Display device

Abstract

Provided is a display device excellent in heat dissipation. A wavelength conversion substrate (3A) comprises: a transparent substrate (31) which has a first main surface and a second main surface; a partition wall layer (34) which is provided on the first main surface and has a plurality of first through-holes arranged in first and second directions crossing each other; a plurality of functional layers (36R, 36G, 36B) which are respectively provided at the positions of the plurality of first through-holes, and one or more of the functional layers are wavelength conversion layers for converting light emitted by a light source into light of another color; and a heat transfer layer (38) which faces the first main surface with the partition wall layer and the plurality of functional layers interposed therebetween, is light-transmissive at the positions of the plurality of first through-holes, and has higher heat conductivity compared to the plurality of functional layers.

Description

display device

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

[0002] In display devices, light-emitting elements such as light-emitting diodes are used, for example, as light sources of backlight units or as components of pixels or sub-pixels (see Patent Documents 1 and 2).

[0003] Japanese Patent Publication No. 2000-131683 Japanese Patent Publication No. 2009-244383

[0004] An object of the present invention is to provide a display device with excellent heat dissipation properties.

[0005] According to one aspect of the present invention, there is provided a wavelength conversion substrate comprising: a transparent substrate having a first main surface and a second main surface; a partition layer provided on the first main surface and having a plurality of first through holes arranged in a first direction and a second direction intersecting each other; a plurality of functional layers provided at positions of the plurality of first through holes, at least one of which is a wavelength conversion layer that converts light emitted by a light source into light of a different color; and a heat transfer layer facing the first main surface with the partition layer and the plurality of functional layers sandwiched therebetween, which is light transmissive at the positions of the plurality of first through holes and has a higher thermal conductivity than the plurality of functional layers.

[0006] According to another aspect of the present invention, there is provided a wavelength conversion substrate according to the above aspect, wherein the heat transfer layer has one or more openings, and the one or more openings are arranged so that a first orthogonal projection of an opening of each of the plurality of first through holes on the opposite side of the transparent substrate onto the first main surface at least partially overlaps with a second orthogonal projection of the one or more openings onto the first main surface.

[0007] According to yet another aspect of the present invention, there is provided a wavelength conversion substrate according to the above aspect, wherein an overlapping portion between the first orthogonal projection and the second orthogonal projection is smaller than the first orthogonal projection.

[0008] According to yet another aspect of the present invention, there is provided the wavelength conversion substrate according to the above aspect, wherein the area of ​​the overlapping portion accounts for 50% or less of the area of ​​the first orthogonal projection.

[0009] According to yet another aspect of the present invention, there is provided the wavelength conversion substrate according to any one of the above aspects, wherein the heat transfer layer has a plurality of second through holes at positions corresponding to the plurality of first through holes, respectively.

[0010] According to yet another aspect of the present invention, there is provided a wavelength conversion substrate according to any of the above aspects, wherein the heat transfer layer has a plurality of second through holes arranged in the first direction and the second direction, and each of the second through holes is arranged to span two or more of the plurality of first through holes.

[0011] According to yet another aspect of the present invention, there is provided the wavelength conversion substrate according to any one of the above aspects, wherein the heat transfer layer includes one or more strip-shaped portions.

[0012] According to yet another aspect of the present invention, there is provided the wavelength conversion substrate according to any one of the above aspects, wherein the heat transfer layer includes a layer made of a metal or an alloy.

[0013] According to yet another aspect of the present invention, there is provided the wavelength conversion substrate according to any one of the above aspects, wherein the heat transfer layer is made of a transparent oxide layer.

[0014] According to yet another aspect of the present invention, there is provided the wavelength conversion substrate according to any one of the above aspects, wherein the heat transfer layer is made of a material having a thermal conductivity of 15 W / m·K or more.

[0015] According to yet another aspect of the present invention, there is provided the wavelength conversion substrate according to any one of the above aspects, wherein the heat transfer layer has a thickness in the range of 100 to 5000 nm.

[0016] According to yet another aspect of the present invention, there is provided the wavelength conversion substrate according to any one of the above aspects, wherein the partition layer has a thickness in the range of 10 to 40 μm.

[0017] According to yet another aspect of the present invention, there is provided the wavelength conversion substrate according to any one of the above aspects, further comprising an overcoat layer interposed between the plurality of functional layers and the heat transfer layer.

[0018] According to yet another aspect of the present invention, there is provided the wavelength conversion substrate according to any one of the above aspects, wherein the overcoat layer is further interposed between the partition wall layer and the heat transfer layer.

[0019] According to yet another aspect of the present invention, there is provided a display device comprising: a wavelength conversion substrate according to any of the above aspects; a dimming device arranged to face the first main surface; and an adhesive layer interposed between the wavelength conversion substrate and the dimming device and bonding them together.

[0020] According to yet another aspect of the present invention, there is provided a display device according to the above aspect, further comprising a heat sink located outside the laminate of the wavelength conversion substrate, the dimming device, and the adhesive layer, and a heat conductor that conducts heat from the heat transfer layer to the heat sink.

[0021] According to yet another aspect of the present invention, there is provided a display device according to the above aspect, wherein the heat sink includes a back surface heat sink arranged to face the wavelength conversion substrate with the dimming device and the adhesive layer sandwiched therebetween.

[0022] According to yet another aspect of the present invention, there is provided a display device according to the above aspect, wherein the back surface heat dissipator is a back surface heat dissipation layer provided on the light control device.

[0023] According to yet another aspect of the present invention, there is provided the display device according to any one of the above aspects, wherein at least a portion of the heat transfer body is provided outside the stack.

[0024] According to yet another aspect of the present invention, there is provided a display device according to the above aspect, wherein the heat transfer body at least partially covers an end face of the laminate.

[0025] According to yet another aspect of the present invention, there is provided a display device according to the above aspect, in which the dimming device has one or more through holes, and the heat transfer body is at least partially positioned within the one or more through holes.

[0026] According to yet another aspect of the present invention, there is provided a display device according to any one of the above aspects, wherein the light control device includes a plurality of light emitting elements.

[0027] According to yet another aspect of the present invention, there is provided a display device according to any one of the above aspects, wherein the light control device includes a plurality of light emitting diodes.

[0028] According to the present invention, a display device with excellent heat dissipation properties is provided.

[0029] FIG. 1 is a plan view showing a part of a display device according to a first embodiment of the present invention. FIG. 2 is an equivalent circuit diagram of the display device shown in FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III of the display device shown in FIG. 1. FIG. 4 is a cross-sectional view taken along line IV-IV of the display device shown in FIG. 1. FIG. 5 is a plan view showing a part of a wavelength conversion substrate included in the display device of FIG. 1. FIG. 6 is a cross-sectional view showing a part of a display device according to a second embodiment of the present invention. FIG. 7 is a plan view showing a part of a wavelength conversion substrate included in a display device according to a first modified example. FIG. 8 is a plan view showing a part of a wavelength conversion substrate included in a display device according to a second modified example.

[0030] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments described below are more specific embodiments of any of the above aspects. The following items can be incorporated into each of the above aspects, either singly or in combination.

[0031] Furthermore, the embodiments shown below are merely examples of configurations for embodying the technical idea of ​​the present invention, and the technical idea of ​​the present invention is not limited by the materials, shapes, structures, etc. of the components described below. Various modifications can be made to the technical idea of ​​the present invention within the technical scope defined by the claims.

