Indication device

Abstract

To provide a display device that can display a bright image using a light emitting diode.SOLUTION: A display device 1A includes a substrate 2, a partition layer 3 provided on the substrate 2 and having a plurality of through holes, a plurality of light emitting diodes 4 respectively arranged in the plurality of through holes, and a plurality of lenses 5 arranged respectively at the positions of the plurality of through holes. The lens 5 has a first surface 5a facing the substrate 2 with the light emitting diode 4 in between, and a second surface 5b that is the back surface thereof. The second surface 5b is a convex surface. The height H5T of the top of the convex surface with respect to the substrate 2 is greater than the height H3 of the upper surface of the partition layer 3 with respect to the substrate 2.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Head-mounted displays such as AR glasses and MR glasses can be used for virtual reality (VR), augmented reality (AR), or mixed reality (MR) experiences. The display device mounted on the head-mounted display is required to be low power consumption, small and lightweight, and capable of displaying high-brightness and high-definition images.

[0003] As small display devices that can be mounted on head-mounted displays, various display devices such as LCOS (Liquid Crystal on Silicon) microdisplays, LBS (Laser Beam Scanning) displays, and OLED-on-Silicon microdisplays have been developed. However, none of these can fully meet the above requirements.

[0004] Micro LED (Light-Emitting Diode) displays are said to be the display devices that are most likely to meet the above requirements. Therefore, research and development on micro LED displays are in full swing.

[0005] In a small micro LED display that can be mounted on a head-mounted display, a microlens may be installed in front of the light-emitting diode (Patent Documents 1 and 2). The light emitted by the light-emitting diode is diffused light. The microlens makes the diffused light emitted by the light-emitting diode approach collimated light.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] The present invention aims to provide a display device capable of displaying bright images using light-emitting diodes. [Means for solving the problem]

[0008] According to one aspect of the present invention, a display device is provided comprising a substrate, a partition layer provided on the substrate and having a plurality of through holes, a plurality of light-emitting diodes (LEDs) each disposed in the plurality of through holes, and a plurality of lenses each disposed at the positions of the plurality of through holes, wherein the lenses have a first surface facing the substrate with the light-emitting diodes in between and a second surface which is the back surface, the second surface is a convex surface, and the height of the top of the convex surface with respect to the substrate is greater than the height of the upper surface of the partition layer with respect to the substrate.

[0009] According to another aspect of the present invention, a display device is provided in which the height of the peripheral edge of the convex surface with respect to the substrate is less than or equal to the height of the upper surface of the partition layer with respect to the substrate.

[0010] According to yet another aspect of the present invention, a display device according to any of the above aspects is provided, further comprising one or more layers located in each of the plurality of through holes and interposed between the lens and the light-emitting diode.

[0011] According to yet another aspect of the present invention, a display device is provided in which, among the one or more layers, the refractive index of the layer adjacent to the lens is smaller than the refractive index of the lens.

[0012] According to yet another aspect of the present invention, a display device is provided wherein the partition layer includes a light-transmitting portion in contact with at least one of the one or more layers, and the refractive index of the one or more layers in contact with the light-transmitting portion is greater than the refractive index of the light-transmitting portion.

[0013] According to yet another aspect of the present invention, a display device according to any of the above aspects is provided, wherein the partition layer has a multilayer structure.

[0014] According to yet another aspect of the present invention, a display device is provided relating to the above aspect, wherein the partition layer comprises a light-shielding first layer and a second layer provided on the first layer and made of a light-transmitting resin.

[0015] According to yet another aspect of the present invention, a display device according to the above aspect is provided, wherein the partition layer further includes a light-shielding third layer provided on the second layer.

[0016] According to yet another aspect of the present invention, a display device according to any of the above aspects is provided, further comprising a plurality of filling layers, each of which fills the plurality of through holes and embeds a light-emitting diode interposed between one of the plurality of lenses and the substrate, and facing the lens.

[0017] According to yet another aspect of the present invention, a display device is provided in which at least a portion of the plurality of packed layers includes a wavelength conversion layer.

[0018] According to yet another aspect of the present invention, a display device is provided which, among the plurality of packed layers, includes the wavelength conversion layer, further including a colored layer interposed between the wavelength conversion layer and the lens.

[0019] According to yet another aspect of the present invention, a display device is provided in which at least a portion of the plurality of filling layers includes a transparent resin layer, according to any of the above aspects. [Effects of the Invention]

[0020] According to the present invention, there is provided a display device capable of displaying a bright image by a light emitting diode.

