Display device and wavelength conversion laminate

Abstract

Provided are a display device and a wavelength conversion laminate used in same, wherein the display device has, in this order, a color filter layer, an inorganic barrier layer, a color conversion layer, and a blue light-emitting diode having a maximum emission wavelength in a range of 400-500 nm. The color filter layer has respective color filters of blue pixels, green pixels, and red pixels. The color filter layer, the inorganic barrier layer, and the color conversion layer are adjacent to each other, and satisfy all the following formulas (1)-(3). Formula (2) (n I -n B ) < (n I -n G ) Formula (3): (n I -n B ) < (n I -n R ) In the formulas, λ A denotes the maximum emission wavelength of the blue light-emitting diode, d I denotes the film thickness of the inorganic barrier layer, and n I , n B , n G and n R denote refractive indices of the inorganic barrier layer, the color filter of the blue pixels, the color filter of the green pixels, and the color filter of the red pixels, respectively. m is a natural number, and units of λ A and d I are all nm.

Description

Display device and wavelength conversion laminate

[0001] The present invention relates to a display device and a wavelength converting laminate.

[0002] Organic electroluminescence (OLED) display devices are devices that display images by utilizing the spontaneous emission of OLED elements. Therefore, compared to various display devices such as liquid crystal display devices and plasma display devices, they have advantages such as a high contrast ratio, excellent color reproducibility, a wide viewing angle, fast response, and the possibility of being thin and lightweight. In addition to these advantages, OLED display devices are also being actively researched and developed as next-generation display devices due to their flexibility.

[0003] In recent years, quantum dot organic electroluminescence (QD-OLED) display devices have become known, which use blue LEDs (blue light-emitting diodes) instead of white LEDs (white light-emitting diodes) as light sources, and obtain the three colors R (red), G (green), and B (blue) by using quantum dots (QDs) that convert blue light into red and green, in combination with color filters. QD-OLED display devices can achieve clearer, brighter, and wider color gamut displays than OLED display devices. For example, Patent Document 1 describes an OLED display device including blue light-emitting elements, quantum dots (QDs), and color filters as the configuration of a self-luminous display device used in a simulation of ambient light reflection.

[0004] International Publication No. 2021 / 162115

[0005] While QD-OLED display devices have the above advantages, the light conversion efficiency of QDs, which do not use highly toxic cadmium, is not sufficiently high. Furthermore, in color conversion layers containing QDs, blue light that is not converted to red or green light is absorbed by the red and green color filters. Therefore, improvements are needed from the perspectives of improving energy efficiency and reducing power consumption.

[0006] The present invention aims to provide a technology that can contribute to improving the energy efficiency of display devices that use blue light-emitting diodes as light sources, such as QD-OLED display devices, by allowing blue light that has not been converted in a color conversion layer to re-enter the color conversion layer and be subjected to color conversion again. Specifically, the present invention aims to provide a display device that uses blue light-emitting diodes as light sources, and that can selectively increase the reflectance of blue light in red and green color filters while suppressing the reflectance of blue light in a blue color filter, and a wavelength conversion laminate used therein.

[0007]

[0009] As a result of intensive research conducted by the present inventors in light of the above-mentioned problems, it has been found that by providing an inorganic barrier layer adjacent to a color filter layer and a color conversion layer, controlling the refractive index difference between the color filter layer and the inorganic barrier layer, and further setting the film thickness of the inorganic barrier layer so that reflected blue light is reinforced by optical interference in a display device configuration, it is possible to selectively increase the reflectance of blue light from the red and green color filters while suppressing the reflectance of blue light from the blue color filter, and to enable blue light that has not been converted by the color conversion layer to be re-entered into the color conversion layer by interfacial reflection. The present invention was completed after further research based on this finding.

[0008] That is, the above-mentioned problems have been solved by the following means: <1> A display device comprising, in this order, a color filter layer, an inorganic barrier layer, a color conversion layer, and a blue light-emitting diode having a maximum emission wavelength in the range of 400 to 500 nm, wherein the color filter layer comprises a color filter for a blue pixel, a color filter for a green pixel, and a color filter for a red pixel, the color filter layer, the inorganic barrier layer, and the color conversion layer are adjacent to one another, and all of the following formulas (1) to (3) are satisfied: Formula (2) (n Ｉ -n Ｂ ) < (n Ｉ -n Ｇ ) Formula (3) (n Ｉ -n Ｂ ) < (n Ｉ -n Ｒ ) In the above formula, λＡ represents the maximum emission wavelength of the blue light-emitting diode, and d Ｉ represents the thickness of the inorganic barrier layer, and n Ｉ represents the refractive index of the inorganic barrier layer, and n Ｂ represents the refractive index of the color filter of the blue pixel, and n Ｇ represents the refractive index of the color filter of the green pixel, and n Ｒ represents the refractive index of the color filter of the red pixel, m is a natural number, and λ Ａ and d Ｉ <2> A wavelength-converting laminate for light from a blue light-emitting diode having a maximum emission wavelength in the range of 400 to 500 nm, the wavelength-converting laminate having a color filter layer, an inorganic barrier layer, and a color conversion layer adjacent to one another, the color filter layer having a color filter for a blue pixel, a color filter for a green pixel, and a color filter for a red pixel, and satisfying all of the following formulas (1) to (3): Formula (2) (n Ｉ -n Ｂ ) < (n Ｉ -n Ｇ ) Formula (3) (n Ｉ -n Ｂ ) < (n Ｉ -n Ｒ ) In the above formula, λ Ａ represents the maximum emission wavelength of the light from the blue light-emitting diode, and d Ｉ represents the thickness of the inorganic barrier layer, and n Ｉ represents the refractive index of the inorganic barrier layer, and n Ｂ represents the refractive index of the color filter of the blue pixel, and n Ｇ represents the refractive index of the color filter of the green pixel, and n Ｒ represents the refractive index of the color filter of the red pixel, m is a natural number, and λ Ａ and d Ｉ The units are all nm.

[0009] In the present invention, unless otherwise specified, each layer (color filter layer, inorganic barrier layer, and color conversion layer) constituting the display device or wavelength conversion laminate may contain one or more components constituting each layer. Furthermore, in the present invention, a numerical range expressed using "to" means a range including the numerical values ​​before and after "to" as the lower and upper limits. In the present invention, blue light (B light) means light in the wavelength range of 400 to 500 nm, green light (G light) means light in the wavelength range of more than 500 nm and not more than 600 nm, and red light (R light) means light in the wavelength range of more than 600 nm and not more than 700 nm. In the present invention, the "refractive index" is the value at 450 nm at 25°C measured by Method B (a method for measuring the refractive index of a powder or granular transparent material by a microscope immersion method (utilizing the Becke line phenomenon)) described in JIS (Japanese Industrial Standards) K7142 (2014). In the present invention, the film thickness d Ｉ is an average value of values ​​measured at five random locations by cutting a cross section of a laminate including a color filter layer, an inorganic barrier layer, and a color conversion layer, observing the cut cross section using a scanning electron microscope such as S-4800 (trade name, manufactured by Hitachi High-Technologies Corporation).

[0010] The display device of the present invention is a display device that has a blue light-emitting diode as a light source, and the reflectance of blue light in the blue color filter is suppressed while the reflectance of blue light in the red and green color filters is selectively increased. Furthermore, by applying the wavelength conversion laminate of the present invention to a display device that has a blue light-emitting diode as a light source, the reflectance of blue light in the blue color filter can be suppressed while the reflectance of blue light in the red and green color filters can be selectively increased.