[0032] In the drawings, elements having the same or similar functions are denoted by the same reference numerals, and redundant explanations will be omitted. Furthermore, the drawings are schematic, and the relationship between dimensions in one direction and dimensions in another direction, and the relationship between the dimensions of one member and the dimensions of another member, etc. may differ from the actual relationship.

[0033] <1> First Embodiment Fig. 1 is a plan view showing a part of a display device according to a first embodiment of the present invention. Fig. 2 is an equivalent circuit diagram of the display device shown in Fig. 1. Fig. 3 is a cross-sectional view taken along line III-III of the display device shown in Fig. 1. Fig. 4 is a cross-sectional view taken along line IV-IV of the display device shown in Fig. 1. Fig. 5 is a plan view showing a part of a wavelength conversion substrate included in the display device of Fig. 1. In Fig. 1, the area surrounded by a dashed line represents the opening of a third through-hole on the transparent substrate 31 side of a black matrix 32, as will be described later.

[0034] The display device 1A shown in FIGS. 1 to 4 is a micro LED display capable of color display using an active matrix driving method, in which each sub-pixel includes a light-emitting diode (LED).

[0035] In each figure, the X direction and the Y direction are parallel to the display surface of the display device 1A and intersect with each other. According to one example, the X direction and the Y direction are perpendicular to each other. The Z direction is perpendicular to the X direction and the Y direction. That is, the Z direction is the thickness direction of the display device 1A.

[0036] As shown in FIG. 2, the display device 1A includes video signal lines VSL, power supply lines PSL, scanning signal lines SSL, pixels PX, a video signal line driver VDR, and a scanning signal line driver SDR.

[0037] The video signal lines VSL and power supply lines PSL each extend in the Y direction and are alternately arranged in the X direction. The scanning signal lines SSL each extend in the X direction and are arranged in the Y direction.

[0038] The pixels PX are arranged in the X and Y directions. Each pixel PX includes a first sub-pixel PXR, a second sub-pixel PXG, and a third sub-pixel PXB. The first sub-pixel PXR, the second sub-pixel PXG, and the third sub-pixel PXB are arranged corresponding to intersections between the video signal lines VSL and the scanning signal lines SSL.

[0039] The first sub-pixel PXR, the second sub-pixel PXG, and the third sub-pixel PXB emit light of different colors. Here, as an example, the first sub-pixel PXR, the second sub-pixel PXG, and the third sub-pixel PXB emit red light, green light, and blue light, respectively.

[0040] In each pixel PX, the first sub-pixel PXR, the second sub-pixel PXG, and the third sub-pixel PXB are arranged in this order in the X direction. The arrangement order of the first sub-pixel PXR, the second sub-pixel PXG, and the third sub-pixel PXB in each pixel PX can be changed.

[0041] Here, the first sub-pixel PXR, the second sub-pixel PXG, and the third sub-pixel PXB form a stripe arrangement. The first sub-pixel PXR, the second sub-pixel PXG, and the third sub-pixel PXB may form other arrangements such as a delta arrangement or a mosaic arrangement.

[0042] Each of the first sub-pixel PXR, the second sub-pixel PXG, and the third sub-pixel PXB includes a light-emitting element D, a drive control element DR, a switch SW, and a capacitor C.

[0043] The light-emitting element D is a light-emitting diode. The light-emitting diode is, for example, a light-emitting diode made of an inorganic material. A light-emitting diode made of an inorganic material can be obtained, for example, by dividing a laminate having a similar layer structure into a plurality of parts. The light-emitting element D may be an electroluminescence element, which is a light-emitting diode made of an organic material. The cathode of the light-emitting element D is connected to a ground electrode. Here, as an example, the light-emitting element D is assumed to be a blue light-emitting diode made of an inorganic material that emits blue light.

[0044] The drive control element DR and the switch SW are field-effect transistors. Here, the drive control element DR is a p-channel thin-film transistor, and the switch SW is an n-channel thin-film transistor. The drive control element DR has a gate connected to the drain of the switch SW, a source connected to a power supply line PSL, and a drain connected to the anode of the light-emitting element D. The switch SW has a gate connected to a scanning signal line SSL and a source connected to a video signal line VSL.

[0045] The capacitor C is, for example, a thin film capacitor. One electrode of the capacitor C is connected to the gate of the drive control element DR, and the other electrode is connected to the power supply line PSL.

[0046] The first subpixel PXR further includes a first wavelength conversion layer 36R and a first colored layer 33R shown in FIGS.

[0047] The first wavelength conversion layer 36R is disposed to face the light-emitting element D of the first subpixel PXR. The first wavelength conversion layer 36R converts the light emitted by the light-emitting element D of the first subpixel PXR into first light of a specific color. For example, the first wavelength conversion layer 36R converts blue light emitted by the light-emitting element D of the first subpixel PXR into red light.

[0048] The first colored layer 33R is disposed to face the light-emitting element D of the first sub-pixel PXR, with the first wavelength conversion layer 36R sandwiched therebetween. The first colored layer 33R transmits light whose wavelength has been converted by the first wavelength conversion layer 36R, and absorbs light whose wavelength has not been converted by the first wavelength conversion layer 36R. The first colored layer 33R is, for example, a red colored layer that transmits red light whose wavelength has been converted by the first wavelength conversion layer 36R, and absorbs blue light and the like whose wavelength has not been converted by the first wavelength conversion layer 36R.

[0049] The second subpixel PXG further includes a second wavelength conversion layer 36G and a second colored layer 33G shown in FIG.

[0050] The second wavelength conversion layer 36G is disposed to face the light-emitting element D of the second subpixel PXG. The second wavelength conversion layer 36G converts the light emitted by the light-emitting element D of the second subpixel PXG into second light having a color different from the first light. For example, the second wavelength conversion layer 36G converts blue light emitted by the light-emitting element D of the second subpixel PXG into green light.

[0051] The second colored layer 33G is disposed to face the light-emitting element D of the second subpixel PXG with the second wavelength conversion layer 36G sandwiched therebetween. The second colored layer 33G transmits light whose wavelength has been converted by the second wavelength conversion layer 36G and absorbs light whose wavelength has not been converted by the second wavelength conversion layer 36G. The second colored layer 33G is, for example, a green colored layer that transmits green light whose wavelength has been converted by the second wavelength conversion layer 36G and absorbs blue light and the like whose wavelength has not been converted by the second wavelength conversion layer 36G.

[0052] The third subpixel PXB further includes the underlayer 33B and the filling layer 36B shown in FIG.

[0053] The filling layer 36B is disposed so as to face the light-emitting element D of the third sub-pixel PXB. The filling layer 36B is, for example, a colorless and transparent layer. The filling layer 36B can be omitted.

[0054] The base layer 33B is disposed to face the light-emitting element D of the third subpixel PXB with the filling layer 36B sandwiched therebetween. The base layer 33B transmits light emitted by the light-emitting element D of the third subpixel PXB as third light. The base layer 33B is, for example, a colorless light-transmitting layer or a blue-colored layer that transmits blue light emitted by the light-emitting element D of the third subpixel PXB.

[0055] The video signal line driver VDR and the scan signal line driver SDR are mounted on the display panel using a chip on glass (COG) method, as shown in Fig. 2. The video signal line driver VDR and the scan signal line driver SDR may be mounted using a tape carrier package (TCP) instead of using a COG method.

[0056] The video signal line driver VDR is connected to the video signal line VSL and the power supply line PSL, and outputs a voltage signal as a video signal to the video signal line VSL.