Brief Description of Drawings

[0021] [Figure 1] FIG. 1 is a cross-sectional view of a display device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of a display device according to a second embodiment of the present invention. [Figure 3] FIG. 3 is a cross-sectional view of a display device according to a third embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view of a display device according to a fourth embodiment of the present invention. [Figure 5] FIG. 5 is a cross-sectional view of a display device according to a fifth embodiment of the present invention. [Figure 6] FIG. 6 is a cross-sectional view of a display device according to a sixth embodiment of the present invention. [Figure 7] FIG. 7 is a cross-sectional view of a display device according to a seventh embodiment of the present invention.

Modes for Carrying Out the Invention

[0022] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments described below are more specific forms of any of the above aspects. The matters described below can be incorporated into each of the above aspects alone or in combination.

[0023] In addition, the embodiments shown below are 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 following constituent members. Various modifications can be made to the technical idea of the present invention within the technical scope defined by the claims described in the claims.

[0024] Elements with similar or identical functions are given the same reference numerals in the drawings referenced below, and redundant explanations are omitted. Furthermore, the drawings are schematic, and the relationships between dimensions in one direction and those in another, and the relationships between the dimensions of one component and those of other components, may differ from reality.

[0025] <1> First Embodiment Figure 1 is a cross-sectional view of a display device according to a first embodiment of the present invention. The display device 1A shown in Figure 1 is a micro-LED display that can be mounted on a head-mounted display and displays monochrome images.

[0026] The display device 1A includes a substrate 2, a partition layer 3, a light-emitting diode 4, a lens 5, and a packed layer 6.

[0027] The substrate 2 includes, for example, a semiconductor substrate or an insulating substrate and a circuit provided on one of its main surfaces. The semiconductor substrate is, for example, a silicon substrate. The insulating substrate is, for example, a glass substrate. The circuit is, for example, an active matrix drive of the light-emitting diode 4. The circuit may also be a passive matrix drive of the light-emitting diode 4. In one example, the substrate 2 is a CMOS (Complementary Metal Oxide Semiconductor) backplane.

[0028] In the diagram, the X and Y directions are parallel to and intersect each other with respect to the surface of the substrate 2 on which the circuit is provided. In one example, the X and Y directions are perpendicular to each other. The Z direction is the thickness direction of the substrate 2 and is perpendicular to the X and Y directions.

[0029] The partition layer 3 is provided on the surface of the substrate 2 on which the circuit is located. The partition layer 3 has multiple through holes. Each of these through holes extends in the Z direction and is arranged in the X and Y directions.

[0030] As will be described later, the light-emitting diodes 4 are each placed within these through-holes. The partition layer 3 suppresses or prevents light emitted by a light-emitting diode 4 located in one through-hole from entering other through-holes.

[0031] Each through-hole in the partition layer 3 has a square-shaped opening on its upper side. This opening may have other shapes, such as a circle. Here, "upper surface" of a certain component refers to the back surface of the component that faces the substrate 2.

[0032] In this case, each through-hole has a rectangular cross-section parallel to the Z-direction. The cross-section parallel to the Z-direction of the through-hole may have other shapes. For example, the cross-section parallel to the Z-direction of the through-hole may be tapered.

[0033] The partition layer 3 is made of, for example, resin. The partition layer 3 may be transparent or light-scattering. A light-scattering partition layer 3 is made of, for example, a mixture containing a transparent resin and transparent particles with a different refractive index. When light-scattering particles are not used, it is desirable from the viewpoint of improving light extraction efficiency to coat the partition layer made of transparent resin with an optically reflective metal film.

[0034] The height H3 of the upper surface of the partition layer 3 relative to the substrate 2, i.e., the thickness of the partition layer 3, is preferably in the range of 2.8 to 15 μm, and more preferably in the range of 5 to 10 μm.

[0035] The maximum diameter of the through-holes on the upper surface of the partition layer 3 is preferably in the range of 1 to 10 μm, and more preferably in the range of 2 to 5 μm.

[0036] Each light-emitting diode 4 is positioned within a through-hole in the partition layer 3. The light-emitting diodes 4 are, for example, inorganic light-emitting diodes. The two electrodes of each light-emitting diode 4 are connected to the circuit on the substrate 2.

[0037] These light-emitting diodes 4 have identical emission spectra. In one example, light-emitting diode 4 is a blue light-emitting diode. In another example, light-emitting diode 4 is an ultraviolet light-emitting diode.

