Wavelength conversion substrate and display device

Abstract

To provide a technique capable of preventing deterioration in color reproducibility caused by positional deviation between a wavelength conversion substrate and a dimmer.SOLUTION: A wavelength conversion substrate 3A includes: a transparent substrate 31 having first and second main surfaces; a partition wall layer provided on the first main surface and having a plurality of through-holes arranged in first and second directions intersecting each other; and a plurality of functional layers provided at positions of the plurality of through-holes, respectively. The plurality of functional layers include a first wavelength conversion layer 36R that converts light emitted by a light source into first light and a second wavelength conversion layer 36G that converts light emitted by the light source into second light different in color from the first light. Each of the functional layers includes first portions 36R1, 36G1 located in the through-hole in which the functional layer is provided and second portions 36R2, 36G2 that at least partially cover a peripheral region surrounding an opening of the through hole in which the functional layer is provided on an upper surface of the partition wall layer.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] In display devices, light-emitting elements such as light-emitting diodes are used, for example, as light sources for backlight units or as components of pixels or sub-pixels (see Patent Documents 1 and 2). In such display devices, partitions may be provided to separate the light-emitting elements or the pixels or sub-pixels from each other. The partitions, for example, enable efficient use of light emitted by the light-emitting elements or prevent light emitted by one light-emitting element from entering an area where light emitted by another light-emitting element should be incident. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-131683 A [Patent Document 2] JP 2009-244383 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a technique that can prevent deterioration of color reproducibility caused by misalignment between a wavelength conversion board and a light control device. [Means for solving the problem]

[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 through holes arranged in a first direction and a second direction intersecting each other; and a plurality of functional layers respectively provided at the positions of the plurality of through holes, the plurality of functional layers including a first wavelength conversion layer that converts light emitted by a light source into a first light, and a second wavelength conversion layer that converts the light emitted by the light source into a second light having a color different from that of the first light, each of the plurality of functional layers including a first portion located in the through hole in which this functional layer is provided, and a second portion at least partially covering a peripheral region of an upper surface of the partition layer surrounding an opening of the through hole in which the functional layer is provided.

[0006] According to another aspect of the present invention, there is provided a wavelength conversion substrate relating to the above aspect, in which the opening of each of the plurality of through holes has a shape extending in the second direction, and the second portion of each of the plurality of functional layers covers an area of ​​the peripheral region sandwiched between the openings of the through holes adjacent to each other in the first direction.

[0007] 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 plurality of functional layers include those adjacent to each other in the first direction and in which the second portions overlap each other.

[0008] According to yet another aspect of the present invention, there is provided a wavelength conversion substrate relating to any of the above aspects, wherein the functional layers further include a filling layer that either transmits the light emitted by the light source as is or converts the light into a third light having a color different from the first and second lights, and the functional layers each extend in the first direction and form a plurality of rows arranged in the second direction, and each of the plurality of rows includes the first wavelength conversion layer, the second wavelength conversion layer, and the filling layer.

[0009] According to yet another aspect of the present invention, there is provided a wavelength conversion substrate according to any of the above aspects, wherein a ratio H3 / H1 of a maximum thickness H3 of the second portion to a thickness H1 of the partition layer is in a range of 0.01 to 0.95.

[0010] According to yet another aspect of the present invention, there is provided a wavelength conversion substrate according to any of the above aspects, further comprising a black matrix interposed between the transparent substrate and the partition layer, the black matrix having a plurality of first through holes at positions of the plurality of through holes, respectively.

[0011] 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 partition layer includes a resin layer having a plurality of second through holes at positions of the plurality of through holes, respectively.

[0012] According to yet another aspect of the present invention, there is provided the wavelength conversion substrate according to the above aspect, wherein the partition layer further includes a reflective layer at least partially covering side walls of the plurality of second through holes.

[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, further comprising a color filter including a plurality of colored layers arranged at at least some positions of the plurality of through holes, respectively.

[0014] According to yet another aspect of the present invention, there is provided a wavelength conversion substrate according to any one of the above aspects, further comprising an overcoat layer covering the first portion of each of the plurality of functional layers.

