Display device

Abstract

To provide a display device capable of improving light emission efficiency and reducing power consumption by reducing a light loss.SOLUTION: A display device comprises: a light-emitting device array substrate 120 including a plurality of light-emitting devices 121; a color conversion structure 110 disposed on the light-emitting device array substrate 120; and a junction section 130 cohering the light-emitting device array substrate 120 with the color conversion structure 110. The color conversion structure 110 includes: a transparent substrate 111; partition walls 114 defining pixel regions 140 of color pixels of red pixels, green pixels, and blue pixels on the transparent substrate 111; a color conversion layer 115 which is formed in at least one of the pixel regions 140 of the color pixels and by which light incident to the pixel region 140 is converted into a color corresponding to the respective color pixels; a light transmissive resin layer 116 formed on the color conversion layer 115; and a reflection layer 117 formed on the light transmissive resin layer 116 and including openings 117a formed correspondingly to the respective pixels in such a manner that light of the light-emitting elements 121 is guided to the inside of the partition walls 114 of the respective color pixels.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] While LCD (liquid crystal display) displays and OLED (organic light emitting diode) displays are widely used as display devices, in recent years displays using micro-LEDs (micro-light emitting diodes) as light emitting elements have been attracting attention. Micro-LED displays are the next generation of display devices that have a fast response speed, are free of burn-in problems, and can display high-brightness, high-definition images with low power consumption.

[0003] Conventionally, among micro LED display devices, there is a full-color display device having a structure that converts the color of light emitted from the micro LED and emits it to the outside. Such a full-color display device has a structure that combines a light-emitting element array substrate having a plurality of micro LEDs with a color conversion panel having a color conversion layer. The color of the light that passes through the color conversion layer is, for example, red, green, and blue, and the light of each color is emitted to the outside to realize a full-color display.

[0004] In addition, the display device of Non-Patent Document 1 has a configuration in which a color conversion layer having a phosphor is arranged on a blue micro LED, a reflective structure is arranged on the lower surface of the color conversion layer, and a dichroic filter is arranged on the upper surface. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Juwon Jung, Young-Joo Kim, “Enhanced Quantum Dot Conversion Layer Using Light Recycling Structure for Blue μ-LED Display”, PROCEEDINGS OF THE INTERNATIONAL DISPLAY WORKSHOPS, VOL.29, 2022, p.255-258 Summary of the Invention [Problem to be solved by the invention]

[0006] In a self-luminous display device in which an array substrate mounting self-luminous elements such as micro LEDs as disclosed in Non-Patent Document 1 is bonded to a color conversion layer, light emitted from the light-emitting elements passes through the color conversion layer and is emitted to the outside.

[0007] However, in the display device, a part of the light emitted from the light emitting element may be reflected on the surface of the color conversion layer, resulting in optical loss.Furthermore, in the display device, a part of the light that has passed through the color conversion layer and has been color-converted may be emitted toward the light emitting element, resulting in optical loss due to backward emission.

[0008] In a display device, reducing the above-mentioned light loss is an extremely important improvement because it leads to improved luminous efficiency and brightness in the color conversion layer and also enables reduced power consumption. However, the device in Non-Patent Document 1 does not provide sufficient measures against the above-mentioned light loss, and there is room for improvement.

[0009] The present invention has been made in consideration of the above-mentioned circumstances, and specifically, an object of the present invention is to provide a display device that can reduce optical loss of light emitted from a light-emitting element and color-converted light that has passed through a color conversion layer, thereby improving luminous efficiency and achieving low power consumption. [Means for solving the problem]

[0010] The above object can be achieved by any one of the following means (1) to (13).

[0011] (1) A display device comprising: a light-emitting element array substrate having a plurality of light-emitting elements; a color conversion structure disposed on the light-emitting element array substrate; and a bonding portion for bonding the light-emitting element array substrate and the color conversion structure, the color conversion structure including: a transparent substrate; partition walls defining pixel regions of each of red, green and blue pixels on the transparent substrate; a color conversion layer formed in at least one of the pixel regions of each color pixel for converting light incident on the pixel region into a color corresponding to each color pixel; a light-transmitting resin layer formed on the color conversion layer; and a reflective layer formed on the light-transmitting resin layer and having openings corresponding to each pixel so as to guide light from the light-emitting elements into the partition walls of each color pixel.

[0012] (2) The display device according to (1) above, wherein the opening has an opening size equal to or larger than an element size of the light-emitting element in a plan view.

[0013] (3) The reflective layer is made of an Al-Al alloy, an Ag-Ag alloy, a Cu-Cu alloy, a Pd-Pd alloy, Rh, or TiO 2 Mixed resin, Al 2 O 3 The display device according to (1) or (2) above, which is made of a material containing any one of the mixed resins.

[0014] (4) The display device according to any one of (1) to (3) above, wherein the light-transmitting resin layer has a transmittance of 70% or more and 100% or less.

[0015] (5) The display device according to any one of (1) to (4) above, wherein the pixel region corresponding to the blue pixel is filled with a light-transmitting resin mixed with light-diffusing particles.