[0011] Fig. 1 is a longitudinal cross-sectional view showing a part of the display region of a display device according to an embodiment of the present invention. Fig. 2 is a schematic diagram showing the reflected light R1 and R2 of light incident from the color conversion layer to the inorganic barrier layer in the configuration of a wavelength conversion laminate unit for a green pixel or red pixel prepared in the examples. Fig. 3 is a schematic diagram showing the reflected light R3 and R4 of light incident from the scattering layer to the inorganic barrier layer in the configuration of a wavelength conversion laminate unit for a blue pixel prepared in the examples. The arrows pointing diagonally upward to the upper right represent transmitted light.

[0012] While the present invention can be embodied in various forms and in various modifications, specific embodiments are illustrated in the drawings and described in detail in the detailed description. The advantages and features of the present invention, as well as methods for achieving them, will become clearer with reference to the following detailed description of the embodiments together with the drawings. However, the present invention is not limited to the embodiments disclosed below, and can be embodied in various forms.

[0013] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. When describing with reference to the drawings, identical or corresponding components will be given the same reference numerals and redundant description thereof will be omitted.

[0014] In the following embodiments, terms such as first and second are not used in a limiting sense but are used to distinguish one component from another.

[0015] In the following embodiments, when a part such as a film, region, or component is said to be on another part, unless otherwise specified, this includes not only the case where it is directly on top of the other part, but also the case where another film, region, component, etc. is interposed between them.

[0016] In the drawings, the size of components may be exaggerated or reduced for the sake of convenience of explanation. For example, the size and thickness of each component shown in the drawings are arbitrarily depicted for the sake of convenience of explanation, and the present invention is not necessarily limited to what is shown in the drawings.

[0017] In the following embodiments, when a film, region, component, etc. is said to be connected, unless otherwise specified, this includes not only a case where the film, region, component, etc. is directly connected, but also a case where the film, region, component, etc. is indirectly connected via another film, region, component, etc. interposed between them. For example, in the present invention, when a film, region, component, etc. is said to be electrically connected, this includes not only a case where the film, region, component, etc. is directly electrically connected, but also a case where the film, region, component, etc. is indirectly electrically connected via another film, region, component, etc. interposed between them.

[0018] A display device is a device that displays images, and includes organic light-emitting display devices (organic light-emitting display apparatuses) including micro LED display devices, mini LED display devices, and quantum dot organic electroluminescence (QD-OLED) display devices, inorganic light-emitting display devices, and quantum dot light-emitting display devices.

[0019] [Display Device] The display device of the present invention comprises, in this order, a color filter layer, an inorganic barrier layer, a color conversion layer, and a blue light-emitting diode having a maximum emission wavelength in the range of 400 to 500 nm, wherein the color filter layer comprises a color filter for a blue pixel, a color filter for a green pixel, and a color filter for a red pixel, the color filter layer, the inorganic barrier layer, and the color conversion layer are adjacent to one another, and the display device satisfies all of the following formulas (1) to (3):

[0020]

[0021] Formula (2) (n Ｉ -n Ｂ ) < (n Ｉ -n Ｇ ) Formula (3) (n Ｉ -n Ｂ ) < (n Ｉ -n Ｒ )

[0022] In the above formula, λ Ａrepresents the maximum emission wavelength of the blue light-emitting diode, and d Ｉ represents the thickness of the inorganic barrier layer, and n Ｉ represents the refractive index of the inorganic barrier layer, and n Ｂ represents the refractive index of the color filter of the blue pixel, and n Ｇ represents the refractive index of the color filter of the green pixel, and n Ｒ λ denotes the refractive index of the color filter of the red pixel. Ａ and d Ｉ In the above formula (1), m is a natural number, and λ Ａ , d Ｉ and n Ｉ This means that, under the specified conditions, if there is a natural number m that satisfies formula (1), optical interference occurs. In the present invention, "adjacent" means directly in contact with the inorganic barrier layer. That is, in the display device of the present invention, the color filter layer and the inorganic barrier layer are in direct contact with each other without any other layer interposed therebetween, and the inorganic barrier layer and the color conversion layer are in direct contact with each other without any other layer interposed therebetween. Furthermore, in the present invention, the "blue light-emitting diode" is not particularly limited as long as it has a maximum emission wavelength in the range of 400 to 500 nm, and examples thereof include organic blue LEDs, inorganic blue LEDs, and blue laser diode light sources.

[0023] The display device of the present invention has an inorganic barrier layer disposed adjacent to the color filter layer and the color conversion layer, and the thickness of the inorganic barrier layer satisfies the above formula (1), i.e., the reflected blue light from the inorganic barrier layer is reinforced by optical interference. Furthermore, the display device of the present invention satisfies the above formulas (2) and (3), i.e., the refractive index difference n between the color filter and the inorganic barrier layer in the green pixel and the red pixel is Ｉ -n Ｇ and n Ｉ -n Ｒ The refractive index difference n between the color filter and the inorganic barrier layer in the blue pixel is Ｉ -n ＢBy adopting a configuration in which the reflectance is small, it is possible to suppress reflection of blue light in the blue pixel, while at the same time increasing reflection of blue light in the red and green pixels while keeping reflection of red and green light low, and to allow blue light that has not been converted by the color conversion layer to re-enter the color conversion layer by interfacial reflection. In contrast, in a display device configuration in which there is no inorganic barrier layer between the color filter layer and the color conversion layer, the color filter layer and the color conversion layer cannot be considered thin films, and therefore no interfacial reflection occurs.

[0024] In the above formula (1), {(m-1 / 2) × λ Ａ} / 2n Ｉ (where m is a natural number) exists in the range d Ｉ From the viewpoint of a configuration in which the reflected light of blue light is reinforced by the inorganic barrier layer due to optical interference, d Ｉ ±30 nm is preferred, and d Ｉ ±15 nm is more preferable, and d Ｉ ±10 nm is more preferable.

[0025] From the viewpoint of selectively increasing the reflectance of blue light in the green color filter while suppressing the reflectance of blue light in the blue color filter, the above formula (2) is preferably the following formula (2A), more preferably the following formula (2B), and even more preferably the following formula (2C): Formula (2A) (n Ｉ -n Ｂ ) + 0.10 < (n Ｉ -n Ｇ ) Formula (2B) (n Ｉ -n Ｂ ) + 0.20 < (n Ｉ -n Ｇ ) Formula (2C) (n Ｉ -n Ｂ ) + 0.25 < (n Ｉ -n Ｇ From the viewpoint of selectively increasing the reflectance of blue light in the red color filter while suppressing the reflectance of blue light in the blue color filter, the above formula (3) is preferably the following formula (3A), more preferably the following formula (3B), and even more preferably the following formula (3C): Formula (3A) (n Ｉ -nＢ ) + 0.10 < (n Ｉ -n Ｒ ) Formula (3B) (n Ｉ -n Ｂ ) + 0.20 < (n Ｉ -n Ｒ ) Formula (3C) (n Ｉ -n Ｂ ) + 0.25 < (n Ｉ -n Ｒ )

[0026] In the above formulas (2), (2A) to (2C), (3), and (3A) to (3C), the above [n Ｉ -n Ｇ ] and [n Ｉ -n Ｒ From the viewpoint of generating a certain level of reflection at the interface between the color filter and the inorganic barrier layer in the green pixel and the red pixel, the above [n Ｉ -n Ｇ ] and [n Ｉ -n Ｒ The upper limit of the above [n Ｉ -n Ｇ ] and [n Ｉ -n Ｒ The value of [n] is preferably greater than 0.05 and less than 1.20, more preferably from 0.10 to 1.20, even more preferably from 0.15 to 1.00, and particularly preferably from 0.20 to 0.80. Ｉ -n Ｂ The value of ] is preferably −0.10 to 0.60, more preferably 0.00 to 0.50, even more preferably 0.10 to 0.40, particularly preferably 0.10 to 0.35, and especially preferably 0.15 to 0.35.

