Display device

Abstract

To provide a display device capable of extracting light that has passed through a wavelength conversion layer to the outside more efficiently.SOLUTION: A display device includes: a light source which is provided in each of a first pixel and a second pixel, and emits light in a first wavelength; a first wavelength conversion layer which is provided in the first pixel to convert light in the first wavelength into light in a second wavelength; a second wavelength conversion layer which is provided in the second pixel to convert the light in the first wavelength into light in a third wavelength different from the second wavelength; a first color filter which is provided in the first pixel to selectively transmit the light in the second wavelength; a second color filter which is provided in the second pixel to selectively transmit the light in the third wavelength; and a high-refractive-index dielectric. The high-refractive-index dielectrics are a plurality of nano members on which the light in the second wavelength and the light in the third wavelength are incident. The plurality of nano members are arranged in the first pixel in a first cycle and in the second pixel in a second cycle different from the first cycle.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a display device.

Background Art

[0002] In recent years, the development of display devices having a wavelength conversion layer has been advanced. In such a display device, the wavelength of light emitted from a light source is converted by the wavelength conversion layer and taken out to the outside.

[0003] In addition, a method of enhancing the utilization efficiency of light by using a plurality of nanostructures has been proposed (for example, Patent Document 1, Non-Patent Document 1, etc.).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Non-Patent Documents

[0005]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In a display device having a wavelength conversion layer, it is desirable to more efficiently extract the light transmitted through the wavelength conversion layer to the outside.

[0007] The present invention has been made in view of the above circumstances, and an object thereof is to provide a display device capable of more efficiently extracting the light transmitted through the wavelength conversion layer to the outside.

Means for Solving the Problem

[0008] The above problem is achieved by any one of the following means (1) to (18).

[0009] (1) A light source provided for each of the first pixel and the second pixel, which emits light of a first wavelength; a first wavelength conversion layer provided in the first pixel, which converts the light of the first wavelength into light of a second wavelength; a second wavelength conversion layer provided in the second pixel, which converts the light of the first wavelength into light of a third wavelength different from the second wavelength; a first color filter provided in the first pixel, which selectively transmits the light of the second wavelength; a second color filter provided in the second pixel, which selectively transmits the light of the third wavelength; and at least a high refractive index dielectric, wherein the high refractive index dielectric is a plurality of nano members into which the light of the second wavelength and the light of the third wavelength are incident, and the plurality of nano members are arranged in the first pixel with a first period and in the second pixel with a second period different from the first period. A display device.

[0010] (2) The display device according to (1) above, further having an overcoat layer provided between the first color filter and the first wavelength conversion layer and between the second color filter and the second wavelength conversion layer, and the plurality of nano members are provided between the overcoat layer and each of the first wavelength conversion layer and the second wavelength conversion layer.

[0011] (3) The display device according to (1) or (2) above, wherein the light source is further provided in a third pixel, and the plurality of nano members are further arranged in the third pixel with a third period different from the first period and the second period.

[0012] (4) The display device according to (3) above, wherein the light of the second wavelength is light in the red wavelength range, and the light of the third wavelength is light in the green wavelength range.

[0013] (5) The display device according to (4) above, wherein the first period is longer than the second period, and the second period is longer than the third period.

[0014] (6) The display device according to (4) or (5) above, wherein the first period is 500 nm or more and 700 nm or less, the second period is 450 nm or more and 500 nm or less, and the third period is 350 nm or more and 430 nm or less.

[0015] (7) The display device according to any one of (1) to (6) above, wherein the plurality of nano-members arranged in the first period resonate with light of the second wavelength, and the plurality of nano-members arranged in the second period resonate with light of the third wavelength.

[0016] (8) The display device according to any one of (1) to (7) above, wherein the high refractive index dielectric has a refractive index of 2.0 or more.

[0017] (9) The display device according to any one of (1) to (8) above, wherein the high refractive index dielectric contains at least one of titanium oxide (TiO2) and silicon (Si).

[0018] (10) The display device according to any one of (1) to (9) above, wherein the plurality of nano-members have a shape of a column, a cone, a hemisphere, or a cap.

[0019] (11) The display device according to any one of (1) to (10) above, wherein each of the first wavelength conversion layer and the second wavelength conversion layer contains a plurality of nano-particles.

[0020] (12) The display device according to (11) above, wherein each of the plurality of nano-particles contains at least one of silver (Ag) and aluminum (Al).

[0021] (13) The display device according to any one of (1) to (12) above, wherein the light source includes a micro LED (Light Emitting Diode).

[0022] The display device according to any one of (1) to (13) above, wherein the light of the first wavelength is light in the blue wavelength range.

[0023] (15) The display device according to any one of (1) to (14) above, wherein each of the first wavelength conversion layer and the second wavelength conversion layer contains at least one of a quantum dot and a phosphor.

[0024] (16) The display device according to (1) above, further comprising an overcoat layer provided between the first color filter and the first wavelength conversion layer and between the second color filter and the second wavelength conversion layer, and a transparent substrate facing the overcoat layer with the first color filter and the second color filter therebetween, wherein the plurality of nano members are provided between the transparent substrate and the first color filter and the second color filter.

[0025] (17) The display device according to (2) or (16) above, wherein the overcoat layer has a refractive index of 1.3 or less.