[0015] According to yet another aspect of the present invention, there is provided a display device including the wavelength conversion substrate according to any one of the above aspects and a light control device disposed so as to face the first main surface.

[0016] According to yet another aspect of the present invention, there is provided a display device according to the above aspect, wherein the light control device includes a plurality of light emitting elements arranged corresponding to the plurality of through holes. Effect of the Invention

[0017] According to the present invention, a technique is provided that can prevent deterioration of color reproducibility caused by misalignment between a wavelength conversion board and a light control device. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a plan view showing a part of a display device according to one embodiment of the present invention. [Diagram 2] FIG. 2 is an equivalent circuit diagram of the display device shown in FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III of the display device shown in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV of the display device shown in FIG. [Diagram 5] FIG. 5 is an enlarged plan view showing a part of a wavelength conversion substrate included in the display device of FIG. [Figure 6] FIG. 6 is an enlarged plan view of a portion of the structure shown in FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII of the structure shown in FIG. [Figure 8] FIG. 8 is an enlarged cross-sectional view showing a part of a wavelength conversion substrate included in a display device according to one modification. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] 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 alone or in combination.

[0020] The embodiments described 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.

[0021] In addition, elements having the same or similar functions are given the same reference numerals in the drawings referred to below, and duplicated explanations are omitted. In addition, the drawings are schematic, and the relationship between dimensions in one direction and dimensions in another direction, the relationship between the dimensions of one member and the dimensions of another member, etc. may differ from the actual ones.

[0022] Fig. 1 is a plan view showing a part of a display device according to one 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 an enlarged plan view showing a part of a wavelength conversion substrate included in the display device of Fig. 1. Fig. 6 is an enlarged plan view showing a part of the structure shown in Fig. 5. Fig. 7 is a cross-sectional view taken along line VII-VII of the structure shown in Fig. 6.

[0023] 1, the area surrounded by the dashed line represents the opening of the first through hole on the transparent substrate 31 side of the black matrix 32, as described later. Also, in Fig. 5 and Fig. 6, the area surrounded by the dashed line represents the opening of the second through hole provided in the resin layer 34 on the opposite side to the transparent substrate 31.

[0024] A 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).

[0025] In each figure, the X direction and the Y direction are parallel to the display surface of the display device 1A and cross 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.

[0026] 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.

[0027] 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.

[0028] 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 the intersections of the video signal lines VSL and the scanning signal lines SSL.

[0029] The first sub-pixel PXR, the second sub-pixel PXG, and the third sub-pixel PXB emit light of different colors. In this 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.

[0030] In each pixel PX, the second sub-pixel PXG, the third sub-pixel PXB, and the first sub-pixel PXR 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.

[0031] 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.

[0032] 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.

[0033] The light-emitting element D is a light source, and is a light-emitting diode here. The light-emitting diode is, for example, a light-emitting diode made of an inorganic material. The 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 that 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 a blue light-emitting diode made of an inorganic material that emits blue light.

[0034] 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.

[0035] 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.

[0036] The first subpixel PXR further includes a first wavelength conversion layer 36R and a first colored layer 33R shown in FIGS.

[0037] Each of the first wavelength conversion layers 36R is a functional layer and 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 a first light of a specific color. For example, the first wavelength conversion layer 36R converts the blue light emitted by the light emitting element D of the first subpixel PXR into red light.

[0038] The first colored layer 33R is disposed to face the light-emitting element D of the first subpixel PXR with the first wavelength conversion layer 36R sandwiched therebetween. The first colored layer 33R transmits light after wavelength conversion by the first wavelength conversion layer 36R and absorbs light that has not been wavelength-converted by the first wavelength conversion layer 36R. The first colored layer 33R is, for example, a red colored layer that transmits red light after wavelength conversion by the first wavelength conversion layer 36R and absorbs blue light and the like that has not been wavelength-converted by the first wavelength conversion layer 36R.

[0039] The second subpixel PXG further includes a second wavelength conversion layer 36G and a second colored layer 33G shown in FIG.

[0040] Each of the second wavelength conversion layers 36G is another of the functional layers and 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 a second light having a color different from the first light. For example, the second wavelength conversion layer 36G converts the blue light emitted by the light emitting element D of the second subpixel PXG into green light.