[0027] In the display device of the present invention, the green pixel and the red pixel are provided with color conversion layers for converting light from a blue light-emitting diode into green and red, respectively. On the other hand, the blue pixel can use light from the blue light-emitting diode as is, so no color conversion layer is necessary, and it is preferable to have, for example, a scattering layer that scatters blue light instead of the color conversion layer in the green pixel and the red pixel. That is, in the blue pixel, it is sufficient that the color filter layer and the inorganic barrier layer are adjacent to each other, and if a scattering layer is provided, it is preferable that the color filter layer, the inorganic barrier layer, and the scattering layer are adjacent to each other. The color conversion layer and the inorganic barrier layer in the green pixel are usually in a relationship where green light converted in the color conversion layer passes through the inorganic barrier layer, and the refractive index n of the color conversion layer in the green pixel is ＱＧ <Refractive index n of inorganic barrier layer Ｉ The refractive index n of the color conversion layer of the green pixel satisfies the relationship ＱＧ +0.20<refractive index n of the inorganic barrier layer Ｉ It is preferable that the refractive index n of the color conversion layer for the green pixel satisfies the relationship ＱＧ +0.30<refractive index n of the inorganic barrier layer Ｉ Similarly, the color conversion layer and inorganic barrier layer in the red pixel are usually in a relationship where red light converted in the color conversion layer is transmitted through the inorganic barrier layer, and the refractive index n ＱＲ <Refractive index n of inorganic barrier layer Ｉ The refractive index n of the color conversion layer of the red pixel satisfies the relationship ＱＲ +0.20<refractive index n of the inorganic barrier layer Ｉ It is preferable that the refractive index n of the color conversion layer for the red pixel satisfies the relationship ＱＲ +0.30<refractive index n of the inorganic barrier layer Ｉ Similarly, the scattering layer and the inorganic barrier layer in the blue pixel are usually in a relationship where blue light is transmitted from the scattering layer to the inorganic barrier layer, and the refractive index n of the scattering layer is Ｓ <Refractive index n of inorganic barrier layer Ｉ The refractive index n of the scattering layer satisfies the relationship Ｓ +0.10<refractive index n of the inorganic barrier layer ＩIt is preferable that the refractive index n of the scattering layer satisfies the relationship Ｓ +0.20<refractive index n of the inorganic barrier layer Ｉ It is more preferable that the following relationship is satisfied.

[0028] From the viewpoint of satisfying the relationship of the above formula (1) and the relationship of the refractive index between each layer including the above formulas (2) and (3), in commonly used color filters, inorganic barrier layers, color conversion layers, and scattering layers, for example, a material constituting the inorganic barrier layer should have a high refractive index n Ｉ In this embodiment, a material having a refractive index n of the inorganic barrier layer is selected, and low refractive index particles are contained in the color filters for the green and red pixels, and high refractive index particles are contained in the color filter for the blue pixel. Ｉ is preferably 1.80 to 2.50, more preferably 1.90 to 2.40, and even more preferably 2.00 to 2.25. The low refractive index particles contained in the color filters for green and red pixels and the high refractive index particles contained in the color filter for blue pixels can be described in the description of the low refractive index particles and high refractive index particles in the color filters R-CF, G-CF, and B-CF described later.

[0029] Hereinafter, a QD-OLED display device having a blue light emitting diode as a light source will be described as an example of a display device according to an embodiment of the present invention, but the display device of the present invention is not limited thereto, and various types of display devices can be used.

[0030] FIG. 1 is a vertical cross-sectional view schematically showing a part of a display area of ​​a display device according to one embodiment of the present invention.

[0031] As shown in Figure 1, the display device of the present invention has blue light-emitting diodes B-LED1, B-LED2, and B-LED3, each having a maximum emission wavelength in the range of 400 to 500 nm. The blue pixel PB emits blue light by transmitting blue light emitted from the blue light-emitting diode B-LED3 through the scattering layer S, the first inorganic barrier layer 410, and the blue color filter B-CF without wavelength conversion. The green pixel PG emits green light by transmitting blue light emitted from the blue light-emitting diode B-LED2 through the green conversion layer QDG, the first inorganic barrier layer 410, and the green color filter G-CF. The red pixel PR emits red light by transmitting blue light emitted from the blue light-emitting diode B-LED1 through the red conversion layer QDR, the first inorganic barrier layer 410, and the red color filter R-CF.

[0032] The arrangement of the blue pixels PB, green pixels PG, and red pixels PR is not particularly limited, and they can be arranged in various arrangements such as a stripe arrangement, a pentile matrix arrangement, a mosaic arrangement, a delta arrangement, etc.

[0033] The display device of the present invention includes a driving thin film transistor T1, which is connected to a driving voltage line and a storage capacitor and can control a driving current flowing from the driving voltage line to blue light emitting diodes B-LED1, B-LED2, and B-LED3 according to the voltage value stored in the storage capacitor. The blue light emitting diodes B-LED1, B-LED2, and B-LED3 can emit light having a predetermined brightness in response to the driving current.

[0034] The display area of ​​the display device includes a plurality of red pixels PR, green pixels PG, and blue pixels PB, and each of the color pixels PR, PG, and PB includes a light-emitting region where light is generated and emitted to the outside. Non-light-emitting regions are disposed between the light-emitting regions, and the light-emitting regions of the color pixels PR, PG, and PB are separated by the non-light-emitting regions.

[0035] The display device of the present invention has a color conversion layer. For example, as shown in Figure 1, the red pixel PR has a red conversion layer QDR, and the green pixel PG has a green conversion layer QDG. The color conversion layers QDR and QDG may contain quantum dots (QDs) and scattering particles.

[0036] On the other hand, in the light-emitting region of the blue pixel PB, there is no corresponding color conversion layer, and instead a scattering layer S is disposed. The scattering layer S may be a layer that scatters the light emitted from the blue light-emitting diode B-LED3 of the blue pixel PB without wavelength conversion, and may be, for example, a layer made of a resin such as an acrylic resin and TiO ２ and the like. The scattering layer S may be formed of a transmission window.

[0037] The first blue light emitting diode B-LED1 included in the red pixel PR, the second blue light emitting diode B-LED2 included in the green pixel PG, and the third blue light emitting diode B-LED3 included in the blue pixel PB can each emit light of the same color or different colors.

[0038] The configuration of the display device shown in FIG. 1 will be described in detail below.

[0039] The substrate 100 may be made of glass, ceramic, or metal, and may further include a material having flexible or bendable properties. If the substrate 100 is flexible or bendable, it may include a polymer resin such as polyethersulfone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyarylate, polyimide (PI), polycarbonate (PC), or cellulose acetate propionate (CAP). The substrate 100 may have a single-layer structure or a multi-layer structure of the above-mentioned materials, and in the case of a multi-layer structure, it may further include an inorganic layer. Alternatively, the substrate 100 may have a structure in which layers are stacked in the order of organic / inorganic / organic.

[0040] A planarization layer 113 is disposed on the substrate 100. The planarization layer 113 is formed of a single layer or multilayer film made of an organic material and serves to provide a flat upper surface. Such planarization layer 113 may be formed from a general-purpose polymer such as benzocyclobutene (BCB), polyimide (PI), hexamethyldisiloxane (HMDSO), polymethyl methacrylate (PMM), or polystyrene (PS), a polymer derivative containing a phenol, an acrylic polymer, an imide polymer, an aryl ether polymer, an amide polymer, a fluorine-based polymer, a p-xylene polymer, or a vinyl alcohol polymer, or may be formed from a mixture of two or more of these.