[0026] (18) The display device according to any one of (1) to (17) above, further comprising a first dichroic filter provided between the first wavelength conversion layer and the first color filter and transmitting the light of the second wavelength and reflecting the light of the first wavelength, and a second dichroic filter provided between the second wavelength conversion layer and the second color filter and transmitting the light of the third wavelength and reflecting the light of the first wavelength.

Advantages of the Invention

[0027] In the display device according to an embodiment of the present invention, a plurality of nano members are arranged in the first pixel at the first period, and a plurality of nano members are arranged in the second pixel at the second period. In other words, a plurality of nano members are arranged at a period corresponding to each of the light of the second wavelength and the light of the third wavelength. Therefore, it becomes possible to efficiently extract each of the light of the second wavelength and the light of the third wavelength from the display device. Thus, it becomes possible to more efficiently extract the light transmitted through the wavelength conversion layer to the outside.

Brief Description of the Drawings

[0028]

Figure 1

Figure 2A

Figure 2B

Figure 3A

Figure 3B

Figure 3C

Figure 3D

Figure 4A

Figure 4B

Figure 5A

Figure 5B

Figure 6A

Figure 6B

Figure 7

Figure 8

Modes for Carrying Out the Invention

[0029] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. In the following drawings, the same reference numerals denote the same components, and in the drawings, the sizes of the respective components may be exaggerated for clarity and convenience of explanation. On the other hand, the embodiments described below are merely exemplary, and various modifications are possible from such embodiments.

[0030] In the following, the terms "upper part" and "above" include not only those in direct contact and directly above, but also those not in contact and above. Similarly, the terms "lower part" and "below" include not only those in direct contact and directly below, but also those not in contact and below.

[0031] Singular expressions include plural expressions unless the context clearly indicates otherwise. Also, when a part "includes", "comprises", or "has" a certain component, it means that, unless otherwise specified to the contrary, it does not exclude other components and may further include other components.

[0032] Regarding the steps constituting a method, if the order is clearly described or there is no contrary description, the steps are executed in an appropriate order. It is not necessarily limited to the described order of the steps. The use of all examples or exemplary terms is merely for explaining the technical idea, and unless limited by the claims, the scope is not limited by the said examples or exemplary terms.

[0033] In the following description, when ordinal numbers such as "first" and "second" are used for explanation, unless otherwise specified, they are used for convenience and do not define any order.

[0034] [First Embodiment] FIG. 1 shows an example of a cross-sectional configuration of a display device (display device 100) according to the first embodiment. The display device 100 has, for example, a first structure 110, a second structure 120, and a bonding portion 130. In the display device 100, for example, the second structure 120 and the first structure 110 are laminated, and the bonding portion 130 is provided therebetween. The second structure 120 includes a light source 122. The light emitted from the light source 122 passes through the bonding portion 130 and the first structure 110 in this order, and is taken out to the outside of the display device 100. The light source 122 emits light in a blue wavelength range (for example, 430 nm to 495 nm). The light source 122 may emit light in other wavelength ranges such as ultraviolet light.

[0035] In this display device 100, a plurality of red pixels 10r, a plurality of green pixels 10g, and a plurality of blue pixels 10b are arranged in a matrix. Light in a red wavelength range (for example, 600 nm to 750 nm) is taken out from the red pixel 10r, light in a green wavelength range (for example, 495 nm to 570 nm) is taken out from the green pixel 10g, and light in a blue wavelength range is taken out from the blue pixel 10b. In the following description, the stacking direction of the second structure 120 and the first structure 110 may be referred to as the Z direction, and the arrangement directions of the red pixel 10r, the green pixel 10g, and the blue pixel 10b may be referred to as the X direction and the Y direction.

[0036] <Configuration of Display Device 100> (First Structure 110) The first structure 110 includes, for example, a transparent substrate 111, a light shielding matrix 112, a color filter 113, an overcoat layer 114, a nano member 115 that is a high refractive index dielectric, a partition wall 116, a color conversion layer 117, and a transparent layer 118. The color filter 113 includes, for example, a red color filter 113r, a green color filter 113g, and a blue color filter 113b. The color conversion layer 117 includes, for example, a red conversion layer 117r and a green conversion layer 117g.

[0037] In the red pixel 10r, along the Z direction, a transparent substrate 111, a red color filter 113r, an overcoat layer 114, a nano member 115, and a red conversion layer 117r are arranged in this order. In the green pixel 10g, along the Z direction, a transparent substrate 111, a green color filter 113g, an overcoat layer 114, a nano member 115, and a green conversion layer 117g are arranged in this order. In the blue pixel 10b, along the Z direction, a transparent substrate 111, a blue color filter 113b, an overcoat layer 114, a nano member 115, and a transparent layer 118 are arranged in this order.

[0038] The transparent substrate 111 is, for example, a plate-like member having a rectangular planar (XY plane) shape. The transparent substrate 111 has light transmissivity. The transparent substrate 111 contains, for example, a glass material or a resin material or the like. The resin material is, for example, polyimide or the like. The transparent substrate 111 may have flexibility.

[0039] The light-shielding matrix 112 is a so-called black matrix. The light-shielding matrix 112 is provided, for example, between one main surface of the transparent substrate 111 and the overcoat layer 114 together with the color filter 113. The light-shielding matrix 112 plays a role of preventing color mixing of light emitted from each of the red pixel 10r, the green pixel 10g, and the blue pixel 10b. The light-shielding matrix 112 is provided, for example, between the red color filter 113r and the green color filter 113g, between the green color filter 113g and the blue color filter 113b, and between the blue color filter 113b and the red color filter 113r. The end of the light-shielding matrix 112 may overlap with the end of the color filter 113. The light-shielding matrix 112 is composed of a light-shielding material that can be patterned.