[0041] The second colored layer 33G is disposed to face the light-emitting element D of the second sub-pixel PXG with the second wavelength conversion layer 36G sandwiched therebetween. The second colored layer 33G transmits light after wavelength conversion by the second wavelength conversion layer 36G and absorbs light that has not been wavelength-converted by the second wavelength conversion layer 36G. The second colored layer 33G is, for example, a green colored layer that transmits green light after wavelength conversion by the second wavelength conversion layer 36G and absorbs blue light and the like that has not been wavelength-converted by the second wavelength conversion layer 36G.

[0042] The third subpixel PXB further includes an underlayer 33B and a fill layer 36B shown in FIG.

[0043] Each of the filling layers 36B is yet another one of the functional layers, and is disposed to face the light-emitting element D of the third sub-pixel PXB. The filling layer 36B transmits the light emitted by the light-emitting element D of the third sub-pixel PXB as a third light. The filling layer 36B is, for example, a colorless and transparent layer.

[0044] 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. The base layer 33B may be omitted.

[0045] The video signal line driver VDR and the scan signal line driver SDR are mounted on a display panel using a chip on glass (COG) as shown in Fig. 2. The video signal line driver VDR and the scan signal line driver SDR may be mounted on a tape carrier package (TCP) instead of using a COG.

[0046] 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.

[0047] 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 being connected to the video signal line driver VDR.

[0048] The display device 1A will now be described in more detail. The display device 1A includes a light control device 2, a wavelength conversion substrate 3A, and an adhesive layer 4, as shown in FIGS.

[0049] The light control device is a device that emits light toward a wavelength conversion substrate and can adjust 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 Fig. 3 and Fig. 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.

[0050] The substrate 21 includes an insulating substrate such as a glass substrate. The substrate 21 may further include an undercoat layer provided on a 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 laminated on the insulating substrate. The substrate 21 may be a semiconductor substrate such as a silicon substrate. The substrate 21 may be either hard or flexible.

[0051] 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 between them.

[0052] The conductor layer 23A is a conductor pattern provided on the main surface of the substrate 21. The conductor layer 23A constitutes 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.

[0053] 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 a part of the insulating layer 24A. In addition, the dielectric layer of each capacitor C is another part of the insulating layer 24A.

[0054] 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 the switch SW is a 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.

[0055] 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, a plasma CVD (chemical vapor deposition) method.

[0056] 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. That is, the scanning signal line SSL and the source electrode SE and the drain electrode DE may be formed by the conductor layer 23C.

[0057] The insulating layer 24C covers the conductor layer 23C and the insulating layer 24B. The insulating layer 24C is a passivation film. The insulating layer 24C is made of an inorganic insulator such as silicon nitride.

[0058] The conductor layer 23D is a conductor pattern provided on the insulating layer 24C. The conductor layer 23D constitutes electrode pads arranged in the X direction and the Y direction 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 laminate consisting 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 the 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.

[0059] The contour 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 of 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 serve as a reflective layer. In this case, the reflective layer that serves this role may or may not be provided separately from the electrode pad.

[0060] 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.

[0061] 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."

[0062] The light emitting element 25 has a multi-layer 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.

[0063] Each light emitting element 25 includes an anode and a cathode. The light emitting element 25 has an anode and a cathode on one surface. 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 surface and a cathode on the other surface, 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 surface, the conductor layer 28 may be omitted, and electrode pads for connecting to the cathode of the light emitting element 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, and the light emitting element 25 may be bonded to the electrode pad and the conductor layer 28 and the anode and cathode may be connected to the electrode pads by flip chip bonding.

[0064] 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.

[0065] 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 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.

[0066] 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 joint between the light emitting element 25 and the electrode. 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 constituting the surface of the partition layer 26.

[0067] 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 is provided so as to partially cover the cathode of the light-emitting element 25.

[0068] The wavelength conversion board 3A faces the light control device 2. Specifically, the wavelength conversion board 3A faces the board 21 with the light emitting element 25 and the like sandwiched therebetween.

[0069] The wavelength conversion substrate 3A includes a transparent substrate 31, a black matrix 32, a resin layer 34, a reflective layer 35, 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, and a filling layer 36B.

