JP2000284705A - Optical display device and production of optical display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently use the light emitted by a fluorescent substance and to obtain high emission luminance by controlling a refractive index of a color converting layer higher than the refractive index of a translucent layer and forming the interface between the color converting layer and the translucent layer into a rugged pattern. SOLUTION: The refractive index of a color converting layer 14 is controlled to be higher than the refractive index of a translucent layer 12, and the interface between the color converting layer 14 and the translucent layer 12 is made into a rugged pattern. The EL light emitted by an org. EL device 10 propagates from the emission face 11 to the translucent layer 12. In this case, since the transmittance for light of the translucent layer 12 is increased, the EL light is mostly passed without absorbed. Then the EL light passes through an interface 13 to the color converting layer 14. Then the EL light entering the color converting layer 14 is absorbed by the fluorescent material 16 uniformly dispersed in the color converting layer 14. Therefore, the fluorescent material 16 is efficiently excited by the EL light, and the fluorescent light is emitted to all directions from the fluorescent material 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical display device having a high light emission luminance, for example, an organic electroluminescence device (hereinafter sometimes simply referred to as an organic EL device), and such an optical display device. The present invention relates to a method for manufacturing an optical display device which can efficiently obtain the optical display device.

[0002]

BACKGROUND OF THE INVENTION Electronic display devices are generally
An electronic device that transmits various kinds of information from various devices (machines) to humans (man) through visual perception, as referred to as an-machine-interface, and has an important bridging role (in) between humans and devices.
terface). The electronic device includes a light emitting system and a light receiving system. Examples of the light emitting system include a CRT (cathode ray tube), PDP (plasma display), ELD (electroluminescence display), VFD (fluorescent display tube), and LED. (Light emitting diode) and the like. On the other hand, as a light receiving system, for example, LCD (liquid crystal display), ECD (electrochemical display), EPID (electrophoretic display), SPD (dispersed particle orientation type display), TBD
(Colored particle rotating display), PLZT (transparent ferroelectric PLZT [(Pb, La) (Zr, Ti) O ₃ ] ceramic display) and the like.

Here, as a method of full color in the light emitting type display, there is a method of (1) arranging light emitting portions of multicolors (for example, three primary colors of red, blue and green) in a plane and emitting light respectively. , (2) including LCD,
A method of separating white light of a backlight into multiple colors by a color filter; and (3) a method of absorbing light of a certain color (for example, blue) into fluorescence conversion films arranged and separated in a plane, and different fluorescence from each fluorescence conversion film. (For example, red, green) is known.

However, in the above method (1), it is necessary to produce red, blue, and green luminous elements (elements), and it is necessary to select a material for each luminous element and finely separate the luminous elements in a plane. In some cases, the arrangement process may be difficult. In the method (2), the brightness of each color is reduced in order to separate white light into multiple colors (one third in the case of three primary colors). ) Is inevitable.

On the other hand, in the method using the fluorescence conversion film of the above (3), if there is a luminescent material of a certain color, the fluorescence conversion film finely separated and arranged in a plane is separated from the position where light emission can be absorbed. Since it is sufficient to dispose them, it is presumed that the process is easy, and there is a problem that the brightness of each color is not reduced by fluorescence conversion in principle.

[0006] Therefore, regarding a method of performing fluorescence conversion of multicolor light emission from a light emitter of one color using a fluorescence conversion film, it is desirable that one color emits light with high energy, and in the case of visible light, blue light is used. For example, conversion into green or red with lower energy becomes possible, and multi-light emission of three primary colors becomes possible. Similarly, in the case of ultraviolet light, multi-light emission of three primary colors is possible. In particular, organic electroluminescence (hereinafter, referred to as
“Electroluminescence” is abbreviated as EL. In the case of a light-emitting element, blue light emission with high efficiency and high luminance is realized, and since the light-emitting element is composed of an organic material, it is highly expected that light emission of all colors will be achieved by designing the organic material.

On the other hand, luminance is an important factor in a color display. The same applies to a color display comprising an organic EL light emitting element using a fluorescence conversion film,
In this case, the overall light emission luminance is adjusted according to the light emission luminance from the fluorescence conversion film. That is, by increasing the emission luminance from the fluorescence conversion film, the overall emission luminance can be increased. As a method for increasing the fluorescent luminance from the fluorescent conversion film, a method for increasing the emission luminance of the organic EL light emitting element as a light source and a method for increasing the conversion efficiency of the fluorescent conversion film have been proposed.

For example, in order to increase the light emission luminance of an EL light emitting element, Japanese Patent Laid-Open No. 7-37688 discloses an EL structure in which an EL structure 130 is formed on a substrate 125 as shown in FIG.
An L element 120 is disclosed. On the light emitting surface side of the substrate 125 in the EL element 120, the spectral filter 12
EL elements of the substrate 125
On the structure 130 side, a high-refractive-index portion 133 formed of a material having a cylindrical shape in the thickness direction and having a higher refractive index than the surroundings.
Is provided.

Japanese Patent Application Laid-Open No. Hei 10-189237 discloses, as shown in FIG. 7, for the purpose of increasing the light emission luminance of the EL element (plane light emitter) 144 and making the light emission uniform.
EL having a luminance distribution control material 139 provided on the light emitting surface of the EL element
An element (plane light emitter) 144 is disclosed.

Further, Japanese Patent Application Laid-Open No. 4-192290 discloses that the light-emitting surface of the EL element 155 as shown in FIG. Thin-film EL device 1 including microlens 150
54 are disclosed. On the other hand, as a method for increasing the conversion efficiency of the fluorescence conversion film, Japanese Patent Application Laid-Open No. H11-8070 discloses a display device in which a light diffusion layer 162 is disposed on the front surface of an EL element 168 as shown in FIG. Is disclosed.
The light diffusion layer 162 is formed by dispersing light scattering fine particles in a transparent resin binder.

[0011]

However, in the organic EL device disclosed in Japanese Patent Application Laid-Open No. 11-8070,
Of the light emitted by the fluorescent substance, the light returning to the light emitting surface side of the EL element could not be sufficiently utilized, and thus a problem that the obtained light emission luminance was insufficient was observed. In addition, it is necessary to use a substrate having a special structure, a luminance distribution control material, or the like for any of the organic EL elements and the like, and there has been a problem that the structure is complicated or manufacturing is difficult.

Therefore, the inventors of the present invention diligently studied the above-mentioned problems, and determined the magnitude relationship between the refractive index of the color conversion layer and the refractive index of the light-transmitting layer. By devising the interface structure with the layer and the like, it has been found that light emitted by the fluorescent substance can be sufficiently used, and the emission luminance can be easily improved. That is, an object of the present invention is to provide an optical display device capable of obtaining high light emission luminance with a simple structure and a method of manufacturing an optical display device capable of efficiently obtaining such an optical display device. .

[0013]

SUMMARY OF THE INVENTION One aspect of the present invention provides
In an optical display device in which a light-transmitting layer and a color conversion layer are sequentially laminated on the light-emitting surface side of the planar light-emitting body, the refractive index of the color conversion layer is made larger than the refractive index of the light-transmitting layer. An optical display device characterized in that the interface between the color conversion layer and the light-transmitting layer has an uneven shape. With this configuration,
With a simple structure of the optical display device, light emitted from the fluorescent substance can be sufficiently used, and high light emission luminance can be obtained.

Further, in constituting the optical display device of the present invention, it is preferable that the average distance between vertices of adjacent convex portions in the uneven shape is a value within a range of 0.5 to 10 μm.

Further, in constituting the optical display device of the present invention, it is preferable that the average distance between the top of the convex portion and the bottom of the concave portion in the concave / convex shape is a value within a range of 0.5 to 10 μm.

Further, in constituting the optical display device of the present invention, it is preferable that the color conversion layer is a fluorescence conversion layer that emits light having a longer wavelength than the light incident on the color conversion layer.

Further, in constituting the optical display device of the present invention, it is preferable that the planar illuminant is an organic electroluminescence element.

