrier sealing film composed of a multilayer of an inorganic film such as a silicon oxide film and an organic film may be used. As described above, it is preferable that the light emitting portion of the organic EL element is configured not to come into contact with moisture and oxygen in the atmosphere by the sealing member.

  In addition, in the above-mentioned examples, as the translucent substrate 1, a quartz or glass plate, a metal plate or a metal foil, a bendable resin substrate, a plastic film or a sheet, or the like can be used. A glass plate and a transparent plate made of synthetic resin such as polyester, polymethacrylate, polycarbonate and polysulfone are particularly preferable. When using a synthetic resin substrate, it is necessary to pay attention to the gas barrier property. If the gas barrier property of the substrate is too small, the organic EL element may be deteriorated by the outside air passing through the substrate, which is not preferable. Therefore, a method of providing a dense silicon oxide film or the like on at least one surface of the synthetic resin substrate to secure the gas barrier property is also one of the preferable methods.

  In order to increase the extraction efficiency of the output light, the front surface 1a of the substrate 1 covers the light emitting portion and has a light extraction uneven structure with an area exceeding this, for example, an uneven surface structure by a water blast method or a fine sandblast method. (Not shown) may be made, and a light extraction film (not shown) may be further attached.

  Further, in the above-described embodiment, a so-called bottom emission type organic EL panel in which the translucent electrode 2 is formed on the back surface of the translucent substrate 1 and the light generated in the organic layer 3 is extracted from the front surface 1a of the substrate 1 is provided. As described above, in a further embodiment, a mirror device of a so-called top emission type organic EL panel can be constructed.

  Hereinafter, with respect to the top emission type embodiment 3 in which the film forming order of the translucent electrode and the reflective electrode is exchanged, the part different from the embodiment 1 will be mainly described with reference to FIG. The elements denoted by the same reference numerals as those in the first embodiment are the same, and therefore their explanations are omitted.

  As shown in FIG. 13, Example 3 uses a bank BKA having a forward taper structure and arranges the reflective electrode 4A, the organic layer 3 and the translucent electrode 2 in order from the substrate, and further, for example, a cathode. The strip-shaped reflective electrode 4A and the metal mirror surface portion MIR are arranged in parallel with each other between the banks BKA on the substrate 1 so as to extend in parallel in the y direction, and are arranged side by side. As shown in FIG. 13, in each of the organic EL elements of the mirror device of the top emission type organic EL panel, the transparent electrode 2 extends on the organic layer 3 and the metal mirror surface portion MIR along the xy direction. It has been formed into a film. The transparent electrode 2 functions as a common anode, for example, for a plurality of organic EL elements OEL. The metal mirror surface portion MIR is electrically connected to the translucent electrode 2. The metal mirror surface portion MIR is connected to a power source (not shown), and the metal mirror surface portion MIR functions as a bus line that supplies a power supply voltage to the connected transparent electrode 2. In this example, by applying a voltage between the transparent electrode 2 and the reflective electrode 4A, almost all the light generated in the organic layer 3 is extracted from the transparent electrode 2 side.

  Further, although the organic layer is the light emitting laminate in the above-mentioned embodiments, the light emitting laminate can also be formed by laminating the inorganic material films.

  Further, in the above embodiment, an example in which a plurality of organic EL elements R, G, B are arranged side by side is shown, but the present invention is not limited to this, and a laminated structure or a mixture of light emitting layers such as a tandem structure each including a plurality of light emitting layers. Similar effects can be obtained even when a plurality of white light emitting organic EL elements using the light emitting layer are arranged in parallel.

1 substrate 2 translucent electrode 3 organic layer 3a hole injection layer 3b hole transport layer 3c light emitting layer 3d electron transport layer 3e electron injection layer 4 reflective electrode 4M metal film BK bank MBL bus line MIR metal mirror surface OEL organic EL element

Claims (1)

Board,
A plurality of organic EL elements arranged on one surface of the substrate,
A plurality of metal mirror surface portions arranged on the one surface;
Equipped with
Each of the plurality of organic EL elements has an organic layer formed between a translucent electrode and a reflective electrode,
The metal mirror surface portion is separated from the organic layer,
A light emitting device, wherein at least a part of the translucent electrode overlaps with the metal mirror surface portion when viewed from a direction perpendicular to the first surface.

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