[0070] The transparent substrate 31 has visible light transmissibility. 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, a transparent resin, or a combination thereof. The transparent substrate 31 may be hard 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 rear surface of the first main surface.

[0071] 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 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 color by subtractive color mixing, for example, a mixture containing a blue pigment, a green pigment, and a red pigment. In one example, the black matrix 32 is a layer containing carbon materials such as graphite, graphene, and carbon nanotubes. In another example, the black matrix 32 is a laminate of a chromium layer and a chromium oxide layer.

[0072] The black matrix 32 has first through holes at the positions of the light emitting elements 25. The first through holes are arranged in a first direction and a second direction that intersect with each other, here, the first direction and the second direction. The opening of each first 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.

[0073] Here, the opening of the first through hole on the transparent substrate 31 side has a shape extending in the Y direction as shown by the dashed line in FIG. 1. Each portion of the black matrix 32 corresponding to the pixel PX includes a first through hole provided at the position of the first sub-pixel PXR, a first through hole provided at the position of the second sub-pixel PXG, and a first through hole provided at the position of the third sub-pixel PXB, and these three first through holes are arranged in the X direction. A plurality of first through hole groups each consisting of these three first through holes are arranged in the X direction and the Y direction. The distance between adjacent first through hole groups in the X direction is larger than the distance between first through holes included in the same through hole group. The distance between adjacent first through hole groups in the Y direction is also larger than the distance between first through holes included in the same through hole group.

[0074] In each first through hole group, the arrangement pitch of the first through holes in the X direction is preferably in the range of 15 to 300 μm, more preferably in the range of 40 to 150 μm. The arrangement pitch of the first through hole groups in the X direction is preferably in the range of 80 to 900 μm, more preferably in the range of 100 to 600 μm. The arrangement pitch of the first through hole groups in the Y direction is preferably in the range of 80 to 900 μm, more preferably in the range of 100 to 600 μm.

[0075] 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 further preferably in the range of 5 to 20%. Light-emitting diodes made of inorganic materials can emit light brightly even when the light-emitting surface is small, and have a long life. Therefore, when the light-emitting element 25 is a light-emitting diode made of inorganic materials, a bright display is possible even if the aperture ratio of the black matrix 32 is reduced. Furthermore, by reducing the aperture ratio of the black matrix 32, reflection of external light can be suppressed, and a deeper black color can be displayed, thereby achieving a higher contrast ratio.

[0076] The thickness of the black matrix 32 is preferably in the range of 0.1 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 in achieving high light blocking properties. However, if the black matrix 32 is made thick, light may not reach the depths of the coating film made of a photosensitive black composition with sufficient intensity during pattern exposure, making it difficult to achieve high shape accuracy.

[0077] 3 and 4, the resin layer 34 is provided on the black matrix 32. According to one example, the resin layer 34 is transparent. In this case, the resin layer 34 may be colored or colorless. The resin layer 34 may have light scattering properties.

[0078] The resin layer 34 has second through holes at the positions of the first through holes, respectively. Here, the openings of the second through holes on the opposite side to the transparent substrate 31 have a shape extending in the Y direction as shown by the dashed line in Figs. 5 and 6. The openings of the second through holes are larger than the first through holes. Each of the second through holes is provided such that the center of the opening thereof coincides with the center of the opening of the first through hole.

[0079] These second through holes constitute a second through hole group corresponding to the first through hole group. Each of the second through hole groups is composed of three second through holes arranged in the X direction. The second through hole groups are arranged in a first direction and a second direction that intersect with each other, here, the X direction and the Y direction.

[0080] Distance W between adjacent second through hole groups in the X direction x 1 is the distance W between the second through holes included in the same through hole group x 2. The distance W between adjacent second through hole groups in the Y direction is larger than that of y 1, the distance W between the second through holes included in the same through hole group x 2. Note that the "distance" mentioned for the second through hole and the second through hole group is the distance focusing on the opening of the second through hole on the opposite side to the transparent substrate 31.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] Distance W x 1 and distance W x Ratio to 2W x 1 / W x 2 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, the distance W x It may be less than 2.

[0085] Distance W y 1 and distance W x Ratio to 2W 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, the distance W x It may be less than 2.