In another aspect of the present invention, a light-transmitting layer, an intermediate layer, and a color conversion layer are sequentially laminated on the light-emitting surface side of the planar light-emitting body. An optical display device characterized in that the refractive index is larger than the refractive index of the intermediate layer, and the interface between the intermediate layer and the light-transmitting layer has an uneven shape. With this configuration, it is possible to sufficiently utilize light emitted from the fluorescent substance while keeping the surface of the color conversion layer smooth, and to obtain excellent emission luminance.

In another aspect of the present invention, a light-transmitting layer and a color conversion layer are sequentially laminated on the light-emitting surface side of the planar light-emitting body, and the refractive index of the color conversion layer is reduced. What is claimed is: 1. A method for manufacturing an optical display device having a refractive index larger than that of a light-transmitting layer, comprising the step of forming an interface between a color conversion layer and a light-transmitting layer into an uneven shape. It is a manufacturing method. When implemented in this manner, an optical display device having a simple structure and capable of obtaining excellent light emission luminance can be efficiently obtained.

In carrying out the method of manufacturing an optical display device according to the present invention, the surface of the color conversion layer is subjected to chemical treatment and physical treatment in the step of forming the interface between the color conversion layer and the light-transmitting layer into an uneven shape. It is preferable to carry out a mechanical treatment (mechanical treatment) or any one of the treatments. With such an implementation, the interface between the color conversion layer and the light-transmitting layer can be easily made uneven. In addition, when implemented in this manner, the uneven shape can be inspected before forming the light-transmitting layer.

In carrying out the method of manufacturing an optical display device according to the present invention, in the step of forming the interface between the color conversion layer and the light-transmitting layer into an uneven shape, the release film having the uneven shape on the surface is formed. It is preferable that the color conversion layer is light-cured or heat-cured in a state where the heat treatment is performed. When implemented in this way,
At the same time that the color conversion layer is formed, the interface can be made uneven. In addition, when implemented in this manner, the uneven shape can be inspected before forming the light-transmitting layer.

In carrying out the method of manufacturing an optical display device according to the present invention, in the step of forming the interface between the color conversion layer and the light-transmitting layer into an uneven shape, the light-transmitting layer having the uneven shape on the surface is formed. It is preferable that the color conversion layer is light-cured or heat-cured in the laminated state. According to this embodiment, it is possible to form the color conversion layer and, at the same time, form an uneven shape at the interface with the light-transmitting layer. Also, when implemented in this way,
The uneven shape is first provided on the light-transmitting layer. At this stage, the uneven shape can be inspected.

In another aspect of the present invention, a light-transmitting layer, an intermediate layer, and a color conversion layer are sequentially laminated on the light-emitting surface side of the planar light-emitting body. Is a method for manufacturing an optical display device having a refractive index higher than that of a light-transmitting layer, characterized by including a step of forming an interface between the intermediate layer and the light-transmitting layer into an uneven shape. According to this embodiment, it is possible to efficiently obtain an optical display device capable of obtaining more excellent light emission luminance while keeping the color conversion layer smooth.

[0024]

Embodiments of the present invention will be specifically described below with reference to the drawings. The drawings referred to merely schematically show the size, shape, and arrangement of each component so that the present invention can be understood. Therefore, the present invention is not limited only to the illustrated example. In the drawings, hatching representing a cross section may be omitted.

[First Embodiment] In a first embodiment, as shown in FIG. 1, a light-transmitting layer 12 and a color conversion layer are provided on the light-emitting surface side of an organic EL element (plane light emitter) 10. 14 is a diagram schematically illustrating a cross section of an organic EL display device 18 in which the organic EL display devices 14 and 14 are sequentially stacked. The refractive index (sometimes referred to as n1) of the color conversion layer 14 is made larger than the refractive index (sometimes referred to as n2) of the light-transmitting layer 12, and the light-transmitting property of the color conversion layer 14 is increased. Since the interface with the layer 12 has an irregular shape, regions A and B satisfying the expression of the critical angle of total reflection are formed. In FIG. 1, arrows indicated by symbols L1 to L4 represent optical paths of fluorescence emitted from the fluorescent substance (fluorescent dye) 16 in all directions, and arrows indicated by symbols L5 to L6 are: The light paths of the reflected light at the interface between the color conversion layer 14 and the translucent layer 12 among the fluorescent light emitted from the fluorescent substance 16 are shown. Hereinafter, the configuration and operation of the organic EL display device 18 according to the first embodiment will be specifically described with reference to FIG. 1 and in comparison with FIG.

(1) Operation First, in the organic EL display device 18 according to the first embodiment, the organic EL element 10 can emit light by applying a predetermined voltage between the electrodes of the organic EL element 10. . Then, the EL light emitted by the light emission of the organic EL element 10 enters the light transmitting layer 12 from the light emitting surface 11 of the organic EL element 10. At this time, since the light transmittance of the translucent layer 12 is increased, the EL light can pass through with little light absorption. After that, the EL light enters the color conversion layer 14 via the interface 13.

Next, the EL light incident on the color conversion layer 14 is applied to the fluorescent substance 16 uniformly dispersed in the color conversion layer 14.
Is absorbed by Therefore, the fluorescent substance 16 is efficiently excited by the EL light, and emits fluorescent light from the fluorescent substance 16 in all directions. The optical paths in this state are represented by L1 to L4 in the drawing. Here, the fluorescences L1 to L emitted from the fluorescent substance 16 in all directions are shown.
4, the fluorescent light L directed to the emission surface 15 of the color conversion layer 14.
1 to L2 are taken out as indicated by the optical path L7. On the other hand, among the fluorescent light L1 to L4 emitted from the fluorescent substance 16 in all directions, the fluorescent light L3 to L4 directed to the side opposite to the emission surface 15 of the color conversion layer 14 satisfies the critical angle expression of total reflection. In this case, the light is efficiently reflected at an area, for example, the point A or the point B, the traveling direction is changed, and the light travels in a direction substantially perpendicular to the emission surface 15 of the color conversion layer 14. Therefore, if the angle of incidence (Θ) of the reflected light with respect to the emission surface 15 is within the critical angle of total reflection in relation to the refractive index of the color conversion layer 14 and the refractive index of air, as indicated by the optical path L6. Then, the light is extracted outside (in the air), and is visually recognized in combination with the light indicated by the optical path L7 originally extracted outside.

On the other hand, the conventional organic EL display device 1
In 18, the interface 111 between the color conversion layer 114 and the organic EL element (plane light emitter) 110 is smooth, as schematically shown in FIG. In FIG. 2, similarly to FIG. 1, the optical paths of the fluorescent light and the like emitted from the fluorescent substance 116 are indicated by symbols L′ 1 to L′ 7, respectively. Therefore,
In the conventional organic EL display device 118, the fluorescent substance 11
Fluorescence L′ 1 to L′ 4 emitted in all directions from No. 6
Of these, the fluorescent light L′ 3 to L′ 4 directed to the side opposite to the emission surface 115 of the color conversion layer 114 enters the organic EL element 10 as it is because there are few regions that satisfy the expression for the critical angle of total reflection. Increase the ratio. The optical path returning into the organic EL element 10 is indicated by an arrow L'6 in the drawing.

A part of the fluorescence L'1 to L'4 is A
The light is reflected at the point '′ and goes to the emission surface 115 of the color conversion layer 114, but enters the emission surface 115 of the color conversion layer 114 at a relatively small angle (Θ ′). Therefore, the angle between the refractive index of the color conversion layer 114 and the refractive index of air tends to be equal to or larger than the critical angle of total reflection, and as shown in the drawing, the light is reflected at the point B and effectively applied to the outside (in the air). I can't take it out. Therefore, in the conventional organic EL display device 118, only the light indicated by the symbol L7 can be extracted to the outside, and the organic EL display device 18 of the first embodiment can be extracted.
, The amount of light visually recognized outside is reduced.

(2) Color Conversion Layer In the organic EL display device 18 according to the first embodiment,
The constituent material of the color conversion layer 14 is not particularly limited. For example, the color conversion layer 14 is made of a fluorescent dye and a resin, or only a fluorescent dye, and the fluorescent dye and the resin dissolve the fluorescent dye in the pigment resin and / or the binder resin. Alternatively, a dispersed solid state can be used.