[0038] The ratio H4 of the height H4 of the upper surface of the light-emitting diode 4 relative to the substrate 2 and H3 of the height H3 of the upper surface of the partition layer 3 relative to the substrate 2 is preferably in the range of 0.36 to 0.8, and more preferably in the range of 0.4 to 0.7.

[0039] The lenses 5 are positioned at the locations of the through-holes in the partition layer 3. Each of the lenses 5 is a convex lens. Each lens 5 has a first surface 5a and a second surface 5b.

[0040] The first surface 5a faces the substrate 2 with the light-emitting diode 4 in between. The first surface 5a is a flat surface. The second surface 5b is the back surface of the first surface 5a. The second surface 5b is a convex surface. Lens 5 brings the diffused light incident on the first surface 5a closer to the collimated light and emits it from the second surface 5b.

[0041] Lens 5 is made of a transparent material. This transparent material may be organic or inorganic.

[0042] As described above, the second surface 5b of lens 5 is a convex surface. The height H of the apex of this convex surface, relative to the edge of the convex surface, is preferably in the range of 0.3 to 3 μm, and more preferably in the range of 0.6 to 1.5 μm.

[0043] The ratio H / D between the height H and the maximum diameter D of the lens 5 is preferably in the range of 0.03 to 3, and more preferably in the range of 0.06 to 1.5. The maximum diameter D of the lens 5 is equal to or slightly smaller than the maximum diameter of the through hole in the upper surface of the partition layer 3.

[0044] The height H5T of the top of the second surface 5b relative to the substrate 2 is greater than the height H3 of the top surface of the partition layer 3 relative to the substrate 2. As will be described later, when this structure is adopted, a brighter image can be displayed compared to when the height H5T is less than or equal to the height H3.

[0045] The difference between height H5T and height H3, H5T-H3, is preferably in the range of 0.02 to 1.5 μm, and more preferably in the range of 0.1 to 0.5 μm.

[0046] The height H5P of the peripheral edge of the convex surface relative to the substrate 2 is less than or equal to the height H3 of the upper surface of the partition layer 3 relative to the substrate 2. The height H5P may be greater than the height H3, but in this case, some of the light incident on the first surface 5a will not pass through the second surface 5b, but will instead pass through, for example, the side surface of the lens 5. When the height H5P is less than or equal to the height H3, the effect of the lens 5 in bringing diffused light closer to collimated light is greater compared to when the height H5P is greater than the height H3.

[0047] The packing layers 6 fill each of the through-holes in the partition layers 3. Each of the packing layers 6 is interposed between one of the lenses 5 and the substrate 2, and a light-emitting diode 4 facing that lens 5 is embedded within it. Each of the packing layers 6 contains one or more layers interposed between the lens 5 and the light-emitting diode 4.

[0048] Preferably, the refractive index of one or more layers contained in the packing layer 6 that are adjacent to the lens 5 is smaller than the refractive index of the lens 5. Here, "refractive index" is the refractive index of light emitted from the packing layer 6 and incident on the lens 5. When the refractive index satisfies the above relationship, it is possible to suppress the reflection of light traveling from the packing layer 6 toward the lens 5 by the interface between them.

[0049] As described above, the partition layer 3 is either entirely transparent or light-scattering. That is, the partition layer 3 includes a light-transmitting portion that is in contact with at least one of the one or more layers contained in the packing layer 6. Preferably, the refractive index of the one or more layers contained in the packing layer 6 that is in contact with the light-transmitting portion is greater than the refractive index of the light-transmitting portion. Here, "refractive index" is the refractive index of light traveling from the one or more layers contained in the packing layer 6 that is in contact with the light-transmitting portion toward the light-transmitting portion. When the refractive index satisfies the above relationship, it is possible to suppress the incidence of light traveling from the packing layer 6 toward the partition layer 3 toward the partition layer 3.

[0050] Each of the packed beds 6 includes a lower packed bed 61 and an upper packed bed 62. The lower packed layer 61 embeds the light-emitting diode 4. The lower packed layer 61 is, for example, a wavelength conversion layer. The wavelength conversion layer is a layer containing a phosphor such as a quantum dot phosphor and a transparent resin. In one example, the wavelength conversion layer converts the blue light emitted by the light-emitting diode 4 into light of another color, such as yellow light. In another example, the wavelength conversion layer converts the ultraviolet light emitted by the light-emitting diode 4 into visible light. When the light-emitting diode 4 emits visible light, the lower packed layer 61 does not need to have a wavelength conversion function.