[0086] Each of the second through holes exposes an edge region surrounding the opening of the first through hole on the upper surface of the black matrix 32. The opening of the second through hole on the side of the light control device 2 has a dimension L x is preferably in the range of 25 to 250 μm, and more preferably in the range of 30 to 150 μm. x Ratio of L1 / L x is preferably in the range of 0.50 to 0.99, and more preferably in the range of 0.70 to 0.95. In addition, the opening of the second through hole on the side of the light control device 2 has a dimension L y However, the dimension L1 and the dimension L2 in the Y direction of the first through hole are preferably in the range of 60 to 850 μm, and more preferably in the range of 70 to 550 μm. y Ratio of L2 / L y is preferably in the range of 0.01 to 0.80, and more preferably in the range of 0.10 to 0.70.

[0087] Here, each of the second through holes has a shape extending in the Y direction. y and dimension L x Compared to L y / L x is preferably larger than the ratio of the dimension in the Y direction to the dimension in the X direction of the first through hole. In such a structure, even if air bubbles remain between the inner surface of the recess formed by the second through hole and the wavelength conversion layer or the like, the influence of the air bubbles on the display is small. y / L x is preferably in the range of 1.3 to 100, and more preferably in the range of 1.3 to 25.

[0088] The portion of the resin layer 34 that is sandwiched between the adjacent second through holes, i.e., the partition wall portion, has a forward tapered cross-sectional shape. This partition wall portion may have a rectangular cross-sectional shape, a reverse tapered cross-sectional shape, or another cross-sectional shape.

[0089] The thickness of the resin 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 resin layer 34 is small, it is difficult to increase the thickness of the layer formed in the second through hole. If the resin layer 34 is made thick, the shape accuracy of the partition wall portion sandwiched between the adjacent second through holes decreases.

[0090] The reflective layer 35 at least partially covers the edge region and the side walls of each of the second through holes. Here, the reflective layer 35 includes a portion covering the upper surface of the resin layer 34, a portion covering the side walls of the second through holes, and a portion partially covering the edge region. The resin layer 34 and the portion of the reflective layer 35 that covers the resin layer 34 constitute a first partition layer. This first partition layer has a third through hole at the position of the second through hole. The first partition layer has a recess formed at the position of the third through hole.

[0091] The reflective layer 35 may not cover a portion of the upper surface of the resin layer 34. For example, a through hole or a slit may be provided in the portion of the reflective layer 35 that covers the upper surface of the resin layer.

[0092] The reflective layer 35 may not cover a part of the side wall of the second through hole. For example, the reflective layer 35 may not cover at least one of a part of at least one side wall of the second through hole that is adjacent to the black matrix 32 and a part of at least one side wall of the second through hole that is adjacent to the upper surface of the resin layer 34.

[0093] The portion of the reflective layer 35 located in the second through hole is open at the position of the first colored layer 33R, the second colored layer 33G, or the underlayer 33B. The area S2 of each of these openings is preferably larger than the area S1 of the opening of the first through hole. The ratio S2 / S1 of the area S2 to the area S1 is preferably in the range of 1 to 100, more preferably in the range of 1 to 30, and even more preferably in the range of 1 to 2.

[0094] The reflective layer 35 may have a single-layer structure or a multi-layer structure. The layer included in the reflective layer 35 is, for example, a metal, an alloy, or a transparent dielectric. From the viewpoint of thermal conductivity, the reflective layer 35 preferably includes a layer made of a metal or an alloy. According to one example, the reflective layer 35 is made of aluminum, an aluminum alloy, or a neodymium alloy.

[0095] The thickness of the reflective layer 35 covering the upper surface of the resin layer 34 is preferably in the range of 100 to 500 nm, and more preferably in the range of 100 to 250 nm. Increasing the thickness of the reflective layer 35 improves the thermal conductivity in the in-plane direction. However, increasing the thickness of the reflective layer 35 increases the manufacturing cost.

[0096] The reflective layer 35 can be formed by, for example, performing film formation by a vapor phase deposition method such as sputtering and 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.