[0041] In the display region of the substrate 100, a driving thin film transistor T1, a pixel electrode (anode) 310, and first to third blue light-emitting diodes B-LED1, B-LED2, and B-LED3 are arranged in this order on a planarization layer 113. The planarization layer 113 is also arranged between the driving thin film transistor T1, the pixel electrode (anode) 310, and the first to third blue light-emitting diodes B-LED1, B-LED2, and B-LED3. The first blue light-emitting diode B-LED1 is arranged in the region of the red pixel PR, the second blue light-emitting diode B-LED2 is arranged in the region of the green pixel PG, and the third blue light-emitting diode B-LED3 is arranged in the region of the blue pixel PB. The first to third blue light-emitting diodes B-LED1, B-LED2, and B-LED3 function as blue light-emitting diodes together with the pixel electrode (anode) 310 and the counter electrode (cathode) 330 arranged on either side thereof.

[0042] The driving thin film transistor T1 may be a commonly used driving thin film transistor without any particular limitation. The semiconductor layer included in the driving thin film transistor T1 may include amorphous silicon or polysilicon. In another embodiment, the semiconductor layer may include an oxide of at least one material selected from the group consisting of indium (In), gallium (Ga), tin (Sn), zirconium (Zr), vanadium (V), hafnium (Hf), cadmium (Cd), germanium (Ge), chromium (Cr), titanium (Ti), aluminum (Al), cesium (Cs), cerium (Ce), and zinc (Zn). In some embodiments, the semiconductor layer may be formed of a Zn-oxide-based material, such as Zn oxide, In—Zn oxide, or Ga—In—Zn oxide. In yet another embodiment, the semiconductor layer may be an IGZO (In-Ga-Zn-O), ITZO (In-Sn-Zn-O), or IGTZO (In-Ga-Sn-Zn-O) semiconductor, in which metals such as indium (In), gallium (Ga), or tin (Sn) are doped into ZnO. The semiconductor layer includes a channel region and source and drain regions disposed on either side of the channel region. The semiconductor layer may be configured as a single layer or multiple layers.

[0043] The pixel electrode 310 can be electrically connected to the pixel circuit. The pixel electrode 310 can be a transparent electrode, a semi-transparent electrode, or a reflective electrode. In some embodiments, the pixel electrode 310 can include a reflective layer made of Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or a compound thereof, and a transparent or semi-transparent electrode layer formed on the reflective layer. The transparent or semi-transparent electrode layer can include at least one selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide (In2O3), indium gallium oxide (IGO), and aluminum zinc oxide (AZO). In some embodiments, the pixel electrode 310 can be formed of ITO / Ag / ITO.

[0044] Although not shown, the first to third blue light-emitting diodes B-LED1, B-LED2, and B-LED3 each have an appropriately selected functional layer such as a hole transport layer, a light-emitting layer, a hole injection layer (HIL), an electron transport layer (ETL), and an electron injection layer (EIL).

[0045] In the present invention, the light-emitting layers of the first to third blue light-emitting diodes B-LED1, B-LED2, and B-LED3 are preferably formed of an organic material that emits blue light having a maximum emission wavelength in the range of 400 to 500 nm.

[0046] The light-emitting layer may be formed by using, for example, a blue dopant in a predetermined host material. For example, the light-emitting layer may be formed of a phosphorescent material containing a host material including 4,4'-N,N'-dicarbazol-biphenyl (CBP) or N,N'-dicarbazolyl-3,5-benzene (mCP) and a dopant material including (F2ppy)2Ir(picolinate) (F2ppy means 2-(4',6'-difluorophenyl)pyridinato). Alternatively, the light-emitting layer may be made of a fluorescent material including, but not limited to, any one selected from the group consisting of spiro-DPVBi (4,4'-Bis(2,2-diphenylvinyl)-1,1'-biphenyl), spiro-6P, distyrylbenzene (DSB), distyrylarylene (DSA), polyfluorene (PFO)-based polymers, and polyparaphenylene vinylene (PPV)-based polymers.

[0047] The hole transport layer is disposed between the pixel electrode 310 and the light-emitting layer. The hole transport layer smoothly moves holes transferred from the pixel electrode 310, which is a positive electrode, to the light-emitting layer, and can retain electrons transferred from the counter electrode 330, which is a negative electrode, in the light-emitting layer. For details of the hole transport layer, the description relating to the hole transport layer in JP 2022-78975 A can be applied to the present invention.

[0048] In this embodiment, the colors finally emitted by the red pixel PR, the green pixel PG, and the blue pixel PB are colors seen outside an optical functional film such as the anti-reflection film 203. When the same light-emitting layer is applied to the first to third blue light-emitting diodes B-LED1, B-LED2, and B-LED3, the voltage supplied to the first to third blue light-emitting diodes B-LED1, B-LED2, and B-LED3 may be changed depending on the light conversion efficiency of the red conversion layer QDR and the green conversion layer QDG.

[0049] The counter electrode 330 is a cathode, which is an electron injection electrode. The material for the counter electrode 330 can be a metal, an alloy, or a conductive compound having a low work function, or any combination thereof. The counter electrode 330 can be a transparent electrode, a semi-transparent electrode, or a reflective electrode.

[0050] The counter electrode 330 may include lithium (Li), silver (Ag), magnesium (Mg), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), ytterbium (Yb), silver-ytterbium (Ag-Yb), ITO (tin oxide), IZO (indium zinc oxide), or any combination thereof. The counter electrode 330 may have a single-layer structure, which is a single layer, or a multi-layer structure having multiple layers.

[0051] The counter electrode 330 is disposed on the planarization layer 113 and the first to third blue light emitting diodes B-LED1, B-LED2, and B-LED3. The counter electrode 330 is integrally formed on the plurality of blue light emitting diodes B-LED1, B-LED2, and B-LED3, and can correspond to the plurality of pixel electrodes 310.

[0052] A planarization layer 118 is disposed on the counter electrode (cathode) 330. The planarization layer 118 is formed of a single layer or a multilayer film made of an organic material, and serves to provide a flat upper surface. The description of the planarization layer 113 above can be applied to this planarization layer 118.

[0053] A third inorganic barrier layer 450, an adhesive layer 440, and a second inorganic barrier layer 430 are disposed on the planarization layer 118 in this order from the planarization layer 118 side. The first to third blue light-emitting diodes B-LED1, B-LED2, and B-LED3 are easily damaged by external moisture, oxygen, and the like, and therefore are preferably covered and protected by the third inorganic barrier layer 450, the adhesive layer 440, and the second inorganic barrier layer 430.

[0054] The third inorganic barrier layer 450 covers the planarization layer 118 and may include silicon oxide, silicon nitride, and / or silicon oxynitride. Although not shown, other layers, such as a capping layer, may be interposed between the third inorganic barrier layer 450 and the planarization layer 118, if necessary. The adhesion layer 440 provided on the third inorganic barrier layer 450 may include one or more materials selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, polyarylate, and hexamethyldisiloxane. The second inorganic barrier layer 430 provided on the adhesion layer 440 may include silicon oxide, silicon nitride, and / or silicon oxynitride.

[0055] The third inorganic barrier layer 450, the adhesive layer 440, and the second inorganic barrier layer 430 have such a multilayer structure that, if a crack occurs in any of the third inorganic barrier layer 450, the adhesive layer 440, and the second inorganic barrier layer 430, the crack does not connect between the first inorganic barrier layer 410 and the adhesive layer 440 or between the adhesive layer 440 and the second inorganic barrier layer 430. This can prevent or minimize the formation of a path through which moisture, oxygen, etc. from the outside can permeate into the display region.

[0056] The color conversion layers QDR and QDG, the scattering layer S, and the black barrier ribs 210 are disposed on the first inorganic barrier layer 410. The black barrier ribs 210 may further include scattering particles (not shown). Although not shown, a filler may be disposed between the first inorganic barrier layer 410 and the conversion layers QDR and QDG, the scattering layer S, and the black barrier ribs 210, if necessary. Examples of the filler include organic materials such as methyl silicone, phenyl silicone, and polyimide that can provide a buffering effect against external pressure. Examples of the filler include organic sealants such as urethane resins, epoxy resins, and acrylic resins, or inorganic sealants such as silicone.