[0016] (6) The inner peripheral surface of the partition wall is made of an Al-Al alloy, an Ag-Ag alloy, a Cu-Cu alloy, a Pd-Pd alloy, Rh, TiO 2 Mixed resin, Al 2 O 3 The display device according to any one of (1) to (5) above, which has a reflective portion formed of a material containing any one of the mixed resins.

[0017] (7) The display device according to any one of (1) to (6) above, wherein an optically functional layer including an overcoat layer having a refractive index of 1.0 or more and 1.3 or less and / or an air layer is formed between the color conversion layer and the transparent substrate.

[0018] (8) The display device according to any one of (1) to (7) above, wherein the reflective layer is formed so as not to overlap with the pixel region of the blue pixel in a plan view.

[0019] (9) The display device according to any one of (1) to (8) above, wherein a first optical filter that transmits blue light and reflects green light and red light is formed on a surface of the color conversion layer facing the light emitting element.

[0020] (10) The display device according to any one of (1) to (9) above, wherein a second optical filter that reflects blue light and transmits green light and red light is formed on a surface of the color conversion layer facing the transparent substrate.

[0021] (11) The display device according to any one of (1) to (10) above, wherein the color conversion layer and the light-transmitting resin layer are formed within the pixel region partitioned by the partition wall, the pixel region corresponding to at least one of the pixels.

[0022] (12) The display device according to any one of (1) to (11) above, wherein the height of the partition is 5 μm or more and 50 μm or less, and the thickness of the light-transmitting resin layer is 2 μm or more and 20 μm or less.

[0023] (13) The display device according to any one of (1) to (12) above, wherein the light-emitting element is a micro LED. Effect of the Invention

[0024] According to an embodiment of the present invention, a display device includes a color conversion structure having a reflective layer with an opening formed to guide light emitted from a corresponding light emitting element within a pixel region of each color pixel on a transparent substrate, thereby reducing light loss due to back-reflected light emitted from the light emitting element and color-converted backward emission, thereby improving luminous efficiency and reducing power consumption. [Brief description of the drawings]

[0025] [Figure 1] 1 is a cross-sectional view showing a display device according to a first embodiment. [Diagram 2] 1 is a diagram showing the color conversion structure of the display device according to the first embodiment as viewed from the reflective surface side. [Diagram 3] FIG. 11 is a cross-sectional view showing a display device according to a second embodiment. [Figure 4] 13 is a diagram showing the color conversion structure of the display device according to the second embodiment, as viewed from the reflective surface side. FIG. [Diagram 5] FIG. 11 is a cross-sectional view showing a display device according to a first modified example. [Figure 6] 13 is a diagram showing the color conversion structure of the display device according to Modification Example 1 as viewed from the reflective surface side. FIG. [Figure 7] FIG. 11 is a cross-sectional view showing a display device according to a second modified example. [Figure 8] FIG. 11 is a view showing the color conversion structure of the display device according to Modification Example 2 as viewed from the reflective surface side. [Figure 9] FIG. 11 is a cross-sectional view showing a display device according to a third modified example. [Figure 10] FIG. 11 is a view showing the color conversion structure of a display device according to Modification Example 3, as viewed from the reflective surface side. [Figure 11] FIG. 13 is a cross-sectional view showing a display device according to a fourth modified example. [Figure 12] FIG. 13 is a view showing the color conversion structure of a display device according to Modification Example 4, as viewed from the reflective surface side. [Figure 13] 1 is a table showing test results of examples and comparative examples of performance tests. [Figure 14] 1 is a graph showing test results of examples and comparative examples of performance tests. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following drawings, the same reference numerals refer to the same components, and the size of each component in the drawings may be exaggerated for clarity and convenience of explanation. Meanwhile, the embodiments described below are merely examples, and various modifications are possible from such embodiments.

[0027] In the following, the terms "upper" and "above" may include not only what is directly above in contact with something, but also what is above without contact. Similarly, the terms "lower" and "below" may include not only what is directly below in contact with something, but also what is below without contact.

[0028] The singular expression includes the plural expression unless the context clearly indicates otherwise. In addition, when a part is described as "comprising," "having," or "having" a certain element, it does not mean excluding other elements, but may further include other elements, unless otherwise specified to the contrary.

[0029] Unless the steps constituting the method are explicitly described in order or described to the contrary, the steps may be performed in any suitable order, and the method is not necessarily limited to the order of the steps described. The use of any examples or exemplary terms is merely for the purpose of illustrating the technical idea, and the scope of the invention is not limited by the examples or exemplary terms, except as otherwise provided by the claims.

[0030] In each figure, the axes parallel to two orthogonal sides of the transparent substrate of the display device according to the embodiment are the X-axis and the Y-axis, respectively, and the direction orthogonal to the X-axis and the Y-axis is the Z-axis. The direction along the X-axis is the X-direction, the direction along the Y-axis is the Y-direction, and the direction along the Z-axis is the Z-direction. However, each direction does not limit the orientation of the display device when in use, and the orientation of the display device when in use is arbitrary.

[0031] In the following description, when ordinal numbers such as "first" and "second" are used, unless otherwise specified, they are used for convenience and do not dictate any order.

[0032] [First embodiment] A display device 100 according to a first embodiment will be described.