[0097] The first colored layer 33R fills the first through-hole at the position of the first sub-pixel PXR, as shown in Figure 3 and Figure 4. As described above, here, the first colored layer 33R is a red colored layer.

[0098] The second colored layer 33G fills the first through hole at the position of the second sub-pixel PXG, as shown in Fig. 3. As described above, here, the second colored layer 33G is a green colored layer.

[0099] The base layer 33B fills the first through-hole at the position of the third sub-pixel PXB, as shown in Fig. 3. As described above, here, the base layer 33B is a colorless light-transmitting layer or a blue colored layer. When the base layer 33B is a colorless light-transmitting layer, it may be an overcoat layer that is interposed between the black matrix 32 and the resin layer 34, covers the color filter, and fills the first through-hole where the first colored layer 33R or the second colored layer 33G is not disposed, as shown in Fig. 8.

[0100] 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.

[0101] The first wavelength conversion layer 36R includes a first portion 36R1 and a second portion 36R2. The first portion 36R1 is located in the third through hole. The first portion 36R1 is provided on the first colored layer 33R. The first portion 36R1 fills at least the bottom of a recess formed by a first partition layer including the resin layer 34 and a portion of the reflective layer 35 that covers the resin layer 34. The second portion 36R2 at least partially covers a peripheral region of the upper surface of the first partition layer that surrounds the opening of the third through hole in which the first wavelength conversion layer 36R is provided.

[0102] 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 red light.

[0103] The second wavelength conversion layer 36G includes a first portion 36G1 and a second portion 36G2. The first portion 36G1 is located in the third through hole. The first portion 36G1 is provided on the second colored layer 33G. The first portion 36G1 fills at least the bottom of the recess formed by the first partition layer. The second portion 36G2 at least partially covers a peripheral region of the upper surface of the first partition layer that surrounds the opening of the third through hole in which the second wavelength conversion layer 36G is provided.

[0104] As described above, the filling layer 36B is a colorless and transparent layer, and is made of, for example, a transparent resin.

[0105] The filling layer 36B includes a first portion 36B1 and a second portion 36B2. The first portion 36B1 is located in the third through hole. The first portion 36B1 is provided on the underlayer 33B. The first portion 36B1 fills at least the bottom of the recess formed by the first partition layer. The second portion 36B2 at least partially covers a peripheral region of the upper surface of the first partition layer that surrounds the opening of the third through hole in which the filling layer 36B is provided.

[0106] The first wavelength conversion layer 36R, the second wavelength conversion layer 36G and the filling layer 36B, each including the second portions 36R2, 36G2 and 36B2, can be formed by increasing the dimensions of the light-transmitting portion in the photomask, for example, when they are made of a negative-type photosensitive resin.

[0107] Each of the second portions 36R2, 36G2, and 36B2 covers a region of the peripheral region sandwiched between the openings of the third through holes adjacent in the X direction. Here, each of the second portions 36R2, 36G2, and 36B2 is provided around the entire periphery of the opening of the third through hole. The second portions 36R2, 36G2, and 36B2 form a second partition layer on the first partition layer.

[0108] Here, the first wavelength conversion layer 36R, the second wavelength conversion layer 36G, and the filling layer 36B include layers adjacent to each other in the X direction and having overlapping second portions. Specifically, as shown in FIG. 6, the first wavelength conversion layer 36R and the second wavelength conversion layer 36G adjacent to each other with the filling layer 36B sandwiched therebetween overlap the edges of the filling layer 36B. That is, the second portion 36G2 and the second portion 36B2 overlap as shown in FIG. 7, and the second portion 36R2 and the second portion 36B2 overlap in the same manner. The second portions do not have to overlap. However, when a structure in which the second portions overlap is adopted, the thickness of the second partition wall layer can be made larger than when a structure in which the second portions do not overlap is adopted.

[0109] For example, when a structure in which the second portions do not overlap is adopted, the maximum thickness of the second partition layer is height H2 shown in Fig. 7. In contrast, when a structure in which the second portions overlap is adopted, the maximum thickness of the second partition layer is height H3 shown in Fig. 7.

