JP2003257661A - Organic electroluminescence element, image forming device using it, portable terminal unit, and manufacturing method for such electroluminescence element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic electroluminescence element of long lifetime capable of maintaining a high light emitting performance, an image forming device of long lifetime capable of maintaining a high light emitting performance, a portable terminal unit light in the weight and assuring a long service time, and also provide a method to manufacture such electroluminescence elements through simple processes, with a high easiness to conduct the works, and with a high productivity. <P>SOLUTION: The organic electroluminescence element includes a base board 1 on which at least an anode 2 to inject holes, a light emitting layer 4 having a light emission region, and a cathode to inject electrons are provided, wherein the area of the light emission part including the light emitting layer is formed greater than the area of an opening to take out the light from the light emitting layer. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to various display devices, light sources or backlights of display devices, organic electroluminescence elements used for light emitting elements used in optical communication equipment, and image forming apparatuses using the same. , A portable terminal, and a method for manufacturing an organic electroluminescent element.

[0002]

2. Description of the Related Art An electroluminescence element is a light emitting device utilizing the electroluminescence of a solid fluorescent substance. At present, an inorganic electroluminescence element using an inorganic material as a light emitter has been put into practical use, and it is used as a backlight of a liquid crystal display. Some applications are being developed for flat displays and the like. However, the voltage required to emit light from an inorganic electroluminescent device is 100V.
Since it is high as described above and it is difficult to emit blue light, it is difficult to realize full color by the three primary colors of RGB. Further, in the inorganic electroluminescence element, since the material used as the light emitter has a very large refractive index, it is strongly affected by total reflection at the interface and the extraction efficiency of light into the air for actual light emission is 10 to 20. %, Which is low and it is difficult to achieve high efficiency.

On the other hand, research on electroluminescent elements using organic materials has been attracting attention for a long time and various studies have been made, but since the luminous efficiency is very poor, it has not progressed to full-scale practical research. It was

However, in 1987, Kodak C.I.
W. Tang et al. Proposed an organic electroluminescence device having a function-separated laminated structure in which an organic material is divided into two layers, a hole transport layer and a light emitting layer, and 1000 cd / m ² or more despite a low voltage of 10 V or less. It was revealed that a high emission luminance of [C. W. Tan
g and S. A. Vanslyke: Appl. P
hys. Lett, 51 (1987) 913, etc.].
Since then, organic electroluminescent elements have begun to receive a lot of attention, and even now, research is being actively conducted on organic electroluminescent elements having a similar function-separated laminated structure, especially for the practical application of organic electroluminescent elements. High efficiency and long life, which are indispensable for OLEDs, have been thoroughly studied, and in recent years, displays and the like using organic electroluminescence elements have been put to practical use.

Here, the structure of a conventional general organic electroluminescent element will be described with reference to FIG.

FIG. 11 is a cross-sectional view of a main part of a conventional organic electroluminescence device.

In FIG. 11, 1 is a substrate, 2 is an anode, 3
Is a hole transport layer, 4 is a light emitting layer, and 5 is a cathode.

As shown in FIG. 11, the organic electroluminescence element is an ITO formed on a substrate made of glass or the like by a sputtering method or a resistance heating vapor deposition method.
And the like, and N, N'-diphenyl-N, N'-bis (3-methylphenyl) -1, which is also formed on the anode 2 by a resistance heating vapor deposition method or the like.
1'-diphenyl-4,4'-diamine (hereinafter, TPD
) And the like, and 8-Hydroxy formed on the hole transport layer 3 by a resistance heating vapor deposition method or the like.
quinoline Aluminum (hereinafter, Alq
₃ ) and the like, and a cathode 5 made of a metal film having a film thickness of 100 nm to 300 nm formed on the light emitting layer 4 by a resistance heating vapor deposition method or the like.

When a DC voltage or a DC current is applied with the anode 2 of the organic electroluminescence device having the above structure as a positive electrode and the cathode 5 as a negative electrode, a voltage is applied from the anode 2 to the light emitting layer 4 via the hole transport layer 3. Holes are injected and electrons are injected from the cathode 5 into the light emitting layer 4. Light emitting layer 4
In this case, recombination of holes and electrons occurs, and a luminescence phenomenon occurs when the excitons generated accompanying this transition from the excited state to the ground state.

FIG. 6 is a graph showing the relationship between the driving time and the relative luminance in the organic electroluminescence element. FIG. 6 shows changes in brightness for three types of initial brightness.

FIG. 7 is a graph showing the relationship between the driving time and the brightness in the organic electroluminescence element. As shown in FIG. 6, as the brightness becomes higher, the driving time of the element, that is, the life becomes shorter. Further, as shown in FIG. 7, the drive voltage must be increased in order to increase the brightness. Therefore, in order to realize an organic electroluminescence device that can maintain a long life and high light emission performance, it is important to reduce the brightness and increase the light emission efficiency. However, in order to put the organic electroluminescence device into practical use, sufficient brightness is required, and therefore simply lowering the brightness is not effective.

As described above, the organic electroluminescence device has a correlation between brightness and life. Therefore, there is a demand for an organic electroluminescence device that sufficiently satisfies both the improvement in brightness and the long life.

As a conventional organic electroluminescence element, Japanese Patent Publication No. 2773720 discloses an organic thin film electroluminescence element used for a light source for segment or dot display, which is formed by forming a lens structure on the light extraction side of a substrate. An organic thin film electroluminescent device that improves the extraction efficiency is described.

Further, Japanese Unexamined Patent Publication No. 10-189251 discloses a display device using an organic electroluminescence element or the like, and describes forming a means for converting a light emission angle in a transparent substrate.

Further, Japanese Unexamined Patent Publication No. 10-308286 discloses an organic electroluminescence light emitting device which is suitable for use in consumer and industrial display devices and color displays, in which a light reflecting layer is formed on the side surface of the lower electrode. Describes an organic electroluminescent device that improves the light extraction efficiency.

[0016]

However, the above-mentioned conventional organic electroluminescence device has the following problems.

(1) Although the light extraction efficiency is improved, there is a problem that both the improvement in brightness and the long life are not sufficiently satisfied and the life is not extended.

(2) When used as an image forming apparatus such as a display constituted by an assembly of minute pixels, the area of the opening and the light emitting portion in the pixel area becomes small,
There is a problem that it is necessary to emit light with high brightness.

(3) There is a problem that the device structure does not prolong the service life.

(4) There is a problem that the visibility is deteriorated due to a change in the orientation of light, such as a decrease in viewing angle.

(5) Especially when used in a full-color display or the like, there is a problem that a color shift occurs because the viewing angle for each color is different.

The present invention solves the above-mentioned conventional problems, and provides an organic electroluminescence device capable of maintaining a long life and high light emission performance, and an image forming apparatus capable of maintaining a long life and high light emission performance. It is an object of the present invention to provide a portable terminal that is light in weight, has a long usage time, can be formed in a simple process, has high workability, and has high productivity.

[0023]

In order to solve the above-mentioned problems, the organic electroluminescence device of the present invention has an anode on which at least holes are injected, a light-emitting layer having a light-emitting region, and electrons on a substrate. In the organic electroluminescence device having the cathode, the area of the light emitting portion including the light emitting layer is formed larger than the area of the opening for taking out light from the light emitting layer.

With this structure, it is possible to provide an organic electroluminescence device which has a long life and can maintain high light emission performance.

The organic electroluminescence device of the present invention is an organic electroluminescence device having at least an anode for injecting holes, a light emitting layer having a light emitting region, and a cathode for injecting electrons on a substrate. hand,
The light emitting portion including the light emitting layer has a structure formed on a surface that is in a non-parallel relationship with the opening for taking out light from the light emitting layer.

With this structure, it is possible to provide an organic electroluminescence device which has a long life and can maintain high light emission performance.

Further, the image forming apparatus of the present invention is an organic electroluminescence device having at least an anode for injecting holes, a light emitting layer having a light emitting region, and a cathode for injecting electrons on a substrate, The area of the light emitting portion including the light emitting layer is larger than the area of the opening for taking out the light from the light emitting layer. The anode and the cathode of the organic electroluminescence element are individually electrically separated in a stripe shape to form one area. It is configured to have an image display array including the above pixels.

With this configuration, it is possible to provide an image forming apparatus using an organic electroluminescence element that can maintain a long life and high light emission performance.

Further, the image forming apparatus of the present invention is an organic electroluminescent device comprising, on a substrate, at least an anode for injecting holes, a light emitting layer having a light emitting region, and a cathode for injecting electrons, The area of the light emitting portion including the light emitting layer is formed to be larger than the area of the opening for taking out the light from the light emitting layer, and the anode or the cathode of the organic electroluminescence element is electrically isolated for each pixel. The anode or the cathode is configured to have an image display array by being scanned through at least one or more switching elements.

With this structure, it is possible to provide an image forming apparatus using an organic electroluminescence element capable of maintaining a long life and high emission performance.

Further, the portable terminal of the present invention includes a voice signal conversion unit for converting voice into a voice signal, an operation unit for inputting a telephone number and the like, and a display unit for displaying an incoming call display and a telephone number and the like.
A mobile terminal comprising: a transmission unit that converts a voice signal into a transmission signal; a reception unit that converts a reception signal into a voice signal; an antenna that transmits and receives a transmission signal and a reception signal; and a control unit that controls each unit. An organic electroluminescence device in which the display means has at least an anode for injecting holes, a light emitting layer having a light emitting region, and a cathode for injecting electrons on a substrate, and an area of a light emitting portion including the light emitting layer. Is an image display array in which an anode and a cathode of an organic electroluminescence element, which are formed to have a larger area than an opening for extracting light from a light emitting layer, are electrically separated into stripes, and each of which has one or more pixels. Or an organic electroluminescence device having an anode for injecting at least holes, a light emitting layer having a light emitting region, and a cathode for injecting electrons on a substrate. The area of the light emitting portion including the light emitting layer is larger than the area of the opening for extracting light from the light emitting layer, and the anode or the cathode of the organic electroluminescence element is electrically connected to each pixel. Separately configured, the anode or the cathode is configured to include an image forming apparatus having an image display array by being scanned through at least one or more switching elements.

With this configuration, it is possible to provide a portable terminal which is light in weight and long in use.

Further, in the method for manufacturing an organic electroluminescence element of the present invention, a concavo-convex structure is formed on a transparent substrate using a transparent material, and an anode for injecting at least holes and a light emitting region are formed on the upper surface thereof. And a cathode for injecting electrons.

With this configuration, it can be formed by a simple process,
It is possible to provide a method for manufacturing an organic electroluminescence device having high workability and high productivity.

Further, in the method for manufacturing an organic electroluminescence element of the present invention, a concavo-convex structure is formed on a substrate, and an anode for injecting at least holes, a light emitting layer having a light emitting region, and electrons are injected on the upper surface thereof. Is formed, and a transparent flattening structure is formed on the upper surface of the cathode using a transparent material so that the opening is flat.

With this structure, it can be formed by a simple process,
It is possible to provide a method for manufacturing an organic electroluminescence device having high workability and high productivity.