To explain a specific fluorescent dye, as a fluorescent dye for converting luminescence from near-ultraviolet light to blue light emission in an organic EL device, 1,4-bis (2-methylstyryl) benzene (hereinafter referred to as Bis- MBS), stilbene dyes such as trans-4,4'-diphenylstilbene (hereinafter DPS), and coumarin dyes such as 7-hydroxy-4-methylcoumarin (hereinafter coumarin 4).

Next, as a fluorescent dye for converting blue, blue-green or white light emission into green light emission in an organic EL element, for example, 2,3,5,6-1H, 4H-tetrahydro-8-tri Flormethylquinolizino (9,9
a, 1-gh) coumarin (hereinafter coumarin 153), 3-
Coumarin dyes such as (2'-benzothiazolyl) -7-diethylaminocoumarin (hereinafter coumarin 6), 3- (2'-benzimidazolyl) -7-N, N-diethylaminocoumarin (hereinafter coumarin 7), and other coumarin dye-based dyes And naphthalimide dyes such as Basic Yellow 51, Solvent Yellow 11, and Solvent Yellow 116.

The fluorescent dye for converting the emission of blue to green or white light from the organic EL device to emission of orange to red light is, for example, 4-dicyanomethylene-2-methyl-6 Cyanine dyes such as (p-dimethylaminostillyl) -4H-pyran (hereinafter DCM), 1-ethyl-2- (4- (p-dimethylaminophenyl) -1,3-butadienyl) -pyridinium-perchlorate (Hereinafter referred to as pyridine 1), rhodamine dyes such as rhodamine B and rhodamine 6G, and oxazine dyes.

Further, various dyes (direct dyes, acid dyes,
Basic dyes, disperse dyes, etc.) can also be selected as fluorescent dyes if they have fluorescence. Also, the fluorescent dye is kneaded in advance in a pigment resin such as polymethacrylic acid ester, polyvinyl chloride, vinyl chloride vinyl acetate copolymer, alkyd resin, aromatic sulfonamide resin, urea resin, melanin resin, benzoguanamine resin and the like. May be used. In addition, these fluorescent dyes or pigments may be used alone or in combination as needed.

On the other hand, the binder resin is preferably a transparent material (having a light transmittance of 50% or more in visible light). For example, transparent resins (polymers) such as polymethyl methacrylate, polyacrylate, polycarbonate, polyvinyl alcohol, polyvinyl pyrrolidone, hydroxyethyl cellulose, and carboxymethyl cellulose are exemplified.

It is to be noted that a photosensitive resin to which a photolithography method can be applied in order to separate and arrange the color conversion layers in a plane is also selected. For example, acrylic acid type, methacrylic acid type,
Photo-curable resist materials having a reactive vinyl group, such as polyvinyl cinnamate and ring rubber, can be used. When a printing method is used, a printing ink (medium) using a transparent resin is selected. For example, polyvinyl chloride resin, melamine resin, phenol resin, alkyd resin, epoxy resin, polyurethane resin, polyester resin, maleic resin, polyamide resin monomer, oligomer, polymer, polymethyl methacrylate, polyacrylate, polycarbonate, polyvinyl alcohol And a transparent resin such as polyvinylpyrrolidone, hydroxyethylcellulose and carboxymethylcellulose.

When the color conversion layer is mainly composed of a fluorescent dye,
A film is formed by a vacuum evaporation or sputtering method through a mask of a desired color conversion layer pattern.On the other hand, when a fluorescent dye and a resin are used, the fluorescent dye, the resin and an appropriate solvent are mixed, dispersed or solubilized. Liquid, spin coat,
It is common to form a film by a method such as roll coating or casting, and pattern it with a desired color conversion layer pattern by a photolithography method, or pattern it with a desired color conversion layer pattern by a method such as screen printing. is there.

When a photocurable resin is used, it is preferable to add a photoinitiator or a sensitizer. With this configuration, the photocurable resin can be easily cured. Such photoinitiators include acetophenone compounds, benzoin compounds, benzophenone compounds, thioxanthone compounds, triazine compounds,
Examples include a radical generator and a photoacid generator. Examples of the sensitizer include triethanolamine, 4,4'-dimethylaminobenzophenone, and ethyl 4-dimethylaminobenzoate.

It is preferable to add an ultraviolet absorber to the photocurable resin. This is because such a configuration makes it possible to prevent deterioration of the organic fluorescent substance. Such an ultraviolet absorber is preferably, for example, at least one compound selected from the group consisting of salicylic acid compounds, benzophenone compounds, benzotriazole compounds, triazine compounds, and cyanoacrylate compounds.

It is also preferred that the photocurable resin contains an antioxidant and / or a light stabilizer or one of the compounds. This is because excellent durability can be obtained by adding an antioxidant or a light stabilizer as described above. Preferred antioxidants include 2,6-di-tert-butyl-
p-cresol, butylated hydroxyanisole (BH
A) and tetrakis- [methylene-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate] methane. Preferred light stabilizers are nickel bis (octylphenyl) sulfide, [2,2′-thiobis (4-tert-octylphenolate)]-n-butylamine nickel,
Nickel complex-3,5-di-tert-butyl-4-hydroxybenzyl-phosphate monoethylate,
Nickel-dibutyl dithiocarbamate and the like.

For reference, the preferred color conversion layer 14
The refractive index of the constituent materials (pigment resin, binder resin) is as follows. Vinyl chloride resin: 1.54 (wavelength 589 nm) Vinylidene chloride resin: 1.60 (wavelength 589 nm) Vinyl acetate resin: 1.45 (wavelength 589 nm) Polyethylene resin: 1.51 (wavelength 589 nm) Polystyrene resin: 1.59 ( Methyl methacrylate resin: 1.49 (wavelength 589 nm) Melamine resin: 1.60 (wavelength 589 nm)

In the organic EL display device 18 according to the first embodiment, the thickness of the color conversion layer 14 is not particularly limited, but may be, for example, 0.1 μm to 1 m.
It is preferable that the value be within the range of m. The reason for this is that if the thickness of the color conversion layer 14 is less than 0.1 μm, the mechanical strength may be reduced or it may be difficult to laminate. On the other hand, if the thickness of the color conversion layer 14 exceeds 1 mm, the light transmittance is significantly reduced, and the amount of light that can be extracted to the outside is reduced, or it may be difficult to reduce the thickness of the organic EL display device 18. It is. Therefore, the thickness of the color conversion layer 14 is preferably set to a value in the range of 0.1 μm to 1 mm, more preferably to a value in the range of 1 μm to 500 μm, and to a value in the range of 5 μm to 100 μm. More preferably,

Although only one color conversion layer 14 is shown for convenience in the organic EL display device 18 shown in FIG. 1, a plurality of color conversion layers 14 may be provided on the same plane. For example, a color conversion layer for red, a color conversion layer for blue, and a color conversion layer for green may be arranged close to each other on the light emitting surface 11 on the organic EL element 10. With this configuration, the colorization of the organic EL display device 18 can be easily achieved.

(3) Translucent Layer In the organic EL display device 18 according to the first embodiment,
The light transmitting layer 12 preferably has a light transmittance of 50% or more at a wavelength of 400 to 700 nm. The reason is that when the light transmittance of the light transmitting layer 12 is less than 50%, the amount of light that can be extracted to the outside through the light transmitting layer 12 may be reduced. Therefore, at a wavelength of 400 to 700 nm, the light transmittance of the light transmitting layer 12 is more preferably 70% or more, and further preferably 90% or more.

The constituent material of the light-transmitting layer 12 includes polyacrylic resin, polymethacrylic resin, polyester resin, polyamide resin, polycarbonate resin, polyvinyl alcohol resin, and polyvinylpyrrolidone resin. , A kind of polyurethane resin, epoxy resin, cyanate resin, melamine resin, phenolic resin, maleic resin, vinyl acetate resin, polyacetal resin, silicone resin, fluorine resin, hydroxyethyl cellulose, carboxymethyl cellulose, etc. A single material or a combination of two or more organic materials can be used.