[0110] In FIG. 7, the width W1 of the portion of the upper surface of the first partition layer sandwiched between the third through holes adjacent in the X direction is the distance W x2. In each pixel PX, the ratio W / W1 of the width W of the portion located on the partition wall to the width W1 of each of the second portions 36R2, 36G2, and 36B2 is preferably in the range of 1.01 to 2.0, and more preferably in the range of 1.1 to 1.5. In order to obtain the above structure in which the second portions overlap, it is preferable that the ratio W / W1 is large. However, if the ratio W / W1 is large, higher positional accuracy is required for the first wavelength conversion layer 36R, the second wavelength conversion layer 36G, and the filling layer 36B.

[0111] To obtain the above structure in which the second portions overlap, the sum W2+W3 of the width W2 of one portion located on the partition and the width W3 of the other portion is made larger than the width W1. The ratio (W2+W3) / W1 of the sum W2+W3 to the width W1 is preferably in the range of 1.01 to 2.0, more preferably in the range of 1.1 to 1.5. Increasing the ratio (W2+W3) / W1 allows the ratio H3 / H2 of the height H3 to the height H2 to be increased. The widths W2 and W3 may be equal to each other or different from each other.

[0112] The ratio H3 / H1 of the maximum thickness H3 of the second portion to the thickness H1 of the first barrier layer is preferably in the range of 0.01 to 0.95, more preferably in the range of 0.05 to 0.5. If the ratio H3 / H1 is small, the effect of the second barrier layer is reduced. It is difficult to form a structure with a large ratio H3 / H1.

[0113] The adhesive layer 4 is interposed between the light control device 2 and the wavelength conversion substrate 3A, and bonds them to each other. 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.

[0114] In a display device having the same structure as the display device 1A except for omitting the second portions 36R2, 36G2, and 36B2, for example, when a positional deviation occurs in the X direction between the light control device and the wavelength conversion substrate, a part of the light emitted by the light emitting element 25 of a certain subpixel may enter the third through hole of another subpixel adjacent to the certain subpixel in the X direction, which may result in a decrease in color reproducibility.

[0115] In the display device 1A, as described above, the second partition layer is provided on the first partition layer. Therefore, in this display device 1A, even if a positional deviation occurs in the X direction between the light control device 2 and the wavelength conversion substrate 3A, at least a part of the light emitted by the light emitting element 25 of a certain subpixel and traveling toward the third through hole of another subpixel adjacent to the subpixel in the X direction is reflected by the side wall of the partition part of the second partition layer. In addition, when a part of the light emitted by the light emitting element 25 of a certain subpixel enters the partition part of the second partition layer, wavelength conversion may occur due to the wavelength conversion material contained in the partition layer, but since the phosphor emits light isotropically, most of the light wavelength-converted in the second part does not enter the third through hole of the adjacent subpixel.

[0116] Therefore, when the above-described structure is adopted for the display device 1A, deterioration in color reproducibility caused by misalignment between the wavelength conversion substrate 3A and the light control device 2 can be made less likely to occur.

[0117] The above-mentioned display device and wavelength conversion substrate can be modified in various ways, as exemplified below.

[0118] 8 is an enlarged cross-sectional view of a part of a wavelength conversion substrate included in a display device according to one modification. The display device according to this modification is similar to the display device 1A described above, except that it includes a wavelength conversion substrate 3B instead of the wavelength conversion substrate 3A. The wavelength conversion substrate 3B is similar to the wavelength conversion substrate described above, except that it further includes an overcoat layer 38 that covers first portions of each of the multiple functional layers. The overcoat layer 38 is made of, for example, a transparent resin.

[0119] A circuit provided in the light control device 2 or the like may have a configuration different from that shown in FIG. 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, in each of the first sub-pixel PXR, the second sub-pixel PXG, and the third sub-pixel PXB, the gate-source voltage of the drive control element DR may be set to a value corresponding to this current signal during a write period in which a video signal is written, and a drive current having a magnitude corresponding to the gate-source voltage may be passed to the light-emitting element D during a light-emitting period. In addition, the light control device 2 may employ a circuit for displaying an image by a passive matrix driving method instead of a circuit for displaying an image by an active matrix driving method.

[0120] 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 sub-pixel PXB into a 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.