[0057] The color conversion layers QDR and QDG each preferably contain quantum dots. In the present invention, quantum dots refer to crystals of semiconductor compounds and may include any material that can emit light of various emission wavelengths depending on the size of the crystals.

[0058] Quantum dots exhibit unique excitation and emission properties depending on their material and size, thereby converting incident light into a predetermined color light. A variety of materials can be used as quantum dots. For example, quantum dots can be made of Group II-VI compounds, Group III-V compounds, Group III-VI compounds, Group I-III-VI semiconductor compounds, Group IV-VI semiconductor compounds, and Group IV elements or compounds. Quantum dots can contain one of these or a combination of two or more of them.

[0059] The II-VI compounds are binary compounds selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS and mixtures thereof; CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, ternary compounds selected from CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, and mixtures thereof; and quaternary compounds selected from HgZnTeS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, and mixtures thereof.

[0060] The III-V compounds include binary compounds selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and mixtures thereof, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InAlP, InNAs, InNSb, InPAs , InPSb, GaAlNP, and mixtures thereof, and quaternary compounds selected from GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and mixtures thereof. The III-V semiconductor compound may further contain a Group II element. Examples of III-V semiconductor compounds further containing a Group II element include InZnP, InGaZnP, and InAlZnP.

[0061] Examples of III-VI semiconductor compounds are GaS, GaSe, Ga ２ Se ３ , GaTe, InS, InSe, In ２ S ３ , In ２ Se ３ and binary compounds such as InTe, and InGaS ３ and InGaSe ３ and other ternary compounds.

[0062] Examples of I-III-VI group semiconductor compounds are AgInS, AgInS ２ , CuInS, CuInS ２ ,CuGaO ２ , AgGaO ２ and AgAlO ２ and other ternary compounds.

[0063] The IV-VI compound can be selected from binary compounds selected from SnS, SnSe, SnTe, PbS, PbSe, PbTe, and mixtures thereof; ternary compounds selected from SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and mixtures thereof; and quaternary compounds selected from SnPbSSe, SnPbSeTe, SnPbSTe, and mixtures thereof.

[0064] The group IV element may be selected from Si, Ge and mixtures thereof. The group IV compound may be a binary compound selected from SiC, SiGe and mixtures thereof.

[0065] When quantum dots contain two or more types of binary compounds, ternary compounds, and quaternary compounds, they can be present in the particle at a uniform concentration or can be present in the same particle with partially different concentration distributions.

[0066] The quantum dots may also be formed in a core-shell structure having a core and a shell. The interface between the core and the shell may have a concentration gradient in which the concentration of the element present in the shell decreases toward the center.

[0067] The shell of a quantum dot can function as a protective layer to prevent chemical modification of the core and maintain its semiconducting properties, and / or as a charging layer to impart electrophoretic properties to the quantum dot. The shell can be single-layered or multi-layered. The interface between the core and the shell can have a concentration gradient in which the concentration of elements present in the shell decreases toward the center.

[0068] Examples of the shell of the quantum dot include oxides of metals, semi-metals or non-metals, semiconductor compounds, or combinations thereof. Examples of oxides of metals, semi-metals or non-metals include SiO ２ , Al ２ O ３ , TiO ２ , ZnO, MnO, Mn ２ O ３ , Mn ３ O ４ , CuO, FeO, Fe２ O ３ , Fe ３ O ４ , CoO, Co ３ O ４ , binary compounds such as NiO, MgAl ２ O ４ , CoFe ２ O ４ , NiFe ２ O ４ , CoMn ２ O ４ and ternary compounds such as, or any combination thereof. Examples of semiconductor compounds include the above-mentioned III-VI semiconductor compounds, II-VI semiconductor compounds, III-V semiconductor compounds, III-VI semiconductor compounds, I-III-VI semiconductor compounds, and IV-VI semiconductor compounds, as well as any combination thereof. Specific examples of semiconductor compounds include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, and AlSb, as well as any combination thereof.

[0069] The particle diameter of the quantum dots is usually about 45 nm or less, preferably about 40 nm or less, and more preferably about 30 nm or less, and within these ranges, color purity and / or color reproducibility can be improved. Furthermore, light emitted through such quantum dots is emitted in all directions, improving the light viewing angle.

[0070] The shape of the quantum dots is not particularly limited to shapes commonly used in the field of display devices, but specific examples include spherical, pyramidal, multi-arm or cubic nanoparticles, nanotubes, nanowires, nanofibers, and nanoplate-like particles.

[0071] The core of the quantum dot has a diameter of 2 to 10 nm. When exposed to light, the quantum dots can emit light of a specific frequency depending on the particle size and type of material. The average size of the quantum dots included in the red conversion layer QDR and the average size of the quantum dots included in the green conversion layer QDG are different. For example, the larger the quantum dot size, the longer the wavelength of the color emitted. Therefore, the size of the quantum dots can be selected according to the color of the red pixel PR and the green pixel PG.

[0072] The color conversion layers QDR and QDG may further include various materials in addition to the quantum dots to mix and properly disperse them, such as scattering particles, solvents, photoinitiators, binder polymers, and dispersants.

[0073] The light-emitting region of the blue pixel PB does not include a color conversion layer, but instead includes a scattering layer S. The scattering layer S may be made of an organic material that can emit light emitted from the third blue light-emitting diode B-LED3 of the blue pixel PB without wavelength conversion. The scattering layer S includes scattering particles for achieving uniform color diffusion. The scattering particles preferably have a diameter in the range of approximately 200 nm to 400 nm.

[0074] In this embodiment, the first blue light emitting diode B-LED1 and the second blue light emitting diode B-LED2 included in the red pixel PR and the green pixel PG can emit light of the same wavelength, and the colors of the red pixel PR and the green pixel PG are determined as the red and green colors emitted by the quantum dots in the red conversion layer QDR and the quantum dots in the green conversion layer QDG.

[0075] Meanwhile, since no color conversion layer is provided in the light-emitting area of ​​the blue pixel PB, the color of the blue pixel PB is determined as the blue color emitted by the third blue light-emitting diode B-LED3.

[0076] The black partition 210 is disposed between the red conversion layer QDR, the green conversion layer QDG, and the scattering layer S so as to correspond to the non-light-emitting region. Specifically, the black partition 210 can be disposed between the red conversion layer QDR and the green conversion layer QDG, between the green conversion layer QDG and the scattering layer S, etc.

[0077] The black barrier ribs 210 may include an organic material and a material for adjusting optical density, such as Cr, CrOx, Cr / CrOx, Cr / CrOx / CrNy, resin (carbon pigment, RGB mixed pigment), graphite, and non-Cr-based materials. Alternatively, the black barrier ribs 210 may include a pigment that emits a color such as red, green, or yellow. The black barrier ribs 210 may function as a black matrix for preventing color mixing and improving visibility.

[0078] In the present invention, a first inorganic barrier layer 410 is provided between the color conversion layers QDR and QDG, the scattering layer S, and the black partition wall 210 and the color filters R-CF, G-CF, and BC.

[0079] The first inorganic barrier layer 410 has a thickness d Ｉ and refractive index n Ｉ The maximum emission wavelength λ of each of the blue light-emitting diodes B-LED1, B-LED2, and B-LED3 is Ａ and satisfy the relationship of the above-mentioned formula (1), and the refractive index n Ｉ is the refractive index n of each of the color filters B-CF, G-CF, and R-CF. Ｂ , n Ｇ and n Ｒ As the material of the first inorganic barrier layer 410, any commonly used inorganic barrier layer can be used as long as it satisfies the above-mentioned formulas (1) to (3). Ｉ SiO, refractive index n Ｉ ZrO ２ or refractive index n Ｉ Si where is 2.06 ３ N ４ Among these, SiO is preferred from the viewpoint of being easily adjusted to satisfy the relationships of the above-mentioned formulas (1) to (3) and having high gas barrier properties. ＩFor example, the thickness of the film that satisfies the above-mentioned formula (1) may be in the range of 110 to 210 nm, preferably in the range of 135 to 190 nm, and more preferably in the range of 150 to 175 nm.