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION To achieve this object, an organic electroluminescence device according to claim 1 of the present invention comprises, on a substrate, an anode for injecting at least holes, and a light emitting layer having a light emitting region. An organic electroluminescence device having a cathode for injecting electrons, in which an area of a light emitting portion including a light emitting layer is formed to be larger than an opening area for taking out light from the light emitting layer. .

With this configuration, the following effects can be obtained.

(1) By increasing the area of the light emitting portion with respect to the area of the opening for taking out light, the luminance of the light emitting portion can be reduced while maintaining the effective luminance at a practical level.

(2) Since the luminance of the light emitting portion can be lowered, the highly efficient light emitting performance can be maintained for a long period of time.

(3) A high-brightness organic electroluminescence can be produced by using a conventional light-emitting layer having a low brightness but a long life.

(4) An organic electroluminescence device having a long life can be prepared by using a conventional light emitting layer having a high brightness but a short life, particularly a light emitting layer having a remarkable decrease in life with respect to increase in brightness. .

(5) By devising the arrangement of the light emitting layer, a more efficient organic electroluminescent element can be produced.

The opening in the present invention is a surface through which light emitted from the light emitting portion of the organic electroluminescence element is taken out into the air, and the light emitting portion is a surface on which light is actually emitted including the light emitting layer. That is.

Here, a transparent or semitransparent substrate can be used as the substrate, and an opaque substrate can be used when the surface opposite to the substrate is to be the opening.

As the substrate material, transparent or translucent soda lime glass, barium-strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, quartz glass, or other inorganic oxide glass, inorganic Inorganic glass, such as fluoride glass,
Alternatively, transparent or translucent polyethylene terephthalate, polycarbonate, polymethylmethacrylate,
Polymer films such as polyether sulfone, polyvinyl fluoride, polypropylene, polyethylene, polyacrylate, amorphous polyolefin, and fluororesin, or transparent or translucent As ₂ S ₃ , As ₄₀ S ₁₀ , S ₄₀
Chalcogenoid glass such as Ge ₁₀ , ZnO, Nb ₂ O ₅ ,
Materials such as metal oxides and nitrides such as Ta ₂ O ₅ , SiO, Si ₃ N ₄ , HfO ₂ , and TiO ₂ , or opaque silicon, germanium, silicon carbide, gallium arsenide,
A laminated substrate in which a plurality of substrate materials are laminated can be appropriately selected and used from semiconductor materials such as gallium nitride or the like, the transparent substrate material containing a pigment or the like, a metal material whose surface is subjected to an insulation treatment, and the like. It can also be used. Also,
A circuit composed of a resistor, a capacitor, an inductor, a diode, a transistor, etc. for driving the organic electroluminescence element may be formed on the surface of the substrate or inside the substrate.

A transparent electrode can be used as the anode. Materials for the transparent electrode include indium tin oxide (ITO), tin oxide (SnO ₂ ), zinc oxide (Zn oxide).
O) or the like, a transparent conductive film made of a mixture of metal oxides such as SnO: Sb (antimony), ZnO: Al (aluminum), or Al (aluminum), Cu ( Copper), Ti
A metal thin film such as (titanium) or Ag (silver), a metal thin film such as a mixed thin film of these metals or a laminated thin film, or a conductive polymer such as polypyrrole can be used. It is also possible to form a transparent electrode by laminating a plurality of the above-mentioned transparent electrode materials, and it is formed by various polymerization methods such as resistance heating evaporation, electron beam evaporation, sputtering method or electric field polymerization method. The transparent electrode preferably has a thickness of 1 nm or more in order to have sufficient conductivity or prevent uneven light emission due to unevenness on the substrate surface. In addition, 500n in order to have sufficient transparency
It is desirable to set the thickness to m or less.

Further, as the anode, in addition to the transparent electrode, Cr (chrome), Ni (nickel), Cu (copper),
Metals having a large work function such as Sn (tin), W (tungsten), Au (gold), or alloys containing these metals,
An oxide or the like can be used, and a stacked structure including a plurality of materials using these anode materials can also be used.

When the transparent electrode is not used as the anode, the cathode may be a transparent electrode. In that case, the anode is preferably formed of a material that reflects light, or the anode is preferably formed of a material that absorbs light in order to minimize the influence of external light.

An amorphous carbon film may be provided on the anode. In this case, both have a function as a hole injecting electrode. That is, holes are injected from the anode into the light emitting layer or the hole transport layer through the amorphous carbon film. The amorphous carbon film is formed between the anode and the light emitting layer or the hole transport layer by the sputtering method. Carbon targets obtained by sputtering include isotropic graphite, anisotropic graphite, glassy carbon and the like, and is not particularly limited, but isotropic graphite having high purity is suitable. Specifically, the advantage of the amorphous carbon film is that when the work function of the amorphous carbon film is measured using a surface analyzer AC-1 manufactured by Riken Keiki, the work of the amorphous carbon film is measured. The function is Wc = 5.40 eV. Here, the work function of ITO, which is generally used as an anode, is W
_{Since ITO} = 5.05 eV, it is possible to efficiently inject holes into the light emitting layer or the hole transport layer by using the amorphous carbon film. Further, in order to control the electric resistance value of the amorphous carbon film when the amorphous carbon film is formed by the sputtering method,
Reactive sputtering is performed in a mixed gas atmosphere of nitrogen or hydrogen and argon. Further, in the thin film forming technique such as the sputtering method, if the film thickness is 5 nm or less, the film has an island structure and a uniform film cannot be obtained. Therefore, if the thickness of the amorphous carbon film is 5 nm or less, efficient light emission cannot be obtained, and the effect of the amorphous carbon film cannot be expected. Also,
When the thickness of the amorphous carbon film is 200 nm or more, the color of the film becomes blackish, and the light emitted from the organic electroluminescence element cannot be sufficiently transmitted.

The material of the light emitting layer is preferably a phosphor having a fluorescent property in the visible region and having a good film-forming property, such as Alq ₃ or Be-benzoquinolinol (B
In addition to the eBq _2), 2,5- bis (5,7-di -t- pentyl-2-benzoxazolyl) -1,3,4-thiadiazole, 4,4'-bis (5,7 Bench-2-
Benzoxazolyl) stilbene, 4,4′-bis [5,7-di- (2-methyl-2-butyl) -2-benzoxazolyl] stilbene, 2,5-bis (5,7-
Di-t-benzyl-2-benzoxazolyl) thiophine, 2,5-bis ([5-α, α-dimethylbenzyl]
2-benzoxazolyl) thiophene, 2,5-bis [5,7-di- (2-methyl-2-butyl) -2-benzoxazolyl] -3,4-diphenylthiophene,
2,5-bis (5-methyl-2-benzoxazolyl)
Thiophene, 4,4'-bis (2-benzoxazolyl) biphenyl, 5-methyl-2- [2- [4- (5-
Methyl-2-benzoxazolyl) phenyl] vinyl] benzoxazolyl, 2- [2- (4-chlorophenyl) vinyl] naphtho [1,2-d] oxazole and other benzoxazoles, 2,2′- Benzothiazoles such as (p-phenylenedivinylene) -bisbenzothiazole, 2- [2- [4- (2-benzimidazolyl))
Phenyl] vinyl] benzimidazole, 2- [2-
(4-Carboxyphenyl) vinyl] benzimidazole-based optical brighteners such as benzimidazole, bis (8-quinolinol) magnesium, bis (benzo-8)
-Quinolinol) zinc, bis (2-methyl-8-quinolinolate) aluminum oxide, tris (8-quinolinol) indium, tris (5-methyl-8-quinolinol) aluminum, 8-quinolinol lithium, tris (5-chloro-8). -Quinolinol) gallium, bis (5-chloro-8-quinolinol) calcium, poly [zinc-bis (8-hydroxy-5-quinolinonyl) methane] and other 8-hydroxyquinoline-based metal complexes, dilithium epindridione, etc. Metal chelated oxinoid compounds, 1,4-bis (2-methylstyryl) benzene, 1,4- (3-methylstyryl) benzene, 1,4
-Bis (4-methylstyryl) benzene, distyrylbenzene, 1,4-bis (2-ethylstyryl) benzene, 1,4-bis (3-ethylstyryl) benzene,
Styrylbenzene compounds such as 1,4-bis (2-methylstyryl) 2-methylbenzene and 2,5-bis (4
-Methylstyryl) pyrazine, 2,5-bis (4-ethylstyryl) pyrazine, 2,5-bis [2- (1-naphthyl) vinyl] pyrazine, 2,5-bis (4-methoxystyryl) pyrazine, 2 , 5-bis [2- (4-biphenyl) vinyl] pyrazine, 2,5-bis [2- (1-pyrenyl) vinyl] pyrazine and other distilpyrazine derivatives, naphthalimide derivatives, perylene derivatives and oxa A diazole derivative, an aldazine derivative, a cyclopentadiene derivative, a styrylamine derivative, a coumarin derivative, an aromatic dimethylidin derivative, etc. are used. Furthermore, anthracene, salicylate, pyrene,
Coronene or the like is also used. Alternatively, a phosphorescent material such as faq-tris (2-phenylpyridine) iridium may be used.

The cathode is an electrode for injecting electrons, and it is necessary to efficiently inject the electrons into the light emitting layer or the electron transporting layer, and Al (aluminum) having a small work function,
Metals such as In (indium), Mg (magnesium), Ti (titanium), Ag (silver), Ca (calcium), and Sr (strontium), or oxides or fluorides of these metals and their alloys and laminated bodies. Etc. are generally used. When the anode is a transparent electrode, it is preferable that the cathode, which is the counter electrode, be formed of a material that reflects light, or the cathode be formed of a material that absorbs light in order to minimize the influence of external light. Preferably.

Further, as the cathode, an ultrathin film having a high light transmittance using a metal having a small work function is formed at the interface in contact with the light emitting layer or the electron transport layer, and a transparent electrode is laminated on the ultrathin film. It is also possible to form a transparent cathode. In particular, Mg, Mg-Ag alloys having a small work function, Al-Li alloys and Sr described in JP-A-5-121172.
A -Mg alloy, an Al-Sr alloy, an Al-Ba alloy or the like, or a laminated structure of LiO ₂ / Al, LiF / Al or the like is suitable as a cathode material.

Further, resistance heating vapor deposition, electron beam vapor deposition, and sputtering are used as the film forming method for these cathodes.

In addition to the single-layer structure of only the light emitting layer, a two-layer structure of a hole transporting layer and a light emitting layer or a light emitting layer and an electron transporting layer,
Any of a three-layer structure of a hole transport layer, a light emitting layer and an electron transport layer may be used. However, in the case of such a two-layer structure or a three-layer structure, the hole transport layer and the anode or the electron transport layer and the cathode are laminated so as to be in contact with each other.