[0121] Instead of using a single type of light-emitting diode, multiple types of light-emitting diodes may be used as the light-emitting element 25. For example, a red light-emitting diode, a green light-emitting diode, and a blue light-emitting diode may be used in the first sub-pixel PXR, the second sub-pixel PXG, and the third sub-pixel PXB, respectively. In this case, instead of the first colored layer 33R and the second colored layer 33G, a layer similar to that described above for the base layer 33B may be provided, and instead of the first wavelength conversion layer 36R and the second wavelength conversion layer 36G, a layer similar to that described above for the filling layer 36B may be provided.

[0122] The display device may be a display device other than a micro LED display, such as an organic electroluminescent display device, although the display device preferably includes light emitting elements. [Explanation of symbols]

[0123] 1A...display device, 2...light control device, 3A...wavelength conversion substrate, 3B...wavelength conversion substrate, 4...adhesive layer, 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, 31...transparent substrate, 32...black matrix, 34...resin grease layer, 35...reflective layer, 33R...first colored layer, 33G...second colored layer, 33B...base layer, 36B...filling layer, 36G...second wavelength conversion layer, 36R...first wavelength conversion layer, 38...overcoat layer, 251...first layer, 252...second layer, 253...third layer, C...capacitor, D...light-emitting element, DE...drain electrode, DR...drive control element, H1...thickness, H2...height, H3...height (maximum thickness), L x …Dimension, L y ...dimension, 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, W1...width, W2...width, W3...width.

Claims

1. a transparent substrate having a first major surface and a second major surface; a partition layer provided on the first main surface and having a plurality of through holes arranged in a first direction and a second direction intersecting each other; A plurality of functional layers provided at the positions of the plurality of through holes, respectively; Equipped with The plurality of functional layers include a first wavelength conversion layer that converts light emitted by a light source into a first light, and a second wavelength conversion layer that converts the light emitted by the light source into a second light having a color different from that of the first light, Each of the plurality of functional layers is a first portion located in the through hole in which the functional layer is provided; and a second portion at least partially covering a peripheral region of the upper surface of the partition layer surrounding the opening of the through hole on which the functional layer is provided; A wavelength conversion substrate comprising:

2. 2. The wavelength conversion substrate according to claim 1, wherein the opening of each of the plurality of through holes has a shape extending in the second direction, and the second portion of each of the plurality of functional layers covers an area of ​​the peripheral region sandwiched between the openings of the through holes adjacent to each other in the first direction.

3. The wavelength conversion substrate according to claim 1 , wherein the plurality of functional layers include functional layers that are adjacent to each other in the first direction and have the second portions overlapping each other.

4. 2. The wavelength conversion substrate according to claim 1, wherein the functional layers further include a filling layer that either transmits the light emitted by the light source as is or converts the light into a third light having a color different from the first and second lights, the functional layers each extending in the first direction and forming a plurality of rows arranged in the second direction, each of the plurality of rows including the first wavelength conversion layer, the second wavelength conversion layer, and the filling layer.

5. 2. The wavelength conversion substrate according to claim 1, wherein a ratio H3 / H1 of a maximum thickness H3 of the second portion to a thickness H1 of the partition layer is in a range of 0.01 to 0.

95.

6. 2 . The wavelength conversion board according to claim 1 , further comprising a black matrix interposed between the transparent substrate and the partition wall layer, the black matrix having a plurality of first through holes at positions corresponding to the plurality of through holes.

7. The wavelength conversion substrate according to claim 1 , wherein the partition layer includes a resin layer having a plurality of second through holes at positions corresponding to the plurality of through holes.

8. The wavelength conversion substrate according to claim 7 , wherein the partition layer further includes a reflective layer at least partially covering side walls of the second through holes.

9. The wavelength conversion substrate according to claim 1 , further comprising a color filter including a plurality of colored layers disposed at at least some of the through holes.

10. The wavelength conversion substrate according to claim 1 , further comprising an overcoat layer covering the first portion of each of the plurality of functional layers.

11. A wavelength conversion substrate according to any one of claims 1 to 10, a light control device disposed so as to face the first main surface; A display device comprising:

12. The display device according to claim 11 , wherein the light control device includes a plurality of light emitting elements arranged corresponding to the plurality of through holes.

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