Optical thin films and display devices

Abstract

The optical thin film of the present invention comprises: a transparent substrate; a coloring layer, consisting of one or more layers, containing a first color material with a maximum absorption wavelength of 470 nm to 530 nm and a half-width at half-maximum (WHM) of 15 nm to 45 nm, a second color material with a maximum absorption wavelength of 560 nm to 620 nm and a WHM of 15 nm to 55 nm, and a third color material with the lowest transmittance in the wavelength range of 400 nm to 780 nm, in the wavelength range of 650 nm to 780 nm; and one or more functional layers sandwiching the coloring layer and disposed on the opposite side of the transparent substrate. The functional layers include an ultraviolet absorption layer. In the optical thin film, a* and b* are each in the range of -5 to +5.

Description

Technical Field

[0001] This invention relates to optical thin films and display devices. This case asserts priority against Japanese Patent Application No. 2021-040749, filed in Japan on March 12, 2021, and its contents are incorporated herein by reference. Prior Technology

[0002] Self-emissive display devices, equipped with organic light-emitting elements (OLEDs) and other self-emissive components, differ from liquid crystal displays (LCDs) in that they possess superior miniaturization, low power consumption, high brightness, and fast response times, making them highly anticipated as next-generation display devices. Metal electrodes and wiring are formed within the display surface of a self-emissive display device. Therefore, light incident from outside the display screen (i.e., external light) is easily reflected by the electrodes or wiring, leading to reduced contrast and other degraded display quality.

[0003] To address the aforementioned issues, proposals have included assembling a polarizing plate and a phase delay plate on the surface of a self-emissive display device. However, in this configuration, when light emitted from the display device passes through the polarizing plate and phase delay plate before being emitted to the outside, a significant portion of the light is lost, which can easily lead to a reduction in component lifespan.

[0004] Furthermore, display devices require high color purity. Color purity refers to the breadth of colors a display device can display, also known as the color reproduction range. Therefore, high color purity means a wide color reproduction range and good color reproduction performance. As a means to improve color reproduction performance, techniques such as using color filters to separate colors from light sources emitting white light, or using color filters to correct light sources emitting monochromatic light of the three primary colors (RGB) and reduce their half-width at half-maximum (HWHM), are already known. However, using color filters to improve the color reproduction performance of display devices necessitates thicker color filters and higher concentrations of color materials, leading to problems such as deterioration in pixel shape and viewing angle characteristics, resulting in reduced display quality. Moreover, for display devices emitting monochromatic light of the three primary colors (RGB), the process of forming color filters becomes necessary, increasing costs.

[0005] As a display device different from those configured with polarizing plates and phase retardation plates, and using color filters, Patent Document 1 discloses, for example, an organic light-emitting display device. This device includes a display substrate containing organic light-emitting elements and a sealing substrate disposed at a distance from the display substrate. A filler is embedded in the space between the display substrate and the sealing substrate, and this filler selectively absorbs external light for each wavelength band to adjust transmittance. This configuration suppresses external light reflection and improves visual recognizability, and selectively absorbs light from wavelength bands that would particularly reduce color purity, thus improving color purity. However, the disclosed technology does not sufficiently suppress external light reflection, and there is a problem of reflected light having a tint. Furthermore, the reliability of the color material absorbing specific wavelengths of light, such as lightfastness, is insufficient, making it difficult to put into practical use. [Previous Technical Documents] [Patent Literature]

[0006] [Patent Document 1] Japanese Patent No. 5673713 Summary of the Invention

[0007] [The problem the invention aims to solve]

[0008] However, the aforementioned prior art has the following problems. While devices using polarizing plates and phase delay plates can suppress the amount of reflected light caused by external light, they also reduce the amount of display light emitted by organic light-emitting elements. Furthermore, a proposal disclosed in Patent Document 1 discloses a wavelength-selective absorption filler comprising pigments with maximum absorption wavelengths in the 480nm-510nm wavelength region and pigments with maximum absorption wavelengths in the 580nm-610nm wavelength region. Therefore, there is a problem of difficulty in removing the influence of external light in wavelength bands below 480nm and above 610nm. If external light in these wavelength bands cannot be suppressed, the effect of reducing reflectivity is insufficient, and there is also a problem of deterioration in reflected hue. Moreover, the reliability of the aforementioned wavelength-selective absorption pigment system, such as its lightfastness, is insufficient; without improving reliability, it is difficult to put it into practical use.

[0009] In view of the above, the present invention provides an optical thin film that can improve display quality and achieve a longer lifespan for light-emitting elements, and a display device using the same. [Methods used to solve problems]

[0010] To address the aforementioned issues, the first-state optical film of the present invention comprises: a transparent substrate; one or more coloring layers containing pigment, overlapping the transparent substrate; and one or more functional layers sandwiching the coloring layer and disposed on the opposite side of the transparent substrate. The aforementioned coloring layer comprises one or more layers of a first color material having a maximum absorption wavelength in the range of 470 nm to 530 nm and a half-width at half-maximum (WHM) of the absorption spectrum of 15 nm to 45 nm, a second color material having a maximum absorption wavelength in the range of 560 nm to 620 nm and a WHM of the absorption spectrum of 15 nm to 55 nm, and a third color material having the lowest transmittance in the wavelength range of 400 nm to 780 nm with a wavelength range of 650 nm to 780 nm, and the chromaticity indexes a* and b* of the reflected hue as defined by formulas (1) to (9) are in the range of -5 to +5, respectively. a* and b* are calculated from the reflectance R(λ) of the light source irradiating the outermost layer of the functional layer in the thickness direction with a D65 light source. The reflectance RE(λ) of the bottommost layer of the transparent substrate is calculated under the condition that 100% reflection occurs across all wavelengths from 380 nm to 780 nm. Furthermore, the aforementioned functional layer includes at least an ultraviolet (UV) absorbing layer, which, according to JIS L 1925, has a UV shielding rate of 85% or higher.

[0011]

[0012] Here, λ represents the wavelength variable, and t represents the ratio of X, Y, Z to Xn, Yn, Zn. The a* and b* values ​​calculated by equations (1) to (3) are calculated according to the calculation method of the CIE1976 L*a*b* color space (CIELAB color space). In equations (1) and (2), Xn, Yn, and Zn are the tristimulus values ​​of the white point of the D65 light source. In equation (4), RE(λ) represents the reflectance [%] of the fully diffuse reflective surface (100% for each wavelength), R2(λ) represents the surface reflectance [%] of the outermost surface of the aforementioned optical film on the opposite side of the aforementioned transparent substrate, and T(λ) represents the transmittance [%] of the aforementioned optical film. In equations (6) to (9), P D65(λ) is the spectrum of the D65 light source, and the upper horizontal lines x(λ), y(λ), and z(λ) are color matching functions in the 2° field of view of CIE1931. The definite integrals in equations (6) to (9) can be obtained by appropriate numerical integration. The wavelength interval for numerical integration is, for example, 1 nm.

[0013] In equation (5), R(λ) represents the reflectivity of the optical film for incident light from the side opposite to the transparent substrate, taking into account the internal reflection of the transparent substrate in the optical film. X, Y, and Z in equations (6) to (8) represent the 3-stimulus values ​​of the white point of the D65 light source.

[0014] The second aspect of the present invention provides a display device comprising a light source and the aforementioned optical thin film. [Effects of the Invention]

[0015] According to the present invention, an optical thin film and a display device are provided that can improve the display quality based on external light reflection and improve the lifespan of the light-emitting elements of the display device. Simple Explanation of the Diagram

[0016] Figure 1 is a schematic cross-sectional view showing an example of an optical thin film and display device according to a first embodiment of the present invention. Figure 2 is an explanatory diagram of the method for calculating the color chromaticity indices a* and b* of the reflectance hue of the optical thin film of the present invention. Figure 3 is a schematic cross-sectional view showing an example of an optical thin film and display device according to a second embodiment of the present invention. Figure 4 is a schematic cross-sectional view showing an example of an optical thin film and display device according to a third embodiment of the present invention. Figure 5 is a schematic cross-sectional view showing an example of an optical thin film and display device according to a fourth embodiment of the present invention. Figure 6 is a graph showing the spectrum of white display output by the organic EL light source and color filter in the embodiment. Figure 7 is a graph showing the spectra of red, green, and blue displays output by the organic EL light source and color filter in the embodiment. Figure 8 shows the electrode reflectivity of the organic EL display device with the calculated display device reflection characteristics 2 and display device reflection hue 2 in the embodiment. Implementation

[0017] [The form in which the invention is carried out]

[0018] The embodiments of the present invention are described below with reference to the accompanying drawings. In all the drawings, even in different embodiments, the same or equivalent components are given the same reference numerals, and common descriptions are omitted.

[0019] [First Implementation Form] The first embodiment of the present invention describes an optical thin film and a display device. Figure 1 is a schematic cross-sectional view showing an example of an optical thin film and display device according to a first embodiment of the present invention. The display device 50A of this embodiment, shown in Figure 1 as a cross-section in the thickness direction, displays color images based on image signals. The display device 50A includes a display unit 20 and an optical thin film 10A of this embodiment.

[0020] The display unit 20 includes a substrate 21, a light-emitting element 22, and a color filter unit 23. The substrate 21 is formed, for example, from a silicon substrate. The light-emitting element 22 emits white light. For example, an organic EL element can also be used as the light-emitting element 22. In an organic EL element, a DC voltage is applied between the anode and cathode, and electrons and holes are injected into the organic light-emitting layer and recombine to generate excitons. The light emitted when these excitons lose their activity is used to emit light. The light from the light-emitting element 22 is emitted in a direction from the bottom to the top of the diagram, centered on an optical axis orthogonal to the organic light-emitting layer. The light-emitting element 22 is, for example, fabricated on the substrate 21 using a semiconductor process.

[0021] The electrodes in each light-emitting element 22 are connected to a driving circuit (not shown) via metal wiring formed on the substrate 21. The driving circuit controls the lighting and extinguishing of each light-emitting element 22 based on image signals. For example, the light-emitting element 22 is configured in each pixel for color display with a first light-emitting element 22R that illuminates the image signal corresponding to the red component, a second light-emitting element 22G that illuminates the image signal corresponding to the green component, and a third light-emitting element 22B that illuminates the image signal corresponding to the blue component.