[0040] The color filter 113 selectively transmits light in a predetermined wavelength range. The red color filter 113r selectively transmits light in the red wavelength range. The green color filter 113g selectively transmits light in the green wavelength range. The blue color filter 113b selectively transmits light in the blue wavelength range. By providing such a color filter 113, the color purity of the light extracted from each of the red pixel 10r, the green pixel 10g, and the blue pixel 10b can be enhanced. The color filter 113 contains, for example, a resin material.

[0041] The overcoat layer 114 is provided between the color filter 113 and the nano member 115, and between the light-shielding matrix 112 and the partition wall 116. This overcoat layer 114 serves to planarize the main surface side of the transparent substrate 111 on which the light-shielding matrix 112 and the color filter 113 are provided, and also plays a role in protecting the color filter 113. The overcoat layer 114 contains, for example, a photosensitive acrylic resin. The refractive index of the overcoat layer 114 is, for example, about 1.5.

[0042] A plurality of nano members 115 are provided in each of the red pixel 10r, the green pixel 10g, and the blue pixel 10b. In the red pixel 10r, a plurality of nano members 115 are provided between the red color filter 113r and the red conversion layer 117r. In the green pixel 10g, a plurality of nano members 115 are provided between the green color filter 113g and the green conversion layer 117g. In the blue pixel 10b, a plurality of nano members 115 are provided between the blue color filter 113b and the transparent layer 118.

[0043] The nano member 115 contains a high refractive index dielectric. The high refractive index dielectric is, for example, a substance having a refractive index of 2.0 or more. The high refractive index dielectric is, for example, titanium oxide (TiO2), zinc oxide (ZnO), zirconium oxide (ZrO2), silicon (Si), or the like. For example, the refractive index at a wavelength of 600 nm is 2.5 for titanium oxide, 2.0 for zinc oxide, 2.1 for zirconium oxide, and 4.2 for silicon. The nano member 115 preferably contains at least one of titanium oxide and silicon. The nano member 115 includes, for example, a resin material and nano particles of a high refractive index dielectric dispersed in the resin material. The nano member 115 may be composed of a high refractive index dielectric.

[0044] FIG. 2A and FIG. 2B show an example of the configuration of a plurality of nano members 115 provided in the red pixel 10r together with the red conversion layer 117r. FIG. 2A shows an example of the arrangement of a plurality of nano members 115 in the XY plane, and FIG. 2B shows a cross-sectional configuration along the line B-B shown in FIG. 2A.

[0045] The nano member 115 has, for example, a cylindrical shape. The height direction of this cylinder is arranged parallel to the Z direction. The diameter D of this nano member 115 is, for example, 300 nm to 450 nm in the red pixel 10r, 250 nm to 350 nm in the green pixel 10g, and 200 nm to 300 nm in the blue pixel 10b. The height H of the nano member 115 is 150 nm to 300 nm. The plurality of nano members 115 are regularly arranged in the red pixel 10r, the green pixel 10g, and the blue pixel 10b, respectively. In the red pixel 10r, the green pixel 10g, and the blue pixel 10b, for example, a plurality of nano members 115 are arranged in a triangular lattice.

[0046] When light with a wavelength in the visible region is incident on such a plurality of nano - members 115, Mie resonance occurs, and optical localization occurs in the vicinity of each nano - member 115. The localized light is diffracted by the periodic arrangement of the nano - members 115 and then emitted. Therefore, the traveling direction of light can be changed by the plurality of nano - members 115. Specifically, the relationship between the incident light and the diffracted light in the plurality of nano - members 115 is represented by the following formula (1).

[0047] [Number]

[0048] [Number]

[0049] In this embodiment, the arrangement period of the plurality of nano - members 115 is different among the red pixel 10r, the green pixel 10g, and the blue pixel 10b. In other words, the period of the plurality of nano - members 115 can be adjusted according to the wavelength of the light extracted from each of the red pixel 10r, the green pixel 10g, and the blue pixel 10b. The plurality of nano - members 115 are arranged, for example, with a period Pr for the red pixel 10r, a period Pg for the green pixel 10g, and a period Pb for the blue pixel 10b, respectively.

[0050] The lattice - coupled resonance occurs in the light in the red - wavelength region due to the plurality of nano - members 115 arranged with the period Pr. The lattice - coupled resonance occurs in the light in the green - wavelength region due to the plurality of nano - members 115 arranged with the period Pg. The lattice - coupled resonance occurs in the light in the blue - wavelength region due to the plurality of nano - members 115 arranged with the period Pb. Due to this lattice - coupled resonance, optical localization occurs in the vicinity of each of the plurality of nano - members 115, and the directivity of the light extracted from each of the red pixel 10r, the green pixel 10g, and the blue pixel 10b is enhanced. Although details will be described later, this makes it possible to efficiently extract the light in each of the red - wavelength region, the green - wavelength region, and the blue - wavelength region from the display device 100 to the outside.

[0051] For example, the longer the wavelength of the light extracted from the pixel, the longer the period of the plurality of nano-members 115. For example, the period Pr is longer than the period Pg, and the period Pg is longer than the period Pb. That is, the periods Pr, Pg, and Pb satisfy the following formula (2).