[0057] The scanning signal line driver SDR is connected to the scanning signal line SSL. The scanning signal line driver SDR outputs a voltage signal as a scanning signal to the scanning signal line SSL. The power supply line PSL may be connected to the scanning signal line driver SDR instead of to the video signal line driver VDR.

[0058] The display device 1A will be described in more detail below. As shown in Figures 3 and 4, the display device 1A includes a light control device 2, a wavelength conversion substrate 3A, an adhesive layer 4, a heat sink 5A, and a heat conductor including a main heat conductor 6A and an auxiliary heat conductor 7.

[0059] The light control device is a device that emits light toward a wavelength conversion substrate and is capable of adjusting at least one of the intensity of the light and the time for emitting the light for each pixel or each subpixel. The light control device 2 shown in Figures 3 and 4 includes a substrate 21, a semiconductor layer 22, conductor layers 23A, 23B, 23C, and 23D, insulating layers 24A, 24B, and 24C, a light emitting element 25, a partition layer 26, a filling layer 27, and a conductor layer 28.

[0060] The substrate 21 includes, for example, an insulating substrate such as a glass substrate. The substrate 21 may further include an undercoat layer provided on the main surface of the insulating substrate facing the wavelength conversion substrate 3A. The undercoat layer is, for example, a laminate of a silicon nitride layer and a silicon oxide layer sequentially stacked on the insulating substrate. The substrate 21 may be a semiconductor substrate such as a silicon substrate. The substrate 21 may be rigid or flexible.

[0061] The semiconductor layers 22 are arranged on the main surface of the substrate 21 facing the wavelength conversion substrate 3A. The semiconductor layers 22 are, for example, polysilicon layers. The semiconductor layers 22 are semiconductor layers of thin film transistors constituting the drive control elements DR or the switches SW. Each semiconductor layer 22 includes a source and a drain and a channel region interposed therebetween.

[0062] The conductor layer 23A is a conductor pattern provided on the main surface of the substrate 21. The conductor layer 23A forms the video signal line VSL, the power supply line PSL, the source electrode SE, the drain electrode DE, and the lower electrode (not shown) of the capacitor C. The source electrode SE and the drain electrode DE are connected to the source and drain of the semiconductor layer 22, respectively. The conductor layer 23A is made of a metal or an alloy. The conductor layer 23A may have a single-layer structure or a multi-layer structure.

[0063] The insulating layer 24A covers the conductor layer 23A and the main surface of the substrate 21. The insulating layer 24A can be formed using, for example, TEOS (tetraethyl orthosilicate). The gate insulating film of each thin-film transistor constituting the drive control element DR or the switch SW is part of the insulating layer 24A. The dielectric layer of each capacitor C is another part of the insulating layer 24A.

[0064] The conductor layer 23B is a conductor pattern provided on the insulating layer 24A. The gate electrode GE of each thin-film transistor constituting the drive control element DR or switch SW is part of the conductor layer 23B. Each gate electrode GE faces the channel region of the semiconductor layer 22 with the insulating layer 24A sandwiched therebetween. The upper electrode (not shown) of each capacitor C is another part of the conductor layer 23B. Each upper electrode faces the lower electrode of the capacitor C including this upper electrode with the insulating layer 24A sandwiched therebetween. The conductor layer 23B is made of a metal or an alloy. The conductor layer 23B may have a single-layer structure or a multi-layer structure.

[0065] The insulating layer 24B covers the conductor layer 23B and the insulating layer 24A. The insulating layer 24B is an interlayer insulating film. The insulating layer 24B is made of an inorganic insulator such as silicon oxide. The insulating layer made of an inorganic insulator can be formed by, for example, plasma CVD (chemical vapor deposition).

[0066] 4, the conductor layer 23C is a conductor pattern provided on the insulating layer 24B. The conductor layer 23C constitutes the scanning signal line SSL. The source electrode SE and the drain electrode DE may be provided on the insulating layer 24B instead of on the insulating layer 24A. In other words, the scanning signal line SSL and the source electrode SE and the drain electrode DE may be formed by the conductor layer 23C.

[0067] The insulating layer 24C covers the conductor layer 23C and the insulating layer 24B. The insulating layer 24C is a passivation film and is made of an inorganic insulator such as silicon nitride.

[0068] The conductor layer 23D is a conductor pattern provided on the insulating layer 24C. The conductor layer 23D forms electrode pads arranged in the X and Y directions corresponding to the first sub-pixel PXR, the second sub-pixel PXG, and the third sub-pixel PXB. A through-hole is provided in the laminated body made up of the insulating layers 24A, 24B, and 24C at the position of the drain electrode DE connected to the drain of the drive control element DR. Each electrode pad is connected to the drain electrode DE via this through-hole. The conductor layer 23D is made of, for example, a metal or an alloy. The conductor layer 23D may have a single-layer structure or a multi-layer structure.

[0069] The outline of the orthogonal projection of each electrode pad onto a plane perpendicular to the Z direction is spaced apart from and surrounds the orthogonal projection onto a plane beyond the light-emitting element 25 placed on the electrode pad. That is, the electrode pad has a larger dimension in the direction perpendicular to the Z direction than the light-emitting element 25. Therefore, the electrode pad also serves as a reflective layer that reflects light traveling toward the substrate 21. The electrode pad does not have to fulfill this role as a reflective layer. In this case, a reflective layer that fulfills this role may or may not be provided separately from the electrode pad.

[0070] The light emitting element 25 shown in Figures 3 and 4 is the light emitting element D shown in Figure 2. The light emitting element 25 is disposed on an electrode pad.

[0071] Here, the light emitting element 25 is a light emitting diode made of an inorganic material. Note that a substrate including a light emitting diode as the light emitting element 25 is sometimes called an "LED substrate."

[0072] The light-emitting element 25 has a multilayer structure including a plurality of layers, for example, a first layer 251, a second layer 252, and a third layer 253. Here, the stacking direction of the layers included in the light-emitting element 25 is the Z direction. This stacking direction may be perpendicular to the Z direction.

[0073] Each light-emitting element 25 includes an anode and a cathode. The light-emitting element 25 has an anode and a cathode on one side. The anode of the light-emitting element 25 is connected to an electrode pad via a bonding wire (not shown). When the light-emitting element 25 has an anode on one side and a cathode on the other side, the light-emitting element 25 may be bonded to the electrode pad and the anode may be connected to the electrode pad by die bonding using a conductive material such as a conductive paste as a bonding material. When the light-emitting element 25 has an anode and a cathode on one side, the conductor layer 28 may be omitted, and electrode pads for connecting to the cathodes of the light-emitting elements 25 may be further provided on the insulating layer 24C, and wiring connected to these electrode pads may be further provided between the insulating layers. The electrode pads of the light-emitting element 25 may be bonded to the conductor layer 28 and the anode and cathode may be connected to the electrode pads by flip-chip bonding.

[0074] The dimensions of the light-emitting element 25 in the X and Y directions are preferably in the range of 1 to 100 μm, more preferably in the range of 5 to 80 μm, and even more preferably in the range of 10 to 60 μm. The dimension of the light-emitting element 25 in the Z direction is preferably in the range of 1 to 20 μm, more preferably in the range of 1 to 15 μm, and even more preferably in the range of 1 to 10 μm.

[0075] The partition layer 26 is provided on the insulating layer 24C. The partition layer 26 has through holes at the positions of the electrode pads. The light-emitting elements 25 are respectively located in these through holes. The partition layer 26 is made of, for example, a resin. Such a partition layer 26 can be formed by photolithography using a photosensitive resin. The partition layer 26 may include a resin layer having through holes and a reflective layer covering the side walls of the through holes and, optionally, the upper surface of the resin layer. The reflective layer may have a single-layer structure or a multi-layer structure. The layers included in the reflective layer are, for example, metals, alloys, or transparent dielectrics. The partition layer 26 may be omitted.