[0080] Between the first inorganic barrier layer 410 and the upper substrate 200, color filters R-CF, G-CF, and BC are provided.

[0081] The color filters R-CF, G-CF, and B-CF are introduced to realize full-color images, improve color purity, and improve outdoor visibility. The red color filter R-CF can pass light converted by the red conversion layer QDR and absorb light that is not converted. Similarly, the green color filter G-CF can pass light converted by the green conversion layer QDG and absorb light that is not converted. The blue color filter B-CF is realized with the same color as the light emitted from the blue light-emitting diode B-LED3. Furthermore, the color filters R-CF, G-CF, and B-CF can block light incident from outside and suppress light emission by the quantum dots in the color conversion layers QDR and QDG.

[0082] In the present invention, the color filters R-CF, G-CF, and B-CF have refractive indices n Ｒ , n Ｇ and n Ｂ is the refractive index n of the first inorganic barrier layer 410 Ｉ The materials for the color filters R-CF, G-CF, and B-CF may be any materials that are commonly used for color filters so long as they satisfy the relationships of the above-mentioned formulas (2) and (3). Materials that are commonly used for color filters can be used so as to satisfy the above-mentioned formulas (2) and (3). For example, the materials for the colored layers in the color filters described in paragraph

[0087] of JP-A No. 2016-109929 can be used. In the present invention, the refractive indexes n Ｒ , n Ｇ and n Ｂ It is preferable to contain a component for adjusting the refractive index n of the color filter R-CF.Ｒ and the refractive index n of the color filter G-CF Ｇ From the viewpoint of adjusting the refractive index n of the color filter R-CF and the color filter G-CF so as to satisfy the above-mentioned formulas (2) and (3), it is preferable that low refractive index particles are contained in the color filters R-CF and G-CF. Examples of low refractive index particles include hollow particles, and hollow silica particles are preferred. The refractive index n of the color filter B-CF is Ｂ From the viewpoint of adjusting the refractive index so as to satisfy the above-mentioned formulas (2) and (3), it is preferable that high refractive index particles are contained in the color filter B-CF. Examples of high refractive index particles include the high refractive index fine particles described in paragraph

[0037] of JP-A-2016-109929, and TiO ２ The particle diameters of the low refractive index particles and the high refractive index particles are not particularly limited, and for example, particles having an average primary particle diameter of 5 to 500 nm can be used. The average primary particle diameter means the average primary particle diameter on a volume basis.

[0083] The positional relationship between the red color filter R-CF, the green color filter G-CF, and the blue color filter B-CF can be appropriately interchanged. When the positional relationship is interchanged, the positional relationship between the color conversion layers QDR and QDG and the scattering layer S is also interchanged accordingly.

[0084] Although not shown, light-blocking patterns may be disposed between the R-CF, G-CF, and B-CF color filters to correspond to non-emitting regions, if necessary. The light-blocking patterns also function as black matrices to improve color clarity and contrast. The light-blocking patterns may include at least one of black pigments, black dyes, and black particles. In some embodiments, the light-blocking patterns may include materials such as Cr, CrOx, Cr / CrOx, Cr / CrOx / CrNy, resins (carbon pigments, RGB mixed pigments), graphite, and non-Cr materials.

[0085] Among the color filters R-CF, G-CF, and B-CF, adjacent color filters are arranged to overlap in a non-light-emitting region. By providing color filters of different colors to overlap, it is possible to improve the light blocking rate.

[0086] An upper substrate 200 made of glass, transparent polyimide, etc. is provided on the color filters R-CF, G-CF, and B-CF. An optically functional film such as an anti-reflection film 203 is appropriately provided on the upper substrate 200 via an adhesive layer 201 made of an adhesive such as a pressure-sensitive adhesive.

[0087] 1, the display device of the present invention may be formed by bonding the substrate 100 and the upper substrate 200 together using a sealing member. The sealing member may be formed to surround the outer surfaces of the substrate 100 and the upper substrate 200, and may bond the substrate 100 and the upper substrate 200 together.

[0088] [Wavelength-converting laminate] The wavelength-converting laminate of the present invention is a wavelength-converting laminate for light from a blue light-emitting diode having a maximum emission wavelength in the range of 400 to 500 nm, comprising a color filter layer, an inorganic barrier layer, and a color conversion layer adjacent to one another, the color filter layer comprising a color filter for a blue pixel, a color filter for a green pixel, and a color filter for a red pixel, and satisfying all of the following formulas (1) to (3):

[0089]

[0090] Formula (2) (n Ｉ -n Ｂ ) < (n Ｉ -n Ｇ ) Formula (3) (n Ｉ -n Ｂ ) < (n Ｉ -n Ｒ )

[0091] In the above formula, λ Ａ represents the maximum emission wavelength of the light from the blue light-emitting diode, and d Ｉ represents the thickness of the inorganic barrier layer, and n Ｉ represents the refractive index of the inorganic barrier layer, and nＢ represents the refractive index of the color filter of the blue pixel, and n Ｇ represents the refractive index of the color filter of the green pixel, and n Ｒ represents the refractive index of the color filter of the red pixel, m is a natural number, and λ Ａ and d Ｉ The units are all nm.

[0092] The above descriptions of the color filter layer, inorganic barrier layer, and color conversion layer in the display device of the present invention can be applied to the color filter layer, inorganic barrier layer, and color conversion layer in the wavelength-converting laminate of the present invention. Ａ The descriptions of formulas (1) to (3) in the display device of the present invention can be applied to the above, except that "the maximum emission wavelength of the blue light-emitting diode" in the display device of the present invention is replaced with "the maximum emission wavelength of the light of the blue light-emitting diode." The wavelength conversion laminate of the present invention has a wavelength conversion function that converts the light of a blue light-emitting diode having a maximum emission wavelength in the range of 400 to 500 nm into green and red, and can keep the blue light of the blue light-emitting diode blue. Therefore, it can be suitably used in combination with a blue light-emitting diode having a maximum emission wavelength in the range of 400 to 500 nm, particularly in combination with a display device that uses this blue light-emitting diode as a light source.

[0093] The above has described embodiments that can be applied to the present invention. Such embodiments can be embodied in separate embodiments, or can be realized as embodiments in combination with each other. For example, the display device described in JP 2022-78975 A can also be applied to the present invention, except that the color filter layer and the color conversion layer are adjacent to each other via an inorganic barrier layer, and all of the above formulas (1) to (3) are satisfied.

[0094] Although the present invention has been described with reference to the embodiments shown in the drawings, these are merely illustrative, and those skilled in the art of display devices will recognize that various modifications and equivalent embodiments are possible. Therefore, the true technical scope of the present invention should be determined by the technical spirit of the claims.

[0095] The present invention will be explained in more detail below with reference to examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the examples shown below. Note that room temperature means 25°C.

[0096] [Preparation of wavelength converting laminate] The materials used in the preparation of each wavelength converting laminate unit are shown below. <Color filter for red pixel> C.I. Pigment Red 177 3 parts by mass C.I. Pigment Red 254 4 parts by mass Polysulfonic acid type polymer dispersant 3 parts by mass Curable resin composition A described below 23 parts by mass 3-methoxybutyl acetate 5 parts by mass Hollow silica particle dispersion described below 62 parts by mass <Color filter for green pixel> C.I. Pigment Green 58 7 parts by mass C.I. Pigment Yellow 138 1 part by mass Polysulfonic acid type polymer dispersant 3 parts by mass Curable resin composition A described below 22 parts by mass 3-methoxybutyl acetate 5 parts by mass Hollow silica particle dispersion described below 62 parts by mass <Color filter for blue pixel> C.I. Pigment Blue 15:6 5 parts by weight Polysulfonic acid type polymer dispersant 3 parts by weight Curable resin composition A below 25 parts by weight 3-methoxybutyl acetate 5 parts by weight Particles 62 parts by weight The particles in the color filter of the blue pixel were TiO ２ The particle dispersion or the hollow silica particle dispersion described below was used.