[0052] [Number]

[0053] The period Pr is, for example, 500 nm or more and 700 nm or less, the period Pg is, for example, 450 nm or more and 500 nm or less, and the period Pb is, for example, 350 nm or more and 430 nm or less.

[0054] The periods Pr, Pg, and Pb of the nano-member 115 and the resonance wavelength (scattering wavelength) by the nano-member 115 have, for example, the following relationship. At this time, the diameter D of the cylindrical nano-member 115 is 400 nm, the height H is 300 nm, and the nano-member 115 is arranged in a triangular lattice. The nano-member 115 contains silicon. For example, when the period Pr is 550 nm, 580 nm, or 600 nm, the resonance wavelength of the nano-member 115 is 600 nm, 630 nm, or 650 nm. When the period Pg is 450 nm, 480 nm, or 500 nm, the resonance wavelength of the nano-member 115 is 500 nm, 530 nm, or 550 nm. When the period Pb is 350 nm, 400 nm, or 430 nm, the resonance wavelength of the nano-member 115 is 400 nm, 430 nm, or 480 nm.

[0055] FIG. 3A, FIG. 3B, FIG. 3C, and FIG. 3D illustrate other examples of the nano member 115 shown in FIG. 2B. The nano member 115 may have a hemispherical shape (FIGS. 3A and 3D). At this time, the flat surface of the hemisphere may be arranged facing the red conversion layer 117r (FIG. 3A), or the spherical surface of the hemisphere may be arranged facing the red conversion layer 117r (FIG. 3B). The nano member 115 may have a cap shape (FIG. 3B). Alternatively, the nano member 115 may have a conical shape such as a cone, a triangular pyramid, and a quadrangular pyramid. The nano member 115 may have a columnar shape other than a cylinder, for example, a shape such as a triangular prism and a quadrangular prism (not shown).

[0056] The partition wall 116 partitions the red pixel 10r, the green pixel 10g, and the blue pixel 10b. The height (size in the Z direction) of the partition wall 116 is substantially the same as the thicknesses of the red conversion layer 117r, the green conversion layer 117g, and the transparent layer 118. The height of the partition wall 116 is, for example, 5 μm or more and 50 μm or less. The partition wall 116 preferably has a light reflection characteristic with respect to the light in the wavelength range emitted from the light source 122 and the light in the wavelength range converted by the red conversion layer 117r and the green conversion layer 117g. Thereby, the light directly from the light source 122 or the light transmitted through the red conversion layer 117r and the green conversion layer 117g from the light source 122 and directed toward the partition wall 116 is reflected by the partition wall 116. Therefore, the utilization efficiency of the light emitted from the light source 122 is increased, and it is possible to improve the light extraction efficiency. The partition wall 116 contains, for example, a white pigment and a resin material. As the resin material, for example, a photosensitive resin material such as an acrylic resin, an epoxy resin, a silicone resin, and a polyimide resin can be preferably used.

[0057] The color conversion layers 117 provided in the red pixel 10r and the green pixel 10g convert the wavelength of the light incident from the second structure 120 side and transmit it to the plurality of nano member 115 sides.

[0058] FIG. 4A shows an example of the configuration of the red conversion layer 117r, and FIG. 4B shows an example of the configuration of the green conversion layer 117g. The red conversion layer 117r provided in the red pixel 10r includes, for example, a wavelength conversion material 1171r, nanoparticles 1172, and a binder 1173. The green conversion layer 117g provided in the green pixel 10g includes, for example, a wavelength conversion material 1171g, nanoparticles 1172, and a binder 1173.

[0059] The wavelength conversion materials 1171r and 1171g are, for example, phosphors or quantum dots. In other words, the red conversion layer 117r and the green conversion layer 117g include at least one of a phosphor and a quantum dot. The wavelength conversion material 1171r converts the wavelength of the light emitted from the light source 122 into the red wavelength range. The wavelength conversion material 1171g converts the wavelength of the light emitted from the light source 122 into the green wavelength range.

[0060] In the red conversion layer 117r and the green conversion layer 117g, a plurality of nanoparticles 1172 are dispersed in the binder 1173. The nanoparticles 1172 are configured to be able to absorb plasmons of the light emitted from the light source 122. The nanoparticles 1172 include, for example, a metal material. The nanoparticles 1172 preferably include at least one of silver (Ag) and aluminum (Al). The nanoparticles 1172 have, for example, a spherical shape. The particle size (diameter) of the nanoparticles 1172 is, for example, 60 nm or more and 100 nm or less. For example, the resonance wavelength of the nanoparticles 1172 overlaps with the wavelength of the light emitted from the light source 122. For example, in the case of the nanoparticles 1172 containing silver and having a spherical shape, when the particle size is 60 nm, the resonance wavelength (absorption wavelength) is 410 nm, when the particle size is 70 nm, the resonance wavelength is 430 nm, when the particle size is 80 nm, the resonance wavelength is 450 nm, when the particle size is 90 nm, the resonance wavelength is 470 nm, and when the particle size is 100 nm, the resonance wavelength is 490 nm.

[0061] In the red conversion layer 117r and the green conversion layer 117g containing such nanoparticles 1172, the wavelength conversion efficiency of the light emitted from the light source 122 can be improved. Specifically, when the light emitted from the light source 122 is incident on the red conversion layer 117r and the green conversion layer 117g, this light is plasmon-absorbed by the nanoparticles 1172, and an enhanced electric field is generated. By the action of this enhanced electric field on the wavelength conversion materials 1171r, 1171g, the wavelength of the light emitted from the light source 122 can be converted more efficiently. That is, it becomes possible to more efficiently extract light in the red wavelength range and light in the green wavelength range from the red conversion layer 117r and the green conversion layer 117g.