Here, the hole transport layer is preferably one having a high hole mobility, being transparent and having a good film-forming property. In addition to TPD, porphine, tetraphenylporphine copper, phthalocyanine, copper phthalocyanine, titanium phthalocyanine oxide, and other porphyrin compounds, 1,1-bis {4- (di-P-tolylamino) phenyl} cyclohexane, 4,4 ′, 4 ″ -trimethyltriphenylamine, N, N, N ′, N′-tetrakis (P-tolyl)
-P-phenylenediamine, 1- (N, N-di-P-tolylamino) naphthalene, 4,4'-bis (dimethylamino) -2-2'-dimethyltriphenylmethane, N,
N, N ', N'-tetraphenyl-4,4'-diaminobiphenyl, N, N'-diphenyl-N, N'-di-m
-Tolyl-4, N, N-diphenyl-N, N'-bis (3-methylphenyl) -1,1'-4,4'-diamine, 4'-diaminobiphenyl, N-phenylcarbazol, etc. Aromatic tertiary amines, 4-di-P-tolylaminostilbene, 4- (di-P-tolylamino) -4 '
A stilbene compound such as-[4- (di-P-tolylamino) styryl] stilbene, a triazole derivative, an oxazizazole derivative, an imidazole derivative, a polyarylalkane derivative, a pyrazoline derivative, a pyrazolone derivative, a phenylenediamine derivative, , Annealed amine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, silazane derivatives, polysilane-based aniline-based copolymers, polymer oligomers, and styrylamine compounds Alternatively, an organic material such as an aromatic dimethylidene compound or poly-3-methylthiophene is used. Further, a polymer-dispersed hole transport layer in which a low molecular weight organic material for a hole transport layer is dispersed in a polymer such as polycarbonate is also used.

As the electron transport layer, oxadiazole derivatives such as 1,3-bis (4-tert-butylphenyl-1,3,4-oxadiazolyl) phenylene (OXD-7) and anthraquinodimethane derivatives are used. , Diphenylquinone derivatives and the like are used.

At least one of the anode and the cathode may be a transparent electrode. Further, both may be transparent electrodes, but in order to improve the light extraction efficiency, it is preferable that one is a transparent electrode and the other is formed of a material that reflects light. In order to minimize the influence of external light, if one is a transparent electrode, the other is made of a material that absorbs light, or a combination of a material that transmits light and a material that absorbs light. Is preferred.

Here, the transparency of the material constituting the organic electroluminescence element in the present invention includes that it is semitransparent, and it is at least transparent to the extent that it does not hinder the visual recognition of light emission by the organic electroluminescence element. Is shown.

The organic electroluminescent device according to claim 2 is an organic electroluminescent device comprising, on a substrate, at least an anode for injecting holes, a light emitting layer having a light emitting region, and a cathode for injecting electrons. Therefore, the light emitting portion including the light emitting layer is configured to be formed on a surface that is in a non-parallel relationship with the opening portion through which light from the light emitting layer is taken out. Since it is formed on a surface that is in a non-parallel relationship with the opening for extracting light from the layer, it is possible to improve light extraction efficiency and maintain highly efficient light emission performance.

(2) Since the light extraction efficiency can be improved, the luminance in the light emitting portion can be lowered, and the highly efficient light emitting performance can be maintained for a long period of time.

(3) By forming non-parallel surfaces, the area can be increased and the luminance in the light emitting portion can be further reduced, so that highly efficient light emitting performance can be maintained for a longer period of time.

(3) Since the manufacturing method for forming the light emitting portions on the surfaces having a non-parallel relationship is simple, the productivity is high.

(4) Since the light emitting surface can be freely laid out, it is easy to increase the area of the light emitting portion.

(5) Since the light emitting surface can be freely laid out, it is possible to optimize the design such as the life priority or the efficiency priority depending on the light emitting material. The effect is obtained.

Here, in the organic electroluminescence element in which the area of the light emitting portion including the light emitting layer is larger than the area of the opening for taking out light from the light emitting layer, the opening and the light emitting portion are in a parallel relationship. In this case, there is a method of stacking a plurality of light-transmissive elements, but since the manufacturing method becomes complicated, in order to realize such a structure more easily, a non-parallel relationship with the opening is used. It is effective to form the light emitting portion on the surface located at. Further, when a complicated manufacturing method may be adopted, it is possible to further increase the area by stacking the non-parallel surfaces as described above.

The invention described in claim 3 is the invention according to claim 1 or 2.
An organic electroluminescent element according to,
The light emitting portion is configured to be formed at least on the top of the uneven structure formed on the surface of the substrate. With this configuration, (1) the area of the light emitting portion is larger than the area of the opening portion, which is effective. When the same luminance is used, the life is improved as compared with the case where the same light emitting elements are used in parallel.

(2) Since the light emitting portion is in a non-parallel relationship with the opening, the light extraction efficiency can be improved and the luminance in the light emitting portion can be lowered.

(3) Since the brightness in the light emitting portion can be lowered, highly efficient light emitting performance can be maintained for a long period of time. The effect is obtained.

Here, for the concavo-convex structure, the same material as the substrate material can be used. Further, when the opening for taking out light is the substrate surface, it is preferable that the uneven structure is made of a transparent material.

Here, as the method of forming the uneven structure, a method of processing the surface of the substrate into an uneven shape by engraving or scraping, a method of exposing and developing using a highly workable material such as a resist material, There is a method of dropping corresponding to. For example, a method such as introducing a resist or the like instead of the ink of an inkjet printer and printing so as to obtain an appropriate uneven pattern, coating the entire surface with resist, and roughening the surface when it has an appropriate hardness gives unevenness. There are a forming method, a method of pasting a sheet-like material having an uneven structure previously formed thereon, and a method of forming the uneven structure on another medium and transferring it by heat or pressure.

The invention described in claim 4 is the same as claim 3
An organic electroluminescent element according to,
The concavo-convex structure is configured to have a quadrangular pyramid shape, a conical shape, or a curved shape. With this structure, (1) a quadrangular pyramid shape, a conical shape, or a curved shape is formed. Therefore, the angle design of the light is easy. In addition, the orientation of light can be provided with directivity.

(2) Since it has an isotropic structure, the angle design of light in all directions is easy. In addition, the orientation of light can be provided with directivity.

(3) Since it has an isotropic structure, it can be densely arranged in the plane, and the light extraction efficiency from any place is improved. In addition, the orientation of light can be provided with directivity.

(4) The quadrangular pyramid has symmetrical visual characteristics in the vertical and horizontal directions, the cone has symmetrical visual characteristics in all directions, and the curved line symmetric with respect to the axis in the height direction is all symmetrical. The visual characteristics in directions are symmetrical. The effect is obtained.

Here, the concavo-convex structure is a structure including a surface formed on the surface of the substrate and having a non-parallel relationship with the substrate, and specifically, for example, a triangular pyramid, a quadrangular pyramid, or a cone. Or other polygonal pyramid, or a truncated pyramid, a truncated pyramid, a truncated cone or other polygonal pyramid whose apex side is a plane,
Alternatively, it is a shape formed of a spherical surface or a paraboloid, or a structure different from a flat surface having an arbitrary shape, or a shape formed of a composite body thereof or the like. In order to have an isotropic visual characteristic, a symmetrical structure is preferable,
More preferably, it has a structure that is rotationally symmetric with respect to the axis in the height direction. Alternatively, isotropic visual characteristics can be obtained by arranging a plurality of arbitrary minute structures that are sufficiently small with respect to the pixels. For example, when used for a display or the like, the central pixel is provided with directivity in the front direction, and the peripheral pixels are provided with directivity in the central direction, thereby further reducing power consumption. be able to.

The invention according to claim 5 is the invention according to claim 3 or 4.
An organic electroluminescent element according to,
The substrate, the concavo-convex structure, and the anode or cathode formed on the substrate have a transparent structure. With this structure, (1) since they are made of a transparent material, light loss inside the element is prevented. Since the luminance can be reduced and the luminance in the light emitting portion can be lowered, highly efficient light emitting performance is maintained for a long period of time.

(2) Since the well-known method for forming an organic electroluminescence element can be used as it is, the formation is easy. The effect is obtained.

The invention described in claim 6 is the invention according to claims 3 to 5.
In the organic electroluminescence element according to any one of 1, a cathode or a cathode facing the reflection electrode, wherein an anode or a cathode formed on the uneven structure on the substrate is used as a reflection electrode for reflecting light emitted from the light emitting layer, The anode is a transparent electrode, and a transparent flattening structure having a light extraction surface as a flat surface is formed above the transparent electrode. With this configuration, (1) a thick member such as a substrate is eliminated. Therefore, bleeding of light is suppressed.

(2) Since the light loss inside the element can be reduced and the brightness in the light emitting portion can be lowered, highly efficient light emitting performance can be maintained for a long period of time.

(3) Since a free material can be selected as the substrate, it is possible to reduce the weight, improve the strength, enhance the function, and reduce the thickness.

(4) It is possible to enhance the functionality by embedding a driving circuit in the substrate, using a flexible substrate, or the like. The effect is obtained.

Here, as the transparent flattening structure, as a light-transmissive material, the materials mentioned above as the transparent substrate material, the transparent resist material, the transparent adhesive, or a transparent material obtained by combining them is used. It can be used, or can be appropriately selected and used from a composite means such as a sheet and an adhesive transparent resin having an uneven structure corresponding to the unevenness on a substrate formed into a sheet.

Further, the transparent flattening structure for making the opening used as a plane when the surface opposite to the substrate is the light extraction surface has unevenness corresponding to the uneven structure formed on the substrate surface. The surface opposite to this is a flat structure. This transparent structure can be formed by adhering a structure having an uneven surface corresponding to the uneven structure formed on the substrate surface by using an adhesion means such as transparent resin, or on the uneven structure. A transparent material having fluidity is poured into the formed organic electroluminescence element,
It can also be formed by curing with means such as ultraviolet rays, heat and cooling. Materials such as optical adhesives and resists are used as the transparent material having fluidity.

The invention according to claim 7 is the organic electroluminescent element according to claim 6, wherein the transparent planarizing structure is formed on a protective film formed on the transparent electrode. With this configuration, (1) a protective film is formed, and a transparent flattening film is formed on the upper surface of the protective film. Therefore, heat, stress, plasma, scratches, etc. on the transparent electrode and the lower organic layer are prevented. Organic electroluminescence can be manufactured without damaging stress, water, reactive gases such as oxygen, and the like.

(2) It is possible to freely select the forming method and the forming material to be formed on the protective film.

(3) Since the protective film is formed, the organic electroluminescence device can be shielded from the outside air and is excellent in long-term stability. The effect is obtained.

Here, as the protective film, SiON or Si is used.
Thin films of inorganic oxides such as O, SiN, SiO ₂ , Al ₂ O ₃ , and LiF, inorganic nitrides, inorganic fluorides, inorganic oxides, inorganic nitrides, inorganic fluorides, etc., or mixtures thereof. A glass film made of, for example, a thermosetting or photocurable resin, a silane-based polymer material having a sealing effect, or the like is used, and is formed by vapor deposition, sputtering, or a coating method. Alternatively, even a resin having a low gas barrier property can be used as a protective film in combination with another material having a high gas barrier property such as SiON.