[0051] The upper packed layer 62 is provided on the lower packed layer 61. The upper packed layer 62 is a layer that serves, for example, as a planarization layer. When the light-emitting diode 4 emits blue light and the lower packed layer 61 is a wavelength conversion layer that converts blue light to yellow light, the upper packed layer 62 transmits, for example, the blue light that has passed through the wavelength conversion layer without wavelength conversion and the yellow light that has been converted from blue light by the wavelength conversion layer. In this case, for example, it is possible to display white by additive color mixing of blue and yellow.

[0052] The upper packed layer 62 may also serve as an optical filter. For example, the upper packed layer 62 may absorb or block a portion of visible light, at least a portion of ultraviolet light, or both. The upper packed layer 62 may be omitted.

[0053] In this display device 1A, each pixel PX includes one light-emitting diode 4, a lens 5 facing it, and a packed layer 6 interposed between them. If the substrate 2 is an active matrix drive for the light-emitting diodes, each pixel PX further includes a pixel circuit that controls the light-emitting operation of the light-emitting diode 4 contained in that pixel PX, from among the pixel circuits included in the circuit of the substrate 2.

[0054] This display device 1A can be manufactured, for example, by the following method. First, the light-emitting diodes 4 are mounted onto the substrate 2. For this mounting, for example, flip-chip bonding technology or wire bonding technology can be used.

[0055] Next, the partition layer 3, the lower filling layer 61, and the upper filling layer 62 are formed on the substrate 2 in this order. The partition layer 3, the lower filling layer 61, and the upper filling layer 62 can be formed, for example, by photolithography using a photosensitive resin such as an ultraviolet curing resin.

[0056] Next, lens 5 is formed. Lens 5 is formed, for example, by the following method. First, a coating made of photosensitive resin is formed to cover the upper filling layer 62 and the partition layer 3. Next, by pattern exposure and development of this coating, multiple columnar bodies are formed, each positioned on the central part of the upper filling layer 62. After that, the lens 5 is obtained by reflowing these columnar bodies.

[0057] Alternatively, first, a coating film made of a positive-type photosensitive resin is formed to cover the upper filling layer 62 and the partition layer 3. Next, the coating film is exposed to light through a gray tone mask designed so that the exposure amount gradually increases from the portion corresponding to the center of each through-hole in the partition layer 3 toward the portion corresponding to the side wall of the through-hole, and so that the exposure amount is maximized in the portion of the partition directly above the partition layer 3. After that, development and curing are performed to obtain the lens 5.

[0058] Alternatively, a negative-type photosensitive resin is first coated onto the upper filling layer 62 and the partition layer 3. Here, it is assumed that the upper filling layer 62 and the partition layer 3 have different surface free energies. Furthermore, it is assumed that the surface tension of the photosensitive resin is approximately equal to the surface free energy of the upper filling layer 62 and significantly different from the surface free energy of the partition layer 3. In this case, the upper filling layer 62 is easily wetted by the photosensitive resin, while the partition layer 3 is not easily wetted by the photosensitive resin. Therefore, island-like portions made of photosensitive resin with a convex curved upper surface are formed on the upper filling layer 62. Subsequently, the lens 5 is obtained by exposing the island-like portions to light.

[0059] Alternatively, first, a transparent material layer is formed covering the upper filling layer 62. The transparent material layer may be formed to further cover the partition layer 3. Next, an etching mask consisting of island-shaped patterns corresponding to the central part of the lens 5 is formed on the transparent material layer. Then, the transparent material layer is etched to remove the portion of the transparent material layer exposed from the etching mask, and to cause side etching below the etching mask. After that, the etching mask is removed to obtain the lens 5.

[0060] After forming the lens 5 as described above, the upper surface of the partition layer 3 is etched to reduce its thickness. This etching can be omitted. However, by performing this etching, it becomes possible to more reliably obtain a structure with a height H5T greater than that of the height H3.

[0061] The above-described light-emitting diode 4 can be obtained, for example, by fragmenting a laminate having a similar layer structure into multiple parts. Each of the light-emitting diodes 4 obtained in this way has a region near its end face that has been damaged by the fragmentation process. The damaged region has lower luminescence efficiency compared to the undamaged region.

[0062] Micro-LED displays, especially those suitable for use in head-mounted displays, have small light-emitting diodes (LEDs). Consequently, a large proportion of the LED surface area is damaged due to the fragmentation process.

[0063] Generally, light-emitting diodes (LEDs) can achieve high brightness. However, for the reasons mentioned above, there is room for improvement in terms of image brightness for micro-LED displays, especially those that can be used in head-mounted displays.