[0033] 1, the display device 100 includes a color conversion structure 110, a light-emitting element array substrate 120, and a joint 130. The color conversion structure 110 and the light-emitting element array substrate 120 are joined together via the joint 130 in a state where they are butted up and down (butted in the Z direction).

[0034] <Color conversion structure> The color conversion structure 110 includes a transparent substrate 111, a light-shielding matrix 112, a color filter 113 (a red color filter 113r, a green color filter 113g), a partition 114, a color conversion layer 115 (a red color conversion layer 115r, a green color conversion layer 115g), a light-transmitting resin layer 116, and a reflective layer 117.

[0035] <Transparent substrate> The transparent substrate 111 is made of a transparent material having optical transparency, such as a glass material or a resin material such as polyimide, etc. In particular, in the case of a resin material, the transparent substrate 111 may be in the form of a flexible film.

[0036] <Light-shielding matrix> The light-shielding matrix 112 is made of a light-shielding material that can be patterned. Usually, the light-shielding matrix 112 is black and has no light transmittance (or has extremely low light transmittance), and is called a black matrix. The light-shielding matrix 112 separates each pixel on a pixel-by-pixel basis. The light-shielding matrix 112 does not necessarily have to be formed.

[0037] Color Filter The color filter 113 is composed of a red color filter 113r and a green color filter 113g. The color filter 113 suppresses light of wavelengths other than the respective color components contained in the light emitted from the light emitting element (micro LED) 121. This improves the color purity of the display device 100, enabling vivid color reproduction. Note that the color filter 113 does not have to be formed.

[0038] <Bulkhead> The partitions 114 individually partition each color pixel corresponding to the light emitting element 121. The regions partitioned by the partitions 114 adjacent to each other in the X direction or the Y direction function as pixel regions 140 (red pixel region 140r, green pixel region 140g, blue pixel region 140b) of each color pixel that becomes a subpixel. The color conversion layer 115 (red conversion layer 115r, green conversion layer 115g), the light transmitting layer 115b, etc. may be formed in the pixel region 140. The height of the partitions 114 is 5 μm or more and 50 μm or less.

[0039] The material for forming the partition wall 114 may be, for example, a photosensitive resin such as an acrylic resin, an epoxy resin, a silicone resin, or a polyimide resin.

[0040] Color conversion layer The color conversion layer 115 is formed in at least one of the pixel regions 140 of each color pixel, and converts light incident on the pixel region 140 into a color corresponding to each color pixel. The color conversion layer 115 includes a red conversion layer 115r and a green conversion layer 115g.

[0041] The red conversion layer 115r and the green conversion layer 115g include phosphors (which may include quantum dots). The phosphors convert a single color, for example, blue light or ultraviolet light, into a desired color. The red conversion layer 115r includes, for example, a phosphor for converting blue light into red light, and is formed in the red pixel region 140r. The green conversion layer 115g includes a phosphor for converting blue light into green light, and is formed in the green pixel region 140g. In this embodiment, since a blue micro LED is used as the light emitting element 121, the color conversion layer 115 is not used for the blue pixel region 140b.

[0042] In this embodiment, the blue pixel region 140b is formed with a light transmitting layer 115b instead of the color conversion layer 115. The light emitting element 121 in this embodiment is a blue micro LED, and the color filter 113 and the color conversion layer 115 are not used in the blue pixel region 140b. In this embodiment, the blue pixel region 140b is formed with a light transmitting layer 115b in order to have the same thickness as the other colors. The light transmitting layer 115b can be formed with the same material as the light transmitting resin layer 116. The resin applicable to the color conversion layer 115 has a refractive index of 1.3 or more and 1.7 or less.

[0043] In addition, when the light emitting element 121 emits ultraviolet light, the color conversion layer 115 can be used in place of the light transmitting layer 115b in the blue pixel region 140b. A blue color filter may be used in the blue pixel region 140b. Furthermore, the blue pixel region 140b may be left empty without forming the light transmitting layer 115b, or may be filled with the bonding material of the bonding portion 130.

[0044] The red conversion layer 115r, the green conversion layer 115g, and the light transmitting layer 115b each have a thickness of 5 μm or more and 50 μm or less. The thickness of each layer is appropriately set according to the height of the pixel region 140 (i.e., the height of the partition wall 114) so ​​that each layer fits within the pixel region 140 defined by the partition wall 114.

[0045] <Light-transparent resin layer> The light-transmitting resin layer 116 is a layer interposed between the color conversion layer 115 and the reflection layer 117. By disposing the light-transmitting resin layer 116 between the color conversion layer 115 and the reflection layer 117, it is possible to improve the emission efficiency in the light guide direction (the display surface side of the display device 100, the direction from the light-emitting element 121 toward the transparent substrate 111 along the Z direction) when the emitted light from the light-emitting element 121 and the color-converted light that has passed through the color conversion layer 115 are reflected by the reflection layer 117 between the color conversion layer 115 and the reflection layer 117. The light-transmitting resin layer 116 has a thickness of 2 μm or more and 20 μm or less.

[0046] The material for forming the light-transmitting resin layer 116 is a resin having a refractive index of 1.25 or more and a light transmittance of 70% or more and 100% or less. For example, an acrylic resin, an epoxy resin, a silicone resin and / or a mixture thereof, a photocurable and / or thermosetting fluorine-based resin, etc. can be suitably used.