[0062] The binder in which the wavelength conversion materials 1171r, 1171g and the nanoparticles 1172 are dispersed contains a resin material such as a silicone-based resin, an epoxy-based resin or an acrylic-based resin.

[0063] The transparent layer 118 provided in the blue pixel 10b has a high transmittance and transmits the light emitted from the light source 122 to the transparent substrate 111 side. The transparent layer 118 transmits the light emitted from the light source 122 with a transmittance of, for example, 70% or more. The transparent layer 118 contains, for example, a resin material.

[0064] (Second structure 120) The second structure 120 includes, for example, a TFT (Thin Film Transistor) substrate 121, a light source 122 and an anisotropic conductive film 123.

[0065] The TFT substrate 121 is arranged to face the transparent substrate 111 in the Z direction. This TFT substrate 121 is a substrate for driving the light source 122 and includes, for example, a base material, a wiring layer provided on the base material, and a TFT. The wiring layer may have other driving elements instead of the TFT. Alternatively, the display device 100 may be driven in a passive matrix.

[0066] On the TFT substrate 121, a plurality of light sources 122 are provided. The light sources 122 are provided for each of the red pixel 10r, the green pixel 10g, and the blue pixel 10b. The light source 122 includes, for example, a micro LED. This light source 122 has, for example, a rectangular planar (XY plane) shape. The size of one side of this rectangle is, for example, 1 μm or more and 100 μm or less. The light source 122 has a three-dimensional shape such as a substantially rectangular parallelepiped or a substantially cube. The light source 122 includes, for example, a gallium nitride (GaN)-based semiconductor material and emits light in the ultraviolet to blue wavelength range. The anisotropic conductive film 123 is provided on the TFT substrate 121 together with the plurality of light sources 122.

[0067] (Joint portion 130) The joint portion 130 provided between the first structure 110 and the second structure 120 joins the first structure 110 and the second structure 120. The thickness (size in the Z direction) of the joint portion 130 is, for example, 5 μm or less. The joint portion 130 includes an adhesive or an adhesive agent, etc. The joint portion 130 preferably includes, for example, a transparent epoxy resin and a silicone resin, etc.

[0068] <Manufacturing method of the display device 100> Next, the manufacturing method of the display device 100 will be described.

[0069] The first structure 110 is manufactured, for example, as follows. First, a light-shielding matrix 112 and a color filter 113 are formed on the transparent substrate 111 in this order. In the formation of the color filter 113, a red color filter 113r is formed for the red pixel 10r, a green color filter 113g is formed for the green pixel 10g, and a blue color filter 113b is formed for the blue pixel 10b. Subsequently, an overcoat layer 114 is formed on the transparent substrate 111 so as to cover the light-shielding matrix 112 and the color filter 113.

[0070] Next, a plurality of nano members 115 are formed on the overcoat layer 114.

[0071] FIG. 5A and FIG. 5B illustrate an example of a method for forming a plurality of nano-members 115. The plurality of nano-members 115 can be formed, for example, as follows. First, a resin 1151 containing nano-particles 1152 is applied onto an overcoat layer 114 (FIG. 5A). The resin 1151 includes, for example, a light-transmissive UV (Ultraviolet) resin. The nano-particles 1152 are composed of, for example, titanium oxide or silicon nano-particles. Thereafter, a plurality of nano-members 115 are formed using a nanoimprint method (FIG. 5B). Specifically, a nanoimprint mold 200 having a predetermined pattern is provided on the resin 1151 containing the nano-particles 1152, and ultraviolet light Luv is irradiated. At this time, a plurality of nano-members 115 are formed for the red pixel 10r with a period Pr, for the green pixel 10g with a period Pg, and for the blue pixel 10b with a period Pb, respectively.

[0072] Subsequently, a partition wall 116 is formed on the overcoat layer 114 using a photolithography process. Next, a color conversion layer 117 and a transparent layer 118 are formed in a region surrounded by the partition wall 116. Thereby, the first structure 110 is formed.

[0073] The second structure 120 is manufactured, for example, as follows. First, a TFT substrate 121 is formed. Thereafter, a light source 122 and an anisotropic conductive film 123 are formed on the TFT substrate 121.

[0074] After the first structure 110 and the second structure 120 are formed, the first structure 110 and the second structure 120 are joined as follows. First, a joining material that becomes a joining portion 130 is applied onto the second structure 120. Next, the first structure 110 is positioned and overlapped on the surface of the second structure 120 onto which the joining material is applied. Subsequently, under reduced pressure, the first structure 110 and the second structure 120 are pressed in a direction to bring them closer. Thereafter, energy such as heat or ultraviolet light is applied to the joining material to cure it, thereby forming the joining portion 130. For example, a display device 100 for full-color display can be manufactured in this way.