[0064] The above-mentioned display device 1A is capable of displaying bright images. This will be explained below.

[0065] When the height H5T of the top of the second surface 5b of lens 5 is greater than the height H3 of partition layer 3, the proportion of light emitted by lens 5 that is incident on or reflected by the portion of partition layer 3 near the surface, i.e., the portion of partition layer 3 sandwiched between adjacent lenses 5, is smaller compared to when height H5T is equal to height H3 or when height H5T is less than height H3. Much of the light incident on the portion of partition layer 3 near the surface is not used for display or becomes noise. Furthermore, light attenuation due to reflection is unavoidable. Therefore, the above-described display device 1A can efficiently utilize the light emitted by lens 5 for display, and thus can display a bright image.

[0066] Furthermore, by making the height H5T of the top of the second surface 5b of the lens 5 greater than the height H3 of the partition layer 3, the distance from the light-emitting diode 4 to the second surface 5b of the lens 5 can be increased compared to when the height H5T is equal to the height H3 or when the height H5T is less than the height H3.

[0067] If the lower packed layer 61 does not have a wavelength conversion function, increasing the distance from the light-emitting diode 4 to the second surface 5b of the lens 5 increases the proportion of light components incident on the first surface 5a of the lens 5 at a small angle of incidence. This is because, as this distance increases, the light components of the light emitted by the light-emitting diode 4 that are incident on the first surface 5a without being reflected by the side walls of the through-holes in the partition layer 3 are limited to those with no attenuation due to reflection and a small angle of incidence, while the light components that are incident on the first surface 5a after being reflected once or more by the side walls of the through-holes may change their direction of propagation during reflection. For example, if the portion of the partition layer 3 sandwiched between adjacent through-holes has a forward tapered cross-sectional shape, the light component emitted by the light-emitting diode 4 on the wide-angle side is reflected by the side walls of the through-holes, causing its direction of propagation to become closer to the vertical. If the directivity of the light emitted by the lens 5 is high (the degree of diffusion is small), the proportion of light incident on the observer's eye can be increased, making it possible to display a bright image.

[0068] Furthermore, increasing the distance from the light-emitting diode 4 to the second surface 5b of the lens 5 allows the packed layer 6 to be made thicker, and therefore the lower packed layer 61 can also be made thicker. Increasing the thickness of the lower packed layer 61, which has a wavelength conversion function, increases the wavelength conversion efficiency. Therefore, even when the lower packed layer 61 has a wavelength conversion function, it becomes possible to display a bright image. For the reasons stated above, the display device 1A is capable of displaying bright images.

[0069] <2> Second Embodiment Figure 2 is a cross-sectional view of a display device according to a second embodiment of the present invention. The display device 1B shown in Figure 2 is the same as the display device 1A described with reference to Figure 1, except that the partition layer 3 employs the following structure.

[0070] In other words, the partition layer 3 of the display device 1B has a multilayer structure. Specifically, this partition layer 3 includes a first layer 31 and a second layer 32.

[0071] The first layer 31 is light-shielding. In one example, the first layer 31 is a black layer. Such a first layer 31 consists 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 produce black by subtractive color mixing, such as a mixture containing a blue pigment, a green pigment and a red pigment. The first layer 31 is provided with a first through-hole, which is the lower part of the through-hole provided in the partition layer 3.

[0072] The second layer 32 is provided on the first layer 31. The second layer 32 is made of a light-transmitting resin. For example, the second layer 32 is made of a transparent resin. The second layer 32 is provided with a second through-hole, which is another part of the through-hole provided in the partition layer 3. The side wall of the second through-hole is flush with the side wall of the first through-hole.

[0073] This display device 1B has the same effect as the display device 1A described above. Furthermore, in this display device 1B, a portion of the light emitted by the light-emitting diode 4 of a certain pixel PX and traveling toward the lower packed layer 61 of the adjacent pixel PX is absorbed by the first layer 31. Therefore, for example, if the lower packed layer 61 has a wavelength conversion function, the possibility of the light emitted by the light-emitting diode 4 of a certain pixel PX being wavelength-converted by the lower packed layer 61 of the adjacent pixel PX is low. In other words, adopting the structure shown in Figure 2 for the partition layer 3 makes crosstalk less likely to occur.

[0074] Furthermore, if the entire partition layer 3 is black, the light absorption by the partition layer 3 is large. Since the partition layer 3 in Figure 2 includes a second layer 32 made of light-transmitting resin, adopting the structure of Figure 2 for the partition layer 3 does not result in excessively large light absorption by the partition layer 3.