As a constituent material of the light transmitting layer 12, glass material, silicon oxide, aluminum oxide, titanium oxide,
Yttrium oxide, germanium oxide, zinc oxide, magnesium oxide, calcium oxide, strontium oxide,
Barium oxide, lead oxide, sodium oxide, zirconia, sodium oxide, lithium oxide, boron oxide, silicon nitride and the like may be used alone or in combination of two or more inorganic materials. Preferred glass materials include soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, and barium borosilicate glass as constituent materials of the light-transmitting layer.

Incidentally, for reference, a preferable light-transmitting layer 12 is used.
The refractive index of the constituent material example is as follows. Methyl methacrylate resin: 1.49 (wavelength 589 nm) Silicon oxide (SiO ₂ ): 1.54 (wavelength 589 nm) Boron oxide (B ₂ O ₃ ): 1.77 (wavelength 546 nm) Glass: 1.49 (wavelength 589 nm) ) Tetrafluoroethylene resin: 1.49 (wavelength 589 nm)

Although the thickness of the light-transmitting layer 12 is not particularly limited, it is specifically preferable that the thickness be in the range of 0.1 μm to 1 mm. This is because the translucent layer 1
If the thickness of the light-transmitting layer 12 is less than 0.1 μm, the mechanical strength may be reduced or the lamination may be difficult. This is because the light transmittance may be significantly reduced. Therefore, the thickness of the translucent layer 12 is more preferably set to a value in the range of 1 μm to 500 μm, and even more preferably to a value in the range of 1 μm to 100 μm.

(4) Concavo-convex Shape at Interface In the organic EL display device 18 according to the first embodiment,
The size of the uneven shape at the interface 13 between the translucent layer 12 and the color conversion layer 14 is not particularly limited, but the average distance between vertices of adjacent convex portions in the convex shape (in FIG. 1, (Indicated by the symbol S)) is preferably in the range of 0.5 to 10 μm. The reason for this is that if the average distance between the vertices of the projections is out of the range of 0.5 to 10 μm, the light reflection efficiency at the interface 13 may decrease. Therefore, the average distance between the vertices of the convex part is
The value is more preferably in the range of 0.6 to 8 μm, and even more preferably in the range of 1 to 5 μm.

The average distance (indicated by the symbol T in FIG. 1) between the apex of the convex portion and the bottom point of the concave portion at the interface 13 between the light-transmitting layer 12 and the color conversion layer 14 is set to 0.1. 5-10μ
It is preferable that the value be within the range of m. The reason is that the average distance between the top of the projection and the bottom of the recess is 0.5 to 10 μm.
Is out of the range, the light reflection efficiency at the interface 13 may decrease. Therefore, the average distance between the vertices of the convex portions is more preferably set to a value in the range of 0.6 to 8 μm, and even more preferably to a value in the range of 1 to 5 μm.

Further, the uneven shape of the interface 13 is not particularly limited as long as it can provide a larger number of regions satisfying the expression of the critical angle of total reflection as compared with the flat shape. It may be a corrugated shape as shown in the figure, or a continuous pyramid shape (square pyramid)
Or it may be a discontinuous pyramid shape. In particular, in the case of a pyramid shape, the apex angle is preferably around 90 ° C. By configuring the pyramid shape in this way,
A region that satisfies the expression for the critical angle of total reflection can be provided more efficiently.

(5) Organic EL element In the first embodiment, an LED,
VFD, PDP, etc. can also be mentioned, but since organic thinning is possible and energy efficiency is high, organic E
It is preferable to use the L element 10. More specifically, as shown in FIG.
It is preferable to use the organic EL element 10 composed of (30, 32, 34), the cathode layer 20, and the organic light emitting layers 24, 26, 28 sandwiched therebetween. By using the organic EL element 10 configured as described above as a planar light-emitting body, it is possible to provide the organic EL display device 18 which has a high emission luminance and is capable of full color display.

First, referring to FIG.
The organic light-emitting layers 24, 26, and 28 include organic light-emitting materials corresponding to emission colors. Such an organic light emitting material is not particularly limited, but preferably has, for example, the following three functions. (A) Charge injection function: a function of injecting holes from an anode or a hole injection layer while applying an electric field, while injecting electrons from a cathode layer or an electron injection layer. (B) Transport function: a function of moving injected holes and electrons by the force of an electric field. (C) Light-emitting function: a function of providing a field for recombination of electrons and holes and connecting them to light emission. Therefore, as an organic light emitting material having such a function, an aromatic ring compound having a styryl group can be given.
In other words, the use of an aromatic ring compound having a styryl group is preferable in that excellent light emitting characteristics and durability can be obtained.

The organic light emitting layers 24, 26, and 28 may be provided with a benzothiazole-based, benzimidazole-based, benzoxazole-based fluorescent whitening agent, a styrylbenzene-based compound, or a metal having an 8-quinolinol derivative as a ligand. It is also preferable to use a complex in combination. Further, an organic light-emitting material having a distyrylarylene skeleton, for example, 4,4′-bis (2,2-
It is also preferable to use, as a host, diphenylvinyl) biphenyl) or the like, and to combine the host with a strong fluorescent substance from blue to red, for example, a coumarin-based fluorescent substance or a fluorescent substance similar to the host.

The thickness of the organic light-emitting layers 24, 26 and 28 is not particularly limited and can be appropriately selected depending on the situation, but is preferably in the range of 5 nm to 5 μm. This is because the thickness of the organic light emitting layer is 5 nm.
When the thickness is less than the above, the emission luminance and the durability may decrease. On the other hand, when the thickness of the organic light emitting layer exceeds 5 μm, the value of the applied voltage may increase. Therefore, the thickness of the organic light emitting layer is more preferably set to a value within the range of 10 nm to 3 μm, and even more preferably set to a value within the range of 20 nm to 1 μm.

Next, the anode layer 2 in the organic EL device 10
2 (30, 32, 34) will be described. The anode layer 22 has a large work function (for example, 4.0 eV
Above) It is preferable to use metals, alloys, electrically conductive compounds or mixtures thereof. Specifically, one kind of indium tin oxide (ITO), indium copper, tin, zinc oxide, gold, platinum, palladium and the like can be used alone or in combination of two or more kinds. The thickness of the anode layer 22 is not particularly limited, but is preferably in the range of 10 to 1000 nm, and more preferably in the range of 10 to 200 nm. Further, regarding the anode layer 22, the organic light emitting layer 2
In order that the light emitted from 4, 26, 28 can be effectively extracted to the outside, it is preferable that it is substantially transparent, more specifically, the light transmittance is 10% or more.

Next, the cathode layer 2 in the organic EL element 10
0 will be described. For the cathode layer 20, it is preferable to use a metal, an alloy, an electrically conductive compound, or a mixture thereof having a small work function (for example, less than 4.0 eV). Specifically, one of magnesium, aluminum, indium, lithium, sodium, cesium, silver, etc.
The species can be used alone or in combination of two or more. The thickness of the cathode layer 20 is not particularly limited, but is preferably in the range of 10 to 1000 nm, and more preferably in the range of 10 to 200 nm.

Next, the support substrate 40 in the organic EL device 10 will be described. As the support substrate 40, a substrate commonly used in this type of organic electroluminescence display device can be used as it is, as long as it has excellent mechanical strength and low moisture and oxygen permeability. Specifically, for example, glass and ceramics can be used.

The organic EL display device 18 of the first embodiment can use the organic EL element 10 having the following configuration, but is combined with another component, for example, a hole injection layer or an electron injection layer. The use of the organic EL element 10 is also conceivable. Hereinafter, structural examples 1 to 3 of other preferable organic EL elements 10 are also shown. Anode / organic light emitting layer / cathode layer anode / hole injection layer / organic light emitting layer / cathode layer anode / organic light emitting layer / electron injection layer / cathode layer anode / hole injection layer / organic light emitting layer / electron injection layer / cathode layer

[Second Embodiment] The second embodiment relates to a method for manufacturing an organic EL display device, and includes a step of forming a color conversion layer (referred to as a first step) and the color. A step of forming the surface of the conversion layer into an uneven shape (referred to as a second step), a step of forming a light-transmitting layer (referred to as a third step), and a step of stacking the organic EL elements (fourth) ).). Since the configuration itself of the organic EL display device can be the same as that of the first embodiment, the detailed description is omitted here, and FIGS. 3A to 3D are omitted. The contents of the method for manufacturing the organic EL display device will be mainly described with reference to FIG.