[0075] <Operation and effect of display device 100> In this display device 100, for example, light in the blue wavelength range is emitted from light sources 122 provided for each of the red pixel 10r, green pixel 10g, and blue pixel 10b, and passes through the joint portion 130. In the red pixel 10r, the light that has passed through the joint portion 130 enters the red conversion layer 117r and is converted into light in the red wavelength range. This light in the red wavelength range is diffracted by a plurality of nano-members 115 arranged at a period Pr, and passes through the overcoat layer 114, the red color filter 113r, and the transparent substrate 111 in this order. In the green pixel 10g, the light that has passed through the joint portion 130 enters the green conversion layer 117g and is converted into light in the green wavelength range. This light in the green wavelength range is diffracted by a plurality of nano-members 115 arranged at a period Pg, and passes through the overcoat layer 114, the green color filter 113g, and the transparent substrate 111 in this order. In the blue pixel 10b, the light emitted from the light source 122 passes through the joint portion 130 and the transparent layer 118, and then is diffracted by a plurality of nano-members 115 arranged at a period Pb. After that, this diffracted light passes through the overcoat layer 114, the blue color filter 113b, and the transparent substrate 111 in this order.

[0076] In the display device 100 of the present embodiment, a plurality of nano-members 115 are arranged in the red pixel 10r, green pixel 10g, and blue pixel 10b at different periods (periods Pr, Pg, Pb) from each other. In other words, nano-members 115 with periods Pr, Pg, Pb are arranged in accordance with the light in each of the red wavelength range, green wavelength range, and blue wavelength range. Therefore, it becomes possible to efficiently extract the light in each of the red wavelength range, green wavelength range, and blue wavelength range from the display device 100 to the outside. Hereinafter, this operation and effect will be described using a comparative example.

[0077] FIG. 6A shows the configuration of the main part of the display device 1000 according to the comparative example, and FIG. 6B shows the configuration of the main part of the display device 100 according to the present embodiment. In the display device 1000 according to the comparative example, no nano member (for example, the nano member 115 in FIG. 1) is provided. In such a display device 1000, since the light Lr from the red conversion layer 117r travels isotropically, when taken out from the transparent substrate, loss of the light Lr due to Fresnel reflection is likely to occur. For example, the light Lr incident on the transparent substrate at an angle of 41.8 degrees or more is totally reflected and cannot be taken out to the outside of the display device 1000. The same applies to the light from the green conversion layer and the transparent layer.

[0078] On the other hand, since the display device 100 is provided with a plurality of nano members 115, optical localization due to Mie resonance occurs in the vicinity of the nano member 115 in the light Lr from the red conversion layer 117r. Similarly, optical localization occurs in the vicinity of the nano member 115 in the light from the green conversion layer 117g and the light from the transparent layer 118. Thereby, the traveling direction of the light changes. As shown in the above formula (1), the wave number vector of the diffracted light is represented using the lattice vector. This lattice vector depends on the arrangement period of the nano members 115.

[0079] The plurality of nano members 115 arranged at the period Pr in the red pixel 10r improve the directivity of the light in the red wavelength region. The plurality of nano members 115 arranged at the period Pg in the green pixel 10g improve the directivity of the light in the green wavelength region. The plurality of nano members 115 arranged at the period Pb in the blue pixel 10b improve the directivity of the light in the blue wavelength region. Therefore, the directivity of the light in each wavelength region taken out from each of the red pixel 10r, the green pixel 10g, and the blue pixel 10b is improved, and the loss of light due to Fresnel reflection can be suppressed. Thus, in the display device 100, it is possible to more efficiently take out the light transmitted through each of the red conversion layer 117r, the green conversion layer 117g, and the transparent layer 118 to the outside. For example, compared with the display device 1000, light with an intensity about 2.8 times that of the red pixel 10r and the green pixel 10g and about 2.0 times that of the blue pixel 10b can be taken out.

[0080] In the display device 100, since the red conversion layer 117r and the green conversion layer 117g each contain a plurality of nanoparticles 1172, the light emitted from the light source 122 can be more efficiently converted into light in the red wavelength range and light in the green wavelength range. For example, compared with a red conversion layer and a green conversion layer that do not contain nanoparticles, light with about 1.4 times the intensity can be extracted. Furthermore, since the red conversion layer 117r and the green conversion layer 117g each contain a plurality of nanoparticles 1172, wavelength conversion can be efficiently performed even when the concentrations of the wavelength conversion materials 1171r and 1171g are lowered. Therefore, the cost can be further reduced.

[0081] Hereinafter, other embodiments and modifications of the display device 100 described in the first embodiment will be described. In the following, in order to avoid duplication of description, detailed description of configurations similar to those of the display device 100 described in the first embodiment will be omitted.

[0082] [Second Embodiment] FIG. 7 shows an example of the configuration of the red pixel 10r of the display device 100A according to the second embodiment. In the red pixel 10r of the display device 100A, a plurality of nano members 115 are provided between the transparent substrate 111 and the red color filter 113r. Except for this point, the display device 100A has the same configuration as the display device 100 of the first embodiment.

[0083] A plurality of nano members 115 arranged at a period Pr are provided between the transparent substrate 111 and the red color filter 113r. A plurality of nano members 115 arranged at a period Pg are provided between the transparent substrate 111 and the green color filter 113g (not shown). A plurality of nano members 115 arranged at a period Pb are provided between the transparent substrate 111 and the blue color filter 113b (not shown).

[0084] This display device 100A is formed, for example, as follows. First, amorphous silicon (a-Si) is deposited on a transparent substrate 111 using a CVD (Chemical Vapor Deposition) method at 200°C or lower. Next, the amorphous silicon is heated and melted using an excimer laser to form a low-temperature polysilicon (p-Si) film. Subsequently, a resist film is applied on this low-temperature polysilicon film, and then electron beam lithography and lift-off are performed to pattern the low-temperature polysilicon film. As a result, a plurality of nano-members 115 are formed on the transparent substrate 111.