[0047] <Reflection layer> The reflective layer 117 is formed on the light-transmitting resin layer 116. The reflective layer 117 has an opening 117a as shown in FIG. 2. The opening 117a has an opening size equal to or larger than the element size of the light-emitting element 121 in a planar view. The opening size of the opening 117a is equal to or larger than the element size of the light-emitting element 121 in a planar view so as not to prevent the light emitted from the light-emitting element 121 from entering the pixel region 140, and is equal to or smaller than the bottom size (opening size) of the pixel region 140 so as to prevent unnecessary diffuse reflection. In FIG. 2, the opening size of the opening 117a corresponds to the area (opening area) of the region defined by the vertical side extending in the X direction and the horizontal side extending in the Y direction. The element size of the light-emitting element 121 is the area within the outer edge of the light-emitting element 121 corresponding to the opening 117a in a planar view.

[0048] The openings 117a are formed at positions where the entire plane of the corresponding light-emitting element 121 can be seen from the openings 117a in a plan view. The openings 117a can be formed such that the centroid of the openings 117a in a plan view coincides with the centroid of the light-emitting element 121 in a plan view in the thickness direction of the display device 100 (the stacking direction of the color conversion structure 110 and the light-emitting element array substrate 120 along the Z direction).

[0049] The shape of the opening 117a is not particularly limited, and may be rectangular, polygonal, or circular. The opening 117a can be appropriately designed based on the planar shape of the corresponding light-emitting element 121 and the bottom shape of the pixel region 140. The end of the opening 117a may be in contact with the light-transmitting resin layer 116 formed in the corresponding pixel region 140, or may be in contact with the edge of the partition wall 114 without being in contact with the light-transmitting resin layer 116.

[0050] The reflective layer 117 has an opening 117a corresponding to the light emitting element 121, and therefore can reflect and recycle, toward the light guide direction, back reflected light that is light emitted from the light emitting element 121 and reflected on the surface of the color conversion layer 115, and backward emitted light that is color converted light that has passed through the color conversion layer 115 and is emitted on the light emitting element 121 side. Therefore, the display device 100 can reflect light that may cause light loss, such as back reflected light and backward light, toward the light guide direction, thereby reducing light loss and improving light emission efficiency while reducing power consumption. Furthermore, if the reflective layer 117 has an opening 117a formed with an opening size equal to or larger than the element size of the corresponding light emitting element 121 in a plan view, the light can be recycled more effectively, improving light emission efficiency.

[0051] The reflective layer 117 is formed from an Al-Al alloy, an Ag-Ag alloy, a Cu-Cu alloy, a Pd-Pd alloy, Rh, or TiO 2 Mixed resin, Al 2 O 3 A material containing any one of the mixed resins can be preferably used. 2 Mixed resin and Al 2 O 3 The resin used in the mixed resin may be any resin that can be used in the light-transmitting resin layer 116 .

[0052] The thickness of the reflective layer 117 is 50 nm or more. The thickness of the reflective layer 117 can be appropriately set according to the product specifications of the display device 100.

[0053] <Light emitting element array substrate> The light emitting element array substrate 120 has a TFT (Thin Film Transistor), a wiring layer, and the like formed thereon, and also has light emitting elements 121 mounted thereon. In this embodiment, the light emitting element 121 is a monochromatic light emitting element such as a micro LED. The micro LED emits, for example, blue light or ultraviolet light. The emitted blue light or ultraviolet light is converted into a desired color by the color conversion layer 115.

[0054] The light emitting element array substrate 120 may be appropriately formed including AFC (anisotropic conductive film), conductive adhesive, solder, metal bumps made of copper or aluminum, bump plating by electrolytic plating, etc. as necessary for mounting the light emitting elements 121.

[0055] <Joint part> The bonding portion 130 bonds the color conversion structure 110 and the light emitting element array substrate 120. The bonding portion 130 is formed to be interposed between the color conversion structure 110 and the light emitting element array substrate 120 to bond them together. The bonding portion 130 has a thickness of 5 μm or less.

[0056] The joint 130 is made of a joint material such as a pressure sensitive adhesive or a bonding agent, etc. As the joint material, for example, a transparent epoxy resin, a silicone resin, etc. can be suitably used.

[0057] [Display device manufacturing method] Next, a method for manufacturing the display device 100 will be described.

[0058] (Manufacturing color conversion panels) The color conversion structure 110 is manufactured, for example, as follows: First, a black resist is applied onto a transparent substrate 111, and a light-shielding matrix 112 (black matrix) for separating pixels is formed using a photolithography process.

[0059] Next, in order to form red, green, and blue pixel regions 140 that will become sub-pixels, partition walls 114 are formed using a photolithography process. Next, red color filters 113r and green color filters 113g are formed in the red pixel region 140r and green pixel region 140g using a photolithography process. If necessary, an overcoat layer may be applied from above the red color filter 113r and green color filter 113g. This allows the substrate surface to be flattened by the overcoat layer.