[0022] The color filter section 23 is arranged in the light emission direction of each light-emitting element 22. The color filter section 23 has a red filter that allows red light to pass through, a green filter that allows green light to pass through, and a blue filter that allows blue light to pass through. The red filter is positioned opposite the first light-emitting element 22R, the green filter is positioned opposite the second light-emitting element 22G, and the blue filter is positioned opposite the third light-emitting element 22B. The color filter section 23 may also have a lens that focuses the light that passes through each red filter, each green filter and each blue filter.

[0023] In this embodiment, the optical thin film 10A is disposed on the color filter section 23 of the display unit 20. The optical thin film 10A is provided to improve the color purity in the display area of ​​the display unit 20 and to improve the display quality based on external light reflection. The optical thin film 10A has a transparent substrate 11, a coloring layer 12, an ultraviolet absorption layer 13 (functional layer) and a low refractive index layer 14A (functional layer) sequentially provided in the light emission direction of the display unit 20.

[0024] The transparent substrate 11 is a plate or sheet having a first surface 11a and a second surface 11b in the thickness direction. The second surface 11b of the transparent substrate 11 is disposed on the side of the color filter portion 23 of the display portion 20. The closer the visible light transmittance of the material of the transparent substrate 11 is to 100%, the better. Visible light here refers to light in the visible light wavelength band between 380nm and 780nm.

[0025] The transparent substrate 11 can be made of polyethylene, polypropylene and other polyolefins, polyesters such as polybutylene terephthalate and polyethylene naphthalate, polyacrylates such as polymethyl methacrylate, polyamides such as nylon 6 and nylon 66, polyimide, polyarylate, polycarbonate, triacetyl cellulose, polyvinyl alcohol, polyvinyl chloride, cyclic olefin copolymers, resins containing norbornene, polyether ether, polyurethane and other transparent resins, and inorganic glass. Suitable materials include polyethylene terephthalate films (PET), triacetyl cellulose films (TAC), polymethyl methacrylate films (PMMA), and polyester films. The thickness of the transparent substrate 11 is not particularly limited, but is preferably set to 10 μm to 100 μm.

[0026] The coloring layer 12 is a layered portion containing pigment, which is overlapped with the first surface 11a of the transparent substrate 11. The coloring layer 12 contains a first color material, a second color material, and a third color material as pigments. The first color material has a maximum absorption wavelength in the range of 470nm to 530nm, and a full width at half maximum (FWHM) of the absorption spectrum of 15nm to 45nm. Here, the maximum absorption wavelength refers to the wavelength that imparts the maximum value among the maximum values ​​of light absorption in the light absorption spectrum (absorption spectrum). In the light transmittance spectrum, it refers to the wavelength that imparts the minimum value among the minimum values. The same applies below. The second color material has a maximum absorption wavelength in the range of 560nm to 620nm, and a half-width at half-maximum (FWHM) of the absorption spectrum of 15nm to 55nm. The third color material has the lowest transmittance in the wavelength range of 400nm to 780nm, with the wavelength being between 650nm and 780nm. The full width at half maximum (FWHM) of the absorption spectrum of the third color material is, for example, between 10nm and 300nm, but is not specifically limited. In the following cases, the first, second, and third color materials will be referred to collectively, or sometimes simply as color materials.

[0027] As the first, second, and third colorants included in the coloring layer 12, compounds comprising the following can be used: compounds selected from the group consisting of compounds having any one of the following structures: porphyrin, phthalocyanine, azo, cyanine, squarylium, coumarin, polyene, quinone, tetrazaporphyrin, pyrromethene, and indigo, and their metal complexes. For example, the Tejas series uses compounds with intramolecular structures such as porphyrin, pyrrole methylene, phthalocyanine, and squaric acid ontium. The coloring layer 12 in this embodiment does not contain a dye with a main absorption wavelength band of 390~435nm. The coloring layer 12 may also contain dyes with a main absorption wavelength band of 390-435 nm. However, dyes with a main absorption wavelength band of 390-435 nm do not have the function of improving the reliability of lightfastness and heat resistance, which is the purpose of this invention. Therefore, simply to adjust the color characteristics of the coloring layer 12, the coloring layer 12 may contain dyes with a main absorption wavelength band of 390-435 nm. Furthermore, by containing dyes with a main absorption wavelength band of 390-435 nm in the upper functional layer of the coloring layer 12, the reliability of the coloring layer 12 can be improved.

[0028] Furthermore, when the optical thin film 10A of the present invention is irradiated with a D65 light source from the outermost surface (surface 10a) opposite to the transparent substrate 11, and the reflectance R(λ) of the second surface 11b of the lowest layer of the optical thin film is measured from the surface 10a side for complete diffuse reflection, the chromaticity indices (values) a* and b* of the reflected hue caused by the optical thin film as shown in equations (1) to (9) above are in the range of -5 to +5. The aforementioned hue is a uniform color space defined by the International Commission on Illumination (CIE) (also known as the CIE1976 L*a*b* color space or the CIE LAB color space), and is represented by a 3-dimensional orthogonal coordinate system, which uses the above equations (1) and (2) plus the three values ​​of the lightness index L* shown in equation (10) below as axes.

[0029]

[0030] Here, the tristimulus value of the reflected light under the reflectivity R(λ) of the Y-series D65 light source is calculated from the above equations (4), (5), (7), and (9), and the tristimulus value of the white point of the Yn-series D65 light source is obtained.

[0031] Figure 2 details the calculation method of the color indexes a* and b*, which are indicators of the external light reflection hue of the optical thin film of the present invention.

[0032] When a D65 light source is irradiated from the surface 10a of the optical thin film 10A, which is opposite to the second surface 11b of the transparent substrate 11, in the thickness direction, the light emitted from the optical thin film 10A can be divided into surface reflection components and internal reflection components. The surface reflection component is defined by R2(λ)[%], which is the surface reflectivity of the surface 10a. The internal reflection component is defined by R1(λ)[%], which is calculated from the reflectivity RE(λ)[%] of a perfectly diffuse surface that is 100% regardless of wavelength, the transmittance T(λ) of the optical thin film 10A, and the surface reflectivity R2(λ)[%] of the surface 10a, using Equation (4). If the reflectivity of the optical film 10A on the surface 10a side of the D65 light source is set as R(λ)[%], then R(λ) is calculated by the above formula (5). R(λ), like R1(λ) and R2(λ), is a function of wavelength λ. Therefore, by finding the definite integrals of equations (6) to (9) related to λ, the three stimulus values ​​X, Y, and Z can be obtained. Here, the definite integrals can also be obtained by appropriate numerical integration. For example, the wavelength intervals when performing numerical integration can be equal intervals, such as 1 nm intervals.

[0033] As mentioned above, X, Y, and Z in equations (1) and (2) represent the tristimulus values ​​of the reflectivity R(λ) of the D65 light source on the surface 10a side of the aforementioned optical thin film 10A, and Xn, Yn, and Zn represent the tristimulus values ​​of the white point of the D65 light source. From this, the chromaticity indices a* and b*, which serve as hue indicators of the external light reflection of the optical thin film 10A, can be calculated. From the viewpoint of improving the display quality of external light reflection, the chromaticity indices (values) a* and b* of the optical thin film 10A are preferably within the range of -5 to +5, respectively. The internal reflectivity generated on the inner surface of the display section and electrode wiring section of self-emissive display devices such as organic light-emitting display devices generally has different values ​​in each wavelength from 380nm to 780nm. However, the results of detailed research in this invention show that when RE(λ) is set to the reflectivity of a completely diffuse surface that is 100% in all wavelengths, and the chromaticity index (values) a* and b* of the optical thin film 10A caused by external light are in the range of -5 to +5, even when RE(λ) is replaced with the internal reflectivity of the display section 20 of the actual self-emissive display device, the chromaticity indexes a* and b*, which are indicators of the chromaticity of external light reflection, are also in the range of -5 to +5, resulting in excellent display quality.

[0034] Based on this configuration of the color layer 12, it has a large absorption wavelength in the range of 470nm to 530nm and 560nm to 620nm, and since the third color material, which includes the range of 400nm to 780nm, has a maximum absorption wavelength in the range of 650nm to 780nm, a spectroscopic absorption spectrum with a very small absorption wavelength in the range of 620nm to 780nm can be obtained. Therefore, most of the red, green, and blue light emitted from the display unit 20 penetrates the color layer 12. In contrast, the transmittance of wavelength components between the maximum wavelengths of red and green light, wavelength components between the maximum wavelengths of green and blue light, and portions of ultraviolet and infrared light is reduced in the color layer 12. Therefore, wavelength components that reduce the color purity of the displayed light, such as those reflected from external light through the wiring of the display unit 20, are absorbed by the color layer 12.

[0035] The coloring layer 12 may also contain at least one of a free radical scavenger, a singlet oxygen quencher, and a peroxide decomposer as an additive. By containing such an additive, as explained below, fading of the colorant contained in the coloring layer 12 due to light or heat can be suppressed, thereby improving durability.

[0036] Free radical scavengers inhibit pigment degradation (fading) by capturing free radicals generated during pigment oxidation and deterioration, thus suppressing auto-oxidation. Using hindered amine light stabilizers with a molecular weight of 2000 or higher as free radical scavengers yields high fading inhibition. Low molecular weight free radical scavengers are more volatile, leaving fewer molecules in the colored layer and thus failing to achieve sufficient fading inhibition. Suitable materials for use as free radical scavengers include: BASF's Chimassorb 2020FDL and 944FDL, Tinuvin 622, and ADEKA's LA-63P.

[0037] Singlet oxygen quenchers function by inactivating highly reactive singlet oxygen, which readily causes pigment oxidation and deterioration (fading), thereby inhibiting pigment oxidation and deterioration (fading). Examples of singlet oxygen quenchers include transition metal complexes, pigments, amines, phenols, and sulfides. Dialkyl phosphates, dialkyl dithiocarbamates, or benzenedithiophenol transition metal complexes are particularly suitable materials, with nickel, copper, or cobalt being suitable as the central metal. Examples include NKX1199, NKX113, and NKX114 manufactured by Hayashibara Biochemical Research Institute Photosensitive Pigment Research Institute Co., Ltd., and D1781, B1350, B4360, and T3204 manufactured by Tokyo Chemical Co., Ltd.