[0075] Furthermore, if the entire partition layer 3 is black, the photosensitive resin used to form it is also black. Such photosensitive resins generally exhibit high absorption rates to the light used for pattern exposure. Therefore, it is difficult to form a thick black layer with through holes with high shape accuracy. The partition layer in Figure 2 includes not only the first layer 31 which is a black layer, but also the second layer 32 made of a light-transmitting resin, making it easy to form a thick layer with high shape accuracy.

[0076] In this case, the height of the top surface of the first layer 31 relative to the substrate 2 is smaller than the height of the top surface of the light-emitting diode 4 relative to the substrate 2. The height of the top surface of the first layer 31 relative to the substrate 2 may be equal to the height of the top surface of the light-emitting diode 4 relative to the substrate 2, or it may be greater than this height.

[0077] <3> Third Embodiment Figure 3 is a cross-sectional view of a display device according to the third embodiment of the present invention. The display device 1C shown in Figure 3 is the same as the display device 1B described with reference to Figure 2, except that the partition layer 3 employs the following structure.

[0078] In other words, in the partition layer 3 of the display device 1C, the second layer 32 covers not only the upper surface of the first layer 31 but also the side walls of the through holes provided in the first layer 31.

[0079] Display device 1C exhibits the same effects as those described above for display devices 1A and 1B. Furthermore, with this structure, a portion of the light emitted by the light-emitting diode 4 and traveling toward the first layer 31 is reflected by the interface between the second layer 32 and the lower filling layer 61. Therefore, in display device 1C, light absorption by the first layer 31 is less likely to occur compared with display device 1B.

[0080] <4> Fourth Embodiment Figure 4 is a cross-sectional view of a display device according to the fourth embodiment of the present invention. The display device 1D shown in Figure 4 is the same as the display device 1B described with reference to Figure 2, except that the partition layer 3 employs the following structure.

[0081] In other words, in the partition layer 3 of the display device 1D, the diameter of the first through-hole provided in the first layer 31 is smaller than the diameter of the second through-hole provided in the second layer 32. For this reason, the side walls of the through-holes provided in the partition layer 3 have a step at the boundary between the first layer 31 and the second layer 32, so that the diameter increases from bottom to top.

[0082] Display device 1D provides the same effects as those described above for display devices 1A and 1B. Furthermore, by adopting this structure, the influence of the position of the second through-hole relative to the first through-hole on display performance can be reduced. In other words, adopting this structure increases the margin of the manufacturing process.

[0083] <5> Fifth Embodiment Figure 5 is a cross-sectional view of a display device according to the fifth embodiment of the present invention. The display device 1E shown in Figure 5 is the same as the display device 1B described with reference to Figure 2, except that the partition layer 3 employs the following structure.

[0084] That is, the partition layer 3 of the display device 1E further includes a third layer 33. The third layer 33 is provided on the second layer 32. The third layer 33 is light-shielding. In one example, the third layer 33 is a black layer. The third layer 33 is made of the same material as described above for the first layer 31. The third layer 33 is provided with a third through-hole as the upper part of the through-hole provided in the partition layer 3. The side wall of the third through-hole is flush with the side wall of the second through-hole. The side wall of the third through-hole does not have to be flush with the side wall of the second through-hole.

[0085] The display device 1E exhibits the same effects as those described above for display devices 1A and 1B. Furthermore, when light is shone from the outside onto the surface on which the lens 5 is provided, the third layer 33 of the display device 1E can absorb this light. Therefore, the display device 1E can display deeper blacks compared to the display device 1B, and thus can achieve a higher contrast ratio.

[0086] <6> Sixth Embodiment Figure 6 is a cross-sectional view of a display device according to the sixth embodiment of the present invention. The display device 1F shown in Figure 6 is the same as the display device 1B described with reference to Figure 2, except that it further includes a coating layer 7.

[0087] The coating layer 7 covers the partition layer 3 and the lens 5. The coating layer 7 can transmit light transmitted by the lens 5. The coating layer 7 is, for example, a transparent layer made of transparent resin. The refractive index of the coating layer 7 with respect to the above light is smaller than that of the refractive index of the lens 5 with respect to this light.

[0088] This display device 1F provides the same effects as the display device 1A described above. Furthermore, the coating layer 7 serves, for example, as a planarizing layer or a protective layer. Therefore, this display device 1F is easily combined with other devices and is less susceptible to performance degradation due to damage.

[0089] <7> Seventh Embodiment Figure 7 is a cross-sectional view of a display device according to the seventh embodiment of the present invention. The display device 1G shown in Figure 7 is a microLED display that can be mounted on a head-mounted display and displays color images.