[0060] Next, a resin containing a phosphor is filled into the red pixel region 140r and the green pixel region 140g surrounded by the partition wall 114 and cured (thermal and / or ultraviolet curing) to form the color conversion layer 115. A red conversion layer 115r that converts the light emitted from the light emitting element 121 to red is formed in the red pixel region 140r. A green conversion layer 115g that converts the light emitted from the light emitting element 121 to green is formed in the green pixel region 140g. Furthermore, a light-transmitting resin not containing a phosphor is filled into the portion of the blue pixel region 140b and the color conversion layer 115 surrounded by the partition wall 114 and cured (thermal and / or ultraviolet curing) to form the light-transmitting layer 115b and the light-transmitting resin layer 116.

[0061] Next, a reflective layer 117 is formed on the surfaces of the partition walls 114 and the light-transmitting resin layer 116 by a sputtering process, and an opening 117a having a size equal to or larger than the element size of the light-emitting element 121 is patterned in accordance with the arrangement position of the light-emitting element 121.

[0062] In this manner, the color conversion structure 110 is formed.

[0063] (Joining color conversion panel and light-emitting element array substrate) The bonding between the color conversion structure 110 and the light emitting element array substrate 120 is performed by first applying a bonding material to the bonding portion 130 on the light emitting element array substrate 120. The light emitting element array substrate 120 to be used is provided with TFTs, wiring layers, etc., and is also provided with micro LED chips as light emitting elements 121. The light emitting element array substrate 120 can be formed by mounting micro LEDs through a known forming process. The color conversion structure 110 is positioned and superimposed on the surface of the light emitting element array substrate 120 on which the bonding material is applied, and the two are bonded together by applying pressure in a direction to bring them closer together under reduced pressure. Thereafter, energy such as heat or ultraviolet light is applied to harden the bonding material. At this time, light emitted from the LEDs on the light emitting element array substrate 120 may be used.

[0064] In this manner, a full-color display device 100 can be fabricated.

[0065] The display device 100 of the first embodiment includes a reflective layer 117 having openings 117a formed therein corresponding to the light emitting elements 121 of each color pixel on a light-transmitting resin layer 116 formed on a color conversion layer 115, and therefore can reflect the above-mentioned back reflected light and backward light, etc., toward the light guide direction and recycle them. Therefore, the display device 100A can reduce light loss and achieve low power consumption while improving light emission efficiency.

[0066] [Second embodiment] Next, a display device 100A according to a second embodiment of the present invention will be described. In the description of the second embodiment, differences from the above-mentioned embodiment will be mainly described, and components having the same functions as those of other embodiments will be given the same or related reference numerals and detailed descriptions will be omitted, and will not be mentioned in particular. In addition, the configuration, members, and method of use may be the same as those of the first embodiment.

[0067] FIG. 3 is a cross-sectional view showing the configuration of a display device 100A according to the second embodiment, and FIG. 4 is a view of the color conversion structure 110 of the display device 100A according to the second embodiment viewed from the reflective layer 117 side.

[0068] In the second embodiment of the display device 100A, a red conversion layer 115r and a light-transmitting resin layer 116 which become the color conversion layer 115 are laminated in a red pixel region 140r surrounded by a partition 114, a green conversion layer 115g and a light-transmitting resin layer 116 are laminated in a green pixel region 140g, and a light-transmitting resin layer 116 which functions as a light-transmitting layer 115b is formed in a blue pixel region 140b.

[0069] The display device 100A differs from the first embodiment in that a color conversion layer 115 and a light-transmitting resin layer 116 are filled in the pixel region 140.

[0070] As shown in FIG. 3, in the display device 100A, a reflective layer 117 is formed on the bottom surface of a light-transmitting resin layer 116 so that an opening 117a is disposed therein.

[0071] The display device 100A of the second embodiment has a light-transmitting resin layer 116 formed in the pixel region 140 of each color pixel, and has a reflective layer 117 having an opening 117a as shown in FIG. 4, similar to the display device 100 of the first embodiment, so that the back reflected light and backward light can be reflected toward the light guide direction to recycle the light. Therefore, the display device 100A can reduce light loss and reduce power consumption while improving light emission efficiency. In addition, since the display device 100A has a light-transmitting resin layer 116 formed in each pixel region 140, the light emitted from the light emitting element 121 corresponding to each pixel region 140 is less likely to enter the adjacent pixel region 140, so that color mixing can be reduced.

[0072] [Example of modification] The display devices 100, 100A of the present invention can be modified as appropriate as in the following modified examples. In the following description of each modified example, differences from the above-mentioned embodiment are mainly described, and components having the same functions as those in other embodiments are denoted by the same or related reference numerals, detailed description is omitted, and no particular mention is made. The configuration, members, and method of use may be the same as those in each embodiment. Furthermore, each modified example can be implemented in combination with other embodiments by appropriately selecting necessary configurations from those shown in each modified example within the scope of the present invention.

[0073] <Modification Example 1> A display device 100B according to the first modified example will be described.

[0074] The display device 100B of the first modified example is a configuration in which a part of the display device 100A of the first embodiment is modified to add an optical function layer 150 and the like.