[0038] Peroxide decomposing agents decompose the peroxides produced during pigment oxidation and degradation, thereby stopping the auto-oxidation cycle and inhibiting pigment degradation (fading). Phosphorus-based antioxidants and sulfur-based antioxidants can be used as peroxide decomposing agents.

[0039] Examples of phosphorus-based antioxidants include: 2,2'-methylenebis(4,6-di-tert-butyl-1-phenoxy)(2-ethylhexyloxy)phosphine, 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, and 6-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]dioxaphosphepin, etc.

[0040] Examples of sulfur-based antioxidants include: bis[3-(dodecylthio)propionic acid]2,2-bis({[3-(dodecylthio)propionic acid]oxy}methyl)-1,3-propanediyl ester, 2-mercaptobenzimidazole, dilaurate of 3,3'-thiodipropionate, dimyristyl ester of 3,3'-thiodipropionate, distearate of 3,3'-thiodipropionate, neopentyltetroxide-tetra(3-laurylthiopropionate), and 2-mercaptobenzothiazole.

[0041] The ultraviolet absorption layer 13 is a layered portion with an ultraviolet shielding rate of 85% or higher. Here, the ultraviolet shielding rate is measured and calculated based on JIS L 1925 and is expressed as a value [%] obtained by subtracting the average transmittance (in units; [%]) in the wavelength range of 290nm to 400nm from 100%. The absorption wavelength range of the ultraviolet absorption layer 13 in the ultraviolet region is preferably between 290 nm and 370 nm. Here, the absorption wavelength range is defined as the wavelength region where the absorption rate of ultraviolet light is 90% or higher.

[0042] The ultraviolet absorbing layer 13 is disposed on the opposite side of the transparent substrate 11, sandwiching the coloring layer 12 therebetween. In the example shown in FIG1, the ultraviolet absorbing layer 13 is deposited on the coloring layer 12, but the ultraviolet absorbing layer 13 may also be disposed sandwiching other layers between the coloring layer 12. Although the various color materials contained in the color layer 12 have excellent color correction functions, they are not sufficiently resistant to light, especially ultraviolet light. Therefore, if exposed to ultraviolet light, they will deteriorate over time and become unable to absorb light near the maximum absorption wavelength. In this embodiment, in the optical thin film 10A, an ultraviolet absorption layer 13 is disposed on the side where external light is incident first, compared to the coloring layer 12. Therefore, when the external light includes ultraviolet light, the amount of ultraviolet light incident on the coloring layer 12 can be suppressed. Thus, the light resistance of the coloring layer 12 to ultraviolet light can be improved.

[0043] The ultraviolet absorption layer 13 is formed by coating a composition containing an energy line hardening resin, a photopolymerization initiator, an ultraviolet absorber, and a solvent, drying it, and then irradiating it with ultraviolet and other energy lines to harden it.

[0044] The ultraviolet absorption layer 13 contains an energy-line curing resin, which is a resin that is polymerized and cured by irradiation with active energy lines such as ultraviolet light and electron beams. For example, monofunctional, difunctional, or trifunctional (meth)acrylate monomers can be used. In addition, in this specification, "(meth)acrylate" is a general term for both acrylate and methacrylate, and "(meth)acryl" is a general term for both acrylonitrile and methacryl.

[0045] Examples of monofunctional (meth)acrylate compounds include: 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tributyl (meth)acrylate, glycidyl (meth)acrylate, acrylonitrile, N-vinylpyrrolidone, tetrahydrofurfuryl acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isocamphene (meth)acrylate, etc. (Meth)isodecyl acrylate, (Meth)lauryl acrylate, (Meth)tridecyl acrylate, (Meth)cetiyl acrylate, (Meth)stearyl acrylate, (Meth)benzyl acrylate, (Meth)2-ethoxyethyl acrylate, (Meth)3-methoxybutyl acrylate, ethyl carbitol (Meth)acrylate, phosphate (Meth)acrylate, ethylene oxide modified phosphate (Meth)acrylate, (Meth)acrylate phenoxy ester, ethylene oxide modified (Meth)acrylate phenoxy ester, propylene oxide modified (Meth)acrylate Acrylic acid phenoxy ester, nonylphenol (meth) acrylate, ethylene oxide modified nonylphenol (meth) acrylate, propylene oxide modified nonylphenol (meth) acrylate, methoxydiethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, methoxypropylene glycol (meth) acrylate, 2-(meth)acrylic acid acrylate, 2-hydroxy-3-phenoxypropyl phthalate, 2-(meth)acrylic acid acrylate, 2-(meth)acrylic acid acrylate, 2-hydroxy-3-phenoxypropyl phthalate, 2-(meth)acrylic acid acrylate, 2-hydroxy-3-phenoxypropyl phthalate 2-(meth)propenyl acrylate, 2-(meth)propenyl acrylate, 2-(meth)propenyl acrylate, dimethylamine ethyl acrylate, trifluoroethyl acrylate, tetrafluoropropyl acrylate, hexafluoropropyl acrylate, octafluoropropyl acrylate, and other adamantane derivatives such as adamantane acrylates derived from 2-adamantane and adamantanediol, which are mono(meth)acrylates with a single valence.

[0046] Examples of difunctional (meth)acrylate compounds include: ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, butanediol di(meth)acrylate, hexanediol di(meth)acrylate, nonanediol di(meth)acrylate, ethylene glycol di(meth)acrylate oxyhexanediol di(meth)acrylate, propionyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide neopentyl glycol di(meth)acrylate, hydroxytrimethylacetic acid neopentyl glycol di(meth)acrylate, and other di(meth)acrylates.

[0047] Examples of trifunctional or higher (meth)acrylate compounds include: trimethylolpropane trimethacrylate, ethoxylated trimethylolpropane trimethacrylate, propoxylated trimethylolpropane trimethacrylate, trimethylolpropane trimethacrylate, tri-2-hydroxyethyl triisocyanate trimethacrylate, glycerol trimethacrylate, neopentyltetrol trimethacrylate, dinepentyltetrol trimethacrylate, di-trimethylolpropane trimethacrylate, and other trifunctional (meth)acrylates. Compounds; and polyfunctional (meth)acrylate compounds with three or more functions, such as neopentyl tetroxide tetra(meth)acrylate, di-trimethylolpropane tetra(meth)acrylate, di-neopentyl tetroxide penta(meth)acrylate, di-trimethylolpropane penta(meth)acrylate, di-neopentyl tetroxide hexa(meth)acrylate, and di-trimethylolpropane hexa(meth)acrylate; and polyfunctional (meth)acrylate compounds formed by replacing a portion of these (meth)acrylates with alkyl groups or ε-caprolactones.

[0048] Furthermore, urethane (meth)acrylates can also be used as active energy line curing resins. Examples of urethane (meth)acrylates include those obtained by reacting hydroxyl-containing (meth)acrylate monomers with a product obtained by reacting isocyanate monomers or prepolymers with polyester polyols.

[0049] Examples of methacrylates include: neopentyl tert-acrylate hexamethylene diisocyanate methacrylate prepolymer, dinepentyl tert-acrylate hexamethylene diisocyanate methacrylate prepolymer, neopentyl tert-acrylate toluene diisocyanate methacrylate prepolymer, dinepentyl tert-acrylate toluene diisocyanate methacrylate prepolymer, neopentyl tert-acrylate isophorone diisocyanate methacrylate prepolymer, and dinepentyl tert-acrylate isophorone diisocyanate methacrylate prepolymer.

[0050] The above-mentioned resin can be used in one form or in combination of two or more forms. Furthermore, the above-mentioned resin in the composition for forming a hard coating can be a monomer or a partially polymerized oligomer.

[0051] The ultraviolet absorber contained in the ultraviolet absorbing layer 13 may be benzophenone-based, benzotriazole-based, triazine-based, oxaliplatin-based, or cyanoacrylate-based compounds, preferably one or more of these, so that the absorption wavelength range of the ultraviolet region based on the ultraviolet absorber is in the range of 290 nm to 370 nm.

[0052] Furthermore, the photopolymerization initiator contained in the ultraviolet absorbing layer 13 is preferably one or more whose absorption wavelength range in the ultraviolet region differs from that of the ultraviolet absorber in the ultraviolet region. In this case, light in the ultraviolet region not absorbed by the ultraviolet absorber can harden the energy line hardening compound, thus efficiently forming a hardened film. When the absorption wavelength range of the ultraviolet absorber is set to the range of 290 nm to 370 nm, a phosphine oxide-based photopolymerization initiator with an absorption wavelength range different from that range can be used appropriately, such as diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide or phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide. By using an ultraviolet absorber with an absorption wavelength range different from that of the photopolymerization initiator, the hardening obstacle during the formation of the ultraviolet absorbing layer containing the ultraviolet absorber can be suppressed, and the deterioration of the pigment contained in the coloring layer 12 after hardening due to ultraviolet light can be suppressed.

[0053] Other photopolymerization initiators used in the composition for forming the ultraviolet absorbing layer 13 may include, for example, 2,2-ethoxyacetophenone, 1-hydroxycyclohexylphenyl ketone, dibenzoyl, benzoin, benzoin methyl ether, benzoin ethyl ether, p-chlorobenzophenone, p-methoxybenzophenone, milchnerone, acetophenone, 2-chlorothioxanthone, etc. One of these may be used alone, or two or more may be used in combination.

[0054] As the solvent used in the composition for forming the ultraviolet absorption layer 13, examples include: dibutyl ether, dimethoxymethane, dimethoxyethane, diethoxyethane, propylene oxide, 1,4-dioxane 、1,3-dioxane 、1,3,5-trioxane 、tetrahydrofuran, anisole, phenetole and other ethers; also, ketones such as acetone, methyl ethyl ketone, diethyl ketone, diacetone, diisobutyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone and methyl cyclohexanone; also, esters such as ethyl formate, propyl formate, n-pentyl formate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, n-pentyl acetate and γ-butyrolactone; furthermore, cellulose ethers such as methyl cellulose, cellulose, butyl cellulose, cellulose acetate. These can be used alone or in combination of two or more.