The invention according to claim 8 is the organic electroluminescent element according to any one of claims 3 to 7, wherein the concavo-convex structure has a full angle of 60 to 170 with respect to the normal direction of the substrate. Angle of °, preferably 100-140 °
In this configuration, a high light extraction efficiency can be realized when the angle of the concavo-convex structure is the angle of this side.

(2) Since the angle of the concavo-convex structure is gradual, the possibility of short-circuiting of the organic electroluminescent element is reduced, and a long-life organic electroluminescent element can be manufactured.

(3) The possibility of disconnection of the electrodes and wirings of the organic electroluminescence element is reduced. The effect is obtained.

Here, in the case of an internal light-emitting device such as an organic electroluminescence device having a refractive index, the light emitted from the phosphor in the light emitting layer is emitted in all directions centering on the phosphor, When passing through the boundary surface of each medium, light is refracted / reflected according to Snell's law, and when the refractive index of the medium on the incident side is larger than the refractive index on the outgoing side, the outgoing angle of the refracted wave becomes 90. Light incident at an angle greater than the critical angle, ie, the critical angle, cannot pass through the interface and is totally reflected and the light is not extracted into the air. Therefore,
It is preferable that the concavo-convex structure is a structure that increases the area of the light emitting portion as compared with the opening, and is a structure that can effectively extract light. Considering the ease of designing such extraction of light and the ease of forming the structure, the uneven structure is preferably an isotropic uneven structure or an aggregate thereof, and in particular, a quadrangular pyramid and a cone. ,
Alternatively, a spherical shape having an appropriate curvature is preferable.

FIG. 8 is a conceptual diagram illustrating the layer structure of the organic electroluminescent element of the present invention. As shown in FIG. 8, the substrate 1, the anode 2, the light emitting layer 4, and the cathode 5 on which the quadrangular pyramidal concavo-convex structure 6 is formed are sequentially laminated. Note that θ is the apex angle of the concavo-convex structure 6.

The area of the light emitting portion of the organic electroluminescence element having such a structure is 1 with respect to the area of the opening.
/ Sin (90−θ / 2), and for example, the concavo-convex structure 6
When the irregular apex angle θ is 80 °, the area of the light emitting portion is 1.3 times. That is, according to the formula of 1 / sin (90−θ / 2), the light emitting portion area increases as the uneven apex angle θ becomes smaller. Therefore, the smaller the uneven apex angle θ is, the more advantageous the light emitting area becomes. I understand.

However, when such a concavo-convex structure is used, the light extraction efficiency greatly changes depending on the value of the concavo-convex apex angle θ and the refractive index of the concavo-convex portion. Must be considered. As shown by the arrow in FIG. 8, the light emitted from the light emitting layer 4 is directly extracted into the air through the uneven structure 6 or reaches the light emitting layer 4 on the opposite side through the uneven structure 6, Some of them are extracted into the air after being reflected by the cathode 5, or some of them are extracted by repeating total reflection at the interface and repeating these reflections, or light that is not extracted by total reflection. And so on.

Therefore, based on the layer structure of the organic electroluminescence device shown in FIG. 8, an optical simulation was carried out on the light extraction efficiency when the uneven top angle θ of the uneven structure was changed.

FIG. 9 shows the result of this optical simulation. FIG. 9 is a graph showing the result of the optical simulation, and shows the light extraction efficiency when the apex angle θ of the concavo-convex structure is changed, as a relative value with respect to the light extraction efficiency in the flat substrate having no concavo-convex structure. .

Here, the conditions of the optical simulation will be specifically described. The refractive index of each layer is as follows.
7, ITO = 2.0, substrate = 1.5, concavo-convex structure = 1.
7, air = 1.0, and the film thickness of each layer is the light emitting layer =
150 nm, ITO = 150 nm, substrate = 1 mm, and concavo-convex structure = 10 μm. Further, light from the light emitting layer is assumed to be totally reflected at the interface between the light emitting layer and the cathode,
Only absorption in ITO and substrate was considered. That is,
The cathode has a reflectance of 100%, and the light emitting layer, the ITO, the substrate, and the concavo-convex structure have transmittances of 80%, 97%, 97%, and 97, respectively.
%. Here, the value of the uneven top angle θ of the uneven structure is θ = 1
The simulation was performed at 40, 120, 100, and 80 °.

Under the above-mentioned conditions, FIG. 9 shows the calculation of the extraction efficiency value when the uneven top angle θ of the uneven structure is changed. The extraction efficiency is obtained when the uneven top angle θ is around 120 °. It can be seen that the value of is the largest.

From the above, the refractive index of the concavo-convex structure is 1.
7. Consider the life of the organic electroluminescence device when the apex angle θ is 120 °. In this case, as shown in FIG. 9, the light extraction efficiency is 1.7 times that of the organic electroluminescence element having no uneven structure. When the organic electroluminescence device having no uneven structure is illuminated with the same brightness, the light extraction efficiency is 1.7.
Therefore, the light required for the opening is 1 / 1.7, and since the area of the light emitting section is 1.15 times the area of the opening, the brightness in the light emitting section is (1 / 1.7). ) ×
(1 / 1.15) = 1 / 1.96, which is about 1/2
Therefore, the device is very advantageous in terms of life. Moreover, since the efficiency of the element is 1.7 times,
By using such a concavo-convex structure, a highly efficient and long-life device can be realized.

As can be seen from the results of the optical simulation described above, it is preferable that the concavo-convex structure is made of a surface in a specific angle range in order to increase the light extraction efficiency. Further, the organic electroluminescence element is made of a very thin film of about 150 nm, and when the uneven structure is formed at a steep angle, a defect such as a short circuit occurs at that angle, so the angle of the uneven structure is gentle. Preferably, the concavo-convex structure is 60 with respect to the normal direction of the substrate.
It is preferably in the range of 170 ° to 170 °, and more preferably in the range of 100 ° to 140 °.

The invention described in claim 9 is the invention according to claims 3 to 8.
The organic electroluminescence element according to any one of the items 1 to 4, wherein the uneven structure has a refractive index of 1.4 to 2.0,
The configuration is preferably 1.7 to 1.9. With this configuration, (1) light loss due to total internal reflection at the interface with the uneven structure increases as the refractive index of the material forming the uneven structure increases. Is smaller, the light extraction efficiency from the light emitting layer into the uneven structure is improved. The effect is obtained.

Here, based on the layer structure of the organic electroluminescence device shown in FIG. 8, an optical simulation was carried out on the light extraction efficiency when the refractive index of the concavo-convex structure was changed.

FIG. 10 shows the result of this optical simulation. FIG. 10 is a graph showing the result of the optical simulation, and shows the light extraction efficiency when the refractive index of the concavo-convex structure is changed, as a relative value with respect to the light extraction efficiency of the flat plate substrate having no concavo-convex structure.

Here, the conditions of the optical simulation will be specifically described. The refractive index of each layer is as follows.
7, ITO = 2.0, substrate = 1.5, air = 1.0, and the thickness of each layer is as follows: light emitting layer = 150 nm, ITO
= 150 nm, substrate = 1 mm, concavo-convex structure = 10 µm, and the concavo-convex apex angle θ of the concavo-convex structure was set to 120 °. It should be noted that all the light from the light emitting layer is reflected at the interface between the light emitting layer and the cathode, and only absorption in the light emitting layer, ITO and the substrate was considered. That is, the cathode has a reflectance of 100%, a light emitting layer,
The transmittance of ITO, the substrate, and the concavo-convex structure are 80%,
97%, 97% and 97%. Where the concavo-convex structure =
Simulations were performed with 1.3, 1.5, 1.7 and 1.9.

Under the above-mentioned conditions, FIG. 10 shows the calculated values of the extraction efficiency when the refractive index of the concavo-convex structure is changed, and the values of the extraction efficiency are around the refractive index value of 1.7. It turns out that it becomes the largest.

In addition, the uneven structure formed on the surface of the substrate or the structure corresponding to the opening in the transparent flattening structure is made of a transparent material having a small difference in refractive index from the organic material forming the light emitting layer. As is clear from the result of the optical simulation, it is preferable to use a material having a specific refractive index in order to increase the light extraction efficiency, and the material forming the concavo-convex structure has a refractive index of 1.4 to 2.0.
Is preferable, and more preferably 1.7 to 1.
It is 9.

Examples of the high refractive index material used as such a material include fluoride glass such as BaF or a high refractive index resin. For example, LaSF has a refractive index of 1.
8. BaSF has a refractive index of 1.7, polycarbonate has a refractive index of 1.6, and acrylic has a refractive index of 1.5. Alternatively, when the concavo-convex structure is minute, the transmittance in the visible light region may be somewhat low, so an inorganic oxide such as TiO ₂ or a material having a small light transmittance such as a transparent resist or a transparent adhesive is used. It is also possible.

According to a tenth aspect of the image forming apparatus, the anode and the cathode of the organic electroluminescent element according to any one of the first to ninth aspects are individually and electrically separated in a stripe shape, and one or more of them are formed. This configuration has an image display array composed of pixels of (1). With this configuration, (1) the light loss inside the element can be reduced, so that highly efficient light emission performance can be achieved over a long period of time. Can be maintained, and good display in a simple matrix system can be performed.

(2) Since the anode and the cathode are individually electrically separated into stripes, a large light emitting portion in a pixel can be taken.

(3) In the case of a simple matrix, instantaneous high brightness is required. Therefore, high efficiency and low brightness of the light emitting portion are very important. The effect is obtained.

Here, the organic electroluminescent element of the present invention can be used as an image forming apparatus for displaying an image, and these image forming apparatuses include a mobile phone, a PH.
It can be used for displays of portable information terminals such as S and PDA, displays for televisions, personal computers, car navigations, etc., displays for AV equipment such as stereos, radios, etc.

Further, it can be used for a lighting device as a light source such as a laser printer or a scanner. Alternatively, it can be used as a lighting device as a simple light source such as a lighting fixture such as an interior light or a light stand.

Among these, in consideration of advantages such as low power consumption of the organic electroluminescence element, easy reduction in weight and thickness, and fast response speed, a display device as a display for displaying an image in various electronic devices or It is preferably used for an image forming apparatus such as a lighting device as a light source such as a laser printer or a scanner.

Here, when the organic electroluminescence element is used as a display device such as a display or an illuminating device such as a printer light source, the above-mentioned design of light orientation is important.

When the uneven structure or the like in the present invention is used,
By making the uneven structure isotropic or linear, it is possible to give directivity to the light orientation, or by making the uneven structure anisotropic or non-linear, the light orientation is diffusive. Can have Alternatively, a light-collecting member such as a lens array is formed in the opening of the element having no directivity to obtain light emission with high directivity, or to form a member that scatters light in the opening of the element with high directivity. By that,
It is also possible to obtain uniform light emission without directivity.