[0075] 5, the display device 100B includes a color conversion structure 110, a light-emitting element array substrate 120, and a joint 130. The color conversion structure 110 and the light-emitting element array substrate 120 are joined together by the joint 130 in a butted relationship.

[0076] As shown in Figure 5 or Figure 6, the color conversion structure 110 includes a transparent substrate 111, a light-shielding matrix 112, a color filter 113 (red color filter 113r, green color filter 113g), a partition 114, a color conversion layer 115 (red color conversion layer 115r, green color conversion layer 115g), a light-transmitting layer 115b containing light-diffusing particles, a light-transmitting resin layer 116, a reflective layer 117 having an opening 117a, an optically functional layer 150, and a reflective portion 160.

[0077] The optical functional layer 150 is composed of an overcoat layer and / or an air layer formed of a low refractive index material having a refractive index of 1.0 to 1.3. The optical functional layer 150 can be composed of at least one of an overcoat layer and an air layer. The thickness of the optical functional layer 150 is 3 μm or less for both the overcoat layer and the air layer, but it is preferable to form it thinner while maintaining the functional properties.

[0078] The optical function layer 150 can return the color-converted light at an angle that does not allow it to be emitted from the color conversion layer 115 back to the color conversion layer 115, and convert it to an angle at which it can be emitted. Therefore, the display device 100B has an improved light recycling effect.

[0079] The display device 100B has a reflecting portion 160 on the inner circumferential surface 114a of the partition wall 114 (the surface on the side partitioned by the pixel region 140). The reflecting portion 160 can be formed using the constituent material of the reflecting layer 117. The reflecting portion 160 may form a smooth surface with a uniform thickness over the entire surface of the inner circumferential surface 114a, or may form a surface having a partially or entirely uneven shape. From the viewpoint of improving reflection efficiency, the reflecting portion 160 is preferably formed as a smooth surface covering the entire circumference of the inner circumferential surface 114a. By providing the reflecting portion 160, the display device 100B improves reflection efficiency in the pixel region 140 and improves the emission efficiency of color-converted light, etc.

[0080] The display device 100B contains light diffusing particles having a light diffusing effect in the light transmitting layer 115b filled in the blue pixel region 140b. The light diffusing particles may be any known material that is applicable to the display device 100B and can exhibit a light diffusing effect. This can improve the viewing angle characteristics of the display device 100B.

[0081] The display device 100B of modified example 1 has a reflective portion 160 on the optical functional layer 150 and the inner surface 114a of the partition 114, and therefore can effectively recycle the color-converted light that has passed through the color conversion layer 115, thereby achieving further improvement in luminous efficiency while reducing power consumption.

[0082] <Modification Example 2> A display device 100C according to a second modified example will be described.

[0083] As shown in FIG. 7, the display device 100C of modified example 2 is a configuration in which, in the display device 100B of modified example 1, only the constituent resin of the light-transmitting resin layer 116 is applied to the light-transmitting layer 115b, and a reflective layer 117 is formed so as not to overlap with the blue pixel region 140b.

[0084] 7, the display device 100C includes a color conversion structure 110, a light-emitting element array substrate 120, and a joint 130. The color conversion structure 110 and the light-emitting element array substrate 120 are joined together by the joint 130 in a butted relationship.

[0085] As shown in Figure 7 or Figure 8, the color conversion structure 110 includes a transparent substrate 111, a light-shielding matrix 112, a color filter 113 (red color filter 113r, green color filter 113g), a partition 114, a color conversion layer 115 (red conversion layer 115r, green conversion layer 115g), a light-transmitting layer 115b, a light-transmitting resin layer 116, a reflective layer 117 having an opening 117a, an optically functional layer 150, and a reflective portion 160.

[0086] 8, the display device 100C of the second modified example can make the area of ​​the opening 117a for the blue pixel region 140b larger than the other openings 117a by forming the reflective layer 117 so as not to overlap with the blue pixel region 140b. Therefore, the display device 100C can efficiently allow the emitted light from the light emitting element 121 to be incident on the blue pixel region 140b, thereby improving the light emission efficiency.

[0087] <Modification Example 3> A display device 100D according to a third modified example will be described.

[0088] As shown in FIG. 9, the display device 100D of modified example 3 has a configuration in which, in the display device 100A of the second embodiment, an optical functional layer 150 is added, the height of the partition 114 is extended, a color conversion layer 115 and a light-transmitting resin layer 116 are filled in each pixel region 140, light-diffusing particles are contained in the light-transmitting layer 115b, and an optical filter 170 is formed on the upper and / or lower surface of the red conversion layer 115r in the red pixel region 140r and on the upper and / or lower surface of the green conversion layer 115g in the green pixel region 140g.

[0089] 9, the display device 100D includes a color conversion structure 110, a light-emitting element array substrate 120, and a joint 130. The color conversion structure 110 and the light-emitting element array substrate 120 are joined together by the joint 130 in a vertically butted state.

[0090] As shown in Figure 9 or Figure 10, the color conversion structure 110 includes a transparent substrate 111, a light-shielding matrix 112, a color filter 113 (red color filter 113r, green color filter 113g), a partition 114, a color conversion layer 115 (red conversion layer 115r, green conversion layer 115g), a light-transmitting layer 115b containing light-diffusing particles, a light-transmitting resin layer 116, a reflective layer 117 having an opening 117a, an optically functional layer 150, a reflective portion 160, and an optical filter 170.