[0085] Next, a color filter 113 and an overcoat layer 114 are formed on the transparent substrate 111 in this order so as to cover the plurality of nano-members 115. After this, a red conversion layer 117r, a green conversion layer 117g, and a transparent layer 118 are formed on the overcoat layer 114. As a result, the first structure 110 is formed. Finally, the display device 100A can be manufactured by bonding this first structure 110 and a second structure 120 (see FIG. 1).

[0086] In the red pixel 10r of this display device 100A, the light in the red wavelength range that has passed through the red conversion layer 117r is diffracted by the plurality of nano-members 115 arranged at a period Pr after passing through the overcoat layer 114 and the red color filter 113r. This diffracted light passes through the transparent substrate 111. The same applies to the green pixel 10g and the blue pixel 10b.

[0087] In the display device 100A according to the second embodiment as well, a plurality of nano-members 115 are arranged in the red pixel 10r, the green pixel 10g, and the blue pixel 10b at mutually different periods (periods Pr, Pg, Pb). Therefore, similar to what was described in the first embodiment above, it is possible to efficiently extract the light in each of the red wavelength range, the green wavelength range, and the blue wavelength range from the display device 100A to the outside.

[0088] In addition, in this display device 100A, since a plurality of nano members 115 are formed on the transparent substrate 111, the temperature used when forming the plurality of nano members 115 is allowed up to the heat-resistant temperature of the transparent substrate 111. Therefore, the degree of freedom in the method for forming the plurality of nano members 115 is improved. Further, since the transparent substrate 111 has high flatness, it becomes possible to form the plurality of nano members 115 with a more accurate period (periods Pr, Pg, Pb).

[0089] [Modification Example 1] FIG. 8 shows an example of the configuration of the red pixel 10r of the display device 100A according to Modification Example 1. The red pixel 10r of this display device 100A has a dichroic filter 119r between the red conversion layer 117r and the red color filter 113r. Except for this point, the display device 100A according to Modification Example 1 has the same configuration as the display device 100A of the above-described second embodiment.

[0090] The dichroic filter 119r transmits light in the red wavelength range and reflects light in the blue wavelength range. Thereby, the light (light in the blue wavelength range) that was not wavelength-converted by the red conversion layer 117r is reflected by the dichroic filter 119r and enters the red conversion layer 117r again.

[0091] The green pixel 10g of the display device 100A may have a dichroic filter between the green conversion layer 117g and the green color filter 113g (not shown). This dichroic filter transmits light in the green wavelength range and reflects light in the blue wavelength range. Thereby, the light (light in the blue wavelength range) that was not wavelength-converted by the green conversion layer 117g is reflected by the dichroic filter and enters the green conversion layer 117g again.

[0092] The display device 100A may have an overcoat layer (for example, the overcoat layer 114 in FIG. 7) between the dichroic filter 119r and the red conversion layer 117r.

[0093] In the display device 100A according to Modification 1 as well, a plurality of nano - members 115 are arranged in the red pixels 10r, green pixels 10g, and blue pixels 10b at mutually different periods (periods Pr, Pg, Pb). Therefore, similar to what was described in the first embodiment, it is possible to efficiently extract light in each of the red wavelength range, green wavelength range, and blue wavelength range from the display device 100A to the outside.

[0094] Also, since this display device 100A has a dichroic filter (for example, the dichroic filter 119r in FIG. 8), it is possible to more efficiently convert light in the blue wavelength range into light in the red wavelength range and light in the green wavelength range.

[0095] [Modification 2] The display device 100A according to Modification 2 has an over - coat layer 114 with a low refractive index (not shown). The refractive index of this over - coat layer 114 is, for example, 1.0 or more and 1.3 or less. Except for this point, the display device 100A according to Modification 1 has the same configuration as the display device 100A of the second embodiment.

[0096] In this display device 100A, light (light in the blue wavelength range) that has not been wavelength - converted by the red conversion layer 117r and the green conversion layer 117g is likely to be reflected between the red conversion layer 117r and the green conversion layer 117g and the over - coat layer 114. This reflected light is incident on the red conversion layer 117r and the green conversion layer 117g again.

[0097] In the display device 100A according to Modification 2 as well, a plurality of nano - members 115 are arranged in the red pixels 10r, green pixels 10g, and blue pixels 10b at mutually different periods (periods Pr, Pg, Pb). Therefore, similar to what was described in the first embodiment, it is possible to efficiently extract light in each of the red wavelength range, green wavelength range, and blue wavelength range from the display device 100A to the outside.

[0098] In addition, since this display device 100A has an overcoat layer 114 with a low refractive index, it is possible to more efficiently convert light in the blue wavelength range into light in the red wavelength range and light in the green wavelength range.

[0099] The configuration of the display device 100 described above has described the main configuration in explaining the features of the above-described embodiments and modified examples, and is not limited to the above-described configuration, and various modifications can be made within the scope of the claims. Also, it does not exclude the configurations provided in general display devices.

[0100] For example, in the above-described embodiments and the like, an example in which the red conversion layer 117r and the green conversion layer 117g contain the nanoparticles 1172 has been described, but the red conversion layer 117r and the green conversion layer 117g may not contain nanoparticles. One of the red conversion layer 117r and the green conversion layer 117g may not contain nanoparticles.