[0055] In this embodiment, the surface hardness of the optical film 10A including the ultraviolet absorption layer 13 is H or more in terms of pencil hardness under a load of 500 g. The pencil hardness is measured based on JIS-K5600-5-4:1999. Therefore, the ultraviolet absorption layer 13 in this embodiment functions as an ultraviolet protection layer, protecting the coloring layer 12 from ultraviolet rays outside the optical film 10A, and also functions as a hard coat layer, protecting the coloring layer 12 against external loads. As in this embodiment, the ultraviolet absorption layer 13 that also serves as an ultraviolet protection layer and a hard coat layer can be manufactured, for example, by using the above-mentioned energy ray curable resin, adjusting the balance of the absorption wavelengths of the ultraviolet absorber and the photoinitiator, and suppressing the curing inhibition to form a hard resin layer.

[0056] Also, for the purpose of adjusting the refractive index of the hard coat layer and imparting hardness, metal oxide fine particles can also be contained. Examples of the metal oxide fine particles include: zirconia, titanium oxide, niobium oxide, antimony trioxide, antimony pentoxide, tin oxide, indium oxide, indium tin oxide, zinc oxide, etc.

[0057] In the ultraviolet absorption layer 13, for the purpose of imparting at least one of water repellency and oil repellency, any one of silicon oxides, fluorine-containing silane compounds, fluoroalkylsilazanes, fluoroalkylsilanes, fluorine-containing silicon-based compounds, and silane coupling agents containing perfluoropolyether groups that improve antifouling properties can also be contained.

[0058] Leveling agents, defoamers, antioxidants, light stabilizers, photosensitizers, conductive materials, etc., can also be added to the ultraviolet absorption layer 13 as other additives.

[0059] When the optical thin film 10A is applied to the display device 50A, the low refractive index layer 14A is disposed on the side closest to the user (visual observer) viewing the display. In this embodiment, the low refractive index layer 14A is deposited on the surface of the ultraviolet absorption layer 13 opposite to the coloring layer 12. The thickness of the low refractive index layer 14A is, for example, not particularly limited, and can be formed to be about 40 nm to 1 μm. The low-refractive-index layer 14A is made of a material with a lower refractive index than the ultraviolet-absorbing layer 13. As a result, external light incident from the outside interferes with the reflected light at the interface with the ultraviolet-absorbing layer 13 and the reflected light on the surface of the low-refractive-index layer 14A, thereby reducing the surface reflectivity of external light. By setting a low refractive index layer 14A, surface reflection of external light can be suppressed, thus improving the visual recognition of the display device 50A. The low-refractive-index layer 14A is a layered portion containing inorganic materials or inorganic compounds. Examples of inorganic materials or inorganic compounds include microparticles such as LiF, MgF, 3NaF·AlF, AlF, and Na3AlF6, or silicon oxide microparticles. Furthermore, using porous silicon oxide microparticles or hollow silicon oxide microparticles, which have internal voids, is effective for low-refractive-index formation. Additionally, the photopolymerization initiator, solvent, and other additives described in the ultraviolet absorption layer 13 can also be appropriately incorporated into the low-refractive-index forming composition.

[0060] The material of the low refractive index layer 14A may further contain any of the following: silicon oxide, fluorinated silane compound, fluoroalkyl silazane, fluoroalkyl silane, fluorinated silicon compound, or silane coupling agent containing perfluoropolyether group. By containing such materials, at least one of water-repellent and oil-repellent properties can be imparted to the low refractive index layer 14, thereby improving stain resistance.

[0061] In the optical thin film 10A of this embodiment, the ultraviolet absorption layer 13 and the low refractive index layer 14A constitute one or more functional layers, which sandwich the aforementioned coloring layer and are disposed on the opposite side of the aforementioned transparent substrate. As long as the optical film 10A can achieve the required frontal luminance, external light reflection visual recognition and display light color purity, a suitable functional layer can also be provided between the coloring layer 12 and the ultraviolet absorption layer 13.

[0062] The optical thin film 10A can be manufactured by sequentially forming a colored layer 12, an ultraviolet absorption layer 13 and a low refractive index layer 14A on the first surface 11a of the transparent substrate 11. The coloring layer 12, the ultraviolet absorbing layer 13, and the low refractive index layer 14A can be formed, for example, by coating a liquid containing the constituent materials of each layer, drying it, and then irradiating it with active energy lines such as ultraviolet light to harden it. The low refractive index layer 14A can also be formed by vapor deposition or sputtering.

[0063] The composition for forming the coloring layer 12 contains an active energy line curing resin, a photopolymerization initiator, a pigment, and a solvent, and may also contain additives as needed. The active energy line curing resin, photopolymerization initiator, and solvent described for the ultraviolet absorption layer 13 can be used. The pigment includes the first, second, and third pigments mentioned above. It may also contain at least one of a free radical scavenger, a peroxide decomposer, and a singlet oxygen quencher as an additive.

[0064] The ultraviolet absorption layer 13 can be formed by coating a composition containing at least an energy line hardening compound, a photopolymerization initiator, an ultraviolet absorber, and a solvent onto the coloring layer 12, and then hardening the composition by irradiating an energy line that initiates photopolymerization. The low refractive index layer 14A can also be formed in the same way as the ultraviolet absorption layer 13 by coating the ultraviolet absorption layer 13 with the material that forms the low refractive index layer 14A, and then hardening the composition by irradiating the energy line that initiates photopolymerization.

[0065] The display device 50A can be manufactured by preparing a display section 20 and attaching and fixing the second surface 11b of the transparent substrate 11 of the optical film 10A to the surface of the color filter section 23 through an adhesive layer or the like.

[0066] According to the display device 50A of this embodiment, when the light-emitting element 22 is turned on in response to an image signal, the display light generated by the light-emitting element 22 penetrates the color filter section 23. Thereby, the light system from the first light-emitting element 22R is red light, the light system from the second light-emitting element 22G is green light, and the light system from the third light-emitting element 22B is blue light, which penetrate the transparent substrate 11, the color layer 12, the ultraviolet absorption layer 13, and the low refractive index layer 14A, and are emitted to the outside of the optical film 10A. At this time, the color layer 12 has wavelength bands with good transmittance of red, green and blue wavelengths of display light, and each display light system maintains color purity when emitted. The ultraviolet absorption layer 13 mainly absorbs light from the ultraviolet region, so the brightness of the light system is almost not reduced and it can pass through. The low-refractive-index layer 14A has good transmittance of visible light, so the brightness of the display system is almost not reduced and it is emitted to the outside.

[0067] On the other hand, in the display device 50A, external light is incident through the optical thin film 10A. By using the low refractive index layer 14A, the surface reflectivity of external light can be suppressed, thus suppressing the reduction in visual recognition caused by excessive surface reflection of external light. External light incident on the ultraviolet absorption layer 13 is incident on the coloring layer 12 in a state where the wavelength component in the ultraviolet region is absorbed by the ultraviolet absorber. The coloring layer 12 further absorbs wavelength components of external light that are near the absorption wavelengths of the various color materials contained in the coloring layer 12. Then, the external light penetrates the transparent substrate 11 and the color filter portion 23, reaching the substrate 21. The substrate 21 includes highly reflective metal portions such as wiring and electrodes. Therefore, external light is reflected by wiring and electrodes, and sequentially passes through the color filter section 23, transparent substrate 11, coloring layer 12, ultraviolet absorption layer 13 and low refractive index layer 14A before being emitted to the outside. An observer of the display device 50A will see reflected light in addition to the display light. This reflected light is a combination of surface reflected light caused by external light from the display device 50A and internal reflected light from external light that penetrates and reflects into the display device 50A.

[0068] In this embodiment, external light passes through the color layer 12 twice before exiting to the outside, thereby reducing wavelength components that are different from the display light. As a result, internal reflection of external light can be reduced, and the reduction in the brightness of the display light can be suppressed. Even if the external light and the display light overlap, the color purity of the display light can be well maintained. Furthermore, when the display device 50A is in a non-display state, by making the values ​​of the color indexes a* and b*, which are the color hue indicators of the external reflected light of the optical film 10A, between -5 and +5, the hue influence of the optical film is reduced, and the black tone of the displayed image can be maintained. In this embodiment, because the ultraviolet light component of external light is absorbed by the ultraviolet absorption layer 13, the deterioration of the color material due to ultraviolet light absorption by the color layer 12 can be prevented. Therefore, the spectral characteristics of the color material in the color layer 12 can be easily maintained over time.

[0069] [Second Implementation] The optical thin film and display device of the second embodiment of the present invention are described. Figure 3 is a schematic cross-sectional view showing an example of an optical thin film and display device according to a second embodiment of the present invention. The display device 50B of this embodiment, shown in Figure 3 as a cross-section in the thickness direction, has an optical thin film 10B of this embodiment instead of the optical thin film 10A of the display device 50A of the first embodiment. The optical thin film 10B has an oxygen barrier layer 15 (functional layer) between the coloring layer 12 and the ultraviolet absorption layer 13. Otherwise, it is constructed in the same way as the optical thin film 10A. The following explanation focuses on the differences from the first embodiment.

[0070] The oxygen barrier layer 15 is a transparent layer with light transmittance. The oxygen permeability of the oxygen barrier layer 15 is less than 10 cc / m²·day·atm. Preferably, the main constituent materials of the oxygen barrier layer 15 contain polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH), vinylidene chloride, siloxane resin, etc., and materials such as MAXIVE (registered trademark) manufactured by Mitsubishi Gas Chemical Co., Ltd., EVAL and POVAL manufactured by Kuraray Co., Ltd., and Saran Latex and Saran Resin manufactured by Asahi Kasei Corporation can be used. Furthermore, to reduce oxygen permeability, inorganic particles such as silicon oxide particles, alumina particles, silver particles, copper particles, titanium particles, zirconium oxide particles, and tin particles may also be dispersed in the oxygen barrier layer 15.

[0071] When the optical thin film 10B is installed in the display device 50B, oxygen contained in the external gas will not reach the color layer 12 as long as it does not penetrate the oxygen barrier layer 15. This suppresses the degradation of the color materials in the color layer 12 caused by oxygen in the external gas. Therefore, the light absorption performance of the color layer 12 is maintained over a long period.