[0091] The optical filter 170 is a so-called dichroic filter that reflects light in a specific wavelength range and transmits the remaining wavelength range. The optical filter 170 includes a first optical filter 171 that transmits the light (blue light) emitted from the light emitting element 121 and reflects green and red light, and a second optical filter 172 that reflects the light (blue light) emitted from the light emitting element 121 and transmits green and red light. The thickness of the optical filter 170 is 5 μm or less, and is preferably thin, provided that optical characteristics are ensured.

[0092] The first optical filter 171 is formed on the surfaces (lower surfaces) of the red conversion layer 115r and the green conversion layer 115g facing the light emitting element 121. The second optical filter 172 is formed on the surfaces (upper surfaces) of the red conversion layer 115r and the green conversion layer 115g facing the transparent substrate 111.

[0093] The first optical filter 171 and the second optical filter 172 may be formed on both the red conversion layer 115r and the green conversion layer 115g, or on only one of them.

[0094] The display device 100D of the fourth modified example includes the optical filter 170, and therefore can effectively recycle the color-converted light, thereby improving the luminous efficiency and reducing power consumption.

[0095] <Modification Example 4> A display device 100E according to the fourth modified example will be described.

[0096] The display device 100E of the fourth modified example has a configuration in which the height of the partition walls 114 of the display device 100B of the first modified example is extended, and each pixel region 140 is filled with a color conversion layer 115 and a light-transmitting resin layer .

[0097] 11, the display device 100E includes a color conversion structure 110, a light-emitting element array substrate 120, and a joint 130. The color conversion structure 110 and the light-emitting element array substrate 120 are joined together by the joint 130 in a butted relationship.

[0098] As shown in FIG. 11 or 12, the display device 100E includes a transparent substrate 111, a light-shielding matrix 112, a color filter 113 (a red color filter 113r, a green color filter 113g), a partition 114, a color conversion layer 115 (a red color conversion layer 115r, a green color conversion layer 115g), a light-transmitting layer 115b containing light-diffusing particles, a light-transmitting resin layer 116, a reflective layer 117 having an opening 117a, an optically functional layer 150, and a reflective portion 160.

[0099] The display device 100E of modified example 4 has a reflective portion 160 on the optical functional layer 150 and the inner surface 114a of the partition 114, and therefore can effectively recycle the color-converted light that has passed through the color conversion layer 115, thereby improving the light-emitting efficiency while reducing power consumption.

[0100] As described above, the display device 100 according to the present invention includes a light-emitting element array substrate 120 having a plurality of light-emitting elements 121, a color conversion structure 110 arranged on the light-emitting element array substrate 120, and a joint 130 for bonding the light-emitting element array substrate 120 and the color conversion structure 110. The color conversion structure 110 includes a transparent substrate 111, partition walls 114 for partitioning pixel regions 140 of each color pixel, i.e., red, green, and blue pixels, on the transparent substrate 111, a color conversion layer 115 formed in at least one of the pixel regions 140 of each color pixel and for converting light incident on the pixel region 140 into a color corresponding to each color pixel, a light-transmitting resin layer 116 formed on the color conversion layer 115, and a reflective layer 117 formed on the light-transmitting resin layer 116 and having openings 117a formed corresponding to each pixel so as to guide light from the light-emitting element 121 into the partition walls 114 of each color pixel.

[0101] With this configuration, the display device 100 can reduce light loss due to back-reflected light when light emitted from the light-emitting element 121 is reflected on the surface of the color conversion layer 115 and color-converted backward emission, thereby improving the light-emitting efficiency and reducing power consumption. EXAMPLES

[0102] The effects of the present invention will be described using the following examples and comparative examples, although the technical scope of the present invention is not limited to the following examples.

[0103] In the following evaluation tests, the output performance of the display device according to the present invention was evaluated.

[0104] <Test Overview> The evaluation test was carried out as follows: The evaluation test was carried out using simulation software "Light Tools (manufactured by Synopsys)."

[0105] The following conditions were set for the simulation. The sample was made by laminating a transparent substrate, a partition wall, a reflective layer, a joint, and a light-emitting element array substrate in this order from the top, and forming a color conversion layer within the partition wall. Transparent substrate: Thickness 100μm Red CF RI: 1.69 CF opening size: 74μm×200μm Bonding layer thickness: 2μm Partition: 95% reflective mirror Aperture size: X; 40μm, Y; 25μm Partition height: 12μm In the simulation, the partition height was based on Comparative Example 1 (without light-transmitting resin), and was appropriately extended in Examples 1 to 4 according to the resin height. Examples 1 to 4 had a color conversion structure with partition reflection, a reflective layer with an opening, and a light-transmitting resin formed on the reflective layer. Comparative Example 1 had a color conversion structure with partition reflection, a reflective layer with an opening, and no light-transmitting resin layer. The difference in configuration between the Comparative Example and each Example is the presence or absence of a light-transmitting resin layer formed under the color conversion layer.