For example, when it is used as a display of a mobile terminal or a cash dispenser, its display state needs to be recognizable only by the user himself, and it is preferable that the visibility from the surroundings is low. Since it is required that strong light can be emitted only to the portion of the photoconductor corresponding to, it is sufficient that there is brightness in the front direction from the opening, and it is preferable that the light emission in the peripheral direction is small. In the above cases, it is preferable that the light emitted from the opening is strongly emitted in the frontal direction and weakly in the peripheral direction, and it is preferable that the light is extracted with high directivity.

Alternatively, when used as a display for a plurality of people such as a television or a display for advertisement,
The display state preferably has high visibility from the surroundings as well as the visibility in the front direction, and when used as a light source such as indoor lighting, it is preferable that the illumination target is uniformly irradiated with light. In the above case, it is preferable that the light emitted from the opening be uniformly emitted in all directions, and that uniform light extraction without directivity be performed.

In a display using an organic electroluminescence element having a concavo-convex structure, visibility may be reduced due to the influence of moire or the like. In order to suppress such a decrease in visibility, it is preferable that the concavo-convex structure is randomly arranged, or it is preferable that the concavo-convex structure is sufficiently small.

According to an eleventh aspect of the present invention, in the image forming apparatus, the anode or the cathode of the organic electroluminescence element according to any one of the first to ninth aspects is electrically separated for each pixel. At least one anode or cathode
By being scanned through one or more switching elements,
This structure is provided with an image display array. (1) Since the light loss inside the element can be reduced by this structure, it is possible to maintain highly efficient light emission performance and Good display in a matrix system can be performed.

(2) Since the anode or the cathode is electrically isolated for each pixel, it is not necessary to have a momentary high brightness, the brightness required for practical use is sufficient, and the brightness is stable for a long period of time. The light emission can be maintained.

(3) Since the anode or the cathode is scanned through at least one or more switching elements, free image formation can be realized and the high-speed response characteristic of the organic electroluminescence element can be fully utilized. it can.

(4) In the case of the active matrix, the area of the light emitting portion is likely to be small due to the switching elements and wirings arranged in the pixel. Therefore, such a large area and highly efficient measure is very advantageous. The effect is obtained.

Here, the organic electroluminescence element of the present invention can be used as an image forming apparatus for displaying an image, and these image forming apparatuses are a mobile phone, a PH.
It can be used for displays of portable information terminals such as S and PDA, displays for televisions, personal computers, car navigations, etc., displays for AV equipment such as stereos, radios, etc.

Further, it can be used for a lighting device as a light source such as a laser printer or a scanner. Alternatively, it can be used as a lighting device as a simple light source such as a lighting fixture such as an interior light or a light stand.

Among these, considering the advantages of the organic electroluminescence element such as low power consumption, easy weight reduction and thinning, and fast response speed, a display device as a display for displaying an image in various electronic devices or It is preferably used for an image forming apparatus such as a lighting device as a light source such as a laser printer or a scanner.

Here, when the organic electroluminescence element is used as a display device such as a display or an illuminating device such as a printer light source, the design of the above-mentioned light orientation is important.

When the uneven structure or the like in the present invention is used,
By making the uneven structure isotropic or linear, it is possible to give directivity to the light orientation, or by making the uneven structure anisotropic or non-linear, the light orientation is diffusive. Can have Alternatively, a light-collecting member such as a lens array is formed in the opening of the element having no directivity to obtain light emission with high directivity, or to form a member that scatters light in the opening of the element with high directivity. By that,
It is also possible to obtain uniform light emission without directivity.

For example, when it is used as a display of a mobile terminal or a cash dispenser, its display state needs to be recognizable only by the user himself, and it is preferable that the visibility from the surroundings is low, or when it is used as a printer light source, an opening portion. Since it is required that strong light can be emitted only to the portion of the photoconductor corresponding to, it is sufficient that there is brightness in the front direction from the opening, and it is preferable that the light emission in the peripheral direction is small. In the above cases, it is preferable that the light emitted from the opening is strongly emitted in the frontal direction and weakly in the peripheral direction, and it is preferable that the light is extracted with high directivity.

Alternatively, when it is used as a display for a plurality of people such as a television or a display for advertisement,
The display state preferably has high visibility from the surroundings as well as the visibility in the front direction, and when used as a light source such as indoor lighting, it is preferable that the illumination target is uniformly irradiated with light. In the above case, it is preferable that the light emitted from the opening be uniformly emitted in all directions, and that uniform light extraction without directivity be performed.

In a display using an organic electroluminescence element having a concavo-convex structure, visibility may be lowered due to the influence of moire or the like. In order to suppress such a decrease in visibility, it is preferable that the concavo-convex structure is randomly arranged, or it is preferable that the concavo-convex structure is sufficiently small.

According to a twelfth aspect of the invention, there is provided the image forming apparatus according to the tenth aspect or the eleventh aspect, wherein the concavo-convex structure is formed so that the size in the plane direction is smaller than the size in the plane direction of the pixel. With this configuration, (1) since the size of the concavo-convex structure in the plane direction is smaller than the size of the pixel in the plane direction, the concavo-convex structure can be freely arranged on the pixel. be able to.

(2) Since the openings in the pixels can be effectively arranged and the luminance in the light emitting portion can be lowered, the light emitting performance can be maintained for a long period of time.

(3) A plurality of concavo-convex structures can be arranged in one pixel, the orientation of light (angle distribution and intensity distribution and angle distribution in the pixel) can be designed, and optimal visibility can be designed. It is possible.

(4) When the apex angle is the same, the height of the unevenness is low, and it is difficult for problems such as short circuit and disconnection to occur. The effect is obtained.

According to a thirteenth aspect of the present invention, the display means is a portable terminal comprising the image forming apparatus according to any one of the tenth to twelfth aspects, and a voice signal for converting a voice into a voice signal. Conversion means, operation means for inputting a telephone number, etc., display means for displaying an incoming call display, telephone number, etc., communication means for converting a voice signal into a transmission signal, and reception means for converting a reception signal into a voice signal The antenna is configured to include an antenna that transmits and receives a transmission signal and a reception signal, and a control unit that controls each unit. With this configuration, (1) optical loss inside the element can be reduced, Highly efficient light emitting performance can be maintained, and weight reduction or long use time can be achieved by reducing the battery capacity and the like.

(2) Since the orientation of light can be changed, a higher function can be provided. The effect is obtained.

Here, when the organic electroluminescence element of the present invention is used as a display device such as a display or an illuminating device such as a printer light source, the design of the above-mentioned light orientation is important. For example, when used as a display of a mobile terminal or a cash dispenser, the display state needs only to be recognized by the user himself, and it is preferable that the visibility from the surroundings is low, or when used as a printer light source, it corresponds to the opening. Since it is required to irradiate strong light only to the photoconductor portion, it is sufficient that the opening has a brightness in the front direction, and it is preferable that the light emission in the peripheral direction is small.

The fourteenth aspect of the present invention is a method for manufacturing an organic electroluminescence device, which comprises forming a concavo-convex structure using a transparent material on a transparent substrate, and injecting at least holes into the upper surface thereof. This structure has an anode, a light emitting layer having a light emitting region, and a cathode for injecting electrons. With this structure, (1) the light emitting performance is maintained over a long period of time by a simple process. It is possible to create organic electroluminescence that can.

(2) Since the forming method is simple, workability is high and productivity is high. The effect is obtained.

A fifteenth aspect of the present invention is a method for manufacturing an organic electroluminescence device, wherein an uneven structure is formed on a substrate, and an anode for injecting at least holes and a light emitting region is formed on the upper surface of the uneven structure. A layer and a cathode for injecting electrons are formed, and a transparent flattening structure is formed on the upper surface of the layer using a transparent material so that the opening becomes a flat surface. With this configuration, (1) With a simple process, it is possible to produce organic electroluminescence capable of maintaining the light emitting performance for a long period of time.

(2) Since the forming method is simple, workability is high and productivity is high. The effect is obtained.

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

(Embodiment 1) An organic electroluminescence element according to Embodiment 1 of the present invention will be described.

FIG. 1 is a sectional view of an essential part of an organic electroluminescent element according to the first embodiment of the present invention.

In FIG. 1, 1 is a substrate, 6 is an uneven structure formed on the substrate 1, and 5 is a metal film having a thickness of 100 nm to 300 nm formed on the uneven structure 6 by a resistance heating vapor deposition method or the like. Cathode 4 is a light emitting layer made of Alq ₃ or the like formed on cathode 5 by resistance heating vapor deposition or the like, and 3 is a TP formed on light emitting layer 4 by resistance heating vapor deposition or the like.
A hole transport layer 2 made of D or the like, and ITO formed on the hole transport layer 3 by a sputtering method, a resistance heating vapor deposition method, or the like.
Is an anode composed of a transparent conductive film such as.

The anode 2 of the organic electroluminescent element in the first embodiment is used as a positive electrode, and the cathode 5 is used.
When a DC voltage or a DC current is applied with the negative electrode as a negative electrode, holes are injected from the anode 2 into the light emitting layer 4 through the hole transport layer 3 and electrons are injected from the cathode 5 into the light emitting layer 4. In the light emitting layer 4, recombination of holes and electrons occurs, and when the excitons generated accompanying this transition from the excited state to the ground state, a light emitting phenomenon occurs.

The organic electroluminescence element according to the first embodiment has the uneven structure 6 on the surface of the substrate 1 which is in contact with the cathode 5. Due to the concavo-convex structure 6, the area of the light emitting layer 4 is larger than the area of the light extraction opening, and due to the concavo-convex structure 6, the light emitted from the light emitting layer 4 is efficiently taken out into the air. It is supposed to be.

In the first embodiment, the case where the cathode 5 is formed on the upper surface of the substrate 1 has been described.
The structure is not particularly limited to this as described above, and the anode 2 can be formed on the upper surface of the substrate 1.

As for the form of sealing, an appropriate means such as forming a protective film and sealing can be adopted.
Alternatively, a combination of a protective film and a shield material may be used.

As described above, according to this embodiment, light can be efficiently extracted and the effective area of the light emitting layer can be increased, so that light emission with high efficiency and long life can be achieved. The performance can be maintained.

Further, the organic electroluminescent element according to the first embodiment can be used as an image forming apparatus such as a lighting device or a display device.

The constituent materials and forming methods of the substrate 1, the anode 2, the hole transporting layer 3, the light emitting layer 4, the cathode 5 and the concavo-convex structure 6 may be those mentioned above. it can.

Further, in the present embodiment, the case of the two-layer structure composed of the hole transport layer and the light emitting layer has been described, but the structure is not particularly limited to this as described above.

(Embodiment 2) An organic electroluminescent element according to Embodiment 2 of the present invention will be described.

FIG. 2 is a sectional view of an essential part of an organic electroluminescence element according to the second embodiment of the present invention.

In FIG. 2, 1 is a substrate, 2 is an anode, 3 is a hole transport layer, 4 is a light emitting layer, 5 is a cathode, 6 is a concavo-convex structure, and 7
Is a transparent flattening structure formed on the anode 2.