(1) First Step As shown in FIG. 3A, the first step is, for example, a composition for a color conversion layer containing a photocurable resin, an organic fluorescent substance, and an ultraviolet absorber. In this step, the object (color conversion layer) 42 is formed on, for example, the base material 44 and then light-cured. Also, the base material 4
4 is made of a transparent material such as a glass substrate, a polycarbonate resin, or a polyester resin.

Here, in molding the composition 42 for a color conversion layer, a photo-curable resin, an organic fluorescent substance, an ultraviolet absorbent and the like were uniformly mixed using a mixing machine such as a mixer or a three-roll machine. Then, using a knife coater, a gravure coater, or a spin coater, for example, a thickness of 1 to 100 μm
m. In the case where an organic solvent is added in order to uniformly apply the color conversion layer composition 42, after the application, a temperature of 50 to 100 ° C.
It is preferred that the organic solvent is scattered by heating for up to 60 minutes. Next, in order to photo-cure the color conversion layer composition (color conversion layer) 42, a predetermined amount of ultraviolet rays, for example, 100 to 200, is used using a halogen lamp, a metal halide lamp, or the like.
Exposure is preferably performed within the range of 0 mJ / cm ² . This is because the photocurable resin may not be light-cured when the exposure amount of ultraviolet light is less than 100 mJ / cm ² , whereas when the exposure amount exceeds 2000 mJ / cm ² , the degradation of the organic fluorescent substance is deteriorated. May be promoted. Further, it is preferable that the wavelength of the ultraviolet light is set to a value within a range of 350 to 400 nm. The reason for this is that if the wavelength of the ultraviolet light is less than 350 nm, the deterioration of the organic fluorescent substance may be accelerated.
If the thickness exceeds 00 nm, the photocurable resin may not be photocured.

It is also preferable to use a thermosetting resin instead of the photocurable resin of the composition 42 for the color conversion layer.
In that case, it is preferable to heat and cure by heating, for example, at a temperature of 50 to 180 ° C. for a time of 10 to 180 minutes instead of irradiating the ultraviolet rays.

(2) Second Step As shown in FIG. 3B, the second step is a step of forming an uneven shape 47 on the surface of the color conversion layer composition (color conversion layer) 42. The method of providing the concave-convex shape 47 is not particularly limited, and examples thereof include the following method. After the color conversion layer composition (color conversion layer) 42 is cured, the surface thereof is subjected to a chemical treatment and / or a physical treatment (mechanical treatment) (a first method). Before curing the color conversion layer composition (color conversion layer) 42, a release film (not shown) having an uneven shape is disposed on the surface thereof, and the color conversion layer composition (color conversion layer) is arranged. 42
Is light-cured or heat-cured (second method). Before the color conversion layer composition (color conversion layer) 42 is cured, a light transmitting layer film (not shown) having an uneven shape is disposed on the surface thereof, and the color conversion layer composition (color (Conversion layer) 42 is light-cured or heat-cured (third method)

In the first method, the chemical treatment includes chemical etching, solvent treatment, and the like. Examples of the physical treatment include polishing treatment, shot blast treatment, tumbling treatment, sputter etching treatment, glow discharge treatment, corona discharge treatment, and the like, either alone or in combination of two or more. Of these,
In particular, by performing the polishing treatment, the uneven shape 47 can be easily provided. Specifically, in the polishing process,
Sandpaper and wrapping film (polishing film with fine particles such as alumina and diamond powder fixed on the film)
While applying manually or using a rotary polishing machine,
Further, it is preferable to use abrasive particles such as alumina as the abrasive.

As the release film having an uneven surface on the surface used in the second method, a fluorine-based film, a siliconized film, a polyethylene resin film, a polypropylene resin film, or the like is preferably used. Further, it is preferable to use a film in which the surface is provided with an uneven shape by a method such as embossing or polishing treatment in advance for these release films. And
The release film is used as a composition for a color conversion layer (color conversion layer) 4
The composition for color conversion layer (color conversion layer) 42 is light-cured or heat-cured by irradiating it with ultraviolet light or heating it in the same manner as in the first step. Since such a release film can be reused many times, its production is extremely economical. In addition, since the uneven shape on the release film can be inspected in advance, as a result, the desired uneven shape can be accurately provided on the surface of the color conversion layer composition (color conversion layer) 42.

The composition for the color conversion layer (color conversion layer) 42
In the case where is composed of a photocurable resin, it is preferable to use a release film having ultraviolet light resistance. When the color conversion layer composition (color conversion layer) 42 is made of a thermosetting resin, it is preferable to use a release film having heat resistance.

Further, in the third method, a film for a light-transmitting layer having an uneven surface provided in advance is arranged, and the composition for a color conversion layer (color conversion layer) 42 is photo-cured or heat-cured. Is what you do. That is, the third method is characterized in that the light-transmitting layer film is formed without being removed after the light-transmitting layer film is light-cured or heat-cured to form the color conversion layer 42, and is directly used as the light-transmitting layer 48. . Therefore, by performing the above-described steps, the second step and a third step described later can be performed at the same time, so that an advantage that the number of steps is reduced is obtained. The method for manufacturing the light-transmitting layer film and the method for forming the color conversion layer 42 are the same as those for the release film in the second method and the method for forming the color conversion layer 42 in the first step. be able to.

(3) Third Step In the third step, as shown in FIG. 3 (c), a light-transmitting composition is applied on a color conversion layer 46 having a surface with irregularities. Forming the light-transmitting layer 48. Here, the second
As the translucent composition used in the embodiment, the material described in the first embodiment can be used as it is. However, the composition for the translucent layer 45 between the color conversion layer 46 and the translucent layer 48 can be used. It is more preferable to apply a light-transmitting composition adjusted to a low viscosity so that air bubbles and the like do not enter. In particular,
An organic solvent or the like is added to the composition for translucency, and 10 to 1000
It is preferable to set the value in the range of 0 cps (temperature of 25 ° C.). Also, there is no particular limitation on the method of coating, for example, a knife coater, a gravure coater,
Alternatively, using a spin coater, for example, a thickness of 1 to 10
It is preferable to apply it in a layer within the range of 0 μm. In addition,
When the translucent composition is composed of a photocurable material, the composition can be photocured by irradiating ultraviolet rays, and when the translucent composition is composed of a thermosetting material. Can be thermally cured by heating.

(4) Fourth Step The fourth step is a step of laminating the organic EL element 50 on the base material 44 side of the cured color conversion layer 46 as shown in FIG. . There is no particular limitation on the lamination method, and the organic EL element 50 prepared in advance may be laminated using an adhesive or the like, or the base material 44 may be used.
An electrode and an organic light emitting layer may be sequentially formed thereon.

[Third Embodiment] A third embodiment is another embodiment relating to a method of manufacturing the organic EL display device 62. In the third embodiment, a step of forming a color conversion layer 54 (referred to as a fifth step) and an uneven surface 55
(A sixth step), a step of forming the light-transmitting layer 58 (a seventh step), and a step of laminating the organic EL element 60 (the sixth step). 8
This is referred to as a step. ). Less than,
With reference to FIGS. 4 (a) to 4 (d), a description will be given mainly of contents different from the first and second embodiments.

(1) Fifth Step The fifth step is shown in FIG. 4A, which is a step of forming the color conversion layer 54 on the base material 52, and is the first step in the second embodiment. Are substantially the same as those described above, and a description thereof will be omitted.