[0101] Also, in the above-described embodiments and the like, the case where the light source 122 emits light in the ultraviolet to blue wavelength range has been described, but the light source 122 may emit light in other wavelength ranges. Alternatively, light sources 122 that emit light in different wavelength ranges may be provided for the red pixel 10r, the green pixel 10g, and the blue pixel 10b.

[0102] Also, in the above-described embodiments and the like, an example in which the light source 122 includes a micro LED has been described, but the light source 122 may include other light-emitting elements. For example, the light source 122 may include an LED or an OLED (Organic Light Emitting Diode), etc. The display device 100 may include a liquid crystal display element.

[0103] Also, in the above-described embodiments and the like, the plurality of nano members 115 provided in the red pixel 10r, the green pixel 10g, and the blue pixel 10b may have the same shape as each other, or may have different shapes from each other.

[0104] In the above-described embodiments and the like, an example in which the blue pixel 10b has the transparent layer 118 has been described, but the blue pixel 10b may have a wavelength conversion layer.

[0105] In the above-described embodiments and the like, the case where light in the red wavelength range, light in the green wavelength range, and light in the blue wavelength range are extracted from the display device 100 has been described, but the wavelength range of the light extracted from the display device 100 is not limited to this.

[0106] In the above-described Modification 1 and Modification 2, the display device 100A according to the second embodiment has been described, but the display device 100 according to the first embodiment may have a similar configuration. Specifically, the display device 100 may have a dichroic filter 119r or the like, or may have an overcoat layer 114 with a low refractive index.

Explanation of Reference Numerals

[0107] 100 Display device, 10r Red pixel, 10g Green pixel, 10b Blue pixel, 110 First structure, 111 Transparent substrate, 112 Light-shielding matrix, 113 Color filter 113r Red color filter, 113g Green color filter, 113b Green color filter, 114 Overcoat layer 115 Nanostructure 116 Partition wall, 117r Red conversion layer, 117g Green conversion layer, 118 Transparent layer, 119r Dichroic filter, 120 Second structure, 121 TFT substrate, 122 Light source, 123 Anisotropic conductive film, 130 Bonding layer.

Claims

1. A light source provided in each of the first pixel and the second pixel, which emits light of a first wavelength; A first wavelength conversion layer provided in the first pixel, which converts the light of the first wavelength into light of a second wavelength; A second wavelength conversion layer provided in the second pixel, which converts the light of the first wavelength into light of a third wavelength different from the second wavelength; A first color filter provided in the first pixel, which selectively transmits the light of the second wavelength; A second color filter provided in the second pixel, which selectively transmits the light of the third wavelength; At least including a high refractive index dielectric; The high refractive index dielectric is a plurality of nano members into which the light of the second wavelength and the light of the third wavelength are incident, The plurality of nano members are arranged in the first pixel with a first period, and arranged in the second pixel with a second period different from the first period. A display device.

2. Further having an overcoat layer provided between the first color filter and the first wavelength conversion layer, and between the second color filter and the second wavelength conversion layer, The plurality of nano members are provided between the overcoat layer and each of the first wavelength conversion layer and the second wavelength conversion layer. The display device according to claim 1.

3. The light source is further provided in a third pixel, The plurality of nano members are further arranged in the third pixel with a third period different from the first period and the second period. The display device according to claim 1.

4. The light of the second wavelength is light in the red wavelength range, and the light of the third wavelength is light in the green wavelength range. The display device according to claim 3.

5. The first period is longer than the second period, The second period is longer than the third period. The display device according to claim 4.

6. The first period is 500 nm or more and 700 nm or less, the second period is 450 nm or more and 500 nm or less, and the third period is 350 nm or more and 430 nm or less. The display device according to claim 4.

7. The plurality of nano members arranged with the first period resonate with the light of the second wavelength, The plurality of nano members arranged with the second period resonate with the light of the third wavelength. The display device according to claim 1.

8. The high refractive index dielectric has a refractive index of 2.0 or more. The display device according to claim 1.

9. The high refractive index dielectric contains at least one of titanium oxide (TiO ２ ) and silicon (Si). The display device according to claim 1.

10. The plurality of nano members have a shape of a column, a cone, a hemisphere or a cap. The display device according to claim 1.

11. The display device according to claim 1, wherein the first wavelength conversion layer and the second wavelength conversion layer each include a plurality of nanoparticles.

12. The display device according to claim 11, wherein each of the plurality of nanoparticles includes at least one of silver (Ag) and aluminum (Al).

13. The display device according to claim 1, wherein the light source includes a micro LED (Light Emitting Diode).

14. The display device according to claim 1, wherein the light of the first wavelength is light in a blue wavelength range.

15. The display device according to claim 1, wherein the first wavelength conversion layer and the second wavelength conversion layer each include at least one of quantum dots and phosphors.

16. An overcoat layer provided between the first color filter and the first wavelength conversion layer and between the second color filter and the second wavelength conversion layer, and a transparent substrate facing the overcoat layer with the first color filter and the second color filter therebetween, wherein the plurality of nano members are provided between the transparent substrate and the first color filter and the second color filter. The display device according to claim 1.

17. The display device according to claim 2 or 16, wherein the overcoat layer has a refractive index of 1.3 or less.

18. A first dichroic filter provided between the first wavelength conversion layer and the first color filter, and transmitting the light of the second wavelength and reflecting the light of the first wavelength, and a second dichroic filter provided between the second wavelength conversion layer and the second color filter, and transmitting the light of the third wavelength and reflecting the light of the first wavelength The display device according to claim 1, further comprising.

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