The organic electroluminescence element according to the second embodiment has the uneven structure 6 on the surface of the substrate 1 which is in contact with the anode. Due to this uneven structure 6, the area of the light emitting layer is larger than the area of the light extraction opening, and the light emitted from the light emitting layer is efficiently taken out into the air by the transparent flattening structure. It is preferable that the The constituent material and forming method of the concavo-convex structure or the transparent flattening structure may be appropriately selected from the above-mentioned constituent materials, forming methods and conventionally known materials so as not to prevent extraction of light emission from the light emitting layer. it can.

In the second embodiment, the case where the cathode 5 is formed on the upper surface of the substrate 1 has been described.
The structure is not particularly limited to this as described above, and the anode 2 can be formed on the upper surface of the substrate 1.

As for the form of sealing, an appropriate means such as forming a protective film and sealing can be adopted.
Alternatively, a combination of a protective film and a shield material may be used.

As described above, according to the present embodiment, light can be efficiently extracted and the effective area of the light emitting layer can be increased, so that light emission with high efficiency and long life can be achieved. The performance can be maintained.

The organic electroluminescent element according to the second embodiment can be used as an image forming apparatus such as a lighting device and a display device.

As the constituent material and forming method of the substrate 1, the anode 2, the hole transporting layer 3, the light emitting layer 4, and the cathode 5, the above-described constituent materials and forming methods and conventionally known materials can be used.

Further, in the present embodiment, the case of the two-layer structure composed of the hole transport layer and the light emitting layer has been described, but the structure is not particularly limited to this as described above.

(Embodiment 3) An image forming apparatus using an organic electroluminescence element according to Embodiment 3 of the present invention will be described.

FIG. 3 is a schematic perspective view of an image forming apparatus using an organic electroluminescence element according to the third embodiment of the present invention.

In FIG. 3, a substrate 1, an anode 2, a hole transport layer 3, a light emitting layer 4, a cathode 5, an uneven structure 6 and a transparent flattening structure 7 are shown.

In the third embodiment, as shown in FIG. 3, the anode 2 is linearly patterned, and the cathode 5 is also linearly patterned so as to be substantially orthogonal thereto.

The anode 2 and the cathode 5 of this image forming apparatus are connected to a drive circuit (driver) as drive means (not shown) with the anode 2 on the plus side and the cathode 5 on the minus side.
When a DC voltage or a DC current is applied to the light emitting layer 4, the light emitting layers 4 in the orthogonal portions emit light, which can be used as a simple matrix type image forming apparatus.

In the third embodiment, the substrate 1 has the concavo-convex structure 6 on the surface in contact with the anode 2. Due to the uneven structure 6, the area of the light emitting layer is larger than the area of the pixel opening, and the light extraction surface is flattened by the transparent flattening structure 7. The light is efficiently extracted by the combination of. Further, in FIG. 3, the case where the concavo-convex structure 6 and the size of the pixel are the same is shown, but the concavo-convex structure 6 is sufficiently larger than the size of each pixel in order to avoid a visual problem such as moire. It is preferable that a plurality of concavo-convex structures 6 are arranged in one pixel.

As described above, also in the image forming apparatus according to the third embodiment, the effective area of the light emitting layer can be increased and the light can be efficiently extracted, so that high efficiency and It is possible to maintain long-lived light emission performance.

The anode 2, the hole transport layer 3, the light emitting layer 4,
As the constituent material and the forming method of the cathode 5, the above-described constituent materials and forming methods and conventionally known materials can be used.

Further, in the third embodiment, the simple matrix type image forming apparatus has been described, but an active matrix type image forming apparatus may be used. In that case, light extraction is reduced to at least a pixel forming region. Instead, the uneven structure that increases the area of the light emitting layer may be formed. Alternatively, by forming a concavo-convex structure on a driving circuit such as a TFT, it is possible to increase the area of the opening, and it is possible to produce an image forming apparatus with higher efficiency and longer life.

Also, in the third embodiment, the light extraction surface is the surface side facing the substrate 1 (transparent flattening structure 7 side).
The case where the light extraction surface is the substrate 1 is described above.
In this case, the electrode on the substrate 1 side may be a transparent electrode, the electrode on the light extraction side may be a reflection (or absorption) electrode, and a flattening structure or a protective layer may be formed on the reflection electrode as needed. Good. In that case, the planarization structure does not need to be transparent.

Further, in the third embodiment, the case where the anode 2 is formed on the upper surface of the substrate 1 has been described.
The structure is not particularly limited to this, and the cathode 5 is formed on the upper surface of the substrate 1 and the concavo-convex structure 6, and the light emitting layer 4, the hole transport layer 3, the anode 2, and the transparent flattening structure 7 are arranged in this order. It may have a laminated structure.

The organic electroluminescent element of the present invention can be used not only as a display device for displaying an image but also as a lighting device for a light source such as a laser printer or a scanner. Further, the anode 2 and the cathode 5 may be made to emit light over the entire surface without being linearly patterned and used as a simple lighting device.

(Embodiment 4) A mobile terminal using an organic electroluminescence element according to Embodiment 4 of the present invention will be described.

FIG. 4 is a perspective view showing a portable terminal equipped with an image forming apparatus using an organic electroluminescence element according to the fourth embodiment of the present invention, and FIG. 5 is an organic electroluminescence according to the fourth embodiment of the present invention. It is a block diagram showing a portable terminal provided with an image forming apparatus using an element.

In FIG. 4 and FIG. 5, 9 is a microphone for converting a voice into a voice signal, 10 is a speaker for converting a voice signal into a voice, 11 is an operation unit including dial buttons, and 12 is an incoming call display. A display unit that is configured by the image forming apparatus using the organic electroluminescence of the present invention, 13 is an antenna, 14 is a transmission unit that converts the audio signal from the microphone 9 into a transmission signal, and the transmission unit 14
The transmission signal created in 1 is emitted to the outside through the antenna 13. Reference numeral 15 is a receiving unit that converts a reception signal received by the antenna 13 into a voice signal, and the voice signal created by the receiving unit 15 is converted into voice by the speaker 10. 16
Is a control unit that controls the transmission unit 14, the reception unit 15, the operation unit 11, and the display unit 12.

The voice of the user (caller) during a call is input to the microphone 9, and the voice and notification sound of the other party are output from the speaker 10 and transmitted to the user (receiver).
When using a pager as a mobile terminal,
The microphone need not be provided in particular.

Further, the operation section 11 is provided with a ten key as a dial button and various function keys. Also,
Not only the numeric keypad and various function keys but also character keys and the like may be provided. From this operation unit 11, phone number, name, time, setting of various functions, e-mail address, URL
Predetermined data such as is input. Furthermore, the operation unit 11 may use a pen input device, a voice input device, a magnetic or optical input device, in addition to the operation using the keyboard.

The display unit 12 displays predetermined data input from the operation unit 11, data such as telephone numbers, e-mail addresses, URLs, etc. stored in the memory, character icons, or the like.

Further, the antenna 13 performs at least one of transmission and reception of radio waves. Note that in this embodiment, an antenna (helical antenna, planar antenna, or the like) is provided because signals are transmitted and received by radio waves; however, in the case of performing optical communication or the like, a light-emitting element or a light-receiving element is used as an antenna. It may be provided instead. In this case, the light emitting element transmits a signal to another communication device or the like, and the light receiving element receives a signal from the outside.

The transmitting unit 14 and the receiving unit 15 respectively convert a voice signal into a transmission signal and a received reception signal into a voice signal.

Further, the control section 16 uses C (not shown).
It is configured by a conventionally known method using a PU, a memory, etc., and includes a transmission unit 14, a reception unit 15, and an operation unit 11,
The display unit 12 is controlled. More specifically, an instruction is given to each control circuit, drive circuit, etc. (not shown) provided in each of these sections. For example, the display control circuit that receives the display command from the control unit 16 drives the display drive circuit, and the display unit 12 displays.

The operation will be described below.

First, when there is an incoming call, the receiving section 15
Sends an incoming signal to the control unit 16, the control unit 16 causes the display unit 12 to display a predetermined character or the like based on the incoming signal, and a button or the like for receiving an incoming call from the operation unit 11 is pressed. Then, a signal is sent to the control unit 16,
The control unit 16 sets each unit to the incoming call mode. That is, the signal received by the antenna 13 is converted into a voice signal by the receiving unit 15, the voice signal is output as voice from the speaker 10, and the voice input from the microphone 9 is converted into a voice signal, and the transmitting unit 14 is operated. To the outside through the antenna 13.

Next, the case of making a call will be described.

First, in the case of making a call, a signal to the effect of making a call is input to the control unit 16 from the operation unit 11. Subsequently, when a signal corresponding to the telephone number is sent from the operation unit 11 to the control unit 16, the control unit 16 sends a signal corresponding to the telephone number from the antenna 13 via the transmission unit 14. When the transmission signal establishes communication with the other party,
When a signal to that effect is sent to the control unit 16 via the receiving unit 15 via the antenna 13, the control unit 16 sets each unit to the transmission mode. That is, the signal received by the antenna 13 is converted into a voice signal by the receiving unit 15, the voice signal is output as voice from the speaker 10, and the voice input from the microphone 9 is converted into a voice signal, and the transmitting unit 14 is operated. To the outside through the antenna 13.

In this embodiment, an example in which voice is transmitted and received is shown, but the same applies to a portable terminal that transmits or receives data other than voice such as character data in addition to voice. The effect can be obtained.

In such a portable terminal according to the present embodiment as described above, it is possible to maintain a highly efficient and long-lived light emitting performance, so that it is possible to suppress the power consumption of the battery or the like. As a result, the mobile terminal can be used for a long time, or the battery can be reduced in size to reduce its weight.

Particularly in recent years, display devices used for mobile terminals are required to have higher image quality and lower power consumption, which is effective, and improvement in life, which is one of the disadvantages of conventional organic electroluminescence devices, is improved. Made,
High efficiency devices bring great advantages. Higher efficiency makes it possible to reduce the battery capacity, and it is possible to achieve weight reduction and longer operating time. Furthermore, it is preferable to use a polymer film as a substrate material of the organic electroluminescence element, because it can bring about a dramatic weight reduction.

[0193]

EXAMPLE (Example 1) On a transparent substrate made of glass,
A transparent negative resist material is applied by spin coating to form a resist film having a thickness of 10 μm, and the resist film is patterned into a predetermined shape by masking, exposing and developing, and then the substrate is heat-treated at 220 ° C. A substrate with irregularly-shaped minute structures arranged periodically was formed. Next, after forming an ITO film having a film thickness of 160 nm on the concavo-convex structure of this substrate, a resist material for patterning (manufactured by Tokyo Ohka Kogyo Co., Ltd., OFPR-800) was applied on the ITO film by spin coating to a thickness of 50 μm. The resist film was formed, and the resist film corresponding to the resist film was exposed, and developed to pattern the resist film into a predetermined shape. Next, this substrate is 60
After immersing in 50% hydrochloric acid at ℃ to etch the ITO film in the part where the resist film is not formed, the ITO film patterning resist film is also removed to form an anode made of the ITO film having a predetermined pattern. A patterned substrate was obtained.