[0072] In this embodiment, instead of or in addition to the oxygen barrier layer 15, an oxygen barrier layer may be provided on the second surface 11b side of the transparent substrate 11. In this case, the oxygen barrier layer protects the color materials of the color layer 12 from being affected by the oxygen present in the display device 50B.

[0073] The optical thin film 10B and display device 50B according to this embodiment have the same function as the first embodiment because they have the same coloring layer 12, ultraviolet absorption layer 13 and low refractive index layer 14A as the first embodiment. In particular, the optical thin film 10B of this embodiment has an oxygen barrier layer 15, which can suppress the oxidative degradation of the pigment in the coloring layer 12 caused by the influence of oxygen.

[0074] [Third Implementation Form] The optical thin film and display device of the third embodiment of the present invention are described. Figure 4 is a schematic cross-sectional view showing an example of an optical thin film and display device according to a third embodiment of the present invention. The display device 50C of this embodiment, shown in Figure 4 as a cross-section in the thickness direction, includes an optical thin film 10C of this embodiment instead of the optical thin film 10A of the display device 50A of the first embodiment. The optical film 10C has an ultraviolet absorbing anti-glare layer 16 (ultraviolet absorbing layer, functional layer, anti-glare layer) to replace the low refractive index layer 14A and the ultraviolet absorbing layer 13. Otherwise, it is constructed in the same way as the optical film 10A. The following explanation focuses on the differences from the first embodiment.

[0075] The UV-absorbing anti-glare layer 16 series is a layered structure that combines UV absorption and anti-glare functions. The UV blocking rate of the UV absorbing anti-glare layer 16 is the same as that of the UV absorbing layer 13, which is 85% or higher. The absorption wavelength range of the UV absorbing anti-glare layer 16 is preferably between 290 nm and 370 nm. Anti-glare function refers to the function of having micro-uneven surfaces that scatter external light, thereby reducing the amount of external light reflected. The pencil hardness of the UV-absorbing anti-glare layer 16 is the same as that of the UV-absorbing layer 13, which is H or higher.

[0076] The ultraviolet-absorbing anti-glare layer 16 can be formed by curing a coating liquid containing at least one of organic microparticles and inorganic microparticles that impart anti-glare functionality in the same composition as the ultraviolet-absorbing layer 13. The organic microparticles are those that form fine irregularities on the surface of the ultraviolet-absorbing anti-glare layer 16 to impart the function of diffusing external light. For example, resin particles containing light-transmitting resin materials such as acrylic resin, polystyrene resin, styrene-(meth)acrylate copolymer, polyethylene resin, epoxy resin, polysiloxane resin, polyvinylidene fluoride, and ethylene fluoride resin can be used. To adjust the refractive index and the dispersion of the resin particles, two or more resin particles with different materials (refractive indices) can also be mixed. The inorganic microparticles are those that adjust the sedimentation and aggregation of the organic microparticles in the ultraviolet-absorbing anti-glare layer 16, and can include silicon oxide microparticles, metal oxide microparticles, and various mineral microparticles. Examples of silica microparticles include colloidal silica and silica microparticles surface-modified with reactive functional groups such as (meth)acrylic acid. Examples of metal oxide microparticles include aluminum oxide, zinc oxide, tin oxide, antimony oxide, indium oxide, titanium oxide, or zirconium oxide. Examples of mineral microparticles include mica, synthetic mica, vermiculite, microcrystalline kaolinite, iron microcrystalline kaolinite, bentonite, aluminum bentonite, magnesium bentonite, lithium bentonite, talc, iron bentonite, sodium silicate, illite, sodium silicate hydrous, layered titanate, bentonite, and synthetic bentonite. Mineral microparticles can be either natural or synthetic (including substituted forms and derivatives), or mixtures of both. Layered organoclay is particularly preferred among mineral microparticles. Layered organoclay refers to clay formed by introducing organonium ions into the interlayer of bentonite. There are no restrictions on the type of organic bentonite ions that can be organically converted using the cation exchange properties of bentonite. When using layered organic clay minerals as mineral microparticles, the aforementioned synthetic bentonite can be used appropriately. Synthetic bentonite has the functions of increasing the viscosity of the coating liquid used to form the anti-glare layer, inhibiting the sedimentation of resin particles and inorganic microparticles, and adjusting the surface irregularity of the optical functional layer.

[0077] The composition used to form the ultraviolet-absorbing anti-glare layer 16 may also contain any one of silicon oxide, fluorinated silane compound, fluoroalkyl silazane, fluoroalkyl silane, fluorinated silicone compound, or silane coupling agent containing perfluoropolyether group. These materials can impart at least one of water-repellent and oil-repellent properties to the ultraviolet-absorbing anti-glare layer 16 to improve the antifouling properties of the optical film 10C.

[0078] The ultraviolet-absorbing anti-glare layer 16 can also be formed by sequentially stacking layers with relatively high refractive index and relatively low refractive index from the side of the colored layer 12. The ultraviolet-absorbing anti-glare layer 16, formed by non-uniform material distribution, can be formed, for example, by coating a composition containing a low-refractive-index material and a high-refractive-index material, and utilizing the difference in surface free energy between the two to separate them into phases. The low-refractive-index material contains surface-modified silica microparticles or hollow silica microparticles. When the ultraviolet-absorbing anti-glare layer 16 is constructed as a phase-separated double layer, it is preferable to set the refractive index of the layer with relatively high refractive index on the side of the colored layer 12 to 1.50~2.40, and the refractive index of the layer with relatively low refractive index on the surface side of the optical thin film 10C to 1.20~1.55.

[0079] The optical thin film 10C of this embodiment is an example of an ultraviolet absorbing anti-glare layer 16 that also serves as an anti-glare layer, while being an ultraviolet absorbing layer. The optical film 10C and display device 50C according to this embodiment have the same function as the first embodiment because they have the same coloring layer 12 as the first embodiment and the same ultraviolet absorbing anti-glare layer 16 with ultraviolet absorption properties as the ultraviolet absorbing layer 13. In particular, the optical film 10C of this embodiment has an ultraviolet-absorbing anti-glare layer 16 that also functions as an anti-glare layer, and external light is scattered by the ultraviolet-absorbing anti-glare layer 16. Therefore, the surface reflection and reflection of external light are suppressed, thereby improving the visual recognition of the displayed image and the displayed light, and suppressing the reduction in display quality caused by external light reflection.

[0080] [First Variation] This invention describes an optical thin film and display device as a modification of the third embodiment (the first modification) of the present invention. As shown in Figure 1, a cross-section in the thickness direction is presented. The display device 50D of this modified example includes the optical thin film 10D of this modified example to replace the optical thin film 10C of the display device 50C of the third embodiment. The optical film 10D has the same ultraviolet absorption layer 13 and anti-glare layer 17 (functional layer) as in the first embodiment to replace the ultraviolet absorption anti-glare layer 16, and otherwise is constructed in the same way as the optical film 10C. The following explanation focuses on the differences from the third embodiment.

[0081] The anti-glare layer 17 is a layered portion with anti-glare function. The arrangement of the anti-glare layer 17 is not particularly limited, as long as it is positioned on the side of the ultraviolet absorption layer 13 opposite to the transparent substrate 11 relative to the coloring layer 12. The closer the anti-glare layer 17 is to the surface of the optical film 10D, the better. For example, in the example shown in FIG1, the anti-glare layer 17 is arranged covering the outer side of the ultraviolet absorption layer 13 and located on the outer surface of the optical film 10D.

[0082] In this modified example, the optical thin film 10D is an example in which the ultraviolet absorption layer 13 and the anti-glare layer 17 are separate layers. The optical thin film 10D and the display device 50D according to this modified example have the same function as the first embodiment because they have the same coloring layer 12 and ultraviolet absorption layer 13 as the first embodiment. In particular, the optical film 10D in this modified example has an anti-glare layer 17, and external light is scattered by the anti-glare layer 17. Therefore, the surface reflection and reflection of external light can be suppressed, thus improving the visual recognition of the displayed image and the display light, and suppressing the reduction in display quality caused by external light reflection.

[0083] [Fourth Implementation Form] The optical thin film and display device of the fourth embodiment of the present invention are described. Figure 5 is a schematic cross-sectional view showing an example of an optical thin film and display device according to a fourth embodiment of the present invention. The display device 50E of this embodiment, shown in Figure 5 as a cross-section in the thickness direction, includes an optical thin film 10E of this embodiment instead of the optical thin film 10C of the display device 50C of the third embodiment. The optical thin film 10E has a low refractive index layer 14E (functional layer) deposited on the ultraviolet absorption anti-glare layer 16, and otherwise is composed in the same manner as the optical thin film 10C. The following explanation focuses on the differences from the third embodiment.

[0084] The low refractive index layer 14E has a lower refractive index than the ultraviolet absorption anti-glare layer 16, but otherwise it is the same as the low refractive index layer 14A in the first embodiment. In this way, external light incident from the outside interferes with the reflected light at the interface with the ultraviolet absorbing anti-glare layer 16 and the reflected light on the surface of the low refractive index layer 14E, thus reducing the surface reflectivity of the external light. By setting a low refractive index layer 14E, surface reflection of external light can be suppressed, thus improving the visual recognition of the display device 50E. The material of the low refractive index layer 14E is not particularly limited as long as it is a transparent material with a lower refractive index than the ultraviolet absorption anti-glare layer 16. The same material as the low refractive index layer 14A in the first embodiment can be used as the material of the low refractive index layer 14E.

[0085] The optical thin film 10E and the display device 50E according to this embodiment have the same function as those in the third embodiment because they have the same coloring layer 12 and ultraviolet absorption anti-glare layer 16. In particular, the optical thin film 10E of this embodiment has a low refractive index layer 14E on the outer side, which can suppress the surface reflection and reflection of external light, thereby improving the visual recognition of the displayed image and the display light, and suppressing the reduction in display quality caused by external light reflection.

[0086] Furthermore, the above embodiments and variations illustrate cases where the light-emitting element is an organic EL element. However, the types of light-emitting elements are not limited to organic EL elements. For example, examples of light-emitting elements include LED elements, inorganic phosphor light-emitting elements, quantum dot light-emitting elements, etc.; when the light source emits monochromatic light of the three primary colors RGB, it can also be configured as a display unit 20 with the color filter section 23 removed.