[0097] <Inorganic barrier layer> SiO: silicon monoxide formed by sputtering SiO ２ : Silicon dioxide formed by sputtering method

[0098] <Red color conversion layer> Acrylic resin: the following curable resin composition A R-QD: InP / ZnS quantum dots (fluorescence wavelength 650 nm, manufactured by Sigma-Aldrich) TiO ２ : TiO having an average primary particle size of 200 nm ２(Rutile type) fine particles (manufactured by Ionic Liquids Technologies GmbH) <Green color conversion layer> Acrylic resin: the following curable resin composition A G-QD: InP / ZnS quantum dots (fluorescence wavelength 530 nm, manufactured by Sigma-Aldrich) TiO ２ : TiO having an average primary particle size of 200 nm ２ (Rutile type) fine particles (manufactured by Ionic Liquids Technologies GmbH)

[0099] <Scattering layer> Acrylic resin: the following curable resin composition A TiO ２ : TiO having an average primary particle size of 200 nm ２ (Rutile type) fine particles (manufactured by Ionic Liquids Technologies GmbH)

[0100] (Preparation of Curable Resin Composition A) The following materials were stirred and mixed at room temperature to obtain Curable Resin Composition A. -------------------------------- Composition of Curable Resin Composition A-------------------------------- 16 parts by mass of the following copolymer resin solution (solid content 50%) - 24 parts by mass of dipentaerythritol pentaacrylate (manufactured by Sartomer Corporation, product name: SR399) - 4 parts by mass of orthocresol novolac epoxy resin (manufactured by Yuka Shell Epoxy Co., Ltd., product name: Epicoat 180S70) - 4 parts by mass of 2-methyl-1-(4-methylthiophenyl)-2-morpholino-propan-1-one - 52 parts by mass of diethylene glycol dimethyl ether ----------------------------------

[0101] (Preparation of Copolymer Resin Solution) 63 parts by mass of methyl methacrylate, 12 parts by mass of acrylic acid, 6 parts by mass of 2-hydroxyethyl methacrylate, and 88 parts by mass of diethylene glycol dimethyl ether were charged into a polymerization vessel and stirred to dissolve, after which 7 parts by mass of 2,2'-azobis(2-methylbutyronitrile) was added and uniformly dissolved. The mixture was then stirred at 85°C for 2 hours under a nitrogen stream, and further reacted at 100°C for 1 hour. To the resulting solution, 7 parts by mass of glycidyl methacrylate, 0.4 parts by mass of triethylamine, and 0.2 parts by mass of hydroquinone were added, and the mixture was stirred at 100°C for 5 hours to obtain a copolymer resin solution (solids content 50%).

[0102] (Preparation of Hollow Silica Particle Dispersion) 500 parts by mass of hollow silica particle sol (isopropyl alcohol silica sol, manufactured by Catalysts and Chemical Industries, Ltd., product name: CS60-IPA, average particle size 60 nm, shell thickness 10 nm, silica concentration 20%, refractive index of silica particles 1.31), 30.5 parts by mass of acryloyloxypropyltrimethoxysilane, and 1.51 parts by mass of diisopropoxyaluminum ethyl acetate were mixed, and then 9 parts by mass of ion-exchanged water was added. Next, the resulting solution was reacted at 60°C for 8 hours, cooled to room temperature, and 1.8 parts by mass of acetylacetone was added to obtain a dispersion. Thereafter, solvent replacement was performed by vacuum distillation at a pressure of 30 Torr while adding cyclohexanone so that the silica content remained approximately constant. Finally, the concentration was adjusted to obtain a hollow silica particle dispersion with a solids concentration of 18.2% by mass. The amount of remaining IPA (isopropyl alcohol) in the resulting dispersion was analyzed by gas chromatography and found to be 0.5% or less. (TiO ２ Preparation of particle dispersion) 5 parts by mass of the copolymer resin solution was dissolved in 75 parts by mass of 3-methoxybutyl acetate, and TiO ２ The resulting mixture was dispersed using a media-agitation type mill (product name "4TSG-1 / 8" manufactured by Igarashi Machinery Works, Ltd.) under the following conditions: media: zirconia beads with an outer diameter of 0.3 mm, treatment temperature: 20°C, treatment time: 9 hours, to obtain a TiO2 powder with a solids concentration of 20% by mass. ２ A particle dispersion was obtained.

[0103] (1) Preparation of wavelength conversion laminate units After a 2.5 μm-thick green or red pixel color filter was applied to a glass substrate, a 164 nm-thick inorganic barrier layer was formed by sputtering. A 10 μm-thick color conversion layer was then applied to the inorganic barrier layer. As shown in FIG. 2 below, the color conversion layer QD, the inorganic barrier layer IB, and the green or red pixel color filter CF were stacked in this order to prepare green pixel wavelength conversion laminate units No. 1G and c12G and red pixel wavelength conversion laminate units No. 1R and c12R, each having the configuration shown in Table 1 below. Furthermore, a 2.5 μm-thick blue pixel color filter was applied to a glass substrate, and a 164 nm-thick inorganic barrier layer was then formed by sputtering. Furthermore, a scattering layer having a thickness of 10 μm was coated on the inorganic barrier layer, and as shown in FIG. 3 described below, wavelength conversion laminate units No. 1B, c11B, and c12B for blue pixels were fabricated, in which the scattering layer S, inorganic barrier layer IB, and blue pixel color filter CF were stacked in this order. These units had the configurations shown in Table 1 below. Note that, except for the configurations shown in Table 1 below, the materials constituting the color filter, color conversion layer, and scattering layer were used as described above. Furthermore, for the coating of the color filter, color conversion layer, and scattering layer, the materials constituting the above-described layers were applied to the underlying layer by spin coating, and then dried in an oven at 70°C for 3 minutes. Next, a heat treatment was performed for 15 minutes in an atmosphere at 230°C to form the color filter, color conversion layer, and scattering layer, respectively.

[0104] (2) Configuration of wavelength conversion laminate The inorganic barrier layer is made of SiO or SiO ２ Since the inorganic barrier layer is formed by sputtering, the thickness of the inorganic barrier layer is the same in the wavelength-converting laminates for the green, red, and blue pixels. Therefore, examples of wavelength-converting laminates for the green, red, and blue pixels that are constructed from the wavelength-converting laminate units prepared as described above include wavelength-converting laminates No. 101, c201, and c202, each having the configuration shown in Table 1 below. The wavelength-converting laminates No. 101, c201, and c202 are shown in Table 1 below. ＡA blue LED with a wavelength of 453 nm was used. Ｉ = 2.07) is {(m-1 / 2) × λ in formula (1). Ａ} / 2n Ｉ The value of d may be 55 nm, 164 nm, 274 nm, or 383 nm, and the thickness d of the inorganic barrier layer may be Ｉ = 164 nm, which satisfied the formula (1), and the condition that the reflected blue light components are reinforced by optical interference was satisfied. Ｉ = 1.50) is {(m-1 / 2) × λ in formula (1). Ａ} / 2n Ｉ The value of d is 76 nm, 227 nm, 378 nm, 529 nm, etc., and the thickness d of the inorganic barrier layer Ｉ = 164 nm, the formula (1) was not satisfied, and the condition that the reflected blue light components are reinforced by optical interference was not satisfied.