(2) Sixth Step As shown in FIG. 4B, the sixth step is a step of forming an intermediate layer 56 having an uneven shape 55 on the surface. The method for providing the uneven shape 55 is not particularly limited, but includes the following method. After the intermediate layer 56 is formed on the color conversion layer 54, the surface of the intermediate layer 56 is subjected to a chemical treatment and / or a physical treatment (fourth method). The composition for the intermediate layer is photo-cured or heat-cured in a state where a release film (not shown) having an uneven surface is arranged on the surface of the composition for the intermediate layer (fifth method). An intermediate layer 56 having an uneven shape on the surface is formed in advance using the intermediate layer composition, and the intermediate layer 56 is laminated on the color conversion layer 54 (sixth method).

Here, the fourth and fifth methods are the same as the first and second methods in the second embodiment, and the description thereof will be omitted. Further, as the constituent material of the intermediate layer 56, the same kind of content can be used as long as the refractive index is smaller than the refractive index of the light transmitting layer 58. Therefore, organic materials such as polyacrylic resin and polymethacrylic resin, and inorganic materials such as glass material and zirconia oxide can be used.

In the sixth method, the method of previously forming the intermediate layer 56 having the unevenness 55 on the surface is not particularly limited, but is easily formed by, for example, die molding or embossing. be able to. As described above, if the intermediate layer 56 is provided with the uneven shape 55 in advance, the uneven shape 55 can be inspected in advance. Therefore, the desired concavo-convex shape 55 is formed by the composition (color conversion layer) 54 for the color conversion layer.
Can be more accurately provided on the surface. FIG.
In (b), the concavo-convex shape 55 is a continuous pyramid shape (square pyramid), but may be a corrugated or irregularly shaped concavo-convex shape or a discontinuous pyramid shape.

(3) Seventh Step As shown in FIG. 4C, the seventh step is
Is formed on the intermediate layer 56. Since the seventh step is substantially the same as the third step in the second embodiment, a detailed description thereof will be omitted.

(4) Eighth Step The eighth step is a step of laminating the organic EL element 60 on the base material 52 side of the cured color conversion layer 54 as shown in FIG. 4D. Since this step is substantially the same as the third step in the second embodiment, a detailed description thereof will be omitted.

[0078]

EXAMPLES Example 1 (1) Production of Color Conversion Layer First, 82 g of a benzoguanamine resin, 66 g (6% by weight) of coumarin as an organic fluorescent substance, and rhodamine B
A fluorescent pigment composed of 6 g (6% by weight) and 6 g (6% by weight) of rhodamine 6G was composed. Next, 30 g (30% by weight) of a fluorescent pigment was uniformly mixed with 70 g (70% by weight) of a polyvinyl chloride resin (average molecular weight: 20,000), and cyclohexanone was added thereto to obtain a viscosity of 8%.
The composition for red fluorescence conversion layer of 000 cps (temperature of 25 ° C.) was obtained.

The obtained composition for red fluorescence conversion layer was
On a glass substrate (Corning 7059) having a size of 5 mm, a width of 75 mm and a thickness of 1.1 mm, a bar coater was used to cover 20 μm.
And dried at a temperature of 80 ° C. for a time period of 10 minutes to obtain a red fluorescence conversion layer. Next, # 80
Using a sandpaper of No. 0, lapping polishing is performed on the red fluorescence conversion layer while spraying pure water, and further, a rotary polishing machine (Sp
The surface of the red fluorescence conversion layer was polished while spraying pure water with an alumina fine particle abrasive (Eed Fam). In this state, when the unevenness on the surface of the red fluorescence conversion layer was measured using a laser microscope, the average distance between the vertices of adjacent convex portions in the uneven shape was 2.5 μm.
The average distance between the top of the projection and the bottom of the recess in the uneven shape was 1.1 μm. Further, the refractive index of the red fluorescence conversion layer was measured using a refractometer.
58 (wavelength 600 nm).

Next, on the polished red fluorescence conversion layer, an acrylate-based photocurable resin JNP was used as a light-transmitting layer.
C06 (manufactured by JSR Corporation, solid content 38% by weight) was spin-coated, and dried by heating at a temperature of 80 ° C. for 10 minutes. In this state, the apparatus was mounted on a contact type exposure machine using a high-pressure mercury lamp as a light source, and was irradiated with ultraviolet rays (wavelength: 365 nm) so that the exposure amount became 600 mJ / cm ^2, and further, at a temperature of 160
The composition was thermally cured at 30 ° C. for 30 minutes. Thus, a red fluorescence conversion substrate provided with a translucent layer was produced. When the refractive index of only the light-transmitting layer was measured using a refractometer,
1.54 (600 nm), which was smaller than the refractive index of the red fluorescence conversion layer.

(2) Preparation of Organic EL Element On the other hand, a 120 nm thick ITO film was entirely formed on a glass substrate (Corning 7059) having a length of 25 mm, a width of 75 mm and a thickness of 1.1 mm by a sputtering method. .
A positive photoresist HPR204 is formed on the ITO film.
(Fuji Hunt Electronics Technology Co., Ltd.)
Was spin-coated and dried under the conditions of a temperature of 80 ° C. and a time of 10 minutes. Next, the exposure amount is set to 10 through a photomask.
Contact exposure was performed using a high-pressure mercury lamp as a light source so as to obtain 0 mJ / cm ² . The exposed part was developed using TMAH (tetramethylammonium hydroxide) as a developing solution. Then, using an oven, the temperature is 130 ° C.
After the post-baking treatment, the ITO film was etched using a hydrobromic acid aqueous solution as an etchant. Thereafter, the positive resist was removed using a stripping solution N303 (manufactured by Nagase & Co., Ltd.) to form an ITO pattern of 150 mm × 50 mm.

Next, the glass substrate on which the ITO pattern is formed is washed with isopropyl alcohol and ultraviolet light, and then the substrate is deposited on a vapor deposition apparatus (Nihon Vacuum Technology Co., Ltd.).
). Then, on a molybdenum heating board in the vapor deposition device, as a hole injection material,
4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (MT
DATA), 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), and 4,4'-bis (2,2-diphenylvinyl) biphenyl (DPVBi) as an organic light emitting material. ), Tris (8-quinolinol) aluminum (Al)
q), and a silver wire as a counter electrode (cathode) material was mounted on a tungsten filament, and a magnesium ribbon was mounted on a molybdenum heating board. In this state, the degree of vacuum of the vapor deposition device is set to 5 × 10 ^−7.
The pressure is reduced to Torr, and from the hole injection layer to the formation of the cathode, the layers are successively laminated by a single evacuation from the hole injecting layer to the formation of the cathode so that the following deposition rates and film thicknesses are obtained. did. In addition, silver and magnesium of the counter electrode were simultaneously vapor-deposited, respectively, to form a film with a total thickness of 200 nm. MTDATA: evaporation rate 0.1 to 0.3 nm / sec. , Film thickness 60 nm NPD: evaporation rate 0.1 to 0.3 nm / sec. , Film thickness 20 nm DPVBi: evaporation rate 0.1-0.3 nm / sec. , Film thickness 50 nm Alq: evaporation rate 0.1-0.3 nm / sec. , Thickness: 20 nm Mg: deposition rate: 1.3 to 1.4 nm / sec. , Thickness 200 nm Ag: evaporation rate 0.1 nm / sec. , Thickness 200nm

The lower electrode (ITO) of the obtained organic EL device
Pattern, anode) and upper electrode (cathode) as the counter electrode
During this period, a voltage of 12 V DC was applied to emit light. When the light emission luminance was measured using a colorimeter CS100 (manufactured by Minolta Co., Ltd.), a value of 200 cd / m ² was obtained, and the CIE chromaticity coordinates were X = 0.14, Y = 0.20.
It was confirmed that blue light emission was obtained.

(3) Production of Organic EL Display Device The red conversion substrate formed on the glass substrate obtained in the above (1) was replaced with the organic E obtained in the above (2) from the transparent layer side.
The organic EL display device of Example 1 was obtained by laminating on the light emitting surface (lower electrode side) of the L element. In the obtained organic EL display device, a voltage of 12 V DC was applied between the lower electrode (ITO pattern, anode) and the upper electrode (cathode) as a counter electrode to emit light. The light emission luminance was measured using a color difference meter CS100 (manufactured by Minolta Co., Ltd.).
A value of cd / m ² was obtained, and it was confirmed that the conversion efficiency was 35%. In addition, the JI
CIE chromaticity coordinates based on SZ8701 are represented by X =
0.61, Y = 0.34, and it was confirmed that strong red (red) light emission was obtained.