[0106] <Evaluation Results> The evaluation results are shown in Figures 13 and 14. The evaluation results shown in Figures 13 and 14 show the output efficiency when the output of a sample without a light-transmitting resin layer, without a reflective layer, and without partition wall reflection is taken as 100%.

[0107] As shown in Figs. 13 and 14, the output of Comparative Example 1 was 136% (60.3 mW). In contrast, the outputs of Examples 1 to 4 were 158% (70.3 mW) to 164% (73.0 mW), and Example 2 (partition height 22 µm, light-transmitting resin layer thickness (resin thickness) 10 µm) and Example 3 (partition height 25 µm, light-transmitting resin layer thickness 13 µm) both had an output of 164%, which was the highest output efficiency. From the results of Comparative Example 1 and Examples 1 to 4, it was confirmed that providing a reflective layer having an opening and a reflective portion in the partition is effective for improving the output efficiency in a display device.

[0108] In addition, the structural difference between Examples 1 to 4 and the Comparative Example is the presence or absence of a light-transmitting resin layer. From this, it was confirmed that by forming a light-transmitting resin layer between the color conversion layer and the reflective layer as in Examples 1 to 4, the back reflected light of the light emitted from the light-emitting element and the like can be efficiently recycled via the light-transmitting resin layer and the reflective layer, and the output efficiency can be further improved.

[0109] As described above, since the display device of the present invention comprises a reflective layer having an opening and a light-transmitting resin layer formed on the reflective layer, it can effectively recycle back-reflected light from the light-emitting element and color-converted light that has passed through the color conversion layer, thereby reducing light loss and improving luminous efficiency while reducing power consumption. [Explanation of symbols]

[0110] 100, 100A~100E display device, 110 Color conversion structure, 111 Transparent substrate, 112 Light-shielding matrix, 113 Color Filter 113r Red color filter, 113g Green color filter, 114 Bulkhead; 115 color conversion layer, 115r red conversion layer, 115g green conversion layer, 115b light transmitting layer, 116 Light-transparent resin layer, 117 reflective layer (117a opening), 120 Light emitting element array substrate, 121 Light emitting element (micro LED), 130 bonding layer, 140 pixel area, 140r red pixel area, 140g Green pixel area, 140b blue pixel area; 150 optical functional layer, 160 Reflector, 170 Optical filters, 171 first optical filter, 172 Second optical filter.

Claims

1. a light emitting element array substrate having a plurality of light emitting elements, a color conversion structure disposed on the light emitting element array substrate, and a bonding portion bonding the light emitting element array substrate and the color conversion structure together; the color conversion structure includes a transparent substrate, partition walls that partition pixel regions of each color pixel, i.e., red, green and blue pixels, on the transparent substrate, a color conversion layer that is formed in at least one of the pixel regions of each color pixel and converts light that is incident on the pixel region into a color corresponding to each color pixel, a light-transmitting resin layer that is formed on the color conversion layer, and a reflective layer that is formed on the light-transmitting resin layer and has an opening that is formed corresponding to each pixel so as to guide light from the light-emitting element into the partition walls of each color pixel.

2. The display device according to claim 1 , wherein the opening has an opening size equal to or larger than an element size of the light emitting element in a plan view.

3. The reflective layer is made of an Al-Al alloy, an Ag-Ag alloy, a Cu-Cu alloy, a Pd-Pd alloy, Rh, TiO ２ Mixed resin, Al ２ O ３ The display device according to claim 1 , which is made of a material containing any one of the mixed resins.

4. The display device according to claim 1 , wherein the light-transmitting resin layer has a transmittance of 70% or more and 100% or less.

5. The display device according to claim 1 , wherein the pixel region corresponding to the blue pixel is filled with a light-transmitting resin mixed with light-diffusing particles.

6. The inner peripheral surface of the partition wall is made of an Al-Al alloy, an Ag-Ag alloy, a Cu-Cu alloy, a Pd-Pd alloy, Rh, TiO ２ Mixed resin, Al ２ O ３ The display device according to claim 1 , further comprising a reflecting portion formed of a material containing any one of the mixed resins.

7. 2. The display device according to claim 1, further comprising an optically functional layer including an overcoat layer having a refractive index of 1.0 to 1.3 and / or an air layer between the color conversion layer and the transparent substrate.

8. The display device according to claim 1 , wherein the reflective layer is formed so as not to overlap with the pixel region of the blue pixel in a plan view.

9. The display device according to claim 1 , further comprising a first optical filter formed on a surface of the color conversion layer facing the light emitting element, the first optical filter transmitting blue light and reflecting green light and red light.

10. 2 . The display device according to claim 1 , further comprising a second optical filter formed on a surface of the color conversion layer facing the transparent substrate, the second optical filter reflecting blue light and transmitting green light and red light.

11. 2. The display device according to claim 1, wherein the color conversion layer and the light-transmitting resin layer are formed in the pixel region partitioned by the partition wall and corresponding to at least one of the pixels.

12. 2. The display device according to claim 1, wherein the height of the partition wall is 5 μm or more and 50 μm or less, and the thickness of the light-transmitting resin layer is 2 μm or more and 20 μm or less.

13. The display device according to any one of claims 1 to 12, wherein the light-emitting element is a micro LED.

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