[0087] Although the above-described embodiments and variations describe the composition of various functional layers, the composition of functional layers is not limited to these. For example, although it is stated that the ultraviolet absorbing layer 13 serves as both an ultraviolet absorbing layer and a hard coating layer, it may also have an ultraviolet absorbing layer with a pencil hardness less than H and a hard coating layer with a pencil hardness of H or higher. In this case, the hard coating layer is preferably located on the outer side of the ultraviolet absorbing layer. For example, a low refractive index layer or an anti-glare layer can also serve as a hard coating. For example, as a functional layer, it may also include at least one of an antistatic layer containing an antistatic agent and a water-repellent antifouling layer. However, the antistatic layer and the antifouling layer may also be a combination of the above-mentioned functional layers. [Example]

[0088] The optical thin film of the present invention is further illustrated using Examples 1-10 and Comparative Examples 1-6. The present invention is not limited by the specific content of the following examples.

[0089] In Examples 1-10 and Comparative Examples 1-6 below, optical films 1-16 with the layer composition shown in Tables 1 and 2 were fabricated. The characteristics of the fabricated optical films 1-13 were evaluated. Furthermore, the display device characteristics of the organic EL panel were confirmed by simulation using optical films 8, 10, 14-16.

[0090] [Table 1] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Optical thin films Optical thin films 1 Optical thin films 2 Optical thin films 3 Optical thin films 4 Optical thin films 5 Optical thin films 6 Optical thin films 7 Optical thin films 8 Optical thin films 9 Optical thin films 10 Functional layer 1 - - Low refractive index layer 1 Anti-glare layer 2 Low refractive index layer 1 Low refractive index layer 1 Low refractive index layer 1 Low refractive index layer 1 Low refractive index layer 1 Low refractive index layer 1 Functional layer 2 Hard coating 1 Anti-glare layer 1 Hard coating 1 Hard coating 1 Anti-glare layer 1 Hard coating 1 Hard coating 1 Hard coating 1 Hard coating 1 Hard coating 1 Functional layer 3 - - - - - - - - oxygen barrier layer 1 - Color layer Color layer 1 Color layer 1 Color layer 1 Color layer 1 Color layer 1 Color layer 2 Color layer 3 Color layer 4 Color layer 1 Color layer 5 transparent Substrate TAC TAC TAC TAC TAC TAC TAC TAC TAC TAC

[0091] [Table 2] Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 Comparative example 6 Optical thin films Optical thin films 11 Optical thin films 12 Optical thin films 13 Optical thin films 14 Optical thin films 15 Optical thin films 16 Functional layer 1 Low refractive index layer 1 Low refractive index layer 1 Low refractive index layer 1 Low refractive index layer 1 Low refractive index layer 1 Low refractive index layer 1 Functional layer 2 Hard coating 2 Hard coating 2 Hard coating 3 Hard coating 1 Hard coating 1 Hard coating 2 Functional layer 3 - - - - - - Color layer Color layer 1 Color layer 6 Color layer 1 Color layer 7 Color layer 8 - transparent Substrate TAC TAC TAC TAC TAC TAC

[0092] Fabrication of Optical Thin Films The following explains the formation method of each layer.

[0093] [Formation of the coloring layer] (Materials used in the composition for forming the coloring layer) The following materials are used as components for forming a color layer. Furthermore, the maximum absorption wavelength and full width at half maximum (FWHM) of the colorant are characteristic values ​​in the hardened coating calculated from the spectral transmittance. ･1st color material: Dye-1 is a pyrrole-methylene cobalt complex dye as shown in Formula 1 below (maximum absorption wavelength 493 nm, full width at half maximum 26 nm).

[0094] (Chemical Formula 1)

[0095] ･Second color material: Dye-2 is a tetrazaporphyrin copper complex dye (FDG-007 manufactured by Yamada Chemical Co., Ltd., with a maximum absorption wavelength of 595 nm and a full width at half maximum (FWHM) of 22 nm). Dye-3 is a tetrazaporphyrin copper chelate dye (PD-311S manufactured by Yamamoto Chemical Co., Ltd., with a maximum absorption wavelength of 586 nm and a full width at half maximum (FWHM) of 22 nm). ･Third color material: Dye-4 Phthalochrome Bronze Complex Dye (Yamada Chemical Co., Ltd., FDN-002, maximum absorption wavelength 800nm) Dye-5 is a cobalt phthalocyanine complex dye (FDR-002 manufactured by Yamada Chemical Co., Ltd., with a maximum absorption wavelength of 683 nm). ·additive: Hindered amine light stabilizer Chimassorb (registered trademark) 944FDL (manufactured by BASF JAPAN, molecular weight 2000~3100) Hindered amine light stabilizer Tinuvin (registered trademark) 249 (manufactured by BASF JAPAN, molecular weight 482) Singlet oxygen quencher D1781 (manufactured by Tokyo Chemical Industry Co., Ltd.) • Ultraviolet absorber: Tinuvin (registered trademark) 479 (manufactured by BASF JAPAN, maximum absorption wavelength 322nm) LA-36 (manufactured by ADEKA, maximum absorption wavelengths 310nm and 350nm) • Active energy line curing resin: UA-306H (manufactured by Kyoeisha Chemical Co., Ltd., neopentyl terephthalate triacrylate hexamethylene diisocyanate carbamate prepolymer) DPHA (Dipentaerythritol Hexaacrylate) PETA (neoprene tetraethyl orthocyanin triacrylate) • Initiator: Omnirad (registered trademark) TPO (manufactured by IGM Resing BV, peak absorption wavelength 275nm, 379nm) Solvent: MEK (Methyl Ethyl Ketone) Methyl acetate The coloring layer used in this embodiment does not contain dyes with a main absorption wavelength band of 390~435nm.

[0096] (Formation of the coloring layer) As a transparent substrate, a 60 μm thick triacetyl cellulose film was used. The coloring layer composition shown in Table 3 was coated onto one side of the transparent substrate and dried in an oven at 80°C for 60 seconds. Subsequently, the coating was hardened by ultraviolet irradiation at a dose of 150 mJ / cm² (manufactured by Fusion UV systems Japan, H bulb), forming coloring layers 1 to 8 as shown in Table 3 below with a hardened film thickness of 5.0 μm. Furthermore, the addition amounts are by mass ratio.

[0097] [Table 3] Color layer 1 Color layer 2 Color layer 3 Color layer 4 Color layer 5 Color layer 6 Color layer 7 Color layer 8 color material 1st color material Dye-1 Added amount 0.28% 0.31% 0.28% 0.12% 0.36% 2nd color material Dye-2 / Dye-3 Dye-2 Dye-2 / Dye-3 ratio 60 / 40 88 / 22 60 / 40 100 10 / 90 Added amount 0.44% 0.42% 0.44% 0.61% 0.82% 3rd color material Dye-4 / Dye-5 - ratio 79 / 21 75 / 25 79 / 21 87 / 13 - Added amount 1.90% 1.86% 1.90% 1.73% - additive type - Tinuvin249 Chimassorb 944FDL Chimassorb 944FDL / D1781 Chimassorb 944FDL / D1781 - - - ratio - 100 100 67 / 33 67 / 33 - - - Added amount - 1.40% 1.40% 2.18% 2.18% - - - Ultraviolet rays absorbent type - - - Tinuvin479 / LA36 - - ratio - - - 40 / 60 - - Added amount - - - 3.20% - - active Energy Line hardened resin type UA-306H / DPHA / PETA ratio 70 / 20 / 10 Added amount 42.85% 41.44% 41.44% 40.66% 40.69% 39.64% 43.00% 44.28% Photopolymerization Initiator type Omnirad TPO Added amount 4.54% solvent type MEK / methyl acetate ratio 50 / 50 Added amount 50.00%

[0098] [Form of Functional Layers] • Oxygen barrier layer 1 composition: PVA117 (manufactured by Kuraray) 80% aqueous solution

[0099] (Formation of an oxygen barrier layer) The above-mentioned composition for forming the oxygen barrier layer was applied to the structure of Example 9 shown in [Table 1] and dried to form an oxygen barrier layer 1 with an oxygen permeability of 1 cc / m²·day·atm.

[0100] (Materials used in the composition for hard coating formation) The following materials are used as components for forming hard coatings. • Ultraviolet absorber: Tinuvin (registered trademark) 479 (manufactured by BASF JAPAN, maximum absorption wavelength 322nm) LA-36 (manufactured by ADEKA, maximum absorption wavelengths 310nm and 350nm) • Active energy line curing resin: UA-306H (manufactured by Kyoeisha Chemical Co., Ltd., neopentyl terephthalate triacrylate hexamethylene diisocyanate carbamate prepolymer) DPHA (Dipentaerythritol Hexaacrylate) PETA (neoprene tetraethyl orthocyanin triacrylate) • Initiator: Omnirad (registered trademark) TPO (manufactured by IGM Resins BV, absorption peak wavelength 275nm, 379nm) Omnirad (registered trademark) 184 (manufactured by IGM Resins BV, peak absorption wavelengths 243nm and 331nm) Solvent: MEK (Methyl Ethyl Ketone) Methyl acetate

[0101] (Hard coating formation) The hard coating composition shown in Table 4 below is applied to the colored layer shown in Tables 1 and 2 or to a transparent substrate and dried in an oven at 80°C for 60 seconds. Then, the coating is hardened by irradiation with ultraviolet light at a dose of 150 mJ / cm2 using an ultraviolet irradiation device (manufactured by Fusion UV systems Japan, light source H bulb), forming hard coatings 1 to 3 with a hardened film thickness of 5.0 μm as described in Tables 1 and 2.