[0090] The display device 1G shown in Figure 7 is the same as the display device 1A described with reference to Figure 1, except that it employs the following configuration.

[0091] In other words, the display device 1G includes pixels PXG instead of pixels PX. These pixels PXG are arranged in the X and Y directions.

[0092] Each pixel PXG contains a first subpixel PX1, a second subpixel PX2, and a third subpixel PX3. In each pixel PXG, the first subpixel PX1, the second subpixel PX2, and the third subpixel PX3 are arranged in the X direction. In each pixel PXG, other arrangements such as a delta arrangement may be used for the first subpixel PX1, the second subpixel PX2, and the third subpixel PX3.

[0093] The first subpixel PX1, the second subpixel PX2, and the third subpixel PX3 are the same as pixel PX, except for the following:

[0094] The first subpixel PX1 emits blue light. The first subpixel PX1 includes a first packed layer 6A, which includes a first lower packed layer 61A and a first upper packed layer 62A, instead of the packed layer 6, which includes a lower packed layer 61 and an upper packed layer 62.

[0095] The second subpixel PX2 emits green light. The second subpixel PX2 includes a second packed layer 6B, which includes a second lower packed layer 61B and a second upper packed layer 62B, instead of the packed layer 6, which includes the lower packed layer 61 and the upper packed layer 62.

[0096] The third subpixel PX3 emits red light. The third subpixel PX3 includes a third packed layer 6C, which includes a third lower packed layer 61C and a third upper packed layer 62C, instead of the packed layer 6, which includes a lower packed layer 61 and an upper packed layer 62.

[0097] When the light-emitting diode 4 emits blue light, the first lower packed layer 61A is a colorless and transparent layer that transmits blue light without wavelength conversion, the second lower packed layer 61B is a wavelength conversion layer that converts blue light to green light, and the third lower packed layer 61C is a wavelength conversion layer that converts blue light to red light. In this case, the first upper packed layer 62A is either a colorless and transparent layer or a blue-colored layer that absorbs or blocks green and red light and transmits blue light, the second upper packed layer 62B is a green-colored layer that absorbs or blocks blue and red light and transmits green light, and the third upper packed layer 62C is a red-colored layer that absorbs or blocks blue and green light and transmits red light. Thus, when displaying a color image using a light-emitting diode 4 that emits blue light, a wavelength conversion layer and a color filter including a coloring layer are provided.

[0098] When the light-emitting diode 4 emits ultraviolet light, the first lower packed layer 61A is a wavelength conversion layer that converts ultraviolet light to blue light, the second lower packed layer 61B is a wavelength conversion layer that converts ultraviolet light to green light, and the third lower packed layer 61C is a wavelength conversion layer that converts ultraviolet light to red light. In this case, the first upper packed layer 62A is either a colorless and transparent layer, or a blue-colored layer that absorbs or blocks green and red light and transmits blue light, the second upper packed layer 62B is either a colorless and transparent layer, or a green-colored layer that absorbs or blocks blue and red light and transmits green light, and the third upper packed layer 62C is either a colorless and transparent layer, or a red-colored layer that absorbs or blocks blue and green light and transmits red light. Thus, when displaying a color image using a light-emitting diode 4 that emits ultraviolet light, a wavelength conversion layer is provided. In this case, a color filter including a colored layer is optional.

[0099] This display device 1G provides the same effects as display device 1A described above. Furthermore, this display device 1G can display not only monochrome images but also color images.

[0100] <8> Variation The above-mentioned display device can be modified in various ways. For example, the side walls of the through holes provided in the partition layer 3 may be at least partially covered with the reflective layer. Furthermore, the upper surface of the partition layer 3 may be further covered at least partially with this reflective layer. Providing the reflective layer improves the efficiency of light utilization. The reflective layer may have a single-layer structure or a multi-layer structure. The layers included in the reflective layer are, for example, an inorganic dielectric layer or a metal layer. The layers included in the reflective layer can be formed, for example, by vapor deposition methods such as vacuum deposition and sputtering.

[0101] In the display device 1G, instead of having the first upper filling layer 62A, the second upper filling layer 62B, and the third upper filling layer 62C perform the role of color filters, a color filter may be installed above the lens 5. For example, a color filter may be formed on the lens 5 and the partition layer 3. Alternatively, a color filter substrate including a transparent substrate and a color filter provided on it may be prepared and installed so that the color filter faces the lens 5. However, if a color filter is formed on the lens 5 and the partition layer 3, it is difficult to control the uniformity of the film thickness of the color filter, which raises concerns about display inconsistencies. Furthermore, when installing a color filter substrate, high precision is required for the alignment of the color filter substrate and the LED substrate on which the light-emitting diodes 4 are provided.