Example 2 Example 1 was repeated, except that the # 800 sandpaper was replaced with a # 600 alumina-fixed wrapping film (manufactured by Sumitomo 3M Ltd.). A red conversion layer having an uneven shape on the surface was produced. When the unevenness on the surface of the red fluorescence conversion layer was measured using a laser microscope, the average distance between the apexes of adjacent convex portions in the uneven shape was 4.0 μm. Was 2.5 μm.

Next, a translucent layer was laminated on the polished red fluorescence conversion layer in the same manner as in Example 1 to produce a red fluorescence conversion substrate provided with a translucent layer. Next, the obtained red fluorescence conversion substrate was used in the same manner as in Example 1 to produce an organic EL.
The organic EL display device of Example 2 was formed by laminating on the light emitting surface (lower electrode side) of the element. In the obtained organic EL display device, a voltage of 12 V DC was applied between the lower electrode and the upper electrode to emit light. When the light emission luminance was measured using the color difference meter CS100, a value of 68 cd / m ² was obtained, and it was confirmed that the conversion efficiency was 34%. The CIE chromaticity coordinates of the obtained light emission are represented by X =
0.62, Y = 0.34, and it was confirmed that strong red (red) light emission was obtained.

Example 3 A red conversion layer having an uneven surface was produced in the same manner as in Example 1 except that sandblasting was performed instead of sandpaper # 800 in Example 1. When the unevenness on the surface of the red fluorescence conversion layer was measured using a laser microscope, the average distance between the apexes of adjacent convex portions in the uneven shape was 7.0 μm.
And the average distance between the top of the protrusion and the bottom of the recess in the uneven shape was 4.0 μm. Next, a translucent layer was laminated on the polished red fluorescence conversion layer in the same manner as in Example 1 to produce a red fluorescence conversion substrate with a translucent layer.
Next, the obtained red fluorescence conversion substrate was laminated on the light emitting surface (lower electrode side) of the organic EL element manufactured in the same manner as in Example 1, to obtain an organic EL display device of Example 3. In the obtained organic EL display device, a voltage of 12 V DC was applied between the lower electrode and the upper electrode to emit light. When the emission luminance was measured using a color difference meter CS100, 66
A value of cd / m ² was obtained, and it was confirmed that the conversion efficiency was 33%. In addition, the CIE for the obtained light emission
The chromaticity coordinates were X = 0.61 and Y = 0.35, and it was confirmed that strong red (red) light emission was obtained.

Example 4 Instead of the photocurable resin JNPC06 in Example 1, a polyvinyl alcohol aqueous solution (average molecular weight: 20,000, concentration: 10) was used as the light-transmitting layer.
Wt%), except that a red conversion substrate with a light-transmitting layer was prepared in the same manner as in Example 1. The refractive index of this translucent layer alone was measured using a refractometer and found to be 1.53 (wavelength 600 nm), which was the refractive index of the red fluorescence conversion layer (1.
58). In addition, when the unevenness on the surface of the red fluorescence conversion layer before the light-transmitting layer was laminated was measured using a laser microscope, the average distance between vertices of adjacent convex portions in the uneven shape was 2.5 μm,
The average distance between the top of the protrusion and the bottom of the recess in the uneven shape was 1.1 μm. Next, the obtained red fluorescence conversion substrate provided with the light-transmitting layer was laminated on the light emitting surface (lower electrode side) of the organic EL device manufactured in the same manner as in Example 1, and Example 4 was performed.
Organic EL display device. In the obtained organic EL display device, DC 12 V was applied between the lower electrode and the upper electrode.
Was applied to emit light. When the light emission luminance was measured using the color difference meter CS100, a value of 68 cd / m ² was obtained, and it was confirmed that the conversion efficiency was 34%. The CIE chromaticity coordinates of the obtained light emission are as follows:
X = 0.62 and Y = 0.36, and it was confirmed that strong red (red) light emission was obtained.

Example 5 A polyvinyl chloride resin (average weight molecular weight 2) in the composition for a red fluorescence conversion layer of Example 1
Acrylate-based photocurable resist V25
A composition for a red fluorescence conversion layer was obtained in the same manner as in Example 1, except that 9PA (manufactured by Nippon Steel Chemical Co., Ltd., solid content: 50% by weight) was used. The obtained composition for a red fluorescence conversion layer was applied in a length of 25 m.
It was applied on a glass substrate (Corning 7059) having a width of 75 mm, a width of 75 mm and a thickness of 1.1 mm using a spin coater, and was dried at a temperature of 80 ° C. for 10 minutes. In this state,
Attached to a contact type exposure machine using a high pressure mercury lamp as a light source,
The exposure amount is 100 from the lamination surface side of the composition for a red fluorescence conversion layer.
0 mJ / cm ² so that ultraviolet rays (wavelength 365 n
m) to obtain a red fluorescence conversion layer having a thickness of 20 μm. When the refractive index of this red fluorescence conversion layer was measured using a refractometer, it was 1.59 (600 nm). Next, as in Example 1, irregularities were formed on the film surface. When measured using a laser microscope, the average distance between the vertices of adjacent convex portions in the uneven shape was 3.2 μm.
The average distance between the top of the projection and the bottom of the recess in the uneven shape was 1.7 μm. Next, a tetrachloroethane solution of polymethyl methacrylate (average weight molecular weight: 25,000), which is a material for a light-transmitting layer, was spin-coated on the obtained red fluorescence conversion layer, and the temperature was 80 ° C. for 10 hours.
After drying under the conditions of minutes, a red fluorescence conversion substrate with a translucent layer was produced. In addition, when the refractive index of only the translucent layer was measured using a refractometer, it was 1.47 (600 nm), and it was confirmed that it was smaller than the refractive index of the red fluorescence conversion layer. Next, the obtained red fluorescence conversion substrate with a light-transmitting layer was laminated on the light emitting surface (lower electrode side) of the organic EL device manufactured in the same manner as in Example 1, and the organic EL display device of Example 5 did. In the obtained organic EL display device, a voltage of 12 V DC was applied between the lower electrode and the upper electrode (cathode) to emit light. When the light emission luminance was measured using the color difference meter CS100, a value of 66 cd / m ² was obtained, and it was confirmed that the conversion efficiency was 33%. Also,
The CIE chromaticity coordinates for the resulting luminescence were X = 0.6
1, Y = 0.35, and it was confirmed that strong red light emission was obtained.

Example 6 A silicon dioxide (SiO ₂ ) film was further formed as a protective film on the translucent layer laminated on the red fluorescence conversion substrate prepared in Example 5, and a substrate temperature of 160.
℃, the degree of vacuum 1 × 10 ^-6 under sputtering conditions,
A film was formed. Next, an organic EL element was formed on the silicon dioxide (SiO ₂ ) film in the same manner as in Example 1. That is, an ITO film having a thickness of 150 nm (a surface resistance of 20Ω / □)
Was entirely formed by a sputtering method. This IT
After the O film and the like were washed with isopropyl alcohol and ultraviolet light, they were fixed to a substrate holder in a vapor deposition apparatus (manufactured by Nippon Vacuum Engineering Co., Ltd.). Then, a heating board made of molybdenum in the vapor deposition apparatus is filled with MTDATA and NPD as hole injection materials, DPVBi as an organic light emitting material, DPAVB as a dopant, and Alq as an electron injection material, respectively, and further, a counter electrode (cathode) material. Was mounted on a tungsten filament, and a magnesium ribbon was mounted on a molybdenum heating board.
In this state, the degree of vacuum of the vapor deposition apparatus was reduced to 5 × 10 ⁻⁷ torr, and the vacuum was not broken during the process from the hole injection layer to the formation of the cathode once, so that the following vapor deposition rate and film thickness were obtained. Were sequentially laminated by vacuuming to produce an organic EL device. Note that DPVBi and DPAVB were simultaneously deposited to form a film so that the weight ratio of the DPAVB dopant was 1.4. In addition, silver and magnesium of the counter electrode were simultaneously vapor-deposited to form a film with a total thickness of 200 nm. MTDATA: evaporation rate 0.1 to 0.3 nm / sec. , Film thickness 60 nm NPD: evaporation rate 0.1 to 0.3 nm / sec. , Film thickness 20 nm DPVBi: evaporation rate 0.1-0.3 nm / sec. DPAVB: deposition rate 0.05 nm / sec. Alq: deposition rate of 0.1 to 0.3 nm / sec. , Thickness: 20 nm Mg: deposition rate: 1.3 to 1.4 nm / sec. , Thickness 200 nm Ag: evaporation rate 0.1 nm / sec. , Thickness 200nm