[0102] [Table 4] Hard coating 1 Hard coating 2 Hard coating 3 UV absorber type Tinuvin479 / LA36 - Tinuvin479 / LA36 ratio 40 / 60 - 40 / 60 Added amount 3.2% - 3.2% active Energy Line hardened resin type UA-306H / DPHA / PETA ratio 70 / 20 / 10 Added amount 42.2% 45.4% 42.2% Photopolymerization Initiator type Omnirad TPO Omnirad 184 Added amount 4.6% solvent type MEK / methyl acetate ratio 50 / 50 Added amount 50.0%

[0103] (Materials used in the composition of the anti-glare layer) • Ultraviolet absorber: Tinuvin (registered trademark) 479 (manufactured by BASF JAPAN, maximum absorption wavelength 322nm) LA-36 (manufactured by ADEKA, maximum absorption wavelengths 310nm and 350nm) • Active energy line curing resin: Light acrylate PE-3A (manufactured by Kyoei Chemical Co., Ltd., refractive index 1.52) Photopolymerization initiator: Omnirad (registered trademark) TPO (manufactured by IGM Resins BV, absorption peak wavelength 275nm, 379nm) • Resin particles: Styrene-methyl methacrylate copolymer particles (refractive index 1.515, average particle size 2.0 μm) Inorganic microparticles 1: Synthetic bentonite Inorganic microparticles 2: Alumina nanoparticles, with an average particle size of 40 nm Solvent Toluene Isopropanol

[0104] (Form of the anti-glare layer) The anti-glare layer composition shown in Table 5 was applied to the coloring layer and hardening layer shown in Table 1, and dried in an oven at 80°C for 60 seconds. Then, the coating was hardened by irradiation with ultraviolet light at a dose of 150 mJ / cm2 using an ultraviolet irradiation device (manufactured by Fusion UV systems Japan, light source H bulb), forming anti-glare layers 1 and 2 as described in Table 1 with a hardened film thickness of 5.0 μm.

[0105] [Table 5] Anti-glare layer 1 Anti-glare layer 2 UV absorber type Tinuvin479 / LA36 - ratio 40 / 60 - Added amount 3.20% - active Energy Line hardened resin type PE-3A PE-3A Added amount 40.5% 43.7% organic microparticles type Styrene-methacrylic acid Methyl ester copolymer particles Styrene-methacrylic acid Methyl ester copolymer particles Added amount 0.5% 0.5% Inorganic microparticles type Synthetic bentonite / Alumina nanoparticles Synthetic bentonite / Alumina nanoparticles ratio 20 / 80 20 / 80 Added amount 1.25% 1.25% Photopolymerization Initiator type Omnirad TPO Omnirad TPO Added amount 4.55% 4.55% solvent type Toluene / Isopropanol Toluene / Isopropanol ratio 30 / 70 30 / 70 Added amount 50% 50%

[0106] (Composition for forming low refractive index layer 1) The following materials are used as components for forming the low refractive index layer 1. • Refractive index adjuster: Porous silica microparticle dispersion (average particle size 75 nm, solid content 20%, solvent methyl isobutyl ketone) 8.5 parts by weight • Antifouling agent: OPTOOL (registered trademark) AR-110 (manufactured by Daikin Industries, Ltd., 15% solids, solvent: methyl isobutyl ketone) 5.6 parts by weight • Active energy line curing resin: 0.4 parts by weight of neopentyltetraol triacrylate • Initiator: Omnirad (registered trademark) 184 (manufactured by IGM Resins BV) 0.07 parts by weight Leveling agent: RS-77 (manufactured by DIC) 1.7 parts by weight Solvent: 83.73 parts by weight of methyl isobutyl ketone

[0107] (Formation of low-refractive-index layer 1) The composition for forming a low refractive index layer with the above-mentioned composition was coated on the hard coating layer and the anti-glare layer as described in [Table 1] and [Table 2], and dried in an oven at 80°C for 60 seconds. Then, the coating was hardened by irradiation with ultraviolet light using an ultraviolet irradiation device (manufactured by Fusion UV systems Japan, light source H bulb) at an irradiation dose of 200 mJ / cm 2, forming a low refractive index layer 1 with a hardened film thickness of 100 nm as described in [Table 1] and [Table 2].

[0108] [Thin Film Property Evaluation] The obtained optical thin films 1 to 13 were evaluated as follows.

[0109] (UV shielding rate) For the ultraviolet absorption layer formed on the colored layer of the obtained optical thin film, a transparent tape (cellophane tape) according to the JIS-K5600 adhesion test was used to peel it off from the colored layer. Using an automatic spectrophotometer (Hitachi, Ltd., U-4100), with the adhesive tape as a reference, the transmittance of a single layer of ultraviolet absorption layer was measured, and the average transmittance [%] in the ultraviolet region (290nm~400nm) was calculated. The ultraviolet blocking rate [%] was calculated by subtracting the average transmittance [%] in the ultraviolet region (290nm~400nm) from 100%.

[0110] (Pencil Hardness Test) For the surface of optical thin films, a Clement type scratch hardness tester (TESTER SANGYO Co., Ltd., HA-301) was used. According to JIS-K5600-5-4:1999, a pencil (Mitsubishi Pencil Co., Ltd. UNI, pencil hardness H) with a load of 500gf (4.9N) (hereinafter, 500g load) was used for the test. The appearance change caused by scratches was visually evaluated. The absence of scratches was considered good (marked as "○" in Tables 6 and 7 below), and the presence of scratches was considered poor (marked as "×" in Table 7 below).

[0111] (Lightfastness test) As a reliability test for the optical thin film containing the obtained colored layer, a xenon weathering tester (manufactured by Suga Test Instruments Co., Ltd., X75) was used. The test was conducted for 120 hours under the conditions of xenon lamp illuminance of 60W / cm2 (300nm~400nm), internal temperature of 45℃ and humidity of 50%RH. Before and after the test, the transmittance was measured using an automatic spectrophotometer (manufactured by Hitachi, Ltd., U-4100). The transmittance difference ΔTλ1 before and after the test was calculated at the wavelength λ1 with the minimum transmittance before the test in the wavelength range of 470nm~530nm, the transmittance difference ΔTλ2 before and after the test at the wavelength λ2 with the minimum transmittance before the test in the wavelength range of 560nm~620nm, and the transmittance difference ΔTλ3 before and after the test at the wavelength with the minimum transmittance before the test in the wavelength range of 650nm~780nm. A good result is one where the difference in penetration rate is close to zero; a better result is one where |ΔTλN|≤20 (N=1~3); and an even better result is one where |ΔTλN|≤10 (N=1~3).

[0112] The evaluation results for the above items are shown in Tables 6 and 7 below.

[0113] [Table 6] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 UV absorption layer Hard coating 1 Anti-glare layer 1 Hard coating 1 Hard coating 1 Hard coating 1 Hard coating 1 Hard coating 1 Hard coating 1 Hard coating 1 Hard coating 1 On the color layer UV shielding rate 90.4% 90.4% 90.5% 90.4% 90.5% 90.5% 90.5% 90.5% 90.5% 90.5% pencil hardness ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ Lightfastness ⊿Tλ1 19.5 19.2 19.8 19.0 19.2 19.4 8.4 6.5 6.4 7.0 ⊿Tλ2 8.0 8.1 8.0 8.3 8.0 7.6 6.2 2.5 3.5 3.0 ⊿Tλ3 13.4 13.2 13.2 13.0 13.5 11.2 6.4 4.5 2.8 5.1

[0114] [Table 7] Comparative Example 1 Comparative Example 2 Comparative Example 3 UV absorbing layer - Color layer 6 Hard coating 3 On the color layer UV shielding rate 7.2% 7.2% 90.5% Pencil hardness ○ ○ × Lightfastness ⊿Tλ1 41.4 46.0 27.6 ⊿Tλ2 49.1 25.0 22.0 ⊿Tλ3 19.5 8.2 13.0

[0115] As shown in Tables 6 and 7, the lightfastness of the coloring layers containing the first to third colorants is significantly improved by having an ultraviolet-absorbing layer with an ultraviolet shielding rate of over 85% on top. Placing the ultraviolet absorption energy within the coloring layer system has limited effect; it is preferable to form it as a separate layer on top. Furthermore, the lightfastness of the coloring layer is further improved by using a laminated oxygen barrier layer and by including a high-molecular-weight hindered amine light stabilizer as a free radical scavenger and a nickel dithiocarbamate complex as a singlet oxygen quencher within the coloring layer. Additionally, by differentiating the absorption wavelengths of the photopolymerization initiator and the ultraviolet absorber contained in the ultraviolet-absorbing layer, both ultraviolet absorption energy and hardness can be achieved.

[0116] [Display Device Characteristic Evaluation] The following evaluations were performed on the obtained optical thin films 8, 10, and 14-16.

[0117] (White displays penetration characteristics) The transmittance of the optical thin film was measured using an automatic spectrophotometer (Hitachi, Ltd., U-4100). This transmittance was used to calculate the light efficiency through the optical thin film during white display, which was then used to evaluate the white display transmittance characteristics. The aforementioned efficiency was calculated as the ratio of the light intensity at each wavelength of the white display emitted from a white organic EL light source (hereinafter sometimes referred to as an organic EL light source) and output through a color filter to the light intensity at each wavelength of the light penetrating the optical thin film, with each wavelength representing 100. A higher light intensity ratio indicates a higher luminance efficiency of the light source. The spectrum of the light emitted from the EL light source is shown in Figure 6. In Figure 6, the horizontal axis represents wavelength (nm), and the vertical axis represents transmitted light intensity (au).

[0118] (Reflective characteristics of display devices 1) The transmittance T(λ) and surface reflectance R2(λ) of the optical thin film were measured using an automatic spectrophotometer (Hitachi, Ltd., U-4100). For the surface reflectance R2(λ), a matte black coating was applied to the surface of a transparent triacetyl cellulose film without a coloring layer or functional layer to perform anti-reflection treatment. The reflectance was measured at an incident angle of 5° and recorded as surface reflectance R2(λ). The electrode reflectance RE(λ) was set to 100% across wavelengths from 380 nm to 780 nm. Ignoring interfacial and surface reflections at each layer, the relative reflectance value was calculated based on equations (4), (5), (7), and (9) above, with the intensity of the reflected light from the D65 light source without the optical thin film set to 100. This value was used to evaluate the reflectance characteristic 1 of the display device. A lower relative reflectance value indicates lower reflected light intensity and higher display quality.