[0076] The filling layer 27 fills the gap between the light emitting element 25 and the partition layer 26. The filling layer 27 is a light-transmitting layer that transmits light emitted by the light emitting element 25. The filling layer 27 also serves as a protective layer that protects the light emitting element 25 and the joints between the light emitting element 25 and the electrodes. The filling layer 27 is made of, for example, a resin. It is preferable that the refractive index of the filling layer 27 is different from the refractive index of the material that forms the surface of the partition layer 26.

[0077] The conductor layer 28 is provided on the partition layer 26 and the filling layer 27. The cathode of the light-emitting element 25 is connected to the conductor layer 28. When the conductor layer 28 is made of a conductive transparent oxide, it can be provided so as to cover the entire cathode of the light-emitting element 25. When the conductor layer 28 is made of a metal or an alloy, it is preferable that the conductor layer 28 be provided so as to partially cover the cathode of the light-emitting element 25.

[0078] The wavelength conversion substrate 3A faces the light control device 2. Specifically, the wavelength conversion substrate 3A faces the substrate 21 with the light emitting element 25 and the like sandwiched therebetween.

[0079] The wavelength conversion substrate 3A includes a transparent substrate 31, a black matrix 32, a partition layer 34, a color filter including a first colored layer 33R and a second colored layer 33G, a base layer 33B, a first wavelength conversion layer 36R, a second wavelength conversion layer 36G, a filling layer 36B, an overcoat layer 37, and a heat transfer layer 38. Each of the first wavelength conversion layer 36R, the second wavelength conversion layer 36G, and the filling layer 36B is a functional layer.

[0080] The transparent substrate 31 is transparent to visible light. The transparent substrate 31 is, for example, a colorless substrate. The transparent substrate 31 may have a single-layer structure or a multi-layer structure. The transparent substrate 31 is made of, for example, glass, transparent resin, or a combination thereof. The transparent substrate 31 may be rigid or flexible. The transparent substrate 31 has a first main surface facing the light control device 2 and a second main surface that is the back surface of the first main surface.

[0081] The black matrix 32 is provided on the first main surface of the transparent substrate 31. The black matrix 32 is a black layer that blocks visible light. The black matrix 32 can be omitted.

[0082] The black matrix 32 is made of, for example, a mixture containing a binder resin and a colorant. The colorant is, for example, a black pigment or a mixture of pigments that exhibit black through subtractive color mixing, such as a mixture containing blue, green, and red pigments.

[0083] The black matrix 32 has third through holes at the positions of the light emitting elements 25. The opening of each third through hole on the transparent substrate 31 side has a larger dimension in the direction perpendicular to the Z direction than the light emitting elements 25.

[0084] Here, the openings of the third through holes on the transparent substrate 31 side have a shape extending in the Y direction, as shown by the dashed lines in FIG. 1 . Each portion of the black matrix 32 corresponding to a pixel PX includes a third through hole provided at the position of the first sub-pixel PXR, a third through hole provided at the position of the second sub-pixel PXG, and a third through hole provided at the position of the third sub-pixel PXB, and these three third through holes are arranged in the X direction. A plurality of third through hole groups, each consisting of these three third through holes, are arranged in the X and Y directions. The distance between adjacent third through hole groups in the X direction is greater than the distance between third through holes included in the same through hole group. The distance between adjacent third through hole groups in the Y direction is also greater than the distance between third through holes included in the same through hole group.

[0085] The aperture ratio of the black matrix 32 is preferably in the range of 5 to 66%, more preferably in the range of 5 to 40%, and even more preferably in the range of 5 to 20%. Light-emitting diodes made of inorganic materials can emit bright light even when their light-emitting surface is small, and they also have a long lifespan. Therefore, when the light-emitting elements 25 are light-emitting diodes made of inorganic materials, a bright display is possible even if the aperture ratio of the black matrix 32 is reduced. Furthermore, reducing the aperture ratio of the black matrix 32 can suppress reflection of external light, allowing for a deeper black color to be displayed, thereby achieving a higher contrast ratio.

[0086] The thickness of the black matrix 32 is preferably in the range of 1 to 30 μm, more preferably in the range of 1 to 15 μm, and even more preferably in the range of 1 to 5 μm. A thick black matrix 32 is advantageous for achieving high light-blocking properties. However, if the black matrix 32 is too thick, light may not reach deep into the coating film made of a photosensitive black composition during pattern exposure, making it difficult to achieve high shape accuracy.

[0087] As shown in FIGS. 3 and 4 , the partition wall layer 34 is provided on the black matrix 32. According to one example, the partition wall layer 34 is a resin layer. This resin layer is, for example, transparent. In this case, the resin layer may be colored or colorless. The resin layer may have light scattering properties. According to one example, the resin layer is made of a composite material in which metal oxide particles or carbon particles are dispersed in a resin, and is a light-shielding layer having an optical density (OD value) of 3 or less for all light having a wavelength in the range of 400 to 700 nm.

[0088] The partition layer 34 has first through holes at the positions of the third through holes, respectively. These first through holes constitute first through hole groups corresponding to the above-mentioned third through hole groups. Here, each first through hole group consists of three first through holes arranged in the X direction. The first through hole groups are arranged in first and second directions that intersect with each other, here, the X direction and the Y direction.

[0089] As shown in FIG. 5, the distance W between adjacent first through-hole groups in the X direction is ｘ 1 is the distance W between the first through holes included in the same through hole group ｘ 2. The distance W between adjacent first through-hole groups in the Y direction is ｙ 1 also represents the distance W between the first through holes included in the same through hole group. ｘ It is larger compared to 2.

[0090] Distance W ｘ 2 is preferably in the range of 5 to 80 μm, more preferably in the range of 5 to 40 μm, and even more preferably in the range of 5 to 20 μm.

[0091] Distance W ｘ 1 is preferably in the range of 5 to 250 μm, more preferably in the range of 50 to 250 μm, and even more preferably in the range of 100 to 250 μm.

[0092] Distance W ｙ 1 is preferably in the range of 5 to 250 μm, more preferably in the range of 5 to 100 μm, and even more preferably in the range of 5 to 50 μm.

[0093] Distance W ｘ 1 and distance W ｘ Ratio to 2 W ｘ 1 / W ｘ The distance W is preferably in the range of 0.1 to 50, more preferably in the range of 2 to 20, and even more preferably in the range of 5 to 15. ｘ 1 is the distance W ｘ 2, and the distance W ｘ It may be smaller than 2.

[0094] Distance W ｙ 1 and distance W ｘ Ratio to 2 W ｙ 1 / W ｘ The distance W is preferably in the range of 0.1 to 50, more preferably in the range of 0.1 to 10, and even more preferably in the range of 0.1 to 5. ｙ 1 is the distance W ｘ 2, and the distance W ｘ It may be smaller than 2.

[0095] The first through-holes are provided such that the outlines of the orthogonal projections of the openings on the transparent substrate 31 side onto the first main surface (hereinafter referred to as first outlines) surround the outlines of the orthogonal projections of the third through-holes onto the first main surface (hereinafter referred to as second outlines). The first outlines do not have to surround the second outlines. In a structure in which the first outlines surround the second outlines, the effect of stray light on display is smaller than in a structure in which the first outlines do not surround the second outlines.