Next, the patterned substrate was ultrasonically cleaned with a detergent (Semicoclean, manufactured by Furuuchi Chemical Co., Ltd.) for 5 minutes, ultrasonically cleaned with pure water for 10 minutes, and then overexposed to ammonia water 1 (volume ratio). After performing a cleaning treatment in order of 5 minutes of ultrasonic cleaning with a solution of a mixture of hydrogen oxide water 1 and water 5 and ultrasonic cleaning with pure water of 70 ° C. for 5 minutes, the water adhering to the substrate was removed with a nitrogen blower, It was further heated and dried.

Next, on the surface of the patterning substrate on the anode side, TPD was used as a hole transport layer in an amount of about 50 as a hole transport layer in a resistance heating evaporation apparatus depressurized to a vacuum degree of 2 × 10 ⁻⁶ Torr or less.
It was formed with a film thickness of nm.

Next, similarly, Alq ₃ was formed as a light emitting layer on the hole transport layer in a resistance heating vapor deposition apparatus to a film thickness of about 50 nm. The vapor deposition rates of TPD and Alq ₃ were both 1.0 nm / s.

Next, similarly, in the resistance heating vapor deposition apparatus, a cathode was formed into a film having a thickness of 150 nm on the light emitting layer using an Al—Li alloy containing 15 at% of Li as a vapor deposition source.

Example 2 By imprinting a plurality of conical plates arranged in a plane made of steel on a transparent substrate made of polycarbonate, the heights 50 densely arranged in the plane are formed.
A substrate having a conical concave-convex structure with a μm and an apex angle of 120 ° was formed. Next, an ITO film having a film thickness of 160 nm was formed on the concavo-convex structure of this substrate using a metal mask to obtain a patterned substrate in which an anode made of an ITO film having a predetermined pattern was formed.

Next, the patterned substrate was ultrasonically cleaned with a detergent (Furuuchi Chemical Co., Ltd., Semicoclean) for 5 minutes, ultrasonically cleaned with pure water for 10 minutes, and then overwhelmed with ammonia water 1 (volume ratio). After performing a cleaning treatment in order of 5 minutes of ultrasonic cleaning with a solution of a mixture of hydrogen oxide water 1 and water 5 and ultrasonic cleaning with pure water of 70 ° C. for 5 minutes, the water adhering to the substrate was removed with a nitrogen blower, It was further heated and dried.

Next, on the surface of the patterned substrate on the anode side, TPD was used as a hole transport layer in an amount of about 50 as a hole transport layer in a resistance heating deposition apparatus depressurized to a vacuum degree of 2 × 10 ⁻⁶ Torr or less.
It was formed with a film thickness of nm.

Next, similarly, Alq ₃ was formed as a light emitting layer on the hole transport layer in a resistance heating vapor deposition apparatus to a film thickness of about 50 nm. The vapor deposition rates of TPD and Alq ₃ were both 1.0 nm / s.

Similarly, in the resistance heating vapor deposition apparatus, a cathode was formed into a film having a thickness of 150 nm on the light emitting layer using an Al-Li alloy containing 15 at% of Li as a vapor deposition source.

(Embodiment 3) A transparent substrate made of glass is used to heat and soften the surface of the substrate, and a quadrangular pyramidal plate made of steel is imprinted on the substrate to imprint a predetermined uneven structure. Transferred, densely arranged in the plane, height 30 μm,
A substrate with a concavo-convex structure in the shape of a quadrangular pyramid having a vertical angle of 120 ° and a square bottom surface was formed. Next, the substrate with the concavo-convex structure was subjected to ultrasonic cleaning for 5 minutes with a detergent (Semicoclean, manufactured by Furuuchi Chemical Co., Ltd.), ultrasonic cleaning for 10 minutes with pure water, and peroxidized with ammonia water 1 (volume ratio). Ultrasonic cleaning for 5 minutes with a mixture of hydrogen water 1 and water 5, 7
After performing a cleaning treatment in the order of ultrasonic cleaning with pure water at 0 ° C. for 5 minutes, water adhering to the substrate was removed with a nitrogen blower, and the substrate was further heated and dried.

Next, on the uneven structure of the substrate with the uneven structure,
Masked with a metal mask in a resistance heating vapor deposition apparatus depressurized to a vacuum degree of 2 × 10 ⁻⁶ Torr or less, 15 at
% Of Li was used as an evaporation source to form a cathode with a film thickness of 150 nm.

Next, in the resistance heating vapor deposition device, A
Alq ₃ having a thickness of about 50 nm is formed as a light emitting layer on the l-Li alloy, and similarly, Tq is formed as a hole transporting layer on the light emitting layer.
PD was formed with a film thickness of about 50 nm. In addition, TPD and A
The deposition rate of lq ₃ was 1.0 nm / s in both cases.

Next, in a low damage sputtering apparatus depressurized to a vacuum degree of 2 × 10 ^-6 Torr or less, a 160 nm-thick ITO film having a predetermined shape was patterned on the light emitting layer using a metal mask. A film was formed to obtain an uneven organic electroluminescence element.

Next, in the same manner as above, a silicon nitride film having a film thickness of 3 μm was formed as a protective film on the upper front surface of the uneven organic electroluminescent element in the low damage sputtering apparatus.

Then, a U film having a thickness of 20 μm was formed by spin coating so as to flatten the unevenness of the uneven organic electroluminescence element protected by this protective film.
A V-curable transparent resin was applied in a planar shape, and UV irradiation was applied to this to cure it.

(Comparative Example 1) As in Example 1, after forming an ITO film having a thickness of 160 nm on a transparent substrate made of glass, a resist material (manufactured by Tokyo Ohka Co., OFP) was formed on the ITO film.
R-800) is applied by spin coating to a thickness of 10
A resist film having a thickness of μm was formed, and the resist film was patterned into a predetermined shape by masking, exposing and developing. Next, this substrate is dipped in 50% hydrochloric acid at 60 ° C. to etch the ITO film in the portion where the resist film is not formed, and then the resist film is also removed to form an anode made of the ITO film having a predetermined pattern. A patterned substrate on which was formed was obtained.

Next, this patterned substrate was ultrasonically cleaned with a detergent (Semicoclean, manufactured by Furuuchi Chemical Co., Ltd.) for 5 minutes, ultrasonically cleaned with pure water for 10 minutes, and treated with ammonia water 1 (volume ratio). After performing a cleaning treatment in order of 5 minutes of ultrasonic cleaning with a solution of a mixture of hydrogen oxide water 1 and water 5 and ultrasonic cleaning with pure water of 70 ° C. for 5 minutes, the water adhering to the substrate was removed with a nitrogen blower, It was further heated and dried.

Next, on the surface of the patterned substrate on the anode side, TPD was used as a hole transport layer in an amount of about 50 as a hole transport layer in a resistance heating vapor deposition apparatus depressurized to a vacuum degree of 2 × 10 ⁻⁶ Torr or less.
It was formed with a film thickness of nm.

Then, similarly, Alq ₃ was formed as a light emitting layer on the hole transport layer in a resistance heating vapor deposition apparatus to a film thickness of about 60 nm. The vapor deposition rates of TPD and Alq ₃ were both 0.2 nm / s.

Similarly, in the resistance heating vapor deposition apparatus, a cathode was formed into a film having a thickness of 150 nm on the light emitting layer using an Al-Li alloy containing 15 at% of Li as a vapor deposition source.

[0214]

[Table 1]

Here, the evaluation method and the evaluation criteria for the evaluation items in (Table 1) will be described.

The drive life of the device was evaluated by the time until the brightness was reduced to half when a current was supplied so that the initial brightness was constant in the opening of the organic electroluminescence device and this current value was maintained. The evaluation criteria are ⊚: very excellent, ∘: excellent, and Δ: acceptable with respect to the driving life of Comparative Example 1.

The luminous efficiency of the device was evaluated with respect to the initial luminance when a constant current was applied to the organic electroluminescent device. The evaluation criteria are ⊚: very good, ∘: excellent, and Δ: with respect to the emission luminance of Comparative Example 1.
Is acceptable.

The visibility of the light emitting surface was evaluated by visually observing the degree of visibility with respect to light bleeding and blurring when an organic electroluminescence element was used as an image forming apparatus having 300 μm pixels. The evaluation is a three-level evaluation of ◎, ○, △, and the evaluation criteria are ◎: very excellent,
◯: Excellent, Δ: Acceptable.

As is clear from Table 1, Example 1,
Each of the organic electroluminescence elements of Nos. 2 and 3 was superior to the organic electroluminescence element of Comparative Example 1 in terms of driving life, light emission brightness, and light emission surface visibility. In particular, in Example 1, the driving life and the visibility of the light emitting surface are very excellent, and in Example 3, the driving life, the emission luminance, and the visibility of the light emitting surface are all very excellent as compared with Comparative Example 1. became. It can be seen that the organic electroluminescent element of the present example is an organic electroluminescent element having a remarkably long life, high luminous efficiency, and excellent visibility as compared with the comparative example.

[0220]

As described above, according to the organic electroluminescence device of the present invention, the following advantageous effects can be obtained.

That is, the present invention provides an organic electroluminescence element capable of maintaining a long life and a high light emitting performance, an image forming apparatus capable of maintaining a long life and a high light emitting performance, and a light weight. It is possible to provide a portable terminal that takes a long time, can be formed in a simple process, has high workability, and can provide a method of manufacturing an organic electroluminescence element having high productivity.

According to the invention described in claim 1, (1) the effective luminance is kept at a practical level by increasing the area of the light emitting portion with respect to the area of the opening for taking out light. As it is, the brightness in the light emitting portion can be reduced.

(2) Since the luminance of the light emitting section can be lowered, highly efficient light emitting performance can be maintained for a long period of time.

(3) A high-luminance organic electroluminescence can be prepared by using the conventional light-emitting layer having low luminance but long life.

(4) An organic electroluminescence device having a long life can be prepared by using a conventional light emitting layer having a high brightness but a short life, in particular, a light emitting layer having a remarkable decrease in life with an increase in brightness. .

(5) By devising the arrangement of the light emitting layer, a more efficient organic electroluminescent element can be prepared.

According to the invention of claim 2, claim 1
In addition to the effect of (1), since it is formed on a surface that is in a non-parallel relationship with the opening for extracting light from the light emitting layer, the light extraction efficiency can be improved, and highly efficient light emission performance can be achieved. Can be maintained.

(2) Since the light extraction efficiency can be improved, the brightness in the light emitting portion can be lowered, and the highly efficient light emitting performance can be maintained for a long period of time.

(3) By forming non-parallel surfaces, the area can be increased and the luminance in the light emitting portion can be further lowered, so that highly efficient light emitting performance can be maintained for a longer period of time.

(4) Since the manufacturing method for forming the light emitting portions on the surfaces having a non-parallel relationship is simple, the productivity is high.

(5) Since the light emitting surface can be freely laid out, it is easy to increase the area of the light emitting portion.

(6) Since the light emitting surface can be freely laid out, it is possible to optimize the design such as life priority or efficiency priority depending on the light emitting material.