[0105]

[0106] (Table notes) n Ｉ represents the refractive index of the inorganic barrier layer, and n Ｂ represents the refractive index of the color filter of the blue pixel, and n Ｇ represents the refractive index of the color filter of the green pixel, and n Ｒ represents the refractive index of the color filter of the red pixel, and n Ｓ denotes the refractive index of the scattering layer, and n ＱＧ represents the refractive index of the color conversion layer in the wavelength converting laminate unit of the green pixel, and n ＱＲ indicates the refractive index of the color conversion layer in the wavelength converting laminate unit of the red pixel. Note that each refractive index is a value measured by Method B described in JIS K7142 (2014), and the details are as described above. Ｉ -n Ｇ , n Ｉ -n Ｒ :n Ｉ From n Ｇ minus the value, and n Ｉ From n Ｒ The values ​​obtained by subtracting n are shown. Ｉ -nＢ :n Ｉ From n Ｂ The reflectance values ​​shown are obtained by subtracting the reflectance of blue light in the wavelength range of 440 to 460 nm. The reflectance of green light in the wavelength range of 520 to 550 nm, and the reflectance of red light in the wavelength range of 620 to 660 nm are shown in the B, G, and R columns for reflectance, respectively. The "-" in the G and R columns for reflectance of the wavelength conversion laminate of the blue pixel indicates that no light other than blue light is incident. The reflectance is a value calculated by calculating the influence of thin film interference from the reflectance at each interlayer interface calculated from the refractive index of each layer according to Fresnel's formula and the film thickness of each layer. The Fresnel's formula is described, for example, in "Hecht, Optics I, 5th Edition (Maruzen Publishing)." Thin film interference is described, for example, in "Hecht, Optics II, 5th Edition (Maruzen Publishing)." The color filters, color conversion layers, and scattering layers constituting the wavelength conversion laminates No. 101, c201, and c202 all had thicknesses that did not cause thin film interference. As shown in Figure 2, the reflectances B, G, and R in the red and green pixels refer to the sum of the proportions of light (R2) reflected at the interface between the inorganic barrier layer IB and the color conversion layer QD and light (R1) reflected at the interface between the color filter CF and the inorganic barrier layer IB, all of which account for the light incident from the color conversion layer QD to the inorganic barrier layer IB. Also, as shown in Figure 3, the reflectance B in the blue pixel refers to the sum of the proportions of light (R4) reflected at the interface between the inorganic barrier layer IB and the scattering layer S and light (R3) reflected at the interface between the color filter CF and the inorganic barrier layer IB, all of which account for the light incident from the scattering layer S to the inorganic barrier layer IB. Ｉ The cross section obtained by cutting was observed using a scanning electron microscope S-4800 (trade name, manufactured by Hitachi High-Technologies Corporation), and the average value was measured at five random locations.

[0107] The results in Table 1 above reveal the following: Wavelength converting laminate No. c201 satisfies formula (1), but n Ｉ -n Ｂ The value of n Ｉ -n Ｇ and n Ｉ -n ＲSince the values ​​of n are the same, 0.62, the formulas (2) and (3) are not satisfied, and the reflectance of the blue pixel is high, at 4.1%. In addition, the wavelength converting laminate No. c202 does not satisfy the formula (1), and further, Ｉ -n Ｂ The value of n Ｉ -n Ｇ and n Ｉ -n Ｒ Since the values ​​of n were the same, 0.05, the formulas (2) and (3) were not satisfied, and the reflectance of blue light in the red and green pixels was low at 0.2%. In contrast, wavelength-converting laminate No. 101 satisfied the condition of formula (1), that is, the reflected blue light is constructively interfered by light, and n Ｉ -n Ｂ The value of n Ｉ -n Ｇ and n Ｉ -n Ｒ and thus satisfying formulas (2) and (3), the reflectance of blue light in the blue pixel was kept low at 1.7%, while the reflectance of blue light in the red and green pixels was 4.7%, which was selectively increased compared to the reflectances of red and green light, 3.2% and 1.5%. Thus, the present invention suppresses the reflection of blue light in the blue pixel, while suppressing the reflection of red and green light at the red and green pixels and increasing the reflection of blue light, so that blue light not converted by the color conversion layer can be re-incident on the color conversion layer by interfacial reflection. It is believed that further improvements to the present invention can further suppress the reflection of blue light in the blue pixel while further increasing the reflection of blue light in the red and green pixels, so that blue light not converted by the color conversion layer can be re-incident on the color conversion layer for color conversion again, thereby contributing to improved energy efficiency of OLED display devices.

[0108] This application claims priority based on Japanese Patent Application No. 2023-170301, filed in Japan on September 29, 2023, the contents of which are incorporated herein by reference as part of the present specification.

[0109] 1 QD-OLED display device 100 Substrate 113 Planarization layer 118 Planarization layer 200 Upper substrate 201 Adhesive layer 203 Anti-reflection film 210 Black partition 310 Pixel electrode (anode) 330 Counter electrode (cathode) 410 First inorganic barrier layer 430 Second inorganic barrier layer 440 Adhesive layer 450 Third inorganic barrier layer R-CF Red color filter G-CF Green color filter B-CF Blue color filter B-LED1 First blue light-emitting diode B-LED2 Second blue light-emitting diode B-LED3 Third blue light-emitting diode PR Red pixel PG Green pixel PB Blue pixel QDR Red conversion layer QDG Green conversion layer T1 Driving thin film transistor S Scattering layer R1 Light reflected at the interface between the color filter and the inorganic barrier layer R2 Light reflected at the interface between the inorganic barrier layer and the color conversion layer R3 Light reflected at the interface between the color filter and the inorganic barrier layer R4 Light reflected at the interface between the inorganic barrier layer and the scattering layer CF Color filter IB Inorganic barrier layer QD Color conversion layer

Claims

1. A display device comprising, in this order, a color filter layer, an inorganic barrier layer, a color conversion layer, and a blue light emitting diode having a maximum emission wavelength in the range of 400 to 500 nm, the color filter layer having a color filter for a blue pixel, a color filter for a green pixel, and a color filter for a red pixel, the color filter layer, the inorganic barrier layer, and the color conversion layer being adjacent to one another, and satisfying all of the following formulas (1) to (3): Formula (2) (n Ｉ -n Ｂ ) < (n Ｉ -n Ｇ ) Formula (3) (n Ｉ -n Ｂ ) < (n Ｉ -n Ｒ In the above formula, λ Ａ represents the maximum emission wavelength of the blue light emitting diode, and d Ｉ represents the thickness of the inorganic barrier layer, and n Ｉ represents the refractive index of the inorganic barrier layer, and n Ｂ represents the refractive index of the color filter of the blue pixel, and n Ｇ represents the refractive index of the color filter of the green pixel, and n Ｒ represents the refractive index of the color filter of the red pixel, m is a natural number, and λ Ａ and d Ｉ The unit is nm in all cases.

2. A wavelength-converting laminate for light from a blue light-emitting diode having a maximum emission wavelength in the range of 400 to 500 nm, comprising a color filter layer, an inorganic barrier layer, and a color conversion layer adjacent to each other, the color filter layer comprising a blue pixel color filter, a green pixel color filter, and a red pixel color filter, and satisfying all of the following formulas (1) to (3): Formula (2) (n Ｉ -n Ｂ ) < (n Ｉ -n Ｇ ) Formula (3) (n Ｉ -n Ｂ ) < (n Ｉ -n Ｒ In the above formula, λ Ａ represents the maximum emission wavelength of the blue light emitting diode, and d Ｉ represents the thickness of the inorganic barrier layer, and n Ｉ represents the refractive index of the inorganic barrier layer, and n Ｂ represents the refractive index of the color filter of the blue pixel, and n Ｇ represents the refractive index of the color filter of the green pixel, and n Ｒ represents the refractive index of the color filter of the red pixel, m is a natural number, and λ Ａ and d Ｉ The unit is nm in all cases.

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