[0096] The partition wall layer 34 has a portion sandwiched between adjacent first through holes, i.e., a partition wall portion, which has a forward tapered cross-sectional shape. The partition wall portion may have a rectangular cross-sectional shape, a reverse tapered cross-sectional shape, or another cross-sectional shape.

[0097] The thickness of the partition wall layer 34 is preferably in the range of 5 to 50 μm, more preferably in the range of 5 to 40 μm, even more preferably in the range of 10 to 40 μm, and most preferably in the range of 10 to 25 μm. If the thickness of the partition wall layer 34 is small, it is difficult to increase the total thickness of the layers formed in the first through holes. If the partition wall layer 34 is made thicker, the shape accuracy of the partition wall portions sandwiched between adjacent first through holes decreases.

[0098] The partition wall layer 34 may have a single-layer structure or a multi-layer structure. According to one example, the partition wall layer 34 having a multi-layer structure includes a resin layer having the shape described above for the partition wall layer 34, and a reflective layer covering the side walls of the through holes provided in the resin layer.

[0099] The reflective layer may cover the entire sidewall of the through-hole provided in the resin layer, or may partially cover the sidewall. The reflective layer may further cover the upper surface of the resin layer. The reflective layer may cover the entire upper surface of the resin layer, or may partially cover the upper surface of the resin layer. The reflective layer may further cover the upper surfaces of each of the first colored layer 33R, the second colored layer 33G, and the base layer 33B. The reflective layer may cover the entire upper surface of each of the first colored layer 33R, the second colored layer 33G, and the base layer 33B, or may partially cover these upper surfaces.

[0100] The reflective layer may have a single layer structure or a multilayer structure. The layers included in the reflective layer are made of, for example, a metal, an alloy, or a transparent dielectric.

[0101] 3 and 4, the first colored layer 33R fills the third through-hole at the position of the first sub-pixel PXR. As described above, here, the first colored layer 33R is a red colored layer.

[0102] The second colored layer 33G fills the third through-hole at the position of the second sub-pixel PXG, as shown in Fig. 3. As described above, the second colored layer 33G is a green colored layer here.

[0103] The base layer 33B fills the third through-hole at the position of the third sub-pixel PXB, as shown in Fig. 3. As described above, the base layer 33B is a colorless light-transmitting layer or a blue colored layer here.

[0104] The first wavelength conversion layer 36R is provided on the first colored layer 33R and fills at least the bottom of the second recess. The first wavelength conversion layer 36R is a layer containing a phosphor such as a quantum dot phosphor and a transparent resin. As described above, the first wavelength conversion layer 36R converts the blue light emitted by the light-emitting element D of the first sub-pixel PXR into red light.

[0105] The second wavelength conversion layer 36G is provided on the second colored layer 33G and fills at least the bottom of the second recess. The second wavelength conversion layer 36G is a layer containing a phosphor such as a quantum dot phosphor and a transparent resin. As described above, the second wavelength conversion layer 36G converts the blue light emitted by the light-emitting element D of the second sub-pixel PXG into green light.

[0106] The filling layer 36B is provided on the base layer 33B and fills at least the bottom of the second recess. As described above, the filling layer 36B is a colorless and transparent layer. In this case, the filling layer 36B is made of, for example, a transparent resin.

[0107] The overcoat layer 37 is interposed between the functional layer and the heat transfer layer 38. Here, the overcoat layer 37 is further interposed between the partition wall layer 34 and the heat transfer layer 38. As described above, the functional layers are the first wavelength conversion layer 36R, the second wavelength conversion layer 36G, and the filling layer 36B.

[0108] The overcoat layer 37 is a colorless and transparent layer. The overcoat layer 37 is made of, for example, a cured resin. The overcoat layer 37 can be omitted.

[0109] The overcoat layer 37 can function as a planarizing layer. The overcoat layer 37 can also make it difficult for heat to be conducted from the heat transfer layer 38 to the functional layer. The thickness of the portion of the overcoat layer 37 that covers the functional layer is preferably 1 μm or more, and more preferably 3 μm or more.

[0110] The thickness of the portion of the overcoat layer 37 that covers the functional layer is W ｘ 2 / 2 or less, and W ｘ It is more preferable that the thickness of the overcoat layer 37 is 2 / 3 or less. If the overcoat layer 37 is made thicker, the wavelength conversion substrate 3A becomes thicker, and therefore the display device 1A also becomes thicker. In addition, there is a possibility that color mixing occurs due to waveguiding to adjacent pixels.

[0111] The portions of the overcoat layer 37 further interposed between the partition wall layer 34 and the heat transfer layer 38 may be omitted. However, if the overcoat layer 37 includes these portions, it is possible to make it difficult for heat to be conducted from the heat transfer layer 38 to the partition wall layer 34, and therefore it is possible to make it difficult for heat to be conducted from the heat transfer layer 38 to the functional layer via the partition wall layer 34. The thickness of the portions of the overcoat layer 37 further interposed between the partition wall layer 34 and the heat transfer layer 38 is preferably 1 μm or more, and more preferably 3 μm or more.

[0112] The heat transfer layer 38 faces the first main surface of the transparent substrate 31, with the partition layer 34 and the functional layer sandwiched therebetween. Here, the heat transfer layer 38 is provided on the overcoat layer 37.

[0113] In this display device 1A, the main heat source is the light emitting element 25. As will be described later, part of the heat generated in the light emitting element 25 is conducted to the heat sink 5A via the heat transfer layer 38 and the heat transfer body.

[0114] The heat transfer layer 38 is optically transparent at the positions of the first through holes provided in the partition layer 34. Therefore, the heat transfer layer 38 allows the light emitted by the light emitting element 25 to enter the functional layer.

[0115] The heat transfer layer 38 has one or more openings. More specifically, as shown in FIG. 5 , the heat transfer layer 38 has second through holes at the positions of the first through holes provided in the partition wall layer 34.

[0116] 5, a rectangle having an outline made of dashed dotted lines represents the opening of the first through-hole on the opposite side of the transparent substrate 31 and corresponds to a first orthogonal projection of this opening onto the first main surface. Also, in FIG. 5, a rectangle made of solid lines represents an opening (here, the second through-hole) provided in the heat transfer layer 38 and corresponds to a second orthogonal projection of the opening onto the first main surface. The first orthogonal projection at least partially overlaps with the second orthogonal projection.

[0117] Here, the contour of the first orthogonal projection surrounds the second orthogonal projection. Therefore, the overlapping portion between the first and second orthogonal projections is smaller than that of the first orthogonal projection. The area of ​​this overlapping portion is preferably 50% or less, and more preferably 10% or less, of the area of ​​the first orthogonal projection. Reducing this ratio makes it more difficult for heat to be conducted from the light-emitting element 25 to the functional layer.

[0118] The ratio of the area of ​​the overlapping portion to the area of ​​the first orthogonal projection is preferably 1% or more, and more preferably 5% or more. If the heat transfer layer 38 is light-blocking at positions other than the openings, reducing the ratio may increase the ratio of light emitted by the light-emitting element 25 that is blocked by the heat transfer layer 38 and does not enter the functional layer.

[0119] The heat transfer layer 38 has a higher thermal conductivity than the functional layer 31. Preferably, the heat transfer layer 38 has a higher thermal conductivity than the overcoat layer 37.

[0120] The heat transfer layer 38 is preferably made of a material having a thermal conductivity of 15 W / m·K or more, and more preferably made of a material having a thermal conductivity of 150 W / m·K or more. The thermal conductivity of the material constituting the heat transfer layer 38 is, for example, 450 W / m·K or less.