According to the invention of claim 3, claim 1
In addition to the effect of (2), (1) since the area of the light emitting portion is larger than the area of the opening portion, when the effective luminance is the same, the life is improved as compared with the case where the same light emitting elements are used in parallel.

(2) Since the light emitting portion is in a non-parallel relationship with the opening, the light extraction efficiency can be improved and the brightness in the light emitting portion can be lowered.

(3) Since the brightness in the light emitting section can be lowered, highly efficient light emitting performance can be maintained for a long period of time.

According to the invention of claim 4, claim 3
In addition to the effect of (1), since it is formed in a quadrangular pyramid shape, a conical shape, or a curved shape, the angle design of light is easy. In addition, the orientation of light can be provided with directivity.

(2) Since the structure is isotropic, the angle design of light in all directions is easy. In addition, the orientation of light can be provided with directivity.

(3) Since they are densely arranged in the plane, the light extraction efficiency from any place is improved. Also,
It is possible to give directivity to the orientation of light.

(4) The quadrangular pyramid has symmetrical visual characteristics in the vertical and horizontal directions, the cone has symmetrical visual characteristics in all directions, and the curve symmetric with respect to the axis in the height direction is totally symmetrical. The visual characteristics in directions are symmetrical.

According to the invention of claim 5, claim 3
In addition to the effects of 4), (1) Since it is formed of a transparent material, light loss inside the element can be reduced and the brightness in the light emitting portion can be lowered, so that highly efficient light emission can be achieved for a long period of time. Maintain performance.

(2) Since the well-known method for forming an organic electroluminescence element can be used as it is, the formation is easy.

According to the invention of claim 6, claim 3
In addition to the effect of any one of (1) to (5), (1) since a thick member such as the substrate is eliminated, light bleeding or the like is suppressed.

(2) Since the light loss inside the element can be reduced and the luminance in the light emitting portion can be lowered, the highly efficient light emitting performance can be maintained for a long period of time. The effect is obtained.

(3) Since a free material can be selected as the substrate, it is possible to reduce the weight, improve the strength, enhance the function, and reduce the thickness.

(4) It is possible to enhance the functionality by embedding a driving circuit in the substrate, using a flexible substrate, or the like.

According to the invention of claim 7, claim 6
In addition to the effect of any one of (1), since a protective film is formed and a transparent flattening film is formed on the upper surface thereof, heat and stress on the transparent electrode and the lower organic layer, stress such as plasma and scratches, and moisture. The organic electroluminescence can be manufactured without damaging reactive gases such as oxygen.

(2) The forming method and forming material for forming on the protective film can be freely selected.

(3) Since the protective film is formed, the organic electroluminescence element can be shielded from the outside air and is excellent in long-term stability.

According to the invention of claim 8, claim 3
In addition to the effect of any one of (1) to (7), (1) if the angle of the concavo-convex structure is the angle of this side, high light extraction efficiency can be realized.

(2) Since the angle of the concavo-convex structure is gradual, the possibility of short-circuiting of the organic electroluminescent element is reduced, and a long-life organic electroluminescent element can be manufactured.

(3) The possibility of disconnection of the electrodes and wirings of the organic electroluminescence element is reduced.

According to the invention of claim 9, claim 3
In addition to the effect of any one of (1) to (8), (1) as the refractive index of the material forming the concavo-convex structure increases, the light loss due to total reflection at the interface with the concavo-convex structure decreases, so The efficiency of extracting light into the inside is improved.

According to the invention of claim 10, in addition to the effect of any one of claims 1 to 9, (1) it is possible to reduce the optical loss inside the element, so that it is possible to achieve a long-term It is possible to maintain high-efficiency light emission performance, and it is possible to perform good display in a simple matrix system.

(2) Since the anode and the cathode are individually electrically separated into stripes, a large light emitting portion in the pixel can be taken.

(3) In the case of a simple matrix, instantaneous high brightness is required. Therefore, high efficiency and low brightness of the light emitting portion are very important.

According to the invention described in Item 11, in addition to the effect of any one of Items 1 to 10, (1) It is possible to reduce the light loss inside the element, so that highly efficient light emission is achieved. The performance can be maintained, and good display in the active matrix system can be performed.

(2) Since the anode or the cathode is electrically electrically separated for each pixel, it is not necessary to have a momentary high brightness, and the brightness required for practical use is sufficient and stable for a long period of time. The light emission can be maintained.

(3) Since the anode or the cathode is scanned through at least one or more switching elements, free image formation can be realized and the high-speed response characteristic of the organic electroluminescence element can be fully utilized. it can.

(4) In the case of the active matrix, the area of the light emitting portion is likely to be small due to the switching elements and wirings arranged in the pixel. Therefore, such a large area and highly efficient measure is very advantageous.

According to the twelfth aspect of the invention, in addition to the effect of the tenth or eleventh aspect, (1) the size of the concavo-convex structure in the plane direction is smaller than the size of the pixel in the plane direction. Therefore, the concavo-convex structure can be freely arranged on the pixel.

(2) Since the openings in the pixels can be effectively arranged and the luminance in the light emitting portion can be lowered, the light emitting performance can be maintained for a long period of time.

(3) A plurality of concavo-convex structures can be arranged in one pixel, the orientation of light (angle distribution and intensity distribution and angle distribution in the pixel) can be designed, and optimum visibility can be designed. It is possible.

(4) When the apex angles are the same, the height of the unevenness is low, and it is difficult for problems such as short circuit and disconnection to occur.

According to the thirteenth aspect of the invention, (1) the light loss inside the element can be reduced, so that the highly efficient light emitting performance can be maintained and the reduction of the battery capacity and the like It is possible to reduce the weight or lengthen the usage time.

(2) Since the orientation of light can be changed, a higher function can be provided.

According to the fourteenth aspect of the invention, (1) it is possible to produce an organic electroluminescence device which can maintain the light emitting performance for a long period of time by a simple process.

(2) Since the forming method is simple, workability is high and productivity is high.

According to the fifteenth aspect of the invention, (1) it is possible to produce an organic electroluminescence device which can maintain the light emitting performance for a long period of time by a simple process.

(2) Since the forming method is simple, workability is high and productivity is high.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main part of an organic electroluminescent element according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part of an organic electroluminescent element according to a second embodiment of the present invention.

FIG. 3 is a schematic perspective view of an image forming apparatus using an organic electroluminescent element according to a third embodiment of the present invention.

FIG. 4 is a perspective view showing a mobile terminal equipped with an image forming apparatus using an organic electroluminescence element according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram showing a mobile terminal equipped with an image forming apparatus using an organic electroluminescence element according to a fourth embodiment of the present invention.

FIG. 6 is a graph showing the relationship between drive time and relative period brightness in an organic electroluminescence device.

FIG. 7 is a graph showing the relationship between drive voltage and brightness in an organic electroluminescence element.

FIG. 8 is a conceptual diagram illustrating the layer structure of the organic electroluminescence element of the present invention.

FIG. 9 is a graph showing the result of optical simulation.

FIG. 10 is a graph showing the result of optical simulation.

FIG. 11 is a cross-sectional view of a main part of a conventional organic electroluminescence element.

[Explanation of symbols]

1 substrate 2 anode 3 Hole transport layer 4 Light emitting layer 5 cathode 6 uneven structure 7 Transparent flattened structure 9 microphone 10 speakers 11 Operation part 12 Display 13 antennas 14 Transmitter 15 Receiver 16 Control unit

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Naohide Wakita             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 3K007 AB02 AB03 AB08 AB11 AB17                       AB18 CC01 CC04 DB03 FA00

Claims (15)

[Claims] 1. An organic electroluminescence device comprising, on a substrate, at least an anode for injecting holes, a light emitting layer having a light emitting region, and a cathode for injecting electrons, the light emitting section including the light emitting layer. Is larger than the area of the opening for taking out the light from the light emitting layer. 2. An organic electroluminescence device comprising, on a substrate, at least an anode for injecting holes, a light emitting layer having a light emitting region, and a cathode for injecting electrons, the light emitting section including the light emitting layer. Is formed on a surface that is in a non-parallel relationship with the opening for taking out light from the light emitting layer. 3. The organic electroluminescent element according to claim 1, wherein the light emitting portion is formed at least on an uneven structure formed on the surface of the substrate. 4. The organic electroluminescence device according to claim 3, wherein the concavo-convex structure is formed in a quadrangular pyramid shape, a conical shape, or a curved shape. 5. The organic electroluminescence device according to claim 3, wherein the substrate, the concavo-convex structure, and the anode or the cathode formed on the substrate are transparent. 6. An anode or a cathode formed on the concavo-convex structure on the substrate is a reflective electrode that reflects light emitted from the light emitting layer, and a cathode or an anode facing the reflective electrode is a transparent electrode. The organic electroluminescent element according to claim 3, wherein a transparent flattening structure having a light extraction surface as a plane is formed above the transparent electrode. 7. The organic electroluminescence device according to claim 6, wherein the transparent flattening structure is formed on a protective film formed on the transparent electrode. 8. The concavo-convex structure is formed with an inclination angle of 60 to 170 °, preferably 100 to 140 ° with respect to the normal direction of the substrate. The organic electroluminescence device according to any one of the above. 9. The refractive index of the concavo-convex structure is 1.4 to 2.
It is 0, preferably 1.7-1.9, The organic electroluminescent element in any one of Claim 3 thru | or 8 characterized by the above-mentioned. 10. An image display array in which the anode and the cathode of the organic electroluminescent element according to claim 1 are electrically isolated in stripes and each pixel is composed of one or more pixels. An image forming apparatus comprising: 11. The organic electroluminescent device according to claim 1, wherein the anode or the cathode is electrically isolated for each pixel, and the anode or the cathode is An image forming apparatus having an image display array by being scanned through at least one or more switching elements. 12. The image forming apparatus according to claim 10, wherein a size of the concavo-convex structure in the plane direction is smaller than a size of the pixel in the plane direction. 13. A voice signal conversion unit for converting voice into a voice signal, an operation unit for inputting a telephone number, a display unit for displaying an incoming call display, a telephone number, etc., and a transmission for converting a voice signal into a transmission signal. A portable terminal comprising: a unit, a receiving unit for converting a reception signal into an audio signal, an antenna for transmitting and receiving the transmission signal and the reception signal, and a control unit for controlling each unit, wherein the display unit comprises: Any one of 10 to 12
A mobile terminal comprising the image forming apparatus according to item 1. 14. An uneven structure is formed on a transparent substrate using a transparent material, and an anode for injecting at least holes, a light emitting layer having a light emitting region, and a cathode for injecting electrons are formed on the upper surface of the uneven structure. A method for manufacturing an organic electroluminescence device, comprising: 15. An uneven structure is formed on a substrate, an anode for injecting at least holes, a light emitting layer having a light emitting region, and a cathode for injecting electrons are formed on the upper surface of the uneven structure, and the upper surface is made transparent. A method for manufacturing an organic electroluminescence device, which comprises forming a transparent flattening structure using a material so that an opening becomes a flat surface.