A voltage of DC 8 V was applied between the lower electrode of the obtained organic EL device and the upper electrode (cathode) as a counter electrode to emit light. When the emission luminance was measured using the colorimeter CS100, a value of 33 cd / m ² was obtained, and the CIE chromaticity coordinates were X = 0.61 and Y = 0.3.
It was confirmed that a strong red light emission of 5 was obtained. When the red fluorescence conversion layer was mechanically shaved and the emission of the base was measured, a value of 100 cd / m ² was obtained.
The IE chromaticity coordinates confirmed that blue light emission with X = 0.16 and Y = 0.24 was obtained.

Comparative Example 1 A red fluorescence conversion layer was produced in the same manner as in Example 1, except that the polishing treatment of the red fluorescence conversion layer was not performed. When the unevenness on the surface of the red fluorescence conversion layer was measured using a laser microscope, the surface was smooth, and no particular surface unevenness was observed. Moreover, the refractive index of the red fluorescence conversion layer was measured using a refractometer, and was 1.58 (600 nm).

Next, a translucent layer was laminated on the smooth red fluorescence conversion layer in the same manner as in Example 1 to produce a red fluorescence conversion layer with a translucent layer. When the refractive index of only the light transmitting layer was measured using a refractometer, it was 1.54 (60
0 nm). Next, the obtained red fluorescence conversion substrate with a light-transmitting layer was prepared in the same manner as in Example 1 by using an organic EL.
The organic EL display device of Comparative Example 1 was obtained by laminating on the light emitting surface (lower electrode side) of the element. In the obtained organic EL display device, a voltage of 12 V DC was applied between the lower electrode (ITO pattern, anode) and the upper electrode (cathode) as a counter electrode to emit light. The emission luminance was measured using a color difference meter CS100. As a result, a value of 60 cd / m ² was obtained, and it was confirmed that the conversion efficiency was 30%. Also,
The CIE chromaticity coordinates for the resulting luminescence were X = 0.5
9, Y = 0.36, and it was confirmed that red (red) light emission was obtained.

[0094]

As described above, according to the optical display device of the present invention, the relationship between the refractive index of the color conversion layer and the refractive index of the light-transmitting layer is defined, and the color conversion layer and the light-transmitting layer are By devising the interface structure of (1), the light emitted in all directions by the fluorescent material can be sufficiently utilized, and the emission luminance can be easily improved. According to another optical display device of the present invention, the magnitude relationship between the refractive index of the intermediate layer and the refractive index of the light-transmitting layer is defined, and the interface structure between the intermediate layer and the light-transmitting layer is determined. By devising, the light emitted in all directions by the fluorescent substance can be sufficiently used, and the emission luminance can be easily improved.
Further, according to the method for manufacturing an optical display device of the present invention, light emitted in all directions by a fluorescent substance can be sufficiently used, and an optical display device having high emission luminance can be efficiently obtained. Now you can. In addition, since the optical display device of the present invention can convert light emitted from the organic EL element into a long wavelength, in combination with the organic EL element,
It can also be used as a color conversion display device.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating a cross section of an organic EL display device according to a first embodiment.

FIG. 2 is a diagram schematically showing a cross section of a conventional organic EL display device (No. 1).

FIG. 3 is a diagram schematically showing a manufacturing process of an organic EL display device according to a second embodiment.

FIG. 4 is a diagram schematically showing a manufacturing process of an organic EL display device according to a third embodiment.

FIG. 5 is a view schematically showing a cross section of an organic EL element.

FIG. 6 is a diagram schematically showing a cross section of a conventional organic EL display device (part 2).

FIG. 7 is a diagram schematically showing a cross section of a conventional organic EL display device (part 3).

FIG. 8 is a diagram schematically showing a cross section of a conventional organic EL display device (part 4).

FIG. 9 is a view schematically showing a cross section of a conventional organic EL display device (part 5).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Planar light-emitting body (organic EL element) 11 Light-emitting surface 12 Translucent layer (translucent base material) 13 Emission surface (interface) 14 Color conversion layer (composition for color conversion) 15 Interface 16 Fluorescent substance 18 Optical Display device (organic EL display device) 20 Cathode 22 Anode 24, 26, 28 Color conversion layer 30, 32, 34 Anode 40, 44, 52 Base material 42, 54 Color conversion layer (composition for color conversion) 45 Interface 47, 55 Roughness 48,58 Translucent layer 50,60 Organic EL device 56 Intermediate layer

Claims (11)

[Claims] 1. A light-transmitting layer on a light-emitting surface side of a planar light-emitting body,
In an optical display device in which a color conversion layer and a color conversion layer are sequentially laminated, the refractive index of the color conversion layer is made larger than the refractive index of the light transmissive layer, and the color conversion layer and the light transmissive layer An optical display device, characterized in that the interface of (1) has an uneven shape. 2. The optical display device according to claim 1, wherein an average distance between vertexes of adjacent convex portions in the concave-convex shape is a value within a range of 0.5 to 10 μm. 3. The optical device according to claim 1, wherein the average distance between the top of the convex portion and the bottom of the concave portion in the concave / convex shape is a value within a range of 0.5 to 10 μm. Display device. 4. The color conversion layer according to claim 1, wherein the color conversion layer is a fluorescence conversion layer that emits light having a longer wavelength than light incident on the color conversion layer. Optical display device. 5. The optical display device according to claim 1, wherein the planar luminous body is an organic electroluminescence element. 6. A light-transmitting layer on a light-emitting surface side of a planar light-emitting body,
In an optical display device in which an intermediate layer and a color conversion layer are sequentially laminated, the refractive index of the color conversion layer is larger than the refractive index of the intermediate layer, and the intermediate layer and the light-transmitting layer An optical display device, wherein the interface with the substrate has an uneven shape. 7. A light-transmitting layer on a light-emitting surface side of a planar light-emitting body,
A method for manufacturing an optical display device in which a color conversion layer and a color conversion layer are sequentially laminated, and the refractive index of the color conversion layer is larger than the refractive index of the light transmissive layer, wherein the color conversion layer and the light transmissive layer A method of manufacturing an optical display device, the method comprising: 8. In the step of forming the interface between the color conversion layer and the light-transmitting layer into an uneven shape, the surface of the color conversion layer may be subjected to a chemical treatment and / or a physical treatment. A method for manufacturing an optical display device according to claim 7, wherein: 9. In the step of forming an interface between the color conversion layer and the light-transmitting layer into an uneven shape, the color conversion layer is light-cured or cured with a release film having an uneven shape on the surface. 9. The method of claim 7, wherein the thermosetting is performed.
3. The method for manufacturing an optical display device according to 1. 10. In the step of forming an interface between the color conversion layer and the light-transmitting layer into an uneven shape, the color conversion layer is light-cured or laminated while a light-transmitting layer having an uneven shape on the surface is laminated. The method for manufacturing an optical display device according to claim 7, wherein the optical display device is thermally cured. 11. A light-transmitting layer, an intermediate layer, and a color conversion layer are sequentially laminated on the light-emitting surface side of the planar light-emitting body, and the refractive index of the color conversion layer is a light-transmitting layer. A method of manufacturing an optical display device having a refractive index higher than the refractive index of the optical display device, the method including a step of forming an interface between the intermediate layer and the light-transmitting layer into an uneven shape.