[0121] The heat transfer layer 38 may have a single-layer structure or a multi-layer structure. The layers included in the heat transfer layer 38 are made of, for example, a metal, an alloy, or a transparent oxide. From the viewpoint of thermal conductivity, the heat transfer layer 38 preferably includes a layer made of a metal or an alloy. Examples of metals include titanium, chromium, aluminum, copper, or silver. Examples of alloys include aluminum alloys such as aluminum-neodymium alloys. Examples of transparent oxides include inorganic oxides such as silicon oxide, aluminum oxide, and titanium oxide. Here, as an example, the heat transfer layer 38 includes a layer made of a metal or an alloy.

[0122] The thickness of the heat transfer layer 38 is preferably in the range of 100 to 5000 nm, and more preferably in the range of 100 to 1000 nm. Increasing the thickness of the heat transfer layer 38 improves the thermal conductivity in the in-plane direction. However, increasing the thickness of the heat transfer layer 38 increases the manufacturing cost.

[0123] The heat transfer layer 38 can be formed by, for example, performing film formation by a vapor phase deposition method such as sputtering or vacuum deposition, forming an etching mask, and etching such as wet etching in this order. The etching mask can be formed by photolithography using a photosensitive resin. The transparent resin layer used as the etching mask may or may not be removed after the above etching.

[0124] The adhesive layer 4 is interposed between the light control device 2 and the wavelength conversion substrate 3A and bonds them together. The adhesive layer 4 transmits light emitted by the light emitting element 25. The adhesive layer 4 is, for example, a colorless and transparent layer. The adhesive layer 4 is made of an adhesive or a pressure-sensitive adhesive.

[0125] The heat sink 5A is located outside the laminate of the light control device 2, the wavelength conversion substrate 3A, and the adhesive layer 4. Here, the heat sink 5A is a back surface heat sink provided to face the wavelength conversion substrate 3A with the light control device 2 and the adhesive layer 4 sandwiched therebetween. More specifically, the heat sink 5A here is a back surface heat dissipation layer provided on the light control device 2.

[0126] The heat sink 5A is made of a highly thermally conductive material. Examples of the highly thermally conductive material include metals such as copper, aluminum, iron, silver, titanium, molybdenum, tantalum, tungsten, and niobium; alloys containing one or more of these metals; carbides such as tungsten carbide; carbon materials such as graphite, graphene, carbon nanotubes, and diamond; other insulating ceramics; and composites containing one or more of these. The heat sink 5A may have a single-layer structure or a multi-layer structure.

[0127] The heat sink 5A has a flat surface. The heat sink 5A with a flat surface can be formed, for example, by forming a film on the dimmer 2. Alternatively, the heat sink 5A with a flat surface can be provided on the dimmer 2 by being attached to the dimmer 2. The heat sink 5A with a flat surface makes it easy to form the heat sink 5A or to install the heat sink 5A on the dimmer 2.

[0128] The heat sink 5A may have an uneven surface. For example, the heat sink 5A may have a plurality of fins or pins on the surface. Such a heat sink 5A has a large surface area and is excellent in heat dissipation.

[0129] Apparent area S of the heat sink 5A ＲＢ and the area S of the back surface of the light control device 2 Ｂ Ratio to S ＲＢ / S Ｂ is preferably 0.5 or more, and more preferably 0.8 or more. ＲＢ / S Ｂ The larger the ratio S, the higher the heat dissipation. ＲＢ / S Ｂ The upper limit of the ratio S is, for example, 1. ＲＢ / S Ｂ may be greater than one.

[0130] The minimum thickness of the heat sink 5A is preferably 100 μm or more, and more preferably 1000 μm or more. Increasing the minimum thickness of the heat sink 5A increases the heat capacity of the heat sink 5A and decreases the thermal resistance of the heat sink 5A. Although there is no upper limit to the minimum thickness of the heat sink 5A, increasing the minimum thickness of the heat sink 5A increases the thickness of the display device 1A. From this perspective, the minimum thickness of the heat sink 5A is preferably 5 mm or less.

[0131] The heat conductor is at least partially provided outside the laminate. The heat conductor conducts heat from the heat transfer layer 38 to the heat sink 5A. Here, the heat conductor at least partially covers the end face of the laminate. As a result, the heat conductor is in contact with the heat transfer layer 38 and the heat sink 5A at the end face of the laminate. It is preferable that the heat conductor be in contact with the heat transfer layer 38 and the heat sink 5A over substantially the entire periphery of the laminate.

[0132] As described above, the heat transfer body here is composed of the main heat transfer body 6A and the auxiliary heat transfer body 7. The main heat transfer body 6A is provided outside the stack. Here, the main heat transfer body 6A at least partially covers the end face of the stack. According to one example, the main heat transfer body 6A is made of a highly thermally conductive material and is a member attached to the end face of the stack. According to another example, the main heat transfer body 6A is made of a highly thermally conductive material and is a layer formed on the end face of the stack.

[0133] The auxiliary heat conductor 7 is provided on the heat transfer layer 38 at the peripheral edge of the wavelength conversion substrate 3A. According to one example, the auxiliary heat conductor 7 is a member made of a highly thermally conductive material and placed on the heat transfer layer 38 at the peripheral edge of the wavelength conversion substrate 3A. According to another example, the auxiliary heat conductor 7 is a layer made of a highly thermally conductive material and formed on the heat transfer layer 38 at the peripheral edge of the wavelength conversion substrate 3A. Here, the auxiliary heat conductor 7 is in contact with the heat transfer layer 38 and the main heat conductor 6A. Thus, the auxiliary heat conductor 7 assists in heat transfer from the heat transfer layer 38 to the main heat conductor 6A. The auxiliary heat conductor 7 can be omitted.

[0134] As described above, the main heat transfer body 6A and the auxiliary heat transfer body 7 are made of a highly thermally conductive material. Examples of the highly thermally conductive material that can be used include those exemplified for the heat sink 5A. Each of the main heat transfer body 6A and the auxiliary heat transfer body 7 may have a single-layer structure or a multi-layer structure.

[0135] In this display device 1A, the light emitting element 25 is the main heat source. A portion of the heat generated in the light emitting element 25 is conducted to the heat sink 5A disposed outside the laminate via the heat transfer layer 38 and the heat conductor. Therefore, this display device 1A is less likely to accumulate heat inside the laminate, and has excellent heat dissipation properties.

[0136] The display device 1A has such excellent heat dissipation properties, and is therefore less susceptible to deterioration, brightness reduction, and color shift, as will be described below.

[0137] In recent years, with the expansion of display device applications, there has been a demand for display devices with increased output and brightness to improve outdoor visibility. However, when display devices using light-emitting diodes are increased in output, heat generated by the light-emitting diodes can cause problems such as thermal degradation of nearby components such as wiring and encapsulating resins. Furthermore, phosphors such as quantum dots suffer from thermal degradation and a decrease in brightness and color shift (a shift in the wavelength showing the maximum intensity in the visible range; hereinafter referred to as wavelength shift) when emitting light at high temperatures. In particular, in display devices that include light-emitting diodes and have a structure in which a pair of substrates are bonded together via an adhesive layer, the light-emitting diodes, which are heat sources, are isolated from the atmosphere, so heat is likely to accumulate internally. Therefore, high-brightness display devices that convert short-wavelength light (blue light or ultraviolet light) emitted by light-emitting diodes into blue, green, and red light using phosphors such as quantum dots to provide a full-color display require excellent heat dissipation capabilities.