[0102] The structure described above for one display device, or a combination of the structures described above for multiple display devices, may be applied to other display devices.

[0103] For example, the structures described above for the first layer 31 and the second layer 32 with reference to Figure 3 or Figure 4 may be applied to the first layer 31 and the second layer 32 of the display device 1E. The structures or combinations thereof described for the partition layer 3 with reference to Figures 2 to 5 may be applied to the partition layer 3 of the display device 1G. In addition, the coating layer 7 described with reference to Figure 6 may be provided in other display devices. [Explanation of symbols]

[0104] 1A…Display device, 1B…Display device, 1C…Display device, 1D…Display device, 1E…Display device, 1F…Display device, 1G…Display device, 2…Substrate, 3…Partition layer, 4…Light-emitting diode, 5…Lens, 5a…First surface, 5b…Second surface, 6…Filling layer, 6A…First filling layer, 6B…Second filling layer, 6C…Third filling layer, 7…Coating layer, 31…First layer, 32…Second layer, 33…Third layer, 61…Bottom filling layer , 61A...First lower packed layer, 61B...Second lower packed layer, 61C...Third lower packed layer, 62...Upper packed layer, 62A...First upper packed layer, 62B...Second upper packed layer, 62C...Third upper packed layer, D...Maximum diameter, H...Height, H3...Height, H4...Height, H5P...Height, H5T...Height, PX...Pixel, PX1...First sub-pixel, PX2...Second sub-pixel, PX3...Third sub-pixel, PXG...Pixel.

Claims

1. circuit board and A partition wall layer having a plurality of through holes is provided on the substrate, Multiple light-emitting diodes are arranged in each of the multiple through holes, The system comprises a plurality of lenses positioned at the locations of the plurality of through holes, The lens has a first surface facing the substrate with the light-emitting diode in between, and a second surface which is its back surface. The second surface is convex, and the height of the top of the convex surface relative to the substrate is greater than the height of the upper surface of the partition layer relative to the substrate, and the lower surface of the lens is located below the upper surface of the partition layer. A display device characterized in that each of the plurality of through holes has a rectangular cross-section parallel to the thickness direction of the substrate.

2. The display device according to claim 1, wherein the height of the peripheral edge of the convex surface with respect to the substrate is less than or equal to the height of the upper surface of the partition layer with respect to the substrate.

3. The display device according to claim 1, further comprising one or more layers located in each of the plurality of through holes and interposed between the lens and the light-emitting diode.

4. The display device according to claim 3, wherein the refractive index of one or more of the above layers adjacent to the lens is smaller than the refractive index of the lens.

5. The display device according to claim 3, wherein the partition layer includes a light-transmitting portion in contact with at least one of the one or more layers, and the refractive index of the one or more layers in contact with the light-transmitting portion is greater than the refractive index of the light-transmitting portion.

6. The display device according to claim 1, wherein the partition layer has a multilayer structure.

7. A substrate and A partition wall layer having a plurality of through holes is provided on the substrate, Multiple light-emitting diodes are arranged in each of the multiple through holes, The system comprises a plurality of lenses positioned at the locations of the plurality of through holes, The lens has a first surface facing the substrate with the light-emitting diode in between, and a second surface which is the back surface of the first surface, the second surface being a convex surface, and the height of the top of the convex surface relative to the substrate is greater than the height of the upper surface of the partition layer relative to the substrate. The aforementioned partition layer has a multilayer structure, The display device is characterized in that the partition layer includes a light-shielding first layer and a second layer provided on the first layer and made of a light-transmitting resin.

8. The display device according to claim 7, wherein the partition layer further includes a light-shielding third layer provided on the second layer.

9. The display device according to claim 1, further comprising a plurality of filled layers, each of which fills the plurality of through holes, and each of which is interposed between one of the plurality of lenses and the substrate, and in which a light-emitting diode facing the lens is embedded.

10. The display device according to claim 9, wherein at least a portion of the plurality of packed layers includes a wavelength conversion layer.

11. The display device according to claim 10, wherein the plurality of packed layers, including the wavelength conversion layer, further includes a colored layer interposed between the wavelength conversion layer and the lens.

12. The display device according to claim 9, wherein at least a portion of the plurality of filling layers includes a transparent resin layer.

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