[0119] (The display device reflects hue 1) The transmittance T(λ) and surface reflectance R2(λ) of the optical thin film were measured using an automatic spectrophotometer (model: U-4100, manufactured by Hitachi, Ltd.). For the measurement of surface reflectance R2(λ), a matte black coating was applied to the surface of a triacetyl cellulose film on a transparent substrate without a colored layer or functional layer to perform anti-reflection treatment, and the reflectance was measured at an incident angle of 5° as the surface reflectance R2(λ). The electrode reflectance RE(λ) was set to 100% for all wavelengths from 380 nm to 780 nm, and the interfacial and surface reflections of each layer were not considered. Based on the above equations (1) to (9), the chromaticity index (value) a* and b* of the reflected hue relative to the D65 light source were calculated and evaluated as the reflected hue 1 of the display device. The closer a* and b* are to zero, the less hue there is and the better; the better is between -5 and +5.

[0120] (Reflective characteristics of display devices 2) The electrode reflectivity RE(λ) is set to the electrode reflectivity measured from the organic light-emitting display device (OLED55C8PJA, manufactured by LG Electronics) shown in Figure 8. Otherwise, it is calculated in the same manner as display device reflectivity characteristic 1, and the calculation result is used as display device reflectivity characteristic 2 for evaluation. Similar to display device reflectivity characteristic 1, a lower relative reflectance value indicates lower reflected light intensity and higher display quality. In Figure 8, the horizontal axis represents wavelength (nm), and the vertical axis represents reflectivity (%).

[0121] (The display device reflects hue 2) The electrode reflectance RE(λ) is set to the electrode reflectance measured from the organic light-emitting display device (OLED55C8PJA, manufactured by LG Electronics) shown in Figure 8. Otherwise, it is calculated in the same way as the display device's reflectance hue 1, and the calculation result is used as the display device's reflectance hue 2 for evaluation. Similar to the display device's reflectance hue 1, the closer a* and b* are to zero, the less hue is considered good, with an optimal range of -5 to +5.

[0122] (Color reproduction) The transmittance of the optical thin film was measured using an automatic spectrophotometer (Hitachi, Ltd., U-4100). Using this transmittance and the red, green, and blue display spectra shown in Figure 7, which were generated by passing through an organic EL light source and a color filter as shown in Figure 6, the CIE1931 chromaticity value was calculated. The NTSC ratio was then calculated from this chromaticity value and used as an evaluation of color reproducibility. A higher NTSC ratio results in a wider and better color reproduction range. In Figure 7, the horizontal axis represents wavelength (nm) and the vertical axis represents transmitted light intensity (au).

[0123] The results of the evaluation of the above projects are shown in [Table 8].

[0124] [Table 8] Example 8 Example 10 Comparative Example 4 Comparative Example 5 Comparative Example 6 White display transparency characteristics 51.9 51.8 52.6 50.1 91.4 Comparative Example 6 57% 57% 58% 55% 100% Reflective characteristics of display devices 1 25.8 25.7 25.8 25.8 83.7 Comparative Example 6 31% 31% 31% 31% 100% The display device reflects hue 1 a * 4.5 2.5 11.0 12.0 -0.2 b * -4.8 -3.0 -21.3 -10.0 0.9 Reflective characteristics of display devices 2 11.2 11.2 11.2 11.3 34.8 Comparative Example 6 32% 32% 32% 32% 100% The display device reflects hue 2 a * 4.4 3.0 9.0 10.5 1.4 b * -1.7 -0.4 -13.4 -4.9 2.7 Color reproduction NTSC ratio 97.0% 96.8% 98.3% 101.8% 91.7%

[0125] As shown in [Table 8], the reflectivity of the display device with the color layer is significantly reduced. Furthermore, it is said that transmittance is halved in a circular polarizer; in contrast, as shown in the white display transmittance evaluation value, the display device with the color layer also exhibits excellent luminance efficiency and improved color reproduction. Moreover, the color layer with the first, second, and third color materials shown in this embodiment allows adjustment of the absorption intensity of the color materials so that the chromaticity indices a* and b* of the reflected hue when the electrode reflection RE(λ) is 100% across all wavelengths from 380nm to 780nm are respectively within the range of -5 to +5. That is, the reflected hue can be made close to neutral. Furthermore, this characteristic is also demonstrated in the reflected hue 2 of the display device with the electrode reflectivity changed to that of an actual organic light-emitting display device, showing that the reflected hue can be maintained at neutral, confirming an improvement in the display quality of the display device. As mentioned above, by adjusting the mixing ratio of the first, second, and third color materials relative to the electrode reflectivity of an organic light-emitting display device with various wavelength dispersions, the reflective hue of the optical thin film with the color layer is made neutral. This is also one aspect of the present invention.

[0126] While the preferred embodiments and modifications of the present invention have been described above together with the examples, the present invention is not limited to the various embodiments and examples. Additions, omissions, substitutions, and other changes to the configuration may be made without departing from the spirit of the present invention. Furthermore, the present invention is not limited by the foregoing description, but only by the scope of the appended patent applications. [Potential for industrial application]

[0127] According to the present invention, an optical thin film and a display device are provided that can improve the display quality based on external light reflection and improve the lifespan of the light-emitting elements of the display device.

[0128] 10A, 10B, 10C, 10D, 10E: Optical thin films 11: Transparent substrate 11a: Page 1 11b: Page 2 12: Shading layer 13: Ultraviolet Absorption Layer (Functional Layer) 14A, 14E: Low refractive index layer (functional layer) 15: Oxygen barrier layer (functional layer) 16: UV Absorption Anti-Glare Layer (UV Absorption Layer, Functional Layer, Anti-Glare Layer) 17: Anti-glare layer (functional layer) 20: Display Section 21:Substrate 22: Light-emitting element 22R: First light-emitting element 22G: Second light-emitting element 22B: Third light-emitting element 23: Color Filter Section 50A, 50B, 50C, 50D, 50E: Display devices

Claims

1. An optical thin film comprising: a transparent substrate; a coloring layer consisting of one or more layers containing pigment, stacked on the transparent substrate; and one or more functional layers sandwiching the coloring layer and disposed on the opposite side of the transparent substrate; the coloring layer comprising: a first color material having a maximum absorption wavelength in the range of 470 nm to 530 nm and a half-width at half-maximum (WHM) of the absorption spectrum of 15 nm to 45 nm; a second color material having a maximum absorption wavelength in the range of 560 nm to 620 nm and a WHM of the absorption spectrum of 15 nm to 55 nm; and a third color material having a wavelength with the lowest transmittance in the wavelength range of 400 nm to 780 nm in the range of 650 nm to 780 nm; and hue values ​​a* and b* defined by the following formulas (1) to (9) being in the range of -5 to +5 respectively, the functional layer having an ultraviolet absorption layer with an ultraviolet shielding rate of 85% or higher, and a surface pencil hardness of H or higher under a 500g load; Here, λ represents the wavelength variable, and t represents the ratio of X, Y, Z to Xn, Yn, Zn; a* and b* calculated by equations (1) to (3) are calculated according to the CIE1976 L*a*b* color space (CIELAB color space); in equations (1) and (2), Xn, Yn, and Zn are the tristimulus values ​​of the white point of the D65 light source; in equation (4), RE(λ) represents the reflectance [%] of the perfectly diffuse surface (100% for each wavelength), R2(λ) represents the surface reflectance [%] of the outermost surface of the optical film on the opposite side of the transparent substrate, and T(λ) represents the transmittance [%] of the optical film; in equations (6) to (9), PD65(λ) is the spectrum of the D65 light source, and the upper horizontal lines x(λ), y(λ), and z(λ) are calculated according to the CIE1976 L*a*b* color space (CIELAB color space). Color matching function in 2° field of view; The definite integrals in equations (6) to (9) can be obtained by appropriate numerical integration; The wavelength interval for numerical integration is, for example, 1 nm interval.

2. The optical thin film of claim 1, wherein the coloring layer does not contain a dye having a main absorption wavelength band of 390-435 nm.

3. The optical film of claim 1 or 2, wherein the ultraviolet absorbing layer is composed of a hardened film containing a composition of an energy line hardening compound, a photopolymerization initiator and an ultraviolet absorber; the absorption wavelength range of the photopolymerization initiator in the ultraviolet region is different from that of the ultraviolet absorber in the ultraviolet region, and the absorption wavelength range of the ultraviolet absorbing layer in the ultraviolet region is in the range of 290 nm to 370 nm.

4. The optical film of claim 1 or 2, wherein the functional layer has a low refractive index layer with a refractive index lower than that of the ultraviolet absorbing layer; the low refractive index layer is deposited on the surface of the ultraviolet absorbing layer opposite to the surface opposite to the colored layer.

5. The optical film of claim 1 or 2, wherein the functional layer further comprises an anti-glare layer; the ultraviolet absorption layer and the anti-glare layer are arranged sequentially in the direction from the transparent substrate toward the colored layer.

6. The optical film of claim 1 or 2, wherein the ultraviolet absorbing layer is an anti-glare layer containing an ultraviolet absorber.

7. The optical film of claim 1 or 2, wherein the functional layer further comprises at least one of an antistatic layer containing an antistatic agent and a water-repellent antifouling layer.

8. The optical thin film of claim 1 or 2, wherein the colored layer contains at least one of a free radical scavenger, a peroxide decomposer, and a singlet oxygen quencher.

9. The optical film of claim 8, wherein the colored layer contains a hindered amine light stabilizer with a molecular weight of 2000 or more as the free radical scavenger.

10. The optical thin film of claim 8, wherein the colored layer contains any one of dialkyl phosphate, dialkyl dithiocarbamate, benzodithiophenol and such transition metal complexes as the singlet oxygen quencher.

11. The optical film of claim 1 or 2, wherein the pigment comprises: at least one compound selected from the group consisting of compounds having any one of the following structures: porphyrin, phthalocyanine, azo, cyanine, squarylium, coumarin, polyene, quinone, tetrazaporphyrin, pyrromethene, and indigo, and their metal complexes.

12. The optical thin film of claim 1 or 2, wherein the functional layer comprises a layer with an oxygen permeability of less than 10 cc / m2·day·atm.

13. A display device comprising a light source and an optical thin film as claimed in any one of claims 1 to 12.

14. The display device of claim 13, wherein the light source comprises a plurality of light-emitting elements that emit light based on image signals.

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