[0138] As described above, in the display device 1A, a portion of the heat generated in the light-emitting element 25 is conducted to the heat sink 5A disposed outside the laminate via the heat transfer layer 38 and the heat transfer body. Therefore, the display device 1A is less likely to accumulate heat inside the laminate, and the internal temperature is less likely to become excessively high. Therefore, the display device 1A is less likely to experience deterioration of quantum dots, brightness reduction, and color shift (wavelength shift).

[0139] Furthermore, in the display device 1A, the heat sink 5A is provided on the rear surface, so that the heat sink 5A does not interfere with the display. Therefore, various structures can be employed for the heat sink 5A.

[0140] <2> Second Embodiment Fig. 6 is a cross-sectional view showing a portion of a display device according to a second embodiment of the present invention. The display device 1B shown in Fig. 6 is similar to the display device 1A described above, except for the following configuration. That is, the display device 1B includes a dimming device 2B, which is substantially the same as the dimming device 2, except that it has one or more through holes extending in the Z direction, instead of the dimming device 2. In the display device 1B, the heat transfer body is provided inside a laminate of the dimming device 2B, the wavelength conversion substrate 3A, and the adhesive layer 4, and includes a main heat transfer body 29 and an auxiliary heat transfer body 6 instead of the main heat transfer body 6A and the auxiliary heat transfer body 7. The heat sink 5 is similar to the heat sink 5A described above.

[0141] The main heat conductor 29 is made of a highly thermally conductive material that fills a through-hole provided in the light control device 2B. The main heat conductor 29 may be formed by coating the sidewall of a through-hole provided in the light control device 2B with a highly thermally conductive material. The main heat conductor 29 promotes heat transfer from the heat transfer layer 38 to the heat sink 5A.

[0142] The auxiliary heat conductor 6 is disposed between the main heat conductor 29 and the heat transfer layer 38. The auxiliary heat conductor 6 is made of a highly thermally conductive material. The auxiliary heat conductor 6 promotes heat transfer from the heat transfer layer 38 to the main heat conductor 29. The auxiliary heat conductor 6 may be omitted.

[0143] As described above, the main heat transfer body 29 and the auxiliary heat transfer body 6 are made of a highly thermally conductive material. Examples of highly thermally conductive materials that can be used include those exemplified for the heat dissipation body 5A. Each of the main heat transfer body 29 and the auxiliary heat transfer body 6 may have a single-layer structure or a multi-layer structure. Like the display device 1A, the display device 1B also has excellent heat dissipation properties.

[0144] <3> Modifications The display device and wavelength conversion substrate described above can be modified in various ways, as exemplified below.

[0145] FIG. 7 is a plan view showing a part of a wavelength conversion substrate included in a display device according to a first modification.

[0146] The display device according to the first modification is similar to the display device 1A, except that it includes a wavelength conversion substrate 3B shown in Fig. 7 instead of the wavelength conversion substrate 3A. The wavelength conversion substrate 3B is similar to the wavelength conversion substrate 3A, except that it has the following configuration.

[0147] That is, in the wavelength conversion substrate 3B, the heat transfer layer 38 has a plurality of second through holes arranged in the X direction and the Y direction, and each of these second through holes is provided so as to straddle two or more of the first through holes. Here, each of the second through holes is provided so as to straddle three of the first through holes arranged in the X direction.

[0148] A display device including the wavelength conversion substrate 3B instead of the wavelength conversion substrate 3A also has excellent heat dissipation properties, similar to the display device 1A.

[0149] The structure described above for the wavelength conversion substrate 3B may have a smaller effect of preventing heat transfer to the functional layer than the structure described above for the wavelength conversion substrate 3A. However, when the relative position between the wavelength conversion substrate and the light control device 2 is shifted in the X direction, the structure described above for the wavelength conversion substrate 3B has a smaller effect on the display due to the positional shift than the structure described above for the wavelength conversion substrate 3A.

[0150] FIG. 8 is a plan view showing a part of a wavelength conversion substrate included in a display device according to a second modification.

[0151] The display device according to the second modification is similar to the display device 1A, except that it includes a wavelength conversion substrate 3C shown in Fig. 8 instead of the wavelength conversion substrate 3A. The wavelength conversion substrate 3C is similar to the wavelength conversion substrate 3A, except that it has the following configuration.

[0152] That is, in the wavelength conversion substrate 3C, the heat transfer layer 38 includes one or more strip portions. Here, the heat transfer layer 38 includes a plurality of strip portions that extend in a serpentine manner in the Y direction and are arranged in the X direction. Each of the strip portions is made up of first through holes arranged in the Y direction and faces three rows arranged in the X direction.

[0153] A display device including the wavelength conversion substrate 3C instead of the wavelength conversion substrate 3A also has excellent heat dissipation properties, similar to the display device 1A.

[0154] The structure described above for the wavelength conversion substrate 3C may have a smaller effect of preventing heat transfer to the functional layer than the structure described above for the wavelength conversion substrate 3A. However, the heat transfer layer 38 described above for the wavelength conversion substrate 3B can be formed not only by the above-mentioned method using vapor deposition, but also by a method such as printing a conductive paste.

[0155] Further modifications are possible to the display device and wavelength conversion substrate described above. For example, the wavelength conversion substrates 3B and 3C may be used in the display device 1B.

[0156] The heat transfer layer 38 may have other shapes such as a grid or stripe pattern. The heat transfer layer 38 may be composed of a plurality of portions spaced apart from each other and arranged in the X and Y directions. In consideration of heat dissipation, it is preferable that all portions constituting the heat transfer layer 38 be in contact with the heat transfer body.

[0157] The heat transfer layer 38 may be a transparent oxide layer. In this case, the heat transfer layer 38 may be a solid film without any openings.

[0158] The display device described above may be provided with a front heat dissipation body instead of the heat dissipation body 5A as a back surface heat dissipation body. The front heat dissipation body is, for example, a front heat dissipation layer provided on the second main surface of the transparent substrate 31. The front heat dissipation body is open at the position of the third through-hole provided in the black matrix 32.

[0159] The front heat sink is made of a highly thermally conductive material. Examples of the highly thermally conductive material that can be used include those exemplified for the heat sink 5A. The front heat sink may have a single-layer structure or a multi-layer structure.

[0160] The front heat sink preferably has a black surface. The front heat sink having a black surface may include, for example, one or more of chromium, copper oxide nitride, carbon nanotubes, graphite, and graphene on the surface or the entire surface. The front heat sink having a black surface may function similarly to the black matrix 32.

[0161] In this way, a display device provided with a front heat sink instead of a rear heat sink also has excellent heat dissipation properties, similar to the display device 1A.

[0162] The display device may be provided with both a rear surface heat sink and a front surface heat sink, in which case particularly excellent heat dissipation can be achieved.

[0163] The display device described above may not include a heat sink. In this case, the heat transfer body may also be omitted. If a heat sink or the like is omitted, the heat dissipation effect is not as high as when a heat sink or the like is provided. However, even if a heat sink or the like is omitted, the heat transfer layer 38 prevents heat transfer to the functional layer and promotes heat transfer from the center to the periphery of the display body. Therefore, even if a heat sink or the like is omitted, excellent heat dissipation performance can be achieved, although not as good as when a heat sink or the like is provided.

[0164] A circuit provided in a light control device or the like may have a configuration different from that shown in FIG. 2 . For example, the video signal line driver VDR may supply a current signal as a video signal to the video signal line VSL. In this case, the first subpixel PXR, the second subpixel PXG, and the third subpixel PXB may each be configured such that, during a write period in which a video signal is written, the gate-source voltage of the drive control element DR is set to a value corresponding to this current signal, and during a light emission period, a drive current having a magnitude corresponding to the gate-source voltage flows to the light-emitting element D. Furthermore, instead of employing a circuit for displaying an image using an active matrix drive system, the light control device 2 may employ a circuit for displaying an image using a passive matrix drive system.

[0165] Instead of using a blue light-emitting diode, an ultraviolet light-emitting diode may be used as the light-emitting element 25. In this case, the filling layer 36B is a wavelength conversion layer that converts the light emitted by the light-emitting element 25 of the third subpixel PXB into third light having a color different from the first light and the second light. For example, the first wavelength conversion layer 36R, the second wavelength conversion layer 36G, and the filling layer 36B convert the ultraviolet light emitted by the light-emitting element 25 into red light, green light, and blue light, respectively.

[0166] Although the above-described display device is capable of displaying color images, the display device may also display monochrome images. For example, in the display device 1A, the first subpixel PXR and the second subpixel PXG are omitted, a blue light-emitting diode is used as the light-emitting element 25, and the filler layer 36B is configured as a wavelength conversion layer that converts blue light to yellow light. If the filler layer 36B converts a portion of the blue light incident thereon into yellow light and transmits the remainder, it is possible to display white by additively mixing blue and yellow colors.

[0167] The wavelength conversion substrate may further include an overcoat layer interposed between the black matrix 32 and the partition wall layer 34. The overcoat layer may include a transparent resin and one or more of an ultraviolet absorber, a yellow pigment, and transparent particles. The overcoat layer including the ultraviolet absorber can absorb stray light incident on the partition wall layer 34 when the stray light is ultraviolet light.

[0168] The display device may be other than a micro LED display, such as an organic electroluminescent display device, although it is preferred that the display device includes a light emitting element.

[0169] DESCRIPTION OF SYMBOLS 1A...display device, 1B...display device, 2...light control device, 2B...light control device, 3A...wavelength conversion substrate, 3B...wavelength conversion substrate, 3C...wavelength conversion substrate, 4...adhesive layer, 5...heat sink, 5A...heat sink, 6...auxiliary heat conductor, 6A...main heat conductor, 7...auxiliary heat conductor, 21...substrate, 22...semiconductor layer, 23A...conductor layer, 23B...conductor layer, 23C...conductor layer, 23D...conductor layer, 24A...insulating layer, 24B...insulating layer, 24C...insulating layer, 25...light emitting element, 26...partition layer, 27...filling layer, 28...conductor layer, 29...main heat conductor, 31...transparent substrate, 32...black matrix, 33B...underlayer, 33G...second colored layer , 33R...first colored layer, 34...partition wall layer, 36B...filling layer, 36G...second wavelength conversion layer, 36R...first wavelength conversion layer, 37...overcoat layer, 38...heat transfer layer, 251...first layer, 252...second layer, 253...third layer, C...capacitor, D...light emitting element, DE...drain electrode, DR...drive control element, GE...gate electrode, PSL...power supply line, PX...pixel, PXB...third subpixel, PXG...second subpixel, PXR...first subpixel, SDR...scanning signal line driver, SE...source electrode, SSL...scanning signal line, SW...switch, VDR...video signal line driver, VSL...video signal line, W ｘ 1...Distance, W ｘ 2...Distance, W ｙ 1...Distance.

Claims

1. A wavelength conversion substrate comprising: a transparent substrate having a first main surface and a second main surface; a partition layer provided on said first main surface, said partition layer having a plurality of first through holes arranged in a first direction and a second direction intersecting each other; a plurality of functional layers provided at positions of said plurality of first through holes, at least one of which is a wavelength conversion layer that converts light emitted by a light source into light of a different color; and a heat transfer layer facing said first main surface with said partition layer and said plurality of functional layers in between, said heat transfer layer being optically transparent at positions of said plurality of first through holes and having a higher thermal conductivity than said plurality of functional layers.

2. The wavelength conversion substrate according to claim 1, wherein the heat transfer layer has one or more openings, the one or more openings being provided such that a first orthogonal projection of an opening of each of the plurality of first through holes on a side opposite the transparent substrate, onto the first main surface, at least partially overlaps with a second orthogonal projection of the one or more openings onto the first main surface.

3. The wavelength conversion substrate according to claim 2, wherein an overlapping portion between the first orthogonal projection and the second orthogonal projection is smaller than that of the first orthogonal projection.

4. The wavelength conversion substrate according to claim 3, wherein the area of ​​said overlapping portion accounts for 50% or less of the area of ​​said first orthogonal projection.

5. A wavelength conversion substrate according to any one of claims 1 to 4, wherein the heat transfer layer has a plurality of second through holes at the positions of the plurality of first through holes, respectively.

6. A wavelength conversion substrate according to any one of claims 1 to 4, wherein the heat transfer layer has a plurality of second through holes arranged in the first direction and the second direction, and each of the second through holes is arranged to span two or more of the first through holes.

7. A wavelength conversion substrate according to any one of claims 1 to 4, wherein the heat transfer layer includes one or more strip-shaped portions.

8. A wavelength conversion substrate according to any one of claims 1 to 7, wherein the heat transfer layer includes a layer made of a metal or an alloy.

9. The wavelength conversion substrate according to any one of claims 1 to 7, wherein the heat transfer layer is made of a transparent oxide layer.

10. A wavelength conversion substrate according to any one of claims 1 to 9, wherein the heat transfer layer is made of a material having a thermal conductivity of 15 W / m·K or more.

11. The wavelength conversion substrate according to any one of claims 1 to 10, wherein the heat transfer layer has a thickness in the range of 100 to 5000 nm.

12. A wavelength conversion substrate according to any one of claims 1 to 11, wherein the partition layer has a thickness within a range of 10 to 40 µm.

13. The wavelength conversion substrate according to any one of claims 1 to 12, further comprising an overcoat layer interposed between the plurality of functional layers and the heat transfer layer.

14. The wavelength conversion substrate according to claim 13, wherein the overcoat layer is further interposed between the partition layer and the heat transfer layer.

15. A display device comprising: a wavelength conversion substrate according to any one of claims 1 to 14; a dimming device arranged to face the first main surface; and an adhesive layer interposed between the wavelength conversion substrate and the dimming device and bonding them together.

16. The display device according to claim 15, further comprising: a heat sink positioned outside a laminate of the wavelength conversion substrate, the light control device, and the adhesive layer; and a heat conductor that conducts heat from the heat transfer layer to the heat sink.

17. The display device according to claim 16, wherein the heat sink includes a back surface heat sink provided to face the wavelength conversion substrate with the light control device and the adhesive layer sandwiched therebetween.

18. The display device according to claim 17, wherein the rear surface heat sink is a rear surface heat sink layer provided on the light control device.

19. The display device according to any one of claims 16 to 18, wherein at least a portion of the heat transfer body is provided outside the laminate.

20. The display device according to claim 19, wherein the heat conductor at least partially covers the end face of the laminate.

21. The display device according to any one of claims 16 to 19, wherein the light control device is provided with one or more through holes, and the heat transfer body is at least partially located within the one or more through holes.

22. The display device according to any one of claims 15 to 21, wherein the light control device includes a plurality of light emitting elements.

23. The display device according to any one of claims 15 to 21, wherein the dimming device includes a plurality of light emitting diodes.

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